// map from global address to Field at that address
func globalsMap(d *Dump, w *dwarf.Data, t map[dwarf.Offset]dwarfType) *heap {
h := new(heap)
r := w.Reader()
for {
e, err := r.Next()
if err != nil {
log.Fatal(err)
}
if e == nil {
break
}
if e.Tag != dwarf.TagVariable {
continue
}
name := e.Val(dwarf.AttrName).(string)
typ := t[e.Val(dwarf.AttrType).(dwarf.Offset)]
locexpr := e.Val(dwarf.AttrLocation).([]uint8)
if len(locexpr) == 0 || locexpr[0] != dw_op_addr {
continue
}
loc := readPtr(d, locexpr[1:])
if typ == nil {
// lots of non-Go global symbols hit here (rodata, reflect.cvtFloat·f, ...)
h.Insert(loc, Field{FieldKindPtr, 0, "~" + name, ""})
continue
}
for _, f := range typ.Fields() {
h.Insert(loc+f.Offset, Field{f.Kind, 0, joinNames(name, f.Name), f.BaseType})
}
}
return h
}
//============================================================================
// 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()
}
func findVariable(d *dwarf.Data, name string) (*variable, error) {
dr := d.Reader()
for {
e, err := dr.Next()
if e == nil || err != nil {
return nil, err
}
if e.Tag != dwarf.TagVariable {
continue
}
aname, ok := e.Val(dwarf.AttrName).(string)
if !ok || aname != name {
continue
}
loc, ok := e.Val(dwarf.AttrLocation).([]uint8)
if !ok {
continue
}
if loc[0] != 3 {
return nil, fmt.Errorf("can't determine variable addr")
}
addr := uint64(0)
switch len(loc) {
case 5:
addr = uint64(binary.LittleEndian.Uint32(loc[1:]))
case 9:
addr = uint64(binary.LittleEndian.Uint64(loc[1:]))
default:
return nil, fmt.Errorf("unknown addr size")
}
off, ok := e.Val(dwarf.AttrType).(dwarf.Offset)
if !ok {
continue
}
typ, err := d.Type(off)
if err != nil {
return nil, err
}
return &variable{Addr: addr, Type: typ}, nil
}
return nil, nil
}
// Makes a map from <function name, offset in arg area> to name of field.
func argsMap(d *Dump, w *dwarf.Data, t map[dwarf.Offset]dwarfType) map[localKey]string {
m := make(map[localKey]string, 0)
r := w.Reader()
var funcname string
for {
e, err := r.Next()
if err != nil {
log.Fatal(err)
}
if e == nil {
break
}
switch e.Tag {
case dwarf.TagSubprogram:
funcname = e.Val(dwarf.AttrName).(string)
case dwarf.TagFormalParameter:
if e.Val(dwarf.AttrName) == nil {
continue
}
name := e.Val(dwarf.AttrName).(string)
typ := t[e.Val(dwarf.AttrType).(dwarf.Offset)]
loc := e.Val(dwarf.AttrLocation).([]uint8)
if len(loc) == 0 || loc[0] != dw_op_call_frame_cfa {
break
}
var offset int64
if len(loc) == 1 {
offset = 0
} else if len(loc) >= 3 && loc[1] == dw_op_consts && loc[len(loc)-1] == dw_op_plus {
loc, offset = readSleb(loc[2 : len(loc)-1])
if len(loc) != 0 {
break
}
}
for _, f := range typ.Fields() {
m[localKey{funcname, uint64(offset)}] = joinNames(name, f.Name)
}
}
}
return m
}
// New returns a reader for the specified dwarf data.
func New(data *dwarf.Data) *Reader {
return &Reader{data.Reader(), 0}
}
// load a map of all of the dwarf types
func typeMap(d *Dump, w *dwarf.Data) map[dwarf.Offset]dwarfType {
t := make(map[dwarf.Offset]dwarfType)
// pass 1: make a dwarfType for all of the types in the file
r := w.Reader()
for {
e, err := r.Next()
if err != nil {
log.Fatal(err)
}
if e == nil {
break
}
if e.Val(dwarf.AttrName) == nil {
// Dwarf info from non-go sources might be missing a name
continue
}
switch e.Tag {
case dwarf.TagBaseType:
x := new(dwarfBaseType)
x.name = e.Val(dwarf.AttrName).(string)
x.size = uint64(e.Val(dwarf.AttrByteSize).(int64))
x.encoding = e.Val(dwarf.AttrEncoding).(int64)
t[e.Offset] = x
case dwarf.TagPointerType:
x := new(dwarfPtrType)
x.name = e.Val(dwarf.AttrName).(string)
x.size = d.PtrSize
t[e.Offset] = x
case dwarf.TagStructType:
x := new(dwarfStructType)
x.name = e.Val(dwarf.AttrName).(string)
x.size = uint64(e.Val(dwarf.AttrByteSize).(int64))
for _, a := range adjTypeNames {
if k := a.matcher.FindStringSubmatch(x.name); k != nil {
var i []interface{}
for _, j := range k[1:] {
i = append(i, j)
}
x.name = fmt.Sprintf(a.formatter, i...)
}
}
t[e.Offset] = x
case dwarf.TagArrayType:
x := new(dwarfArrayType)
x.name = e.Val(dwarf.AttrName).(string)
x.size = uint64(e.Val(dwarf.AttrByteSize).(int64))
t[e.Offset] = x
case dwarf.TagTypedef:
x := new(dwarfTypedef)
x.name = e.Val(dwarf.AttrName).(string)
t[e.Offset] = x
case dwarf.TagSubroutineType:
x := new(dwarfFuncType)
x.name = e.Val(dwarf.AttrName).(string)
x.size = d.PtrSize
t[e.Offset] = x
}
}
// pass 2: fill in / link up the types
r = w.Reader()
var currentStruct *dwarfStructType
for {
e, err := r.Next()
if err != nil {
log.Fatal(err)
}
if e == nil {
break
}
switch e.Tag {
case dwarf.TagTypedef:
t[e.Offset].(*dwarfTypedef).type_ = t[e.Val(dwarf.AttrType).(dwarf.Offset)]
if t[e.Offset].(*dwarfTypedef).type_ == nil {
log.Fatalf("can't find referent for %s %d\n", t[e.Offset].(*dwarfTypedef).name, e.Val(dwarf.AttrType).(dwarf.Offset))
}
case dwarf.TagPointerType:
i := e.Val(dwarf.AttrType)
if i != nil {
t[e.Offset].(*dwarfPtrType).elem = t[i.(dwarf.Offset)]
}
// The only nil cases are unsafe.Pointer and reflect.iword
case dwarf.TagArrayType:
t[e.Offset].(*dwarfArrayType).elem = t[e.Val(dwarf.AttrType).(dwarf.Offset)]
case dwarf.TagStructType:
currentStruct = t[e.Offset].(*dwarfStructType)
case dwarf.TagMember:
name := e.Val(dwarf.AttrName).(string)
type_ := t[e.Val(dwarf.AttrType).(dwarf.Offset)]
loc := e.Val(dwarf.AttrDataMemberLoc).([]uint8)
var offset uint64
if len(loc) == 0 {
offset = 0
} else if len(loc) >= 2 && loc[0] == dw_op_consts && loc[len(loc)-1] == dw_op_plus {
loc, offset = readUleb(loc[1 : len(loc)-1])
if len(loc) != 0 {
break
}
}
currentStruct.members = append(currentStruct.members, dwarfTypeMember{name, offset, type_})
}
}
return t
}