| // 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 ( | |
| "errors" | |
| "fmt" | |
| "sort" | |
| "strings" | |
| ) | |
| // InfoPrefix is the prefix for all the symbols containing DWARF info entries. | |
| const InfoPrefix = "go.info." | |
| // RangePrefix is the prefix for all the symbols containing DWARF location lists. | |
| const LocPrefix = "go.loc." | |
| // RangePrefix is the prefix for all the symbols containing DWARF range lists. | |
| const RangePrefix = "go.range." | |
| // IsStmtPrefix is the prefix for all the symbols containing DWARF is_stmt info for the line number table. | |
| const IsStmtPrefix = "go.isstmt." | |
| // 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 { | |
| Len() 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 | |
| } | |
| func EnableLogging(doit bool) { | |
| logDwarf = doit | |
| } | |
| // UnifyRanges merges the list of ranges of c into the list of ranges of s | |
| func (s *Scope) UnifyRanges(c *Scope) { | |
| out := make([]Range, 0, len(s.Ranges)+len(c.Ranges)) | |
| i, j := 0, 0 | |
| for { | |
| var cur Range | |
| if i < len(s.Ranges) && j < len(c.Ranges) { | |
| if s.Ranges[i].Start < c.Ranges[j].Start { | |
| cur = s.Ranges[i] | |
| i++ | |
| } else { | |
| cur = c.Ranges[j] | |
| j++ | |
| } | |
| } else if i < len(s.Ranges) { | |
| cur = s.Ranges[i] | |
| i++ | |
| } else if j < len(c.Ranges) { | |
| cur = c.Ranges[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) | |
| } | |
| } | |
| s.Ranges = out | |
| } | |
| 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) | |
| AddSectionOffset(s Sym, size int, t interface{}, ofs int64) | |
| AddDWARFSectionOffset(s Sym, size int, 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, and there will be | |
| * only a handful of them. 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_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_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 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}, | |
| }, | |
| }, | |
| /* 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}, | |
| }, | |
| }, | |
| /* 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}, | |
| }, | |
| }, | |
| /* 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 { | |
| 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.AddDWARFSectionOffset(s, 4, 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.AddDWARFSectionOffset(s, 4, 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) { | |
| 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 returns true if 'die' uses an abbrev that supports children. | |
| func HasChildren(die *DWDie) bool { | |
| 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) | |
| } | |
| // PutRanges writes a range table to sym. All addresses in ranges are | |
| // relative to some base address. If base is not nil, then they're | |
| // relative to the start of base. If base is nil, then the caller must | |
| // arrange a base address some other way (such as a DW_AT_low_pc | |
| // attribute). | |
| func PutRanges(ctxt Context, sym Sym, base Sym, ranges []Range) { | |
| ps := ctxt.PtrSize() | |
| // Write base address entry. | |
| if base != nil { | |
| ctxt.AddInt(sym, ps, -1) | |
| ctxt.AddAddress(sym, base, 0) | |
| } | |
| // 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) | |
| } | |
| // 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 = 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.Len(), s.Ranges) | |
| PutRanges(ctxt, s.Ranges, s.StartPC, 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) | |
| putattr(ctxt, s.Info, abbrev, DW_FORM_udata, 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)) | |
| putattr(ctxt, s.Info, DW_ABRV_FUNCTION, DW_FORM_string, DW_CLS_STRING, int64(len(s.Name)), s.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.Len(), s.Ranges) | |
| PutRanges(ctxt, s.Ranges, s.StartPC, 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.Len(), 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] } |