| // 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/src" |
| "errors" |
| "fmt" |
| "internal/buildcfg" |
| "os/exec" |
| "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 { |
| } |
| |
| // A Var represents a local variable or a function parameter. |
| type Var struct { |
| Name string |
| Tag int // Either DW_TAG_variable or DW_TAG_formal_parameter |
| WithLoclist bool |
| IsReturnValue bool |
| IsInlFormal bool |
| DictIndex uint16 // index of the dictionary entry describing the type of this variable |
| 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 |
| ClosureOffset int64 // if non-zero this is the offset of this variable in the closure struct |
| } |
| |
| // 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 |
| Info Sym |
| Loc Sym |
| Ranges Sym |
| Absfn Sym |
| StartPC Sym |
| StartPos src.Pos |
| Size int64 |
| External bool |
| Scopes []Scope |
| InlCalls InlCalls |
| UseBASEntries bool |
| |
| dictIndexToOffset []int64 |
| } |
| |
| 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 |
| |
| // Position of the inlined call site. |
| CallPos src.Pos |
| |
| // 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 |
| Size(s Sym) int64 |
| 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) |
| 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_go_dict_index = 0x2906 // Attribute for DW_TAG_typedef_type, index of the dictionary entry describing the real type of this type shape |
| DW_AT_go_closure_offset = 0x2907 // Attribute for DW_TAG_variable, offset in the closure struct where this captured variable resides |
| |
| DW_AT_internal_location = 253 // params and locals; not emitted |
| ) |
| |
| // Index into the abbrevs table below. |
| const ( |
| DW_ABRV_NULL = iota |
| DW_ABRV_COMPUNIT |
| DW_ABRV_COMPUNIT_TEXTLESS |
| DW_ABRV_FUNCTION |
| DW_ABRV_WRAPPER |
| DW_ABRV_FUNCTION_ABSTRACT |
| DW_ABRV_FUNCTION_CONCRETE |
| DW_ABRV_WRAPPER_CONCRETE |
| DW_ABRV_INLINED_SUBROUTINE |
| DW_ABRV_INLINED_SUBROUTINE_RANGES |
| DW_ABRV_VARIABLE |
| DW_ABRV_INT_CONSTANT |
| 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_ABRV_DICT_INDEX |
| DW_ABRV_PUTVAR_START |
| ) |
| |
| 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 buildcfg.GOOS == "darwin" || buildcfg.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 |
| } |
| abbrevs = append(abbrevs, putvarAbbrevs...) |
| for i := 1; i < len(abbrevs); 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 = []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_decl_line, DW_FORM_udata}, |
| {DW_AT_external, DW_FORM_flag}, |
| }, |
| }, |
| |
| /* WRAPPER */ |
| { |
| 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_trampoline, 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_decl_line, DW_FORM_udata}, |
| {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}, |
| }, |
| }, |
| |
| /* WRAPPER_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}, |
| {DW_AT_trampoline, DW_FORM_flag}, |
| }, |
| }, |
| |
| /* 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}, |
| }, |
| }, |
| |
| /* 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}, |
| {DW_AT_go_runtime_type, DW_FORM_addr}, |
| }, |
| }, |
| |
| /* 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}, |
| }, |
| }, |
| |
| /* DICT_INDEX */ |
| { |
| DW_TAG_typedef, |
| DW_CHILDREN_no, |
| []dwAttrForm{ |
| {DW_AT_name, DW_FORM_string}, |
| {DW_AT_type, DW_FORM_ref_addr}, |
| {DW_AT_go_dict_index, DW_FORM_udata}, |
| }, |
| }, |
| } |
| |
| // GetAbbrev returns the contents of the .debug_abbrev section. |
| func GetAbbrev() []byte { |
| abbrevs := Abbrevs() |
| var buf []byte |
| for i := 1; i < len(abbrevs); 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) |
| } |
| |
| // PutGlobal writes a DIE for a global variable. |
| func PutGlobal(ctxt Context, info, typ, gvar Sym, name string) { |
| Uleb128put(ctxt, info, DW_ABRV_VARIABLE) |
| putattr(ctxt, info, DW_ABRV_VARIABLE, DW_FORM_string, DW_CLS_STRING, int64(len(name)), name) |
| putattr(ctxt, info, DW_ABRV_VARIABLE, DW_FORM_block1, DW_CLS_ADDRESS, 0, gvar) |
| putattr(ctxt, info, DW_ABRV_VARIABLE, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, typ) |
| putattr(ctxt, info, DW_ABRV_VARIABLE, DW_FORM_flag, DW_CLS_FLAG, 1, 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 |
| } |
| |
| s.dictIndexToOffset = putparamtypes(ctxt, s, scopes, fnabbrev) |
| |
| 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, `"".`) { |
| return fmt.Errorf("unqualified symbol name: %v", s.Name) |
| } |
| 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) |
| |
| // TODO(mdempsky): Shouldn't we write out StartPos.FileIndex() too? |
| putattr(ctxt, s.Absfn, abbrev, DW_FORM_udata, DW_CLS_CONSTANT, int64(s.StartPos.RelLine()), 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, 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(callee=%v,abbrev=%d)\n", 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, ctxt.Size(s.Ranges), 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. |
| putattr(ctxt, s.Info, abbrev, DW_FORM_data4, DW_CLS_CONSTANT, int64(1+ic.CallPos.FileIndex()), nil) // 1-based file table |
| form := int(expandPseudoForm(DW_FORM_udata_pseudo)) |
| putattr(ctxt, s.Info, abbrev, form, DW_CLS_CONSTANT, int64(ic.CallPos.RelLine()), 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) { |
| err := putInlinedFunc(ctxt, s, 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, isWrapper bool) error { |
| if logDwarf { |
| ctxt.Logf("PutConcreteFunc(%v)\n", s.Info) |
| } |
| abbrev := DW_ABRV_FUNCTION_CONCRETE |
| if isWrapper { |
| abbrev = DW_ABRV_WRAPPER_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}) |
| |
| if isWrapper { |
| putattr(ctxt, s.Info, abbrev, DW_FORM_flag, DW_CLS_FLAG, int64(1), 0) |
| } |
| |
| // Scopes |
| if err := putPrunedScopes(ctxt, s, abbrev); err != nil { |
| return err |
| } |
| |
| // Inlined subroutines. |
| for _, sib := range inlChildren(-1, &s.InlCalls) { |
| err := putInlinedFunc(ctxt, s, 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, isWrapper bool) error { |
| if logDwarf { |
| ctxt.Logf("PutDefaultFunc(%v)\n", s.Info) |
| } |
| abbrev := DW_ABRV_FUNCTION |
| if isWrapper { |
| abbrev = DW_ABRV_WRAPPER |
| } |
| Uleb128put(ctxt, s.Info, int64(abbrev)) |
| |
| name := s.Name |
| if strings.HasPrefix(name, `"".`) { |
| return fmt.Errorf("unqualified symbol name: %v", name) |
| } |
| |
| 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}) |
| if isWrapper { |
| putattr(ctxt, s.Info, abbrev, DW_FORM_flag, DW_CLS_FLAG, int64(1), 0) |
| } else { |
| putattr(ctxt, s.Info, abbrev, DW_FORM_data4, DW_CLS_CONSTANT, int64(1+s.StartPos.FileIndex()), nil) // 1-based file index |
| putattr(ctxt, s.Info, abbrev, DW_FORM_udata, DW_CLS_CONSTANT, int64(s.StartPos.RelLine()), nil) |
| |
| 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) { |
| err := putInlinedFunc(ctxt, s, sib) |
| if err != nil { |
| return err |
| } |
| } |
| |
| Uleb128put(ctxt, s.Info, 0) |
| return nil |
| } |
| |
| // putparamtypes writes typedef DIEs for any parametric types that are used by this function. |
| func putparamtypes(ctxt Context, s *FnState, scopes []Scope, fnabbrev int) []int64 { |
| if fnabbrev == DW_ABRV_FUNCTION_CONCRETE { |
| return nil |
| } |
| |
| maxDictIndex := uint16(0) |
| |
| for i := range scopes { |
| for _, v := range scopes[i].Vars { |
| if v.DictIndex > maxDictIndex { |
| maxDictIndex = v.DictIndex |
| } |
| } |
| } |
| |
| if maxDictIndex == 0 { |
| return nil |
| } |
| |
| dictIndexToOffset := make([]int64, maxDictIndex) |
| |
| for i := range scopes { |
| for _, v := range scopes[i].Vars { |
| if v.DictIndex == 0 || dictIndexToOffset[v.DictIndex-1] != 0 { |
| continue |
| } |
| |
| dictIndexToOffset[v.DictIndex-1] = ctxt.CurrentOffset(s.Info) |
| |
| Uleb128put(ctxt, s.Info, int64(DW_ABRV_DICT_INDEX)) |
| n := fmt.Sprintf(".param%d", v.DictIndex-1) |
| putattr(ctxt, s.Info, DW_ABRV_DICT_INDEX, DW_FORM_string, DW_CLS_STRING, int64(len(n)), n) |
| putattr(ctxt, s.Info, DW_ABRV_DICT_INDEX, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, v.Type) |
| putattr(ctxt, s.Info, DW_ABRV_DICT_INDEX, DW_FORM_udata, DW_CLS_CONSTANT, int64(v.DictIndex-1), nil) |
| } |
| } |
| |
| return dictIndexToOffset |
| } |
| |
| 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, ctxt.Size(s.Ranges), s.Ranges) |
| |
| s.PutRanges(ctxt, scope.Ranges) |
| } |
| |
| curscope = putscope(ctxt, s, scopes, curscope, fnabbrev, encbuf) |
| |
| Uleb128put(ctxt, s.Info, 0) |
| } |
| return curscope |
| } |
| |
| func concreteVar(fnabbrev int, v *Var) bool { |
| concrete := true |
| switch fnabbrev { |
| case DW_ABRV_FUNCTION, DW_ABRV_WRAPPER: |
| concrete = false |
| case DW_ABRV_FUNCTION_CONCRETE, DW_ABRV_WRAPPER_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") |
| } |
| return concrete |
| } |
| |
| // Emit DWARF attributes for a variable belonging to an 'abstract' subprogram. |
| func putAbstractVar(ctxt Context, info Sym, v *Var) { |
| // The contents of this functions are used to generate putAbstractVarAbbrev automatically, see TestPutVarAbbrevGenerator. |
| abbrev := putAbstractVarAbbrev(v) |
| Uleb128put(ctxt, info, int64(abbrev)) |
| putattr(ctxt, info, abbrev, DW_FORM_string, DW_CLS_STRING, int64(len(v.Name)), v.Name) // DW_AT_name |
| |
| // Isreturn attribute if this is a param |
| if v.Tag == DW_TAG_formal_parameter { |
| var isReturn int64 |
| if v.IsReturnValue { |
| isReturn = 1 |
| } |
| putattr(ctxt, info, abbrev, DW_FORM_flag, DW_CLS_FLAG, isReturn, nil) // DW_AT_variable_parameter |
| } |
| |
| // Line |
| if v.Tag == DW_TAG_variable { |
| // 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) // DW_AT_decl_line |
| } |
| |
| // Type |
| putattr(ctxt, info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, v.Type) // DW_AT_type |
| |
| // Var has no children => no terminator |
| } |
| |
| func putvar(ctxt Context, s *FnState, v *Var, absfn Sym, fnabbrev, inlIndex int, encbuf []byte) { |
| // The contents of this functions are used to generate putvarAbbrev automatically, see TestPutVarAbbrevGenerator. |
| concrete := concreteVar(fnabbrev, v) |
| hasParametricType := !concrete && (v.DictIndex > 0 && s.dictIndexToOffset != nil && s.dictIndexToOffset[v.DictIndex-1] != 0) |
| withLoclist := v.WithLoclist && v.PutLocationList != nil |
| |
| abbrev := putvarAbbrev(v, concrete, withLoclist) |
| 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) // DW_AT_abstract_origin |
| 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) // DW_AT_name |
| if v.Tag == DW_TAG_formal_parameter { |
| var isReturn int64 |
| if v.IsReturnValue { |
| isReturn = 1 |
| } |
| putattr(ctxt, s.Info, abbrev, DW_FORM_flag, DW_CLS_FLAG, isReturn, nil) // DW_AT_variable_parameter |
| } |
| putattr(ctxt, s.Info, abbrev, DW_FORM_udata, DW_CLS_CONSTANT, int64(v.DeclLine), nil) // DW_AT_decl_line |
| if hasParametricType { |
| // If the type of this variable is parametric use the entry emitted by putparamtypes |
| putattr(ctxt, s.Info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, s.dictIndexToOffset[v.DictIndex-1], s.Info) // DW_AT_type |
| } else { |
| putattr(ctxt, s.Info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, v.Type) // DW_AT_type |
| } |
| |
| if v.ClosureOffset > 0 { |
| putattr(ctxt, s.Info, abbrev, DW_FORM_udata, DW_CLS_CONSTANT, v.ClosureOffset, nil) // DW_AT_go_closure_offset |
| } |
| } |
| |
| if withLoclist { |
| putattr(ctxt, s.Info, abbrev, DW_FORM_sec_offset, DW_CLS_PTR, ctxt.Size(s.Loc), s.Loc) // DW_AT_location |
| v.PutLocationList(s.Loc, s.StartPC) |
| } else { |
| loc := encbuf[:0] |
| switch { |
| case v.WithLoclist: |
| 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) // DW_AT_location |
| } |
| |
| // Var has no children => no terminator |
| } |
| |
| // 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] } |
| |
| // IsDWARFEnabledOnAIXLd 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) { |
| name, args := extld[0], extld[1:] |
| args = append(args, "-Wl,-V") |
| out, err := exec.Command(name, args...).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 |
| } |
