Adding upstream version 1.16.10.upstream/1.16.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

56 files changed, 28923 insertions, 0 deletions

diff --git a/src/cmd/vendor/github.com/google/pprof/AUTHORS b/src/cmd/vendor/github.com/google/pprof/AUTHORS
new file mode 100644
index 0000000..fd736cb
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/AUTHORS
@@ -0,0 +1,7 @@
+# This is the official list of pprof authors for copyright purposes.
+# This file is distinct from the CONTRIBUTORS files.
+# See the latter for an explanation.
+# Names should be added to this file as:
+# Name or Organization <email address>
+# The email address is not required for organizations.
+Google Inc.
\ No newline at end of file
diff --git a/src/cmd/vendor/github.com/google/pprof/CONTRIBUTORS b/src/cmd/vendor/github.com/google/pprof/CONTRIBUTORS
new file mode 100644
index 0000000..8c8c37d
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/CONTRIBUTORS
@@ -0,0 +1,16 @@
+# People who have agreed to one of the CLAs and can contribute patches.
+# The AUTHORS file lists the copyright holders; this file
+# lists people.  For example, Google employees are listed here
+# but not in AUTHORS, because Google holds the copyright.
+#
+# https://developers.google.com/open-source/cla/individual
+# https://developers.google.com/open-source/cla/corporate
+#
+# Names should be added to this file as:
+#     Name <email address>
+Raul Silvera <rsilvera@google.com>
+Tipp Moseley <tipp@google.com>
+Hyoun Kyu Cho <netforce@google.com>
+Martin Spier <spiermar@gmail.com>
+Taco de Wolff <tacodewolff@gmail.com>
+Andrew Hunter <andrewhhunter@gmail.com>
diff --git a/src/cmd/vendor/github.com/google/pprof/LICENSE b/src/cmd/vendor/github.com/google/pprof/LICENSE
new file mode 100644
index 0000000..d645695
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/LICENSE
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/src/cmd/vendor/github.com/google/pprof/driver/driver.go b/src/cmd/vendor/github.com/google/pprof/driver/driver.go
new file mode 100644
index 0000000..e65bc2f
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/driver/driver.go
@@ -0,0 +1,296 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package driver provides an external entry point to the pprof driver.
+package driver
+
+import (
+	"io"
+	"net/http"
+	"regexp"
+	"time"
+
+	internaldriver "github.com/google/pprof/internal/driver"
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/profile"
+)
+
+// PProf acquires a profile, and symbolizes it using a profile
+// manager. Then it generates a report formatted according to the
+// options selected through the flags package.
+func PProf(o *Options) error {
+	return internaldriver.PProf(o.internalOptions())
+}
+
+func (o *Options) internalOptions() *plugin.Options {
+	var obj plugin.ObjTool
+	if o.Obj != nil {
+		obj = &internalObjTool{o.Obj}
+	}
+	var sym plugin.Symbolizer
+	if o.Sym != nil {
+		sym = &internalSymbolizer{o.Sym}
+	}
+	var httpServer func(args *plugin.HTTPServerArgs) error
+	if o.HTTPServer != nil {
+		httpServer = func(args *plugin.HTTPServerArgs) error {
+			return o.HTTPServer(((*HTTPServerArgs)(args)))
+		}
+	}
+	return &plugin.Options{
+		Writer:        o.Writer,
+		Flagset:       o.Flagset,
+		Fetch:         o.Fetch,
+		Sym:           sym,
+		Obj:           obj,
+		UI:            o.UI,
+		HTTPServer:    httpServer,
+		HTTPTransport: o.HTTPTransport,
+	}
+}
+
+// HTTPServerArgs contains arguments needed by an HTTP server that
+// is exporting a pprof web interface.
+type HTTPServerArgs plugin.HTTPServerArgs
+
+// Options groups all the optional plugins into pprof.
+type Options struct {
+	Writer        Writer
+	Flagset       FlagSet
+	Fetch         Fetcher
+	Sym           Symbolizer
+	Obj           ObjTool
+	UI            UI
+	HTTPServer    func(*HTTPServerArgs) error
+	HTTPTransport http.RoundTripper
+}
+
+// Writer provides a mechanism to write data under a certain name,
+// typically a filename.
+type Writer interface {
+	Open(name string) (io.WriteCloser, error)
+}
+
+// A FlagSet creates and parses command-line flags.
+// It is similar to the standard flag.FlagSet.
+type FlagSet interface {
+	// Bool, Int, Float64, and String define new flags,
+	// like the functions of the same name in package flag.
+	Bool(name string, def bool, usage string) *bool
+	Int(name string, def int, usage string) *int
+	Float64(name string, def float64, usage string) *float64
+	String(name string, def string, usage string) *string
+
+	// StringList is similar to String but allows multiple values for a
+	// single flag
+	StringList(name string, def string, usage string) *[]*string
+
+	// ExtraUsage returns any additional text that should be printed after the
+	// standard usage message. The extra usage message returned includes all text
+	// added with AddExtraUsage().
+	// The typical use of ExtraUsage is to show any custom flags defined by the
+	// specific pprof plugins being used.
+	ExtraUsage() string
+
+	// AddExtraUsage appends additional text to the end of the extra usage message.
+	AddExtraUsage(eu string)
+
+	// Parse initializes the flags with their values for this run
+	// and returns the non-flag command line arguments.
+	// If an unknown flag is encountered or there are no arguments,
+	// Parse should call usage and return nil.
+	Parse(usage func()) []string
+}
+
+// A Fetcher reads and returns the profile named by src, using
+// the specified duration and timeout. It returns the fetched
+// profile and a string indicating a URL from where the profile
+// was fetched, which may be different than src.
+type Fetcher interface {
+	Fetch(src string, duration, timeout time.Duration) (*profile.Profile, string, error)
+}
+
+// A Symbolizer introduces symbol information into a profile.
+type Symbolizer interface {
+	Symbolize(mode string, srcs MappingSources, prof *profile.Profile) error
+}
+
+// MappingSources map each profile.Mapping to the source of the profile.
+// The key is either Mapping.File or Mapping.BuildId.
+type MappingSources map[string][]struct {
+	Source string // URL of the source the mapping was collected from
+	Start  uint64 // delta applied to addresses from this source (to represent Merge adjustments)
+}
+
+// An ObjTool inspects shared libraries and executable files.
+type ObjTool interface {
+	// Open opens the named object file. If the object is a shared
+	// library, start/limit/offset are the addresses where it is mapped
+	// into memory in the address space being inspected.
+	Open(file string, start, limit, offset uint64) (ObjFile, error)
+
+	// Disasm disassembles the named object file, starting at
+	// the start address and stopping at (before) the end address.
+	Disasm(file string, start, end uint64, intelSyntax bool) ([]Inst, error)
+}
+
+// An Inst is a single instruction in an assembly listing.
+type Inst struct {
+	Addr     uint64 // virtual address of instruction
+	Text     string // instruction text
+	Function string // function name
+	File     string // source file
+	Line     int    // source line
+}
+
+// An ObjFile is a single object file: a shared library or executable.
+type ObjFile interface {
+	// Name returns the underlying file name, if available.
+	Name() string
+
+	// Base returns the base address to use when looking up symbols in the file.
+	Base() uint64
+
+	// BuildID returns the GNU build ID of the file, or an empty string.
+	BuildID() string
+
+	// SourceLine reports the source line information for a given
+	// address in the file. Due to inlining, the source line information
+	// is in general a list of positions representing a call stack,
+	// with the leaf function first.
+	SourceLine(addr uint64) ([]Frame, error)
+
+	// Symbols returns a list of symbols in the object file.
+	// If r is not nil, Symbols restricts the list to symbols
+	// with names matching the regular expression.
+	// If addr is not zero, Symbols restricts the list to symbols
+	// containing that address.
+	Symbols(r *regexp.Regexp, addr uint64) ([]*Sym, error)
+
+	// Close closes the file, releasing associated resources.
+	Close() error
+}
+
+// A Frame describes a single line in a source file.
+type Frame struct {
+	Func string // name of function
+	File string // source file name
+	Line int    // line in file
+}
+
+// A Sym describes a single symbol in an object file.
+type Sym struct {
+	Name  []string // names of symbol (many if symbol was dedup'ed)
+	File  string   // object file containing symbol
+	Start uint64   // start virtual address
+	End   uint64   // virtual address of last byte in sym (Start+size-1)
+}
+
+// A UI manages user interactions.
+type UI interface {
+	// Read returns a line of text (a command) read from the user.
+	// prompt is printed before reading the command.
+	ReadLine(prompt string) (string, error)
+
+	// Print shows a message to the user.
+	// It formats the text as fmt.Print would and adds a final \n if not already present.
+	// For line-based UI, Print writes to standard error.
+	// (Standard output is reserved for report data.)
+	Print(...interface{})
+
+	// PrintErr shows an error message to the user.
+	// It formats the text as fmt.Print would and adds a final \n if not already present.
+	// For line-based UI, PrintErr writes to standard error.
+	PrintErr(...interface{})
+
+	// IsTerminal returns whether the UI is known to be tied to an
+	// interactive terminal (as opposed to being redirected to a file).
+	IsTerminal() bool
+
+	// WantBrowser indicates whether browser should be opened with the -http option.
+	WantBrowser() bool
+
+	// SetAutoComplete instructs the UI to call complete(cmd) to obtain
+	// the auto-completion of cmd, if the UI supports auto-completion at all.
+	SetAutoComplete(complete func(string) string)
+}
+
+// internalObjTool is a wrapper to map from the pprof external
+// interface to the internal interface.
+type internalObjTool struct {
+	ObjTool
+}
+
+func (o *internalObjTool) Open(file string, start, limit, offset uint64) (plugin.ObjFile, error) {
+	f, err := o.ObjTool.Open(file, start, limit, offset)
+	if err != nil {
+		return nil, err
+	}
+	return &internalObjFile{f}, err
+}
+
+type internalObjFile struct {
+	ObjFile
+}
+
+func (f *internalObjFile) SourceLine(frame uint64) ([]plugin.Frame, error) {
+	frames, err := f.ObjFile.SourceLine(frame)
+	if err != nil {
+		return nil, err
+	}
+	var pluginFrames []plugin.Frame
+	for _, f := range frames {
+		pluginFrames = append(pluginFrames, plugin.Frame(f))
+	}
+	return pluginFrames, nil
+}
+
+func (f *internalObjFile) Symbols(r *regexp.Regexp, addr uint64) ([]*plugin.Sym, error) {
+	syms, err := f.ObjFile.Symbols(r, addr)
+	if err != nil {
+		return nil, err
+	}
+	var pluginSyms []*plugin.Sym
+	for _, s := range syms {
+		ps := plugin.Sym(*s)
+		pluginSyms = append(pluginSyms, &ps)
+	}
+	return pluginSyms, nil
+}
+
+func (o *internalObjTool) Disasm(file string, start, end uint64, intelSyntax bool) ([]plugin.Inst, error) {
+	insts, err := o.ObjTool.Disasm(file, start, end, intelSyntax)
+	if err != nil {
+		return nil, err
+	}
+	var pluginInst []plugin.Inst
+	for _, inst := range insts {
+		pluginInst = append(pluginInst, plugin.Inst(inst))
+	}
+	return pluginInst, nil
+}
+
+// internalSymbolizer is a wrapper to map from the pprof external
+// interface to the internal interface.
+type internalSymbolizer struct {
+	Symbolizer
+}
+
+func (s *internalSymbolizer) Symbolize(mode string, srcs plugin.MappingSources, prof *profile.Profile) error {
+	isrcs := MappingSources{}
+	for m, s := range srcs {
+		isrcs[m] = s
+	}
+	return s.Symbolizer.Symbolize(mode, isrcs, prof)
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner.go b/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner.go
new file mode 100644
index 0000000..c0661bf
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner.go
@@ -0,0 +1,242 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package binutils
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os/exec"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/google/pprof/internal/plugin"
+)
+
+const (
+	defaultAddr2line = "addr2line"
+
+	// addr2line may produce multiple lines of output. We
+	// use this sentinel to identify the end of the output.
+	sentinel = ^uint64(0)
+)
+
+// addr2Liner is a connection to an addr2line command for obtaining
+// address and line number information from a binary.
+type addr2Liner struct {
+	mu   sync.Mutex
+	rw   lineReaderWriter
+	base uint64
+
+	// nm holds an addr2Liner using nm tool. Certain versions of addr2line
+	// produce incomplete names due to
+	// https://sourceware.org/bugzilla/show_bug.cgi?id=17541. As a workaround,
+	// the names from nm are used when they look more complete. See addrInfo()
+	// code below for the exact heuristic.
+	nm *addr2LinerNM
+}
+
+// lineReaderWriter is an interface to abstract the I/O to an addr2line
+// process. It writes a line of input to the job, and reads its output
+// one line at a time.
+type lineReaderWriter interface {
+	write(string) error
+	readLine() (string, error)
+	close()
+}
+
+type addr2LinerJob struct {
+	cmd *exec.Cmd
+	in  io.WriteCloser
+	out *bufio.Reader
+}
+
+func (a *addr2LinerJob) write(s string) error {
+	_, err := fmt.Fprint(a.in, s+"\n")
+	return err
+}
+
+func (a *addr2LinerJob) readLine() (string, error) {
+	return a.out.ReadString('\n')
+}
+
+// close releases any resources used by the addr2liner object.
+func (a *addr2LinerJob) close() {
+	a.in.Close()
+	a.cmd.Wait()
+}
+
+// newAddr2liner starts the given addr2liner command reporting
+// information about the given executable file. If file is a shared
+// library, base should be the address at which it was mapped in the
+// program under consideration.
+func newAddr2Liner(cmd, file string, base uint64) (*addr2Liner, error) {
+	if cmd == "" {
+		cmd = defaultAddr2line
+	}
+
+	j := &addr2LinerJob{
+		cmd: exec.Command(cmd, "-aif", "-e", file),
+	}
+
+	var err error
+	if j.in, err = j.cmd.StdinPipe(); err != nil {
+		return nil, err
+	}
+
+	outPipe, err := j.cmd.StdoutPipe()
+	if err != nil {
+		return nil, err
+	}
+
+	j.out = bufio.NewReader(outPipe)
+	if err := j.cmd.Start(); err != nil {
+		return nil, err
+	}
+
+	a := &addr2Liner{
+		rw:   j,
+		base: base,
+	}
+
+	return a, nil
+}
+
+func (d *addr2Liner) readString() (string, error) {
+	s, err := d.rw.readLine()
+	if err != nil {
+		return "", err
+	}
+	return strings.TrimSpace(s), nil
+}
+
+// readFrame parses the addr2line output for a single address. It
+// returns a populated plugin.Frame and whether it has reached the end of the
+// data.
+func (d *addr2Liner) readFrame() (plugin.Frame, bool) {
+	funcname, err := d.readString()
+	if err != nil {
+		return plugin.Frame{}, true
+	}
+	if strings.HasPrefix(funcname, "0x") {
+		// If addr2line returns a hex address we can assume it is the
+		// sentinel. Read and ignore next two lines of output from
+		// addr2line
+		d.readString()
+		d.readString()
+		return plugin.Frame{}, true
+	}
+
+	fileline, err := d.readString()
+	if err != nil {
+		return plugin.Frame{}, true
+	}
+
+	linenumber := 0
+
+	if funcname == "??" {
+		funcname = ""
+	}
+
+	if fileline == "??:0" {
+		fileline = ""
+	} else {
+		if i := strings.LastIndex(fileline, ":"); i >= 0 {
+			// Remove discriminator, if present
+			if disc := strings.Index(fileline, " (discriminator"); disc > 0 {
+				fileline = fileline[:disc]
+			}
+			// If we cannot parse a number after the last ":", keep it as
+			// part of the filename.
+			if line, err := strconv.Atoi(fileline[i+1:]); err == nil {
+				linenumber = line
+				fileline = fileline[:i]
+			}
+		}
+	}
+
+	return plugin.Frame{
+		Func: funcname,
+		File: fileline,
+		Line: linenumber}, false
+}
+
+func (d *addr2Liner) rawAddrInfo(addr uint64) ([]plugin.Frame, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if err := d.rw.write(fmt.Sprintf("%x", addr-d.base)); err != nil {
+		return nil, err
+	}
+
+	if err := d.rw.write(fmt.Sprintf("%x", sentinel)); err != nil {
+		return nil, err
+	}
+
+	resp, err := d.readString()
+	if err != nil {
+		return nil, err
+	}
+
+	if !strings.HasPrefix(resp, "0x") {
+		return nil, fmt.Errorf("unexpected addr2line output: %s", resp)
+	}
+
+	var stack []plugin.Frame
+	for {
+		frame, end := d.readFrame()
+		if end {
+			break
+		}
+
+		if frame != (plugin.Frame{}) {
+			stack = append(stack, frame)
+		}
+	}
+	return stack, err
+}
+
+// addrInfo returns the stack frame information for a specific program
+// address. It returns nil if the address could not be identified.
+func (d *addr2Liner) addrInfo(addr uint64) ([]plugin.Frame, error) {
+	stack, err := d.rawAddrInfo(addr)
+	if err != nil {
+		return nil, err
+	}
+
+	// Certain versions of addr2line produce incomplete names due to
+	// https://sourceware.org/bugzilla/show_bug.cgi?id=17541. Attempt to replace
+	// the name with a better one from nm.
+	if len(stack) > 0 && d.nm != nil {
+		nm, err := d.nm.addrInfo(addr)
+		if err == nil && len(nm) > 0 {
+			// Last entry in frame list should match since it is non-inlined. As a
+			// simple heuristic, we only switch to the nm-based name if it is longer
+			// by 2 or more characters. We consider nm names that are longer by 1
+			// character insignificant to avoid replacing foo with _foo on MacOS (for
+			// unknown reasons read2line produces the former and nm produces the
+			// latter on MacOS even though both tools are asked to produce mangled
+			// names).
+			nmName := nm[len(nm)-1].Func
+			a2lName := stack[len(stack)-1].Func
+			if len(nmName) > len(a2lName)+1 {
+				stack[len(stack)-1].Func = nmName
+			}
+		}
+	}
+
+	return stack, nil
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_llvm.go b/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_llvm.go
new file mode 100644
index 0000000..68fa559
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_llvm.go
@@ -0,0 +1,175 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package binutils
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os/exec"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/google/pprof/internal/plugin"
+)
+
+const (
+	defaultLLVMSymbolizer = "llvm-symbolizer"
+)
+
+// llvmSymbolizer is a connection to an llvm-symbolizer command for
+// obtaining address and line number information from a binary.
+type llvmSymbolizer struct {
+	sync.Mutex
+	filename string
+	rw       lineReaderWriter
+	base     uint64
+}
+
+type llvmSymbolizerJob struct {
+	cmd *exec.Cmd
+	in  io.WriteCloser
+	out *bufio.Reader
+}
+
+func (a *llvmSymbolizerJob) write(s string) error {
+	_, err := fmt.Fprint(a.in, s+"\n")
+	return err
+}
+
+func (a *llvmSymbolizerJob) readLine() (string, error) {
+	return a.out.ReadString('\n')
+}
+
+// close releases any resources used by the llvmSymbolizer object.
+func (a *llvmSymbolizerJob) close() {
+	a.in.Close()
+	a.cmd.Wait()
+}
+
+// newLlvmSymbolizer starts the given llvmSymbolizer command reporting
+// information about the given executable file. If file is a shared
+// library, base should be the address at which it was mapped in the
+// program under consideration.
+func newLLVMSymbolizer(cmd, file string, base uint64) (*llvmSymbolizer, error) {
+	if cmd == "" {
+		cmd = defaultLLVMSymbolizer
+	}
+
+	j := &llvmSymbolizerJob{
+		cmd: exec.Command(cmd, "-inlining", "-demangle=false"),
+	}
+
+	var err error
+	if j.in, err = j.cmd.StdinPipe(); err != nil {
+		return nil, err
+	}
+
+	outPipe, err := j.cmd.StdoutPipe()
+	if err != nil {
+		return nil, err
+	}
+
+	j.out = bufio.NewReader(outPipe)
+	if err := j.cmd.Start(); err != nil {
+		return nil, err
+	}
+
+	a := &llvmSymbolizer{
+		filename: file,
+		rw:       j,
+		base:     base,
+	}
+
+	return a, nil
+}
+
+func (d *llvmSymbolizer) readString() (string, error) {
+	s, err := d.rw.readLine()
+	if err != nil {
+		return "", err
+	}
+	return strings.TrimSpace(s), nil
+}
+
+// readFrame parses the llvm-symbolizer output for a single address. It
+// returns a populated plugin.Frame and whether it has reached the end of the
+// data.
+func (d *llvmSymbolizer) readFrame() (plugin.Frame, bool) {
+	funcname, err := d.readString()
+	if err != nil {
+		return plugin.Frame{}, true
+	}
+
+	switch funcname {
+	case "":
+		return plugin.Frame{}, true
+	case "??":
+		funcname = ""
+	}
+
+	fileline, err := d.readString()
+	if err != nil {
+		return plugin.Frame{Func: funcname}, true
+	}
+
+	linenumber := 0
+	if fileline == "??:0" {
+		fileline = ""
+	} else {
+		switch split := strings.Split(fileline, ":"); len(split) {
+		case 1:
+			// filename
+			fileline = split[0]
+		case 2, 3:
+			// filename:line , or
+			// filename:line:disc , or
+			fileline = split[0]
+			if line, err := strconv.Atoi(split[1]); err == nil {
+				linenumber = line
+			}
+		default:
+			// Unrecognized, ignore
+		}
+	}
+
+	return plugin.Frame{Func: funcname, File: fileline, Line: linenumber}, false
+}
+
+// addrInfo returns the stack frame information for a specific program
+// address. It returns nil if the address could not be identified.
+func (d *llvmSymbolizer) addrInfo(addr uint64) ([]plugin.Frame, error) {
+	d.Lock()
+	defer d.Unlock()
+
+	if err := d.rw.write(fmt.Sprintf("%s 0x%x", d.filename, addr-d.base)); err != nil {
+		return nil, err
+	}
+
+	var stack []plugin.Frame
+	for {
+		frame, end := d.readFrame()
+		if end {
+			break
+		}
+
+		if frame != (plugin.Frame{}) {
+			stack = append(stack, frame)
+		}
+	}
+
+	return stack, nil
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_nm.go b/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_nm.go
new file mode 100644
index 0000000..1987bd3
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/binutils/addr2liner_nm.go
@@ -0,0 +1,124 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package binutils
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"os/exec"
+	"strconv"
+	"strings"
+
+	"github.com/google/pprof/internal/plugin"
+)
+
+const (
+	defaultNM = "nm"
+)
+
+// addr2LinerNM is a connection to an nm command for obtaining address
+// information from a binary.
+type addr2LinerNM struct {
+	m []symbolInfo // Sorted list of addresses from binary.
+}
+
+type symbolInfo struct {
+	address uint64
+	name    string
+}
+
+//  newAddr2LinerNM starts the given nm command reporting information about the
+// given executable file. If file is a shared library, base should be
+// the address at which it was mapped in the program under
+// consideration.
+func newAddr2LinerNM(cmd, file string, base uint64) (*addr2LinerNM, error) {
+	if cmd == "" {
+		cmd = defaultNM
+	}
+	var b bytes.Buffer
+	c := exec.Command(cmd, "-n", file)
+	c.Stdout = &b
+	if err := c.Run(); err != nil {
+		return nil, err
+	}
+	return parseAddr2LinerNM(base, &b)
+}
+
+func parseAddr2LinerNM(base uint64, nm io.Reader) (*addr2LinerNM, error) {
+	a := &addr2LinerNM{
+		m: []symbolInfo{},
+	}
+
+	// Parse nm output and populate symbol map.
+	// Skip lines we fail to parse.
+	buf := bufio.NewReader(nm)
+	for {
+		line, err := buf.ReadString('\n')
+		if line == "" && err != nil {
+			if err == io.EOF {
+				break
+			}
+			return nil, err
+		}
+		line = strings.TrimSpace(line)
+		fields := strings.SplitN(line, " ", 3)
+		if len(fields) != 3 {
+			continue
+		}
+		address, err := strconv.ParseUint(fields[0], 16, 64)
+		if err != nil {
+			continue
+		}
+		a.m = append(a.m, symbolInfo{
+			address: address + base,
+			name:    fields[2],
+		})
+	}
+
+	return a, nil
+}
+
+// addrInfo returns the stack frame information for a specific program
+// address. It returns nil if the address could not be identified.
+func (a *addr2LinerNM) addrInfo(addr uint64) ([]plugin.Frame, error) {
+	if len(a.m) == 0 || addr < a.m[0].address || addr > a.m[len(a.m)-1].address {
+		return nil, nil
+	}
+
+	// Binary search. Search until low, high are separated by 1.
+	low, high := 0, len(a.m)
+	for low+1 < high {
+		mid := (low + high) / 2
+		v := a.m[mid].address
+		if addr == v {
+			low = mid
+			break
+		} else if addr > v {
+			low = mid
+		} else {
+			high = mid
+		}
+	}
+
+	// Address is between a.m[low] and a.m[high].
+	// Pick low, as it represents [low, high).
+	f := []plugin.Frame{
+		{
+			Func: a.m[low].name,
+		},
+	}
+	return f, nil
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go b/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go
new file mode 100644
index 0000000..4b67cc4
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/binutils/binutils.go
@@ -0,0 +1,568 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package binutils provides access to the GNU binutils.
+package binutils
+
+import (
+	"debug/elf"
+	"debug/macho"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/google/pprof/internal/elfexec"
+	"github.com/google/pprof/internal/plugin"
+)
+
+// A Binutils implements plugin.ObjTool by invoking the GNU binutils.
+type Binutils struct {
+	mu  sync.Mutex
+	rep *binrep
+}
+
+var objdumpLLVMVerRE = regexp.MustCompile(`LLVM version (?:(\d*)\.(\d*)\.(\d*)|.*(trunk).*)`)
+
+// binrep is an immutable representation for Binutils.  It is atomically
+// replaced on every mutation to provide thread-safe access.
+type binrep struct {
+	// Commands to invoke.
+	llvmSymbolizer      string
+	llvmSymbolizerFound bool
+	addr2line           string
+	addr2lineFound      bool
+	nm                  string
+	nmFound             bool
+	objdump             string
+	objdumpFound        bool
+	isLLVMObjdump       bool
+
+	// if fast, perform symbolization using nm (symbol names only),
+	// instead of file-line detail from the slower addr2line.
+	fast bool
+}
+
+// get returns the current representation for bu, initializing it if necessary.
+func (bu *Binutils) get() *binrep {
+	bu.mu.Lock()
+	r := bu.rep
+	if r == nil {
+		r = &binrep{}
+		initTools(r, "")
+		bu.rep = r
+	}
+	bu.mu.Unlock()
+	return r
+}
+
+// update modifies the rep for bu via the supplied function.
+func (bu *Binutils) update(fn func(r *binrep)) {
+	r := &binrep{}
+	bu.mu.Lock()
+	defer bu.mu.Unlock()
+	if bu.rep == nil {
+		initTools(r, "")
+	} else {
+		*r = *bu.rep
+	}
+	fn(r)
+	bu.rep = r
+}
+
+// String returns string representation of the binutils state for debug logging.
+func (bu *Binutils) String() string {
+	r := bu.get()
+	var llvmSymbolizer, addr2line, nm, objdump string
+	if r.llvmSymbolizerFound {
+		llvmSymbolizer = r.llvmSymbolizer
+	}
+	if r.addr2lineFound {
+		addr2line = r.addr2line
+	}
+	if r.nmFound {
+		nm = r.nm
+	}
+	if r.objdumpFound {
+		objdump = r.objdump
+	}
+	return fmt.Sprintf("llvm-symbolizer=%q addr2line=%q nm=%q objdump=%q fast=%t",
+		llvmSymbolizer, addr2line, nm, objdump, r.fast)
+}
+
+// SetFastSymbolization sets a toggle that makes binutils use fast
+// symbolization (using nm), which is much faster than addr2line but
+// provides only symbol name information (no file/line).
+func (bu *Binutils) SetFastSymbolization(fast bool) {
+	bu.update(func(r *binrep) { r.fast = fast })
+}
+
+// SetTools processes the contents of the tools option. It
+// expects a set of entries separated by commas; each entry is a pair
+// of the form t:path, where cmd will be used to look only for the
+// tool named t. If t is not specified, the path is searched for all
+// tools.
+func (bu *Binutils) SetTools(config string) {
+	bu.update(func(r *binrep) { initTools(r, config) })
+}
+
+func initTools(b *binrep, config string) {
+	// paths collect paths per tool; Key "" contains the default.
+	paths := make(map[string][]string)
+	for _, t := range strings.Split(config, ",") {
+		name, path := "", t
+		if ct := strings.SplitN(t, ":", 2); len(ct) == 2 {
+			name, path = ct[0], ct[1]
+		}
+		paths[name] = append(paths[name], path)
+	}
+
+	defaultPath := paths[""]
+	b.llvmSymbolizer, b.llvmSymbolizerFound = chooseExe([]string{"llvm-symbolizer"}, []string{}, append(paths["llvm-symbolizer"], defaultPath...))
+	b.addr2line, b.addr2lineFound = chooseExe([]string{"addr2line"}, []string{"gaddr2line"}, append(paths["addr2line"], defaultPath...))
+	// The "-n" option is supported by LLVM since 2011. The output of llvm-nm
+	// and GNU nm with "-n" option is interchangeable for our purposes, so we do
+	// not need to differrentiate them.
+	b.nm, b.nmFound = chooseExe([]string{"llvm-nm", "nm"}, []string{"gnm"}, append(paths["nm"], defaultPath...))
+	b.objdump, b.objdumpFound, b.isLLVMObjdump = findObjdump(append(paths["objdump"], defaultPath...))
+}
+
+// findObjdump finds and returns path to preferred objdump binary.
+// Order of preference is: llvm-objdump, objdump.
+// On MacOS only, also looks for gobjdump with least preference.
+// Accepts a list of paths and returns:
+// a string with path to the preferred objdump binary if found,
+// or an empty string if not found;
+// a boolean if any acceptable objdump was found;
+// a boolean indicating if it is an LLVM objdump.
+func findObjdump(paths []string) (string, bool, bool) {
+	objdumpNames := []string{"llvm-objdump", "objdump"}
+	if runtime.GOOS == "darwin" {
+		objdumpNames = append(objdumpNames, "gobjdump")
+	}
+
+	for _, objdumpName := range objdumpNames {
+		if objdump, objdumpFound := findExe(objdumpName, paths); objdumpFound {
+			cmdOut, err := exec.Command(objdump, "--version").Output()
+			if err != nil {
+				continue
+			}
+			if isLLVMObjdump(string(cmdOut)) {
+				return objdump, true, true
+			}
+			if isBuObjdump(string(cmdOut)) {
+				return objdump, true, false
+			}
+		}
+	}
+	return "", false, false
+}
+
+// chooseExe finds and returns path to preferred binary. names is a list of
+// names to search on both Linux and OSX. osxNames is a list of names specific
+// to OSX. names always has a higher priority than osxNames. The order of
+// the name within each list decides its priority (e.g. the first name has a
+// higher priority than the second name in the list).
+//
+// It returns a string with path to the binary and a boolean indicating if any
+// acceptable binary was found.
+func chooseExe(names, osxNames []string, paths []string) (string, bool) {
+	if runtime.GOOS == "darwin" {
+		names = append(names, osxNames...)
+	}
+	for _, name := range names {
+		if binary, found := findExe(name, paths); found {
+			return binary, true
+		}
+	}
+	return "", false
+}
+
+// isLLVMObjdump accepts a string with path to an objdump binary,
+// and returns a boolean indicating if the given binary is an LLVM
+// objdump binary of an acceptable version.
+func isLLVMObjdump(output string) bool {
+	fields := objdumpLLVMVerRE.FindStringSubmatch(output)
+	if len(fields) != 5 {
+		return false
+	}
+	if fields[4] == "trunk" {
+		return true
+	}
+	verMajor, err := strconv.Atoi(fields[1])
+	if err != nil {
+		return false
+	}
+	verPatch, err := strconv.Atoi(fields[3])
+	if err != nil {
+		return false
+	}
+	if runtime.GOOS == "linux" && verMajor >= 8 {
+		// Ensure LLVM objdump is at least version 8.0 on Linux.
+		// Some flags, like --demangle, and double dashes for options are
+		// not supported by previous versions.
+		return true
+	}
+	if runtime.GOOS == "darwin" {
+		// Ensure LLVM objdump is at least version 10.0.1 on MacOS.
+		return verMajor > 10 || (verMajor == 10 && verPatch >= 1)
+	}
+	return false
+}
+
+// isBuObjdump accepts a string with path to an objdump binary,
+// and returns a boolean indicating if the given binary is a GNU
+// binutils objdump binary. No version check is performed.
+func isBuObjdump(output string) bool {
+	return strings.Contains(output, "GNU objdump")
+}
+
+// findExe looks for an executable command on a set of paths.
+// If it cannot find it, returns cmd.
+func findExe(cmd string, paths []string) (string, bool) {
+	for _, p := range paths {
+		cp := filepath.Join(p, cmd)
+		if c, err := exec.LookPath(cp); err == nil {
+			return c, true
+		}
+	}
+	return cmd, false
+}
+
+// Disasm returns the assembly instructions for the specified address range
+// of a binary.
+func (bu *Binutils) Disasm(file string, start, end uint64, intelSyntax bool) ([]plugin.Inst, error) {
+	b := bu.get()
+	if !b.objdumpFound {
+		return nil, errors.New("cannot disasm: no objdump tool available")
+	}
+	args := []string{"--disassemble-all", "--demangle", "--no-show-raw-insn",
+		"--line-numbers", fmt.Sprintf("--start-address=%#x", start),
+		fmt.Sprintf("--stop-address=%#x", end)}
+
+	if intelSyntax {
+		if b.isLLVMObjdump {
+			args = append(args, "--x86-asm-syntax=intel")
+		} else {
+			args = append(args, "-M", "intel")
+		}
+	}
+
+	args = append(args, file)
+	cmd := exec.Command(b.objdump, args...)
+	out, err := cmd.Output()
+	if err != nil {
+		return nil, fmt.Errorf("%v: %v", cmd.Args, err)
+	}
+
+	return disassemble(out)
+}
+
+// Open satisfies the plugin.ObjTool interface.
+func (bu *Binutils) Open(name string, start, limit, offset uint64) (plugin.ObjFile, error) {
+	b := bu.get()
+
+	// Make sure file is a supported executable.
+	// This uses magic numbers, mainly to provide better error messages but
+	// it should also help speed.
+
+	if _, err := os.Stat(name); err != nil {
+		// For testing, do not require file name to exist.
+		if strings.Contains(b.addr2line, "testdata/") {
+			return &fileAddr2Line{file: file{b: b, name: name}}, nil
+		}
+		return nil, err
+	}
+
+	// Read the first 4 bytes of the file.
+
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, fmt.Errorf("error opening %s: %v", name, err)
+	}
+	defer f.Close()
+
+	var header [4]byte
+	if _, err = io.ReadFull(f, header[:]); err != nil {
+		return nil, fmt.Errorf("error reading magic number from %s: %v", name, err)
+	}
+
+	elfMagic := string(header[:])
+
+	// Match against supported file types.
+	if elfMagic == elf.ELFMAG {
+		f, err := b.openELF(name, start, limit, offset)
+		if err != nil {
+			return nil, fmt.Errorf("error reading ELF file %s: %v", name, err)
+		}
+		return f, nil
+	}
+
+	// Mach-O magic numbers can be big or little endian.
+	machoMagicLittle := binary.LittleEndian.Uint32(header[:])
+	machoMagicBig := binary.BigEndian.Uint32(header[:])
+
+	if machoMagicLittle == macho.Magic32 || machoMagicLittle == macho.Magic64 ||
+		machoMagicBig == macho.Magic32 || machoMagicBig == macho.Magic64 {
+		f, err := b.openMachO(name, start, limit, offset)
+		if err != nil {
+			return nil, fmt.Errorf("error reading Mach-O file %s: %v", name, err)
+		}
+		return f, nil
+	}
+	if machoMagicLittle == macho.MagicFat || machoMagicBig == macho.MagicFat {
+		f, err := b.openFatMachO(name, start, limit, offset)
+		if err != nil {
+			return nil, fmt.Errorf("error reading fat Mach-O file %s: %v", name, err)
+		}
+		return f, nil
+	}
+
+	return nil, fmt.Errorf("unrecognized binary format: %s", name)
+}
+
+func (b *binrep) openMachOCommon(name string, of *macho.File, start, limit, offset uint64) (plugin.ObjFile, error) {
+
+	// Subtract the load address of the __TEXT section. Usually 0 for shared
+	// libraries or 0x100000000 for executables. You can check this value by
+	// running `objdump -private-headers <file>`.
+
+	textSegment := of.Segment("__TEXT")
+	if textSegment == nil {
+		return nil, fmt.Errorf("could not identify base for %s: no __TEXT segment", name)
+	}
+	if textSegment.Addr > start {
+		return nil, fmt.Errorf("could not identify base for %s: __TEXT segment address (0x%x) > mapping start address (0x%x)",
+			name, textSegment.Addr, start)
+	}
+
+	base := start - textSegment.Addr
+
+	if b.fast || (!b.addr2lineFound && !b.llvmSymbolizerFound) {
+		return &fileNM{file: file{b: b, name: name, base: base}}, nil
+	}
+	return &fileAddr2Line{file: file{b: b, name: name, base: base}}, nil
+}
+
+func (b *binrep) openFatMachO(name string, start, limit, offset uint64) (plugin.ObjFile, error) {
+	of, err := macho.OpenFat(name)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing %s: %v", name, err)
+	}
+	defer of.Close()
+
+	if len(of.Arches) == 0 {
+		return nil, fmt.Errorf("empty fat Mach-O file: %s", name)
+	}
+
+	var arch macho.Cpu
+	// Use the host architecture.
+	// TODO: This is not ideal because the host architecture may not be the one
+	// that was profiled. E.g. an amd64 host can profile a 386 program.
+	switch runtime.GOARCH {
+	case "386":
+		arch = macho.Cpu386
+	case "amd64", "amd64p32":
+		arch = macho.CpuAmd64
+	case "arm", "armbe", "arm64", "arm64be":
+		arch = macho.CpuArm
+	case "ppc":
+		arch = macho.CpuPpc
+	case "ppc64", "ppc64le":
+		arch = macho.CpuPpc64
+	default:
+		return nil, fmt.Errorf("unsupported host architecture for %s: %s", name, runtime.GOARCH)
+	}
+	for i := range of.Arches {
+		if of.Arches[i].Cpu == arch {
+			return b.openMachOCommon(name, of.Arches[i].File, start, limit, offset)
+		}
+	}
+	return nil, fmt.Errorf("architecture not found in %s: %s", name, runtime.GOARCH)
+}
+
+func (b *binrep) openMachO(name string, start, limit, offset uint64) (plugin.ObjFile, error) {
+	of, err := macho.Open(name)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing %s: %v", name, err)
+	}
+	defer of.Close()
+
+	return b.openMachOCommon(name, of, start, limit, offset)
+}
+
+func (b *binrep) openELF(name string, start, limit, offset uint64) (plugin.ObjFile, error) {
+	ef, err := elf.Open(name)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing %s: %v", name, err)
+	}
+	defer ef.Close()
+
+	var stextOffset *uint64
+	var pageAligned = func(addr uint64) bool { return addr%4096 == 0 }
+	if strings.Contains(name, "vmlinux") || !pageAligned(start) || !pageAligned(limit) || !pageAligned(offset) {
+		// Reading all Symbols is expensive, and we only rarely need it so
+		// we don't want to do it every time. But if _stext happens to be
+		// page-aligned but isn't the same as Vaddr, we would symbolize
+		// wrong. So if the name the addresses aren't page aligned, or if
+		// the name is "vmlinux" we read _stext. We can be wrong if: (1)
+		// someone passes a kernel path that doesn't contain "vmlinux" AND
+		// (2) _stext is page-aligned AND (3) _stext is not at Vaddr
+		symbols, err := ef.Symbols()
+		if err != nil && err != elf.ErrNoSymbols {
+			return nil, err
+		}
+		for _, s := range symbols {
+			if s.Name == "_stext" {
+				// The kernel may use _stext as the mapping start address.
+				stextOffset = &s.Value
+				break
+			}
+		}
+	}
+
+	base, err := elfexec.GetBase(&ef.FileHeader, elfexec.FindTextProgHeader(ef), stextOffset, start, limit, offset)
+	if err != nil {
+		return nil, fmt.Errorf("could not identify base for %s: %v", name, err)
+	}
+
+	buildID := ""
+	if f, err := os.Open(name); err == nil {
+		if id, err := elfexec.GetBuildID(f); err == nil {
+			buildID = fmt.Sprintf("%x", id)
+		}
+	}
+	if b.fast || (!b.addr2lineFound && !b.llvmSymbolizerFound) {
+		return &fileNM{file: file{b, name, base, buildID}}, nil
+	}
+	return &fileAddr2Line{file: file{b, name, base, buildID}}, nil
+}
+
+// file implements the binutils.ObjFile interface.
+type file struct {
+	b       *binrep
+	name    string
+	base    uint64
+	buildID string
+}
+
+func (f *file) Name() string {
+	return f.name
+}
+
+func (f *file) Base() uint64 {
+	return f.base
+}
+
+func (f *file) BuildID() string {
+	return f.buildID
+}
+
+func (f *file) SourceLine(addr uint64) ([]plugin.Frame, error) {
+	return []plugin.Frame{}, nil
+}
+
+func (f *file) Close() error {
+	return nil
+}
+
+func (f *file) Symbols(r *regexp.Regexp, addr uint64) ([]*plugin.Sym, error) {
+	// Get from nm a list of symbols sorted by address.
+	cmd := exec.Command(f.b.nm, "-n", f.name)
+	out, err := cmd.Output()
+	if err != nil {
+		return nil, fmt.Errorf("%v: %v", cmd.Args, err)
+	}
+
+	return findSymbols(out, f.name, r, addr)
+}
+
+// fileNM implements the binutils.ObjFile interface, using 'nm' to map
+// addresses to symbols (without file/line number information). It is
+// faster than fileAddr2Line.
+type fileNM struct {
+	file
+	addr2linernm *addr2LinerNM
+}
+
+func (f *fileNM) SourceLine(addr uint64) ([]plugin.Frame, error) {
+	if f.addr2linernm == nil {
+		addr2liner, err := newAddr2LinerNM(f.b.nm, f.name, f.base)
+		if err != nil {
+			return nil, err
+		}
+		f.addr2linernm = addr2liner
+	}
+	return f.addr2linernm.addrInfo(addr)
+}
+
+// fileAddr2Line implements the binutils.ObjFile interface, using
+// llvm-symbolizer, if that's available, or addr2line to map addresses to
+// symbols (with file/line number information). It can be slow for large
+// binaries with debug information.
+type fileAddr2Line struct {
+	once sync.Once
+	file
+	addr2liner     *addr2Liner
+	llvmSymbolizer *llvmSymbolizer
+}
+
+func (f *fileAddr2Line) SourceLine(addr uint64) ([]plugin.Frame, error) {
+	f.once.Do(f.init)
+	if f.llvmSymbolizer != nil {
+		return f.llvmSymbolizer.addrInfo(addr)
+	}
+	if f.addr2liner != nil {
+		return f.addr2liner.addrInfo(addr)
+	}
+	return nil, fmt.Errorf("could not find local addr2liner")
+}
+
+func (f *fileAddr2Line) init() {
+	if llvmSymbolizer, err := newLLVMSymbolizer(f.b.llvmSymbolizer, f.name, f.base); err == nil {
+		f.llvmSymbolizer = llvmSymbolizer
+		return
+	}
+
+	if addr2liner, err := newAddr2Liner(f.b.addr2line, f.name, f.base); err == nil {
+		f.addr2liner = addr2liner
+
+		// When addr2line encounters some gcc compiled binaries, it
+		// drops interesting parts of names in anonymous namespaces.
+		// Fallback to NM for better function names.
+		if nm, err := newAddr2LinerNM(f.b.nm, f.name, f.base); err == nil {
+			f.addr2liner.nm = nm
+		}
+	}
+}
+
+func (f *fileAddr2Line) Close() error {
+	if f.llvmSymbolizer != nil {
+		f.llvmSymbolizer.rw.close()
+		f.llvmSymbolizer = nil
+	}
+	if f.addr2liner != nil {
+		f.addr2liner.rw.close()
+		f.addr2liner = nil
+	}
+	return nil
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/binutils/disasm.go b/src/cmd/vendor/github.com/google/pprof/internal/binutils/disasm.go
new file mode 100644
index 0000000..d0be614
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/binutils/disasm.go
@@ -0,0 +1,177 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package binutils
+
+import (
+	"bytes"
+	"io"
+	"regexp"
+	"strconv"
+
+	"github.com/google/pprof/internal/plugin"
+	"github.com/ianlancetaylor/demangle"
+)
+
+var (
+	nmOutputRE                = regexp.MustCompile(`^\s*([[:xdigit:]]+)\s+(.)\s+(.*)`)
+	objdumpAsmOutputRE        = regexp.MustCompile(`^\s*([[:xdigit:]]+):\s+(.*)`)
+	objdumpOutputFileLine     = regexp.MustCompile(`^;?\s?(.*):([0-9]+)`)
+	objdumpOutputFunction     = regexp.MustCompile(`^;?\s?(\S.*)\(\):`)
+	objdumpOutputFunctionLLVM = regexp.MustCompile(`^([[:xdigit:]]+)?\s?(.*):`)
+)
+
+func findSymbols(syms []byte, file string, r *regexp.Regexp, address uint64) ([]*plugin.Sym, error) {
+	// Collect all symbols from the nm output, grouping names mapped to
+	// the same address into a single symbol.
+
+	// The symbols to return.
+	var symbols []*plugin.Sym
+
+	// The current group of symbol names, and the address they are all at.
+	names, start := []string{}, uint64(0)
+
+	buf := bytes.NewBuffer(syms)
+
+	for {
+		symAddr, name, err := nextSymbol(buf)
+		if err == io.EOF {
+			// Done. If there was an unfinished group, append it.
+			if len(names) != 0 {
+				if match := matchSymbol(names, start, symAddr-1, r, address); match != nil {
+					symbols = append(symbols, &plugin.Sym{Name: match, File: file, Start: start, End: symAddr - 1})
+				}
+			}
+
+			// And return the symbols.
+			return symbols, nil
+		}
+
+		if err != nil {
+			// There was some kind of serious error reading nm's output.
+			return nil, err
+		}
+
+		// If this symbol is at the same address as the current group, add it to the group.
+		if symAddr == start {
+			names = append(names, name)
+			continue
+		}
+
+		// Otherwise append the current group to the list of symbols.
+		if match := matchSymbol(names, start, symAddr-1, r, address); match != nil {
+			symbols = append(symbols, &plugin.Sym{Name: match, File: file, Start: start, End: symAddr - 1})
+		}
+
+		// And start a new group.
+		names, start = []string{name}, symAddr
+	}
+}
+
+// matchSymbol checks if a symbol is to be selected by checking its
+// name to the regexp and optionally its address. It returns the name(s)
+// to be used for the matched symbol, or nil if no match
+func matchSymbol(names []string, start, end uint64, r *regexp.Regexp, address uint64) []string {
+	if address != 0 && address >= start && address <= end {
+		return names
+	}
+	for _, name := range names {
+		if r == nil || r.MatchString(name) {
+			return []string{name}
+		}
+
+		// Match all possible demangled versions of the name.
+		for _, o := range [][]demangle.Option{
+			{demangle.NoClones},
+			{demangle.NoParams},
+			{demangle.NoParams, demangle.NoTemplateParams},
+		} {
+			if demangled, err := demangle.ToString(name, o...); err == nil && r.MatchString(demangled) {
+				return []string{demangled}
+			}
+		}
+	}
+	return nil
+}
+
+// disassemble parses the output of the objdump command and returns
+// the assembly instructions in a slice.
+func disassemble(asm []byte) ([]plugin.Inst, error) {
+	buf := bytes.NewBuffer(asm)
+	function, file, line := "", "", 0
+	var assembly []plugin.Inst
+	for {
+		input, err := buf.ReadString('\n')
+		if err != nil {
+			if err != io.EOF {
+				return nil, err
+			}
+			if input == "" {
+				break
+			}
+		}
+
+		if fields := objdumpAsmOutputRE.FindStringSubmatch(input); len(fields) == 3 {
+			if address, err := strconv.ParseUint(fields[1], 16, 64); err == nil {
+				assembly = append(assembly,
+					plugin.Inst{
+						Addr:     address,
+						Text:     fields[2],
+						Function: function,
+						File:     file,
+						Line:     line,
+					})
+				continue
+			}
+		}
+		if fields := objdumpOutputFileLine.FindStringSubmatch(input); len(fields) == 3 {
+			if l, err := strconv.ParseUint(fields[2], 10, 32); err == nil {
+				file, line = fields[1], int(l)
+			}
+			continue
+		}
+		if fields := objdumpOutputFunction.FindStringSubmatch(input); len(fields) == 2 {
+			function = fields[1]
+			continue
+		} else {
+			if fields := objdumpOutputFunctionLLVM.FindStringSubmatch(input); len(fields) == 3 {
+				function = fields[2]
+				continue
+			}
+		}
+		// Reset on unrecognized lines.
+		function, file, line = "", "", 0
+	}
+
+	return assembly, nil
+}
+
+// nextSymbol parses the nm output to find the next symbol listed.
+// Skips over any output it cannot recognize.
+func nextSymbol(buf *bytes.Buffer) (uint64, string, error) {
+	for {
+		line, err := buf.ReadString('\n')
+		if err != nil {
+			if err != io.EOF || line == "" {
+				return 0, "", err
+			}
+		}
+
+		if fields := nmOutputRE.FindStringSubmatch(line); len(fields) == 4 {
+			if address, err := strconv.ParseUint(fields[1], 16, 64); err == nil {
+				return address, fields[3], nil
+			}
+		}
+	}
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/cli.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/cli.go
new file mode 100644
index 0000000..492400c
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/cli.go
@@ -0,0 +1,367 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/google/pprof/internal/binutils"
+	"github.com/google/pprof/internal/plugin"
+)
+
+type source struct {
+	Sources   []string
+	ExecName  string
+	BuildID   string
+	Base      []string
+	DiffBase  bool
+	Normalize bool
+
+	Seconds            int
+	Timeout            int
+	Symbolize          string
+	HTTPHostport       string
+	HTTPDisableBrowser bool
+	Comment            string
+}
+
+// parseFlags parses the command lines through the specified flags package
+// and returns the source of the profile and optionally the command
+// for the kind of report to generate (nil for interactive use).
+func parseFlags(o *plugin.Options) (*source, []string, error) {
+	flag := o.Flagset
+	// Comparisons.
+	flagDiffBase := flag.StringList("diff_base", "", "Source of base profile for comparison")
+	flagBase := flag.StringList("base", "", "Source of base profile for profile subtraction")
+	// Source options.
+	flagSymbolize := flag.String("symbolize", "", "Options for profile symbolization")
+	flagBuildID := flag.String("buildid", "", "Override build id for first mapping")
+	flagTimeout := flag.Int("timeout", -1, "Timeout in seconds for fetching a profile")
+	flagAddComment := flag.String("add_comment", "", "Annotation string to record in the profile")
+	// CPU profile options
+	flagSeconds := flag.Int("seconds", -1, "Length of time for dynamic profiles")
+	// Heap profile options
+	flagInUseSpace := flag.Bool("inuse_space", false, "Display in-use memory size")
+	flagInUseObjects := flag.Bool("inuse_objects", false, "Display in-use object counts")
+	flagAllocSpace := flag.Bool("alloc_space", false, "Display allocated memory size")
+	flagAllocObjects := flag.Bool("alloc_objects", false, "Display allocated object counts")
+	// Contention profile options
+	flagTotalDelay := flag.Bool("total_delay", false, "Display total delay at each region")
+	flagContentions := flag.Bool("contentions", false, "Display number of delays at each region")
+	flagMeanDelay := flag.Bool("mean_delay", false, "Display mean delay at each region")
+	flagTools := flag.String("tools", os.Getenv("PPROF_TOOLS"), "Path for object tool pathnames")
+
+	flagHTTP := flag.String("http", "", "Present interactive web UI at the specified http host:port")
+	flagNoBrowser := flag.Bool("no_browser", false, "Skip opening a browswer for the interactive web UI")
+
+	// Flags that set configuration properties.
+	cfg := currentConfig()
+	configFlagSetter := installConfigFlags(flag, &cfg)
+
+	flagCommands := make(map[string]*bool)
+	flagParamCommands := make(map[string]*string)
+	for name, cmd := range pprofCommands {
+		if cmd.hasParam {
+			flagParamCommands[name] = flag.String(name, "", "Generate a report in "+name+" format, matching regexp")
+		} else {
+			flagCommands[name] = flag.Bool(name, false, "Generate a report in "+name+" format")
+		}
+	}
+
+	args := flag.Parse(func() {
+		o.UI.Print(usageMsgHdr +
+			usage(true) +
+			usageMsgSrc +
+			flag.ExtraUsage() +
+			usageMsgVars)
+	})
+	if len(args) == 0 {
+		return nil, nil, errors.New("no profile source specified")
+	}
+
+	var execName string
+	// Recognize first argument as an executable or buildid override.
+	if len(args) > 1 {
+		arg0 := args[0]
+		if file, err := o.Obj.Open(arg0, 0, ^uint64(0), 0); err == nil {
+			file.Close()
+			execName = arg0
+			args = args[1:]
+		} else if *flagBuildID == "" && isBuildID(arg0) {
+			*flagBuildID = arg0
+			args = args[1:]
+		}
+	}
+
+	// Apply any specified flags to cfg.
+	if err := configFlagSetter(); err != nil {
+		return nil, nil, err
+	}
+
+	cmd, err := outputFormat(flagCommands, flagParamCommands)
+	if err != nil {
+		return nil, nil, err
+	}
+	if cmd != nil && *flagHTTP != "" {
+		return nil, nil, errors.New("-http is not compatible with an output format on the command line")
+	}
+
+	if *flagNoBrowser && *flagHTTP == "" {
+		return nil, nil, errors.New("-no_browser only makes sense with -http")
+	}
+
+	si := cfg.SampleIndex
+	si = sampleIndex(flagTotalDelay, si, "delay", "-total_delay", o.UI)
+	si = sampleIndex(flagMeanDelay, si, "delay", "-mean_delay", o.UI)
+	si = sampleIndex(flagContentions, si, "contentions", "-contentions", o.UI)
+	si = sampleIndex(flagInUseSpace, si, "inuse_space", "-inuse_space", o.UI)
+	si = sampleIndex(flagInUseObjects, si, "inuse_objects", "-inuse_objects", o.UI)
+	si = sampleIndex(flagAllocSpace, si, "alloc_space", "-alloc_space", o.UI)
+	si = sampleIndex(flagAllocObjects, si, "alloc_objects", "-alloc_objects", o.UI)
+	cfg.SampleIndex = si
+
+	if *flagMeanDelay {
+		cfg.Mean = true
+	}
+
+	source := &source{
+		Sources:            args,
+		ExecName:           execName,
+		BuildID:            *flagBuildID,
+		Seconds:            *flagSeconds,
+		Timeout:            *flagTimeout,
+		Symbolize:          *flagSymbolize,
+		HTTPHostport:       *flagHTTP,
+		HTTPDisableBrowser: *flagNoBrowser,
+		Comment:            *flagAddComment,
+	}
+
+	if err := source.addBaseProfiles(*flagBase, *flagDiffBase); err != nil {
+		return nil, nil, err
+	}
+
+	normalize := cfg.Normalize
+	if normalize && len(source.Base) == 0 {
+		return nil, nil, errors.New("must have base profile to normalize by")
+	}
+	source.Normalize = normalize
+
+	if bu, ok := o.Obj.(*binutils.Binutils); ok {
+		bu.SetTools(*flagTools)
+	}
+
+	setCurrentConfig(cfg)
+	return source, cmd, nil
+}
+
+// addBaseProfiles adds the list of base profiles or diff base profiles to
+// the source. This function will return an error if both base and diff base
+// profiles are specified.
+func (source *source) addBaseProfiles(flagBase, flagDiffBase []*string) error {
+	base, diffBase := dropEmpty(flagBase), dropEmpty(flagDiffBase)
+	if len(base) > 0 && len(diffBase) > 0 {
+		return errors.New("-base and -diff_base flags cannot both be specified")
+	}
+
+	source.Base = base
+	if len(diffBase) > 0 {
+		source.Base, source.DiffBase = diffBase, true
+	}
+	return nil
+}
+
+// dropEmpty list takes a slice of string pointers, and outputs a slice of
+// non-empty strings associated with the flag.
+func dropEmpty(list []*string) []string {
+	var l []string
+	for _, s := range list {
+		if *s != "" {
+			l = append(l, *s)
+		}
+	}
+	return l
+}
+
+// installConfigFlags creates command line flags for configuration
+// fields and returns a function which can be called after flags have
+// been parsed to copy any flags specified on the command line to
+// *cfg.
+func installConfigFlags(flag plugin.FlagSet, cfg *config) func() error {
+	// List of functions for setting the different parts of a config.
+	var setters []func()
+	var err error // Holds any errors encountered while running setters.
+
+	for _, field := range configFields {
+		n := field.name
+		help := configHelp[n]
+		var setter func()
+		switch ptr := cfg.fieldPtr(field).(type) {
+		case *bool:
+			f := flag.Bool(n, *ptr, help)
+			setter = func() { *ptr = *f }
+		case *int:
+			f := flag.Int(n, *ptr, help)
+			setter = func() { *ptr = *f }
+		case *float64:
+			f := flag.Float64(n, *ptr, help)
+			setter = func() { *ptr = *f }
+		case *string:
+			if len(field.choices) == 0 {
+				f := flag.String(n, *ptr, help)
+				setter = func() { *ptr = *f }
+			} else {
+				// Make a separate flag per possible choice.
+				// Set all flags to initially false so we can
+				// identify conflicts.
+				bools := make(map[string]*bool)
+				for _, choice := range field.choices {
+					bools[choice] = flag.Bool(choice, false, configHelp[choice])
+				}
+				setter = func() {
+					var set []string
+					for k, v := range bools {
+						if *v {
+							set = append(set, k)
+						}
+					}
+					switch len(set) {
+					case 0:
+						// Leave as default value.
+					case 1:
+						*ptr = set[0]
+					default:
+						err = fmt.Errorf("conflicting options set: %v", set)
+					}
+				}
+			}
+		}
+		setters = append(setters, setter)
+	}
+
+	return func() error {
+		// Apply the setter for every flag.
+		for _, setter := range setters {
+			setter()
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+}
+
+// isBuildID determines if the profile may contain a build ID, by
+// checking that it is a string of hex digits.
+func isBuildID(id string) bool {
+	return strings.Trim(id, "0123456789abcdefABCDEF") == ""
+}
+
+func sampleIndex(flag *bool, si string, sampleType, option string, ui plugin.UI) string {
+	if *flag {
+		if si == "" {
+			return sampleType
+		}
+		ui.PrintErr("Multiple value selections, ignoring ", option)
+	}
+	return si
+}
+
+func outputFormat(bcmd map[string]*bool, acmd map[string]*string) (cmd []string, err error) {
+	for n, b := range bcmd {
+		if *b {
+			if cmd != nil {
+				return nil, errors.New("must set at most one output format")
+			}
+			cmd = []string{n}
+		}
+	}
+	for n, s := range acmd {
+		if *s != "" {
+			if cmd != nil {
+				return nil, errors.New("must set at most one output format")
+			}
+			cmd = []string{n, *s}
+		}
+	}
+	return cmd, nil
+}
+
+var usageMsgHdr = `usage:
+
+Produce output in the specified format.
+
+   pprof <format> [options] [binary] <source> ...
+
+Omit the format to get an interactive shell whose commands can be used
+to generate various views of a profile
+
+   pprof [options] [binary] <source> ...
+
+Omit the format and provide the "-http" flag to get an interactive web
+interface at the specified host:port that can be used to navigate through
+various views of a profile.
+
+   pprof -http [host]:[port] [options] [binary] <source> ...
+
+Details:
+`
+
+var usageMsgSrc = "\n\n" +
+	"  Source options:\n" +
+	"    -seconds              Duration for time-based profile collection\n" +
+	"    -timeout              Timeout in seconds for profile collection\n" +
+	"    -buildid              Override build id for main binary\n" +
+	"    -add_comment          Free-form annotation to add to the profile\n" +
+	"                          Displayed on some reports or with pprof -comments\n" +
+	"    -diff_base source     Source of base profile for comparison\n" +
+	"    -base source          Source of base profile for profile subtraction\n" +
+	"    profile.pb.gz         Profile in compressed protobuf format\n" +
+	"    legacy_profile        Profile in legacy pprof format\n" +
+	"    http://host/profile   URL for profile handler to retrieve\n" +
+	"    -symbolize=           Controls source of symbol information\n" +
+	"      none                  Do not attempt symbolization\n" +
+	"      local                 Examine only local binaries\n" +
+	"      fastlocal             Only get function names from local binaries\n" +
+	"      remote                Do not examine local binaries\n" +
+	"      force                 Force re-symbolization\n" +
+	"    Binary                  Local path or build id of binary for symbolization\n"
+
+var usageMsgVars = "\n\n" +
+	"  Misc options:\n" +
+	"   -http              Provide web interface at host:port.\n" +
+	"                      Host is optional and 'localhost' by default.\n" +
+	"                      Port is optional and a randomly available port by default.\n" +
+	"   -no_browser        Skip opening a browser for the interactive web UI.\n" +
+	"   -tools             Search path for object tools\n" +
+	"\n" +
+	"  Legacy convenience options:\n" +
+	"   -inuse_space           Same as -sample_index=inuse_space\n" +
+	"   -inuse_objects         Same as -sample_index=inuse_objects\n" +
+	"   -alloc_space           Same as -sample_index=alloc_space\n" +
+	"   -alloc_objects         Same as -sample_index=alloc_objects\n" +
+	"   -total_delay           Same as -sample_index=delay\n" +
+	"   -contentions           Same as -sample_index=contentions\n" +
+	"   -mean_delay            Same as -mean -sample_index=delay\n" +
+	"\n" +
+	"  Environment Variables:\n" +
+	"   PPROF_TMPDIR       Location for saved profiles (default $HOME/pprof)\n" +
+	"   PPROF_TOOLS        Search path for object-level tools\n" +
+	"   PPROF_BINARY_PATH  Search path for local binary files\n" +
+	"                      default: $HOME/pprof/binaries\n" +
+	"                      searches $name, $path, $buildid/$name, $path/$buildid\n" +
+	"   * On Windows, %USERPROFILE% is used instead of $HOME"
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/commands.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/commands.go
new file mode 100644
index 0000000..4397e25
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/commands.go
@@ -0,0 +1,451 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"runtime"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/internal/report"
+)
+
+// commands describes the commands accepted by pprof.
+type commands map[string]*command
+
+// command describes the actions for a pprof command. Includes a
+// function for command-line completion, the report format to use
+// during report generation, any postprocessing functions, and whether
+// the command expects a regexp parameter (typically a function name).
+type command struct {
+	format      int           // report format to generate
+	postProcess PostProcessor // postprocessing to run on report
+	visualizer  PostProcessor // display output using some callback
+	hasParam    bool          // collect a parameter from the CLI
+	description string        // single-line description text saying what the command does
+	usage       string        // multi-line help text saying how the command is used
+}
+
+// help returns a help string for a command.
+func (c *command) help(name string) string {
+	message := c.description + "\n"
+	if c.usage != "" {
+		message += "  Usage:\n"
+		lines := strings.Split(c.usage, "\n")
+		for _, line := range lines {
+			message += fmt.Sprintf("    %s\n", line)
+		}
+	}
+	return message + "\n"
+}
+
+// AddCommand adds an additional command to the set of commands
+// accepted by pprof. This enables extensions to add new commands for
+// specialized visualization formats. If the command specified already
+// exists, it is overwritten.
+func AddCommand(cmd string, format int, post PostProcessor, desc, usage string) {
+	pprofCommands[cmd] = &command{format, post, nil, false, desc, usage}
+}
+
+// SetVariableDefault sets the default value for a pprof
+// variable. This enables extensions to set their own defaults.
+func SetVariableDefault(variable, value string) {
+	configure(variable, value)
+}
+
+// PostProcessor is a function that applies post-processing to the report output
+type PostProcessor func(input io.Reader, output io.Writer, ui plugin.UI) error
+
+// interactiveMode is true if pprof is running on interactive mode, reading
+// commands from its shell.
+var interactiveMode = false
+
+// pprofCommands are the report generation commands recognized by pprof.
+var pprofCommands = commands{
+	// Commands that require no post-processing.
+	"comments": {report.Comments, nil, nil, false, "Output all profile comments", ""},
+	"disasm":   {report.Dis, nil, nil, true, "Output assembly listings annotated with samples", listHelp("disasm", true)},
+	"dot":      {report.Dot, nil, nil, false, "Outputs a graph in DOT format", reportHelp("dot", false, true)},
+	"list":     {report.List, nil, nil, true, "Output annotated source for functions matching regexp", listHelp("list", false)},
+	"peek":     {report.Tree, nil, nil, true, "Output callers/callees of functions matching regexp", "peek func_regex\nDisplay callers and callees of functions matching func_regex."},
+	"raw":      {report.Raw, nil, nil, false, "Outputs a text representation of the raw profile", ""},
+	"tags":     {report.Tags, nil, nil, false, "Outputs all tags in the profile", "tags [tag_regex]* [-ignore_regex]* [>file]\nList tags with key:value matching tag_regex and exclude ignore_regex."},
+	"text":     {report.Text, nil, nil, false, "Outputs top entries in text form", reportHelp("text", true, true)},
+	"top":      {report.Text, nil, nil, false, "Outputs top entries in text form", reportHelp("top", true, true)},
+	"traces":   {report.Traces, nil, nil, false, "Outputs all profile samples in text form", ""},
+	"tree":     {report.Tree, nil, nil, false, "Outputs a text rendering of call graph", reportHelp("tree", true, true)},
+
+	// Save binary formats to a file
+	"callgrind": {report.Callgrind, nil, awayFromTTY("callgraph.out"), false, "Outputs a graph in callgrind format", reportHelp("callgrind", false, true)},
+	"proto":     {report.Proto, nil, awayFromTTY("pb.gz"), false, "Outputs the profile in compressed protobuf format", ""},
+	"topproto":  {report.TopProto, nil, awayFromTTY("pb.gz"), false, "Outputs top entries in compressed protobuf format", ""},
+
+	// Generate report in DOT format and postprocess with dot
+	"gif": {report.Dot, invokeDot("gif"), awayFromTTY("gif"), false, "Outputs a graph image in GIF format", reportHelp("gif", false, true)},
+	"pdf": {report.Dot, invokeDot("pdf"), awayFromTTY("pdf"), false, "Outputs a graph in PDF format", reportHelp("pdf", false, true)},
+	"png": {report.Dot, invokeDot("png"), awayFromTTY("png"), false, "Outputs a graph image in PNG format", reportHelp("png", false, true)},
+	"ps":  {report.Dot, invokeDot("ps"), awayFromTTY("ps"), false, "Outputs a graph in PS format", reportHelp("ps", false, true)},
+
+	// Save SVG output into a file
+	"svg": {report.Dot, massageDotSVG(), awayFromTTY("svg"), false, "Outputs a graph in SVG format", reportHelp("svg", false, true)},
+
+	// Visualize postprocessed dot output
+	"eog":    {report.Dot, invokeDot("svg"), invokeVisualizer("svg", []string{"eog"}), false, "Visualize graph through eog", reportHelp("eog", false, false)},
+	"evince": {report.Dot, invokeDot("pdf"), invokeVisualizer("pdf", []string{"evince"}), false, "Visualize graph through evince", reportHelp("evince", false, false)},
+	"gv":     {report.Dot, invokeDot("ps"), invokeVisualizer("ps", []string{"gv --noantialias"}), false, "Visualize graph through gv", reportHelp("gv", false, false)},
+	"web":    {report.Dot, massageDotSVG(), invokeVisualizer("svg", browsers()), false, "Visualize graph through web browser", reportHelp("web", false, false)},
+
+	// Visualize callgrind output
+	"kcachegrind": {report.Callgrind, nil, invokeVisualizer("grind", kcachegrind), false, "Visualize report in KCachegrind", reportHelp("kcachegrind", false, false)},
+
+	// Visualize HTML directly generated by report.
+	"weblist": {report.WebList, nil, invokeVisualizer("html", browsers()), true, "Display annotated source in a web browser", listHelp("weblist", false)},
+}
+
+// configHelp contains help text per configuration parameter.
+var configHelp = map[string]string{
+	// Filename for file-based output formats, stdout by default.
+	"output": helpText("Output filename for file-based outputs"),
+
+	// Comparisons.
+	"drop_negative": helpText(
+		"Ignore negative differences",
+		"Do not show any locations with values <0."),
+
+	// Graph handling options.
+	"call_tree": helpText(
+		"Create a context-sensitive call tree",
+		"Treat locations reached through different paths as separate."),
+
+	// Display options.
+	"relative_percentages": helpText(
+		"Show percentages relative to focused subgraph",
+		"If unset, percentages are relative to full graph before focusing",
+		"to facilitate comparison with original graph."),
+	"unit": helpText(
+		"Measurement units to display",
+		"Scale the sample values to this unit.",
+		"For time-based profiles, use seconds, milliseconds, nanoseconds, etc.",
+		"For memory profiles, use megabytes, kilobytes, bytes, etc.",
+		"Using auto will scale each value independently to the most natural unit."),
+	"compact_labels": "Show minimal headers",
+	"source_path":    "Search path for source files",
+	"trim_path":      "Path to trim from source paths before search",
+	"intel_syntax": helpText(
+		"Show assembly in Intel syntax",
+		"Only applicable to commands `disasm` and `weblist`"),
+
+	// Filtering options
+	"nodecount": helpText(
+		"Max number of nodes to show",
+		"Uses heuristics to limit the number of locations to be displayed.",
+		"On graphs, dotted edges represent paths through nodes that have been removed."),
+	"nodefraction": "Hide nodes below <f>*total",
+	"edgefraction": "Hide edges below <f>*total",
+	"trim": helpText(
+		"Honor nodefraction/edgefraction/nodecount defaults",
+		"Set to false to get the full profile, without any trimming."),
+	"focus": helpText(
+		"Restricts to samples going through a node matching regexp",
+		"Discard samples that do not include a node matching this regexp.",
+		"Matching includes the function name, filename or object name."),
+	"ignore": helpText(
+		"Skips paths going through any nodes matching regexp",
+		"If set, discard samples that include a node matching this regexp.",
+		"Matching includes the function name, filename or object name."),
+	"prune_from": helpText(
+		"Drops any functions below the matched frame.",
+		"If set, any frames matching the specified regexp and any frames",
+		"below it will be dropped from each sample."),
+	"hide": helpText(
+		"Skips nodes matching regexp",
+		"Discard nodes that match this location.",
+		"Other nodes from samples that include this location will be shown.",
+		"Matching includes the function name, filename or object name."),
+	"show": helpText(
+		"Only show nodes matching regexp",
+		"If set, only show nodes that match this location.",
+		"Matching includes the function name, filename or object name."),
+	"show_from": helpText(
+		"Drops functions above the highest matched frame.",
+		"If set, all frames above the highest match are dropped from every sample.",
+		"Matching includes the function name, filename or object name."),
+	"tagfocus": helpText(
+		"Restricts to samples with tags in range or matched by regexp",
+		"Use name=value syntax to limit the matching to a specific tag.",
+		"Numeric tag filter examples: 1kb, 1kb:10kb, memory=32mb:",
+		"String tag filter examples: foo, foo.*bar, mytag=foo.*bar"),
+	"tagignore": helpText(
+		"Discard samples with tags in range or matched by regexp",
+		"Use name=value syntax to limit the matching to a specific tag.",
+		"Numeric tag filter examples: 1kb, 1kb:10kb, memory=32mb:",
+		"String tag filter examples: foo, foo.*bar, mytag=foo.*bar"),
+	"tagshow": helpText(
+		"Only consider tags matching this regexp",
+		"Discard tags that do not match this regexp"),
+	"taghide": helpText(
+		"Skip tags matching this regexp",
+		"Discard tags that match this regexp"),
+	// Heap profile options
+	"divide_by": helpText(
+		"Ratio to divide all samples before visualization",
+		"Divide all samples values by a constant, eg the number of processors or jobs."),
+	"mean": helpText(
+		"Average sample value over first value (count)",
+		"For memory profiles, report average memory per allocation.",
+		"For time-based profiles, report average time per event."),
+	"sample_index": helpText(
+		"Sample value to report (0-based index or name)",
+		"Profiles contain multiple values per sample.",
+		"Use sample_index=i to select the ith value (starting at 0)."),
+	"normalize": helpText(
+		"Scales profile based on the base profile."),
+
+	// Data sorting criteria
+	"flat": helpText("Sort entries based on own weight"),
+	"cum":  helpText("Sort entries based on cumulative weight"),
+
+	// Output granularity
+	"functions": helpText(
+		"Aggregate at the function level.",
+		"Ignores the filename where the function was defined."),
+	"filefunctions": helpText(
+		"Aggregate at the function level.",
+		"Takes into account the filename where the function was defined."),
+	"files": "Aggregate at the file level.",
+	"lines": "Aggregate at the source code line level.",
+	"addresses": helpText(
+		"Aggregate at the address level.",
+		"Includes functions' addresses in the output."),
+	"noinlines": helpText(
+		"Ignore inlines.",
+		"Attributes inlined functions to their first out-of-line caller."),
+}
+
+func helpText(s ...string) string {
+	return strings.Join(s, "\n") + "\n"
+}
+
+// usage returns a string describing the pprof commands and configuration
+// options.  if commandLine is set, the output reflect cli usage.
+func usage(commandLine bool) string {
+	var prefix string
+	if commandLine {
+		prefix = "-"
+	}
+	fmtHelp := func(c, d string) string {
+		return fmt.Sprintf("    %-16s %s", c, strings.SplitN(d, "\n", 2)[0])
+	}
+
+	var commands []string
+	for name, cmd := range pprofCommands {
+		commands = append(commands, fmtHelp(prefix+name, cmd.description))
+	}
+	sort.Strings(commands)
+
+	var help string
+	if commandLine {
+		help = "  Output formats (select at most one):\n"
+	} else {
+		help = "  Commands:\n"
+		commands = append(commands, fmtHelp("o/options", "List options and their current values"))
+		commands = append(commands, fmtHelp("q/quit/exit/^D", "Exit pprof"))
+	}
+
+	help = help + strings.Join(commands, "\n") + "\n\n" +
+		"  Options:\n"
+
+	// Print help for configuration options after sorting them.
+	// Collect choices for multi-choice options print them together.
+	var variables []string
+	var radioStrings []string
+	for _, f := range configFields {
+		if len(f.choices) == 0 {
+			variables = append(variables, fmtHelp(prefix+f.name, configHelp[f.name]))
+			continue
+		}
+		// Format help for for this group.
+		s := []string{fmtHelp(f.name, "")}
+		for _, choice := range f.choices {
+			s = append(s, "  "+fmtHelp(prefix+choice, configHelp[choice]))
+		}
+		radioStrings = append(radioStrings, strings.Join(s, "\n"))
+	}
+	sort.Strings(variables)
+	sort.Strings(radioStrings)
+	return help + strings.Join(variables, "\n") + "\n\n" +
+		"  Option groups (only set one per group):\n" +
+		strings.Join(radioStrings, "\n")
+}
+
+func reportHelp(c string, cum, redirect bool) string {
+	h := []string{
+		c + " [n] [focus_regex]* [-ignore_regex]*",
+		"Include up to n samples",
+		"Include samples matching focus_regex, and exclude ignore_regex.",
+	}
+	if cum {
+		h[0] += " [-cum]"
+		h = append(h, "-cum sorts the output by cumulative weight")
+	}
+	if redirect {
+		h[0] += " >f"
+		h = append(h, "Optionally save the report on the file f")
+	}
+	return strings.Join(h, "\n")
+}
+
+func listHelp(c string, redirect bool) string {
+	h := []string{
+		c + "<func_regex|address> [-focus_regex]* [-ignore_regex]*",
+		"Include functions matching func_regex, or including the address specified.",
+		"Include samples matching focus_regex, and exclude ignore_regex.",
+	}
+	if redirect {
+		h[0] += " >f"
+		h = append(h, "Optionally save the report on the file f")
+	}
+	return strings.Join(h, "\n")
+}
+
+// browsers returns a list of commands to attempt for web visualization.
+func browsers() []string {
+	var cmds []string
+	if userBrowser := os.Getenv("BROWSER"); userBrowser != "" {
+		cmds = append(cmds, userBrowser)
+	}
+	switch runtime.GOOS {
+	case "darwin":
+		cmds = append(cmds, "/usr/bin/open")
+	case "windows":
+		cmds = append(cmds, "cmd /c start")
+	default:
+		// Commands opening browsers are prioritized over xdg-open, so browser()
+		// command can be used on linux to open the .svg file generated by the -web
+		// command (the .svg file includes embedded javascript so is best viewed in
+		// a browser).
+		cmds = append(cmds, []string{"chrome", "google-chrome", "chromium", "firefox", "sensible-browser"}...)
+		if os.Getenv("DISPLAY") != "" {
+			// xdg-open is only for use in a desktop environment.
+			cmds = append(cmds, "xdg-open")
+		}
+	}
+	return cmds
+}
+
+var kcachegrind = []string{"kcachegrind"}
+
+// awayFromTTY saves the output in a file if it would otherwise go to
+// the terminal screen. This is used to avoid dumping binary data on
+// the screen.
+func awayFromTTY(format string) PostProcessor {
+	return func(input io.Reader, output io.Writer, ui plugin.UI) error {
+		if output == os.Stdout && (ui.IsTerminal() || interactiveMode) {
+			tempFile, err := newTempFile("", "profile", "."+format)
+			if err != nil {
+				return err
+			}
+			ui.PrintErr("Generating report in ", tempFile.Name())
+			output = tempFile
+		}
+		_, err := io.Copy(output, input)
+		return err
+	}
+}
+
+func invokeDot(format string) PostProcessor {
+	return func(input io.Reader, output io.Writer, ui plugin.UI) error {
+		cmd := exec.Command("dot", "-T"+format)
+		cmd.Stdin, cmd.Stdout, cmd.Stderr = input, output, os.Stderr
+		if err := cmd.Run(); err != nil {
+			return fmt.Errorf("failed to execute dot. Is Graphviz installed? Error: %v", err)
+		}
+		return nil
+	}
+}
+
+// massageDotSVG invokes the dot tool to generate an SVG image and alters
+// the image to have panning capabilities when viewed in a browser.
+func massageDotSVG() PostProcessor {
+	generateSVG := invokeDot("svg")
+	return func(input io.Reader, output io.Writer, ui plugin.UI) error {
+		baseSVG := new(bytes.Buffer)
+		if err := generateSVG(input, baseSVG, ui); err != nil {
+			return err
+		}
+		_, err := output.Write([]byte(massageSVG(baseSVG.String())))
+		return err
+	}
+}
+
+func invokeVisualizer(suffix string, visualizers []string) PostProcessor {
+	return func(input io.Reader, output io.Writer, ui plugin.UI) error {
+		tempFile, err := newTempFile(os.TempDir(), "pprof", "."+suffix)
+		if err != nil {
+			return err
+		}
+		deferDeleteTempFile(tempFile.Name())
+		if _, err := io.Copy(tempFile, input); err != nil {
+			return err
+		}
+		tempFile.Close()
+		// Try visualizers until one is successful
+		for _, v := range visualizers {
+			// Separate command and arguments for exec.Command.
+			args := strings.Split(v, " ")
+			if len(args) == 0 {
+				continue
+			}
+			viewer := exec.Command(args[0], append(args[1:], tempFile.Name())...)
+			viewer.Stderr = os.Stderr
+			if err = viewer.Start(); err == nil {
+				// Wait for a second so that the visualizer has a chance to
+				// open the input file. This needs to be done even if we're
+				// waiting for the visualizer as it can be just a wrapper that
+				// spawns a browser tab and returns right away.
+				defer func(t <-chan time.Time) {
+					<-t
+				}(time.After(time.Second))
+				// On interactive mode, let the visualizer run in the background
+				// so other commands can be issued.
+				if !interactiveMode {
+					return viewer.Wait()
+				}
+				return nil
+			}
+		}
+		return err
+	}
+}
+
+// stringToBool is a custom parser for bools. We avoid using strconv.ParseBool
+// to remain compatible with old pprof behavior (e.g., treating "" as true).
+func stringToBool(s string) (bool, error) {
+	switch strings.ToLower(s) {
+	case "true", "t", "yes", "y", "1", "":
+		return true, nil
+	case "false", "f", "no", "n", "0":
+		return false, nil
+	default:
+		return false, fmt.Errorf(`illegal value "%s" for bool variable`, s)
+	}
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/config.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/config.go
new file mode 100644
index 0000000..b3f82f2
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/config.go
@@ -0,0 +1,367 @@
+package driver
+
+import (
+	"fmt"
+	"net/url"
+	"reflect"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+// config holds settings for a single named config.
+// The JSON tag name for a field is used both for JSON encoding and as
+// a named variable.
+type config struct {
+	// Filename for file-based output formats, stdout by default.
+	Output string `json:"-"`
+
+	// Display options.
+	CallTree            bool    `json:"call_tree,omitempty"`
+	RelativePercentages bool    `json:"relative_percentages,omitempty"`
+	Unit                string  `json:"unit,omitempty"`
+	CompactLabels       bool    `json:"compact_labels,omitempty"`
+	SourcePath          string  `json:"-"`
+	TrimPath            string  `json:"-"`
+	IntelSyntax         bool    `json:"intel_syntax,omitempty"`
+	Mean                bool    `json:"mean,omitempty"`
+	SampleIndex         string  `json:"-"`
+	DivideBy            float64 `json:"-"`
+	Normalize           bool    `json:"normalize,omitempty"`
+	Sort                string  `json:"sort,omitempty"`
+
+	// Filtering options
+	DropNegative bool    `json:"drop_negative,omitempty"`
+	NodeCount    int     `json:"nodecount,omitempty"`
+	NodeFraction float64 `json:"nodefraction,omitempty"`
+	EdgeFraction float64 `json:"edgefraction,omitempty"`
+	Trim         bool    `json:"trim,omitempty"`
+	Focus        string  `json:"focus,omitempty"`
+	Ignore       string  `json:"ignore,omitempty"`
+	PruneFrom    string  `json:"prune_from,omitempty"`
+	Hide         string  `json:"hide,omitempty"`
+	Show         string  `json:"show,omitempty"`
+	ShowFrom     string  `json:"show_from,omitempty"`
+	TagFocus     string  `json:"tagfocus,omitempty"`
+	TagIgnore    string  `json:"tagignore,omitempty"`
+	TagShow      string  `json:"tagshow,omitempty"`
+	TagHide      string  `json:"taghide,omitempty"`
+	NoInlines    bool    `json:"noinlines,omitempty"`
+
+	// Output granularity
+	Granularity string `json:"granularity,omitempty"`
+}
+
+// defaultConfig returns the default configuration values; it is unaffected by
+// flags and interactive assignments.
+func defaultConfig() config {
+	return config{
+		Unit:         "minimum",
+		NodeCount:    -1,
+		NodeFraction: 0.005,
+		EdgeFraction: 0.001,
+		Trim:         true,
+		DivideBy:     1.0,
+		Sort:         "flat",
+		Granularity:  "functions",
+	}
+}
+
+// currentConfig holds the current configuration values; it is affected by
+// flags and interactive assignments.
+var currentCfg = defaultConfig()
+var currentMu sync.Mutex
+
+func currentConfig() config {
+	currentMu.Lock()
+	defer currentMu.Unlock()
+	return currentCfg
+}
+
+func setCurrentConfig(cfg config) {
+	currentMu.Lock()
+	defer currentMu.Unlock()
+	currentCfg = cfg
+}
+
+// configField contains metadata for a single configuration field.
+type configField struct {
+	name         string              // JSON field name/key in variables
+	urlparam     string              // URL parameter name
+	saved        bool                // Is field saved in settings?
+	field        reflect.StructField // Field in config
+	choices      []string            // Name Of variables in group
+	defaultValue string              // Default value for this field.
+}
+
+var (
+	configFields []configField // Precomputed metadata per config field
+
+	// configFieldMap holds an entry for every config field as well as an
+	// entry for every valid choice for a multi-choice field.
+	configFieldMap map[string]configField
+)
+
+func init() {
+	// Config names for fields that are not saved in settings and therefore
+	// do not have a JSON name.
+	notSaved := map[string]string{
+		// Not saved in settings, but present in URLs.
+		"SampleIndex": "sample_index",
+
+		// Following fields are also not placed in URLs.
+		"Output":     "output",
+		"SourcePath": "source_path",
+		"TrimPath":   "trim_path",
+		"DivideBy":   "divide_by",
+	}
+
+	// choices holds the list of allowed values for config fields that can
+	// take on one of a bounded set of values.
+	choices := map[string][]string{
+		"sort":        {"cum", "flat"},
+		"granularity": {"functions", "filefunctions", "files", "lines", "addresses"},
+	}
+
+	// urlparam holds the mapping from a config field name to the URL
+	// parameter used to hold that config field. If no entry is present for
+	// a name, the corresponding field is not saved in URLs.
+	urlparam := map[string]string{
+		"drop_negative":        "dropneg",
+		"call_tree":            "calltree",
+		"relative_percentages": "rel",
+		"unit":                 "unit",
+		"compact_labels":       "compact",
+		"intel_syntax":         "intel",
+		"nodecount":            "n",
+		"nodefraction":         "nf",
+		"edgefraction":         "ef",
+		"trim":                 "trim",
+		"focus":                "f",
+		"ignore":               "i",
+		"prune_from":           "prunefrom",
+		"hide":                 "h",
+		"show":                 "s",
+		"show_from":            "sf",
+		"tagfocus":             "tf",
+		"tagignore":            "ti",
+		"tagshow":              "ts",
+		"taghide":              "th",
+		"mean":                 "mean",
+		"sample_index":         "si",
+		"normalize":            "norm",
+		"sort":                 "sort",
+		"granularity":          "g",
+		"noinlines":            "noinlines",
+	}
+
+	def := defaultConfig()
+	configFieldMap = map[string]configField{}
+	t := reflect.TypeOf(config{})
+	for i, n := 0, t.NumField(); i < n; i++ {
+		field := t.Field(i)
+		js := strings.Split(field.Tag.Get("json"), ",")
+		if len(js) == 0 {
+			continue
+		}
+		// Get the configuration name for this field.
+		name := js[0]
+		if name == "-" {
+			name = notSaved[field.Name]
+			if name == "" {
+				// Not a configurable field.
+				continue
+			}
+		}
+		f := configField{
+			name:     name,
+			urlparam: urlparam[name],
+			saved:    (name == js[0]),
+			field:    field,
+			choices:  choices[name],
+		}
+		f.defaultValue = def.get(f)
+		configFields = append(configFields, f)
+		configFieldMap[f.name] = f
+		for _, choice := range f.choices {
+			configFieldMap[choice] = f
+		}
+	}
+}
+
+// fieldPtr returns a pointer to the field identified by f in *cfg.
+func (cfg *config) fieldPtr(f configField) interface{} {
+	// reflect.ValueOf: converts to reflect.Value
+	// Elem: dereferences cfg to make *cfg
+	// FieldByIndex: fetches the field
+	// Addr: takes address of field
+	// Interface: converts back from reflect.Value to a regular value
+	return reflect.ValueOf(cfg).Elem().FieldByIndex(f.field.Index).Addr().Interface()
+}
+
+// get returns the value of field f in cfg.
+func (cfg *config) get(f configField) string {
+	switch ptr := cfg.fieldPtr(f).(type) {
+	case *string:
+		return *ptr
+	case *int:
+		return fmt.Sprint(*ptr)
+	case *float64:
+		return fmt.Sprint(*ptr)
+	case *bool:
+		return fmt.Sprint(*ptr)
+	}
+	panic(fmt.Sprintf("unsupported config field type %v", f.field.Type))
+}
+
+// set sets the value of field f in cfg to value.
+func (cfg *config) set(f configField, value string) error {
+	switch ptr := cfg.fieldPtr(f).(type) {
+	case *string:
+		if len(f.choices) > 0 {
+			// Verify that value is one of the allowed choices.
+			for _, choice := range f.choices {
+				if choice == value {
+					*ptr = value
+					return nil
+				}
+			}
+			return fmt.Errorf("invalid %q value %q", f.name, value)
+		}
+		*ptr = value
+	case *int:
+		v, err := strconv.Atoi(value)
+		if err != nil {
+			return err
+		}
+		*ptr = v
+	case *float64:
+		v, err := strconv.ParseFloat(value, 64)
+		if err != nil {
+			return err
+		}
+		*ptr = v
+	case *bool:
+		v, err := stringToBool(value)
+		if err != nil {
+			return err
+		}
+		*ptr = v
+	default:
+		panic(fmt.Sprintf("unsupported config field type %v", f.field.Type))
+	}
+	return nil
+}
+
+// isConfigurable returns true if name is either the name of a config field, or
+// a valid value for a multi-choice config field.
+func isConfigurable(name string) bool {
+	_, ok := configFieldMap[name]
+	return ok
+}
+
+// isBoolConfig returns true if name is either name of a boolean config field,
+// or a valid value for a multi-choice config field.
+func isBoolConfig(name string) bool {
+	f, ok := configFieldMap[name]
+	if !ok {
+		return false
+	}
+	if name != f.name {
+		return true // name must be one possible value for the field
+	}
+	var cfg config
+	_, ok = cfg.fieldPtr(f).(*bool)
+	return ok
+}
+
+// completeConfig returns the list of configurable names starting with prefix.
+func completeConfig(prefix string) []string {
+	var result []string
+	for v := range configFieldMap {
+		if strings.HasPrefix(v, prefix) {
+			result = append(result, v)
+		}
+	}
+	return result
+}
+
+// configure stores the name=value mapping into the current config, correctly
+// handling the case when name identifies a particular choice in a field.
+func configure(name, value string) error {
+	currentMu.Lock()
+	defer currentMu.Unlock()
+	f, ok := configFieldMap[name]
+	if !ok {
+		return fmt.Errorf("unknown config field %q", name)
+	}
+	if f.name == name {
+		return currentCfg.set(f, value)
+	}
+	// name must be one of the choices. If value is true, set field-value
+	// to name.
+	if v, err := strconv.ParseBool(value); v && err == nil {
+		return currentCfg.set(f, name)
+	}
+	return fmt.Errorf("unknown config field %q", name)
+}
+
+// resetTransient sets all transient fields in *cfg to their currently
+// configured values.
+func (cfg *config) resetTransient() {
+	current := currentConfig()
+	cfg.Output = current.Output
+	cfg.SourcePath = current.SourcePath
+	cfg.TrimPath = current.TrimPath
+	cfg.DivideBy = current.DivideBy
+	cfg.SampleIndex = current.SampleIndex
+}
+
+// applyURL updates *cfg based on params.
+func (cfg *config) applyURL(params url.Values) error {
+	for _, f := range configFields {
+		var value string
+		if f.urlparam != "" {
+			value = params.Get(f.urlparam)
+		}
+		if value == "" {
+			continue
+		}
+		if err := cfg.set(f, value); err != nil {
+			return fmt.Errorf("error setting config field %s: %v", f.name, err)
+		}
+	}
+	return nil
+}
+
+// makeURL returns a URL based on initialURL that contains the config contents
+// as parameters.  The second result is true iff a parameter value was changed.
+func (cfg *config) makeURL(initialURL url.URL) (url.URL, bool) {
+	q := initialURL.Query()
+	changed := false
+	for _, f := range configFields {
+		if f.urlparam == "" || !f.saved {
+			continue
+		}
+		v := cfg.get(f)
+		if v == f.defaultValue {
+			v = "" // URL for of default value is the empty string.
+		} else if f.field.Type.Kind() == reflect.Bool {
+			// Shorten bool values to "f" or "t"
+			v = v[:1]
+		}
+		if q.Get(f.urlparam) == v {
+			continue
+		}
+		changed = true
+		if v == "" {
+			q.Del(f.urlparam)
+		} else {
+			q.Set(f.urlparam, v)
+		}
+	}
+	if changed {
+		initialURL.RawQuery = q.Encode()
+	}
+	return initialURL, changed
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/driver.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/driver.go
new file mode 100644
index 0000000..878f2e1
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/driver.go
@@ -0,0 +1,340 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package driver implements the core pprof functionality. It can be
+// parameterized with a flag implementation, fetch and symbolize
+// mechanisms.
+package driver
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/internal/report"
+	"github.com/google/pprof/profile"
+)
+
+// PProf acquires a profile, and symbolizes it using a profile
+// manager. Then it generates a report formatted according to the
+// options selected through the flags package.
+func PProf(eo *plugin.Options) error {
+	// Remove any temporary files created during pprof processing.
+	defer cleanupTempFiles()
+
+	o := setDefaults(eo)
+
+	src, cmd, err := parseFlags(o)
+	if err != nil {
+		return err
+	}
+
+	p, err := fetchProfiles(src, o)
+	if err != nil {
+		return err
+	}
+
+	if cmd != nil {
+		return generateReport(p, cmd, currentConfig(), o)
+	}
+
+	if src.HTTPHostport != "" {
+		return serveWebInterface(src.HTTPHostport, p, o, src.HTTPDisableBrowser)
+	}
+	return interactive(p, o)
+}
+
+func generateRawReport(p *profile.Profile, cmd []string, cfg config, o *plugin.Options) (*command, *report.Report, error) {
+	p = p.Copy() // Prevent modification to the incoming profile.
+
+	// Identify units of numeric tags in profile.
+	numLabelUnits := identifyNumLabelUnits(p, o.UI)
+
+	// Get report output format
+	c := pprofCommands[cmd[0]]
+	if c == nil {
+		panic("unexpected nil command")
+	}
+
+	cfg = applyCommandOverrides(cmd[0], c.format, cfg)
+
+	// Delay focus after configuring report to get percentages on all samples.
+	relative := cfg.RelativePercentages
+	if relative {
+		if err := applyFocus(p, numLabelUnits, cfg, o.UI); err != nil {
+			return nil, nil, err
+		}
+	}
+	ropt, err := reportOptions(p, numLabelUnits, cfg)
+	if err != nil {
+		return nil, nil, err
+	}
+	ropt.OutputFormat = c.format
+	if len(cmd) == 2 {
+		s, err := regexp.Compile(cmd[1])
+		if err != nil {
+			return nil, nil, fmt.Errorf("parsing argument regexp %s: %v", cmd[1], err)
+		}
+		ropt.Symbol = s
+	}
+
+	rpt := report.New(p, ropt)
+	if !relative {
+		if err := applyFocus(p, numLabelUnits, cfg, o.UI); err != nil {
+			return nil, nil, err
+		}
+	}
+	if err := aggregate(p, cfg); err != nil {
+		return nil, nil, err
+	}
+
+	return c, rpt, nil
+}
+
+func generateReport(p *profile.Profile, cmd []string, cfg config, o *plugin.Options) error {
+	c, rpt, err := generateRawReport(p, cmd, cfg, o)
+	if err != nil {
+		return err
+	}
+
+	// Generate the report.
+	dst := new(bytes.Buffer)
+	if err := report.Generate(dst, rpt, o.Obj); err != nil {
+		return err
+	}
+	src := dst
+
+	// If necessary, perform any data post-processing.
+	if c.postProcess != nil {
+		dst = new(bytes.Buffer)
+		if err := c.postProcess(src, dst, o.UI); err != nil {
+			return err
+		}
+		src = dst
+	}
+
+	// If no output is specified, use default visualizer.
+	output := cfg.Output
+	if output == "" {
+		if c.visualizer != nil {
+			return c.visualizer(src, os.Stdout, o.UI)
+		}
+		_, err := src.WriteTo(os.Stdout)
+		return err
+	}
+
+	// Output to specified file.
+	o.UI.PrintErr("Generating report in ", output)
+	out, err := o.Writer.Open(output)
+	if err != nil {
+		return err
+	}
+	if _, err := src.WriteTo(out); err != nil {
+		out.Close()
+		return err
+	}
+	return out.Close()
+}
+
+func applyCommandOverrides(cmd string, outputFormat int, cfg config) config {
+	// Some report types override the trim flag to false below. This is to make
+	// sure the default heuristics of excluding insignificant nodes and edges
+	// from the call graph do not apply. One example where it is important is
+	// annotated source or disassembly listing. Those reports run on a specific
+	// function (or functions), but the trimming is applied before the function
+	// data is selected. So, with trimming enabled, the report could end up
+	// showing no data if the specified function is "uninteresting" as far as the
+	// trimming is concerned.
+	trim := cfg.Trim
+
+	switch cmd {
+	case "disasm", "weblist":
+		trim = false
+		cfg.Granularity = "addresses"
+		// Force the 'noinlines' mode so that source locations for a given address
+		// collapse and there is only one for the given address. Without this
+		// cumulative metrics would be double-counted when annotating the assembly.
+		// This is because the merge is done by address and in case of an inlined
+		// stack each of the inlined entries is a separate callgraph node.
+		cfg.NoInlines = true
+	case "peek":
+		trim = false
+	case "list":
+		trim = false
+		cfg.Granularity = "lines"
+		// Do not force 'noinlines' to be false so that specifying
+		// "-list foo -noinlines" is supported and works as expected.
+	case "text", "top", "topproto":
+		if cfg.NodeCount == -1 {
+			cfg.NodeCount = 0
+		}
+	default:
+		if cfg.NodeCount == -1 {
+			cfg.NodeCount = 80
+		}
+	}
+
+	switch outputFormat {
+	case report.Proto, report.Raw, report.Callgrind:
+		trim = false
+		cfg.Granularity = "addresses"
+		cfg.NoInlines = false
+	}
+
+	if !trim {
+		cfg.NodeCount = 0
+		cfg.NodeFraction = 0
+		cfg.EdgeFraction = 0
+	}
+	return cfg
+}
+
+func aggregate(prof *profile.Profile, cfg config) error {
+	var function, filename, linenumber, address bool
+	inlines := !cfg.NoInlines
+	switch cfg.Granularity {
+	case "addresses":
+		if inlines {
+			return nil
+		}
+		function = true
+		filename = true
+		linenumber = true
+		address = true
+	case "lines":
+		function = true
+		filename = true
+		linenumber = true
+	case "files":
+		filename = true
+	case "functions":
+		function = true
+	case "filefunctions":
+		function = true
+		filename = true
+	default:
+		return fmt.Errorf("unexpected granularity")
+	}
+	return prof.Aggregate(inlines, function, filename, linenumber, address)
+}
+
+func reportOptions(p *profile.Profile, numLabelUnits map[string]string, cfg config) (*report.Options, error) {
+	si, mean := cfg.SampleIndex, cfg.Mean
+	value, meanDiv, sample, err := sampleFormat(p, si, mean)
+	if err != nil {
+		return nil, err
+	}
+
+	stype := sample.Type
+	if mean {
+		stype = "mean_" + stype
+	}
+
+	if cfg.DivideBy == 0 {
+		return nil, fmt.Errorf("zero divisor specified")
+	}
+
+	var filters []string
+	addFilter := func(k string, v string) {
+		if v != "" {
+			filters = append(filters, k+"="+v)
+		}
+	}
+	addFilter("focus", cfg.Focus)
+	addFilter("ignore", cfg.Ignore)
+	addFilter("hide", cfg.Hide)
+	addFilter("show", cfg.Show)
+	addFilter("show_from", cfg.ShowFrom)
+	addFilter("tagfocus", cfg.TagFocus)
+	addFilter("tagignore", cfg.TagIgnore)
+	addFilter("tagshow", cfg.TagShow)
+	addFilter("taghide", cfg.TagHide)
+
+	ropt := &report.Options{
+		CumSort:      cfg.Sort == "cum",
+		CallTree:     cfg.CallTree,
+		DropNegative: cfg.DropNegative,
+
+		CompactLabels: cfg.CompactLabels,
+		Ratio:         1 / cfg.DivideBy,
+
+		NodeCount:    cfg.NodeCount,
+		NodeFraction: cfg.NodeFraction,
+		EdgeFraction: cfg.EdgeFraction,
+
+		ActiveFilters: filters,
+		NumLabelUnits: numLabelUnits,
+
+		SampleValue:       value,
+		SampleMeanDivisor: meanDiv,
+		SampleType:        stype,
+		SampleUnit:        sample.Unit,
+
+		OutputUnit: cfg.Unit,
+
+		SourcePath: cfg.SourcePath,
+		TrimPath:   cfg.TrimPath,
+
+		IntelSyntax: cfg.IntelSyntax,
+	}
+
+	if len(p.Mapping) > 0 && p.Mapping[0].File != "" {
+		ropt.Title = filepath.Base(p.Mapping[0].File)
+	}
+
+	return ropt, nil
+}
+
+// identifyNumLabelUnits returns a map of numeric label keys to the units
+// associated with those keys.
+func identifyNumLabelUnits(p *profile.Profile, ui plugin.UI) map[string]string {
+	numLabelUnits, ignoredUnits := p.NumLabelUnits()
+
+	// Print errors for tags with multiple units associated with
+	// a single key.
+	for k, units := range ignoredUnits {
+		ui.PrintErr(fmt.Sprintf("For tag %s used unit %s, also encountered unit(s) %s", k, numLabelUnits[k], strings.Join(units, ", ")))
+	}
+	return numLabelUnits
+}
+
+type sampleValueFunc func([]int64) int64
+
+// sampleFormat returns a function to extract values out of a profile.Sample,
+// and the type/units of those values.
+func sampleFormat(p *profile.Profile, sampleIndex string, mean bool) (value, meanDiv sampleValueFunc, v *profile.ValueType, err error) {
+	if len(p.SampleType) == 0 {
+		return nil, nil, nil, fmt.Errorf("profile has no samples")
+	}
+	index, err := p.SampleIndexByName(sampleIndex)
+	if err != nil {
+		return nil, nil, nil, err
+	}
+	value = valueExtractor(index)
+	if mean {
+		meanDiv = valueExtractor(0)
+	}
+	v = p.SampleType[index]
+	return
+}
+
+func valueExtractor(ix int) sampleValueFunc {
+	return func(v []int64) int64 {
+		return v[ix]
+	}
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/driver_focus.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/driver_focus.go
new file mode 100644
index 0000000..fd05adb
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/driver_focus.go
@@ -0,0 +1,219 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/google/pprof/internal/measurement"
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/profile"
+)
+
+var tagFilterRangeRx = regexp.MustCompile("([+-]?[[:digit:]]+)([[:alpha:]]+)?")
+
+// applyFocus filters samples based on the focus/ignore options
+func applyFocus(prof *profile.Profile, numLabelUnits map[string]string, cfg config, ui plugin.UI) error {
+	focus, err := compileRegexOption("focus", cfg.Focus, nil)
+	ignore, err := compileRegexOption("ignore", cfg.Ignore, err)
+	hide, err := compileRegexOption("hide", cfg.Hide, err)
+	show, err := compileRegexOption("show", cfg.Show, err)
+	showfrom, err := compileRegexOption("show_from", cfg.ShowFrom, err)
+	tagfocus, err := compileTagFilter("tagfocus", cfg.TagFocus, numLabelUnits, ui, err)
+	tagignore, err := compileTagFilter("tagignore", cfg.TagIgnore, numLabelUnits, ui, err)
+	prunefrom, err := compileRegexOption("prune_from", cfg.PruneFrom, err)
+	if err != nil {
+		return err
+	}
+
+	fm, im, hm, hnm := prof.FilterSamplesByName(focus, ignore, hide, show)
+	warnNoMatches(focus == nil || fm, "Focus", ui)
+	warnNoMatches(ignore == nil || im, "Ignore", ui)
+	warnNoMatches(hide == nil || hm, "Hide", ui)
+	warnNoMatches(show == nil || hnm, "Show", ui)
+
+	sfm := prof.ShowFrom(showfrom)
+	warnNoMatches(showfrom == nil || sfm, "ShowFrom", ui)
+
+	tfm, tim := prof.FilterSamplesByTag(tagfocus, tagignore)
+	warnNoMatches(tagfocus == nil || tfm, "TagFocus", ui)
+	warnNoMatches(tagignore == nil || tim, "TagIgnore", ui)
+
+	tagshow, err := compileRegexOption("tagshow", cfg.TagShow, err)
+	taghide, err := compileRegexOption("taghide", cfg.TagHide, err)
+	tns, tnh := prof.FilterTagsByName(tagshow, taghide)
+	warnNoMatches(tagshow == nil || tns, "TagShow", ui)
+	warnNoMatches(taghide == nil || tnh, "TagHide", ui)
+
+	if prunefrom != nil {
+		prof.PruneFrom(prunefrom)
+	}
+	return err
+}
+
+func compileRegexOption(name, value string, err error) (*regexp.Regexp, error) {
+	if value == "" || err != nil {
+		return nil, err
+	}
+	rx, err := regexp.Compile(value)
+	if err != nil {
+		return nil, fmt.Errorf("parsing %s regexp: %v", name, err)
+	}
+	return rx, nil
+}
+
+func compileTagFilter(name, value string, numLabelUnits map[string]string, ui plugin.UI, err error) (func(*profile.Sample) bool, error) {
+	if value == "" || err != nil {
+		return nil, err
+	}
+
+	tagValuePair := strings.SplitN(value, "=", 2)
+	var wantKey string
+	if len(tagValuePair) == 2 {
+		wantKey = tagValuePair[0]
+		value = tagValuePair[1]
+	}
+
+	if numFilter := parseTagFilterRange(value); numFilter != nil {
+		ui.PrintErr(name, ":Interpreted '", value, "' as range, not regexp")
+		labelFilter := func(vals []int64, unit string) bool {
+			for _, val := range vals {
+				if numFilter(val, unit) {
+					return true
+				}
+			}
+			return false
+		}
+		numLabelUnit := func(key string) string {
+			return numLabelUnits[key]
+		}
+		if wantKey == "" {
+			return func(s *profile.Sample) bool {
+				for key, vals := range s.NumLabel {
+					if labelFilter(vals, numLabelUnit(key)) {
+						return true
+					}
+				}
+				return false
+			}, nil
+		}
+		return func(s *profile.Sample) bool {
+			if vals, ok := s.NumLabel[wantKey]; ok {
+				return labelFilter(vals, numLabelUnit(wantKey))
+			}
+			return false
+		}, nil
+	}
+
+	var rfx []*regexp.Regexp
+	for _, tagf := range strings.Split(value, ",") {
+		fx, err := regexp.Compile(tagf)
+		if err != nil {
+			return nil, fmt.Errorf("parsing %s regexp: %v", name, err)
+		}
+		rfx = append(rfx, fx)
+	}
+	if wantKey == "" {
+		return func(s *profile.Sample) bool {
+		matchedrx:
+			for _, rx := range rfx {
+				for key, vals := range s.Label {
+					for _, val := range vals {
+						// TODO: Match against val, not key:val in future
+						if rx.MatchString(key + ":" + val) {
+							continue matchedrx
+						}
+					}
+				}
+				return false
+			}
+			return true
+		}, nil
+	}
+	return func(s *profile.Sample) bool {
+		if vals, ok := s.Label[wantKey]; ok {
+			for _, rx := range rfx {
+				for _, val := range vals {
+					if rx.MatchString(val) {
+						return true
+					}
+				}
+			}
+		}
+		return false
+	}, nil
+}
+
+// parseTagFilterRange returns a function to checks if a value is
+// contained on the range described by a string. It can recognize
+// strings of the form:
+// "32kb" -- matches values == 32kb
+// ":64kb" -- matches values <= 64kb
+// "4mb:" -- matches values >= 4mb
+// "12kb:64mb" -- matches values between 12kb and 64mb (both included).
+func parseTagFilterRange(filter string) func(int64, string) bool {
+	ranges := tagFilterRangeRx.FindAllStringSubmatch(filter, 2)
+	if len(ranges) == 0 {
+		return nil // No ranges were identified
+	}
+	v, err := strconv.ParseInt(ranges[0][1], 10, 64)
+	if err != nil {
+		panic(fmt.Errorf("failed to parse int %s: %v", ranges[0][1], err))
+	}
+	scaledValue, unit := measurement.Scale(v, ranges[0][2], ranges[0][2])
+	if len(ranges) == 1 {
+		switch match := ranges[0][0]; filter {
+		case match:
+			return func(v int64, u string) bool {
+				sv, su := measurement.Scale(v, u, unit)
+				return su == unit && sv == scaledValue
+			}
+		case match + ":":
+			return func(v int64, u string) bool {
+				sv, su := measurement.Scale(v, u, unit)
+				return su == unit && sv >= scaledValue
+			}
+		case ":" + match:
+			return func(v int64, u string) bool {
+				sv, su := measurement.Scale(v, u, unit)
+				return su == unit && sv <= scaledValue
+			}
+		}
+		return nil
+	}
+	if filter != ranges[0][0]+":"+ranges[1][0] {
+		return nil
+	}
+	if v, err = strconv.ParseInt(ranges[1][1], 10, 64); err != nil {
+		panic(fmt.Errorf("failed to parse int %s: %v", ranges[1][1], err))
+	}
+	scaledValue2, unit2 := measurement.Scale(v, ranges[1][2], unit)
+	if unit != unit2 {
+		return nil
+	}
+	return func(v int64, u string) bool {
+		sv, su := measurement.Scale(v, u, unit)
+		return su == unit && sv >= scaledValue && sv <= scaledValue2
+	}
+}
+
+func warnNoMatches(match bool, option string, ui plugin.UI) {
+	if !match {
+		ui.PrintErr(option + " expression matched no samples")
+	}
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch.go
new file mode 100644
index 0000000..b8a69e8
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/fetch.go
@@ -0,0 +1,587 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/google/pprof/internal/measurement"
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/profile"
+)
+
+// fetchProfiles fetches and symbolizes the profiles specified by s.
+// It will merge all the profiles it is able to retrieve, even if
+// there are some failures. It will return an error if it is unable to
+// fetch any profiles.
+func fetchProfiles(s *source, o *plugin.Options) (*profile.Profile, error) {
+	sources := make([]profileSource, 0, len(s.Sources))
+	for _, src := range s.Sources {
+		sources = append(sources, profileSource{
+			addr:   src,
+			source: s,
+		})
+	}
+
+	bases := make([]profileSource, 0, len(s.Base))
+	for _, src := range s.Base {
+		bases = append(bases, profileSource{
+			addr:   src,
+			source: s,
+		})
+	}
+
+	p, pbase, m, mbase, save, err := grabSourcesAndBases(sources, bases, o.Fetch, o.Obj, o.UI, o.HTTPTransport)
+	if err != nil {
+		return nil, err
+	}
+
+	if pbase != nil {
+		if s.DiffBase {
+			pbase.SetLabel("pprof::base", []string{"true"})
+		}
+		if s.Normalize {
+			err := p.Normalize(pbase)
+			if err != nil {
+				return nil, err
+			}
+		}
+		pbase.Scale(-1)
+		p, m, err = combineProfiles([]*profile.Profile{p, pbase}, []plugin.MappingSources{m, mbase})
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// Symbolize the merged profile.
+	if err := o.Sym.Symbolize(s.Symbolize, m, p); err != nil {
+		return nil, err
+	}
+	p.RemoveUninteresting()
+	unsourceMappings(p)
+
+	if s.Comment != "" {
+		p.Comments = append(p.Comments, s.Comment)
+	}
+
+	// Save a copy of the merged profile if there is at least one remote source.
+	if save {
+		dir, err := setTmpDir(o.UI)
+		if err != nil {
+			return nil, err
+		}
+
+		prefix := "pprof."
+		if len(p.Mapping) > 0 && p.Mapping[0].File != "" {
+			prefix += filepath.Base(p.Mapping[0].File) + "."
+		}
+		for _, s := range p.SampleType {
+			prefix += s.Type + "."
+		}
+
+		tempFile, err := newTempFile(dir, prefix, ".pb.gz")
+		if err == nil {
+			if err = p.Write(tempFile); err == nil {
+				o.UI.PrintErr("Saved profile in ", tempFile.Name())
+			}
+		}
+		if err != nil {
+			o.UI.PrintErr("Could not save profile: ", err)
+		}
+	}
+
+	if err := p.CheckValid(); err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}
+
+func grabSourcesAndBases(sources, bases []profileSource, fetch plugin.Fetcher, obj plugin.ObjTool, ui plugin.UI, tr http.RoundTripper) (*profile.Profile, *profile.Profile, plugin.MappingSources, plugin.MappingSources, bool, error) {
+	wg := sync.WaitGroup{}
+	wg.Add(2)
+	var psrc, pbase *profile.Profile
+	var msrc, mbase plugin.MappingSources
+	var savesrc, savebase bool
+	var errsrc, errbase error
+	var countsrc, countbase int
+	go func() {
+		defer wg.Done()
+		psrc, msrc, savesrc, countsrc, errsrc = chunkedGrab(sources, fetch, obj, ui, tr)
+	}()
+	go func() {
+		defer wg.Done()
+		pbase, mbase, savebase, countbase, errbase = chunkedGrab(bases, fetch, obj, ui, tr)
+	}()
+	wg.Wait()
+	save := savesrc || savebase
+
+	if errsrc != nil {
+		return nil, nil, nil, nil, false, fmt.Errorf("problem fetching source profiles: %v", errsrc)
+	}
+	if errbase != nil {
+		return nil, nil, nil, nil, false, fmt.Errorf("problem fetching base profiles: %v,", errbase)
+	}
+	if countsrc == 0 {
+		return nil, nil, nil, nil, false, fmt.Errorf("failed to fetch any source profiles")
+	}
+	if countbase == 0 && len(bases) > 0 {
+		return nil, nil, nil, nil, false, fmt.Errorf("failed to fetch any base profiles")
+	}
+	if want, got := len(sources), countsrc; want != got {
+		ui.PrintErr(fmt.Sprintf("Fetched %d source profiles out of %d", got, want))
+	}
+	if want, got := len(bases), countbase; want != got {
+		ui.PrintErr(fmt.Sprintf("Fetched %d base profiles out of %d", got, want))
+	}
+
+	return psrc, pbase, msrc, mbase, save, nil
+}
+
+// chunkedGrab fetches the profiles described in source and merges them into
+// a single profile. It fetches a chunk of profiles concurrently, with a maximum
+// chunk size to limit its memory usage.
+func chunkedGrab(sources []profileSource, fetch plugin.Fetcher, obj plugin.ObjTool, ui plugin.UI, tr http.RoundTripper) (*profile.Profile, plugin.MappingSources, bool, int, error) {
+	const chunkSize = 64
+
+	var p *profile.Profile
+	var msrc plugin.MappingSources
+	var save bool
+	var count int
+
+	for start := 0; start < len(sources); start += chunkSize {
+		end := start + chunkSize
+		if end > len(sources) {
+			end = len(sources)
+		}
+		chunkP, chunkMsrc, chunkSave, chunkCount, chunkErr := concurrentGrab(sources[start:end], fetch, obj, ui, tr)
+		switch {
+		case chunkErr != nil:
+			return nil, nil, false, 0, chunkErr
+		case chunkP == nil:
+			continue
+		case p == nil:
+			p, msrc, save, count = chunkP, chunkMsrc, chunkSave, chunkCount
+		default:
+			p, msrc, chunkErr = combineProfiles([]*profile.Profile{p, chunkP}, []plugin.MappingSources{msrc, chunkMsrc})
+			if chunkErr != nil {
+				return nil, nil, false, 0, chunkErr
+			}
+			if chunkSave {
+				save = true
+			}
+			count += chunkCount
+		}
+	}
+
+	return p, msrc, save, count, nil
+}
+
+// concurrentGrab fetches multiple profiles concurrently
+func concurrentGrab(sources []profileSource, fetch plugin.Fetcher, obj plugin.ObjTool, ui plugin.UI, tr http.RoundTripper) (*profile.Profile, plugin.MappingSources, bool, int, error) {
+	wg := sync.WaitGroup{}
+	wg.Add(len(sources))
+	for i := range sources {
+		go func(s *profileSource) {
+			defer wg.Done()
+			s.p, s.msrc, s.remote, s.err = grabProfile(s.source, s.addr, fetch, obj, ui, tr)
+		}(&sources[i])
+	}
+	wg.Wait()
+
+	var save bool
+	profiles := make([]*profile.Profile, 0, len(sources))
+	msrcs := make([]plugin.MappingSources, 0, len(sources))
+	for i := range sources {
+		s := &sources[i]
+		if err := s.err; err != nil {
+			ui.PrintErr(s.addr + ": " + err.Error())
+			continue
+		}
+		save = save || s.remote
+		profiles = append(profiles, s.p)
+		msrcs = append(msrcs, s.msrc)
+		*s = profileSource{}
+	}
+
+	if len(profiles) == 0 {
+		return nil, nil, false, 0, nil
+	}
+
+	p, msrc, err := combineProfiles(profiles, msrcs)
+	if err != nil {
+		return nil, nil, false, 0, err
+	}
+	return p, msrc, save, len(profiles), nil
+}
+
+func combineProfiles(profiles []*profile.Profile, msrcs []plugin.MappingSources) (*profile.Profile, plugin.MappingSources, error) {
+	// Merge profiles.
+	if err := measurement.ScaleProfiles(profiles); err != nil {
+		return nil, nil, err
+	}
+
+	p, err := profile.Merge(profiles)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Combine mapping sources.
+	msrc := make(plugin.MappingSources)
+	for _, ms := range msrcs {
+		for m, s := range ms {
+			msrc[m] = append(msrc[m], s...)
+		}
+	}
+	return p, msrc, nil
+}
+
+type profileSource struct {
+	addr   string
+	source *source
+
+	p      *profile.Profile
+	msrc   plugin.MappingSources
+	remote bool
+	err    error
+}
+
+func homeEnv() string {
+	switch runtime.GOOS {
+	case "windows":
+		return "USERPROFILE"
+	case "plan9":
+		return "home"
+	default:
+		return "HOME"
+	}
+}
+
+// setTmpDir prepares the directory to use to save profiles retrieved
+// remotely. It is selected from PPROF_TMPDIR, defaults to $HOME/pprof, and, if
+// $HOME is not set, falls back to os.TempDir().
+func setTmpDir(ui plugin.UI) (string, error) {
+	var dirs []string
+	if profileDir := os.Getenv("PPROF_TMPDIR"); profileDir != "" {
+		dirs = append(dirs, profileDir)
+	}
+	if homeDir := os.Getenv(homeEnv()); homeDir != "" {
+		dirs = append(dirs, filepath.Join(homeDir, "pprof"))
+	}
+	dirs = append(dirs, os.TempDir())
+	for _, tmpDir := range dirs {
+		if err := os.MkdirAll(tmpDir, 0755); err != nil {
+			ui.PrintErr("Could not use temp dir ", tmpDir, ": ", err.Error())
+			continue
+		}
+		return tmpDir, nil
+	}
+	return "", fmt.Errorf("failed to identify temp dir")
+}
+
+const testSourceAddress = "pproftest.local"
+
+// grabProfile fetches a profile. Returns the profile, sources for the
+// profile mappings, a bool indicating if the profile was fetched
+// remotely, and an error.
+func grabProfile(s *source, source string, fetcher plugin.Fetcher, obj plugin.ObjTool, ui plugin.UI, tr http.RoundTripper) (p *profile.Profile, msrc plugin.MappingSources, remote bool, err error) {
+	var src string
+	duration, timeout := time.Duration(s.Seconds)*time.Second, time.Duration(s.Timeout)*time.Second
+	if fetcher != nil {
+		p, src, err = fetcher.Fetch(source, duration, timeout)
+		if err != nil {
+			return
+		}
+	}
+	if err != nil || p == nil {
+		// Fetch the profile over HTTP or from a file.
+		p, src, err = fetch(source, duration, timeout, ui, tr)
+		if err != nil {
+			return
+		}
+	}
+
+	if err = p.CheckValid(); err != nil {
+		return
+	}
+
+	// Update the binary locations from command line and paths.
+	locateBinaries(p, s, obj, ui)
+
+	// Collect the source URL for all mappings.
+	if src != "" {
+		msrc = collectMappingSources(p, src)
+		remote = true
+		if strings.HasPrefix(src, "http://"+testSourceAddress) {
+			// Treat test inputs as local to avoid saving
+			// testcase profiles during driver testing.
+			remote = false
+		}
+	}
+	return
+}
+
+// collectMappingSources saves the mapping sources of a profile.
+func collectMappingSources(p *profile.Profile, source string) plugin.MappingSources {
+	ms := plugin.MappingSources{}
+	for _, m := range p.Mapping {
+		src := struct {
+			Source string
+			Start  uint64
+		}{
+			source, m.Start,
+		}
+		key := m.BuildID
+		if key == "" {
+			key = m.File
+		}
+		if key == "" {
+			// If there is no build id or source file, use the source as the
+			// mapping file. This will enable remote symbolization for this
+			// mapping, in particular for Go profiles on the legacy format.
+			// The source is reset back to empty string by unsourceMapping
+			// which is called after symbolization is finished.
+			m.File = source
+			key = source
+		}
+		ms[key] = append(ms[key], src)
+	}
+	return ms
+}
+
+// unsourceMappings iterates over the mappings in a profile and replaces file
+// set to the remote source URL by collectMappingSources back to empty string.
+func unsourceMappings(p *profile.Profile) {
+	for _, m := range p.Mapping {
+		if m.BuildID == "" {
+			if u, err := url.Parse(m.File); err == nil && u.IsAbs() {
+				m.File = ""
+			}
+		}
+	}
+}
+
+// locateBinaries searches for binary files listed in the profile and, if found,
+// updates the profile accordingly.
+func locateBinaries(p *profile.Profile, s *source, obj plugin.ObjTool, ui plugin.UI) {
+	// Construct search path to examine
+	searchPath := os.Getenv("PPROF_BINARY_PATH")
+	if searchPath == "" {
+		// Use $HOME/pprof/binaries as default directory for local symbolization binaries
+		searchPath = filepath.Join(os.Getenv(homeEnv()), "pprof", "binaries")
+	}
+mapping:
+	for _, m := range p.Mapping {
+		var baseName string
+		if m.File != "" {
+			baseName = filepath.Base(m.File)
+		}
+
+		for _, path := range filepath.SplitList(searchPath) {
+			var fileNames []string
+			if m.BuildID != "" {
+				fileNames = []string{filepath.Join(path, m.BuildID, baseName)}
+				if matches, err := filepath.Glob(filepath.Join(path, m.BuildID, "*")); err == nil {
+					fileNames = append(fileNames, matches...)
+				}
+				fileNames = append(fileNames, filepath.Join(path, m.File, m.BuildID)) // perf path format
+			}
+			if m.File != "" {
+				// Try both the basename and the full path, to support the same directory
+				// structure as the perf symfs option.
+				if baseName != "" {
+					fileNames = append(fileNames, filepath.Join(path, baseName))
+				}
+				fileNames = append(fileNames, filepath.Join(path, m.File))
+			}
+			for _, name := range fileNames {
+				if f, err := obj.Open(name, m.Start, m.Limit, m.Offset); err == nil {
+					defer f.Close()
+					fileBuildID := f.BuildID()
+					if m.BuildID != "" && m.BuildID != fileBuildID {
+						ui.PrintErr("Ignoring local file " + name + ": build-id mismatch (" + m.BuildID + " != " + fileBuildID + ")")
+					} else {
+						m.File = name
+						continue mapping
+					}
+				}
+			}
+		}
+	}
+	if len(p.Mapping) == 0 {
+		// If there are no mappings, add a fake mapping to attempt symbolization.
+		// This is useful for some profiles generated by the golang runtime, which
+		// do not include any mappings. Symbolization with a fake mapping will only
+		// be successful against a non-PIE binary.
+		m := &profile.Mapping{ID: 1}
+		p.Mapping = []*profile.Mapping{m}
+		for _, l := range p.Location {
+			l.Mapping = m
+		}
+	}
+	// Replace executable filename/buildID with the overrides from source.
+	// Assumes the executable is the first Mapping entry.
+	if execName, buildID := s.ExecName, s.BuildID; execName != "" || buildID != "" {
+		m := p.Mapping[0]
+		if execName != "" {
+			m.File = execName
+		}
+		if buildID != "" {
+			m.BuildID = buildID
+		}
+	}
+}
+
+// fetch fetches a profile from source, within the timeout specified,
+// producing messages through the ui. It returns the profile and the
+// url of the actual source of the profile for remote profiles.
+func fetch(source string, duration, timeout time.Duration, ui plugin.UI, tr http.RoundTripper) (p *profile.Profile, src string, err error) {
+	var f io.ReadCloser
+
+	if sourceURL, timeout := adjustURL(source, duration, timeout); sourceURL != "" {
+		ui.Print("Fetching profile over HTTP from " + sourceURL)
+		if duration > 0 {
+			ui.Print(fmt.Sprintf("Please wait... (%v)", duration))
+		}
+		f, err = fetchURL(sourceURL, timeout, tr)
+		src = sourceURL
+	} else if isPerfFile(source) {
+		f, err = convertPerfData(source, ui)
+	} else {
+		f, err = os.Open(source)
+	}
+	if err == nil {
+		defer f.Close()
+		p, err = profile.Parse(f)
+	}
+	return
+}
+
+// fetchURL fetches a profile from a URL using HTTP.
+func fetchURL(source string, timeout time.Duration, tr http.RoundTripper) (io.ReadCloser, error) {
+	client := &http.Client{
+		Transport: tr,
+		Timeout:   timeout + 5*time.Second,
+	}
+	resp, err := client.Get(source)
+	if err != nil {
+		return nil, fmt.Errorf("http fetch: %v", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		defer resp.Body.Close()
+		return nil, statusCodeError(resp)
+	}
+
+	return resp.Body, nil
+}
+
+func statusCodeError(resp *http.Response) error {
+	if resp.Header.Get("X-Go-Pprof") != "" && strings.Contains(resp.Header.Get("Content-Type"), "text/plain") {
+		// error is from pprof endpoint
+		if body, err := ioutil.ReadAll(resp.Body); err == nil {
+			return fmt.Errorf("server response: %s - %s", resp.Status, body)
+		}
+	}
+	return fmt.Errorf("server response: %s", resp.Status)
+}
+
+// isPerfFile checks if a file is in perf.data format. It also returns false
+// if it encounters an error during the check.
+func isPerfFile(path string) bool {
+	sourceFile, openErr := os.Open(path)
+	if openErr != nil {
+		return false
+	}
+	defer sourceFile.Close()
+
+	// If the file is the output of a perf record command, it should begin
+	// with the string PERFILE2.
+	perfHeader := []byte("PERFILE2")
+	actualHeader := make([]byte, len(perfHeader))
+	if _, readErr := sourceFile.Read(actualHeader); readErr != nil {
+		return false
+	}
+	return bytes.Equal(actualHeader, perfHeader)
+}
+
+// convertPerfData converts the file at path which should be in perf.data format
+// using the perf_to_profile tool and returns the file containing the
+// profile.proto formatted data.
+func convertPerfData(perfPath string, ui plugin.UI) (*os.File, error) {
+	ui.Print(fmt.Sprintf(
+		"Converting %s to a profile.proto... (May take a few minutes)",
+		perfPath))
+	profile, err := newTempFile(os.TempDir(), "pprof_", ".pb.gz")
+	if err != nil {
+		return nil, err
+	}
+	deferDeleteTempFile(profile.Name())
+	cmd := exec.Command("perf_to_profile", "-i", perfPath, "-o", profile.Name(), "-f")
+	cmd.Stdout, cmd.Stderr = os.Stdout, os.Stderr
+	if err := cmd.Run(); err != nil {
+		profile.Close()
+		return nil, fmt.Errorf("failed to convert perf.data file. Try github.com/google/perf_data_converter: %v", err)
+	}
+	return profile, nil
+}
+
+// adjustURL validates if a profile source is a URL and returns an
+// cleaned up URL and the timeout to use for retrieval over HTTP.
+// If the source cannot be recognized as a URL it returns an empty string.
+func adjustURL(source string, duration, timeout time.Duration) (string, time.Duration) {
+	u, err := url.Parse(source)
+	if err != nil || (u.Host == "" && u.Scheme != "" && u.Scheme != "file") {
+		// Try adding http:// to catch sources of the form hostname:port/path.
+		// url.Parse treats "hostname" as the scheme.
+		u, err = url.Parse("http://" + source)
+	}
+	if err != nil || u.Host == "" {
+		return "", 0
+	}
+
+	// Apply duration/timeout overrides to URL.
+	values := u.Query()
+	if duration > 0 {
+		values.Set("seconds", fmt.Sprint(int(duration.Seconds())))
+	} else {
+		if urlSeconds := values.Get("seconds"); urlSeconds != "" {
+			if us, err := strconv.ParseInt(urlSeconds, 10, 32); err == nil {
+				duration = time.Duration(us) * time.Second
+			}
+		}
+	}
+	if timeout <= 0 {
+		if duration > 0 {
+			timeout = duration + duration/2
+		} else {
+			timeout = 60 * time.Second
+		}
+	}
+	u.RawQuery = values.Encode()
+	return u.String(), timeout
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/flags.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/flags.go
new file mode 100644
index 0000000..5390319
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/flags.go
@@ -0,0 +1,71 @@
+//  Copyright 2018 Google Inc. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+
+package driver
+
+import (
+	"flag"
+	"strings"
+)
+
+// GoFlags implements the plugin.FlagSet interface.
+type GoFlags struct {
+	UsageMsgs []string
+}
+
+// Bool implements the plugin.FlagSet interface.
+func (*GoFlags) Bool(o string, d bool, c string) *bool {
+	return flag.Bool(o, d, c)
+}
+
+// Int implements the plugin.FlagSet interface.
+func (*GoFlags) Int(o string, d int, c string) *int {
+	return flag.Int(o, d, c)
+}
+
+// Float64 implements the plugin.FlagSet interface.
+func (*GoFlags) Float64(o string, d float64, c string) *float64 {
+	return flag.Float64(o, d, c)
+}
+
+// String implements the plugin.FlagSet interface.
+func (*GoFlags) String(o, d, c string) *string {
+	return flag.String(o, d, c)
+}
+
+// StringList implements the plugin.FlagSet interface.
+func (*GoFlags) StringList(o, d, c string) *[]*string {
+	return &[]*string{flag.String(o, d, c)}
+}
+
+// ExtraUsage implements the plugin.FlagSet interface.
+func (f *GoFlags) ExtraUsage() string {
+	return strings.Join(f.UsageMsgs, "\n")
+}
+
+// AddExtraUsage implements the plugin.FlagSet interface.
+func (f *GoFlags) AddExtraUsage(eu string) {
+	f.UsageMsgs = append(f.UsageMsgs, eu)
+}
+
+// Parse implements the plugin.FlagSet interface.
+func (*GoFlags) Parse(usage func()) []string {
+	flag.Usage = usage
+	flag.Parse()
+	args := flag.Args()
+	if len(args) == 0 {
+		usage()
+	}
+	return args
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/flamegraph.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/flamegraph.go
new file mode 100644
index 0000000..fbeb765
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/flamegraph.go
@@ -0,0 +1,106 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"encoding/json"
+	"html/template"
+	"net/http"
+	"strings"
+
+	"github.com/google/pprof/internal/graph"
+	"github.com/google/pprof/internal/measurement"
+	"github.com/google/pprof/internal/report"
+)
+
+type treeNode struct {
+	Name      string      `json:"n"`
+	FullName  string      `json:"f"`
+	Cum       int64       `json:"v"`
+	CumFormat string      `json:"l"`
+	Percent   string      `json:"p"`
+	Children  []*treeNode `json:"c"`
+}
+
+// flamegraph generates a web page containing a flamegraph.
+func (ui *webInterface) flamegraph(w http.ResponseWriter, req *http.Request) {
+	// Force the call tree so that the graph is a tree.
+	// Also do not trim the tree so that the flame graph contains all functions.
+	rpt, errList := ui.makeReport(w, req, []string{"svg"}, func(cfg *config) {
+		cfg.CallTree = true
+		cfg.Trim = false
+	})
+	if rpt == nil {
+		return // error already reported
+	}
+
+	// Generate dot graph.
+	g, config := report.GetDOT(rpt)
+	var nodes []*treeNode
+	nroots := 0
+	rootValue := int64(0)
+	nodeArr := []string{}
+	nodeMap := map[*graph.Node]*treeNode{}
+	// Make all nodes and the map, collect the roots.
+	for _, n := range g.Nodes {
+		v := n.CumValue()
+		fullName := n.Info.PrintableName()
+		node := &treeNode{
+			Name:      graph.ShortenFunctionName(fullName),
+			FullName:  fullName,
+			Cum:       v,
+			CumFormat: config.FormatValue(v),
+			Percent:   strings.TrimSpace(measurement.Percentage(v, config.Total)),
+		}
+		nodes = append(nodes, node)
+		if len(n.In) == 0 {
+			nodes[nroots], nodes[len(nodes)-1] = nodes[len(nodes)-1], nodes[nroots]
+			nroots++
+			rootValue += v
+		}
+		nodeMap[n] = node
+		// Get all node names into an array.
+		nodeArr = append(nodeArr, n.Info.Name)
+	}
+	// Populate the child links.
+	for _, n := range g.Nodes {
+		node := nodeMap[n]
+		for child := range n.Out {
+			node.Children = append(node.Children, nodeMap[child])
+		}
+	}
+
+	rootNode := &treeNode{
+		Name:      "root",
+		FullName:  "root",
+		Cum:       rootValue,
+		CumFormat: config.FormatValue(rootValue),
+		Percent:   strings.TrimSpace(measurement.Percentage(rootValue, config.Total)),
+		Children:  nodes[0:nroots],
+	}
+
+	// JSON marshalling flame graph
+	b, err := json.Marshal(rootNode)
+	if err != nil {
+		http.Error(w, "error serializing flame graph", http.StatusInternalServerError)
+		ui.options.UI.PrintErr(err)
+		return
+	}
+
+	ui.render(w, req, "flamegraph", rpt, errList, config.Labels, webArgs{
+		FlameGraph: template.JS(b),
+		Nodes:      nodeArr,
+	})
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/interactive.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/interactive.go
new file mode 100644
index 0000000..777fb90
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/interactive.go
@@ -0,0 +1,418 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"fmt"
+	"io"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/internal/report"
+	"github.com/google/pprof/profile"
+)
+
+var commentStart = "//:" // Sentinel for comments on options
+var tailDigitsRE = regexp.MustCompile("[0-9]+$")
+
+// interactive starts a shell to read pprof commands.
+func interactive(p *profile.Profile, o *plugin.Options) error {
+	// Enter command processing loop.
+	o.UI.SetAutoComplete(newCompleter(functionNames(p)))
+	configure("compact_labels", "true")
+	configHelp["sample_index"] += fmt.Sprintf("Or use sample_index=name, with name in %v.\n", sampleTypes(p))
+
+	// Do not wait for the visualizer to complete, to allow multiple
+	// graphs to be visualized simultaneously.
+	interactiveMode = true
+	shortcuts := profileShortcuts(p)
+
+	greetings(p, o.UI)
+	for {
+		input, err := o.UI.ReadLine("(pprof) ")
+		if err != nil {
+			if err != io.EOF {
+				return err
+			}
+			if input == "" {
+				return nil
+			}
+		}
+
+		for _, input := range shortcuts.expand(input) {
+			// Process assignments of the form variable=value
+			if s := strings.SplitN(input, "=", 2); len(s) > 0 {
+				name := strings.TrimSpace(s[0])
+				var value string
+				if len(s) == 2 {
+					value = s[1]
+					if comment := strings.LastIndex(value, commentStart); comment != -1 {
+						value = value[:comment]
+					}
+					value = strings.TrimSpace(value)
+				}
+				if isConfigurable(name) {
+					// All non-bool options require inputs
+					if len(s) == 1 && !isBoolConfig(name) {
+						o.UI.PrintErr(fmt.Errorf("please specify a value, e.g. %s=<val>", name))
+						continue
+					}
+					if name == "sample_index" {
+						// Error check sample_index=xxx to ensure xxx is a valid sample type.
+						index, err := p.SampleIndexByName(value)
+						if err != nil {
+							o.UI.PrintErr(err)
+							continue
+						}
+						if index < 0 || index >= len(p.SampleType) {
+							o.UI.PrintErr(fmt.Errorf("invalid sample_index %q", value))
+							continue
+						}
+						value = p.SampleType[index].Type
+					}
+					if err := configure(name, value); err != nil {
+						o.UI.PrintErr(err)
+					}
+					continue
+				}
+			}
+
+			tokens := strings.Fields(input)
+			if len(tokens) == 0 {
+				continue
+			}
+
+			switch tokens[0] {
+			case "o", "options":
+				printCurrentOptions(p, o.UI)
+				continue
+			case "exit", "quit", "q":
+				return nil
+			case "help":
+				commandHelp(strings.Join(tokens[1:], " "), o.UI)
+				continue
+			}
+
+			args, cfg, err := parseCommandLine(tokens)
+			if err == nil {
+				err = generateReportWrapper(p, args, cfg, o)
+			}
+
+			if err != nil {
+				o.UI.PrintErr(err)
+			}
+		}
+	}
+}
+
+var generateReportWrapper = generateReport // For testing purposes.
+
+// greetings prints a brief welcome and some overall profile
+// information before accepting interactive commands.
+func greetings(p *profile.Profile, ui plugin.UI) {
+	numLabelUnits := identifyNumLabelUnits(p, ui)
+	ropt, err := reportOptions(p, numLabelUnits, currentConfig())
+	if err == nil {
+		rpt := report.New(p, ropt)
+		ui.Print(strings.Join(report.ProfileLabels(rpt), "\n"))
+		if rpt.Total() == 0 && len(p.SampleType) > 1 {
+			ui.Print(`No samples were found with the default sample value type.`)
+			ui.Print(`Try "sample_index" command to analyze different sample values.`, "\n")
+		}
+	}
+	ui.Print(`Entering interactive mode (type "help" for commands, "o" for options)`)
+}
+
+// shortcuts represents composite commands that expand into a sequence
+// of other commands.
+type shortcuts map[string][]string
+
+func (a shortcuts) expand(input string) []string {
+	input = strings.TrimSpace(input)
+	if a != nil {
+		if r, ok := a[input]; ok {
+			return r
+		}
+	}
+	return []string{input}
+}
+
+var pprofShortcuts = shortcuts{
+	":": []string{"focus=", "ignore=", "hide=", "tagfocus=", "tagignore="},
+}
+
+// profileShortcuts creates macros for convenience and backward compatibility.
+func profileShortcuts(p *profile.Profile) shortcuts {
+	s := pprofShortcuts
+	// Add shortcuts for sample types
+	for _, st := range p.SampleType {
+		command := fmt.Sprintf("sample_index=%s", st.Type)
+		s[st.Type] = []string{command}
+		s["total_"+st.Type] = []string{"mean=0", command}
+		s["mean_"+st.Type] = []string{"mean=1", command}
+	}
+	return s
+}
+
+func sampleTypes(p *profile.Profile) []string {
+	types := make([]string, len(p.SampleType))
+	for i, t := range p.SampleType {
+		types[i] = t.Type
+	}
+	return types
+}
+
+func printCurrentOptions(p *profile.Profile, ui plugin.UI) {
+	var args []string
+	current := currentConfig()
+	for _, f := range configFields {
+		n := f.name
+		v := current.get(f)
+		comment := ""
+		switch {
+		case len(f.choices) > 0:
+			values := append([]string{}, f.choices...)
+			sort.Strings(values)
+			comment = "[" + strings.Join(values, " | ") + "]"
+		case n == "sample_index":
+			st := sampleTypes(p)
+			if v == "" {
+				// Apply default (last sample index).
+				v = st[len(st)-1]
+			}
+			// Add comments for all sample types in profile.
+			comment = "[" + strings.Join(st, " | ") + "]"
+		case n == "source_path":
+			continue
+		case n == "nodecount" && v == "-1":
+			comment = "default"
+		case v == "":
+			// Add quotes for empty values.
+			v = `""`
+		}
+		if comment != "" {
+			comment = commentStart + " " + comment
+		}
+		args = append(args, fmt.Sprintf("  %-25s = %-20s %s", n, v, comment))
+	}
+	sort.Strings(args)
+	ui.Print(strings.Join(args, "\n"))
+}
+
+// parseCommandLine parses a command and returns the pprof command to
+// execute and the configuration to use for the report.
+func parseCommandLine(input []string) ([]string, config, error) {
+	cmd, args := input[:1], input[1:]
+	name := cmd[0]
+
+	c := pprofCommands[name]
+	if c == nil {
+		// Attempt splitting digits on abbreviated commands (eg top10)
+		if d := tailDigitsRE.FindString(name); d != "" && d != name {
+			name = name[:len(name)-len(d)]
+			cmd[0], args = name, append([]string{d}, args...)
+			c = pprofCommands[name]
+		}
+	}
+	if c == nil {
+		if _, ok := configHelp[name]; ok {
+			value := "<val>"
+			if len(args) > 0 {
+				value = args[0]
+			}
+			return nil, config{}, fmt.Errorf("did you mean: %s=%s", name, value)
+		}
+		return nil, config{}, fmt.Errorf("unrecognized command: %q", name)
+	}
+
+	if c.hasParam {
+		if len(args) == 0 {
+			return nil, config{}, fmt.Errorf("command %s requires an argument", name)
+		}
+		cmd = append(cmd, args[0])
+		args = args[1:]
+	}
+
+	// Copy config since options set in the command line should not persist.
+	vcopy := currentConfig()
+
+	var focus, ignore string
+	for i := 0; i < len(args); i++ {
+		t := args[i]
+		if n, err := strconv.ParseInt(t, 10, 32); err == nil {
+			vcopy.NodeCount = int(n)
+			continue
+		}
+		switch t[0] {
+		case '>':
+			outputFile := t[1:]
+			if outputFile == "" {
+				i++
+				if i >= len(args) {
+					return nil, config{}, fmt.Errorf("unexpected end of line after >")
+				}
+				outputFile = args[i]
+			}
+			vcopy.Output = outputFile
+		case '-':
+			if t == "--cum" || t == "-cum" {
+				vcopy.Sort = "cum"
+				continue
+			}
+			ignore = catRegex(ignore, t[1:])
+		default:
+			focus = catRegex(focus, t)
+		}
+	}
+
+	if name == "tags" {
+		if focus != "" {
+			vcopy.TagFocus = focus
+		}
+		if ignore != "" {
+			vcopy.TagIgnore = ignore
+		}
+	} else {
+		if focus != "" {
+			vcopy.Focus = focus
+		}
+		if ignore != "" {
+			vcopy.Ignore = ignore
+		}
+	}
+	if vcopy.NodeCount == -1 && (name == "text" || name == "top") {
+		vcopy.NodeCount = 10
+	}
+
+	return cmd, vcopy, nil
+}
+
+func catRegex(a, b string) string {
+	if a != "" && b != "" {
+		return a + "|" + b
+	}
+	return a + b
+}
+
+// commandHelp displays help and usage information for all Commands
+// and Variables or a specific Command or Variable.
+func commandHelp(args string, ui plugin.UI) {
+	if args == "" {
+		help := usage(false)
+		help = help + `
+  :   Clear focus/ignore/hide/tagfocus/tagignore
+
+  type "help <cmd|option>" for more information
+`
+
+		ui.Print(help)
+		return
+	}
+
+	if c := pprofCommands[args]; c != nil {
+		ui.Print(c.help(args))
+		return
+	}
+
+	if help, ok := configHelp[args]; ok {
+		ui.Print(help + "\n")
+		return
+	}
+
+	ui.PrintErr("Unknown command: " + args)
+}
+
+// newCompleter creates an autocompletion function for a set of commands.
+func newCompleter(fns []string) func(string) string {
+	return func(line string) string {
+		switch tokens := strings.Fields(line); len(tokens) {
+		case 0:
+			// Nothing to complete
+		case 1:
+			// Single token -- complete command name
+			if match := matchVariableOrCommand(tokens[0]); match != "" {
+				return match
+			}
+		case 2:
+			if tokens[0] == "help" {
+				if match := matchVariableOrCommand(tokens[1]); match != "" {
+					return tokens[0] + " " + match
+				}
+				return line
+			}
+			fallthrough
+		default:
+			// Multiple tokens -- complete using functions, except for tags
+			if cmd := pprofCommands[tokens[0]]; cmd != nil && tokens[0] != "tags" {
+				lastTokenIdx := len(tokens) - 1
+				lastToken := tokens[lastTokenIdx]
+				if strings.HasPrefix(lastToken, "-") {
+					lastToken = "-" + functionCompleter(lastToken[1:], fns)
+				} else {
+					lastToken = functionCompleter(lastToken, fns)
+				}
+				return strings.Join(append(tokens[:lastTokenIdx], lastToken), " ")
+			}
+		}
+		return line
+	}
+}
+
+// matchVariableOrCommand attempts to match a string token to the prefix of a Command.
+func matchVariableOrCommand(token string) string {
+	token = strings.ToLower(token)
+	var matches []string
+	for cmd := range pprofCommands {
+		if strings.HasPrefix(cmd, token) {
+			matches = append(matches, cmd)
+		}
+	}
+	matches = append(matches, completeConfig(token)...)
+	if len(matches) == 1 {
+		return matches[0]
+	}
+	return ""
+}
+
+// functionCompleter replaces provided substring with a function
+// name retrieved from a profile if a single match exists. Otherwise,
+// it returns unchanged substring. It defaults to no-op if the profile
+// is not specified.
+func functionCompleter(substring string, fns []string) string {
+	found := ""
+	for _, fName := range fns {
+		if strings.Contains(fName, substring) {
+			if found != "" {
+				return substring
+			}
+			found = fName
+		}
+	}
+	if found != "" {
+		return found
+	}
+	return substring
+}
+
+func functionNames(p *profile.Profile) []string {
+	var fns []string
+	for _, fn := range p.Function {
+		fns = append(fns, fn.Name)
+	}
+	return fns
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/options.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/options.go
new file mode 100644
index 0000000..6e8f9fc
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/options.go
@@ -0,0 +1,100 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/google/pprof/internal/binutils"
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/internal/symbolizer"
+	"github.com/google/pprof/internal/transport"
+)
+
+// setDefaults returns a new plugin.Options with zero fields sets to
+// sensible defaults.
+func setDefaults(o *plugin.Options) *plugin.Options {
+	d := &plugin.Options{}
+	if o != nil {
+		*d = *o
+	}
+	if d.Writer == nil {
+		d.Writer = oswriter{}
+	}
+	if d.Flagset == nil {
+		d.Flagset = &GoFlags{}
+	}
+	if d.Obj == nil {
+		d.Obj = &binutils.Binutils{}
+	}
+	if d.UI == nil {
+		d.UI = &stdUI{r: bufio.NewReader(os.Stdin)}
+	}
+	if d.HTTPTransport == nil {
+		d.HTTPTransport = transport.New(d.Flagset)
+	}
+	if d.Sym == nil {
+		d.Sym = &symbolizer.Symbolizer{Obj: d.Obj, UI: d.UI, Transport: d.HTTPTransport}
+	}
+	return d
+}
+
+type stdUI struct {
+	r *bufio.Reader
+}
+
+func (ui *stdUI) ReadLine(prompt string) (string, error) {
+	os.Stdout.WriteString(prompt)
+	return ui.r.ReadString('\n')
+}
+
+func (ui *stdUI) Print(args ...interface{}) {
+	ui.fprint(os.Stderr, args)
+}
+
+func (ui *stdUI) PrintErr(args ...interface{}) {
+	ui.fprint(os.Stderr, args)
+}
+
+func (ui *stdUI) IsTerminal() bool {
+	return false
+}
+
+func (ui *stdUI) WantBrowser() bool {
+	return true
+}
+
+func (ui *stdUI) SetAutoComplete(func(string) string) {
+}
+
+func (ui *stdUI) fprint(f *os.File, args []interface{}) {
+	text := fmt.Sprint(args...)
+	if !strings.HasSuffix(text, "\n") {
+		text += "\n"
+	}
+	f.WriteString(text)
+}
+
+// oswriter implements the Writer interface using a regular file.
+type oswriter struct{}
+
+func (oswriter) Open(name string) (io.WriteCloser, error) {
+	f, err := os.Create(name)
+	return f, err
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/settings.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/settings.go
new file mode 100644
index 0000000..f72314b
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/settings.go
@@ -0,0 +1,157 @@
+package driver
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/url"
+	"os"
+	"path/filepath"
+)
+
+// settings holds pprof settings.
+type settings struct {
+	// Configs holds a list of named UI configurations.
+	Configs []namedConfig `json:"configs"`
+}
+
+// namedConfig associates a name with a config.
+type namedConfig struct {
+	Name string `json:"name"`
+	config
+}
+
+// settingsFileName returns the name of the file where settings should be saved.
+func settingsFileName() (string, error) {
+	// Return "pprof/settings.json" under os.UserConfigDir().
+	dir, err := os.UserConfigDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(dir, "pprof", "settings.json"), nil
+}
+
+// readSettings reads settings from fname.
+func readSettings(fname string) (*settings, error) {
+	data, err := ioutil.ReadFile(fname)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return &settings{}, nil
+		}
+		return nil, fmt.Errorf("could not read settings: %w", err)
+	}
+	settings := &settings{}
+	if err := json.Unmarshal(data, settings); err != nil {
+		return nil, fmt.Errorf("could not parse settings: %w", err)
+	}
+	for i := range settings.Configs {
+		settings.Configs[i].resetTransient()
+	}
+	return settings, nil
+}
+
+// writeSettings saves settings to fname.
+func writeSettings(fname string, settings *settings) error {
+	data, err := json.MarshalIndent(settings, "", "  ")
+	if err != nil {
+		return fmt.Errorf("could not encode settings: %w", err)
+	}
+
+	// create the settings directory if it does not exist
+	// XDG specifies permissions 0700 when creating settings dirs:
+	// https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
+	if err := os.MkdirAll(filepath.Dir(fname), 0700); err != nil {
+		return fmt.Errorf("failed to create settings directory: %w", err)
+	}
+
+	if err := ioutil.WriteFile(fname, data, 0644); err != nil {
+		return fmt.Errorf("failed to write settings: %w", err)
+	}
+	return nil
+}
+
+// configMenuEntry holds information for a single config menu entry.
+type configMenuEntry struct {
+	Name       string
+	URL        string
+	Current    bool // Is this the currently selected config?
+	UserConfig bool // Is this a user-provided config?
+}
+
+// configMenu returns a list of items to add to a menu in the web UI.
+func configMenu(fname string, url url.URL) []configMenuEntry {
+	// Start with system configs.
+	configs := []namedConfig{{Name: "Default", config: defaultConfig()}}
+	if settings, err := readSettings(fname); err == nil {
+		// Add user configs.
+		configs = append(configs, settings.Configs...)
+	}
+
+	// Convert to menu entries.
+	result := make([]configMenuEntry, len(configs))
+	lastMatch := -1
+	for i, cfg := range configs {
+		dst, changed := cfg.config.makeURL(url)
+		if !changed {
+			lastMatch = i
+		}
+		result[i] = configMenuEntry{
+			Name:       cfg.Name,
+			URL:        dst.String(),
+			UserConfig: (i != 0),
+		}
+	}
+	// Mark the last matching config as currennt
+	if lastMatch >= 0 {
+		result[lastMatch].Current = true
+	}
+	return result
+}
+
+// editSettings edits settings by applying fn to them.
+func editSettings(fname string, fn func(s *settings) error) error {
+	settings, err := readSettings(fname)
+	if err != nil {
+		return err
+	}
+	if err := fn(settings); err != nil {
+		return err
+	}
+	return writeSettings(fname, settings)
+}
+
+// setConfig saves the config specified in request to fname.
+func setConfig(fname string, request url.URL) error {
+	q := request.Query()
+	name := q.Get("config")
+	if name == "" {
+		return fmt.Errorf("invalid config name")
+	}
+	cfg := currentConfig()
+	if err := cfg.applyURL(q); err != nil {
+		return err
+	}
+	return editSettings(fname, func(s *settings) error {
+		for i, c := range s.Configs {
+			if c.Name == name {
+				s.Configs[i].config = cfg
+				return nil
+			}
+		}
+		s.Configs = append(s.Configs, namedConfig{Name: name, config: cfg})
+		return nil
+	})
+}
+
+// removeConfig removes config from fname.
+func removeConfig(fname, config string) error {
+	return editSettings(fname, func(s *settings) error {
+		for i, c := range s.Configs {
+			if c.Name == config {
+				s.Configs = append(s.Configs[:i], s.Configs[i+1:]...)
+				return nil
+			}
+		}
+		return fmt.Errorf("config %s not found", config)
+	})
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/svg.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/svg.go
new file mode 100644
index 0000000..62767e7
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/svg.go
@@ -0,0 +1,80 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/google/pprof/third_party/svgpan"
+)
+
+var (
+	viewBox  = regexp.MustCompile(`<svg\s*width="[^"]+"\s*height="[^"]+"\s*viewBox="[^"]+"`)
+	graphID  = regexp.MustCompile(`<g id="graph\d"`)
+	svgClose = regexp.MustCompile(`</svg>`)
+)
+
+// massageSVG enhances the SVG output from DOT to provide better
+// panning inside a web browser. It uses the svgpan library, which is
+// embedded into the svgpan.JSSource variable.
+func massageSVG(svg string) string {
+	// Work around for dot bug which misses quoting some ampersands,
+	// resulting on unparsable SVG.
+	svg = strings.Replace(svg, "&;", "&amp;;", -1)
+
+	// Dot's SVG output is
+	//
+	//    <svg width="___" height="___"
+	//     viewBox="___" xmlns=...>
+	//    <g id="graph0" transform="...">
+	//    ...
+	//    </g>
+	//    </svg>
+	//
+	// Change it to
+	//
+	//    <svg width="100%" height="100%"
+	//     xmlns=...>
+
+	//    <script type="text/ecmascript"><![CDATA[` ..$(svgpan.JSSource)... `]]></script>`
+	//    <g id="viewport" transform="translate(0,0)">
+	//    <g id="graph0" transform="...">
+	//    ...
+	//    </g>
+	//    </g>
+	//    </svg>
+
+	if loc := viewBox.FindStringIndex(svg); loc != nil {
+		svg = svg[:loc[0]] +
+			`<svg width="100%" height="100%"` +
+			svg[loc[1]:]
+	}
+
+	if loc := graphID.FindStringIndex(svg); loc != nil {
+		svg = svg[:loc[0]] +
+			`<script type="text/ecmascript"><![CDATA[` + string(svgpan.JSSource) + `]]></script>` +
+			`<g id="viewport" transform="scale(0.5,0.5) translate(0,0)">` +
+			svg[loc[0]:]
+	}
+
+	if loc := svgClose.FindStringIndex(svg); loc != nil {
+		svg = svg[:loc[0]] +
+			`</g>` +
+			svg[loc[0]:]
+	}
+
+	return svg
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/tempfile.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/tempfile.go
new file mode 100644
index 0000000..b6c8776
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/tempfile.go
@@ -0,0 +1,60 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+)
+
+// newTempFile returns a new output file in dir with the provided prefix and suffix.
+func newTempFile(dir, prefix, suffix string) (*os.File, error) {
+	for index := 1; index < 10000; index++ {
+		switch f, err := os.OpenFile(filepath.Join(dir, fmt.Sprintf("%s%03d%s", prefix, index, suffix)), os.O_RDWR|os.O_CREATE|os.O_EXCL, 0666); {
+		case err == nil:
+			return f, nil
+		case !os.IsExist(err):
+			return nil, err
+		}
+	}
+	// Give up
+	return nil, fmt.Errorf("could not create file of the form %s%03d%s", prefix, 1, suffix)
+}
+
+var tempFiles []string
+var tempFilesMu = sync.Mutex{}
+
+// deferDeleteTempFile marks a file to be deleted by next call to Cleanup()
+func deferDeleteTempFile(path string) {
+	tempFilesMu.Lock()
+	tempFiles = append(tempFiles, path)
+	tempFilesMu.Unlock()
+}
+
+// cleanupTempFiles removes any temporary files selected for deferred cleaning.
+func cleanupTempFiles() error {
+	tempFilesMu.Lock()
+	defer tempFilesMu.Unlock()
+	var lastErr error
+	for _, f := range tempFiles {
+		if err := os.Remove(f); err != nil {
+			lastErr = err
+		}
+	}
+	tempFiles = nil
+	return lastErr
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go
new file mode 100644
index 0000000..4f7610c
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/webhtml.go
@@ -0,0 +1,1403 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"html/template"
+
+	"github.com/google/pprof/third_party/d3"
+	"github.com/google/pprof/third_party/d3flamegraph"
+)
+
+// addTemplates adds a set of template definitions to templates.
+func addTemplates(templates *template.Template) {
+	template.Must(templates.Parse(`{{define "d3script"}}` + d3.JSSource + `{{end}}`))
+	template.Must(templates.Parse(`{{define "d3flamegraphscript"}}` + d3flamegraph.JSSource + `{{end}}`))
+	template.Must(templates.Parse(`{{define "d3flamegraphcss"}}` + d3flamegraph.CSSSource + `{{end}}`))
+	template.Must(templates.Parse(`
+{{define "css"}}
+<style type="text/css">
+* {
+  margin: 0;
+  padding: 0;
+  box-sizing: border-box;
+}
+html, body {
+  height: 100%;
+}
+body {
+  font-family: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
+  font-size: 13px;
+  line-height: 1.4;
+  display: flex;
+  flex-direction: column;
+}
+a {
+  color: #2a66d9;
+}
+.header {
+  display: flex;
+  align-items: center;
+  height: 44px;
+  min-height: 44px;
+  background-color: #eee;
+  color: #212121;
+  padding: 0 1rem;
+}
+.header > div {
+  margin: 0 0.125em;
+}
+.header .title h1 {
+  font-size: 1.75em;
+  margin-right: 1rem;
+}
+.header .title a {
+  color: #212121;
+  text-decoration: none;
+}
+.header .title a:hover {
+  text-decoration: underline;
+}
+.header .description {
+  width: 100%;
+  text-align: right;
+  white-space: nowrap;
+}
+@media screen and (max-width: 799px) {
+  .header input {
+    display: none;
+  }
+}
+#detailsbox {
+  display: none;
+  z-index: 1;
+  position: fixed;
+  top: 40px;
+  right: 20px;
+  background-color: #ffffff;
+  box-shadow: 0 1px 5px rgba(0,0,0,.3);
+  line-height: 24px;
+  padding: 1em;
+  text-align: left;
+}
+.header input {
+  background: white url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' style='pointer-events:none;display:block;width:100%25;height:100%25;fill:%23757575'%3E%3Cpath d='M15.5 14h-.79l-.28-.27C15.41 12.59 16 11.11 16 9.5 16 5.91 13.09 3 9.5 3S3 5.91 3 9.5 5.91 16 9.5 16c1.61.0 3.09-.59 4.23-1.57l.27.28v.79l5 4.99L20.49 19l-4.99-5zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z'/%3E%3C/svg%3E") no-repeat 4px center/20px 20px;
+  border: 1px solid #d1d2d3;
+  border-radius: 2px 0 0 2px;
+  padding: 0.25em;
+  padding-left: 28px;
+  margin-left: 1em;
+  font-family: 'Roboto', 'Noto', sans-serif;
+  font-size: 1em;
+  line-height: 24px;
+  color: #212121;
+}
+.downArrow {
+  border-top: .36em solid #ccc;
+  border-left: .36em solid transparent;
+  border-right: .36em solid transparent;
+  margin-bottom: .05em;
+  margin-left: .5em;
+  transition: border-top-color 200ms;
+}
+.menu-item {
+  height: 100%;
+  text-transform: uppercase;
+  font-family: 'Roboto Medium', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
+  position: relative;
+}
+.menu-item .menu-name:hover {
+  opacity: 0.75;
+}
+.menu-item .menu-name:hover .downArrow {
+  border-top-color: #666;
+}
+.menu-name {
+  height: 100%;
+  padding: 0 0.5em;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+.submenu {
+  display: none;
+  z-index: 1;
+  margin-top: -4px;
+  min-width: 10em;
+  position: absolute;
+  left: 0px;
+  background-color: white;
+  box-shadow: 0 1px 5px rgba(0,0,0,.3);
+  font-size: 100%;
+  text-transform: none;
+}
+.menu-item, .submenu {
+  user-select: none;
+  -moz-user-select: none;
+  -ms-user-select: none;
+  -webkit-user-select: none;
+}
+.submenu hr {
+  border: 0;
+  border-top: 2px solid #eee;
+}
+.submenu a {
+  display: block;
+  padding: .5em 1em;
+  text-decoration: none;
+}
+.submenu a:hover, .submenu a.active {
+  color: white;
+  background-color: #6b82d6;
+}
+.submenu a.disabled {
+  color: gray;
+  pointer-events: none;
+}
+.menu-check-mark {
+  position: absolute;
+  left: 2px;
+}
+.menu-delete-btn {
+  position: absolute;
+  right: 2px;
+}
+
+{{/* Used to disable events when a modal dialog is displayed */}}
+#dialog-overlay {
+  display: none;
+  position: fixed;
+  left: 0px;
+  top: 0px;
+  width: 100%;
+  height: 100%;
+  background-color: rgba(1,1,1,0.1);
+}
+
+.dialog {
+  {{/* Displayed centered horizontally near the top */}}
+  display: none;
+  position: fixed;
+  margin: 0px;
+  top: 60px;
+  left: 50%;
+  transform: translateX(-50%);
+
+  z-index: 3;
+  font-size: 125%;
+  background-color: #ffffff;
+  box-shadow: 0 1px 5px rgba(0,0,0,.3);
+}
+.dialog-header {
+  font-size: 120%;
+  border-bottom: 1px solid #CCCCCC;
+  width: 100%;
+  text-align: center;
+  background: #EEEEEE;
+  user-select: none;
+}
+.dialog-footer {
+  border-top: 1px solid #CCCCCC;
+  width: 100%;
+  text-align: right;
+  padding: 10px;
+}
+.dialog-error {
+  margin: 10px;
+  color: red;
+}
+.dialog input {
+  margin: 10px;
+  font-size: inherit;
+}
+.dialog button {
+  margin-left: 10px;
+  font-size: inherit;
+}
+#save-dialog, #delete-dialog {
+  width: 50%;
+  max-width: 20em;
+}
+#delete-prompt {
+  padding: 10px;
+}
+
+#content {
+  overflow-y: scroll;
+  padding: 1em;
+}
+#top {
+  overflow-y: scroll;
+}
+#graph {
+  overflow: hidden;
+}
+#graph svg {
+  width: 100%;
+  height: auto;
+  padding: 10px;
+}
+#content.source .filename {
+  margin-top: 0;
+  margin-bottom: 1em;
+  font-size: 120%;
+}
+#content.source pre {
+  margin-bottom: 3em;
+}
+table {
+  border-spacing: 0px;
+  width: 100%;
+  padding-bottom: 1em;
+  white-space: nowrap;
+}
+table thead {
+  font-family: 'Roboto Medium', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
+}
+table tr th {
+  position: sticky;
+  top: 0;
+  background-color: #ddd;
+  text-align: right;
+  padding: .3em .5em;
+}
+table tr td {
+  padding: .3em .5em;
+  text-align: right;
+}
+#top table tr th:nth-child(6),
+#top table tr th:nth-child(7),
+#top table tr td:nth-child(6),
+#top table tr td:nth-child(7) {
+  text-align: left;
+}
+#top table tr td:nth-child(6) {
+  width: 100%;
+  text-overflow: ellipsis;
+  overflow: hidden;
+  white-space: nowrap;
+}
+#flathdr1, #flathdr2, #cumhdr1, #cumhdr2, #namehdr {
+  cursor: ns-resize;
+}
+.hilite {
+  background-color: #ebf5fb;
+  font-weight: bold;
+}
+</style>
+{{end}}
+
+{{define "header"}}
+<div class="header">
+  <div class="title">
+    <h1><a href="./">pprof</a></h1>
+  </div>
+
+  <div id="view" class="menu-item">
+    <div class="menu-name">
+      View
+      <i class="downArrow"></i>
+    </div>
+    <div class="submenu">
+      <a title="{{.Help.top}}"  href="./top" id="topbtn">Top</a>
+      <a title="{{.Help.graph}}" href="./" id="graphbtn">Graph</a>
+      <a title="{{.Help.flamegraph}}" href="./flamegraph" id="flamegraph">Flame Graph</a>
+      <a title="{{.Help.peek}}" href="./peek" id="peek">Peek</a>
+      <a title="{{.Help.list}}" href="./source" id="list">Source</a>
+      <a title="{{.Help.disasm}}" href="./disasm" id="disasm">Disassemble</a>
+    </div>
+  </div>
+
+  {{$sampleLen := len .SampleTypes}}
+  {{if gt $sampleLen 1}}
+  <div id="sample" class="menu-item">
+    <div class="menu-name">
+      Sample
+      <i class="downArrow"></i>
+    </div>
+    <div class="submenu">
+      {{range .SampleTypes}}
+      <a href="?si={{.}}" id="{{.}}">{{.}}</a>
+      {{end}}
+    </div>
+  </div>
+  {{end}}
+
+  <div id="refine" class="menu-item">
+    <div class="menu-name">
+      Refine
+      <i class="downArrow"></i>
+    </div>
+    <div class="submenu">
+      <a title="{{.Help.focus}}" href="?" id="focus">Focus</a>
+      <a title="{{.Help.ignore}}" href="?" id="ignore">Ignore</a>
+      <a title="{{.Help.hide}}" href="?" id="hide">Hide</a>
+      <a title="{{.Help.show}}" href="?" id="show">Show</a>
+      <a title="{{.Help.show_from}}" href="?" id="show-from">Show from</a>
+      <hr>
+      <a title="{{.Help.reset}}" href="?">Reset</a>
+    </div>
+  </div>
+
+  <div id="config" class="menu-item">
+    <div class="menu-name">
+      Config
+      <i class="downArrow"></i>
+    </div>
+    <div class="submenu">
+      <a title="{{.Help.save_config}}" id="save-config">Save as ...</a>
+      <hr>
+      {{range .Configs}}
+        <a href="{{.URL}}">
+          {{if .Current}}<span class="menu-check-mark">✓</span>{{end}}
+          {{.Name}}
+          {{if .UserConfig}}<span class="menu-delete-btn" data-config={{.Name}}>🗙</span>{{end}}
+        </a>
+      {{end}}
+    </div>
+  </div>
+
+  <div>
+    <input id="search" type="text" placeholder="Search regexp" autocomplete="off" autocapitalize="none" size=40>
+  </div>
+
+  <div class="description">
+    <a title="{{.Help.details}}" href="#" id="details">{{.Title}}</a>
+    <div id="detailsbox">
+      {{range .Legend}}<div>{{.}}</div>{{end}}
+    </div>
+  </div>
+</div>
+
+<div id="dialog-overlay"></div>
+
+<div class="dialog" id="save-dialog">
+  <div class="dialog-header">Save options as</div>
+  <datalist id="config-list">
+    {{range .Configs}}{{if .UserConfig}}<option value="{{.Name}}" />{{end}}{{end}}
+  </datalist>
+  <input id="save-name" type="text" list="config-list" placeholder="New config" />
+  <div class="dialog-footer">
+    <span class="dialog-error" id="save-error"></span>
+    <button id="save-cancel">Cancel</button>
+    <button id="save-confirm">Save</button>
+  </div>
+</div>
+
+<div class="dialog" id="delete-dialog">
+  <div class="dialog-header" id="delete-dialog-title">Delete config</div>
+  <div id="delete-prompt"></div>
+  <div class="dialog-footer">
+    <span class="dialog-error" id="delete-error"></span>
+    <button id="delete-cancel">Cancel</button>
+    <button id="delete-confirm">Delete</button>
+  </div>
+</div>
+
+<div id="errors">{{range .Errors}}<div>{{.}}</div>{{end}}</div>
+{{end}}
+
+{{define "graph" -}}
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>{{.Title}}</title>
+  {{template "css" .}}
+</head>
+<body>
+  {{template "header" .}}
+  <div id="graph">
+    {{.HTMLBody}}
+  </div>
+  {{template "script" .}}
+  <script>viewer(new URL(window.location.href), {{.Nodes}});</script>
+</body>
+</html>
+{{end}}
+
+{{define "script"}}
+<script>
+// Make svg pannable and zoomable.
+// Call clickHandler(t) if a click event is caught by the pan event handlers.
+function initPanAndZoom(svg, clickHandler) {
+  'use strict';
+
+  // Current mouse/touch handling mode
+  const IDLE = 0;
+  const MOUSEPAN = 1;
+  const TOUCHPAN = 2;
+  const TOUCHZOOM = 3;
+  let mode = IDLE;
+
+  // State needed to implement zooming.
+  let currentScale = 1.0;
+  const initWidth = svg.viewBox.baseVal.width;
+  const initHeight = svg.viewBox.baseVal.height;
+
+  // State needed to implement panning.
+  let panLastX = 0;      // Last event X coordinate
+  let panLastY = 0;      // Last event Y coordinate
+  let moved = false;     // Have we seen significant movement
+  let touchid = null;    // Current touch identifier
+
+  // State needed for pinch zooming
+  let touchid2 = null;     // Second id for pinch zooming
+  let initGap = 1.0;       // Starting gap between two touches
+  let initScale = 1.0;     // currentScale when pinch zoom started
+  let centerPoint = null;  // Center point for scaling
+
+  // Convert event coordinates to svg coordinates.
+  function toSvg(x, y) {
+    const p = svg.createSVGPoint();
+    p.x = x;
+    p.y = y;
+    let m = svg.getCTM();
+    if (m == null) m = svg.getScreenCTM(); // Firefox workaround.
+    return p.matrixTransform(m.inverse());
+  }
+
+  // Change the scaling for the svg to s, keeping the point denoted
+  // by u (in svg coordinates]) fixed at the same screen location.
+  function rescale(s, u) {
+    // Limit to a good range.
+    if (s < 0.2) s = 0.2;
+    if (s > 10.0) s = 10.0;
+
+    currentScale = s;
+
+    // svg.viewBox defines the visible portion of the user coordinate
+    // system.  So to magnify by s, divide the visible portion by s,
+    // which will then be stretched to fit the viewport.
+    const vb = svg.viewBox;
+    const w1 = vb.baseVal.width;
+    const w2 = initWidth / s;
+    const h1 = vb.baseVal.height;
+    const h2 = initHeight / s;
+    vb.baseVal.width = w2;
+    vb.baseVal.height = h2;
+
+    // We also want to adjust vb.baseVal.x so that u.x remains at same
+    // screen X coordinate.  In other words, want to change it from x1 to x2
+    // so that:
+    //     (u.x - x1) / w1 = (u.x - x2) / w2
+    // Simplifying that, we get
+    //     (u.x - x1) * (w2 / w1) = u.x - x2
+    //     x2 = u.x - (u.x - x1) * (w2 / w1)
+    vb.baseVal.x = u.x - (u.x - vb.baseVal.x) * (w2 / w1);
+    vb.baseVal.y = u.y - (u.y - vb.baseVal.y) * (h2 / h1);
+  }
+
+  function handleWheel(e) {
+    if (e.deltaY == 0) return;
+    // Change scale factor by 1.1 or 1/1.1
+    rescale(currentScale * (e.deltaY < 0 ? 1.1 : (1/1.1)),
+            toSvg(e.offsetX, e.offsetY));
+  }
+
+  function setMode(m) {
+    mode = m;
+    touchid = null;
+    touchid2 = null;
+  }
+
+  function panStart(x, y) {
+    moved = false;
+    panLastX = x;
+    panLastY = y;
+  }
+
+  function panMove(x, y) {
+    let dx = x - panLastX;
+    let dy = y - panLastY;
+    if (Math.abs(dx) <= 2 && Math.abs(dy) <= 2) return; // Ignore tiny moves
+
+    moved = true;
+    panLastX = x;
+    panLastY = y;
+
+    // Firefox workaround: get dimensions from parentNode.
+    const swidth = svg.clientWidth || svg.parentNode.clientWidth;
+    const sheight = svg.clientHeight || svg.parentNode.clientHeight;
+
+    // Convert deltas from screen space to svg space.
+    dx *= (svg.viewBox.baseVal.width / swidth);
+    dy *= (svg.viewBox.baseVal.height / sheight);
+
+    svg.viewBox.baseVal.x -= dx;
+    svg.viewBox.baseVal.y -= dy;
+  }
+
+  function handleScanStart(e) {
+    if (e.button != 0) return; // Do not catch right-clicks etc.
+    setMode(MOUSEPAN);
+    panStart(e.clientX, e.clientY);
+    e.preventDefault();
+    svg.addEventListener('mousemove', handleScanMove);
+  }
+
+  function handleScanMove(e) {
+    if (e.buttons == 0) {
+      // Missed an end event, perhaps because mouse moved outside window.
+      setMode(IDLE);
+      svg.removeEventListener('mousemove', handleScanMove);
+      return;
+    }
+    if (mode == MOUSEPAN) panMove(e.clientX, e.clientY);
+  }
+
+  function handleScanEnd(e) {
+    if (mode == MOUSEPAN) panMove(e.clientX, e.clientY);
+    setMode(IDLE);
+    svg.removeEventListener('mousemove', handleScanMove);
+    if (!moved) clickHandler(e.target);
+  }
+
+  // Find touch object with specified identifier.
+  function findTouch(tlist, id) {
+    for (const t of tlist) {
+      if (t.identifier == id) return t;
+    }
+    return null;
+  }
+
+  // Return distance between two touch points
+  function touchGap(t1, t2) {
+    const dx = t1.clientX - t2.clientX;
+    const dy = t1.clientY - t2.clientY;
+    return Math.hypot(dx, dy);
+  }
+
+  function handleTouchStart(e) {
+    if (mode == IDLE && e.changedTouches.length == 1) {
+      // Start touch based panning
+      const t = e.changedTouches[0];
+      setMode(TOUCHPAN);
+      touchid = t.identifier;
+      panStart(t.clientX, t.clientY);
+      e.preventDefault();
+    } else if (mode == TOUCHPAN && e.touches.length == 2) {
+      // Start pinch zooming
+      setMode(TOUCHZOOM);
+      const t1 = e.touches[0];
+      const t2 = e.touches[1];
+      touchid = t1.identifier;
+      touchid2 = t2.identifier;
+      initScale = currentScale;
+      initGap = touchGap(t1, t2);
+      centerPoint = toSvg((t1.clientX + t2.clientX) / 2,
+                          (t1.clientY + t2.clientY) / 2);
+      e.preventDefault();
+    }
+  }
+
+  function handleTouchMove(e) {
+    if (mode == TOUCHPAN) {
+      const t = findTouch(e.changedTouches, touchid);
+      if (t == null) return;
+      if (e.touches.length != 1) {
+        setMode(IDLE);
+        return;
+      }
+      panMove(t.clientX, t.clientY);
+      e.preventDefault();
+    } else if (mode == TOUCHZOOM) {
+      // Get two touches; new gap; rescale to ratio.
+      const t1 = findTouch(e.touches, touchid);
+      const t2 = findTouch(e.touches, touchid2);
+      if (t1 == null || t2 == null) return;
+      const gap = touchGap(t1, t2);
+      rescale(initScale * gap / initGap, centerPoint);
+      e.preventDefault();
+    }
+  }
+
+  function handleTouchEnd(e) {
+    if (mode == TOUCHPAN) {
+      const t = findTouch(e.changedTouches, touchid);
+      if (t == null) return;
+      panMove(t.clientX, t.clientY);
+      setMode(IDLE);
+      e.preventDefault();
+      if (!moved) clickHandler(t.target);
+    } else if (mode == TOUCHZOOM) {
+      setMode(IDLE);
+      e.preventDefault();
+    }
+  }
+
+  svg.addEventListener('mousedown', handleScanStart);
+  svg.addEventListener('mouseup', handleScanEnd);
+  svg.addEventListener('touchstart', handleTouchStart);
+  svg.addEventListener('touchmove', handleTouchMove);
+  svg.addEventListener('touchend', handleTouchEnd);
+  svg.addEventListener('wheel', handleWheel, true);
+}
+
+function initMenus() {
+  'use strict';
+
+  let activeMenu = null;
+  let activeMenuHdr = null;
+
+  function cancelActiveMenu() {
+    if (activeMenu == null) return;
+    activeMenu.style.display = 'none';
+    activeMenu = null;
+    activeMenuHdr = null;
+  }
+
+  // Set click handlers on every menu header.
+  for (const menu of document.getElementsByClassName('submenu')) {
+    const hdr = menu.parentElement;
+    if (hdr == null) return;
+    if (hdr.classList.contains('disabled')) return;
+    function showMenu(e) {
+      // menu is a child of hdr, so this event can fire for clicks
+      // inside menu. Ignore such clicks.
+      if (e.target.parentElement != hdr) return;
+      activeMenu = menu;
+      activeMenuHdr = hdr;
+      menu.style.display = 'block';
+    }
+    hdr.addEventListener('mousedown', showMenu);
+    hdr.addEventListener('touchstart', showMenu);
+  }
+
+  // If there is an active menu and a down event outside, retract the menu.
+  for (const t of ['mousedown', 'touchstart']) {
+    document.addEventListener(t, (e) => {
+      // Note: to avoid unnecessary flicker, if the down event is inside
+      // the active menu header, do not retract the menu.
+      if (activeMenuHdr != e.target.closest('.menu-item')) {
+        cancelActiveMenu();
+      }
+    }, { passive: true, capture: true });
+  }
+
+  // If there is an active menu and an up event inside, retract the menu.
+  document.addEventListener('mouseup', (e) => {
+    if (activeMenu == e.target.closest('.submenu')) {
+      cancelActiveMenu();
+    }
+  }, { passive: true, capture: true });
+}
+
+function sendURL(method, url, done) {
+  fetch(url.toString(), {method: method})
+      .then((response) => { done(response.ok); })
+      .catch((error) => { done(false); });
+}
+
+// Initialize handlers for saving/loading configurations.
+function initConfigManager() {
+  'use strict';
+
+  // Initialize various elements.
+  function elem(id) {
+    const result = document.getElementById(id);
+    if (!result) console.warn('element ' + id + ' not found');
+    return result;
+  }
+  const overlay = elem('dialog-overlay');
+  const saveDialog = elem('save-dialog');
+  const saveInput = elem('save-name');
+  const saveError = elem('save-error');
+  const delDialog = elem('delete-dialog');
+  const delPrompt = elem('delete-prompt');
+  const delError = elem('delete-error');
+
+  let currentDialog = null;
+  let currentDeleteTarget = null;
+
+  function showDialog(dialog) {
+    if (currentDialog != null) {
+      overlay.style.display = 'none';
+      currentDialog.style.display = 'none';
+    }
+    currentDialog = dialog;
+    if (dialog != null) {
+      overlay.style.display = 'block';
+      dialog.style.display = 'block';
+    }
+  }
+
+  function cancelDialog(e) {
+    showDialog(null);
+  }
+
+  // Show dialog for saving the current config.
+  function showSaveDialog(e) {
+    saveError.innerText = '';
+    showDialog(saveDialog);
+    saveInput.focus();
+  }
+
+  // Commit save config.
+  function commitSave(e) {
+    const name = saveInput.value;
+    const url = new URL(document.URL);
+    // Set path relative to existing path.
+    url.pathname = new URL('./saveconfig', document.URL).pathname;
+    url.searchParams.set('config', name);
+    saveError.innerText = '';
+    sendURL('POST', url, (ok) => {
+      if (!ok) {
+        saveError.innerText = 'Save failed';
+      } else {
+        showDialog(null);
+        location.reload();  // Reload to show updated config menu
+      }
+    });
+  }
+
+  function handleSaveInputKey(e) {
+    if (e.key === 'Enter') commitSave(e);
+  }
+
+  function deleteConfig(e, elem) {
+    e.preventDefault();
+    const config = elem.dataset.config;
+    delPrompt.innerText = 'Delete ' + config + '?';
+    currentDeleteTarget = elem;
+    showDialog(delDialog);
+  }
+
+  function commitDelete(e, elem) {
+    if (!currentDeleteTarget) return;
+    const config = currentDeleteTarget.dataset.config;
+    const url = new URL('./deleteconfig', document.URL);
+    url.searchParams.set('config', config);
+    delError.innerText = '';
+    sendURL('DELETE', url, (ok) => {
+      if (!ok) {
+        delError.innerText = 'Delete failed';
+        return;
+      }
+      showDialog(null);
+      // Remove menu entry for this config.
+      if (currentDeleteTarget && currentDeleteTarget.parentElement) {
+        currentDeleteTarget.parentElement.remove();
+      }
+    });
+  }
+
+  // Bind event on elem to fn.
+  function bind(event, elem, fn) {
+    if (elem == null) return;
+    elem.addEventListener(event, fn);
+    if (event == 'click') {
+      // Also enable via touch.
+      elem.addEventListener('touchstart', fn);
+    }
+  }
+
+  bind('click', elem('save-config'), showSaveDialog);
+  bind('click', elem('save-cancel'), cancelDialog);
+  bind('click', elem('save-confirm'), commitSave);
+  bind('keydown', saveInput, handleSaveInputKey);
+
+  bind('click', elem('delete-cancel'), cancelDialog);
+  bind('click', elem('delete-confirm'), commitDelete);
+
+  // Activate deletion button for all config entries in menu.
+  for (const del of Array.from(document.getElementsByClassName('menu-delete-btn'))) {
+    bind('click', del, (e) => {
+      deleteConfig(e, del);
+    });
+  }
+}
+
+function viewer(baseUrl, nodes) {
+  'use strict';
+
+  // Elements
+  const search = document.getElementById('search');
+  const graph0 = document.getElementById('graph0');
+  const svg = (graph0 == null ? null : graph0.parentElement);
+  const toptable = document.getElementById('toptable');
+
+  let regexpActive = false;
+  let selected = new Map();
+  let origFill = new Map();
+  let searchAlarm = null;
+  let buttonsEnabled = true;
+
+  function handleDetails(e) {
+    e.preventDefault();
+    const detailsText = document.getElementById('detailsbox');
+    if (detailsText != null) {
+      if (detailsText.style.display === 'block') {
+        detailsText.style.display = 'none';
+      } else {
+        detailsText.style.display = 'block';
+      }
+    }
+  }
+
+  function handleKey(e) {
+    if (e.keyCode != 13) return;
+    setHrefParams(window.location, function (params) {
+      params.set('f', search.value);
+    });
+    e.preventDefault();
+  }
+
+  function handleSearch() {
+    // Delay expensive processing so a flurry of key strokes is handled once.
+    if (searchAlarm != null) {
+      clearTimeout(searchAlarm);
+    }
+    searchAlarm = setTimeout(selectMatching, 300);
+
+    regexpActive = true;
+    updateButtons();
+  }
+
+  function selectMatching() {
+    searchAlarm = null;
+    let re = null;
+    if (search.value != '') {
+      try {
+        re = new RegExp(search.value);
+      } catch (e) {
+        // TODO: Display error state in search box
+        return;
+      }
+    }
+
+    function match(text) {
+      return re != null && re.test(text);
+    }
+
+    // drop currently selected items that do not match re.
+    selected.forEach(function(v, n) {
+      if (!match(nodes[n])) {
+        unselect(n, document.getElementById('node' + n));
+      }
+    })
+
+    // add matching items that are not currently selected.
+    if (nodes) {
+      for (let n = 0; n < nodes.length; n++) {
+        if (!selected.has(n) && match(nodes[n])) {
+          select(n, document.getElementById('node' + n));
+        }
+      }
+    }
+
+    updateButtons();
+  }
+
+  function toggleSvgSelect(elem) {
+    // Walk up to immediate child of graph0
+    while (elem != null && elem.parentElement != graph0) {
+      elem = elem.parentElement;
+    }
+    if (!elem) return;
+
+    // Disable regexp mode.
+    regexpActive = false;
+
+    const n = nodeId(elem);
+    if (n < 0) return;
+    if (selected.has(n)) {
+      unselect(n, elem);
+    } else {
+      select(n, elem);
+    }
+    updateButtons();
+  }
+
+  function unselect(n, elem) {
+    if (elem == null) return;
+    selected.delete(n);
+    setBackground(elem, false);
+  }
+
+  function select(n, elem) {
+    if (elem == null) return;
+    selected.set(n, true);
+    setBackground(elem, true);
+  }
+
+  function nodeId(elem) {
+    const id = elem.id;
+    if (!id) return -1;
+    if (!id.startsWith('node')) return -1;
+    const n = parseInt(id.slice(4), 10);
+    if (isNaN(n)) return -1;
+    if (n < 0 || n >= nodes.length) return -1;
+    return n;
+  }
+
+  function setBackground(elem, set) {
+    // Handle table row highlighting.
+    if (elem.nodeName == 'TR') {
+      elem.classList.toggle('hilite', set);
+      return;
+    }
+
+    // Handle svg element highlighting.
+    const p = findPolygon(elem);
+    if (p != null) {
+      if (set) {
+        origFill.set(p, p.style.fill);
+        p.style.fill = '#ccccff';
+      } else if (origFill.has(p)) {
+        p.style.fill = origFill.get(p);
+      }
+    }
+  }
+
+  function findPolygon(elem) {
+    if (elem.localName == 'polygon') return elem;
+    for (const c of elem.children) {
+      const p = findPolygon(c);
+      if (p != null) return p;
+    }
+    return null;
+  }
+
+  // convert a string to a regexp that matches that string.
+  function quotemeta(str) {
+    return str.replace(/([\\\.?+*\[\](){}|^$])/g, '\\$1');
+  }
+
+  function setSampleIndexLink(id) {
+    const elem = document.getElementById(id);
+    if (elem != null) {
+      setHrefParams(elem, function (params) {
+        params.set("si", id);
+      });
+    }
+  }
+
+  // Update id's href to reflect current selection whenever it is
+  // liable to be followed.
+  function makeSearchLinkDynamic(id) {
+    const elem = document.getElementById(id);
+    if (elem == null) return;
+
+    // Most links copy current selection into the 'f' parameter,
+    // but Refine menu links are different.
+    let param = 'f';
+    if (id == 'ignore') param = 'i';
+    if (id == 'hide') param = 'h';
+    if (id == 'show') param = 's';
+    if (id == 'show-from') param = 'sf';
+
+    // We update on mouseenter so middle-click/right-click work properly.
+    elem.addEventListener('mouseenter', updater);
+    elem.addEventListener('touchstart', updater);
+
+    function updater() {
+      // The selection can be in one of two modes: regexp-based or
+      // list-based.  Construct regular expression depending on mode.
+      let re = regexpActive
+        ? search.value
+        : Array.from(selected.keys()).map(key => quotemeta(nodes[key])).join('|');
+
+      setHrefParams(elem, function (params) {
+        if (re != '') {
+          // For focus/show/show-from, forget old parameter. For others, add to re.
+          if (param != 'f' && param != 's' && param != 'sf' && params.has(param)) {
+            const old = params.get(param);
+            if (old != '') {
+              re += '|' + old;
+            }
+          }
+          params.set(param, re);
+        } else {
+          params.delete(param);
+        }
+      });
+    }
+  }
+
+  function setHrefParams(elem, paramSetter) {
+    let url = new URL(elem.href);
+    url.hash = '';
+
+    // Copy params from this page's URL.
+    const params = url.searchParams;
+    for (const p of new URLSearchParams(window.location.search)) {
+      params.set(p[0], p[1]);
+    }
+
+    // Give the params to the setter to modify.
+    paramSetter(params);
+
+    elem.href = url.toString();
+  }
+
+  function handleTopClick(e) {
+    // Walk back until we find TR and then get the Name column (index 5)
+    let elem = e.target;
+    while (elem != null && elem.nodeName != 'TR') {
+      elem = elem.parentElement;
+    }
+    if (elem == null || elem.children.length < 6) return;
+
+    e.preventDefault();
+    const tr = elem;
+    const td = elem.children[5];
+    if (td.nodeName != 'TD') return;
+    const name = td.innerText;
+    const index = nodes.indexOf(name);
+    if (index < 0) return;
+
+    // Disable regexp mode.
+    regexpActive = false;
+
+    if (selected.has(index)) {
+      unselect(index, elem);
+    } else {
+      select(index, elem);
+    }
+    updateButtons();
+  }
+
+  function updateButtons() {
+    const enable = (search.value != '' || selected.size != 0);
+    if (buttonsEnabled == enable) return;
+    buttonsEnabled = enable;
+    for (const id of ['focus', 'ignore', 'hide', 'show', 'show-from']) {
+      const link = document.getElementById(id);
+      if (link != null) {
+        link.classList.toggle('disabled', !enable);
+      }
+    }
+  }
+
+  // Initialize button states
+  updateButtons();
+
+  // Setup event handlers
+  initMenus();
+  if (svg != null) {
+    initPanAndZoom(svg, toggleSvgSelect);
+  }
+  if (toptable != null) {
+    toptable.addEventListener('mousedown', handleTopClick);
+    toptable.addEventListener('touchstart', handleTopClick);
+  }
+
+  const ids = ['topbtn', 'graphbtn', 'flamegraph', 'peek', 'list', 'disasm',
+               'focus', 'ignore', 'hide', 'show', 'show-from'];
+  ids.forEach(makeSearchLinkDynamic);
+
+  const sampleIDs = [{{range .SampleTypes}}'{{.}}', {{end}}];
+  sampleIDs.forEach(setSampleIndexLink);
+
+  // Bind action to button with specified id.
+  function addAction(id, action) {
+    const btn = document.getElementById(id);
+    if (btn != null) {
+      btn.addEventListener('click', action);
+      btn.addEventListener('touchstart', action);
+    }
+  }
+
+  addAction('details', handleDetails);
+  initConfigManager();
+
+  search.addEventListener('input', handleSearch);
+  search.addEventListener('keydown', handleKey);
+
+  // Give initial focus to main container so it can be scrolled using keys.
+  const main = document.getElementById('bodycontainer');
+  if (main) {
+    main.focus();
+  }
+}
+</script>
+{{end}}
+
+{{define "top" -}}
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>{{.Title}}</title>
+  {{template "css" .}}
+  <style type="text/css">
+  </style>
+</head>
+<body>
+  {{template "header" .}}
+  <div id="top">
+    <table id="toptable">
+      <thead>
+        <tr>
+          <th id="flathdr1">Flat</th>
+          <th id="flathdr2">Flat%</th>
+          <th>Sum%</th>
+          <th id="cumhdr1">Cum</th>
+          <th id="cumhdr2">Cum%</th>
+          <th id="namehdr">Name</th>
+          <th>Inlined?</th>
+        </tr>
+      </thead>
+      <tbody id="rows"></tbody>
+    </table>
+  </div>
+  {{template "script" .}}
+  <script>
+    function makeTopTable(total, entries) {
+      const rows = document.getElementById('rows');
+      if (rows == null) return;
+
+      // Store initial index in each entry so we have stable node ids for selection.
+      for (let i = 0; i < entries.length; i++) {
+        entries[i].Id = 'node' + i;
+      }
+
+      // Which column are we currently sorted by and in what order?
+      let currentColumn = '';
+      let descending = false;
+      sortBy('Flat');
+
+      function sortBy(column) {
+        // Update sort criteria
+        if (column == currentColumn) {
+          descending = !descending; // Reverse order
+        } else {
+          currentColumn = column;
+          descending = (column != 'Name');
+        }
+
+        // Sort according to current criteria.
+        function cmp(a, b) {
+          const av = a[currentColumn];
+          const bv = b[currentColumn];
+          if (av < bv) return -1;
+          if (av > bv) return +1;
+          return 0;
+        }
+        entries.sort(cmp);
+        if (descending) entries.reverse();
+
+        function addCell(tr, val) {
+          const td = document.createElement('td');
+          td.textContent = val;
+          tr.appendChild(td);
+        }
+
+        function percent(v) {
+          return (v * 100.0 / total).toFixed(2) + '%';
+        }
+
+        // Generate rows
+        const fragment = document.createDocumentFragment();
+        let sum = 0;
+        for (const row of entries) {
+          const tr = document.createElement('tr');
+          tr.id = row.Id;
+          sum += row.Flat;
+          addCell(tr, row.FlatFormat);
+          addCell(tr, percent(row.Flat));
+          addCell(tr, percent(sum));
+          addCell(tr, row.CumFormat);
+          addCell(tr, percent(row.Cum));
+          addCell(tr, row.Name);
+          addCell(tr, row.InlineLabel);
+          fragment.appendChild(tr);
+        }
+
+        rows.textContent = ''; // Remove old rows
+        rows.appendChild(fragment);
+      }
+
+      // Make different column headers trigger sorting.
+      function bindSort(id, column) {
+        const hdr = document.getElementById(id);
+        if (hdr == null) return;
+        const fn = function() { sortBy(column) };
+        hdr.addEventListener('click', fn);
+        hdr.addEventListener('touch', fn);
+      }
+      bindSort('flathdr1', 'Flat');
+      bindSort('flathdr2', 'Flat');
+      bindSort('cumhdr1', 'Cum');
+      bindSort('cumhdr2', 'Cum');
+      bindSort('namehdr', 'Name');
+    }
+
+    viewer(new URL(window.location.href), {{.Nodes}});
+    makeTopTable({{.Total}}, {{.Top}});
+  </script>
+</body>
+</html>
+{{end}}
+
+{{define "sourcelisting" -}}
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>{{.Title}}</title>
+  {{template "css" .}}
+  {{template "weblistcss" .}}
+  {{template "weblistjs" .}}
+</head>
+<body>
+  {{template "header" .}}
+  <div id="content" class="source">
+    {{.HTMLBody}}
+  </div>
+  {{template "script" .}}
+  <script>viewer(new URL(window.location.href), null);</script>
+</body>
+</html>
+{{end}}
+
+{{define "plaintext" -}}
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>{{.Title}}</title>
+  {{template "css" .}}
+</head>
+<body>
+  {{template "header" .}}
+  <div id="content">
+    <pre>
+      {{.TextBody}}
+    </pre>
+  </div>
+  {{template "script" .}}
+  <script>viewer(new URL(window.location.href), null);</script>
+</body>
+</html>
+{{end}}
+
+{{define "flamegraph" -}}
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>{{.Title}}</title>
+  {{template "css" .}}
+  <style type="text/css">{{template "d3flamegraphcss" .}}</style>
+  <style type="text/css">
+    .flamegraph-content {
+      width: 90%;
+      min-width: 80%;
+      margin-left: 5%;
+    }
+    .flamegraph-details {
+      height: 1.2em;
+      width: 90%;
+      min-width: 90%;
+      margin-left: 5%;
+      padding: 15px 0 35px;
+    }
+  </style>
+</head>
+<body>
+  {{template "header" .}}
+  <div id="bodycontainer">
+    <div id="flamegraphdetails" class="flamegraph-details"></div>
+    <div class="flamegraph-content">
+      <div id="chart"></div>
+    </div>
+  </div>
+  {{template "script" .}}
+  <script>viewer(new URL(window.location.href), {{.Nodes}});</script>
+  <script>{{template "d3script" .}}</script>
+  <script>{{template "d3flamegraphscript" .}}</script>
+  <script>
+    var data = {{.FlameGraph}};
+
+    var width = document.getElementById('chart').clientWidth;
+
+    var flameGraph = d3.flamegraph()
+      .width(width)
+      .cellHeight(18)
+      .minFrameSize(1)
+      .transitionDuration(750)
+      .transitionEase(d3.easeCubic)
+      .inverted(true)
+      .sort(true)
+      .title('')
+      .tooltip(false)
+      .details(document.getElementById('flamegraphdetails'));
+
+    // <full name> (percentage, value)
+    flameGraph.label((d) => d.data.f + ' (' + d.data.p + ', ' + d.data.l + ')');
+
+    (function(flameGraph) {
+      var oldColorMapper = flameGraph.color();
+      function colorMapper(d) {
+        // Hack to force default color mapper to use 'warm' color scheme by not passing libtype
+        const { data, highlight } = d;
+        return oldColorMapper({ data: { n: data.n }, highlight });
+      }
+
+      flameGraph.color(colorMapper);
+    }(flameGraph));
+
+    d3.select('#chart')
+      .datum(data)
+      .call(flameGraph);
+
+    function clear() {
+      flameGraph.clear();
+    }
+
+    function resetZoom() {
+      flameGraph.resetZoom();
+    }
+
+    window.addEventListener('resize', function() {
+      var width = document.getElementById('chart').clientWidth;
+      var graphs = document.getElementsByClassName('d3-flame-graph');
+      if (graphs.length > 0) {
+        graphs[0].setAttribute('width', width);
+      }
+      flameGraph.width(width);
+      flameGraph.resetZoom();
+    }, true);
+
+    var search = document.getElementById('search');
+    var searchAlarm = null;
+
+    function selectMatching() {
+      searchAlarm = null;
+
+      if (search.value != '') {
+        flameGraph.search(search.value);
+      } else {
+        flameGraph.clear();
+      }
+    }
+
+    function handleSearch() {
+      // Delay expensive processing so a flurry of key strokes is handled once.
+      if (searchAlarm != null) {
+        clearTimeout(searchAlarm);
+      }
+      searchAlarm = setTimeout(selectMatching, 300);
+    }
+
+    search.addEventListener('input', handleSearch);
+  </script>
+</body>
+</html>
+{{end}}
+`))
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go
new file mode 100644
index 0000000..52dc688
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/driver/webui.go
@@ -0,0 +1,460 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package driver
+
+import (
+	"bytes"
+	"fmt"
+	"html/template"
+	"net"
+	"net/http"
+	gourl "net/url"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/google/pprof/internal/graph"
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/internal/report"
+	"github.com/google/pprof/profile"
+)
+
+// webInterface holds the state needed for serving a browser based interface.
+type webInterface struct {
+	prof         *profile.Profile
+	options      *plugin.Options
+	help         map[string]string
+	templates    *template.Template
+	settingsFile string
+}
+
+func makeWebInterface(p *profile.Profile, opt *plugin.Options) (*webInterface, error) {
+	settingsFile, err := settingsFileName()
+	if err != nil {
+		return nil, err
+	}
+	templates := template.New("templategroup")
+	addTemplates(templates)
+	report.AddSourceTemplates(templates)
+	return &webInterface{
+		prof:         p,
+		options:      opt,
+		help:         make(map[string]string),
+		templates:    templates,
+		settingsFile: settingsFile,
+	}, nil
+}
+
+// maxEntries is the maximum number of entries to print for text interfaces.
+const maxEntries = 50
+
+// errorCatcher is a UI that captures errors for reporting to the browser.
+type errorCatcher struct {
+	plugin.UI
+	errors []string
+}
+
+func (ec *errorCatcher) PrintErr(args ...interface{}) {
+	ec.errors = append(ec.errors, strings.TrimSuffix(fmt.Sprintln(args...), "\n"))
+	ec.UI.PrintErr(args...)
+}
+
+// webArgs contains arguments passed to templates in webhtml.go.
+type webArgs struct {
+	Title       string
+	Errors      []string
+	Total       int64
+	SampleTypes []string
+	Legend      []string
+	Help        map[string]string
+	Nodes       []string
+	HTMLBody    template.HTML
+	TextBody    string
+	Top         []report.TextItem
+	FlameGraph  template.JS
+	Configs     []configMenuEntry
+}
+
+func serveWebInterface(hostport string, p *profile.Profile, o *plugin.Options, disableBrowser bool) error {
+	host, port, err := getHostAndPort(hostport)
+	if err != nil {
+		return err
+	}
+	interactiveMode = true
+	ui, err := makeWebInterface(p, o)
+	if err != nil {
+		return err
+	}
+	for n, c := range pprofCommands {
+		ui.help[n] = c.description
+	}
+	for n, help := range configHelp {
+		ui.help[n] = help
+	}
+	ui.help["details"] = "Show information about the profile and this view"
+	ui.help["graph"] = "Display profile as a directed graph"
+	ui.help["reset"] = "Show the entire profile"
+	ui.help["save_config"] = "Save current settings"
+
+	server := o.HTTPServer
+	if server == nil {
+		server = defaultWebServer
+	}
+	args := &plugin.HTTPServerArgs{
+		Hostport: net.JoinHostPort(host, strconv.Itoa(port)),
+		Host:     host,
+		Port:     port,
+		Handlers: map[string]http.Handler{
+			"/":             http.HandlerFunc(ui.dot),
+			"/top":          http.HandlerFunc(ui.top),
+			"/disasm":       http.HandlerFunc(ui.disasm),
+			"/source":       http.HandlerFunc(ui.source),
+			"/peek":         http.HandlerFunc(ui.peek),
+			"/flamegraph":   http.HandlerFunc(ui.flamegraph),
+			"/saveconfig":   http.HandlerFunc(ui.saveConfig),
+			"/deleteconfig": http.HandlerFunc(ui.deleteConfig),
+		},
+	}
+
+	url := "http://" + args.Hostport
+
+	o.UI.Print("Serving web UI on ", url)
+
+	if o.UI.WantBrowser() && !disableBrowser {
+		go openBrowser(url, o)
+	}
+	return server(args)
+}
+
+func getHostAndPort(hostport string) (string, int, error) {
+	host, portStr, err := net.SplitHostPort(hostport)
+	if err != nil {
+		return "", 0, fmt.Errorf("could not split http address: %v", err)
+	}
+	if host == "" {
+		host = "localhost"
+	}
+	var port int
+	if portStr == "" {
+		ln, err := net.Listen("tcp", net.JoinHostPort(host, "0"))
+		if err != nil {
+			return "", 0, fmt.Errorf("could not generate random port: %v", err)
+		}
+		port = ln.Addr().(*net.TCPAddr).Port
+		err = ln.Close()
+		if err != nil {
+			return "", 0, fmt.Errorf("could not generate random port: %v", err)
+		}
+	} else {
+		port, err = strconv.Atoi(portStr)
+		if err != nil {
+			return "", 0, fmt.Errorf("invalid port number: %v", err)
+		}
+	}
+	return host, port, nil
+}
+func defaultWebServer(args *plugin.HTTPServerArgs) error {
+	ln, err := net.Listen("tcp", args.Hostport)
+	if err != nil {
+		return err
+	}
+	isLocal := isLocalhost(args.Host)
+	handler := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		if isLocal {
+			// Only allow local clients
+			host, _, err := net.SplitHostPort(req.RemoteAddr)
+			if err != nil || !isLocalhost(host) {
+				http.Error(w, "permission denied", http.StatusForbidden)
+				return
+			}
+		}
+		h := args.Handlers[req.URL.Path]
+		if h == nil {
+			// Fall back to default behavior
+			h = http.DefaultServeMux
+		}
+		h.ServeHTTP(w, req)
+	})
+
+	// We serve the ui at /ui/ and redirect there from the root. This is done
+	// to surface any problems with serving the ui at a non-root early. See:
+	//
+	// https://github.com/google/pprof/pull/348
+	mux := http.NewServeMux()
+	mux.Handle("/ui/", http.StripPrefix("/ui", handler))
+	mux.Handle("/", redirectWithQuery("/ui"))
+	s := &http.Server{Handler: mux}
+	return s.Serve(ln)
+}
+
+func redirectWithQuery(path string) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		pathWithQuery := &gourl.URL{Path: path, RawQuery: r.URL.RawQuery}
+		http.Redirect(w, r, pathWithQuery.String(), http.StatusTemporaryRedirect)
+	}
+}
+
+func isLocalhost(host string) bool {
+	for _, v := range []string{"localhost", "127.0.0.1", "[::1]", "::1"} {
+		if host == v {
+			return true
+		}
+	}
+	return false
+}
+
+func openBrowser(url string, o *plugin.Options) {
+	// Construct URL.
+	baseURL, _ := gourl.Parse(url)
+	current := currentConfig()
+	u, _ := current.makeURL(*baseURL)
+
+	// Give server a little time to get ready.
+	time.Sleep(time.Millisecond * 500)
+
+	for _, b := range browsers() {
+		args := strings.Split(b, " ")
+		if len(args) == 0 {
+			continue
+		}
+		viewer := exec.Command(args[0], append(args[1:], u.String())...)
+		viewer.Stderr = os.Stderr
+		if err := viewer.Start(); err == nil {
+			return
+		}
+	}
+	// No visualizer succeeded, so just print URL.
+	o.UI.PrintErr(u.String())
+}
+
+// makeReport generates a report for the specified command.
+// If configEditor is not null, it is used to edit the config used for the report.
+func (ui *webInterface) makeReport(w http.ResponseWriter, req *http.Request,
+	cmd []string, configEditor func(*config)) (*report.Report, []string) {
+	cfg := currentConfig()
+	if err := cfg.applyURL(req.URL.Query()); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return nil, nil
+	}
+	if configEditor != nil {
+		configEditor(&cfg)
+	}
+	catcher := &errorCatcher{UI: ui.options.UI}
+	options := *ui.options
+	options.UI = catcher
+	_, rpt, err := generateRawReport(ui.prof, cmd, cfg, &options)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return nil, nil
+	}
+	return rpt, catcher.errors
+}
+
+// render generates html using the named template based on the contents of data.
+func (ui *webInterface) render(w http.ResponseWriter, req *http.Request, tmpl string,
+	rpt *report.Report, errList, legend []string, data webArgs) {
+	file := getFromLegend(legend, "File: ", "unknown")
+	profile := getFromLegend(legend, "Type: ", "unknown")
+	data.Title = file + " " + profile
+	data.Errors = errList
+	data.Total = rpt.Total()
+	data.SampleTypes = sampleTypes(ui.prof)
+	data.Legend = legend
+	data.Help = ui.help
+	data.Configs = configMenu(ui.settingsFile, *req.URL)
+
+	html := &bytes.Buffer{}
+	if err := ui.templates.ExecuteTemplate(html, tmpl, data); err != nil {
+		http.Error(w, "internal template error", http.StatusInternalServerError)
+		ui.options.UI.PrintErr(err)
+		return
+	}
+	w.Header().Set("Content-Type", "text/html")
+	w.Write(html.Bytes())
+}
+
+// dot generates a web page containing an svg diagram.
+func (ui *webInterface) dot(w http.ResponseWriter, req *http.Request) {
+	rpt, errList := ui.makeReport(w, req, []string{"svg"}, nil)
+	if rpt == nil {
+		return // error already reported
+	}
+
+	// Generate dot graph.
+	g, config := report.GetDOT(rpt)
+	legend := config.Labels
+	config.Labels = nil
+	dot := &bytes.Buffer{}
+	graph.ComposeDot(dot, g, &graph.DotAttributes{}, config)
+
+	// Convert to svg.
+	svg, err := dotToSvg(dot.Bytes())
+	if err != nil {
+		http.Error(w, "Could not execute dot; may need to install graphviz.",
+			http.StatusNotImplemented)
+		ui.options.UI.PrintErr("Failed to execute dot. Is Graphviz installed?\n", err)
+		return
+	}
+
+	// Get all node names into an array.
+	nodes := []string{""} // dot starts with node numbered 1
+	for _, n := range g.Nodes {
+		nodes = append(nodes, n.Info.Name)
+	}
+
+	ui.render(w, req, "graph", rpt, errList, legend, webArgs{
+		HTMLBody: template.HTML(string(svg)),
+		Nodes:    nodes,
+	})
+}
+
+func dotToSvg(dot []byte) ([]byte, error) {
+	cmd := exec.Command("dot", "-Tsvg")
+	out := &bytes.Buffer{}
+	cmd.Stdin, cmd.Stdout, cmd.Stderr = bytes.NewBuffer(dot), out, os.Stderr
+	if err := cmd.Run(); err != nil {
+		return nil, err
+	}
+
+	// Fix dot bug related to unquoted ampersands.
+	svg := bytes.Replace(out.Bytes(), []byte("&;"), []byte("&amp;;"), -1)
+
+	// Cleanup for embedding by dropping stuff before the <svg> start.
+	if pos := bytes.Index(svg, []byte("<svg")); pos >= 0 {
+		svg = svg[pos:]
+	}
+	return svg, nil
+}
+
+func (ui *webInterface) top(w http.ResponseWriter, req *http.Request) {
+	rpt, errList := ui.makeReport(w, req, []string{"top"}, func(cfg *config) {
+		cfg.NodeCount = 500
+	})
+	if rpt == nil {
+		return // error already reported
+	}
+	top, legend := report.TextItems(rpt)
+	var nodes []string
+	for _, item := range top {
+		nodes = append(nodes, item.Name)
+	}
+
+	ui.render(w, req, "top", rpt, errList, legend, webArgs{
+		Top:   top,
+		Nodes: nodes,
+	})
+}
+
+// disasm generates a web page containing disassembly.
+func (ui *webInterface) disasm(w http.ResponseWriter, req *http.Request) {
+	args := []string{"disasm", req.URL.Query().Get("f")}
+	rpt, errList := ui.makeReport(w, req, args, nil)
+	if rpt == nil {
+		return // error already reported
+	}
+
+	out := &bytes.Buffer{}
+	if err := report.PrintAssembly(out, rpt, ui.options.Obj, maxEntries); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return
+	}
+
+	legend := report.ProfileLabels(rpt)
+	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
+		TextBody: out.String(),
+	})
+
+}
+
+// source generates a web page containing source code annotated with profile
+// data.
+func (ui *webInterface) source(w http.ResponseWriter, req *http.Request) {
+	args := []string{"weblist", req.URL.Query().Get("f")}
+	rpt, errList := ui.makeReport(w, req, args, nil)
+	if rpt == nil {
+		return // error already reported
+	}
+
+	// Generate source listing.
+	var body bytes.Buffer
+	if err := report.PrintWebList(&body, rpt, ui.options.Obj, maxEntries); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return
+	}
+
+	legend := report.ProfileLabels(rpt)
+	ui.render(w, req, "sourcelisting", rpt, errList, legend, webArgs{
+		HTMLBody: template.HTML(body.String()),
+	})
+}
+
+// peek generates a web page listing callers/callers.
+func (ui *webInterface) peek(w http.ResponseWriter, req *http.Request) {
+	args := []string{"peek", req.URL.Query().Get("f")}
+	rpt, errList := ui.makeReport(w, req, args, func(cfg *config) {
+		cfg.Granularity = "lines"
+	})
+	if rpt == nil {
+		return // error already reported
+	}
+
+	out := &bytes.Buffer{}
+	if err := report.Generate(out, rpt, ui.options.Obj); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return
+	}
+
+	legend := report.ProfileLabels(rpt)
+	ui.render(w, req, "plaintext", rpt, errList, legend, webArgs{
+		TextBody: out.String(),
+	})
+}
+
+// saveConfig saves URL configuration.
+func (ui *webInterface) saveConfig(w http.ResponseWriter, req *http.Request) {
+	if err := setConfig(ui.settingsFile, *req.URL); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return
+	}
+}
+
+// deleteConfig deletes a configuration.
+func (ui *webInterface) deleteConfig(w http.ResponseWriter, req *http.Request) {
+	name := req.URL.Query().Get("config")
+	if err := removeConfig(ui.settingsFile, name); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		ui.options.UI.PrintErr(err)
+		return
+	}
+}
+
+// getFromLegend returns the suffix of an entry in legend that starts
+// with param.  It returns def if no such entry is found.
+func getFromLegend(legend []string, param, def string) string {
+	for _, s := range legend {
+		if strings.HasPrefix(s, param) {
+			return s[len(param):]
+		}
+	}
+	return def
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go b/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go
new file mode 100644
index 0000000..d520765
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/elfexec/elfexec.go
@@ -0,0 +1,285 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package elfexec provides utility routines to examine ELF binaries.
+package elfexec
+
+import (
+	"bufio"
+	"debug/elf"
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+const (
+	maxNoteSize        = 1 << 20 // in bytes
+	noteTypeGNUBuildID = 3
+)
+
+// elfNote is the payload of a Note Section in an ELF file.
+type elfNote struct {
+	Name string // Contents of the "name" field, omitting the trailing zero byte.
+	Desc []byte // Contents of the "desc" field.
+	Type uint32 // Contents of the "type" field.
+}
+
+// parseNotes returns the notes from a SHT_NOTE section or PT_NOTE segment.
+func parseNotes(reader io.Reader, alignment int, order binary.ByteOrder) ([]elfNote, error) {
+	r := bufio.NewReader(reader)
+
+	// padding returns the number of bytes required to pad the given size to an
+	// alignment boundary.
+	padding := func(size int) int {
+		return ((size + (alignment - 1)) &^ (alignment - 1)) - size
+	}
+
+	var notes []elfNote
+	for {
+		noteHeader := make([]byte, 12) // 3 4-byte words
+		if _, err := io.ReadFull(r, noteHeader); err == io.EOF {
+			break
+		} else if err != nil {
+			return nil, err
+		}
+		namesz := order.Uint32(noteHeader[0:4])
+		descsz := order.Uint32(noteHeader[4:8])
+		typ := order.Uint32(noteHeader[8:12])
+
+		if uint64(namesz) > uint64(maxNoteSize) {
+			return nil, fmt.Errorf("note name too long (%d bytes)", namesz)
+		}
+		var name string
+		if namesz > 0 {
+			// Documentation differs as to whether namesz is meant to include the
+			// trailing zero, but everyone agrees that name is null-terminated.
+			// So we'll just determine the actual length after the fact.
+			var err error
+			name, err = r.ReadString('\x00')
+			if err == io.EOF {
+				return nil, fmt.Errorf("missing note name (want %d bytes)", namesz)
+			} else if err != nil {
+				return nil, err
+			}
+			namesz = uint32(len(name))
+			name = name[:len(name)-1]
+		}
+
+		// Drop padding bytes until the desc field.
+		for n := padding(len(noteHeader) + int(namesz)); n > 0; n-- {
+			if _, err := r.ReadByte(); err == io.EOF {
+				return nil, fmt.Errorf(
+					"missing %d bytes of padding after note name", n)
+			} else if err != nil {
+				return nil, err
+			}
+		}
+
+		if uint64(descsz) > uint64(maxNoteSize) {
+			return nil, fmt.Errorf("note desc too long (%d bytes)", descsz)
+		}
+		desc := make([]byte, int(descsz))
+		if _, err := io.ReadFull(r, desc); err == io.EOF {
+			return nil, fmt.Errorf("missing desc (want %d bytes)", len(desc))
+		} else if err != nil {
+			return nil, err
+		}
+
+		notes = append(notes, elfNote{Name: name, Desc: desc, Type: typ})
+
+		// Drop padding bytes until the next note or the end of the section,
+		// whichever comes first.
+		for n := padding(len(desc)); n > 0; n-- {
+			if _, err := r.ReadByte(); err == io.EOF {
+				// We hit the end of the section before an alignment boundary.
+				// This can happen if this section is at the end of the file or the next
+				// section has a smaller alignment requirement.
+				break
+			} else if err != nil {
+				return nil, err
+			}
+		}
+	}
+	return notes, nil
+}
+
+// GetBuildID returns the GNU build-ID for an ELF binary.
+//
+// If no build-ID was found but the binary was read without error, it returns
+// (nil, nil).
+func GetBuildID(binary io.ReaderAt) ([]byte, error) {
+	f, err := elf.NewFile(binary)
+	if err != nil {
+		return nil, err
+	}
+
+	findBuildID := func(notes []elfNote) ([]byte, error) {
+		var buildID []byte
+		for _, note := range notes {
+			if note.Name == "GNU" && note.Type == noteTypeGNUBuildID {
+				if buildID == nil {
+					buildID = note.Desc
+				} else {
+					return nil, fmt.Errorf("multiple build ids found, don't know which to use")
+				}
+			}
+		}
+		return buildID, nil
+	}
+
+	for _, p := range f.Progs {
+		if p.Type != elf.PT_NOTE {
+			continue
+		}
+		notes, err := parseNotes(p.Open(), int(p.Align), f.ByteOrder)
+		if err != nil {
+			return nil, err
+		}
+		if b, err := findBuildID(notes); b != nil || err != nil {
+			return b, err
+		}
+	}
+	for _, s := range f.Sections {
+		if s.Type != elf.SHT_NOTE {
+			continue
+		}
+		notes, err := parseNotes(s.Open(), int(s.Addralign), f.ByteOrder)
+		if err != nil {
+			return nil, err
+		}
+		if b, err := findBuildID(notes); b != nil || err != nil {
+			return b, err
+		}
+	}
+	return nil, nil
+}
+
+// GetBase determines the base address to subtract from virtual
+// address to get symbol table address. For an executable, the base
+// is 0. Otherwise, it's a shared library, and the base is the
+// address where the mapping starts. The kernel is special, and may
+// use the address of the _stext symbol as the mmap start. _stext
+// offset can be obtained with `nm vmlinux | grep _stext`
+func GetBase(fh *elf.FileHeader, loadSegment *elf.ProgHeader, stextOffset *uint64, start, limit, offset uint64) (uint64, error) {
+	const (
+		pageSize = 4096
+		// PAGE_OFFSET for PowerPC64, see arch/powerpc/Kconfig in the kernel sources.
+		pageOffsetPpc64 = 0xc000000000000000
+	)
+
+	if start == 0 && offset == 0 && (limit == ^uint64(0) || limit == 0) {
+		// Some tools may introduce a fake mapping that spans the entire
+		// address space. Assume that the address has already been
+		// adjusted, so no additional base adjustment is necessary.
+		return 0, nil
+	}
+
+	switch fh.Type {
+	case elf.ET_EXEC:
+		if loadSegment == nil {
+			// Assume fixed-address executable and so no adjustment.
+			return 0, nil
+		}
+		if stextOffset == nil && start > 0 && start < 0x8000000000000000 {
+			// A regular user-mode executable. Compute the base offset using same
+			// arithmetics as in ET_DYN case below, see the explanation there.
+			// Ideally, the condition would just be "stextOffset == nil" as that
+			// represents the address of _stext symbol in the vmlinux image. Alas,
+			// the caller may skip reading it from the binary (it's expensive to scan
+			// all the symbols) and so it may be nil even for the kernel executable.
+			// So additionally check that the start is within the user-mode half of
+			// the 64-bit address space.
+			return start - offset + loadSegment.Off - loadSegment.Vaddr, nil
+		}
+		// Various kernel heuristics and cases follow.
+		if loadSegment.Vaddr == start-offset {
+			return offset, nil
+		}
+		if start == 0 && limit != 0 {
+			// ChromeOS remaps its kernel to 0. Nothing else should come
+			// down this path. Empirical values:
+			//       VADDR=0xffffffff80200000
+			// stextOffset=0xffffffff80200198
+			if stextOffset != nil {
+				return -*stextOffset, nil
+			}
+			return -loadSegment.Vaddr, nil
+		}
+		if start >= loadSegment.Vaddr && limit > start && (offset == 0 || offset == pageOffsetPpc64 || offset == start) {
+			// Some kernels look like:
+			//       VADDR=0xffffffff80200000
+			// stextOffset=0xffffffff80200198
+			//       Start=0xffffffff83200000
+			//       Limit=0xffffffff84200000
+			//      Offset=0 (0xc000000000000000 for PowerPC64) (== Start for ASLR kernel)
+			// So the base should be:
+			if stextOffset != nil && (start%pageSize) == (*stextOffset%pageSize) {
+				// perf uses the address of _stext as start. Some tools may
+				// adjust for this before calling GetBase, in which case the page
+				// alignment should be different from that of stextOffset.
+				return start - *stextOffset, nil
+			}
+
+			return start - loadSegment.Vaddr, nil
+		} else if start%pageSize != 0 && stextOffset != nil && *stextOffset%pageSize == start%pageSize {
+			// ChromeOS remaps its kernel to 0 + start%pageSize. Nothing
+			// else should come down this path. Empirical values:
+			//       start=0x198 limit=0x2f9fffff offset=0
+			//       VADDR=0xffffffff81000000
+			// stextOffset=0xffffffff81000198
+			return start - *stextOffset, nil
+		}
+
+		return 0, fmt.Errorf("don't know how to handle EXEC segment: %v start=0x%x limit=0x%x offset=0x%x", *loadSegment, start, limit, offset)
+	case elf.ET_REL:
+		if offset != 0 {
+			return 0, fmt.Errorf("don't know how to handle mapping.Offset")
+		}
+		return start, nil
+	case elf.ET_DYN:
+		// The process mapping information, start = start of virtual address range,
+		// and offset = offset in the executable file of the start address, tells us
+		// that a runtime virtual address x maps to a file offset
+		// fx = x - start + offset.
+		if loadSegment == nil {
+			return start - offset, nil
+		}
+		// The program header, if not nil, indicates the offset in the file where
+		// the executable segment is located (loadSegment.Off), and the base virtual
+		// address where the first byte of the segment is loaded
+		// (loadSegment.Vaddr). A file offset fx maps to a virtual (symbol) address
+		// sx = fx - loadSegment.Off + loadSegment.Vaddr.
+		//
+		// Thus, a runtime virtual address x maps to a symbol address
+		// sx = x - start + offset - loadSegment.Off + loadSegment.Vaddr.
+		return start - offset + loadSegment.Off - loadSegment.Vaddr, nil
+	}
+	return 0, fmt.Errorf("don't know how to handle FileHeader.Type %v", fh.Type)
+}
+
+// FindTextProgHeader finds the program segment header containing the .text
+// section or nil if the segment cannot be found.
+func FindTextProgHeader(f *elf.File) *elf.ProgHeader {
+	for _, s := range f.Sections {
+		if s.Name == ".text" {
+			// Find the LOAD segment containing the .text section.
+			for _, p := range f.Progs {
+				if p.Type == elf.PT_LOAD && p.Flags&elf.PF_X != 0 && s.Addr >= p.Vaddr && s.Addr < p.Vaddr+p.Memsz {
+					return &p.ProgHeader
+				}
+			}
+		}
+	}
+	return nil
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph.go b/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph.go
new file mode 100644
index 0000000..8cb87da
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/graph/dotgraph.go
@@ -0,0 +1,491 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package graph
+
+import (
+	"fmt"
+	"io"
+	"math"
+	"path/filepath"
+	"strings"
+
+	"github.com/google/pprof/internal/measurement"
+)
+
+// DotAttributes contains details about the graph itself, giving
+// insight into how its elements should be rendered.
+type DotAttributes struct {
+	Nodes map[*Node]*DotNodeAttributes // A map allowing each Node to have its own visualization option
+}
+
+// DotNodeAttributes contains Node specific visualization options.
+type DotNodeAttributes struct {
+	Shape       string                 // The optional shape of the node when rendered visually
+	Bold        bool                   // If the node should be bold or not
+	Peripheries int                    // An optional number of borders to place around a node
+	URL         string                 // An optional url link to add to a node
+	Formatter   func(*NodeInfo) string // An optional formatter for the node's label
+}
+
+// DotConfig contains attributes about how a graph should be
+// constructed and how it should look.
+type DotConfig struct {
+	Title     string   // The title of the DOT graph
+	LegendURL string   // The URL to link to from the legend.
+	Labels    []string // The labels for the DOT's legend
+
+	FormatValue func(int64) string // A formatting function for values
+	Total       int64              // The total weight of the graph, used to compute percentages
+}
+
+const maxNodelets = 4 // Number of nodelets for labels (both numeric and non)
+
+// ComposeDot creates and writes a in the DOT format to the writer, using
+// the configurations given.
+func ComposeDot(w io.Writer, g *Graph, a *DotAttributes, c *DotConfig) {
+	builder := &builder{w, a, c}
+
+	// Begin constructing DOT by adding a title and legend.
+	builder.start()
+	defer builder.finish()
+	builder.addLegend()
+
+	if len(g.Nodes) == 0 {
+		return
+	}
+
+	// Preprocess graph to get id map and find max flat.
+	nodeIDMap := make(map[*Node]int)
+	hasNodelets := make(map[*Node]bool)
+
+	maxFlat := float64(abs64(g.Nodes[0].FlatValue()))
+	for i, n := range g.Nodes {
+		nodeIDMap[n] = i + 1
+		if float64(abs64(n.FlatValue())) > maxFlat {
+			maxFlat = float64(abs64(n.FlatValue()))
+		}
+	}
+
+	edges := EdgeMap{}
+
+	// Add nodes and nodelets to DOT builder.
+	for _, n := range g.Nodes {
+		builder.addNode(n, nodeIDMap[n], maxFlat)
+		hasNodelets[n] = builder.addNodelets(n, nodeIDMap[n])
+
+		// Collect all edges. Use a fake node to support multiple incoming edges.
+		for _, e := range n.Out {
+			edges[&Node{}] = e
+		}
+	}
+
+	// Add edges to DOT builder. Sort edges by frequency as a hint to the graph layout engine.
+	for _, e := range edges.Sort() {
+		builder.addEdge(e, nodeIDMap[e.Src], nodeIDMap[e.Dest], hasNodelets[e.Src])
+	}
+}
+
+// builder wraps an io.Writer and understands how to compose DOT formatted elements.
+type builder struct {
+	io.Writer
+	attributes *DotAttributes
+	config     *DotConfig
+}
+
+// start generates a title and initial node in DOT format.
+func (b *builder) start() {
+	graphname := "unnamed"
+	if b.config.Title != "" {
+		graphname = b.config.Title
+	}
+	fmt.Fprintln(b, `digraph "`+graphname+`" {`)
+	fmt.Fprintln(b, `node [style=filled fillcolor="#f8f8f8"]`)
+}
+
+// finish closes the opening curly bracket in the constructed DOT buffer.
+func (b *builder) finish() {
+	fmt.Fprintln(b, "}")
+}
+
+// addLegend generates a legend in DOT format.
+func (b *builder) addLegend() {
+	labels := b.config.Labels
+	if len(labels) == 0 {
+		return
+	}
+	title := labels[0]
+	fmt.Fprintf(b, `subgraph cluster_L { "%s" [shape=box fontsize=16`, title)
+	fmt.Fprintf(b, ` label="%s\l"`, strings.Join(escapeAllForDot(labels), `\l`))
+	if b.config.LegendURL != "" {
+		fmt.Fprintf(b, ` URL="%s" target="_blank"`, b.config.LegendURL)
+	}
+	if b.config.Title != "" {
+		fmt.Fprintf(b, ` tooltip="%s"`, b.config.Title)
+	}
+	fmt.Fprintf(b, "] }\n")
+}
+
+// addNode generates a graph node in DOT format.
+func (b *builder) addNode(node *Node, nodeID int, maxFlat float64) {
+	flat, cum := node.FlatValue(), node.CumValue()
+	attrs := b.attributes.Nodes[node]
+
+	// Populate label for node.
+	var label string
+	if attrs != nil && attrs.Formatter != nil {
+		label = attrs.Formatter(&node.Info)
+	} else {
+		label = multilinePrintableName(&node.Info)
+	}
+
+	flatValue := b.config.FormatValue(flat)
+	if flat != 0 {
+		label = label + fmt.Sprintf(`%s (%s)`,
+			flatValue,
+			strings.TrimSpace(measurement.Percentage(flat, b.config.Total)))
+	} else {
+		label = label + "0"
+	}
+	cumValue := flatValue
+	if cum != flat {
+		if flat != 0 {
+			label = label + `\n`
+		} else {
+			label = label + " "
+		}
+		cumValue = b.config.FormatValue(cum)
+		label = label + fmt.Sprintf(`of %s (%s)`,
+			cumValue,
+			strings.TrimSpace(measurement.Percentage(cum, b.config.Total)))
+	}
+
+	// Scale font sizes from 8 to 24 based on percentage of flat frequency.
+	// Use non linear growth to emphasize the size difference.
+	baseFontSize, maxFontGrowth := 8, 16.0
+	fontSize := baseFontSize
+	if maxFlat != 0 && flat != 0 && float64(abs64(flat)) <= maxFlat {
+		fontSize += int(math.Ceil(maxFontGrowth * math.Sqrt(float64(abs64(flat))/maxFlat)))
+	}
+
+	// Determine node shape.
+	shape := "box"
+	if attrs != nil && attrs.Shape != "" {
+		shape = attrs.Shape
+	}
+
+	// Create DOT attribute for node.
+	attr := fmt.Sprintf(`label="%s" id="node%d" fontsize=%d shape=%s tooltip="%s (%s)" color="%s" fillcolor="%s"`,
+		label, nodeID, fontSize, shape, escapeForDot(node.Info.PrintableName()), cumValue,
+		dotColor(float64(node.CumValue())/float64(abs64(b.config.Total)), false),
+		dotColor(float64(node.CumValue())/float64(abs64(b.config.Total)), true))
+
+	// Add on extra attributes if provided.
+	if attrs != nil {
+		// Make bold if specified.
+		if attrs.Bold {
+			attr += ` style="bold,filled"`
+		}
+
+		// Add peripheries if specified.
+		if attrs.Peripheries != 0 {
+			attr += fmt.Sprintf(` peripheries=%d`, attrs.Peripheries)
+		}
+
+		// Add URL if specified. target="_blank" forces the link to open in a new tab.
+		if attrs.URL != "" {
+			attr += fmt.Sprintf(` URL="%s" target="_blank"`, attrs.URL)
+		}
+	}
+
+	fmt.Fprintf(b, "N%d [%s]\n", nodeID, attr)
+}
+
+// addNodelets generates the DOT boxes for the node tags if they exist.
+func (b *builder) addNodelets(node *Node, nodeID int) bool {
+	var nodelets string
+
+	// Populate two Tag slices, one for LabelTags and one for NumericTags.
+	var ts []*Tag
+	lnts := make(map[string][]*Tag)
+	for _, t := range node.LabelTags {
+		ts = append(ts, t)
+	}
+	for l, tm := range node.NumericTags {
+		for _, t := range tm {
+			lnts[l] = append(lnts[l], t)
+		}
+	}
+
+	// For leaf nodes, print cumulative tags (includes weight from
+	// children that have been deleted).
+	// For internal nodes, print only flat tags.
+	flatTags := len(node.Out) > 0
+
+	// Select the top maxNodelets alphanumeric labels by weight.
+	SortTags(ts, flatTags)
+	if len(ts) > maxNodelets {
+		ts = ts[:maxNodelets]
+	}
+	for i, t := range ts {
+		w := t.CumValue()
+		if flatTags {
+			w = t.FlatValue()
+		}
+		if w == 0 {
+			continue
+		}
+		weight := b.config.FormatValue(w)
+		nodelets += fmt.Sprintf(`N%d_%d [label = "%s" id="N%d_%d" fontsize=8 shape=box3d tooltip="%s"]`+"\n", nodeID, i, t.Name, nodeID, i, weight)
+		nodelets += fmt.Sprintf(`N%d -> N%d_%d [label=" %s" weight=100 tooltip="%s" labeltooltip="%s"]`+"\n", nodeID, nodeID, i, weight, weight, weight)
+		if nts := lnts[t.Name]; nts != nil {
+			nodelets += b.numericNodelets(nts, maxNodelets, flatTags, fmt.Sprintf(`N%d_%d`, nodeID, i))
+		}
+	}
+
+	if nts := lnts[""]; nts != nil {
+		nodelets += b.numericNodelets(nts, maxNodelets, flatTags, fmt.Sprintf(`N%d`, nodeID))
+	}
+
+	fmt.Fprint(b, nodelets)
+	return nodelets != ""
+}
+
+func (b *builder) numericNodelets(nts []*Tag, maxNumNodelets int, flatTags bool, source string) string {
+	nodelets := ""
+
+	// Collapse numeric labels into maxNumNodelets buckets, of the form:
+	// 1MB..2MB, 3MB..5MB, ...
+	for j, t := range b.collapsedTags(nts, maxNumNodelets, flatTags) {
+		w, attr := t.CumValue(), ` style="dotted"`
+		if flatTags || t.FlatValue() == t.CumValue() {
+			w, attr = t.FlatValue(), ""
+		}
+		if w != 0 {
+			weight := b.config.FormatValue(w)
+			nodelets += fmt.Sprintf(`N%s_%d [label = "%s" id="N%s_%d" fontsize=8 shape=box3d tooltip="%s"]`+"\n", source, j, t.Name, source, j, weight)
+			nodelets += fmt.Sprintf(`%s -> N%s_%d [label=" %s" weight=100 tooltip="%s" labeltooltip="%s"%s]`+"\n", source, source, j, weight, weight, weight, attr)
+		}
+	}
+	return nodelets
+}
+
+// addEdge generates a graph edge in DOT format.
+func (b *builder) addEdge(edge *Edge, from, to int, hasNodelets bool) {
+	var inline string
+	if edge.Inline {
+		inline = `\n (inline)`
+	}
+	w := b.config.FormatValue(edge.WeightValue())
+	attr := fmt.Sprintf(`label=" %s%s"`, w, inline)
+	if b.config.Total != 0 {
+		// Note: edge.weight > b.config.Total is possible for profile diffs.
+		if weight := 1 + int(min64(abs64(edge.WeightValue()*100/b.config.Total), 100)); weight > 1 {
+			attr = fmt.Sprintf(`%s weight=%d`, attr, weight)
+		}
+		if width := 1 + int(min64(abs64(edge.WeightValue()*5/b.config.Total), 5)); width > 1 {
+			attr = fmt.Sprintf(`%s penwidth=%d`, attr, width)
+		}
+		attr = fmt.Sprintf(`%s color="%s"`, attr,
+			dotColor(float64(edge.WeightValue())/float64(abs64(b.config.Total)), false))
+	}
+	arrow := "->"
+	if edge.Residual {
+		arrow = "..."
+	}
+	tooltip := fmt.Sprintf(`"%s %s %s (%s)"`,
+		escapeForDot(edge.Src.Info.PrintableName()), arrow,
+		escapeForDot(edge.Dest.Info.PrintableName()), w)
+	attr = fmt.Sprintf(`%s tooltip=%s labeltooltip=%s`, attr, tooltip, tooltip)
+
+	if edge.Residual {
+		attr = attr + ` style="dotted"`
+	}
+
+	if hasNodelets {
+		// Separate children further if source has tags.
+		attr = attr + " minlen=2"
+	}
+
+	fmt.Fprintf(b, "N%d -> N%d [%s]\n", from, to, attr)
+}
+
+// dotColor returns a color for the given score (between -1.0 and
+// 1.0), with -1.0 colored red, 0.0 colored grey, and 1.0 colored
+// green. If isBackground is true, then a light (low-saturation)
+// color is returned (suitable for use as a background color);
+// otherwise, a darker color is returned (suitable for use as a
+// foreground color).
+func dotColor(score float64, isBackground bool) string {
+	// A float between 0.0 and 1.0, indicating the extent to which
+	// colors should be shifted away from grey (to make positive and
+	// negative values easier to distinguish, and to make more use of
+	// the color range.)
+	const shift = 0.7
+
+	// Saturation and value (in hsv colorspace) for background colors.
+	const bgSaturation = 0.1
+	const bgValue = 0.93
+
+	// Saturation and value (in hsv colorspace) for foreground colors.
+	const fgSaturation = 1.0
+	const fgValue = 0.7
+
+	// Choose saturation and value based on isBackground.
+	var saturation float64
+	var value float64
+	if isBackground {
+		saturation = bgSaturation
+		value = bgValue
+	} else {
+		saturation = fgSaturation
+		value = fgValue
+	}
+
+	// Limit the score values to the range [-1.0, 1.0].
+	score = math.Max(-1.0, math.Min(1.0, score))
+
+	// Reduce saturation near score=0 (so it is colored grey, rather than yellow).
+	if math.Abs(score) < 0.2 {
+		saturation *= math.Abs(score) / 0.2
+	}
+
+	// Apply 'shift' to move scores away from 0.0 (grey).
+	if score > 0.0 {
+		score = math.Pow(score, (1.0 - shift))
+	}
+	if score < 0.0 {
+		score = -math.Pow(-score, (1.0 - shift))
+	}
+
+	var r, g, b float64 // red, green, blue
+	if score < 0.0 {
+		g = value
+		r = value * (1 + saturation*score)
+	} else {
+		r = value
+		g = value * (1 - saturation*score)
+	}
+	b = value * (1 - saturation)
+	return fmt.Sprintf("#%02x%02x%02x", uint8(r*255.0), uint8(g*255.0), uint8(b*255.0))
+}
+
+func multilinePrintableName(info *NodeInfo) string {
+	infoCopy := *info
+	infoCopy.Name = escapeForDot(ShortenFunctionName(infoCopy.Name))
+	infoCopy.Name = strings.Replace(infoCopy.Name, "::", `\n`, -1)
+	infoCopy.Name = strings.Replace(infoCopy.Name, ".", `\n`, -1)
+	if infoCopy.File != "" {
+		infoCopy.File = filepath.Base(infoCopy.File)
+	}
+	return strings.Join(infoCopy.NameComponents(), `\n`) + `\n`
+}
+
+// collapsedTags trims and sorts a slice of tags.
+func (b *builder) collapsedTags(ts []*Tag, count int, flatTags bool) []*Tag {
+	ts = SortTags(ts, flatTags)
+	if len(ts) <= count {
+		return ts
+	}
+
+	tagGroups := make([][]*Tag, count)
+	for i, t := range (ts)[:count] {
+		tagGroups[i] = []*Tag{t}
+	}
+	for _, t := range (ts)[count:] {
+		g, d := 0, tagDistance(t, tagGroups[0][0])
+		for i := 1; i < count; i++ {
+			if nd := tagDistance(t, tagGroups[i][0]); nd < d {
+				g, d = i, nd
+			}
+		}
+		tagGroups[g] = append(tagGroups[g], t)
+	}
+
+	var nts []*Tag
+	for _, g := range tagGroups {
+		l, w, c := b.tagGroupLabel(g)
+		nts = append(nts, &Tag{
+			Name: l,
+			Flat: w,
+			Cum:  c,
+		})
+	}
+	return SortTags(nts, flatTags)
+}
+
+func tagDistance(t, u *Tag) float64 {
+	v, _ := measurement.Scale(u.Value, u.Unit, t.Unit)
+	if v < float64(t.Value) {
+		return float64(t.Value) - v
+	}
+	return v - float64(t.Value)
+}
+
+func (b *builder) tagGroupLabel(g []*Tag) (label string, flat, cum int64) {
+	if len(g) == 1 {
+		t := g[0]
+		return measurement.Label(t.Value, t.Unit), t.FlatValue(), t.CumValue()
+	}
+	min := g[0]
+	max := g[0]
+	df, f := min.FlatDiv, min.Flat
+	dc, c := min.CumDiv, min.Cum
+	for _, t := range g[1:] {
+		if v, _ := measurement.Scale(t.Value, t.Unit, min.Unit); int64(v) < min.Value {
+			min = t
+		}
+		if v, _ := measurement.Scale(t.Value, t.Unit, max.Unit); int64(v) > max.Value {
+			max = t
+		}
+		f += t.Flat
+		df += t.FlatDiv
+		c += t.Cum
+		dc += t.CumDiv
+	}
+	if df != 0 {
+		f = f / df
+	}
+	if dc != 0 {
+		c = c / dc
+	}
+
+	// Tags are not scaled with the selected output unit because tags are often
+	// much smaller than other values which appear, so the range of tag sizes
+	// sometimes would appear to be "0..0" when scaled to the selected output unit.
+	return measurement.Label(min.Value, min.Unit) + ".." + measurement.Label(max.Value, max.Unit), f, c
+}
+
+func min64(a, b int64) int64 {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+// escapeAllForDot applies escapeForDot to all strings in the given slice.
+func escapeAllForDot(in []string) []string {
+	var out = make([]string, len(in))
+	for i := range in {
+		out[i] = escapeForDot(in[i])
+	}
+	return out
+}
+
+// escapeForDot escapes double quotes and backslashes, and replaces Graphviz's
+// "center" character (\n) with a left-justified character.
+// See https://graphviz.org/doc/info/attrs.html#k:escString for more info.
+func escapeForDot(str string) string {
+	return strings.ReplaceAll(strings.ReplaceAll(strings.ReplaceAll(str, `\`, `\\`), `"`, `\"`), "\n", `\l`)
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/graph/graph.go b/src/cmd/vendor/github.com/google/pprof/internal/graph/graph.go
new file mode 100644
index 0000000..74b904c
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/graph/graph.go
@@ -0,0 +1,1170 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package graph collects a set of samples into a directed graph.
+package graph
+
+import (
+	"fmt"
+	"math"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+
+	"github.com/google/pprof/profile"
+)
+
+var (
+	// Removes package name and method arguments for Java method names.
+	// See tests for examples.
+	javaRegExp = regexp.MustCompile(`^(?:[a-z]\w*\.)*([A-Z][\w\$]*\.(?:<init>|[a-z][\w\$]*(?:\$\d+)?))(?:(?:\()|$)`)
+	// Removes package name and method arguments for Go function names.
+	// See tests for examples.
+	goRegExp = regexp.MustCompile(`^(?:[\w\-\.]+\/)+(.+)`)
+	// Removes potential module versions in a package path.
+	goVerRegExp = regexp.MustCompile(`^(.*?)/v(?:[2-9]|[1-9][0-9]+)([./].*)$`)
+	// Strips C++ namespace prefix from a C++ function / method name.
+	// NOTE: Make sure to keep the template parameters in the name. Normally,
+	// template parameters are stripped from the C++ names but when
+	// -symbolize=demangle=templates flag is used, they will not be.
+	// See tests for examples.
+	cppRegExp                = regexp.MustCompile(`^(?:[_a-zA-Z]\w*::)+(_*[A-Z]\w*::~?[_a-zA-Z]\w*(?:<.*>)?)`)
+	cppAnonymousPrefixRegExp = regexp.MustCompile(`^\(anonymous namespace\)::`)
+)
+
+// Graph summarizes a performance profile into a format that is
+// suitable for visualization.
+type Graph struct {
+	Nodes Nodes
+}
+
+// Options encodes the options for constructing a graph
+type Options struct {
+	SampleValue       func(s []int64) int64      // Function to compute the value of a sample
+	SampleMeanDivisor func(s []int64) int64      // Function to compute the divisor for mean graphs, or nil
+	FormatTag         func(int64, string) string // Function to format a sample tag value into a string
+	ObjNames          bool                       // Always preserve obj filename
+	OrigFnNames       bool                       // Preserve original (eg mangled) function names
+
+	CallTree     bool // Build a tree instead of a graph
+	DropNegative bool // Drop nodes with overall negative values
+
+	KeptNodes NodeSet // If non-nil, only use nodes in this set
+}
+
+// Nodes is an ordered collection of graph nodes.
+type Nodes []*Node
+
+// Node is an entry on a profiling report. It represents a unique
+// program location.
+type Node struct {
+	// Info describes the source location associated to this node.
+	Info NodeInfo
+
+	// Function represents the function that this node belongs to. On
+	// graphs with sub-function resolution (eg line number or
+	// addresses), two nodes in a NodeMap that are part of the same
+	// function have the same value of Node.Function. If the Node
+	// represents the whole function, it points back to itself.
+	Function *Node
+
+	// Values associated to this node. Flat is exclusive to this node,
+	// Cum includes all descendents.
+	Flat, FlatDiv, Cum, CumDiv int64
+
+	// In and out Contains the nodes immediately reaching or reached by
+	// this node.
+	In, Out EdgeMap
+
+	// LabelTags provide additional information about subsets of a sample.
+	LabelTags TagMap
+
+	// NumericTags provide additional values for subsets of a sample.
+	// Numeric tags are optionally associated to a label tag. The key
+	// for NumericTags is the name of the LabelTag they are associated
+	// to, or "" for numeric tags not associated to a label tag.
+	NumericTags map[string]TagMap
+}
+
+// FlatValue returns the exclusive value for this node, computing the
+// mean if a divisor is available.
+func (n *Node) FlatValue() int64 {
+	if n.FlatDiv == 0 {
+		return n.Flat
+	}
+	return n.Flat / n.FlatDiv
+}
+
+// CumValue returns the inclusive value for this node, computing the
+// mean if a divisor is available.
+func (n *Node) CumValue() int64 {
+	if n.CumDiv == 0 {
+		return n.Cum
+	}
+	return n.Cum / n.CumDiv
+}
+
+// AddToEdge increases the weight of an edge between two nodes. If
+// there isn't such an edge one is created.
+func (n *Node) AddToEdge(to *Node, v int64, residual, inline bool) {
+	n.AddToEdgeDiv(to, 0, v, residual, inline)
+}
+
+// AddToEdgeDiv increases the weight of an edge between two nodes. If
+// there isn't such an edge one is created.
+func (n *Node) AddToEdgeDiv(to *Node, dv, v int64, residual, inline bool) {
+	if n.Out[to] != to.In[n] {
+		panic(fmt.Errorf("asymmetric edges %v %v", *n, *to))
+	}
+
+	if e := n.Out[to]; e != nil {
+		e.WeightDiv += dv
+		e.Weight += v
+		if residual {
+			e.Residual = true
+		}
+		if !inline {
+			e.Inline = false
+		}
+		return
+	}
+
+	info := &Edge{Src: n, Dest: to, WeightDiv: dv, Weight: v, Residual: residual, Inline: inline}
+	n.Out[to] = info
+	to.In[n] = info
+}
+
+// NodeInfo contains the attributes for a node.
+type NodeInfo struct {
+	Name              string
+	OrigName          string
+	Address           uint64
+	File              string
+	StartLine, Lineno int
+	Objfile           string
+}
+
+// PrintableName calls the Node's Formatter function with a single space separator.
+func (i *NodeInfo) PrintableName() string {
+	return strings.Join(i.NameComponents(), " ")
+}
+
+// NameComponents returns the components of the printable name to be used for a node.
+func (i *NodeInfo) NameComponents() []string {
+	var name []string
+	if i.Address != 0 {
+		name = append(name, fmt.Sprintf("%016x", i.Address))
+	}
+	if fun := i.Name; fun != "" {
+		name = append(name, fun)
+	}
+
+	switch {
+	case i.Lineno != 0:
+		// User requested line numbers, provide what we have.
+		name = append(name, fmt.Sprintf("%s:%d", i.File, i.Lineno))
+	case i.File != "":
+		// User requested file name, provide it.
+		name = append(name, i.File)
+	case i.Name != "":
+		// User requested function name. It was already included.
+	case i.Objfile != "":
+		// Only binary name is available
+		name = append(name, "["+filepath.Base(i.Objfile)+"]")
+	default:
+		// Do not leave it empty if there is no information at all.
+		name = append(name, "<unknown>")
+	}
+	return name
+}
+
+// NodeMap maps from a node info struct to a node. It is used to merge
+// report entries with the same info.
+type NodeMap map[NodeInfo]*Node
+
+// NodeSet is a collection of node info structs.
+type NodeSet map[NodeInfo]bool
+
+// NodePtrSet is a collection of nodes. Trimming a graph or tree requires a set
+// of objects which uniquely identify the nodes to keep. In a graph, NodeInfo
+// works as a unique identifier; however, in a tree multiple nodes may share
+// identical NodeInfos. A *Node does uniquely identify a node so we can use that
+// instead. Though a *Node also uniquely identifies a node in a graph,
+// currently, during trimming, graphs are rebuilt from scratch using only the
+// NodeSet, so there would not be the required context of the initial graph to
+// allow for the use of *Node.
+type NodePtrSet map[*Node]bool
+
+// FindOrInsertNode takes the info for a node and either returns a matching node
+// from the node map if one exists, or adds one to the map if one does not.
+// If kept is non-nil, nodes are only added if they can be located on it.
+func (nm NodeMap) FindOrInsertNode(info NodeInfo, kept NodeSet) *Node {
+	if kept != nil {
+		if _, ok := kept[info]; !ok {
+			return nil
+		}
+	}
+
+	if n, ok := nm[info]; ok {
+		return n
+	}
+
+	n := &Node{
+		Info:        info,
+		In:          make(EdgeMap),
+		Out:         make(EdgeMap),
+		LabelTags:   make(TagMap),
+		NumericTags: make(map[string]TagMap),
+	}
+	nm[info] = n
+	if info.Address == 0 && info.Lineno == 0 {
+		// This node represents the whole function, so point Function
+		// back to itself.
+		n.Function = n
+		return n
+	}
+	// Find a node that represents the whole function.
+	info.Address = 0
+	info.Lineno = 0
+	n.Function = nm.FindOrInsertNode(info, nil)
+	return n
+}
+
+// EdgeMap is used to represent the incoming/outgoing edges from a node.
+type EdgeMap map[*Node]*Edge
+
+// Edge contains any attributes to be represented about edges in a graph.
+type Edge struct {
+	Src, Dest *Node
+	// The summary weight of the edge
+	Weight, WeightDiv int64
+
+	// residual edges connect nodes that were connected through a
+	// separate node, which has been removed from the report.
+	Residual bool
+	// An inline edge represents a call that was inlined into the caller.
+	Inline bool
+}
+
+// WeightValue returns the weight value for this edge, normalizing if a
+// divisor is available.
+func (e *Edge) WeightValue() int64 {
+	if e.WeightDiv == 0 {
+		return e.Weight
+	}
+	return e.Weight / e.WeightDiv
+}
+
+// Tag represent sample annotations
+type Tag struct {
+	Name          string
+	Unit          string // Describe the value, "" for non-numeric tags
+	Value         int64
+	Flat, FlatDiv int64
+	Cum, CumDiv   int64
+}
+
+// FlatValue returns the exclusive value for this tag, computing the
+// mean if a divisor is available.
+func (t *Tag) FlatValue() int64 {
+	if t.FlatDiv == 0 {
+		return t.Flat
+	}
+	return t.Flat / t.FlatDiv
+}
+
+// CumValue returns the inclusive value for this tag, computing the
+// mean if a divisor is available.
+func (t *Tag) CumValue() int64 {
+	if t.CumDiv == 0 {
+		return t.Cum
+	}
+	return t.Cum / t.CumDiv
+}
+
+// TagMap is a collection of tags, classified by their name.
+type TagMap map[string]*Tag
+
+// SortTags sorts a slice of tags based on their weight.
+func SortTags(t []*Tag, flat bool) []*Tag {
+	ts := tags{t, flat}
+	sort.Sort(ts)
+	return ts.t
+}
+
+// New summarizes performance data from a profile into a graph.
+func New(prof *profile.Profile, o *Options) *Graph {
+	if o.CallTree {
+		return newTree(prof, o)
+	}
+	g, _ := newGraph(prof, o)
+	return g
+}
+
+// newGraph computes a graph from a profile. It returns the graph, and
+// a map from the profile location indices to the corresponding graph
+// nodes.
+func newGraph(prof *profile.Profile, o *Options) (*Graph, map[uint64]Nodes) {
+	nodes, locationMap := CreateNodes(prof, o)
+	seenNode := make(map[*Node]bool)
+	seenEdge := make(map[nodePair]bool)
+	for _, sample := range prof.Sample {
+		var w, dw int64
+		w = o.SampleValue(sample.Value)
+		if o.SampleMeanDivisor != nil {
+			dw = o.SampleMeanDivisor(sample.Value)
+		}
+		if dw == 0 && w == 0 {
+			continue
+		}
+		for k := range seenNode {
+			delete(seenNode, k)
+		}
+		for k := range seenEdge {
+			delete(seenEdge, k)
+		}
+		var parent *Node
+		// A residual edge goes over one or more nodes that were not kept.
+		residual := false
+
+		labels := joinLabels(sample)
+		// Group the sample frames, based on a global map.
+		for i := len(sample.Location) - 1; i >= 0; i-- {
+			l := sample.Location[i]
+			locNodes := locationMap[l.ID]
+			for ni := len(locNodes) - 1; ni >= 0; ni-- {
+				n := locNodes[ni]
+				if n == nil {
+					residual = true
+					continue
+				}
+				// Add cum weight to all nodes in stack, avoiding double counting.
+				if _, ok := seenNode[n]; !ok {
+					seenNode[n] = true
+					n.addSample(dw, w, labels, sample.NumLabel, sample.NumUnit, o.FormatTag, false)
+				}
+				// Update edge weights for all edges in stack, avoiding double counting.
+				if _, ok := seenEdge[nodePair{n, parent}]; !ok && parent != nil && n != parent {
+					seenEdge[nodePair{n, parent}] = true
+					parent.AddToEdgeDiv(n, dw, w, residual, ni != len(locNodes)-1)
+				}
+				parent = n
+				residual = false
+			}
+		}
+		if parent != nil && !residual {
+			// Add flat weight to leaf node.
+			parent.addSample(dw, w, labels, sample.NumLabel, sample.NumUnit, o.FormatTag, true)
+		}
+	}
+
+	return selectNodesForGraph(nodes, o.DropNegative), locationMap
+}
+
+func selectNodesForGraph(nodes Nodes, dropNegative bool) *Graph {
+	// Collect nodes into a graph.
+	gNodes := make(Nodes, 0, len(nodes))
+	for _, n := range nodes {
+		if n == nil {
+			continue
+		}
+		if n.Cum == 0 && n.Flat == 0 {
+			continue
+		}
+		if dropNegative && isNegative(n) {
+			continue
+		}
+		gNodes = append(gNodes, n)
+	}
+	return &Graph{gNodes}
+}
+
+type nodePair struct {
+	src, dest *Node
+}
+
+func newTree(prof *profile.Profile, o *Options) (g *Graph) {
+	parentNodeMap := make(map[*Node]NodeMap, len(prof.Sample))
+	for _, sample := range prof.Sample {
+		var w, dw int64
+		w = o.SampleValue(sample.Value)
+		if o.SampleMeanDivisor != nil {
+			dw = o.SampleMeanDivisor(sample.Value)
+		}
+		if dw == 0 && w == 0 {
+			continue
+		}
+		var parent *Node
+		labels := joinLabels(sample)
+		// Group the sample frames, based on a per-node map.
+		for i := len(sample.Location) - 1; i >= 0; i-- {
+			l := sample.Location[i]
+			lines := l.Line
+			if len(lines) == 0 {
+				lines = []profile.Line{{}} // Create empty line to include location info.
+			}
+			for lidx := len(lines) - 1; lidx >= 0; lidx-- {
+				nodeMap := parentNodeMap[parent]
+				if nodeMap == nil {
+					nodeMap = make(NodeMap)
+					parentNodeMap[parent] = nodeMap
+				}
+				n := nodeMap.findOrInsertLine(l, lines[lidx], o)
+				if n == nil {
+					continue
+				}
+				n.addSample(dw, w, labels, sample.NumLabel, sample.NumUnit, o.FormatTag, false)
+				if parent != nil {
+					parent.AddToEdgeDiv(n, dw, w, false, lidx != len(lines)-1)
+				}
+				parent = n
+			}
+		}
+		if parent != nil {
+			parent.addSample(dw, w, labels, sample.NumLabel, sample.NumUnit, o.FormatTag, true)
+		}
+	}
+
+	nodes := make(Nodes, len(prof.Location))
+	for _, nm := range parentNodeMap {
+		nodes = append(nodes, nm.nodes()...)
+	}
+	return selectNodesForGraph(nodes, o.DropNegative)
+}
+
+// ShortenFunctionName returns a shortened version of a function's name.
+func ShortenFunctionName(f string) string {
+	f = cppAnonymousPrefixRegExp.ReplaceAllString(f, "")
+	f = goVerRegExp.ReplaceAllString(f, `${1}${2}`)
+	for _, re := range []*regexp.Regexp{goRegExp, javaRegExp, cppRegExp} {
+		if matches := re.FindStringSubmatch(f); len(matches) >= 2 {
+			return strings.Join(matches[1:], "")
+		}
+	}
+	return f
+}
+
+// TrimTree trims a Graph in forest form, keeping only the nodes in kept. This
+// will not work correctly if even a single node has multiple parents.
+func (g *Graph) TrimTree(kept NodePtrSet) {
+	// Creates a new list of nodes
+	oldNodes := g.Nodes
+	g.Nodes = make(Nodes, 0, len(kept))
+
+	for _, cur := range oldNodes {
+		// A node may not have multiple parents
+		if len(cur.In) > 1 {
+			panic("TrimTree only works on trees")
+		}
+
+		// If a node should be kept, add it to the new list of nodes
+		if _, ok := kept[cur]; ok {
+			g.Nodes = append(g.Nodes, cur)
+			continue
+		}
+
+		// If a node has no parents, then delete all of the in edges of its
+		// children to make them each roots of their own trees.
+		if len(cur.In) == 0 {
+			for _, outEdge := range cur.Out {
+				delete(outEdge.Dest.In, cur)
+			}
+			continue
+		}
+
+		// Get the parent. This works since at this point cur.In must contain only
+		// one element.
+		if len(cur.In) != 1 {
+			panic("Get parent assertion failed. cur.In expected to be of length 1.")
+		}
+		var parent *Node
+		for _, edge := range cur.In {
+			parent = edge.Src
+		}
+
+		parentEdgeInline := parent.Out[cur].Inline
+
+		// Remove the edge from the parent to this node
+		delete(parent.Out, cur)
+
+		// Reconfigure every edge from the current node to now begin at the parent.
+		for _, outEdge := range cur.Out {
+			child := outEdge.Dest
+
+			delete(child.In, cur)
+			child.In[parent] = outEdge
+			parent.Out[child] = outEdge
+
+			outEdge.Src = parent
+			outEdge.Residual = true
+			// If the edge from the parent to the current node and the edge from the
+			// current node to the child are both inline, then this resulting residual
+			// edge should also be inline
+			outEdge.Inline = parentEdgeInline && outEdge.Inline
+		}
+	}
+	g.RemoveRedundantEdges()
+}
+
+func joinLabels(s *profile.Sample) string {
+	if len(s.Label) == 0 {
+		return ""
+	}
+
+	var labels []string
+	for key, vals := range s.Label {
+		for _, v := range vals {
+			labels = append(labels, key+":"+v)
+		}
+	}
+	sort.Strings(labels)
+	return strings.Join(labels, `\n`)
+}
+
+// isNegative returns true if the node is considered as "negative" for the
+// purposes of drop_negative.
+func isNegative(n *Node) bool {
+	switch {
+	case n.Flat < 0:
+		return true
+	case n.Flat == 0 && n.Cum < 0:
+		return true
+	default:
+		return false
+	}
+}
+
+// CreateNodes creates graph nodes for all locations in a profile. It
+// returns set of all nodes, plus a mapping of each location to the
+// set of corresponding nodes (one per location.Line).
+func CreateNodes(prof *profile.Profile, o *Options) (Nodes, map[uint64]Nodes) {
+	locations := make(map[uint64]Nodes, len(prof.Location))
+	nm := make(NodeMap, len(prof.Location))
+	for _, l := range prof.Location {
+		lines := l.Line
+		if len(lines) == 0 {
+			lines = []profile.Line{{}} // Create empty line to include location info.
+		}
+		nodes := make(Nodes, len(lines))
+		for ln := range lines {
+			nodes[ln] = nm.findOrInsertLine(l, lines[ln], o)
+		}
+		locations[l.ID] = nodes
+	}
+	return nm.nodes(), locations
+}
+
+func (nm NodeMap) nodes() Nodes {
+	nodes := make(Nodes, 0, len(nm))
+	for _, n := range nm {
+		nodes = append(nodes, n)
+	}
+	return nodes
+}
+
+func (nm NodeMap) findOrInsertLine(l *profile.Location, li profile.Line, o *Options) *Node {
+	var objfile string
+	if m := l.Mapping; m != nil && m.File != "" {
+		objfile = m.File
+	}
+
+	if ni := nodeInfo(l, li, objfile, o); ni != nil {
+		return nm.FindOrInsertNode(*ni, o.KeptNodes)
+	}
+	return nil
+}
+
+func nodeInfo(l *profile.Location, line profile.Line, objfile string, o *Options) *NodeInfo {
+	if line.Function == nil {
+		return &NodeInfo{Address: l.Address, Objfile: objfile}
+	}
+	ni := &NodeInfo{
+		Address: l.Address,
+		Lineno:  int(line.Line),
+		Name:    line.Function.Name,
+	}
+	if fname := line.Function.Filename; fname != "" {
+		ni.File = filepath.Clean(fname)
+	}
+	if o.OrigFnNames {
+		ni.OrigName = line.Function.SystemName
+	}
+	if o.ObjNames || (ni.Name == "" && ni.OrigName == "") {
+		ni.Objfile = objfile
+		ni.StartLine = int(line.Function.StartLine)
+	}
+	return ni
+}
+
+type tags struct {
+	t    []*Tag
+	flat bool
+}
+
+func (t tags) Len() int      { return len(t.t) }
+func (t tags) Swap(i, j int) { t.t[i], t.t[j] = t.t[j], t.t[i] }
+func (t tags) Less(i, j int) bool {
+	if !t.flat {
+		if t.t[i].Cum != t.t[j].Cum {
+			return abs64(t.t[i].Cum) > abs64(t.t[j].Cum)
+		}
+	}
+	if t.t[i].Flat != t.t[j].Flat {
+		return abs64(t.t[i].Flat) > abs64(t.t[j].Flat)
+	}
+	return t.t[i].Name < t.t[j].Name
+}
+
+// Sum adds the flat and cum values of a set of nodes.
+func (ns Nodes) Sum() (flat int64, cum int64) {
+	for _, n := range ns {
+		flat += n.Flat
+		cum += n.Cum
+	}
+	return
+}
+
+func (n *Node) addSample(dw, w int64, labels string, numLabel map[string][]int64, numUnit map[string][]string, format func(int64, string) string, flat bool) {
+	// Update sample value
+	if flat {
+		n.FlatDiv += dw
+		n.Flat += w
+	} else {
+		n.CumDiv += dw
+		n.Cum += w
+	}
+
+	// Add string tags
+	if labels != "" {
+		t := n.LabelTags.findOrAddTag(labels, "", 0)
+		if flat {
+			t.FlatDiv += dw
+			t.Flat += w
+		} else {
+			t.CumDiv += dw
+			t.Cum += w
+		}
+	}
+
+	numericTags := n.NumericTags[labels]
+	if numericTags == nil {
+		numericTags = TagMap{}
+		n.NumericTags[labels] = numericTags
+	}
+	// Add numeric tags
+	if format == nil {
+		format = defaultLabelFormat
+	}
+	for k, nvals := range numLabel {
+		units := numUnit[k]
+		for i, v := range nvals {
+			var t *Tag
+			if len(units) > 0 {
+				t = numericTags.findOrAddTag(format(v, units[i]), units[i], v)
+			} else {
+				t = numericTags.findOrAddTag(format(v, k), k, v)
+			}
+			if flat {
+				t.FlatDiv += dw
+				t.Flat += w
+			} else {
+				t.CumDiv += dw
+				t.Cum += w
+			}
+		}
+	}
+}
+
+func defaultLabelFormat(v int64, key string) string {
+	return strconv.FormatInt(v, 10)
+}
+
+func (m TagMap) findOrAddTag(label, unit string, value int64) *Tag {
+	l := m[label]
+	if l == nil {
+		l = &Tag{
+			Name:  label,
+			Unit:  unit,
+			Value: value,
+		}
+		m[label] = l
+	}
+	return l
+}
+
+// String returns a text representation of a graph, for debugging purposes.
+func (g *Graph) String() string {
+	var s []string
+
+	nodeIndex := make(map[*Node]int, len(g.Nodes))
+
+	for i, n := range g.Nodes {
+		nodeIndex[n] = i + 1
+	}
+
+	for i, n := range g.Nodes {
+		name := n.Info.PrintableName()
+		var in, out []int
+
+		for _, from := range n.In {
+			in = append(in, nodeIndex[from.Src])
+		}
+		for _, to := range n.Out {
+			out = append(out, nodeIndex[to.Dest])
+		}
+		s = append(s, fmt.Sprintf("%d: %s[flat=%d cum=%d] %x -> %v ", i+1, name, n.Flat, n.Cum, in, out))
+	}
+	return strings.Join(s, "\n")
+}
+
+// DiscardLowFrequencyNodes returns a set of the nodes at or over a
+// specific cum value cutoff.
+func (g *Graph) DiscardLowFrequencyNodes(nodeCutoff int64) NodeSet {
+	return makeNodeSet(g.Nodes, nodeCutoff)
+}
+
+// DiscardLowFrequencyNodePtrs returns a NodePtrSet of nodes at or over a
+// specific cum value cutoff.
+func (g *Graph) DiscardLowFrequencyNodePtrs(nodeCutoff int64) NodePtrSet {
+	cutNodes := getNodesAboveCumCutoff(g.Nodes, nodeCutoff)
+	kept := make(NodePtrSet, len(cutNodes))
+	for _, n := range cutNodes {
+		kept[n] = true
+	}
+	return kept
+}
+
+func makeNodeSet(nodes Nodes, nodeCutoff int64) NodeSet {
+	cutNodes := getNodesAboveCumCutoff(nodes, nodeCutoff)
+	kept := make(NodeSet, len(cutNodes))
+	for _, n := range cutNodes {
+		kept[n.Info] = true
+	}
+	return kept
+}
+
+// getNodesAboveCumCutoff returns all the nodes which have a Cum value greater
+// than or equal to cutoff.
+func getNodesAboveCumCutoff(nodes Nodes, nodeCutoff int64) Nodes {
+	cutoffNodes := make(Nodes, 0, len(nodes))
+	for _, n := range nodes {
+		if abs64(n.Cum) < nodeCutoff {
+			continue
+		}
+		cutoffNodes = append(cutoffNodes, n)
+	}
+	return cutoffNodes
+}
+
+// TrimLowFrequencyTags removes tags that have less than
+// the specified weight.
+func (g *Graph) TrimLowFrequencyTags(tagCutoff int64) {
+	// Remove nodes with value <= total*nodeFraction
+	for _, n := range g.Nodes {
+		n.LabelTags = trimLowFreqTags(n.LabelTags, tagCutoff)
+		for s, nt := range n.NumericTags {
+			n.NumericTags[s] = trimLowFreqTags(nt, tagCutoff)
+		}
+	}
+}
+
+func trimLowFreqTags(tags TagMap, minValue int64) TagMap {
+	kept := TagMap{}
+	for s, t := range tags {
+		if abs64(t.Flat) >= minValue || abs64(t.Cum) >= minValue {
+			kept[s] = t
+		}
+	}
+	return kept
+}
+
+// TrimLowFrequencyEdges removes edges that have less than
+// the specified weight. Returns the number of edges removed
+func (g *Graph) TrimLowFrequencyEdges(edgeCutoff int64) int {
+	var droppedEdges int
+	for _, n := range g.Nodes {
+		for src, e := range n.In {
+			if abs64(e.Weight) < edgeCutoff {
+				delete(n.In, src)
+				delete(src.Out, n)
+				droppedEdges++
+			}
+		}
+	}
+	return droppedEdges
+}
+
+// SortNodes sorts the nodes in a graph based on a specific heuristic.
+func (g *Graph) SortNodes(cum bool, visualMode bool) {
+	// Sort nodes based on requested mode
+	switch {
+	case visualMode:
+		// Specialized sort to produce a more visually-interesting graph
+		g.Nodes.Sort(EntropyOrder)
+	case cum:
+		g.Nodes.Sort(CumNameOrder)
+	default:
+		g.Nodes.Sort(FlatNameOrder)
+	}
+}
+
+// SelectTopNodePtrs returns a set of the top maxNodes *Node in a graph.
+func (g *Graph) SelectTopNodePtrs(maxNodes int, visualMode bool) NodePtrSet {
+	set := make(NodePtrSet)
+	for _, node := range g.selectTopNodes(maxNodes, visualMode) {
+		set[node] = true
+	}
+	return set
+}
+
+// SelectTopNodes returns a set of the top maxNodes nodes in a graph.
+func (g *Graph) SelectTopNodes(maxNodes int, visualMode bool) NodeSet {
+	return makeNodeSet(g.selectTopNodes(maxNodes, visualMode), 0)
+}
+
+// selectTopNodes returns a slice of the top maxNodes nodes in a graph.
+func (g *Graph) selectTopNodes(maxNodes int, visualMode bool) Nodes {
+	if maxNodes > 0 {
+		if visualMode {
+			var count int
+			// If generating a visual graph, count tags as nodes. Update
+			// maxNodes to account for them.
+			for i, n := range g.Nodes {
+				tags := countTags(n)
+				if tags > maxNodelets {
+					tags = maxNodelets
+				}
+				if count += tags + 1; count >= maxNodes {
+					maxNodes = i + 1
+					break
+				}
+			}
+		}
+	}
+	if maxNodes > len(g.Nodes) {
+		maxNodes = len(g.Nodes)
+	}
+	return g.Nodes[:maxNodes]
+}
+
+// countTags counts the tags with flat count. This underestimates the
+// number of tags being displayed, but in practice is close enough.
+func countTags(n *Node) int {
+	count := 0
+	for _, e := range n.LabelTags {
+		if e.Flat != 0 {
+			count++
+		}
+	}
+	for _, t := range n.NumericTags {
+		for _, e := range t {
+			if e.Flat != 0 {
+				count++
+			}
+		}
+	}
+	return count
+}
+
+// RemoveRedundantEdges removes residual edges if the destination can
+// be reached through another path. This is done to simplify the graph
+// while preserving connectivity.
+func (g *Graph) RemoveRedundantEdges() {
+	// Walk the nodes and outgoing edges in reverse order to prefer
+	// removing edges with the lowest weight.
+	for i := len(g.Nodes); i > 0; i-- {
+		n := g.Nodes[i-1]
+		in := n.In.Sort()
+		for j := len(in); j > 0; j-- {
+			e := in[j-1]
+			if !e.Residual {
+				// Do not remove edges heavier than a non-residual edge, to
+				// avoid potential confusion.
+				break
+			}
+			if isRedundantEdge(e) {
+				delete(e.Src.Out, e.Dest)
+				delete(e.Dest.In, e.Src)
+			}
+		}
+	}
+}
+
+// isRedundantEdge determines if there is a path that allows e.Src
+// to reach e.Dest after removing e.
+func isRedundantEdge(e *Edge) bool {
+	src, n := e.Src, e.Dest
+	seen := map[*Node]bool{n: true}
+	queue := Nodes{n}
+	for len(queue) > 0 {
+		n := queue[0]
+		queue = queue[1:]
+		for _, ie := range n.In {
+			if e == ie || seen[ie.Src] {
+				continue
+			}
+			if ie.Src == src {
+				return true
+			}
+			seen[ie.Src] = true
+			queue = append(queue, ie.Src)
+		}
+	}
+	return false
+}
+
+// nodeSorter is a mechanism used to allow a report to be sorted
+// in different ways.
+type nodeSorter struct {
+	rs   Nodes
+	less func(l, r *Node) bool
+}
+
+func (s nodeSorter) Len() int           { return len(s.rs) }
+func (s nodeSorter) Swap(i, j int)      { s.rs[i], s.rs[j] = s.rs[j], s.rs[i] }
+func (s nodeSorter) Less(i, j int) bool { return s.less(s.rs[i], s.rs[j]) }
+
+// Sort reorders a slice of nodes based on the specified ordering
+// criteria. The result is sorted in decreasing order for (absolute)
+// numeric quantities, alphabetically for text, and increasing for
+// addresses.
+func (ns Nodes) Sort(o NodeOrder) error {
+	var s nodeSorter
+
+	switch o {
+	case FlatNameOrder:
+		s = nodeSorter{ns,
+			func(l, r *Node) bool {
+				if iv, jv := abs64(l.Flat), abs64(r.Flat); iv != jv {
+					return iv > jv
+				}
+				if iv, jv := l.Info.PrintableName(), r.Info.PrintableName(); iv != jv {
+					return iv < jv
+				}
+				if iv, jv := abs64(l.Cum), abs64(r.Cum); iv != jv {
+					return iv > jv
+				}
+				return compareNodes(l, r)
+			},
+		}
+	case FlatCumNameOrder:
+		s = nodeSorter{ns,
+			func(l, r *Node) bool {
+				if iv, jv := abs64(l.Flat), abs64(r.Flat); iv != jv {
+					return iv > jv
+				}
+				if iv, jv := abs64(l.Cum), abs64(r.Cum); iv != jv {
+					return iv > jv
+				}
+				if iv, jv := l.Info.PrintableName(), r.Info.PrintableName(); iv != jv {
+					return iv < jv
+				}
+				return compareNodes(l, r)
+			},
+		}
+	case NameOrder:
+		s = nodeSorter{ns,
+			func(l, r *Node) bool {
+				if iv, jv := l.Info.Name, r.Info.Name; iv != jv {
+					return iv < jv
+				}
+				return compareNodes(l, r)
+			},
+		}
+	case FileOrder:
+		s = nodeSorter{ns,
+			func(l, r *Node) bool {
+				if iv, jv := l.Info.File, r.Info.File; iv != jv {
+					return iv < jv
+				}
+				if iv, jv := l.Info.StartLine, r.Info.StartLine; iv != jv {
+					return iv < jv
+				}
+				return compareNodes(l, r)
+			},
+		}
+	case AddressOrder:
+		s = nodeSorter{ns,
+			func(l, r *Node) bool {
+				if iv, jv := l.Info.Address, r.Info.Address; iv != jv {
+					return iv < jv
+				}
+				return compareNodes(l, r)
+			},
+		}
+	case CumNameOrder, EntropyOrder:
+		// Hold scoring for score-based ordering
+		var score map[*Node]int64
+		scoreOrder := func(l, r *Node) bool {
+			if iv, jv := abs64(score[l]), abs64(score[r]); iv != jv {
+				return iv > jv
+			}
+			if iv, jv := l.Info.PrintableName(), r.Info.PrintableName(); iv != jv {
+				return iv < jv
+			}
+			if iv, jv := abs64(l.Flat), abs64(r.Flat); iv != jv {
+				return iv > jv
+			}
+			return compareNodes(l, r)
+		}
+
+		switch o {
+		case CumNameOrder:
+			score = make(map[*Node]int64, len(ns))
+			for _, n := range ns {
+				score[n] = n.Cum
+			}
+			s = nodeSorter{ns, scoreOrder}
+		case EntropyOrder:
+			score = make(map[*Node]int64, len(ns))
+			for _, n := range ns {
+				score[n] = entropyScore(n)
+			}
+			s = nodeSorter{ns, scoreOrder}
+		}
+	default:
+		return fmt.Errorf("report: unrecognized sort ordering: %d", o)
+	}
+	sort.Sort(s)
+	return nil
+}
+
+// compareNodes compares two nodes to provide a deterministic ordering
+// between them. Two nodes cannot have the same Node.Info value.
+func compareNodes(l, r *Node) bool {
+	return fmt.Sprint(l.Info) < fmt.Sprint(r.Info)
+}
+
+// entropyScore computes a score for a node representing how important
+// it is to include this node on a graph visualization. It is used to
+// sort the nodes and select which ones to display if we have more
+// nodes than desired in the graph. This number is computed by looking
+// at the flat and cum weights of the node and the incoming/outgoing
+// edges. The fundamental idea is to penalize nodes that have a simple
+// fallthrough from their incoming to the outgoing edge.
+func entropyScore(n *Node) int64 {
+	score := float64(0)
+
+	if len(n.In) == 0 {
+		score++ // Favor entry nodes
+	} else {
+		score += edgeEntropyScore(n, n.In, 0)
+	}
+
+	if len(n.Out) == 0 {
+		score++ // Favor leaf nodes
+	} else {
+		score += edgeEntropyScore(n, n.Out, n.Flat)
+	}
+
+	return int64(score*float64(n.Cum)) + n.Flat
+}
+
+// edgeEntropyScore computes the entropy value for a set of edges
+// coming in or out of a node. Entropy (as defined in information
+// theory) refers to the amount of information encoded by the set of
+// edges. A set of edges that have a more interesting distribution of
+// samples gets a higher score.
+func edgeEntropyScore(n *Node, edges EdgeMap, self int64) float64 {
+	score := float64(0)
+	total := self
+	for _, e := range edges {
+		if e.Weight > 0 {
+			total += abs64(e.Weight)
+		}
+	}
+	if total != 0 {
+		for _, e := range edges {
+			frac := float64(abs64(e.Weight)) / float64(total)
+			score += -frac * math.Log2(frac)
+		}
+		if self > 0 {
+			frac := float64(abs64(self)) / float64(total)
+			score += -frac * math.Log2(frac)
+		}
+	}
+	return score
+}
+
+// NodeOrder sets the ordering for a Sort operation
+type NodeOrder int
+
+// Sorting options for node sort.
+const (
+	FlatNameOrder NodeOrder = iota
+	FlatCumNameOrder
+	CumNameOrder
+	NameOrder
+	FileOrder
+	AddressOrder
+	EntropyOrder
+)
+
+// Sort returns a slice of the edges in the map, in a consistent
+// order. The sort order is first based on the edge weight
+// (higher-to-lower) and then by the node names to avoid flakiness.
+func (e EdgeMap) Sort() []*Edge {
+	el := make(edgeList, 0, len(e))
+	for _, w := range e {
+		el = append(el, w)
+	}
+
+	sort.Sort(el)
+	return el
+}
+
+// Sum returns the total weight for a set of nodes.
+func (e EdgeMap) Sum() int64 {
+	var ret int64
+	for _, edge := range e {
+		ret += edge.Weight
+	}
+	return ret
+}
+
+type edgeList []*Edge
+
+func (el edgeList) Len() int {
+	return len(el)
+}
+
+func (el edgeList) Less(i, j int) bool {
+	if el[i].Weight != el[j].Weight {
+		return abs64(el[i].Weight) > abs64(el[j].Weight)
+	}
+
+	from1 := el[i].Src.Info.PrintableName()
+	from2 := el[j].Src.Info.PrintableName()
+	if from1 != from2 {
+		return from1 < from2
+	}
+
+	to1 := el[i].Dest.Info.PrintableName()
+	to2 := el[j].Dest.Info.PrintableName()
+
+	return to1 < to2
+}
+
+func (el edgeList) Swap(i, j int) {
+	el[i], el[j] = el[j], el[i]
+}
+
+func abs64(i int64) int64 {
+	if i < 0 {
+		return -i
+	}
+	return i
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/measurement/measurement.go b/src/cmd/vendor/github.com/google/pprof/internal/measurement/measurement.go
new file mode 100644
index 0000000..e95b261
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/measurement/measurement.go
@@ -0,0 +1,328 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package measurement export utility functions to manipulate/format performance profile sample values.
+package measurement
+
+import (
+	"fmt"
+	"math"
+	"strings"
+	"time"
+
+	"github.com/google/pprof/profile"
+)
+
+// ScaleProfiles updates the units in a set of profiles to make them
+// compatible. It scales the profiles to the smallest unit to preserve
+// data.
+func ScaleProfiles(profiles []*profile.Profile) error {
+	if len(profiles) == 0 {
+		return nil
+	}
+	periodTypes := make([]*profile.ValueType, 0, len(profiles))
+	for _, p := range profiles {
+		if p.PeriodType != nil {
+			periodTypes = append(periodTypes, p.PeriodType)
+		}
+	}
+	periodType, err := CommonValueType(periodTypes)
+	if err != nil {
+		return fmt.Errorf("period type: %v", err)
+	}
+
+	// Identify common sample types
+	numSampleTypes := len(profiles[0].SampleType)
+	for _, p := range profiles[1:] {
+		if numSampleTypes != len(p.SampleType) {
+			return fmt.Errorf("inconsistent samples type count: %d != %d", numSampleTypes, len(p.SampleType))
+		}
+	}
+	sampleType := make([]*profile.ValueType, numSampleTypes)
+	for i := 0; i < numSampleTypes; i++ {
+		sampleTypes := make([]*profile.ValueType, len(profiles))
+		for j, p := range profiles {
+			sampleTypes[j] = p.SampleType[i]
+		}
+		sampleType[i], err = CommonValueType(sampleTypes)
+		if err != nil {
+			return fmt.Errorf("sample types: %v", err)
+		}
+	}
+
+	for _, p := range profiles {
+		if p.PeriodType != nil && periodType != nil {
+			period, _ := Scale(p.Period, p.PeriodType.Unit, periodType.Unit)
+			p.Period, p.PeriodType.Unit = int64(period), periodType.Unit
+		}
+		ratios := make([]float64, len(p.SampleType))
+		for i, st := range p.SampleType {
+			if sampleType[i] == nil {
+				ratios[i] = 1
+				continue
+			}
+			ratios[i], _ = Scale(1, st.Unit, sampleType[i].Unit)
+			p.SampleType[i].Unit = sampleType[i].Unit
+		}
+		if err := p.ScaleN(ratios); err != nil {
+			return fmt.Errorf("scale: %v", err)
+		}
+	}
+	return nil
+}
+
+// CommonValueType returns the finest type from a set of compatible
+// types.
+func CommonValueType(ts []*profile.ValueType) (*profile.ValueType, error) {
+	if len(ts) <= 1 {
+		return nil, nil
+	}
+	minType := ts[0]
+	for _, t := range ts[1:] {
+		if !compatibleValueTypes(minType, t) {
+			return nil, fmt.Errorf("incompatible types: %v %v", *minType, *t)
+		}
+		if ratio, _ := Scale(1, t.Unit, minType.Unit); ratio < 1 {
+			minType = t
+		}
+	}
+	rcopy := *minType
+	return &rcopy, nil
+}
+
+func compatibleValueTypes(v1, v2 *profile.ValueType) bool {
+	if v1 == nil || v2 == nil {
+		return true // No grounds to disqualify.
+	}
+	// Remove trailing 's' to permit minor mismatches.
+	if t1, t2 := strings.TrimSuffix(v1.Type, "s"), strings.TrimSuffix(v2.Type, "s"); t1 != t2 {
+		return false
+	}
+
+	return v1.Unit == v2.Unit ||
+		(isTimeUnit(v1.Unit) && isTimeUnit(v2.Unit)) ||
+		(isMemoryUnit(v1.Unit) && isMemoryUnit(v2.Unit))
+}
+
+// Scale a measurement from an unit to a different unit and returns
+// the scaled value and the target unit. The returned target unit
+// will be empty if uninteresting (could be skipped).
+func Scale(value int64, fromUnit, toUnit string) (float64, string) {
+	// Avoid infinite recursion on overflow.
+	if value < 0 && -value > 0 {
+		v, u := Scale(-value, fromUnit, toUnit)
+		return -v, u
+	}
+	if m, u, ok := memoryLabel(value, fromUnit, toUnit); ok {
+		return m, u
+	}
+	if t, u, ok := timeLabel(value, fromUnit, toUnit); ok {
+		return t, u
+	}
+	// Skip non-interesting units.
+	switch toUnit {
+	case "count", "sample", "unit", "minimum", "auto":
+		return float64(value), ""
+	default:
+		return float64(value), toUnit
+	}
+}
+
+// Label returns the label used to describe a certain measurement.
+func Label(value int64, unit string) string {
+	return ScaledLabel(value, unit, "auto")
+}
+
+// ScaledLabel scales the passed-in measurement (if necessary) and
+// returns the label used to describe a float measurement.
+func ScaledLabel(value int64, fromUnit, toUnit string) string {
+	v, u := Scale(value, fromUnit, toUnit)
+	sv := strings.TrimSuffix(fmt.Sprintf("%.2f", v), ".00")
+	if sv == "0" || sv == "-0" {
+		return "0"
+	}
+	return sv + u
+}
+
+// Percentage computes the percentage of total of a value, and encodes
+// it as a string. At least two digits of precision are printed.
+func Percentage(value, total int64) string {
+	var ratio float64
+	if total != 0 {
+		ratio = math.Abs(float64(value)/float64(total)) * 100
+	}
+	switch {
+	case math.Abs(ratio) >= 99.95 && math.Abs(ratio) <= 100.05:
+		return "  100%"
+	case math.Abs(ratio) >= 1.0:
+		return fmt.Sprintf("%5.2f%%", ratio)
+	default:
+		return fmt.Sprintf("%5.2g%%", ratio)
+	}
+}
+
+// isMemoryUnit returns whether a name is recognized as a memory size
+// unit.
+func isMemoryUnit(unit string) bool {
+	switch strings.TrimSuffix(strings.ToLower(unit), "s") {
+	case "byte", "b", "kilobyte", "kb", "megabyte", "mb", "gigabyte", "gb":
+		return true
+	}
+	return false
+}
+
+func memoryLabel(value int64, fromUnit, toUnit string) (v float64, u string, ok bool) {
+	fromUnit = strings.TrimSuffix(strings.ToLower(fromUnit), "s")
+	toUnit = strings.TrimSuffix(strings.ToLower(toUnit), "s")
+
+	switch fromUnit {
+	case "byte", "b":
+	case "kb", "kbyte", "kilobyte":
+		value *= 1024
+	case "mb", "mbyte", "megabyte":
+		value *= 1024 * 1024
+	case "gb", "gbyte", "gigabyte":
+		value *= 1024 * 1024 * 1024
+	case "tb", "tbyte", "terabyte":
+		value *= 1024 * 1024 * 1024 * 1024
+	case "pb", "pbyte", "petabyte":
+		value *= 1024 * 1024 * 1024 * 1024 * 1024
+	default:
+		return 0, "", false
+	}
+
+	if toUnit == "minimum" || toUnit == "auto" {
+		switch {
+		case value < 1024:
+			toUnit = "b"
+		case value < 1024*1024:
+			toUnit = "kb"
+		case value < 1024*1024*1024:
+			toUnit = "mb"
+		case value < 1024*1024*1024*1024:
+			toUnit = "gb"
+		case value < 1024*1024*1024*1024*1024:
+			toUnit = "tb"
+		default:
+			toUnit = "pb"
+		}
+	}
+
+	var output float64
+	switch toUnit {
+	default:
+		output, toUnit = float64(value), "B"
+	case "kb", "kbyte", "kilobyte":
+		output, toUnit = float64(value)/1024, "kB"
+	case "mb", "mbyte", "megabyte":
+		output, toUnit = float64(value)/(1024*1024), "MB"
+	case "gb", "gbyte", "gigabyte":
+		output, toUnit = float64(value)/(1024*1024*1024), "GB"
+	case "tb", "tbyte", "terabyte":
+		output, toUnit = float64(value)/(1024*1024*1024*1024), "TB"
+	case "pb", "pbyte", "petabyte":
+		output, toUnit = float64(value)/(1024*1024*1024*1024*1024), "PB"
+	}
+	return output, toUnit, true
+}
+
+// isTimeUnit returns whether a name is recognized as a time unit.
+func isTimeUnit(unit string) bool {
+	unit = strings.ToLower(unit)
+	if len(unit) > 2 {
+		unit = strings.TrimSuffix(unit, "s")
+	}
+
+	switch unit {
+	case "nanosecond", "ns", "microsecond", "millisecond", "ms", "s", "second", "sec", "hr", "day", "week", "year":
+		return true
+	}
+	return false
+}
+
+func timeLabel(value int64, fromUnit, toUnit string) (v float64, u string, ok bool) {
+	fromUnit = strings.ToLower(fromUnit)
+	if len(fromUnit) > 2 {
+		fromUnit = strings.TrimSuffix(fromUnit, "s")
+	}
+
+	toUnit = strings.ToLower(toUnit)
+	if len(toUnit) > 2 {
+		toUnit = strings.TrimSuffix(toUnit, "s")
+	}
+
+	var d time.Duration
+	switch fromUnit {
+	case "nanosecond", "ns":
+		d = time.Duration(value) * time.Nanosecond
+	case "microsecond":
+		d = time.Duration(value) * time.Microsecond
+	case "millisecond", "ms":
+		d = time.Duration(value) * time.Millisecond
+	case "second", "sec", "s":
+		d = time.Duration(value) * time.Second
+	case "cycle":
+		return float64(value), "", true
+	default:
+		return 0, "", false
+	}
+
+	if toUnit == "minimum" || toUnit == "auto" {
+		switch {
+		case d < 1*time.Microsecond:
+			toUnit = "ns"
+		case d < 1*time.Millisecond:
+			toUnit = "us"
+		case d < 1*time.Second:
+			toUnit = "ms"
+		case d < 1*time.Minute:
+			toUnit = "sec"
+		case d < 1*time.Hour:
+			toUnit = "min"
+		case d < 24*time.Hour:
+			toUnit = "hour"
+		case d < 15*24*time.Hour:
+			toUnit = "day"
+		case d < 120*24*time.Hour:
+			toUnit = "week"
+		default:
+			toUnit = "year"
+		}
+	}
+
+	var output float64
+	dd := float64(d)
+	switch toUnit {
+	case "ns", "nanosecond":
+		output, toUnit = dd/float64(time.Nanosecond), "ns"
+	case "us", "microsecond":
+		output, toUnit = dd/float64(time.Microsecond), "us"
+	case "ms", "millisecond":
+		output, toUnit = dd/float64(time.Millisecond), "ms"
+	case "min", "minute":
+		output, toUnit = dd/float64(time.Minute), "mins"
+	case "hour", "hr":
+		output, toUnit = dd/float64(time.Hour), "hrs"
+	case "day":
+		output, toUnit = dd/float64(24*time.Hour), "days"
+	case "week", "wk":
+		output, toUnit = dd/float64(7*24*time.Hour), "wks"
+	case "year", "yr":
+		output, toUnit = dd/float64(365*24*time.Hour), "yrs"
+	default:
+		// "sec", "second", "s" handled by default case.
+		output, toUnit = dd/float64(time.Second), "s"
+	}
+	return output, toUnit, true
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/plugin/plugin.go b/src/cmd/vendor/github.com/google/pprof/internal/plugin/plugin.go
new file mode 100644
index 0000000..3a8d0af
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/plugin/plugin.go
@@ -0,0 +1,213 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package plugin defines the plugin implementations that the main pprof driver requires.
+package plugin
+
+import (
+	"io"
+	"net/http"
+	"regexp"
+	"time"
+
+	"github.com/google/pprof/profile"
+)
+
+// Options groups all the optional plugins into pprof.
+type Options struct {
+	Writer  Writer
+	Flagset FlagSet
+	Fetch   Fetcher
+	Sym     Symbolizer
+	Obj     ObjTool
+	UI      UI
+
+	// HTTPServer is a function that should block serving http requests,
+	// including the handlers specified in args.  If non-nil, pprof will
+	// invoke this function if necessary to provide a web interface.
+	//
+	// If HTTPServer is nil, pprof will use its own internal HTTP server.
+	//
+	// A common use for a custom HTTPServer is to provide custom
+	// authentication checks.
+	HTTPServer    func(args *HTTPServerArgs) error
+	HTTPTransport http.RoundTripper
+}
+
+// Writer provides a mechanism to write data under a certain name,
+// typically a filename.
+type Writer interface {
+	Open(name string) (io.WriteCloser, error)
+}
+
+// A FlagSet creates and parses command-line flags.
+// It is similar to the standard flag.FlagSet.
+type FlagSet interface {
+	// Bool, Int, Float64, and String define new flags,
+	// like the functions of the same name in package flag.
+	Bool(name string, def bool, usage string) *bool
+	Int(name string, def int, usage string) *int
+	Float64(name string, def float64, usage string) *float64
+	String(name string, def string, usage string) *string
+
+	// StringList is similar to String but allows multiple values for a
+	// single flag
+	StringList(name string, def string, usage string) *[]*string
+
+	// ExtraUsage returns any additional text that should be printed after the
+	// standard usage message. The extra usage message returned includes all text
+	// added with AddExtraUsage().
+	// The typical use of ExtraUsage is to show any custom flags defined by the
+	// specific pprof plugins being used.
+	ExtraUsage() string
+
+	// AddExtraUsage appends additional text to the end of the extra usage message.
+	AddExtraUsage(eu string)
+
+	// Parse initializes the flags with their values for this run
+	// and returns the non-flag command line arguments.
+	// If an unknown flag is encountered or there are no arguments,
+	// Parse should call usage and return nil.
+	Parse(usage func()) []string
+}
+
+// A Fetcher reads and returns the profile named by src. src can be a
+// local file path or a URL. duration and timeout are units specified
+// by the end user, or 0 by default. duration refers to the length of
+// the profile collection, if applicable, and timeout is the amount of
+// time to wait for a profile before returning an error. Returns the
+// fetched profile, the URL of the actual source of the profile, or an
+// error.
+type Fetcher interface {
+	Fetch(src string, duration, timeout time.Duration) (*profile.Profile, string, error)
+}
+
+// A Symbolizer introduces symbol information into a profile.
+type Symbolizer interface {
+	Symbolize(mode string, srcs MappingSources, prof *profile.Profile) error
+}
+
+// MappingSources map each profile.Mapping to the source of the profile.
+// The key is either Mapping.File or Mapping.BuildId.
+type MappingSources map[string][]struct {
+	Source string // URL of the source the mapping was collected from
+	Start  uint64 // delta applied to addresses from this source (to represent Merge adjustments)
+}
+
+// An ObjTool inspects shared libraries and executable files.
+type ObjTool interface {
+	// Open opens the named object file. If the object is a shared
+	// library, start/limit/offset are the addresses where it is mapped
+	// into memory in the address space being inspected.
+	Open(file string, start, limit, offset uint64) (ObjFile, error)
+
+	// Disasm disassembles the named object file, starting at
+	// the start address and stopping at (before) the end address.
+	Disasm(file string, start, end uint64, intelSyntax bool) ([]Inst, error)
+}
+
+// An Inst is a single instruction in an assembly listing.
+type Inst struct {
+	Addr     uint64 // virtual address of instruction
+	Text     string // instruction text
+	Function string // function name
+	File     string // source file
+	Line     int    // source line
+}
+
+// An ObjFile is a single object file: a shared library or executable.
+type ObjFile interface {
+	// Name returns the underlyinf file name, if available
+	Name() string
+
+	// Base returns the base address to use when looking up symbols in the file.
+	Base() uint64
+
+	// BuildID returns the GNU build ID of the file, or an empty string.
+	BuildID() string
+
+	// SourceLine reports the source line information for a given
+	// address in the file. Due to inlining, the source line information
+	// is in general a list of positions representing a call stack,
+	// with the leaf function first.
+	SourceLine(addr uint64) ([]Frame, error)
+
+	// Symbols returns a list of symbols in the object file.
+	// If r is not nil, Symbols restricts the list to symbols
+	// with names matching the regular expression.
+	// If addr is not zero, Symbols restricts the list to symbols
+	// containing that address.
+	Symbols(r *regexp.Regexp, addr uint64) ([]*Sym, error)
+
+	// Close closes the file, releasing associated resources.
+	Close() error
+}
+
+// A Frame describes a single line in a source file.
+type Frame struct {
+	Func string // name of function
+	File string // source file name
+	Line int    // line in file
+}
+
+// A Sym describes a single symbol in an object file.
+type Sym struct {
+	Name  []string // names of symbol (many if symbol was dedup'ed)
+	File  string   // object file containing symbol
+	Start uint64   // start virtual address
+	End   uint64   // virtual address of last byte in sym (Start+size-1)
+}
+
+// A UI manages user interactions.
+type UI interface {
+	// Read returns a line of text (a command) read from the user.
+	// prompt is printed before reading the command.
+	ReadLine(prompt string) (string, error)
+
+	// Print shows a message to the user.
+	// It formats the text as fmt.Print would and adds a final \n if not already present.
+	// For line-based UI, Print writes to standard error.
+	// (Standard output is reserved for report data.)
+	Print(...interface{})
+
+	// PrintErr shows an error message to the user.
+	// It formats the text as fmt.Print would and adds a final \n if not already present.
+	// For line-based UI, PrintErr writes to standard error.
+	PrintErr(...interface{})
+
+	// IsTerminal returns whether the UI is known to be tied to an
+	// interactive terminal (as opposed to being redirected to a file).
+	IsTerminal() bool
+
+	// WantBrowser indicates whether a browser should be opened with the -http option.
+	WantBrowser() bool
+
+	// SetAutoComplete instructs the UI to call complete(cmd) to obtain
+	// the auto-completion of cmd, if the UI supports auto-completion at all.
+	SetAutoComplete(complete func(string) string)
+}
+
+// HTTPServerArgs contains arguments needed by an HTTP server that
+// is exporting a pprof web interface.
+type HTTPServerArgs struct {
+	// Hostport contains the http server address (derived from flags).
+	Hostport string
+
+	Host string // Host portion of Hostport
+	Port int    // Port portion of Hostport
+
+	// Handlers maps from URL paths to the handler to invoke to
+	// serve that path.
+	Handlers map[string]http.Handler
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/report/report.go b/src/cmd/vendor/github.com/google/pprof/internal/report/report.go
new file mode 100644
index 0000000..bc5685d
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/report/report.go
@@ -0,0 +1,1313 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package report summarizes a performance profile into a
+// human-readable report.
+package report
+
+import (
+	"fmt"
+	"io"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"text/tabwriter"
+	"time"
+
+	"github.com/google/pprof/internal/graph"
+	"github.com/google/pprof/internal/measurement"
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/profile"
+)
+
+// Output formats.
+const (
+	Callgrind = iota
+	Comments
+	Dis
+	Dot
+	List
+	Proto
+	Raw
+	Tags
+	Text
+	TopProto
+	Traces
+	Tree
+	WebList
+)
+
+// Options are the formatting and filtering options used to generate a
+// profile.
+type Options struct {
+	OutputFormat int
+
+	CumSort       bool
+	CallTree      bool
+	DropNegative  bool
+	CompactLabels bool
+	Ratio         float64
+	Title         string
+	ProfileLabels []string
+	ActiveFilters []string
+	NumLabelUnits map[string]string
+
+	NodeCount    int
+	NodeFraction float64
+	EdgeFraction float64
+
+	SampleValue       func(s []int64) int64
+	SampleMeanDivisor func(s []int64) int64
+	SampleType        string
+	SampleUnit        string // Unit for the sample data from the profile.
+
+	OutputUnit string // Units for data formatting in report.
+
+	Symbol     *regexp.Regexp // Symbols to include on disassembly report.
+	SourcePath string         // Search path for source files.
+	TrimPath   string         // Paths to trim from source file paths.
+
+	IntelSyntax bool // Whether or not to print assembly in Intel syntax.
+}
+
+// Generate generates a report as directed by the Report.
+func Generate(w io.Writer, rpt *Report, obj plugin.ObjTool) error {
+	o := rpt.options
+
+	switch o.OutputFormat {
+	case Comments:
+		return printComments(w, rpt)
+	case Dot:
+		return printDOT(w, rpt)
+	case Tree:
+		return printTree(w, rpt)
+	case Text:
+		return printText(w, rpt)
+	case Traces:
+		return printTraces(w, rpt)
+	case Raw:
+		fmt.Fprint(w, rpt.prof.String())
+		return nil
+	case Tags:
+		return printTags(w, rpt)
+	case Proto:
+		return printProto(w, rpt)
+	case TopProto:
+		return printTopProto(w, rpt)
+	case Dis:
+		return printAssembly(w, rpt, obj)
+	case List:
+		return printSource(w, rpt)
+	case WebList:
+		return printWebSource(w, rpt, obj)
+	case Callgrind:
+		return printCallgrind(w, rpt)
+	}
+	return fmt.Errorf("unexpected output format")
+}
+
+// newTrimmedGraph creates a graph for this report, trimmed according
+// to the report options.
+func (rpt *Report) newTrimmedGraph() (g *graph.Graph, origCount, droppedNodes, droppedEdges int) {
+	o := rpt.options
+
+	// Build a graph and refine it. On each refinement step we must rebuild the graph from the samples,
+	// as the graph itself doesn't contain enough information to preserve full precision.
+	visualMode := o.OutputFormat == Dot
+	cumSort := o.CumSort
+
+	// The call_tree option is only honored when generating visual representations of the callgraph.
+	callTree := o.CallTree && (o.OutputFormat == Dot || o.OutputFormat == Callgrind)
+
+	// First step: Build complete graph to identify low frequency nodes, based on their cum weight.
+	g = rpt.newGraph(nil)
+	totalValue, _ := g.Nodes.Sum()
+	nodeCutoff := abs64(int64(float64(totalValue) * o.NodeFraction))
+	edgeCutoff := abs64(int64(float64(totalValue) * o.EdgeFraction))
+
+	// Filter out nodes with cum value below nodeCutoff.
+	if nodeCutoff > 0 {
+		if callTree {
+			if nodesKept := g.DiscardLowFrequencyNodePtrs(nodeCutoff); len(g.Nodes) != len(nodesKept) {
+				droppedNodes = len(g.Nodes) - len(nodesKept)
+				g.TrimTree(nodesKept)
+			}
+		} else {
+			if nodesKept := g.DiscardLowFrequencyNodes(nodeCutoff); len(g.Nodes) != len(nodesKept) {
+				droppedNodes = len(g.Nodes) - len(nodesKept)
+				g = rpt.newGraph(nodesKept)
+			}
+		}
+	}
+	origCount = len(g.Nodes)
+
+	// Second step: Limit the total number of nodes. Apply specialized heuristics to improve
+	// visualization when generating dot output.
+	g.SortNodes(cumSort, visualMode)
+	if nodeCount := o.NodeCount; nodeCount > 0 {
+		// Remove low frequency tags and edges as they affect selection.
+		g.TrimLowFrequencyTags(nodeCutoff)
+		g.TrimLowFrequencyEdges(edgeCutoff)
+		if callTree {
+			if nodesKept := g.SelectTopNodePtrs(nodeCount, visualMode); len(g.Nodes) != len(nodesKept) {
+				g.TrimTree(nodesKept)
+				g.SortNodes(cumSort, visualMode)
+			}
+		} else {
+			if nodesKept := g.SelectTopNodes(nodeCount, visualMode); len(g.Nodes) != len(nodesKept) {
+				g = rpt.newGraph(nodesKept)
+				g.SortNodes(cumSort, visualMode)
+			}
+		}
+	}
+
+	// Final step: Filter out low frequency tags and edges, and remove redundant edges that clutter
+	// the graph.
+	g.TrimLowFrequencyTags(nodeCutoff)
+	droppedEdges = g.TrimLowFrequencyEdges(edgeCutoff)
+	if visualMode {
+		g.RemoveRedundantEdges()
+	}
+	return
+}
+
+func (rpt *Report) selectOutputUnit(g *graph.Graph) {
+	o := rpt.options
+
+	// Select best unit for profile output.
+	// Find the appropriate units for the smallest non-zero sample
+	if o.OutputUnit != "minimum" || len(g.Nodes) == 0 {
+		return
+	}
+	var minValue int64
+
+	for _, n := range g.Nodes {
+		nodeMin := abs64(n.FlatValue())
+		if nodeMin == 0 {
+			nodeMin = abs64(n.CumValue())
+		}
+		if nodeMin > 0 && (minValue == 0 || nodeMin < minValue) {
+			minValue = nodeMin
+		}
+	}
+	maxValue := rpt.total
+	if minValue == 0 {
+		minValue = maxValue
+	}
+
+	if r := o.Ratio; r > 0 && r != 1 {
+		minValue = int64(float64(minValue) * r)
+		maxValue = int64(float64(maxValue) * r)
+	}
+
+	_, minUnit := measurement.Scale(minValue, o.SampleUnit, "minimum")
+	_, maxUnit := measurement.Scale(maxValue, o.SampleUnit, "minimum")
+
+	unit := minUnit
+	if minUnit != maxUnit && minValue*100 < maxValue && o.OutputFormat != Callgrind {
+		// Minimum and maximum values have different units. Scale
+		// minimum by 100 to use larger units, allowing minimum value to
+		// be scaled down to 0.01, except for callgrind reports since
+		// they can only represent integer values.
+		_, unit = measurement.Scale(100*minValue, o.SampleUnit, "minimum")
+	}
+
+	if unit != "" {
+		o.OutputUnit = unit
+	} else {
+		o.OutputUnit = o.SampleUnit
+	}
+}
+
+// newGraph creates a new graph for this report. If nodes is non-nil,
+// only nodes whose info matches are included. Otherwise, all nodes
+// are included, without trimming.
+func (rpt *Report) newGraph(nodes graph.NodeSet) *graph.Graph {
+	o := rpt.options
+
+	// Clean up file paths using heuristics.
+	prof := rpt.prof
+	for _, f := range prof.Function {
+		f.Filename = trimPath(f.Filename, o.TrimPath, o.SourcePath)
+	}
+	// Removes all numeric tags except for the bytes tag prior
+	// to making graph.
+	// TODO: modify to select first numeric tag if no bytes tag
+	for _, s := range prof.Sample {
+		numLabels := make(map[string][]int64, len(s.NumLabel))
+		numUnits := make(map[string][]string, len(s.NumLabel))
+		for k, vs := range s.NumLabel {
+			if k == "bytes" {
+				unit := o.NumLabelUnits[k]
+				numValues := make([]int64, len(vs))
+				numUnit := make([]string, len(vs))
+				for i, v := range vs {
+					numValues[i] = v
+					numUnit[i] = unit
+				}
+				numLabels[k] = append(numLabels[k], numValues...)
+				numUnits[k] = append(numUnits[k], numUnit...)
+			}
+		}
+		s.NumLabel = numLabels
+		s.NumUnit = numUnits
+	}
+
+	// Remove label marking samples from the base profiles, so it does not appear
+	// as a nodelet in the graph view.
+	prof.RemoveLabel("pprof::base")
+
+	formatTag := func(v int64, key string) string {
+		return measurement.ScaledLabel(v, key, o.OutputUnit)
+	}
+
+	gopt := &graph.Options{
+		SampleValue:       o.SampleValue,
+		SampleMeanDivisor: o.SampleMeanDivisor,
+		FormatTag:         formatTag,
+		CallTree:          o.CallTree && (o.OutputFormat == Dot || o.OutputFormat == Callgrind),
+		DropNegative:      o.DropNegative,
+		KeptNodes:         nodes,
+	}
+
+	// Only keep binary names for disassembly-based reports, otherwise
+	// remove it to allow merging of functions across binaries.
+	switch o.OutputFormat {
+	case Raw, List, WebList, Dis, Callgrind:
+		gopt.ObjNames = true
+	}
+
+	return graph.New(rpt.prof, gopt)
+}
+
+// printProto writes the incoming proto via thw writer w.
+// If the divide_by option has been specified, samples are scaled appropriately.
+func printProto(w io.Writer, rpt *Report) error {
+	p, o := rpt.prof, rpt.options
+
+	// Apply the sample ratio to all samples before saving the profile.
+	if r := o.Ratio; r > 0 && r != 1 {
+		for _, sample := range p.Sample {
+			for i, v := range sample.Value {
+				sample.Value[i] = int64(float64(v) * r)
+			}
+		}
+	}
+	return p.Write(w)
+}
+
+// printTopProto writes a list of the hottest routines in a profile as a profile.proto.
+func printTopProto(w io.Writer, rpt *Report) error {
+	p := rpt.prof
+	o := rpt.options
+	g, _, _, _ := rpt.newTrimmedGraph()
+	rpt.selectOutputUnit(g)
+
+	out := profile.Profile{
+		SampleType: []*profile.ValueType{
+			{Type: "cum", Unit: o.OutputUnit},
+			{Type: "flat", Unit: o.OutputUnit},
+		},
+		TimeNanos:     p.TimeNanos,
+		DurationNanos: p.DurationNanos,
+		PeriodType:    p.PeriodType,
+		Period:        p.Period,
+	}
+	functionMap := make(functionMap)
+	for i, n := range g.Nodes {
+		f, added := functionMap.findOrAdd(n.Info)
+		if added {
+			out.Function = append(out.Function, f)
+		}
+		flat, cum := n.FlatValue(), n.CumValue()
+		l := &profile.Location{
+			ID:      uint64(i + 1),
+			Address: n.Info.Address,
+			Line: []profile.Line{
+				{
+					Line:     int64(n.Info.Lineno),
+					Function: f,
+				},
+			},
+		}
+
+		fv, _ := measurement.Scale(flat, o.SampleUnit, o.OutputUnit)
+		cv, _ := measurement.Scale(cum, o.SampleUnit, o.OutputUnit)
+		s := &profile.Sample{
+			Location: []*profile.Location{l},
+			Value:    []int64{int64(cv), int64(fv)},
+		}
+		out.Location = append(out.Location, l)
+		out.Sample = append(out.Sample, s)
+	}
+
+	return out.Write(w)
+}
+
+type functionMap map[string]*profile.Function
+
+// findOrAdd takes a node representing a function, adds the function
+// represented by the node to the map if the function is not already present,
+// and returns the function the node represents. This also returns a boolean,
+// which is true if the function was added and false otherwise.
+func (fm functionMap) findOrAdd(ni graph.NodeInfo) (*profile.Function, bool) {
+	fName := fmt.Sprintf("%q%q%q%d", ni.Name, ni.OrigName, ni.File, ni.StartLine)
+
+	if f := fm[fName]; f != nil {
+		return f, false
+	}
+
+	f := &profile.Function{
+		ID:         uint64(len(fm) + 1),
+		Name:       ni.Name,
+		SystemName: ni.OrigName,
+		Filename:   ni.File,
+		StartLine:  int64(ni.StartLine),
+	}
+	fm[fName] = f
+	return f, true
+}
+
+// printAssembly prints an annotated assembly listing.
+func printAssembly(w io.Writer, rpt *Report, obj plugin.ObjTool) error {
+	return PrintAssembly(w, rpt, obj, -1)
+}
+
+// PrintAssembly prints annotated disassembly of rpt to w.
+func PrintAssembly(w io.Writer, rpt *Report, obj plugin.ObjTool, maxFuncs int) error {
+	o := rpt.options
+	prof := rpt.prof
+
+	g := rpt.newGraph(nil)
+
+	// If the regexp source can be parsed as an address, also match
+	// functions that land on that address.
+	var address *uint64
+	if hex, err := strconv.ParseUint(o.Symbol.String(), 0, 64); err == nil {
+		address = &hex
+	}
+
+	fmt.Fprintln(w, "Total:", rpt.formatValue(rpt.total))
+	symbols := symbolsFromBinaries(prof, g, o.Symbol, address, obj)
+	symNodes := nodesPerSymbol(g.Nodes, symbols)
+
+	// Sort for printing.
+	var syms []*objSymbol
+	for s := range symNodes {
+		syms = append(syms, s)
+	}
+	byName := func(a, b *objSymbol) bool {
+		if na, nb := a.sym.Name[0], b.sym.Name[0]; na != nb {
+			return na < nb
+		}
+		return a.sym.Start < b.sym.Start
+	}
+	if maxFuncs < 0 {
+		sort.Sort(orderSyms{syms, byName})
+	} else {
+		byFlatSum := func(a, b *objSymbol) bool {
+			suma, _ := symNodes[a].Sum()
+			sumb, _ := symNodes[b].Sum()
+			if suma != sumb {
+				return suma > sumb
+			}
+			return byName(a, b)
+		}
+		sort.Sort(orderSyms{syms, byFlatSum})
+		if len(syms) > maxFuncs {
+			syms = syms[:maxFuncs]
+		}
+	}
+
+	// Correlate the symbols from the binary with the profile samples.
+	for _, s := range syms {
+		sns := symNodes[s]
+
+		// Gather samples for this symbol.
+		flatSum, cumSum := sns.Sum()
+
+		// Get the function assembly.
+		insts, err := obj.Disasm(s.sym.File, s.sym.Start, s.sym.End, o.IntelSyntax)
+		if err != nil {
+			return err
+		}
+
+		ns := annotateAssembly(insts, sns, s.base)
+
+		fmt.Fprintf(w, "ROUTINE ======================== %s\n", s.sym.Name[0])
+		for _, name := range s.sym.Name[1:] {
+			fmt.Fprintf(w, "    AKA ======================== %s\n", name)
+		}
+		fmt.Fprintf(w, "%10s %10s (flat, cum) %s of Total\n",
+			rpt.formatValue(flatSum), rpt.formatValue(cumSum),
+			measurement.Percentage(cumSum, rpt.total))
+
+		function, file, line := "", "", 0
+		for _, n := range ns {
+			locStr := ""
+			// Skip loc information if it hasn't changed from previous instruction.
+			if n.function != function || n.file != file || n.line != line {
+				function, file, line = n.function, n.file, n.line
+				if n.function != "" {
+					locStr = n.function + " "
+				}
+				if n.file != "" {
+					locStr += n.file
+					if n.line != 0 {
+						locStr += fmt.Sprintf(":%d", n.line)
+					}
+				}
+			}
+			switch {
+			case locStr == "":
+				// No location info, just print the instruction.
+				fmt.Fprintf(w, "%10s %10s %10x: %s\n",
+					valueOrDot(n.flatValue(), rpt),
+					valueOrDot(n.cumValue(), rpt),
+					n.address, n.instruction,
+				)
+			case len(n.instruction) < 40:
+				// Short instruction, print loc on the same line.
+				fmt.Fprintf(w, "%10s %10s %10x: %-40s;%s\n",
+					valueOrDot(n.flatValue(), rpt),
+					valueOrDot(n.cumValue(), rpt),
+					n.address, n.instruction,
+					locStr,
+				)
+			default:
+				// Long instruction, print loc on a separate line.
+				fmt.Fprintf(w, "%74s;%s\n", "", locStr)
+				fmt.Fprintf(w, "%10s %10s %10x: %s\n",
+					valueOrDot(n.flatValue(), rpt),
+					valueOrDot(n.cumValue(), rpt),
+					n.address, n.instruction,
+				)
+			}
+		}
+	}
+	return nil
+}
+
+// symbolsFromBinaries examines the binaries listed on the profile
+// that have associated samples, and identifies symbols matching rx.
+func symbolsFromBinaries(prof *profile.Profile, g *graph.Graph, rx *regexp.Regexp, address *uint64, obj plugin.ObjTool) []*objSymbol {
+	hasSamples := make(map[string]bool)
+	// Only examine mappings that have samples that match the
+	// regexp. This is an optimization to speed up pprof.
+	for _, n := range g.Nodes {
+		if name := n.Info.PrintableName(); rx.MatchString(name) && n.Info.Objfile != "" {
+			hasSamples[n.Info.Objfile] = true
+		}
+	}
+
+	// Walk all mappings looking for matching functions with samples.
+	var objSyms []*objSymbol
+	for _, m := range prof.Mapping {
+		if !hasSamples[m.File] {
+			if address == nil || !(m.Start <= *address && *address <= m.Limit) {
+				continue
+			}
+		}
+
+		f, err := obj.Open(m.File, m.Start, m.Limit, m.Offset)
+		if err != nil {
+			fmt.Printf("%v\n", err)
+			continue
+		}
+
+		// Find symbols in this binary matching the user regexp.
+		var addr uint64
+		if address != nil {
+			addr = *address
+		}
+		msyms, err := f.Symbols(rx, addr)
+		base := f.Base()
+		f.Close()
+		if err != nil {
+			continue
+		}
+		for _, ms := range msyms {
+			objSyms = append(objSyms,
+				&objSymbol{
+					sym:  ms,
+					base: base,
+					file: f,
+				},
+			)
+		}
+	}
+
+	return objSyms
+}
+
+// objSym represents a symbol identified from a binary. It includes
+// the SymbolInfo from the disasm package and the base that must be
+// added to correspond to sample addresses
+type objSymbol struct {
+	sym  *plugin.Sym
+	base uint64
+	file plugin.ObjFile
+}
+
+// orderSyms is a wrapper type to sort []*objSymbol by a supplied comparator.
+type orderSyms struct {
+	v    []*objSymbol
+	less func(a, b *objSymbol) bool
+}
+
+func (o orderSyms) Len() int           { return len(o.v) }
+func (o orderSyms) Less(i, j int) bool { return o.less(o.v[i], o.v[j]) }
+func (o orderSyms) Swap(i, j int)      { o.v[i], o.v[j] = o.v[j], o.v[i] }
+
+// nodesPerSymbol classifies nodes into a group of symbols.
+func nodesPerSymbol(ns graph.Nodes, symbols []*objSymbol) map[*objSymbol]graph.Nodes {
+	symNodes := make(map[*objSymbol]graph.Nodes)
+	for _, s := range symbols {
+		// Gather samples for this symbol.
+		for _, n := range ns {
+			address := n.Info.Address - s.base
+			if address >= s.sym.Start && address < s.sym.End {
+				symNodes[s] = append(symNodes[s], n)
+			}
+		}
+	}
+	return symNodes
+}
+
+type assemblyInstruction struct {
+	address         uint64
+	instruction     string
+	function        string
+	file            string
+	line            int
+	flat, cum       int64
+	flatDiv, cumDiv int64
+	startsBlock     bool
+	inlineCalls     []callID
+}
+
+type callID struct {
+	file string
+	line int
+}
+
+func (a *assemblyInstruction) flatValue() int64 {
+	if a.flatDiv != 0 {
+		return a.flat / a.flatDiv
+	}
+	return a.flat
+}
+
+func (a *assemblyInstruction) cumValue() int64 {
+	if a.cumDiv != 0 {
+		return a.cum / a.cumDiv
+	}
+	return a.cum
+}
+
+// annotateAssembly annotates a set of assembly instructions with a
+// set of samples. It returns a set of nodes to display. base is an
+// offset to adjust the sample addresses.
+func annotateAssembly(insts []plugin.Inst, samples graph.Nodes, base uint64) []assemblyInstruction {
+	// Add end marker to simplify printing loop.
+	insts = append(insts, plugin.Inst{
+		Addr: ^uint64(0),
+	})
+
+	// Ensure samples are sorted by address.
+	samples.Sort(graph.AddressOrder)
+
+	s := 0
+	asm := make([]assemblyInstruction, 0, len(insts))
+	for ix, in := range insts[:len(insts)-1] {
+		n := assemblyInstruction{
+			address:     in.Addr,
+			instruction: in.Text,
+			function:    in.Function,
+			line:        in.Line,
+		}
+		if in.File != "" {
+			n.file = filepath.Base(in.File)
+		}
+
+		// Sum all the samples until the next instruction (to account
+		// for samples attributed to the middle of an instruction).
+		for next := insts[ix+1].Addr; s < len(samples) && samples[s].Info.Address-base < next; s++ {
+			sample := samples[s]
+			n.flatDiv += sample.FlatDiv
+			n.flat += sample.Flat
+			n.cumDiv += sample.CumDiv
+			n.cum += sample.Cum
+			if f := sample.Info.File; f != "" && n.file == "" {
+				n.file = filepath.Base(f)
+			}
+			if ln := sample.Info.Lineno; ln != 0 && n.line == 0 {
+				n.line = ln
+			}
+			if f := sample.Info.Name; f != "" && n.function == "" {
+				n.function = f
+			}
+		}
+		asm = append(asm, n)
+	}
+
+	return asm
+}
+
+// valueOrDot formats a value according to a report, intercepting zero
+// values.
+func valueOrDot(value int64, rpt *Report) string {
+	if value == 0 {
+		return "."
+	}
+	return rpt.formatValue(value)
+}
+
+// printTags collects all tags referenced in the profile and prints
+// them in a sorted table.
+func printTags(w io.Writer, rpt *Report) error {
+	p := rpt.prof
+
+	o := rpt.options
+	formatTag := func(v int64, key string) string {
+		return measurement.ScaledLabel(v, key, o.OutputUnit)
+	}
+
+	// Hashtable to keep accumulate tags as key,value,count.
+	tagMap := make(map[string]map[string]int64)
+	for _, s := range p.Sample {
+		for key, vals := range s.Label {
+			for _, val := range vals {
+				valueMap, ok := tagMap[key]
+				if !ok {
+					valueMap = make(map[string]int64)
+					tagMap[key] = valueMap
+				}
+				valueMap[val] += o.SampleValue(s.Value)
+			}
+		}
+		for key, vals := range s.NumLabel {
+			unit := o.NumLabelUnits[key]
+			for _, nval := range vals {
+				val := formatTag(nval, unit)
+				valueMap, ok := tagMap[key]
+				if !ok {
+					valueMap = make(map[string]int64)
+					tagMap[key] = valueMap
+				}
+				valueMap[val] += o.SampleValue(s.Value)
+			}
+		}
+	}
+
+	tagKeys := make([]*graph.Tag, 0, len(tagMap))
+	for key := range tagMap {
+		tagKeys = append(tagKeys, &graph.Tag{Name: key})
+	}
+	tabw := tabwriter.NewWriter(w, 0, 0, 1, ' ', tabwriter.AlignRight)
+	for _, tagKey := range graph.SortTags(tagKeys, true) {
+		var total int64
+		key := tagKey.Name
+		tags := make([]*graph.Tag, 0, len(tagMap[key]))
+		for t, c := range tagMap[key] {
+			total += c
+			tags = append(tags, &graph.Tag{Name: t, Flat: c})
+		}
+
+		f, u := measurement.Scale(total, o.SampleUnit, o.OutputUnit)
+		fmt.Fprintf(tabw, "%s:\t Total %.1f%s\n", key, f, u)
+		for _, t := range graph.SortTags(tags, true) {
+			f, u := measurement.Scale(t.FlatValue(), o.SampleUnit, o.OutputUnit)
+			if total > 0 {
+				fmt.Fprintf(tabw, " \t%.1f%s (%s):\t %s\n", f, u, measurement.Percentage(t.FlatValue(), total), t.Name)
+			} else {
+				fmt.Fprintf(tabw, " \t%.1f%s:\t %s\n", f, u, t.Name)
+			}
+		}
+		fmt.Fprintln(tabw)
+	}
+	return tabw.Flush()
+}
+
+// printComments prints all freeform comments in the profile.
+func printComments(w io.Writer, rpt *Report) error {
+	p := rpt.prof
+
+	for _, c := range p.Comments {
+		fmt.Fprintln(w, c)
+	}
+	return nil
+}
+
+// TextItem holds a single text report entry.
+type TextItem struct {
+	Name                  string
+	InlineLabel           string // Not empty if inlined
+	Flat, Cum             int64  // Raw values
+	FlatFormat, CumFormat string // Formatted values
+}
+
+// TextItems returns a list of text items from the report and a list
+// of labels that describe the report.
+func TextItems(rpt *Report) ([]TextItem, []string) {
+	g, origCount, droppedNodes, _ := rpt.newTrimmedGraph()
+	rpt.selectOutputUnit(g)
+	labels := reportLabels(rpt, g, origCount, droppedNodes, 0, false)
+
+	var items []TextItem
+	var flatSum int64
+	for _, n := range g.Nodes {
+		name, flat, cum := n.Info.PrintableName(), n.FlatValue(), n.CumValue()
+
+		var inline, noinline bool
+		for _, e := range n.In {
+			if e.Inline {
+				inline = true
+			} else {
+				noinline = true
+			}
+		}
+
+		var inl string
+		if inline {
+			if noinline {
+				inl = "(partial-inline)"
+			} else {
+				inl = "(inline)"
+			}
+		}
+
+		flatSum += flat
+		items = append(items, TextItem{
+			Name:        name,
+			InlineLabel: inl,
+			Flat:        flat,
+			Cum:         cum,
+			FlatFormat:  rpt.formatValue(flat),
+			CumFormat:   rpt.formatValue(cum),
+		})
+	}
+	return items, labels
+}
+
+// printText prints a flat text report for a profile.
+func printText(w io.Writer, rpt *Report) error {
+	items, labels := TextItems(rpt)
+	fmt.Fprintln(w, strings.Join(labels, "\n"))
+	fmt.Fprintf(w, "%10s %5s%% %5s%% %10s %5s%%\n",
+		"flat", "flat", "sum", "cum", "cum")
+	var flatSum int64
+	for _, item := range items {
+		inl := item.InlineLabel
+		if inl != "" {
+			inl = " " + inl
+		}
+		flatSum += item.Flat
+		fmt.Fprintf(w, "%10s %s %s %10s %s  %s%s\n",
+			item.FlatFormat, measurement.Percentage(item.Flat, rpt.total),
+			measurement.Percentage(flatSum, rpt.total),
+			item.CumFormat, measurement.Percentage(item.Cum, rpt.total),
+			item.Name, inl)
+	}
+	return nil
+}
+
+// printTraces prints all traces from a profile.
+func printTraces(w io.Writer, rpt *Report) error {
+	fmt.Fprintln(w, strings.Join(ProfileLabels(rpt), "\n"))
+
+	prof := rpt.prof
+	o := rpt.options
+
+	const separator = "-----------+-------------------------------------------------------"
+
+	_, locations := graph.CreateNodes(prof, &graph.Options{})
+	for _, sample := range prof.Sample {
+		type stk struct {
+			*graph.NodeInfo
+			inline bool
+		}
+		var stack []stk
+		for _, loc := range sample.Location {
+			nodes := locations[loc.ID]
+			for i, n := range nodes {
+				// The inline flag may be inaccurate if 'show' or 'hide' filter is
+				// used. See https://github.com/google/pprof/issues/511.
+				inline := i != len(nodes)-1
+				stack = append(stack, stk{&n.Info, inline})
+			}
+		}
+
+		if len(stack) == 0 {
+			continue
+		}
+
+		fmt.Fprintln(w, separator)
+		// Print any text labels for the sample.
+		var labels []string
+		for s, vs := range sample.Label {
+			labels = append(labels, fmt.Sprintf("%10s:  %s\n", s, strings.Join(vs, " ")))
+		}
+		sort.Strings(labels)
+		fmt.Fprint(w, strings.Join(labels, ""))
+
+		// Print any numeric labels for the sample
+		var numLabels []string
+		for key, vals := range sample.NumLabel {
+			unit := o.NumLabelUnits[key]
+			numValues := make([]string, len(vals))
+			for i, vv := range vals {
+				numValues[i] = measurement.Label(vv, unit)
+			}
+			numLabels = append(numLabels, fmt.Sprintf("%10s:  %s\n", key, strings.Join(numValues, " ")))
+		}
+		sort.Strings(numLabels)
+		fmt.Fprint(w, strings.Join(numLabels, ""))
+
+		var d, v int64
+		v = o.SampleValue(sample.Value)
+		if o.SampleMeanDivisor != nil {
+			d = o.SampleMeanDivisor(sample.Value)
+		}
+		// Print call stack.
+		if d != 0 {
+			v = v / d
+		}
+		for i, s := range stack {
+			var vs, inline string
+			if i == 0 {
+				vs = rpt.formatValue(v)
+			}
+			if s.inline {
+				inline = " (inline)"
+			}
+			fmt.Fprintf(w, "%10s   %s%s\n", vs, s.PrintableName(), inline)
+		}
+	}
+	fmt.Fprintln(w, separator)
+	return nil
+}
+
+// printCallgrind prints a graph for a profile on callgrind format.
+func printCallgrind(w io.Writer, rpt *Report) error {
+	o := rpt.options
+	rpt.options.NodeFraction = 0
+	rpt.options.EdgeFraction = 0
+	rpt.options.NodeCount = 0
+
+	g, _, _, _ := rpt.newTrimmedGraph()
+	rpt.selectOutputUnit(g)
+
+	nodeNames := getDisambiguatedNames(g)
+
+	fmt.Fprintln(w, "positions: instr line")
+	fmt.Fprintln(w, "events:", o.SampleType+"("+o.OutputUnit+")")
+
+	objfiles := make(map[string]int)
+	files := make(map[string]int)
+	names := make(map[string]int)
+
+	// prevInfo points to the previous NodeInfo.
+	// It is used to group cost lines together as much as possible.
+	var prevInfo *graph.NodeInfo
+	for _, n := range g.Nodes {
+		if prevInfo == nil || n.Info.Objfile != prevInfo.Objfile || n.Info.File != prevInfo.File || n.Info.Name != prevInfo.Name {
+			fmt.Fprintln(w)
+			fmt.Fprintln(w, "ob="+callgrindName(objfiles, n.Info.Objfile))
+			fmt.Fprintln(w, "fl="+callgrindName(files, n.Info.File))
+			fmt.Fprintln(w, "fn="+callgrindName(names, n.Info.Name))
+		}
+
+		addr := callgrindAddress(prevInfo, n.Info.Address)
+		sv, _ := measurement.Scale(n.FlatValue(), o.SampleUnit, o.OutputUnit)
+		fmt.Fprintf(w, "%s %d %d\n", addr, n.Info.Lineno, int64(sv))
+
+		// Print outgoing edges.
+		for _, out := range n.Out.Sort() {
+			c, _ := measurement.Scale(out.Weight, o.SampleUnit, o.OutputUnit)
+			callee := out.Dest
+			fmt.Fprintln(w, "cfl="+callgrindName(files, callee.Info.File))
+			fmt.Fprintln(w, "cfn="+callgrindName(names, nodeNames[callee]))
+			// pprof doesn't have a flat weight for a call, leave as 0.
+			fmt.Fprintf(w, "calls=0 %s %d\n", callgrindAddress(prevInfo, callee.Info.Address), callee.Info.Lineno)
+			// TODO: This address may be in the middle of a call
+			// instruction. It would be best to find the beginning
+			// of the instruction, but the tools seem to handle
+			// this OK.
+			fmt.Fprintf(w, "* * %d\n", int64(c))
+		}
+
+		prevInfo = &n.Info
+	}
+
+	return nil
+}
+
+// getDisambiguatedNames returns a map from each node in the graph to
+// the name to use in the callgrind output. Callgrind merges all
+// functions with the same [file name, function name]. Add a [%d/n]
+// suffix to disambiguate nodes with different values of
+// node.Function, which we want to keep separate. In particular, this
+// affects graphs created with --call_tree, where nodes from different
+// contexts are associated to different Functions.
+func getDisambiguatedNames(g *graph.Graph) map[*graph.Node]string {
+	nodeName := make(map[*graph.Node]string, len(g.Nodes))
+
+	type names struct {
+		file, function string
+	}
+
+	// nameFunctionIndex maps the callgrind names (filename, function)
+	// to the node.Function values found for that name, and each
+	// node.Function value to a sequential index to be used on the
+	// disambiguated name.
+	nameFunctionIndex := make(map[names]map[*graph.Node]int)
+	for _, n := range g.Nodes {
+		nm := names{n.Info.File, n.Info.Name}
+		p, ok := nameFunctionIndex[nm]
+		if !ok {
+			p = make(map[*graph.Node]int)
+			nameFunctionIndex[nm] = p
+		}
+		if _, ok := p[n.Function]; !ok {
+			p[n.Function] = len(p)
+		}
+	}
+
+	for _, n := range g.Nodes {
+		nm := names{n.Info.File, n.Info.Name}
+		nodeName[n] = n.Info.Name
+		if p := nameFunctionIndex[nm]; len(p) > 1 {
+			// If there is more than one function, add suffix to disambiguate.
+			nodeName[n] += fmt.Sprintf(" [%d/%d]", p[n.Function]+1, len(p))
+		}
+	}
+	return nodeName
+}
+
+// callgrindName implements the callgrind naming compression scheme.
+// For names not previously seen returns "(N) name", where N is a
+// unique index. For names previously seen returns "(N)" where N is
+// the index returned the first time.
+func callgrindName(names map[string]int, name string) string {
+	if name == "" {
+		return ""
+	}
+	if id, ok := names[name]; ok {
+		return fmt.Sprintf("(%d)", id)
+	}
+	id := len(names) + 1
+	names[name] = id
+	return fmt.Sprintf("(%d) %s", id, name)
+}
+
+// callgrindAddress implements the callgrind subposition compression scheme if
+// possible. If prevInfo != nil, it contains the previous address. The current
+// address can be given relative to the previous address, with an explicit +/-
+// to indicate it is relative, or * for the same address.
+func callgrindAddress(prevInfo *graph.NodeInfo, curr uint64) string {
+	abs := fmt.Sprintf("%#x", curr)
+	if prevInfo == nil {
+		return abs
+	}
+
+	prev := prevInfo.Address
+	if prev == curr {
+		return "*"
+	}
+
+	diff := int64(curr - prev)
+	relative := fmt.Sprintf("%+d", diff)
+
+	// Only bother to use the relative address if it is actually shorter.
+	if len(relative) < len(abs) {
+		return relative
+	}
+
+	return abs
+}
+
+// printTree prints a tree-based report in text form.
+func printTree(w io.Writer, rpt *Report) error {
+	const separator = "----------------------------------------------------------+-------------"
+	const legend = "      flat  flat%   sum%        cum   cum%   calls calls% + context 	 	 "
+
+	g, origCount, droppedNodes, _ := rpt.newTrimmedGraph()
+	rpt.selectOutputUnit(g)
+
+	fmt.Fprintln(w, strings.Join(reportLabels(rpt, g, origCount, droppedNodes, 0, false), "\n"))
+
+	fmt.Fprintln(w, separator)
+	fmt.Fprintln(w, legend)
+	var flatSum int64
+
+	rx := rpt.options.Symbol
+	for _, n := range g.Nodes {
+		name, flat, cum := n.Info.PrintableName(), n.FlatValue(), n.CumValue()
+
+		// Skip any entries that do not match the regexp (for the "peek" command).
+		if rx != nil && !rx.MatchString(name) {
+			continue
+		}
+
+		fmt.Fprintln(w, separator)
+		// Print incoming edges.
+		inEdges := n.In.Sort()
+		for _, in := range inEdges {
+			var inline string
+			if in.Inline {
+				inline = " (inline)"
+			}
+			fmt.Fprintf(w, "%50s %s |   %s%s\n", rpt.formatValue(in.Weight),
+				measurement.Percentage(in.Weight, cum), in.Src.Info.PrintableName(), inline)
+		}
+
+		// Print current node.
+		flatSum += flat
+		fmt.Fprintf(w, "%10s %s %s %10s %s                | %s\n",
+			rpt.formatValue(flat),
+			measurement.Percentage(flat, rpt.total),
+			measurement.Percentage(flatSum, rpt.total),
+			rpt.formatValue(cum),
+			measurement.Percentage(cum, rpt.total),
+			name)
+
+		// Print outgoing edges.
+		outEdges := n.Out.Sort()
+		for _, out := range outEdges {
+			var inline string
+			if out.Inline {
+				inline = " (inline)"
+			}
+			fmt.Fprintf(w, "%50s %s |   %s%s\n", rpt.formatValue(out.Weight),
+				measurement.Percentage(out.Weight, cum), out.Dest.Info.PrintableName(), inline)
+		}
+	}
+	if len(g.Nodes) > 0 {
+		fmt.Fprintln(w, separator)
+	}
+	return nil
+}
+
+// GetDOT returns a graph suitable for dot processing along with some
+// configuration information.
+func GetDOT(rpt *Report) (*graph.Graph, *graph.DotConfig) {
+	g, origCount, droppedNodes, droppedEdges := rpt.newTrimmedGraph()
+	rpt.selectOutputUnit(g)
+	labels := reportLabels(rpt, g, origCount, droppedNodes, droppedEdges, true)
+
+	c := &graph.DotConfig{
+		Title:       rpt.options.Title,
+		Labels:      labels,
+		FormatValue: rpt.formatValue,
+		Total:       rpt.total,
+	}
+	return g, c
+}
+
+// printDOT prints an annotated callgraph in DOT format.
+func printDOT(w io.Writer, rpt *Report) error {
+	g, c := GetDOT(rpt)
+	graph.ComposeDot(w, g, &graph.DotAttributes{}, c)
+	return nil
+}
+
+// ProfileLabels returns printable labels for a profile.
+func ProfileLabels(rpt *Report) []string {
+	label := []string{}
+	prof := rpt.prof
+	o := rpt.options
+	if len(prof.Mapping) > 0 {
+		if prof.Mapping[0].File != "" {
+			label = append(label, "File: "+filepath.Base(prof.Mapping[0].File))
+		}
+		if prof.Mapping[0].BuildID != "" {
+			label = append(label, "Build ID: "+prof.Mapping[0].BuildID)
+		}
+	}
+	// Only include comments that do not start with '#'.
+	for _, c := range prof.Comments {
+		if !strings.HasPrefix(c, "#") {
+			label = append(label, c)
+		}
+	}
+	if o.SampleType != "" {
+		label = append(label, "Type: "+o.SampleType)
+	}
+	if prof.TimeNanos != 0 {
+		const layout = "Jan 2, 2006 at 3:04pm (MST)"
+		label = append(label, "Time: "+time.Unix(0, prof.TimeNanos).Format(layout))
+	}
+	if prof.DurationNanos != 0 {
+		duration := measurement.Label(prof.DurationNanos, "nanoseconds")
+		totalNanos, totalUnit := measurement.Scale(rpt.total, o.SampleUnit, "nanoseconds")
+		var ratio string
+		if totalUnit == "ns" && totalNanos != 0 {
+			ratio = "(" + measurement.Percentage(int64(totalNanos), prof.DurationNanos) + ")"
+		}
+		label = append(label, fmt.Sprintf("Duration: %s, Total samples = %s %s", duration, rpt.formatValue(rpt.total), ratio))
+	}
+	return label
+}
+
+// reportLabels returns printable labels for a report. Includes
+// profileLabels.
+func reportLabels(rpt *Report, g *graph.Graph, origCount, droppedNodes, droppedEdges int, fullHeaders bool) []string {
+	nodeFraction := rpt.options.NodeFraction
+	edgeFraction := rpt.options.EdgeFraction
+	nodeCount := len(g.Nodes)
+
+	var label []string
+	if len(rpt.options.ProfileLabels) > 0 {
+		label = append(label, rpt.options.ProfileLabels...)
+	} else if fullHeaders || !rpt.options.CompactLabels {
+		label = ProfileLabels(rpt)
+	}
+
+	var flatSum int64
+	for _, n := range g.Nodes {
+		flatSum = flatSum + n.FlatValue()
+	}
+
+	if len(rpt.options.ActiveFilters) > 0 {
+		activeFilters := legendActiveFilters(rpt.options.ActiveFilters)
+		label = append(label, activeFilters...)
+	}
+
+	label = append(label, fmt.Sprintf("Showing nodes accounting for %s, %s of %s total", rpt.formatValue(flatSum), strings.TrimSpace(measurement.Percentage(flatSum, rpt.total)), rpt.formatValue(rpt.total)))
+
+	if rpt.total != 0 {
+		if droppedNodes > 0 {
+			label = append(label, genLabel(droppedNodes, "node", "cum",
+				rpt.formatValue(abs64(int64(float64(rpt.total)*nodeFraction)))))
+		}
+		if droppedEdges > 0 {
+			label = append(label, genLabel(droppedEdges, "edge", "freq",
+				rpt.formatValue(abs64(int64(float64(rpt.total)*edgeFraction)))))
+		}
+		if nodeCount > 0 && nodeCount < origCount {
+			label = append(label, fmt.Sprintf("Showing top %d nodes out of %d",
+				nodeCount, origCount))
+		}
+	}
+
+	// Help new users understand the graph.
+	// A new line is intentionally added here to better show this message.
+	if fullHeaders {
+		label = append(label, "\nSee https://git.io/JfYMW for how to read the graph")
+	}
+
+	return label
+}
+
+func legendActiveFilters(activeFilters []string) []string {
+	legendActiveFilters := make([]string, len(activeFilters)+1)
+	legendActiveFilters[0] = "Active filters:"
+	for i, s := range activeFilters {
+		if len(s) > 80 {
+			s = s[:80] + "…"
+		}
+		legendActiveFilters[i+1] = "   " + s
+	}
+	return legendActiveFilters
+}
+
+func genLabel(d int, n, l, f string) string {
+	if d > 1 {
+		n = n + "s"
+	}
+	return fmt.Sprintf("Dropped %d %s (%s <= %s)", d, n, l, f)
+}
+
+// New builds a new report indexing the sample values interpreting the
+// samples with the provided function.
+func New(prof *profile.Profile, o *Options) *Report {
+	format := func(v int64) string {
+		if r := o.Ratio; r > 0 && r != 1 {
+			fv := float64(v) * r
+			v = int64(fv)
+		}
+		return measurement.ScaledLabel(v, o.SampleUnit, o.OutputUnit)
+	}
+	return &Report{prof, computeTotal(prof, o.SampleValue, o.SampleMeanDivisor),
+		o, format}
+}
+
+// NewDefault builds a new report indexing the last sample value
+// available.
+func NewDefault(prof *profile.Profile, options Options) *Report {
+	index := len(prof.SampleType) - 1
+	o := &options
+	if o.Title == "" && len(prof.Mapping) > 0 && prof.Mapping[0].File != "" {
+		o.Title = filepath.Base(prof.Mapping[0].File)
+	}
+	o.SampleType = prof.SampleType[index].Type
+	o.SampleUnit = strings.ToLower(prof.SampleType[index].Unit)
+	o.SampleValue = func(v []int64) int64 {
+		return v[index]
+	}
+	return New(prof, o)
+}
+
+// computeTotal computes the sum of the absolute value of all sample values.
+// If any samples have label indicating they belong to the diff base, then the
+// total will only include samples with that label.
+func computeTotal(prof *profile.Profile, value, meanDiv func(v []int64) int64) int64 {
+	var div, total, diffDiv, diffTotal int64
+	for _, sample := range prof.Sample {
+		var d, v int64
+		v = value(sample.Value)
+		if meanDiv != nil {
+			d = meanDiv(sample.Value)
+		}
+		if v < 0 {
+			v = -v
+		}
+		total += v
+		div += d
+		if sample.DiffBaseSample() {
+			diffTotal += v
+			diffDiv += d
+		}
+	}
+	if diffTotal > 0 {
+		total = diffTotal
+		div = diffDiv
+	}
+	if div != 0 {
+		return total / div
+	}
+	return total
+}
+
+// Report contains the data and associated routines to extract a
+// report from a profile.
+type Report struct {
+	prof        *profile.Profile
+	total       int64
+	options     *Options
+	formatValue func(int64) string
+}
+
+// Total returns the total number of samples in a report.
+func (rpt *Report) Total() int64 { return rpt.total }
+
+func abs64(i int64) int64 {
+	if i < 0 {
+		return -i
+	}
+	return i
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/report/source.go b/src/cmd/vendor/github.com/google/pprof/internal/report/source.go
new file mode 100644
index 0000000..b480535
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/report/source.go
@@ -0,0 +1,653 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package report
+
+// This file contains routines related to the generation of annotated
+// source listings.
+
+import (
+	"bufio"
+	"fmt"
+	"html/template"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/google/pprof/internal/graph"
+	"github.com/google/pprof/internal/measurement"
+	"github.com/google/pprof/internal/plugin"
+)
+
+// printSource prints an annotated source listing, include all
+// functions with samples that match the regexp rpt.options.symbol.
+// The sources are sorted by function name and then by filename to
+// eliminate potential nondeterminism.
+func printSource(w io.Writer, rpt *Report) error {
+	o := rpt.options
+	g := rpt.newGraph(nil)
+
+	// Identify all the functions that match the regexp provided.
+	// Group nodes for each matching function.
+	var functions graph.Nodes
+	functionNodes := make(map[string]graph.Nodes)
+	for _, n := range g.Nodes {
+		if !o.Symbol.MatchString(n.Info.Name) {
+			continue
+		}
+		if functionNodes[n.Info.Name] == nil {
+			functions = append(functions, n)
+		}
+		functionNodes[n.Info.Name] = append(functionNodes[n.Info.Name], n)
+	}
+	functions.Sort(graph.NameOrder)
+
+	sourcePath := o.SourcePath
+	if sourcePath == "" {
+		wd, err := os.Getwd()
+		if err != nil {
+			return fmt.Errorf("could not stat current dir: %v", err)
+		}
+		sourcePath = wd
+	}
+	reader := newSourceReader(sourcePath, o.TrimPath)
+
+	fmt.Fprintf(w, "Total: %s\n", rpt.formatValue(rpt.total))
+	for _, fn := range functions {
+		name := fn.Info.Name
+
+		// Identify all the source files associated to this function.
+		// Group nodes for each source file.
+		var sourceFiles graph.Nodes
+		fileNodes := make(map[string]graph.Nodes)
+		for _, n := range functionNodes[name] {
+			if n.Info.File == "" {
+				continue
+			}
+			if fileNodes[n.Info.File] == nil {
+				sourceFiles = append(sourceFiles, n)
+			}
+			fileNodes[n.Info.File] = append(fileNodes[n.Info.File], n)
+		}
+
+		if len(sourceFiles) == 0 {
+			fmt.Fprintf(w, "No source information for %s\n", name)
+			continue
+		}
+
+		sourceFiles.Sort(graph.FileOrder)
+
+		// Print each file associated with this function.
+		for _, fl := range sourceFiles {
+			filename := fl.Info.File
+			fns := fileNodes[filename]
+			flatSum, cumSum := fns.Sum()
+
+			fnodes, _, err := getSourceFromFile(filename, reader, fns, 0, 0)
+			fmt.Fprintf(w, "ROUTINE ======================== %s in %s\n", name, filename)
+			fmt.Fprintf(w, "%10s %10s (flat, cum) %s of Total\n",
+				rpt.formatValue(flatSum), rpt.formatValue(cumSum),
+				measurement.Percentage(cumSum, rpt.total))
+
+			if err != nil {
+				fmt.Fprintf(w, " Error: %v\n", err)
+				continue
+			}
+
+			for _, fn := range fnodes {
+				fmt.Fprintf(w, "%10s %10s %6d:%s\n", valueOrDot(fn.Flat, rpt), valueOrDot(fn.Cum, rpt), fn.Info.Lineno, fn.Info.Name)
+			}
+		}
+	}
+	return nil
+}
+
+// printWebSource prints an annotated source listing, include all
+// functions with samples that match the regexp rpt.options.symbol.
+func printWebSource(w io.Writer, rpt *Report, obj plugin.ObjTool) error {
+	printHeader(w, rpt)
+	if err := PrintWebList(w, rpt, obj, -1); err != nil {
+		return err
+	}
+	printPageClosing(w)
+	return nil
+}
+
+// PrintWebList prints annotated source listing of rpt to w.
+func PrintWebList(w io.Writer, rpt *Report, obj plugin.ObjTool, maxFiles int) error {
+	o := rpt.options
+	g := rpt.newGraph(nil)
+
+	// If the regexp source can be parsed as an address, also match
+	// functions that land on that address.
+	var address *uint64
+	if hex, err := strconv.ParseUint(o.Symbol.String(), 0, 64); err == nil {
+		address = &hex
+	}
+
+	sourcePath := o.SourcePath
+	if sourcePath == "" {
+		wd, err := os.Getwd()
+		if err != nil {
+			return fmt.Errorf("could not stat current dir: %v", err)
+		}
+		sourcePath = wd
+	}
+	reader := newSourceReader(sourcePath, o.TrimPath)
+
+	type fileFunction struct {
+		fileName, functionName string
+	}
+
+	// Extract interesting symbols from binary files in the profile and
+	// classify samples per symbol.
+	symbols := symbolsFromBinaries(rpt.prof, g, o.Symbol, address, obj)
+	symNodes := nodesPerSymbol(g.Nodes, symbols)
+
+	// Identify sources associated to a symbol by examining
+	// symbol samples. Classify samples per source file.
+	fileNodes := make(map[fileFunction]graph.Nodes)
+	if len(symNodes) == 0 {
+		for _, n := range g.Nodes {
+			if n.Info.File == "" || !o.Symbol.MatchString(n.Info.Name) {
+				continue
+			}
+			ff := fileFunction{n.Info.File, n.Info.Name}
+			fileNodes[ff] = append(fileNodes[ff], n)
+		}
+	} else {
+		for _, nodes := range symNodes {
+			for _, n := range nodes {
+				if n.Info.File != "" {
+					ff := fileFunction{n.Info.File, n.Info.Name}
+					fileNodes[ff] = append(fileNodes[ff], n)
+				}
+			}
+		}
+	}
+
+	if len(fileNodes) == 0 {
+		return fmt.Errorf("no source information for %s", o.Symbol.String())
+	}
+
+	sourceFiles := make(graph.Nodes, 0, len(fileNodes))
+	for _, nodes := range fileNodes {
+		sNode := *nodes[0]
+		sNode.Flat, sNode.Cum = nodes.Sum()
+		sourceFiles = append(sourceFiles, &sNode)
+	}
+
+	// Limit number of files printed?
+	if maxFiles < 0 {
+		sourceFiles.Sort(graph.FileOrder)
+	} else {
+		sourceFiles.Sort(graph.FlatNameOrder)
+		if maxFiles < len(sourceFiles) {
+			sourceFiles = sourceFiles[:maxFiles]
+		}
+	}
+
+	// Print each file associated with this function.
+	for _, n := range sourceFiles {
+		ff := fileFunction{n.Info.File, n.Info.Name}
+		fns := fileNodes[ff]
+
+		asm := assemblyPerSourceLine(symbols, fns, ff.fileName, obj, o.IntelSyntax)
+		start, end := sourceCoordinates(asm)
+
+		fnodes, path, err := getSourceFromFile(ff.fileName, reader, fns, start, end)
+		if err != nil {
+			fnodes, path = getMissingFunctionSource(ff.fileName, asm, start, end)
+		}
+
+		printFunctionHeader(w, ff.functionName, path, n.Flat, n.Cum, rpt)
+		for _, fn := range fnodes {
+			printFunctionSourceLine(w, fn, asm[fn.Info.Lineno], reader, rpt)
+		}
+		printFunctionClosing(w)
+	}
+	return nil
+}
+
+// sourceCoordinates returns the lowest and highest line numbers from
+// a set of assembly statements.
+func sourceCoordinates(asm map[int][]assemblyInstruction) (start, end int) {
+	for l := range asm {
+		if start == 0 || l < start {
+			start = l
+		}
+		if end == 0 || l > end {
+			end = l
+		}
+	}
+	return start, end
+}
+
+// assemblyPerSourceLine disassembles the binary containing a symbol
+// and classifies the assembly instructions according to its
+// corresponding source line, annotating them with a set of samples.
+func assemblyPerSourceLine(objSyms []*objSymbol, rs graph.Nodes, src string, obj plugin.ObjTool, intelSyntax bool) map[int][]assemblyInstruction {
+	assembly := make(map[int][]assemblyInstruction)
+	// Identify symbol to use for this collection of samples.
+	o := findMatchingSymbol(objSyms, rs)
+	if o == nil {
+		return assembly
+	}
+
+	// Extract assembly for matched symbol
+	insts, err := obj.Disasm(o.sym.File, o.sym.Start, o.sym.End, intelSyntax)
+	if err != nil {
+		return assembly
+	}
+
+	srcBase := filepath.Base(src)
+	anodes := annotateAssembly(insts, rs, o.base)
+	var lineno = 0
+	var prevline = 0
+	for _, an := range anodes {
+		// Do not rely solely on the line number produced by Disasm
+		// since it is not what we want in the presence of inlining.
+		//
+		// E.g., suppose we are printing source code for F and this
+		// instruction is from H where F called G called H and both
+		// of those calls were inlined. We want to use the line
+		// number from F, not from H (which is what Disasm gives us).
+		//
+		// So find the outer-most linenumber in the source file.
+		found := false
+		if frames, err := o.file.SourceLine(an.address + o.base); err == nil {
+			for i := len(frames) - 1; i >= 0; i-- {
+				if filepath.Base(frames[i].File) == srcBase {
+					for j := i - 1; j >= 0; j-- {
+						an.inlineCalls = append(an.inlineCalls, callID{frames[j].File, frames[j].Line})
+					}
+					lineno = frames[i].Line
+					found = true
+					break
+				}
+			}
+		}
+		if !found && filepath.Base(an.file) == srcBase {
+			lineno = an.line
+		}
+
+		if lineno != 0 {
+			if lineno != prevline {
+				// This instruction starts a new block
+				// of contiguous instructions on this line.
+				an.startsBlock = true
+			}
+			prevline = lineno
+			assembly[lineno] = append(assembly[lineno], an)
+		}
+	}
+
+	return assembly
+}
+
+// findMatchingSymbol looks for the symbol that corresponds to a set
+// of samples, by comparing their addresses.
+func findMatchingSymbol(objSyms []*objSymbol, ns graph.Nodes) *objSymbol {
+	for _, n := range ns {
+		for _, o := range objSyms {
+			if filepath.Base(o.sym.File) == filepath.Base(n.Info.Objfile) &&
+				o.sym.Start <= n.Info.Address-o.base &&
+				n.Info.Address-o.base <= o.sym.End {
+				return o
+			}
+		}
+	}
+	return nil
+}
+
+// printHeader prints the page header for a weblist report.
+func printHeader(w io.Writer, rpt *Report) {
+	fmt.Fprintln(w, `
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="UTF-8">
+<title>Pprof listing</title>`)
+	fmt.Fprintln(w, weblistPageCSS)
+	fmt.Fprintln(w, weblistPageScript)
+	fmt.Fprint(w, "</head>\n<body>\n\n")
+
+	var labels []string
+	for _, l := range ProfileLabels(rpt) {
+		labels = append(labels, template.HTMLEscapeString(l))
+	}
+
+	fmt.Fprintf(w, `<div class="legend">%s<br>Total: %s</div>`,
+		strings.Join(labels, "<br>\n"),
+		rpt.formatValue(rpt.total),
+	)
+}
+
+// printFunctionHeader prints a function header for a weblist report.
+func printFunctionHeader(w io.Writer, name, path string, flatSum, cumSum int64, rpt *Report) {
+	fmt.Fprintf(w, `<h2>%s</h2><p class="filename">%s</p>
+<pre onClick="pprof_toggle_asm(event)">
+  Total:  %10s %10s (flat, cum) %s
+`,
+		template.HTMLEscapeString(name), template.HTMLEscapeString(path),
+		rpt.formatValue(flatSum), rpt.formatValue(cumSum),
+		measurement.Percentage(cumSum, rpt.total))
+}
+
+// printFunctionSourceLine prints a source line and the corresponding assembly.
+func printFunctionSourceLine(w io.Writer, fn *graph.Node, assembly []assemblyInstruction, reader *sourceReader, rpt *Report) {
+	if len(assembly) == 0 {
+		fmt.Fprintf(w,
+			"<span class=line> %6d</span> <span class=nop>  %10s %10s %8s  %s </span>\n",
+			fn.Info.Lineno,
+			valueOrDot(fn.Flat, rpt), valueOrDot(fn.Cum, rpt),
+			"", template.HTMLEscapeString(fn.Info.Name))
+		return
+	}
+
+	fmt.Fprintf(w,
+		"<span class=line> %6d</span> <span class=deadsrc>  %10s %10s %8s  %s </span>",
+		fn.Info.Lineno,
+		valueOrDot(fn.Flat, rpt), valueOrDot(fn.Cum, rpt),
+		"", template.HTMLEscapeString(fn.Info.Name))
+	srcIndent := indentation(fn.Info.Name)
+	fmt.Fprint(w, "<span class=asm>")
+	var curCalls []callID
+	for i, an := range assembly {
+		if an.startsBlock && i != 0 {
+			// Insert a separator between discontiguous blocks.
+			fmt.Fprintf(w, " %8s %28s\n", "", "⋮")
+		}
+
+		var fileline string
+		if an.file != "" {
+			fileline = fmt.Sprintf("%s:%d", template.HTMLEscapeString(an.file), an.line)
+		}
+		flat, cum := an.flat, an.cum
+		if an.flatDiv != 0 {
+			flat = flat / an.flatDiv
+		}
+		if an.cumDiv != 0 {
+			cum = cum / an.cumDiv
+		}
+
+		// Print inlined call context.
+		for j, c := range an.inlineCalls {
+			if j < len(curCalls) && curCalls[j] == c {
+				// Skip if same as previous instruction.
+				continue
+			}
+			curCalls = nil
+			fline, ok := reader.line(c.file, c.line)
+			if !ok {
+				fline = ""
+			}
+			text := strings.Repeat(" ", srcIndent+4+4*j) + strings.TrimSpace(fline)
+			fmt.Fprintf(w, " %8s %10s %10s %8s  <span class=inlinesrc>%s</span> <span class=unimportant>%s:%d</span>\n",
+				"", "", "", "",
+				template.HTMLEscapeString(fmt.Sprintf("%-80s", text)),
+				template.HTMLEscapeString(filepath.Base(c.file)), c.line)
+		}
+		curCalls = an.inlineCalls
+		text := strings.Repeat(" ", srcIndent+4+4*len(curCalls)) + an.instruction
+		fmt.Fprintf(w, " %8s %10s %10s %8x: %s <span class=unimportant>%s</span>\n",
+			"", valueOrDot(flat, rpt), valueOrDot(cum, rpt), an.address,
+			template.HTMLEscapeString(fmt.Sprintf("%-80s", text)),
+			template.HTMLEscapeString(fileline))
+	}
+	fmt.Fprintln(w, "</span>")
+}
+
+// printFunctionClosing prints the end of a function in a weblist report.
+func printFunctionClosing(w io.Writer) {
+	fmt.Fprintln(w, "</pre>")
+}
+
+// printPageClosing prints the end of the page in a weblist report.
+func printPageClosing(w io.Writer) {
+	fmt.Fprintln(w, weblistPageClosing)
+}
+
+// getSourceFromFile collects the sources of a function from a source
+// file and annotates it with the samples in fns. Returns the sources
+// as nodes, using the info.name field to hold the source code.
+func getSourceFromFile(file string, reader *sourceReader, fns graph.Nodes, start, end int) (graph.Nodes, string, error) {
+	lineNodes := make(map[int]graph.Nodes)
+
+	// Collect source coordinates from profile.
+	const margin = 5 // Lines before first/after last sample.
+	if start == 0 {
+		if fns[0].Info.StartLine != 0 {
+			start = fns[0].Info.StartLine
+		} else {
+			start = fns[0].Info.Lineno - margin
+		}
+	} else {
+		start -= margin
+	}
+	if end == 0 {
+		end = fns[0].Info.Lineno
+	}
+	end += margin
+	for _, n := range fns {
+		lineno := n.Info.Lineno
+		nodeStart := n.Info.StartLine
+		if nodeStart == 0 {
+			nodeStart = lineno - margin
+		}
+		nodeEnd := lineno + margin
+		if nodeStart < start {
+			start = nodeStart
+		} else if nodeEnd > end {
+			end = nodeEnd
+		}
+		lineNodes[lineno] = append(lineNodes[lineno], n)
+	}
+	if start < 1 {
+		start = 1
+	}
+
+	var src graph.Nodes
+	for lineno := start; lineno <= end; lineno++ {
+		line, ok := reader.line(file, lineno)
+		if !ok {
+			break
+		}
+		flat, cum := lineNodes[lineno].Sum()
+		src = append(src, &graph.Node{
+			Info: graph.NodeInfo{
+				Name:   strings.TrimRight(line, "\n"),
+				Lineno: lineno,
+			},
+			Flat: flat,
+			Cum:  cum,
+		})
+	}
+	if err := reader.fileError(file); err != nil {
+		return nil, file, err
+	}
+	return src, file, nil
+}
+
+// getMissingFunctionSource creates a dummy function body to point to
+// the source file and annotates it with the samples in asm.
+func getMissingFunctionSource(filename string, asm map[int][]assemblyInstruction, start, end int) (graph.Nodes, string) {
+	var fnodes graph.Nodes
+	for i := start; i <= end; i++ {
+		insts := asm[i]
+		if len(insts) == 0 {
+			continue
+		}
+		var group assemblyInstruction
+		for _, insn := range insts {
+			group.flat += insn.flat
+			group.cum += insn.cum
+			group.flatDiv += insn.flatDiv
+			group.cumDiv += insn.cumDiv
+		}
+		flat := group.flatValue()
+		cum := group.cumValue()
+		fnodes = append(fnodes, &graph.Node{
+			Info: graph.NodeInfo{
+				Name:   "???",
+				Lineno: i,
+			},
+			Flat: flat,
+			Cum:  cum,
+		})
+	}
+	return fnodes, filename
+}
+
+// sourceReader provides access to source code with caching of file contents.
+type sourceReader struct {
+	// searchPath is a filepath.ListSeparator-separated list of directories where
+	// source files should be searched.
+	searchPath string
+
+	// trimPath is a filepath.ListSeparator-separated list of paths to trim.
+	trimPath string
+
+	// files maps from path name to a list of lines.
+	// files[*][0] is unused since line numbering starts at 1.
+	files map[string][]string
+
+	// errors collects errors encountered per file. These errors are
+	// consulted before returning out of these module.
+	errors map[string]error
+}
+
+func newSourceReader(searchPath, trimPath string) *sourceReader {
+	return &sourceReader{
+		searchPath,
+		trimPath,
+		make(map[string][]string),
+		make(map[string]error),
+	}
+}
+
+func (reader *sourceReader) fileError(path string) error {
+	return reader.errors[path]
+}
+
+func (reader *sourceReader) line(path string, lineno int) (string, bool) {
+	lines, ok := reader.files[path]
+	if !ok {
+		// Read and cache file contents.
+		lines = []string{""} // Skip 0th line
+		f, err := openSourceFile(path, reader.searchPath, reader.trimPath)
+		if err != nil {
+			reader.errors[path] = err
+		} else {
+			s := bufio.NewScanner(f)
+			for s.Scan() {
+				lines = append(lines, s.Text())
+			}
+			f.Close()
+			if s.Err() != nil {
+				reader.errors[path] = err
+			}
+		}
+		reader.files[path] = lines
+	}
+	if lineno <= 0 || lineno >= len(lines) {
+		return "", false
+	}
+	return lines[lineno], true
+}
+
+// openSourceFile opens a source file from a name encoded in a profile. File
+// names in a profile after can be relative paths, so search them in each of
+// the paths in searchPath and their parents. In case the profile contains
+// absolute paths, additional paths may be configured to trim from the source
+// paths in the profile. This effectively turns the path into a relative path
+// searching it using searchPath as usual).
+func openSourceFile(path, searchPath, trim string) (*os.File, error) {
+	path = trimPath(path, trim, searchPath)
+	// If file is still absolute, require file to exist.
+	if filepath.IsAbs(path) {
+		f, err := os.Open(path)
+		return f, err
+	}
+	// Scan each component of the path.
+	for _, dir := range filepath.SplitList(searchPath) {
+		// Search up for every parent of each possible path.
+		for {
+			filename := filepath.Join(dir, path)
+			if f, err := os.Open(filename); err == nil {
+				return f, nil
+			}
+			parent := filepath.Dir(dir)
+			if parent == dir {
+				break
+			}
+			dir = parent
+		}
+	}
+
+	return nil, fmt.Errorf("could not find file %s on path %s", path, searchPath)
+}
+
+// trimPath cleans up a path by removing prefixes that are commonly
+// found on profiles plus configured prefixes.
+// TODO(aalexand): Consider optimizing out the redundant work done in this
+// function if it proves to matter.
+func trimPath(path, trimPath, searchPath string) string {
+	// Keep path variable intact as it's used below to form the return value.
+	sPath, searchPath := filepath.ToSlash(path), filepath.ToSlash(searchPath)
+	if trimPath == "" {
+		// If the trim path is not configured, try to guess it heuristically:
+		// search for basename of each search path in the original path and, if
+		// found, strip everything up to and including the basename. So, for
+		// example, given original path "/some/remote/path/my-project/foo/bar.c"
+		// and search path "/my/local/path/my-project" the heuristic will return
+		// "/my/local/path/my-project/foo/bar.c".
+		for _, dir := range filepath.SplitList(searchPath) {
+			want := "/" + filepath.Base(dir) + "/"
+			if found := strings.Index(sPath, want); found != -1 {
+				return path[found+len(want):]
+			}
+		}
+	}
+	// Trim configured trim prefixes.
+	trimPaths := append(filepath.SplitList(filepath.ToSlash(trimPath)), "/proc/self/cwd/./", "/proc/self/cwd/")
+	for _, trimPath := range trimPaths {
+		if !strings.HasSuffix(trimPath, "/") {
+			trimPath += "/"
+		}
+		if strings.HasPrefix(sPath, trimPath) {
+			return path[len(trimPath):]
+		}
+	}
+	return path
+}
+
+func indentation(line string) int {
+	column := 0
+	for _, c := range line {
+		if c == ' ' {
+			column++
+		} else if c == '\t' {
+			column++
+			for column%8 != 0 {
+				column++
+			}
+		} else {
+			break
+		}
+	}
+	return column
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/report/source_html.go b/src/cmd/vendor/github.com/google/pprof/internal/report/source_html.go
new file mode 100644
index 0000000..02a6d77
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/report/source_html.go
@@ -0,0 +1,84 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package report
+
+import (
+	"html/template"
+)
+
+// AddSourceTemplates adds templates used by PrintWebList to t.
+func AddSourceTemplates(t *template.Template) {
+	template.Must(t.Parse(`{{define "weblistcss"}}` + weblistPageCSS + `{{end}}`))
+	template.Must(t.Parse(`{{define "weblistjs"}}` + weblistPageScript + `{{end}}`))
+}
+
+const weblistPageCSS = `<style type="text/css">
+body {
+font-family: sans-serif;
+}
+h1 {
+  font-size: 1.5em;
+  margin-bottom: 4px;
+}
+.legend {
+  font-size: 1.25em;
+}
+.line, .nop, .unimportant {
+  color: #aaaaaa;
+}
+.inlinesrc {
+  color: #000066;
+}
+.deadsrc {
+cursor: pointer;
+}
+.deadsrc:hover {
+background-color: #eeeeee;
+}
+.livesrc {
+color: #0000ff;
+cursor: pointer;
+}
+.livesrc:hover {
+background-color: #eeeeee;
+}
+.asm {
+color: #008800;
+display: none;
+}
+</style>`
+
+const weblistPageScript = `<script type="text/javascript">
+function pprof_toggle_asm(e) {
+  var target;
+  if (!e) e = window.event;
+  if (e.target) target = e.target;
+  else if (e.srcElement) target = e.srcElement;
+
+  if (target) {
+    var asm = target.nextSibling;
+    if (asm && asm.className == "asm") {
+      asm.style.display = (asm.style.display == "block" ? "" : "block");
+      e.preventDefault();
+      return false;
+    }
+  }
+}
+</script>`
+
+const weblistPageClosing = `
+</body>
+</html>
+`
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/symbolizer/symbolizer.go b/src/cmd/vendor/github.com/google/pprof/internal/symbolizer/symbolizer.go
new file mode 100644
index 0000000..d741e7a
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/symbolizer/symbolizer.go
@@ -0,0 +1,361 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package symbolizer provides a routine to populate a profile with
+// symbol, file and line number information. It relies on the
+// addr2liner and demangle packages to do the actual work.
+package symbolizer
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"path/filepath"
+	"strings"
+
+	"github.com/google/pprof/internal/binutils"
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/internal/symbolz"
+	"github.com/google/pprof/profile"
+	"github.com/ianlancetaylor/demangle"
+)
+
+// Symbolizer implements the plugin.Symbolize interface.
+type Symbolizer struct {
+	Obj       plugin.ObjTool
+	UI        plugin.UI
+	Transport http.RoundTripper
+}
+
+// test taps for dependency injection
+var symbolzSymbolize = symbolz.Symbolize
+var localSymbolize = doLocalSymbolize
+var demangleFunction = Demangle
+
+// Symbolize attempts to symbolize profile p. First uses binutils on
+// local binaries; if the source is a URL it attempts to get any
+// missed entries using symbolz.
+func (s *Symbolizer) Symbolize(mode string, sources plugin.MappingSources, p *profile.Profile) error {
+	remote, local, fast, force, demanglerMode := true, true, false, false, ""
+	for _, o := range strings.Split(strings.ToLower(mode), ":") {
+		switch o {
+		case "":
+			continue
+		case "none", "no":
+			return nil
+		case "local":
+			remote, local = false, true
+		case "fastlocal":
+			remote, local, fast = false, true, true
+		case "remote":
+			remote, local = true, false
+		case "force":
+			force = true
+		default:
+			switch d := strings.TrimPrefix(o, "demangle="); d {
+			case "full", "none", "templates":
+				demanglerMode = d
+				force = true
+				continue
+			case "default":
+				continue
+			}
+			s.UI.PrintErr("ignoring unrecognized symbolization option: " + mode)
+			s.UI.PrintErr("expecting -symbolize=[local|fastlocal|remote|none][:force][:demangle=[none|full|templates|default]")
+		}
+	}
+
+	var err error
+	if local {
+		// Symbolize locally using binutils.
+		if err = localSymbolize(p, fast, force, s.Obj, s.UI); err != nil {
+			s.UI.PrintErr("local symbolization: " + err.Error())
+		}
+	}
+	if remote {
+		post := func(source, post string) ([]byte, error) {
+			return postURL(source, post, s.Transport)
+		}
+		if err = symbolzSymbolize(p, force, sources, post, s.UI); err != nil {
+			return err // Ran out of options.
+		}
+	}
+
+	demangleFunction(p, force, demanglerMode)
+	return nil
+}
+
+// postURL issues a POST to a URL over HTTP.
+func postURL(source, post string, tr http.RoundTripper) ([]byte, error) {
+	client := &http.Client{
+		Transport: tr,
+	}
+	resp, err := client.Post(source, "application/octet-stream", strings.NewReader(post))
+	if err != nil {
+		return nil, fmt.Errorf("http post %s: %v", source, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("http post %s: %v", source, statusCodeError(resp))
+	}
+	return ioutil.ReadAll(resp.Body)
+}
+
+func statusCodeError(resp *http.Response) error {
+	if resp.Header.Get("X-Go-Pprof") != "" && strings.Contains(resp.Header.Get("Content-Type"), "text/plain") {
+		// error is from pprof endpoint
+		if body, err := ioutil.ReadAll(resp.Body); err == nil {
+			return fmt.Errorf("server response: %s - %s", resp.Status, body)
+		}
+	}
+	return fmt.Errorf("server response: %s", resp.Status)
+}
+
+// doLocalSymbolize adds symbol and line number information to all locations
+// in a profile. mode enables some options to control
+// symbolization.
+func doLocalSymbolize(prof *profile.Profile, fast, force bool, obj plugin.ObjTool, ui plugin.UI) error {
+	if fast {
+		if bu, ok := obj.(*binutils.Binutils); ok {
+			bu.SetFastSymbolization(true)
+		}
+	}
+
+	mt, err := newMapping(prof, obj, ui, force)
+	if err != nil {
+		return err
+	}
+	defer mt.close()
+
+	functions := make(map[profile.Function]*profile.Function)
+	for _, l := range mt.prof.Location {
+		m := l.Mapping
+		segment := mt.segments[m]
+		if segment == nil {
+			// Nothing to do.
+			continue
+		}
+
+		stack, err := segment.SourceLine(l.Address)
+		if err != nil || len(stack) == 0 {
+			// No answers from addr2line.
+			continue
+		}
+
+		l.Line = make([]profile.Line, len(stack))
+		l.IsFolded = false
+		for i, frame := range stack {
+			if frame.Func != "" {
+				m.HasFunctions = true
+			}
+			if frame.File != "" {
+				m.HasFilenames = true
+			}
+			if frame.Line != 0 {
+				m.HasLineNumbers = true
+			}
+			f := &profile.Function{
+				Name:       frame.Func,
+				SystemName: frame.Func,
+				Filename:   frame.File,
+			}
+			if fp := functions[*f]; fp != nil {
+				f = fp
+			} else {
+				functions[*f] = f
+				f.ID = uint64(len(mt.prof.Function)) + 1
+				mt.prof.Function = append(mt.prof.Function, f)
+			}
+			l.Line[i] = profile.Line{
+				Function: f,
+				Line:     int64(frame.Line),
+			}
+		}
+
+		if len(stack) > 0 {
+			m.HasInlineFrames = true
+		}
+	}
+
+	return nil
+}
+
+// Demangle updates the function names in a profile with demangled C++
+// names, simplified according to demanglerMode. If force is set,
+// overwrite any names that appear already demangled.
+func Demangle(prof *profile.Profile, force bool, demanglerMode string) {
+	if force {
+		// Remove the current demangled names to force demangling
+		for _, f := range prof.Function {
+			if f.Name != "" && f.SystemName != "" {
+				f.Name = f.SystemName
+			}
+		}
+	}
+
+	var options []demangle.Option
+	switch demanglerMode {
+	case "": // demangled, simplified: no parameters, no templates, no return type
+		options = []demangle.Option{demangle.NoParams, demangle.NoTemplateParams}
+	case "templates": // demangled, simplified: no parameters, no return type
+		options = []demangle.Option{demangle.NoParams}
+	case "full":
+		options = []demangle.Option{demangle.NoClones}
+	case "none": // no demangling
+		return
+	}
+
+	// Copy the options because they may be updated by the call.
+	o := make([]demangle.Option, len(options))
+	for _, fn := range prof.Function {
+		if fn.Name != "" && fn.SystemName != fn.Name {
+			continue // Already demangled.
+		}
+		copy(o, options)
+		if demangled := demangle.Filter(fn.SystemName, o...); demangled != fn.SystemName {
+			fn.Name = demangled
+			continue
+		}
+		// Could not demangle. Apply heuristics in case the name is
+		// already demangled.
+		name := fn.SystemName
+		if looksLikeDemangledCPlusPlus(name) {
+			if demanglerMode == "" || demanglerMode == "templates" {
+				name = removeMatching(name, '(', ')')
+			}
+			if demanglerMode == "" {
+				name = removeMatching(name, '<', '>')
+			}
+		}
+		fn.Name = name
+	}
+}
+
+// looksLikeDemangledCPlusPlus is a heuristic to decide if a name is
+// the result of demangling C++. If so, further heuristics will be
+// applied to simplify the name.
+func looksLikeDemangledCPlusPlus(demangled string) bool {
+	if strings.Contains(demangled, ".<") { // Skip java names of the form "class.<init>"
+		return false
+	}
+	return strings.ContainsAny(demangled, "<>[]") || strings.Contains(demangled, "::")
+}
+
+// removeMatching removes nested instances of start..end from name.
+func removeMatching(name string, start, end byte) string {
+	s := string(start) + string(end)
+	var nesting, first, current int
+	for index := strings.IndexAny(name[current:], s); index != -1; index = strings.IndexAny(name[current:], s) {
+		switch current += index; name[current] {
+		case start:
+			nesting++
+			if nesting == 1 {
+				first = current
+			}
+		case end:
+			nesting--
+			switch {
+			case nesting < 0:
+				return name // Mismatch, abort
+			case nesting == 0:
+				name = name[:first] + name[current+1:]
+				current = first - 1
+			}
+		}
+		current++
+	}
+	return name
+}
+
+// newMapping creates a mappingTable for a profile.
+func newMapping(prof *profile.Profile, obj plugin.ObjTool, ui plugin.UI, force bool) (*mappingTable, error) {
+	mt := &mappingTable{
+		prof:     prof,
+		segments: make(map[*profile.Mapping]plugin.ObjFile),
+	}
+
+	// Identify used mappings
+	mappings := make(map[*profile.Mapping]bool)
+	for _, l := range prof.Location {
+		mappings[l.Mapping] = true
+	}
+
+	missingBinaries := false
+	for midx, m := range prof.Mapping {
+		if !mappings[m] {
+			continue
+		}
+
+		// Do not attempt to re-symbolize a mapping that has already been symbolized.
+		if !force && (m.HasFunctions || m.HasFilenames || m.HasLineNumbers) {
+			continue
+		}
+
+		if m.File == "" {
+			if midx == 0 {
+				ui.PrintErr("Main binary filename not available.")
+				continue
+			}
+			missingBinaries = true
+			continue
+		}
+
+		// Skip well-known system mappings
+		if m.Unsymbolizable() {
+			continue
+		}
+
+		// Skip mappings pointing to a source URL
+		if m.BuildID == "" {
+			if u, err := url.Parse(m.File); err == nil && u.IsAbs() && strings.Contains(strings.ToLower(u.Scheme), "http") {
+				continue
+			}
+		}
+
+		name := filepath.Base(m.File)
+		f, err := obj.Open(m.File, m.Start, m.Limit, m.Offset)
+		if err != nil {
+			ui.PrintErr("Local symbolization failed for ", name, ": ", err)
+			missingBinaries = true
+			continue
+		}
+		if fid := f.BuildID(); m.BuildID != "" && fid != "" && fid != m.BuildID {
+			ui.PrintErr("Local symbolization failed for ", name, ": build ID mismatch")
+			f.Close()
+			continue
+		}
+
+		mt.segments[m] = f
+	}
+	if missingBinaries {
+		ui.PrintErr("Some binary filenames not available. Symbolization may be incomplete.\n" +
+			"Try setting PPROF_BINARY_PATH to the search path for local binaries.")
+	}
+	return mt, nil
+}
+
+// mappingTable contains the mechanisms for symbolization of a
+// profile.
+type mappingTable struct {
+	prof     *profile.Profile
+	segments map[*profile.Mapping]plugin.ObjFile
+}
+
+// Close releases any external processes being used for the mapping.
+func (mt *mappingTable) close() {
+	for _, segment := range mt.segments {
+		segment.Close()
+	}
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/symbolz/symbolz.go b/src/cmd/vendor/github.com/google/pprof/internal/symbolz/symbolz.go
new file mode 100644
index 0000000..7be3048
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/symbolz/symbolz.go
@@ -0,0 +1,200 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package symbolz symbolizes a profile using the output from the symbolz
+// service.
+package symbolz
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/url"
+	"path"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/google/pprof/internal/plugin"
+	"github.com/google/pprof/profile"
+)
+
+var (
+	symbolzRE = regexp.MustCompile(`(0x[[:xdigit:]]+)\s+(.*)`)
+)
+
+// Symbolize symbolizes profile p by parsing data returned by a symbolz
+// handler. syms receives the symbolz query (hex addresses separated by '+')
+// and returns the symbolz output in a string. If force is false, it will only
+// symbolize locations from mappings not already marked as HasFunctions. Never
+// attempts symbolization of addresses from unsymbolizable system
+// mappings as those may look negative - e.g. "[vsyscall]".
+func Symbolize(p *profile.Profile, force bool, sources plugin.MappingSources, syms func(string, string) ([]byte, error), ui plugin.UI) error {
+	for _, m := range p.Mapping {
+		if !force && m.HasFunctions {
+			// Only check for HasFunctions as symbolz only populates function names.
+			continue
+		}
+		// Skip well-known system mappings.
+		if m.Unsymbolizable() {
+			continue
+		}
+		mappingSources := sources[m.File]
+		if m.BuildID != "" {
+			mappingSources = append(mappingSources, sources[m.BuildID]...)
+		}
+		for _, source := range mappingSources {
+			if symz := symbolz(source.Source); symz != "" {
+				if err := symbolizeMapping(symz, int64(source.Start)-int64(m.Start), syms, m, p); err != nil {
+					return err
+				}
+				m.HasFunctions = true
+				break
+			}
+		}
+	}
+
+	return nil
+}
+
+// hasGperftoolsSuffix checks whether path ends with one of the suffixes listed in
+// pprof_remote_servers.html from the gperftools distribution
+func hasGperftoolsSuffix(path string) bool {
+	suffixes := []string{
+		"/pprof/heap",
+		"/pprof/growth",
+		"/pprof/profile",
+		"/pprof/pmuprofile",
+		"/pprof/contention",
+	}
+	for _, s := range suffixes {
+		if strings.HasSuffix(path, s) {
+			return true
+		}
+	}
+	return false
+}
+
+// symbolz returns the corresponding symbolz source for a profile URL.
+func symbolz(source string) string {
+	if url, err := url.Parse(source); err == nil && url.Host != "" {
+		// All paths in the net/http/pprof Go package contain /debug/pprof/
+		if strings.Contains(url.Path, "/debug/pprof/") || hasGperftoolsSuffix(url.Path) {
+			url.Path = path.Clean(url.Path + "/../symbol")
+		} else {
+			url.Path = "/symbolz"
+		}
+		url.RawQuery = ""
+		return url.String()
+	}
+
+	return ""
+}
+
+// symbolizeMapping symbolizes locations belonging to a Mapping by querying
+// a symbolz handler. An offset is applied to all addresses to take care of
+// normalization occurred for merged Mappings.
+func symbolizeMapping(source string, offset int64, syms func(string, string) ([]byte, error), m *profile.Mapping, p *profile.Profile) error {
+	// Construct query of addresses to symbolize.
+	var a []string
+	for _, l := range p.Location {
+		if l.Mapping == m && l.Address != 0 && len(l.Line) == 0 {
+			// Compensate for normalization.
+			addr, overflow := adjust(l.Address, offset)
+			if overflow {
+				return fmt.Errorf("cannot adjust address %d by %d, it would overflow (mapping %v)", l.Address, offset, l.Mapping)
+			}
+			a = append(a, fmt.Sprintf("%#x", addr))
+		}
+	}
+
+	if len(a) == 0 {
+		// No addresses to symbolize.
+		return nil
+	}
+
+	lines := make(map[uint64]profile.Line)
+	functions := make(map[string]*profile.Function)
+
+	b, err := syms(source, strings.Join(a, "+"))
+	if err != nil {
+		return err
+	}
+
+	buf := bytes.NewBuffer(b)
+	for {
+		l, err := buf.ReadString('\n')
+
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+
+		if symbol := symbolzRE.FindStringSubmatch(l); len(symbol) == 3 {
+			origAddr, err := strconv.ParseUint(symbol[1], 0, 64)
+			if err != nil {
+				return fmt.Errorf("unexpected parse failure %s: %v", symbol[1], err)
+			}
+			// Reapply offset expected by the profile.
+			addr, overflow := adjust(origAddr, -offset)
+			if overflow {
+				return fmt.Errorf("cannot adjust symbolz address %d by %d, it would overflow", origAddr, -offset)
+			}
+
+			name := symbol[2]
+			fn := functions[name]
+			if fn == nil {
+				fn = &profile.Function{
+					ID:         uint64(len(p.Function) + 1),
+					Name:       name,
+					SystemName: name,
+				}
+				functions[name] = fn
+				p.Function = append(p.Function, fn)
+			}
+
+			lines[addr] = profile.Line{Function: fn}
+		}
+	}
+
+	for _, l := range p.Location {
+		if l.Mapping != m {
+			continue
+		}
+		if line, ok := lines[l.Address]; ok {
+			l.Line = []profile.Line{line}
+		}
+	}
+
+	return nil
+}
+
+// adjust shifts the specified address by the signed offset. It returns the
+// adjusted address. It signals that the address cannot be adjusted without an
+// overflow by returning true in the second return value.
+func adjust(addr uint64, offset int64) (uint64, bool) {
+	adj := uint64(int64(addr) + offset)
+	if offset < 0 {
+		if adj >= addr {
+			return 0, true
+		}
+	} else {
+		if adj < addr {
+			return 0, true
+		}
+	}
+	return adj, false
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/internal/transport/transport.go b/src/cmd/vendor/github.com/google/pprof/internal/transport/transport.go
new file mode 100644
index 0000000..b5fb1dd
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/internal/transport/transport.go
@@ -0,0 +1,131 @@
+// Copyright 2018 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package transport provides a mechanism to send requests with https cert,
+// key, and CA.
+package transport
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"sync"
+
+	"github.com/google/pprof/internal/plugin"
+)
+
+type transport struct {
+	cert       *string
+	key        *string
+	ca         *string
+	caCertPool *x509.CertPool
+	certs      []tls.Certificate
+	initOnce   sync.Once
+	initErr    error
+}
+
+const extraUsage = `    -tls_cert             TLS client certificate file for fetching profile and symbols
+    -tls_key              TLS private key file for fetching profile and symbols
+    -tls_ca               TLS CA certs file for fetching profile and symbols`
+
+// New returns a round tripper for making requests with the
+// specified cert, key, and ca. The flags tls_cert, tls_key, and tls_ca are
+// added to the flagset to allow a user to specify the cert, key, and ca. If
+// the flagset is nil, no flags will be added, and users will not be able to
+// use these flags.
+func New(flagset plugin.FlagSet) http.RoundTripper {
+	if flagset == nil {
+		return &transport{}
+	}
+	flagset.AddExtraUsage(extraUsage)
+	return &transport{
+		cert: flagset.String("tls_cert", "", "TLS client certificate file for fetching profile and symbols"),
+		key:  flagset.String("tls_key", "", "TLS private key file for fetching profile and symbols"),
+		ca:   flagset.String("tls_ca", "", "TLS CA certs file for fetching profile and symbols"),
+	}
+}
+
+// initialize uses the cert, key, and ca to initialize the certs
+// to use these when making requests.
+func (tr *transport) initialize() error {
+	var cert, key, ca string
+	if tr.cert != nil {
+		cert = *tr.cert
+	}
+	if tr.key != nil {
+		key = *tr.key
+	}
+	if tr.ca != nil {
+		ca = *tr.ca
+	}
+
+	if cert != "" && key != "" {
+		tlsCert, err := tls.LoadX509KeyPair(cert, key)
+		if err != nil {
+			return fmt.Errorf("could not load certificate/key pair specified by -tls_cert and -tls_key: %v", err)
+		}
+		tr.certs = []tls.Certificate{tlsCert}
+	} else if cert == "" && key != "" {
+		return fmt.Errorf("-tls_key is specified, so -tls_cert must also be specified")
+	} else if cert != "" && key == "" {
+		return fmt.Errorf("-tls_cert is specified, so -tls_key must also be specified")
+	}
+
+	if ca != "" {
+		caCertPool := x509.NewCertPool()
+		caCert, err := ioutil.ReadFile(ca)
+		if err != nil {
+			return fmt.Errorf("could not load CA specified by -tls_ca: %v", err)
+		}
+		caCertPool.AppendCertsFromPEM(caCert)
+		tr.caCertPool = caCertPool
+	}
+
+	return nil
+}
+
+// RoundTrip executes a single HTTP transaction, returning
+// a Response for the provided Request.
+func (tr *transport) RoundTrip(req *http.Request) (*http.Response, error) {
+	tr.initOnce.Do(func() {
+		tr.initErr = tr.initialize()
+	})
+	if tr.initErr != nil {
+		return nil, tr.initErr
+	}
+
+	tlsConfig := &tls.Config{
+		RootCAs:      tr.caCertPool,
+		Certificates: tr.certs,
+	}
+
+	if req.URL.Scheme == "https+insecure" {
+		// Make shallow copy of request, and req.URL, so the request's URL can be
+		// modified.
+		r := *req
+		*r.URL = *req.URL
+		req = &r
+		tlsConfig.InsecureSkipVerify = true
+		req.URL.Scheme = "https"
+	}
+
+	transport := http.Transport{
+		Proxy:           http.ProxyFromEnvironment,
+		TLSClientConfig: tlsConfig,
+	}
+
+	return transport.RoundTrip(req)
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/encode.go b/src/cmd/vendor/github.com/google/pprof/profile/encode.go
new file mode 100644
index 0000000..1e84c72
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/profile/encode.go
@@ -0,0 +1,567 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package profile
+
+import (
+	"errors"
+	"sort"
+)
+
+func (p *Profile) decoder() []decoder {
+	return profileDecoder
+}
+
+// preEncode populates the unexported fields to be used by encode
+// (with suffix X) from the corresponding exported fields. The
+// exported fields are cleared up to facilitate testing.
+func (p *Profile) preEncode() {
+	strings := make(map[string]int)
+	addString(strings, "")
+
+	for _, st := range p.SampleType {
+		st.typeX = addString(strings, st.Type)
+		st.unitX = addString(strings, st.Unit)
+	}
+
+	for _, s := range p.Sample {
+		s.labelX = nil
+		var keys []string
+		for k := range s.Label {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+		for _, k := range keys {
+			vs := s.Label[k]
+			for _, v := range vs {
+				s.labelX = append(s.labelX,
+					label{
+						keyX: addString(strings, k),
+						strX: addString(strings, v),
+					},
+				)
+			}
+		}
+		var numKeys []string
+		for k := range s.NumLabel {
+			numKeys = append(numKeys, k)
+		}
+		sort.Strings(numKeys)
+		for _, k := range numKeys {
+			keyX := addString(strings, k)
+			vs := s.NumLabel[k]
+			units := s.NumUnit[k]
+			for i, v := range vs {
+				var unitX int64
+				if len(units) != 0 {
+					unitX = addString(strings, units[i])
+				}
+				s.labelX = append(s.labelX,
+					label{
+						keyX:  keyX,
+						numX:  v,
+						unitX: unitX,
+					},
+				)
+			}
+		}
+		s.locationIDX = make([]uint64, len(s.Location))
+		for i, loc := range s.Location {
+			s.locationIDX[i] = loc.ID
+		}
+	}
+
+	for _, m := range p.Mapping {
+		m.fileX = addString(strings, m.File)
+		m.buildIDX = addString(strings, m.BuildID)
+	}
+
+	for _, l := range p.Location {
+		for i, ln := range l.Line {
+			if ln.Function != nil {
+				l.Line[i].functionIDX = ln.Function.ID
+			} else {
+				l.Line[i].functionIDX = 0
+			}
+		}
+		if l.Mapping != nil {
+			l.mappingIDX = l.Mapping.ID
+		} else {
+			l.mappingIDX = 0
+		}
+	}
+	for _, f := range p.Function {
+		f.nameX = addString(strings, f.Name)
+		f.systemNameX = addString(strings, f.SystemName)
+		f.filenameX = addString(strings, f.Filename)
+	}
+
+	p.dropFramesX = addString(strings, p.DropFrames)
+	p.keepFramesX = addString(strings, p.KeepFrames)
+
+	if pt := p.PeriodType; pt != nil {
+		pt.typeX = addString(strings, pt.Type)
+		pt.unitX = addString(strings, pt.Unit)
+	}
+
+	p.commentX = nil
+	for _, c := range p.Comments {
+		p.commentX = append(p.commentX, addString(strings, c))
+	}
+
+	p.defaultSampleTypeX = addString(strings, p.DefaultSampleType)
+
+	p.stringTable = make([]string, len(strings))
+	for s, i := range strings {
+		p.stringTable[i] = s
+	}
+}
+
+func (p *Profile) encode(b *buffer) {
+	for _, x := range p.SampleType {
+		encodeMessage(b, 1, x)
+	}
+	for _, x := range p.Sample {
+		encodeMessage(b, 2, x)
+	}
+	for _, x := range p.Mapping {
+		encodeMessage(b, 3, x)
+	}
+	for _, x := range p.Location {
+		encodeMessage(b, 4, x)
+	}
+	for _, x := range p.Function {
+		encodeMessage(b, 5, x)
+	}
+	encodeStrings(b, 6, p.stringTable)
+	encodeInt64Opt(b, 7, p.dropFramesX)
+	encodeInt64Opt(b, 8, p.keepFramesX)
+	encodeInt64Opt(b, 9, p.TimeNanos)
+	encodeInt64Opt(b, 10, p.DurationNanos)
+	if pt := p.PeriodType; pt != nil && (pt.typeX != 0 || pt.unitX != 0) {
+		encodeMessage(b, 11, p.PeriodType)
+	}
+	encodeInt64Opt(b, 12, p.Period)
+	encodeInt64s(b, 13, p.commentX)
+	encodeInt64(b, 14, p.defaultSampleTypeX)
+}
+
+var profileDecoder = []decoder{
+	nil, // 0
+	// repeated ValueType sample_type = 1
+	func(b *buffer, m message) error {
+		x := new(ValueType)
+		pp := m.(*Profile)
+		pp.SampleType = append(pp.SampleType, x)
+		return decodeMessage(b, x)
+	},
+	// repeated Sample sample = 2
+	func(b *buffer, m message) error {
+		x := new(Sample)
+		pp := m.(*Profile)
+		pp.Sample = append(pp.Sample, x)
+		return decodeMessage(b, x)
+	},
+	// repeated Mapping mapping = 3
+	func(b *buffer, m message) error {
+		x := new(Mapping)
+		pp := m.(*Profile)
+		pp.Mapping = append(pp.Mapping, x)
+		return decodeMessage(b, x)
+	},
+	// repeated Location location = 4
+	func(b *buffer, m message) error {
+		x := new(Location)
+		x.Line = make([]Line, 0, 8) // Pre-allocate Line buffer
+		pp := m.(*Profile)
+		pp.Location = append(pp.Location, x)
+		err := decodeMessage(b, x)
+		var tmp []Line
+		x.Line = append(tmp, x.Line...) // Shrink to allocated size
+		return err
+	},
+	// repeated Function function = 5
+	func(b *buffer, m message) error {
+		x := new(Function)
+		pp := m.(*Profile)
+		pp.Function = append(pp.Function, x)
+		return decodeMessage(b, x)
+	},
+	// repeated string string_table = 6
+	func(b *buffer, m message) error {
+		err := decodeStrings(b, &m.(*Profile).stringTable)
+		if err != nil {
+			return err
+		}
+		if m.(*Profile).stringTable[0] != "" {
+			return errors.New("string_table[0] must be ''")
+		}
+		return nil
+	},
+	// int64 drop_frames = 7
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).dropFramesX) },
+	// int64 keep_frames = 8
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).keepFramesX) },
+	// int64 time_nanos = 9
+	func(b *buffer, m message) error {
+		if m.(*Profile).TimeNanos != 0 {
+			return errConcatProfile
+		}
+		return decodeInt64(b, &m.(*Profile).TimeNanos)
+	},
+	// int64 duration_nanos = 10
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).DurationNanos) },
+	// ValueType period_type = 11
+	func(b *buffer, m message) error {
+		x := new(ValueType)
+		pp := m.(*Profile)
+		pp.PeriodType = x
+		return decodeMessage(b, x)
+	},
+	// int64 period = 12
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).Period) },
+	// repeated int64 comment = 13
+	func(b *buffer, m message) error { return decodeInt64s(b, &m.(*Profile).commentX) },
+	// int64 defaultSampleType = 14
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).defaultSampleTypeX) },
+}
+
+// postDecode takes the unexported fields populated by decode (with
+// suffix X) and populates the corresponding exported fields.
+// The unexported fields are cleared up to facilitate testing.
+func (p *Profile) postDecode() error {
+	var err error
+	mappings := make(map[uint64]*Mapping, len(p.Mapping))
+	mappingIds := make([]*Mapping, len(p.Mapping)+1)
+	for _, m := range p.Mapping {
+		m.File, err = getString(p.stringTable, &m.fileX, err)
+		m.BuildID, err = getString(p.stringTable, &m.buildIDX, err)
+		if m.ID < uint64(len(mappingIds)) {
+			mappingIds[m.ID] = m
+		} else {
+			mappings[m.ID] = m
+		}
+	}
+
+	functions := make(map[uint64]*Function, len(p.Function))
+	functionIds := make([]*Function, len(p.Function)+1)
+	for _, f := range p.Function {
+		f.Name, err = getString(p.stringTable, &f.nameX, err)
+		f.SystemName, err = getString(p.stringTable, &f.systemNameX, err)
+		f.Filename, err = getString(p.stringTable, &f.filenameX, err)
+		if f.ID < uint64(len(functionIds)) {
+			functionIds[f.ID] = f
+		} else {
+			functions[f.ID] = f
+		}
+	}
+
+	locations := make(map[uint64]*Location, len(p.Location))
+	locationIds := make([]*Location, len(p.Location)+1)
+	for _, l := range p.Location {
+		if id := l.mappingIDX; id < uint64(len(mappingIds)) {
+			l.Mapping = mappingIds[id]
+		} else {
+			l.Mapping = mappings[id]
+		}
+		l.mappingIDX = 0
+		for i, ln := range l.Line {
+			if id := ln.functionIDX; id != 0 {
+				l.Line[i].functionIDX = 0
+				if id < uint64(len(functionIds)) {
+					l.Line[i].Function = functionIds[id]
+				} else {
+					l.Line[i].Function = functions[id]
+				}
+			}
+		}
+		if l.ID < uint64(len(locationIds)) {
+			locationIds[l.ID] = l
+		} else {
+			locations[l.ID] = l
+		}
+	}
+
+	for _, st := range p.SampleType {
+		st.Type, err = getString(p.stringTable, &st.typeX, err)
+		st.Unit, err = getString(p.stringTable, &st.unitX, err)
+	}
+
+	for _, s := range p.Sample {
+		labels := make(map[string][]string, len(s.labelX))
+		numLabels := make(map[string][]int64, len(s.labelX))
+		numUnits := make(map[string][]string, len(s.labelX))
+		for _, l := range s.labelX {
+			var key, value string
+			key, err = getString(p.stringTable, &l.keyX, err)
+			if l.strX != 0 {
+				value, err = getString(p.stringTable, &l.strX, err)
+				labels[key] = append(labels[key], value)
+			} else if l.numX != 0 {
+				numValues := numLabels[key]
+				units := numUnits[key]
+				if l.unitX != 0 {
+					var unit string
+					unit, err = getString(p.stringTable, &l.unitX, err)
+					units = padStringArray(units, len(numValues))
+					numUnits[key] = append(units, unit)
+				}
+				numLabels[key] = append(numLabels[key], l.numX)
+			}
+		}
+		if len(labels) > 0 {
+			s.Label = labels
+		}
+		if len(numLabels) > 0 {
+			s.NumLabel = numLabels
+			for key, units := range numUnits {
+				if len(units) > 0 {
+					numUnits[key] = padStringArray(units, len(numLabels[key]))
+				}
+			}
+			s.NumUnit = numUnits
+		}
+		s.Location = make([]*Location, len(s.locationIDX))
+		for i, lid := range s.locationIDX {
+			if lid < uint64(len(locationIds)) {
+				s.Location[i] = locationIds[lid]
+			} else {
+				s.Location[i] = locations[lid]
+			}
+		}
+		s.locationIDX = nil
+	}
+
+	p.DropFrames, err = getString(p.stringTable, &p.dropFramesX, err)
+	p.KeepFrames, err = getString(p.stringTable, &p.keepFramesX, err)
+
+	if pt := p.PeriodType; pt == nil {
+		p.PeriodType = &ValueType{}
+	}
+
+	if pt := p.PeriodType; pt != nil {
+		pt.Type, err = getString(p.stringTable, &pt.typeX, err)
+		pt.Unit, err = getString(p.stringTable, &pt.unitX, err)
+	}
+
+	for _, i := range p.commentX {
+		var c string
+		c, err = getString(p.stringTable, &i, err)
+		p.Comments = append(p.Comments, c)
+	}
+
+	p.commentX = nil
+	p.DefaultSampleType, err = getString(p.stringTable, &p.defaultSampleTypeX, err)
+	p.stringTable = nil
+	return err
+}
+
+// padStringArray pads arr with enough empty strings to make arr
+// length l when arr's length is less than l.
+func padStringArray(arr []string, l int) []string {
+	if l <= len(arr) {
+		return arr
+	}
+	return append(arr, make([]string, l-len(arr))...)
+}
+
+func (p *ValueType) decoder() []decoder {
+	return valueTypeDecoder
+}
+
+func (p *ValueType) encode(b *buffer) {
+	encodeInt64Opt(b, 1, p.typeX)
+	encodeInt64Opt(b, 2, p.unitX)
+}
+
+var valueTypeDecoder = []decoder{
+	nil, // 0
+	// optional int64 type = 1
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*ValueType).typeX) },
+	// optional int64 unit = 2
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*ValueType).unitX) },
+}
+
+func (p *Sample) decoder() []decoder {
+	return sampleDecoder
+}
+
+func (p *Sample) encode(b *buffer) {
+	encodeUint64s(b, 1, p.locationIDX)
+	encodeInt64s(b, 2, p.Value)
+	for _, x := range p.labelX {
+		encodeMessage(b, 3, x)
+	}
+}
+
+var sampleDecoder = []decoder{
+	nil, // 0
+	// repeated uint64 location = 1
+	func(b *buffer, m message) error { return decodeUint64s(b, &m.(*Sample).locationIDX) },
+	// repeated int64 value = 2
+	func(b *buffer, m message) error { return decodeInt64s(b, &m.(*Sample).Value) },
+	// repeated Label label = 3
+	func(b *buffer, m message) error {
+		s := m.(*Sample)
+		n := len(s.labelX)
+		s.labelX = append(s.labelX, label{})
+		return decodeMessage(b, &s.labelX[n])
+	},
+}
+
+func (p label) decoder() []decoder {
+	return labelDecoder
+}
+
+func (p label) encode(b *buffer) {
+	encodeInt64Opt(b, 1, p.keyX)
+	encodeInt64Opt(b, 2, p.strX)
+	encodeInt64Opt(b, 3, p.numX)
+	encodeInt64Opt(b, 4, p.unitX)
+}
+
+var labelDecoder = []decoder{
+	nil, // 0
+	// optional int64 key = 1
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*label).keyX) },
+	// optional int64 str = 2
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*label).strX) },
+	// optional int64 num = 3
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*label).numX) },
+	// optional int64 num = 4
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*label).unitX) },
+}
+
+func (p *Mapping) decoder() []decoder {
+	return mappingDecoder
+}
+
+func (p *Mapping) encode(b *buffer) {
+	encodeUint64Opt(b, 1, p.ID)
+	encodeUint64Opt(b, 2, p.Start)
+	encodeUint64Opt(b, 3, p.Limit)
+	encodeUint64Opt(b, 4, p.Offset)
+	encodeInt64Opt(b, 5, p.fileX)
+	encodeInt64Opt(b, 6, p.buildIDX)
+	encodeBoolOpt(b, 7, p.HasFunctions)
+	encodeBoolOpt(b, 8, p.HasFilenames)
+	encodeBoolOpt(b, 9, p.HasLineNumbers)
+	encodeBoolOpt(b, 10, p.HasInlineFrames)
+}
+
+var mappingDecoder = []decoder{
+	nil, // 0
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Mapping).ID) },            // optional uint64 id = 1
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Mapping).Start) },         // optional uint64 memory_offset = 2
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Mapping).Limit) },         // optional uint64 memory_limit = 3
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Mapping).Offset) },        // optional uint64 file_offset = 4
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Mapping).fileX) },          // optional int64 filename = 5
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Mapping).buildIDX) },       // optional int64 build_id = 6
+	func(b *buffer, m message) error { return decodeBool(b, &m.(*Mapping).HasFunctions) },    // optional bool has_functions = 7
+	func(b *buffer, m message) error { return decodeBool(b, &m.(*Mapping).HasFilenames) },    // optional bool has_filenames = 8
+	func(b *buffer, m message) error { return decodeBool(b, &m.(*Mapping).HasLineNumbers) },  // optional bool has_line_numbers = 9
+	func(b *buffer, m message) error { return decodeBool(b, &m.(*Mapping).HasInlineFrames) }, // optional bool has_inline_frames = 10
+}
+
+func (p *Location) decoder() []decoder {
+	return locationDecoder
+}
+
+func (p *Location) encode(b *buffer) {
+	encodeUint64Opt(b, 1, p.ID)
+	encodeUint64Opt(b, 2, p.mappingIDX)
+	encodeUint64Opt(b, 3, p.Address)
+	for i := range p.Line {
+		encodeMessage(b, 4, &p.Line[i])
+	}
+	encodeBoolOpt(b, 5, p.IsFolded)
+}
+
+var locationDecoder = []decoder{
+	nil, // 0
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Location).ID) },         // optional uint64 id = 1;
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Location).mappingIDX) }, // optional uint64 mapping_id = 2;
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Location).Address) },    // optional uint64 address = 3;
+	func(b *buffer, m message) error { // repeated Line line = 4
+		pp := m.(*Location)
+		n := len(pp.Line)
+		pp.Line = append(pp.Line, Line{})
+		return decodeMessage(b, &pp.Line[n])
+	},
+	func(b *buffer, m message) error { return decodeBool(b, &m.(*Location).IsFolded) }, // optional bool is_folded = 5;
+}
+
+func (p *Line) decoder() []decoder {
+	return lineDecoder
+}
+
+func (p *Line) encode(b *buffer) {
+	encodeUint64Opt(b, 1, p.functionIDX)
+	encodeInt64Opt(b, 2, p.Line)
+}
+
+var lineDecoder = []decoder{
+	nil, // 0
+	// optional uint64 function_id = 1
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Line).functionIDX) },
+	// optional int64 line = 2
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Line).Line) },
+}
+
+func (p *Function) decoder() []decoder {
+	return functionDecoder
+}
+
+func (p *Function) encode(b *buffer) {
+	encodeUint64Opt(b, 1, p.ID)
+	encodeInt64Opt(b, 2, p.nameX)
+	encodeInt64Opt(b, 3, p.systemNameX)
+	encodeInt64Opt(b, 4, p.filenameX)
+	encodeInt64Opt(b, 5, p.StartLine)
+}
+
+var functionDecoder = []decoder{
+	nil, // 0
+	// optional uint64 id = 1
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Function).ID) },
+	// optional int64 function_name = 2
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Function).nameX) },
+	// optional int64 function_system_name = 3
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Function).systemNameX) },
+	// repeated int64 filename = 4
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Function).filenameX) },
+	// optional int64 start_line = 5
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Function).StartLine) },
+}
+
+func addString(strings map[string]int, s string) int64 {
+	i, ok := strings[s]
+	if !ok {
+		i = len(strings)
+		strings[s] = i
+	}
+	return int64(i)
+}
+
+func getString(strings []string, strng *int64, err error) (string, error) {
+	if err != nil {
+		return "", err
+	}
+	s := int(*strng)
+	if s < 0 || s >= len(strings) {
+		return "", errMalformed
+	}
+	*strng = 0
+	return strings[s], nil
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/filter.go b/src/cmd/vendor/github.com/google/pprof/profile/filter.go
new file mode 100644
index 0000000..ea8e66c
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/profile/filter.go
@@ -0,0 +1,270 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package profile
+
+// Implements methods to filter samples from profiles.
+
+import "regexp"
+
+// FilterSamplesByName filters the samples in a profile and only keeps
+// samples where at least one frame matches focus but none match ignore.
+// Returns true is the corresponding regexp matched at least one sample.
+func (p *Profile) FilterSamplesByName(focus, ignore, hide, show *regexp.Regexp) (fm, im, hm, hnm bool) {
+	focusOrIgnore := make(map[uint64]bool)
+	hidden := make(map[uint64]bool)
+	for _, l := range p.Location {
+		if ignore != nil && l.matchesName(ignore) {
+			im = true
+			focusOrIgnore[l.ID] = false
+		} else if focus == nil || l.matchesName(focus) {
+			fm = true
+			focusOrIgnore[l.ID] = true
+		}
+
+		if hide != nil && l.matchesName(hide) {
+			hm = true
+			l.Line = l.unmatchedLines(hide)
+			if len(l.Line) == 0 {
+				hidden[l.ID] = true
+			}
+		}
+		if show != nil {
+			l.Line = l.matchedLines(show)
+			if len(l.Line) == 0 {
+				hidden[l.ID] = true
+			} else {
+				hnm = true
+			}
+		}
+	}
+
+	s := make([]*Sample, 0, len(p.Sample))
+	for _, sample := range p.Sample {
+		if focusedAndNotIgnored(sample.Location, focusOrIgnore) {
+			if len(hidden) > 0 {
+				var locs []*Location
+				for _, loc := range sample.Location {
+					if !hidden[loc.ID] {
+						locs = append(locs, loc)
+					}
+				}
+				if len(locs) == 0 {
+					// Remove sample with no locations (by not adding it to s).
+					continue
+				}
+				sample.Location = locs
+			}
+			s = append(s, sample)
+		}
+	}
+	p.Sample = s
+
+	return
+}
+
+// ShowFrom drops all stack frames above the highest matching frame and returns
+// whether a match was found. If showFrom is nil it returns false and does not
+// modify the profile.
+//
+// Example: consider a sample with frames [A, B, C, B], where A is the root.
+// ShowFrom(nil) returns false and has frames [A, B, C, B].
+// ShowFrom(A) returns true and has frames [A, B, C, B].
+// ShowFrom(B) returns true and has frames [B, C, B].
+// ShowFrom(C) returns true and has frames [C, B].
+// ShowFrom(D) returns false and drops the sample because no frames remain.
+func (p *Profile) ShowFrom(showFrom *regexp.Regexp) (matched bool) {
+	if showFrom == nil {
+		return false
+	}
+	// showFromLocs stores location IDs that matched ShowFrom.
+	showFromLocs := make(map[uint64]bool)
+	// Apply to locations.
+	for _, loc := range p.Location {
+		if filterShowFromLocation(loc, showFrom) {
+			showFromLocs[loc.ID] = true
+			matched = true
+		}
+	}
+	// For all samples, strip locations after the highest matching one.
+	s := make([]*Sample, 0, len(p.Sample))
+	for _, sample := range p.Sample {
+		for i := len(sample.Location) - 1; i >= 0; i-- {
+			if showFromLocs[sample.Location[i].ID] {
+				sample.Location = sample.Location[:i+1]
+				s = append(s, sample)
+				break
+			}
+		}
+	}
+	p.Sample = s
+	return matched
+}
+
+// filterShowFromLocation tests a showFrom regex against a location, removes
+// lines after the last match and returns whether a match was found. If the
+// mapping is matched, then all lines are kept.
+func filterShowFromLocation(loc *Location, showFrom *regexp.Regexp) bool {
+	if m := loc.Mapping; m != nil && showFrom.MatchString(m.File) {
+		return true
+	}
+	if i := loc.lastMatchedLineIndex(showFrom); i >= 0 {
+		loc.Line = loc.Line[:i+1]
+		return true
+	}
+	return false
+}
+
+// lastMatchedLineIndex returns the index of the last line that matches a regex,
+// or -1 if no match is found.
+func (loc *Location) lastMatchedLineIndex(re *regexp.Regexp) int {
+	for i := len(loc.Line) - 1; i >= 0; i-- {
+		if fn := loc.Line[i].Function; fn != nil {
+			if re.MatchString(fn.Name) || re.MatchString(fn.Filename) {
+				return i
+			}
+		}
+	}
+	return -1
+}
+
+// FilterTagsByName filters the tags in a profile and only keeps
+// tags that match show and not hide.
+func (p *Profile) FilterTagsByName(show, hide *regexp.Regexp) (sm, hm bool) {
+	matchRemove := func(name string) bool {
+		matchShow := show == nil || show.MatchString(name)
+		matchHide := hide != nil && hide.MatchString(name)
+
+		if matchShow {
+			sm = true
+		}
+		if matchHide {
+			hm = true
+		}
+		return !matchShow || matchHide
+	}
+	for _, s := range p.Sample {
+		for lab := range s.Label {
+			if matchRemove(lab) {
+				delete(s.Label, lab)
+			}
+		}
+		for lab := range s.NumLabel {
+			if matchRemove(lab) {
+				delete(s.NumLabel, lab)
+			}
+		}
+	}
+	return
+}
+
+// matchesName returns whether the location matches the regular
+// expression. It checks any available function names, file names, and
+// mapping object filename.
+func (loc *Location) matchesName(re *regexp.Regexp) bool {
+	for _, ln := range loc.Line {
+		if fn := ln.Function; fn != nil {
+			if re.MatchString(fn.Name) || re.MatchString(fn.Filename) {
+				return true
+			}
+		}
+	}
+	if m := loc.Mapping; m != nil && re.MatchString(m.File) {
+		return true
+	}
+	return false
+}
+
+// unmatchedLines returns the lines in the location that do not match
+// the regular expression.
+func (loc *Location) unmatchedLines(re *regexp.Regexp) []Line {
+	if m := loc.Mapping; m != nil && re.MatchString(m.File) {
+		return nil
+	}
+	var lines []Line
+	for _, ln := range loc.Line {
+		if fn := ln.Function; fn != nil {
+			if re.MatchString(fn.Name) || re.MatchString(fn.Filename) {
+				continue
+			}
+		}
+		lines = append(lines, ln)
+	}
+	return lines
+}
+
+// matchedLines returns the lines in the location that match
+// the regular expression.
+func (loc *Location) matchedLines(re *regexp.Regexp) []Line {
+	if m := loc.Mapping; m != nil && re.MatchString(m.File) {
+		return loc.Line
+	}
+	var lines []Line
+	for _, ln := range loc.Line {
+		if fn := ln.Function; fn != nil {
+			if !re.MatchString(fn.Name) && !re.MatchString(fn.Filename) {
+				continue
+			}
+		}
+		lines = append(lines, ln)
+	}
+	return lines
+}
+
+// focusedAndNotIgnored looks up a slice of ids against a map of
+// focused/ignored locations. The map only contains locations that are
+// explicitly focused or ignored. Returns whether there is at least
+// one focused location but no ignored locations.
+func focusedAndNotIgnored(locs []*Location, m map[uint64]bool) bool {
+	var f bool
+	for _, loc := range locs {
+		if focus, focusOrIgnore := m[loc.ID]; focusOrIgnore {
+			if focus {
+				// Found focused location. Must keep searching in case there
+				// is an ignored one as well.
+				f = true
+			} else {
+				// Found ignored location. Can return false right away.
+				return false
+			}
+		}
+	}
+	return f
+}
+
+// TagMatch selects tags for filtering
+type TagMatch func(s *Sample) bool
+
+// FilterSamplesByTag removes all samples from the profile, except
+// those that match focus and do not match the ignore regular
+// expression.
+func (p *Profile) FilterSamplesByTag(focus, ignore TagMatch) (fm, im bool) {
+	samples := make([]*Sample, 0, len(p.Sample))
+	for _, s := range p.Sample {
+		focused, ignored := true, false
+		if focus != nil {
+			focused = focus(s)
+		}
+		if ignore != nil {
+			ignored = ignore(s)
+		}
+		fm = fm || focused
+		im = im || ignored
+		if focused && !ignored {
+			samples = append(samples, s)
+		}
+	}
+	p.Sample = samples
+	return
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/index.go b/src/cmd/vendor/github.com/google/pprof/profile/index.go
new file mode 100644
index 0000000..bef1d60
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/profile/index.go
@@ -0,0 +1,64 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package profile
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// SampleIndexByName returns the appropriate index for a value of sample index.
+// If numeric, it returns the number, otherwise it looks up the text in the
+// profile sample types.
+func (p *Profile) SampleIndexByName(sampleIndex string) (int, error) {
+	if sampleIndex == "" {
+		if dst := p.DefaultSampleType; dst != "" {
+			for i, t := range sampleTypes(p) {
+				if t == dst {
+					return i, nil
+				}
+			}
+		}
+		// By default select the last sample value
+		return len(p.SampleType) - 1, nil
+	}
+	if i, err := strconv.Atoi(sampleIndex); err == nil {
+		if i < 0 || i >= len(p.SampleType) {
+			return 0, fmt.Errorf("sample_index %s is outside the range [0..%d]", sampleIndex, len(p.SampleType)-1)
+		}
+		return i, nil
+	}
+
+	// Remove the inuse_ prefix to support legacy pprof options
+	// "inuse_space" and "inuse_objects" for profiles containing types
+	// "space" and "objects".
+	noInuse := strings.TrimPrefix(sampleIndex, "inuse_")
+	for i, t := range p.SampleType {
+		if t.Type == sampleIndex || t.Type == noInuse {
+			return i, nil
+		}
+	}
+
+	return 0, fmt.Errorf("sample_index %q must be one of: %v", sampleIndex, sampleTypes(p))
+}
+
+func sampleTypes(p *Profile) []string {
+	types := make([]string, len(p.SampleType))
+	for i, t := range p.SampleType {
+		types[i] = t.Type
+	}
+	return types
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/legacy_java_profile.go b/src/cmd/vendor/github.com/google/pprof/profile/legacy_java_profile.go
new file mode 100644
index 0000000..91f45e5
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/profile/legacy_java_profile.go
@@ -0,0 +1,315 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file implements parsers to convert java legacy profiles into
+// the profile.proto format.
+
+package profile
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var (
+	attributeRx            = regexp.MustCompile(`([\w ]+)=([\w ]+)`)
+	javaSampleRx           = regexp.MustCompile(` *(\d+) +(\d+) +@ +([ x0-9a-f]*)`)
+	javaLocationRx         = regexp.MustCompile(`^\s*0x([[:xdigit:]]+)\s+(.*)\s*$`)
+	javaLocationFileLineRx = regexp.MustCompile(`^(.*)\s+\((.+):(-?[[:digit:]]+)\)$`)
+	javaLocationPathRx     = regexp.MustCompile(`^(.*)\s+\((.*)\)$`)
+)
+
+// javaCPUProfile returns a new Profile from profilez data.
+// b is the profile bytes after the header, period is the profiling
+// period, and parse is a function to parse 8-byte chunks from the
+// profile in its native endianness.
+func javaCPUProfile(b []byte, period int64, parse func(b []byte) (uint64, []byte)) (*Profile, error) {
+	p := &Profile{
+		Period:     period * 1000,
+		PeriodType: &ValueType{Type: "cpu", Unit: "nanoseconds"},
+		SampleType: []*ValueType{{Type: "samples", Unit: "count"}, {Type: "cpu", Unit: "nanoseconds"}},
+	}
+	var err error
+	var locs map[uint64]*Location
+	if b, locs, err = parseCPUSamples(b, parse, false, p); err != nil {
+		return nil, err
+	}
+
+	if err = parseJavaLocations(b, locs, p); err != nil {
+		return nil, err
+	}
+
+	// Strip out addresses for better merge.
+	if err = p.Aggregate(true, true, true, true, false); err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}
+
+// parseJavaProfile returns a new profile from heapz or contentionz
+// data. b is the profile bytes after the header.
+func parseJavaProfile(b []byte) (*Profile, error) {
+	h := bytes.SplitAfterN(b, []byte("\n"), 2)
+	if len(h) < 2 {
+		return nil, errUnrecognized
+	}
+
+	p := &Profile{
+		PeriodType: &ValueType{},
+	}
+	header := string(bytes.TrimSpace(h[0]))
+
+	var err error
+	var pType string
+	switch header {
+	case "--- heapz 1 ---":
+		pType = "heap"
+	case "--- contentionz 1 ---":
+		pType = "contention"
+	default:
+		return nil, errUnrecognized
+	}
+
+	if b, err = parseJavaHeader(pType, h[1], p); err != nil {
+		return nil, err
+	}
+	var locs map[uint64]*Location
+	if b, locs, err = parseJavaSamples(pType, b, p); err != nil {
+		return nil, err
+	}
+	if err = parseJavaLocations(b, locs, p); err != nil {
+		return nil, err
+	}
+
+	// Strip out addresses for better merge.
+	if err = p.Aggregate(true, true, true, true, false); err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}
+
+// parseJavaHeader parses the attribute section on a java profile and
+// populates a profile. Returns the remainder of the buffer after all
+// attributes.
+func parseJavaHeader(pType string, b []byte, p *Profile) ([]byte, error) {
+	nextNewLine := bytes.IndexByte(b, byte('\n'))
+	for nextNewLine != -1 {
+		line := string(bytes.TrimSpace(b[0:nextNewLine]))
+		if line != "" {
+			h := attributeRx.FindStringSubmatch(line)
+			if h == nil {
+				// Not a valid attribute, exit.
+				return b, nil
+			}
+
+			attribute, value := strings.TrimSpace(h[1]), strings.TrimSpace(h[2])
+			var err error
+			switch pType + "/" + attribute {
+			case "heap/format", "cpu/format", "contention/format":
+				if value != "java" {
+					return nil, errUnrecognized
+				}
+			case "heap/resolution":
+				p.SampleType = []*ValueType{
+					{Type: "inuse_objects", Unit: "count"},
+					{Type: "inuse_space", Unit: value},
+				}
+			case "contention/resolution":
+				p.SampleType = []*ValueType{
+					{Type: "contentions", Unit: "count"},
+					{Type: "delay", Unit: value},
+				}
+			case "contention/sampling period":
+				p.PeriodType = &ValueType{
+					Type: "contentions", Unit: "count",
+				}
+				if p.Period, err = strconv.ParseInt(value, 0, 64); err != nil {
+					return nil, fmt.Errorf("failed to parse attribute %s: %v", line, err)
+				}
+			case "contention/ms since reset":
+				millis, err := strconv.ParseInt(value, 0, 64)
+				if err != nil {
+					return nil, fmt.Errorf("failed to parse attribute %s: %v", line, err)
+				}
+				p.DurationNanos = millis * 1000 * 1000
+			default:
+				return nil, errUnrecognized
+			}
+		}
+		// Grab next line.
+		b = b[nextNewLine+1:]
+		nextNewLine = bytes.IndexByte(b, byte('\n'))
+	}
+	return b, nil
+}
+
+// parseJavaSamples parses the samples from a java profile and
+// populates the Samples in a profile. Returns the remainder of the
+// buffer after the samples.
+func parseJavaSamples(pType string, b []byte, p *Profile) ([]byte, map[uint64]*Location, error) {
+	nextNewLine := bytes.IndexByte(b, byte('\n'))
+	locs := make(map[uint64]*Location)
+	for nextNewLine != -1 {
+		line := string(bytes.TrimSpace(b[0:nextNewLine]))
+		if line != "" {
+			sample := javaSampleRx.FindStringSubmatch(line)
+			if sample == nil {
+				// Not a valid sample, exit.
+				return b, locs, nil
+			}
+
+			// Java profiles have data/fields inverted compared to other
+			// profile types.
+			var err error
+			value1, value2, value3 := sample[2], sample[1], sample[3]
+			addrs, err := parseHexAddresses(value3)
+			if err != nil {
+				return nil, nil, fmt.Errorf("malformed sample: %s: %v", line, err)
+			}
+
+			var sloc []*Location
+			for _, addr := range addrs {
+				loc := locs[addr]
+				if locs[addr] == nil {
+					loc = &Location{
+						Address: addr,
+					}
+					p.Location = append(p.Location, loc)
+					locs[addr] = loc
+				}
+				sloc = append(sloc, loc)
+			}
+			s := &Sample{
+				Value:    make([]int64, 2),
+				Location: sloc,
+			}
+
+			if s.Value[0], err = strconv.ParseInt(value1, 0, 64); err != nil {
+				return nil, nil, fmt.Errorf("parsing sample %s: %v", line, err)
+			}
+			if s.Value[1], err = strconv.ParseInt(value2, 0, 64); err != nil {
+				return nil, nil, fmt.Errorf("parsing sample %s: %v", line, err)
+			}
+
+			switch pType {
+			case "heap":
+				const javaHeapzSamplingRate = 524288 // 512K
+				if s.Value[0] == 0 {
+					return nil, nil, fmt.Errorf("parsing sample %s: second value must be non-zero", line)
+				}
+				s.NumLabel = map[string][]int64{"bytes": {s.Value[1] / s.Value[0]}}
+				s.Value[0], s.Value[1] = scaleHeapSample(s.Value[0], s.Value[1], javaHeapzSamplingRate)
+			case "contention":
+				if period := p.Period; period != 0 {
+					s.Value[0] = s.Value[0] * p.Period
+					s.Value[1] = s.Value[1] * p.Period
+				}
+			}
+			p.Sample = append(p.Sample, s)
+		}
+		// Grab next line.
+		b = b[nextNewLine+1:]
+		nextNewLine = bytes.IndexByte(b, byte('\n'))
+	}
+	return b, locs, nil
+}
+
+// parseJavaLocations parses the location information in a java
+// profile and populates the Locations in a profile. It uses the
+// location addresses from the profile as both the ID of each
+// location.
+func parseJavaLocations(b []byte, locs map[uint64]*Location, p *Profile) error {
+	r := bytes.NewBuffer(b)
+	fns := make(map[string]*Function)
+	for {
+		line, err := r.ReadString('\n')
+		if err != nil {
+			if err != io.EOF {
+				return err
+			}
+			if line == "" {
+				break
+			}
+		}
+
+		if line = strings.TrimSpace(line); line == "" {
+			continue
+		}
+
+		jloc := javaLocationRx.FindStringSubmatch(line)
+		if len(jloc) != 3 {
+			continue
+		}
+		addr, err := strconv.ParseUint(jloc[1], 16, 64)
+		if err != nil {
+			return fmt.Errorf("parsing sample %s: %v", line, err)
+		}
+		loc := locs[addr]
+		if loc == nil {
+			// Unused/unseen
+			continue
+		}
+		var lineFunc, lineFile string
+		var lineNo int64
+
+		if fileLine := javaLocationFileLineRx.FindStringSubmatch(jloc[2]); len(fileLine) == 4 {
+			// Found a line of the form: "function (file:line)"
+			lineFunc, lineFile = fileLine[1], fileLine[2]
+			if n, err := strconv.ParseInt(fileLine[3], 10, 64); err == nil && n > 0 {
+				lineNo = n
+			}
+		} else if filePath := javaLocationPathRx.FindStringSubmatch(jloc[2]); len(filePath) == 3 {
+			// If there's not a file:line, it's a shared library path.
+			// The path isn't interesting, so just give the .so.
+			lineFunc, lineFile = filePath[1], filepath.Base(filePath[2])
+		} else if strings.Contains(jloc[2], "generated stub/JIT") {
+			lineFunc = "STUB"
+		} else {
+			// Treat whole line as the function name. This is used by the
+			// java agent for internal states such as "GC" or "VM".
+			lineFunc = jloc[2]
+		}
+		fn := fns[lineFunc]
+
+		if fn == nil {
+			fn = &Function{
+				Name:       lineFunc,
+				SystemName: lineFunc,
+				Filename:   lineFile,
+			}
+			fns[lineFunc] = fn
+			p.Function = append(p.Function, fn)
+		}
+		loc.Line = []Line{
+			{
+				Function: fn,
+				Line:     lineNo,
+			},
+		}
+		loc.Address = 0
+	}
+
+	p.remapLocationIDs()
+	p.remapFunctionIDs()
+	p.remapMappingIDs()
+
+	return nil
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/legacy_profile.go b/src/cmd/vendor/github.com/google/pprof/profile/legacy_profile.go
new file mode 100644
index 0000000..0c8f3bb
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/profile/legacy_profile.go
@@ -0,0 +1,1225 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file implements parsers to convert legacy profiles into the
+// profile.proto format.
+
+package profile
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"math"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var (
+	countStartRE = regexp.MustCompile(`\A(\S+) profile: total \d+\z`)
+	countRE      = regexp.MustCompile(`\A(\d+) @(( 0x[0-9a-f]+)+)\z`)
+
+	heapHeaderRE = regexp.MustCompile(`heap profile: *(\d+): *(\d+) *\[ *(\d+): *(\d+) *\] *@ *(heap[_a-z0-9]*)/?(\d*)`)
+	heapSampleRE = regexp.MustCompile(`(-?\d+): *(-?\d+) *\[ *(\d+): *(\d+) *] @([ x0-9a-f]*)`)
+
+	contentionSampleRE = regexp.MustCompile(`(\d+) *(\d+) @([ x0-9a-f]*)`)
+
+	hexNumberRE = regexp.MustCompile(`0x[0-9a-f]+`)
+
+	growthHeaderRE = regexp.MustCompile(`heap profile: *(\d+): *(\d+) *\[ *(\d+): *(\d+) *\] @ growthz?`)
+
+	fragmentationHeaderRE = regexp.MustCompile(`heap profile: *(\d+): *(\d+) *\[ *(\d+): *(\d+) *\] @ fragmentationz?`)
+
+	threadzStartRE = regexp.MustCompile(`--- threadz \d+ ---`)
+	threadStartRE  = regexp.MustCompile(`--- Thread ([[:xdigit:]]+) \(name: (.*)/(\d+)\) stack: ---`)
+
+	// Regular expressions to parse process mappings. Support the format used by Linux /proc/.../maps and other tools.
+	// Recommended format:
+	// Start   End     object file name     offset(optional)   linker build id
+	// 0x40000-0x80000 /path/to/binary      (@FF00)            abc123456
+	spaceDigits = `\s+[[:digit:]]+`
+	hexPair     = `\s+[[:xdigit:]]+:[[:xdigit:]]+`
+	oSpace      = `\s*`
+	// Capturing expressions.
+	cHex           = `(?:0x)?([[:xdigit:]]+)`
+	cHexRange      = `\s*` + cHex + `[\s-]?` + oSpace + cHex + `:?`
+	cSpaceString   = `(?:\s+(\S+))?`
+	cSpaceHex      = `(?:\s+([[:xdigit:]]+))?`
+	cSpaceAtOffset = `(?:\s+\(@([[:xdigit:]]+)\))?`
+	cPerm          = `(?:\s+([-rwxp]+))?`
+
+	procMapsRE  = regexp.MustCompile(`^` + cHexRange + cPerm + cSpaceHex + hexPair + spaceDigits + cSpaceString)
+	briefMapsRE = regexp.MustCompile(`^` + cHexRange + cPerm + cSpaceString + cSpaceAtOffset + cSpaceHex)
+
+	// Regular expression to parse log data, of the form:
+	// ... file:line] msg...
+	logInfoRE = regexp.MustCompile(`^[^\[\]]+:[0-9]+]\s`)
+)
+
+func isSpaceOrComment(line string) bool {
+	trimmed := strings.TrimSpace(line)
+	return len(trimmed) == 0 || trimmed[0] == '#'
+}
+
+// parseGoCount parses a Go count profile (e.g., threadcreate or
+// goroutine) and returns a new Profile.
+func parseGoCount(b []byte) (*Profile, error) {
+	s := bufio.NewScanner(bytes.NewBuffer(b))
+	// Skip comments at the beginning of the file.
+	for s.Scan() && isSpaceOrComment(s.Text()) {
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+	m := countStartRE.FindStringSubmatch(s.Text())
+	if m == nil {
+		return nil, errUnrecognized
+	}
+	profileType := m[1]
+	p := &Profile{
+		PeriodType: &ValueType{Type: profileType, Unit: "count"},
+		Period:     1,
+		SampleType: []*ValueType{{Type: profileType, Unit: "count"}},
+	}
+	locations := make(map[uint64]*Location)
+	for s.Scan() {
+		line := s.Text()
+		if isSpaceOrComment(line) {
+			continue
+		}
+		if strings.HasPrefix(line, "---") {
+			break
+		}
+		m := countRE.FindStringSubmatch(line)
+		if m == nil {
+			return nil, errMalformed
+		}
+		n, err := strconv.ParseInt(m[1], 0, 64)
+		if err != nil {
+			return nil, errMalformed
+		}
+		fields := strings.Fields(m[2])
+		locs := make([]*Location, 0, len(fields))
+		for _, stk := range fields {
+			addr, err := strconv.ParseUint(stk, 0, 64)
+			if err != nil {
+				return nil, errMalformed
+			}
+			// Adjust all frames by -1 to land on top of the call instruction.
+			addr--
+			loc := locations[addr]
+			if loc == nil {
+				loc = &Location{
+					Address: addr,
+				}
+				locations[addr] = loc
+				p.Location = append(p.Location, loc)
+			}
+			locs = append(locs, loc)
+		}
+		p.Sample = append(p.Sample, &Sample{
+			Location: locs,
+			Value:    []int64{n},
+		})
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	if err := parseAdditionalSections(s, p); err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+// remapLocationIDs ensures there is a location for each address
+// referenced by a sample, and remaps the samples to point to the new
+// location ids.
+func (p *Profile) remapLocationIDs() {
+	seen := make(map[*Location]bool, len(p.Location))
+	var locs []*Location
+
+	for _, s := range p.Sample {
+		for _, l := range s.Location {
+			if seen[l] {
+				continue
+			}
+			l.ID = uint64(len(locs) + 1)
+			locs = append(locs, l)
+			seen[l] = true
+		}
+	}
+	p.Location = locs
+}
+
+func (p *Profile) remapFunctionIDs() {
+	seen := make(map[*Function]bool, len(p.Function))
+	var fns []*Function
+
+	for _, l := range p.Location {
+		for _, ln := range l.Line {
+			fn := ln.Function
+			if fn == nil || seen[fn] {
+				continue
+			}
+			fn.ID = uint64(len(fns) + 1)
+			fns = append(fns, fn)
+			seen[fn] = true
+		}
+	}
+	p.Function = fns
+}
+
+// remapMappingIDs matches location addresses with existing mappings
+// and updates them appropriately. This is O(N*M), if this ever shows
+// up as a bottleneck, evaluate sorting the mappings and doing a
+// binary search, which would make it O(N*log(M)).
+func (p *Profile) remapMappingIDs() {
+	// Some profile handlers will incorrectly set regions for the main
+	// executable if its section is remapped. Fix them through heuristics.
+
+	if len(p.Mapping) > 0 {
+		// Remove the initial mapping if named '/anon_hugepage' and has a
+		// consecutive adjacent mapping.
+		if m := p.Mapping[0]; strings.HasPrefix(m.File, "/anon_hugepage") {
+			if len(p.Mapping) > 1 && m.Limit == p.Mapping[1].Start {
+				p.Mapping = p.Mapping[1:]
+			}
+		}
+	}
+
+	// Subtract the offset from the start of the main mapping if it
+	// ends up at a recognizable start address.
+	if len(p.Mapping) > 0 {
+		const expectedStart = 0x400000
+		if m := p.Mapping[0]; m.Start-m.Offset == expectedStart {
+			m.Start = expectedStart
+			m.Offset = 0
+		}
+	}
+
+	// Associate each location with an address to the corresponding
+	// mapping. Create fake mapping if a suitable one isn't found.
+	var fake *Mapping
+nextLocation:
+	for _, l := range p.Location {
+		a := l.Address
+		if l.Mapping != nil || a == 0 {
+			continue
+		}
+		for _, m := range p.Mapping {
+			if m.Start <= a && a < m.Limit {
+				l.Mapping = m
+				continue nextLocation
+			}
+		}
+		// Work around legacy handlers failing to encode the first
+		// part of mappings split into adjacent ranges.
+		for _, m := range p.Mapping {
+			if m.Offset != 0 && m.Start-m.Offset <= a && a < m.Start {
+				m.Start -= m.Offset
+				m.Offset = 0
+				l.Mapping = m
+				continue nextLocation
+			}
+		}
+		// If there is still no mapping, create a fake one.
+		// This is important for the Go legacy handler, which produced
+		// no mappings.
+		if fake == nil {
+			fake = &Mapping{
+				ID:    1,
+				Limit: ^uint64(0),
+			}
+			p.Mapping = append(p.Mapping, fake)
+		}
+		l.Mapping = fake
+	}
+
+	// Reset all mapping IDs.
+	for i, m := range p.Mapping {
+		m.ID = uint64(i + 1)
+	}
+}
+
+var cpuInts = []func([]byte) (uint64, []byte){
+	get32l,
+	get32b,
+	get64l,
+	get64b,
+}
+
+func get32l(b []byte) (uint64, []byte) {
+	if len(b) < 4 {
+		return 0, nil
+	}
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24, b[4:]
+}
+
+func get32b(b []byte) (uint64, []byte) {
+	if len(b) < 4 {
+		return 0, nil
+	}
+	return uint64(b[3]) | uint64(b[2])<<8 | uint64(b[1])<<16 | uint64(b[0])<<24, b[4:]
+}
+
+func get64l(b []byte) (uint64, []byte) {
+	if len(b) < 8 {
+		return 0, nil
+	}
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56, b[8:]
+}
+
+func get64b(b []byte) (uint64, []byte) {
+	if len(b) < 8 {
+		return 0, nil
+	}
+	return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 | uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56, b[8:]
+}
+
+// parseCPU parses a profilez legacy profile and returns a newly
+// populated Profile.
+//
+// The general format for profilez samples is a sequence of words in
+// binary format. The first words are a header with the following data:
+//   1st word -- 0
+//   2nd word -- 3
+//   3rd word -- 0 if a c++ application, 1 if a java application.
+//   4th word -- Sampling period (in microseconds).
+//   5th word -- Padding.
+func parseCPU(b []byte) (*Profile, error) {
+	var parse func([]byte) (uint64, []byte)
+	var n1, n2, n3, n4, n5 uint64
+	for _, parse = range cpuInts {
+		var tmp []byte
+		n1, tmp = parse(b)
+		n2, tmp = parse(tmp)
+		n3, tmp = parse(tmp)
+		n4, tmp = parse(tmp)
+		n5, tmp = parse(tmp)
+
+		if tmp != nil && n1 == 0 && n2 == 3 && n3 == 0 && n4 > 0 && n5 == 0 {
+			b = tmp
+			return cpuProfile(b, int64(n4), parse)
+		}
+		if tmp != nil && n1 == 0 && n2 == 3 && n3 == 1 && n4 > 0 && n5 == 0 {
+			b = tmp
+			return javaCPUProfile(b, int64(n4), parse)
+		}
+	}
+	return nil, errUnrecognized
+}
+
+// cpuProfile returns a new Profile from C++ profilez data.
+// b is the profile bytes after the header, period is the profiling
+// period, and parse is a function to parse 8-byte chunks from the
+// profile in its native endianness.
+func cpuProfile(b []byte, period int64, parse func(b []byte) (uint64, []byte)) (*Profile, error) {
+	p := &Profile{
+		Period:     period * 1000,
+		PeriodType: &ValueType{Type: "cpu", Unit: "nanoseconds"},
+		SampleType: []*ValueType{
+			{Type: "samples", Unit: "count"},
+			{Type: "cpu", Unit: "nanoseconds"},
+		},
+	}
+	var err error
+	if b, _, err = parseCPUSamples(b, parse, true, p); err != nil {
+		return nil, err
+	}
+
+	// If *most* samples have the same second-to-the-bottom frame, it
+	// strongly suggests that it is an uninteresting artifact of
+	// measurement -- a stack frame pushed by the signal handler. The
+	// bottom frame is always correct as it is picked up from the signal
+	// structure, not the stack. Check if this is the case and if so,
+	// remove.
+
+	// Remove up to two frames.
+	maxiter := 2
+	// Allow one different sample for this many samples with the same
+	// second-to-last frame.
+	similarSamples := 32
+	margin := len(p.Sample) / similarSamples
+
+	for iter := 0; iter < maxiter; iter++ {
+		addr1 := make(map[uint64]int)
+		for _, s := range p.Sample {
+			if len(s.Location) > 1 {
+				a := s.Location[1].Address
+				addr1[a] = addr1[a] + 1
+			}
+		}
+
+		for id1, count := range addr1 {
+			if count >= len(p.Sample)-margin {
+				// Found uninteresting frame, strip it out from all samples
+				for _, s := range p.Sample {
+					if len(s.Location) > 1 && s.Location[1].Address == id1 {
+						s.Location = append(s.Location[:1], s.Location[2:]...)
+					}
+				}
+				break
+			}
+		}
+	}
+
+	if err := p.ParseMemoryMap(bytes.NewBuffer(b)); err != nil {
+		return nil, err
+	}
+
+	cleanupDuplicateLocations(p)
+	return p, nil
+}
+
+func cleanupDuplicateLocations(p *Profile) {
+	// The profile handler may duplicate the leaf frame, because it gets
+	// its address both from stack unwinding and from the signal
+	// context. Detect this and delete the duplicate, which has been
+	// adjusted by -1. The leaf address should not be adjusted as it is
+	// not a call.
+	for _, s := range p.Sample {
+		if len(s.Location) > 1 && s.Location[0].Address == s.Location[1].Address+1 {
+			s.Location = append(s.Location[:1], s.Location[2:]...)
+		}
+	}
+}
+
+// parseCPUSamples parses a collection of profilez samples from a
+// profile.
+//
+// profilez samples are a repeated sequence of stack frames of the
+// form:
+//    1st word -- The number of times this stack was encountered.
+//    2nd word -- The size of the stack (StackSize).
+//    3rd word -- The first address on the stack.
+//    ...
+//    StackSize + 2 -- The last address on the stack
+// The last stack trace is of the form:
+//   1st word -- 0
+//   2nd word -- 1
+//   3rd word -- 0
+//
+// Addresses from stack traces may point to the next instruction after
+// each call. Optionally adjust by -1 to land somewhere on the actual
+// call (except for the leaf, which is not a call).
+func parseCPUSamples(b []byte, parse func(b []byte) (uint64, []byte), adjust bool, p *Profile) ([]byte, map[uint64]*Location, error) {
+	locs := make(map[uint64]*Location)
+	for len(b) > 0 {
+		var count, nstk uint64
+		count, b = parse(b)
+		nstk, b = parse(b)
+		if b == nil || nstk > uint64(len(b)/4) {
+			return nil, nil, errUnrecognized
+		}
+		var sloc []*Location
+		addrs := make([]uint64, nstk)
+		for i := 0; i < int(nstk); i++ {
+			addrs[i], b = parse(b)
+		}
+
+		if count == 0 && nstk == 1 && addrs[0] == 0 {
+			// End of data marker
+			break
+		}
+		for i, addr := range addrs {
+			if adjust && i > 0 {
+				addr--
+			}
+			loc := locs[addr]
+			if loc == nil {
+				loc = &Location{
+					Address: addr,
+				}
+				locs[addr] = loc
+				p.Location = append(p.Location, loc)
+			}
+			sloc = append(sloc, loc)
+		}
+		p.Sample = append(p.Sample,
+			&Sample{
+				Value:    []int64{int64(count), int64(count) * p.Period},
+				Location: sloc,
+			})
+	}
+	// Reached the end without finding the EOD marker.
+	return b, locs, nil
+}
+
+// parseHeap parses a heapz legacy or a growthz profile and
+// returns a newly populated Profile.
+func parseHeap(b []byte) (p *Profile, err error) {
+	s := bufio.NewScanner(bytes.NewBuffer(b))
+	if !s.Scan() {
+		if err := s.Err(); err != nil {
+			return nil, err
+		}
+		return nil, errUnrecognized
+	}
+	p = &Profile{}
+
+	sampling := ""
+	hasAlloc := false
+
+	line := s.Text()
+	p.PeriodType = &ValueType{Type: "space", Unit: "bytes"}
+	if header := heapHeaderRE.FindStringSubmatch(line); header != nil {
+		sampling, p.Period, hasAlloc, err = parseHeapHeader(line)
+		if err != nil {
+			return nil, err
+		}
+	} else if header = growthHeaderRE.FindStringSubmatch(line); header != nil {
+		p.Period = 1
+	} else if header = fragmentationHeaderRE.FindStringSubmatch(line); header != nil {
+		p.Period = 1
+	} else {
+		return nil, errUnrecognized
+	}
+
+	if hasAlloc {
+		// Put alloc before inuse so that default pprof selection
+		// will prefer inuse_space.
+		p.SampleType = []*ValueType{
+			{Type: "alloc_objects", Unit: "count"},
+			{Type: "alloc_space", Unit: "bytes"},
+			{Type: "inuse_objects", Unit: "count"},
+			{Type: "inuse_space", Unit: "bytes"},
+		}
+	} else {
+		p.SampleType = []*ValueType{
+			{Type: "objects", Unit: "count"},
+			{Type: "space", Unit: "bytes"},
+		}
+	}
+
+	locs := make(map[uint64]*Location)
+	for s.Scan() {
+		line := strings.TrimSpace(s.Text())
+
+		if isSpaceOrComment(line) {
+			continue
+		}
+
+		if isMemoryMapSentinel(line) {
+			break
+		}
+
+		value, blocksize, addrs, err := parseHeapSample(line, p.Period, sampling, hasAlloc)
+		if err != nil {
+			return nil, err
+		}
+
+		var sloc []*Location
+		for _, addr := range addrs {
+			// Addresses from stack traces point to the next instruction after
+			// each call. Adjust by -1 to land somewhere on the actual call.
+			addr--
+			loc := locs[addr]
+			if locs[addr] == nil {
+				loc = &Location{
+					Address: addr,
+				}
+				p.Location = append(p.Location, loc)
+				locs[addr] = loc
+			}
+			sloc = append(sloc, loc)
+		}
+
+		p.Sample = append(p.Sample, &Sample{
+			Value:    value,
+			Location: sloc,
+			NumLabel: map[string][]int64{"bytes": {blocksize}},
+		})
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+	if err := parseAdditionalSections(s, p); err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+func parseHeapHeader(line string) (sampling string, period int64, hasAlloc bool, err error) {
+	header := heapHeaderRE.FindStringSubmatch(line)
+	if header == nil {
+		return "", 0, false, errUnrecognized
+	}
+
+	if len(header[6]) > 0 {
+		if period, err = strconv.ParseInt(header[6], 10, 64); err != nil {
+			return "", 0, false, errUnrecognized
+		}
+	}
+
+	if (header[3] != header[1] && header[3] != "0") || (header[4] != header[2] && header[4] != "0") {
+		hasAlloc = true
+	}
+
+	switch header[5] {
+	case "heapz_v2", "heap_v2":
+		return "v2", period, hasAlloc, nil
+	case "heapprofile":
+		return "", 1, hasAlloc, nil
+	case "heap":
+		return "v2", period / 2, hasAlloc, nil
+	default:
+		return "", 0, false, errUnrecognized
+	}
+}
+
+// parseHeapSample parses a single row from a heap profile into a new Sample.
+func parseHeapSample(line string, rate int64, sampling string, includeAlloc bool) (value []int64, blocksize int64, addrs []uint64, err error) {
+	sampleData := heapSampleRE.FindStringSubmatch(line)
+	if len(sampleData) != 6 {
+		return nil, 0, nil, fmt.Errorf("unexpected number of sample values: got %d, want 6", len(sampleData))
+	}
+
+	// This is a local-scoped helper function to avoid needing to pass
+	// around rate, sampling and many return parameters.
+	addValues := func(countString, sizeString string, label string) error {
+		count, err := strconv.ParseInt(countString, 10, 64)
+		if err != nil {
+			return fmt.Errorf("malformed sample: %s: %v", line, err)
+		}
+		size, err := strconv.ParseInt(sizeString, 10, 64)
+		if err != nil {
+			return fmt.Errorf("malformed sample: %s: %v", line, err)
+		}
+		if count == 0 && size != 0 {
+			return fmt.Errorf("%s count was 0 but %s bytes was %d", label, label, size)
+		}
+		if count != 0 {
+			blocksize = size / count
+			if sampling == "v2" {
+				count, size = scaleHeapSample(count, size, rate)
+			}
+		}
+		value = append(value, count, size)
+		return nil
+	}
+
+	if includeAlloc {
+		if err := addValues(sampleData[3], sampleData[4], "allocation"); err != nil {
+			return nil, 0, nil, err
+		}
+	}
+
+	if err := addValues(sampleData[1], sampleData[2], "inuse"); err != nil {
+		return nil, 0, nil, err
+	}
+
+	addrs, err = parseHexAddresses(sampleData[5])
+	if err != nil {
+		return nil, 0, nil, fmt.Errorf("malformed sample: %s: %v", line, err)
+	}
+
+	return value, blocksize, addrs, nil
+}
+
+// parseHexAddresses extracts hex numbers from a string, attempts to convert
+// each to an unsigned 64-bit number and returns the resulting numbers as a
+// slice, or an error if the string contains hex numbers which are too large to
+// handle (which means a malformed profile).
+func parseHexAddresses(s string) ([]uint64, error) {
+	hexStrings := hexNumberRE.FindAllString(s, -1)
+	var addrs []uint64
+	for _, s := range hexStrings {
+		if addr, err := strconv.ParseUint(s, 0, 64); err == nil {
+			addrs = append(addrs, addr)
+		} else {
+			return nil, fmt.Errorf("failed to parse as hex 64-bit number: %s", s)
+		}
+	}
+	return addrs, nil
+}
+
+// scaleHeapSample adjusts the data from a heapz Sample to
+// account for its probability of appearing in the collected
+// data. heapz profiles are a sampling of the memory allocations
+// requests in a program. We estimate the unsampled value by dividing
+// each collected sample by its probability of appearing in the
+// profile. heapz v2 profiles rely on a poisson process to determine
+// which samples to collect, based on the desired average collection
+// rate R. The probability of a sample of size S to appear in that
+// profile is 1-exp(-S/R).
+func scaleHeapSample(count, size, rate int64) (int64, int64) {
+	if count == 0 || size == 0 {
+		return 0, 0
+	}
+
+	if rate <= 1 {
+		// if rate==1 all samples were collected so no adjustment is needed.
+		// if rate<1 treat as unknown and skip scaling.
+		return count, size
+	}
+
+	avgSize := float64(size) / float64(count)
+	scale := 1 / (1 - math.Exp(-avgSize/float64(rate)))
+
+	return int64(float64(count) * scale), int64(float64(size) * scale)
+}
+
+// parseContention parses a mutex or contention profile. There are 2 cases:
+// "--- contentionz " for legacy C++ profiles (and backwards compatibility)
+// "--- mutex:" or "--- contention:" for profiles generated by the Go runtime.
+func parseContention(b []byte) (*Profile, error) {
+	s := bufio.NewScanner(bytes.NewBuffer(b))
+	if !s.Scan() {
+		if err := s.Err(); err != nil {
+			return nil, err
+		}
+		return nil, errUnrecognized
+	}
+
+	switch l := s.Text(); {
+	case strings.HasPrefix(l, "--- contentionz "):
+	case strings.HasPrefix(l, "--- mutex:"):
+	case strings.HasPrefix(l, "--- contention:"):
+	default:
+		return nil, errUnrecognized
+	}
+
+	p := &Profile{
+		PeriodType: &ValueType{Type: "contentions", Unit: "count"},
+		Period:     1,
+		SampleType: []*ValueType{
+			{Type: "contentions", Unit: "count"},
+			{Type: "delay", Unit: "nanoseconds"},
+		},
+	}
+
+	var cpuHz int64
+	// Parse text of the form "attribute = value" before the samples.
+	const delimiter = "="
+	for s.Scan() {
+		line := s.Text()
+		if line = strings.TrimSpace(line); isSpaceOrComment(line) {
+			continue
+		}
+		if strings.HasPrefix(line, "---") {
+			break
+		}
+		attr := strings.SplitN(line, delimiter, 2)
+		if len(attr) != 2 {
+			break
+		}
+		key, val := strings.TrimSpace(attr[0]), strings.TrimSpace(attr[1])
+		var err error
+		switch key {
+		case "cycles/second":
+			if cpuHz, err = strconv.ParseInt(val, 0, 64); err != nil {
+				return nil, errUnrecognized
+			}
+		case "sampling period":
+			if p.Period, err = strconv.ParseInt(val, 0, 64); err != nil {
+				return nil, errUnrecognized
+			}
+		case "ms since reset":
+			ms, err := strconv.ParseInt(val, 0, 64)
+			if err != nil {
+				return nil, errUnrecognized
+			}
+			p.DurationNanos = ms * 1000 * 1000
+		case "format":
+			// CPP contentionz profiles don't have format.
+			return nil, errUnrecognized
+		case "resolution":
+			// CPP contentionz profiles don't have resolution.
+			return nil, errUnrecognized
+		case "discarded samples":
+		default:
+			return nil, errUnrecognized
+		}
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	locs := make(map[uint64]*Location)
+	for {
+		line := strings.TrimSpace(s.Text())
+		if strings.HasPrefix(line, "---") {
+			break
+		}
+		if !isSpaceOrComment(line) {
+			value, addrs, err := parseContentionSample(line, p.Period, cpuHz)
+			if err != nil {
+				return nil, err
+			}
+			var sloc []*Location
+			for _, addr := range addrs {
+				// Addresses from stack traces point to the next instruction after
+				// each call. Adjust by -1 to land somewhere on the actual call.
+				addr--
+				loc := locs[addr]
+				if locs[addr] == nil {
+					loc = &Location{
+						Address: addr,
+					}
+					p.Location = append(p.Location, loc)
+					locs[addr] = loc
+				}
+				sloc = append(sloc, loc)
+			}
+			p.Sample = append(p.Sample, &Sample{
+				Value:    value,
+				Location: sloc,
+			})
+		}
+		if !s.Scan() {
+			break
+		}
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	if err := parseAdditionalSections(s, p); err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}
+
+// parseContentionSample parses a single row from a contention profile
+// into a new Sample.
+func parseContentionSample(line string, period, cpuHz int64) (value []int64, addrs []uint64, err error) {
+	sampleData := contentionSampleRE.FindStringSubmatch(line)
+	if sampleData == nil {
+		return nil, nil, errUnrecognized
+	}
+
+	v1, err := strconv.ParseInt(sampleData[1], 10, 64)
+	if err != nil {
+		return nil, nil, fmt.Errorf("malformed sample: %s: %v", line, err)
+	}
+	v2, err := strconv.ParseInt(sampleData[2], 10, 64)
+	if err != nil {
+		return nil, nil, fmt.Errorf("malformed sample: %s: %v", line, err)
+	}
+
+	// Unsample values if period and cpuHz are available.
+	// - Delays are scaled to cycles and then to nanoseconds.
+	// - Contentions are scaled to cycles.
+	if period > 0 {
+		if cpuHz > 0 {
+			cpuGHz := float64(cpuHz) / 1e9
+			v1 = int64(float64(v1) * float64(period) / cpuGHz)
+		}
+		v2 = v2 * period
+	}
+
+	value = []int64{v2, v1}
+	addrs, err = parseHexAddresses(sampleData[3])
+	if err != nil {
+		return nil, nil, fmt.Errorf("malformed sample: %s: %v", line, err)
+	}
+
+	return value, addrs, nil
+}
+
+// parseThread parses a Threadz profile and returns a new Profile.
+func parseThread(b []byte) (*Profile, error) {
+	s := bufio.NewScanner(bytes.NewBuffer(b))
+	// Skip past comments and empty lines seeking a real header.
+	for s.Scan() && isSpaceOrComment(s.Text()) {
+	}
+
+	line := s.Text()
+	if m := threadzStartRE.FindStringSubmatch(line); m != nil {
+		// Advance over initial comments until first stack trace.
+		for s.Scan() {
+			if line = s.Text(); isMemoryMapSentinel(line) || strings.HasPrefix(line, "-") {
+				break
+			}
+		}
+	} else if t := threadStartRE.FindStringSubmatch(line); len(t) != 4 {
+		return nil, errUnrecognized
+	}
+
+	p := &Profile{
+		SampleType: []*ValueType{{Type: "thread", Unit: "count"}},
+		PeriodType: &ValueType{Type: "thread", Unit: "count"},
+		Period:     1,
+	}
+
+	locs := make(map[uint64]*Location)
+	// Recognize each thread and populate profile samples.
+	for !isMemoryMapSentinel(line) {
+		if strings.HasPrefix(line, "---- no stack trace for") {
+			line = ""
+			break
+		}
+		if t := threadStartRE.FindStringSubmatch(line); len(t) != 4 {
+			return nil, errUnrecognized
+		}
+
+		var addrs []uint64
+		var err error
+		line, addrs, err = parseThreadSample(s)
+		if err != nil {
+			return nil, err
+		}
+		if len(addrs) == 0 {
+			// We got a --same as previous threads--. Bump counters.
+			if len(p.Sample) > 0 {
+				s := p.Sample[len(p.Sample)-1]
+				s.Value[0]++
+			}
+			continue
+		}
+
+		var sloc []*Location
+		for i, addr := range addrs {
+			// Addresses from stack traces point to the next instruction after
+			// each call. Adjust by -1 to land somewhere on the actual call
+			// (except for the leaf, which is not a call).
+			if i > 0 {
+				addr--
+			}
+			loc := locs[addr]
+			if locs[addr] == nil {
+				loc = &Location{
+					Address: addr,
+				}
+				p.Location = append(p.Location, loc)
+				locs[addr] = loc
+			}
+			sloc = append(sloc, loc)
+		}
+
+		p.Sample = append(p.Sample, &Sample{
+			Value:    []int64{1},
+			Location: sloc,
+		})
+	}
+
+	if err := parseAdditionalSections(s, p); err != nil {
+		return nil, err
+	}
+
+	cleanupDuplicateLocations(p)
+	return p, nil
+}
+
+// parseThreadSample parses a symbolized or unsymbolized stack trace.
+// Returns the first line after the traceback, the sample (or nil if
+// it hits a 'same-as-previous' marker) and an error.
+func parseThreadSample(s *bufio.Scanner) (nextl string, addrs []uint64, err error) {
+	var line string
+	sameAsPrevious := false
+	for s.Scan() {
+		line = strings.TrimSpace(s.Text())
+		if line == "" {
+			continue
+		}
+
+		if strings.HasPrefix(line, "---") {
+			break
+		}
+		if strings.Contains(line, "same as previous thread") {
+			sameAsPrevious = true
+			continue
+		}
+
+		curAddrs, err := parseHexAddresses(line)
+		if err != nil {
+			return "", nil, fmt.Errorf("malformed sample: %s: %v", line, err)
+		}
+		addrs = append(addrs, curAddrs...)
+	}
+	if err := s.Err(); err != nil {
+		return "", nil, err
+	}
+	if sameAsPrevious {
+		return line, nil, nil
+	}
+	return line, addrs, nil
+}
+
+// parseAdditionalSections parses any additional sections in the
+// profile, ignoring any unrecognized sections.
+func parseAdditionalSections(s *bufio.Scanner, p *Profile) error {
+	for !isMemoryMapSentinel(s.Text()) && s.Scan() {
+	}
+	if err := s.Err(); err != nil {
+		return err
+	}
+	return p.ParseMemoryMapFromScanner(s)
+}
+
+// ParseProcMaps parses a memory map in the format of /proc/self/maps.
+// ParseMemoryMap should be called after setting on a profile to
+// associate locations to the corresponding mapping based on their
+// address.
+func ParseProcMaps(rd io.Reader) ([]*Mapping, error) {
+	s := bufio.NewScanner(rd)
+	return parseProcMapsFromScanner(s)
+}
+
+func parseProcMapsFromScanner(s *bufio.Scanner) ([]*Mapping, error) {
+	var mapping []*Mapping
+
+	var attrs []string
+	const delimiter = "="
+	r := strings.NewReplacer()
+	for s.Scan() {
+		line := r.Replace(removeLoggingInfo(s.Text()))
+		m, err := parseMappingEntry(line)
+		if err != nil {
+			if err == errUnrecognized {
+				// Recognize assignments of the form: attr=value, and replace
+				// $attr with value on subsequent mappings.
+				if attr := strings.SplitN(line, delimiter, 2); len(attr) == 2 {
+					attrs = append(attrs, "$"+strings.TrimSpace(attr[0]), strings.TrimSpace(attr[1]))
+					r = strings.NewReplacer(attrs...)
+				}
+				// Ignore any unrecognized entries
+				continue
+			}
+			return nil, err
+		}
+		if m == nil {
+			continue
+		}
+		mapping = append(mapping, m)
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+	return mapping, nil
+}
+
+// removeLoggingInfo detects and removes log prefix entries generated
+// by the glog package. If no logging prefix is detected, the string
+// is returned unmodified.
+func removeLoggingInfo(line string) string {
+	if match := logInfoRE.FindStringIndex(line); match != nil {
+		return line[match[1]:]
+	}
+	return line
+}
+
+// ParseMemoryMap parses a memory map in the format of
+// /proc/self/maps, and overrides the mappings in the current profile.
+// It renumbers the samples and locations in the profile correspondingly.
+func (p *Profile) ParseMemoryMap(rd io.Reader) error {
+	return p.ParseMemoryMapFromScanner(bufio.NewScanner(rd))
+}
+
+// ParseMemoryMapFromScanner parses a memory map in the format of
+// /proc/self/maps or a variety of legacy format, and overrides the
+// mappings in the current profile.  It renumbers the samples and
+// locations in the profile correspondingly.
+func (p *Profile) ParseMemoryMapFromScanner(s *bufio.Scanner) error {
+	mapping, err := parseProcMapsFromScanner(s)
+	if err != nil {
+		return err
+	}
+	p.Mapping = append(p.Mapping, mapping...)
+	p.massageMappings()
+	p.remapLocationIDs()
+	p.remapFunctionIDs()
+	p.remapMappingIDs()
+	return nil
+}
+
+func parseMappingEntry(l string) (*Mapping, error) {
+	var start, end, perm, file, offset, buildID string
+	if me := procMapsRE.FindStringSubmatch(l); len(me) == 6 {
+		start, end, perm, offset, file = me[1], me[2], me[3], me[4], me[5]
+	} else if me := briefMapsRE.FindStringSubmatch(l); len(me) == 7 {
+		start, end, perm, file, offset, buildID = me[1], me[2], me[3], me[4], me[5], me[6]
+	} else {
+		return nil, errUnrecognized
+	}
+
+	var err error
+	mapping := &Mapping{
+		File:    file,
+		BuildID: buildID,
+	}
+	if perm != "" && !strings.Contains(perm, "x") {
+		// Skip non-executable entries.
+		return nil, nil
+	}
+	if mapping.Start, err = strconv.ParseUint(start, 16, 64); err != nil {
+		return nil, errUnrecognized
+	}
+	if mapping.Limit, err = strconv.ParseUint(end, 16, 64); err != nil {
+		return nil, errUnrecognized
+	}
+	if offset != "" {
+		if mapping.Offset, err = strconv.ParseUint(offset, 16, 64); err != nil {
+			return nil, errUnrecognized
+		}
+	}
+	return mapping, nil
+}
+
+var memoryMapSentinels = []string{
+	"--- Memory map: ---",
+	"MAPPED_LIBRARIES:",
+}
+
+// isMemoryMapSentinel returns true if the string contains one of the
+// known sentinels for memory map information.
+func isMemoryMapSentinel(line string) bool {
+	for _, s := range memoryMapSentinels {
+		if strings.Contains(line, s) {
+			return true
+		}
+	}
+	return false
+}
+
+func (p *Profile) addLegacyFrameInfo() {
+	switch {
+	case isProfileType(p, heapzSampleTypes):
+		p.DropFrames, p.KeepFrames = allocRxStr, allocSkipRxStr
+	case isProfileType(p, contentionzSampleTypes):
+		p.DropFrames, p.KeepFrames = lockRxStr, ""
+	default:
+		p.DropFrames, p.KeepFrames = cpuProfilerRxStr, ""
+	}
+}
+
+var heapzSampleTypes = [][]string{
+	{"allocations", "size"}, // early Go pprof profiles
+	{"objects", "space"},
+	{"inuse_objects", "inuse_space"},
+	{"alloc_objects", "alloc_space"},
+	{"alloc_objects", "alloc_space", "inuse_objects", "inuse_space"}, // Go pprof legacy profiles
+}
+var contentionzSampleTypes = [][]string{
+	{"contentions", "delay"},
+}
+
+func isProfileType(p *Profile, types [][]string) bool {
+	st := p.SampleType
+nextType:
+	for _, t := range types {
+		if len(st) != len(t) {
+			continue
+		}
+
+		for i := range st {
+			if st[i].Type != t[i] {
+				continue nextType
+			}
+		}
+		return true
+	}
+	return false
+}
+
+var allocRxStr = strings.Join([]string{
+	// POSIX entry points.
+	`calloc`,
+	`cfree`,
+	`malloc`,
+	`free`,
+	`memalign`,
+	`do_memalign`,
+	`(__)?posix_memalign`,
+	`pvalloc`,
+	`valloc`,
+	`realloc`,
+
+	// TC malloc.
+	`tcmalloc::.*`,
+	`tc_calloc`,
+	`tc_cfree`,
+	`tc_malloc`,
+	`tc_free`,
+	`tc_memalign`,
+	`tc_posix_memalign`,
+	`tc_pvalloc`,
+	`tc_valloc`,
+	`tc_realloc`,
+	`tc_new`,
+	`tc_delete`,
+	`tc_newarray`,
+	`tc_deletearray`,
+	`tc_new_nothrow`,
+	`tc_newarray_nothrow`,
+
+	// Memory-allocation routines on OS X.
+	`malloc_zone_malloc`,
+	`malloc_zone_calloc`,
+	`malloc_zone_valloc`,
+	`malloc_zone_realloc`,
+	`malloc_zone_memalign`,
+	`malloc_zone_free`,
+
+	// Go runtime
+	`runtime\..*`,
+
+	// Other misc. memory allocation routines
+	`BaseArena::.*`,
+	`(::)?do_malloc_no_errno`,
+	`(::)?do_malloc_pages`,
+	`(::)?do_malloc`,
+	`DoSampledAllocation`,
+	`MallocedMemBlock::MallocedMemBlock`,
+	`_M_allocate`,
+	`__builtin_(vec_)?delete`,
+	`__builtin_(vec_)?new`,
+	`__gnu_cxx::new_allocator::allocate`,
+	`__libc_malloc`,
+	`__malloc_alloc_template::allocate`,
+	`allocate`,
+	`cpp_alloc`,
+	`operator new(\[\])?`,
+	`simple_alloc::allocate`,
+}, `|`)
+
+var allocSkipRxStr = strings.Join([]string{
+	// Preserve Go runtime frames that appear in the middle/bottom of
+	// the stack.
+	`runtime\.panic`,
+	`runtime\.reflectcall`,
+	`runtime\.call[0-9]*`,
+}, `|`)
+
+var cpuProfilerRxStr = strings.Join([]string{
+	`ProfileData::Add`,
+	`ProfileData::prof_handler`,
+	`CpuProfiler::prof_handler`,
+	`__pthread_sighandler`,
+	`__restore`,
+}, `|`)
+
+var lockRxStr = strings.Join([]string{
+	`RecordLockProfileData`,
+	`(base::)?RecordLockProfileData.*`,
+	`(base::)?SubmitMutexProfileData.*`,
+	`(base::)?SubmitSpinLockProfileData.*`,
+	`(base::Mutex::)?AwaitCommon.*`,
+	`(base::Mutex::)?Unlock.*`,
+	`(base::Mutex::)?UnlockSlow.*`,
+	`(base::Mutex::)?ReaderUnlock.*`,
+	`(base::MutexLock::)?~MutexLock.*`,
+	`(Mutex::)?AwaitCommon.*`,
+	`(Mutex::)?Unlock.*`,
+	`(Mutex::)?UnlockSlow.*`,
+	`(Mutex::)?ReaderUnlock.*`,
+	`(MutexLock::)?~MutexLock.*`,
+	`(SpinLock::)?Unlock.*`,
+	`(SpinLock::)?SlowUnlock.*`,
+	`(SpinLockHolder::)?~SpinLockHolder.*`,
+}, `|`)
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/merge.go b/src/cmd/vendor/github.com/google/pprof/profile/merge.go
new file mode 100644
index 0000000..4dcc27f
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/profile/merge.go
@@ -0,0 +1,479 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package profile
+
+import (
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// Compact performs garbage collection on a profile to remove any
+// unreferenced fields. This is useful to reduce the size of a profile
+// after samples or locations have been removed.
+func (p *Profile) Compact() *Profile {
+	p, _ = Merge([]*Profile{p})
+	return p
+}
+
+// Merge merges all the profiles in profs into a single Profile.
+// Returns a new profile independent of the input profiles. The merged
+// profile is compacted to eliminate unused samples, locations,
+// functions and mappings. Profiles must have identical profile sample
+// and period types or the merge will fail. profile.Period of the
+// resulting profile will be the maximum of all profiles, and
+// profile.TimeNanos will be the earliest nonzero one.
+func Merge(srcs []*Profile) (*Profile, error) {
+	if len(srcs) == 0 {
+		return nil, fmt.Errorf("no profiles to merge")
+	}
+	p, err := combineHeaders(srcs)
+	if err != nil {
+		return nil, err
+	}
+
+	pm := &profileMerger{
+		p:         p,
+		samples:   make(map[sampleKey]*Sample, len(srcs[0].Sample)),
+		locations: make(map[locationKey]*Location, len(srcs[0].Location)),
+		functions: make(map[functionKey]*Function, len(srcs[0].Function)),
+		mappings:  make(map[mappingKey]*Mapping, len(srcs[0].Mapping)),
+	}
+
+	for _, src := range srcs {
+		// Clear the profile-specific hash tables
+		pm.locationsByID = make(map[uint64]*Location, len(src.Location))
+		pm.functionsByID = make(map[uint64]*Function, len(src.Function))
+		pm.mappingsByID = make(map[uint64]mapInfo, len(src.Mapping))
+
+		if len(pm.mappings) == 0 && len(src.Mapping) > 0 {
+			// The Mapping list has the property that the first mapping
+			// represents the main binary. Take the first Mapping we see,
+			// otherwise the operations below will add mappings in an
+			// arbitrary order.
+			pm.mapMapping(src.Mapping[0])
+		}
+
+		for _, s := range src.Sample {
+			if !isZeroSample(s) {
+				pm.mapSample(s)
+			}
+		}
+	}
+
+	for _, s := range p.Sample {
+		if isZeroSample(s) {
+			// If there are any zero samples, re-merge the profile to GC
+			// them.
+			return Merge([]*Profile{p})
+		}
+	}
+
+	return p, nil
+}
+
+// Normalize normalizes the source profile by multiplying each value in profile by the
+// ratio of the sum of the base profile's values of that sample type to the sum of the
+// source profile's value of that sample type.
+func (p *Profile) Normalize(pb *Profile) error {
+
+	if err := p.compatible(pb); err != nil {
+		return err
+	}
+
+	baseVals := make([]int64, len(p.SampleType))
+	for _, s := range pb.Sample {
+		for i, v := range s.Value {
+			baseVals[i] += v
+		}
+	}
+
+	srcVals := make([]int64, len(p.SampleType))
+	for _, s := range p.Sample {
+		for i, v := range s.Value {
+			srcVals[i] += v
+		}
+	}
+
+	normScale := make([]float64, len(baseVals))
+	for i := range baseVals {
+		if srcVals[i] == 0 {
+			normScale[i] = 0.0
+		} else {
+			normScale[i] = float64(baseVals[i]) / float64(srcVals[i])
+		}
+	}
+	p.ScaleN(normScale)
+	return nil
+}
+
+func isZeroSample(s *Sample) bool {
+	for _, v := range s.Value {
+		if v != 0 {
+			return false
+		}
+	}
+	return true
+}
+
+type profileMerger struct {
+	p *Profile
+
+	// Memoization tables within a profile.
+	locationsByID map[uint64]*Location
+	functionsByID map[uint64]*Function
+	mappingsByID  map[uint64]mapInfo
+
+	// Memoization tables for profile entities.
+	samples   map[sampleKey]*Sample
+	locations map[locationKey]*Location
+	functions map[functionKey]*Function
+	mappings  map[mappingKey]*Mapping
+}
+
+type mapInfo struct {
+	m      *Mapping
+	offset int64
+}
+
+func (pm *profileMerger) mapSample(src *Sample) *Sample {
+	s := &Sample{
+		Location: make([]*Location, len(src.Location)),
+		Value:    make([]int64, len(src.Value)),
+		Label:    make(map[string][]string, len(src.Label)),
+		NumLabel: make(map[string][]int64, len(src.NumLabel)),
+		NumUnit:  make(map[string][]string, len(src.NumLabel)),
+	}
+	for i, l := range src.Location {
+		s.Location[i] = pm.mapLocation(l)
+	}
+	for k, v := range src.Label {
+		vv := make([]string, len(v))
+		copy(vv, v)
+		s.Label[k] = vv
+	}
+	for k, v := range src.NumLabel {
+		u := src.NumUnit[k]
+		vv := make([]int64, len(v))
+		uu := make([]string, len(u))
+		copy(vv, v)
+		copy(uu, u)
+		s.NumLabel[k] = vv
+		s.NumUnit[k] = uu
+	}
+	// Check memoization table. Must be done on the remapped location to
+	// account for the remapped mapping. Add current values to the
+	// existing sample.
+	k := s.key()
+	if ss, ok := pm.samples[k]; ok {
+		for i, v := range src.Value {
+			ss.Value[i] += v
+		}
+		return ss
+	}
+	copy(s.Value, src.Value)
+	pm.samples[k] = s
+	pm.p.Sample = append(pm.p.Sample, s)
+	return s
+}
+
+// key generates sampleKey to be used as a key for maps.
+func (sample *Sample) key() sampleKey {
+	ids := make([]string, len(sample.Location))
+	for i, l := range sample.Location {
+		ids[i] = strconv.FormatUint(l.ID, 16)
+	}
+
+	labels := make([]string, 0, len(sample.Label))
+	for k, v := range sample.Label {
+		labels = append(labels, fmt.Sprintf("%q%q", k, v))
+	}
+	sort.Strings(labels)
+
+	numlabels := make([]string, 0, len(sample.NumLabel))
+	for k, v := range sample.NumLabel {
+		numlabels = append(numlabels, fmt.Sprintf("%q%x%x", k, v, sample.NumUnit[k]))
+	}
+	sort.Strings(numlabels)
+
+	return sampleKey{
+		strings.Join(ids, "|"),
+		strings.Join(labels, ""),
+		strings.Join(numlabels, ""),
+	}
+}
+
+type sampleKey struct {
+	locations string
+	labels    string
+	numlabels string
+}
+
+func (pm *profileMerger) mapLocation(src *Location) *Location {
+	if src == nil {
+		return nil
+	}
+
+	if l, ok := pm.locationsByID[src.ID]; ok {
+		pm.locationsByID[src.ID] = l
+		return l
+	}
+
+	mi := pm.mapMapping(src.Mapping)
+	l := &Location{
+		ID:       uint64(len(pm.p.Location) + 1),
+		Mapping:  mi.m,
+		Address:  uint64(int64(src.Address) + mi.offset),
+		Line:     make([]Line, len(src.Line)),
+		IsFolded: src.IsFolded,
+	}
+	for i, ln := range src.Line {
+		l.Line[i] = pm.mapLine(ln)
+	}
+	// Check memoization table. Must be done on the remapped location to
+	// account for the remapped mapping ID.
+	k := l.key()
+	if ll, ok := pm.locations[k]; ok {
+		pm.locationsByID[src.ID] = ll
+		return ll
+	}
+	pm.locationsByID[src.ID] = l
+	pm.locations[k] = l
+	pm.p.Location = append(pm.p.Location, l)
+	return l
+}
+
+// key generates locationKey to be used as a key for maps.
+func (l *Location) key() locationKey {
+	key := locationKey{
+		addr:     l.Address,
+		isFolded: l.IsFolded,
+	}
+	if l.Mapping != nil {
+		// Normalizes address to handle address space randomization.
+		key.addr -= l.Mapping.Start
+		key.mappingID = l.Mapping.ID
+	}
+	lines := make([]string, len(l.Line)*2)
+	for i, line := range l.Line {
+		if line.Function != nil {
+			lines[i*2] = strconv.FormatUint(line.Function.ID, 16)
+		}
+		lines[i*2+1] = strconv.FormatInt(line.Line, 16)
+	}
+	key.lines = strings.Join(lines, "|")
+	return key
+}
+
+type locationKey struct {
+	addr, mappingID uint64
+	lines           string
+	isFolded        bool
+}
+
+func (pm *profileMerger) mapMapping(src *Mapping) mapInfo {
+	if src == nil {
+		return mapInfo{}
+	}
+
+	if mi, ok := pm.mappingsByID[src.ID]; ok {
+		return mi
+	}
+
+	// Check memoization tables.
+	mk := src.key()
+	if m, ok := pm.mappings[mk]; ok {
+		mi := mapInfo{m, int64(m.Start) - int64(src.Start)}
+		pm.mappingsByID[src.ID] = mi
+		return mi
+	}
+	m := &Mapping{
+		ID:              uint64(len(pm.p.Mapping) + 1),
+		Start:           src.Start,
+		Limit:           src.Limit,
+		Offset:          src.Offset,
+		File:            src.File,
+		BuildID:         src.BuildID,
+		HasFunctions:    src.HasFunctions,
+		HasFilenames:    src.HasFilenames,
+		HasLineNumbers:  src.HasLineNumbers,
+		HasInlineFrames: src.HasInlineFrames,
+	}
+	pm.p.Mapping = append(pm.p.Mapping, m)
+
+	// Update memoization tables.
+	pm.mappings[mk] = m
+	mi := mapInfo{m, 0}
+	pm.mappingsByID[src.ID] = mi
+	return mi
+}
+
+// key generates encoded strings of Mapping to be used as a key for
+// maps.
+func (m *Mapping) key() mappingKey {
+	// Normalize addresses to handle address space randomization.
+	// Round up to next 4K boundary to avoid minor discrepancies.
+	const mapsizeRounding = 0x1000
+
+	size := m.Limit - m.Start
+	size = size + mapsizeRounding - 1
+	size = size - (size % mapsizeRounding)
+	key := mappingKey{
+		size:   size,
+		offset: m.Offset,
+	}
+
+	switch {
+	case m.BuildID != "":
+		key.buildIDOrFile = m.BuildID
+	case m.File != "":
+		key.buildIDOrFile = m.File
+	default:
+		// A mapping containing neither build ID nor file name is a fake mapping. A
+		// key with empty buildIDOrFile is used for fake mappings so that they are
+		// treated as the same mapping during merging.
+	}
+	return key
+}
+
+type mappingKey struct {
+	size, offset  uint64
+	buildIDOrFile string
+}
+
+func (pm *profileMerger) mapLine(src Line) Line {
+	ln := Line{
+		Function: pm.mapFunction(src.Function),
+		Line:     src.Line,
+	}
+	return ln
+}
+
+func (pm *profileMerger) mapFunction(src *Function) *Function {
+	if src == nil {
+		return nil
+	}
+	if f, ok := pm.functionsByID[src.ID]; ok {
+		return f
+	}
+	k := src.key()
+	if f, ok := pm.functions[k]; ok {
+		pm.functionsByID[src.ID] = f
+		return f
+	}
+	f := &Function{
+		ID:         uint64(len(pm.p.Function) + 1),
+		Name:       src.Name,
+		SystemName: src.SystemName,
+		Filename:   src.Filename,
+		StartLine:  src.StartLine,
+	}
+	pm.functions[k] = f
+	pm.functionsByID[src.ID] = f
+	pm.p.Function = append(pm.p.Function, f)
+	return f
+}
+
+// key generates a struct to be used as a key for maps.
+func (f *Function) key() functionKey {
+	return functionKey{
+		f.StartLine,
+		f.Name,
+		f.SystemName,
+		f.Filename,
+	}
+}
+
+type functionKey struct {
+	startLine                  int64
+	name, systemName, fileName string
+}
+
+// combineHeaders checks that all profiles can be merged and returns
+// their combined profile.
+func combineHeaders(srcs []*Profile) (*Profile, error) {
+	for _, s := range srcs[1:] {
+		if err := srcs[0].compatible(s); err != nil {
+			return nil, err
+		}
+	}
+
+	var timeNanos, durationNanos, period int64
+	var comments []string
+	seenComments := map[string]bool{}
+	var defaultSampleType string
+	for _, s := range srcs {
+		if timeNanos == 0 || s.TimeNanos < timeNanos {
+			timeNanos = s.TimeNanos
+		}
+		durationNanos += s.DurationNanos
+		if period == 0 || period < s.Period {
+			period = s.Period
+		}
+		for _, c := range s.Comments {
+			if seen := seenComments[c]; !seen {
+				comments = append(comments, c)
+				seenComments[c] = true
+			}
+		}
+		if defaultSampleType == "" {
+			defaultSampleType = s.DefaultSampleType
+		}
+	}
+
+	p := &Profile{
+		SampleType: make([]*ValueType, len(srcs[0].SampleType)),
+
+		DropFrames: srcs[0].DropFrames,
+		KeepFrames: srcs[0].KeepFrames,
+
+		TimeNanos:     timeNanos,
+		DurationNanos: durationNanos,
+		PeriodType:    srcs[0].PeriodType,
+		Period:        period,
+
+		Comments:          comments,
+		DefaultSampleType: defaultSampleType,
+	}
+	copy(p.SampleType, srcs[0].SampleType)
+	return p, nil
+}
+
+// compatible determines if two profiles can be compared/merged.
+// returns nil if the profiles are compatible; otherwise an error with
+// details on the incompatibility.
+func (p *Profile) compatible(pb *Profile) error {
+	if !equalValueType(p.PeriodType, pb.PeriodType) {
+		return fmt.Errorf("incompatible period types %v and %v", p.PeriodType, pb.PeriodType)
+	}
+
+	if len(p.SampleType) != len(pb.SampleType) {
+		return fmt.Errorf("incompatible sample types %v and %v", p.SampleType, pb.SampleType)
+	}
+
+	for i := range p.SampleType {
+		if !equalValueType(p.SampleType[i], pb.SampleType[i]) {
+			return fmt.Errorf("incompatible sample types %v and %v", p.SampleType, pb.SampleType)
+		}
+	}
+	return nil
+}
+
+// equalValueType returns true if the two value types are semantically
+// equal. It ignores the internal fields used during encode/decode.
+func equalValueType(st1, st2 *ValueType) bool {
+	return st1.Type == st2.Type && st1.Unit == st2.Unit
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/profile.go b/src/cmd/vendor/github.com/google/pprof/profile/profile.go
new file mode 100644
index 0000000..d94d8b3
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/profile/profile.go
@@ -0,0 +1,793 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package profile provides a representation of profile.proto and
+// methods to encode/decode profiles in this format.
+package profile
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+)
+
+// Profile is an in-memory representation of profile.proto.
+type Profile struct {
+	SampleType        []*ValueType
+	DefaultSampleType string
+	Sample            []*Sample
+	Mapping           []*Mapping
+	Location          []*Location
+	Function          []*Function
+	Comments          []string
+
+	DropFrames string
+	KeepFrames string
+
+	TimeNanos     int64
+	DurationNanos int64
+	PeriodType    *ValueType
+	Period        int64
+
+	// The following fields are modified during encoding and copying,
+	// so are protected by a Mutex.
+	encodeMu sync.Mutex
+
+	commentX           []int64
+	dropFramesX        int64
+	keepFramesX        int64
+	stringTable        []string
+	defaultSampleTypeX int64
+}
+
+// ValueType corresponds to Profile.ValueType
+type ValueType struct {
+	Type string // cpu, wall, inuse_space, etc
+	Unit string // seconds, nanoseconds, bytes, etc
+
+	typeX int64
+	unitX int64
+}
+
+// Sample corresponds to Profile.Sample
+type Sample struct {
+	Location []*Location
+	Value    []int64
+	Label    map[string][]string
+	NumLabel map[string][]int64
+	NumUnit  map[string][]string
+
+	locationIDX []uint64
+	labelX      []label
+}
+
+// label corresponds to Profile.Label
+type label struct {
+	keyX int64
+	// Exactly one of the two following values must be set
+	strX int64
+	numX int64 // Integer value for this label
+	// can be set if numX has value
+	unitX int64
+}
+
+// Mapping corresponds to Profile.Mapping
+type Mapping struct {
+	ID              uint64
+	Start           uint64
+	Limit           uint64
+	Offset          uint64
+	File            string
+	BuildID         string
+	HasFunctions    bool
+	HasFilenames    bool
+	HasLineNumbers  bool
+	HasInlineFrames bool
+
+	fileX    int64
+	buildIDX int64
+}
+
+// Location corresponds to Profile.Location
+type Location struct {
+	ID       uint64
+	Mapping  *Mapping
+	Address  uint64
+	Line     []Line
+	IsFolded bool
+
+	mappingIDX uint64
+}
+
+// Line corresponds to Profile.Line
+type Line struct {
+	Function *Function
+	Line     int64
+
+	functionIDX uint64
+}
+
+// Function corresponds to Profile.Function
+type Function struct {
+	ID         uint64
+	Name       string
+	SystemName string
+	Filename   string
+	StartLine  int64
+
+	nameX       int64
+	systemNameX int64
+	filenameX   int64
+}
+
+// Parse parses a profile and checks for its validity. The input
+// may be a gzip-compressed encoded protobuf or one of many legacy
+// profile formats which may be unsupported in the future.
+func Parse(r io.Reader) (*Profile, error) {
+	data, err := ioutil.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+	return ParseData(data)
+}
+
+// ParseData parses a profile from a buffer and checks for its
+// validity.
+func ParseData(data []byte) (*Profile, error) {
+	var p *Profile
+	var err error
+	if len(data) >= 2 && data[0] == 0x1f && data[1] == 0x8b {
+		gz, err := gzip.NewReader(bytes.NewBuffer(data))
+		if err == nil {
+			data, err = ioutil.ReadAll(gz)
+		}
+		if err != nil {
+			return nil, fmt.Errorf("decompressing profile: %v", err)
+		}
+	}
+	if p, err = ParseUncompressed(data); err != nil && err != errNoData && err != errConcatProfile {
+		p, err = parseLegacy(data)
+	}
+
+	if err != nil {
+		return nil, fmt.Errorf("parsing profile: %v", err)
+	}
+
+	if err := p.CheckValid(); err != nil {
+		return nil, fmt.Errorf("malformed profile: %v", err)
+	}
+	return p, nil
+}
+
+var errUnrecognized = fmt.Errorf("unrecognized profile format")
+var errMalformed = fmt.Errorf("malformed profile format")
+var errNoData = fmt.Errorf("empty input file")
+var errConcatProfile = fmt.Errorf("concatenated profiles detected")
+
+func parseLegacy(data []byte) (*Profile, error) {
+	parsers := []func([]byte) (*Profile, error){
+		parseCPU,
+		parseHeap,
+		parseGoCount, // goroutine, threadcreate
+		parseThread,
+		parseContention,
+		parseJavaProfile,
+	}
+
+	for _, parser := range parsers {
+		p, err := parser(data)
+		if err == nil {
+			p.addLegacyFrameInfo()
+			return p, nil
+		}
+		if err != errUnrecognized {
+			return nil, err
+		}
+	}
+	return nil, errUnrecognized
+}
+
+// ParseUncompressed parses an uncompressed protobuf into a profile.
+func ParseUncompressed(data []byte) (*Profile, error) {
+	if len(data) == 0 {
+		return nil, errNoData
+	}
+	p := &Profile{}
+	if err := unmarshal(data, p); err != nil {
+		return nil, err
+	}
+
+	if err := p.postDecode(); err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}
+
+var libRx = regexp.MustCompile(`([.]so$|[.]so[._][0-9]+)`)
+
+// massageMappings applies heuristic-based changes to the profile
+// mappings to account for quirks of some environments.
+func (p *Profile) massageMappings() {
+	// Merge adjacent regions with matching names, checking that the offsets match
+	if len(p.Mapping) > 1 {
+		mappings := []*Mapping{p.Mapping[0]}
+		for _, m := range p.Mapping[1:] {
+			lm := mappings[len(mappings)-1]
+			if adjacent(lm, m) {
+				lm.Limit = m.Limit
+				if m.File != "" {
+					lm.File = m.File
+				}
+				if m.BuildID != "" {
+					lm.BuildID = m.BuildID
+				}
+				p.updateLocationMapping(m, lm)
+				continue
+			}
+			mappings = append(mappings, m)
+		}
+		p.Mapping = mappings
+	}
+
+	// Use heuristics to identify main binary and move it to the top of the list of mappings
+	for i, m := range p.Mapping {
+		file := strings.TrimSpace(strings.Replace(m.File, "(deleted)", "", -1))
+		if len(file) == 0 {
+			continue
+		}
+		if len(libRx.FindStringSubmatch(file)) > 0 {
+			continue
+		}
+		if file[0] == '[' {
+			continue
+		}
+		// Swap what we guess is main to position 0.
+		p.Mapping[0], p.Mapping[i] = p.Mapping[i], p.Mapping[0]
+		break
+	}
+
+	// Keep the mapping IDs neatly sorted
+	for i, m := range p.Mapping {
+		m.ID = uint64(i + 1)
+	}
+}
+
+// adjacent returns whether two mapping entries represent the same
+// mapping that has been split into two. Check that their addresses are adjacent,
+// and if the offsets match, if they are available.
+func adjacent(m1, m2 *Mapping) bool {
+	if m1.File != "" && m2.File != "" {
+		if m1.File != m2.File {
+			return false
+		}
+	}
+	if m1.BuildID != "" && m2.BuildID != "" {
+		if m1.BuildID != m2.BuildID {
+			return false
+		}
+	}
+	if m1.Limit != m2.Start {
+		return false
+	}
+	if m1.Offset != 0 && m2.Offset != 0 {
+		offset := m1.Offset + (m1.Limit - m1.Start)
+		if offset != m2.Offset {
+			return false
+		}
+	}
+	return true
+}
+
+func (p *Profile) updateLocationMapping(from, to *Mapping) {
+	for _, l := range p.Location {
+		if l.Mapping == from {
+			l.Mapping = to
+		}
+	}
+}
+
+func serialize(p *Profile) []byte {
+	p.encodeMu.Lock()
+	p.preEncode()
+	b := marshal(p)
+	p.encodeMu.Unlock()
+	return b
+}
+
+// Write writes the profile as a gzip-compressed marshaled protobuf.
+func (p *Profile) Write(w io.Writer) error {
+	zw := gzip.NewWriter(w)
+	defer zw.Close()
+	_, err := zw.Write(serialize(p))
+	return err
+}
+
+// WriteUncompressed writes the profile as a marshaled protobuf.
+func (p *Profile) WriteUncompressed(w io.Writer) error {
+	_, err := w.Write(serialize(p))
+	return err
+}
+
+// CheckValid tests whether the profile is valid. Checks include, but are
+// not limited to:
+//   - len(Profile.Sample[n].value) == len(Profile.value_unit)
+//   - Sample.id has a corresponding Profile.Location
+func (p *Profile) CheckValid() error {
+	// Check that sample values are consistent
+	sampleLen := len(p.SampleType)
+	if sampleLen == 0 && len(p.Sample) != 0 {
+		return fmt.Errorf("missing sample type information")
+	}
+	for _, s := range p.Sample {
+		if s == nil {
+			return fmt.Errorf("profile has nil sample")
+		}
+		if len(s.Value) != sampleLen {
+			return fmt.Errorf("mismatch: sample has %d values vs. %d types", len(s.Value), len(p.SampleType))
+		}
+		for _, l := range s.Location {
+			if l == nil {
+				return fmt.Errorf("sample has nil location")
+			}
+		}
+	}
+
+	// Check that all mappings/locations/functions are in the tables
+	// Check that there are no duplicate ids
+	mappings := make(map[uint64]*Mapping, len(p.Mapping))
+	for _, m := range p.Mapping {
+		if m == nil {
+			return fmt.Errorf("profile has nil mapping")
+		}
+		if m.ID == 0 {
+			return fmt.Errorf("found mapping with reserved ID=0")
+		}
+		if mappings[m.ID] != nil {
+			return fmt.Errorf("multiple mappings with same id: %d", m.ID)
+		}
+		mappings[m.ID] = m
+	}
+	functions := make(map[uint64]*Function, len(p.Function))
+	for _, f := range p.Function {
+		if f == nil {
+			return fmt.Errorf("profile has nil function")
+		}
+		if f.ID == 0 {
+			return fmt.Errorf("found function with reserved ID=0")
+		}
+		if functions[f.ID] != nil {
+			return fmt.Errorf("multiple functions with same id: %d", f.ID)
+		}
+		functions[f.ID] = f
+	}
+	locations := make(map[uint64]*Location, len(p.Location))
+	for _, l := range p.Location {
+		if l == nil {
+			return fmt.Errorf("profile has nil location")
+		}
+		if l.ID == 0 {
+			return fmt.Errorf("found location with reserved id=0")
+		}
+		if locations[l.ID] != nil {
+			return fmt.Errorf("multiple locations with same id: %d", l.ID)
+		}
+		locations[l.ID] = l
+		if m := l.Mapping; m != nil {
+			if m.ID == 0 || mappings[m.ID] != m {
+				return fmt.Errorf("inconsistent mapping %p: %d", m, m.ID)
+			}
+		}
+		for _, ln := range l.Line {
+			f := ln.Function
+			if f == nil {
+				return fmt.Errorf("location id: %d has a line with nil function", l.ID)
+			}
+			if f.ID == 0 || functions[f.ID] != f {
+				return fmt.Errorf("inconsistent function %p: %d", f, f.ID)
+			}
+		}
+	}
+	return nil
+}
+
+// Aggregate merges the locations in the profile into equivalence
+// classes preserving the request attributes. It also updates the
+// samples to point to the merged locations.
+func (p *Profile) Aggregate(inlineFrame, function, filename, linenumber, address bool) error {
+	for _, m := range p.Mapping {
+		m.HasInlineFrames = m.HasInlineFrames && inlineFrame
+		m.HasFunctions = m.HasFunctions && function
+		m.HasFilenames = m.HasFilenames && filename
+		m.HasLineNumbers = m.HasLineNumbers && linenumber
+	}
+
+	// Aggregate functions
+	if !function || !filename {
+		for _, f := range p.Function {
+			if !function {
+				f.Name = ""
+				f.SystemName = ""
+			}
+			if !filename {
+				f.Filename = ""
+			}
+		}
+	}
+
+	// Aggregate locations
+	if !inlineFrame || !address || !linenumber {
+		for _, l := range p.Location {
+			if !inlineFrame && len(l.Line) > 1 {
+				l.Line = l.Line[len(l.Line)-1:]
+			}
+			if !linenumber {
+				for i := range l.Line {
+					l.Line[i].Line = 0
+				}
+			}
+			if !address {
+				l.Address = 0
+			}
+		}
+	}
+
+	return p.CheckValid()
+}
+
+// NumLabelUnits returns a map of numeric label keys to the units
+// associated with those keys and a map of those keys to any units
+// that were encountered but not used.
+// Unit for a given key is the first encountered unit for that key. If multiple
+// units are encountered for values paired with a particular key, then the first
+// unit encountered is used and all other units are returned in sorted order
+// in map of ignored units.
+// If no units are encountered for a particular key, the unit is then inferred
+// based on the key.
+func (p *Profile) NumLabelUnits() (map[string]string, map[string][]string) {
+	numLabelUnits := map[string]string{}
+	ignoredUnits := map[string]map[string]bool{}
+	encounteredKeys := map[string]bool{}
+
+	// Determine units based on numeric tags for each sample.
+	for _, s := range p.Sample {
+		for k := range s.NumLabel {
+			encounteredKeys[k] = true
+			for _, unit := range s.NumUnit[k] {
+				if unit == "" {
+					continue
+				}
+				if wantUnit, ok := numLabelUnits[k]; !ok {
+					numLabelUnits[k] = unit
+				} else if wantUnit != unit {
+					if v, ok := ignoredUnits[k]; ok {
+						v[unit] = true
+					} else {
+						ignoredUnits[k] = map[string]bool{unit: true}
+					}
+				}
+			}
+		}
+	}
+	// Infer units for keys without any units associated with
+	// numeric tag values.
+	for key := range encounteredKeys {
+		unit := numLabelUnits[key]
+		if unit == "" {
+			switch key {
+			case "alignment", "request":
+				numLabelUnits[key] = "bytes"
+			default:
+				numLabelUnits[key] = key
+			}
+		}
+	}
+
+	// Copy ignored units into more readable format
+	unitsIgnored := make(map[string][]string, len(ignoredUnits))
+	for key, values := range ignoredUnits {
+		units := make([]string, len(values))
+		i := 0
+		for unit := range values {
+			units[i] = unit
+			i++
+		}
+		sort.Strings(units)
+		unitsIgnored[key] = units
+	}
+
+	return numLabelUnits, unitsIgnored
+}
+
+// String dumps a text representation of a profile. Intended mainly
+// for debugging purposes.
+func (p *Profile) String() string {
+	ss := make([]string, 0, len(p.Comments)+len(p.Sample)+len(p.Mapping)+len(p.Location))
+	for _, c := range p.Comments {
+		ss = append(ss, "Comment: "+c)
+	}
+	if pt := p.PeriodType; pt != nil {
+		ss = append(ss, fmt.Sprintf("PeriodType: %s %s", pt.Type, pt.Unit))
+	}
+	ss = append(ss, fmt.Sprintf("Period: %d", p.Period))
+	if p.TimeNanos != 0 {
+		ss = append(ss, fmt.Sprintf("Time: %v", time.Unix(0, p.TimeNanos)))
+	}
+	if p.DurationNanos != 0 {
+		ss = append(ss, fmt.Sprintf("Duration: %.4v", time.Duration(p.DurationNanos)))
+	}
+
+	ss = append(ss, "Samples:")
+	var sh1 string
+	for _, s := range p.SampleType {
+		dflt := ""
+		if s.Type == p.DefaultSampleType {
+			dflt = "[dflt]"
+		}
+		sh1 = sh1 + fmt.Sprintf("%s/%s%s ", s.Type, s.Unit, dflt)
+	}
+	ss = append(ss, strings.TrimSpace(sh1))
+	for _, s := range p.Sample {
+		ss = append(ss, s.string())
+	}
+
+	ss = append(ss, "Locations")
+	for _, l := range p.Location {
+		ss = append(ss, l.string())
+	}
+
+	ss = append(ss, "Mappings")
+	for _, m := range p.Mapping {
+		ss = append(ss, m.string())
+	}
+
+	return strings.Join(ss, "\n") + "\n"
+}
+
+// string dumps a text representation of a mapping. Intended mainly
+// for debugging purposes.
+func (m *Mapping) string() string {
+	bits := ""
+	if m.HasFunctions {
+		bits = bits + "[FN]"
+	}
+	if m.HasFilenames {
+		bits = bits + "[FL]"
+	}
+	if m.HasLineNumbers {
+		bits = bits + "[LN]"
+	}
+	if m.HasInlineFrames {
+		bits = bits + "[IN]"
+	}
+	return fmt.Sprintf("%d: %#x/%#x/%#x %s %s %s",
+		m.ID,
+		m.Start, m.Limit, m.Offset,
+		m.File,
+		m.BuildID,
+		bits)
+}
+
+// string dumps a text representation of a location. Intended mainly
+// for debugging purposes.
+func (l *Location) string() string {
+	ss := []string{}
+	locStr := fmt.Sprintf("%6d: %#x ", l.ID, l.Address)
+	if m := l.Mapping; m != nil {
+		locStr = locStr + fmt.Sprintf("M=%d ", m.ID)
+	}
+	if l.IsFolded {
+		locStr = locStr + "[F] "
+	}
+	if len(l.Line) == 0 {
+		ss = append(ss, locStr)
+	}
+	for li := range l.Line {
+		lnStr := "??"
+		if fn := l.Line[li].Function; fn != nil {
+			lnStr = fmt.Sprintf("%s %s:%d s=%d",
+				fn.Name,
+				fn.Filename,
+				l.Line[li].Line,
+				fn.StartLine)
+			if fn.Name != fn.SystemName {
+				lnStr = lnStr + "(" + fn.SystemName + ")"
+			}
+		}
+		ss = append(ss, locStr+lnStr)
+		// Do not print location details past the first line
+		locStr = "             "
+	}
+	return strings.Join(ss, "\n")
+}
+
+// string dumps a text representation of a sample. Intended mainly
+// for debugging purposes.
+func (s *Sample) string() string {
+	ss := []string{}
+	var sv string
+	for _, v := range s.Value {
+		sv = fmt.Sprintf("%s %10d", sv, v)
+	}
+	sv = sv + ": "
+	for _, l := range s.Location {
+		sv = sv + fmt.Sprintf("%d ", l.ID)
+	}
+	ss = append(ss, sv)
+	const labelHeader = "                "
+	if len(s.Label) > 0 {
+		ss = append(ss, labelHeader+labelsToString(s.Label))
+	}
+	if len(s.NumLabel) > 0 {
+		ss = append(ss, labelHeader+numLabelsToString(s.NumLabel, s.NumUnit))
+	}
+	return strings.Join(ss, "\n")
+}
+
+// labelsToString returns a string representation of a
+// map representing labels.
+func labelsToString(labels map[string][]string) string {
+	ls := []string{}
+	for k, v := range labels {
+		ls = append(ls, fmt.Sprintf("%s:%v", k, v))
+	}
+	sort.Strings(ls)
+	return strings.Join(ls, " ")
+}
+
+// numLabelsToString returns a string representation of a map
+// representing numeric labels.
+func numLabelsToString(numLabels map[string][]int64, numUnits map[string][]string) string {
+	ls := []string{}
+	for k, v := range numLabels {
+		units := numUnits[k]
+		var labelString string
+		if len(units) == len(v) {
+			values := make([]string, len(v))
+			for i, vv := range v {
+				values[i] = fmt.Sprintf("%d %s", vv, units[i])
+			}
+			labelString = fmt.Sprintf("%s:%v", k, values)
+		} else {
+			labelString = fmt.Sprintf("%s:%v", k, v)
+		}
+		ls = append(ls, labelString)
+	}
+	sort.Strings(ls)
+	return strings.Join(ls, " ")
+}
+
+// SetLabel sets the specified key to the specified value for all samples in the
+// profile.
+func (p *Profile) SetLabel(key string, value []string) {
+	for _, sample := range p.Sample {
+		if sample.Label == nil {
+			sample.Label = map[string][]string{key: value}
+		} else {
+			sample.Label[key] = value
+		}
+	}
+}
+
+// RemoveLabel removes all labels associated with the specified key for all
+// samples in the profile.
+func (p *Profile) RemoveLabel(key string) {
+	for _, sample := range p.Sample {
+		delete(sample.Label, key)
+	}
+}
+
+// HasLabel returns true if a sample has a label with indicated key and value.
+func (s *Sample) HasLabel(key, value string) bool {
+	for _, v := range s.Label[key] {
+		if v == value {
+			return true
+		}
+	}
+	return false
+}
+
+// DiffBaseSample returns true if a sample belongs to the diff base and false
+// otherwise.
+func (s *Sample) DiffBaseSample() bool {
+	return s.HasLabel("pprof::base", "true")
+}
+
+// Scale multiplies all sample values in a profile by a constant.
+func (p *Profile) Scale(ratio float64) {
+	if ratio == 1 {
+		return
+	}
+	ratios := make([]float64, len(p.SampleType))
+	for i := range p.SampleType {
+		ratios[i] = ratio
+	}
+	p.ScaleN(ratios)
+}
+
+// ScaleN multiplies each sample values in a sample by a different amount.
+func (p *Profile) ScaleN(ratios []float64) error {
+	if len(p.SampleType) != len(ratios) {
+		return fmt.Errorf("mismatched scale ratios, got %d, want %d", len(ratios), len(p.SampleType))
+	}
+	allOnes := true
+	for _, r := range ratios {
+		if r != 1 {
+			allOnes = false
+			break
+		}
+	}
+	if allOnes {
+		return nil
+	}
+	for _, s := range p.Sample {
+		for i, v := range s.Value {
+			if ratios[i] != 1 {
+				s.Value[i] = int64(float64(v) * ratios[i])
+			}
+		}
+	}
+	return nil
+}
+
+// HasFunctions determines if all locations in this profile have
+// symbolized function information.
+func (p *Profile) HasFunctions() bool {
+	for _, l := range p.Location {
+		if l.Mapping != nil && !l.Mapping.HasFunctions {
+			return false
+		}
+	}
+	return true
+}
+
+// HasFileLines determines if all locations in this profile have
+// symbolized file and line number information.
+func (p *Profile) HasFileLines() bool {
+	for _, l := range p.Location {
+		if l.Mapping != nil && (!l.Mapping.HasFilenames || !l.Mapping.HasLineNumbers) {
+			return false
+		}
+	}
+	return true
+}
+
+// Unsymbolizable returns true if a mapping points to a binary for which
+// locations can't be symbolized in principle, at least now. Examples are
+// "[vdso]", [vsyscall]" and some others, see the code.
+func (m *Mapping) Unsymbolizable() bool {
+	name := filepath.Base(m.File)
+	return strings.HasPrefix(name, "[") || strings.HasPrefix(name, "linux-vdso") || strings.HasPrefix(m.File, "/dev/dri/")
+}
+
+// Copy makes a fully independent copy of a profile.
+func (p *Profile) Copy() *Profile {
+	pp := &Profile{}
+	if err := unmarshal(serialize(p), pp); err != nil {
+		panic(err)
+	}
+	if err := pp.postDecode(); err != nil {
+		panic(err)
+	}
+
+	return pp
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/proto.go b/src/cmd/vendor/github.com/google/pprof/profile/proto.go
new file mode 100644
index 0000000..539ad3a
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/profile/proto.go
@@ -0,0 +1,370 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// This file is a simple protocol buffer encoder and decoder.
+// The format is described at
+// https://developers.google.com/protocol-buffers/docs/encoding
+//
+// A protocol message must implement the message interface:
+//   decoder() []decoder
+//   encode(*buffer)
+//
+// The decode method returns a slice indexed by field number that gives the
+// function to decode that field.
+// The encode method encodes its receiver into the given buffer.
+//
+// The two methods are simple enough to be implemented by hand rather than
+// by using a protocol compiler.
+//
+// See profile.go for examples of messages implementing this interface.
+//
+// There is no support for groups, message sets, or "has" bits.
+
+package profile
+
+import (
+	"errors"
+	"fmt"
+)
+
+type buffer struct {
+	field int // field tag
+	typ   int // proto wire type code for field
+	u64   uint64
+	data  []byte
+	tmp   [16]byte
+}
+
+type decoder func(*buffer, message) error
+
+type message interface {
+	decoder() []decoder
+	encode(*buffer)
+}
+
+func marshal(m message) []byte {
+	var b buffer
+	m.encode(&b)
+	return b.data
+}
+
+func encodeVarint(b *buffer, x uint64) {
+	for x >= 128 {
+		b.data = append(b.data, byte(x)|0x80)
+		x >>= 7
+	}
+	b.data = append(b.data, byte(x))
+}
+
+func encodeLength(b *buffer, tag int, len int) {
+	encodeVarint(b, uint64(tag)<<3|2)
+	encodeVarint(b, uint64(len))
+}
+
+func encodeUint64(b *buffer, tag int, x uint64) {
+	// append varint to b.data
+	encodeVarint(b, uint64(tag)<<3)
+	encodeVarint(b, x)
+}
+
+func encodeUint64s(b *buffer, tag int, x []uint64) {
+	if len(x) > 2 {
+		// Use packed encoding
+		n1 := len(b.data)
+		for _, u := range x {
+			encodeVarint(b, u)
+		}
+		n2 := len(b.data)
+		encodeLength(b, tag, n2-n1)
+		n3 := len(b.data)
+		copy(b.tmp[:], b.data[n2:n3])
+		copy(b.data[n1+(n3-n2):], b.data[n1:n2])
+		copy(b.data[n1:], b.tmp[:n3-n2])
+		return
+	}
+	for _, u := range x {
+		encodeUint64(b, tag, u)
+	}
+}
+
+func encodeUint64Opt(b *buffer, tag int, x uint64) {
+	if x == 0 {
+		return
+	}
+	encodeUint64(b, tag, x)
+}
+
+func encodeInt64(b *buffer, tag int, x int64) {
+	u := uint64(x)
+	encodeUint64(b, tag, u)
+}
+
+func encodeInt64s(b *buffer, tag int, x []int64) {
+	if len(x) > 2 {
+		// Use packed encoding
+		n1 := len(b.data)
+		for _, u := range x {
+			encodeVarint(b, uint64(u))
+		}
+		n2 := len(b.data)
+		encodeLength(b, tag, n2-n1)
+		n3 := len(b.data)
+		copy(b.tmp[:], b.data[n2:n3])
+		copy(b.data[n1+(n3-n2):], b.data[n1:n2])
+		copy(b.data[n1:], b.tmp[:n3-n2])
+		return
+	}
+	for _, u := range x {
+		encodeInt64(b, tag, u)
+	}
+}
+
+func encodeInt64Opt(b *buffer, tag int, x int64) {
+	if x == 0 {
+		return
+	}
+	encodeInt64(b, tag, x)
+}
+
+func encodeString(b *buffer, tag int, x string) {
+	encodeLength(b, tag, len(x))
+	b.data = append(b.data, x...)
+}
+
+func encodeStrings(b *buffer, tag int, x []string) {
+	for _, s := range x {
+		encodeString(b, tag, s)
+	}
+}
+
+func encodeBool(b *buffer, tag int, x bool) {
+	if x {
+		encodeUint64(b, tag, 1)
+	} else {
+		encodeUint64(b, tag, 0)
+	}
+}
+
+func encodeBoolOpt(b *buffer, tag int, x bool) {
+	if x {
+		encodeBool(b, tag, x)
+	}
+}
+
+func encodeMessage(b *buffer, tag int, m message) {
+	n1 := len(b.data)
+	m.encode(b)
+	n2 := len(b.data)
+	encodeLength(b, tag, n2-n1)
+	n3 := len(b.data)
+	copy(b.tmp[:], b.data[n2:n3])
+	copy(b.data[n1+(n3-n2):], b.data[n1:n2])
+	copy(b.data[n1:], b.tmp[:n3-n2])
+}
+
+func unmarshal(data []byte, m message) (err error) {
+	b := buffer{data: data, typ: 2}
+	return decodeMessage(&b, m)
+}
+
+func le64(p []byte) uint64 {
+	return uint64(p[0]) | uint64(p[1])<<8 | uint64(p[2])<<16 | uint64(p[3])<<24 | uint64(p[4])<<32 | uint64(p[5])<<40 | uint64(p[6])<<48 | uint64(p[7])<<56
+}
+
+func le32(p []byte) uint32 {
+	return uint32(p[0]) | uint32(p[1])<<8 | uint32(p[2])<<16 | uint32(p[3])<<24
+}
+
+func decodeVarint(data []byte) (uint64, []byte, error) {
+	var u uint64
+	for i := 0; ; i++ {
+		if i >= 10 || i >= len(data) {
+			return 0, nil, errors.New("bad varint")
+		}
+		u |= uint64(data[i]&0x7F) << uint(7*i)
+		if data[i]&0x80 == 0 {
+			return u, data[i+1:], nil
+		}
+	}
+}
+
+func decodeField(b *buffer, data []byte) ([]byte, error) {
+	x, data, err := decodeVarint(data)
+	if err != nil {
+		return nil, err
+	}
+	b.field = int(x >> 3)
+	b.typ = int(x & 7)
+	b.data = nil
+	b.u64 = 0
+	switch b.typ {
+	case 0:
+		b.u64, data, err = decodeVarint(data)
+		if err != nil {
+			return nil, err
+		}
+	case 1:
+		if len(data) < 8 {
+			return nil, errors.New("not enough data")
+		}
+		b.u64 = le64(data[:8])
+		data = data[8:]
+	case 2:
+		var n uint64
+		n, data, err = decodeVarint(data)
+		if err != nil {
+			return nil, err
+		}
+		if n > uint64(len(data)) {
+			return nil, errors.New("too much data")
+		}
+		b.data = data[:n]
+		data = data[n:]
+	case 5:
+		if len(data) < 4 {
+			return nil, errors.New("not enough data")
+		}
+		b.u64 = uint64(le32(data[:4]))
+		data = data[4:]
+	default:
+		return nil, fmt.Errorf("unknown wire type: %d", b.typ)
+	}
+
+	return data, nil
+}
+
+func checkType(b *buffer, typ int) error {
+	if b.typ != typ {
+		return errors.New("type mismatch")
+	}
+	return nil
+}
+
+func decodeMessage(b *buffer, m message) error {
+	if err := checkType(b, 2); err != nil {
+		return err
+	}
+	dec := m.decoder()
+	data := b.data
+	for len(data) > 0 {
+		// pull varint field# + type
+		var err error
+		data, err = decodeField(b, data)
+		if err != nil {
+			return err
+		}
+		if b.field >= len(dec) || dec[b.field] == nil {
+			continue
+		}
+		if err := dec[b.field](b, m); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func decodeInt64(b *buffer, x *int64) error {
+	if err := checkType(b, 0); err != nil {
+		return err
+	}
+	*x = int64(b.u64)
+	return nil
+}
+
+func decodeInt64s(b *buffer, x *[]int64) error {
+	if b.typ == 2 {
+		// Packed encoding
+		data := b.data
+		tmp := make([]int64, 0, len(data)) // Maximally sized
+		for len(data) > 0 {
+			var u uint64
+			var err error
+
+			if u, data, err = decodeVarint(data); err != nil {
+				return err
+			}
+			tmp = append(tmp, int64(u))
+		}
+		*x = append(*x, tmp...)
+		return nil
+	}
+	var i int64
+	if err := decodeInt64(b, &i); err != nil {
+		return err
+	}
+	*x = append(*x, i)
+	return nil
+}
+
+func decodeUint64(b *buffer, x *uint64) error {
+	if err := checkType(b, 0); err != nil {
+		return err
+	}
+	*x = b.u64
+	return nil
+}
+
+func decodeUint64s(b *buffer, x *[]uint64) error {
+	if b.typ == 2 {
+		data := b.data
+		// Packed encoding
+		tmp := make([]uint64, 0, len(data)) // Maximally sized
+		for len(data) > 0 {
+			var u uint64
+			var err error
+
+			if u, data, err = decodeVarint(data); err != nil {
+				return err
+			}
+			tmp = append(tmp, u)
+		}
+		*x = append(*x, tmp...)
+		return nil
+	}
+	var u uint64
+	if err := decodeUint64(b, &u); err != nil {
+		return err
+	}
+	*x = append(*x, u)
+	return nil
+}
+
+func decodeString(b *buffer, x *string) error {
+	if err := checkType(b, 2); err != nil {
+		return err
+	}
+	*x = string(b.data)
+	return nil
+}
+
+func decodeStrings(b *buffer, x *[]string) error {
+	var s string
+	if err := decodeString(b, &s); err != nil {
+		return err
+	}
+	*x = append(*x, s)
+	return nil
+}
+
+func decodeBool(b *buffer, x *bool) error {
+	if err := checkType(b, 0); err != nil {
+		return err
+	}
+	if int64(b.u64) == 0 {
+		*x = false
+	} else {
+		*x = true
+	}
+	return nil
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/profile/prune.go b/src/cmd/vendor/github.com/google/pprof/profile/prune.go
new file mode 100644
index 0000000..02d21a8
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/profile/prune.go
@@ -0,0 +1,178 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Implements methods to remove frames from profiles.
+
+package profile
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+var (
+	reservedNames = []string{"(anonymous namespace)", "operator()"}
+	bracketRx     = func() *regexp.Regexp {
+		var quotedNames []string
+		for _, name := range append(reservedNames, "(") {
+			quotedNames = append(quotedNames, regexp.QuoteMeta(name))
+		}
+		return regexp.MustCompile(strings.Join(quotedNames, "|"))
+	}()
+)
+
+// simplifyFunc does some primitive simplification of function names.
+func simplifyFunc(f string) string {
+	// Account for leading '.' on the PPC ELF v1 ABI.
+	funcName := strings.TrimPrefix(f, ".")
+	// Account for unsimplified names -- try  to remove the argument list by trimming
+	// starting from the first '(', but skipping reserved names that have '('.
+	for _, ind := range bracketRx.FindAllStringSubmatchIndex(funcName, -1) {
+		foundReserved := false
+		for _, res := range reservedNames {
+			if funcName[ind[0]:ind[1]] == res {
+				foundReserved = true
+				break
+			}
+		}
+		if !foundReserved {
+			funcName = funcName[:ind[0]]
+			break
+		}
+	}
+	return funcName
+}
+
+// Prune removes all nodes beneath a node matching dropRx, and not
+// matching keepRx. If the root node of a Sample matches, the sample
+// will have an empty stack.
+func (p *Profile) Prune(dropRx, keepRx *regexp.Regexp) {
+	prune := make(map[uint64]bool)
+	pruneBeneath := make(map[uint64]bool)
+
+	for _, loc := range p.Location {
+		var i int
+		for i = len(loc.Line) - 1; i >= 0; i-- {
+			if fn := loc.Line[i].Function; fn != nil && fn.Name != "" {
+				funcName := simplifyFunc(fn.Name)
+				if dropRx.MatchString(funcName) {
+					if keepRx == nil || !keepRx.MatchString(funcName) {
+						break
+					}
+				}
+			}
+		}
+
+		if i >= 0 {
+			// Found matching entry to prune.
+			pruneBeneath[loc.ID] = true
+
+			// Remove the matching location.
+			if i == len(loc.Line)-1 {
+				// Matched the top entry: prune the whole location.
+				prune[loc.ID] = true
+			} else {
+				loc.Line = loc.Line[i+1:]
+			}
+		}
+	}
+
+	// Prune locs from each Sample
+	for _, sample := range p.Sample {
+		// Scan from the root to the leaves to find the prune location.
+		// Do not prune frames before the first user frame, to avoid
+		// pruning everything.
+		foundUser := false
+		for i := len(sample.Location) - 1; i >= 0; i-- {
+			id := sample.Location[i].ID
+			if !prune[id] && !pruneBeneath[id] {
+				foundUser = true
+				continue
+			}
+			if !foundUser {
+				continue
+			}
+			if prune[id] {
+				sample.Location = sample.Location[i+1:]
+				break
+			}
+			if pruneBeneath[id] {
+				sample.Location = sample.Location[i:]
+				break
+			}
+		}
+	}
+}
+
+// RemoveUninteresting prunes and elides profiles using built-in
+// tables of uninteresting function names.
+func (p *Profile) RemoveUninteresting() error {
+	var keep, drop *regexp.Regexp
+	var err error
+
+	if p.DropFrames != "" {
+		if drop, err = regexp.Compile("^(" + p.DropFrames + ")$"); err != nil {
+			return fmt.Errorf("failed to compile regexp %s: %v", p.DropFrames, err)
+		}
+		if p.KeepFrames != "" {
+			if keep, err = regexp.Compile("^(" + p.KeepFrames + ")$"); err != nil {
+				return fmt.Errorf("failed to compile regexp %s: %v", p.KeepFrames, err)
+			}
+		}
+		p.Prune(drop, keep)
+	}
+	return nil
+}
+
+// PruneFrom removes all nodes beneath the lowest node matching dropRx, not including itself.
+//
+// Please see the example below to understand this method as well as
+// the difference from Prune method.
+//
+// A sample contains Location of [A,B,C,B,D] where D is the top frame and there's no inline.
+//
+// PruneFrom(A) returns [A,B,C,B,D] because there's no node beneath A.
+// Prune(A, nil) returns [B,C,B,D] by removing A itself.
+//
+// PruneFrom(B) returns [B,C,B,D] by removing all nodes beneath the first B when scanning from the bottom.
+// Prune(B, nil) returns [D] because a matching node is found by scanning from the root.
+func (p *Profile) PruneFrom(dropRx *regexp.Regexp) {
+	pruneBeneath := make(map[uint64]bool)
+
+	for _, loc := range p.Location {
+		for i := 0; i < len(loc.Line); i++ {
+			if fn := loc.Line[i].Function; fn != nil && fn.Name != "" {
+				funcName := simplifyFunc(fn.Name)
+				if dropRx.MatchString(funcName) {
+					// Found matching entry to prune.
+					pruneBeneath[loc.ID] = true
+					loc.Line = loc.Line[i:]
+					break
+				}
+			}
+		}
+	}
+
+	// Prune locs from each Sample
+	for _, sample := range p.Sample {
+		// Scan from the bottom leaf to the root to find the prune location.
+		for i, loc := range sample.Location {
+			if pruneBeneath[loc.ID] {
+				sample.Location = sample.Location[i:]
+				break
+			}
+		}
+	}
+}
diff --git a/src/cmd/vendor/github.com/google/pprof/third_party/d3/LICENSE b/src/cmd/vendor/github.com/google/pprof/third_party/d3/LICENSE
new file mode 100644
index 0000000..1d9d875
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/third_party/d3/LICENSE
@@ -0,0 +1,27 @@
+Copyright 2010-2017 Mike Bostock
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of the author nor the names of contributors may be used to
+  endorse or promote products derived from this software without specific prior
+  written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/src/cmd/vendor/github.com/google/pprof/third_party/d3/README.md b/src/cmd/vendor/github.com/google/pprof/third_party/d3/README.md
new file mode 100644
index 0000000..53e6eb6
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/third_party/d3/README.md
@@ -0,0 +1,119 @@
+# Building a customized D3.js bundle
+
+The D3.js version distributed with pprof is customized to only include the modules required by pprof.
+
+## Dependencies
+
+First, it's necessary to pull all bundle dependencies. We will use a JavaScript package manager, [npm](https://www.npmjs.com/), to accomplish that. npm dependencies are declared in a `package.json` file, so create one with the following configuration:
+
+```js
+{
+  "name": "d3-pprof",
+  "version": "1.0.0",
+  "description": "A d3.js bundle for pprof.",
+  "scripts": {
+    "prepare": "rollup -c && uglifyjs d3.js -c -m -o d3.min.js"
+  },
+  "license": "Apache-2.0",
+  "devDependencies": {
+    "d3-selection": "1.1.0",
+    "d3-hierarchy": "1.1.5",
+    "d3-scale": "1.0.6",
+    "d3-format": "1.2.0",
+    "d3-ease": "1.0.3",
+    "d3-array": "1.2.1",
+    "d3-collection": "1.0.4",
+    "d3-transition": "1.1.0",
+    "rollup": "0.51.8",
+    "rollup-plugin-node-resolve": "3",
+    "uglify-js": "3.1.10"
+  }
+}
+```
+
+Besides the bundle dependencies, the `package.json` file also specifies a script called `prepare`, which will be executed to create the bundle after `Rollup` is installed.
+
+## Bundler
+
+The simplest way of creating a custom bundle is to use a bundler, such as [Rollup](https://rollupjs.org/) or [Webpack](https://webpack.js.org/). Rollup will be used in this example.
+
+First, create a `rollup.config.js` file, containing the configuration Rollup should use to build the bundle.
+
+```js
+import node from "rollup-plugin-node-resolve";
+
+export default {
+  input: "index.js",
+  output: {
+    format: "umd",
+    file: "d3.js"
+  },
+  name: "d3",
+  plugins: [node()],
+  sourcemap: false
+};
+```
+
+Then create an `index.js` file containing all the functions that need to be exported in the bundle.
+
+```js
+export {
+  select,
+  selection,
+  event,
+} from "d3-selection";
+
+export {
+    hierarchy,
+    partition,
+} from "d3-hierarchy";
+
+export {
+    scaleLinear,
+} from "d3-scale";
+
+export {
+    format,
+} from "d3-format";
+
+export {
+    easeCubic,
+} from "d3-ease";
+
+export {
+    ascending,
+} from "d3-array";
+
+export {
+    map,
+} from "d3-collection";
+
+export {
+    transition,
+} from "d3-transition";
+```
+
+## Building
+
+Once all files were created, execute the following commands to pull all dependencies and build the bundle.
+
+```
+% npm install
+% npm run prepare
+```
+
+This will create two files, `d3.js` and `d3.min.js`, the custom D3.js bundle and its minified version respectively.
+
+# References
+
+## D3 Custom Bundle
+
+A demonstration of building a custom D3 4.0 bundle using ES2015 modules and Rollup. 
+
+[bl.ocks.org/mbostock/bb09af4c39c79cffcde4](https://bl.ocks.org/mbostock/bb09af4c39c79cffcde4)
+
+## d3-pprof
+
+A repository containing all previously mentioned configuration files and the generated custom bundle.
+
+[github.com/spiermar/d3-pprof](https://github.com/spiermar/d3-pprof)
\ No newline at end of file
diff --git a/src/cmd/vendor/github.com/google/pprof/third_party/d3/d3.go b/src/cmd/vendor/github.com/google/pprof/third_party/d3/d3.go
new file mode 100644
index 0000000..7d217c7
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/third_party/d3/d3.go
@@ -0,0 +1,4675 @@
+// D3.js is a JavaScript library for manipulating documents based on data.
+// https://github.com/d3/d3
+// See LICENSE file for license details
+// Custom build for pprof (https://github.com/spiermar/d3-pprof)
+
+package d3
+
+// JSSource returns the d3.js file
+const JSSource = `
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
+	typeof define === 'function' && define.amd ? define(['exports'], factory) :
+	(factory((global.d3 = {})));
+}(this, (function (exports) { 'use strict';
+
+var xhtml = "http://www.w3.org/1999/xhtml";
+
+var namespaces = {
+  svg: "http://www.w3.org/2000/svg",
+  xhtml: xhtml,
+  xlink: "http://www.w3.org/1999/xlink",
+  xml: "http://www.w3.org/XML/1998/namespace",
+  xmlns: "http://www.w3.org/2000/xmlns/"
+};
+
+var namespace = function(name) {
+  var prefix = name += "", i = prefix.indexOf(":");
+  if (i >= 0 && (prefix = name.slice(0, i)) !== "xmlns") name = name.slice(i + 1);
+  return namespaces.hasOwnProperty(prefix) ? {space: namespaces[prefix], local: name} : name;
+};
+
+function creatorInherit(name) {
+  return function() {
+    var document = this.ownerDocument,
+        uri = this.namespaceURI;
+    return uri === xhtml && document.documentElement.namespaceURI === xhtml
+        ? document.createElement(name)
+        : document.createElementNS(uri, name);
+  };
+}
+
+function creatorFixed(fullname) {
+  return function() {
+    return this.ownerDocument.createElementNS(fullname.space, fullname.local);
+  };
+}
+
+var creator = function(name) {
+  var fullname = namespace(name);
+  return (fullname.local
+      ? creatorFixed
+      : creatorInherit)(fullname);
+};
+
+var matcher = function(selector) {
+  return function() {
+    return this.matches(selector);
+  };
+};
+
+if (typeof document !== "undefined") {
+  var element = document.documentElement;
+  if (!element.matches) {
+    var vendorMatches = element.webkitMatchesSelector
+        || element.msMatchesSelector
+        || element.mozMatchesSelector
+        || element.oMatchesSelector;
+    matcher = function(selector) {
+      return function() {
+        return vendorMatches.call(this, selector);
+      };
+    };
+  }
+}
+
+var matcher$1 = matcher;
+
+var filterEvents = {};
+
+exports.event = null;
+
+if (typeof document !== "undefined") {
+  var element$1 = document.documentElement;
+  if (!("onmouseenter" in element$1)) {
+    filterEvents = {mouseenter: "mouseover", mouseleave: "mouseout"};
+  }
+}
+
+function filterContextListener(listener, index, group) {
+  listener = contextListener(listener, index, group);
+  return function(event) {
+    var related = event.relatedTarget;
+    if (!related || (related !== this && !(related.compareDocumentPosition(this) & 8))) {
+      listener.call(this, event);
+    }
+  };
+}
+
+function contextListener(listener, index, group) {
+  return function(event1) {
+    var event0 = exports.event; // Events can be reentrant (e.g., focus).
+    exports.event = event1;
+    try {
+      listener.call(this, this.__data__, index, group);
+    } finally {
+      exports.event = event0;
+    }
+  };
+}
+
+function parseTypenames(typenames) {
+  return typenames.trim().split(/^|\s+/).map(function(t) {
+    var name = "", i = t.indexOf(".");
+    if (i >= 0) name = t.slice(i + 1), t = t.slice(0, i);
+    return {type: t, name: name};
+  });
+}
+
+function onRemove(typename) {
+  return function() {
+    var on = this.__on;
+    if (!on) return;
+    for (var j = 0, i = -1, m = on.length, o; j < m; ++j) {
+      if (o = on[j], (!typename.type || o.type === typename.type) && o.name === typename.name) {
+        this.removeEventListener(o.type, o.listener, o.capture);
+      } else {
+        on[++i] = o;
+      }
+    }
+    if (++i) on.length = i;
+    else delete this.__on;
+  };
+}
+
+function onAdd(typename, value, capture) {
+  var wrap = filterEvents.hasOwnProperty(typename.type) ? filterContextListener : contextListener;
+  return function(d, i, group) {
+    var on = this.__on, o, listener = wrap(value, i, group);
+    if (on) for (var j = 0, m = on.length; j < m; ++j) {
+      if ((o = on[j]).type === typename.type && o.name === typename.name) {
+        this.removeEventListener(o.type, o.listener, o.capture);
+        this.addEventListener(o.type, o.listener = listener, o.capture = capture);
+        o.value = value;
+        return;
+      }
+    }
+    this.addEventListener(typename.type, listener, capture);
+    o = {type: typename.type, name: typename.name, value: value, listener: listener, capture: capture};
+    if (!on) this.__on = [o];
+    else on.push(o);
+  };
+}
+
+var selection_on = function(typename, value, capture) {
+  var typenames = parseTypenames(typename + ""), i, n = typenames.length, t;
+
+  if (arguments.length < 2) {
+    var on = this.node().__on;
+    if (on) for (var j = 0, m = on.length, o; j < m; ++j) {
+      for (i = 0, o = on[j]; i < n; ++i) {
+        if ((t = typenames[i]).type === o.type && t.name === o.name) {
+          return o.value;
+        }
+      }
+    }
+    return;
+  }
+
+  on = value ? onAdd : onRemove;
+  if (capture == null) capture = false;
+  for (i = 0; i < n; ++i) this.each(on(typenames[i], value, capture));
+  return this;
+};
+
+function none() {}
+
+var selector = function(selector) {
+  return selector == null ? none : function() {
+    return this.querySelector(selector);
+  };
+};
+
+var selection_select = function(select) {
+  if (typeof select !== "function") select = selector(select);
+
+  for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
+    for (var group = groups[j], n = group.length, subgroup = subgroups[j] = new Array(n), node, subnode, i = 0; i < n; ++i) {
+      if ((node = group[i]) && (subnode = select.call(node, node.__data__, i, group))) {
+        if ("__data__" in node) subnode.__data__ = node.__data__;
+        subgroup[i] = subnode;
+      }
+    }
+  }
+
+  return new Selection(subgroups, this._parents);
+};
+
+function empty() {
+  return [];
+}
+
+var selectorAll = function(selector) {
+  return selector == null ? empty : function() {
+    return this.querySelectorAll(selector);
+  };
+};
+
+var selection_selectAll = function(select) {
+  if (typeof select !== "function") select = selectorAll(select);
+
+  for (var groups = this._groups, m = groups.length, subgroups = [], parents = [], j = 0; j < m; ++j) {
+    for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
+      if (node = group[i]) {
+        subgroups.push(select.call(node, node.__data__, i, group));
+        parents.push(node);
+      }
+    }
+  }
+
+  return new Selection(subgroups, parents);
+};
+
+var selection_filter = function(match) {
+  if (typeof match !== "function") match = matcher$1(match);
+
+  for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
+    for (var group = groups[j], n = group.length, subgroup = subgroups[j] = [], node, i = 0; i < n; ++i) {
+      if ((node = group[i]) && match.call(node, node.__data__, i, group)) {
+        subgroup.push(node);
+      }
+    }
+  }
+
+  return new Selection(subgroups, this._parents);
+};
+
+var sparse = function(update) {
+  return new Array(update.length);
+};
+
+var selection_enter = function() {
+  return new Selection(this._enter || this._groups.map(sparse), this._parents);
+};
+
+function EnterNode(parent, datum) {
+  this.ownerDocument = parent.ownerDocument;
+  this.namespaceURI = parent.namespaceURI;
+  this._next = null;
+  this._parent = parent;
+  this.__data__ = datum;
+}
+
+EnterNode.prototype = {
+  constructor: EnterNode,
+  appendChild: function(child) { return this._parent.insertBefore(child, this._next); },
+  insertBefore: function(child, next) { return this._parent.insertBefore(child, next); },
+  querySelector: function(selector) { return this._parent.querySelector(selector); },
+  querySelectorAll: function(selector) { return this._parent.querySelectorAll(selector); }
+};
+
+var constant = function(x) {
+  return function() {
+    return x;
+  };
+};
+
+var keyPrefix = "$"; // Protect against keys like “__proto__”.
+
+function bindIndex(parent, group, enter, update, exit, data) {
+  var i = 0,
+      node,
+      groupLength = group.length,
+      dataLength = data.length;
+
+  // Put any non-null nodes that fit into update.
+  // Put any null nodes into enter.
+  // Put any remaining data into enter.
+  for (; i < dataLength; ++i) {
+    if (node = group[i]) {
+      node.__data__ = data[i];
+      update[i] = node;
+    } else {
+      enter[i] = new EnterNode(parent, data[i]);
+    }
+  }
+
+  // Put any non-null nodes that don’t fit into exit.
+  for (; i < groupLength; ++i) {
+    if (node = group[i]) {
+      exit[i] = node;
+    }
+  }
+}
+
+function bindKey(parent, group, enter, update, exit, data, key) {
+  var i,
+      node,
+      nodeByKeyValue = {},
+      groupLength = group.length,
+      dataLength = data.length,
+      keyValues = new Array(groupLength),
+      keyValue;
+
+  // Compute the key for each node.
+  // If multiple nodes have the same key, the duplicates are added to exit.
+  for (i = 0; i < groupLength; ++i) {
+    if (node = group[i]) {
+      keyValues[i] = keyValue = keyPrefix + key.call(node, node.__data__, i, group);
+      if (keyValue in nodeByKeyValue) {
+        exit[i] = node;
+      } else {
+        nodeByKeyValue[keyValue] = node;
+      }
+    }
+  }
+
+  // Compute the key for each datum.
+  // If there a node associated with this key, join and add it to update.
+  // If there is not (or the key is a duplicate), add it to enter.
+  for (i = 0; i < dataLength; ++i) {
+    keyValue = keyPrefix + key.call(parent, data[i], i, data);
+    if (node = nodeByKeyValue[keyValue]) {
+      update[i] = node;
+      node.__data__ = data[i];
+      nodeByKeyValue[keyValue] = null;
+    } else {
+      enter[i] = new EnterNode(parent, data[i]);
+    }
+  }
+
+  // Add any remaining nodes that were not bound to data to exit.
+  for (i = 0; i < groupLength; ++i) {
+    if ((node = group[i]) && (nodeByKeyValue[keyValues[i]] === node)) {
+      exit[i] = node;
+    }
+  }
+}
+
+var selection_data = function(value, key) {
+  if (!value) {
+    data = new Array(this.size()), j = -1;
+    this.each(function(d) { data[++j] = d; });
+    return data;
+  }
+
+  var bind = key ? bindKey : bindIndex,
+      parents = this._parents,
+      groups = this._groups;
+
+  if (typeof value !== "function") value = constant(value);
+
+  for (var m = groups.length, update = new Array(m), enter = new Array(m), exit = new Array(m), j = 0; j < m; ++j) {
+    var parent = parents[j],
+        group = groups[j],
+        groupLength = group.length,
+        data = value.call(parent, parent && parent.__data__, j, parents),
+        dataLength = data.length,
+        enterGroup = enter[j] = new Array(dataLength),
+        updateGroup = update[j] = new Array(dataLength),
+        exitGroup = exit[j] = new Array(groupLength);
+
+    bind(parent, group, enterGroup, updateGroup, exitGroup, data, key);
+
+    // Now connect the enter nodes to their following update node, such that
+    // appendChild can insert the materialized enter node before this node,
+    // rather than at the end of the parent node.
+    for (var i0 = 0, i1 = 0, previous, next; i0 < dataLength; ++i0) {
+      if (previous = enterGroup[i0]) {
+        if (i0 >= i1) i1 = i0 + 1;
+        while (!(next = updateGroup[i1]) && ++i1 < dataLength);
+        previous._next = next || null;
+      }
+    }
+  }
+
+  update = new Selection(update, parents);
+  update._enter = enter;
+  update._exit = exit;
+  return update;
+};
+
+var selection_exit = function() {
+  return new Selection(this._exit || this._groups.map(sparse), this._parents);
+};
+
+var selection_merge = function(selection$$1) {
+
+  for (var groups0 = this._groups, groups1 = selection$$1._groups, m0 = groups0.length, m1 = groups1.length, m = Math.min(m0, m1), merges = new Array(m0), j = 0; j < m; ++j) {
+    for (var group0 = groups0[j], group1 = groups1[j], n = group0.length, merge = merges[j] = new Array(n), node, i = 0; i < n; ++i) {
+      if (node = group0[i] || group1[i]) {
+        merge[i] = node;
+      }
+    }
+  }
+
+  for (; j < m0; ++j) {
+    merges[j] = groups0[j];
+  }
+
+  return new Selection(merges, this._parents);
+};
+
+var selection_order = function() {
+
+  for (var groups = this._groups, j = -1, m = groups.length; ++j < m;) {
+    for (var group = groups[j], i = group.length - 1, next = group[i], node; --i >= 0;) {
+      if (node = group[i]) {
+        if (next && next !== node.nextSibling) next.parentNode.insertBefore(node, next);
+        next = node;
+      }
+    }
+  }
+
+  return this;
+};
+
+var selection_sort = function(compare) {
+  if (!compare) compare = ascending;
+
+  function compareNode(a, b) {
+    return a && b ? compare(a.__data__, b.__data__) : !a - !b;
+  }
+
+  for (var groups = this._groups, m = groups.length, sortgroups = new Array(m), j = 0; j < m; ++j) {
+    for (var group = groups[j], n = group.length, sortgroup = sortgroups[j] = new Array(n), node, i = 0; i < n; ++i) {
+      if (node = group[i]) {
+        sortgroup[i] = node;
+      }
+    }
+    sortgroup.sort(compareNode);
+  }
+
+  return new Selection(sortgroups, this._parents).order();
+};
+
+function ascending(a, b) {
+  return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
+}
+
+var selection_call = function() {
+  var callback = arguments[0];
+  arguments[0] = this;
+  callback.apply(null, arguments);
+  return this;
+};
+
+var selection_nodes = function() {
+  var nodes = new Array(this.size()), i = -1;
+  this.each(function() { nodes[++i] = this; });
+  return nodes;
+};
+
+var selection_node = function() {
+
+  for (var groups = this._groups, j = 0, m = groups.length; j < m; ++j) {
+    for (var group = groups[j], i = 0, n = group.length; i < n; ++i) {
+      var node = group[i];
+      if (node) return node;
+    }
+  }
+
+  return null;
+};
+
+var selection_size = function() {
+  var size = 0;
+  this.each(function() { ++size; });
+  return size;
+};
+
+var selection_empty = function() {
+  return !this.node();
+};
+
+var selection_each = function(callback) {
+
+  for (var groups = this._groups, j = 0, m = groups.length; j < m; ++j) {
+    for (var group = groups[j], i = 0, n = group.length, node; i < n; ++i) {
+      if (node = group[i]) callback.call(node, node.__data__, i, group);
+    }
+  }
+
+  return this;
+};
+
+function attrRemove(name) {
+  return function() {
+    this.removeAttribute(name);
+  };
+}
+
+function attrRemoveNS(fullname) {
+  return function() {
+    this.removeAttributeNS(fullname.space, fullname.local);
+  };
+}
+
+function attrConstant(name, value) {
+  return function() {
+    this.setAttribute(name, value);
+  };
+}
+
+function attrConstantNS(fullname, value) {
+  return function() {
+    this.setAttributeNS(fullname.space, fullname.local, value);
+  };
+}
+
+function attrFunction(name, value) {
+  return function() {
+    var v = value.apply(this, arguments);
+    if (v == null) this.removeAttribute(name);
+    else this.setAttribute(name, v);
+  };
+}
+
+function attrFunctionNS(fullname, value) {
+  return function() {
+    var v = value.apply(this, arguments);
+    if (v == null) this.removeAttributeNS(fullname.space, fullname.local);
+    else this.setAttributeNS(fullname.space, fullname.local, v);
+  };
+}
+
+var selection_attr = function(name, value) {
+  var fullname = namespace(name);
+
+  if (arguments.length < 2) {
+    var node = this.node();
+    return fullname.local
+        ? node.getAttributeNS(fullname.space, fullname.local)
+        : node.getAttribute(fullname);
+  }
+
+  return this.each((value == null
+      ? (fullname.local ? attrRemoveNS : attrRemove) : (typeof value === "function"
+      ? (fullname.local ? attrFunctionNS : attrFunction)
+      : (fullname.local ? attrConstantNS : attrConstant)))(fullname, value));
+};
+
+var defaultView = function(node) {
+  return (node.ownerDocument && node.ownerDocument.defaultView) // node is a Node
+      || (node.document && node) // node is a Window
+      || node.defaultView; // node is a Document
+};
+
+function styleRemove(name) {
+  return function() {
+    this.style.removeProperty(name);
+  };
+}
+
+function styleConstant(name, value, priority) {
+  return function() {
+    this.style.setProperty(name, value, priority);
+  };
+}
+
+function styleFunction(name, value, priority) {
+  return function() {
+    var v = value.apply(this, arguments);
+    if (v == null) this.style.removeProperty(name);
+    else this.style.setProperty(name, v, priority);
+  };
+}
+
+var selection_style = function(name, value, priority) {
+  return arguments.length > 1
+      ? this.each((value == null
+            ? styleRemove : typeof value === "function"
+            ? styleFunction
+            : styleConstant)(name, value, priority == null ? "" : priority))
+      : styleValue(this.node(), name);
+};
+
+function styleValue(node, name) {
+  return node.style.getPropertyValue(name)
+      || defaultView(node).getComputedStyle(node, null).getPropertyValue(name);
+}
+
+function propertyRemove(name) {
+  return function() {
+    delete this[name];
+  };
+}
+
+function propertyConstant(name, value) {
+  return function() {
+    this[name] = value;
+  };
+}
+
+function propertyFunction(name, value) {
+  return function() {
+    var v = value.apply(this, arguments);
+    if (v == null) delete this[name];
+    else this[name] = v;
+  };
+}
+
+var selection_property = function(name, value) {
+  return arguments.length > 1
+      ? this.each((value == null
+          ? propertyRemove : typeof value === "function"
+          ? propertyFunction
+          : propertyConstant)(name, value))
+      : this.node()[name];
+};
+
+function classArray(string) {
+  return string.trim().split(/^|\s+/);
+}
+
+function classList(node) {
+  return node.classList || new ClassList(node);
+}
+
+function ClassList(node) {
+  this._node = node;
+  this._names = classArray(node.getAttribute("class") || "");
+}
+
+ClassList.prototype = {
+  add: function(name) {
+    var i = this._names.indexOf(name);
+    if (i < 0) {
+      this._names.push(name);
+      this._node.setAttribute("class", this._names.join(" "));
+    }
+  },
+  remove: function(name) {
+    var i = this._names.indexOf(name);
+    if (i >= 0) {
+      this._names.splice(i, 1);
+      this._node.setAttribute("class", this._names.join(" "));
+    }
+  },
+  contains: function(name) {
+    return this._names.indexOf(name) >= 0;
+  }
+};
+
+function classedAdd(node, names) {
+  var list = classList(node), i = -1, n = names.length;
+  while (++i < n) list.add(names[i]);
+}
+
+function classedRemove(node, names) {
+  var list = classList(node), i = -1, n = names.length;
+  while (++i < n) list.remove(names[i]);
+}
+
+function classedTrue(names) {
+  return function() {
+    classedAdd(this, names);
+  };
+}
+
+function classedFalse(names) {
+  return function() {
+    classedRemove(this, names);
+  };
+}
+
+function classedFunction(names, value) {
+  return function() {
+    (value.apply(this, arguments) ? classedAdd : classedRemove)(this, names);
+  };
+}
+
+var selection_classed = function(name, value) {
+  var names = classArray(name + "");
+
+  if (arguments.length < 2) {
+    var list = classList(this.node()), i = -1, n = names.length;
+    while (++i < n) if (!list.contains(names[i])) return false;
+    return true;
+  }
+
+  return this.each((typeof value === "function"
+      ? classedFunction : value
+      ? classedTrue
+      : classedFalse)(names, value));
+};
+
+function textRemove() {
+  this.textContent = "";
+}
+
+function textConstant(value) {
+  return function() {
+    this.textContent = value;
+  };
+}
+
+function textFunction(value) {
+  return function() {
+    var v = value.apply(this, arguments);
+    this.textContent = v == null ? "" : v;
+  };
+}
+
+var selection_text = function(value) {
+  return arguments.length
+      ? this.each(value == null
+          ? textRemove : (typeof value === "function"
+          ? textFunction
+          : textConstant)(value))
+      : this.node().textContent;
+};
+
+function htmlRemove() {
+  this.innerHTML = "";
+}
+
+function htmlConstant(value) {
+  return function() {
+    this.innerHTML = value;
+  };
+}
+
+function htmlFunction(value) {
+  return function() {
+    var v = value.apply(this, arguments);
+    this.innerHTML = v == null ? "" : v;
+  };
+}
+
+var selection_html = function(value) {
+  return arguments.length
+      ? this.each(value == null
+          ? htmlRemove : (typeof value === "function"
+          ? htmlFunction
+          : htmlConstant)(value))
+      : this.node().innerHTML;
+};
+
+function raise() {
+  if (this.nextSibling) this.parentNode.appendChild(this);
+}
+
+var selection_raise = function() {
+  return this.each(raise);
+};
+
+function lower() {
+  if (this.previousSibling) this.parentNode.insertBefore(this, this.parentNode.firstChild);
+}
+
+var selection_lower = function() {
+  return this.each(lower);
+};
+
+var selection_append = function(name) {
+  var create = typeof name === "function" ? name : creator(name);
+  return this.select(function() {
+    return this.appendChild(create.apply(this, arguments));
+  });
+};
+
+function constantNull() {
+  return null;
+}
+
+var selection_insert = function(name, before) {
+  var create = typeof name === "function" ? name : creator(name),
+      select = before == null ? constantNull : typeof before === "function" ? before : selector(before);
+  return this.select(function() {
+    return this.insertBefore(create.apply(this, arguments), select.apply(this, arguments) || null);
+  });
+};
+
+function remove() {
+  var parent = this.parentNode;
+  if (parent) parent.removeChild(this);
+}
+
+var selection_remove = function() {
+  return this.each(remove);
+};
+
+var selection_datum = function(value) {
+  return arguments.length
+      ? this.property("__data__", value)
+      : this.node().__data__;
+};
+
+function dispatchEvent(node, type, params) {
+  var window = defaultView(node),
+      event = window.CustomEvent;
+
+  if (typeof event === "function") {
+    event = new event(type, params);
+  } else {
+    event = window.document.createEvent("Event");
+    if (params) event.initEvent(type, params.bubbles, params.cancelable), event.detail = params.detail;
+    else event.initEvent(type, false, false);
+  }
+
+  node.dispatchEvent(event);
+}
+
+function dispatchConstant(type, params) {
+  return function() {
+    return dispatchEvent(this, type, params);
+  };
+}
+
+function dispatchFunction(type, params) {
+  return function() {
+    return dispatchEvent(this, type, params.apply(this, arguments));
+  };
+}
+
+var selection_dispatch = function(type, params) {
+  return this.each((typeof params === "function"
+      ? dispatchFunction
+      : dispatchConstant)(type, params));
+};
+
+var root = [null];
+
+function Selection(groups, parents) {
+  this._groups = groups;
+  this._parents = parents;
+}
+
+function selection() {
+  return new Selection([[document.documentElement]], root);
+}
+
+Selection.prototype = selection.prototype = {
+  constructor: Selection,
+  select: selection_select,
+  selectAll: selection_selectAll,
+  filter: selection_filter,
+  data: selection_data,
+  enter: selection_enter,
+  exit: selection_exit,
+  merge: selection_merge,
+  order: selection_order,
+  sort: selection_sort,
+  call: selection_call,
+  nodes: selection_nodes,
+  node: selection_node,
+  size: selection_size,
+  empty: selection_empty,
+  each: selection_each,
+  attr: selection_attr,
+  style: selection_style,
+  property: selection_property,
+  classed: selection_classed,
+  text: selection_text,
+  html: selection_html,
+  raise: selection_raise,
+  lower: selection_lower,
+  append: selection_append,
+  insert: selection_insert,
+  remove: selection_remove,
+  datum: selection_datum,
+  on: selection_on,
+  dispatch: selection_dispatch
+};
+
+var select = function(selector) {
+  return typeof selector === "string"
+      ? new Selection([[document.querySelector(selector)]], [document.documentElement])
+      : new Selection([[selector]], root);
+};
+
+function count(node) {
+  var sum = 0,
+      children = node.children,
+      i = children && children.length;
+  if (!i) sum = 1;
+  else while (--i >= 0) sum += children[i].value;
+  node.value = sum;
+}
+
+var node_count = function() {
+  return this.eachAfter(count);
+};
+
+var node_each = function(callback) {
+  var node = this, current, next = [node], children, i, n;
+  do {
+    current = next.reverse(), next = [];
+    while (node = current.pop()) {
+      callback(node), children = node.children;
+      if (children) for (i = 0, n = children.length; i < n; ++i) {
+        next.push(children[i]);
+      }
+    }
+  } while (next.length);
+  return this;
+};
+
+var node_eachBefore = function(callback) {
+  var node = this, nodes = [node], children, i;
+  while (node = nodes.pop()) {
+    callback(node), children = node.children;
+    if (children) for (i = children.length - 1; i >= 0; --i) {
+      nodes.push(children[i]);
+    }
+  }
+  return this;
+};
+
+var node_eachAfter = function(callback) {
+  var node = this, nodes = [node], next = [], children, i, n;
+  while (node = nodes.pop()) {
+    next.push(node), children = node.children;
+    if (children) for (i = 0, n = children.length; i < n; ++i) {
+      nodes.push(children[i]);
+    }
+  }
+  while (node = next.pop()) {
+    callback(node);
+  }
+  return this;
+};
+
+var node_sum = function(value) {
+  return this.eachAfter(function(node) {
+    var sum = +value(node.data) || 0,
+        children = node.children,
+        i = children && children.length;
+    while (--i >= 0) sum += children[i].value;
+    node.value = sum;
+  });
+};
+
+var node_sort = function(compare) {
+  return this.eachBefore(function(node) {
+    if (node.children) {
+      node.children.sort(compare);
+    }
+  });
+};
+
+var node_path = function(end) {
+  var start = this,
+      ancestor = leastCommonAncestor(start, end),
+      nodes = [start];
+  while (start !== ancestor) {
+    start = start.parent;
+    nodes.push(start);
+  }
+  var k = nodes.length;
+  while (end !== ancestor) {
+    nodes.splice(k, 0, end);
+    end = end.parent;
+  }
+  return nodes;
+};
+
+function leastCommonAncestor(a, b) {
+  if (a === b) return a;
+  var aNodes = a.ancestors(),
+      bNodes = b.ancestors(),
+      c = null;
+  a = aNodes.pop();
+  b = bNodes.pop();
+  while (a === b) {
+    c = a;
+    a = aNodes.pop();
+    b = bNodes.pop();
+  }
+  return c;
+}
+
+var node_ancestors = function() {
+  var node = this, nodes = [node];
+  while (node = node.parent) {
+    nodes.push(node);
+  }
+  return nodes;
+};
+
+var node_descendants = function() {
+  var nodes = [];
+  this.each(function(node) {
+    nodes.push(node);
+  });
+  return nodes;
+};
+
+var node_leaves = function() {
+  var leaves = [];
+  this.eachBefore(function(node) {
+    if (!node.children) {
+      leaves.push(node);
+    }
+  });
+  return leaves;
+};
+
+var node_links = function() {
+  var root = this, links = [];
+  root.each(function(node) {
+    if (node !== root) { // Don’t include the root’s parent, if any.
+      links.push({source: node.parent, target: node});
+    }
+  });
+  return links;
+};
+
+function hierarchy(data, children) {
+  var root = new Node(data),
+      valued = +data.value && (root.value = data.value),
+      node,
+      nodes = [root],
+      child,
+      childs,
+      i,
+      n;
+
+  if (children == null) children = defaultChildren;
+
+  while (node = nodes.pop()) {
+    if (valued) node.value = +node.data.value;
+    if ((childs = children(node.data)) && (n = childs.length)) {
+      node.children = new Array(n);
+      for (i = n - 1; i >= 0; --i) {
+        nodes.push(child = node.children[i] = new Node(childs[i]));
+        child.parent = node;
+        child.depth = node.depth + 1;
+      }
+    }
+  }
+
+  return root.eachBefore(computeHeight);
+}
+
+function node_copy() {
+  return hierarchy(this).eachBefore(copyData);
+}
+
+function defaultChildren(d) {
+  return d.children;
+}
+
+function copyData(node) {
+  node.data = node.data.data;
+}
+
+function computeHeight(node) {
+  var height = 0;
+  do node.height = height;
+  while ((node = node.parent) && (node.height < ++height));
+}
+
+function Node(data) {
+  this.data = data;
+  this.depth =
+  this.height = 0;
+  this.parent = null;
+}
+
+Node.prototype = hierarchy.prototype = {
+  constructor: Node,
+  count: node_count,
+  each: node_each,
+  eachAfter: node_eachAfter,
+  eachBefore: node_eachBefore,
+  sum: node_sum,
+  sort: node_sort,
+  path: node_path,
+  ancestors: node_ancestors,
+  descendants: node_descendants,
+  leaves: node_leaves,
+  links: node_links,
+  copy: node_copy
+};
+
+var roundNode = function(node) {
+  node.x0 = Math.round(node.x0);
+  node.y0 = Math.round(node.y0);
+  node.x1 = Math.round(node.x1);
+  node.y1 = Math.round(node.y1);
+};
+
+var treemapDice = function(parent, x0, y0, x1, y1) {
+  var nodes = parent.children,
+      node,
+      i = -1,
+      n = nodes.length,
+      k = parent.value && (x1 - x0) / parent.value;
+
+  while (++i < n) {
+    node = nodes[i], node.y0 = y0, node.y1 = y1;
+    node.x0 = x0, node.x1 = x0 += node.value * k;
+  }
+};
+
+var partition = function() {
+  var dx = 1,
+      dy = 1,
+      padding = 0,
+      round = false;
+
+  function partition(root) {
+    var n = root.height + 1;
+    root.x0 =
+    root.y0 = padding;
+    root.x1 = dx;
+    root.y1 = dy / n;
+    root.eachBefore(positionNode(dy, n));
+    if (round) root.eachBefore(roundNode);
+    return root;
+  }
+
+  function positionNode(dy, n) {
+    return function(node) {
+      if (node.children) {
+        treemapDice(node, node.x0, dy * (node.depth + 1) / n, node.x1, dy * (node.depth + 2) / n);
+      }
+      var x0 = node.x0,
+          y0 = node.y0,
+          x1 = node.x1 - padding,
+          y1 = node.y1 - padding;
+      if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
+      if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
+      node.x0 = x0;
+      node.y0 = y0;
+      node.x1 = x1;
+      node.y1 = y1;
+    };
+  }
+
+  partition.round = function(x) {
+    return arguments.length ? (round = !!x, partition) : round;
+  };
+
+  partition.size = function(x) {
+    return arguments.length ? (dx = +x[0], dy = +x[1], partition) : [dx, dy];
+  };
+
+  partition.padding = function(x) {
+    return arguments.length ? (padding = +x, partition) : padding;
+  };
+
+  return partition;
+};
+
+var ascending$1 = function(a, b) {
+  return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
+};
+
+var bisector = function(compare) {
+  if (compare.length === 1) compare = ascendingComparator(compare);
+  return {
+    left: function(a, x, lo, hi) {
+      if (lo == null) lo = 0;
+      if (hi == null) hi = a.length;
+      while (lo < hi) {
+        var mid = lo + hi >>> 1;
+        if (compare(a[mid], x) < 0) lo = mid + 1;
+        else hi = mid;
+      }
+      return lo;
+    },
+    right: function(a, x, lo, hi) {
+      if (lo == null) lo = 0;
+      if (hi == null) hi = a.length;
+      while (lo < hi) {
+        var mid = lo + hi >>> 1;
+        if (compare(a[mid], x) > 0) hi = mid;
+        else lo = mid + 1;
+      }
+      return lo;
+    }
+  };
+};
+
+function ascendingComparator(f) {
+  return function(d, x) {
+    return ascending$1(f(d), x);
+  };
+}
+
+var ascendingBisect = bisector(ascending$1);
+var bisectRight = ascendingBisect.right;
+
+var e10 = Math.sqrt(50);
+var e5 = Math.sqrt(10);
+var e2 = Math.sqrt(2);
+
+var ticks = function(start, stop, count) {
+  var reverse,
+      i = -1,
+      n,
+      ticks,
+      step;
+
+  stop = +stop, start = +start, count = +count;
+  if (start === stop && count > 0) return [start];
+  if (reverse = stop < start) n = start, start = stop, stop = n;
+  if ((step = tickIncrement(start, stop, count)) === 0 || !isFinite(step)) return [];
+
+  if (step > 0) {
+    start = Math.ceil(start / step);
+    stop = Math.floor(stop / step);
+    ticks = new Array(n = Math.ceil(stop - start + 1));
+    while (++i < n) ticks[i] = (start + i) * step;
+  } else {
+    start = Math.floor(start * step);
+    stop = Math.ceil(stop * step);
+    ticks = new Array(n = Math.ceil(start - stop + 1));
+    while (++i < n) ticks[i] = (start - i) / step;
+  }
+
+  if (reverse) ticks.reverse();
+
+  return ticks;
+};
+
+function tickIncrement(start, stop, count) {
+  var step = (stop - start) / Math.max(0, count),
+      power = Math.floor(Math.log(step) / Math.LN10),
+      error = step / Math.pow(10, power);
+  return power >= 0
+      ? (error >= e10 ? 10 : error >= e5 ? 5 : error >= e2 ? 2 : 1) * Math.pow(10, power)
+      : -Math.pow(10, -power) / (error >= e10 ? 10 : error >= e5 ? 5 : error >= e2 ? 2 : 1);
+}
+
+function tickStep(start, stop, count) {
+  var step0 = Math.abs(stop - start) / Math.max(0, count),
+      step1 = Math.pow(10, Math.floor(Math.log(step0) / Math.LN10)),
+      error = step0 / step1;
+  if (error >= e10) step1 *= 10;
+  else if (error >= e5) step1 *= 5;
+  else if (error >= e2) step1 *= 2;
+  return stop < start ? -step1 : step1;
+}
+
+var prefix = "$";
+
+function Map() {}
+
+Map.prototype = map$1.prototype = {
+  constructor: Map,
+  has: function(key) {
+    return (prefix + key) in this;
+  },
+  get: function(key) {
+    return this[prefix + key];
+  },
+  set: function(key, value) {
+    this[prefix + key] = value;
+    return this;
+  },
+  remove: function(key) {
+    var property = prefix + key;
+    return property in this && delete this[property];
+  },
+  clear: function() {
+    for (var property in this) if (property[0] === prefix) delete this[property];
+  },
+  keys: function() {
+    var keys = [];
+    for (var property in this) if (property[0] === prefix) keys.push(property.slice(1));
+    return keys;
+  },
+  values: function() {
+    var values = [];
+    for (var property in this) if (property[0] === prefix) values.push(this[property]);
+    return values;
+  },
+  entries: function() {
+    var entries = [];
+    for (var property in this) if (property[0] === prefix) entries.push({key: property.slice(1), value: this[property]});
+    return entries;
+  },
+  size: function() {
+    var size = 0;
+    for (var property in this) if (property[0] === prefix) ++size;
+    return size;
+  },
+  empty: function() {
+    for (var property in this) if (property[0] === prefix) return false;
+    return true;
+  },
+  each: function(f) {
+    for (var property in this) if (property[0] === prefix) f(this[property], property.slice(1), this);
+  }
+};
+
+function map$1(object, f) {
+  var map = new Map;
+
+  // Copy constructor.
+  if (object instanceof Map) object.each(function(value, key) { map.set(key, value); });
+
+  // Index array by numeric index or specified key function.
+  else if (Array.isArray(object)) {
+    var i = -1,
+        n = object.length,
+        o;
+
+    if (f == null) while (++i < n) map.set(i, object[i]);
+    else while (++i < n) map.set(f(o = object[i], i, object), o);
+  }
+
+  // Convert object to map.
+  else if (object) for (var key in object) map.set(key, object[key]);
+
+  return map;
+}
+
+function Set() {}
+
+var proto = map$1.prototype;
+
+Set.prototype = set.prototype = {
+  constructor: Set,
+  has: proto.has,
+  add: function(value) {
+    value += "";
+    this[prefix + value] = value;
+    return this;
+  },
+  remove: proto.remove,
+  clear: proto.clear,
+  values: proto.keys,
+  size: proto.size,
+  empty: proto.empty,
+  each: proto.each
+};
+
+function set(object, f) {
+  var set = new Set;
+
+  // Copy constructor.
+  if (object instanceof Set) object.each(function(value) { set.add(value); });
+
+  // Otherwise, assume it’s an array.
+  else if (object) {
+    var i = -1, n = object.length;
+    if (f == null) while (++i < n) set.add(object[i]);
+    else while (++i < n) set.add(f(object[i], i, object));
+  }
+
+  return set;
+}
+
+var array$1 = Array.prototype;
+
+var map$3 = array$1.map;
+var slice$2 = array$1.slice;
+
+var define = function(constructor, factory, prototype) {
+  constructor.prototype = factory.prototype = prototype;
+  prototype.constructor = constructor;
+};
+
+function extend(parent, definition) {
+  var prototype = Object.create(parent.prototype);
+  for (var key in definition) prototype[key] = definition[key];
+  return prototype;
+}
+
+function Color() {}
+
+var darker = 0.7;
+var brighter = 1 / darker;
+
+var reI = "\\s*([+-]?\\d+)\\s*";
+var reN = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)\\s*";
+var reP = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)%\\s*";
+var reHex3 = /^#([0-9a-f]{3})$/;
+var reHex6 = /^#([0-9a-f]{6})$/;
+var reRgbInteger = new RegExp("^rgb\\(" + [reI, reI, reI] + "\\)$");
+var reRgbPercent = new RegExp("^rgb\\(" + [reP, reP, reP] + "\\)$");
+var reRgbaInteger = new RegExp("^rgba\\(" + [reI, reI, reI, reN] + "\\)$");
+var reRgbaPercent = new RegExp("^rgba\\(" + [reP, reP, reP, reN] + "\\)$");
+var reHslPercent = new RegExp("^hsl\\(" + [reN, reP, reP] + "\\)$");
+var reHslaPercent = new RegExp("^hsla\\(" + [reN, reP, reP, reN] + "\\)$");
+
+var named = {
+  aliceblue: 0xf0f8ff,
+  antiquewhite: 0xfaebd7,
+  aqua: 0x00ffff,
+  aquamarine: 0x7fffd4,
+  azure: 0xf0ffff,
+  beige: 0xf5f5dc,
+  bisque: 0xffe4c4,
+  black: 0x000000,
+  blanchedalmond: 0xffebcd,
+  blue: 0x0000ff,
+  blueviolet: 0x8a2be2,
+  brown: 0xa52a2a,
+  burlywood: 0xdeb887,
+  cadetblue: 0x5f9ea0,
+  chartreuse: 0x7fff00,
+  chocolate: 0xd2691e,
+  coral: 0xff7f50,
+  cornflowerblue: 0x6495ed,
+  cornsilk: 0xfff8dc,
+  crimson: 0xdc143c,
+  cyan: 0x00ffff,
+  darkblue: 0x00008b,
+  darkcyan: 0x008b8b,
+  darkgoldenrod: 0xb8860b,
+  darkgray: 0xa9a9a9,
+  darkgreen: 0x006400,
+  darkgrey: 0xa9a9a9,
+  darkkhaki: 0xbdb76b,
+  darkmagenta: 0x8b008b,
+  darkolivegreen: 0x556b2f,
+  darkorange: 0xff8c00,
+  darkorchid: 0x9932cc,
+  darkred: 0x8b0000,
+  darksalmon: 0xe9967a,
+  darkseagreen: 0x8fbc8f,
+  darkslateblue: 0x483d8b,
+  darkslategray: 0x2f4f4f,
+  darkslategrey: 0x2f4f4f,
+  darkturquoise: 0x00ced1,
+  darkviolet: 0x9400d3,
+  deeppink: 0xff1493,
+  deepskyblue: 0x00bfff,
+  dimgray: 0x696969,
+  dimgrey: 0x696969,
+  dodgerblue: 0x1e90ff,
+  firebrick: 0xb22222,
+  floralwhite: 0xfffaf0,
+  forestgreen: 0x228b22,
+  fuchsia: 0xff00ff,
+  gainsboro: 0xdcdcdc,
+  ghostwhite: 0xf8f8ff,
+  gold: 0xffd700,
+  goldenrod: 0xdaa520,
+  gray: 0x808080,
+  green: 0x008000,
+  greenyellow: 0xadff2f,
+  grey: 0x808080,
+  honeydew: 0xf0fff0,
+  hotpink: 0xff69b4,
+  indianred: 0xcd5c5c,
+  indigo: 0x4b0082,
+  ivory: 0xfffff0,
+  khaki: 0xf0e68c,
+  lavender: 0xe6e6fa,
+  lavenderblush: 0xfff0f5,
+  lawngreen: 0x7cfc00,
+  lemonchiffon: 0xfffacd,
+  lightblue: 0xadd8e6,
+  lightcoral: 0xf08080,
+  lightcyan: 0xe0ffff,
+  lightgoldenrodyellow: 0xfafad2,
+  lightgray: 0xd3d3d3,
+  lightgreen: 0x90ee90,
+  lightgrey: 0xd3d3d3,
+  lightpink: 0xffb6c1,
+  lightsalmon: 0xffa07a,
+  lightseagreen: 0x20b2aa,
+  lightskyblue: 0x87cefa,
+  lightslategray: 0x778899,
+  lightslategrey: 0x778899,
+  lightsteelblue: 0xb0c4de,
+  lightyellow: 0xffffe0,
+  lime: 0x00ff00,
+  limegreen: 0x32cd32,
+  linen: 0xfaf0e6,
+  magenta: 0xff00ff,
+  maroon: 0x800000,
+  mediumaquamarine: 0x66cdaa,
+  mediumblue: 0x0000cd,
+  mediumorchid: 0xba55d3,
+  mediumpurple: 0x9370db,
+  mediumseagreen: 0x3cb371,
+  mediumslateblue: 0x7b68ee,
+  mediumspringgreen: 0x00fa9a,
+  mediumturquoise: 0x48d1cc,
+  mediumvioletred: 0xc71585,
+  midnightblue: 0x191970,
+  mintcream: 0xf5fffa,
+  mistyrose: 0xffe4e1,
+  moccasin: 0xffe4b5,
+  navajowhite: 0xffdead,
+  navy: 0x000080,
+  oldlace: 0xfdf5e6,
+  olive: 0x808000,
+  olivedrab: 0x6b8e23,
+  orange: 0xffa500,
+  orangered: 0xff4500,
+  orchid: 0xda70d6,
+  palegoldenrod: 0xeee8aa,
+  palegreen: 0x98fb98,
+  paleturquoise: 0xafeeee,
+  palevioletred: 0xdb7093,
+  papayawhip: 0xffefd5,
+  peachpuff: 0xffdab9,
+  peru: 0xcd853f,
+  pink: 0xffc0cb,
+  plum: 0xdda0dd,
+  powderblue: 0xb0e0e6,
+  purple: 0x800080,
+  rebeccapurple: 0x663399,
+  red: 0xff0000,
+  rosybrown: 0xbc8f8f,
+  royalblue: 0x4169e1,
+  saddlebrown: 0x8b4513,
+  salmon: 0xfa8072,
+  sandybrown: 0xf4a460,
+  seagreen: 0x2e8b57,
+  seashell: 0xfff5ee,
+  sienna: 0xa0522d,
+  silver: 0xc0c0c0,
+  skyblue: 0x87ceeb,
+  slateblue: 0x6a5acd,
+  slategray: 0x708090,
+  slategrey: 0x708090,
+  snow: 0xfffafa,
+  springgreen: 0x00ff7f,
+  steelblue: 0x4682b4,
+  tan: 0xd2b48c,
+  teal: 0x008080,
+  thistle: 0xd8bfd8,
+  tomato: 0xff6347,
+  turquoise: 0x40e0d0,
+  violet: 0xee82ee,
+  wheat: 0xf5deb3,
+  white: 0xffffff,
+  whitesmoke: 0xf5f5f5,
+  yellow: 0xffff00,
+  yellowgreen: 0x9acd32
+};
+
+define(Color, color, {
+  displayable: function() {
+    return this.rgb().displayable();
+  },
+  toString: function() {
+    return this.rgb() + "";
+  }
+});
+
+function color(format) {
+  var m;
+  format = (format + "").trim().toLowerCase();
+  return (m = reHex3.exec(format)) ? (m = parseInt(m[1], 16), new Rgb((m >> 8 & 0xf) | (m >> 4 & 0x0f0), (m >> 4 & 0xf) | (m & 0xf0), ((m & 0xf) << 4) | (m & 0xf), 1)) // #f00
+      : (m = reHex6.exec(format)) ? rgbn(parseInt(m[1], 16)) // #ff0000
+      : (m = reRgbInteger.exec(format)) ? new Rgb(m[1], m[2], m[3], 1) // rgb(255, 0, 0)
+      : (m = reRgbPercent.exec(format)) ? new Rgb(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, 1) // rgb(100%, 0%, 0%)
+      : (m = reRgbaInteger.exec(format)) ? rgba(m[1], m[2], m[3], m[4]) // rgba(255, 0, 0, 1)
+      : (m = reRgbaPercent.exec(format)) ? rgba(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, m[4]) // rgb(100%, 0%, 0%, 1)
+      : (m = reHslPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, 1) // hsl(120, 50%, 50%)
+      : (m = reHslaPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, m[4]) // hsla(120, 50%, 50%, 1)
+      : named.hasOwnProperty(format) ? rgbn(named[format])
+      : format === "transparent" ? new Rgb(NaN, NaN, NaN, 0)
+      : null;
+}
+
+function rgbn(n) {
+  return new Rgb(n >> 16 & 0xff, n >> 8 & 0xff, n & 0xff, 1);
+}
+
+function rgba(r, g, b, a) {
+  if (a <= 0) r = g = b = NaN;
+  return new Rgb(r, g, b, a);
+}
+
+function rgbConvert(o) {
+  if (!(o instanceof Color)) o = color(o);
+  if (!o) return new Rgb;
+  o = o.rgb();
+  return new Rgb(o.r, o.g, o.b, o.opacity);
+}
+
+function rgb(r, g, b, opacity) {
+  return arguments.length === 1 ? rgbConvert(r) : new Rgb(r, g, b, opacity == null ? 1 : opacity);
+}
+
+function Rgb(r, g, b, opacity) {
+  this.r = +r;
+  this.g = +g;
+  this.b = +b;
+  this.opacity = +opacity;
+}
+
+define(Rgb, rgb, extend(Color, {
+  brighter: function(k) {
+    k = k == null ? brighter : Math.pow(brighter, k);
+    return new Rgb(this.r * k, this.g * k, this.b * k, this.opacity);
+  },
+  darker: function(k) {
+    k = k == null ? darker : Math.pow(darker, k);
+    return new Rgb(this.r * k, this.g * k, this.b * k, this.opacity);
+  },
+  rgb: function() {
+    return this;
+  },
+  displayable: function() {
+    return (0 <= this.r && this.r <= 255)
+        && (0 <= this.g && this.g <= 255)
+        && (0 <= this.b && this.b <= 255)
+        && (0 <= this.opacity && this.opacity <= 1);
+  },
+  toString: function() {
+    var a = this.opacity; a = isNaN(a) ? 1 : Math.max(0, Math.min(1, a));
+    return (a === 1 ? "rgb(" : "rgba(")
+        + Math.max(0, Math.min(255, Math.round(this.r) || 0)) + ", "
+        + Math.max(0, Math.min(255, Math.round(this.g) || 0)) + ", "
+        + Math.max(0, Math.min(255, Math.round(this.b) || 0))
+        + (a === 1 ? ")" : ", " + a + ")");
+  }
+}));
+
+function hsla(h, s, l, a) {
+  if (a <= 0) h = s = l = NaN;
+  else if (l <= 0 || l >= 1) h = s = NaN;
+  else if (s <= 0) h = NaN;
+  return new Hsl(h, s, l, a);
+}
+
+function hslConvert(o) {
+  if (o instanceof Hsl) return new Hsl(o.h, o.s, o.l, o.opacity);
+  if (!(o instanceof Color)) o = color(o);
+  if (!o) return new Hsl;
+  if (o instanceof Hsl) return o;
+  o = o.rgb();
+  var r = o.r / 255,
+      g = o.g / 255,
+      b = o.b / 255,
+      min = Math.min(r, g, b),
+      max = Math.max(r, g, b),
+      h = NaN,
+      s = max - min,
+      l = (max + min) / 2;
+  if (s) {
+    if (r === max) h = (g - b) / s + (g < b) * 6;
+    else if (g === max) h = (b - r) / s + 2;
+    else h = (r - g) / s + 4;
+    s /= l < 0.5 ? max + min : 2 - max - min;
+    h *= 60;
+  } else {
+    s = l > 0 && l < 1 ? 0 : h;
+  }
+  return new Hsl(h, s, l, o.opacity);
+}
+
+function hsl(h, s, l, opacity) {
+  return arguments.length === 1 ? hslConvert(h) : new Hsl(h, s, l, opacity == null ? 1 : opacity);
+}
+
+function Hsl(h, s, l, opacity) {
+  this.h = +h;
+  this.s = +s;
+  this.l = +l;
+  this.opacity = +opacity;
+}
+
+define(Hsl, hsl, extend(Color, {
+  brighter: function(k) {
+    k = k == null ? brighter : Math.pow(brighter, k);
+    return new Hsl(this.h, this.s, this.l * k, this.opacity);
+  },
+  darker: function(k) {
+    k = k == null ? darker : Math.pow(darker, k);
+    return new Hsl(this.h, this.s, this.l * k, this.opacity);
+  },
+  rgb: function() {
+    var h = this.h % 360 + (this.h < 0) * 360,
+        s = isNaN(h) || isNaN(this.s) ? 0 : this.s,
+        l = this.l,
+        m2 = l + (l < 0.5 ? l : 1 - l) * s,
+        m1 = 2 * l - m2;
+    return new Rgb(
+      hsl2rgb(h >= 240 ? h - 240 : h + 120, m1, m2),
+      hsl2rgb(h, m1, m2),
+      hsl2rgb(h < 120 ? h + 240 : h - 120, m1, m2),
+      this.opacity
+    );
+  },
+  displayable: function() {
+    return (0 <= this.s && this.s <= 1 || isNaN(this.s))
+        && (0 <= this.l && this.l <= 1)
+        && (0 <= this.opacity && this.opacity <= 1);
+  }
+}));
+
+/* From FvD 13.37, CSS Color Module Level 3 */
+function hsl2rgb(h, m1, m2) {
+  return (h < 60 ? m1 + (m2 - m1) * h / 60
+      : h < 180 ? m2
+      : h < 240 ? m1 + (m2 - m1) * (240 - h) / 60
+      : m1) * 255;
+}
+
+var deg2rad = Math.PI / 180;
+var rad2deg = 180 / Math.PI;
+
+var Kn = 18;
+var Xn = 0.950470;
+var Yn = 1;
+var Zn = 1.088830;
+var t0 = 4 / 29;
+var t1 = 6 / 29;
+var t2 = 3 * t1 * t1;
+var t3 = t1 * t1 * t1;
+
+function labConvert(o) {
+  if (o instanceof Lab) return new Lab(o.l, o.a, o.b, o.opacity);
+  if (o instanceof Hcl) {
+    var h = o.h * deg2rad;
+    return new Lab(o.l, Math.cos(h) * o.c, Math.sin(h) * o.c, o.opacity);
+  }
+  if (!(o instanceof Rgb)) o = rgbConvert(o);
+  var b = rgb2xyz(o.r),
+      a = rgb2xyz(o.g),
+      l = rgb2xyz(o.b),
+      x = xyz2lab((0.4124564 * b + 0.3575761 * a + 0.1804375 * l) / Xn),
+      y = xyz2lab((0.2126729 * b + 0.7151522 * a + 0.0721750 * l) / Yn),
+      z = xyz2lab((0.0193339 * b + 0.1191920 * a + 0.9503041 * l) / Zn);
+  return new Lab(116 * y - 16, 500 * (x - y), 200 * (y - z), o.opacity);
+}
+
+function lab(l, a, b, opacity) {
+  return arguments.length === 1 ? labConvert(l) : new Lab(l, a, b, opacity == null ? 1 : opacity);
+}
+
+function Lab(l, a, b, opacity) {
+  this.l = +l;
+  this.a = +a;
+  this.b = +b;
+  this.opacity = +opacity;
+}
+
+define(Lab, lab, extend(Color, {
+  brighter: function(k) {
+    return new Lab(this.l + Kn * (k == null ? 1 : k), this.a, this.b, this.opacity);
+  },
+  darker: function(k) {
+    return new Lab(this.l - Kn * (k == null ? 1 : k), this.a, this.b, this.opacity);
+  },
+  rgb: function() {
+    var y = (this.l + 16) / 116,
+        x = isNaN(this.a) ? y : y + this.a / 500,
+        z = isNaN(this.b) ? y : y - this.b / 200;
+    y = Yn * lab2xyz(y);
+    x = Xn * lab2xyz(x);
+    z = Zn * lab2xyz(z);
+    return new Rgb(
+      xyz2rgb( 3.2404542 * x - 1.5371385 * y - 0.4985314 * z), // D65 -> sRGB
+      xyz2rgb(-0.9692660 * x + 1.8760108 * y + 0.0415560 * z),
+      xyz2rgb( 0.0556434 * x - 0.2040259 * y + 1.0572252 * z),
+      this.opacity
+    );
+  }
+}));
+
+function xyz2lab(t) {
+  return t > t3 ? Math.pow(t, 1 / 3) : t / t2 + t0;
+}
+
+function lab2xyz(t) {
+  return t > t1 ? t * t * t : t2 * (t - t0);
+}
+
+function xyz2rgb(x) {
+  return 255 * (x <= 0.0031308 ? 12.92 * x : 1.055 * Math.pow(x, 1 / 2.4) - 0.055);
+}
+
+function rgb2xyz(x) {
+  return (x /= 255) <= 0.04045 ? x / 12.92 : Math.pow((x + 0.055) / 1.055, 2.4);
+}
+
+function hclConvert(o) {
+  if (o instanceof Hcl) return new Hcl(o.h, o.c, o.l, o.opacity);
+  if (!(o instanceof Lab)) o = labConvert(o);
+  var h = Math.atan2(o.b, o.a) * rad2deg;
+  return new Hcl(h < 0 ? h + 360 : h, Math.sqrt(o.a * o.a + o.b * o.b), o.l, o.opacity);
+}
+
+function hcl(h, c, l, opacity) {
+  return arguments.length === 1 ? hclConvert(h) : new Hcl(h, c, l, opacity == null ? 1 : opacity);
+}
+
+function Hcl(h, c, l, opacity) {
+  this.h = +h;
+  this.c = +c;
+  this.l = +l;
+  this.opacity = +opacity;
+}
+
+define(Hcl, hcl, extend(Color, {
+  brighter: function(k) {
+    return new Hcl(this.h, this.c, this.l + Kn * (k == null ? 1 : k), this.opacity);
+  },
+  darker: function(k) {
+    return new Hcl(this.h, this.c, this.l - Kn * (k == null ? 1 : k), this.opacity);
+  },
+  rgb: function() {
+    return labConvert(this).rgb();
+  }
+}));
+
+var A = -0.14861;
+var B = +1.78277;
+var C = -0.29227;
+var D = -0.90649;
+var E = +1.97294;
+var ED = E * D;
+var EB = E * B;
+var BC_DA = B * C - D * A;
+
+function cubehelixConvert(o) {
+  if (o instanceof Cubehelix) return new Cubehelix(o.h, o.s, o.l, o.opacity);
+  if (!(o instanceof Rgb)) o = rgbConvert(o);
+  var r = o.r / 255,
+      g = o.g / 255,
+      b = o.b / 255,
+      l = (BC_DA * b + ED * r - EB * g) / (BC_DA + ED - EB),
+      bl = b - l,
+      k = (E * (g - l) - C * bl) / D,
+      s = Math.sqrt(k * k + bl * bl) / (E * l * (1 - l)), // NaN if l=0 or l=1
+      h = s ? Math.atan2(k, bl) * rad2deg - 120 : NaN;
+  return new Cubehelix(h < 0 ? h + 360 : h, s, l, o.opacity);
+}
+
+function cubehelix(h, s, l, opacity) {
+  return arguments.length === 1 ? cubehelixConvert(h) : new Cubehelix(h, s, l, opacity == null ? 1 : opacity);
+}
+
+function Cubehelix(h, s, l, opacity) {
+  this.h = +h;
+  this.s = +s;
+  this.l = +l;
+  this.opacity = +opacity;
+}
+
+define(Cubehelix, cubehelix, extend(Color, {
+  brighter: function(k) {
+    k = k == null ? brighter : Math.pow(brighter, k);
+    return new Cubehelix(this.h, this.s, this.l * k, this.opacity);
+  },
+  darker: function(k) {
+    k = k == null ? darker : Math.pow(darker, k);
+    return new Cubehelix(this.h, this.s, this.l * k, this.opacity);
+  },
+  rgb: function() {
+    var h = isNaN(this.h) ? 0 : (this.h + 120) * deg2rad,
+        l = +this.l,
+        a = isNaN(this.s) ? 0 : this.s * l * (1 - l),
+        cosh = Math.cos(h),
+        sinh = Math.sin(h);
+    return new Rgb(
+      255 * (l + a * (A * cosh + B * sinh)),
+      255 * (l + a * (C * cosh + D * sinh)),
+      255 * (l + a * (E * cosh)),
+      this.opacity
+    );
+  }
+}));
+
+var constant$3 = function(x) {
+  return function() {
+    return x;
+  };
+};
+
+function linear$1(a, d) {
+  return function(t) {
+    return a + t * d;
+  };
+}
+
+function exponential(a, b, y) {
+  return a = Math.pow(a, y), b = Math.pow(b, y) - a, y = 1 / y, function(t) {
+    return Math.pow(a + t * b, y);
+  };
+}
+
+function hue(a, b) {
+  var d = b - a;
+  return d ? linear$1(a, d > 180 || d < -180 ? d - 360 * Math.round(d / 360) : d) : constant$3(isNaN(a) ? b : a);
+}
+
+function gamma(y) {
+  return (y = +y) === 1 ? nogamma : function(a, b) {
+    return b - a ? exponential(a, b, y) : constant$3(isNaN(a) ? b : a);
+  };
+}
+
+function nogamma(a, b) {
+  var d = b - a;
+  return d ? linear$1(a, d) : constant$3(isNaN(a) ? b : a);
+}
+
+var interpolateRgb = (function rgbGamma(y) {
+  var color$$1 = gamma(y);
+
+  function rgb$$1(start, end) {
+    var r = color$$1((start = rgb(start)).r, (end = rgb(end)).r),
+        g = color$$1(start.g, end.g),
+        b = color$$1(start.b, end.b),
+        opacity = nogamma(start.opacity, end.opacity);
+    return function(t) {
+      start.r = r(t);
+      start.g = g(t);
+      start.b = b(t);
+      start.opacity = opacity(t);
+      return start + "";
+    };
+  }
+
+  rgb$$1.gamma = rgbGamma;
+
+  return rgb$$1;
+})(1);
+
+var array$2 = function(a, b) {
+  var nb = b ? b.length : 0,
+      na = a ? Math.min(nb, a.length) : 0,
+      x = new Array(nb),
+      c = new Array(nb),
+      i;
+
+  for (i = 0; i < na; ++i) x[i] = interpolateValue(a[i], b[i]);
+  for (; i < nb; ++i) c[i] = b[i];
+
+  return function(t) {
+    for (i = 0; i < na; ++i) c[i] = x[i](t);
+    return c;
+  };
+};
+
+var date = function(a, b) {
+  var d = new Date;
+  return a = +a, b -= a, function(t) {
+    return d.setTime(a + b * t), d;
+  };
+};
+
+var interpolateNumber = function(a, b) {
+  return a = +a, b -= a, function(t) {
+    return a + b * t;
+  };
+};
+
+var object = function(a, b) {
+  var i = {},
+      c = {},
+      k;
+
+  if (a === null || typeof a !== "object") a = {};
+  if (b === null || typeof b !== "object") b = {};
+
+  for (k in b) {
+    if (k in a) {
+      i[k] = interpolateValue(a[k], b[k]);
+    } else {
+      c[k] = b[k];
+    }
+  }
+
+  return function(t) {
+    for (k in i) c[k] = i[k](t);
+    return c;
+  };
+};
+
+var reA = /[-+]?(?:\d+\.?\d*|\.?\d+)(?:[eE][-+]?\d+)?/g;
+var reB = new RegExp(reA.source, "g");
+
+function zero(b) {
+  return function() {
+    return b;
+  };
+}
+
+function one(b) {
+  return function(t) {
+    return b(t) + "";
+  };
+}
+
+var interpolateString = function(a, b) {
+  var bi = reA.lastIndex = reB.lastIndex = 0, // scan index for next number in b
+      am, // current match in a
+      bm, // current match in b
+      bs, // string preceding current number in b, if any
+      i = -1, // index in s
+      s = [], // string constants and placeholders
+      q = []; // number interpolators
+
+  // Coerce inputs to strings.
+  a = a + "", b = b + "";
+
+  // Interpolate pairs of numbers in a & b.
+  while ((am = reA.exec(a))
+      && (bm = reB.exec(b))) {
+    if ((bs = bm.index) > bi) { // a string precedes the next number in b
+      bs = b.slice(bi, bs);
+      if (s[i]) s[i] += bs; // coalesce with previous string
+      else s[++i] = bs;
+    }
+    if ((am = am[0]) === (bm = bm[0])) { // numbers in a & b match
+      if (s[i]) s[i] += bm; // coalesce with previous string
+      else s[++i] = bm;
+    } else { // interpolate non-matching numbers
+      s[++i] = null;
+      q.push({i: i, x: interpolateNumber(am, bm)});
+    }
+    bi = reB.lastIndex;
+  }
+
+  // Add remains of b.
+  if (bi < b.length) {
+    bs = b.slice(bi);
+    if (s[i]) s[i] += bs; // coalesce with previous string
+    else s[++i] = bs;
+  }
+
+  // Special optimization for only a single match.
+  // Otherwise, interpolate each of the numbers and rejoin the string.
+  return s.length < 2 ? (q[0]
+      ? one(q[0].x)
+      : zero(b))
+      : (b = q.length, function(t) {
+          for (var i = 0, o; i < b; ++i) s[(o = q[i]).i] = o.x(t);
+          return s.join("");
+        });
+};
+
+var interpolateValue = function(a, b) {
+  var t = typeof b, c;
+  return b == null || t === "boolean" ? constant$3(b)
+      : (t === "number" ? interpolateNumber
+      : t === "string" ? ((c = color(b)) ? (b = c, interpolateRgb) : interpolateString)
+      : b instanceof color ? interpolateRgb
+      : b instanceof Date ? date
+      : Array.isArray(b) ? array$2
+      : typeof b.valueOf !== "function" && typeof b.toString !== "function" || isNaN(b) ? object
+      : interpolateNumber)(a, b);
+};
+
+var interpolateRound = function(a, b) {
+  return a = +a, b -= a, function(t) {
+    return Math.round(a + b * t);
+  };
+};
+
+var degrees = 180 / Math.PI;
+
+var identity$2 = {
+  translateX: 0,
+  translateY: 0,
+  rotate: 0,
+  skewX: 0,
+  scaleX: 1,
+  scaleY: 1
+};
+
+var decompose = function(a, b, c, d, e, f) {
+  var scaleX, scaleY, skewX;
+  if (scaleX = Math.sqrt(a * a + b * b)) a /= scaleX, b /= scaleX;
+  if (skewX = a * c + b * d) c -= a * skewX, d -= b * skewX;
+  if (scaleY = Math.sqrt(c * c + d * d)) c /= scaleY, d /= scaleY, skewX /= scaleY;
+  if (a * d < b * c) a = -a, b = -b, skewX = -skewX, scaleX = -scaleX;
+  return {
+    translateX: e,
+    translateY: f,
+    rotate: Math.atan2(b, a) * degrees,
+    skewX: Math.atan(skewX) * degrees,
+    scaleX: scaleX,
+    scaleY: scaleY
+  };
+};
+
+var cssNode;
+var cssRoot;
+var cssView;
+var svgNode;
+
+function parseCss(value) {
+  if (value === "none") return identity$2;
+  if (!cssNode) cssNode = document.createElement("DIV"), cssRoot = document.documentElement, cssView = document.defaultView;
+  cssNode.style.transform = value;
+  value = cssView.getComputedStyle(cssRoot.appendChild(cssNode), null).getPropertyValue("transform");
+  cssRoot.removeChild(cssNode);
+  value = value.slice(7, -1).split(",");
+  return decompose(+value[0], +value[1], +value[2], +value[3], +value[4], +value[5]);
+}
+
+function parseSvg(value) {
+  if (value == null) return identity$2;
+  if (!svgNode) svgNode = document.createElementNS("http://www.w3.org/2000/svg", "g");
+  svgNode.setAttribute("transform", value);
+  if (!(value = svgNode.transform.baseVal.consolidate())) return identity$2;
+  value = value.matrix;
+  return decompose(value.a, value.b, value.c, value.d, value.e, value.f);
+}
+
+function interpolateTransform(parse, pxComma, pxParen, degParen) {
+
+  function pop(s) {
+    return s.length ? s.pop() + " " : "";
+  }
+
+  function translate(xa, ya, xb, yb, s, q) {
+    if (xa !== xb || ya !== yb) {
+      var i = s.push("translate(", null, pxComma, null, pxParen);
+      q.push({i: i - 4, x: interpolateNumber(xa, xb)}, {i: i - 2, x: interpolateNumber(ya, yb)});
+    } else if (xb || yb) {
+      s.push("translate(" + xb + pxComma + yb + pxParen);
+    }
+  }
+
+  function rotate(a, b, s, q) {
+    if (a !== b) {
+      if (a - b > 180) b += 360; else if (b - a > 180) a += 360; // shortest path
+      q.push({i: s.push(pop(s) + "rotate(", null, degParen) - 2, x: interpolateNumber(a, b)});
+    } else if (b) {
+      s.push(pop(s) + "rotate(" + b + degParen);
+    }
+  }
+
+  function skewX(a, b, s, q) {
+    if (a !== b) {
+      q.push({i: s.push(pop(s) + "skewX(", null, degParen) - 2, x: interpolateNumber(a, b)});
+    } else if (b) {
+      s.push(pop(s) + "skewX(" + b + degParen);
+    }
+  }
+
+  function scale(xa, ya, xb, yb, s, q) {
+    if (xa !== xb || ya !== yb) {
+      var i = s.push(pop(s) + "scale(", null, ",", null, ")");
+      q.push({i: i - 4, x: interpolateNumber(xa, xb)}, {i: i - 2, x: interpolateNumber(ya, yb)});
+    } else if (xb !== 1 || yb !== 1) {
+      s.push(pop(s) + "scale(" + xb + "," + yb + ")");
+    }
+  }
+
+  return function(a, b) {
+    var s = [], // string constants and placeholders
+        q = []; // number interpolators
+    a = parse(a), b = parse(b);
+    translate(a.translateX, a.translateY, b.translateX, b.translateY, s, q);
+    rotate(a.rotate, b.rotate, s, q);
+    skewX(a.skewX, b.skewX, s, q);
+    scale(a.scaleX, a.scaleY, b.scaleX, b.scaleY, s, q);
+    a = b = null; // gc
+    return function(t) {
+      var i = -1, n = q.length, o;
+      while (++i < n) s[(o = q[i]).i] = o.x(t);
+      return s.join("");
+    };
+  };
+}
+
+var interpolateTransformCss = interpolateTransform(parseCss, "px, ", "px)", "deg)");
+var interpolateTransformSvg = interpolateTransform(parseSvg, ", ", ")", ")");
+
+var rho = Math.SQRT2;
+
+function cubehelix$1(hue$$1) {
+  return (function cubehelixGamma(y) {
+    y = +y;
+
+    function cubehelix$$1(start, end) {
+      var h = hue$$1((start = cubehelix(start)).h, (end = cubehelix(end)).h),
+          s = nogamma(start.s, end.s),
+          l = nogamma(start.l, end.l),
+          opacity = nogamma(start.opacity, end.opacity);
+      return function(t) {
+        start.h = h(t);
+        start.s = s(t);
+        start.l = l(Math.pow(t, y));
+        start.opacity = opacity(t);
+        return start + "";
+      };
+    }
+
+    cubehelix$$1.gamma = cubehelixGamma;
+
+    return cubehelix$$1;
+  })(1);
+}
+
+cubehelix$1(hue);
+var cubehelixLong = cubehelix$1(nogamma);
+
+var constant$4 = function(x) {
+  return function() {
+    return x;
+  };
+};
+
+var number$1 = function(x) {
+  return +x;
+};
+
+var unit = [0, 1];
+
+function deinterpolateLinear(a, b) {
+  return (b -= (a = +a))
+      ? function(x) { return (x - a) / b; }
+      : constant$4(b);
+}
+
+function deinterpolateClamp(deinterpolate) {
+  return function(a, b) {
+    var d = deinterpolate(a = +a, b = +b);
+    return function(x) { return x <= a ? 0 : x >= b ? 1 : d(x); };
+  };
+}
+
+function reinterpolateClamp(reinterpolate) {
+  return function(a, b) {
+    var r = reinterpolate(a = +a, b = +b);
+    return function(t) { return t <= 0 ? a : t >= 1 ? b : r(t); };
+  };
+}
+
+function bimap(domain, range, deinterpolate, reinterpolate) {
+  var d0 = domain[0], d1 = domain[1], r0 = range[0], r1 = range[1];
+  if (d1 < d0) d0 = deinterpolate(d1, d0), r0 = reinterpolate(r1, r0);
+  else d0 = deinterpolate(d0, d1), r0 = reinterpolate(r0, r1);
+  return function(x) { return r0(d0(x)); };
+}
+
+function polymap(domain, range, deinterpolate, reinterpolate) {
+  var j = Math.min(domain.length, range.length) - 1,
+      d = new Array(j),
+      r = new Array(j),
+      i = -1;
+
+  // Reverse descending domains.
+  if (domain[j] < domain[0]) {
+    domain = domain.slice().reverse();
+    range = range.slice().reverse();
+  }
+
+  while (++i < j) {
+    d[i] = deinterpolate(domain[i], domain[i + 1]);
+    r[i] = reinterpolate(range[i], range[i + 1]);
+  }
+
+  return function(x) {
+    var i = bisectRight(domain, x, 1, j) - 1;
+    return r[i](d[i](x));
+  };
+}
+
+function copy(source, target) {
+  return target
+      .domain(source.domain())
+      .range(source.range())
+      .interpolate(source.interpolate())
+      .clamp(source.clamp());
+}
+
+// deinterpolate(a, b)(x) takes a domain value x in [a,b] and returns the corresponding parameter t in [0,1].
+// reinterpolate(a, b)(t) takes a parameter t in [0,1] and returns the corresponding domain value x in [a,b].
+function continuous(deinterpolate, reinterpolate) {
+  var domain = unit,
+      range = unit,
+      interpolate$$1 = interpolateValue,
+      clamp = false,
+      piecewise,
+      output,
+      input;
+
+  function rescale() {
+    piecewise = Math.min(domain.length, range.length) > 2 ? polymap : bimap;
+    output = input = null;
+    return scale;
+  }
+
+  function scale(x) {
+    return (output || (output = piecewise(domain, range, clamp ? deinterpolateClamp(deinterpolate) : deinterpolate, interpolate$$1)))(+x);
+  }
+
+  scale.invert = function(y) {
+    return (input || (input = piecewise(range, domain, deinterpolateLinear, clamp ? reinterpolateClamp(reinterpolate) : reinterpolate)))(+y);
+  };
+
+  scale.domain = function(_) {
+    return arguments.length ? (domain = map$3.call(_, number$1), rescale()) : domain.slice();
+  };
+
+  scale.range = function(_) {
+    return arguments.length ? (range = slice$2.call(_), rescale()) : range.slice();
+  };
+
+  scale.rangeRound = function(_) {
+    return range = slice$2.call(_), interpolate$$1 = interpolateRound, rescale();
+  };
+
+  scale.clamp = function(_) {
+    return arguments.length ? (clamp = !!_, rescale()) : clamp;
+  };
+
+  scale.interpolate = function(_) {
+    return arguments.length ? (interpolate$$1 = _, rescale()) : interpolate$$1;
+  };
+
+  return rescale();
+}
+
+// Computes the decimal coefficient and exponent of the specified number x with
+// significant digits p, where x is positive and p is in [1, 21] or undefined.
+// For example, formatDecimal(1.23) returns ["123", 0].
+var formatDecimal = function(x, p) {
+  if ((i = (x = p ? x.toExponential(p - 1) : x.toExponential()).indexOf("e")) < 0) return null; // NaN, ±Infinity
+  var i, coefficient = x.slice(0, i);
+
+  // The string returned by toExponential either has the form \d\.\d+e[-+]\d+
+  // (e.g., 1.2e+3) or the form \de[-+]\d+ (e.g., 1e+3).
+  return [
+    coefficient.length > 1 ? coefficient[0] + coefficient.slice(2) : coefficient,
+    +x.slice(i + 1)
+  ];
+};
+
+var exponent = function(x) {
+  return x = formatDecimal(Math.abs(x)), x ? x[1] : NaN;
+};
+
+var formatGroup = function(grouping, thousands) {
+  return function(value, width) {
+    var i = value.length,
+        t = [],
+        j = 0,
+        g = grouping[0],
+        length = 0;
+
+    while (i > 0 && g > 0) {
+      if (length + g + 1 > width) g = Math.max(1, width - length);
+      t.push(value.substring(i -= g, i + g));
+      if ((length += g + 1) > width) break;
+      g = grouping[j = (j + 1) % grouping.length];
+    }
+
+    return t.reverse().join(thousands);
+  };
+};
+
+var formatNumerals = function(numerals) {
+  return function(value) {
+    return value.replace(/[0-9]/g, function(i) {
+      return numerals[+i];
+    });
+  };
+};
+
+var formatDefault = function(x, p) {
+  x = x.toPrecision(p);
+
+  out: for (var n = x.length, i = 1, i0 = -1, i1; i < n; ++i) {
+    switch (x[i]) {
+      case ".": i0 = i1 = i; break;
+      case "0": if (i0 === 0) i0 = i; i1 = i; break;
+      case "e": break out;
+      default: if (i0 > 0) i0 = 0; break;
+    }
+  }
+
+  return i0 > 0 ? x.slice(0, i0) + x.slice(i1 + 1) : x;
+};
+
+var prefixExponent;
+
+var formatPrefixAuto = function(x, p) {
+  var d = formatDecimal(x, p);
+  if (!d) return x + "";
+  var coefficient = d[0],
+      exponent = d[1],
+      i = exponent - (prefixExponent = Math.max(-8, Math.min(8, Math.floor(exponent / 3))) * 3) + 1,
+      n = coefficient.length;
+  return i === n ? coefficient
+      : i > n ? coefficient + new Array(i - n + 1).join("0")
+      : i > 0 ? coefficient.slice(0, i) + "." + coefficient.slice(i)
+      : "0." + new Array(1 - i).join("0") + formatDecimal(x, Math.max(0, p + i - 1))[0]; // less than 1y!
+};
+
+var formatRounded = function(x, p) {
+  var d = formatDecimal(x, p);
+  if (!d) return x + "";
+  var coefficient = d[0],
+      exponent = d[1];
+  return exponent < 0 ? "0." + new Array(-exponent).join("0") + coefficient
+      : coefficient.length > exponent + 1 ? coefficient.slice(0, exponent + 1) + "." + coefficient.slice(exponent + 1)
+      : coefficient + new Array(exponent - coefficient.length + 2).join("0");
+};
+
+var formatTypes = {
+  "": formatDefault,
+  "%": function(x, p) { return (x * 100).toFixed(p); },
+  "b": function(x) { return Math.round(x).toString(2); },
+  "c": function(x) { return x + ""; },
+  "d": function(x) { return Math.round(x).toString(10); },
+  "e": function(x, p) { return x.toExponential(p); },
+  "f": function(x, p) { return x.toFixed(p); },
+  "g": function(x, p) { return x.toPrecision(p); },
+  "o": function(x) { return Math.round(x).toString(8); },
+  "p": function(x, p) { return formatRounded(x * 100, p); },
+  "r": formatRounded,
+  "s": formatPrefixAuto,
+  "X": function(x) { return Math.round(x).toString(16).toUpperCase(); },
+  "x": function(x) { return Math.round(x).toString(16); }
+};
+
+// [[fill]align][sign][symbol][0][width][,][.precision][type]
+var re = /^(?:(.)?([<>=^]))?([+\-\( ])?([$#])?(0)?(\d+)?(,)?(\.\d+)?([a-z%])?$/i;
+
+function formatSpecifier(specifier) {
+  return new FormatSpecifier(specifier);
+}
+
+formatSpecifier.prototype = FormatSpecifier.prototype; // instanceof
+
+function FormatSpecifier(specifier) {
+  if (!(match = re.exec(specifier))) throw new Error("invalid format: " + specifier);
+
+  var match,
+      fill = match[1] || " ",
+      align = match[2] || ">",
+      sign = match[3] || "-",
+      symbol = match[4] || "",
+      zero = !!match[5],
+      width = match[6] && +match[6],
+      comma = !!match[7],
+      precision = match[8] && +match[8].slice(1),
+      type = match[9] || "";
+
+  // The "n" type is an alias for ",g".
+  if (type === "n") comma = true, type = "g";
+
+  // Map invalid types to the default format.
+  else if (!formatTypes[type]) type = "";
+
+  // If zero fill is specified, padding goes after sign and before digits.
+  if (zero || (fill === "0" && align === "=")) zero = true, fill = "0", align = "=";
+
+  this.fill = fill;
+  this.align = align;
+  this.sign = sign;
+  this.symbol = symbol;
+  this.zero = zero;
+  this.width = width;
+  this.comma = comma;
+  this.precision = precision;
+  this.type = type;
+}
+
+FormatSpecifier.prototype.toString = function() {
+  return this.fill
+      + this.align
+      + this.sign
+      + this.symbol
+      + (this.zero ? "0" : "")
+      + (this.width == null ? "" : Math.max(1, this.width | 0))
+      + (this.comma ? "," : "")
+      + (this.precision == null ? "" : "." + Math.max(0, this.precision | 0))
+      + this.type;
+};
+
+var identity$3 = function(x) {
+  return x;
+};
+
+var prefixes = ["y","z","a","f","p","n","µ","m","","k","M","G","T","P","E","Z","Y"];
+
+var formatLocale = function(locale) {
+  var group = locale.grouping && locale.thousands ? formatGroup(locale.grouping, locale.thousands) : identity$3,
+      currency = locale.currency,
+      decimal = locale.decimal,
+      numerals = locale.numerals ? formatNumerals(locale.numerals) : identity$3,
+      percent = locale.percent || "%";
+
+  function newFormat(specifier) {
+    specifier = formatSpecifier(specifier);
+
+    var fill = specifier.fill,
+        align = specifier.align,
+        sign = specifier.sign,
+        symbol = specifier.symbol,
+        zero = specifier.zero,
+        width = specifier.width,
+        comma = specifier.comma,
+        precision = specifier.precision,
+        type = specifier.type;
+
+    // Compute the prefix and suffix.
+    // For SI-prefix, the suffix is lazily computed.
+    var prefix = symbol === "$" ? currency[0] : symbol === "#" && /[boxX]/.test(type) ? "0" + type.toLowerCase() : "",
+        suffix = symbol === "$" ? currency[1] : /[%p]/.test(type) ? percent : "";
+
+    // What format function should we use?
+    // Is this an integer type?
+    // Can this type generate exponential notation?
+    var formatType = formatTypes[type],
+        maybeSuffix = !type || /[defgprs%]/.test(type);
+
+    // Set the default precision if not specified,
+    // or clamp the specified precision to the supported range.
+    // For significant precision, it must be in [1, 21].
+    // For fixed precision, it must be in [0, 20].
+    precision = precision == null ? (type ? 6 : 12)
+        : /[gprs]/.test(type) ? Math.max(1, Math.min(21, precision))
+        : Math.max(0, Math.min(20, precision));
+
+    function format(value) {
+      var valuePrefix = prefix,
+          valueSuffix = suffix,
+          i, n, c;
+
+      if (type === "c") {
+        valueSuffix = formatType(value) + valueSuffix;
+        value = "";
+      } else {
+        value = +value;
+
+        // Perform the initial formatting.
+        var valueNegative = value < 0;
+        value = formatType(Math.abs(value), precision);
+
+        // If a negative value rounds to zero during formatting, treat as positive.
+        if (valueNegative && +value === 0) valueNegative = false;
+
+        // Compute the prefix and suffix.
+        valuePrefix = (valueNegative ? (sign === "(" ? sign : "-") : sign === "-" || sign === "(" ? "" : sign) + valuePrefix;
+        valueSuffix = valueSuffix + (type === "s" ? prefixes[8 + prefixExponent / 3] : "") + (valueNegative && sign === "(" ? ")" : "");
+
+        // Break the formatted value into the integer “value” part that can be
+        // grouped, and fractional or exponential “suffix” part that is not.
+        if (maybeSuffix) {
+          i = -1, n = value.length;
+          while (++i < n) {
+            if (c = value.charCodeAt(i), 48 > c || c > 57) {
+              valueSuffix = (c === 46 ? decimal + value.slice(i + 1) : value.slice(i)) + valueSuffix;
+              value = value.slice(0, i);
+              break;
+            }
+          }
+        }
+      }
+
+      // If the fill character is not "0", grouping is applied before padding.
+      if (comma && !zero) value = group(value, Infinity);
+
+      // Compute the padding.
+      var length = valuePrefix.length + value.length + valueSuffix.length,
+          padding = length < width ? new Array(width - length + 1).join(fill) : "";
+
+      // If the fill character is "0", grouping is applied after padding.
+      if (comma && zero) value = group(padding + value, padding.length ? width - valueSuffix.length : Infinity), padding = "";
+
+      // Reconstruct the final output based on the desired alignment.
+      switch (align) {
+        case "<": value = valuePrefix + value + valueSuffix + padding; break;
+        case "=": value = valuePrefix + padding + value + valueSuffix; break;
+        case "^": value = padding.slice(0, length = padding.length >> 1) + valuePrefix + value + valueSuffix + padding.slice(length); break;
+        default: value = padding + valuePrefix + value + valueSuffix; break;
+      }
+
+      return numerals(value);
+    }
+
+    format.toString = function() {
+      return specifier + "";
+    };
+
+    return format;
+  }
+
+  function formatPrefix(specifier, value) {
+    var f = newFormat((specifier = formatSpecifier(specifier), specifier.type = "f", specifier)),
+        e = Math.max(-8, Math.min(8, Math.floor(exponent(value) / 3))) * 3,
+        k = Math.pow(10, -e),
+        prefix = prefixes[8 + e / 3];
+    return function(value) {
+      return f(k * value) + prefix;
+    };
+  }
+
+  return {
+    format: newFormat,
+    formatPrefix: formatPrefix
+  };
+};
+
+var locale;
+
+var formatPrefix;
+
+defaultLocale({
+  decimal: ".",
+  thousands: ",",
+  grouping: [3],
+  currency: ["$", ""]
+});
+
+function defaultLocale(definition) {
+  locale = formatLocale(definition);
+  exports.format = locale.format;
+  formatPrefix = locale.formatPrefix;
+  return locale;
+}
+
+var precisionFixed = function(step) {
+  return Math.max(0, -exponent(Math.abs(step)));
+};
+
+var precisionPrefix = function(step, value) {
+  return Math.max(0, Math.max(-8, Math.min(8, Math.floor(exponent(value) / 3))) * 3 - exponent(Math.abs(step)));
+};
+
+var precisionRound = function(step, max) {
+  step = Math.abs(step), max = Math.abs(max) - step;
+  return Math.max(0, exponent(max) - exponent(step)) + 1;
+};
+
+var tickFormat = function(domain, count, specifier) {
+  var start = domain[0],
+      stop = domain[domain.length - 1],
+      step = tickStep(start, stop, count == null ? 10 : count),
+      precision;
+  specifier = formatSpecifier(specifier == null ? ",f" : specifier);
+  switch (specifier.type) {
+    case "s": {
+      var value = Math.max(Math.abs(start), Math.abs(stop));
+      if (specifier.precision == null && !isNaN(precision = precisionPrefix(step, value))) specifier.precision = precision;
+      return formatPrefix(specifier, value);
+    }
+    case "":
+    case "e":
+    case "g":
+    case "p":
+    case "r": {
+      if (specifier.precision == null && !isNaN(precision = precisionRound(step, Math.max(Math.abs(start), Math.abs(stop))))) specifier.precision = precision - (specifier.type === "e");
+      break;
+    }
+    case "f":
+    case "%": {
+      if (specifier.precision == null && !isNaN(precision = precisionFixed(step))) specifier.precision = precision - (specifier.type === "%") * 2;
+      break;
+    }
+  }
+  return exports.format(specifier);
+};
+
+function linearish(scale) {
+  var domain = scale.domain;
+
+  scale.ticks = function(count) {
+    var d = domain();
+    return ticks(d[0], d[d.length - 1], count == null ? 10 : count);
+  };
+
+  scale.tickFormat = function(count, specifier) {
+    return tickFormat(domain(), count, specifier);
+  };
+
+  scale.nice = function(count) {
+    if (count == null) count = 10;
+
+    var d = domain(),
+        i0 = 0,
+        i1 = d.length - 1,
+        start = d[i0],
+        stop = d[i1],
+        step;
+
+    if (stop < start) {
+      step = start, start = stop, stop = step;
+      step = i0, i0 = i1, i1 = step;
+    }
+
+    step = tickIncrement(start, stop, count);
+
+    if (step > 0) {
+      start = Math.floor(start / step) * step;
+      stop = Math.ceil(stop / step) * step;
+      step = tickIncrement(start, stop, count);
+    } else if (step < 0) {
+      start = Math.ceil(start * step) / step;
+      stop = Math.floor(stop * step) / step;
+      step = tickIncrement(start, stop, count);
+    }
+
+    if (step > 0) {
+      d[i0] = Math.floor(start / step) * step;
+      d[i1] = Math.ceil(stop / step) * step;
+      domain(d);
+    } else if (step < 0) {
+      d[i0] = Math.ceil(start * step) / step;
+      d[i1] = Math.floor(stop * step) / step;
+      domain(d);
+    }
+
+    return scale;
+  };
+
+  return scale;
+}
+
+function linear() {
+  var scale = continuous(deinterpolateLinear, interpolateNumber);
+
+  scale.copy = function() {
+    return copy(scale, linear());
+  };
+
+  return linearish(scale);
+}
+
+var t0$1 = new Date;
+var t1$1 = new Date;
+
+function newInterval(floori, offseti, count, field) {
+
+  function interval(date) {
+    return floori(date = new Date(+date)), date;
+  }
+
+  interval.floor = interval;
+
+  interval.ceil = function(date) {
+    return floori(date = new Date(date - 1)), offseti(date, 1), floori(date), date;
+  };
+
+  interval.round = function(date) {
+    var d0 = interval(date),
+        d1 = interval.ceil(date);
+    return date - d0 < d1 - date ? d0 : d1;
+  };
+
+  interval.offset = function(date, step) {
+    return offseti(date = new Date(+date), step == null ? 1 : Math.floor(step)), date;
+  };
+
+  interval.range = function(start, stop, step) {
+    var range = [];
+    start = interval.ceil(start);
+    step = step == null ? 1 : Math.floor(step);
+    if (!(start < stop) || !(step > 0)) return range; // also handles Invalid Date
+    do range.push(new Date(+start)); while (offseti(start, step), floori(start), start < stop)
+    return range;
+  };
+
+  interval.filter = function(test) {
+    return newInterval(function(date) {
+      if (date >= date) while (floori(date), !test(date)) date.setTime(date - 1);
+    }, function(date, step) {
+      if (date >= date) {
+        if (step < 0) while (++step <= 0) {
+          while (offseti(date, -1), !test(date)) {} // eslint-disable-line no-empty
+        } else while (--step >= 0) {
+          while (offseti(date, +1), !test(date)) {} // eslint-disable-line no-empty
+        }
+      }
+    });
+  };
+
+  if (count) {
+    interval.count = function(start, end) {
+      t0$1.setTime(+start), t1$1.setTime(+end);
+      floori(t0$1), floori(t1$1);
+      return Math.floor(count(t0$1, t1$1));
+    };
+
+    interval.every = function(step) {
+      step = Math.floor(step);
+      return !isFinite(step) || !(step > 0) ? null
+          : !(step > 1) ? interval
+          : interval.filter(field
+              ? function(d) { return field(d) % step === 0; }
+              : function(d) { return interval.count(0, d) % step === 0; });
+    };
+  }
+
+  return interval;
+}
+
+var millisecond = newInterval(function() {
+  // noop
+}, function(date, step) {
+  date.setTime(+date + step);
+}, function(start, end) {
+  return end - start;
+});
+
+// An optimized implementation for this simple case.
+millisecond.every = function(k) {
+  k = Math.floor(k);
+  if (!isFinite(k) || !(k > 0)) return null;
+  if (!(k > 1)) return millisecond;
+  return newInterval(function(date) {
+    date.setTime(Math.floor(date / k) * k);
+  }, function(date, step) {
+    date.setTime(+date + step * k);
+  }, function(start, end) {
+    return (end - start) / k;
+  });
+};
+
+var durationSecond$1 = 1e3;
+var durationMinute$1 = 6e4;
+var durationHour$1 = 36e5;
+var durationDay$1 = 864e5;
+var durationWeek$1 = 6048e5;
+
+var second = newInterval(function(date) {
+  date.setTime(Math.floor(date / durationSecond$1) * durationSecond$1);
+}, function(date, step) {
+  date.setTime(+date + step * durationSecond$1);
+}, function(start, end) {
+  return (end - start) / durationSecond$1;
+}, function(date) {
+  return date.getUTCSeconds();
+});
+
+var minute = newInterval(function(date) {
+  date.setTime(Math.floor(date / durationMinute$1) * durationMinute$1);
+}, function(date, step) {
+  date.setTime(+date + step * durationMinute$1);
+}, function(start, end) {
+  return (end - start) / durationMinute$1;
+}, function(date) {
+  return date.getMinutes();
+});
+
+var hour = newInterval(function(date) {
+  var offset = date.getTimezoneOffset() * durationMinute$1 % durationHour$1;
+  if (offset < 0) offset += durationHour$1;
+  date.setTime(Math.floor((+date - offset) / durationHour$1) * durationHour$1 + offset);
+}, function(date, step) {
+  date.setTime(+date + step * durationHour$1);
+}, function(start, end) {
+  return (end - start) / durationHour$1;
+}, function(date) {
+  return date.getHours();
+});
+
+var day = newInterval(function(date) {
+  date.setHours(0, 0, 0, 0);
+}, function(date, step) {
+  date.setDate(date.getDate() + step);
+}, function(start, end) {
+  return (end - start - (end.getTimezoneOffset() - start.getTimezoneOffset()) * durationMinute$1) / durationDay$1;
+}, function(date) {
+  return date.getDate() - 1;
+});
+
+function weekday(i) {
+  return newInterval(function(date) {
+    date.setDate(date.getDate() - (date.getDay() + 7 - i) % 7);
+    date.setHours(0, 0, 0, 0);
+  }, function(date, step) {
+    date.setDate(date.getDate() + step * 7);
+  }, function(start, end) {
+    return (end - start - (end.getTimezoneOffset() - start.getTimezoneOffset()) * durationMinute$1) / durationWeek$1;
+  });
+}
+
+var sunday = weekday(0);
+var monday = weekday(1);
+var tuesday = weekday(2);
+var wednesday = weekday(3);
+var thursday = weekday(4);
+var friday = weekday(5);
+var saturday = weekday(6);
+
+var month = newInterval(function(date) {
+  date.setDate(1);
+  date.setHours(0, 0, 0, 0);
+}, function(date, step) {
+  date.setMonth(date.getMonth() + step);
+}, function(start, end) {
+  return end.getMonth() - start.getMonth() + (end.getFullYear() - start.getFullYear()) * 12;
+}, function(date) {
+  return date.getMonth();
+});
+
+var year = newInterval(function(date) {
+  date.setMonth(0, 1);
+  date.setHours(0, 0, 0, 0);
+}, function(date, step) {
+  date.setFullYear(date.getFullYear() + step);
+}, function(start, end) {
+  return end.getFullYear() - start.getFullYear();
+}, function(date) {
+  return date.getFullYear();
+});
+
+// An optimized implementation for this simple case.
+year.every = function(k) {
+  return !isFinite(k = Math.floor(k)) || !(k > 0) ? null : newInterval(function(date) {
+    date.setFullYear(Math.floor(date.getFullYear() / k) * k);
+    date.setMonth(0, 1);
+    date.setHours(0, 0, 0, 0);
+  }, function(date, step) {
+    date.setFullYear(date.getFullYear() + step * k);
+  });
+};
+
+var utcMinute = newInterval(function(date) {
+  date.setUTCSeconds(0, 0);
+}, function(date, step) {
+  date.setTime(+date + step * durationMinute$1);
+}, function(start, end) {
+  return (end - start) / durationMinute$1;
+}, function(date) {
+  return date.getUTCMinutes();
+});
+
+var utcHour = newInterval(function(date) {
+  date.setUTCMinutes(0, 0, 0);
+}, function(date, step) {
+  date.setTime(+date + step * durationHour$1);
+}, function(start, end) {
+  return (end - start) / durationHour$1;
+}, function(date) {
+  return date.getUTCHours();
+});
+
+var utcDay = newInterval(function(date) {
+  date.setUTCHours(0, 0, 0, 0);
+}, function(date, step) {
+  date.setUTCDate(date.getUTCDate() + step);
+}, function(start, end) {
+  return (end - start) / durationDay$1;
+}, function(date) {
+  return date.getUTCDate() - 1;
+});
+
+function utcWeekday(i) {
+  return newInterval(function(date) {
+    date.setUTCDate(date.getUTCDate() - (date.getUTCDay() + 7 - i) % 7);
+    date.setUTCHours(0, 0, 0, 0);
+  }, function(date, step) {
+    date.setUTCDate(date.getUTCDate() + step * 7);
+  }, function(start, end) {
+    return (end - start) / durationWeek$1;
+  });
+}
+
+var utcSunday = utcWeekday(0);
+var utcMonday = utcWeekday(1);
+var utcTuesday = utcWeekday(2);
+var utcWednesday = utcWeekday(3);
+var utcThursday = utcWeekday(4);
+var utcFriday = utcWeekday(5);
+var utcSaturday = utcWeekday(6);
+
+var utcMonth = newInterval(function(date) {
+  date.setUTCDate(1);
+  date.setUTCHours(0, 0, 0, 0);
+}, function(date, step) {
+  date.setUTCMonth(date.getUTCMonth() + step);
+}, function(start, end) {
+  return end.getUTCMonth() - start.getUTCMonth() + (end.getUTCFullYear() - start.getUTCFullYear()) * 12;
+}, function(date) {
+  return date.getUTCMonth();
+});
+
+var utcYear = newInterval(function(date) {
+  date.setUTCMonth(0, 1);
+  date.setUTCHours(0, 0, 0, 0);
+}, function(date, step) {
+  date.setUTCFullYear(date.getUTCFullYear() + step);
+}, function(start, end) {
+  return end.getUTCFullYear() - start.getUTCFullYear();
+}, function(date) {
+  return date.getUTCFullYear();
+});
+
+// An optimized implementation for this simple case.
+utcYear.every = function(k) {
+  return !isFinite(k = Math.floor(k)) || !(k > 0) ? null : newInterval(function(date) {
+    date.setUTCFullYear(Math.floor(date.getUTCFullYear() / k) * k);
+    date.setUTCMonth(0, 1);
+    date.setUTCHours(0, 0, 0, 0);
+  }, function(date, step) {
+    date.setUTCFullYear(date.getUTCFullYear() + step * k);
+  });
+};
+
+function localDate(d) {
+  if (0 <= d.y && d.y < 100) {
+    var date = new Date(-1, d.m, d.d, d.H, d.M, d.S, d.L);
+    date.setFullYear(d.y);
+    return date;
+  }
+  return new Date(d.y, d.m, d.d, d.H, d.M, d.S, d.L);
+}
+
+function utcDate(d) {
+  if (0 <= d.y && d.y < 100) {
+    var date = new Date(Date.UTC(-1, d.m, d.d, d.H, d.M, d.S, d.L));
+    date.setUTCFullYear(d.y);
+    return date;
+  }
+  return new Date(Date.UTC(d.y, d.m, d.d, d.H, d.M, d.S, d.L));
+}
+
+function newYear(y) {
+  return {y: y, m: 0, d: 1, H: 0, M: 0, S: 0, L: 0};
+}
+
+function formatLocale$1(locale) {
+  var locale_dateTime = locale.dateTime,
+      locale_date = locale.date,
+      locale_time = locale.time,
+      locale_periods = locale.periods,
+      locale_weekdays = locale.days,
+      locale_shortWeekdays = locale.shortDays,
+      locale_months = locale.months,
+      locale_shortMonths = locale.shortMonths;
+
+  var periodRe = formatRe(locale_periods),
+      periodLookup = formatLookup(locale_periods),
+      weekdayRe = formatRe(locale_weekdays),
+      weekdayLookup = formatLookup(locale_weekdays),
+      shortWeekdayRe = formatRe(locale_shortWeekdays),
+      shortWeekdayLookup = formatLookup(locale_shortWeekdays),
+      monthRe = formatRe(locale_months),
+      monthLookup = formatLookup(locale_months),
+      shortMonthRe = formatRe(locale_shortMonths),
+      shortMonthLookup = formatLookup(locale_shortMonths);
+
+  var formats = {
+    "a": formatShortWeekday,
+    "A": formatWeekday,
+    "b": formatShortMonth,
+    "B": formatMonth,
+    "c": null,
+    "d": formatDayOfMonth,
+    "e": formatDayOfMonth,
+    "f": formatMicroseconds,
+    "H": formatHour24,
+    "I": formatHour12,
+    "j": formatDayOfYear,
+    "L": formatMilliseconds,
+    "m": formatMonthNumber,
+    "M": formatMinutes,
+    "p": formatPeriod,
+    "Q": formatUnixTimestamp,
+    "s": formatUnixTimestampSeconds,
+    "S": formatSeconds,
+    "u": formatWeekdayNumberMonday,
+    "U": formatWeekNumberSunday,
+    "V": formatWeekNumberISO,
+    "w": formatWeekdayNumberSunday,
+    "W": formatWeekNumberMonday,
+    "x": null,
+    "X": null,
+    "y": formatYear,
+    "Y": formatFullYear,
+    "Z": formatZone,
+    "%": formatLiteralPercent
+  };
+
+  var utcFormats = {
+    "a": formatUTCShortWeekday,
+    "A": formatUTCWeekday,
+    "b": formatUTCShortMonth,
+    "B": formatUTCMonth,
+    "c": null,
+    "d": formatUTCDayOfMonth,
+    "e": formatUTCDayOfMonth,
+    "f": formatUTCMicroseconds,
+    "H": formatUTCHour24,
+    "I": formatUTCHour12,
+    "j": formatUTCDayOfYear,
+    "L": formatUTCMilliseconds,
+    "m": formatUTCMonthNumber,
+    "M": formatUTCMinutes,
+    "p": formatUTCPeriod,
+    "Q": formatUnixTimestamp,
+    "s": formatUnixTimestampSeconds,
+    "S": formatUTCSeconds,
+    "u": formatUTCWeekdayNumberMonday,
+    "U": formatUTCWeekNumberSunday,
+    "V": formatUTCWeekNumberISO,
+    "w": formatUTCWeekdayNumberSunday,
+    "W": formatUTCWeekNumberMonday,
+    "x": null,
+    "X": null,
+    "y": formatUTCYear,
+    "Y": formatUTCFullYear,
+    "Z": formatUTCZone,
+    "%": formatLiteralPercent
+  };
+
+  var parses = {
+    "a": parseShortWeekday,
+    "A": parseWeekday,
+    "b": parseShortMonth,
+    "B": parseMonth,
+    "c": parseLocaleDateTime,
+    "d": parseDayOfMonth,
+    "e": parseDayOfMonth,
+    "f": parseMicroseconds,
+    "H": parseHour24,
+    "I": parseHour24,
+    "j": parseDayOfYear,
+    "L": parseMilliseconds,
+    "m": parseMonthNumber,
+    "M": parseMinutes,
+    "p": parsePeriod,
+    "Q": parseUnixTimestamp,
+    "s": parseUnixTimestampSeconds,
+    "S": parseSeconds,
+    "u": parseWeekdayNumberMonday,
+    "U": parseWeekNumberSunday,
+    "V": parseWeekNumberISO,
+    "w": parseWeekdayNumberSunday,
+    "W": parseWeekNumberMonday,
+    "x": parseLocaleDate,
+    "X": parseLocaleTime,
+    "y": parseYear,
+    "Y": parseFullYear,
+    "Z": parseZone,
+    "%": parseLiteralPercent
+  };
+
+  // These recursive directive definitions must be deferred.
+  formats.x = newFormat(locale_date, formats);
+  formats.X = newFormat(locale_time, formats);
+  formats.c = newFormat(locale_dateTime, formats);
+  utcFormats.x = newFormat(locale_date, utcFormats);
+  utcFormats.X = newFormat(locale_time, utcFormats);
+  utcFormats.c = newFormat(locale_dateTime, utcFormats);
+
+  function newFormat(specifier, formats) {
+    return function(date) {
+      var string = [],
+          i = -1,
+          j = 0,
+          n = specifier.length,
+          c,
+          pad,
+          format;
+
+      if (!(date instanceof Date)) date = new Date(+date);
+
+      while (++i < n) {
+        if (specifier.charCodeAt(i) === 37) {
+          string.push(specifier.slice(j, i));
+          if ((pad = pads[c = specifier.charAt(++i)]) != null) c = specifier.charAt(++i);
+          else pad = c === "e" ? " " : "0";
+          if (format = formats[c]) c = format(date, pad);
+          string.push(c);
+          j = i + 1;
+        }
+      }
+
+      string.push(specifier.slice(j, i));
+      return string.join("");
+    };
+  }
+
+  function newParse(specifier, newDate) {
+    return function(string) {
+      var d = newYear(1900),
+          i = parseSpecifier(d, specifier, string += "", 0),
+          week, day$$1;
+      if (i != string.length) return null;
+
+      // If a UNIX timestamp is specified, return it.
+      if ("Q" in d) return new Date(d.Q);
+
+      // The am-pm flag is 0 for AM, and 1 for PM.
+      if ("p" in d) d.H = d.H % 12 + d.p * 12;
+
+      // Convert day-of-week and week-of-year to day-of-year.
+      if ("V" in d) {
+        if (d.V < 1 || d.V > 53) return null;
+        if (!("w" in d)) d.w = 1;
+        if ("Z" in d) {
+          week = utcDate(newYear(d.y)), day$$1 = week.getUTCDay();
+          week = day$$1 > 4 || day$$1 === 0 ? utcMonday.ceil(week) : utcMonday(week);
+          week = utcDay.offset(week, (d.V - 1) * 7);
+          d.y = week.getUTCFullYear();
+          d.m = week.getUTCMonth();
+          d.d = week.getUTCDate() + (d.w + 6) % 7;
+        } else {
+          week = newDate(newYear(d.y)), day$$1 = week.getDay();
+          week = day$$1 > 4 || day$$1 === 0 ? monday.ceil(week) : monday(week);
+          week = day.offset(week, (d.V - 1) * 7);
+          d.y = week.getFullYear();
+          d.m = week.getMonth();
+          d.d = week.getDate() + (d.w + 6) % 7;
+        }
+      } else if ("W" in d || "U" in d) {
+        if (!("w" in d)) d.w = "u" in d ? d.u % 7 : "W" in d ? 1 : 0;
+        day$$1 = "Z" in d ? utcDate(newYear(d.y)).getUTCDay() : newDate(newYear(d.y)).getDay();
+        d.m = 0;
+        d.d = "W" in d ? (d.w + 6) % 7 + d.W * 7 - (day$$1 + 5) % 7 : d.w + d.U * 7 - (day$$1 + 6) % 7;
+      }
+
+      // If a time zone is specified, all fields are interpreted as UTC and then
+      // offset according to the specified time zone.
+      if ("Z" in d) {
+        d.H += d.Z / 100 | 0;
+        d.M += d.Z % 100;
+        return utcDate(d);
+      }
+
+      // Otherwise, all fields are in local time.
+      return newDate(d);
+    };
+  }
+
+  function parseSpecifier(d, specifier, string, j) {
+    var i = 0,
+        n = specifier.length,
+        m = string.length,
+        c,
+        parse;
+
+    while (i < n) {
+      if (j >= m) return -1;
+      c = specifier.charCodeAt(i++);
+      if (c === 37) {
+        c = specifier.charAt(i++);
+        parse = parses[c in pads ? specifier.charAt(i++) : c];
+        if (!parse || ((j = parse(d, string, j)) < 0)) return -1;
+      } else if (c != string.charCodeAt(j++)) {
+        return -1;
+      }
+    }
+
+    return j;
+  }
+
+  function parsePeriod(d, string, i) {
+    var n = periodRe.exec(string.slice(i));
+    return n ? (d.p = periodLookup[n[0].toLowerCase()], i + n[0].length) : -1;
+  }
+
+  function parseShortWeekday(d, string, i) {
+    var n = shortWeekdayRe.exec(string.slice(i));
+    return n ? (d.w = shortWeekdayLookup[n[0].toLowerCase()], i + n[0].length) : -1;
+  }
+
+  function parseWeekday(d, string, i) {
+    var n = weekdayRe.exec(string.slice(i));
+    return n ? (d.w = weekdayLookup[n[0].toLowerCase()], i + n[0].length) : -1;
+  }
+
+  function parseShortMonth(d, string, i) {
+    var n = shortMonthRe.exec(string.slice(i));
+    return n ? (d.m = shortMonthLookup[n[0].toLowerCase()], i + n[0].length) : -1;
+  }
+
+  function parseMonth(d, string, i) {
+    var n = monthRe.exec(string.slice(i));
+    return n ? (d.m = monthLookup[n[0].toLowerCase()], i + n[0].length) : -1;
+  }
+
+  function parseLocaleDateTime(d, string, i) {
+    return parseSpecifier(d, locale_dateTime, string, i);
+  }
+
+  function parseLocaleDate(d, string, i) {
+    return parseSpecifier(d, locale_date, string, i);
+  }
+
+  function parseLocaleTime(d, string, i) {
+    return parseSpecifier(d, locale_time, string, i);
+  }
+
+  function formatShortWeekday(d) {
+    return locale_shortWeekdays[d.getDay()];
+  }
+
+  function formatWeekday(d) {
+    return locale_weekdays[d.getDay()];
+  }
+
+  function formatShortMonth(d) {
+    return locale_shortMonths[d.getMonth()];
+  }
+
+  function formatMonth(d) {
+    return locale_months[d.getMonth()];
+  }
+
+  function formatPeriod(d) {
+    return locale_periods[+(d.getHours() >= 12)];
+  }
+
+  function formatUTCShortWeekday(d) {
+    return locale_shortWeekdays[d.getUTCDay()];
+  }
+
+  function formatUTCWeekday(d) {
+    return locale_weekdays[d.getUTCDay()];
+  }
+
+  function formatUTCShortMonth(d) {
+    return locale_shortMonths[d.getUTCMonth()];
+  }
+
+  function formatUTCMonth(d) {
+    return locale_months[d.getUTCMonth()];
+  }
+
+  function formatUTCPeriod(d) {
+    return locale_periods[+(d.getUTCHours() >= 12)];
+  }
+
+  return {
+    format: function(specifier) {
+      var f = newFormat(specifier += "", formats);
+      f.toString = function() { return specifier; };
+      return f;
+    },
+    parse: function(specifier) {
+      var p = newParse(specifier += "", localDate);
+      p.toString = function() { return specifier; };
+      return p;
+    },
+    utcFormat: function(specifier) {
+      var f = newFormat(specifier += "", utcFormats);
+      f.toString = function() { return specifier; };
+      return f;
+    },
+    utcParse: function(specifier) {
+      var p = newParse(specifier, utcDate);
+      p.toString = function() { return specifier; };
+      return p;
+    }
+  };
+}
+
+var pads = {"-": "", "_": " ", "0": "0"};
+var numberRe = /^\s*\d+/;
+var percentRe = /^%/;
+var requoteRe = /[\\^$*+?|[\]().{}]/g;
+
+function pad(value, fill, width) {
+  var sign = value < 0 ? "-" : "",
+      string = (sign ? -value : value) + "",
+      length = string.length;
+  return sign + (length < width ? new Array(width - length + 1).join(fill) + string : string);
+}
+
+function requote(s) {
+  return s.replace(requoteRe, "\\$&");
+}
+
+function formatRe(names) {
+  return new RegExp("^(?:" + names.map(requote).join("|") + ")", "i");
+}
+
+function formatLookup(names) {
+  var map = {}, i = -1, n = names.length;
+  while (++i < n) map[names[i].toLowerCase()] = i;
+  return map;
+}
+
+function parseWeekdayNumberSunday(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 1));
+  return n ? (d.w = +n[0], i + n[0].length) : -1;
+}
+
+function parseWeekdayNumberMonday(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 1));
+  return n ? (d.u = +n[0], i + n[0].length) : -1;
+}
+
+function parseWeekNumberSunday(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 2));
+  return n ? (d.U = +n[0], i + n[0].length) : -1;
+}
+
+function parseWeekNumberISO(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 2));
+  return n ? (d.V = +n[0], i + n[0].length) : -1;
+}
+
+function parseWeekNumberMonday(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 2));
+  return n ? (d.W = +n[0], i + n[0].length) : -1;
+}
+
+function parseFullYear(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 4));
+  return n ? (d.y = +n[0], i + n[0].length) : -1;
+}
+
+function parseYear(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 2));
+  return n ? (d.y = +n[0] + (+n[0] > 68 ? 1900 : 2000), i + n[0].length) : -1;
+}
+
+function parseZone(d, string, i) {
+  var n = /^(Z)|([+-]\d\d)(?::?(\d\d))?/.exec(string.slice(i, i + 6));
+  return n ? (d.Z = n[1] ? 0 : -(n[2] + (n[3] || "00")), i + n[0].length) : -1;
+}
+
+function parseMonthNumber(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 2));
+  return n ? (d.m = n[0] - 1, i + n[0].length) : -1;
+}
+
+function parseDayOfMonth(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 2));
+  return n ? (d.d = +n[0], i + n[0].length) : -1;
+}
+
+function parseDayOfYear(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 3));
+  return n ? (d.m = 0, d.d = +n[0], i + n[0].length) : -1;
+}
+
+function parseHour24(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 2));
+  return n ? (d.H = +n[0], i + n[0].length) : -1;
+}
+
+function parseMinutes(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 2));
+  return n ? (d.M = +n[0], i + n[0].length) : -1;
+}
+
+function parseSeconds(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 2));
+  return n ? (d.S = +n[0], i + n[0].length) : -1;
+}
+
+function parseMilliseconds(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 3));
+  return n ? (d.L = +n[0], i + n[0].length) : -1;
+}
+
+function parseMicroseconds(d, string, i) {
+  var n = numberRe.exec(string.slice(i, i + 6));
+  return n ? (d.L = Math.floor(n[0] / 1000), i + n[0].length) : -1;
+}
+
+function parseLiteralPercent(d, string, i) {
+  var n = percentRe.exec(string.slice(i, i + 1));
+  return n ? i + n[0].length : -1;
+}
+
+function parseUnixTimestamp(d, string, i) {
+  var n = numberRe.exec(string.slice(i));
+  return n ? (d.Q = +n[0], i + n[0].length) : -1;
+}
+
+function parseUnixTimestampSeconds(d, string, i) {
+  var n = numberRe.exec(string.slice(i));
+  return n ? (d.Q = (+n[0]) * 1000, i + n[0].length) : -1;
+}
+
+function formatDayOfMonth(d, p) {
+  return pad(d.getDate(), p, 2);
+}
+
+function formatHour24(d, p) {
+  return pad(d.getHours(), p, 2);
+}
+
+function formatHour12(d, p) {
+  return pad(d.getHours() % 12 || 12, p, 2);
+}
+
+function formatDayOfYear(d, p) {
+  return pad(1 + day.count(year(d), d), p, 3);
+}
+
+function formatMilliseconds(d, p) {
+  return pad(d.getMilliseconds(), p, 3);
+}
+
+function formatMicroseconds(d, p) {
+  return formatMilliseconds(d, p) + "000";
+}
+
+function formatMonthNumber(d, p) {
+  return pad(d.getMonth() + 1, p, 2);
+}
+
+function formatMinutes(d, p) {
+  return pad(d.getMinutes(), p, 2);
+}
+
+function formatSeconds(d, p) {
+  return pad(d.getSeconds(), p, 2);
+}
+
+function formatWeekdayNumberMonday(d) {
+  var day$$1 = d.getDay();
+  return day$$1 === 0 ? 7 : day$$1;
+}
+
+function formatWeekNumberSunday(d, p) {
+  return pad(sunday.count(year(d), d), p, 2);
+}
+
+function formatWeekNumberISO(d, p) {
+  var day$$1 = d.getDay();
+  d = (day$$1 >= 4 || day$$1 === 0) ? thursday(d) : thursday.ceil(d);
+  return pad(thursday.count(year(d), d) + (year(d).getDay() === 4), p, 2);
+}
+
+function formatWeekdayNumberSunday(d) {
+  return d.getDay();
+}
+
+function formatWeekNumberMonday(d, p) {
+  return pad(monday.count(year(d), d), p, 2);
+}
+
+function formatYear(d, p) {
+  return pad(d.getFullYear() % 100, p, 2);
+}
+
+function formatFullYear(d, p) {
+  return pad(d.getFullYear() % 10000, p, 4);
+}
+
+function formatZone(d) {
+  var z = d.getTimezoneOffset();
+  return (z > 0 ? "-" : (z *= -1, "+"))
+      + pad(z / 60 | 0, "0", 2)
+      + pad(z % 60, "0", 2);
+}
+
+function formatUTCDayOfMonth(d, p) {
+  return pad(d.getUTCDate(), p, 2);
+}
+
+function formatUTCHour24(d, p) {
+  return pad(d.getUTCHours(), p, 2);
+}
+
+function formatUTCHour12(d, p) {
+  return pad(d.getUTCHours() % 12 || 12, p, 2);
+}
+
+function formatUTCDayOfYear(d, p) {
+  return pad(1 + utcDay.count(utcYear(d), d), p, 3);
+}
+
+function formatUTCMilliseconds(d, p) {
+  return pad(d.getUTCMilliseconds(), p, 3);
+}
+
+function formatUTCMicroseconds(d, p) {
+  return formatUTCMilliseconds(d, p) + "000";
+}
+
+function formatUTCMonthNumber(d, p) {
+  return pad(d.getUTCMonth() + 1, p, 2);
+}
+
+function formatUTCMinutes(d, p) {
+  return pad(d.getUTCMinutes(), p, 2);
+}
+
+function formatUTCSeconds(d, p) {
+  return pad(d.getUTCSeconds(), p, 2);
+}
+
+function formatUTCWeekdayNumberMonday(d) {
+  var dow = d.getUTCDay();
+  return dow === 0 ? 7 : dow;
+}
+
+function formatUTCWeekNumberSunday(d, p) {
+  return pad(utcSunday.count(utcYear(d), d), p, 2);
+}
+
+function formatUTCWeekNumberISO(d, p) {
+  var day$$1 = d.getUTCDay();
+  d = (day$$1 >= 4 || day$$1 === 0) ? utcThursday(d) : utcThursday.ceil(d);
+  return pad(utcThursday.count(utcYear(d), d) + (utcYear(d).getUTCDay() === 4), p, 2);
+}
+
+function formatUTCWeekdayNumberSunday(d) {
+  return d.getUTCDay();
+}
+
+function formatUTCWeekNumberMonday(d, p) {
+  return pad(utcMonday.count(utcYear(d), d), p, 2);
+}
+
+function formatUTCYear(d, p) {
+  return pad(d.getUTCFullYear() % 100, p, 2);
+}
+
+function formatUTCFullYear(d, p) {
+  return pad(d.getUTCFullYear() % 10000, p, 4);
+}
+
+function formatUTCZone() {
+  return "+0000";
+}
+
+function formatLiteralPercent() {
+  return "%";
+}
+
+function formatUnixTimestamp(d) {
+  return +d;
+}
+
+function formatUnixTimestampSeconds(d) {
+  return Math.floor(+d / 1000);
+}
+
+var locale$1;
+var timeFormat;
+var timeParse;
+var utcFormat;
+var utcParse;
+
+defaultLocale$1({
+  dateTime: "%x, %X",
+  date: "%-m/%-d/%Y",
+  time: "%-I:%M:%S %p",
+  periods: ["AM", "PM"],
+  days: ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"],
+  shortDays: ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"],
+  months: ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"],
+  shortMonths: ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
+});
+
+function defaultLocale$1(definition) {
+  locale$1 = formatLocale$1(definition);
+  timeFormat = locale$1.format;
+  timeParse = locale$1.parse;
+  utcFormat = locale$1.utcFormat;
+  utcParse = locale$1.utcParse;
+  return locale$1;
+}
+
+var isoSpecifier = "%Y-%m-%dT%H:%M:%S.%LZ";
+
+function formatIsoNative(date) {
+  return date.toISOString();
+}
+
+var formatIso = Date.prototype.toISOString
+    ? formatIsoNative
+    : utcFormat(isoSpecifier);
+
+function parseIsoNative(string) {
+  var date = new Date(string);
+  return isNaN(date) ? null : date;
+}
+
+var parseIso = +new Date("2000-01-01T00:00:00.000Z")
+    ? parseIsoNative
+    : utcParse(isoSpecifier);
+
+var colors = function(s) {
+  return s.match(/.{6}/g).map(function(x) {
+    return "#" + x;
+  });
+};
+
+colors("1f77b4ff7f0e2ca02cd627289467bd8c564be377c27f7f7fbcbd2217becf");
+
+colors("393b795254a36b6ecf9c9ede6379398ca252b5cf6bcedb9c8c6d31bd9e39e7ba52e7cb94843c39ad494ad6616be7969c7b4173a55194ce6dbdde9ed6");
+
+colors("3182bd6baed69ecae1c6dbefe6550dfd8d3cfdae6bfdd0a231a35474c476a1d99bc7e9c0756bb19e9ac8bcbddcdadaeb636363969696bdbdbdd9d9d9");
+
+colors("1f77b4aec7e8ff7f0effbb782ca02c98df8ad62728ff98969467bdc5b0d58c564bc49c94e377c2f7b6d27f7f7fc7c7c7bcbd22dbdb8d17becf9edae5");
+
+cubehelixLong(cubehelix(300, 0.5, 0.0), cubehelix(-240, 0.5, 1.0));
+
+var warm = cubehelixLong(cubehelix(-100, 0.75, 0.35), cubehelix(80, 1.50, 0.8));
+
+var cool = cubehelixLong(cubehelix(260, 0.75, 0.35), cubehelix(80, 1.50, 0.8));
+
+var rainbow = cubehelix();
+
+function ramp(range) {
+  var n = range.length;
+  return function(t) {
+    return range[Math.max(0, Math.min(n - 1, Math.floor(t * n)))];
+  };
+}
+
+ramp(colors("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"));
+
+var magma = ramp(colors("00000401000501010601010802010902020b02020d03030f03031204041405041606051806051a07061c08071e0907200a08220b09240c09260d0a290e0b2b100b2d110c2f120d31130d34140e36150e38160f3b180f3d19103f1a10421c10441d11471e114920114b21114e22115024125325125527125829115a2a115c2c115f2d11612f116331116533106734106936106b38106c390f6e3b0f703d0f713f0f72400f74420f75440f764510774710784910784a10794c117a4e117b4f127b51127c52137c54137d56147d57157e59157e5a167e5c167f5d177f5f187f601880621980641a80651a80671b80681c816a1c816b1d816d1d816e1e81701f81721f817320817521817621817822817922827b23827c23827e24828025828125818326818426818627818827818928818b29818c29818e2a81902a81912b81932b80942c80962c80982d80992d809b2e7f9c2e7f9e2f7fa02f7fa1307ea3307ea5317ea6317da8327daa337dab337cad347cae347bb0357bb2357bb3367ab5367ab73779b83779ba3878bc3978bd3977bf3a77c03a76c23b75c43c75c53c74c73d73c83e73ca3e72cc3f71cd4071cf4070d0416fd2426fd3436ed5446dd6456cd8456cd9466bdb476adc4869de4968df4a68e04c67e24d66e34e65e44f64e55064e75263e85362e95462ea5661eb5760ec5860ed5a5fee5b5eef5d5ef05f5ef1605df2625df2645cf3655cf4675cf4695cf56b5cf66c5cf66e5cf7705cf7725cf8745cf8765cf9785df9795df97b5dfa7d5efa7f5efa815ffb835ffb8560fb8761fc8961fc8a62fc8c63fc8e64fc9065fd9266fd9467fd9668fd9869fd9a6afd9b6bfe9d6cfe9f6dfea16efea36ffea571fea772fea973feaa74feac76feae77feb078feb27afeb47bfeb67cfeb77efeb97ffebb81febd82febf84fec185fec287fec488fec68afec88cfeca8dfecc8ffecd90fecf92fed194fed395fed597fed799fed89afdda9cfddc9efddea0fde0a1fde2a3fde3a5fde5a7fde7a9fde9aafdebacfcecaefceeb0fcf0b2fcf2b4fcf4b6fcf6b8fcf7b9fcf9bbfcfbbdfcfdbf"));
+
+var inferno = ramp(colors("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"));
+
+var plasma = ramp(colors("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"));
+
+function cubicInOut(t) {
+  return ((t *= 2) <= 1 ? t * t * t : (t -= 2) * t * t + 2) / 2;
+}
+
+var pi = Math.PI;
+
+var tau = 2 * Math.PI;
+
+var noop = {value: function() {}};
+
+function dispatch() {
+  for (var i = 0, n = arguments.length, _ = {}, t; i < n; ++i) {
+    if (!(t = arguments[i] + "") || (t in _)) throw new Error("illegal type: " + t);
+    _[t] = [];
+  }
+  return new Dispatch(_);
+}
+
+function Dispatch(_) {
+  this._ = _;
+}
+
+function parseTypenames$1(typenames, types) {
+  return typenames.trim().split(/^|\s+/).map(function(t) {
+    var name = "", i = t.indexOf(".");
+    if (i >= 0) name = t.slice(i + 1), t = t.slice(0, i);
+    if (t && !types.hasOwnProperty(t)) throw new Error("unknown type: " + t);
+    return {type: t, name: name};
+  });
+}
+
+Dispatch.prototype = dispatch.prototype = {
+  constructor: Dispatch,
+  on: function(typename, callback) {
+    var _ = this._,
+        T = parseTypenames$1(typename + "", _),
+        t,
+        i = -1,
+        n = T.length;
+
+    // If no callback was specified, return the callback of the given type and name.
+    if (arguments.length < 2) {
+      while (++i < n) if ((t = (typename = T[i]).type) && (t = get$1(_[t], typename.name))) return t;
+      return;
+    }
+
+    // If a type was specified, set the callback for the given type and name.
+    // Otherwise, if a null callback was specified, remove callbacks of the given name.
+    if (callback != null && typeof callback !== "function") throw new Error("invalid callback: " + callback);
+    while (++i < n) {
+      if (t = (typename = T[i]).type) _[t] = set$3(_[t], typename.name, callback);
+      else if (callback == null) for (t in _) _[t] = set$3(_[t], typename.name, null);
+    }
+
+    return this;
+  },
+  copy: function() {
+    var copy = {}, _ = this._;
+    for (var t in _) copy[t] = _[t].slice();
+    return new Dispatch(copy);
+  },
+  call: function(type, that) {
+    if ((n = arguments.length - 2) > 0) for (var args = new Array(n), i = 0, n, t; i < n; ++i) args[i] = arguments[i + 2];
+    if (!this._.hasOwnProperty(type)) throw new Error("unknown type: " + type);
+    for (t = this._[type], i = 0, n = t.length; i < n; ++i) t[i].value.apply(that, args);
+  },
+  apply: function(type, that, args) {
+    if (!this._.hasOwnProperty(type)) throw new Error("unknown type: " + type);
+    for (var t = this._[type], i = 0, n = t.length; i < n; ++i) t[i].value.apply(that, args);
+  }
+};
+
+function get$1(type, name) {
+  for (var i = 0, n = type.length, c; i < n; ++i) {
+    if ((c = type[i]).name === name) {
+      return c.value;
+    }
+  }
+}
+
+function set$3(type, name, callback) {
+  for (var i = 0, n = type.length; i < n; ++i) {
+    if (type[i].name === name) {
+      type[i] = noop, type = type.slice(0, i).concat(type.slice(i + 1));
+      break;
+    }
+  }
+  if (callback != null) type.push({name: name, value: callback});
+  return type;
+}
+
+var frame = 0;
+var timeout = 0;
+var interval = 0;
+var pokeDelay = 1000;
+var taskHead;
+var taskTail;
+var clockLast = 0;
+var clockNow = 0;
+var clockSkew = 0;
+var clock = typeof performance === "object" && performance.now ? performance : Date;
+var setFrame = typeof window === "object" && window.requestAnimationFrame ? window.requestAnimationFrame.bind(window) : function(f) { setTimeout(f, 17); };
+
+function now() {
+  return clockNow || (setFrame(clearNow), clockNow = clock.now() + clockSkew);
+}
+
+function clearNow() {
+  clockNow = 0;
+}
+
+function Timer() {
+  this._call =
+  this._time =
+  this._next = null;
+}
+
+Timer.prototype = timer.prototype = {
+  constructor: Timer,
+  restart: function(callback, delay, time) {
+    if (typeof callback !== "function") throw new TypeError("callback is not a function");
+    time = (time == null ? now() : +time) + (delay == null ? 0 : +delay);
+    if (!this._next && taskTail !== this) {
+      if (taskTail) taskTail._next = this;
+      else taskHead = this;
+      taskTail = this;
+    }
+    this._call = callback;
+    this._time = time;
+    sleep();
+  },
+  stop: function() {
+    if (this._call) {
+      this._call = null;
+      this._time = Infinity;
+      sleep();
+    }
+  }
+};
+
+function timer(callback, delay, time) {
+  var t = new Timer;
+  t.restart(callback, delay, time);
+  return t;
+}
+
+function timerFlush() {
+  now(); // Get the current time, if not already set.
+  ++frame; // Pretend we’ve set an alarm, if we haven’t already.
+  var t = taskHead, e;
+  while (t) {
+    if ((e = clockNow - t._time) >= 0) t._call.call(null, e);
+    t = t._next;
+  }
+  --frame;
+}
+
+function wake() {
+  clockNow = (clockLast = clock.now()) + clockSkew;
+  frame = timeout = 0;
+  try {
+    timerFlush();
+  } finally {
+    frame = 0;
+    nap();
+    clockNow = 0;
+  }
+}
+
+function poke() {
+  var now = clock.now(), delay = now - clockLast;
+  if (delay > pokeDelay) clockSkew -= delay, clockLast = now;
+}
+
+function nap() {
+  var t0, t1 = taskHead, t2, time = Infinity;
+  while (t1) {
+    if (t1._call) {
+      if (time > t1._time) time = t1._time;
+      t0 = t1, t1 = t1._next;
+    } else {
+      t2 = t1._next, t1._next = null;
+      t1 = t0 ? t0._next = t2 : taskHead = t2;
+    }
+  }
+  taskTail = t0;
+  sleep(time);
+}
+
+function sleep(time) {
+  if (frame) return; // Soonest alarm already set, or will be.
+  if (timeout) timeout = clearTimeout(timeout);
+  var delay = time - clockNow; // Strictly less than if we recomputed clockNow.
+  if (delay > 24) {
+    if (time < Infinity) timeout = setTimeout(wake, time - clock.now() - clockSkew);
+    if (interval) interval = clearInterval(interval);
+  } else {
+    if (!interval) clockLast = clock.now(), interval = setInterval(poke, pokeDelay);
+    frame = 1, setFrame(wake);
+  }
+}
+
+var timeout$1 = function(callback, delay, time) {
+  var t = new Timer;
+  delay = delay == null ? 0 : +delay;
+  t.restart(function(elapsed) {
+    t.stop();
+    callback(elapsed + delay);
+  }, delay, time);
+  return t;
+};
+
+var emptyOn = dispatch("start", "end", "interrupt");
+var emptyTween = [];
+
+var CREATED = 0;
+var SCHEDULED = 1;
+var STARTING = 2;
+var STARTED = 3;
+var RUNNING = 4;
+var ENDING = 5;
+var ENDED = 6;
+
+var schedule = function(node, name, id, index, group, timing) {
+  var schedules = node.__transition;
+  if (!schedules) node.__transition = {};
+  else if (id in schedules) return;
+  create(node, id, {
+    name: name,
+    index: index, // For context during callback.
+    group: group, // For context during callback.
+    on: emptyOn,
+    tween: emptyTween,
+    time: timing.time,
+    delay: timing.delay,
+    duration: timing.duration,
+    ease: timing.ease,
+    timer: null,
+    state: CREATED
+  });
+};
+
+function init(node, id) {
+  var schedule = node.__transition;
+  if (!schedule || !(schedule = schedule[id]) || schedule.state > CREATED) throw new Error("too late");
+  return schedule;
+}
+
+function set$2(node, id) {
+  var schedule = node.__transition;
+  if (!schedule || !(schedule = schedule[id]) || schedule.state > STARTING) throw new Error("too late");
+  return schedule;
+}
+
+function get(node, id) {
+  var schedule = node.__transition;
+  if (!schedule || !(schedule = schedule[id])) throw new Error("too late");
+  return schedule;
+}
+
+function create(node, id, self) {
+  var schedules = node.__transition,
+      tween;
+
+  // Initialize the self timer when the transition is created.
+  // Note the actual delay is not known until the first callback!
+  schedules[id] = self;
+  self.timer = timer(schedule, 0, self.time);
+
+  function schedule(elapsed) {
+    self.state = SCHEDULED;
+    self.timer.restart(start, self.delay, self.time);
+
+    // If the elapsed delay is less than our first sleep, start immediately.
+    if (self.delay <= elapsed) start(elapsed - self.delay);
+  }
+
+  function start(elapsed) {
+    var i, j, n, o;
+
+    // If the state is not SCHEDULED, then we previously errored on start.
+    if (self.state !== SCHEDULED) return stop();
+
+    for (i in schedules) {
+      o = schedules[i];
+      if (o.name !== self.name) continue;
+
+      // While this element already has a starting transition during this frame,
+      // defer starting an interrupting transition until that transition has a
+      // chance to tick (and possibly end); see d3/d3-transition#54!
+      if (o.state === STARTED) return timeout$1(start);
+
+      // Interrupt the active transition, if any.
+      // Dispatch the interrupt event.
+      if (o.state === RUNNING) {
+        o.state = ENDED;
+        o.timer.stop();
+        o.on.call("interrupt", node, node.__data__, o.index, o.group);
+        delete schedules[i];
+      }
+
+      // Cancel any pre-empted transitions. No interrupt event is dispatched
+      // because the cancelled transitions never started. Note that this also
+      // removes this transition from the pending list!
+      else if (+i < id) {
+        o.state = ENDED;
+        o.timer.stop();
+        delete schedules[i];
+      }
+    }
+
+    // Defer the first tick to end of the current frame; see d3/d3#1576.
+    // Note the transition may be canceled after start and before the first tick!
+    // Note this must be scheduled before the start event; see d3/d3-transition#16!
+    // Assuming this is successful, subsequent callbacks go straight to tick.
+    timeout$1(function() {
+      if (self.state === STARTED) {
+        self.state = RUNNING;
+        self.timer.restart(tick, self.delay, self.time);
+        tick(elapsed);
+      }
+    });
+
+    // Dispatch the start event.
+    // Note this must be done before the tween are initialized.
+    self.state = STARTING;
+    self.on.call("start", node, node.__data__, self.index, self.group);
+    if (self.state !== STARTING) return; // interrupted
+    self.state = STARTED;
+
+    // Initialize the tween, deleting null tween.
+    tween = new Array(n = self.tween.length);
+    for (i = 0, j = -1; i < n; ++i) {
+      if (o = self.tween[i].value.call(node, node.__data__, self.index, self.group)) {
+        tween[++j] = o;
+      }
+    }
+    tween.length = j + 1;
+  }
+
+  function tick(elapsed) {
+    var t = elapsed < self.duration ? self.ease.call(null, elapsed / self.duration) : (self.timer.restart(stop), self.state = ENDING, 1),
+        i = -1,
+        n = tween.length;
+
+    while (++i < n) {
+      tween[i].call(null, t);
+    }
+
+    // Dispatch the end event.
+    if (self.state === ENDING) {
+      self.on.call("end", node, node.__data__, self.index, self.group);
+      stop();
+    }
+  }
+
+  function stop() {
+    self.state = ENDED;
+    self.timer.stop();
+    delete schedules[id];
+    for (var i in schedules) return; // eslint-disable-line no-unused-vars
+    delete node.__transition;
+  }
+}
+
+var interrupt = function(node, name) {
+  var schedules = node.__transition,
+      schedule$$1,
+      active,
+      empty = true,
+      i;
+
+  if (!schedules) return;
+
+  name = name == null ? null : name + "";
+
+  for (i in schedules) {
+    if ((schedule$$1 = schedules[i]).name !== name) { empty = false; continue; }
+    active = schedule$$1.state > STARTING && schedule$$1.state < ENDING;
+    schedule$$1.state = ENDED;
+    schedule$$1.timer.stop();
+    if (active) schedule$$1.on.call("interrupt", node, node.__data__, schedule$$1.index, schedule$$1.group);
+    delete schedules[i];
+  }
+
+  if (empty) delete node.__transition;
+};
+
+var selection_interrupt = function(name) {
+  return this.each(function() {
+    interrupt(this, name);
+  });
+};
+
+function tweenRemove(id, name) {
+  var tween0, tween1;
+  return function() {
+    var schedule$$1 = set$2(this, id),
+        tween = schedule$$1.tween;
+
+    // If this node shared tween with the previous node,
+    // just assign the updated shared tween and we’re done!
+    // Otherwise, copy-on-write.
+    if (tween !== tween0) {
+      tween1 = tween0 = tween;
+      for (var i = 0, n = tween1.length; i < n; ++i) {
+        if (tween1[i].name === name) {
+          tween1 = tween1.slice();
+          tween1.splice(i, 1);
+          break;
+        }
+      }
+    }
+
+    schedule$$1.tween = tween1;
+  };
+}
+
+function tweenFunction(id, name, value) {
+  var tween0, tween1;
+  if (typeof value !== "function") throw new Error;
+  return function() {
+    var schedule$$1 = set$2(this, id),
+        tween = schedule$$1.tween;
+
+    // If this node shared tween with the previous node,
+    // just assign the updated shared tween and we’re done!
+    // Otherwise, copy-on-write.
+    if (tween !== tween0) {
+      tween1 = (tween0 = tween).slice();
+      for (var t = {name: name, value: value}, i = 0, n = tween1.length; i < n; ++i) {
+        if (tween1[i].name === name) {
+          tween1[i] = t;
+          break;
+        }
+      }
+      if (i === n) tween1.push(t);
+    }
+
+    schedule$$1.tween = tween1;
+  };
+}
+
+var transition_tween = function(name, value) {
+  var id = this._id;
+
+  name += "";
+
+  if (arguments.length < 2) {
+    var tween = get(this.node(), id).tween;
+    for (var i = 0, n = tween.length, t; i < n; ++i) {
+      if ((t = tween[i]).name === name) {
+        return t.value;
+      }
+    }
+    return null;
+  }
+
+  return this.each((value == null ? tweenRemove : tweenFunction)(id, name, value));
+};
+
+function tweenValue(transition, name, value) {
+  var id = transition._id;
+
+  transition.each(function() {
+    var schedule$$1 = set$2(this, id);
+    (schedule$$1.value || (schedule$$1.value = {}))[name] = value.apply(this, arguments);
+  });
+
+  return function(node) {
+    return get(node, id).value[name];
+  };
+}
+
+var interpolate = function(a, b) {
+  var c;
+  return (typeof b === "number" ? interpolateNumber
+      : b instanceof color ? interpolateRgb
+      : (c = color(b)) ? (b = c, interpolateRgb)
+      : interpolateString)(a, b);
+};
+
+function attrRemove$1(name) {
+  return function() {
+    this.removeAttribute(name);
+  };
+}
+
+function attrRemoveNS$1(fullname) {
+  return function() {
+    this.removeAttributeNS(fullname.space, fullname.local);
+  };
+}
+
+function attrConstant$1(name, interpolate$$1, value1) {
+  var value00,
+      interpolate0;
+  return function() {
+    var value0 = this.getAttribute(name);
+    return value0 === value1 ? null
+        : value0 === value00 ? interpolate0
+        : interpolate0 = interpolate$$1(value00 = value0, value1);
+  };
+}
+
+function attrConstantNS$1(fullname, interpolate$$1, value1) {
+  var value00,
+      interpolate0;
+  return function() {
+    var value0 = this.getAttributeNS(fullname.space, fullname.local);
+    return value0 === value1 ? null
+        : value0 === value00 ? interpolate0
+        : interpolate0 = interpolate$$1(value00 = value0, value1);
+  };
+}
+
+function attrFunction$1(name, interpolate$$1, value) {
+  var value00,
+      value10,
+      interpolate0;
+  return function() {
+    var value0, value1 = value(this);
+    if (value1 == null) return void this.removeAttribute(name);
+    value0 = this.getAttribute(name);
+    return value0 === value1 ? null
+        : value0 === value00 && value1 === value10 ? interpolate0
+        : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
+  };
+}
+
+function attrFunctionNS$1(fullname, interpolate$$1, value) {
+  var value00,
+      value10,
+      interpolate0;
+  return function() {
+    var value0, value1 = value(this);
+    if (value1 == null) return void this.removeAttributeNS(fullname.space, fullname.local);
+    value0 = this.getAttributeNS(fullname.space, fullname.local);
+    return value0 === value1 ? null
+        : value0 === value00 && value1 === value10 ? interpolate0
+        : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
+  };
+}
+
+var transition_attr = function(name, value) {
+  var fullname = namespace(name), i = fullname === "transform" ? interpolateTransformSvg : interpolate;
+  return this.attrTween(name, typeof value === "function"
+      ? (fullname.local ? attrFunctionNS$1 : attrFunction$1)(fullname, i, tweenValue(this, "attr." + name, value))
+      : value == null ? (fullname.local ? attrRemoveNS$1 : attrRemove$1)(fullname)
+      : (fullname.local ? attrConstantNS$1 : attrConstant$1)(fullname, i, value + ""));
+};
+
+function attrTweenNS(fullname, value) {
+  function tween() {
+    var node = this, i = value.apply(node, arguments);
+    return i && function(t) {
+      node.setAttributeNS(fullname.space, fullname.local, i(t));
+    };
+  }
+  tween._value = value;
+  return tween;
+}
+
+function attrTween(name, value) {
+  function tween() {
+    var node = this, i = value.apply(node, arguments);
+    return i && function(t) {
+      node.setAttribute(name, i(t));
+    };
+  }
+  tween._value = value;
+  return tween;
+}
+
+var transition_attrTween = function(name, value) {
+  var key = "attr." + name;
+  if (arguments.length < 2) return (key = this.tween(key)) && key._value;
+  if (value == null) return this.tween(key, null);
+  if (typeof value !== "function") throw new Error;
+  var fullname = namespace(name);
+  return this.tween(key, (fullname.local ? attrTweenNS : attrTween)(fullname, value));
+};
+
+function delayFunction(id, value) {
+  return function() {
+    init(this, id).delay = +value.apply(this, arguments);
+  };
+}
+
+function delayConstant(id, value) {
+  return value = +value, function() {
+    init(this, id).delay = value;
+  };
+}
+
+var transition_delay = function(value) {
+  var id = this._id;
+
+  return arguments.length
+      ? this.each((typeof value === "function"
+          ? delayFunction
+          : delayConstant)(id, value))
+      : get(this.node(), id).delay;
+};
+
+function durationFunction(id, value) {
+  return function() {
+    set$2(this, id).duration = +value.apply(this, arguments);
+  };
+}
+
+function durationConstant(id, value) {
+  return value = +value, function() {
+    set$2(this, id).duration = value;
+  };
+}
+
+var transition_duration = function(value) {
+  var id = this._id;
+
+  return arguments.length
+      ? this.each((typeof value === "function"
+          ? durationFunction
+          : durationConstant)(id, value))
+      : get(this.node(), id).duration;
+};
+
+function easeConstant(id, value) {
+  if (typeof value !== "function") throw new Error;
+  return function() {
+    set$2(this, id).ease = value;
+  };
+}
+
+var transition_ease = function(value) {
+  var id = this._id;
+
+  return arguments.length
+      ? this.each(easeConstant(id, value))
+      : get(this.node(), id).ease;
+};
+
+var transition_filter = function(match) {
+  if (typeof match !== "function") match = matcher$1(match);
+
+  for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
+    for (var group = groups[j], n = group.length, subgroup = subgroups[j] = [], node, i = 0; i < n; ++i) {
+      if ((node = group[i]) && match.call(node, node.__data__, i, group)) {
+        subgroup.push(node);
+      }
+    }
+  }
+
+  return new Transition(subgroups, this._parents, this._name, this._id);
+};
+
+var transition_merge = function(transition$$1) {
+  if (transition$$1._id !== this._id) throw new Error;
+
+  for (var groups0 = this._groups, groups1 = transition$$1._groups, m0 = groups0.length, m1 = groups1.length, m = Math.min(m0, m1), merges = new Array(m0), j = 0; j < m; ++j) {
+    for (var group0 = groups0[j], group1 = groups1[j], n = group0.length, merge = merges[j] = new Array(n), node, i = 0; i < n; ++i) {
+      if (node = group0[i] || group1[i]) {
+        merge[i] = node;
+      }
+    }
+  }
+
+  for (; j < m0; ++j) {
+    merges[j] = groups0[j];
+  }
+
+  return new Transition(merges, this._parents, this._name, this._id);
+};
+
+function start(name) {
+  return (name + "").trim().split(/^|\s+/).every(function(t) {
+    var i = t.indexOf(".");
+    if (i >= 0) t = t.slice(0, i);
+    return !t || t === "start";
+  });
+}
+
+function onFunction(id, name, listener) {
+  var on0, on1, sit = start(name) ? init : set$2;
+  return function() {
+    var schedule$$1 = sit(this, id),
+        on = schedule$$1.on;
+
+    // If this node shared a dispatch with the previous node,
+    // just assign the updated shared dispatch and we’re done!
+    // Otherwise, copy-on-write.
+    if (on !== on0) (on1 = (on0 = on).copy()).on(name, listener);
+
+    schedule$$1.on = on1;
+  };
+}
+
+var transition_on = function(name, listener) {
+  var id = this._id;
+
+  return arguments.length < 2
+      ? get(this.node(), id).on.on(name)
+      : this.each(onFunction(id, name, listener));
+};
+
+function removeFunction(id) {
+  return function() {
+    var parent = this.parentNode;
+    for (var i in this.__transition) if (+i !== id) return;
+    if (parent) parent.removeChild(this);
+  };
+}
+
+var transition_remove = function() {
+  return this.on("end.remove", removeFunction(this._id));
+};
+
+var transition_select = function(select) {
+  var name = this._name,
+      id = this._id;
+
+  if (typeof select !== "function") select = selector(select);
+
+  for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
+    for (var group = groups[j], n = group.length, subgroup = subgroups[j] = new Array(n), node, subnode, i = 0; i < n; ++i) {
+      if ((node = group[i]) && (subnode = select.call(node, node.__data__, i, group))) {
+        if ("__data__" in node) subnode.__data__ = node.__data__;
+        subgroup[i] = subnode;
+        schedule(subgroup[i], name, id, i, subgroup, get(node, id));
+      }
+    }
+  }
+
+  return new Transition(subgroups, this._parents, name, id);
+};
+
+var transition_selectAll = function(select) {
+  var name = this._name,
+      id = this._id;
+
+  if (typeof select !== "function") select = selectorAll(select);
+
+  for (var groups = this._groups, m = groups.length, subgroups = [], parents = [], j = 0; j < m; ++j) {
+    for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
+      if (node = group[i]) {
+        for (var children = select.call(node, node.__data__, i, group), child, inherit = get(node, id), k = 0, l = children.length; k < l; ++k) {
+          if (child = children[k]) {
+            schedule(child, name, id, k, children, inherit);
+          }
+        }
+        subgroups.push(children);
+        parents.push(node);
+      }
+    }
+  }
+
+  return new Transition(subgroups, parents, name, id);
+};
+
+var Selection$1 = selection.prototype.constructor;
+
+var transition_selection = function() {
+  return new Selection$1(this._groups, this._parents);
+};
+
+function styleRemove$1(name, interpolate$$1) {
+  var value00,
+      value10,
+      interpolate0;
+  return function() {
+    var value0 = styleValue(this, name),
+        value1 = (this.style.removeProperty(name), styleValue(this, name));
+    return value0 === value1 ? null
+        : value0 === value00 && value1 === value10 ? interpolate0
+        : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
+  };
+}
+
+function styleRemoveEnd(name) {
+  return function() {
+    this.style.removeProperty(name);
+  };
+}
+
+function styleConstant$1(name, interpolate$$1, value1) {
+  var value00,
+      interpolate0;
+  return function() {
+    var value0 = styleValue(this, name);
+    return value0 === value1 ? null
+        : value0 === value00 ? interpolate0
+        : interpolate0 = interpolate$$1(value00 = value0, value1);
+  };
+}
+
+function styleFunction$1(name, interpolate$$1, value) {
+  var value00,
+      value10,
+      interpolate0;
+  return function() {
+    var value0 = styleValue(this, name),
+        value1 = value(this);
+    if (value1 == null) value1 = (this.style.removeProperty(name), styleValue(this, name));
+    return value0 === value1 ? null
+        : value0 === value00 && value1 === value10 ? interpolate0
+        : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
+  };
+}
+
+var transition_style = function(name, value, priority) {
+  var i = (name += "") === "transform" ? interpolateTransformCss : interpolate;
+  return value == null ? this
+          .styleTween(name, styleRemove$1(name, i))
+          .on("end.style." + name, styleRemoveEnd(name))
+      : this.styleTween(name, typeof value === "function"
+          ? styleFunction$1(name, i, tweenValue(this, "style." + name, value))
+          : styleConstant$1(name, i, value + ""), priority);
+};
+
+function styleTween(name, value, priority) {
+  function tween() {
+    var node = this, i = value.apply(node, arguments);
+    return i && function(t) {
+      node.style.setProperty(name, i(t), priority);
+    };
+  }
+  tween._value = value;
+  return tween;
+}
+
+var transition_styleTween = function(name, value, priority) {
+  var key = "style." + (name += "");
+  if (arguments.length < 2) return (key = this.tween(key)) && key._value;
+  if (value == null) return this.tween(key, null);
+  if (typeof value !== "function") throw new Error;
+  return this.tween(key, styleTween(name, value, priority == null ? "" : priority));
+};
+
+function textConstant$1(value) {
+  return function() {
+    this.textContent = value;
+  };
+}
+
+function textFunction$1(value) {
+  return function() {
+    var value1 = value(this);
+    this.textContent = value1 == null ? "" : value1;
+  };
+}
+
+var transition_text = function(value) {
+  return this.tween("text", typeof value === "function"
+      ? textFunction$1(tweenValue(this, "text", value))
+      : textConstant$1(value == null ? "" : value + ""));
+};
+
+var transition_transition = function() {
+  var name = this._name,
+      id0 = this._id,
+      id1 = newId();
+
+  for (var groups = this._groups, m = groups.length, j = 0; j < m; ++j) {
+    for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
+      if (node = group[i]) {
+        var inherit = get(node, id0);
+        schedule(node, name, id1, i, group, {
+          time: inherit.time + inherit.delay + inherit.duration,
+          delay: 0,
+          duration: inherit.duration,
+          ease: inherit.ease
+        });
+      }
+    }
+  }
+
+  return new Transition(groups, this._parents, name, id1);
+};
+
+var id = 0;
+
+function Transition(groups, parents, name, id) {
+  this._groups = groups;
+  this._parents = parents;
+  this._name = name;
+  this._id = id;
+}
+
+function transition(name) {
+  return selection().transition(name);
+}
+
+function newId() {
+  return ++id;
+}
+
+var selection_prototype = selection.prototype;
+
+Transition.prototype = transition.prototype = {
+  constructor: Transition,
+  select: transition_select,
+  selectAll: transition_selectAll,
+  filter: transition_filter,
+  merge: transition_merge,
+  selection: transition_selection,
+  transition: transition_transition,
+  call: selection_prototype.call,
+  nodes: selection_prototype.nodes,
+  node: selection_prototype.node,
+  size: selection_prototype.size,
+  empty: selection_prototype.empty,
+  each: selection_prototype.each,
+  on: transition_on,
+  attr: transition_attr,
+  attrTween: transition_attrTween,
+  style: transition_style,
+  styleTween: transition_styleTween,
+  text: transition_text,
+  remove: transition_remove,
+  tween: transition_tween,
+  delay: transition_delay,
+  duration: transition_duration,
+  ease: transition_ease
+};
+
+var defaultTiming = {
+  time: null, // Set on use.
+  delay: 0,
+  duration: 250,
+  ease: cubicInOut
+};
+
+function inherit(node, id) {
+  var timing;
+  while (!(timing = node.__transition) || !(timing = timing[id])) {
+    if (!(node = node.parentNode)) {
+      return defaultTiming.time = now(), defaultTiming;
+    }
+  }
+  return timing;
+}
+
+var selection_transition = function(name) {
+  var id,
+      timing;
+
+  if (name instanceof Transition) {
+    id = name._id, name = name._name;
+  } else {
+    id = newId(), (timing = defaultTiming).time = now(), name = name == null ? null : name + "";
+  }
+
+  for (var groups = this._groups, m = groups.length, j = 0; j < m; ++j) {
+    for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
+      if (node = group[i]) {
+        schedule(node, name, id, i, group, timing || inherit(node, id));
+      }
+    }
+  }
+
+  return new Transition(groups, this._parents, name, id);
+};
+
+selection.prototype.interrupt = selection_interrupt;
+selection.prototype.transition = selection_transition;
+
+exports.select = select;
+exports.selection = selection;
+exports.hierarchy = hierarchy;
+exports.partition = partition;
+exports.scaleLinear = linear;
+exports.easeCubic = cubicInOut;
+exports.ascending = ascending$1;
+exports.map = map$1;
+exports.transition = transition;
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+})));
+`
diff --git a/src/cmd/vendor/github.com/google/pprof/third_party/d3flamegraph/LICENSE b/src/cmd/vendor/github.com/google/pprof/third_party/d3flamegraph/LICENSE
new file mode 100644
index 0000000..8dada3e
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/third_party/d3flamegraph/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/src/cmd/vendor/github.com/google/pprof/third_party/d3flamegraph/d3_flame_graph.go b/src/cmd/vendor/github.com/google/pprof/third_party/d3flamegraph/d3_flame_graph.go
new file mode 100644
index 0000000..58a7fb4
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/third_party/d3flamegraph/d3_flame_graph.go
@@ -0,0 +1,1009 @@
+// A D3.js plugin that produces flame graphs from hierarchical data.
+// https://github.com/spiermar/d3-flame-graph
+// Version 2.0.0-alpha4
+// See LICENSE file for license details
+
+package d3flamegraph
+
+// JSSource returns the d3-flamegraph.js file
+const JSSource = `
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('d3')) :
+	typeof define === 'function' && define.amd ? define(['exports', 'd3'], factory) :
+	(factory((global.d3 = global.d3 || {}),global.d3));
+}(this, (function (exports,d3) { 'use strict';
+
+var d3__default = 'default' in d3 ? d3['default'] : d3;
+
+var commonjsGlobal = typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : {};
+
+
+
+
+
+function createCommonjsModule(fn, module) {
+	return module = { exports: {} }, fn(module, module.exports), module.exports;
+}
+
+var d3Tip = createCommonjsModule(function (module) {
+// d3.tip
+// Copyright (c) 2013 Justin Palmer
+//
+// Tooltips for d3.js SVG visualizations
+
+(function (root, factory) {
+  if (typeof undefined === 'function' && undefined.amd) {
+    // AMD. Register as an anonymous module with d3 as a dependency.
+    undefined(['d3'], factory);
+  } else if ('object' === 'object' && module.exports) {
+    // CommonJS
+    var d3$$1 = d3__default;
+    module.exports = factory(d3$$1);
+  } else {
+    // Browser global.
+    root.d3.tip = factory(root.d3);
+  }
+}(commonjsGlobal, function (d3$$1) {
+
+  // Public - contructs a new tooltip
+  //
+  // Returns a tip
+  return function() {
+    var direction = d3_tip_direction,
+        offset    = d3_tip_offset,
+        html      = d3_tip_html,
+        node      = initNode(),
+        svg       = null,
+        point     = null,
+        target    = null;
+
+    function tip(vis) {
+      svg = getSVGNode(vis);
+      point = svg.createSVGPoint();
+      document.body.appendChild(node);
+    }
+
+    // Public - show the tooltip on the screen
+    //
+    // Returns a tip
+    tip.show = function() {
+      var args = Array.prototype.slice.call(arguments);
+      if(args[args.length - 1] instanceof SVGElement) target = args.pop();
+
+      var content = html.apply(this, args),
+          poffset = offset.apply(this, args),
+          dir     = direction.apply(this, args),
+          nodel   = getNodeEl(),
+          i       = directions.length,
+          coords,
+          scrollTop  = document.documentElement.scrollTop || document.body.scrollTop,
+          scrollLeft = document.documentElement.scrollLeft || document.body.scrollLeft;
+
+      nodel.html(content)
+        .style('opacity', 1).style('pointer-events', 'all');
+
+      while(i--) nodel.classed(directions[i], false);
+      coords = direction_callbacks.get(dir).apply(this);
+      nodel.classed(dir, true)
+      	.style('top', (coords.top +  poffset[0]) + scrollTop + 'px')
+      	.style('left', (coords.left + poffset[1]) + scrollLeft + 'px');
+
+      return tip;
+    };
+
+    // Public - hide the tooltip
+    //
+    // Returns a tip
+    tip.hide = function() {
+      var nodel = getNodeEl();
+      nodel.style('opacity', 0).style('pointer-events', 'none');
+      return tip
+    };
+
+    // Public: Proxy attr calls to the d3 tip container.  Sets or gets attribute value.
+    //
+    // n - name of the attribute
+    // v - value of the attribute
+    //
+    // Returns tip or attribute value
+    tip.attr = function(n, v) {
+      if (arguments.length < 2 && typeof n === 'string') {
+        return getNodeEl().attr(n)
+      } else {
+        var args =  Array.prototype.slice.call(arguments);
+        d3$$1.selection.prototype.attr.apply(getNodeEl(), args);
+      }
+
+      return tip
+    };
+
+    // Public: Proxy style calls to the d3 tip container.  Sets or gets a style value.
+    //
+    // n - name of the property
+    // v - value of the property
+    //
+    // Returns tip or style property value
+    tip.style = function(n, v) {
+      if (arguments.length < 2 && typeof n === 'string') {
+        return getNodeEl().style(n)
+      } else {
+        var args = Array.prototype.slice.call(arguments);
+        d3$$1.selection.prototype.style.apply(getNodeEl(), args);
+      }
+
+      return tip
+    };
+
+    // Public: Set or get the direction of the tooltip
+    //
+    // v - One of n(north), s(south), e(east), or w(west), nw(northwest),
+    //     sw(southwest), ne(northeast) or se(southeast)
+    //
+    // Returns tip or direction
+    tip.direction = function(v) {
+      if (!arguments.length) return direction
+      direction = v == null ? v : functor(v);
+
+      return tip
+    };
+
+    // Public: Sets or gets the offset of the tip
+    //
+    // v - Array of [x, y] offset
+    //
+    // Returns offset or
+    tip.offset = function(v) {
+      if (!arguments.length) return offset
+      offset = v == null ? v : functor(v);
+
+      return tip
+    };
+
+    // Public: sets or gets the html value of the tooltip
+    //
+    // v - String value of the tip
+    //
+    // Returns html value or tip
+    tip.html = function(v) {
+      if (!arguments.length) return html
+      html = v == null ? v : functor(v);
+
+      return tip
+    };
+
+    // Public: destroys the tooltip and removes it from the DOM
+    //
+    // Returns a tip
+    tip.destroy = function() {
+      if(node) {
+        getNodeEl().remove();
+        node = null;
+      }
+      return tip;
+    };
+
+    function d3_tip_direction() { return 'n' }
+    function d3_tip_offset() { return [0, 0] }
+    function d3_tip_html() { return ' ' }
+
+    var direction_callbacks = d3$$1.map({
+      n:  direction_n,
+      s:  direction_s,
+      e:  direction_e,
+      w:  direction_w,
+      nw: direction_nw,
+      ne: direction_ne,
+      sw: direction_sw,
+      se: direction_se
+    }),
+
+    directions = direction_callbacks.keys();
+
+    function direction_n() {
+      var bbox = getScreenBBox();
+      return {
+        top:  bbox.n.y - node.offsetHeight,
+        left: bbox.n.x - node.offsetWidth / 2
+      }
+    }
+
+    function direction_s() {
+      var bbox = getScreenBBox();
+      return {
+        top:  bbox.s.y,
+        left: bbox.s.x - node.offsetWidth / 2
+      }
+    }
+
+    function direction_e() {
+      var bbox = getScreenBBox();
+      return {
+        top:  bbox.e.y - node.offsetHeight / 2,
+        left: bbox.e.x
+      }
+    }
+
+    function direction_w() {
+      var bbox = getScreenBBox();
+      return {
+        top:  bbox.w.y - node.offsetHeight / 2,
+        left: bbox.w.x - node.offsetWidth
+      }
+    }
+
+    function direction_nw() {
+      var bbox = getScreenBBox();
+      return {
+        top:  bbox.nw.y - node.offsetHeight,
+        left: bbox.nw.x - node.offsetWidth
+      }
+    }
+
+    function direction_ne() {
+      var bbox = getScreenBBox();
+      return {
+        top:  bbox.ne.y - node.offsetHeight,
+        left: bbox.ne.x
+      }
+    }
+
+    function direction_sw() {
+      var bbox = getScreenBBox();
+      return {
+        top:  bbox.sw.y,
+        left: bbox.sw.x - node.offsetWidth
+      }
+    }
+
+    function direction_se() {
+      var bbox = getScreenBBox();
+      return {
+        top:  bbox.se.y,
+        left: bbox.e.x
+      }
+    }
+
+    function initNode() {
+      var node = d3$$1.select(document.createElement('div'));
+      node.style('position', 'absolute').style('top', 0).style('opacity', 0)
+      	.style('pointer-events', 'none').style('box-sizing', 'border-box');
+
+      return node.node()
+    }
+
+    function getSVGNode(el) {
+      el = el.node();
+      if(el.tagName.toLowerCase() === 'svg')
+        return el
+
+      return el.ownerSVGElement
+    }
+
+    function getNodeEl() {
+      if(node === null) {
+        node = initNode();
+        // re-add node to DOM
+        document.body.appendChild(node);
+      }
+      return d3$$1.select(node);
+    }
+
+    // Private - gets the screen coordinates of a shape
+    //
+    // Given a shape on the screen, will return an SVGPoint for the directions
+    // n(north), s(south), e(east), w(west), ne(northeast), se(southeast), nw(northwest),
+    // sw(southwest).
+    //
+    //    +-+-+
+    //    |   |
+    //    +   +
+    //    |   |
+    //    +-+-+
+    //
+    // Returns an Object {n, s, e, w, nw, sw, ne, se}
+    function getScreenBBox() {
+      var targetel   = target || d3$$1.event.target;
+
+      while ('undefined' === typeof targetel.getScreenCTM && 'undefined' === targetel.parentNode) {
+          targetel = targetel.parentNode;
+      }
+
+      var bbox       = {},
+          matrix     = targetel.getScreenCTM(),
+          tbbox      = targetel.getBBox(),
+          width      = tbbox.width,
+          height     = tbbox.height,
+          x          = tbbox.x,
+          y          = tbbox.y;
+
+      point.x = x;
+      point.y = y;
+      bbox.nw = point.matrixTransform(matrix);
+      point.x += width;
+      bbox.ne = point.matrixTransform(matrix);
+      point.y += height;
+      bbox.se = point.matrixTransform(matrix);
+      point.x -= width;
+      bbox.sw = point.matrixTransform(matrix);
+      point.y -= height / 2;
+      bbox.w  = point.matrixTransform(matrix);
+      point.x += width;
+      bbox.e = point.matrixTransform(matrix);
+      point.x -= width / 2;
+      point.y -= height / 2;
+      bbox.n = point.matrixTransform(matrix);
+      point.y += height;
+      bbox.s = point.matrixTransform(matrix);
+
+      return bbox
+    }
+    
+    // Private - replace D3JS 3.X d3.functor() function
+    function functor(v) {
+    	return typeof v === "function" ? v : function() {
+        return v
+    	}
+    }
+
+    return tip
+  };
+
+}));
+});
+
+var flamegraph = function () {
+  var w = 960; // graph width
+  var h = null; // graph height
+  var c = 18; // cell height
+  var selection = null; // selection
+  var tooltip = true; // enable tooltip
+  var title = ''; // graph title
+  var transitionDuration = 750;
+  var transitionEase = d3.easeCubic; // tooltip offset
+  var sort = false;
+  var inverted = false; // invert the graph direction
+  var clickHandler = null;
+  var minFrameSize = 0;
+  var details = null;
+
+  var tip = d3Tip()
+    .direction('s')
+    .offset([8, 0])
+    .attr('class', 'd3-flame-graph-tip')
+    .html(function (d) { return label(d) });
+
+  var svg;
+
+  function name (d) {
+    return d.data.n || d.data.name
+  }
+
+  function libtype (d) {
+    return d.data.l || d.data.libtype
+  }
+
+  function children (d) {
+    return d.c || d.children
+  }
+
+  function value (d) {
+    return d.v || d.value
+  }
+
+  var label = function (d) {
+    return name(d) + ' (' + d3.format('.3f')(100 * (d.x1 - d.x0), 3) + '%, ' + value(d) + ' samples)'
+  };
+
+  function setDetails (t) {
+    if (details) { details.innerHTML = t; }
+  }
+
+  var colorMapper = function (d) {
+    return d.highlight ? '#E600E6' : colorHash(name(d), libtype(d))
+  };
+
+  function generateHash (name) {
+    // Return a vector (0.0->1.0) that is a hash of the input string.
+    // The hash is computed to favor early characters over later ones, so
+    // that strings with similar starts have similar vectors. Only the first
+    // 6 characters are considered.
+    const MAX_CHAR = 6;
+
+    var hash = 0;
+    var maxHash = 0;
+    var weight = 1;
+    var mod = 10;
+
+    if (name) {
+      for (var i = 0; i < name.length; i++) {
+        if (i > MAX_CHAR) { break }
+        hash += weight * (name.charCodeAt(i) % mod);
+        maxHash += weight * (mod - 1);
+        weight *= 0.70;
+      }
+      if (maxHash > 0) { hash = hash / maxHash; }
+    }
+    return hash
+  }
+
+  function colorHash (name, libtype) {
+    // Return a color for the given name and library type. The library type
+    // selects the hue, and the name is hashed to a color in that hue.
+
+    var r;
+    var g;
+    var b;
+
+    // Select hue. Order is important.
+    var hue;
+    if (typeof libtype === 'undefined' || libtype === '') {
+      // default when libtype is not in use
+      hue = 'warm';
+    } else {
+      hue = 'red';
+      if (name.match(/::/)) {
+        hue = 'yellow';
+      }
+      if (libtype === 'kernel') {
+        hue = 'orange';
+      } else if (libtype === 'jit') {
+        hue = 'green';
+      } else if (libtype === 'inlined') {
+        hue = 'aqua';
+      }
+    }
+
+    // calculate hash
+    var vector = 0;
+    if (name) {
+      var nameArr = name.split('` + "`" + `');
+      if (nameArr.length > 1) {
+        name = nameArr[nameArr.length - 1]; // drop module name if present
+      }
+      name = name.split('(')[0]; // drop extra info
+      vector = generateHash(name);
+    }
+
+    // calculate color
+    if (hue === 'red') {
+      r = 200 + Math.round(55 * vector);
+      g = 50 + Math.round(80 * vector);
+      b = g;
+    } else if (hue === 'orange') {
+      r = 190 + Math.round(65 * vector);
+      g = 90 + Math.round(65 * vector);
+      b = 0;
+    } else if (hue === 'yellow') {
+      r = 175 + Math.round(55 * vector);
+      g = r;
+      b = 50 + Math.round(20 * vector);
+    } else if (hue === 'green') {
+      r = 50 + Math.round(60 * vector);
+      g = 200 + Math.round(55 * vector);
+      b = r;
+    } else if (hue === 'aqua') {
+      r = 50 + Math.round(60 * vector);
+      g = 165 + Math.round(55 * vector);
+      b = g;
+    } else {
+      // original warm palette
+      r = 200 + Math.round(55 * vector);
+      g = 0 + Math.round(230 * (1 - vector));
+      b = 0 + Math.round(55 * (1 - vector));
+    }
+
+    return 'rgb(' + r + ',' + g + ',' + b + ')'
+  }
+
+  function hide (d) {
+    d.data.hide = true;
+    if (children(d)) {
+      children(d).forEach(hide);
+    }
+  }
+
+  function show (d) {
+    d.data.fade = false;
+    d.data.hide = false;
+    if (children(d)) {
+      children(d).forEach(show);
+    }
+  }
+
+  function getSiblings (d) {
+    var siblings = [];
+    if (d.parent) {
+      var me = d.parent.children.indexOf(d);
+      siblings = d.parent.children.slice(0);
+      siblings.splice(me, 1);
+    }
+    return siblings
+  }
+
+  function hideSiblings (d) {
+    var siblings = getSiblings(d);
+    siblings.forEach(function (s) {
+      hide(s);
+    });
+    if (d.parent) {
+      hideSiblings(d.parent);
+    }
+  }
+
+  function fadeAncestors (d) {
+    if (d.parent) {
+      d.parent.data.fade = true;
+      fadeAncestors(d.parent);
+    }
+  }
+
+  // function getRoot (d) {
+  //   if (d.parent) {
+  //     return getRoot(d.parent)
+  //   }
+  //   return d
+  // }
+
+  function zoom (d) {
+    tip.hide(d);
+    hideSiblings(d);
+    show(d);
+    fadeAncestors(d);
+    update();
+    if (typeof clickHandler === 'function') {
+      clickHandler(d);
+    }
+  }
+
+  function searchTree (d, term) {
+    var re = new RegExp(term);
+    var searchResults = [];
+
+    function searchInner (d) {
+      var label = name(d);
+
+      if (children(d)) {
+        children(d).forEach(function (child) {
+          searchInner(child);
+        });
+      }
+
+      if (label.match(re)) {
+        d.highlight = true;
+        searchResults.push(d);
+      } else {
+        d.highlight = false;
+      }
+    }
+
+    searchInner(d);
+    return searchResults
+  }
+
+  function clear (d) {
+    d.highlight = false;
+    if (children(d)) {
+      children(d).forEach(function (child) {
+        clear(child);
+      });
+    }
+  }
+
+  function doSort (a, b) {
+    if (typeof sort === 'function') {
+      return sort(a, b)
+    } else if (sort) {
+      return d3.ascending(name(a), name(b))
+    }
+  }
+
+  var p = d3.partition();
+
+  function filterNodes (root) {
+    var nodeList = root.descendants();
+    if (minFrameSize > 0) {
+      var kx = w / (root.x1 - root.x0);
+      nodeList = nodeList.filter(function (el) {
+        return ((el.x1 - el.x0) * kx) > minFrameSize
+      });
+    }
+    return nodeList
+  }
+
+  function update () {
+    selection.each(function (root) {
+      var x = d3.scaleLinear().range([0, w]);
+      var y = d3.scaleLinear().range([0, c]);
+
+      if (sort) root.sort(doSort);
+      root.sum(function (d) {
+        if (d.fade || d.hide) {
+          return 0
+        }
+        // The node's self value is its total value minus all children.
+        var v = value(d);
+        if (children(d)) {
+          var c = children(d);
+          for (var i = 0; i < c.length; i++) {
+            v -= value(c[i]);
+          }
+        }
+        return v
+      });
+      p(root);
+
+      var kx = w / (root.x1 - root.x0);
+      function width (d) { return (d.x1 - d.x0) * kx }
+
+      var descendants = filterNodes(root);
+      var g = d3.select(this).select('svg').selectAll('g').data(descendants, function (d) { return d.id });
+
+      g.transition()
+        .duration(transitionDuration)
+        .ease(transitionEase)
+        .attr('transform', function (d) { return 'translate(' + x(d.x0) + ',' + (inverted ? y(d.depth) : (h - y(d.depth) - c)) + ')' });
+
+      g.select('rect')
+        .attr('width', width);
+
+      var node = g.enter()
+        .append('svg:g')
+        .attr('transform', function (d) { return 'translate(' + x(d.x0) + ',' + (inverted ? y(d.depth) : (h - y(d.depth) - c)) + ')' });
+
+      node.append('svg:rect')
+        .transition()
+        .delay(transitionDuration / 2)
+        .attr('width', width);
+
+      if (!tooltip) { node.append('svg:title'); }
+
+      node.append('foreignObject')
+        .append('xhtml:div');
+
+      // Now we have to re-select to see the new elements (why?).
+      g = d3.select(this).select('svg').selectAll('g').data(descendants, function (d) { return d.id });
+
+      g.attr('width', width)
+        .attr('height', function (d) { return c })
+        .attr('name', function (d) { return name(d) })
+        .attr('class', function (d) { return d.data.fade ? 'frame fade' : 'frame' });
+
+      g.select('rect')
+        .attr('height', function (d) { return c })
+        .attr('fill', function (d) { return colorMapper(d) });
+
+      if (!tooltip) {
+        g.select('title')
+          .text(label);
+      }
+
+      g.select('foreignObject')
+        .attr('width', width)
+        .attr('height', function (d) { return c })
+        .select('div')
+        .attr('class', 'd3-flame-graph-label')
+        .style('display', function (d) { return (width(d) < 35) ? 'none' : 'block' })
+        .transition()
+        .delay(transitionDuration)
+        .text(name);
+
+      g.on('click', zoom);
+
+      g.exit()
+        .remove();
+
+      g.on('mouseover', function (d) {
+        if (tooltip) tip.show(d, this);
+        setDetails(label(d));
+      }).on('mouseout', function (d) {
+        if (tooltip) tip.hide(d);
+        setDetails('');
+      });
+    });
+  }
+
+  function merge (data, samples) {
+    samples.forEach(function (sample) {
+      var node = data.find(function (element) {
+        return (element.name === sample.name)
+      });
+
+      if (node) {
+        if (node.original) {
+          node.original += sample.value;
+        } else {
+          node.value += sample.value;
+        }
+        if (sample.children) {
+          if (!node.children) {
+            node.children = [];
+          }
+          merge(node.children, sample.children);
+        }
+      } else {
+        data.push(sample);
+      }
+    });
+  }
+
+  function s4 () {
+    return Math.floor((1 + Math.random()) * 0x10000)
+      .toString(16)
+      .substring(1)
+  }
+
+  function injectIds (node) {
+    node.id = s4() + '-' + s4() + '-' + '-' + s4() + '-' + s4();
+    var children = node.c || node.children || [];
+    for (var i = 0; i < children.length; i++) {
+      injectIds(children[i]);
+    }
+  }
+
+  function chart (s) {
+    var root = d3.hierarchy(
+      s.datum(), function (d) { return children(d) }
+    );
+    injectIds(root);
+    selection = s.datum(root);
+
+    if (!arguments.length) return chart
+
+    if (!h) {
+      h = (root.height + 2) * c;
+    }
+
+    selection.each(function (data) {
+      if (!svg) {
+        svg = d3.select(this)
+          .append('svg:svg')
+          .attr('width', w)
+          .attr('height', h)
+          .attr('class', 'partition d3-flame-graph')
+          .call(tip);
+
+        svg.append('svg:text')
+          .attr('class', 'title')
+          .attr('text-anchor', 'middle')
+          .attr('y', '25')
+          .attr('x', w / 2)
+          .attr('fill', '#808080')
+          .text(title);
+      }
+    });
+
+    // first draw
+    update();
+  }
+
+  chart.height = function (_) {
+    if (!arguments.length) { return h }
+    h = _;
+    return chart
+  };
+
+  chart.width = function (_) {
+    if (!arguments.length) { return w }
+    w = _;
+    return chart
+  };
+
+  chart.cellHeight = function (_) {
+    if (!arguments.length) { return c }
+    c = _;
+    return chart
+  };
+
+  chart.tooltip = function (_) {
+    if (!arguments.length) { return tooltip }
+    if (typeof _ === 'function') {
+      tip = _;
+    }
+    tooltip = !!_;
+    return chart
+  };
+
+  chart.title = function (_) {
+    if (!arguments.length) { return title }
+    title = _;
+    return chart
+  };
+
+  chart.transitionDuration = function (_) {
+    if (!arguments.length) { return transitionDuration }
+    transitionDuration = _;
+    return chart
+  };
+
+  chart.transitionEase = function (_) {
+    if (!arguments.length) { return transitionEase }
+    transitionEase = _;
+    return chart
+  };
+
+  chart.sort = function (_) {
+    if (!arguments.length) { return sort }
+    sort = _;
+    return chart
+  };
+
+  chart.inverted = function (_) {
+    if (!arguments.length) { return inverted }
+    inverted = _;
+    return chart
+  };
+
+  chart.label = function (_) {
+    if (!arguments.length) { return label }
+    label = _;
+    return chart
+  };
+
+  chart.search = function (term) {
+    var searchResults = [];
+    selection.each(function (data) {
+      searchResults = searchTree(data, term);
+      update();
+    });
+    return searchResults
+  };
+
+  chart.clear = function () {
+    selection.each(function (data) {
+      clear(data);
+      update();
+    });
+  };
+
+  chart.zoomTo = function (d) {
+    zoom(d);
+  };
+
+  chart.resetZoom = function () {
+    selection.each(function (data) {
+      zoom(data); // zoom to root
+    });
+  };
+
+  chart.onClick = function (_) {
+    if (!arguments.length) {
+      return clickHandler
+    }
+    clickHandler = _;
+    return chart
+  };
+
+  chart.merge = function (samples) {
+    var newRoot; // Need to re-create hierarchy after data changes.
+    selection.each(function (root) {
+      merge([root.data], [samples]);
+      newRoot = d3.hierarchy(root.data, function (d) { return children(d) });
+      injectIds(newRoot);
+    });
+    selection = selection.datum(newRoot);
+    update();
+  };
+
+  chart.color = function (_) {
+    if (!arguments.length) { return colorMapper }
+    colorMapper = _;
+    return chart
+  };
+
+  chart.minFrameSize = function (_) {
+    if (!arguments.length) { return minFrameSize }
+    minFrameSize = _;
+    return chart
+  };
+
+  chart.details = function (_) {
+    if (!arguments.length) { return details }
+    details = _;
+    return chart
+  };
+
+  return chart
+};
+
+exports.flamegraph = flamegraph;
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+})));
+`
+
+// CSSSource returns the d3-flamegraph.css file
+const CSSSource = `
+.d3-flame-graph rect {
+  stroke: #EEEEEE;
+  fill-opacity: .8;
+}
+
+.d3-flame-graph rect:hover {
+  stroke: #474747;
+  stroke-width: 0.5;
+  cursor: pointer;
+}
+
+.d3-flame-graph-label {
+  pointer-events: none;
+  white-space: nowrap;
+  text-overflow: ellipsis;
+  overflow: hidden;
+  font-size: 12px;
+  font-family: Verdana;
+  margin-left: 4px;
+  margin-right: 4px;
+  line-height: 1.5;
+  padding: 0 0 0;
+  font-weight: 400;
+  color: black;
+  text-align: left;
+}
+
+.d3-flame-graph .fade {
+  opacity: 0.6 !important;
+}
+
+.d3-flame-graph .title {
+  font-size: 20px;
+  font-family: Verdana;
+}
+
+.d3-flame-graph-tip {
+  line-height: 1;
+  font-family: Verdana;
+  font-size: 12px;
+  padding: 12px;
+  background: rgba(0, 0, 0, 0.8);
+  color: #fff;
+  border-radius: 2px;
+  pointer-events: none;
+}
+
+/* Creates a small triangle extender for the tooltip */
+.d3-flame-graph-tip:after {
+  box-sizing: border-box;
+  display: inline;
+  font-size: 10px;
+  width: 100%;
+  line-height: 1;
+  color: rgba(0, 0, 0, 0.8);
+  position: absolute;
+  pointer-events: none;
+}
+
+/* Northward tooltips */
+.d3-flame-graph-tip.n:after {
+  content: "\25BC";
+  margin: -1px 0 0 0;
+  top: 100%;
+  left: 0;
+  text-align: center;
+}
+
+/* Eastward tooltips */
+.d3-flame-graph-tip.e:after {
+  content: "\25C0";
+  margin: -4px 0 0 0;
+  top: 50%;
+  left: -8px;
+}
+
+/* Southward tooltips */
+.d3-flame-graph-tip.s:after {
+  content: "\25B2";
+  margin: 0 0 1px 0;
+  top: -8px;
+  left: 0;
+  text-align: center;
+}
+
+/* Westward tooltips */
+.d3-flame-graph-tip.w:after {
+  content: "\25B6";
+  margin: -4px 0 0 -1px;
+  top: 50%;
+  left: 100%;
+}
+`
diff --git a/src/cmd/vendor/github.com/google/pprof/third_party/svgpan/LICENSE b/src/cmd/vendor/github.com/google/pprof/third_party/svgpan/LICENSE
new file mode 100644
index 0000000..35bc174
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/third_party/svgpan/LICENSE
@@ -0,0 +1,27 @@
+Copyright 2009-2017 Andrea Leofreddi <a.leofreddi@vleo.net>. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification, are
+permitted provided that the following conditions are met:
+
+   1. Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+   2. Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+   3. Neither the name of the copyright holder nor the names of its
+      contributors may be used to endorse or promote products derived from
+      this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS
+OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS OR
+CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+The views and conclusions contained in the software and documentation are those of the
+authors and should not be interpreted as representing official policies, either expressed
+or implied, of Andrea Leofreddi.
diff --git a/src/cmd/vendor/github.com/google/pprof/third_party/svgpan/svgpan.go b/src/cmd/vendor/github.com/google/pprof/third_party/svgpan/svgpan.go
new file mode 100644
index 0000000..6ca08ad
--- /dev/null
+++ b/src/cmd/vendor/github.com/google/pprof/third_party/svgpan/svgpan.go
@@ -0,0 +1,297 @@
+// SVG pan and zoom library.
+// See copyright notice in string constant below.
+
+package svgpan
+
+// https://github.com/aleofreddi/svgpan
+
+// JSSource returns the svgpan.js file
+const JSSource = `
+/**
+ *  SVGPan library 1.2.2
+ * ======================
+ *
+ * Given an unique existing element with id "viewport" (or when missing, the
+ * first g-element), including the library into any SVG adds the following
+ * capabilities:
+ *
+ *  - Mouse panning
+ *  - Mouse zooming (using the wheel)
+ *  - Object dragging
+ *
+ * You can configure the behaviour of the pan/zoom/drag with the variables
+ * listed in the CONFIGURATION section of this file.
+ *
+ * Known issues:
+ *
+ *  - Zooming (while panning) on Safari has still some issues
+ *
+ * Releases:
+ *
+ * 1.2.2, Tue Aug 30 17:21:56 CEST 2011, Andrea Leofreddi
+ *	- Fixed viewBox on root tag (#7)
+ *	- Improved zoom speed (#2)
+ *
+ * 1.2.1, Mon Jul  4 00:33:18 CEST 2011, Andrea Leofreddi
+ *	- Fixed a regression with mouse wheel (now working on Firefox 5)
+ *	- Working with viewBox attribute (#4)
+ *	- Added "use strict;" and fixed resulting warnings (#5)
+ *	- Added configuration variables, dragging is disabled by default (#3)
+ *
+ * 1.2, Sat Mar 20 08:42:50 GMT 2010, Zeng Xiaohui
+ *	Fixed a bug with browser mouse handler interaction
+ *
+ * 1.1, Wed Feb  3 17:39:33 GMT 2010, Zeng Xiaohui
+ *	Updated the zoom code to support the mouse wheel on Safari/Chrome
+ *
+ * 1.0, Andrea Leofreddi
+ *	First release
+ *
+ * This code is licensed under the following BSD license:
+ *
+ * Copyright 2009-2017 Andrea Leofreddi <a.leofreddi@vleo.net>. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *    2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *    3. Neither the name of the copyright holder nor the names of its
+ *       contributors may be used to endorse or promote products derived from
+ *       this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY COPYRIGHT HOLDERS AND CONTRIBUTORS ''AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of Andrea Leofreddi.
+ */
+
+"use strict";
+
+/// CONFIGURATION
+/// ====>
+
+var enablePan = 1; // 1 or 0: enable or disable panning (default enabled)
+var enableZoom = 1; // 1 or 0: enable or disable zooming (default enabled)
+var enableDrag = 0; // 1 or 0: enable or disable dragging (default disabled)
+var zoomScale = 0.2; // Zoom sensitivity
+
+/// <====
+/// END OF CONFIGURATION
+
+var root = document.documentElement;
+
+var state = 'none', svgRoot = null, stateTarget, stateOrigin, stateTf;
+
+setupHandlers(root);
+
+/**
+ * Register handlers
+ */
+function setupHandlers(root){
+	setAttributes(root, {
+		"onmouseup" : "handleMouseUp(evt)",
+		"onmousedown" : "handleMouseDown(evt)",
+		"onmousemove" : "handleMouseMove(evt)",
+		//"onmouseout" : "handleMouseUp(evt)", // Decomment this to stop the pan functionality when dragging out of the SVG element
+	});
+
+	if(navigator.userAgent.toLowerCase().indexOf('webkit') >= 0)
+		window.addEventListener('mousewheel', handleMouseWheel, false); // Chrome/Safari
+	else
+		window.addEventListener('DOMMouseScroll', handleMouseWheel, false); // Others
+}
+
+/**
+ * Retrieves the root element for SVG manipulation. The element is then cached into the svgRoot global variable.
+ */
+function getRoot(root) {
+	if(svgRoot == null) {
+		var r = root.getElementById("viewport") ? root.getElementById("viewport") : root.documentElement, t = r;
+
+		while(t != root) {
+			if(t.getAttribute("viewBox")) {
+				setCTM(r, t.getCTM());
+
+				t.removeAttribute("viewBox");
+			}
+
+			t = t.parentNode;
+		}
+
+		svgRoot = r;
+	}
+
+	return svgRoot;
+}
+
+/**
+ * Instance an SVGPoint object with given event coordinates.
+ */
+function getEventPoint(evt) {
+	var p = root.createSVGPoint();
+
+	p.x = evt.clientX;
+	p.y = evt.clientY;
+
+	return p;
+}
+
+/**
+ * Sets the current transform matrix of an element.
+ */
+function setCTM(element, matrix) {
+	var s = "matrix(" + matrix.a + "," + matrix.b + "," + matrix.c + "," + matrix.d + "," + matrix.e + "," + matrix.f + ")";
+
+	element.setAttribute("transform", s);
+}
+
+/**
+ * Dumps a matrix to a string (useful for debug).
+ */
+function dumpMatrix(matrix) {
+	var s = "[ " + matrix.a + ", " + matrix.c + ", " + matrix.e + "\n  " + matrix.b + ", " + matrix.d + ", " + matrix.f + "\n  0, 0, 1 ]";
+
+	return s;
+}
+
+/**
+ * Sets attributes of an element.
+ */
+function setAttributes(element, attributes){
+	for (var i in attributes)
+		element.setAttributeNS(null, i, attributes[i]);
+}
+
+/**
+ * Handle mouse wheel event.
+ */
+function handleMouseWheel(evt) {
+	if(!enableZoom)
+		return;
+
+	if(evt.preventDefault)
+		evt.preventDefault();
+
+	evt.returnValue = false;
+
+	var svgDoc = evt.target.ownerDocument;
+
+	var delta;
+
+	if(evt.wheelDelta)
+		delta = evt.wheelDelta / 360; // Chrome/Safari
+	else
+		delta = evt.detail / -9; // Mozilla
+
+	var z = Math.pow(1 + zoomScale, delta);
+
+	var g = getRoot(svgDoc);
+	
+	var p = getEventPoint(evt);
+
+	p = p.matrixTransform(g.getCTM().inverse());
+
+	// Compute new scale matrix in current mouse position
+	var k = root.createSVGMatrix().translate(p.x, p.y).scale(z).translate(-p.x, -p.y);
+
+        setCTM(g, g.getCTM().multiply(k));
+
+	if(typeof(stateTf) == "undefined")
+		stateTf = g.getCTM().inverse();
+
+	stateTf = stateTf.multiply(k.inverse());
+}
+
+/**
+ * Handle mouse move event.
+ */
+function handleMouseMove(evt) {
+	if(evt.preventDefault)
+		evt.preventDefault();
+
+	evt.returnValue = false;
+
+	var svgDoc = evt.target.ownerDocument;
+
+	var g = getRoot(svgDoc);
+
+	if(state == 'pan' && enablePan) {
+		// Pan mode
+		var p = getEventPoint(evt).matrixTransform(stateTf);
+
+		setCTM(g, stateTf.inverse().translate(p.x - stateOrigin.x, p.y - stateOrigin.y));
+	} else if(state == 'drag' && enableDrag) {
+		// Drag mode
+		var p = getEventPoint(evt).matrixTransform(g.getCTM().inverse());
+
+		setCTM(stateTarget, root.createSVGMatrix().translate(p.x - stateOrigin.x, p.y - stateOrigin.y).multiply(g.getCTM().inverse()).multiply(stateTarget.getCTM()));
+
+		stateOrigin = p;
+	}
+}
+
+/**
+ * Handle click event.
+ */
+function handleMouseDown(evt) {
+	if(evt.preventDefault)
+		evt.preventDefault();
+
+	evt.returnValue = false;
+
+	var svgDoc = evt.target.ownerDocument;
+
+	var g = getRoot(svgDoc);
+
+	if(
+		evt.target.tagName == "svg"
+		|| !enableDrag // Pan anyway when drag is disabled and the user clicked on an element
+	) {
+		// Pan mode
+		state = 'pan';
+
+		stateTf = g.getCTM().inverse();
+
+		stateOrigin = getEventPoint(evt).matrixTransform(stateTf);
+	} else {
+		// Drag mode
+		state = 'drag';
+
+		stateTarget = evt.target;
+
+		stateTf = g.getCTM().inverse();
+
+		stateOrigin = getEventPoint(evt).matrixTransform(stateTf);
+	}
+}
+
+/**
+ * Handle mouse button release event.
+ */
+function handleMouseUp(evt) {
+	if(evt.preventDefault)
+		evt.preventDefault();
+
+	evt.returnValue = false;
+
+	var svgDoc = evt.target.ownerDocument;
+
+	if(state == 'pan' || state == 'drag') {
+		// Quit pan mode
+		state = '';
+	}
+}
+`
diff --git a/src/cmd/vendor/github.com/ianlancetaylor/demangle/.gitignore b/src/cmd/vendor/github.com/ianlancetaylor/demangle/.gitignore
new file mode 100644
index 0000000..4a8b38f
--- /dev/null
+++ b/src/cmd/vendor/github.com/ianlancetaylor/demangle/.gitignore
@@ -0,0 +1,13 @@
+*.o
+*.a
+*.so
+._*
+.nfs.*
+a.out
+*~
+*.orig
+*.rej
+*.exe
+.*.swp
+core
+demangle.test
diff --git a/src/cmd/vendor/github.com/ianlancetaylor/demangle/LICENSE b/src/cmd/vendor/github.com/ianlancetaylor/demangle/LICENSE
new file mode 100644
index 0000000..d29b372
--- /dev/null
+++ b/src/cmd/vendor/github.com/ianlancetaylor/demangle/LICENSE
@@ -0,0 +1,27 @@
+Copyright (c) 2015 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/src/cmd/vendor/github.com/ianlancetaylor/demangle/README.md b/src/cmd/vendor/github.com/ianlancetaylor/demangle/README.md
new file mode 100644
index 0000000..ef3f94a
--- /dev/null
+++ b/src/cmd/vendor/github.com/ianlancetaylor/demangle/README.md
@@ -0,0 +1,3 @@
+# github.com/ianlancetaylor/demangle
+
+A Go package that can be used to demangle C++ symbol names.
diff --git a/src/cmd/vendor/github.com/ianlancetaylor/demangle/ast.go b/src/cmd/vendor/github.com/ianlancetaylor/demangle/ast.go
new file mode 100644
index 0000000..ccbe5b3
--- /dev/null
+++ b/src/cmd/vendor/github.com/ianlancetaylor/demangle/ast.go
@@ -0,0 +1,3205 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package demangle
+
+import (
+	"fmt"
+	"strings"
+)
+
+// AST is an abstract syntax tree representing a C++ declaration.
+// This is sufficient for the demangler but is by no means a general C++ AST.
+type AST interface {
+	// Internal method to convert to demangled string.
+	print(*printState)
+
+	// Traverse each element of an AST.  If the function returns
+	// false, traversal of children of that element is skipped.
+	Traverse(func(AST) bool)
+
+	// Copy an AST with possible transformations.
+	// If the skip function returns true, no copy is required.
+	// If the copy function returns nil, no copy is required.
+	// The Copy method will do the right thing if copy returns nil
+	// for some components of an AST but not others, so a good
+	// copy function will only return non-nil for AST values that
+	// need to change.
+	// Copy itself returns either a copy or nil.
+	Copy(copy func(AST) AST, skip func(AST) bool) AST
+
+	// Implement the fmt.GoStringer interface.
+	GoString() string
+	goString(indent int, field string) string
+}
+
+// ASTToString returns the demangled name of the AST.
+func ASTToString(a AST, options ...Option) string {
+	tparams := true
+	for _, o := range options {
+		switch o {
+		case NoTemplateParams:
+			tparams = false
+		}
+	}
+
+	ps := printState{tparams: tparams}
+	a.print(&ps)
+	return ps.buf.String()
+}
+
+// The printState type holds information needed to print an AST.
+type printState struct {
+	tparams bool // whether to print template parameters
+
+	buf  strings.Builder
+	last byte // Last byte written to buffer.
+
+	// The inner field is a list of items to print for a type
+	// name.  This is used by types to implement the inside-out
+	// C++ declaration syntax.
+	inner []AST
+
+	// The printing field is a list of items we are currently
+	// printing.  This avoids endless recursion if a substitution
+	// reference creates a cycle in the graph.
+	printing []AST
+}
+
+// writeByte adds a byte to the string being printed.
+func (ps *printState) writeByte(b byte) {
+	ps.last = b
+	ps.buf.WriteByte(b)
+}
+
+// writeString adds a string to the string being printed.
+func (ps *printState) writeString(s string) {
+	if len(s) > 0 {
+		ps.last = s[len(s)-1]
+	}
+	ps.buf.WriteString(s)
+}
+
+// Print an AST.
+func (ps *printState) print(a AST) {
+	c := 0
+	for _, v := range ps.printing {
+		if v == a {
+			// We permit the type to appear once, and
+			// return without printing anything if we see
+			// it twice.  This is for a case like
+			// _Z6outer2IsEPFilES1_, where the
+			// substitution is printed differently the
+			// second time because the set of inner types
+			// is different.
+			c++
+			if c > 1 {
+				return
+			}
+		}
+	}
+	ps.printing = append(ps.printing, a)
+
+	a.print(ps)
+
+	ps.printing = ps.printing[:len(ps.printing)-1]
+}
+
+// Name is an unqualified name.
+type Name struct {
+	Name string
+}
+
+func (n *Name) print(ps *printState) {
+	ps.writeString(n.Name)
+}
+
+func (n *Name) Traverse(fn func(AST) bool) {
+	fn(n)
+}
+
+func (n *Name) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(n) {
+		return nil
+	}
+	return fn(n)
+}
+
+func (n *Name) GoString() string {
+	return n.goString(0, "Name: ")
+}
+
+func (n *Name) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%s%s", indent, "", field, n.Name)
+}
+
+// Typed is a typed name.
+type Typed struct {
+	Name AST
+	Type AST
+}
+
+func (t *Typed) print(ps *printState) {
+	// We are printing a typed name, so ignore the current set of
+	// inner names to print.  Pass down our name as the one to use.
+	holdInner := ps.inner
+	defer func() { ps.inner = holdInner }()
+
+	ps.inner = []AST{t}
+	ps.print(t.Type)
+	if len(ps.inner) > 0 {
+		// The type did not print the name; print it now in
+		// the default location.
+		ps.writeByte(' ')
+		ps.print(t.Name)
+	}
+}
+
+func (t *Typed) printInner(ps *printState) {
+	ps.print(t.Name)
+}
+
+func (t *Typed) Traverse(fn func(AST) bool) {
+	if fn(t) {
+		t.Name.Traverse(fn)
+		t.Type.Traverse(fn)
+	}
+}
+
+func (t *Typed) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(t) {
+		return nil
+	}
+	name := t.Name.Copy(fn, skip)
+	typ := t.Type.Copy(fn, skip)
+	if name == nil && typ == nil {
+		return fn(t)
+	}
+	if name == nil {
+		name = t.Name
+	}
+	if typ == nil {
+		typ = t.Type
+	}
+	t = &Typed{Name: name, Type: typ}
+	if r := fn(t); r != nil {
+		return r
+	}
+	return t
+}
+
+func (t *Typed) GoString() string {
+	return t.goString(0, "")
+}
+
+func (t *Typed) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sTyped:\n%s\n%s", indent, "", field,
+		t.Name.goString(indent+2, "Name: "),
+		t.Type.goString(indent+2, "Type: "))
+}
+
+// Qualified is a name in a scope.
+type Qualified struct {
+	Scope AST
+	Name  AST
+
+	// The LocalName field is true if this is parsed as a
+	// <local-name>.  We shouldn't really need this, but in some
+	// cases (for the unary sizeof operator) the standard
+	// demangler prints a local name slightly differently.  We
+	// keep track of this for compatibility.
+	LocalName bool // A full local name encoding
+}
+
+func (q *Qualified) print(ps *printState) {
+	ps.print(q.Scope)
+	ps.writeString("::")
+	ps.print(q.Name)
+}
+
+func (q *Qualified) Traverse(fn func(AST) bool) {
+	if fn(q) {
+		q.Scope.Traverse(fn)
+		q.Name.Traverse(fn)
+	}
+}
+
+func (q *Qualified) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(q) {
+		return nil
+	}
+	scope := q.Scope.Copy(fn, skip)
+	name := q.Name.Copy(fn, skip)
+	if scope == nil && name == nil {
+		return fn(q)
+	}
+	if scope == nil {
+		scope = q.Scope
+	}
+	if name == nil {
+		name = q.Name
+	}
+	q = &Qualified{Scope: scope, Name: name, LocalName: q.LocalName}
+	if r := fn(q); r != nil {
+		return r
+	}
+	return q
+}
+
+func (q *Qualified) GoString() string {
+	return q.goString(0, "")
+}
+
+func (q *Qualified) goString(indent int, field string) string {
+	s := ""
+	if q.LocalName {
+		s = " LocalName: true"
+	}
+	return fmt.Sprintf("%*s%sQualified:%s\n%s\n%s", indent, "", field,
+		s, q.Scope.goString(indent+2, "Scope: "),
+		q.Name.goString(indent+2, "Name: "))
+}
+
+// Template is a template with arguments.
+type Template struct {
+	Name AST
+	Args []AST
+}
+
+func (t *Template) print(ps *printState) {
+	// Inner types apply to the template as a whole, they don't
+	// cross over into the template.
+	holdInner := ps.inner
+	defer func() { ps.inner = holdInner }()
+
+	ps.inner = nil
+	ps.print(t.Name)
+
+	if !ps.tparams {
+		// Do not print template parameters.
+		return
+	}
+	// We need an extra space after operator<.
+	if ps.last == '<' {
+		ps.writeByte(' ')
+	}
+
+	ps.writeByte('<')
+	first := true
+	for _, a := range t.Args {
+		if ps.isEmpty(a) {
+			continue
+		}
+		if !first {
+			ps.writeString(", ")
+		}
+		ps.print(a)
+		first = false
+	}
+	if ps.last == '>' {
+		// Avoid syntactic ambiguity in old versions of C++.
+		ps.writeByte(' ')
+	}
+	ps.writeByte('>')
+}
+
+func (t *Template) Traverse(fn func(AST) bool) {
+	if fn(t) {
+		t.Name.Traverse(fn)
+		for _, a := range t.Args {
+			a.Traverse(fn)
+		}
+	}
+}
+
+func (t *Template) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(t) {
+		return nil
+	}
+	name := t.Name.Copy(fn, skip)
+	changed := name != nil
+	args := make([]AST, len(t.Args))
+	for i, a := range t.Args {
+		ac := a.Copy(fn, skip)
+		if ac == nil {
+			args[i] = a
+		} else {
+			args[i] = ac
+			changed = true
+		}
+	}
+	if !changed {
+		return fn(t)
+	}
+	if name == nil {
+		name = t.Name
+	}
+	t = &Template{Name: name, Args: args}
+	if r := fn(t); r != nil {
+		return r
+	}
+	return t
+}
+
+func (t *Template) GoString() string {
+	return t.goString(0, "")
+}
+
+func (t *Template) goString(indent int, field string) string {
+	var args string
+	if len(t.Args) == 0 {
+		args = fmt.Sprintf("%*sArgs: nil", indent+2, "")
+	} else {
+		args = fmt.Sprintf("%*sArgs:", indent+2, "")
+		for i, a := range t.Args {
+			args += "\n"
+			args += a.goString(indent+4, fmt.Sprintf("%d: ", i))
+		}
+	}
+	return fmt.Sprintf("%*s%sTemplate (%p):\n%s\n%s", indent, "", field, t,
+		t.Name.goString(indent+2, "Name: "), args)
+}
+
+// TemplateParam is a template parameter.  The Template field is
+// filled in while parsing the demangled string.  We don't normally
+// see these while printing--they are replaced by the simplify
+// function.
+type TemplateParam struct {
+	Index    int
+	Template *Template
+}
+
+func (tp *TemplateParam) print(ps *printState) {
+	if tp.Template == nil {
+		panic("TemplateParam Template field is nil")
+	}
+	if tp.Index >= len(tp.Template.Args) {
+		panic("TemplateParam Index out of bounds")
+	}
+	ps.print(tp.Template.Args[tp.Index])
+}
+
+func (tp *TemplateParam) Traverse(fn func(AST) bool) {
+	fn(tp)
+	// Don't traverse Template--it points elsewhere in the AST.
+}
+
+func (tp *TemplateParam) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(tp) {
+		return nil
+	}
+	return fn(tp)
+}
+
+func (tp *TemplateParam) GoString() string {
+	return tp.goString(0, "")
+}
+
+func (tp *TemplateParam) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sTemplateParam: Template: %p; Index %d", indent, "", field, tp.Template, tp.Index)
+}
+
+// LambdaAuto is a lambda auto parameter.
+type LambdaAuto struct {
+	Index int
+}
+
+func (la *LambdaAuto) print(ps *printState) {
+	// We print the index plus 1 because that is what the standard
+	// demangler does.
+	fmt.Fprintf(&ps.buf, "auto:%d", la.Index+1)
+}
+
+func (la *LambdaAuto) Traverse(fn func(AST) bool) {
+	fn(la)
+}
+
+func (la *LambdaAuto) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(la) {
+		return nil
+	}
+	return fn(la)
+}
+
+func (la *LambdaAuto) GoString() string {
+	return la.goString(0, "")
+}
+
+func (la *LambdaAuto) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sLambdaAuto: Index %d", indent, "", field, la.Index)
+}
+
+// Qualifiers is an ordered list of type qualifiers.
+type Qualifiers struct {
+	Qualifiers []AST
+}
+
+func (qs *Qualifiers) print(ps *printState) {
+	first := true
+	for _, q := range qs.Qualifiers {
+		if !first {
+			ps.writeByte(' ')
+		}
+		q.print(ps)
+		first = false
+	}
+}
+
+func (qs *Qualifiers) Traverse(fn func(AST) bool) {
+	if fn(qs) {
+		for _, q := range qs.Qualifiers {
+			q.Traverse(fn)
+		}
+	}
+}
+
+func (qs *Qualifiers) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(qs) {
+		return nil
+	}
+	changed := false
+	qualifiers := make([]AST, len(qs.Qualifiers))
+	for i, q := range qs.Qualifiers {
+		qc := q.Copy(fn, skip)
+		if qc == nil {
+			qualifiers[i] = q
+		} else {
+			qualifiers[i] = qc
+			changed = true
+		}
+	}
+	if !changed {
+		return fn(qs)
+	}
+	qs = &Qualifiers{Qualifiers: qualifiers}
+	if r := fn(qs); r != nil {
+		return r
+	}
+	return qs
+}
+
+func (qs *Qualifiers) GoString() string {
+	return qs.goString(0, "")
+}
+
+func (qs *Qualifiers) goString(indent int, field string) string {
+	quals := fmt.Sprintf("%*s%s", indent, "", field)
+	for _, q := range qs.Qualifiers {
+		quals += "\n"
+		quals += q.goString(indent+2, "")
+	}
+	return quals
+}
+
+// Qualifier is a single type qualifier.
+type Qualifier struct {
+	Name  string // qualifier name: const, volatile, etc.
+	Exprs []AST  // can be non-nil for noexcept and throw
+}
+
+func (q *Qualifier) print(ps *printState) {
+	ps.writeString(q.Name)
+	if len(q.Exprs) > 0 {
+		ps.writeByte('(')
+		first := true
+		for _, e := range q.Exprs {
+			if !first {
+				ps.writeString(", ")
+			}
+			ps.print(e)
+			first = false
+		}
+		ps.writeByte(')')
+	}
+}
+
+func (q *Qualifier) Traverse(fn func(AST) bool) {
+	if fn(q) {
+		for _, e := range q.Exprs {
+			e.Traverse(fn)
+		}
+	}
+}
+
+func (q *Qualifier) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(q) {
+		return nil
+	}
+	exprs := make([]AST, len(q.Exprs))
+	changed := false
+	for i, e := range q.Exprs {
+		ec := e.Copy(fn, skip)
+		if ec == nil {
+			exprs[i] = e
+		} else {
+			exprs[i] = ec
+			changed = true
+		}
+	}
+	if !changed {
+		return fn(q)
+	}
+	q = &Qualifier{Name: q.Name, Exprs: exprs}
+	if r := fn(q); r != nil {
+		return r
+	}
+	return q
+}
+
+func (q *Qualifier) GoString() string {
+	return q.goString(0, "Qualifier: ")
+}
+
+func (q *Qualifier) goString(indent int, field string) string {
+	qs := fmt.Sprintf("%*s%s%s", indent, "", field, q.Name)
+	if len(q.Exprs) > 0 {
+		for i, e := range q.Exprs {
+			qs += "\n"
+			qs += e.goString(indent+2, fmt.Sprintf("%d: ", i))
+		}
+	}
+	return qs
+}
+
+// TypeWithQualifiers is a type with standard qualifiers.
+type TypeWithQualifiers struct {
+	Base       AST
+	Qualifiers AST
+}
+
+func (twq *TypeWithQualifiers) print(ps *printState) {
+	// Give the base type a chance to print the inner types.
+	ps.inner = append(ps.inner, twq)
+	ps.print(twq.Base)
+	if len(ps.inner) > 0 {
+		// The qualifier wasn't printed by Base.
+		ps.writeByte(' ')
+		ps.print(twq.Qualifiers)
+		ps.inner = ps.inner[:len(ps.inner)-1]
+	}
+}
+
+// Print qualifiers as an inner type by just printing the qualifiers.
+func (twq *TypeWithQualifiers) printInner(ps *printState) {
+	ps.writeByte(' ')
+	ps.print(twq.Qualifiers)
+}
+
+func (twq *TypeWithQualifiers) Traverse(fn func(AST) bool) {
+	if fn(twq) {
+		twq.Base.Traverse(fn)
+	}
+}
+
+func (twq *TypeWithQualifiers) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(twq) {
+		return nil
+	}
+	base := twq.Base.Copy(fn, skip)
+	quals := twq.Qualifiers.Copy(fn, skip)
+	if base == nil && quals == nil {
+		return fn(twq)
+	}
+	if base == nil {
+		base = twq.Base
+	}
+	if quals == nil {
+		quals = twq.Qualifiers
+	}
+	twq = &TypeWithQualifiers{Base: base, Qualifiers: quals}
+	if r := fn(twq); r != nil {
+		return r
+	}
+	return twq
+}
+
+func (twq *TypeWithQualifiers) GoString() string {
+	return twq.goString(0, "")
+}
+
+func (twq *TypeWithQualifiers) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sTypeWithQualifiers:\n%s\n%s", indent, "", field,
+		twq.Qualifiers.goString(indent+2, "Qualifiers: "),
+		twq.Base.goString(indent+2, "Base: "))
+}
+
+// MethodWithQualifiers is a method with qualifiers.
+type MethodWithQualifiers struct {
+	Method       AST
+	Qualifiers   AST
+	RefQualifier string // "" or "&" or "&&"
+}
+
+func (mwq *MethodWithQualifiers) print(ps *printState) {
+	// Give the base type a chance to print the inner types.
+	ps.inner = append(ps.inner, mwq)
+	ps.print(mwq.Method)
+	if len(ps.inner) > 0 {
+		if mwq.Qualifiers != nil {
+			ps.writeByte(' ')
+			ps.print(mwq.Qualifiers)
+		}
+		if mwq.RefQualifier != "" {
+			ps.writeByte(' ')
+			ps.writeString(mwq.RefQualifier)
+		}
+		ps.inner = ps.inner[:len(ps.inner)-1]
+	}
+}
+
+func (mwq *MethodWithQualifiers) printInner(ps *printState) {
+	if mwq.Qualifiers != nil {
+		ps.writeByte(' ')
+		ps.print(mwq.Qualifiers)
+	}
+	if mwq.RefQualifier != "" {
+		ps.writeByte(' ')
+		ps.writeString(mwq.RefQualifier)
+	}
+}
+
+func (mwq *MethodWithQualifiers) Traverse(fn func(AST) bool) {
+	if fn(mwq) {
+		mwq.Method.Traverse(fn)
+	}
+}
+
+func (mwq *MethodWithQualifiers) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(mwq) {
+		return nil
+	}
+	method := mwq.Method.Copy(fn, skip)
+	var quals AST
+	if mwq.Qualifiers != nil {
+		quals = mwq.Qualifiers.Copy(fn, skip)
+	}
+	if method == nil && quals == nil {
+		return fn(mwq)
+	}
+	if method == nil {
+		method = mwq.Method
+	}
+	if quals == nil {
+		quals = mwq.Qualifiers
+	}
+	mwq = &MethodWithQualifiers{Method: method, Qualifiers: quals, RefQualifier: mwq.RefQualifier}
+	if r := fn(mwq); r != nil {
+		return r
+	}
+	return mwq
+}
+
+func (mwq *MethodWithQualifiers) GoString() string {
+	return mwq.goString(0, "")
+}
+
+func (mwq *MethodWithQualifiers) goString(indent int, field string) string {
+	var q string
+	if mwq.Qualifiers != nil {
+		q += "\n" + mwq.Qualifiers.goString(indent+2, "Qualifiers: ")
+	}
+	if mwq.RefQualifier != "" {
+		if q != "" {
+			q += "\n"
+		}
+		q += fmt.Sprintf("%*s%s%s", indent+2, "", "RefQualifier: ", mwq.RefQualifier)
+	}
+	return fmt.Sprintf("%*s%sMethodWithQualifiers:%s\n%s", indent, "", field,
+		q, mwq.Method.goString(indent+2, "Method: "))
+}
+
+// BuiltinType is a builtin type, like "int".
+type BuiltinType struct {
+	Name string
+}
+
+func (bt *BuiltinType) print(ps *printState) {
+	ps.writeString(bt.Name)
+}
+
+func (bt *BuiltinType) Traverse(fn func(AST) bool) {
+	fn(bt)
+}
+
+func (bt *BuiltinType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(bt) {
+		return nil
+	}
+	return fn(bt)
+}
+
+func (bt *BuiltinType) GoString() string {
+	return bt.goString(0, "")
+}
+
+func (bt *BuiltinType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sBuiltinType: %s", indent, "", field, bt.Name)
+}
+
+// printBase is common print code for types that are printed with a
+// simple suffix.
+func printBase(ps *printState, qual, base AST) {
+	ps.inner = append(ps.inner, qual)
+	ps.print(base)
+	if len(ps.inner) > 0 {
+		qual.(innerPrinter).printInner(ps)
+		ps.inner = ps.inner[:len(ps.inner)-1]
+	}
+}
+
+// PointerType is a pointer type.
+type PointerType struct {
+	Base AST
+}
+
+func (pt *PointerType) print(ps *printState) {
+	printBase(ps, pt, pt.Base)
+}
+
+func (pt *PointerType) printInner(ps *printState) {
+	ps.writeString("*")
+}
+
+func (pt *PointerType) Traverse(fn func(AST) bool) {
+	if fn(pt) {
+		pt.Base.Traverse(fn)
+	}
+}
+
+func (pt *PointerType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(pt) {
+		return nil
+	}
+	base := pt.Base.Copy(fn, skip)
+	if base == nil {
+		return fn(pt)
+	}
+	pt = &PointerType{Base: base}
+	if r := fn(pt); r != nil {
+		return r
+	}
+	return pt
+}
+
+func (pt *PointerType) GoString() string {
+	return pt.goString(0, "")
+}
+
+func (pt *PointerType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sPointerType:\n%s", indent, "", field,
+		pt.Base.goString(indent+2, ""))
+}
+
+// ReferenceType is a reference type.
+type ReferenceType struct {
+	Base AST
+}
+
+func (rt *ReferenceType) print(ps *printState) {
+	printBase(ps, rt, rt.Base)
+}
+
+func (rt *ReferenceType) printInner(ps *printState) {
+	ps.writeString("&")
+}
+
+func (rt *ReferenceType) Traverse(fn func(AST) bool) {
+	if fn(rt) {
+		rt.Base.Traverse(fn)
+	}
+}
+
+func (rt *ReferenceType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(rt) {
+		return nil
+	}
+	base := rt.Base.Copy(fn, skip)
+	if base == nil {
+		return fn(rt)
+	}
+	rt = &ReferenceType{Base: base}
+	if r := fn(rt); r != nil {
+		return r
+	}
+	return rt
+}
+
+func (rt *ReferenceType) GoString() string {
+	return rt.goString(0, "")
+}
+
+func (rt *ReferenceType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sReferenceType:\n%s", indent, "", field,
+		rt.Base.goString(indent+2, ""))
+}
+
+// RvalueReferenceType is an rvalue reference type.
+type RvalueReferenceType struct {
+	Base AST
+}
+
+func (rt *RvalueReferenceType) print(ps *printState) {
+	printBase(ps, rt, rt.Base)
+}
+
+func (rt *RvalueReferenceType) printInner(ps *printState) {
+	ps.writeString("&&")
+}
+
+func (rt *RvalueReferenceType) Traverse(fn func(AST) bool) {
+	if fn(rt) {
+		rt.Base.Traverse(fn)
+	}
+}
+
+func (rt *RvalueReferenceType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(rt) {
+		return nil
+	}
+	base := rt.Base.Copy(fn, skip)
+	if base == nil {
+		return fn(rt)
+	}
+	rt = &RvalueReferenceType{Base: base}
+	if r := fn(rt); r != nil {
+		return r
+	}
+	return rt
+}
+
+func (rt *RvalueReferenceType) GoString() string {
+	return rt.goString(0, "")
+}
+
+func (rt *RvalueReferenceType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sRvalueReferenceType:\n%s", indent, "", field,
+		rt.Base.goString(indent+2, ""))
+}
+
+// ComplexType is a complex type.
+type ComplexType struct {
+	Base AST
+}
+
+func (ct *ComplexType) print(ps *printState) {
+	printBase(ps, ct, ct.Base)
+}
+
+func (ct *ComplexType) printInner(ps *printState) {
+	ps.writeString(" _Complex")
+}
+
+func (ct *ComplexType) Traverse(fn func(AST) bool) {
+	if fn(ct) {
+		ct.Base.Traverse(fn)
+	}
+}
+
+func (ct *ComplexType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(ct) {
+		return nil
+	}
+	base := ct.Base.Copy(fn, skip)
+	if base == nil {
+		return fn(ct)
+	}
+	ct = &ComplexType{Base: base}
+	if r := fn(ct); r != nil {
+		return r
+	}
+	return ct
+}
+
+func (ct *ComplexType) GoString() string {
+	return ct.goString(0, "")
+}
+
+func (ct *ComplexType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sComplexType:\n%s", indent, "", field,
+		ct.Base.goString(indent+2, ""))
+}
+
+// ImaginaryType is an imaginary type.
+type ImaginaryType struct {
+	Base AST
+}
+
+func (it *ImaginaryType) print(ps *printState) {
+	printBase(ps, it, it.Base)
+}
+
+func (it *ImaginaryType) printInner(ps *printState) {
+	ps.writeString(" _Imaginary")
+}
+
+func (it *ImaginaryType) Traverse(fn func(AST) bool) {
+	if fn(it) {
+		it.Base.Traverse(fn)
+	}
+}
+
+func (it *ImaginaryType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(it) {
+		return nil
+	}
+	base := it.Base.Copy(fn, skip)
+	if base == nil {
+		return fn(it)
+	}
+	it = &ImaginaryType{Base: base}
+	if r := fn(it); r != nil {
+		return r
+	}
+	return it
+}
+
+func (it *ImaginaryType) GoString() string {
+	return it.goString(0, "")
+}
+
+func (it *ImaginaryType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sImaginaryType:\n%s", indent, "", field,
+		it.Base.goString(indent+2, ""))
+}
+
+// VendorQualifier is a type qualified by a vendor-specific qualifier.
+type VendorQualifier struct {
+	Qualifier AST
+	Type      AST
+}
+
+func (vq *VendorQualifier) print(ps *printState) {
+	ps.inner = append(ps.inner, vq)
+	ps.print(vq.Type)
+	if len(ps.inner) > 0 {
+		ps.printOneInner(nil)
+	}
+}
+
+func (vq *VendorQualifier) printInner(ps *printState) {
+	ps.writeByte(' ')
+	ps.print(vq.Qualifier)
+}
+
+func (vq *VendorQualifier) Traverse(fn func(AST) bool) {
+	if fn(vq) {
+		vq.Qualifier.Traverse(fn)
+		vq.Type.Traverse(fn)
+	}
+}
+
+func (vq *VendorQualifier) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(vq) {
+		return nil
+	}
+	qualifier := vq.Qualifier.Copy(fn, skip)
+	typ := vq.Type.Copy(fn, skip)
+	if qualifier == nil && typ == nil {
+		return fn(vq)
+	}
+	if qualifier == nil {
+		qualifier = vq.Qualifier
+	}
+	if typ == nil {
+		typ = vq.Type
+	}
+	vq = &VendorQualifier{Qualifier: qualifier, Type: vq.Type}
+	if r := fn(vq); r != nil {
+		return r
+	}
+	return vq
+}
+
+func (vq *VendorQualifier) GoString() string {
+	return vq.goString(0, "")
+}
+
+func (vq *VendorQualifier) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sVendorQualifier:\n%s\n%s", indent, "", field,
+		vq.Qualifier.goString(indent+2, "Qualifier: "),
+		vq.Type.goString(indent+2, "Type: "))
+}
+
+// ArrayType is an array type.
+type ArrayType struct {
+	Dimension AST
+	Element   AST
+}
+
+func (at *ArrayType) print(ps *printState) {
+	// Pass the array type down as an inner type so that we print
+	// multi-dimensional arrays correctly.
+	ps.inner = append(ps.inner, at)
+	ps.print(at.Element)
+	if ln := len(ps.inner); ln > 0 {
+		ps.inner = ps.inner[:ln-1]
+		at.printDimension(ps)
+	}
+}
+
+func (at *ArrayType) printInner(ps *printState) {
+	at.printDimension(ps)
+}
+
+// Print the array dimension.
+func (at *ArrayType) printDimension(ps *printState) {
+	space := " "
+	for len(ps.inner) > 0 {
+		// We haven't gotten to the real type yet.  Use
+		// parentheses around that type, except that if it is
+		// an array type we print it as a multi-dimensional
+		// array
+		in := ps.inner[len(ps.inner)-1]
+		if twq, ok := in.(*TypeWithQualifiers); ok {
+			in = twq.Base
+		}
+		if _, ok := in.(*ArrayType); ok {
+			if in == ps.inner[len(ps.inner)-1] {
+				space = ""
+			}
+			ps.printOneInner(nil)
+		} else {
+			ps.writeString(" (")
+			ps.printInner(false)
+			ps.writeByte(')')
+		}
+	}
+	ps.writeString(space)
+	ps.writeByte('[')
+	ps.print(at.Dimension)
+	ps.writeByte(']')
+}
+
+func (at *ArrayType) Traverse(fn func(AST) bool) {
+	if fn(at) {
+		at.Dimension.Traverse(fn)
+		at.Element.Traverse(fn)
+	}
+}
+
+func (at *ArrayType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(at) {
+		return nil
+	}
+	dimension := at.Dimension.Copy(fn, skip)
+	element := at.Element.Copy(fn, skip)
+	if dimension == nil && element == nil {
+		return fn(at)
+	}
+	if dimension == nil {
+		dimension = at.Dimension
+	}
+	if element == nil {
+		element = at.Element
+	}
+	at = &ArrayType{Dimension: dimension, Element: element}
+	if r := fn(at); r != nil {
+		return r
+	}
+	return at
+}
+
+func (at *ArrayType) GoString() string {
+	return at.goString(0, "")
+}
+
+func (at *ArrayType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sArrayType:\n%s\n%s", indent, "", field,
+		at.Dimension.goString(indent+2, "Dimension: "),
+		at.Element.goString(indent+2, "Element: "))
+}
+
+// FunctionType is a function type.  The Return field may be nil for
+// cases where the return type is not part of the mangled name.
+type FunctionType struct {
+	Return AST
+	Args   []AST
+}
+
+func (ft *FunctionType) print(ps *printState) {
+	if ft.Return != nil {
+		// Pass the return type as an inner type in order to
+		// print the arguments in the right location.
+		ps.inner = append(ps.inner, ft)
+		ps.print(ft.Return)
+		if len(ps.inner) == 0 {
+			// Everything was printed.
+			return
+		}
+		ps.inner = ps.inner[:len(ps.inner)-1]
+		ps.writeByte(' ')
+	}
+	ft.printArgs(ps)
+}
+
+func (ft *FunctionType) printInner(ps *printState) {
+	ft.printArgs(ps)
+}
+
+// printArgs prints the arguments of a function type.  It looks at the
+// inner types for spacing.
+func (ft *FunctionType) printArgs(ps *printState) {
+	paren := false
+	space := false
+	for i := len(ps.inner) - 1; i >= 0; i-- {
+		switch ps.inner[i].(type) {
+		case *PointerType, *ReferenceType, *RvalueReferenceType:
+			paren = true
+		case *TypeWithQualifiers, *ComplexType, *ImaginaryType, *PtrMem:
+			space = true
+			paren = true
+		}
+		if paren {
+			break
+		}
+	}
+
+	if paren {
+		if !space && (ps.last != '(' && ps.last != '*') {
+			space = true
+		}
+		if space && ps.last != ' ' {
+			ps.writeByte(' ')
+		}
+		ps.writeByte('(')
+	}
+
+	save := ps.printInner(true)
+
+	if paren {
+		ps.writeByte(')')
+	}
+
+	ps.writeByte('(')
+	first := true
+	for _, a := range ft.Args {
+		if ps.isEmpty(a) {
+			continue
+		}
+		if !first {
+			ps.writeString(", ")
+		}
+		ps.print(a)
+		first = false
+	}
+	ps.writeByte(')')
+
+	ps.inner = save
+	ps.printInner(false)
+}
+
+func (ft *FunctionType) Traverse(fn func(AST) bool) {
+	if fn(ft) {
+		if ft.Return != nil {
+			ft.Return.Traverse(fn)
+		}
+		for _, a := range ft.Args {
+			a.Traverse(fn)
+		}
+	}
+}
+
+func (ft *FunctionType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(ft) {
+		return nil
+	}
+	changed := false
+	var ret AST
+	if ft.Return != nil {
+		ret = ft.Return.Copy(fn, skip)
+		if ret == nil {
+			ret = ft.Return
+		} else {
+			changed = true
+		}
+	}
+	args := make([]AST, len(ft.Args))
+	for i, a := range ft.Args {
+		ac := a.Copy(fn, skip)
+		if ac == nil {
+			args[i] = a
+		} else {
+			args[i] = ac
+			changed = true
+		}
+	}
+	if !changed {
+		return fn(ft)
+	}
+	ft = &FunctionType{Return: ret, Args: args}
+	if r := fn(ft); r != nil {
+		return r
+	}
+	return ft
+}
+
+func (ft *FunctionType) GoString() string {
+	return ft.goString(0, "")
+}
+
+func (ft *FunctionType) goString(indent int, field string) string {
+	var r string
+	if ft.Return == nil {
+		r = fmt.Sprintf("%*sReturn: nil", indent+2, "")
+	} else {
+		r = ft.Return.goString(indent+2, "Return: ")
+	}
+	var args string
+	if len(ft.Args) == 0 {
+		args = fmt.Sprintf("%*sArgs: nil", indent+2, "")
+	} else {
+		args = fmt.Sprintf("%*sArgs:", indent+2, "")
+		for i, a := range ft.Args {
+			args += "\n"
+			args += a.goString(indent+4, fmt.Sprintf("%d: ", i))
+		}
+	}
+	return fmt.Sprintf("%*s%sFunctionType:\n%s\n%s", indent, "", field, r, args)
+}
+
+// FunctionParam is a parameter of a function, used for last-specified
+// return type in a closure.
+type FunctionParam struct {
+	Index int
+}
+
+func (fp *FunctionParam) print(ps *printState) {
+	if fp.Index == 0 {
+		ps.writeString("this")
+	} else {
+		fmt.Fprintf(&ps.buf, "{parm#%d}", fp.Index)
+	}
+}
+
+func (fp *FunctionParam) Traverse(fn func(AST) bool) {
+	fn(fp)
+}
+
+func (fp *FunctionParam) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(fp) {
+		return nil
+	}
+	return fn(fp)
+}
+
+func (fp *FunctionParam) GoString() string {
+	return fp.goString(0, "")
+}
+
+func (fp *FunctionParam) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sFunctionParam: %d", indent, "", field, fp.Index)
+}
+
+// PtrMem is a pointer-to-member expression.
+type PtrMem struct {
+	Class  AST
+	Member AST
+}
+
+func (pm *PtrMem) print(ps *printState) {
+	ps.inner = append(ps.inner, pm)
+	ps.print(pm.Member)
+	if len(ps.inner) > 0 {
+		ps.printOneInner(nil)
+	}
+}
+
+func (pm *PtrMem) printInner(ps *printState) {
+	if ps.last != '(' {
+		ps.writeByte(' ')
+	}
+	ps.print(pm.Class)
+	ps.writeString("::*")
+}
+
+func (pm *PtrMem) Traverse(fn func(AST) bool) {
+	if fn(pm) {
+		pm.Class.Traverse(fn)
+		pm.Member.Traverse(fn)
+	}
+}
+
+func (pm *PtrMem) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(pm) {
+		return nil
+	}
+	class := pm.Class.Copy(fn, skip)
+	member := pm.Member.Copy(fn, skip)
+	if class == nil && member == nil {
+		return fn(pm)
+	}
+	if class == nil {
+		class = pm.Class
+	}
+	if member == nil {
+		member = pm.Member
+	}
+	pm = &PtrMem{Class: class, Member: member}
+	if r := fn(pm); r != nil {
+		return r
+	}
+	return pm
+}
+
+func (pm *PtrMem) GoString() string {
+	return pm.goString(0, "")
+}
+
+func (pm *PtrMem) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sPtrMem:\n%s\n%s", indent, "", field,
+		pm.Class.goString(indent+2, "Class: "),
+		pm.Member.goString(indent+2, "Member: "))
+}
+
+// FixedType is a fixed numeric type of unknown size.
+type FixedType struct {
+	Base  AST
+	Accum bool
+	Sat   bool
+}
+
+func (ft *FixedType) print(ps *printState) {
+	if ft.Sat {
+		ps.writeString("_Sat ")
+	}
+	if bt, ok := ft.Base.(*BuiltinType); ok && bt.Name == "int" {
+		// The standard demangler skips printing "int".
+	} else {
+		ps.print(ft.Base)
+		ps.writeByte(' ')
+	}
+	if ft.Accum {
+		ps.writeString("_Accum")
+	} else {
+		ps.writeString("_Fract")
+	}
+}
+
+func (ft *FixedType) Traverse(fn func(AST) bool) {
+	if fn(ft) {
+		ft.Base.Traverse(fn)
+	}
+}
+
+func (ft *FixedType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(ft) {
+		return nil
+	}
+	base := ft.Base.Copy(fn, skip)
+	if base == nil {
+		return fn(ft)
+	}
+	ft = &FixedType{Base: base, Accum: ft.Accum, Sat: ft.Sat}
+	if r := fn(ft); r != nil {
+		return r
+	}
+	return ft
+}
+
+func (ft *FixedType) GoString() string {
+	return ft.goString(0, "")
+}
+
+func (ft *FixedType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sFixedType: Accum: %t; Sat: %t\n%s", indent, "", field,
+		ft.Accum, ft.Sat,
+		ft.Base.goString(indent+2, "Base: "))
+}
+
+// VectorType is a vector type.
+type VectorType struct {
+	Dimension AST
+	Base      AST
+}
+
+func (vt *VectorType) print(ps *printState) {
+	ps.inner = append(ps.inner, vt)
+	ps.print(vt.Base)
+	if len(ps.inner) > 0 {
+		ps.printOneInner(nil)
+	}
+}
+
+func (vt *VectorType) printInner(ps *printState) {
+	ps.writeString(" __vector(")
+	ps.print(vt.Dimension)
+	ps.writeByte(')')
+}
+
+func (vt *VectorType) Traverse(fn func(AST) bool) {
+	if fn(vt) {
+		vt.Dimension.Traverse(fn)
+		vt.Base.Traverse(fn)
+	}
+}
+
+func (vt *VectorType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(vt) {
+		return nil
+	}
+	dimension := vt.Dimension.Copy(fn, skip)
+	base := vt.Base.Copy(fn, skip)
+	if dimension == nil && base == nil {
+		return fn(vt)
+	}
+	if dimension == nil {
+		dimension = vt.Dimension
+	}
+	if base == nil {
+		base = vt.Base
+	}
+	vt = &VectorType{Dimension: dimension, Base: base}
+	if r := fn(vt); r != nil {
+		return r
+	}
+	return vt
+}
+
+func (vt *VectorType) GoString() string {
+	return vt.goString(0, "")
+}
+
+func (vt *VectorType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sVectorType:\n%s\n%s", indent, "", field,
+		vt.Dimension.goString(indent+2, "Dimension: "),
+		vt.Base.goString(indent+2, "Base: "))
+}
+
+// Decltype is the decltype operator.
+type Decltype struct {
+	Expr AST
+}
+
+func (dt *Decltype) print(ps *printState) {
+	ps.writeString("decltype (")
+	ps.print(dt.Expr)
+	ps.writeByte(')')
+}
+
+func (dt *Decltype) Traverse(fn func(AST) bool) {
+	if fn(dt) {
+		dt.Expr.Traverse(fn)
+	}
+}
+
+func (dt *Decltype) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(dt) {
+		return nil
+	}
+	expr := dt.Expr.Copy(fn, skip)
+	if expr == nil {
+		return fn(dt)
+	}
+	dt = &Decltype{Expr: expr}
+	if r := fn(dt); r != nil {
+		return r
+	}
+	return dt
+}
+
+func (dt *Decltype) GoString() string {
+	return dt.goString(0, "")
+}
+
+func (dt *Decltype) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sDecltype:\n%s", indent, "", field,
+		dt.Expr.goString(indent+2, "Expr: "))
+}
+
+// Operator is an operator.
+type Operator struct {
+	Name string
+}
+
+func (op *Operator) print(ps *printState) {
+	ps.writeString("operator")
+	if isLower(op.Name[0]) {
+		ps.writeByte(' ')
+	}
+	n := op.Name
+	n = strings.TrimSuffix(n, " ")
+	ps.writeString(n)
+}
+
+func (op *Operator) Traverse(fn func(AST) bool) {
+	fn(op)
+}
+
+func (op *Operator) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(op) {
+		return nil
+	}
+	return fn(op)
+}
+
+func (op *Operator) GoString() string {
+	return op.goString(0, "")
+}
+
+func (op *Operator) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sOperator: %s", indent, "", field, op.Name)
+}
+
+// Constructor is a constructor.
+type Constructor struct {
+	Name AST
+}
+
+func (c *Constructor) print(ps *printState) {
+	ps.print(c.Name)
+}
+
+func (c *Constructor) Traverse(fn func(AST) bool) {
+	if fn(c) {
+		c.Name.Traverse(fn)
+	}
+}
+
+func (c *Constructor) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(c) {
+		return nil
+	}
+	name := c.Name.Copy(fn, skip)
+	if name == nil {
+		return fn(c)
+	}
+	c = &Constructor{Name: name}
+	if r := fn(c); r != nil {
+		return r
+	}
+	return c
+}
+
+func (c *Constructor) GoString() string {
+	return c.goString(0, "")
+}
+
+func (c *Constructor) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sConstructor:\n%s", indent, "", field, c.Name.goString(indent+2, "Name: "))
+}
+
+// Destructor is a destructor.
+type Destructor struct {
+	Name AST
+}
+
+func (d *Destructor) print(ps *printState) {
+	ps.writeByte('~')
+	ps.print(d.Name)
+}
+
+func (d *Destructor) Traverse(fn func(AST) bool) {
+	if fn(d) {
+		d.Name.Traverse(fn)
+	}
+}
+
+func (d *Destructor) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(d) {
+		return nil
+	}
+	name := d.Name.Copy(fn, skip)
+	if name == nil {
+		return fn(d)
+	}
+	d = &Destructor{Name: name}
+	if r := fn(d); r != nil {
+		return r
+	}
+	return d
+}
+
+func (d *Destructor) GoString() string {
+	return d.goString(0, "")
+}
+
+func (d *Destructor) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sDestructor:\n%s", indent, "", field, d.Name.goString(indent+2, "Name: "))
+}
+
+// GlobalCDtor is a global constructor or destructor.
+type GlobalCDtor struct {
+	Ctor bool
+	Key  AST
+}
+
+func (gcd *GlobalCDtor) print(ps *printState) {
+	ps.writeString("global ")
+	if gcd.Ctor {
+		ps.writeString("constructors")
+	} else {
+		ps.writeString("destructors")
+	}
+	ps.writeString(" keyed to ")
+	ps.print(gcd.Key)
+}
+
+func (gcd *GlobalCDtor) Traverse(fn func(AST) bool) {
+	if fn(gcd) {
+		gcd.Key.Traverse(fn)
+	}
+}
+
+func (gcd *GlobalCDtor) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(gcd) {
+		return nil
+	}
+	key := gcd.Key.Copy(fn, skip)
+	if key == nil {
+		return fn(gcd)
+	}
+	gcd = &GlobalCDtor{Ctor: gcd.Ctor, Key: key}
+	if r := fn(gcd); r != nil {
+		return r
+	}
+	return gcd
+}
+
+func (gcd *GlobalCDtor) GoString() string {
+	return gcd.goString(0, "")
+}
+
+func (gcd *GlobalCDtor) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sGlobalCDtor: Ctor: %t\n%s", indent, "", field,
+		gcd.Ctor, gcd.Key.goString(indent+2, "Key: "))
+}
+
+// TaggedName is a name with an ABI tag.
+type TaggedName struct {
+	Name AST
+	Tag  AST
+}
+
+func (t *TaggedName) print(ps *printState) {
+	ps.print(t.Name)
+	ps.writeString("[abi:")
+	ps.print(t.Tag)
+	ps.writeByte(']')
+}
+
+func (t *TaggedName) Traverse(fn func(AST) bool) {
+	if fn(t) {
+		t.Name.Traverse(fn)
+		t.Tag.Traverse(fn)
+	}
+}
+
+func (t *TaggedName) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(t) {
+		return nil
+	}
+	name := t.Name.Copy(fn, skip)
+	tag := t.Tag.Copy(fn, skip)
+	if name == nil && tag == nil {
+		return fn(t)
+	}
+	if name == nil {
+		name = t.Name
+	}
+	if tag == nil {
+		tag = t.Tag
+	}
+	t = &TaggedName{Name: name, Tag: tag}
+	if r := fn(t); r != nil {
+		return r
+	}
+	return t
+}
+
+func (t *TaggedName) GoString() string {
+	return t.goString(0, "")
+}
+
+func (t *TaggedName) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sTaggedName:\n%s\n%s", indent, "", field,
+		t.Name.goString(indent+2, "Name: "),
+		t.Tag.goString(indent+2, "Tag: "))
+}
+
+// PackExpansion is a pack expansion.  The Pack field may be nil.
+type PackExpansion struct {
+	Base AST
+	Pack *ArgumentPack
+}
+
+func (pe *PackExpansion) print(ps *printState) {
+	// We normally only get here if the simplify function was
+	// unable to locate and expand the pack.
+	if pe.Pack == nil {
+		parenthesize(ps, pe.Base)
+		ps.writeString("...")
+	} else {
+		ps.print(pe.Base)
+	}
+}
+
+func (pe *PackExpansion) Traverse(fn func(AST) bool) {
+	if fn(pe) {
+		pe.Base.Traverse(fn)
+		// Don't traverse Template--it points elsewhere in the AST.
+	}
+}
+
+func (pe *PackExpansion) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(pe) {
+		return nil
+	}
+	base := pe.Base.Copy(fn, skip)
+	if base == nil {
+		return fn(pe)
+	}
+	pe = &PackExpansion{Base: base, Pack: pe.Pack}
+	if r := fn(pe); r != nil {
+		return r
+	}
+	return pe
+}
+
+func (pe *PackExpansion) GoString() string {
+	return pe.goString(0, "")
+}
+
+func (pe *PackExpansion) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sPackExpansion: Pack: %p\n%s", indent, "", field,
+		pe.Pack, pe.Base.goString(indent+2, "Base: "))
+}
+
+// ArgumentPack is an argument pack.
+type ArgumentPack struct {
+	Args []AST
+}
+
+func (ap *ArgumentPack) print(ps *printState) {
+	for i, a := range ap.Args {
+		if i > 0 {
+			ps.writeString(", ")
+		}
+		ps.print(a)
+	}
+}
+
+func (ap *ArgumentPack) Traverse(fn func(AST) bool) {
+	if fn(ap) {
+		for _, a := range ap.Args {
+			a.Traverse(fn)
+		}
+	}
+}
+
+func (ap *ArgumentPack) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(ap) {
+		return nil
+	}
+	args := make([]AST, len(ap.Args))
+	changed := false
+	for i, a := range ap.Args {
+		ac := a.Copy(fn, skip)
+		if ac == nil {
+			args[i] = a
+		} else {
+			args[i] = ac
+			changed = true
+		}
+	}
+	if !changed {
+		return fn(ap)
+	}
+	ap = &ArgumentPack{Args: args}
+	if r := fn(ap); r != nil {
+		return r
+	}
+	return ap
+}
+
+func (ap *ArgumentPack) GoString() string {
+	return ap.goString(0, "")
+}
+
+func (ap *ArgumentPack) goString(indent int, field string) string {
+	if len(ap.Args) == 0 {
+		return fmt.Sprintf("%*s%sArgumentPack: nil", indent, "", field)
+	}
+	s := fmt.Sprintf("%*s%sArgumentPack:", indent, "", field)
+	for i, a := range ap.Args {
+		s += "\n"
+		s += a.goString(indent+2, fmt.Sprintf("%d: ", i))
+	}
+	return s
+}
+
+// SizeofPack is the sizeof operator applied to an argument pack.
+type SizeofPack struct {
+	Pack *ArgumentPack
+}
+
+func (sp *SizeofPack) print(ps *printState) {
+	ps.writeString(fmt.Sprintf("%d", len(sp.Pack.Args)))
+}
+
+func (sp *SizeofPack) Traverse(fn func(AST) bool) {
+	fn(sp)
+	// Don't traverse the pack--it points elsewhere in the AST.
+}
+
+func (sp *SizeofPack) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(sp) {
+		return nil
+	}
+	sp = &SizeofPack{Pack: sp.Pack}
+	if r := fn(sp); r != nil {
+		return r
+	}
+	return sp
+}
+
+func (sp *SizeofPack) GoString() string {
+	return sp.goString(0, "")
+}
+
+func (sp *SizeofPack) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sSizeofPack: Pack: %p", indent, "", field, sp.Pack)
+}
+
+// SizeofArgs is the size of a captured template parameter pack from
+// an alias template.
+type SizeofArgs struct {
+	Args []AST
+}
+
+func (sa *SizeofArgs) print(ps *printState) {
+	c := 0
+	for _, a := range sa.Args {
+		if ap, ok := a.(*ArgumentPack); ok {
+			c += len(ap.Args)
+		} else if el, ok := a.(*ExprList); ok {
+			c += len(el.Exprs)
+		} else {
+			c++
+		}
+	}
+	ps.writeString(fmt.Sprintf("%d", c))
+}
+
+func (sa *SizeofArgs) Traverse(fn func(AST) bool) {
+	if fn(sa) {
+		for _, a := range sa.Args {
+			a.Traverse(fn)
+		}
+	}
+}
+
+func (sa *SizeofArgs) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(sa) {
+		return nil
+	}
+	changed := false
+	args := make([]AST, len(sa.Args))
+	for i, a := range sa.Args {
+		ac := a.Copy(fn, skip)
+		if ac == nil {
+			args[i] = a
+		} else {
+			args[i] = ac
+			changed = true
+		}
+	}
+	if !changed {
+		return fn(sa)
+	}
+	sa = &SizeofArgs{Args: args}
+	if r := fn(sa); r != nil {
+		return r
+	}
+	return sa
+}
+
+func (sa *SizeofArgs) GoString() string {
+	return sa.goString(0, "")
+}
+
+func (sa *SizeofArgs) goString(indent int, field string) string {
+	var args string
+	if len(sa.Args) == 0 {
+		args = fmt.Sprintf("%*sArgs: nil", indent+2, "")
+	} else {
+		args = fmt.Sprintf("%*sArgs:", indent+2, "")
+		for i, a := range sa.Args {
+			args += "\n"
+			args += a.goString(indent+4, fmt.Sprintf("%d: ", i))
+		}
+	}
+	return fmt.Sprintf("%*s%sSizeofArgs:\n%s", indent, "", field, args)
+}
+
+// Cast is a type cast.
+type Cast struct {
+	To AST
+}
+
+func (c *Cast) print(ps *printState) {
+	ps.writeString("operator ")
+	ps.print(c.To)
+}
+
+func (c *Cast) Traverse(fn func(AST) bool) {
+	if fn(c) {
+		c.To.Traverse(fn)
+	}
+}
+
+func (c *Cast) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(c) {
+		return nil
+	}
+	to := c.To.Copy(fn, skip)
+	if to == nil {
+		return fn(c)
+	}
+	c = &Cast{To: to}
+	if r := fn(c); r != nil {
+		return r
+	}
+	return c
+}
+
+func (c *Cast) GoString() string {
+	return c.goString(0, "")
+}
+
+func (c *Cast) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sCast\n%s", indent, "", field,
+		c.To.goString(indent+2, "To: "))
+}
+
+// The parenthesize function prints the string for val, wrapped in
+// parentheses if necessary.
+func parenthesize(ps *printState, val AST) {
+	paren := false
+	switch v := val.(type) {
+	case *Name, *InitializerList, *FunctionParam:
+	case *Qualified:
+		if v.LocalName {
+			paren = true
+		}
+	default:
+		paren = true
+	}
+	if paren {
+		ps.writeByte('(')
+	}
+	ps.print(val)
+	if paren {
+		ps.writeByte(')')
+	}
+}
+
+// Nullary is an operator in an expression with no arguments, such as
+// throw.
+type Nullary struct {
+	Op AST
+}
+
+func (n *Nullary) print(ps *printState) {
+	if op, ok := n.Op.(*Operator); ok {
+		ps.writeString(op.Name)
+	} else {
+		ps.print(n.Op)
+	}
+}
+
+func (n *Nullary) Traverse(fn func(AST) bool) {
+	if fn(n) {
+		n.Op.Traverse(fn)
+	}
+}
+
+func (n *Nullary) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(n) {
+		return nil
+	}
+	op := n.Op.Copy(fn, skip)
+	if op == nil {
+		return fn(n)
+	}
+	n = &Nullary{Op: op}
+	if r := fn(n); r != nil {
+		return r
+	}
+	return n
+}
+
+func (n *Nullary) GoString() string {
+	return n.goString(0, "")
+}
+
+func (n *Nullary) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sNullary:\n%s", indent, "", field,
+		n.Op.goString(indent+2, "Op: "))
+}
+
+// Unary is a unary operation in an expression.
+type Unary struct {
+	Op         AST
+	Expr       AST
+	Suffix     bool // true for ++ -- when used as postfix
+	SizeofType bool // true for sizeof (type)
+}
+
+func (u *Unary) print(ps *printState) {
+	expr := u.Expr
+
+	// Don't print the argument list when taking the address of a
+	// function.
+	if op, ok := u.Op.(*Operator); ok && op.Name == "&" {
+		if t, ok := expr.(*Typed); ok {
+			if _, ok := t.Type.(*FunctionType); ok {
+				expr = t.Name
+			}
+		}
+	}
+
+	if u.Suffix {
+		parenthesize(ps, expr)
+	}
+
+	if op, ok := u.Op.(*Operator); ok {
+		ps.writeString(op.Name)
+	} else if c, ok := u.Op.(*Cast); ok {
+		ps.writeByte('(')
+		ps.print(c.To)
+		ps.writeByte(')')
+	} else {
+		ps.print(u.Op)
+	}
+
+	if !u.Suffix {
+		if op, ok := u.Op.(*Operator); ok && op.Name == "::" {
+			// Don't use parentheses after ::.
+			ps.print(expr)
+		} else if u.SizeofType {
+			// Always use parentheses for sizeof argument.
+			ps.writeByte('(')
+			ps.print(expr)
+			ps.writeByte(')')
+		} else {
+			parenthesize(ps, expr)
+		}
+	}
+}
+
+func (u *Unary) Traverse(fn func(AST) bool) {
+	if fn(u) {
+		u.Op.Traverse(fn)
+		u.Expr.Traverse(fn)
+	}
+}
+
+func (u *Unary) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(u) {
+		return nil
+	}
+	op := u.Op.Copy(fn, skip)
+	expr := u.Expr.Copy(fn, skip)
+	if op == nil && expr == nil {
+		return fn(u)
+	}
+	if op == nil {
+		op = u.Op
+	}
+	if expr == nil {
+		expr = u.Expr
+	}
+	u = &Unary{Op: op, Expr: expr, Suffix: u.Suffix, SizeofType: u.SizeofType}
+	if r := fn(u); r != nil {
+		return r
+	}
+	return u
+}
+
+func (u *Unary) GoString() string {
+	return u.goString(0, "")
+}
+
+func (u *Unary) goString(indent int, field string) string {
+	var s string
+	if u.Suffix {
+		s = " Suffix: true"
+	}
+	if u.SizeofType {
+		s += " SizeofType: true"
+	}
+	return fmt.Sprintf("%*s%sUnary:%s\n%s\n%s", indent, "", field,
+		s, u.Op.goString(indent+2, "Op: "),
+		u.Expr.goString(indent+2, "Expr: "))
+}
+
+// isDesignatedInitializer reports whether x is a designated
+// initializer.
+func isDesignatedInitializer(x AST) bool {
+	switch x := x.(type) {
+	case *Binary:
+		if op, ok := x.Op.(*Operator); ok {
+			return op.Name == "=" || op.Name == "]="
+		}
+	case *Trinary:
+		if op, ok := x.Op.(*Operator); ok {
+			return op.Name == "[...]="
+		}
+	}
+	return false
+}
+
+// Binary is a binary operation in an expression.
+type Binary struct {
+	Op    AST
+	Left  AST
+	Right AST
+}
+
+func (b *Binary) print(ps *printState) {
+	op, _ := b.Op.(*Operator)
+
+	if op != nil && strings.Contains(op.Name, "cast") {
+		ps.writeString(op.Name)
+		ps.writeByte('<')
+		ps.print(b.Left)
+		ps.writeString(">(")
+		ps.print(b.Right)
+		ps.writeByte(')')
+		return
+	}
+
+	if isDesignatedInitializer(b) {
+		if op.Name == "=" {
+			ps.writeByte('.')
+		} else {
+			ps.writeByte('[')
+		}
+		ps.print(b.Left)
+		if op.Name == "]=" {
+			ps.writeByte(']')
+		}
+		if isDesignatedInitializer(b.Right) {
+			// Don't add anything between designated
+			// initializer chains.
+			ps.print(b.Right)
+		} else {
+			ps.writeByte('=')
+			parenthesize(ps, b.Right)
+		}
+		return
+	}
+
+	// Use an extra set of parentheses around an expression that
+	// uses the greater-than operator, so that it does not get
+	// confused with the '>' that ends template parameters.
+	if op != nil && op.Name == ">" {
+		ps.writeByte('(')
+	}
+
+	left := b.Left
+
+	// For a function call in an expression, don't print the types
+	// of the arguments unless there is a return type.
+	skipParens := false
+	if op != nil && op.Name == "()" {
+		if ty, ok := b.Left.(*Typed); ok {
+			if ft, ok := ty.Type.(*FunctionType); ok {
+				if ft.Return == nil {
+					left = ty.Name
+				} else {
+					skipParens = true
+				}
+			} else {
+				left = ty.Name
+			}
+		}
+	}
+
+	if skipParens {
+		ps.print(left)
+	} else {
+		parenthesize(ps, left)
+	}
+
+	if op != nil && op.Name == "[]" {
+		ps.writeByte('[')
+		ps.print(b.Right)
+		ps.writeByte(']')
+		return
+	}
+
+	if op != nil {
+		if op.Name != "()" {
+			ps.writeString(op.Name)
+		}
+	} else {
+		ps.print(b.Op)
+	}
+
+	parenthesize(ps, b.Right)
+
+	if op != nil && op.Name == ">" {
+		ps.writeByte(')')
+	}
+}
+
+func (b *Binary) Traverse(fn func(AST) bool) {
+	if fn(b) {
+		b.Op.Traverse(fn)
+		b.Left.Traverse(fn)
+		b.Right.Traverse(fn)
+	}
+}
+
+func (b *Binary) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(b) {
+		return nil
+	}
+	op := b.Op.Copy(fn, skip)
+	left := b.Left.Copy(fn, skip)
+	right := b.Right.Copy(fn, skip)
+	if op == nil && left == nil && right == nil {
+		return fn(b)
+	}
+	if op == nil {
+		op = b.Op
+	}
+	if left == nil {
+		left = b.Left
+	}
+	if right == nil {
+		right = b.Right
+	}
+	b = &Binary{Op: op, Left: left, Right: right}
+	if r := fn(b); r != nil {
+		return r
+	}
+	return b
+}
+
+func (b *Binary) GoString() string {
+	return b.goString(0, "")
+}
+
+func (b *Binary) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sBinary:\n%s\n%s\n%s", indent, "", field,
+		b.Op.goString(indent+2, "Op: "),
+		b.Left.goString(indent+2, "Left: "),
+		b.Right.goString(indent+2, "Right: "))
+}
+
+// Trinary is the ?: trinary operation in an expression.
+type Trinary struct {
+	Op     AST
+	First  AST
+	Second AST
+	Third  AST
+}
+
+func (t *Trinary) print(ps *printState) {
+	if isDesignatedInitializer(t) {
+		ps.writeByte('[')
+		ps.print(t.First)
+		ps.writeString(" ... ")
+		ps.print(t.Second)
+		ps.writeByte(']')
+		if isDesignatedInitializer(t.Third) {
+			// Don't add anything between designated
+			// initializer chains.
+			ps.print(t.Third)
+		} else {
+			ps.writeByte('=')
+			parenthesize(ps, t.Third)
+		}
+		return
+	}
+
+	parenthesize(ps, t.First)
+	ps.writeByte('?')
+	parenthesize(ps, t.Second)
+	ps.writeString(" : ")
+	parenthesize(ps, t.Third)
+}
+
+func (t *Trinary) Traverse(fn func(AST) bool) {
+	if fn(t) {
+		t.Op.Traverse(fn)
+		t.First.Traverse(fn)
+		t.Second.Traverse(fn)
+		t.Third.Traverse(fn)
+	}
+}
+
+func (t *Trinary) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(t) {
+		return nil
+	}
+	op := t.Op.Copy(fn, skip)
+	first := t.First.Copy(fn, skip)
+	second := t.Second.Copy(fn, skip)
+	third := t.Third.Copy(fn, skip)
+	if op == nil && first == nil && second == nil && third == nil {
+		return fn(t)
+	}
+	if op == nil {
+		op = t.Op
+	}
+	if first == nil {
+		first = t.First
+	}
+	if second == nil {
+		second = t.Second
+	}
+	if third == nil {
+		third = t.Third
+	}
+	t = &Trinary{Op: op, First: first, Second: second, Third: third}
+	if r := fn(t); r != nil {
+		return r
+	}
+	return t
+}
+
+func (t *Trinary) GoString() string {
+	return t.goString(0, "")
+}
+
+func (t *Trinary) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sTrinary:\n%s\n%s\n%s\n%s", indent, "", field,
+		t.Op.goString(indent+2, "Op: "),
+		t.First.goString(indent+2, "First: "),
+		t.Second.goString(indent+2, "Second: "),
+		t.Third.goString(indent+2, "Third: "))
+}
+
+// Fold is a C++17 fold-expression.  Arg2 is nil for a unary operator.
+type Fold struct {
+	Left bool
+	Op   AST
+	Arg1 AST
+	Arg2 AST
+}
+
+func (f *Fold) print(ps *printState) {
+	op, _ := f.Op.(*Operator)
+	printOp := func() {
+		if op != nil {
+			ps.writeString(op.Name)
+		} else {
+			ps.print(f.Op)
+		}
+	}
+
+	if f.Arg2 == nil {
+		if f.Left {
+			ps.writeString("(...")
+			printOp()
+			parenthesize(ps, f.Arg1)
+			ps.writeString(")")
+		} else {
+			ps.writeString("(")
+			parenthesize(ps, f.Arg1)
+			printOp()
+			ps.writeString("...)")
+		}
+	} else {
+		ps.writeString("(")
+		parenthesize(ps, f.Arg1)
+		printOp()
+		ps.writeString("...")
+		printOp()
+		parenthesize(ps, f.Arg2)
+		ps.writeString(")")
+	}
+}
+
+func (f *Fold) Traverse(fn func(AST) bool) {
+	if fn(f) {
+		f.Op.Traverse(fn)
+		f.Arg1.Traverse(fn)
+		if f.Arg2 != nil {
+			f.Arg2.Traverse(fn)
+		}
+	}
+}
+
+func (f *Fold) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(f) {
+		return nil
+	}
+	op := f.Op.Copy(fn, skip)
+	arg1 := f.Arg1.Copy(fn, skip)
+	var arg2 AST
+	if f.Arg2 != nil {
+		arg2 = f.Arg2.Copy(fn, skip)
+	}
+	if op == nil && arg1 == nil && arg2 == nil {
+		return fn(f)
+	}
+	if op == nil {
+		op = f.Op
+	}
+	if arg1 == nil {
+		arg1 = f.Arg1
+	}
+	if arg2 == nil {
+		arg2 = f.Arg2
+	}
+	f = &Fold{Left: f.Left, Op: op, Arg1: arg1, Arg2: arg2}
+	if r := fn(f); r != nil {
+		return r
+	}
+	return f
+}
+
+func (f *Fold) GoString() string {
+	return f.goString(0, "")
+}
+
+func (f *Fold) goString(indent int, field string) string {
+	if f.Arg2 == nil {
+		return fmt.Sprintf("%*s%sFold: Left: %t\n%s\n%s", indent, "", field,
+			f.Left, f.Op.goString(indent+2, "Op: "),
+			f.Arg1.goString(indent+2, "Arg1: "))
+	} else {
+		return fmt.Sprintf("%*s%sFold: Left: %t\n%s\n%s\n%s", indent, "", field,
+			f.Left, f.Op.goString(indent+2, "Op: "),
+			f.Arg1.goString(indent+2, "Arg1: "),
+			f.Arg2.goString(indent+2, "Arg2: "))
+	}
+}
+
+// New is a use of operator new in an expression.
+type New struct {
+	Op    AST
+	Place AST
+	Type  AST
+	Init  AST
+}
+
+func (n *New) print(ps *printState) {
+	// Op doesn't really matter for printing--we always print "new".
+	ps.writeString("new ")
+	if n.Place != nil {
+		parenthesize(ps, n.Place)
+		ps.writeByte(' ')
+	}
+	ps.print(n.Type)
+	if n.Init != nil {
+		parenthesize(ps, n.Init)
+	}
+}
+
+func (n *New) Traverse(fn func(AST) bool) {
+	if fn(n) {
+		n.Op.Traverse(fn)
+		if n.Place != nil {
+			n.Place.Traverse(fn)
+		}
+		n.Type.Traverse(fn)
+		if n.Init != nil {
+			n.Init.Traverse(fn)
+		}
+	}
+}
+
+func (n *New) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(n) {
+		return nil
+	}
+	op := n.Op.Copy(fn, skip)
+	var place AST
+	if n.Place != nil {
+		place = n.Place.Copy(fn, skip)
+	}
+	typ := n.Type.Copy(fn, skip)
+	var ini AST
+	if n.Init != nil {
+		ini = n.Init.Copy(fn, skip)
+	}
+	if op == nil && place == nil && typ == nil && ini == nil {
+		return fn(n)
+	}
+	if op == nil {
+		op = n.Op
+	}
+	if place == nil {
+		place = n.Place
+	}
+	if typ == nil {
+		typ = n.Type
+	}
+	if ini == nil {
+		ini = n.Init
+	}
+	n = &New{Op: op, Place: place, Type: typ, Init: ini}
+	if r := fn(n); r != nil {
+		return r
+	}
+	return n
+}
+
+func (n *New) GoString() string {
+	return n.goString(0, "")
+}
+
+func (n *New) goString(indent int, field string) string {
+	var place string
+	if n.Place == nil {
+		place = fmt.Sprintf("%*sPlace: nil", indent, "")
+	} else {
+		place = n.Place.goString(indent+2, "Place: ")
+	}
+	var ini string
+	if n.Init == nil {
+		ini = fmt.Sprintf("%*sInit: nil", indent, "")
+	} else {
+		ini = n.Init.goString(indent+2, "Init: ")
+	}
+	return fmt.Sprintf("%*s%sNew:\n%s\n%s\n%s\n%s", indent, "", field,
+		n.Op.goString(indent+2, "Op: "), place,
+		n.Type.goString(indent+2, "Type: "), ini)
+}
+
+// Literal is a literal in an expression.
+type Literal struct {
+	Type AST
+	Val  string
+	Neg  bool
+}
+
+// Suffixes to use for constants of the given integer type.
+var builtinTypeSuffix = map[string]string{
+	"int":                "",
+	"unsigned int":       "u",
+	"long":               "l",
+	"unsigned long":      "ul",
+	"long long":          "ll",
+	"unsigned long long": "ull",
+}
+
+// Builtin float types.
+var builtinTypeFloat = map[string]bool{
+	"double":      true,
+	"long double": true,
+	"float":       true,
+	"__float128":  true,
+	"half":        true,
+}
+
+func (l *Literal) print(ps *printState) {
+	isFloat := false
+	if b, ok := l.Type.(*BuiltinType); ok {
+		if suffix, ok := builtinTypeSuffix[b.Name]; ok {
+			if l.Neg {
+				ps.writeByte('-')
+			}
+			ps.writeString(l.Val)
+			ps.writeString(suffix)
+			return
+		} else if b.Name == "bool" && !l.Neg {
+			switch l.Val {
+			case "0":
+				ps.writeString("false")
+				return
+			case "1":
+				ps.writeString("true")
+				return
+			}
+		} else if b.Name == "decltype(nullptr)" && l.Val == "" {
+			ps.print(l.Type)
+			return
+		} else {
+			isFloat = builtinTypeFloat[b.Name]
+		}
+	}
+
+	ps.writeByte('(')
+	ps.print(l.Type)
+	ps.writeByte(')')
+
+	if isFloat {
+		ps.writeByte('[')
+	}
+	if l.Neg {
+		ps.writeByte('-')
+	}
+	ps.writeString(l.Val)
+	if isFloat {
+		ps.writeByte(']')
+	}
+}
+
+func (l *Literal) Traverse(fn func(AST) bool) {
+	if fn(l) {
+		l.Type.Traverse(fn)
+	}
+}
+
+func (l *Literal) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(l) {
+		return nil
+	}
+	typ := l.Type.Copy(fn, skip)
+	if typ == nil {
+		return fn(l)
+	}
+	l = &Literal{Type: typ, Val: l.Val, Neg: l.Neg}
+	if r := fn(l); r != nil {
+		return r
+	}
+	return l
+}
+
+func (l *Literal) GoString() string {
+	return l.goString(0, "")
+}
+
+func (l *Literal) goString(indent int, field string) string {
+	var neg string
+	if l.Neg {
+		neg = " Neg: true"
+	}
+	return fmt.Sprintf("%*s%sLiteral:%s\n%s\n%*sVal: %s", indent, "", field,
+		neg, l.Type.goString(indent+2, "Type: "),
+		indent+2, "", l.Val)
+}
+
+// ExprList is a list of expressions, typically arguments to a
+// function call in an expression.
+type ExprList struct {
+	Exprs []AST
+}
+
+func (el *ExprList) print(ps *printState) {
+	for i, e := range el.Exprs {
+		if i > 0 {
+			ps.writeString(", ")
+		}
+		ps.print(e)
+	}
+}
+
+func (el *ExprList) Traverse(fn func(AST) bool) {
+	if fn(el) {
+		for _, e := range el.Exprs {
+			e.Traverse(fn)
+		}
+	}
+}
+
+func (el *ExprList) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(el) {
+		return nil
+	}
+	exprs := make([]AST, len(el.Exprs))
+	changed := false
+	for i, e := range el.Exprs {
+		ec := e.Copy(fn, skip)
+		if ec == nil {
+			exprs[i] = e
+		} else {
+			exprs[i] = ec
+			changed = true
+		}
+	}
+	if !changed {
+		return fn(el)
+	}
+	el = &ExprList{Exprs: exprs}
+	if r := fn(el); r != nil {
+		return r
+	}
+	return el
+}
+
+func (el *ExprList) GoString() string {
+	return el.goString(0, "")
+}
+
+func (el *ExprList) goString(indent int, field string) string {
+	if len(el.Exprs) == 0 {
+		return fmt.Sprintf("%*s%sExprList: nil", indent, "", field)
+	}
+	s := fmt.Sprintf("%*s%sExprList:", indent, "", field)
+	for i, e := range el.Exprs {
+		s += "\n"
+		s += e.goString(indent+2, fmt.Sprintf("%d: ", i))
+	}
+	return s
+}
+
+// InitializerList is an initializer list: an optional type with a
+// list of expressions.
+type InitializerList struct {
+	Type  AST
+	Exprs AST
+}
+
+func (il *InitializerList) print(ps *printState) {
+	if il.Type != nil {
+		ps.print(il.Type)
+	}
+	ps.writeByte('{')
+	ps.print(il.Exprs)
+	ps.writeByte('}')
+}
+
+func (il *InitializerList) Traverse(fn func(AST) bool) {
+	if fn(il) {
+		if il.Type != nil {
+			il.Type.Traverse(fn)
+		}
+		il.Exprs.Traverse(fn)
+	}
+}
+
+func (il *InitializerList) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(il) {
+		return nil
+	}
+	var typ AST
+	if il.Type != nil {
+		typ = il.Type.Copy(fn, skip)
+	}
+	exprs := il.Exprs.Copy(fn, skip)
+	if typ == nil && exprs == nil {
+		return fn(il)
+	}
+	if typ == nil {
+		typ = il.Type
+	}
+	if exprs == nil {
+		exprs = il.Exprs
+	}
+	il = &InitializerList{Type: typ, Exprs: exprs}
+	if r := fn(il); r != nil {
+		return r
+	}
+	return il
+}
+
+func (il *InitializerList) GoString() string {
+	return il.goString(0, "")
+}
+
+func (il *InitializerList) goString(indent int, field string) string {
+	var t string
+	if il.Type == nil {
+		t = fmt.Sprintf("%*sType: nil", indent+2, "")
+	} else {
+		t = il.Type.goString(indent+2, "Type: ")
+	}
+	return fmt.Sprintf("%*s%sInitializerList:\n%s\n%s", indent, "", field,
+		t, il.Exprs.goString(indent+2, "Exprs: "))
+}
+
+// DefaultArg holds a default argument for a local name.
+type DefaultArg struct {
+	Num int
+	Arg AST
+}
+
+func (da *DefaultArg) print(ps *printState) {
+	fmt.Fprintf(&ps.buf, "{default arg#%d}::", da.Num+1)
+	ps.print(da.Arg)
+}
+
+func (da *DefaultArg) Traverse(fn func(AST) bool) {
+	if fn(da) {
+		da.Arg.Traverse(fn)
+	}
+}
+
+func (da *DefaultArg) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(da) {
+		return nil
+	}
+	arg := da.Arg.Copy(fn, skip)
+	if arg == nil {
+		return fn(da)
+	}
+	da = &DefaultArg{Num: da.Num, Arg: arg}
+	if r := fn(da); r != nil {
+		return r
+	}
+	return da
+}
+
+func (da *DefaultArg) GoString() string {
+	return da.goString(0, "")
+}
+
+func (da *DefaultArg) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sDefaultArg: Num: %d\n%s", indent, "", field, da.Num,
+		da.Arg.goString(indent+2, "Arg: "))
+}
+
+// Closure is a closure, or lambda expression.
+type Closure struct {
+	Types []AST
+	Num   int
+}
+
+func (cl *Closure) print(ps *printState) {
+	ps.writeString("{lambda(")
+	for i, t := range cl.Types {
+		if i > 0 {
+			ps.writeString(", ")
+		}
+		ps.print(t)
+	}
+	ps.writeString(fmt.Sprintf(")#%d}", cl.Num+1))
+}
+
+func (cl *Closure) Traverse(fn func(AST) bool) {
+	if fn(cl) {
+		for _, t := range cl.Types {
+			t.Traverse(fn)
+		}
+	}
+}
+
+func (cl *Closure) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(cl) {
+		return nil
+	}
+	types := make([]AST, len(cl.Types))
+	changed := false
+	for i, t := range cl.Types {
+		tc := t.Copy(fn, skip)
+		if tc == nil {
+			types[i] = t
+		} else {
+			types[i] = tc
+			changed = true
+		}
+	}
+	if !changed {
+		return fn(cl)
+	}
+	cl = &Closure{Types: types, Num: cl.Num}
+	if r := fn(cl); r != nil {
+		return r
+	}
+	return cl
+}
+
+func (cl *Closure) GoString() string {
+	return cl.goString(0, "")
+}
+
+func (cl *Closure) goString(indent int, field string) string {
+	var types string
+	if len(cl.Types) == 0 {
+		types = fmt.Sprintf("%*sTypes: nil", indent+2, "")
+	} else {
+		types = fmt.Sprintf("%*sTypes:", indent+2, "")
+		for i, t := range cl.Types {
+			types += "\n"
+			types += t.goString(indent+4, fmt.Sprintf("%d: ", i))
+		}
+	}
+	return fmt.Sprintf("%*s%sClosure: Num: %d\n%s", indent, "", field, cl.Num, types)
+}
+
+// UnnamedType is an unnamed type, that just has an index.
+type UnnamedType struct {
+	Num int
+}
+
+func (ut *UnnamedType) print(ps *printState) {
+	ps.writeString(fmt.Sprintf("{unnamed type#%d}", ut.Num+1))
+}
+
+func (ut *UnnamedType) Traverse(fn func(AST) bool) {
+	fn(ut)
+}
+
+func (ut *UnnamedType) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(ut) {
+		return nil
+	}
+	return fn(ut)
+}
+
+func (ut *UnnamedType) GoString() string {
+	return ut.goString(0, "")
+}
+
+func (ut *UnnamedType) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sUnnamedType: Num: %d", indent, "", field, ut.Num)
+}
+
+// Clone is a clone of a function, with a distinguishing suffix.
+type Clone struct {
+	Base   AST
+	Suffix string
+}
+
+func (c *Clone) print(ps *printState) {
+	ps.print(c.Base)
+	ps.writeString(fmt.Sprintf(" [clone %s]", c.Suffix))
+}
+
+func (c *Clone) Traverse(fn func(AST) bool) {
+	if fn(c) {
+		c.Base.Traverse(fn)
+	}
+}
+
+func (c *Clone) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(c) {
+		return nil
+	}
+	base := c.Base.Copy(fn, skip)
+	if base == nil {
+		return fn(c)
+	}
+	c = &Clone{Base: base, Suffix: c.Suffix}
+	if r := fn(c); r != nil {
+		return r
+	}
+	return c
+}
+
+func (c *Clone) GoString() string {
+	return c.goString(0, "")
+}
+
+func (c *Clone) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sClone: Suffix: %s\n%s", indent, "", field,
+		c.Suffix, c.Base.goString(indent+2, "Base: "))
+}
+
+// Special is a special symbol, printed as a prefix plus another
+// value.
+type Special struct {
+	Prefix string
+	Val    AST
+}
+
+func (s *Special) print(ps *printState) {
+	ps.writeString(s.Prefix)
+	ps.print(s.Val)
+}
+
+func (s *Special) Traverse(fn func(AST) bool) {
+	if fn(s) {
+		s.Val.Traverse(fn)
+	}
+}
+
+func (s *Special) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(s) {
+		return nil
+	}
+	val := s.Val.Copy(fn, skip)
+	if val == nil {
+		return fn(s)
+	}
+	s = &Special{Prefix: s.Prefix, Val: val}
+	if r := fn(s); r != nil {
+		return r
+	}
+	return s
+}
+
+func (s *Special) GoString() string {
+	return s.goString(0, "")
+}
+
+func (s *Special) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sSpecial: Prefix: %s\n%s", indent, "", field,
+		s.Prefix, s.Val.goString(indent+2, "Val: "))
+}
+
+// Special2 is like special, but uses two values.
+type Special2 struct {
+	Prefix string
+	Val1   AST
+	Middle string
+	Val2   AST
+}
+
+func (s *Special2) print(ps *printState) {
+	ps.writeString(s.Prefix)
+	ps.print(s.Val1)
+	ps.writeString(s.Middle)
+	ps.print(s.Val2)
+}
+
+func (s *Special2) Traverse(fn func(AST) bool) {
+	if fn(s) {
+		s.Val1.Traverse(fn)
+		s.Val2.Traverse(fn)
+	}
+}
+
+func (s *Special2) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(s) {
+		return nil
+	}
+	val1 := s.Val1.Copy(fn, skip)
+	val2 := s.Val2.Copy(fn, skip)
+	if val1 == nil && val2 == nil {
+		return fn(s)
+	}
+	if val1 == nil {
+		val1 = s.Val1
+	}
+	if val2 == nil {
+		val2 = s.Val2
+	}
+	s = &Special2{Prefix: s.Prefix, Val1: val1, Middle: s.Middle, Val2: val2}
+	if r := fn(s); r != nil {
+		return r
+	}
+	return s
+}
+
+func (s *Special2) GoString() string {
+	return s.goString(0, "")
+}
+
+func (s *Special2) goString(indent int, field string) string {
+	return fmt.Sprintf("%*s%sSpecial2: Prefix: %s\n%s\n%*sMiddle: %s\n%s", indent, "", field,
+		s.Prefix, s.Val1.goString(indent+2, "Val1: "),
+		indent+2, "", s.Middle, s.Val2.goString(indent+2, "Val2: "))
+}
+
+// EnableIf is used by clang for an enable_if attribute.
+type EnableIf struct {
+	Type AST
+	Args []AST
+}
+
+func (ei *EnableIf) print(ps *printState) {
+	ps.print(ei.Type)
+	ps.writeString(" [enable_if:")
+	first := true
+	for _, a := range ei.Args {
+		if !first {
+			ps.writeString(", ")
+		}
+		ps.print(a)
+		first = false
+	}
+	ps.writeString("]")
+}
+
+func (ei *EnableIf) Traverse(fn func(AST) bool) {
+	if fn(ei) {
+		ei.Type.Traverse(fn)
+		for _, a := range ei.Args {
+			a.Traverse(fn)
+		}
+	}
+}
+
+func (ei *EnableIf) Copy(fn func(AST) AST, skip func(AST) bool) AST {
+	if skip(ei) {
+		return nil
+	}
+	typ := ei.Type.Copy(fn, skip)
+	argsChanged := false
+	args := make([]AST, len(ei.Args))
+	for i, a := range ei.Args {
+		ac := a.Copy(fn, skip)
+		if ac == nil {
+			args[i] = a
+		} else {
+			args[i] = ac
+			argsChanged = true
+		}
+	}
+	if typ == nil && !argsChanged {
+		return fn(ei)
+	}
+	if typ == nil {
+		typ = ei.Type
+	}
+	ei = &EnableIf{Type: typ, Args: args}
+	if r := fn(ei); r != nil {
+		return r
+	}
+	return ei
+}
+
+func (ei *EnableIf) GoString() string {
+	return ei.goString(0, "")
+}
+
+func (ei *EnableIf) goString(indent int, field string) string {
+	var args string
+	if len(ei.Args) == 0 {
+		args = fmt.Sprintf("%*sArgs: nil", indent+2, "")
+	} else {
+		args = fmt.Sprintf("%*sArgs:", indent+2, "")
+		for i, a := range ei.Args {
+			args += "\n"
+			args += a.goString(indent+4, fmt.Sprintf("%d: ", i))
+		}
+	}
+	return fmt.Sprintf("%*s%sEnableIf:\n%s\n%s", indent, "", field,
+		ei.Type.goString(indent+2, "Type: "), args)
+}
+
+// Print the inner types.
+func (ps *printState) printInner(prefixOnly bool) []AST {
+	var save []AST
+	var psave *[]AST
+	if prefixOnly {
+		psave = &save
+	}
+	for len(ps.inner) > 0 {
+		ps.printOneInner(psave)
+	}
+	return save
+}
+
+// innerPrinter is an interface for types that can print themselves as
+// inner types.
+type innerPrinter interface {
+	printInner(*printState)
+}
+
+// Print the most recent inner type.  If save is not nil, only print
+// prefixes.
+func (ps *printState) printOneInner(save *[]AST) {
+	if len(ps.inner) == 0 {
+		panic("printOneInner called with no inner types")
+	}
+	ln := len(ps.inner)
+	a := ps.inner[ln-1]
+	ps.inner = ps.inner[:ln-1]
+
+	if save != nil {
+		if _, ok := a.(*MethodWithQualifiers); ok {
+			*save = append(*save, a)
+			return
+		}
+	}
+
+	if ip, ok := a.(innerPrinter); ok {
+		ip.printInner(ps)
+	} else {
+		ps.print(a)
+	}
+}
+
+// isEmpty returns whether printing a will not print anything.
+func (ps *printState) isEmpty(a AST) bool {
+	switch a := a.(type) {
+	case *ArgumentPack:
+		return len(a.Args) == 0
+	case *ExprList:
+		return len(a.Exprs) == 0
+	case *PackExpansion:
+		return a.Pack != nil && ps.isEmpty(a.Base)
+	default:
+		return false
+	}
+}
diff --git a/src/cmd/vendor/github.com/ianlancetaylor/demangle/demangle.go b/src/cmd/vendor/github.com/ianlancetaylor/demangle/demangle.go
new file mode 100644
index 0000000..c266744
--- /dev/null
+++ b/src/cmd/vendor/github.com/ianlancetaylor/demangle/demangle.go
@@ -0,0 +1,2837 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package demangle defines functions that demangle GCC/LLVM C++ symbol names.
+// This package recognizes names that were mangled according to the C++ ABI
+// defined at http://codesourcery.com/cxx-abi/.
+//
+// Most programs will want to call Filter or ToString.
+package demangle
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// ErrNotMangledName is returned by CheckedDemangle if the string does
+// not appear to be a C++ symbol name.
+var ErrNotMangledName = errors.New("not a C++ mangled name")
+
+// Option is the type of demangler options.
+type Option int
+
+const (
+	// The NoParams option disables demangling of function parameters.
+	NoParams Option = iota
+
+	// The NoTemplateParams option disables demangling of template parameters.
+	NoTemplateParams
+
+	// The NoClones option disables inclusion of clone suffixes.
+	// NoParams implies NoClones.
+	NoClones
+
+	// The Verbose option turns on more verbose demangling.
+	Verbose
+)
+
+// Filter demangles a C++ symbol name, returning the human-readable C++ name.
+// If any error occurs during demangling, the input string is returned.
+func Filter(name string, options ...Option) string {
+	ret, err := ToString(name, options...)
+	if err != nil {
+		return name
+	}
+	return ret
+}
+
+// ToString demangles a C++ symbol name, returning a human-readable C++
+// name or an error.
+// If the name does not appear to be a C++ symbol name at all, the
+// error will be ErrNotMangledName.
+func ToString(name string, options ...Option) (string, error) {
+	a, err := ToAST(name, options...)
+	if err != nil {
+		return "", err
+	}
+	return ASTToString(a, options...), nil
+}
+
+// ToAST demangles a C++ symbol name into an abstract syntax tree
+// representing the symbol.
+// If the NoParams option is passed, and the name has a function type,
+// the parameter types are not demangled.
+// If the name does not appear to be a C++ symbol name at all, the
+// error will be ErrNotMangledName.
+func ToAST(name string, options ...Option) (AST, error) {
+	if strings.HasPrefix(name, "_Z") {
+		a, err := doDemangle(name[2:], options...)
+		return a, adjustErr(err, 2)
+	}
+
+	const prefix = "_GLOBAL_"
+	if strings.HasPrefix(name, prefix) {
+		// The standard demangler ignores NoParams for global
+		// constructors.  We are compatible.
+		i := 0
+		for i < len(options) {
+			if options[i] == NoParams {
+				options = append(options[:i], options[i+1:]...)
+			} else {
+				i++
+			}
+		}
+		a, err := globalCDtorName(name[len(prefix):], options...)
+		return a, adjustErr(err, len(prefix))
+	}
+
+	return nil, ErrNotMangledName
+}
+
+// globalCDtorName demangles a global constructor/destructor symbol name.
+// The parameter is the string following the "_GLOBAL_" prefix.
+func globalCDtorName(name string, options ...Option) (AST, error) {
+	if len(name) < 4 {
+		return nil, ErrNotMangledName
+	}
+	switch name[0] {
+	case '.', '_', '$':
+	default:
+		return nil, ErrNotMangledName
+	}
+
+	var ctor bool
+	switch name[1] {
+	case 'I':
+		ctor = true
+	case 'D':
+		ctor = false
+	default:
+		return nil, ErrNotMangledName
+	}
+
+	if name[2] != '_' {
+		return nil, ErrNotMangledName
+	}
+
+	if !strings.HasPrefix(name[3:], "_Z") {
+		return &GlobalCDtor{Ctor: ctor, Key: &Name{Name: name}}, nil
+	} else {
+		a, err := doDemangle(name[5:], options...)
+		if err != nil {
+			return nil, adjustErr(err, 5)
+		}
+		return &GlobalCDtor{Ctor: ctor, Key: a}, nil
+	}
+}
+
+// The doDemangle function is the entry point into the demangler proper.
+func doDemangle(name string, options ...Option) (ret AST, err error) {
+	// When the demangling routines encounter an error, they panic
+	// with a value of type demangleErr.
+	defer func() {
+		if r := recover(); r != nil {
+			if de, ok := r.(demangleErr); ok {
+				ret = nil
+				err = de
+				return
+			}
+			panic(r)
+		}
+	}()
+
+	params := true
+	clones := true
+	verbose := false
+	for _, o := range options {
+		switch o {
+		case NoParams:
+			params = false
+			clones = false
+		case NoTemplateParams:
+		// This is a valid option but only affect printing of the AST.
+		case NoClones:
+			clones = false
+		case Verbose:
+			verbose = true
+		default:
+			return nil, fmt.Errorf("unrecognized demangler option %v", o)
+		}
+	}
+
+	st := &state{str: name, verbose: verbose}
+	a := st.encoding(params, notForLocalName)
+
+	// Accept a clone suffix.
+	if clones {
+		for len(st.str) > 1 && st.str[0] == '.' && (isLower(st.str[1]) || st.str[1] == '_' || isDigit(st.str[1])) {
+			a = st.cloneSuffix(a)
+		}
+	}
+
+	if clones && len(st.str) > 0 {
+		st.fail("unparsed characters at end of mangled name")
+	}
+
+	return a, nil
+}
+
+// A state holds the current state of demangling a string.
+type state struct {
+	str       string        // remainder of string to demangle
+	verbose   bool          // whether to use verbose demangling
+	off       int           // offset of str within original string
+	subs      substitutions // substitutions
+	templates []*Template   // templates being processed
+	inLambda  int           // number of lambdas being parsed
+}
+
+// copy returns a copy of the current state.
+func (st *state) copy() *state {
+	n := new(state)
+	*n = *st
+	return n
+}
+
+// fail panics with demangleErr, to be caught in doDemangle.
+func (st *state) fail(err string) {
+	panic(demangleErr{err: err, off: st.off})
+}
+
+// failEarlier is like fail, but decrements the offset to indicate
+// that the point of failure occurred earlier in the string.
+func (st *state) failEarlier(err string, dec int) {
+	if st.off < dec {
+		panic("internal error")
+	}
+	panic(demangleErr{err: err, off: st.off - dec})
+}
+
+// advance advances the current string offset.
+func (st *state) advance(add int) {
+	if len(st.str) < add {
+		panic("internal error")
+	}
+	st.str = st.str[add:]
+	st.off += add
+}
+
+// checkChar requires that the next character in the string be c, and
+// advances past it.
+func (st *state) checkChar(c byte) {
+	if len(st.str) == 0 || st.str[0] != c {
+		panic("internal error")
+	}
+	st.advance(1)
+}
+
+// A demangleErr is an error at a specific offset in the mangled
+// string.
+type demangleErr struct {
+	err string
+	off int
+}
+
+// Error implements the builtin error interface for demangleErr.
+func (de demangleErr) Error() string {
+	return fmt.Sprintf("%s at %d", de.err, de.off)
+}
+
+// adjustErr adjusts the position of err, if it is a demangleErr,
+// and returns err.
+func adjustErr(err error, adj int) error {
+	if err == nil {
+		return nil
+	}
+	if de, ok := err.(demangleErr); ok {
+		de.off += adj
+		return de
+	}
+	return err
+}
+
+type forLocalNameType int
+
+const (
+	forLocalName forLocalNameType = iota
+	notForLocalName
+)
+
+// encoding ::= <(function) name> <bare-function-type>
+//              <(data) name>
+//              <special-name>
+func (st *state) encoding(params bool, local forLocalNameType) AST {
+	if len(st.str) < 1 {
+		st.fail("expected encoding")
+	}
+
+	if st.str[0] == 'G' || st.str[0] == 'T' {
+		return st.specialName()
+	}
+
+	a := st.name()
+	a = simplify(a)
+
+	if !params {
+		// Don't demangle the parameters.
+
+		// Strip CV-qualifiers, as they apply to the 'this'
+		// parameter, and are not output by the standard
+		// demangler without parameters.
+		if mwq, ok := a.(*MethodWithQualifiers); ok {
+			a = mwq.Method
+		}
+
+		// If this is a local name, there may be CV-qualifiers
+		// on the name that really apply to the top level, and
+		// therefore must be discarded when discarding
+		// parameters.  This can happen when parsing a class
+		// that is local to a function.
+		if q, ok := a.(*Qualified); ok && q.LocalName {
+			p := &q.Name
+			if da, ok := (*p).(*DefaultArg); ok {
+				p = &da.Arg
+			}
+			if mwq, ok := (*p).(*MethodWithQualifiers); ok {
+				*p = mwq.Method
+			}
+		}
+
+		return a
+	}
+
+	if len(st.str) == 0 || st.str[0] == 'E' {
+		// There are no parameters--this is a data symbol, not
+		// a function symbol.
+		return a
+	}
+
+	check := a
+	mwq, _ := check.(*MethodWithQualifiers)
+	if mwq != nil {
+		check = mwq.Method
+	}
+
+	var template *Template
+	switch check := check.(type) {
+	case *Template:
+		template = check
+	case *Qualified:
+		if check.LocalName {
+			n := check.Name
+			if nmwq, ok := n.(*MethodWithQualifiers); ok {
+				n = nmwq.Method
+			}
+			template, _ = n.(*Template)
+		}
+	}
+	var oldInLambda int
+	if template != nil {
+		st.templates = append(st.templates, template)
+		oldInLambda = st.inLambda
+		st.inLambda = 0
+	}
+
+	// Checking for the enable_if attribute here is what the LLVM
+	// demangler does.  This is not very general but perhaps it is
+	// sufficent.
+	const enableIfPrefix = "Ua9enable_ifI"
+	var enableIfArgs []AST
+	if strings.HasPrefix(st.str, enableIfPrefix) {
+		st.advance(len(enableIfPrefix) - 1)
+		enableIfArgs = st.templateArgs()
+	}
+
+	ft := st.bareFunctionType(hasReturnType(a))
+
+	if template != nil {
+		st.templates = st.templates[:len(st.templates)-1]
+		st.inLambda = oldInLambda
+	}
+
+	ft = simplify(ft)
+
+	// For a local name, discard the return type, so that it
+	// doesn't get confused with the top level return type.
+	if local == forLocalName {
+		if functype, ok := ft.(*FunctionType); ok {
+			functype.Return = nil
+		}
+	}
+
+	// Any top-level qualifiers belong to the function type.
+	if mwq != nil {
+		a = mwq.Method
+		mwq.Method = ft
+		ft = mwq
+	}
+	if q, ok := a.(*Qualified); ok && q.LocalName {
+		p := &q.Name
+		if da, ok := (*p).(*DefaultArg); ok {
+			p = &da.Arg
+		}
+		if mwq, ok := (*p).(*MethodWithQualifiers); ok {
+			*p = mwq.Method
+			mwq.Method = ft
+			ft = mwq
+		}
+	}
+
+	r := AST(&Typed{Name: a, Type: ft})
+
+	if len(enableIfArgs) > 0 {
+		r = &EnableIf{Type: r, Args: enableIfArgs}
+	}
+
+	return r
+}
+
+// hasReturnType returns whether the mangled form of a will have a
+// return type.
+func hasReturnType(a AST) bool {
+	switch a := a.(type) {
+	case *Qualified:
+		if a.LocalName {
+			return hasReturnType(a.Name)
+		}
+		return false
+	case *Template:
+		return !isCDtorConversion(a.Name)
+	case *TypeWithQualifiers:
+		return hasReturnType(a.Base)
+	case *MethodWithQualifiers:
+		return hasReturnType(a.Method)
+	default:
+		return false
+	}
+}
+
+// isCDtorConversion returns when an AST is a constructor, a
+// destructor, or a conversion operator.
+func isCDtorConversion(a AST) bool {
+	switch a := a.(type) {
+	case *Qualified:
+		return isCDtorConversion(a.Name)
+	case *Constructor, *Destructor, *Cast:
+		return true
+	default:
+		return false
+	}
+}
+
+// <tagged-name> ::= <name> B <source-name>
+func (st *state) taggedName(a AST) AST {
+	for len(st.str) > 0 && st.str[0] == 'B' {
+		st.advance(1)
+		tag := st.sourceName()
+		a = &TaggedName{Name: a, Tag: tag}
+	}
+	return a
+}
+
+// <name> ::= <nested-name>
+//        ::= <unscoped-name>
+//        ::= <unscoped-template-name> <template-args>
+//        ::= <local-name>
+//
+// <unscoped-name> ::= <unqualified-name>
+//                 ::= St <unqualified-name>
+//
+// <unscoped-template-name> ::= <unscoped-name>
+//                          ::= <substitution>
+func (st *state) name() AST {
+	if len(st.str) < 1 {
+		st.fail("expected name")
+	}
+	switch st.str[0] {
+	case 'N':
+		return st.nestedName()
+	case 'Z':
+		return st.localName()
+	case 'U':
+		a, isCast := st.unqualifiedName()
+		if isCast {
+			st.setTemplate(a, nil)
+		}
+		return a
+	case 'S':
+		if len(st.str) < 2 {
+			st.advance(1)
+			st.fail("expected substitution index")
+		}
+		var a AST
+		isCast := false
+		subst := false
+		if st.str[1] == 't' {
+			st.advance(2)
+			a, isCast = st.unqualifiedName()
+			a = &Qualified{Scope: &Name{Name: "std"}, Name: a, LocalName: false}
+		} else {
+			a = st.substitution(false)
+			subst = true
+		}
+		if len(st.str) > 0 && st.str[0] == 'I' {
+			// This can only happen if we saw
+			// <unscoped-template-name> and are about to see
+			// <template-args>.  <unscoped-template-name> is a
+			// substitution candidate if it did not come from a
+			// substitution.
+			if !subst {
+				st.subs.add(a)
+			}
+			args := st.templateArgs()
+			tmpl := &Template{Name: a, Args: args}
+			if isCast {
+				st.setTemplate(a, tmpl)
+				st.clearTemplateArgs(args)
+				isCast = false
+			}
+			a = tmpl
+		}
+		if isCast {
+			st.setTemplate(a, nil)
+		}
+		return a
+
+	default:
+		a, isCast := st.unqualifiedName()
+		if len(st.str) > 0 && st.str[0] == 'I' {
+			st.subs.add(a)
+			args := st.templateArgs()
+			tmpl := &Template{Name: a, Args: args}
+			if isCast {
+				st.setTemplate(a, tmpl)
+				st.clearTemplateArgs(args)
+				isCast = false
+			}
+			a = tmpl
+		}
+		if isCast {
+			st.setTemplate(a, nil)
+		}
+		return a
+	}
+}
+
+// <nested-name> ::= N [<CV-qualifiers>] [<ref-qualifier>] <prefix> <unqualified-name> E
+//               ::= N [<CV-qualifiers>] [<ref-qualifier>] <template-prefix> <template-args> E
+func (st *state) nestedName() AST {
+	st.checkChar('N')
+	q := st.cvQualifiers()
+	r := st.refQualifier()
+	a := st.prefix()
+	if q != nil || r != "" {
+		a = &MethodWithQualifiers{Method: a, Qualifiers: q, RefQualifier: r}
+	}
+	if len(st.str) == 0 || st.str[0] != 'E' {
+		st.fail("expected E after nested name")
+	}
+	st.advance(1)
+	return a
+}
+
+// <prefix> ::= <prefix> <unqualified-name>
+//          ::= <template-prefix> <template-args>
+//          ::= <template-param>
+//          ::= <decltype>
+//          ::=
+//          ::= <substitution>
+//
+// <template-prefix> ::= <prefix> <(template) unqualified-name>
+//                   ::= <template-param>
+//                   ::= <substitution>
+//
+// <decltype> ::= Dt <expression> E
+//            ::= DT <expression> E
+func (st *state) prefix() AST {
+	var a AST
+
+	// The last name seen, for a constructor/destructor.
+	var last AST
+
+	getLast := func(a AST) AST {
+		for {
+			if t, ok := a.(*Template); ok {
+				a = t.Name
+			} else if q, ok := a.(*Qualified); ok {
+				a = q.Name
+			} else if t, ok := a.(*TaggedName); ok {
+				a = t.Name
+			} else {
+				return a
+			}
+		}
+	}
+
+	isCast := false
+	for {
+		if len(st.str) == 0 {
+			st.fail("expected prefix")
+		}
+		var next AST
+
+		c := st.str[0]
+		if isDigit(c) || isLower(c) || c == 'U' || c == 'L' {
+			un, isUnCast := st.unqualifiedName()
+			next = un
+			if isUnCast {
+				isCast = true
+			}
+		} else {
+			switch st.str[0] {
+			case 'C':
+				inheriting := false
+				st.advance(1)
+				if len(st.str) > 0 && st.str[0] == 'I' {
+					inheriting = true
+					st.advance(1)
+				}
+				if len(st.str) < 1 {
+					st.fail("expected constructor type")
+				}
+				if last == nil {
+					st.fail("constructor before name is seen")
+				}
+				st.advance(1)
+				if inheriting {
+					last = st.demangleType(false)
+				}
+				next = &Constructor{Name: getLast(last)}
+			case 'D':
+				if len(st.str) > 1 && (st.str[1] == 'T' || st.str[1] == 't') {
+					next = st.demangleType(false)
+				} else {
+					if len(st.str) < 2 {
+						st.fail("expected destructor type")
+					}
+					if last == nil {
+						st.fail("destructor before name is seen")
+					}
+					st.advance(2)
+					next = &Destructor{Name: getLast(last)}
+				}
+			case 'S':
+				next = st.substitution(true)
+			case 'I':
+				if a == nil {
+					st.fail("unexpected template arguments")
+				}
+				var args []AST
+				args = st.templateArgs()
+				tmpl := &Template{Name: a, Args: args}
+				if isCast {
+					st.setTemplate(a, tmpl)
+					st.clearTemplateArgs(args)
+					isCast = false
+				}
+				a = nil
+				next = tmpl
+			case 'T':
+				next = st.templateParam()
+			case 'E':
+				if a == nil {
+					st.fail("expected prefix")
+				}
+				if isCast {
+					st.setTemplate(a, nil)
+				}
+				return a
+			case 'M':
+				if a == nil {
+					st.fail("unexpected lambda initializer")
+				}
+				// This is the initializer scope for a
+				// lambda.  We don't need to record
+				// it.  The normal code will treat the
+				// variable has a type scope, which
+				// gives appropriate output.
+				st.advance(1)
+				continue
+			case 'J':
+				// It appears that in some cases clang
+				// can emit a J for a template arg
+				// without the expected I.  I don't
+				// know when this happens, but I've
+				// seen it in some large C++ programs.
+				if a == nil {
+					st.fail("unexpected template arguments")
+				}
+				var args []AST
+				for len(st.str) == 0 || st.str[0] != 'E' {
+					arg := st.templateArg()
+					args = append(args, arg)
+				}
+				st.advance(1)
+				tmpl := &Template{Name: a, Args: args}
+				if isCast {
+					st.setTemplate(a, tmpl)
+					st.clearTemplateArgs(args)
+					isCast = false
+				}
+				a = nil
+				next = tmpl
+			default:
+				st.fail("unrecognized letter in prefix")
+			}
+		}
+		last = next
+		if a == nil {
+			a = next
+		} else {
+			a = &Qualified{Scope: a, Name: next, LocalName: false}
+		}
+
+		if c != 'S' && (len(st.str) == 0 || st.str[0] != 'E') {
+			st.subs.add(a)
+		}
+	}
+}
+
+// <unqualified-name> ::= <operator-name>
+//                    ::= <ctor-dtor-name>
+//                    ::= <source-name>
+//                    ::= <local-source-name>
+//
+//  <local-source-name>	::= L <source-name> <discriminator>
+func (st *state) unqualifiedName() (r AST, isCast bool) {
+	if len(st.str) < 1 {
+		st.fail("expected unqualified name")
+	}
+	var a AST
+	isCast = false
+	c := st.str[0]
+	if isDigit(c) {
+		a = st.sourceName()
+	} else if isLower(c) {
+		a, _ = st.operatorName(false)
+		if _, ok := a.(*Cast); ok {
+			isCast = true
+		}
+		if op, ok := a.(*Operator); ok && op.Name == `operator"" ` {
+			n := st.sourceName()
+			a = &Unary{Op: op, Expr: n, Suffix: false, SizeofType: false}
+		}
+	} else {
+		switch c {
+		case 'C', 'D':
+			st.fail("constructor/destructor not in nested name")
+		case 'L':
+			st.advance(1)
+			a = st.sourceName()
+			a = st.discriminator(a)
+		case 'U':
+			if len(st.str) < 2 {
+				st.advance(1)
+				st.fail("expected closure or unnamed type")
+			}
+			c := st.str[1]
+			switch c {
+			case 'l':
+				a = st.closureTypeName()
+			case 't':
+				a = st.unnamedTypeName()
+			default:
+				st.advance(1)
+				st.fail("expected closure or unnamed type")
+			}
+		default:
+			st.fail("expected unqualified name")
+		}
+	}
+
+	if len(st.str) > 0 && st.str[0] == 'B' {
+		a = st.taggedName(a)
+	}
+
+	return a, isCast
+}
+
+// <source-name> ::= <(positive length) number> <identifier>
+// identifier ::= <(unqualified source code identifier)>
+func (st *state) sourceName() AST {
+	val := st.number()
+	if val <= 0 {
+		st.fail("expected positive number")
+	}
+	if len(st.str) < val {
+		st.fail("not enough characters for identifier")
+	}
+	id := st.str[:val]
+	st.advance(val)
+
+	// Look for GCC encoding of anonymous namespace, and make it
+	// more friendly.
+	const anonPrefix = "_GLOBAL_"
+	if strings.HasPrefix(id, anonPrefix) && len(id) > len(anonPrefix)+2 {
+		c1 := id[len(anonPrefix)]
+		c2 := id[len(anonPrefix)+1]
+		if (c1 == '.' || c1 == '_' || c1 == '$') && c2 == 'N' {
+			id = "(anonymous namespace)"
+		}
+	}
+
+	n := &Name{Name: id}
+	return n
+}
+
+// number ::= [n] <(non-negative decimal integer)>
+func (st *state) number() int {
+	neg := false
+	if len(st.str) > 0 && st.str[0] == 'n' {
+		neg = true
+		st.advance(1)
+	}
+	if len(st.str) == 0 || !isDigit(st.str[0]) {
+		st.fail("missing number")
+	}
+	val := 0
+	for len(st.str) > 0 && isDigit(st.str[0]) {
+		// Number picked to ensure we can't overflow with 32-bit int.
+		// Any very large number here is bogus.
+		if val >= 0x80000000/10-10 {
+			st.fail("numeric overflow")
+		}
+		val = val*10 + int(st.str[0]-'0')
+		st.advance(1)
+	}
+	if neg {
+		val = -val
+	}
+	return val
+}
+
+// An operator is the demangled name, and the number of arguments it
+// takes in an expression.
+type operator struct {
+	name string
+	args int
+}
+
+// The operators map maps the mangled operator names to information
+// about them.
+var operators = map[string]operator{
+	"aN": {"&=", 2},
+	"aS": {"=", 2},
+	"aa": {"&&", 2},
+	"ad": {"&", 1},
+	"an": {"&", 2},
+	"at": {"alignof ", 1},
+	"aw": {"co_await ", 1},
+	"az": {"alignof ", 1},
+	"cc": {"const_cast", 2},
+	"cl": {"()", 2},
+	// cp is not in the ABI but is used by clang "when the call
+	// would use ADL except for being parenthesized."
+	"cp": {"()", 2},
+	"cm": {",", 2},
+	"co": {"~", 1},
+	"dV": {"/=", 2},
+	"dX": {"[...]=", 3},
+	"da": {"delete[] ", 1},
+	"dc": {"dynamic_cast", 2},
+	"de": {"*", 1},
+	"di": {"=", 2},
+	"dl": {"delete ", 1},
+	"ds": {".*", 2},
+	"dt": {".", 2},
+	"dv": {"/", 2},
+	"dx": {"]=", 2},
+	"eO": {"^=", 2},
+	"eo": {"^", 2},
+	"eq": {"==", 2},
+	"fl": {"...", 2},
+	"fr": {"...", 2},
+	"fL": {"...", 3},
+	"fR": {"...", 3},
+	"ge": {">=", 2},
+	"gs": {"::", 1},
+	"gt": {">", 2},
+	"ix": {"[]", 2},
+	"lS": {"<<=", 2},
+	"le": {"<=", 2},
+	"li": {`operator"" `, 1},
+	"ls": {"<<", 2},
+	"lt": {"<", 2},
+	"mI": {"-=", 2},
+	"mL": {"*=", 2},
+	"mi": {"-", 2},
+	"ml": {"*", 2},
+	"mm": {"--", 1},
+	"na": {"new[]", 3},
+	"ne": {"!=", 2},
+	"ng": {"-", 1},
+	"nt": {"!", 1},
+	"nw": {"new", 3},
+	"oR": {"|=", 2},
+	"oo": {"||", 2},
+	"or": {"|", 2},
+	"pL": {"+=", 2},
+	"pl": {"+", 2},
+	"pm": {"->*", 2},
+	"pp": {"++", 1},
+	"ps": {"+", 1},
+	"pt": {"->", 2},
+	"qu": {"?", 3},
+	"rM": {"%=", 2},
+	"rS": {">>=", 2},
+	"rc": {"reinterpret_cast", 2},
+	"rm": {"%", 2},
+	"rs": {">>", 2},
+	"sP": {"sizeof...", 1},
+	"sZ": {"sizeof...", 1},
+	"sc": {"static_cast", 2},
+	"ss": {"<=>", 2},
+	"st": {"sizeof ", 1},
+	"sz": {"sizeof ", 1},
+	"tr": {"throw", 0},
+	"tw": {"throw ", 1},
+}
+
+// operator_name ::= many different two character encodings.
+//               ::= cv <type>
+//               ::= v <digit> <source-name>
+//
+// We need to know whether we are in an expression because it affects
+// how we handle template parameters in the type of a cast operator.
+func (st *state) operatorName(inExpression bool) (AST, int) {
+	if len(st.str) < 2 {
+		st.fail("missing operator code")
+	}
+	code := st.str[:2]
+	st.advance(2)
+	if code[0] == 'v' && isDigit(code[1]) {
+		name := st.sourceName()
+		return &Operator{Name: name.(*Name).Name}, int(code[1] - '0')
+	} else if code == "cv" {
+		// Push a nil on templates to indicate that template
+		// parameters will have their template filled in
+		// later.
+		if !inExpression {
+			st.templates = append(st.templates, nil)
+		}
+
+		t := st.demangleType(!inExpression)
+
+		if !inExpression {
+			st.templates = st.templates[:len(st.templates)-1]
+		}
+
+		return &Cast{To: t}, 1
+	} else if op, ok := operators[code]; ok {
+		return &Operator{Name: op.name}, op.args
+	} else {
+		st.failEarlier("unrecognized operator code", 2)
+		panic("not reached")
+	}
+}
+
+// <local-name> ::= Z <(function) encoding> E <(entity) name> [<discriminator>]
+//              ::= Z <(function) encoding> E s [<discriminator>]
+//              ::= Z <(function) encoding> E d [<parameter> number>] _ <entity name>
+func (st *state) localName() AST {
+	st.checkChar('Z')
+	fn := st.encoding(true, forLocalName)
+	if len(st.str) == 0 || st.str[0] != 'E' {
+		st.fail("expected E after local name")
+	}
+	st.advance(1)
+	if len(st.str) > 0 && st.str[0] == 's' {
+		st.advance(1)
+		var n AST = &Name{Name: "string literal"}
+		n = st.discriminator(n)
+		return &Qualified{Scope: fn, Name: n, LocalName: true}
+	} else {
+		num := -1
+		if len(st.str) > 0 && st.str[0] == 'd' {
+			// Default argument scope.
+			st.advance(1)
+			num = st.compactNumber()
+		}
+		n := st.name()
+		n = st.discriminator(n)
+		if num >= 0 {
+			n = &DefaultArg{Num: num, Arg: n}
+		}
+		return &Qualified{Scope: fn, Name: n, LocalName: true}
+	}
+}
+
+// Parse a Java resource special-name.
+func (st *state) javaResource() AST {
+	off := st.off
+	ln := st.number()
+	if ln <= 1 {
+		st.failEarlier("java resource length less than 1", st.off-off)
+	}
+	if len(st.str) == 0 || st.str[0] != '_' {
+		st.fail("expected _ after number")
+	}
+	st.advance(1)
+	ln--
+	if len(st.str) < ln {
+		st.fail("not enough characters for java resource length")
+	}
+	str := st.str[:ln]
+	final := ""
+	st.advance(ln)
+	for i := 0; i < len(str); i++ {
+		if str[i] != '$' {
+			final += string(str[i])
+		} else {
+			if len(str) <= i+1 {
+				st.failEarlier("java resource escape at end of string", 1)
+			}
+			i++
+			r, ok := map[byte]string{
+				'S': "/",
+				'_': ".",
+				'$': "$",
+			}[str[i]]
+			if !ok {
+				st.failEarlier("unrecognized java resource escape", ln-i-1)
+			}
+			final += r
+		}
+	}
+	return &Special{Prefix: "java resource ", Val: &Name{Name: final}}
+}
+
+// <special-name> ::= TV <type>
+//                ::= TT <type>
+//                ::= TI <type>
+//                ::= TS <type>
+//                ::= TA <template-arg>
+//                ::= GV <(object) name>
+//                ::= T <call-offset> <(base) encoding>
+//                ::= Tc <call-offset> <call-offset> <(base) encoding>
+// Also g++ extensions:
+//                ::= TC <type> <(offset) number> _ <(base) type>
+//                ::= TF <type>
+//                ::= TJ <type>
+//                ::= GR <name>
+//                ::= GA <encoding>
+//                ::= Gr <resource name>
+//                ::= GTt <encoding>
+//                ::= GTn <encoding>
+func (st *state) specialName() AST {
+	if st.str[0] == 'T' {
+		st.advance(1)
+		if len(st.str) == 0 {
+			st.fail("expected special name code")
+		}
+		c := st.str[0]
+		st.advance(1)
+		switch c {
+		case 'V':
+			t := st.demangleType(false)
+			return &Special{Prefix: "vtable for ", Val: t}
+		case 'T':
+			t := st.demangleType(false)
+			return &Special{Prefix: "VTT for ", Val: t}
+		case 'I':
+			t := st.demangleType(false)
+			return &Special{Prefix: "typeinfo for ", Val: t}
+		case 'S':
+			t := st.demangleType(false)
+			return &Special{Prefix: "typeinfo name for ", Val: t}
+		case 'A':
+			t := st.templateArg()
+			return &Special{Prefix: "template parameter object for ", Val: t}
+		case 'h':
+			st.callOffset('h')
+			v := st.encoding(true, notForLocalName)
+			return &Special{Prefix: "non-virtual thunk to ", Val: v}
+		case 'v':
+			st.callOffset('v')
+			v := st.encoding(true, notForLocalName)
+			return &Special{Prefix: "virtual thunk to ", Val: v}
+		case 'c':
+			st.callOffset(0)
+			st.callOffset(0)
+			v := st.encoding(true, notForLocalName)
+			return &Special{Prefix: "covariant return thunk to ", Val: v}
+		case 'C':
+			derived := st.demangleType(false)
+			off := st.off
+			offset := st.number()
+			if offset < 0 {
+				st.failEarlier("expected positive offset", st.off-off)
+			}
+			if len(st.str) == 0 || st.str[0] != '_' {
+				st.fail("expected _ after number")
+			}
+			st.advance(1)
+			base := st.demangleType(false)
+			return &Special2{Prefix: "construction vtable for ", Val1: base, Middle: "-in-", Val2: derived}
+		case 'F':
+			t := st.demangleType(false)
+			return &Special{Prefix: "typeinfo fn for ", Val: t}
+		case 'J':
+			t := st.demangleType(false)
+			return &Special{Prefix: "java Class for ", Val: t}
+		case 'H':
+			n := st.name()
+			return &Special{Prefix: "TLS init function for ", Val: n}
+		case 'W':
+			n := st.name()
+			return &Special{Prefix: "TLS wrapper function for ", Val: n}
+		default:
+			st.fail("unrecognized special T name code")
+			panic("not reached")
+		}
+	} else {
+		st.checkChar('G')
+		if len(st.str) == 0 {
+			st.fail("expected special name code")
+		}
+		c := st.str[0]
+		st.advance(1)
+		switch c {
+		case 'V':
+			n := st.name()
+			return &Special{Prefix: "guard variable for ", Val: n}
+		case 'R':
+			n := st.name()
+			i := st.number()
+			return &Special{Prefix: fmt.Sprintf("reference temporary #%d for ", i), Val: n}
+		case 'A':
+			v := st.encoding(true, notForLocalName)
+			return &Special{Prefix: "hidden alias for ", Val: v}
+		case 'T':
+			if len(st.str) == 0 {
+				st.fail("expected special GT name code")
+			}
+			c := st.str[0]
+			st.advance(1)
+			v := st.encoding(true, notForLocalName)
+			switch c {
+			case 'n':
+				return &Special{Prefix: "non-transaction clone for ", Val: v}
+			default:
+				// The proposal is that different
+				// letters stand for different types
+				// of transactional cloning.  Treat
+				// them all the same for now.
+				fallthrough
+			case 't':
+				return &Special{Prefix: "transaction clone for ", Val: v}
+			}
+		case 'r':
+			return st.javaResource()
+		default:
+			st.fail("unrecognized special G name code")
+			panic("not reached")
+		}
+	}
+}
+
+// <call-offset> ::= h <nv-offset> _
+//               ::= v <v-offset> _
+//
+// <nv-offset> ::= <(offset) number>
+//
+// <v-offset> ::= <(offset) number> _ <(virtual offset) number>
+//
+// The c parameter, if not 0, is a character we just read which is the
+// start of the <call-offset>.
+//
+// We don't display the offset information anywhere.
+func (st *state) callOffset(c byte) {
+	if c == 0 {
+		if len(st.str) == 0 {
+			st.fail("missing call offset")
+		}
+		c = st.str[0]
+		st.advance(1)
+	}
+	switch c {
+	case 'h':
+		st.number()
+	case 'v':
+		st.number()
+		if len(st.str) == 0 || st.str[0] != '_' {
+			st.fail("expected _ after number")
+		}
+		st.advance(1)
+		st.number()
+	default:
+		st.failEarlier("unrecognized call offset code", 1)
+	}
+	if len(st.str) == 0 || st.str[0] != '_' {
+		st.fail("expected _ after call offset")
+	}
+	st.advance(1)
+}
+
+// builtinTypes maps the type letter to the type name.
+var builtinTypes = map[byte]string{
+	'a': "signed char",
+	'b': "bool",
+	'c': "char",
+	'd': "double",
+	'e': "long double",
+	'f': "float",
+	'g': "__float128",
+	'h': "unsigned char",
+	'i': "int",
+	'j': "unsigned int",
+	'l': "long",
+	'm': "unsigned long",
+	'n': "__int128",
+	'o': "unsigned __int128",
+	's': "short",
+	't': "unsigned short",
+	'v': "void",
+	'w': "wchar_t",
+	'x': "long long",
+	'y': "unsigned long long",
+	'z': "...",
+}
+
+// <type> ::= <builtin-type>
+//        ::= <function-type>
+//        ::= <class-enum-type>
+//        ::= <array-type>
+//        ::= <pointer-to-member-type>
+//        ::= <template-param>
+//        ::= <template-template-param> <template-args>
+//        ::= <substitution>
+//        ::= <CV-qualifiers> <type>
+//        ::= P <type>
+//        ::= R <type>
+//        ::= O <type> (C++0x)
+//        ::= C <type>
+//        ::= G <type>
+//        ::= U <source-name> <type>
+//
+// <builtin-type> ::= various one letter codes
+//                ::= u <source-name>
+func (st *state) demangleType(isCast bool) AST {
+	if len(st.str) == 0 {
+		st.fail("expected type")
+	}
+
+	addSubst := true
+
+	q := st.cvQualifiers()
+	if q != nil {
+		if len(st.str) == 0 {
+			st.fail("expected type")
+		}
+
+		// CV-qualifiers before a function type apply to
+		// 'this', so avoid adding the unqualified function
+		// type to the substitution list.
+		if st.str[0] == 'F' {
+			addSubst = false
+		}
+	}
+
+	var ret AST
+
+	// Use correct substitution for a template parameter.
+	var sub AST
+
+	if btype, ok := builtinTypes[st.str[0]]; ok {
+		ret = &BuiltinType{Name: btype}
+		st.advance(1)
+		if q != nil {
+			ret = &TypeWithQualifiers{Base: ret, Qualifiers: q}
+			st.subs.add(ret)
+		}
+		return ret
+	}
+	c := st.str[0]
+	switch c {
+	case 'u':
+		st.advance(1)
+		ret = st.sourceName()
+	case 'F':
+		ret = st.functionType()
+	case 'N', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+		ret = st.name()
+	case 'A':
+		ret = st.arrayType(isCast)
+	case 'M':
+		ret = st.pointerToMemberType(isCast)
+	case 'T':
+		ret = st.templateParam()
+		if len(st.str) > 0 && st.str[0] == 'I' {
+			// See the function comment to explain this.
+			if !isCast {
+				st.subs.add(ret)
+				args := st.templateArgs()
+				ret = &Template{Name: ret, Args: args}
+			} else {
+				ret = st.demangleCastTemplateArgs(ret, true)
+			}
+		}
+	case 'S':
+		// If this is a special substitution, then it
+		// is the start of <class-enum-type>.
+		var c2 byte
+		if len(st.str) > 1 {
+			c2 = st.str[1]
+		}
+		if isDigit(c2) || c2 == '_' || isUpper(c2) {
+			ret = st.substitution(false)
+			if len(st.str) == 0 || st.str[0] != 'I' {
+				addSubst = false
+			} else {
+				// See the function comment to explain this.
+				if _, ok := ret.(*TemplateParam); !ok || !isCast {
+					args := st.templateArgs()
+					ret = &Template{Name: ret, Args: args}
+				} else {
+					next := st.demangleCastTemplateArgs(ret, false)
+					if next == ret {
+						addSubst = false
+					}
+					ret = next
+				}
+			}
+		} else {
+			ret = st.name()
+			// This substitution is not itself a
+			// substitution candidate, unless template
+			// arguments were added.
+			if ret == subAST[c2] || ret == verboseAST[c2] {
+				addSubst = false
+			}
+		}
+	case 'O', 'P', 'R', 'C', 'G':
+		st.advance(1)
+		t := st.demangleType(isCast)
+		switch c {
+		case 'O':
+			ret = &RvalueReferenceType{Base: t}
+		case 'P':
+			ret = &PointerType{Base: t}
+		case 'R':
+			ret = &ReferenceType{Base: t}
+		case 'C':
+			ret = &ComplexType{Base: t}
+		case 'G':
+			ret = &ImaginaryType{Base: t}
+		}
+	case 'U':
+		if len(st.str) < 2 {
+			st.fail("expected source name or unnamed type")
+		}
+		switch st.str[1] {
+		case 'l':
+			ret = st.closureTypeName()
+			addSubst = false
+		case 't':
+			ret = st.unnamedTypeName()
+			addSubst = false
+		default:
+			st.advance(1)
+			n := st.sourceName()
+			if len(st.str) > 0 && st.str[0] == 'I' {
+				args := st.templateArgs()
+				n = &Template{Name: n, Args: args}
+			}
+			t := st.demangleType(isCast)
+			ret = &VendorQualifier{Qualifier: n, Type: t}
+		}
+	case 'D':
+		st.advance(1)
+		if len(st.str) == 0 {
+			st.fail("expected D code for type")
+		}
+		addSubst = false
+		c2 := st.str[0]
+		st.advance(1)
+		switch c2 {
+		case 'T', 't':
+			// decltype(expression)
+			ret = st.expression()
+			if len(st.str) == 0 || st.str[0] != 'E' {
+				st.fail("expected E after expression in type")
+			}
+			st.advance(1)
+			ret = &Decltype{Expr: ret}
+			addSubst = true
+
+		case 'p':
+			t := st.demangleType(isCast)
+			pack := st.findArgumentPack(t)
+			ret = &PackExpansion{Base: t, Pack: pack}
+			addSubst = true
+
+		case 'a':
+			ret = &Name{Name: "auto"}
+		case 'c':
+			ret = &Name{Name: "decltype(auto)"}
+
+		case 'f':
+			ret = &BuiltinType{Name: "decimal32"}
+		case 'd':
+			ret = &BuiltinType{Name: "decimal64"}
+		case 'e':
+			ret = &BuiltinType{Name: "decimal128"}
+		case 'h':
+			ret = &BuiltinType{Name: "half"}
+		case 'u':
+			ret = &BuiltinType{Name: "char8_t"}
+		case 's':
+			ret = &BuiltinType{Name: "char16_t"}
+		case 'i':
+			ret = &BuiltinType{Name: "char32_t"}
+		case 'n':
+			ret = &BuiltinType{Name: "decltype(nullptr)"}
+
+		case 'F':
+			accum := false
+			if len(st.str) > 0 && isDigit(st.str[0]) {
+				accum = true
+				// We don't care about the bits.
+				_ = st.number()
+			}
+			base := st.demangleType(isCast)
+			if len(st.str) > 0 && isDigit(st.str[0]) {
+				// We don't care about the bits.
+				st.number()
+			}
+			sat := false
+			if len(st.str) > 0 {
+				if st.str[0] == 's' {
+					sat = true
+				}
+				st.advance(1)
+			}
+			ret = &FixedType{Base: base, Accum: accum, Sat: sat}
+
+		case 'v':
+			ret = st.vectorType(isCast)
+			addSubst = true
+
+		default:
+			st.fail("unrecognized D code in type")
+		}
+
+	default:
+		st.fail("unrecognized type code")
+	}
+
+	if addSubst {
+		if sub != nil {
+			st.subs.add(sub)
+		} else {
+			st.subs.add(ret)
+		}
+	}
+
+	if q != nil {
+		if _, ok := ret.(*FunctionType); ok {
+			ret = &MethodWithQualifiers{Method: ret, Qualifiers: q, RefQualifier: ""}
+		} else if mwq, ok := ret.(*MethodWithQualifiers); ok {
+			// Merge adjacent qualifiers.  This case
+			// happens with a function with a trailing
+			// ref-qualifier.
+			mwq.Qualifiers = mergeQualifiers(q, mwq.Qualifiers)
+		} else {
+			// Merge adjacent qualifiers.  This case
+			// happens with multi-dimensional array types.
+			if qsub, ok := ret.(*TypeWithQualifiers); ok {
+				q = mergeQualifiers(q, qsub.Qualifiers)
+				ret = qsub.Base
+			}
+			ret = &TypeWithQualifiers{Base: ret, Qualifiers: q}
+		}
+		st.subs.add(ret)
+	}
+
+	return ret
+}
+
+// demangleCastTemplateArgs is for a rather hideous parse.  When we
+// see a template-param followed by a template-args, we need to decide
+// whether we have a template-param or a template-template-param.
+// Normally it is template-template-param, meaning that we pick up the
+// template arguments here.  But, if we are parsing the type for a
+// cast operator, then the only way this can be template-template-param
+// is if there is another set of template-args immediately after this
+// set.  That would look like this:
+//
+// <nested-name>
+// -> <template-prefix> <template-args>
+// -> <prefix> <template-unqualified-name> <template-args>
+// -> <unqualified-name> <template-unqualified-name> <template-args>
+// -> <source-name> <template-unqualified-name> <template-args>
+// -> <source-name> <operator-name> <template-args>
+// -> <source-name> cv <type> <template-args>
+// -> <source-name> cv <template-template-param> <template-args> <template-args>
+//
+// Otherwise, we have this derivation:
+//
+// <nested-name>
+// -> <template-prefix> <template-args>
+// -> <prefix> <template-unqualified-name> <template-args>
+// -> <unqualified-name> <template-unqualified-name> <template-args>
+// -> <source-name> <template-unqualified-name> <template-args>
+// -> <source-name> <operator-name> <template-args>
+// -> <source-name> cv <type> <template-args>
+// -> <source-name> cv <template-param> <template-args>
+//
+// in which the template-args are actually part of the prefix.  For
+// the special case where this arises, demangleType is called with
+// isCast as true.  This function is then responsible for checking
+// whether we see <template-param> <template-args> but there is not
+// another following <template-args>.  In that case, we reset the
+// parse and just return the <template-param>.
+func (st *state) demangleCastTemplateArgs(tp AST, addSubst bool) AST {
+	save := st.copy()
+
+	var args []AST
+	failed := false
+	func() {
+		defer func() {
+			if r := recover(); r != nil {
+				if _, ok := r.(demangleErr); ok {
+					failed = true
+				} else {
+					panic(r)
+				}
+			}
+		}()
+
+		args = st.templateArgs()
+	}()
+
+	if !failed && len(st.str) > 0 && st.str[0] == 'I' {
+		if addSubst {
+			st.subs.add(tp)
+		}
+		return &Template{Name: tp, Args: args}
+	}
+	// Reset back to before we started reading the template arguments.
+	// They will be read again by st.prefix.
+	*st = *save
+	return tp
+}
+
+// mergeQualifiers merges two qualifer lists into one.
+func mergeQualifiers(q1AST, q2AST AST) AST {
+	if q1AST == nil {
+		return q2AST
+	}
+	if q2AST == nil {
+		return q1AST
+	}
+	q1 := q1AST.(*Qualifiers)
+	m := make(map[string]bool)
+	for _, qualAST := range q1.Qualifiers {
+		qual := qualAST.(*Qualifier)
+		if len(qual.Exprs) == 0 {
+			m[qual.Name] = true
+		}
+	}
+	rq := q1.Qualifiers
+	for _, qualAST := range q2AST.(*Qualifiers).Qualifiers {
+		qual := qualAST.(*Qualifier)
+		if len(qual.Exprs) > 0 {
+			rq = append(rq, qualAST)
+		} else if !m[qual.Name] {
+			rq = append(rq, qualAST)
+			m[qual.Name] = true
+		}
+	}
+	q1.Qualifiers = rq
+	return q1
+}
+
+// qualifiers maps from the character used in the mangled name to the
+// string to print.
+var qualifiers = map[byte]string{
+	'r': "restrict",
+	'V': "volatile",
+	'K': "const",
+}
+
+// <CV-qualifiers> ::= [r] [V] [K]
+func (st *state) cvQualifiers() AST {
+	var q []AST
+qualLoop:
+	for len(st.str) > 0 {
+		if qv, ok := qualifiers[st.str[0]]; ok {
+			qual := &Qualifier{Name: qv}
+			q = append([]AST{qual}, q...)
+			st.advance(1)
+		} else if len(st.str) > 1 && st.str[0] == 'D' {
+			var qual AST
+			switch st.str[1] {
+			case 'x':
+				qual = &Qualifier{Name: "transaction_safe"}
+				st.advance(2)
+			case 'o':
+				qual = &Qualifier{Name: "noexcept"}
+				st.advance(2)
+			case 'O':
+				st.advance(2)
+				expr := st.expression()
+				if len(st.str) == 0 || st.str[0] != 'E' {
+					st.fail("expected E after computed noexcept expression")
+				}
+				st.advance(1)
+				qual = &Qualifier{Name: "noexcept", Exprs: []AST{expr}}
+			case 'w':
+				st.advance(2)
+				parmlist := st.parmlist()
+				if len(st.str) == 0 || st.str[0] != 'E' {
+					st.fail("expected E after throw parameter list")
+				}
+				st.advance(1)
+				qual = &Qualifier{Name: "throw", Exprs: parmlist}
+			default:
+				break qualLoop
+			}
+			q = append([]AST{qual}, q...)
+		} else {
+			break
+		}
+	}
+	if len(q) == 0 {
+		return nil
+	}
+	return &Qualifiers{Qualifiers: q}
+}
+
+// <ref-qualifier> ::= R
+//                 ::= O
+func (st *state) refQualifier() string {
+	if len(st.str) > 0 {
+		switch st.str[0] {
+		case 'R':
+			st.advance(1)
+			return "&"
+		case 'O':
+			st.advance(1)
+			return "&&"
+		}
+	}
+	return ""
+}
+
+// <type>+
+func (st *state) parmlist() []AST {
+	var ret []AST
+	for {
+		if len(st.str) < 1 {
+			break
+		}
+		if st.str[0] == 'E' || st.str[0] == '.' {
+			break
+		}
+		if (st.str[0] == 'R' || st.str[0] == 'O') && len(st.str) > 1 && st.str[1] == 'E' {
+			// This is a function ref-qualifier.
+			break
+		}
+		ptype := st.demangleType(false)
+		ret = append(ret, ptype)
+	}
+
+	// There should always be at least one type.  A function that
+	// takes no arguments will have a single parameter type
+	// "void".
+	if len(ret) == 0 {
+		st.fail("expected at least one type in type list")
+	}
+
+	// Omit a single parameter type void.
+	if len(ret) == 1 {
+		if bt, ok := ret[0].(*BuiltinType); ok && bt.Name == "void" {
+			ret = nil
+		}
+	}
+
+	return ret
+}
+
+// <function-type> ::= F [Y] <bare-function-type> [<ref-qualifier>] E
+func (st *state) functionType() AST {
+	st.checkChar('F')
+	if len(st.str) > 0 && st.str[0] == 'Y' {
+		// Function has C linkage.  We don't print this.
+		st.advance(1)
+	}
+	ret := st.bareFunctionType(true)
+	r := st.refQualifier()
+	if r != "" {
+		ret = &MethodWithQualifiers{Method: ret, Qualifiers: nil, RefQualifier: r}
+	}
+	if len(st.str) == 0 || st.str[0] != 'E' {
+		st.fail("expected E after function type")
+	}
+	st.advance(1)
+	return ret
+}
+
+// <bare-function-type> ::= [J]<type>+
+func (st *state) bareFunctionType(hasReturnType bool) AST {
+	if len(st.str) > 0 && st.str[0] == 'J' {
+		hasReturnType = true
+		st.advance(1)
+	}
+	var returnType AST
+	if hasReturnType {
+		returnType = st.demangleType(false)
+	}
+	types := st.parmlist()
+	return &FunctionType{Return: returnType, Args: types}
+}
+
+// <array-type> ::= A <(positive dimension) number> _ <(element) type>
+//              ::= A [<(dimension) expression>] _ <(element) type>
+func (st *state) arrayType(isCast bool) AST {
+	st.checkChar('A')
+
+	if len(st.str) == 0 {
+		st.fail("missing array dimension")
+	}
+
+	var dim AST
+	if st.str[0] == '_' {
+		dim = &Name{Name: ""}
+	} else if isDigit(st.str[0]) {
+		i := 1
+		for len(st.str) > i && isDigit(st.str[i]) {
+			i++
+		}
+		dim = &Name{Name: st.str[:i]}
+		st.advance(i)
+	} else {
+		dim = st.expression()
+	}
+
+	if len(st.str) == 0 || st.str[0] != '_' {
+		st.fail("expected _ after dimension")
+	}
+	st.advance(1)
+
+	t := st.demangleType(isCast)
+
+	arr := &ArrayType{Dimension: dim, Element: t}
+
+	// Qualifiers on the element of an array type go on the whole
+	// array type.
+	if q, ok := arr.Element.(*TypeWithQualifiers); ok {
+		return &TypeWithQualifiers{Base: &ArrayType{Dimension: dim, Element: q.Base}, Qualifiers: q.Qualifiers}
+	}
+
+	return arr
+}
+
+// <vector-type> ::= Dv <number> _ <type>
+//               ::= Dv _ <expression> _ <type>
+func (st *state) vectorType(isCast bool) AST {
+	if len(st.str) == 0 {
+		st.fail("expected vector dimension")
+	}
+
+	var dim AST
+	if st.str[0] == '_' {
+		st.advance(1)
+		dim = st.expression()
+	} else {
+		num := st.number()
+		dim = &Name{Name: fmt.Sprintf("%d", num)}
+	}
+
+	if len(st.str) == 0 || st.str[0] != '_' {
+		st.fail("expected _ after vector dimension")
+	}
+	st.advance(1)
+
+	t := st.demangleType(isCast)
+
+	return &VectorType{Dimension: dim, Base: t}
+}
+
+// <pointer-to-member-type> ::= M <(class) type> <(member) type>
+func (st *state) pointerToMemberType(isCast bool) AST {
+	st.checkChar('M')
+	cl := st.demangleType(false)
+
+	// The ABI says, "The type of a non-static member function is
+	// considered to be different, for the purposes of
+	// substitution, from the type of a namespace-scope or static
+	// member function whose type appears similar. The types of
+	// two non-static member functions are considered to be
+	// different, for the purposes of substitution, if the
+	// functions are members of different classes. In other words,
+	// for the purposes of substitution, the class of which the
+	// function is a member is considered part of the type of
+	// function."
+	//
+	// For a pointer to member function, this call to demangleType
+	// will end up adding a (possibly qualified) non-member
+	// function type to the substitution table, which is not
+	// correct; however, the member function type will never be
+	// used in a substitution, so putting the wrong type in the
+	// substitution table is harmless.
+	mem := st.demangleType(isCast)
+	return &PtrMem{Class: cl, Member: mem}
+}
+
+// <non-negative number> _ */
+func (st *state) compactNumber() int {
+	if len(st.str) == 0 {
+		st.fail("missing index")
+	}
+	if st.str[0] == '_' {
+		st.advance(1)
+		return 0
+	} else if st.str[0] == 'n' {
+		st.fail("unexpected negative number")
+	}
+	n := st.number()
+	if len(st.str) == 0 || st.str[0] != '_' {
+		st.fail("missing underscore after number")
+	}
+	st.advance(1)
+	return n + 1
+}
+
+// <template-param> ::= T_
+//                  ::= T <(parameter-2 non-negative) number> _
+//
+// When a template parameter is a substitution candidate, any
+// reference to that substitution refers to the template parameter
+// with the same index in the currently active template, not to
+// whatever the template parameter would be expanded to here.  We sort
+// this out in substitution and simplify.
+func (st *state) templateParam() AST {
+	if len(st.templates) == 0 && st.inLambda == 0 {
+		st.fail("template parameter not in scope of template")
+	}
+	off := st.off
+
+	st.checkChar('T')
+	n := st.compactNumber()
+
+	if st.inLambda > 0 {
+		// g++ mangles lambda auto params as template params.
+		// Apparently we can't encounter a template within a lambda.
+		// See https://gcc.gnu.org/PR78252.
+		return &LambdaAuto{Index: n}
+	}
+
+	template := st.templates[len(st.templates)-1]
+
+	if template == nil {
+		// We are parsing a cast operator.  If the cast is
+		// itself a template, then this is a forward
+		// reference.  Fill it in later.
+		return &TemplateParam{Index: n, Template: nil}
+	}
+
+	if n >= len(template.Args) {
+		st.failEarlier(fmt.Sprintf("template index out of range (%d >= %d)", n, len(template.Args)), st.off-off)
+	}
+
+	return &TemplateParam{Index: n, Template: template}
+}
+
+// setTemplate sets the Template field of any TemplateParam's in a.
+// This handles the forward referencing template parameters found in
+// cast operators.
+func (st *state) setTemplate(a AST, tmpl *Template) {
+	var seen []AST
+	a.Traverse(func(a AST) bool {
+		switch a := a.(type) {
+		case *TemplateParam:
+			if a.Template != nil {
+				if tmpl != nil {
+					st.fail("duplicate template parameters")
+				}
+				return false
+			}
+			if tmpl == nil {
+				st.fail("cast template parameter not in scope of template")
+			}
+			if a.Index >= len(tmpl.Args) {
+				st.fail(fmt.Sprintf("cast template index out of range (%d >= %d)", a.Index, len(tmpl.Args)))
+			}
+			a.Template = tmpl
+			return false
+		case *Closure:
+			// There are no template params in closure types.
+			// https://gcc.gnu.org/PR78252.
+			return false
+		default:
+			for _, v := range seen {
+				if v == a {
+					return false
+				}
+			}
+			seen = append(seen, a)
+			return true
+		}
+	})
+}
+
+// clearTemplateArgs gives an error for any unset Template field in
+// args.  This handles erroneous cases where a cast operator with a
+// forward referenced template is in the scope of another cast
+// operator.
+func (st *state) clearTemplateArgs(args []AST) {
+	for _, a := range args {
+		st.setTemplate(a, nil)
+	}
+}
+
+// <template-args> ::= I <template-arg>+ E
+func (st *state) templateArgs() []AST {
+	if len(st.str) == 0 || (st.str[0] != 'I' && st.str[0] != 'J') {
+		panic("internal error")
+	}
+	st.advance(1)
+
+	var ret []AST
+	for len(st.str) == 0 || st.str[0] != 'E' {
+		arg := st.templateArg()
+		ret = append(ret, arg)
+	}
+	st.advance(1)
+	return ret
+}
+
+// <template-arg> ::= <type>
+//                ::= X <expression> E
+//                ::= <expr-primary>
+func (st *state) templateArg() AST {
+	if len(st.str) == 0 {
+		st.fail("missing template argument")
+	}
+	switch st.str[0] {
+	case 'X':
+		st.advance(1)
+		expr := st.expression()
+		if len(st.str) == 0 || st.str[0] != 'E' {
+			st.fail("missing end of expression")
+		}
+		st.advance(1)
+		return expr
+
+	case 'L':
+		return st.exprPrimary()
+
+	case 'I', 'J':
+		args := st.templateArgs()
+		return &ArgumentPack{Args: args}
+
+	default:
+		return st.demangleType(false)
+	}
+}
+
+// exprList parses a sequence of expressions up to a terminating character.
+func (st *state) exprList(stop byte) AST {
+	if len(st.str) > 0 && st.str[0] == stop {
+		st.advance(1)
+		return &ExprList{Exprs: nil}
+	}
+
+	var exprs []AST
+	for {
+		e := st.expression()
+		exprs = append(exprs, e)
+		if len(st.str) > 0 && st.str[0] == stop {
+			st.advance(1)
+			break
+		}
+	}
+	return &ExprList{Exprs: exprs}
+}
+
+// <expression> ::= <(unary) operator-name> <expression>
+//              ::= <(binary) operator-name> <expression> <expression>
+//              ::= <(trinary) operator-name> <expression> <expression> <expression>
+//              ::= pp_ <expression>
+//              ::= mm_ <expression>
+//              ::= cl <expression>+ E
+//              ::= cl <expression>+ E
+//              ::= cv <type> <expression>
+//              ::= cv <type> _ <expression>* E
+//              ::= tl <type> <braced-expression>* E
+//              ::= il <braced-expression>* E
+//              ::= [gs] nw <expression>* _ <type> E
+//              ::= [gs] nw <expression>* _ <type> <initializer>
+//              ::= [gs] na <expression>* _ <type> E
+//              ::= [gs] na <expression>* _ <type> <initializer>
+//              ::= [gs] dl <expression>
+//              ::= [gs] da <expression>
+//              ::= dc <type> <expression>
+//              ::= sc <type> <expression>
+//              ::= cc <type> <expression>
+//              ::= rc <type> <expression>
+//              ::= ti <type>
+//              ::= te <expression>
+//              ::= st <type>
+//              ::= sz <expression>
+//              ::= at <type>
+//              ::= az <expression>
+//              ::= nx <expression>
+//              ::= <template-param>
+//              ::= <function-param>
+//              ::= dt <expression> <unresolved-name>
+//              ::= pt <expression> <unresolved-name>
+//              ::= ds <expression> <expression>
+//              ::= sZ <template-param>
+//              ::= sZ <function-param>
+//              ::= sP <template-arg>* E
+//              ::= sp <expression>
+//              ::= fl <binary operator-name> <expression>
+//              ::= fr <binary operator-name> <expression>
+//              ::= fL <binary operator-name> <expression> <expression>
+//              ::= fR <binary operator-name> <expression> <expression>
+//              ::= tw <expression>
+//              ::= tr
+//              ::= <unresolved-name>
+//              ::= <expr-primary>
+//
+// <function-param> ::= fp <CV-qualifiers> _
+//                  ::= fp <CV-qualifiers> <number>
+//                  ::= fL <number> p <CV-qualifiers> _
+//                  ::= fL <number> p <CV-qualifiers> <number>
+//                  ::= fpT
+//
+// <braced-expression> ::= <expression>
+//                     ::= di <field source-name> <braced-expression>
+//                     ::= dx <index expression> <braced-expression>
+//                     ::= dX <range begin expression> <range end expression> <braced-expression>
+//
+func (st *state) expression() AST {
+	if len(st.str) == 0 {
+		st.fail("expected expression")
+	}
+	if st.str[0] == 'L' {
+		return st.exprPrimary()
+	} else if st.str[0] == 'T' {
+		return st.templateParam()
+	} else if st.str[0] == 's' && len(st.str) > 1 && st.str[1] == 'r' {
+		return st.unresolvedName()
+	} else if st.str[0] == 's' && len(st.str) > 1 && st.str[1] == 'p' {
+		st.advance(2)
+		e := st.expression()
+		pack := st.findArgumentPack(e)
+		return &PackExpansion{Base: e, Pack: pack}
+	} else if st.str[0] == 's' && len(st.str) > 1 && st.str[1] == 'Z' {
+		st.advance(2)
+		off := st.off
+		e := st.expression()
+		ap := st.findArgumentPack(e)
+		if ap == nil {
+			st.failEarlier("missing argument pack", st.off-off)
+		}
+		return &SizeofPack{Pack: ap}
+	} else if st.str[0] == 's' && len(st.str) > 1 && st.str[1] == 'P' {
+		st.advance(2)
+		var args []AST
+		for len(st.str) == 0 || st.str[0] != 'E' {
+			arg := st.templateArg()
+			args = append(args, arg)
+		}
+		st.advance(1)
+		return &SizeofArgs{Args: args}
+	} else if st.str[0] == 'f' && len(st.str) > 1 && st.str[1] == 'p' {
+		st.advance(2)
+		if len(st.str) > 0 && st.str[0] == 'T' {
+			st.advance(1)
+			return &FunctionParam{Index: 0}
+		} else {
+			// We can see qualifiers here, but we don't
+			// include them in the demangled string.
+			st.cvQualifiers()
+			index := st.compactNumber()
+			return &FunctionParam{Index: index + 1}
+		}
+	} else if st.str[0] == 'f' && len(st.str) > 2 && st.str[1] == 'L' && isDigit(st.str[2]) {
+		st.advance(2)
+		// We don't include the scope count in the demangled string.
+		st.number()
+		if len(st.str) == 0 || st.str[0] != 'p' {
+			st.fail("expected p after function parameter scope count")
+		}
+		st.advance(1)
+		// We can see qualifiers here, but we don't include them
+		// in the demangled string.
+		st.cvQualifiers()
+		index := st.compactNumber()
+		return &FunctionParam{Index: index + 1}
+	} else if isDigit(st.str[0]) || (st.str[0] == 'o' && len(st.str) > 1 && st.str[1] == 'n') {
+		if st.str[0] == 'o' {
+			// Skip operator function ID.
+			st.advance(2)
+		}
+		n, _ := st.unqualifiedName()
+		if len(st.str) > 0 && st.str[0] == 'I' {
+			args := st.templateArgs()
+			n = &Template{Name: n, Args: args}
+		}
+		return n
+	} else if (st.str[0] == 'i' || st.str[0] == 't') && len(st.str) > 1 && st.str[1] == 'l' {
+		// Brace-enclosed initializer list.
+		c := st.str[0]
+		st.advance(2)
+		var t AST
+		if c == 't' {
+			t = st.demangleType(false)
+		}
+		exprs := st.exprList('E')
+		return &InitializerList{Type: t, Exprs: exprs}
+	} else if st.str[0] == 's' && len(st.str) > 1 && st.str[1] == 't' {
+		o, _ := st.operatorName(true)
+		t := st.demangleType(false)
+		return &Unary{Op: o, Expr: t, Suffix: false, SizeofType: true}
+	} else {
+		if len(st.str) < 2 {
+			st.fail("missing operator code")
+		}
+		code := st.str[:2]
+		o, args := st.operatorName(true)
+		switch args {
+		case 0:
+			return &Nullary{Op: o}
+
+		case 1:
+			suffix := false
+			if code == "pp" || code == "mm" {
+				if len(st.str) > 0 && st.str[0] == '_' {
+					st.advance(1)
+				} else {
+					suffix = true
+				}
+			}
+			var operand AST
+			if _, ok := o.(*Cast); ok && len(st.str) > 0 && st.str[0] == '_' {
+				st.advance(1)
+				operand = st.exprList('E')
+			} else {
+				operand = st.expression()
+			}
+			return &Unary{Op: o, Expr: operand, Suffix: suffix, SizeofType: false}
+
+		case 2:
+			var left, right AST
+			if code == "sc" || code == "dc" || code == "cc" || code == "rc" {
+				left = st.demangleType(false)
+			} else if code[0] == 'f' {
+				left, _ = st.operatorName(true)
+				right = st.expression()
+				return &Fold{Left: code[1] == 'l', Op: left, Arg1: right, Arg2: nil}
+			} else if code == "di" {
+				left, _ = st.unqualifiedName()
+			} else {
+				left = st.expression()
+			}
+			if code == "cl" || code == "cp" {
+				right = st.exprList('E')
+			} else if code == "dt" || code == "pt" {
+				right = st.unresolvedName()
+				if len(st.str) > 0 && st.str[0] == 'I' {
+					args := st.templateArgs()
+					right = &Template{Name: right, Args: args}
+				}
+			} else {
+				right = st.expression()
+			}
+			return &Binary{Op: o, Left: left, Right: right}
+
+		case 3:
+			if code[0] == 'n' {
+				if code[1] != 'w' && code[1] != 'a' {
+					panic("internal error")
+				}
+				place := st.exprList('_')
+				if place.(*ExprList).Exprs == nil {
+					place = nil
+				}
+				t := st.demangleType(false)
+				var ini AST
+				if len(st.str) > 0 && st.str[0] == 'E' {
+					st.advance(1)
+				} else if len(st.str) > 1 && st.str[0] == 'p' && st.str[1] == 'i' {
+					// Parenthesized initializer.
+					st.advance(2)
+					ini = st.exprList('E')
+				} else if len(st.str) > 1 && st.str[0] == 'i' && st.str[1] == 'l' {
+					// Initializer list.
+					ini = st.expression()
+				} else {
+					st.fail("unrecognized new initializer")
+				}
+				return &New{Op: o, Place: place, Type: t, Init: ini}
+			} else if code[0] == 'f' {
+				first, _ := st.operatorName(true)
+				second := st.expression()
+				third := st.expression()
+				return &Fold{Left: code[1] == 'L', Op: first, Arg1: second, Arg2: third}
+			} else {
+				first := st.expression()
+				second := st.expression()
+				third := st.expression()
+				return &Trinary{Op: o, First: first, Second: second, Third: third}
+			}
+
+		default:
+			st.fail(fmt.Sprintf("unsupported number of operator arguments: %d", args))
+			panic("not reached")
+		}
+	}
+}
+
+// <unresolved-name> ::= [gs] <base-unresolved-name>
+//                   ::= sr <unresolved-type> <base-unresolved-name>
+//                   ::= srN <unresolved-type> <unresolved-qualifier-level>+ E <base-unresolved-name>
+//                   ::= [gs] sr <unresolved-qualifier-level>+ E <base-unresolved-name>
+func (st *state) unresolvedName() AST {
+	if len(st.str) >= 2 && st.str[:2] == "gs" {
+		st.advance(2)
+		n := st.unresolvedName()
+		return &Unary{
+			Op:         &Operator{Name: "::"},
+			Expr:       n,
+			Suffix:     false,
+			SizeofType: false,
+		}
+	} else if len(st.str) >= 2 && st.str[:2] == "sr" {
+		st.advance(2)
+		if len(st.str) == 0 {
+			st.fail("expected unresolved type")
+		}
+		switch st.str[0] {
+		case 'T', 'D', 'S':
+			t := st.demangleType(false)
+			n := st.baseUnresolvedName()
+			n = &Qualified{Scope: t, Name: n, LocalName: false}
+			if len(st.str) > 0 && st.str[0] == 'I' {
+				args := st.templateArgs()
+				n = &Template{Name: n, Args: args}
+				st.subs.add(n)
+			}
+			return n
+		default:
+			var s AST
+			if st.str[0] == 'N' {
+				st.advance(1)
+				s = st.demangleType(false)
+			}
+			for len(st.str) == 0 || st.str[0] != 'E' {
+				// GCC does not seem to follow the ABI here.
+				// It can emit type/name without an 'E'.
+				if s != nil && len(st.str) > 0 && !isDigit(st.str[0]) {
+					if q, ok := s.(*Qualified); ok {
+						a := q.Scope
+						if t, ok := a.(*Template); ok {
+							st.subs.add(t.Name)
+							st.subs.add(t)
+						} else {
+							st.subs.add(a)
+						}
+						return s
+					}
+				}
+				n := st.sourceName()
+				if len(st.str) > 0 && st.str[0] == 'I' {
+					st.subs.add(n)
+					args := st.templateArgs()
+					n = &Template{Name: n, Args: args}
+				}
+				if s == nil {
+					s = n
+				} else {
+					s = &Qualified{Scope: s, Name: n, LocalName: false}
+				}
+				st.subs.add(s)
+			}
+			if s == nil {
+				st.fail("missing scope in unresolved name")
+			}
+			st.advance(1)
+			n := st.baseUnresolvedName()
+			return &Qualified{Scope: s, Name: n, LocalName: false}
+		}
+	} else {
+		return st.baseUnresolvedName()
+	}
+}
+
+// <base-unresolved-name> ::= <simple-id>
+//                        ::= on <operator-name>
+//                        ::= on <operator-name> <template-args>
+//                        ::= dn <destructor-name>
+//
+//<simple-id> ::= <source-name> [ <template-args> ]
+func (st *state) baseUnresolvedName() AST {
+	var n AST
+	if len(st.str) >= 2 && st.str[:2] == "on" {
+		st.advance(2)
+		n, _ = st.operatorName(true)
+	} else if len(st.str) >= 2 && st.str[:2] == "dn" {
+		st.advance(2)
+		if len(st.str) > 0 && isDigit(st.str[0]) {
+			n = st.sourceName()
+		} else {
+			n = st.demangleType(false)
+		}
+		n = &Destructor{Name: n}
+	} else if len(st.str) > 0 && isDigit(st.str[0]) {
+		n = st.sourceName()
+	} else {
+		// GCC seems to not follow the ABI here: it can have
+		// an operator name without on.
+		// See https://gcc.gnu.org/PR70182.
+		n, _ = st.operatorName(true)
+	}
+	if len(st.str) > 0 && st.str[0] == 'I' {
+		args := st.templateArgs()
+		n = &Template{Name: n, Args: args}
+	}
+	return n
+}
+
+// <expr-primary> ::= L <type> <(value) number> E
+//                ::= L <type> <(value) float> E
+//                ::= L <mangled-name> E
+func (st *state) exprPrimary() AST {
+	st.checkChar('L')
+	if len(st.str) == 0 {
+		st.fail("expected primary expression")
+
+	}
+
+	// Check for 'Z' here because g++ incorrectly omitted the
+	// underscore until -fabi-version=3.
+	var ret AST
+	if st.str[0] == '_' || st.str[0] == 'Z' {
+		if st.str[0] == '_' {
+			st.advance(1)
+		}
+		if len(st.str) == 0 || st.str[0] != 'Z' {
+			st.fail("expected mangled name")
+		}
+		st.advance(1)
+		ret = st.encoding(true, notForLocalName)
+	} else {
+		t := st.demangleType(false)
+
+		neg := false
+		if len(st.str) > 0 && st.str[0] == 'n' {
+			neg = true
+			st.advance(1)
+		}
+		if len(st.str) > 0 && st.str[0] == 'E' {
+			if bt, ok := t.(*BuiltinType); ok && bt.Name == "decltype(nullptr)" {
+				// A nullptr should not have a value.
+				// We accept one if present because GCC
+				// used to generate one.
+				// https://gcc.gnu.org/PR91979.
+			} else {
+				st.fail("missing literal value")
+			}
+		}
+		i := 0
+		for len(st.str) > i && st.str[i] != 'E' {
+			i++
+		}
+		val := st.str[:i]
+		st.advance(i)
+		ret = &Literal{Type: t, Val: val, Neg: neg}
+	}
+	if len(st.str) == 0 || st.str[0] != 'E' {
+		st.fail("expected E after literal")
+	}
+	st.advance(1)
+	return ret
+}
+
+// <discriminator> ::= _ <(non-negative) number> (when number < 10)
+//                     __ <(non-negative) number> _ (when number >= 10)
+func (st *state) discriminator(a AST) AST {
+	if len(st.str) == 0 || st.str[0] != '_' {
+		return a
+	}
+	off := st.off
+	st.advance(1)
+	trailingUnderscore := false
+	if len(st.str) > 0 && st.str[0] == '_' {
+		st.advance(1)
+		trailingUnderscore = true
+	}
+	d := st.number()
+	if d < 0 {
+		st.failEarlier("invalid negative discriminator", st.off-off)
+	}
+	if trailingUnderscore && d >= 10 {
+		if len(st.str) == 0 || st.str[0] != '_' {
+			st.fail("expected _ after discriminator >= 10")
+		}
+		st.advance(1)
+	}
+	// We don't currently print out the discriminator, so we don't
+	// save it.
+	return a
+}
+
+// <closure-type-name> ::= Ul <lambda-sig> E [ <nonnegative number> ] _
+func (st *state) closureTypeName() AST {
+	st.checkChar('U')
+	st.checkChar('l')
+	st.inLambda++
+	types := st.parmlist()
+	st.inLambda--
+	if len(st.str) == 0 || st.str[0] != 'E' {
+		st.fail("expected E after closure type name")
+	}
+	st.advance(1)
+	num := st.compactNumber()
+	return &Closure{Types: types, Num: num}
+}
+
+// <unnamed-type-name> ::= Ut [ <nonnegative number> ] _
+func (st *state) unnamedTypeName() AST {
+	st.checkChar('U')
+	st.checkChar('t')
+	num := st.compactNumber()
+	ret := &UnnamedType{Num: num}
+	st.subs.add(ret)
+	return ret
+}
+
+// Recognize a clone suffix.  These are not part of the mangling API,
+// but are added by GCC when cloning functions.
+func (st *state) cloneSuffix(a AST) AST {
+	i := 0
+	if len(st.str) > 1 && st.str[0] == '.' && (isLower(st.str[1]) || st.str[1] == '_') {
+		i += 2
+		for len(st.str) > i && (isLower(st.str[i]) || st.str[i] == '_') {
+			i++
+		}
+	}
+	for len(st.str) > i+1 && st.str[i] == '.' && isDigit(st.str[i+1]) {
+		i += 2
+		for len(st.str) > i && isDigit(st.str[i]) {
+			i++
+		}
+	}
+	suffix := st.str[:i]
+	st.advance(i)
+	return &Clone{Base: a, Suffix: suffix}
+}
+
+// substitutions is the list of substitution candidates that may
+// appear later in the string.
+type substitutions []AST
+
+// add adds a new substitution candidate.
+func (subs *substitutions) add(a AST) {
+	*subs = append(*subs, a)
+}
+
+// subAST maps standard substitution codes to the corresponding AST.
+var subAST = map[byte]AST{
+	't': &Name{Name: "std"},
+	'a': &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "allocator"}},
+	'b': &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "basic_string"}},
+	's': &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "string"}},
+	'i': &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "istream"}},
+	'o': &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "ostream"}},
+	'd': &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "iostream"}},
+}
+
+// verboseAST maps standard substitution codes to the long form of the
+// corresponding AST.  We use this when the Verbose option is used, to
+// match the standard demangler.
+var verboseAST = map[byte]AST{
+	't': &Name{Name: "std"},
+	'a': &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "allocator"}},
+	'b': &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "basic_string"}},
+
+	// std::basic_string<char, std::char_traits<char>, std::allocator<char> >
+	's': &Template{
+		Name: &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "basic_string"}},
+		Args: []AST{
+			&BuiltinType{Name: "char"},
+			&Template{
+				Name: &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "char_traits"}},
+				Args: []AST{&BuiltinType{Name: "char"}}},
+			&Template{
+				Name: &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "allocator"}},
+				Args: []AST{&BuiltinType{Name: "char"}}}}},
+	// std::basic_istream<char, std::char_traits<char> >
+	'i': &Template{
+		Name: &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "basic_istream"}},
+		Args: []AST{
+			&BuiltinType{Name: "char"},
+			&Template{
+				Name: &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "char_traits"}},
+				Args: []AST{&BuiltinType{Name: "char"}}}}},
+	// std::basic_ostream<char, std::char_traits<char> >
+	'o': &Template{
+		Name: &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "basic_ostream"}},
+		Args: []AST{
+			&BuiltinType{Name: "char"},
+			&Template{
+				Name: &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "char_traits"}},
+				Args: []AST{&BuiltinType{Name: "char"}}}}},
+	// std::basic_iostream<char, std::char_traits<char> >
+	'd': &Template{
+		Name: &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "basic_iostream"}},
+		Args: []AST{
+			&BuiltinType{Name: "char"},
+			&Template{
+				Name: &Qualified{Scope: &Name{Name: "std"}, Name: &Name{Name: "char_traits"}},
+				Args: []AST{&BuiltinType{Name: "char"}}}}},
+}
+
+// <substitution> ::= S <seq-id> _
+//                ::= S_
+//                ::= St
+//                ::= Sa
+//                ::= Sb
+//                ::= Ss
+//                ::= Si
+//                ::= So
+//                ::= Sd
+func (st *state) substitution(forPrefix bool) AST {
+	st.checkChar('S')
+	if len(st.str) == 0 {
+		st.fail("missing substitution index")
+	}
+	c := st.str[0]
+	st.advance(1)
+	dec := 1
+	if c == '_' || isDigit(c) || isUpper(c) {
+		id := 0
+		if c != '_' {
+			for c != '_' {
+				// Don't overflow a 32-bit int.
+				if id >= 0x80000000/36-36 {
+					st.fail("substitution index overflow")
+				}
+				if isDigit(c) {
+					id = id*36 + int(c-'0')
+				} else if isUpper(c) {
+					id = id*36 + int(c-'A') + 10
+				} else {
+					st.fail("invalid character in substitution index")
+				}
+
+				if len(st.str) == 0 {
+					st.fail("missing end to substitution index")
+				}
+				c = st.str[0]
+				st.advance(1)
+				dec++
+			}
+			id++
+		}
+
+		if id >= len(st.subs) {
+			st.failEarlier(fmt.Sprintf("substitution index out of range (%d >= %d)", id, len(st.subs)), dec)
+		}
+
+		ret := st.subs[id]
+
+		// We need to update any references to template
+		// parameters to refer to the currently active
+		// template.
+
+		// When copying a Typed we may need to adjust
+		// the templates.
+		copyTemplates := st.templates
+		var oldInLambda []int
+
+		// pushTemplate is called from skip, popTemplate from copy.
+		pushTemplate := func(template *Template) {
+			copyTemplates = append(copyTemplates, template)
+			oldInLambda = append(oldInLambda, st.inLambda)
+			st.inLambda = 0
+		}
+		popTemplate := func() {
+			copyTemplates = copyTemplates[:len(copyTemplates)-1]
+			st.inLambda = oldInLambda[len(oldInLambda)-1]
+			oldInLambda = oldInLambda[:len(oldInLambda)-1]
+		}
+
+		copy := func(a AST) AST {
+			var index int
+			switch a := a.(type) {
+			case *Typed:
+				// Remove the template added in skip.
+				if _, ok := a.Name.(*Template); ok {
+					popTemplate()
+				}
+				return nil
+			case *Closure:
+				// Undo the decrement in skip.
+				st.inLambda--
+				return nil
+			case *TemplateParam:
+				index = a.Index
+			case *LambdaAuto:
+				// A lambda auto parameter is represented
+				// as a template parameter, so we may have
+				// to change back when substituting.
+				index = a.Index
+			default:
+				return nil
+			}
+			if st.inLambda > 0 {
+				if _, ok := a.(*LambdaAuto); ok {
+					return nil
+				}
+				return &LambdaAuto{Index: index}
+			}
+			var template *Template
+			if len(copyTemplates) > 0 {
+				template = copyTemplates[len(copyTemplates)-1]
+			} else if rt, ok := ret.(*Template); ok {
+				// At least with clang we can see a template
+				// to start, and sometimes we need to refer
+				// to it. There is probably something wrong
+				// here.
+				template = rt
+			} else {
+				st.failEarlier("substituted template parameter not in scope of template", dec)
+			}
+			if template == nil {
+				// This template parameter is within
+				// the scope of a cast operator.
+				return &TemplateParam{Index: index, Template: nil}
+			}
+
+			if index >= len(template.Args) {
+				st.failEarlier(fmt.Sprintf("substituted template index out of range (%d >= %d)", index, len(template.Args)), dec)
+			}
+
+			return &TemplateParam{Index: index, Template: template}
+		}
+		var seen []AST
+		skip := func(a AST) bool {
+			switch a := a.(type) {
+			case *Typed:
+				if template, ok := a.Name.(*Template); ok {
+					// This template is removed in copy.
+					pushTemplate(template)
+				}
+				return false
+			case *Closure:
+				// This is decremented in copy.
+				st.inLambda++
+				return false
+			case *TemplateParam, *LambdaAuto:
+				return false
+			}
+			for _, v := range seen {
+				if v == a {
+					return true
+				}
+			}
+			seen = append(seen, a)
+			return false
+		}
+
+		if c := ret.Copy(copy, skip); c != nil {
+			return c
+		}
+
+		return ret
+	} else {
+		m := subAST
+		if st.verbose {
+			m = verboseAST
+		}
+		// For compatibility with the standard demangler, use
+		// a longer name for a constructor or destructor.
+		if forPrefix && len(st.str) > 0 && (st.str[0] == 'C' || st.str[0] == 'D') {
+			m = verboseAST
+		}
+		a, ok := m[c]
+		if !ok {
+			st.failEarlier("unrecognized substitution code", 1)
+		}
+
+		if len(st.str) > 0 && st.str[0] == 'B' {
+			a = st.taggedName(a)
+			st.subs.add(a)
+		}
+
+		return a
+	}
+}
+
+// isDigit returns whetner c is a digit for demangling purposes.
+func isDigit(c byte) bool {
+	return c >= '0' && c <= '9'
+}
+
+// isUpper returns whether c is an upper case letter for demangling purposes.
+func isUpper(c byte) bool {
+	return c >= 'A' && c <= 'Z'
+}
+
+// isLower returns whether c is a lower case letter for demangling purposes.
+func isLower(c byte) bool {
+	return c >= 'a' && c <= 'z'
+}
+
+// simplify replaces template parameters with their expansions, and
+// merges qualifiers.
+func simplify(a AST) AST {
+	var seen []AST
+	skip := func(a AST) bool {
+		for _, v := range seen {
+			if v == a {
+				return true
+			}
+		}
+		seen = append(seen, a)
+		return false
+	}
+	if r := a.Copy(simplifyOne, skip); r != nil {
+		return r
+	}
+	return a
+}
+
+// simplifyOne simplifies a single AST.  It returns nil if there is
+// nothing to do.
+func simplifyOne(a AST) AST {
+	switch a := a.(type) {
+	case *TemplateParam:
+		if a.Template != nil && a.Index < len(a.Template.Args) {
+			return a.Template.Args[a.Index]
+		}
+	case *MethodWithQualifiers:
+		if m, ok := a.Method.(*MethodWithQualifiers); ok {
+			ref := a.RefQualifier
+			if ref == "" {
+				ref = m.RefQualifier
+			} else if m.RefQualifier != "" {
+				if ref == "&" || m.RefQualifier == "&" {
+					ref = "&"
+				}
+			}
+			return &MethodWithQualifiers{Method: m.Method, Qualifiers: mergeQualifiers(a.Qualifiers, m.Qualifiers), RefQualifier: ref}
+		}
+		if t, ok := a.Method.(*TypeWithQualifiers); ok {
+			return &MethodWithQualifiers{Method: t.Base, Qualifiers: mergeQualifiers(a.Qualifiers, t.Qualifiers), RefQualifier: a.RefQualifier}
+		}
+	case *TypeWithQualifiers:
+		if ft, ok := a.Base.(*FunctionType); ok {
+			return &MethodWithQualifiers{Method: ft, Qualifiers: a.Qualifiers, RefQualifier: ""}
+		}
+		if t, ok := a.Base.(*TypeWithQualifiers); ok {
+			return &TypeWithQualifiers{Base: t.Base, Qualifiers: mergeQualifiers(a.Qualifiers, t.Qualifiers)}
+		}
+		if m, ok := a.Base.(*MethodWithQualifiers); ok {
+			return &MethodWithQualifiers{Method: m.Method, Qualifiers: mergeQualifiers(a.Qualifiers, m.Qualifiers), RefQualifier: m.RefQualifier}
+		}
+	case *ReferenceType:
+		if rt, ok := a.Base.(*ReferenceType); ok {
+			return rt
+		}
+		if rrt, ok := a.Base.(*RvalueReferenceType); ok {
+			return &ReferenceType{Base: rrt.Base}
+		}
+	case *RvalueReferenceType:
+		if rrt, ok := a.Base.(*RvalueReferenceType); ok {
+			return rrt
+		}
+		if rt, ok := a.Base.(*ReferenceType); ok {
+			return rt
+		}
+	case *ArrayType:
+		// Qualifiers on the element of an array type
+		// go on the whole array type.
+		if q, ok := a.Element.(*TypeWithQualifiers); ok {
+			return &TypeWithQualifiers{
+				Base:       &ArrayType{Dimension: a.Dimension, Element: q.Base},
+				Qualifiers: q.Qualifiers,
+			}
+		}
+	case *PackExpansion:
+		// Expand the pack and replace it with a list of
+		// expressions.
+		if a.Pack != nil {
+			exprs := make([]AST, len(a.Pack.Args))
+			for i, arg := range a.Pack.Args {
+				copy := func(sub AST) AST {
+					// Replace the ArgumentPack
+					// with a specific argument.
+					if sub == a.Pack {
+						return arg
+					}
+					// Copy everything else.
+					return nil
+				}
+
+				var seen []AST
+				skip := func(sub AST) bool {
+					// Don't traverse into another
+					// pack expansion.
+					if _, ok := sub.(*PackExpansion); ok {
+						return true
+					}
+					for _, v := range seen {
+						if v == sub {
+							return true
+						}
+					}
+					seen = append(seen, sub)
+					return false
+				}
+
+				b := a.Base.Copy(copy, skip)
+				if b == nil {
+					b = a.Base
+				}
+				exprs[i] = simplify(b)
+			}
+			return &ExprList{Exprs: exprs}
+		}
+	}
+	return nil
+}
+
+// findArgumentPack walks the AST looking for the argument pack for a
+// pack expansion.  We find it via a template parameter.
+func (st *state) findArgumentPack(a AST) *ArgumentPack {
+	var seen []AST
+	var ret *ArgumentPack
+	a.Traverse(func(a AST) bool {
+		if ret != nil {
+			return false
+		}
+		switch a := a.(type) {
+		case *TemplateParam:
+			if a.Template == nil || a.Index >= len(a.Template.Args) {
+				return true
+			}
+			if pack, ok := a.Template.Args[a.Index].(*ArgumentPack); ok {
+				ret = pack
+				return false
+			}
+		case *PackExpansion, *Closure, *Name:
+			return false
+		case *TaggedName, *Operator, *BuiltinType, *FunctionParam:
+			return false
+		case *UnnamedType, *FixedType, *DefaultArg:
+			return false
+		}
+		for _, v := range seen {
+			if v == a {
+				return false
+			}
+		}
+		seen = append(seen, a)
+		return true
+	})
+	return ret
+}