Adding upstream version 1.20.14.upstream/1.20.14upstream

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

4 files changed, 467 insertions, 0 deletions

diff --git a/src/cmd/internal/cov/mreader.go b/src/cmd/internal/cov/mreader.go
new file mode 100644
index 0000000..30f53d6
--- /dev/null
+++ b/src/cmd/internal/cov/mreader.go
@@ -0,0 +1,85 @@
+// Copyright 2022 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 cov
+
+import (
+	"cmd/internal/bio"
+	"io"
+	"os"
+)
+
+// This file contains the helper "MReader", a wrapper around bio plus
+// an "mmap'd read-only" view of the file obtained from bio.SliceRO().
+// MReader is designed to implement the io.ReaderSeeker interface.
+// Since bio.SliceOS() is not guaranteed to succeed, MReader falls back
+// on explicit reads + seeks provided by bio.Reader if needed.
+
+type MReader struct {
+	f        *os.File
+	rdr      *bio.Reader
+	fileView []byte
+	off      int64
+}
+
+func NewMreader(f *os.File) (*MReader, error) {
+	rdr := bio.NewReader(f)
+	fi, err := f.Stat()
+	if err != nil {
+		return nil, err
+	}
+	r := MReader{
+		f:        f,
+		rdr:      rdr,
+		fileView: rdr.SliceRO(uint64(fi.Size())),
+	}
+	return &r, nil
+}
+
+func (r *MReader) Read(p []byte) (int, error) {
+	if r.fileView != nil {
+		amt := len(p)
+		toread := r.fileView[r.off:]
+		if len(toread) < 1 {
+			return 0, io.EOF
+		}
+		if len(toread) < amt {
+			amt = len(toread)
+		}
+		copy(p, toread)
+		r.off += int64(amt)
+		return amt, nil
+	}
+	return io.ReadFull(r.rdr, p)
+}
+
+func (r *MReader) ReadByte() (byte, error) {
+	if r.fileView != nil {
+		toread := r.fileView[r.off:]
+		if len(toread) < 1 {
+			return 0, io.EOF
+		}
+		rv := toread[0]
+		r.off++
+		return rv, nil
+	}
+	return r.rdr.ReadByte()
+}
+
+func (r *MReader) Seek(offset int64, whence int) (int64, error) {
+	if r.fileView == nil {
+		return r.rdr.MustSeek(offset, whence), nil
+	}
+	switch whence {
+	case io.SeekStart:
+		r.off = offset
+		return offset, nil
+	case io.SeekCurrent:
+		return r.off, nil
+	case io.SeekEnd:
+		r.off = int64(len(r.fileView)) + offset
+		return r.off, nil
+	}
+	panic("other modes not implemented")
+}
diff --git a/src/cmd/internal/cov/read_test.go b/src/cmd/internal/cov/read_test.go
new file mode 100644
index 0000000..cef03fa
--- /dev/null
+++ b/src/cmd/internal/cov/read_test.go
@@ -0,0 +1,98 @@
+// Copyright 2022 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 cov_test
+
+import (
+	"cmd/internal/cov"
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/decodecounter"
+	"internal/coverage/decodemeta"
+	"internal/coverage/pods"
+	"internal/testenv"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// visitor implements the CovDataVisitor interface in a very stripped
+// down way, just keeps track of interesting events.
+type visitor struct {
+	metaFileCount    int
+	counterFileCount int
+	funcCounterData  int
+	metaFuncCount    int
+}
+
+func (v *visitor) BeginPod(p pods.Pod) {}
+func (v *visitor) EndPod(p pods.Pod)   {}
+func (v *visitor) VisitMetaDataFile(mdf string, mfr *decodemeta.CoverageMetaFileReader) {
+	v.metaFileCount++
+}
+func (v *visitor) BeginCounterDataFile(cdf string, cdr *decodecounter.CounterDataReader, dirIdx int) {
+	v.counterFileCount++
+}
+func (v *visitor) EndCounterDataFile(cdf string, cdr *decodecounter.CounterDataReader, dirIdx int) {}
+func (v *visitor) VisitFuncCounterData(payload decodecounter.FuncPayload)                          { v.funcCounterData++ }
+func (v *visitor) EndCounters()                                                                    {}
+func (v *visitor) BeginPackage(pd *decodemeta.CoverageMetaDataDecoder, pkgIdx uint32)              {}
+func (v *visitor) EndPackage(pd *decodemeta.CoverageMetaDataDecoder, pkgIdx uint32)                {}
+func (v *visitor) VisitFunc(pkgIdx uint32, fnIdx uint32, fd *coverage.FuncDesc)                    { v.metaFuncCount++ }
+func (v *visitor) Finish()                                                                         {}
+
+func TestIssue58411(t *testing.T) {
+	testenv.MustHaveGoBuild(t)
+
+	// Build a tiny test program with -cover. Smallness is important;
+	// it is one of the factors that triggers issue 58411.
+	d := t.TempDir()
+	exepath := filepath.Join(d, "small.exe")
+	path := filepath.Join("testdata", "small.go")
+	cmd := testenv.Command(t, testenv.GoToolPath(t), "build",
+		"-o", exepath, "-cover", path)
+	b, err := cmd.CombinedOutput()
+	if len(b) != 0 {
+		t.Logf("## build output:\n%s", b)
+	}
+	if err != nil {
+		t.Fatalf("build error: %v", err)
+	}
+
+	// Run to produce coverage data. Note the large argument; we need a large
+	// argument (more than 4k) to trigger the bug, but the overall file
+	// has to remain small (since large files will be read with mmap).
+	covdir := filepath.Join(d, "covdata")
+	if err = os.Mkdir(covdir, 0777); err != nil {
+		t.Fatalf("creating covdir: %v", err)
+	}
+	large := fmt.Sprintf("%07999d", 0)
+	cmd = testenv.Command(t, exepath, "1", "2", "3", large)
+	cmd.Dir = covdir
+	cmd.Env = append(os.Environ(), "GOCOVERDIR="+covdir)
+	b, err = cmd.CombinedOutput()
+	if err != nil {
+		t.Logf("## run output:\n%s", b)
+		t.Fatalf("build error: %v", err)
+	}
+
+	vis := &visitor{}
+
+	// Read resulting coverage data. Without the fix, this would
+	// yield a "short read" error.
+	const verbosityLevel = 0
+	const flags = 0
+	cdr := cov.MakeCovDataReader(vis, []string{covdir}, verbosityLevel, flags, nil)
+	err = cdr.Visit()
+	if err != nil {
+		t.Fatalf("visit failed: %v", err)
+	}
+
+	// make sure we saw a few things just for grins
+	const want = "{metaFileCount:1 counterFileCount:1 funcCounterData:1 metaFuncCount:1}"
+	got := fmt.Sprintf("%+v", *vis)
+	if want != got {
+		t.Errorf("visitor contents: want %v got %v\n", want, got)
+	}
+}
diff --git a/src/cmd/internal/cov/readcovdata.go b/src/cmd/internal/cov/readcovdata.go
new file mode 100644
index 0000000..7e90e9e
--- /dev/null
+++ b/src/cmd/internal/cov/readcovdata.go
@@ -0,0 +1,277 @@
+// Copyright 2022 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 cov
+
+import (
+	"cmd/internal/bio"
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/decodecounter"
+	"internal/coverage/decodemeta"
+	"internal/coverage/pods"
+	"io"
+	"os"
+)
+
+// CovDataReader is a general-purpose helper/visitor object for
+// reading coverage data files in a structured way. Clients create a
+// CovDataReader to process a given collection of coverage data file
+// directories, then pass in a visitor object with methods that get
+// invoked at various important points. CovDataReader is intended
+// to facilitate common coverage data file operations such as
+// merging or intersecting data files, analyzing data files, or
+// dumping data files.
+type CovDataReader struct {
+	vis            CovDataVisitor
+	indirs         []string
+	matchpkg       func(name string) bool
+	flags          CovDataReaderFlags
+	err            error
+	verbosityLevel int
+}
+
+// MakeCovDataReader creates a CovDataReader object to process the
+// given set of input directories. Here 'vis' is a visitor object
+// providing methods to be invoked as we walk through the data,
+// 'indirs' is the set of coverage data directories to examine,
+// 'verbosityLevel' controls the level of debugging trace messages
+// (zero for off, higher for more output), 'flags' stores flags that
+// indicate what to do if errors are detected, and 'matchpkg' is a
+// caller-provided function that can be used to select specific
+// packages by name (if nil, then all packages are included).
+func MakeCovDataReader(vis CovDataVisitor, indirs []string, verbosityLevel int, flags CovDataReaderFlags, matchpkg func(name string) bool) *CovDataReader {
+	return &CovDataReader{
+		vis:            vis,
+		indirs:         indirs,
+		matchpkg:       matchpkg,
+		verbosityLevel: verbosityLevel,
+		flags:          flags,
+	}
+}
+
+// CovDataVisitor defines hooks for clients of CovDataReader. When the
+// coverage data reader makes its way through a coverage meta-data
+// file and counter data files, it will invoke the methods below to
+// hand off info to the client. The normal sequence of expected
+// visitor method invocations is:
+//
+//	for each pod P {
+//		BeginPod(p)
+//		let MF be the meta-data file for P
+//		VisitMetaDataFile(MF)
+//		for each counter data file D in P {
+//			BeginCounterDataFile(D)
+//			for each live function F in D {
+//				VisitFuncCounterData(F)
+//			}
+//			EndCounterDataFile(D)
+//		}
+//		EndCounters(MF)
+//		for each package PK in MF {
+//			BeginPackage(PK)
+//			if <PK matched according to package pattern and/or modpath> {
+//				for each function PF in PK {
+//					VisitFunc(PF)
+//				}
+//			}
+//			EndPackage(PK)
+//		}
+//		EndPod(p)
+//	}
+//	Finish()
+
+type CovDataVisitor interface {
+	// Invoked at the start and end of a given pod (a pod here is a
+	// specific coverage meta-data files with the counter data files
+	// that correspond to it).
+	BeginPod(p pods.Pod)
+	EndPod(p pods.Pod)
+
+	// Invoked when the reader is starting to examine the meta-data
+	// file for a pod. Here 'mdf' is the path of the file, and 'mfr'
+	// is an open meta-data reader.
+	VisitMetaDataFile(mdf string, mfr *decodemeta.CoverageMetaFileReader)
+
+	// Invoked when the reader processes a counter data file, first
+	// the 'begin' method at the start, then the 'end' method when
+	// we're done with the file.
+	BeginCounterDataFile(cdf string, cdr *decodecounter.CounterDataReader, dirIdx int)
+	EndCounterDataFile(cdf string, cdr *decodecounter.CounterDataReader, dirIdx int)
+
+	// Invoked once for each live function in the counter data file.
+	VisitFuncCounterData(payload decodecounter.FuncPayload)
+
+	// Invoked when we've finished processing the counter files in a
+	// POD (e.g. no more calls to VisitFuncCounterData).
+	EndCounters()
+
+	// Invoked for each package in the meta-data file for the pod,
+	// first the 'begin' method when processinf of hte package starts,
+	// then the 'end' method when we're done
+	BeginPackage(pd *decodemeta.CoverageMetaDataDecoder, pkgIdx uint32)
+	EndPackage(pd *decodemeta.CoverageMetaDataDecoder, pkgIdx uint32)
+
+	// Invoked for each function  the package being visited.
+	VisitFunc(pkgIdx uint32, fnIdx uint32, fd *coverage.FuncDesc)
+
+	// Invoked when all counter + meta-data file processing is complete.
+	Finish()
+}
+
+type CovDataReaderFlags uint32
+
+const (
+	CovDataReaderNoFlags CovDataReaderFlags = 0
+	PanicOnError                            = 1 << iota
+	PanicOnWarning
+)
+
+func (r *CovDataReader) Visit() error {
+	podlist, err := pods.CollectPods(r.indirs, false)
+	if err != nil {
+		return fmt.Errorf("reading inputs: %v", err)
+	}
+	if len(podlist) == 0 {
+		r.warn("no applicable files found in input directories")
+	}
+	for _, p := range podlist {
+		if err := r.visitPod(p); err != nil {
+			return err
+		}
+	}
+	r.vis.Finish()
+	return nil
+}
+
+func (r *CovDataReader) verb(vlevel int, s string, a ...interface{}) {
+	if r.verbosityLevel >= vlevel {
+		fmt.Fprintf(os.Stderr, s, a...)
+		fmt.Fprintf(os.Stderr, "\n")
+	}
+}
+
+func (r *CovDataReader) warn(s string, a ...interface{}) {
+	fmt.Fprintf(os.Stderr, "warning: ")
+	fmt.Fprintf(os.Stderr, s, a...)
+	fmt.Fprintf(os.Stderr, "\n")
+	if (r.flags & PanicOnWarning) != 0 {
+		panic("unexpected warning")
+	}
+}
+
+func (r *CovDataReader) fatal(s string, a ...interface{}) error {
+	if r.err != nil {
+		return nil
+	}
+	errstr := "error: " + fmt.Sprintf(s, a...) + "\n"
+	if (r.flags & PanicOnError) != 0 {
+		fmt.Fprintf(os.Stderr, "%s", errstr)
+		panic("fatal error")
+	}
+	r.err = fmt.Errorf("%s", errstr)
+	return r.err
+}
+
+// visitPod examines a coverage data 'pod', that is, a meta-data file and
+// zero or more counter data files that refer to that meta-data file.
+func (r *CovDataReader) visitPod(p pods.Pod) error {
+	r.verb(1, "visiting pod: metafile %s with %d counter files",
+		p.MetaFile, len(p.CounterDataFiles))
+	r.vis.BeginPod(p)
+
+	// Open meta-file
+	f, err := os.Open(p.MetaFile)
+	if err != nil {
+		return r.fatal("unable to open meta-file %s", p.MetaFile)
+	}
+	defer f.Close()
+	br := bio.NewReader(f)
+	fi, err := f.Stat()
+	if err != nil {
+		return r.fatal("unable to stat metafile %s: %v", p.MetaFile, err)
+	}
+	fileView := br.SliceRO(uint64(fi.Size()))
+	br.MustSeek(0, io.SeekStart)
+
+	r.verb(1, "fileView for pod is length %d", len(fileView))
+
+	var mfr *decodemeta.CoverageMetaFileReader
+	mfr, err = decodemeta.NewCoverageMetaFileReader(f, fileView)
+	if err != nil {
+		return r.fatal("decoding meta-file %s: %s", p.MetaFile, err)
+	}
+	r.vis.VisitMetaDataFile(p.MetaFile, mfr)
+
+	// Read counter data files.
+	for k, cdf := range p.CounterDataFiles {
+		cf, err := os.Open(cdf)
+		if err != nil {
+			return r.fatal("opening counter data file %s: %s", cdf, err)
+		}
+		defer func(f *os.File) {
+			f.Close()
+		}(cf)
+		var mr *MReader
+		mr, err = NewMreader(cf)
+		if err != nil {
+			return r.fatal("creating reader for counter data file %s: %s", cdf, err)
+		}
+		var cdr *decodecounter.CounterDataReader
+		cdr, err = decodecounter.NewCounterDataReader(cdf, mr)
+		if err != nil {
+			return r.fatal("reading counter data file %s: %s", cdf, err)
+		}
+		r.vis.BeginCounterDataFile(cdf, cdr, p.Origins[k])
+		var data decodecounter.FuncPayload
+		for {
+			ok, err := cdr.NextFunc(&data)
+			if err != nil {
+				return r.fatal("reading counter data file %s: %v", cdf, err)
+			}
+			if !ok {
+				break
+			}
+			r.vis.VisitFuncCounterData(data)
+		}
+		r.vis.EndCounterDataFile(cdf, cdr, p.Origins[k])
+	}
+	r.vis.EndCounters()
+
+	// NB: packages in the meta-file will be in dependency order (basically
+	// the order in which init files execute). Do we want an additional sort
+	// pass here, say by packagepath?
+	np := uint32(mfr.NumPackages())
+	payload := []byte{}
+	for pkIdx := uint32(0); pkIdx < np; pkIdx++ {
+		var pd *decodemeta.CoverageMetaDataDecoder
+		pd, payload, err = mfr.GetPackageDecoder(pkIdx, payload)
+		if err != nil {
+			return r.fatal("reading pkg %d from meta-file %s: %s", pkIdx, p.MetaFile, err)
+		}
+		r.processPackage(p.MetaFile, pd, pkIdx)
+	}
+	r.vis.EndPod(p)
+
+	return nil
+}
+
+func (r *CovDataReader) processPackage(mfname string, pd *decodemeta.CoverageMetaDataDecoder, pkgIdx uint32) error {
+	if r.matchpkg != nil {
+		if !r.matchpkg(pd.PackagePath()) {
+			return nil
+		}
+	}
+	r.vis.BeginPackage(pd, pkgIdx)
+	nf := pd.NumFuncs()
+	var fd coverage.FuncDesc
+	for fidx := uint32(0); fidx < nf; fidx++ {
+		if err := pd.ReadFunc(fidx, &fd); err != nil {
+			return r.fatal("reading meta-data file %s: %v", mfname, err)
+		}
+		r.vis.VisitFunc(pkgIdx, fidx, &fd)
+	}
+	r.vis.EndPackage(pd, pkgIdx)
+	return nil
+}
diff --git a/src/cmd/internal/cov/testdata/small.go b/src/cmd/internal/cov/testdata/small.go
new file mode 100644
index 0000000..d81cb70
--- /dev/null
+++ b/src/cmd/internal/cov/testdata/small.go
@@ -0,0 +1,7 @@
+package main
+
+import "os"
+
+func main() {
+	println(len(os.Args))
+}