1 files changed, 139 insertions, 0 deletions
diff --git a/src/cmd/internal/objfile/macho.go b/src/cmd/internal/objfile/macho.go
new file mode 100644
index 0000000..c924975
--- /dev/null
+++ b/src/cmd/internal/objfile/macho.go
@@ -0,0 +1,139 @@
+// 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) {
+	if seg := f.macho.Segment("__TEXT"); seg != nil {
+		return seg.Addr, nil
+	}
+	return 0, fmt.Errorf("unknown load address")
+}
+
+func (f *machoFile) dwarf() (*dwarf.Data, error) {
+	return f.macho.DWARF()
+}