func findEntry(f *macho.File, bits int) (uint64, error) {
var entry uint64
for _, l := range f.Loads {
var cmd macho.LoadCmd
data := l.Raw()
binary.Read(bytes.NewReader(data), f.ByteOrder, &cmd)
if cmd == macho.LoadCmdUnixThread {
// LC_UNIXTHREAD
if bits == 64 {
ip := 144
entry = f.ByteOrder.Uint64(data[ip : ip+8])
} else {
ip := 56
entry = uint64(f.ByteOrder.Uint32(data[ip : ip+4]))
}
return entry, nil
} else if cmd == machoLoadCmdMain {
// [8:16] == entry - __TEXT, data[16:24] == stack size
__TEXT := f.Segment("__TEXT")
if __TEXT == nil {
return 0, errors.New("Found LC_MAIN but did not find __TEXT segment.")
}
entry = f.ByteOrder.Uint64(data[8:16]) + __TEXT.Addr
return entry, nil
}
}
return 0, errors.New("Could not find entry point.")
}
//============================================================================
// main : Entry point.
//----------------------------------------------------------------------------
func main() {
var dwarfData *dwarf.Data
var theFile *macho.File
var theErr os.Error
var relativeAddress uint64
var runtimeAddress uint64
var loadAddress uint64
var segmentAddress uint64
var pathMacho string
var pathDsym string
// Parse our arguments
flag.Uint64Var(&runtimeAddress, "raddr", 0, "")
flag.Uint64Var(&loadAddress, "laddr", 0, "")
flag.StringVar(&pathMacho, "macho", "", "")
flag.StringVar(&pathDsym, "dsym", "", "")
flag.Parse()
if runtimeAddress == 0 || loadAddress == 0 || pathMacho == "" || pathDsym == "" {
printHelp()
}
// Find the text segment address
theFile, theErr = macho.Open(pathMacho)
if theErr != nil {
fatalError("Can't open Mach-O file: " + theErr.String())
}
segmentAddress = theFile.Segment("__TEXT").Addr
theFile.Close()
// Calculate the target address
relativeAddress = runtimeAddress - loadAddress
gTargetAddress = segmentAddress + relativeAddress
// Find the target
theFile, theErr = macho.Open(pathDsym)
if theErr != nil {
fatalError("Can't open .dsym file: " + theErr.String())
}
dwarfData, theErr = theFile.DWARF()
if theErr != nil {
fatalError("Can't find DWARF info: " + theErr.String())
}
processChildren(dwarfData.Reader(), 0, false)
theFile.Close()
}
