diff options
Diffstat (limited to 'src/cmd/internal/objfile')
-rw-r--r-- | src/cmd/internal/objfile/disasm.go | 409 | ||||
-rw-r--r-- | src/cmd/internal/objfile/elf.go | 126 | ||||
-rw-r--r-- | src/cmd/internal/objfile/goobj.go | 341 | ||||
-rw-r--r-- | src/cmd/internal/objfile/macho.go | 136 | ||||
-rw-r--r-- | src/cmd/internal/objfile/objfile.go | 186 | ||||
-rw-r--r-- | src/cmd/internal/objfile/pe.go | 205 | ||||
-rw-r--r-- | src/cmd/internal/objfile/plan9obj.go | 156 | ||||
-rw-r--r-- | src/cmd/internal/objfile/xcoff.go | 163 |
8 files changed, 1722 insertions, 0 deletions
diff --git a/src/cmd/internal/objfile/disasm.go b/src/cmd/internal/objfile/disasm.go new file mode 100644 index 0000000..b5f1cd1 --- /dev/null +++ b/src/cmd/internal/objfile/disasm.go @@ -0,0 +1,409 @@ +// Copyright 2014 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 objfile + +import ( + "bufio" + "bytes" + "cmd/internal/src" + "container/list" + "debug/gosym" + "encoding/binary" + "fmt" + "io" + "io/ioutil" + "os" + "path/filepath" + "regexp" + "sort" + "strings" + "text/tabwriter" + + "golang.org/x/arch/arm/armasm" + "golang.org/x/arch/arm64/arm64asm" + "golang.org/x/arch/ppc64/ppc64asm" + "golang.org/x/arch/x86/x86asm" +) + +// Disasm is a disassembler for a given File. +type Disasm struct { + syms []Sym //symbols in file, sorted by address + pcln Liner // pcln table + text []byte // bytes of text segment (actual instructions) + textStart uint64 // start PC of text + textEnd uint64 // end PC of text + goarch string // GOARCH string + disasm disasmFunc // disassembler function for goarch + byteOrder binary.ByteOrder // byte order for goarch +} + +// Disasm returns a disassembler for the file f. +func (e *Entry) Disasm() (*Disasm, error) { + syms, err := e.Symbols() + if err != nil { + return nil, err + } + + pcln, err := e.PCLineTable() + if err != nil { + return nil, err + } + + textStart, textBytes, err := e.Text() + if err != nil { + return nil, err + } + + goarch := e.GOARCH() + disasm := disasms[goarch] + byteOrder := byteOrders[goarch] + if disasm == nil || byteOrder == nil { + return nil, fmt.Errorf("unsupported architecture") + } + + // Filter out section symbols, overwriting syms in place. + keep := syms[:0] + for _, sym := range syms { + switch sym.Name { + case "runtime.text", "text", "_text", "runtime.etext", "etext", "_etext": + // drop + default: + keep = append(keep, sym) + } + } + syms = keep + d := &Disasm{ + syms: syms, + pcln: pcln, + text: textBytes, + textStart: textStart, + textEnd: textStart + uint64(len(textBytes)), + goarch: goarch, + disasm: disasm, + byteOrder: byteOrder, + } + + return d, nil +} + +// lookup finds the symbol name containing addr. +func (d *Disasm) lookup(addr uint64) (name string, base uint64) { + i := sort.Search(len(d.syms), func(i int) bool { return addr < d.syms[i].Addr }) + if i > 0 { + s := d.syms[i-1] + if s.Addr != 0 && s.Addr <= addr && addr < s.Addr+uint64(s.Size) { + return s.Name, s.Addr + } + } + return "", 0 +} + +// base returns the final element in the path. +// It works on both Windows and Unix paths, +// regardless of host operating system. +func base(path string) string { + path = path[strings.LastIndex(path, "/")+1:] + path = path[strings.LastIndex(path, `\`)+1:] + return path +} + +// CachedFile contains the content of a file split into lines. +type CachedFile struct { + FileName string + Lines [][]byte +} + +// FileCache is a simple LRU cache of file contents. +type FileCache struct { + files *list.List + maxLen int +} + +// NewFileCache returns a FileCache which can contain up to maxLen cached file contents. +func NewFileCache(maxLen int) *FileCache { + return &FileCache{ + files: list.New(), + maxLen: maxLen, + } +} + +// Line returns the source code line for the given file and line number. +// If the file is not already cached, reads it, inserts it into the cache, +// and removes the least recently used file if necessary. +// If the file is in cache, it is moved to the front of the list. +func (fc *FileCache) Line(filename string, line int) ([]byte, error) { + if filepath.Ext(filename) != ".go" { + return nil, nil + } + + // Clean filenames returned by src.Pos.SymFilename() + // or src.PosBase.SymFilename() removing + // the leading src.FileSymPrefix. + filename = strings.TrimPrefix(filename, src.FileSymPrefix) + + // Expand literal "$GOROOT" rewritten by obj.AbsFile() + filename = filepath.Clean(os.ExpandEnv(filename)) + + var cf *CachedFile + var e *list.Element + + for e = fc.files.Front(); e != nil; e = e.Next() { + cf = e.Value.(*CachedFile) + if cf.FileName == filename { + break + } + } + + if e == nil { + content, err := ioutil.ReadFile(filename) + if err != nil { + return nil, err + } + + cf = &CachedFile{ + FileName: filename, + Lines: bytes.Split(content, []byte{'\n'}), + } + fc.files.PushFront(cf) + + if fc.files.Len() >= fc.maxLen { + fc.files.Remove(fc.files.Back()) + } + } else { + fc.files.MoveToFront(e) + } + + // because //line directives can be out-of-range. (#36683) + if line-1 >= len(cf.Lines) || line-1 < 0 { + return nil, nil + } + + return cf.Lines[line-1], nil +} + +// Print prints a disassembly of the file to w. +// If filter is non-nil, the disassembly only includes functions with names matching filter. +// If printCode is true, the disassembly includs corresponding source lines. +// The disassembly only includes functions that overlap the range [start, end). +func (d *Disasm) Print(w io.Writer, filter *regexp.Regexp, start, end uint64, printCode bool, gnuAsm bool) { + if start < d.textStart { + start = d.textStart + } + if end > d.textEnd { + end = d.textEnd + } + printed := false + bw := bufio.NewWriter(w) + + var fc *FileCache + if printCode { + fc = NewFileCache(8) + } + + tw := tabwriter.NewWriter(bw, 18, 8, 1, '\t', tabwriter.StripEscape) + for _, sym := range d.syms { + symStart := sym.Addr + symEnd := sym.Addr + uint64(sym.Size) + relocs := sym.Relocs + if sym.Code != 'T' && sym.Code != 't' || + symStart < d.textStart || + symEnd <= start || end <= symStart || + filter != nil && !filter.MatchString(sym.Name) { + continue + } + if printed { + fmt.Fprintf(bw, "\n") + } + printed = true + + file, _, _ := d.pcln.PCToLine(sym.Addr) + fmt.Fprintf(bw, "TEXT %s(SB) %s\n", sym.Name, file) + + if symEnd > end { + symEnd = end + } + code := d.text[:end-d.textStart] + + var lastFile string + var lastLine int + + d.Decode(symStart, symEnd, relocs, gnuAsm, func(pc, size uint64, file string, line int, text string) { + i := pc - d.textStart + + if printCode { + if file != lastFile || line != lastLine { + if srcLine, err := fc.Line(file, line); err == nil { + fmt.Fprintf(tw, "%s%s%s\n", []byte{tabwriter.Escape}, srcLine, []byte{tabwriter.Escape}) + } + + lastFile, lastLine = file, line + } + + fmt.Fprintf(tw, " %#x\t", pc) + } else { + fmt.Fprintf(tw, " %s:%d\t%#x\t", base(file), line, pc) + } + + if size%4 != 0 || d.goarch == "386" || d.goarch == "amd64" { + // Print instruction as bytes. + fmt.Fprintf(tw, "%x", code[i:i+size]) + } else { + // Print instruction as 32-bit words. + for j := uint64(0); j < size; j += 4 { + if j > 0 { + fmt.Fprintf(tw, " ") + } + fmt.Fprintf(tw, "%08x", d.byteOrder.Uint32(code[i+j:])) + } + } + fmt.Fprintf(tw, "\t%s\t\n", text) + }) + tw.Flush() + } + bw.Flush() +} + +// Decode disassembles the text segment range [start, end), calling f for each instruction. +func (d *Disasm) Decode(start, end uint64, relocs []Reloc, gnuAsm bool, f func(pc, size uint64, file string, line int, text string)) { + if start < d.textStart { + start = d.textStart + } + if end > d.textEnd { + end = d.textEnd + } + code := d.text[:end-d.textStart] + lookup := d.lookup + for pc := start; pc < end; { + i := pc - d.textStart + text, size := d.disasm(code[i:], pc, lookup, d.byteOrder, gnuAsm) + file, line, _ := d.pcln.PCToLine(pc) + sep := "\t" + for len(relocs) > 0 && relocs[0].Addr < i+uint64(size) { + text += sep + relocs[0].Stringer.String(pc-start) + sep = " " + relocs = relocs[1:] + } + f(pc, uint64(size), file, line, text) + pc += uint64(size) + } +} + +type lookupFunc = func(addr uint64) (sym string, base uint64) +type disasmFunc func(code []byte, pc uint64, lookup lookupFunc, ord binary.ByteOrder, _ bool) (text string, size int) + +func disasm_386(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder, gnuAsm bool) (string, int) { + return disasm_x86(code, pc, lookup, 32, gnuAsm) +} + +func disasm_amd64(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder, gnuAsm bool) (string, int) { + return disasm_x86(code, pc, lookup, 64, gnuAsm) +} + +func disasm_x86(code []byte, pc uint64, lookup lookupFunc, arch int, gnuAsm bool) (string, int) { + inst, err := x86asm.Decode(code, arch) + var text string + size := inst.Len + if err != nil || size == 0 || inst.Op == 0 { + size = 1 + text = "?" + } else { + if gnuAsm { + text = fmt.Sprintf("%-36s // %s", x86asm.GoSyntax(inst, pc, lookup), x86asm.GNUSyntax(inst, pc, nil)) + } else { + text = x86asm.GoSyntax(inst, pc, lookup) + } + } + return text, size +} + +type textReader struct { + code []byte + pc uint64 +} + +func (r textReader) ReadAt(data []byte, off int64) (n int, err error) { + if off < 0 || uint64(off) < r.pc { + return 0, io.EOF + } + d := uint64(off) - r.pc + if d >= uint64(len(r.code)) { + return 0, io.EOF + } + n = copy(data, r.code[d:]) + if n < len(data) { + err = io.ErrUnexpectedEOF + } + return +} + +func disasm_arm(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder, gnuAsm bool) (string, int) { + inst, err := armasm.Decode(code, armasm.ModeARM) + var text string + size := inst.Len + if err != nil || size == 0 || inst.Op == 0 { + size = 4 + text = "?" + } else if gnuAsm { + text = fmt.Sprintf("%-36s // %s", armasm.GoSyntax(inst, pc, lookup, textReader{code, pc}), armasm.GNUSyntax(inst)) + } else { + text = armasm.GoSyntax(inst, pc, lookup, textReader{code, pc}) + } + return text, size +} + +func disasm_arm64(code []byte, pc uint64, lookup lookupFunc, byteOrder binary.ByteOrder, gnuAsm bool) (string, int) { + inst, err := arm64asm.Decode(code) + var text string + if err != nil || inst.Op == 0 { + text = "?" + } else if gnuAsm { + text = fmt.Sprintf("%-36s // %s", arm64asm.GoSyntax(inst, pc, lookup, textReader{code, pc}), arm64asm.GNUSyntax(inst)) + } else { + text = arm64asm.GoSyntax(inst, pc, lookup, textReader{code, pc}) + } + return text, 4 +} + +func disasm_ppc64(code []byte, pc uint64, lookup lookupFunc, byteOrder binary.ByteOrder, gnuAsm bool) (string, int) { + inst, err := ppc64asm.Decode(code, byteOrder) + var text string + size := inst.Len + if err != nil || size == 0 { + size = 4 + text = "?" + } else { + if gnuAsm { + text = fmt.Sprintf("%-36s // %s", ppc64asm.GoSyntax(inst, pc, lookup), ppc64asm.GNUSyntax(inst, pc)) + } else { + text = ppc64asm.GoSyntax(inst, pc, lookup) + } + } + return text, size +} + +var disasms = map[string]disasmFunc{ + "386": disasm_386, + "amd64": disasm_amd64, + "arm": disasm_arm, + "arm64": disasm_arm64, + "ppc64": disasm_ppc64, + "ppc64le": disasm_ppc64, +} + +var byteOrders = map[string]binary.ByteOrder{ + "386": binary.LittleEndian, + "amd64": binary.LittleEndian, + "arm": binary.LittleEndian, + "arm64": binary.LittleEndian, + "ppc64": binary.BigEndian, + "ppc64le": binary.LittleEndian, + "s390x": binary.BigEndian, +} + +type Liner interface { + // Given a pc, returns the corresponding file, line, and function data. + // If unknown, returns "",0,nil. + PCToLine(uint64) (string, int, *gosym.Func) +} diff --git a/src/cmd/internal/objfile/elf.go b/src/cmd/internal/objfile/elf.go new file mode 100644 index 0000000..a48a9df --- /dev/null +++ b/src/cmd/internal/objfile/elf.go @@ -0,0 +1,126 @@ +// Copyright 2013 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. + +// Parsing of ELF executables (Linux, FreeBSD, and so on). + +package objfile + +import ( + "debug/dwarf" + "debug/elf" + "encoding/binary" + "fmt" + "io" +) + +type elfFile struct { + elf *elf.File +} + +func openElf(r io.ReaderAt) (rawFile, error) { + f, err := elf.NewFile(r) + if err != nil { + return nil, err + } + return &elfFile{f}, nil +} + +func (f *elfFile) symbols() ([]Sym, error) { + elfSyms, err := f.elf.Symbols() + if err != nil { + return nil, err + } + + var syms []Sym + for _, s := range elfSyms { + sym := Sym{Addr: s.Value, Name: s.Name, Size: int64(s.Size), Code: '?'} + switch s.Section { + case elf.SHN_UNDEF: + sym.Code = 'U' + case elf.SHN_COMMON: + sym.Code = 'B' + default: + i := int(s.Section) + if i < 0 || i >= len(f.elf.Sections) { + break + } + sect := f.elf.Sections[i] + switch sect.Flags & (elf.SHF_WRITE | elf.SHF_ALLOC | elf.SHF_EXECINSTR) { + case elf.SHF_ALLOC | elf.SHF_EXECINSTR: + sym.Code = 'T' + case elf.SHF_ALLOC: + sym.Code = 'R' + case elf.SHF_ALLOC | elf.SHF_WRITE: + sym.Code = 'D' + } + } + if elf.ST_BIND(s.Info) == elf.STB_LOCAL { + sym.Code += 'a' - 'A' + } + syms = append(syms, sym) + } + + return syms, nil +} + +func (f *elfFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) { + if sect := f.elf.Section(".text"); sect != nil { + textStart = sect.Addr + } + if sect := f.elf.Section(".gosymtab"); sect != nil { + if symtab, err = sect.Data(); err != nil { + return 0, nil, nil, err + } + } + if sect := f.elf.Section(".gopclntab"); sect != nil { + if pclntab, err = sect.Data(); err != nil { + return 0, nil, nil, err + } + } + return textStart, symtab, pclntab, nil +} + +func (f *elfFile) text() (textStart uint64, text []byte, err error) { + sect := f.elf.Section(".text") + if sect == nil { + return 0, nil, fmt.Errorf("text section not found") + } + textStart = sect.Addr + text, err = sect.Data() + return +} + +func (f *elfFile) goarch() string { + switch f.elf.Machine { + case elf.EM_386: + return "386" + case elf.EM_X86_64: + return "amd64" + case elf.EM_ARM: + return "arm" + case elf.EM_AARCH64: + return "arm64" + case elf.EM_PPC64: + if f.elf.ByteOrder == binary.LittleEndian { + return "ppc64le" + } + return "ppc64" + case elf.EM_S390: + return "s390x" + } + return "" +} + +func (f *elfFile) loadAddress() (uint64, error) { + for _, p := range f.elf.Progs { + if p.Type == elf.PT_LOAD && p.Flags&elf.PF_X != 0 { + return p.Vaddr, nil + } + } + return 0, fmt.Errorf("unknown load address") +} + +func (f *elfFile) dwarf() (*dwarf.Data, error) { + return f.elf.DWARF() +} diff --git a/src/cmd/internal/objfile/goobj.go b/src/cmd/internal/objfile/goobj.go new file mode 100644 index 0000000..24d2d0b --- /dev/null +++ b/src/cmd/internal/objfile/goobj.go @@ -0,0 +1,341 @@ +// Copyright 2013 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. + +// Parsing of Go intermediate object files and archives. + +package objfile + +import ( + "cmd/internal/archive" + "cmd/internal/goobj" + "cmd/internal/objabi" + "cmd/internal/sys" + "debug/dwarf" + "debug/gosym" + "errors" + "fmt" + "io" + "os" +) + +type goobjFile struct { + goobj *archive.GoObj + r *goobj.Reader + f *os.File + arch *sys.Arch +} + +func openGoFile(f *os.File) (*File, error) { + a, err := archive.Parse(f, false) + if err != nil { + return nil, err + } + entries := make([]*Entry, 0, len(a.Entries)) +L: + for _, e := range a.Entries { + switch e.Type { + case archive.EntryPkgDef: + continue + case archive.EntryGoObj: + o := e.Obj + b := make([]byte, o.Size) + _, err := f.ReadAt(b, o.Offset) + if err != nil { + return nil, err + } + r := goobj.NewReaderFromBytes(b, false) + var arch *sys.Arch + for _, a := range sys.Archs { + if a.Name == e.Obj.Arch { + arch = a + break + } + } + entries = append(entries, &Entry{ + name: e.Name, + raw: &goobjFile{e.Obj, r, f, arch}, + }) + continue + case archive.EntryNativeObj: + nr := io.NewSectionReader(f, e.Offset, e.Size) + for _, try := range openers { + if raw, err := try(nr); err == nil { + entries = append(entries, &Entry{ + name: e.Name, + raw: raw, + }) + continue L + } + } + } + return nil, fmt.Errorf("open %s: unrecognized archive member %s", f.Name(), e.Name) + } + return &File{f, entries}, nil +} + +func goobjName(name string, ver int) string { + if ver == 0 { + return name + } + return fmt.Sprintf("%s<%d>", name, ver) +} + +type goobjReloc struct { + Off int32 + Size uint8 + Type objabi.RelocType + Add int64 + Sym string +} + +func (r goobjReloc) String(insnOffset uint64) string { + delta := int64(r.Off) - int64(insnOffset) + s := fmt.Sprintf("[%d:%d]%s", delta, delta+int64(r.Size), r.Type) + if r.Sym != "" { + if r.Add != 0 { + return fmt.Sprintf("%s:%s+%d", s, r.Sym, r.Add) + } + return fmt.Sprintf("%s:%s", s, r.Sym) + } + if r.Add != 0 { + return fmt.Sprintf("%s:%d", s, r.Add) + } + return s +} + +func (f *goobjFile) symbols() ([]Sym, error) { + r := f.r + var syms []Sym + + // Name of referenced indexed symbols. + nrefName := r.NRefName() + refNames := make(map[goobj.SymRef]string, nrefName) + for i := 0; i < nrefName; i++ { + rn := r.RefName(i) + refNames[rn.Sym()] = rn.Name(r) + } + + abiToVer := func(abi uint16) int { + var ver int + if abi == goobj.SymABIstatic { + // Static symbol + ver = 1 + } + return ver + } + + resolveSymRef := func(s goobj.SymRef) string { + var i uint32 + switch p := s.PkgIdx; p { + case goobj.PkgIdxInvalid: + if s.SymIdx != 0 { + panic("bad sym ref") + } + return "" + case goobj.PkgIdxHashed64: + i = s.SymIdx + uint32(r.NSym()) + case goobj.PkgIdxHashed: + i = s.SymIdx + uint32(r.NSym()+r.NHashed64def()) + case goobj.PkgIdxNone: + i = s.SymIdx + uint32(r.NSym()+r.NHashed64def()+r.NHasheddef()) + case goobj.PkgIdxBuiltin: + name, abi := goobj.BuiltinName(int(s.SymIdx)) + return goobjName(name, abi) + case goobj.PkgIdxSelf: + i = s.SymIdx + default: + return refNames[s] + } + sym := r.Sym(i) + return goobjName(sym.Name(r), abiToVer(sym.ABI())) + } + + // Defined symbols + ndef := uint32(r.NSym() + r.NHashed64def() + r.NHasheddef() + r.NNonpkgdef()) + for i := uint32(0); i < ndef; i++ { + osym := r.Sym(i) + if osym.Name(r) == "" { + continue // not a real symbol + } + name := osym.Name(r) + ver := osym.ABI() + name = goobjName(name, abiToVer(ver)) + typ := objabi.SymKind(osym.Type()) + var code rune = '?' + switch typ { + case objabi.STEXT: + code = 'T' + case objabi.SRODATA: + code = 'R' + case objabi.SNOPTRDATA, objabi.SDATA: + code = 'D' + case objabi.SBSS, objabi.SNOPTRBSS, objabi.STLSBSS: + code = 'B' + } + if ver >= goobj.SymABIstatic { + code += 'a' - 'A' + } + + sym := Sym{ + Name: name, + Addr: uint64(r.DataOff(i)), + Size: int64(osym.Siz()), + Code: code, + } + + relocs := r.Relocs(i) + sym.Relocs = make([]Reloc, len(relocs)) + for j := range relocs { + rel := &relocs[j] + sym.Relocs[j] = Reloc{ + Addr: uint64(r.DataOff(i)) + uint64(rel.Off()), + Size: uint64(rel.Siz()), + Stringer: goobjReloc{ + Off: rel.Off(), + Size: rel.Siz(), + Type: objabi.RelocType(rel.Type()), + Add: rel.Add(), + Sym: resolveSymRef(rel.Sym()), + }, + } + } + + syms = append(syms, sym) + } + + // Referenced symbols + n := ndef + uint32(r.NNonpkgref()) + for i := ndef; i < n; i++ { + osym := r.Sym(i) + sym := Sym{Name: osym.Name(r), Code: 'U'} + syms = append(syms, sym) + } + for i := 0; i < nrefName; i++ { + rn := r.RefName(i) + sym := Sym{Name: rn.Name(r), Code: 'U'} + syms = append(syms, sym) + } + + return syms, nil +} + +func (f *goobjFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) { + // Should never be called. We implement Liner below, callers + // should use that instead. + return 0, nil, nil, fmt.Errorf("pcln not available in go object file") +} + +// Find returns the file name, line, and function data for the given pc. +// Returns "",0,nil if unknown. +// This function implements the Liner interface in preference to pcln() above. +func (f *goobjFile) PCToLine(pc uint64) (string, int, *gosym.Func) { + r := f.r + if f.arch == nil { + return "", 0, nil + } + getSymData := func(s goobj.SymRef) []byte { + if s.PkgIdx != goobj.PkgIdxHashed { + // We don't need the data for non-hashed symbols, yet. + panic("not supported") + } + i := uint32(s.SymIdx + uint32(r.NSym()+r.NHashed64def())) + return r.BytesAt(r.DataOff(i), r.DataSize(i)) + } + + ndef := uint32(r.NSym() + r.NHashed64def() + r.NHasheddef() + r.NNonpkgdef()) + for i := uint32(0); i < ndef; i++ { + osym := r.Sym(i) + addr := uint64(r.DataOff(i)) + if pc < addr || pc >= addr+uint64(osym.Siz()) { + continue + } + var pcfileSym, pclineSym goobj.SymRef + for _, a := range r.Auxs(i) { + switch a.Type() { + case goobj.AuxPcfile: + pcfileSym = a.Sym() + case goobj.AuxPcline: + pclineSym = a.Sym() + } + } + if pcfileSym.IsZero() || pclineSym.IsZero() { + continue + } + pcline := getSymData(pclineSym) + line := int(pcValue(pcline, pc-addr, f.arch)) + pcfile := getSymData(pcfileSym) + fileID := pcValue(pcfile, pc-addr, f.arch) + fileName := r.File(int(fileID)) + // Note: we provide only the name in the Func structure. + // We could provide more if needed. + return fileName, line, &gosym.Func{Sym: &gosym.Sym{Name: osym.Name(r)}} + } + return "", 0, nil +} + +// pcValue looks up the given PC in a pc value table. target is the +// offset of the pc from the entry point. +func pcValue(tab []byte, target uint64, arch *sys.Arch) int32 { + val := int32(-1) + var pc uint64 + for step(&tab, &pc, &val, pc == 0, arch) { + if target < pc { + return val + } + } + return -1 +} + +// step advances to the next pc, value pair in the encoded table. +func step(p *[]byte, pc *uint64, val *int32, first bool, arch *sys.Arch) bool { + uvdelta := readvarint(p) + if uvdelta == 0 && !first { + return false + } + if uvdelta&1 != 0 { + uvdelta = ^(uvdelta >> 1) + } else { + uvdelta >>= 1 + } + vdelta := int32(uvdelta) + pcdelta := readvarint(p) * uint32(arch.MinLC) + *pc += uint64(pcdelta) + *val += vdelta + return true +} + +// readvarint reads, removes, and returns a varint from *p. +func readvarint(p *[]byte) uint32 { + var v, shift uint32 + s := *p + for shift = 0; ; shift += 7 { + b := s[0] + s = s[1:] + v |= (uint32(b) & 0x7F) << shift + if b&0x80 == 0 { + break + } + } + *p = s + return v +} + +// We treat the whole object file as the text section. +func (f *goobjFile) text() (textStart uint64, text []byte, err error) { + text = make([]byte, f.goobj.Size) + _, err = f.f.ReadAt(text, int64(f.goobj.Offset)) + return +} + +func (f *goobjFile) goarch() string { + return f.goobj.Arch +} + +func (f *goobjFile) loadAddress() (uint64, error) { + return 0, fmt.Errorf("unknown load address") +} + +func (f *goobjFile) dwarf() (*dwarf.Data, error) { + return nil, errors.New("no DWARF data in go object file") +} diff --git a/src/cmd/internal/objfile/macho.go b/src/cmd/internal/objfile/macho.go new file mode 100644 index 0000000..1d6963f --- /dev/null +++ b/src/cmd/internal/objfile/macho.go @@ -0,0 +1,136 @@ +// Copyright 2013 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. + +// Parsing of Mach-O executables (OS X). + +package objfile + +import ( + "debug/dwarf" + "debug/macho" + "fmt" + "io" + "sort" +) + +const stabTypeMask = 0xe0 + +type machoFile struct { + macho *macho.File +} + +func openMacho(r io.ReaderAt) (rawFile, error) { + f, err := macho.NewFile(r) + if err != nil { + return nil, err + } + return &machoFile{f}, nil +} + +func (f *machoFile) symbols() ([]Sym, error) { + if f.macho.Symtab == nil { + return nil, nil + } + + // Build sorted list of addresses of all symbols. + // We infer the size of a symbol by looking at where the next symbol begins. + var addrs []uint64 + for _, s := range f.macho.Symtab.Syms { + // Skip stab debug info. + if s.Type&stabTypeMask == 0 { + addrs = append(addrs, s.Value) + } + } + sort.Sort(uint64s(addrs)) + + var syms []Sym + for _, s := range f.macho.Symtab.Syms { + if s.Type&stabTypeMask != 0 { + // Skip stab debug info. + continue + } + sym := Sym{Name: s.Name, Addr: s.Value, Code: '?'} + i := sort.Search(len(addrs), func(x int) bool { return addrs[x] > s.Value }) + if i < len(addrs) { + sym.Size = int64(addrs[i] - s.Value) + } + if s.Sect == 0 { + sym.Code = 'U' + } else if int(s.Sect) <= len(f.macho.Sections) { + sect := f.macho.Sections[s.Sect-1] + switch sect.Seg { + case "__TEXT", "__DATA_CONST": + sym.Code = 'R' + case "__DATA": + sym.Code = 'D' + } + switch sect.Seg + " " + sect.Name { + case "__TEXT __text": + sym.Code = 'T' + case "__DATA __bss", "__DATA __noptrbss": + sym.Code = 'B' + } + } + syms = append(syms, sym) + } + + return syms, nil +} + +func (f *machoFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) { + if sect := f.macho.Section("__text"); sect != nil { + textStart = sect.Addr + } + if sect := f.macho.Section("__gosymtab"); sect != nil { + if symtab, err = sect.Data(); err != nil { + return 0, nil, nil, err + } + } + if sect := f.macho.Section("__gopclntab"); sect != nil { + if pclntab, err = sect.Data(); err != nil { + return 0, nil, nil, err + } + } + return textStart, symtab, pclntab, nil +} + +func (f *machoFile) text() (textStart uint64, text []byte, err error) { + sect := f.macho.Section("__text") + if sect == nil { + return 0, nil, fmt.Errorf("text section not found") + } + textStart = sect.Addr + text, err = sect.Data() + return +} + +func (f *machoFile) goarch() string { + switch f.macho.Cpu { + case macho.Cpu386: + return "386" + case macho.CpuAmd64: + return "amd64" + case macho.CpuArm: + return "arm" + case macho.CpuArm64: + return "arm64" + case macho.CpuPpc64: + return "ppc64" + } + return "" +} + +type uint64s []uint64 + +func (x uint64s) Len() int { return len(x) } +func (x uint64s) Swap(i, j int) { x[i], x[j] = x[j], x[i] } +func (x uint64s) Less(i, j int) bool { return x[i] < x[j] } + +func (f *machoFile) loadAddress() (uint64, error) { + return 0, fmt.Errorf("unknown load address") +} + +func (f *machoFile) dwarf() (*dwarf.Data, error) { + return f.macho.DWARF() +} diff --git a/src/cmd/internal/objfile/objfile.go b/src/cmd/internal/objfile/objfile.go new file mode 100644 index 0000000..d890a0b --- /dev/null +++ b/src/cmd/internal/objfile/objfile.go @@ -0,0 +1,186 @@ +// Copyright 2014 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 objfile implements portable access to OS-specific executable files. +package objfile + +import ( + "cmd/internal/archive" + "debug/dwarf" + "debug/gosym" + "fmt" + "io" + "os" + "sort" +) + +type rawFile interface { + symbols() (syms []Sym, err error) + pcln() (textStart uint64, symtab, pclntab []byte, err error) + text() (textStart uint64, text []byte, err error) + goarch() string + loadAddress() (uint64, error) + dwarf() (*dwarf.Data, error) +} + +// A File is an opened executable file. +type File struct { + r *os.File + entries []*Entry +} + +type Entry struct { + name string + raw rawFile +} + +// A Sym is a symbol defined in an executable file. +type Sym struct { + Name string // symbol name + Addr uint64 // virtual address of symbol + Size int64 // size in bytes + Code rune // nm code (T for text, D for data, and so on) + Type string // XXX? + Relocs []Reloc // in increasing Addr order +} + +type Reloc struct { + Addr uint64 // Address of first byte that reloc applies to. + Size uint64 // Number of bytes + Stringer RelocStringer +} + +type RelocStringer interface { + // insnOffset is the offset of the instruction containing the relocation + // from the start of the symbol containing the relocation. + String(insnOffset uint64) string +} + +var openers = []func(io.ReaderAt) (rawFile, error){ + openElf, + openMacho, + openPE, + openPlan9, + openXcoff, +} + +// Open opens the named file. +// The caller must call f.Close when the file is no longer needed. +func Open(name string) (*File, error) { + r, err := os.Open(name) + if err != nil { + return nil, err + } + if f, err := openGoFile(r); err == nil { + return f, nil + } else if _, ok := err.(archive.ErrGoObjOtherVersion); ok { + return nil, fmt.Errorf("open %s: %v", name, err) + } + for _, try := range openers { + if raw, err := try(r); err == nil { + return &File{r, []*Entry{{raw: raw}}}, nil + } + } + r.Close() + return nil, fmt.Errorf("open %s: unrecognized object file", name) +} + +func (f *File) Close() error { + return f.r.Close() +} + +func (f *File) Entries() []*Entry { + return f.entries +} + +func (f *File) Symbols() ([]Sym, error) { + return f.entries[0].Symbols() +} + +func (f *File) PCLineTable() (Liner, error) { + return f.entries[0].PCLineTable() +} + +func (f *File) Text() (uint64, []byte, error) { + return f.entries[0].Text() +} + +func (f *File) GOARCH() string { + return f.entries[0].GOARCH() +} + +func (f *File) LoadAddress() (uint64, error) { + return f.entries[0].LoadAddress() +} + +func (f *File) DWARF() (*dwarf.Data, error) { + return f.entries[0].DWARF() +} + +func (f *File) Disasm() (*Disasm, error) { + return f.entries[0].Disasm() +} + +func (e *Entry) Name() string { + return e.name +} + +func (e *Entry) Symbols() ([]Sym, error) { + syms, err := e.raw.symbols() + if err != nil { + return nil, err + } + sort.Sort(byAddr(syms)) + return syms, nil +} + +type byAddr []Sym + +func (x byAddr) Less(i, j int) bool { return x[i].Addr < x[j].Addr } +func (x byAddr) Len() int { return len(x) } +func (x byAddr) Swap(i, j int) { x[i], x[j] = x[j], x[i] } + +func (e *Entry) PCLineTable() (Liner, error) { + // If the raw file implements Liner directly, use that. + // Currently, only Go intermediate objects and archives (goobj) use this path. + if pcln, ok := e.raw.(Liner); ok { + return pcln, nil + } + // Otherwise, read the pcln tables and build a Liner out of that. + textStart, symtab, pclntab, err := e.raw.pcln() + if err != nil { + return nil, err + } + syms, err := e.raw.symbols() + if err == nil { + for _, s := range syms { + if s.Name == "runtime.text" { + textStart = s.Addr + break + } + } + } + return gosym.NewTable(symtab, gosym.NewLineTable(pclntab, textStart)) +} + +func (e *Entry) Text() (uint64, []byte, error) { + return e.raw.text() +} + +func (e *Entry) GOARCH() string { + return e.raw.goarch() +} + +// LoadAddress returns the expected load address of the file. +// This differs from the actual load address for a position-independent +// executable. +func (e *Entry) LoadAddress() (uint64, error) { + return e.raw.loadAddress() +} + +// DWARF returns DWARF debug data for the file, if any. +// This is for cmd/pprof to locate cgo functions. +func (e *Entry) DWARF() (*dwarf.Data, error) { + return e.raw.dwarf() +} diff --git a/src/cmd/internal/objfile/pe.go b/src/cmd/internal/objfile/pe.go new file mode 100644 index 0000000..9088866 --- /dev/null +++ b/src/cmd/internal/objfile/pe.go @@ -0,0 +1,205 @@ +// Copyright 2013 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. + +// Parsing of PE executables (Microsoft Windows). + +package objfile + +import ( + "debug/dwarf" + "debug/pe" + "fmt" + "io" + "sort" +) + +type peFile struct { + pe *pe.File +} + +func openPE(r io.ReaderAt) (rawFile, error) { + f, err := pe.NewFile(r) + if err != nil { + return nil, err + } + return &peFile{f}, nil +} + +func (f *peFile) symbols() ([]Sym, error) { + // Build sorted list of addresses of all symbols. + // We infer the size of a symbol by looking at where the next symbol begins. + var addrs []uint64 + + var imageBase uint64 + switch oh := f.pe.OptionalHeader.(type) { + case *pe.OptionalHeader32: + imageBase = uint64(oh.ImageBase) + case *pe.OptionalHeader64: + imageBase = oh.ImageBase + } + + var syms []Sym + for _, s := range f.pe.Symbols { + const ( + N_UNDEF = 0 // An undefined (extern) symbol + N_ABS = -1 // An absolute symbol (e_value is a constant, not an address) + N_DEBUG = -2 // A debugging symbol + ) + sym := Sym{Name: s.Name, Addr: uint64(s.Value), Code: '?'} + switch s.SectionNumber { + case N_UNDEF: + sym.Code = 'U' + case N_ABS: + sym.Code = 'C' + case N_DEBUG: + sym.Code = '?' + default: + if s.SectionNumber < 0 || len(f.pe.Sections) < int(s.SectionNumber) { + return nil, fmt.Errorf("invalid section number in symbol table") + } + sect := f.pe.Sections[s.SectionNumber-1] + const ( + text = 0x20 + data = 0x40 + bss = 0x80 + permW = 0x80000000 + ) + ch := sect.Characteristics + switch { + case ch&text != 0: + sym.Code = 'T' + case ch&data != 0: + if ch&permW == 0 { + sym.Code = 'R' + } else { + sym.Code = 'D' + } + case ch&bss != 0: + sym.Code = 'B' + } + sym.Addr += imageBase + uint64(sect.VirtualAddress) + } + syms = append(syms, sym) + addrs = append(addrs, sym.Addr) + } + + sort.Sort(uint64s(addrs)) + for i := range syms { + j := sort.Search(len(addrs), func(x int) bool { return addrs[x] > syms[i].Addr }) + if j < len(addrs) { + syms[i].Size = int64(addrs[j] - syms[i].Addr) + } + } + + return syms, nil +} + +func (f *peFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) { + var imageBase uint64 + switch oh := f.pe.OptionalHeader.(type) { + case *pe.OptionalHeader32: + imageBase = uint64(oh.ImageBase) + case *pe.OptionalHeader64: + imageBase = oh.ImageBase + default: + return 0, nil, nil, fmt.Errorf("pe file format not recognized") + } + if sect := f.pe.Section(".text"); sect != nil { + textStart = imageBase + uint64(sect.VirtualAddress) + } + if pclntab, err = loadPETable(f.pe, "runtime.pclntab", "runtime.epclntab"); err != nil { + // We didn't find the symbols, so look for the names used in 1.3 and earlier. + // TODO: Remove code looking for the old symbols when we no longer care about 1.3. + var err2 error + if pclntab, err2 = loadPETable(f.pe, "pclntab", "epclntab"); err2 != nil { + return 0, nil, nil, err + } + } + if symtab, err = loadPETable(f.pe, "runtime.symtab", "runtime.esymtab"); err != nil { + // Same as above. + var err2 error + if symtab, err2 = loadPETable(f.pe, "symtab", "esymtab"); err2 != nil { + return 0, nil, nil, err + } + } + return textStart, symtab, pclntab, nil +} + +func (f *peFile) text() (textStart uint64, text []byte, err error) { + var imageBase uint64 + switch oh := f.pe.OptionalHeader.(type) { + case *pe.OptionalHeader32: + imageBase = uint64(oh.ImageBase) + case *pe.OptionalHeader64: + imageBase = oh.ImageBase + default: + return 0, nil, fmt.Errorf("pe file format not recognized") + } + sect := f.pe.Section(".text") + if sect == nil { + return 0, nil, fmt.Errorf("text section not found") + } + textStart = imageBase + uint64(sect.VirtualAddress) + text, err = sect.Data() + return +} + +func findPESymbol(f *pe.File, name string) (*pe.Symbol, error) { + for _, s := range f.Symbols { + if s.Name != name { + continue + } + if s.SectionNumber <= 0 { + return nil, fmt.Errorf("symbol %s: invalid section number %d", name, s.SectionNumber) + } + if len(f.Sections) < int(s.SectionNumber) { + return nil, fmt.Errorf("symbol %s: section number %d is larger than max %d", name, s.SectionNumber, len(f.Sections)) + } + return s, nil + } + return nil, fmt.Errorf("no %s symbol found", name) +} + +func loadPETable(f *pe.File, sname, ename string) ([]byte, error) { + ssym, err := findPESymbol(f, sname) + if err != nil { + return nil, err + } + esym, err := findPESymbol(f, ename) + if err != nil { + return nil, err + } + if ssym.SectionNumber != esym.SectionNumber { + return nil, fmt.Errorf("%s and %s symbols must be in the same section", sname, ename) + } + sect := f.Sections[ssym.SectionNumber-1] + data, err := sect.Data() + if err != nil { + return nil, err + } + return data[ssym.Value:esym.Value], nil +} + +func (f *peFile) goarch() string { + switch f.pe.Machine { + case pe.IMAGE_FILE_MACHINE_I386: + return "386" + case pe.IMAGE_FILE_MACHINE_AMD64: + return "amd64" + case pe.IMAGE_FILE_MACHINE_ARMNT: + return "arm" + case pe.IMAGE_FILE_MACHINE_ARM64: + return "arm64" + default: + return "" + } +} + +func (f *peFile) loadAddress() (uint64, error) { + return 0, fmt.Errorf("unknown load address") +} + +func (f *peFile) dwarf() (*dwarf.Data, error) { + return f.pe.DWARF() +} diff --git a/src/cmd/internal/objfile/plan9obj.go b/src/cmd/internal/objfile/plan9obj.go new file mode 100644 index 0000000..da0b345 --- /dev/null +++ b/src/cmd/internal/objfile/plan9obj.go @@ -0,0 +1,156 @@ +// Copyright 2014 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. + +// Parsing of Plan 9 a.out executables. + +package objfile + +import ( + "debug/dwarf" + "debug/plan9obj" + "errors" + "fmt" + "io" + "sort" +) + +var validSymType = map[rune]bool{ + 'T': true, + 't': true, + 'D': true, + 'd': true, + 'B': true, + 'b': true, +} + +type plan9File struct { + plan9 *plan9obj.File +} + +func openPlan9(r io.ReaderAt) (rawFile, error) { + f, err := plan9obj.NewFile(r) + if err != nil { + return nil, err + } + return &plan9File{f}, nil +} + +func (f *plan9File) symbols() ([]Sym, error) { + plan9Syms, err := f.plan9.Symbols() + if err != nil { + return nil, err + } + + // Build sorted list of addresses of all symbols. + // We infer the size of a symbol by looking at where the next symbol begins. + var addrs []uint64 + for _, s := range plan9Syms { + if !validSymType[s.Type] { + continue + } + addrs = append(addrs, s.Value) + } + sort.Sort(uint64s(addrs)) + + var syms []Sym + + for _, s := range plan9Syms { + if !validSymType[s.Type] { + continue + } + sym := Sym{Addr: s.Value, Name: s.Name, Code: s.Type} + i := sort.Search(len(addrs), func(x int) bool { return addrs[x] > s.Value }) + if i < len(addrs) { + sym.Size = int64(addrs[i] - s.Value) + } + syms = append(syms, sym) + } + + return syms, nil +} + +func (f *plan9File) pcln() (textStart uint64, symtab, pclntab []byte, err error) { + textStart = f.plan9.LoadAddress + f.plan9.HdrSize + if pclntab, err = loadPlan9Table(f.plan9, "runtime.pclntab", "runtime.epclntab"); err != nil { + // We didn't find the symbols, so look for the names used in 1.3 and earlier. + // TODO: Remove code looking for the old symbols when we no longer care about 1.3. + var err2 error + if pclntab, err2 = loadPlan9Table(f.plan9, "pclntab", "epclntab"); err2 != nil { + return 0, nil, nil, err + } + } + if symtab, err = loadPlan9Table(f.plan9, "runtime.symtab", "runtime.esymtab"); err != nil { + // Same as above. + var err2 error + if symtab, err2 = loadPlan9Table(f.plan9, "symtab", "esymtab"); err2 != nil { + return 0, nil, nil, err + } + } + return textStart, symtab, pclntab, nil +} + +func (f *plan9File) text() (textStart uint64, text []byte, err error) { + sect := f.plan9.Section("text") + if sect == nil { + return 0, nil, fmt.Errorf("text section not found") + } + textStart = f.plan9.LoadAddress + f.plan9.HdrSize + text, err = sect.Data() + return +} + +func findPlan9Symbol(f *plan9obj.File, name string) (*plan9obj.Sym, error) { + syms, err := f.Symbols() + if err != nil { + return nil, err + } + for _, s := range syms { + if s.Name != name { + continue + } + return &s, nil + } + return nil, fmt.Errorf("no %s symbol found", name) +} + +func loadPlan9Table(f *plan9obj.File, sname, ename string) ([]byte, error) { + ssym, err := findPlan9Symbol(f, sname) + if err != nil { + return nil, err + } + esym, err := findPlan9Symbol(f, ename) + if err != nil { + return nil, err + } + sect := f.Section("text") + if sect == nil { + return nil, err + } + data, err := sect.Data() + if err != nil { + return nil, err + } + textStart := f.LoadAddress + f.HdrSize + return data[ssym.Value-textStart : esym.Value-textStart], nil +} + +func (f *plan9File) goarch() string { + switch f.plan9.Magic { + case plan9obj.Magic386: + return "386" + case plan9obj.MagicAMD64: + return "amd64" + case plan9obj.MagicARM: + return "arm" + } + return "" +} + +func (f *plan9File) loadAddress() (uint64, error) { + return 0, fmt.Errorf("unknown load address") +} + +func (f *plan9File) dwarf() (*dwarf.Data, error) { + return nil, errors.New("no DWARF data in Plan 9 file") +} diff --git a/src/cmd/internal/objfile/xcoff.go b/src/cmd/internal/objfile/xcoff.go new file mode 100644 index 0000000..d6df4db --- /dev/null +++ b/src/cmd/internal/objfile/xcoff.go @@ -0,0 +1,163 @@ +// Copyright 2018 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. + +// Parsing of XCOFF executable (AIX) + +package objfile + +import ( + "debug/dwarf" + "fmt" + "internal/xcoff" + "io" + "unicode" +) + +type xcoffFile struct { + xcoff *xcoff.File +} + +func openXcoff(r io.ReaderAt) (rawFile, error) { + f, err := xcoff.NewFile(r) + if err != nil { + return nil, err + } + return &xcoffFile{f}, nil +} + +func (f *xcoffFile) symbols() ([]Sym, error) { + var syms []Sym + for _, s := range f.xcoff.Symbols { + const ( + N_UNDEF = 0 // An undefined (extern) symbol + N_ABS = -1 // An absolute symbol (e_value is a constant, not an address) + N_DEBUG = -2 // A debugging symbol + ) + sym := Sym{Name: s.Name, Addr: s.Value, Code: '?'} + + switch s.SectionNumber { + case N_UNDEF: + sym.Code = 'U' + case N_ABS: + sym.Code = 'C' + case N_DEBUG: + sym.Code = '?' + default: + if s.SectionNumber < 0 || len(f.xcoff.Sections) < int(s.SectionNumber) { + return nil, fmt.Errorf("invalid section number in symbol table") + } + sect := f.xcoff.Sections[s.SectionNumber-1] + + // debug/xcoff returns an offset in the section not the actual address + sym.Addr += sect.VirtualAddress + + if s.AuxCSect.SymbolType&0x3 == xcoff.XTY_LD { + // The size of a function is contained in the + // AUX_FCN entry + sym.Size = s.AuxFcn.Size + } else { + sym.Size = s.AuxCSect.Length + } + + sym.Size = s.AuxCSect.Length + + switch sect.Type { + case xcoff.STYP_TEXT: + if s.AuxCSect.StorageMappingClass == xcoff.XMC_RO { + sym.Code = 'R' + } else { + sym.Code = 'T' + } + case xcoff.STYP_DATA: + sym.Code = 'D' + case xcoff.STYP_BSS: + sym.Code = 'B' + } + + if s.StorageClass == xcoff.C_HIDEXT { + // Local symbol + sym.Code = unicode.ToLower(sym.Code) + } + + } + syms = append(syms, sym) + } + + return syms, nil +} + +func (f *xcoffFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) { + if sect := f.xcoff.Section(".text"); sect != nil { + textStart = sect.VirtualAddress + } + if pclntab, err = loadXCOFFTable(f.xcoff, "runtime.pclntab", "runtime.epclntab"); err != nil { + return 0, nil, nil, err + } + symtab, _ = loadXCOFFTable(f.xcoff, "runtime.symtab", "runtime.esymtab") // ignore error, this symbol is not useful anyway + return textStart, symtab, pclntab, nil +} + +func (f *xcoffFile) text() (textStart uint64, text []byte, err error) { + sect := f.xcoff.Section(".text") + if sect == nil { + return 0, nil, fmt.Errorf("text section not found") + } + textStart = sect.VirtualAddress + text, err = sect.Data() + return +} + +func findXCOFFSymbol(f *xcoff.File, name string) (*xcoff.Symbol, error) { + for _, s := range f.Symbols { + if s.Name != name { + continue + } + if s.SectionNumber <= 0 { + return nil, fmt.Errorf("symbol %s: invalid section number %d", name, s.SectionNumber) + } + if len(f.Sections) < int(s.SectionNumber) { + return nil, fmt.Errorf("symbol %s: section number %d is larger than max %d", name, s.SectionNumber, len(f.Sections)) + } + return s, nil + } + return nil, fmt.Errorf("no %s symbol found", name) +} + +func loadXCOFFTable(f *xcoff.File, sname, ename string) ([]byte, error) { + ssym, err := findXCOFFSymbol(f, sname) + if err != nil { + return nil, err + } + esym, err := findXCOFFSymbol(f, ename) + if err != nil { + return nil, err + } + if ssym.SectionNumber != esym.SectionNumber { + return nil, fmt.Errorf("%s and %s symbols must be in the same section", sname, ename) + } + sect := f.Sections[ssym.SectionNumber-1] + data, err := sect.Data() + if err != nil { + return nil, err + } + return data[ssym.Value:esym.Value], nil +} + +func (f *xcoffFile) goarch() string { + switch f.xcoff.TargetMachine { + case xcoff.U802TOCMAGIC: + return "ppc" + case xcoff.U64_TOCMAGIC: + return "ppc64" + } + return "" +} + +func (f *xcoffFile) loadAddress() (uint64, error) { + return 0, fmt.Errorf("unknown load address") +} + +func (f *xcoffFile) dwarf() (*dwarf.Data, error) { + return f.xcoff.DWARF() +} |