| // Copyright 2016 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // Package dwarf generates DWARF debugging information. |
| // DWARF generation is split between the compiler and the linker, |
| // this package contains the shared code. |
| package dwarf |
| |
| import ( |
| "bytes" |
| "cmd/internal/objabi" |
| "errors" |
| "fmt" |
| "os/exec" |
| "sort" |
| "strconv" |
| "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) |
| AddDWARFAddrSectionOffset(s Sym, t interface{}, ofs int64) |
| CurrentOffset(s Sym) int64 |
| RecordDclReference(from Sym, to Sym, dclIdx int, inlIndex int) |
| RecordChildDieOffsets(s Sym, vars []*Var, offsets []int32) |
| AddString(s Sym, v string) |
| AddFileRef(s Sym, f interface{}) |
| Logf(format string, args ...interface{}) |
| } |
| |
| // AppendUleb128 appends v to b using DWARF's unsigned LEB128 encoding. |
| func AppendUleb128(b []byte, v uint64) []byte { |
| for { |
| c := uint8(v & 0x7f) |
| v >>= 7 |
| if v != 0 { |
| c |= 0x80 |
| } |
| b = append(b, c) |
| if c&0x80 == 0 { |
| break |
| } |
| } |
| return b |
| } |
| |
| // AppendSleb128 appends v to b using DWARF's signed LEB128 encoding. |
| func AppendSleb128(b []byte, v int64) []byte { |
| for { |
| c := uint8(v & 0x7f) |
| s := uint8(v & 0x40) |
| v >>= 7 |
| if (v != -1 || s == 0) && (v != 0 || s != 0) { |
| c |= 0x80 |
| } |
| b = append(b, c) |
| if c&0x80 == 0 { |
| break |
| } |
| } |
| return b |
| } |
| |
| // sevenbits contains all unsigned seven bit numbers, indexed by their value. |
| var sevenbits = [...]byte{ |
| 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, |
| 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, |
| 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, |
| 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, |
| 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, |
| 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, |
| 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, |
| 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, |
| } |
| |
| // sevenBitU returns the unsigned LEB128 encoding of v if v is seven bits and nil otherwise. |
| // The contents of the returned slice must not be modified. |
| func sevenBitU(v int64) []byte { |
| if uint64(v) < uint64(len(sevenbits)) { |
| return sevenbits[v : v+1] |
| } |
| return nil |
| } |
| |
| // sevenBitS returns the signed LEB128 encoding of v if v is seven bits and nil otherwise. |
| // The contents of the returned slice must not be modified. |
| func sevenBitS(v int64) []byte { |
| if uint64(v) <= 63 { |
| return sevenbits[v : v+1] |
| } |
| if uint64(-v) <= 64 { |
| return sevenbits[128+v : 128+v+1] |
| } |
| return nil |
| } |
| |
| // Uleb128put appends v to s using DWARF's unsigned LEB128 encoding. |
| func Uleb128put(ctxt Context, s Sym, v int64) { |
| b := sevenBitU(v) |
| if b == nil { |
| var encbuf [20]byte |
| b = AppendUleb128(encbuf[:0], uint64(v)) |
| } |
| ctxt.AddBytes(s, b) |
| } |
| |
| // Sleb128put appends v to s using DWARF's signed LEB128 encoding. |
| func Sleb128put(ctxt Context, s Sym, v int64) { |
| b := sevenBitS(v) |
| if b == nil { |
| var encbuf [20]byte |
| b = AppendSleb128(encbuf[:0], v) |
| } |
| ctxt.AddBytes(s, b) |
| } |
| |
| /* |
| * Defining Abbrevs. This is hardcoded, 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_go_package_name = 0x2905 // Attribute for DW_TAG_compile_unit |
| |
| DW_AT_internal_location = 253 // params and locals; not emitted |
| ) |
| |
| // Index into the abbrevs table below. |
| // Keep in sync with ispubname() and ispubtype() in ld/dwarf.go. |
| // ispubtype considers >= NULLTYPE public |
| const ( |
| DW_ABRV_NULL = iota |
| DW_ABRV_COMPUNIT |
| DW_ABRV_COMPUNIT_TEXTLESS |
| DW_ABRV_FUNCTION |
| DW_ABRV_FUNCTION_ABSTRACT |
| DW_ABRV_FUNCTION_CONCRETE |
| DW_ABRV_INLINED_SUBROUTINE |
| DW_ABRV_INLINED_SUBROUTINE_RANGES |
| DW_ABRV_VARIABLE |
| DW_ABRV_INT_CONSTANT |
| DW_ABRV_AUTO |
| DW_ABRV_AUTO_LOCLIST |
| DW_ABRV_AUTO_ABSTRACT |
| DW_ABRV_AUTO_CONCRETE |
| DW_ABRV_AUTO_CONCRETE_LOCLIST |
| DW_ABRV_PARAM |
| DW_ABRV_PARAM_LOCLIST |
| DW_ABRV_PARAM_ABSTRACT |
| DW_ABRV_PARAM_CONCRETE |
| DW_ABRV_PARAM_CONCRETE_LOCLIST |
| DW_ABRV_LEXICAL_BLOCK_RANGES |
| DW_ABRV_LEXICAL_BLOCK_SIMPLE |
| DW_ABRV_STRUCTFIELD |
| DW_ABRV_FUNCTYPEPARAM |
| DW_ABRV_DOTDOTDOT |
| DW_ABRV_ARRAYRANGE |
| DW_ABRV_NULLTYPE |
| DW_ABRV_BASETYPE |
| DW_ABRV_ARRAYTYPE |
| DW_ABRV_CHANTYPE |
| DW_ABRV_FUNCTYPE |
| DW_ABRV_IFACETYPE |
| DW_ABRV_MAPTYPE |
| DW_ABRV_PTRTYPE |
| DW_ABRV_BARE_PTRTYPE // only for void*, no DW_AT_type attr to please gdb 6. |
| DW_ABRV_SLICETYPE |
| DW_ABRV_STRINGTYPE |
| DW_ABRV_STRUCTTYPE |
| DW_ABRV_TYPEDECL |
| DW_NABRV |
| ) |
| |
| type dwAbbrev struct { |
| tag uint8 |
| children uint8 |
| attr []dwAttrForm |
| } |
| |
| var abbrevs = [DW_NABRV]dwAbbrev{ |
| /* The mandatory DW_ABRV_NULL entry. */ |
| {0, 0, []dwAttrForm{}}, |
| |
| /* COMPUNIT */ |
| { |
| DW_TAG_compile_unit, |
| DW_CHILDREN_yes, |
| []dwAttrForm{ |
| {DW_AT_name, DW_FORM_string}, |
| {DW_AT_language, DW_FORM_data1}, |
| {DW_AT_stmt_list, DW_FORM_sec_offset}, |
| {DW_AT_low_pc, DW_FORM_addr}, |
| {DW_AT_ranges, DW_FORM_sec_offset}, |
| {DW_AT_comp_dir, DW_FORM_string}, |
| {DW_AT_producer, DW_FORM_string}, |
| {DW_AT_go_package_name, DW_FORM_string}, |
| }, |
| }, |
| |
| /* COMPUNIT_TEXTLESS */ |
| { |
| DW_TAG_compile_unit, |
| DW_CHILDREN_yes, |
| []dwAttrForm{ |
| {DW_AT_name, DW_FORM_string}, |
| {DW_AT_language, DW_FORM_data1}, |
| {DW_AT_comp_dir, DW_FORM_string}, |
| {DW_AT_producer, DW_FORM_string}, |
| {DW_AT_go_package_name, DW_FORM_string}, |
| }, |
| }, |
| |
| /* FUNCTION */ |
| { |
| DW_TAG_subprogram, |
| DW_CHILDREN_yes, |
| []dwAttrForm{ |
| {DW_AT_name, DW_FORM_string}, |
| {DW_AT_low_pc, DW_FORM_addr}, |
| {DW_AT_high_pc, DW_FORM_addr}, |
| {DW_AT_frame_base, DW_FORM_block1}, |
| {DW_AT_decl_file, DW_FORM_data4}, |
| {DW_AT_external, DW_FORM_flag}, |
| }, |
| }, |
| |
| /* FUNCTION_ABSTRACT */ |
| { |
| DW_TAG_subprogram, |
| DW_CHILDREN_yes, |
| []dwAttrForm{ |
| {DW_AT_name, DW_FORM_string}, |
| {DW_AT_inline, DW_FORM_data1}, |
| {DW_AT_external, DW_FORM_flag}, |
| }, |
| }, |
| |
| /* FUNCTION_CONCRETE */ |
| { |
| DW_TAG_subprogram, |
| DW_CHILDREN_yes, |
| []dwAttrForm{ |
| {DW_AT_abstract_origin, DW_FORM_ref_addr}, |
| {DW_AT_low_pc, DW_FORM_addr}, |
| {DW_AT_high_pc, DW_FORM_addr}, |
| {DW_AT_frame_base, DW_FORM_block1}, |
| }, |
| }, |
| |
| /* INLINED_SUBROUTINE */ |
| { |
| DW_TAG_inlined_subroutine, |
| DW_CHILDREN_yes, |
| []dwAttrForm{ |
| {DW_AT_abstract_origin, DW_FORM_ref_addr}, |
| {DW_AT_low_pc, DW_FORM_addr}, |
| {DW_AT_high_pc, DW_FORM_addr}, |
| {DW_AT_call_file, DW_FORM_data4}, |
| {DW_AT_call_line, DW_FORM_udata}, |
| }, |
| }, |
| |
| /* 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.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) { |
| 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 { |
| 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 = objabi.PathToPrefix(s.Importpath) + "." + s.Name[3:] |
| } |
| putattr(ctxt, s.Absfn, abbrev, DW_FORM_string, DW_CLS_STRING, int64(len(fullname)), fullname) |
| |
| // DW_AT_inlined value |
| putattr(ctxt, s.Absfn, abbrev, DW_FORM_data1, DW_CLS_CONSTANT, int64(DW_INL_inlined), nil) |
| |
| var ev int64 |
| if s.External { |
| ev = 1 |
| } |
| putattr(ctxt, s.Absfn, abbrev, DW_FORM_flag, DW_CLS_FLAG, ev, 0) |
| |
| // Child variables (may be empty) |
| var flattened []*Var |
| |
| // This slice will hold the offset in bytes for each child var DIE |
| // with respect to the start of the parent subprogram DIE. |
| var offsets []int32 |
| |
| // Scopes/vars |
| if len(s.Scopes) > 0 { |
| // For abstract subprogram DIEs we want to flatten out scope info: |
| // lexical scope DIEs contain range and/or hi/lo PC attributes, |
| // which we explicitly don't want for the abstract subprogram DIE. |
| pvars := inlinedVarTable(&s.InlCalls) |
| for _, scope := range s.Scopes { |
| for i := 0; i < len(scope.Vars); i++ { |
| _, found := pvars[scope.Vars[i]] |
| if found || !scope.Vars[i].IsInAbstract { |
| continue |
| } |
| flattened = append(flattened, scope.Vars[i]) |
| } |
| } |
| if len(flattened) > 0 { |
| sort.Sort(byChildIndex(flattened)) |
| |
| if logDwarf { |
| ctxt.Logf("putAbstractScope(%v): vars:", s.Info) |
| for i, v := range flattened { |
| ctxt.Logf(" %d:%s", i, v.Name) |
| } |
| ctxt.Logf("\n") |
| } |
| |
| // This slice will hold the offset in bytes for each child |
| // variable DIE with respect to the start of the parent |
| // subprogram DIE. |
| for _, v := range flattened { |
| offsets = append(offsets, int32(ctxt.CurrentOffset(s.Absfn))) |
| putAbstractVar(ctxt, s.Absfn, v) |
| } |
| } |
| } |
| ctxt.RecordChildDieOffsets(s.Absfn, flattened, offsets) |
| |
| Uleb128put(ctxt, s.Absfn, 0) |
| return nil |
| } |
| |
| // Emit DWARF attributes and child DIEs for an inlined subroutine. The |
| // first attribute of an inlined subroutine DIE is a reference back to |
| // its corresponding 'abstract' DIE (containing location-independent |
| // attributes such as name, type, etc). Inlined subroutine DIEs can |
| // have other inlined subroutine DIEs as children. |
| func PutInlinedFunc(ctxt Context, s *FnState, callersym Sym, callIdx int) error { |
| ic := s.InlCalls.Calls[callIdx] |
| callee := ic.AbsFunSym |
| |
| abbrev := DW_ABRV_INLINED_SUBROUTINE_RANGES |
| if len(ic.Ranges) == 1 { |
| abbrev = DW_ABRV_INLINED_SUBROUTINE |
| } |
| Uleb128put(ctxt, s.Info, int64(abbrev)) |
| |
| if logDwarf { |
| ctxt.Logf("PutInlinedFunc(caller=%v,callee=%v,abbrev=%d)\n", callersym, callee, abbrev) |
| } |
| |
| // Abstract origin. |
| putattr(ctxt, s.Info, abbrev, DW_FORM_ref_addr, DW_CLS_REFERENCE, 0, callee) |
| |
| if abbrev == DW_ABRV_INLINED_SUBROUTINE_RANGES { |
| putattr(ctxt, s.Info, abbrev, DW_FORM_sec_offset, DW_CLS_PTR, s.Ranges.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] } |
| |
| // IsDWARFEnabledOnAIX returns true if DWARF is possible on the |
| // current extld. |
| // AIX ld doesn't support DWARF with -bnoobjreorder with version |
| // prior to 7.2.2. |
| func IsDWARFEnabledOnAIXLd(extld string) (bool, error) { |
| out, err := exec.Command(extld, "-Wl,-V").CombinedOutput() |
| if err != nil { |
| // The normal output should display ld version and |
| // then fails because ".main" is not defined: |
| // ld: 0711-317 ERROR: Undefined symbol: .main |
| if !bytes.Contains(out, []byte("0711-317")) { |
| return false, fmt.Errorf("%s -Wl,-V failed: %v\n%s", extld, err, out) |
| } |
| } |
| // gcc -Wl,-V output should be: |
| // /usr/bin/ld: LD X.X.X(date) |
| // ... |
| out = bytes.TrimPrefix(out, []byte("/usr/bin/ld: LD ")) |
| vers := string(bytes.Split(out, []byte("("))[0]) |
| subvers := strings.Split(vers, ".") |
| if len(subvers) != 3 { |
| return false, fmt.Errorf("cannot parse %s -Wl,-V (%s): %v\n", extld, out, err) |
| } |
| if v, err := strconv.Atoi(subvers[0]); err != nil || v < 7 { |
| return false, nil |
| } else if v > 7 { |
| return true, nil |
| } |
| if v, err := strconv.Atoi(subvers[1]); err != nil || v < 2 { |
| return false, nil |
| } else if v > 2 { |
| return true, nil |
| } |
| if v, err := strconv.Atoi(subvers[2]); err != nil || v < 2 { |
| return false, nil |
| } |
| return true, nil |
| } |
