obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

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.

7 files changed, 997 insertions, 0 deletions

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
+}
diff --git a/libgo/go/debug/macho/file_test.go b/libgo/go/debug/macho/file_test.go
new file mode 100644
index 000000000..56d8a20be
--- /dev/null
+++ b/libgo/go/debug/macho/file_test.go
@@ -0,0 +1,167 @@
+// 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
+
+import (
+	"reflect"
+	"testing"
+)
+
+type fileTest struct {
+	file     string
+	hdr      FileHeader
+	segments []*SegmentHeader
+	sections []*SectionHeader
+}
+
+var fileTests = []fileTest{
+	{
+		"testdata/gcc-386-darwin-exec",
+		FileHeader{0xfeedface, Cpu386, 0x3, 0x2, 0xc, 0x3c0, 0x85},
+		[]*SegmentHeader{
+			&SegmentHeader{LoadCmdSegment, 0x38, "__PAGEZERO", 0x0, 0x1000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
+			&SegmentHeader{LoadCmdSegment, 0xc0, "__TEXT", 0x1000, 0x1000, 0x0, 0x1000, 0x7, 0x5, 0x2, 0x0},
+			&SegmentHeader{LoadCmdSegment, 0xc0, "__DATA", 0x2000, 0x1000, 0x1000, 0x1000, 0x7, 0x3, 0x2, 0x0},
+			&SegmentHeader{LoadCmdSegment, 0x7c, "__IMPORT", 0x3000, 0x1000, 0x2000, 0x1000, 0x7, 0x7, 0x1, 0x0},
+			&SegmentHeader{LoadCmdSegment, 0x38, "__LINKEDIT", 0x4000, 0x1000, 0x3000, 0x12c, 0x7, 0x1, 0x0, 0x0},
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+		},
+		[]*SectionHeader{
+			&SectionHeader{"__text", "__TEXT", 0x1f68, 0x88, 0xf68, 0x2, 0x0, 0x0, 0x80000400},
+			&SectionHeader{"__cstring", "__TEXT", 0x1ff0, 0xd, 0xff0, 0x0, 0x0, 0x0, 0x2},
+			&SectionHeader{"__data", "__DATA", 0x2000, 0x14, 0x1000, 0x2, 0x0, 0x0, 0x0},
+			&SectionHeader{"__dyld", "__DATA", 0x2014, 0x1c, 0x1014, 0x2, 0x0, 0x0, 0x0},
+			&SectionHeader{"__jump_table", "__IMPORT", 0x3000, 0xa, 0x2000, 0x6, 0x0, 0x0, 0x4000008},
+		},
+	},
+	{
+		"testdata/gcc-amd64-darwin-exec",
+		FileHeader{0xfeedfacf, CpuAmd64, 0x80000003, 0x2, 0xb, 0x568, 0x85},
+		[]*SegmentHeader{
+			&SegmentHeader{LoadCmdSegment64, 0x48, "__PAGEZERO", 0x0, 0x100000000, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
+			&SegmentHeader{LoadCmdSegment64, 0x1d8, "__TEXT", 0x100000000, 0x1000, 0x0, 0x1000, 0x7, 0x5, 0x5, 0x0},
+			&SegmentHeader{LoadCmdSegment64, 0x138, "__DATA", 0x100001000, 0x1000, 0x1000, 0x1000, 0x7, 0x3, 0x3, 0x0},
+			&SegmentHeader{LoadCmdSegment64, 0x48, "__LINKEDIT", 0x100002000, 0x1000, 0x2000, 0x140, 0x7, 0x1, 0x0, 0x0},
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+			nil,
+		},
+		[]*SectionHeader{
+			&SectionHeader{"__text", "__TEXT", 0x100000f14, 0x6d, 0xf14, 0x2, 0x0, 0x0, 0x80000400},
+			&SectionHeader{"__symbol_stub1", "__TEXT", 0x100000f81, 0xc, 0xf81, 0x0, 0x0, 0x0, 0x80000408},
+			&SectionHeader{"__stub_helper", "__TEXT", 0x100000f90, 0x18, 0xf90, 0x2, 0x0, 0x0, 0x0},
+			&SectionHeader{"__cstring", "__TEXT", 0x100000fa8, 0xd, 0xfa8, 0x0, 0x0, 0x0, 0x2},
+			&SectionHeader{"__eh_frame", "__TEXT", 0x100000fb8, 0x48, 0xfb8, 0x3, 0x0, 0x0, 0x6000000b},
+			&SectionHeader{"__data", "__DATA", 0x100001000, 0x1c, 0x1000, 0x3, 0x0, 0x0, 0x0},
+			&SectionHeader{"__dyld", "__DATA", 0x100001020, 0x38, 0x1020, 0x3, 0x0, 0x0, 0x0},
+			&SectionHeader{"__la_symbol_ptr", "__DATA", 0x100001058, 0x10, 0x1058, 0x2, 0x0, 0x0, 0x7},
+		},
+	},
+	{
+		"testdata/gcc-amd64-darwin-exec-debug",
+		FileHeader{0xfeedfacf, CpuAmd64, 0x80000003, 0xa, 0x4, 0x5a0, 0},
+		[]*SegmentHeader{
+			nil,
+			&SegmentHeader{LoadCmdSegment64, 0x1d8, "__TEXT", 0x100000000, 0x1000, 0x0, 0x0, 0x7, 0x5, 0x5, 0x0},
+			&SegmentHeader{LoadCmdSegment64, 0x138, "__DATA", 0x100001000, 0x1000, 0x0, 0x0, 0x7, 0x3, 0x3, 0x0},
+			&SegmentHeader{LoadCmdSegment64, 0x278, "__DWARF", 0x100002000, 0x1000, 0x1000, 0x1bc, 0x7, 0x3, 0x7, 0x0},
+		},
+		[]*SectionHeader{
+			&SectionHeader{"__text", "__TEXT", 0x100000f14, 0x0, 0x0, 0x2, 0x0, 0x0, 0x80000400},
+			&SectionHeader{"__symbol_stub1", "__TEXT", 0x100000f81, 0x0, 0x0, 0x0, 0x0, 0x0, 0x80000408},
+			&SectionHeader{"__stub_helper", "__TEXT", 0x100000f90, 0x0, 0x0, 0x2, 0x0, 0x0, 0x0},
+			&SectionHeader{"__cstring", "__TEXT", 0x100000fa8, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2},
+			&SectionHeader{"__eh_frame", "__TEXT", 0x100000fb8, 0x0, 0x0, 0x3, 0x0, 0x0, 0x6000000b},
+			&SectionHeader{"__data", "__DATA", 0x100001000, 0x0, 0x0, 0x3, 0x0, 0x0, 0x0},
+			&SectionHeader{"__dyld", "__DATA", 0x100001020, 0x0, 0x0, 0x3, 0x0, 0x0, 0x0},
+			&SectionHeader{"__la_symbol_ptr", "__DATA", 0x100001058, 0x0, 0x0, 0x2, 0x0, 0x0, 0x7},
+			&SectionHeader{"__debug_abbrev", "__DWARF", 0x100002000, 0x36, 0x1000, 0x0, 0x0, 0x0, 0x0},
+			&SectionHeader{"__debug_aranges", "__DWARF", 0x100002036, 0x30, 0x1036, 0x0, 0x0, 0x0, 0x0},
+			&SectionHeader{"__debug_frame", "__DWARF", 0x100002066, 0x40, 0x1066, 0x0, 0x0, 0x0, 0x0},
+			&SectionHeader{"__debug_info", "__DWARF", 0x1000020a6, 0x54, 0x10a6, 0x0, 0x0, 0x0, 0x0},
+			&SectionHeader{"__debug_line", "__DWARF", 0x1000020fa, 0x47, 0x10fa, 0x0, 0x0, 0x0, 0x0},
+			&SectionHeader{"__debug_pubnames", "__DWARF", 0x100002141, 0x1b, 0x1141, 0x0, 0x0, 0x0, 0x0},
+			&SectionHeader{"__debug_str", "__DWARF", 0x10000215c, 0x60, 0x115c, 0x0, 0x0, 0x0, 0x0},
+		},
+	},
+}
+
+func TestOpen(t *testing.T) {
+	for i := range fileTests {
+		tt := &fileTests[i]
+
+		f, err := Open(tt.file)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		if !reflect.DeepEqual(f.FileHeader, tt.hdr) {
+			t.Errorf("open %s:\n\thave %#v\n\twant %#v\n", tt.file, f.FileHeader, tt.hdr)
+			continue
+		}
+		for i, l := range f.Loads {
+			if i >= len(tt.segments) {
+				break
+			}
+			sh := tt.segments[i]
+			s, ok := l.(*Segment)
+			if sh == nil {
+				if ok {
+					t.Errorf("open %s, section %d: skipping %#v\n", tt.file, i, &s.SegmentHeader)
+				}
+				continue
+			}
+			if !ok {
+				t.Errorf("open %s, section %d: not *Segment\n", tt.file, i)
+				continue
+			}
+			have := &s.SegmentHeader
+			want := sh
+			if !reflect.DeepEqual(have, want) {
+				t.Errorf("open %s, segment %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+			}
+		}
+		tn := len(tt.segments)
+		fn := len(f.Loads)
+		if tn != fn {
+			t.Errorf("open %s: len(Loads) = %d, want %d", tt.file, fn, tn)
+		}
+
+		for i, sh := range f.Sections {
+			if i >= len(tt.sections) {
+				break
+			}
+			have := &sh.SectionHeader
+			want := tt.sections[i]
+			if !reflect.DeepEqual(have, want) {
+				t.Errorf("open %s, section %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+			}
+		}
+		tn = len(tt.sections)
+		fn = len(f.Sections)
+		if tn != fn {
+			t.Errorf("open %s: len(Sections) = %d, want %d", tt.file, fn, tn)
+		}
+
+	}
+}
+
+func TestOpenFailure(t *testing.T) {
+	filename := "file.go"    // not a Mach-O file
+	_, err := Open(filename) // don't crash
+	if err == nil {
+		t.Errorf("open %s: succeeded unexpectedly", filename)
+	}
+}
diff --git a/libgo/go/debug/macho/macho.go b/libgo/go/debug/macho/macho.go
new file mode 100644
index 000000000..1386f5acf
--- /dev/null
+++ b/libgo/go/debug/macho/macho.go
@@ -0,0 +1,305 @@
+// 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.
+
+// Mach-O header data structures
+// http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/MachORuntime/Reference/reference.html
+
+package macho
+
+import "strconv"
+
+// A FileHeader represents a Mach-O file header.
+type FileHeader struct {
+	Magic  uint32
+	Cpu    Cpu
+	SubCpu uint32
+	Type   Type
+	Ncmd   uint32
+	Cmdsz  uint32
+	Flags  uint32
+}
+
+const (
+	fileHeaderSize32 = 7 * 4
+	fileHeaderSize64 = 8 * 4
+)
+
+const (
+	Magic32 uint32 = 0xfeedface
+	Magic64 uint32 = 0xfeedfacf
+)
+
+// A Type is a Mach-O file type, either an object or an executable.
+type Type uint32
+
+const (
+	TypeObj  Type = 1
+	TypeExec Type = 2
+)
+
+// A Cpu is a Mach-O cpu type.
+type Cpu uint32
+
+const (
+	Cpu386   Cpu = 7
+	CpuAmd64 Cpu = Cpu386 + 1<<24
+)
+
+var cpuStrings = []intName{
+	{uint32(Cpu386), "Cpu386"},
+	{uint32(CpuAmd64), "CpuAmd64"},
+}
+
+func (i Cpu) String() string   { return stringName(uint32(i), cpuStrings, false) }
+func (i Cpu) GoString() string { return stringName(uint32(i), cpuStrings, true) }
+
+// A LoadCmd is a Mach-O load command.
+type LoadCmd uint32
+
+const (
+	LoadCmdSegment    LoadCmd = 1
+	LoadCmdSymtab     LoadCmd = 2
+	LoadCmdThread     LoadCmd = 4
+	LoadCmdUnixThread LoadCmd = 5 // thread+stack
+	LoadCmdDysymtab   LoadCmd = 11
+	LoadCmdDylib      LoadCmd = 12
+	LoadCmdDylinker   LoadCmd = 15
+	LoadCmdSegment64  LoadCmd = 25
+)
+
+var cmdStrings = []intName{
+	{uint32(LoadCmdSegment), "LoadCmdSegment"},
+	{uint32(LoadCmdThread), "LoadCmdThread"},
+	{uint32(LoadCmdUnixThread), "LoadCmdUnixThread"},
+	{uint32(LoadCmdDylib), "LoadCmdDylib"},
+	{uint32(LoadCmdSegment64), "LoadCmdSegment64"},
+}
+
+func (i LoadCmd) String() string   { return stringName(uint32(i), cmdStrings, false) }
+func (i LoadCmd) GoString() string { return stringName(uint32(i), cmdStrings, true) }
+
+// A Segment64 is a 64-bit Mach-O segment load command.
+type Segment64 struct {
+	Cmd     LoadCmd
+	Len     uint32
+	Name    [16]byte
+	Addr    uint64
+	Memsz   uint64
+	Offset  uint64
+	Filesz  uint64
+	Maxprot uint32
+	Prot    uint32
+	Nsect   uint32
+	Flag    uint32
+}
+
+// A Segment32 is a 32-bit Mach-O segment load command.
+type Segment32 struct {
+	Cmd     LoadCmd
+	Len     uint32
+	Name    [16]byte
+	Addr    uint32
+	Memsz   uint32
+	Offset  uint32
+	Filesz  uint32
+	Maxprot uint32
+	Prot    uint32
+	Nsect   uint32
+	Flag    uint32
+}
+
+// A DylibCmd is a Mach-O load dynamic library command.
+type DylibCmd struct {
+	Cmd            LoadCmd
+	Len            uint32
+	Name           uint32
+	Time           uint32
+	CurrentVersion uint32
+	CompatVersion  uint32
+}
+
+// A Section32 is a 32-bit Mach-O section header.
+type Section32 struct {
+	Name     [16]byte
+	Seg      [16]byte
+	Addr     uint32
+	Size     uint32
+	Offset   uint32
+	Align    uint32
+	Reloff   uint32
+	Nreloc   uint32
+	Flags    uint32
+	Reserve1 uint32
+	Reserve2 uint32
+}
+
+// A Section32 is a 64-bit Mach-O section header.
+type Section64 struct {
+	Name     [16]byte
+	Seg      [16]byte
+	Addr     uint64
+	Size     uint64
+	Offset   uint32
+	Align    uint32
+	Reloff   uint32
+	Nreloc   uint32
+	Flags    uint32
+	Reserve1 uint32
+	Reserve2 uint32
+	Reserve3 uint32
+}
+
+// A SymtabCmd is a Mach-O symbol table command.
+type SymtabCmd struct {
+	Cmd     LoadCmd
+	Len     uint32
+	Symoff  uint32
+	Nsyms   uint32
+	Stroff  uint32
+	Strsize uint32
+}
+
+// A DysymtabCmd is a Mach-O dynamic symbol table command.
+type DysymtabCmd struct {
+	Cmd            LoadCmd
+	Len            uint32
+	Ilocalsym      uint32
+	Nlocalsym      uint32
+	Iextdefsym     uint32
+	Nextdefsym     uint32
+	Iundefsym      uint32
+	Nundefsym      uint32
+	Tocoffset      uint32
+	Ntoc           uint32
+	Modtaboff      uint32
+	Nmodtab        uint32
+	Extrefsymoff   uint32
+	Nextrefsyms    uint32
+	Indirectsymoff uint32
+	Nindirectsyms  uint32
+	Extreloff      uint32
+	Nextrel        uint32
+	Locreloff      uint32
+	Nlocrel        uint32
+}
+
+// An Nlist32 is a Mach-O 32-bit symbol table entry.
+type Nlist32 struct {
+	Name  uint32
+	Type  uint8
+	Sect  uint8
+	Desc  uint16
+	Value uint32
+}
+
+// An Nlist64 is a Mach-O 64-bit symbol table entry.
+type Nlist64 struct {
+	Name  uint32
+	Type  uint8
+	Sect  uint8
+	Desc  uint16
+	Value uint64
+}
+
+// A Symbol is a Mach-O 32-bit or 64-bit symbol table entry.
+type Symbol struct {
+	Name  string
+	Type  uint8
+	Sect  uint8
+	Desc  uint16
+	Value uint64
+}
+
+// A Thread is a Mach-O thread state command.
+type Thread struct {
+	Cmd  LoadCmd
+	Len  uint32
+	Type uint32
+	Data []uint32
+}
+
+// Regs386 is the Mach-O 386 register structure.
+type Regs386 struct {
+	AX    uint32
+	BX    uint32
+	CX    uint32
+	DX    uint32
+	DI    uint32
+	SI    uint32
+	BP    uint32
+	SP    uint32
+	SS    uint32
+	FLAGS uint32
+	IP    uint32
+	CS    uint32
+	DS    uint32
+	ES    uint32
+	FS    uint32
+	GS    uint32
+}
+
+// RegsAMD64 is the Mach-O AMD64 register structure.
+type RegsAMD64 struct {
+	AX    uint64
+	BX    uint64
+	CX    uint64
+	DX    uint64
+	DI    uint64
+	SI    uint64
+	BP    uint64
+	SP    uint64
+	R8    uint64
+	R9    uint64
+	R10   uint64
+	R11   uint64
+	R12   uint64
+	R13   uint64
+	R14   uint64
+	R15   uint64
+	IP    uint64
+	FLAGS uint64
+	CS    uint64
+	FS    uint64
+	GS    uint64
+}
+
+type intName struct {
+	i uint32
+	s string
+}
+
+func stringName(i uint32, names []intName, goSyntax bool) string {
+	for _, n := range names {
+		if n.i == i {
+			if goSyntax {
+				return "macho." + n.s
+			}
+			return n.s
+		}
+	}
+	return strconv.Uitoa64(uint64(i))
+}
+
+func flagName(i uint32, names []intName, goSyntax bool) string {
+	s := ""
+	for _, n := range names {
+		if n.i&i == n.i {
+			if len(s) > 0 {
+				s += "+"
+			}
+			if goSyntax {
+				s += "macho."
+			}
+			s += n.s
+			i -= n.i
+		}
+	}
+	if len(s) == 0 {
+		return "0x" + strconv.Uitob64(uint64(i), 16)
+	}
+	if i != 0 {
+		s += "+0x" + strconv.Uitob64(uint64(i), 16)
+	}
+	return s
+}
diff --git a/libgo/go/debug/macho/testdata/gcc-386-darwin-exec b/libgo/go/debug/macho/testdata/gcc-386-darwin-exec
new file mode 100755
index 000000000..03ba1bafa
--- /dev/null
+++ b/libgo/go/debug/macho/testdata/gcc-386-darwin-exec
diff --git a/libgo/go/debug/macho/testdata/gcc-amd64-darwin-exec b/libgo/go/debug/macho/testdata/gcc-amd64-darwin-exec
new file mode 100755
index 000000000..5155a5a26
--- /dev/null
+++ b/libgo/go/debug/macho/testdata/gcc-amd64-darwin-exec
diff --git a/libgo/go/debug/macho/testdata/gcc-amd64-darwin-exec-debug b/libgo/go/debug/macho/testdata/gcc-amd64-darwin-exec-debug
new file mode 100644
index 000000000..a47d3aef7
--- /dev/null
+++ b/libgo/go/debug/macho/testdata/gcc-amd64-darwin-exec-debug
diff --git a/libgo/go/debug/macho/testdata/hello.c b/libgo/go/debug/macho/testdata/hello.c
new file mode 100644
index 000000000..a689d3644
--- /dev/null
+++ b/libgo/go/debug/macho/testdata/hello.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int
+main(void)
+{
+	printf("hello, world\n");
+	return 0;
+}