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-rw-r--r--src/cmd/internal/dwarf/dwarf.go1655
1 files changed, 1655 insertions, 0 deletions
diff --git a/src/cmd/internal/dwarf/dwarf.go b/src/cmd/internal/dwarf/dwarf.go
new file mode 100644
index 0000000..8de4096
--- /dev/null
+++ b/src/cmd/internal/dwarf/dwarf.go
@@ -0,0 +1,1655 @@
+// Copyright 2016 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 dwarf generates DWARF debugging information.
+// DWARF generation is split between the compiler and the linker,
+// this package contains the shared code.
+package dwarf
+
+import (
+ "bytes"
+ "cmd/internal/objabi"
+ "errors"
+ "fmt"
+ exec "internal/execabs"
+ "sort"
+ "strconv"
+ "strings"
+)
+
+// InfoPrefix is the prefix for all the symbols containing DWARF info entries.
+const InfoPrefix = "go.info."
+
+// ConstInfoPrefix is the prefix for all symbols containing DWARF info
+// entries that contain constants.
+const ConstInfoPrefix = "go.constinfo."
+
+// CUInfoPrefix is the prefix for symbols containing information to
+// populate the DWARF compilation unit info entries.
+const CUInfoPrefix = "go.cuinfo."
+
+// Used to form the symbol name assigned to the DWARF 'abstract subprogram"
+// info entry for a function
+const AbstractFuncSuffix = "$abstract"
+
+// Controls logging/debugging for selected aspects of DWARF subprogram
+// generation (functions, scopes).
+var logDwarf bool
+
+// Sym represents a symbol.
+type Sym interface {
+ Length(dwarfContext interface{}) int64
+}
+
+// A Var represents a local variable or a function parameter.
+type Var struct {
+ Name string
+ Abbrev int // Either DW_ABRV_AUTO[_LOCLIST] or DW_ABRV_PARAM[_LOCLIST]
+ IsReturnValue bool
+ IsInlFormal bool
+ StackOffset int32
+ // This package can't use the ssa package, so it can't mention ssa.FuncDebug,
+ // so indirect through a closure.
+ PutLocationList func(listSym, startPC Sym)
+ Scope int32
+ Type Sym
+ DeclFile string
+ DeclLine uint
+ DeclCol uint
+ InlIndex int32 // subtract 1 to form real index into InlTree
+ ChildIndex int32 // child DIE index in abstract function
+ IsInAbstract bool // variable exists in abstract function
+}
+
+// A Scope represents a lexical scope. All variables declared within a
+// scope will only be visible to instructions covered by the scope.
+// Lexical scopes are contiguous in source files but can end up being
+// compiled to discontiguous blocks of instructions in the executable.
+// The Ranges field lists all the blocks of instructions that belong
+// in this scope.
+type Scope struct {
+ Parent int32
+ Ranges []Range
+ Vars []*Var
+}
+
+// A Range represents a half-open interval [Start, End).
+type Range struct {
+ Start, End int64
+}
+
+// This container is used by the PutFunc* variants below when
+// creating the DWARF subprogram DIE(s) for a function.
+type FnState struct {
+ Name string
+ Importpath string
+ Info Sym
+ Filesym Sym
+ Loc Sym
+ Ranges Sym
+ Absfn Sym
+ StartPC Sym
+ Size int64
+ External bool
+ Scopes []Scope
+ InlCalls InlCalls
+ UseBASEntries bool
+}
+
+func EnableLogging(doit bool) {
+ logDwarf = doit
+}
+
+// MergeRanges creates a new range list by merging the ranges from
+// its two arguments, then returns the new list.
+func MergeRanges(in1, in2 []Range) []Range {
+ out := make([]Range, 0, len(in1)+len(in2))
+ i, j := 0, 0
+ for {
+ var cur Range
+ if i < len(in2) && j < len(in1) {
+ if in2[i].Start < in1[j].Start {
+ cur = in2[i]
+ i++
+ } else {
+ cur = in1[j]
+ j++
+ }
+ } else if i < len(in2) {
+ cur = in2[i]
+ i++
+ } else if j < len(in1) {
+ cur = in1[j]
+ j++
+ } else {
+ break
+ }
+
+ if n := len(out); n > 0 && cur.Start <= out[n-1].End {
+ out[n-1].End = cur.End
+ } else {
+ out = append(out, cur)
+ }
+ }
+
+ return out
+}
+
+// UnifyRanges merges the ranges from 'c' into the list of ranges for 's'.
+func (s *Scope) UnifyRanges(c *Scope) {
+ s.Ranges = MergeRanges(s.Ranges, c.Ranges)
+}
+
+// AppendRange adds r to s, if r is non-empty.
+// If possible, it extends the last Range in s.Ranges; if not, it creates a new one.
+func (s *Scope) AppendRange(r Range) {
+ if r.End <= r.Start {
+ return
+ }
+ i := len(s.Ranges)
+ if i > 0 && s.Ranges[i-1].End == r.Start {
+ s.Ranges[i-1].End = r.End
+ return
+ }
+ s.Ranges = append(s.Ranges, r)
+}
+
+type InlCalls struct {
+ Calls []InlCall
+}
+
+type InlCall struct {
+ // index into ctx.InlTree describing the call inlined here
+ InlIndex int
+
+ // Symbol of file containing inlined call site (really *obj.LSym).
+ CallFile Sym
+
+ // Line number of inlined call site.
+ CallLine uint32
+
+ // Dwarf abstract subroutine symbol (really *obj.LSym).
+ AbsFunSym Sym
+
+ // Indices of child inlines within Calls array above.
+ Children []int
+
+ // entries in this list are PAUTO's created by the inliner to
+ // capture the promoted formals and locals of the inlined callee.
+ InlVars []*Var
+
+ // PC ranges for this inlined call.
+ Ranges []Range
+
+ // Root call (not a child of some other call).
+ Root bool
+}
+
+// A Context specifies how to add data to a Sym.
+type Context interface {
+ PtrSize() int
+ AddInt(s Sym, size int, i int64)
+ AddBytes(s Sym, b []byte)
+ AddAddress(s Sym, t interface{}, ofs int64)
+ AddCURelativeAddress(s Sym, t interface{}, ofs int64)
+ AddSectionOffset(s Sym, size int, t interface{}, ofs int64)
+ AddDWARFAddrSectionOffset(s Sym, t interface{}, ofs int64)
+ CurrentOffset(s Sym) int64
+ RecordDclReference(from Sym, to Sym, dclIdx int, inlIndex int)
+ RecordChildDieOffsets(s Sym, vars []*Var, offsets []int32)
+ AddString(s Sym, v string)
+ AddFileRef(s Sym, f interface{})
+ Logf(format string, args ...interface{})
+}
+
+// AppendUleb128 appends v to b using DWARF's unsigned LEB128 encoding.
+func AppendUleb128(b []byte, v uint64) []byte {
+ for {
+ c := uint8(v & 0x7f)
+ v >>= 7
+ if v != 0 {
+ c |= 0x80
+ }
+ b = append(b, c)
+ if c&0x80 == 0 {
+ break
+ }
+ }
+ return b
+}
+
+// AppendSleb128 appends v to b using DWARF's signed LEB128 encoding.
+func AppendSleb128(b []byte, v int64) []byte {
+ for {
+ c := uint8(v & 0x7f)
+ s := uint8(v & 0x40)
+ v >>= 7
+ if (v != -1 || s == 0) && (v != 0 || s != 0) {
+ c |= 0x80
+ }
+ b = append(b, c)
+ if c&0x80 == 0 {
+ break
+ }
+ }
+ return b
+}
+
+// sevenbits contains all unsigned seven bit numbers, indexed by their value.
+var sevenbits = [...]byte{
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+ 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+ 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
+ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
+ 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
+ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
+}
+
+// sevenBitU returns the unsigned LEB128 encoding of v if v is seven bits and nil otherwise.
+// The contents of the returned slice must not be modified.
+func sevenBitU(v int64) []byte {
+ if uint64(v) < uint64(len(sevenbits)) {
+ return sevenbits[v : v+1]
+ }
+ return nil
+}
+
+// sevenBitS returns the signed LEB128 encoding of v if v is seven bits and nil otherwise.
+// The contents of the returned slice must not be modified.
+func sevenBitS(v int64) []byte {
+ if uint64(v) <= 63 {
+ return sevenbits[v : v+1]
+ }
+ if uint64(-v) <= 64 {
+ return sevenbits[128+v : 128+v+1]
+ }
+ return nil
+}
+
+// Uleb128put appends v to s using DWARF's unsigned LEB128 encoding.
+func Uleb128put(ctxt Context, s Sym, v int64) {
+ b := sevenBitU(v)
+ if b == nil {
+ var encbuf [20]byte
+ b = AppendUleb128(encbuf[:0], uint64(v))
+ }
+ ctxt.AddBytes(s, b)
+}
+
+// Sleb128put appends v to s using DWARF's signed LEB128 encoding.
+func Sleb128put(ctxt Context, s Sym, v int64) {
+ b := sevenBitS(v)
+ if b == nil {
+ var encbuf [20]byte
+ b = AppendSleb128(encbuf[:0], v)
+ }
+ ctxt.AddBytes(s, b)
+}
+
+/*
+ * Defining Abbrevs. This is hardcoded on a per-platform basis (that is,
+ * each platform will see a fixed abbrev table for all objects); the number
+ * of abbrev entries is fairly small (compared to C++ objects). The DWARF
+ * spec places no restriction on the ordering of attributes in the
+ * Abbrevs and DIEs, and we will always write them out in the order
+ * of declaration in the abbrev.
+ */
+type dwAttrForm struct {
+ attr uint16
+ form uint8
+}
+
+// Go-specific type attributes.
+const (
+ DW_AT_go_kind = 0x2900
+ DW_AT_go_key = 0x2901
+ DW_AT_go_elem = 0x2902
+ // Attribute for DW_TAG_member of a struct type.
+ // Nonzero value indicates the struct field is an embedded field.
+ DW_AT_go_embedded_field = 0x2903
+ DW_AT_go_runtime_type = 0x2904
+
+ DW_AT_go_package_name = 0x2905 // Attribute for DW_TAG_compile_unit
+
+ DW_AT_internal_location = 253 // params and locals; not emitted
+)
+
+// Index into the abbrevs table below.
+// Keep in sync with ispubname() and ispubtype() in ld/dwarf.go.
+// ispubtype considers >= NULLTYPE public
+const (
+ DW_ABRV_NULL = iota
+ DW_ABRV_COMPUNIT
+ DW_ABRV_COMPUNIT_TEXTLESS
+ DW_ABRV_FUNCTION
+ DW_ABRV_FUNCTION_ABSTRACT
+ DW_ABRV_FUNCTION_CONCRETE
+ DW_ABRV_INLINED_SUBROUTINE
+ DW_ABRV_INLINED_SUBROUTINE_RANGES
+ DW_ABRV_VARIABLE
+ DW_ABRV_INT_CONSTANT
+ DW_ABRV_AUTO
+ DW_ABRV_AUTO_LOCLIST
+ DW_ABRV_AUTO_ABSTRACT
+ DW_ABRV_AUTO_CONCRETE
+ DW_ABRV_AUTO_CONCRETE_LOCLIST
+ DW_ABRV_PARAM
+ DW_ABRV_PARAM_LOCLIST
+ DW_ABRV_PARAM_ABSTRACT
+ DW_ABRV_PARAM_CONCRETE
+ DW_ABRV_PARAM_CONCRETE_LOCLIST
+ DW_ABRV_LEXICAL_BLOCK_RANGES
+ DW_ABRV_LEXICAL_BLOCK_SIMPLE
+ DW_ABRV_STRUCTFIELD
+ DW_ABRV_FUNCTYPEPARAM
+ DW_ABRV_DOTDOTDOT
+ DW_ABRV_ARRAYRANGE
+ DW_ABRV_NULLTYPE
+ DW_ABRV_BASETYPE
+ DW_ABRV_ARRAYTYPE
+ DW_ABRV_CHANTYPE
+ DW_ABRV_FUNCTYPE
+ DW_ABRV_IFACETYPE
+ DW_ABRV_MAPTYPE
+ DW_ABRV_PTRTYPE
+ DW_ABRV_BARE_PTRTYPE // only for void*, no DW_AT_type attr to please gdb 6.
+ DW_ABRV_SLICETYPE
+ DW_ABRV_STRINGTYPE
+ DW_ABRV_STRUCTTYPE
+ DW_ABRV_TYPEDECL
+ DW_NABRV
+)
+
+type dwAbbrev struct {
+ tag uint8
+ children uint8
+ attr []dwAttrForm
+}
+
+var abbrevsFinalized bool
+
+// expandPseudoForm takes an input DW_FORM_xxx value and translates it
+// into a platform-appropriate concrete form. Existing concrete/real
+// DW_FORM values are left untouched. For the moment the only
+// pseudo-form is DW_FORM_udata_pseudo, which gets expanded to
+// DW_FORM_data4 on Darwin and DW_FORM_udata everywhere else. See
+// issue #31459 for more context.
+func expandPseudoForm(form uint8) uint8 {
+ // Is this a pseudo-form?
+ if form != DW_FORM_udata_pseudo {
+ return form
+ }
+ expandedForm := DW_FORM_udata
+ if objabi.GOOS == "darwin" || objabi.GOOS == "ios" {
+ expandedForm = DW_FORM_data4
+ }
+ return uint8(expandedForm)
+}
+
+// Abbrevs() returns the finalized abbrev array for the platform,
+// expanding any DW_FORM pseudo-ops to real values.
+func Abbrevs() []dwAbbrev {
+ if abbrevsFinalized {
+ return abbrevs[:]
+ }
+ for i := 1; i < DW_NABRV; i++ {
+ for j := 0; j < len(abbrevs[i].attr); j++ {
+ abbrevs[i].attr[j].form = expandPseudoForm(abbrevs[i].attr[j].form)
+ }
+ }
+ abbrevsFinalized = true
+ return abbrevs[:]
+}
+
+// abbrevs is a raw table of abbrev entries; it needs to be post-processed
+// by the Abbrevs() function above prior to being consumed, to expand
+// the 'pseudo-form' entries below to real DWARF form values.
+
+var abbrevs = [DW_NABRV]dwAbbrev{
+ /* The mandatory DW_ABRV_NULL entry. */
+ {0, 0, []dwAttrForm{}},
+
+ /* COMPUNIT */
+ {
+ DW_TAG_compile_unit,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_language, DW_FORM_data1},
+ {DW_AT_stmt_list, DW_FORM_sec_offset},
+ {DW_AT_low_pc, DW_FORM_addr},
+ {DW_AT_ranges, DW_FORM_sec_offset},
+ {DW_AT_comp_dir, DW_FORM_string},
+ {DW_AT_producer, DW_FORM_string},
+ {DW_AT_go_package_name, DW_FORM_string},
+ },
+ },
+
+ /* COMPUNIT_TEXTLESS */
+ {
+ DW_TAG_compile_unit,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_language, DW_FORM_data1},
+ {DW_AT_comp_dir, DW_FORM_string},
+ {DW_AT_producer, DW_FORM_string},
+ {DW_AT_go_package_name, DW_FORM_string},
+ },
+ },
+
+ /* FUNCTION */
+ {
+ DW_TAG_subprogram,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_low_pc, DW_FORM_addr},
+ {DW_AT_high_pc, DW_FORM_addr},
+ {DW_AT_frame_base, DW_FORM_block1},
+ {DW_AT_decl_file, DW_FORM_data4},
+ {DW_AT_external, DW_FORM_flag},
+ },
+ },
+
+ /* FUNCTION_ABSTRACT */
+ {
+ DW_TAG_subprogram,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_inline, DW_FORM_data1},
+ {DW_AT_external, DW_FORM_flag},
+ },
+ },
+
+ /* FUNCTION_CONCRETE */
+ {
+ DW_TAG_subprogram,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_abstract_origin, DW_FORM_ref_addr},
+ {DW_AT_low_pc, DW_FORM_addr},
+ {DW_AT_high_pc, DW_FORM_addr},
+ {DW_AT_frame_base, DW_FORM_block1},
+ },
+ },
+
+ /* INLINED_SUBROUTINE */
+ {
+ DW_TAG_inlined_subroutine,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_abstract_origin, DW_FORM_ref_addr},
+ {DW_AT_low_pc, DW_FORM_addr},
+ {DW_AT_high_pc, DW_FORM_addr},
+ {DW_AT_call_file, DW_FORM_data4},
+ {DW_AT_call_line, DW_FORM_udata_pseudo}, // pseudo-form
+ },
+ },
+
+ /* INLINED_SUBROUTINE_RANGES */
+ {
+ DW_TAG_inlined_subroutine,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_abstract_origin, DW_FORM_ref_addr},
+ {DW_AT_ranges, DW_FORM_sec_offset},
+ {DW_AT_call_file, DW_FORM_data4},
+ {DW_AT_call_line, DW_FORM_udata_pseudo}, // pseudo-form
+ },
+ },
+
+ /* VARIABLE */
+ {
+ DW_TAG_variable,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_location, DW_FORM_block1},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_external, DW_FORM_flag},
+ },
+ },
+
+ /* INT CONSTANT */
+ {
+ DW_TAG_constant,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_const_value, DW_FORM_sdata},
+ },
+ },
+
+ /* AUTO */
+ {
+ DW_TAG_variable,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_decl_line, DW_FORM_udata},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_location, DW_FORM_block1},
+ },
+ },
+
+ /* AUTO_LOCLIST */
+ {
+ DW_TAG_variable,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_decl_line, DW_FORM_udata},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_location, DW_FORM_sec_offset},
+ },
+ },
+
+ /* AUTO_ABSTRACT */
+ {
+ DW_TAG_variable,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_decl_line, DW_FORM_udata},
+ {DW_AT_type, DW_FORM_ref_addr},
+ },
+ },
+
+ /* AUTO_CONCRETE */
+ {
+ DW_TAG_variable,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_abstract_origin, DW_FORM_ref_addr},
+ {DW_AT_location, DW_FORM_block1},
+ },
+ },
+
+ /* AUTO_CONCRETE_LOCLIST */
+ {
+ DW_TAG_variable,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_abstract_origin, DW_FORM_ref_addr},
+ {DW_AT_location, DW_FORM_sec_offset},
+ },
+ },
+
+ /* PARAM */
+ {
+ DW_TAG_formal_parameter,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_variable_parameter, DW_FORM_flag},
+ {DW_AT_decl_line, DW_FORM_udata},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_location, DW_FORM_block1},
+ },
+ },
+
+ /* PARAM_LOCLIST */
+ {
+ DW_TAG_formal_parameter,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_variable_parameter, DW_FORM_flag},
+ {DW_AT_decl_line, DW_FORM_udata},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_location, DW_FORM_sec_offset},
+ },
+ },
+
+ /* PARAM_ABSTRACT */
+ {
+ DW_TAG_formal_parameter,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_variable_parameter, DW_FORM_flag},
+ {DW_AT_type, DW_FORM_ref_addr},
+ },
+ },
+
+ /* PARAM_CONCRETE */
+ {
+ DW_TAG_formal_parameter,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_abstract_origin, DW_FORM_ref_addr},
+ {DW_AT_location, DW_FORM_block1},
+ },
+ },
+
+ /* PARAM_CONCRETE_LOCLIST */
+ {
+ DW_TAG_formal_parameter,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_abstract_origin, DW_FORM_ref_addr},
+ {DW_AT_location, DW_FORM_sec_offset},
+ },
+ },
+
+ /* LEXICAL_BLOCK_RANGES */
+ {
+ DW_TAG_lexical_block,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_ranges, DW_FORM_sec_offset},
+ },
+ },
+
+ /* LEXICAL_BLOCK_SIMPLE */
+ {
+ DW_TAG_lexical_block,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_low_pc, DW_FORM_addr},
+ {DW_AT_high_pc, DW_FORM_addr},
+ },
+ },
+
+ /* STRUCTFIELD */
+ {
+ DW_TAG_member,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_data_member_location, DW_FORM_udata},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_go_embedded_field, DW_FORM_flag},
+ },
+ },
+
+ /* FUNCTYPEPARAM */
+ {
+ DW_TAG_formal_parameter,
+ DW_CHILDREN_no,
+
+ // No name!
+ []dwAttrForm{
+ {DW_AT_type, DW_FORM_ref_addr},
+ },
+ },
+
+ /* DOTDOTDOT */
+ {
+ DW_TAG_unspecified_parameters,
+ DW_CHILDREN_no,
+ []dwAttrForm{},
+ },
+
+ /* ARRAYRANGE */
+ {
+ DW_TAG_subrange_type,
+ DW_CHILDREN_no,
+
+ // No name!
+ []dwAttrForm{
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_count, DW_FORM_udata},
+ },
+ },
+
+ // Below here are the types considered public by ispubtype
+ /* NULLTYPE */
+ {
+ DW_TAG_unspecified_type,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ },
+ },
+
+ /* BASETYPE */
+ {
+ DW_TAG_base_type,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_encoding, DW_FORM_data1},
+ {DW_AT_byte_size, DW_FORM_data1},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ },
+ },
+
+ /* ARRAYTYPE */
+ // child is subrange with upper bound
+ {
+ DW_TAG_array_type,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_byte_size, DW_FORM_udata},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ },
+ },
+
+ /* CHANTYPE */
+ {
+ DW_TAG_typedef,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ {DW_AT_go_elem, DW_FORM_ref_addr},
+ },
+ },
+
+ /* FUNCTYPE */
+ {
+ DW_TAG_subroutine_type,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_byte_size, DW_FORM_udata},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ },
+ },
+
+ /* IFACETYPE */
+ {
+ DW_TAG_typedef,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ },
+ },
+
+ /* MAPTYPE */
+ {
+ DW_TAG_typedef,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ {DW_AT_go_key, DW_FORM_ref_addr},
+ {DW_AT_go_elem, DW_FORM_ref_addr},
+ },
+ },
+
+ /* PTRTYPE */
+ {
+ DW_TAG_pointer_type,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_type, DW_FORM_ref_addr},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ },
+ },
+
+ /* BARE_PTRTYPE */
+ {
+ DW_TAG_pointer_type,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ },
+ },
+
+ /* SLICETYPE */
+ {
+ DW_TAG_structure_type,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_byte_size, DW_FORM_udata},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ {DW_AT_go_elem, DW_FORM_ref_addr},
+ },
+ },
+
+ /* STRINGTYPE */
+ {
+ DW_TAG_structure_type,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_byte_size, DW_FORM_udata},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ },
+ },
+
+ /* STRUCTTYPE */
+ {
+ DW_TAG_structure_type,
+ DW_CHILDREN_yes,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_byte_size, DW_FORM_udata},
+ {DW_AT_go_kind, DW_FORM_data1},
+ {DW_AT_go_runtime_type, DW_FORM_addr},
+ },
+ },
+
+ /* TYPEDECL */
+ {
+ DW_TAG_typedef,
+ DW_CHILDREN_no,
+ []dwAttrForm{
+ {DW_AT_name, DW_FORM_string},
+ {DW_AT_type, DW_FORM_ref_addr},
+ },
+ },
+}
+
+// GetAbbrev returns the contents of the .debug_abbrev section.
+func GetAbbrev() []byte {
+ abbrevs := Abbrevs()
+ var buf []byte
+ for i := 1; i < DW_NABRV; i++ {
+ // See section 7.5.3
+ buf = AppendUleb128(buf, uint64(i))
+ buf = AppendUleb128(buf, uint64(abbrevs[i].tag))
+ buf = append(buf, abbrevs[i].children)
+ for _, f := range abbrevs[i].attr {
+ buf = AppendUleb128(buf, uint64(f.attr))
+ buf = AppendUleb128(buf, uint64(f.form))
+ }
+ buf = append(buf, 0, 0)
+ }
+ return append(buf, 0)
+}
+
+/*
+ * Debugging Information Entries and their attributes.
+ */
+
+// DWAttr represents an attribute of a DWDie.
+//
+// For DW_CLS_string and _block, value should contain the length, and
+// data the data, for _reference, value is 0 and data is a DWDie* to
+// the referenced instance, for all others, value is the whole thing
+// and data is null.
+type DWAttr struct {
+ Link *DWAttr
+ Atr uint16 // DW_AT_
+ Cls uint8 // DW_CLS_
+ Value int64
+ Data interface{}
+}
+
+// DWDie represents a DWARF debug info entry.
+type DWDie struct {
+ Abbrev int
+ Link *DWDie
+ Child *DWDie
+ Attr *DWAttr
+ Sym Sym
+}
+
+func putattr(ctxt Context, s Sym, abbrev int, form int, cls int, value int64, data interface{}) error {
+ switch form {
+ case DW_FORM_addr: // address
+ // Allow nil addresses for DW_AT_go_runtime_type.
+ if data == nil && value == 0 {
+ ctxt.AddInt(s, ctxt.PtrSize(), 0)
+ break
+ }
+ if cls == DW_CLS_GO_TYPEREF {
+ ctxt.AddSectionOffset(s, ctxt.PtrSize(), data, value)
+ break
+ }
+ ctxt.AddAddress(s, data, value)
+
+ case DW_FORM_block1: // block
+ if cls == DW_CLS_ADDRESS {
+ ctxt.AddInt(s, 1, int64(1+ctxt.PtrSize()))
+ ctxt.AddInt(s, 1, DW_OP_addr)
+ ctxt.AddAddress(s, data, 0)
+ break
+ }
+
+ value &= 0xff
+ ctxt.AddInt(s, 1, value)
+ p := data.([]byte)[:value]
+ ctxt.AddBytes(s, p)
+
+ case DW_FORM_block2: // block
+ value &= 0xffff
+
+ ctxt.AddInt(s, 2, value)
+ p := data.([]byte)[:value]
+ ctxt.AddBytes(s, p)
+
+ case DW_FORM_block4: // block
+ value &= 0xffffffff
+
+ ctxt.AddInt(s, 4, value)
+ p := data.([]byte)[:value]
+ ctxt.AddBytes(s, p)
+
+ case DW_FORM_block: // block
+ Uleb128put(ctxt, s, value)
+
+ p := data.([]byte)[:value]
+ ctxt.AddBytes(s, p)
+
+ case DW_FORM_data1: // constant
+ ctxt.AddInt(s, 1, value)
+
+ case DW_FORM_data2: // constant
+ ctxt.AddInt(s, 2, value)
+
+ case DW_FORM_data4: // constant, {line,loclist,mac,rangelist}ptr
+ if cls == DW_CLS_PTR { // DW_AT_stmt_list and DW_AT_ranges
+ ctxt.AddDWARFAddrSectionOffset(s, data, value)
+ break
+ }
+ ctxt.AddInt(s, 4, value)
+
+ case DW_FORM_data8: // constant, {line,loclist,mac,rangelist}ptr
+ ctxt.AddInt(s, 8, value)
+
+ case DW_FORM_sdata: // constant
+ Sleb128put(ctxt, s, value)
+
+ case DW_FORM_udata: // constant
+ Uleb128put(ctxt, s, value)
+
+ case DW_FORM_string: // string
+ str := data.(string)
+ ctxt.AddString(s, str)
+ // TODO(ribrdb): verify padded strings are never used and remove this
+ for i := int64(len(str)); i < value; i++ {
+ ctxt.AddInt(s, 1, 0)
+ }
+
+ case DW_FORM_flag: // flag
+ if value != 0 {
+ ctxt.AddInt(s, 1, 1)
+ } else {
+ ctxt.AddInt(s, 1, 0)
+ }
+
+ // As of DWARF 3 the ref_addr is always 32 bits, unless emitting a large
+ // (> 4 GB of debug info aka "64-bit") unit, which we don't implement.
+ case DW_FORM_ref_addr: // reference to a DIE in the .info section
+ fallthrough
+ case DW_FORM_sec_offset: // offset into a DWARF section other than .info
+ if data == nil {
+ return fmt.Errorf("dwarf: null reference in %d", abbrev)
+ }
+ ctxt.AddDWARFAddrSectionOffset(s, data, value)
+
+ case DW_FORM_ref1, // reference within the compilation unit
+ DW_FORM_ref2, // reference
+ DW_FORM_ref4, // reference
+ DW_FORM_ref8, // reference
+ DW_FORM_ref_udata, // reference
+
+ DW_FORM_strp, // string
+ DW_FORM_indirect: // (see Section 7.5.3)
+ fallthrough
+ default:
+ return fmt.Errorf("dwarf: unsupported attribute form %d / class %d", form, cls)
+ }
+ return nil
+}
+
+// PutAttrs writes the attributes for a DIE to symbol 's'.
+//
+// Note that we can (and do) add arbitrary attributes to a DIE, but
+// only the ones actually listed in the Abbrev will be written out.
+func PutAttrs(ctxt Context, s Sym, abbrev int, attr *DWAttr) {
+ abbrevs := Abbrevs()
+Outer:
+ for _, f := range abbrevs[abbrev].attr {
+ for ap := attr; ap != nil; ap = ap.Link {
+ if ap.Atr == f.attr {
+ putattr(ctxt, s, abbrev, int(f.form), int(ap.Cls), ap.Value, ap.Data)
+ continue Outer
+ }
+ }
+
+ putattr(ctxt, s, abbrev, int(f.form), 0, 0, nil)
+ }
+}
+
+// HasChildren reports whether 'die' uses an abbrev that supports children.
+func HasChildren(die *DWDie) bool {
+ abbrevs := Abbrevs()
+ return abbrevs[die.Abbrev].children != 0
+}
+
+// PutIntConst writes a DIE for an integer constant
+func PutIntConst(ctxt Context, info, typ Sym, name string, val int64) {
+ Uleb128put(ctxt, info, DW_ABRV_INT_CONSTANT)
+ putattr(ctxt, info, DW_ABRV_INT_CONSTANT, DW_FORM_string, DW_CLS_STRING, int64(len(name)), name)
+ putattr(ctxt, info, DW_ABRV_INT_CONSTANT, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, typ)
+ putattr(ctxt, info, DW_ABRV_INT_CONSTANT, DW_FORM_sdata, DW_CLS_CONSTANT, val, nil)
+}
+
+// PutBasedRanges writes a range table to sym. All addresses in ranges are
+// relative to some base address, which must be arranged by the caller
+// (e.g., with a DW_AT_low_pc attribute, or in a BASE-prefixed range).
+func PutBasedRanges(ctxt Context, sym Sym, ranges []Range) {
+ ps := ctxt.PtrSize()
+ // Write ranges.
+ for _, r := range ranges {
+ ctxt.AddInt(sym, ps, r.Start)
+ ctxt.AddInt(sym, ps, r.End)
+ }
+ // Write trailer.
+ ctxt.AddInt(sym, ps, 0)
+ ctxt.AddInt(sym, ps, 0)
+}
+
+// PutRanges writes a range table to s.Ranges.
+// All addresses in ranges are relative to s.base.
+func (s *FnState) PutRanges(ctxt Context, ranges []Range) {
+ ps := ctxt.PtrSize()
+ sym, base := s.Ranges, s.StartPC
+
+ if s.UseBASEntries {
+ // Using a Base Address Selection Entry reduces the number of relocations, but
+ // this is not done on macOS because it is not supported by dsymutil/dwarfdump/lldb
+ ctxt.AddInt(sym, ps, -1)
+ ctxt.AddAddress(sym, base, 0)
+ PutBasedRanges(ctxt, sym, ranges)
+ return
+ }
+
+ // Write ranges full of relocations
+ for _, r := range ranges {
+ ctxt.AddCURelativeAddress(sym, base, r.Start)
+ ctxt.AddCURelativeAddress(sym, base, r.End)
+ }
+ // Write trailer.
+ ctxt.AddInt(sym, ps, 0)
+ ctxt.AddInt(sym, ps, 0)
+}
+
+// Return TRUE if the inlined call in the specified slot is empty,
+// meaning it has a zero-length range (no instructions), and all
+// of its children are empty.
+func isEmptyInlinedCall(slot int, calls *InlCalls) bool {
+ ic := &calls.Calls[slot]
+ if ic.InlIndex == -2 {
+ return true
+ }
+ live := false
+ for _, k := range ic.Children {
+ if !isEmptyInlinedCall(k, calls) {
+ live = true
+ }
+ }
+ if len(ic.Ranges) > 0 {
+ live = true
+ }
+ if !live {
+ ic.InlIndex = -2
+ }
+ return !live
+}
+
+// Slot -1: return top-level inlines
+// Slot >= 0: return children of that slot
+func inlChildren(slot int, calls *InlCalls) []int {
+ var kids []int
+ if slot != -1 {
+ for _, k := range calls.Calls[slot].Children {
+ if !isEmptyInlinedCall(k, calls) {
+ kids = append(kids, k)
+ }
+ }
+ } else {
+ for k := 0; k < len(calls.Calls); k += 1 {
+ if calls.Calls[k].Root && !isEmptyInlinedCall(k, calls) {
+ kids = append(kids, k)
+ }
+ }
+ }
+ return kids
+}
+
+func inlinedVarTable(inlcalls *InlCalls) map[*Var]bool {
+ vars := make(map[*Var]bool)
+ for _, ic := range inlcalls.Calls {
+ for _, v := range ic.InlVars {
+ vars[v] = true
+ }
+ }
+ return vars
+}
+
+// The s.Scopes slice contains variables were originally part of the
+// function being emitted, as well as variables that were imported
+// from various callee functions during the inlining process. This
+// function prunes out any variables from the latter category (since
+// they will be emitted as part of DWARF inlined_subroutine DIEs) and
+// then generates scopes for vars in the former category.
+func putPrunedScopes(ctxt Context, s *FnState, fnabbrev int) error {
+ if len(s.Scopes) == 0 {
+ return nil
+ }
+ scopes := make([]Scope, len(s.Scopes), len(s.Scopes))
+ pvars := inlinedVarTable(&s.InlCalls)
+ for k, s := range s.Scopes {
+ var pruned Scope = Scope{Parent: s.Parent, Ranges: s.Ranges}
+ for i := 0; i < len(s.Vars); i++ {
+ _, found := pvars[s.Vars[i]]
+ if !found {
+ pruned.Vars = append(pruned.Vars, s.Vars[i])
+ }
+ }
+ sort.Sort(byChildIndex(pruned.Vars))
+ scopes[k] = pruned
+ }
+ var encbuf [20]byte
+ if putscope(ctxt, s, scopes, 0, fnabbrev, encbuf[:0]) < int32(len(scopes)) {
+ return errors.New("multiple toplevel scopes")
+ }
+ return nil
+}
+
+// Emit DWARF attributes and child DIEs for an 'abstract' subprogram.
+// The abstract subprogram DIE for a function contains its
+// location-independent attributes (name, type, etc). Other instances
+// of the function (any inlined copy of it, or the single out-of-line
+// 'concrete' instance) will contain a pointer back to this abstract
+// DIE (as a space-saving measure, so that name/type etc doesn't have
+// to be repeated for each inlined copy).
+func PutAbstractFunc(ctxt Context, s *FnState) error {
+
+ if logDwarf {
+ ctxt.Logf("PutAbstractFunc(%v)\n", s.Absfn)
+ }
+
+ abbrev := DW_ABRV_FUNCTION_ABSTRACT
+ Uleb128put(ctxt, s.Absfn, int64(abbrev))
+
+ fullname := s.Name
+ if strings.HasPrefix(s.Name, "\"\".") {
+ // Generate a fully qualified name for the function in the
+ // abstract case. This is so as to avoid the need for the
+ // linker to process the DIE with patchDWARFName(); we can't
+ // allow the name attribute of an abstract subprogram DIE to
+ // be rewritten, since it would change the offsets of the
+ // child DIEs (which we're relying on in order for abstract
+ // origin references to work).
+ fullname = objabi.PathToPrefix(s.Importpath) + "." + s.Name[3:]
+ }
+ putattr(ctxt, s.Absfn, abbrev, DW_FORM_string, DW_CLS_STRING, int64(len(fullname)), fullname)
+
+ // DW_AT_inlined value
+ putattr(ctxt, s.Absfn, abbrev, DW_FORM_data1, DW_CLS_CONSTANT, int64(DW_INL_inlined), nil)
+
+ var ev int64
+ if s.External {
+ ev = 1
+ }
+ putattr(ctxt, s.Absfn, abbrev, DW_FORM_flag, DW_CLS_FLAG, ev, 0)
+
+ // Child variables (may be empty)
+ var flattened []*Var
+
+ // This slice will hold the offset in bytes for each child var DIE
+ // with respect to the start of the parent subprogram DIE.
+ var offsets []int32
+
+ // Scopes/vars
+ if len(s.Scopes) > 0 {
+ // For abstract subprogram DIEs we want to flatten out scope info:
+ // lexical scope DIEs contain range and/or hi/lo PC attributes,
+ // which we explicitly don't want for the abstract subprogram DIE.
+ pvars := inlinedVarTable(&s.InlCalls)
+ for _, scope := range s.Scopes {
+ for i := 0; i < len(scope.Vars); i++ {
+ _, found := pvars[scope.Vars[i]]
+ if found || !scope.Vars[i].IsInAbstract {
+ continue
+ }
+ flattened = append(flattened, scope.Vars[i])
+ }
+ }
+ if len(flattened) > 0 {
+ sort.Sort(byChildIndex(flattened))
+
+ if logDwarf {
+ ctxt.Logf("putAbstractScope(%v): vars:", s.Info)
+ for i, v := range flattened {
+ ctxt.Logf(" %d:%s", i, v.Name)
+ }
+ ctxt.Logf("\n")
+ }
+
+ // This slice will hold the offset in bytes for each child
+ // variable DIE with respect to the start of the parent
+ // subprogram DIE.
+ for _, v := range flattened {
+ offsets = append(offsets, int32(ctxt.CurrentOffset(s.Absfn)))
+ putAbstractVar(ctxt, s.Absfn, v)
+ }
+ }
+ }
+ ctxt.RecordChildDieOffsets(s.Absfn, flattened, offsets)
+
+ Uleb128put(ctxt, s.Absfn, 0)
+ return nil
+}
+
+// Emit DWARF attributes and child DIEs for an inlined subroutine. The
+// first attribute of an inlined subroutine DIE is a reference back to
+// its corresponding 'abstract' DIE (containing location-independent
+// attributes such as name, type, etc). Inlined subroutine DIEs can
+// have other inlined subroutine DIEs as children.
+func PutInlinedFunc(ctxt Context, s *FnState, callersym Sym, callIdx int) error {
+ ic := s.InlCalls.Calls[callIdx]
+ callee := ic.AbsFunSym
+
+ abbrev := DW_ABRV_INLINED_SUBROUTINE_RANGES
+ if len(ic.Ranges) == 1 {
+ abbrev = DW_ABRV_INLINED_SUBROUTINE
+ }
+ Uleb128put(ctxt, s.Info, int64(abbrev))
+
+ if logDwarf {
+ ctxt.Logf("PutInlinedFunc(caller=%v,callee=%v,abbrev=%d)\n", callersym, callee, abbrev)
+ }
+
+ // Abstract origin.
+ putattr(ctxt, s.Info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, callee)
+
+ if abbrev == DW_ABRV_INLINED_SUBROUTINE_RANGES {
+ putattr(ctxt, s.Info, abbrev, DW_FORM_sec_offset, DW_CLS_PTR, s.Ranges.Length(ctxt), s.Ranges)
+ s.PutRanges(ctxt, ic.Ranges)
+ } else {
+ st := ic.Ranges[0].Start
+ en := ic.Ranges[0].End
+ putattr(ctxt, s.Info, abbrev, DW_FORM_addr, DW_CLS_ADDRESS, st, s.StartPC)
+ putattr(ctxt, s.Info, abbrev, DW_FORM_addr, DW_CLS_ADDRESS, en, s.StartPC)
+ }
+
+ // Emit call file, line attrs.
+ ctxt.AddFileRef(s.Info, ic.CallFile)
+ form := int(expandPseudoForm(DW_FORM_udata_pseudo))
+ putattr(ctxt, s.Info, abbrev, form, DW_CLS_CONSTANT, int64(ic.CallLine), nil)
+
+ // Variables associated with this inlined routine instance.
+ vars := ic.InlVars
+ sort.Sort(byChildIndex(vars))
+ inlIndex := ic.InlIndex
+ var encbuf [20]byte
+ for _, v := range vars {
+ if !v.IsInAbstract {
+ continue
+ }
+ putvar(ctxt, s, v, callee, abbrev, inlIndex, encbuf[:0])
+ }
+
+ // Children of this inline.
+ for _, sib := range inlChildren(callIdx, &s.InlCalls) {
+ absfn := s.InlCalls.Calls[sib].AbsFunSym
+ err := PutInlinedFunc(ctxt, s, absfn, sib)
+ if err != nil {
+ return err
+ }
+ }
+
+ Uleb128put(ctxt, s.Info, 0)
+ return nil
+}
+
+// Emit DWARF attributes and child DIEs for a 'concrete' subprogram,
+// meaning the out-of-line copy of a function that was inlined at some
+// point during the compilation of its containing package. The first
+// attribute for a concrete DIE is a reference to the 'abstract' DIE
+// for the function (which holds location-independent attributes such
+// as name, type), then the remainder of the attributes are specific
+// to this instance (location, frame base, etc).
+func PutConcreteFunc(ctxt Context, s *FnState) error {
+ if logDwarf {
+ ctxt.Logf("PutConcreteFunc(%v)\n", s.Info)
+ }
+ abbrev := DW_ABRV_FUNCTION_CONCRETE
+ Uleb128put(ctxt, s.Info, int64(abbrev))
+
+ // Abstract origin.
+ putattr(ctxt, s.Info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, s.Absfn)
+
+ // Start/end PC.
+ putattr(ctxt, s.Info, abbrev, DW_FORM_addr, DW_CLS_ADDRESS, 0, s.StartPC)
+ putattr(ctxt, s.Info, abbrev, DW_FORM_addr, DW_CLS_ADDRESS, s.Size, s.StartPC)
+
+ // cfa / frame base
+ putattr(ctxt, s.Info, abbrev, DW_FORM_block1, DW_CLS_BLOCK, 1, []byte{DW_OP_call_frame_cfa})
+
+ // Scopes
+ if err := putPrunedScopes(ctxt, s, abbrev); err != nil {
+ return err
+ }
+
+ // Inlined subroutines.
+ for _, sib := range inlChildren(-1, &s.InlCalls) {
+ absfn := s.InlCalls.Calls[sib].AbsFunSym
+ err := PutInlinedFunc(ctxt, s, absfn, sib)
+ if err != nil {
+ return err
+ }
+ }
+
+ Uleb128put(ctxt, s.Info, 0)
+ return nil
+}
+
+// Emit DWARF attributes and child DIEs for a subprogram. Here
+// 'default' implies that the function in question was not inlined
+// when its containing package was compiled (hence there is no need to
+// emit an abstract version for it to use as a base for inlined
+// routine records).
+func PutDefaultFunc(ctxt Context, s *FnState) error {
+ if logDwarf {
+ ctxt.Logf("PutDefaultFunc(%v)\n", s.Info)
+ }
+ abbrev := DW_ABRV_FUNCTION
+ Uleb128put(ctxt, s.Info, int64(abbrev))
+
+ // Expand '"".' to import path.
+ name := s.Name
+ if s.Importpath != "" {
+ name = strings.Replace(name, "\"\".", objabi.PathToPrefix(s.Importpath)+".", -1)
+ }
+
+ putattr(ctxt, s.Info, DW_ABRV_FUNCTION, DW_FORM_string, DW_CLS_STRING, int64(len(name)), name)
+ putattr(ctxt, s.Info, abbrev, DW_FORM_addr, DW_CLS_ADDRESS, 0, s.StartPC)
+ putattr(ctxt, s.Info, abbrev, DW_FORM_addr, DW_CLS_ADDRESS, s.Size, s.StartPC)
+ putattr(ctxt, s.Info, abbrev, DW_FORM_block1, DW_CLS_BLOCK, 1, []byte{DW_OP_call_frame_cfa})
+ ctxt.AddFileRef(s.Info, s.Filesym)
+
+ var ev int64
+ if s.External {
+ ev = 1
+ }
+ putattr(ctxt, s.Info, abbrev, DW_FORM_flag, DW_CLS_FLAG, ev, 0)
+
+ // Scopes
+ if err := putPrunedScopes(ctxt, s, abbrev); err != nil {
+ return err
+ }
+
+ // Inlined subroutines.
+ for _, sib := range inlChildren(-1, &s.InlCalls) {
+ absfn := s.InlCalls.Calls[sib].AbsFunSym
+ err := PutInlinedFunc(ctxt, s, absfn, sib)
+ if err != nil {
+ return err
+ }
+ }
+
+ Uleb128put(ctxt, s.Info, 0)
+ return nil
+}
+
+func putscope(ctxt Context, s *FnState, scopes []Scope, curscope int32, fnabbrev int, encbuf []byte) int32 {
+
+ if logDwarf {
+ ctxt.Logf("putscope(%v,%d): vars:", s.Info, curscope)
+ for i, v := range scopes[curscope].Vars {
+ ctxt.Logf(" %d:%d:%s", i, v.ChildIndex, v.Name)
+ }
+ ctxt.Logf("\n")
+ }
+
+ for _, v := range scopes[curscope].Vars {
+ putvar(ctxt, s, v, s.Absfn, fnabbrev, -1, encbuf)
+ }
+ this := curscope
+ curscope++
+ for curscope < int32(len(scopes)) {
+ scope := scopes[curscope]
+ if scope.Parent != this {
+ return curscope
+ }
+
+ if len(scopes[curscope].Vars) == 0 {
+ curscope = putscope(ctxt, s, scopes, curscope, fnabbrev, encbuf)
+ continue
+ }
+
+ if len(scope.Ranges) == 1 {
+ Uleb128put(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_SIMPLE)
+ putattr(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_SIMPLE, DW_FORM_addr, DW_CLS_ADDRESS, scope.Ranges[0].Start, s.StartPC)
+ putattr(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_SIMPLE, DW_FORM_addr, DW_CLS_ADDRESS, scope.Ranges[0].End, s.StartPC)
+ } else {
+ Uleb128put(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_RANGES)
+ putattr(ctxt, s.Info, DW_ABRV_LEXICAL_BLOCK_RANGES, DW_FORM_sec_offset, DW_CLS_PTR, s.Ranges.Length(ctxt), s.Ranges)
+
+ s.PutRanges(ctxt, scope.Ranges)
+ }
+
+ curscope = putscope(ctxt, s, scopes, curscope, fnabbrev, encbuf)
+
+ Uleb128put(ctxt, s.Info, 0)
+ }
+ return curscope
+}
+
+// Given a default var abbrev code, select corresponding concrete code.
+func concreteVarAbbrev(varAbbrev int) int {
+ switch varAbbrev {
+ case DW_ABRV_AUTO:
+ return DW_ABRV_AUTO_CONCRETE
+ case DW_ABRV_PARAM:
+ return DW_ABRV_PARAM_CONCRETE
+ case DW_ABRV_AUTO_LOCLIST:
+ return DW_ABRV_AUTO_CONCRETE_LOCLIST
+ case DW_ABRV_PARAM_LOCLIST:
+ return DW_ABRV_PARAM_CONCRETE_LOCLIST
+ default:
+ panic("should never happen")
+ }
+}
+
+// Pick the correct abbrev code for variable or parameter DIE.
+func determineVarAbbrev(v *Var, fnabbrev int) (int, bool, bool) {
+ abbrev := v.Abbrev
+
+ // If the variable was entirely optimized out, don't emit a location list;
+ // convert to an inline abbreviation and emit an empty location.
+ missing := false
+ switch {
+ case abbrev == DW_ABRV_AUTO_LOCLIST && v.PutLocationList == nil:
+ missing = true
+ abbrev = DW_ABRV_AUTO
+ case abbrev == DW_ABRV_PARAM_LOCLIST && v.PutLocationList == nil:
+ missing = true
+ abbrev = DW_ABRV_PARAM
+ }
+
+ // Determine whether to use a concrete variable or regular variable DIE.
+ concrete := true
+ switch fnabbrev {
+ case DW_ABRV_FUNCTION:
+ concrete = false
+ break
+ case DW_ABRV_FUNCTION_CONCRETE:
+ // If we're emitting a concrete subprogram DIE and the variable
+ // in question is not part of the corresponding abstract function DIE,
+ // then use the default (non-concrete) abbrev for this param.
+ if !v.IsInAbstract {
+ concrete = false
+ }
+ case DW_ABRV_INLINED_SUBROUTINE, DW_ABRV_INLINED_SUBROUTINE_RANGES:
+ default:
+ panic("should never happen")
+ }
+
+ // Select proper abbrev based on concrete/non-concrete
+ if concrete {
+ abbrev = concreteVarAbbrev(abbrev)
+ }
+
+ return abbrev, missing, concrete
+}
+
+func abbrevUsesLoclist(abbrev int) bool {
+ switch abbrev {
+ case DW_ABRV_AUTO_LOCLIST, DW_ABRV_AUTO_CONCRETE_LOCLIST,
+ DW_ABRV_PARAM_LOCLIST, DW_ABRV_PARAM_CONCRETE_LOCLIST:
+ return true
+ default:
+ return false
+ }
+}
+
+// Emit DWARF attributes for a variable belonging to an 'abstract' subprogram.
+func putAbstractVar(ctxt Context, info Sym, v *Var) {
+ // Remap abbrev
+ abbrev := v.Abbrev
+ switch abbrev {
+ case DW_ABRV_AUTO, DW_ABRV_AUTO_LOCLIST:
+ abbrev = DW_ABRV_AUTO_ABSTRACT
+ case DW_ABRV_PARAM, DW_ABRV_PARAM_LOCLIST:
+ abbrev = DW_ABRV_PARAM_ABSTRACT
+ }
+
+ Uleb128put(ctxt, info, int64(abbrev))
+ putattr(ctxt, info, abbrev, DW_FORM_string, DW_CLS_STRING, int64(len(v.Name)), v.Name)
+
+ // Isreturn attribute if this is a param
+ if abbrev == DW_ABRV_PARAM_ABSTRACT {
+ var isReturn int64
+ if v.IsReturnValue {
+ isReturn = 1
+ }
+ putattr(ctxt, info, abbrev, DW_FORM_flag, DW_CLS_FLAG, isReturn, nil)
+ }
+
+ // Line
+ if abbrev != DW_ABRV_PARAM_ABSTRACT {
+ // See issue 23374 for more on why decl line is skipped for abs params.
+ putattr(ctxt, info, abbrev, DW_FORM_udata, DW_CLS_CONSTANT, int64(v.DeclLine), nil)
+ }
+
+ // Type
+ putattr(ctxt, info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, v.Type)
+
+ // Var has no children => no terminator
+}
+
+func putvar(ctxt Context, s *FnState, v *Var, absfn Sym, fnabbrev, inlIndex int, encbuf []byte) {
+ // Remap abbrev according to parent DIE abbrev
+ abbrev, missing, concrete := determineVarAbbrev(v, fnabbrev)
+
+ Uleb128put(ctxt, s.Info, int64(abbrev))
+
+ // Abstract origin for concrete / inlined case
+ if concrete {
+ // Here we are making a reference to a child DIE of an abstract
+ // function subprogram DIE. The child DIE has no LSym, so instead
+ // after the call to 'putattr' below we make a call to register
+ // the child DIE reference.
+ putattr(ctxt, s.Info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, absfn)
+ ctxt.RecordDclReference(s.Info, absfn, int(v.ChildIndex), inlIndex)
+ } else {
+ // Var name, line for abstract and default cases
+ n := v.Name
+ putattr(ctxt, s.Info, abbrev, DW_FORM_string, DW_CLS_STRING, int64(len(n)), n)
+ if abbrev == DW_ABRV_PARAM || abbrev == DW_ABRV_PARAM_LOCLIST || abbrev == DW_ABRV_PARAM_ABSTRACT {
+ var isReturn int64
+ if v.IsReturnValue {
+ isReturn = 1
+ }
+ putattr(ctxt, s.Info, abbrev, DW_FORM_flag, DW_CLS_FLAG, isReturn, nil)
+ }
+ putattr(ctxt, s.Info, abbrev, DW_FORM_udata, DW_CLS_CONSTANT, int64(v.DeclLine), nil)
+ putattr(ctxt, s.Info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, v.Type)
+ }
+
+ if abbrevUsesLoclist(abbrev) {
+ putattr(ctxt, s.Info, abbrev, DW_FORM_sec_offset, DW_CLS_PTR, s.Loc.Length(ctxt), s.Loc)
+ v.PutLocationList(s.Loc, s.StartPC)
+ } else {
+ loc := encbuf[:0]
+ switch {
+ case missing:
+ break // no location
+ case v.StackOffset == 0:
+ loc = append(loc, DW_OP_call_frame_cfa)
+ default:
+ loc = append(loc, DW_OP_fbreg)
+ loc = AppendSleb128(loc, int64(v.StackOffset))
+ }
+ putattr(ctxt, s.Info, abbrev, DW_FORM_block1, DW_CLS_BLOCK, int64(len(loc)), loc)
+ }
+
+ // Var has no children => no terminator
+}
+
+// VarsByOffset attaches the methods of sort.Interface to []*Var,
+// sorting in increasing StackOffset.
+type VarsByOffset []*Var
+
+func (s VarsByOffset) Len() int { return len(s) }
+func (s VarsByOffset) Less(i, j int) bool { return s[i].StackOffset < s[j].StackOffset }
+func (s VarsByOffset) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+
+// byChildIndex implements sort.Interface for []*dwarf.Var by child index.
+type byChildIndex []*Var
+
+func (s byChildIndex) Len() int { return len(s) }
+func (s byChildIndex) Less(i, j int) bool { return s[i].ChildIndex < s[j].ChildIndex }
+func (s byChildIndex) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
+
+// IsDWARFEnabledOnAIX returns true if DWARF is possible on the
+// current extld.
+// AIX ld doesn't support DWARF with -bnoobjreorder with version
+// prior to 7.2.2.
+func IsDWARFEnabledOnAIXLd(extld string) (bool, error) {
+ out, err := exec.Command(extld, "-Wl,-V").CombinedOutput()
+ if err != nil {
+ // The normal output should display ld version and
+ // then fails because ".main" is not defined:
+ // ld: 0711-317 ERROR: Undefined symbol: .main
+ if !bytes.Contains(out, []byte("0711-317")) {
+ return false, fmt.Errorf("%s -Wl,-V failed: %v\n%s", extld, err, out)
+ }
+ }
+ // gcc -Wl,-V output should be:
+ // /usr/bin/ld: LD X.X.X(date)
+ // ...
+ out = bytes.TrimPrefix(out, []byte("/usr/bin/ld: LD "))
+ vers := string(bytes.Split(out, []byte("("))[0])
+ subvers := strings.Split(vers, ".")
+ if len(subvers) != 3 {
+ return false, fmt.Errorf("cannot parse %s -Wl,-V (%s): %v\n", extld, out, err)
+ }
+ if v, err := strconv.Atoi(subvers[0]); err != nil || v < 7 {
+ return false, nil
+ } else if v > 7 {
+ return true, nil
+ }
+ if v, err := strconv.Atoi(subvers[1]); err != nil || v < 2 {
+ return false, nil
+ } else if v > 2 {
+ return true, nil
+ }
+ if v, err := strconv.Atoi(subvers[2]); err != nil || v < 2 {
+ return false, nil
+ }
+ return true, nil
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-26 23:18:16 +0000