From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libgo/go/debug/macho/file.go | 517 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 517 insertions(+) create mode 100644 libgo/go/debug/macho/file.go (limited to 'libgo/go/debug/macho/file.go') diff --git a/libgo/go/debug/macho/file.go b/libgo/go/debug/macho/file.go new file mode 100644 index 000000000..fd8da9449 --- /dev/null +++ b/libgo/go/debug/macho/file.go @@ -0,0 +1,517 @@ +// Copyright 2009 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 macho implements access to Mach-O object files, as defined by +// http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html. +package macho + +// High level access to low level data structures. + +import ( + "bytes" + "debug/dwarf" + "encoding/binary" + "fmt" + "io" + "os" +) + +// A File represents an open Mach-O file. +type File struct { + FileHeader + ByteOrder binary.ByteOrder + Loads []Load + Sections []*Section + + Symtab *Symtab + Dysymtab *Dysymtab + + closer io.Closer +} + +// A Load represents any Mach-O load command. +type Load interface { + Raw() []byte +} + +// A LoadBytes is the uninterpreted bytes of a Mach-O load command. +type LoadBytes []byte + +func (b LoadBytes) Raw() []byte { return b } + +// A SegmentHeader is the header for a Mach-O 32-bit or 64-bit load segment command. +type SegmentHeader struct { + Cmd LoadCmd + Len uint32 + Name string + Addr uint64 + Memsz uint64 + Offset uint64 + Filesz uint64 + Maxprot uint32 + Prot uint32 + Nsect uint32 + Flag uint32 +} + +// A Segment represents a Mach-O 32-bit or 64-bit load segment command. +type Segment struct { + LoadBytes + SegmentHeader + + // Embed ReaderAt for ReadAt method. + // Do not embed SectionReader directly + // to avoid having Read and Seek. + // If a client wants Read and Seek it must use + // Open() to avoid fighting over the seek offset + // with other clients. + io.ReaderAt + sr *io.SectionReader +} + +// Data reads and returns the contents of the segment. +func (s *Segment) Data() ([]byte, os.Error) { + dat := make([]byte, s.sr.Size()) + n, err := s.sr.ReadAt(dat, 0) + return dat[0:n], err +} + +// Open returns a new ReadSeeker reading the segment. +func (s *Segment) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) } + +type SectionHeader struct { + Name string + Seg string + Addr uint64 + Size uint64 + Offset uint32 + Align uint32 + Reloff uint32 + Nreloc uint32 + Flags uint32 +} + +type Section struct { + SectionHeader + + // Embed ReaderAt for ReadAt method. + // Do not embed SectionReader directly + // to avoid having Read and Seek. + // If a client wants Read and Seek it must use + // Open() to avoid fighting over the seek offset + // with other clients. + io.ReaderAt + sr *io.SectionReader +} + +// Data reads and returns the contents of the Mach-O section. +func (s *Section) Data() ([]byte, os.Error) { + dat := make([]byte, s.sr.Size()) + n, err := s.sr.ReadAt(dat, 0) + return dat[0:n], err +} + +// Open returns a new ReadSeeker reading the Mach-O section. +func (s *Section) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) } + +// A Dylib represents a Mach-O load dynamic library command. +type Dylib struct { + LoadBytes + Name string + Time uint32 + CurrentVersion uint32 + CompatVersion uint32 +} + +// A Symtab represents a Mach-O symbol table command. +type Symtab struct { + LoadBytes + SymtabCmd + Syms []Symbol +} + +// A Dysymtab represents a Mach-O dynamic symbol table command. +type Dysymtab struct { + LoadBytes + DysymtabCmd + IndirectSyms []uint32 // indices into Symtab.Syms +} + +/* + * Mach-O reader + */ + +type FormatError struct { + off int64 + msg string + val interface{} +} + +func (e *FormatError) String() string { + msg := e.msg + if e.val != nil { + msg += fmt.Sprintf(" '%v'", e.val) + } + msg += fmt.Sprintf(" in record at byte %#x", e.off) + return msg +} + +// Open opens the named file using os.Open and prepares it for use as a Mach-O binary. +func Open(name string) (*File, os.Error) { + f, err := os.Open(name, os.O_RDONLY, 0) + if err != nil { + return nil, err + } + ff, err := NewFile(f) + if err != nil { + f.Close() + return nil, err + } + ff.closer = f + return ff, nil +} + +// Close closes the File. +// If the File was created using NewFile directly instead of Open, +// Close has no effect. +func (f *File) Close() os.Error { + var err os.Error + if f.closer != nil { + err = f.closer.Close() + f.closer = nil + } + return err +} + +// NewFile creates a new File for acecssing a Mach-O binary in an underlying reader. +// The Mach-O binary is expected to start at position 0 in the ReaderAt. +func NewFile(r io.ReaderAt) (*File, os.Error) { + f := new(File) + sr := io.NewSectionReader(r, 0, 1<<63-1) + + // Read and decode Mach magic to determine byte order, size. + // Magic32 and Magic64 differ only in the bottom bit. + var ident [4]byte + if _, err := r.ReadAt(ident[0:], 0); err != nil { + return nil, err + } + be := binary.BigEndian.Uint32(ident[0:]) + le := binary.LittleEndian.Uint32(ident[0:]) + switch Magic32 &^ 1 { + case be &^ 1: + f.ByteOrder = binary.BigEndian + f.Magic = be + case le &^ 1: + f.ByteOrder = binary.LittleEndian + f.Magic = le + default: + return nil, &FormatError{0, "invalid magic number", nil} + } + + // Read entire file header. + if err := binary.Read(sr, f.ByteOrder, &f.FileHeader); err != nil { + return nil, err + } + + // Then load commands. + offset := int64(fileHeaderSize32) + if f.Magic == Magic64 { + offset = fileHeaderSize64 + } + dat := make([]byte, f.Cmdsz) + if _, err := r.ReadAt(dat, offset); err != nil { + return nil, err + } + f.Loads = make([]Load, f.Ncmd) + bo := f.ByteOrder + for i := range f.Loads { + // Each load command begins with uint32 command and length. + if len(dat) < 8 { + return nil, &FormatError{offset, "command block too small", nil} + } + cmd, siz := LoadCmd(bo.Uint32(dat[0:4])), bo.Uint32(dat[4:8]) + if siz < 8 || siz > uint32(len(dat)) { + return nil, &FormatError{offset, "invalid command block size", nil} + } + var cmddat []byte + cmddat, dat = dat[0:siz], dat[siz:] + offset += int64(siz) + var s *Segment + switch cmd { + default: + f.Loads[i] = LoadBytes(cmddat) + + case LoadCmdDylib: + var hdr DylibCmd + b := bytes.NewBuffer(cmddat) + if err := binary.Read(b, bo, &hdr); err != nil { + return nil, err + } + l := new(Dylib) + if hdr.Name >= uint32(len(cmddat)) { + return nil, &FormatError{offset, "invalid name in dynamic library command", hdr.Name} + } + l.Name = cstring(cmddat[hdr.Name:]) + l.Time = hdr.Time + l.CurrentVersion = hdr.CurrentVersion + l.CompatVersion = hdr.CompatVersion + l.LoadBytes = LoadBytes(cmddat) + f.Loads[i] = l + + case LoadCmdSymtab: + var hdr SymtabCmd + b := bytes.NewBuffer(cmddat) + if err := binary.Read(b, bo, &hdr); err != nil { + return nil, err + } + strtab := make([]byte, hdr.Strsize) + if _, err := r.ReadAt(strtab, int64(hdr.Stroff)); err != nil { + return nil, err + } + var symsz int + if f.Magic == Magic64 { + symsz = 16 + } else { + symsz = 12 + } + symdat := make([]byte, int(hdr.Nsyms)*symsz) + if _, err := r.ReadAt(symdat, int64(hdr.Symoff)); err != nil { + return nil, err + } + st, err := f.parseSymtab(symdat, strtab, cmddat, &hdr, offset) + if err != nil { + return nil, err + } + f.Loads[i] = st + f.Symtab = st + + case LoadCmdDysymtab: + var hdr DysymtabCmd + b := bytes.NewBuffer(cmddat) + if err := binary.Read(b, bo, &hdr); err != nil { + return nil, err + } + dat := make([]byte, hdr.Nindirectsyms*4) + if _, err := r.ReadAt(dat, int64(hdr.Indirectsymoff)); err != nil { + return nil, err + } + x := make([]uint32, hdr.Nindirectsyms) + if err := binary.Read(bytes.NewBuffer(dat), bo, x); err != nil { + return nil, err + } + st := new(Dysymtab) + st.LoadBytes = LoadBytes(cmddat) + st.DysymtabCmd = hdr + st.IndirectSyms = x + f.Loads[i] = st + f.Dysymtab = st + + case LoadCmdSegment: + var seg32 Segment32 + b := bytes.NewBuffer(cmddat) + if err := binary.Read(b, bo, &seg32); err != nil { + return nil, err + } + s = new(Segment) + s.LoadBytes = cmddat + s.Cmd = cmd + s.Len = siz + s.Name = cstring(seg32.Name[0:]) + s.Addr = uint64(seg32.Addr) + s.Memsz = uint64(seg32.Memsz) + s.Offset = uint64(seg32.Offset) + s.Filesz = uint64(seg32.Filesz) + s.Maxprot = seg32.Maxprot + s.Prot = seg32.Prot + s.Nsect = seg32.Nsect + s.Flag = seg32.Flag + f.Loads[i] = s + for i := 0; i < int(s.Nsect); i++ { + var sh32 Section32 + if err := binary.Read(b, bo, &sh32); err != nil { + return nil, err + } + sh := new(Section) + sh.Name = cstring(sh32.Name[0:]) + sh.Seg = cstring(sh32.Seg[0:]) + sh.Addr = uint64(sh32.Addr) + sh.Size = uint64(sh32.Size) + sh.Offset = sh32.Offset + sh.Align = sh32.Align + sh.Reloff = sh32.Reloff + sh.Nreloc = sh32.Nreloc + sh.Flags = sh32.Flags + f.pushSection(sh, r) + } + + case LoadCmdSegment64: + var seg64 Segment64 + b := bytes.NewBuffer(cmddat) + if err := binary.Read(b, bo, &seg64); err != nil { + return nil, err + } + s = new(Segment) + s.LoadBytes = cmddat + s.Cmd = cmd + s.Len = siz + s.Name = cstring(seg64.Name[0:]) + s.Addr = seg64.Addr + s.Memsz = seg64.Memsz + s.Offset = seg64.Offset + s.Filesz = seg64.Filesz + s.Maxprot = seg64.Maxprot + s.Prot = seg64.Prot + s.Nsect = seg64.Nsect + s.Flag = seg64.Flag + f.Loads[i] = s + for i := 0; i < int(s.Nsect); i++ { + var sh64 Section64 + if err := binary.Read(b, bo, &sh64); err != nil { + return nil, err + } + sh := new(Section) + sh.Name = cstring(sh64.Name[0:]) + sh.Seg = cstring(sh64.Seg[0:]) + sh.Addr = sh64.Addr + sh.Size = sh64.Size + sh.Offset = sh64.Offset + sh.Align = sh64.Align + sh.Reloff = sh64.Reloff + sh.Nreloc = sh64.Nreloc + sh.Flags = sh64.Flags + f.pushSection(sh, r) + } + } + if s != nil { + s.sr = io.NewSectionReader(r, int64(s.Offset), int64(s.Filesz)) + s.ReaderAt = s.sr + } + } + return f, nil +} + +func (f *File) parseSymtab(symdat, strtab, cmddat []byte, hdr *SymtabCmd, offset int64) (*Symtab, os.Error) { + bo := f.ByteOrder + symtab := make([]Symbol, hdr.Nsyms) + b := bytes.NewBuffer(symdat) + for i := range symtab { + var n Nlist64 + if f.Magic == Magic64 { + if err := binary.Read(b, bo, &n); err != nil { + return nil, err + } + } else { + var n32 Nlist32 + if err := binary.Read(b, bo, &n32); err != nil { + return nil, err + } + n.Name = n32.Name + n.Type = n32.Type + n.Sect = n32.Sect + n.Desc = n32.Desc + n.Value = uint64(n32.Value) + } + sym := &symtab[i] + if n.Name >= uint32(len(strtab)) { + return nil, &FormatError{offset, "invalid name in symbol table", n.Name} + } + sym.Name = cstring(strtab[n.Name:]) + sym.Type = n.Type + sym.Sect = n.Sect + sym.Desc = n.Desc + sym.Value = n.Value + } + st := new(Symtab) + st.LoadBytes = LoadBytes(cmddat) + st.Syms = symtab + return st, nil +} + +func (f *File) pushSection(sh *Section, r io.ReaderAt) { + f.Sections = append(f.Sections, sh) + sh.sr = io.NewSectionReader(r, int64(sh.Offset), int64(sh.Size)) + sh.ReaderAt = sh.sr +} + +func cstring(b []byte) string { + var i int + for i = 0; i < len(b) && b[i] != 0; i++ { + } + return string(b[0:i]) +} + +// Segment returns the first Segment with the given name, or nil if no such segment exists. +func (f *File) Segment(name string) *Segment { + for _, l := range f.Loads { + if s, ok := l.(*Segment); ok && s.Name == name { + return s + } + } + return nil +} + +// Section returns the first section with the given name, or nil if no such +// section exists. +func (f *File) Section(name string) *Section { + for _, s := range f.Sections { + if s.Name == name { + return s + } + } + return nil +} + +// DWARF returns the DWARF debug information for the Mach-O file. +func (f *File) DWARF() (*dwarf.Data, os.Error) { + // There are many other DWARF sections, but these + // are the required ones, and the debug/dwarf package + // does not use the others, so don't bother loading them. + var names = [...]string{"abbrev", "info", "str"} + var dat [len(names)][]byte + for i, name := range names { + name = "__debug_" + name + s := f.Section(name) + if s == nil { + return nil, os.NewError("missing Mach-O section " + name) + } + b, err := s.Data() + if err != nil && uint64(len(b)) < s.Size { + return nil, err + } + dat[i] = b + } + + abbrev, info, str := dat[0], dat[1], dat[2] + return dwarf.New(abbrev, nil, nil, info, nil, nil, nil, str) +} + +// ImportedSymbols returns the names of all symbols +// referred to by the binary f that are expected to be +// satisfied by other libraries at dynamic load time. +func (f *File) ImportedSymbols() ([]string, os.Error) { + if f.Dysymtab == nil || f.Symtab == nil { + return nil, &FormatError{0, "missing symbol table", nil} + } + + st := f.Symtab + dt := f.Dysymtab + var all []string + for _, s := range st.Syms[dt.Iundefsym : dt.Iundefsym+dt.Nundefsym] { + all = append(all, s.Name) + } + return all, nil +} + +// ImportedLibraries returns the paths of all libraries +// referred to by the binary f that are expected to be +// linked with the binary at dynamic link time. +func (f *File) ImportedLibraries() ([]string, os.Error) { + var all []string + for _, l := range f.Loads { + if lib, ok := l.(*Dylib); ok { + all = append(all, lib.Name) + } + } + return all, nil +} -- cgit v1.2.3