/
dwarf.go
1677 lines (1452 loc) · 50.5 KB
/
dwarf.go
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// Copyright 2010 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.
// TODO/NICETOHAVE:
// - eliminate DW_CLS_ if not used
// - package info in compilation units
// - assign global variables and types to their packages
// - gdb uses c syntax, meaning clumsy quoting is needed for go identifiers. eg
// ptype struct '[]uint8' and qualifiers need to be quoted away
// - file:line info for variables
// - make strings a typedef so prettyprinters can see the underlying string type
package ld
import (
"cmd/internal/dwarf"
"cmd/internal/objabi"
"fmt"
"log"
"os"
"strings"
)
type dwctxt struct {
linkctxt *Link
}
func (c dwctxt) PtrSize() int {
return SysArch.PtrSize
}
func (c dwctxt) AddInt(s dwarf.Sym, size int, i int64) {
ls := s.(*Symbol)
adduintxx(c.linkctxt, ls, uint64(i), size)
}
func (c dwctxt) AddBytes(s dwarf.Sym, b []byte) {
ls := s.(*Symbol)
Addbytes(ls, b)
}
func (c dwctxt) AddString(s dwarf.Sym, v string) {
Addstring(s.(*Symbol), v)
}
func (c dwctxt) SymValue(s dwarf.Sym) int64 {
return s.(*Symbol).Value
}
func (c dwctxt) AddAddress(s dwarf.Sym, data interface{}, value int64) {
if value != 0 {
value -= (data.(*Symbol)).Value
}
Addaddrplus(c.linkctxt, s.(*Symbol), data.(*Symbol), value)
}
func (c dwctxt) AddSectionOffset(s dwarf.Sym, size int, t interface{}, ofs int64) {
ls := s.(*Symbol)
switch size {
default:
Errorf(ls, "invalid size %d in adddwarfref\n", size)
fallthrough
case SysArch.PtrSize:
Addaddr(c.linkctxt, ls, t.(*Symbol))
case 4:
addaddrplus4(c.linkctxt, ls, t.(*Symbol), 0)
}
r := &ls.R[len(ls.R)-1]
r.Type = objabi.R_DWARFREF
r.Add = ofs
}
var gdbscript string
var dwarfp []*Symbol
func writeabbrev(ctxt *Link) *Symbol {
s := ctxt.Syms.Lookup(".debug_abbrev", 0)
s.Type = SDWARFSECT
Addbytes(s, dwarf.GetAbbrev())
return s
}
/*
* Root DIEs for compilation units, types and global variables.
*/
var dwroot dwarf.DWDie
var dwtypes dwarf.DWDie
var dwglobals dwarf.DWDie
func newattr(die *dwarf.DWDie, attr uint16, cls int, value int64, data interface{}) *dwarf.DWAttr {
a := new(dwarf.DWAttr)
a.Link = die.Attr
die.Attr = a
a.Atr = attr
a.Cls = uint8(cls)
a.Value = value
a.Data = data
return a
}
// Each DIE (except the root ones) has at least 1 attribute: its
// name. getattr moves the desired one to the front so
// frequently searched ones are found faster.
func getattr(die *dwarf.DWDie, attr uint16) *dwarf.DWAttr {
if die.Attr.Atr == attr {
return die.Attr
}
a := die.Attr
b := a.Link
for b != nil {
if b.Atr == attr {
a.Link = b.Link
b.Link = die.Attr
die.Attr = b
return b
}
a = b
b = b.Link
}
return nil
}
// Every DIE has at least a AT_name attribute (but it will only be
// written out if it is listed in the abbrev).
func newdie(ctxt *Link, parent *dwarf.DWDie, abbrev int, name string, version int) *dwarf.DWDie {
die := new(dwarf.DWDie)
die.Abbrev = abbrev
die.Link = parent.Child
parent.Child = die
newattr(die, dwarf.DW_AT_name, dwarf.DW_CLS_STRING, int64(len(name)), name)
if name != "" && (abbrev <= dwarf.DW_ABRV_VARIABLE || abbrev >= dwarf.DW_ABRV_NULLTYPE) {
if abbrev != dwarf.DW_ABRV_VARIABLE || version == 0 {
sym := ctxt.Syms.Lookup(dwarf.InfoPrefix+name, version)
sym.Attr |= AttrNotInSymbolTable
sym.Type = SDWARFINFO
die.Sym = sym
}
}
return die
}
func walktypedef(die *dwarf.DWDie) *dwarf.DWDie {
if die == nil {
return nil
}
// Resolve typedef if present.
if die.Abbrev == dwarf.DW_ABRV_TYPEDECL {
for attr := die.Attr; attr != nil; attr = attr.Link {
if attr.Atr == dwarf.DW_AT_type && attr.Cls == dwarf.DW_CLS_REFERENCE && attr.Data != nil {
return attr.Data.(*dwarf.DWDie)
}
}
}
return die
}
func walksymtypedef(ctxt *Link, s *Symbol) *Symbol {
if t := ctxt.Syms.ROLookup(s.Name+"..def", int(s.Version)); t != nil {
return t
}
return s
}
// Find child by AT_name using hashtable if available or linear scan
// if not.
func findchild(die *dwarf.DWDie, name string) *dwarf.DWDie {
var prev *dwarf.DWDie
for ; die != prev; prev, die = die, walktypedef(die) {
for a := die.Child; a != nil; a = a.Link {
if name == getattr(a, dwarf.DW_AT_name).Data {
return a
}
}
continue
}
return nil
}
// Used to avoid string allocation when looking up dwarf symbols
var prefixBuf = []byte(dwarf.InfoPrefix)
func find(ctxt *Link, name string) *Symbol {
n := append(prefixBuf, name...)
// The string allocation below is optimized away because it is only used in a map lookup.
s := ctxt.Syms.ROLookup(string(n), 0)
prefixBuf = n[:len(dwarf.InfoPrefix)]
if s != nil && s.Type == SDWARFINFO {
return s
}
return nil
}
func mustFind(ctxt *Link, name string) *Symbol {
r := find(ctxt, name)
if r == nil {
Exitf("dwarf find: cannot find %s", name)
}
return r
}
func adddwarfref(ctxt *Link, s *Symbol, t *Symbol, size int) int64 {
var result int64
switch size {
default:
Errorf(s, "invalid size %d in adddwarfref\n", size)
fallthrough
case SysArch.PtrSize:
result = Addaddr(ctxt, s, t)
case 4:
result = addaddrplus4(ctxt, s, t, 0)
}
r := &s.R[len(s.R)-1]
r.Type = objabi.R_DWARFREF
return result
}
func newrefattr(die *dwarf.DWDie, attr uint16, ref *Symbol) *dwarf.DWAttr {
if ref == nil {
return nil
}
return newattr(die, attr, dwarf.DW_CLS_REFERENCE, 0, ref)
}
func putdies(linkctxt *Link, ctxt dwarf.Context, syms []*Symbol, die *dwarf.DWDie) []*Symbol {
for ; die != nil; die = die.Link {
syms = putdie(linkctxt, ctxt, syms, die)
}
Adduint8(linkctxt, syms[len(syms)-1], 0)
return syms
}
func dtolsym(s dwarf.Sym) *Symbol {
if s == nil {
return nil
}
return s.(*Symbol)
}
func putdie(linkctxt *Link, ctxt dwarf.Context, syms []*Symbol, die *dwarf.DWDie) []*Symbol {
s := dtolsym(die.Sym)
if s == nil {
s = syms[len(syms)-1]
} else {
if s.Attr.OnList() {
log.Fatalf("symbol %s listed multiple times", s.Name)
}
s.Attr |= AttrOnList
syms = append(syms, s)
}
dwarf.Uleb128put(ctxt, s, int64(die.Abbrev))
dwarf.PutAttrs(ctxt, s, die.Abbrev, die.Attr)
if dwarf.HasChildren(die) {
return putdies(linkctxt, ctxt, syms, die.Child)
}
return syms
}
func reverselist(list **dwarf.DWDie) {
curr := *list
var prev *dwarf.DWDie
for curr != nil {
var next *dwarf.DWDie = curr.Link
curr.Link = prev
prev = curr
curr = next
}
*list = prev
}
func reversetree(list **dwarf.DWDie) {
reverselist(list)
for die := *list; die != nil; die = die.Link {
if dwarf.HasChildren(die) {
reversetree(&die.Child)
}
}
}
func newmemberoffsetattr(die *dwarf.DWDie, offs int32) {
var block [20]byte
b := append(block[:0], dwarf.DW_OP_plus_uconst)
b = dwarf.AppendUleb128(b, uint64(offs))
newattr(die, dwarf.DW_AT_data_member_location, dwarf.DW_CLS_BLOCK, int64(len(b)), b)
}
// GDB doesn't like FORM_addr for AT_location, so emit a
// location expression that evals to a const.
func newabslocexprattr(die *dwarf.DWDie, addr int64, sym *Symbol) {
newattr(die, dwarf.DW_AT_location, dwarf.DW_CLS_ADDRESS, addr, sym)
// below
}
// Lookup predefined types
func lookupOrDiag(ctxt *Link, n string) *Symbol {
s := ctxt.Syms.ROLookup(n, 0)
if s == nil || s.Size == 0 {
Exitf("dwarf: missing type: %s", n)
}
return s
}
func dotypedef(ctxt *Link, parent *dwarf.DWDie, name string, def *dwarf.DWDie) {
// Only emit typedefs for real names.
if strings.HasPrefix(name, "map[") {
return
}
if strings.HasPrefix(name, "struct {") {
return
}
if strings.HasPrefix(name, "chan ") {
return
}
if name[0] == '[' || name[0] == '*' {
return
}
if def == nil {
Errorf(nil, "dwarf: bad def in dotypedef")
}
sym := ctxt.Syms.Lookup(dtolsym(def.Sym).Name+"..def", 0)
sym.Attr |= AttrNotInSymbolTable
sym.Type = SDWARFINFO
def.Sym = sym
// The typedef entry must be created after the def,
// so that future lookups will find the typedef instead
// of the real definition. This hooks the typedef into any
// circular definition loops, so that gdb can understand them.
die := newdie(ctxt, parent, dwarf.DW_ABRV_TYPEDECL, name, 0)
newrefattr(die, dwarf.DW_AT_type, sym)
}
// Define gotype, for composite ones recurse into constituents.
func defgotype(ctxt *Link, gotype *Symbol) *Symbol {
if gotype == nil {
return mustFind(ctxt, "<unspecified>")
}
if !strings.HasPrefix(gotype.Name, "type.") {
Errorf(gotype, "dwarf: type name doesn't start with \"type.\"")
return mustFind(ctxt, "<unspecified>")
}
name := gotype.Name[5:] // could also decode from Type.string
sdie := find(ctxt, name)
if sdie != nil {
return sdie
}
return newtype(ctxt, gotype).Sym.(*Symbol)
}
func newtype(ctxt *Link, gotype *Symbol) *dwarf.DWDie {
name := gotype.Name[5:] // could also decode from Type.string
kind := decodetypeKind(gotype)
bytesize := decodetypeSize(ctxt.Arch, gotype)
var die *dwarf.DWDie
switch kind {
case objabi.KindBool:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_BASETYPE, name, 0)
newattr(die, dwarf.DW_AT_encoding, dwarf.DW_CLS_CONSTANT, dwarf.DW_ATE_boolean, 0)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
case objabi.KindInt,
objabi.KindInt8,
objabi.KindInt16,
objabi.KindInt32,
objabi.KindInt64:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_BASETYPE, name, 0)
newattr(die, dwarf.DW_AT_encoding, dwarf.DW_CLS_CONSTANT, dwarf.DW_ATE_signed, 0)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
case objabi.KindUint,
objabi.KindUint8,
objabi.KindUint16,
objabi.KindUint32,
objabi.KindUint64,
objabi.KindUintptr:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_BASETYPE, name, 0)
newattr(die, dwarf.DW_AT_encoding, dwarf.DW_CLS_CONSTANT, dwarf.DW_ATE_unsigned, 0)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
case objabi.KindFloat32,
objabi.KindFloat64:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_BASETYPE, name, 0)
newattr(die, dwarf.DW_AT_encoding, dwarf.DW_CLS_CONSTANT, dwarf.DW_ATE_float, 0)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
case objabi.KindComplex64,
objabi.KindComplex128:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_BASETYPE, name, 0)
newattr(die, dwarf.DW_AT_encoding, dwarf.DW_CLS_CONSTANT, dwarf.DW_ATE_complex_float, 0)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
case objabi.KindArray:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_ARRAYTYPE, name, 0)
dotypedef(ctxt, &dwtypes, name, die)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
s := decodetypeArrayElem(gotype)
newrefattr(die, dwarf.DW_AT_type, defgotype(ctxt, s))
fld := newdie(ctxt, die, dwarf.DW_ABRV_ARRAYRANGE, "range", 0)
// use actual length not upper bound; correct for 0-length arrays.
newattr(fld, dwarf.DW_AT_count, dwarf.DW_CLS_CONSTANT, decodetypeArrayLen(ctxt.Arch, gotype), 0)
newrefattr(fld, dwarf.DW_AT_type, mustFind(ctxt, "uintptr"))
case objabi.KindChan:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_CHANTYPE, name, 0)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
s := decodetypeChanElem(gotype)
newrefattr(die, dwarf.DW_AT_go_elem, defgotype(ctxt, s))
// Save elem type for synthesizechantypes. We could synthesize here
// but that would change the order of DIEs we output.
newrefattr(die, dwarf.DW_AT_type, s)
case objabi.KindFunc:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_FUNCTYPE, name, 0)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
dotypedef(ctxt, &dwtypes, name, die)
newrefattr(die, dwarf.DW_AT_type, mustFind(ctxt, "void"))
nfields := decodetypeFuncInCount(ctxt.Arch, gotype)
var fld *dwarf.DWDie
var s *Symbol
for i := 0; i < nfields; i++ {
s = decodetypeFuncInType(gotype, i)
fld = newdie(ctxt, die, dwarf.DW_ABRV_FUNCTYPEPARAM, s.Name[5:], 0)
newrefattr(fld, dwarf.DW_AT_type, defgotype(ctxt, s))
}
if decodetypeFuncDotdotdot(ctxt.Arch, gotype) {
newdie(ctxt, die, dwarf.DW_ABRV_DOTDOTDOT, "...", 0)
}
nfields = decodetypeFuncOutCount(ctxt.Arch, gotype)
for i := 0; i < nfields; i++ {
s = decodetypeFuncOutType(ctxt.Arch, gotype, i)
fld = newdie(ctxt, die, dwarf.DW_ABRV_FUNCTYPEPARAM, s.Name[5:], 0)
newrefattr(fld, dwarf.DW_AT_type, defptrto(ctxt, defgotype(ctxt, s)))
}
case objabi.KindInterface:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_IFACETYPE, name, 0)
dotypedef(ctxt, &dwtypes, name, die)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
nfields := int(decodetypeIfaceMethodCount(ctxt.Arch, gotype))
var s *Symbol
if nfields == 0 {
s = lookupOrDiag(ctxt, "type.runtime.eface")
} else {
s = lookupOrDiag(ctxt, "type.runtime.iface")
}
newrefattr(die, dwarf.DW_AT_type, defgotype(ctxt, s))
case objabi.KindMap:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_MAPTYPE, name, 0)
s := decodetypeMapKey(gotype)
newrefattr(die, dwarf.DW_AT_go_key, defgotype(ctxt, s))
s = decodetypeMapValue(gotype)
newrefattr(die, dwarf.DW_AT_go_elem, defgotype(ctxt, s))
// Save gotype for use in synthesizemaptypes. We could synthesize here,
// but that would change the order of the DIEs.
newrefattr(die, dwarf.DW_AT_type, gotype)
case objabi.KindPtr:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_PTRTYPE, name, 0)
dotypedef(ctxt, &dwtypes, name, die)
s := decodetypePtrElem(gotype)
newrefattr(die, dwarf.DW_AT_type, defgotype(ctxt, s))
case objabi.KindSlice:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_SLICETYPE, name, 0)
dotypedef(ctxt, &dwtypes, name, die)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
s := decodetypeArrayElem(gotype)
elem := defgotype(ctxt, s)
newrefattr(die, dwarf.DW_AT_go_elem, elem)
case objabi.KindString:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_STRINGTYPE, name, 0)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
case objabi.KindStruct:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_STRUCTTYPE, name, 0)
dotypedef(ctxt, &dwtypes, name, die)
newattr(die, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, bytesize, 0)
nfields := decodetypeStructFieldCount(ctxt.Arch, gotype)
for i := 0; i < nfields; i++ {
f := decodetypeStructFieldName(gotype, i)
s := decodetypeStructFieldType(gotype, i)
if f == "" {
f = s.Name[5:] // skip "type."
}
fld := newdie(ctxt, die, dwarf.DW_ABRV_STRUCTFIELD, f, 0)
newrefattr(fld, dwarf.DW_AT_type, defgotype(ctxt, s))
offsetAnon := decodetypeStructFieldOffsAnon(ctxt.Arch, gotype, i)
newmemberoffsetattr(fld, int32(offsetAnon>>1))
if offsetAnon&1 != 0 { // is embedded field
newattr(fld, dwarf.DW_AT_go_embedded_field, dwarf.DW_CLS_FLAG, 1, 0)
}
}
case objabi.KindUnsafePointer:
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_BARE_PTRTYPE, name, 0)
default:
Errorf(gotype, "dwarf: definition of unknown kind %d", kind)
die = newdie(ctxt, &dwtypes, dwarf.DW_ABRV_TYPEDECL, name, 0)
newrefattr(die, dwarf.DW_AT_type, mustFind(ctxt, "<unspecified>"))
}
newattr(die, dwarf.DW_AT_go_kind, dwarf.DW_CLS_CONSTANT, int64(kind), 0)
if _, ok := prototypedies[gotype.Name]; ok {
prototypedies[gotype.Name] = die
}
return die
}
func nameFromDIESym(dwtype *Symbol) string {
return strings.TrimSuffix(dwtype.Name[len(dwarf.InfoPrefix):], "..def")
}
// Find or construct *T given T.
func defptrto(ctxt *Link, dwtype *Symbol) *Symbol {
ptrname := "*" + nameFromDIESym(dwtype)
die := find(ctxt, ptrname)
if die == nil {
pdie := newdie(ctxt, &dwtypes, dwarf.DW_ABRV_PTRTYPE, ptrname, 0)
newrefattr(pdie, dwarf.DW_AT_type, dwtype)
return dtolsym(pdie.Sym)
}
return die
}
// Copies src's children into dst. Copies attributes by value.
// DWAttr.data is copied as pointer only. If except is one of
// the top-level children, it will not be copied.
func copychildrenexcept(ctxt *Link, dst *dwarf.DWDie, src *dwarf.DWDie, except *dwarf.DWDie) {
for src = src.Child; src != nil; src = src.Link {
if src == except {
continue
}
c := newdie(ctxt, dst, src.Abbrev, getattr(src, dwarf.DW_AT_name).Data.(string), 0)
for a := src.Attr; a != nil; a = a.Link {
newattr(c, a.Atr, int(a.Cls), a.Value, a.Data)
}
copychildrenexcept(ctxt, c, src, nil)
}
reverselist(&dst.Child)
}
func copychildren(ctxt *Link, dst *dwarf.DWDie, src *dwarf.DWDie) {
copychildrenexcept(ctxt, dst, src, nil)
}
// Search children (assumed to have TAG_member) for the one named
// field and set its AT_type to dwtype
func substitutetype(structdie *dwarf.DWDie, field string, dwtype *Symbol) {
child := findchild(structdie, field)
if child == nil {
Exitf("dwarf substitutetype: %s does not have member %s",
getattr(structdie, dwarf.DW_AT_name).Data, field)
return
}
a := getattr(child, dwarf.DW_AT_type)
if a != nil {
a.Data = dwtype
} else {
newrefattr(child, dwarf.DW_AT_type, dwtype)
}
}
func findprotodie(ctxt *Link, name string) *dwarf.DWDie {
die, ok := prototypedies[name]
if ok && die == nil {
defgotype(ctxt, lookupOrDiag(ctxt, name))
die = prototypedies[name]
}
return die
}
func synthesizestringtypes(ctxt *Link, die *dwarf.DWDie) {
prototype := walktypedef(findprotodie(ctxt, "type.runtime.stringStructDWARF"))
if prototype == nil {
return
}
for ; die != nil; die = die.Link {
if die.Abbrev != dwarf.DW_ABRV_STRINGTYPE {
continue
}
copychildren(ctxt, die, prototype)
}
}
func synthesizeslicetypes(ctxt *Link, die *dwarf.DWDie) {
prototype := walktypedef(findprotodie(ctxt, "type.runtime.slice"))
if prototype == nil {
return
}
for ; die != nil; die = die.Link {
if die.Abbrev != dwarf.DW_ABRV_SLICETYPE {
continue
}
copychildren(ctxt, die, prototype)
elem := getattr(die, dwarf.DW_AT_go_elem).Data.(*Symbol)
substitutetype(die, "array", defptrto(ctxt, elem))
}
}
func mkinternaltypename(base string, arg1 string, arg2 string) string {
var buf string
if arg2 == "" {
buf = fmt.Sprintf("%s<%s>", base, arg1)
} else {
buf = fmt.Sprintf("%s<%s,%s>", base, arg1, arg2)
}
n := buf
return n
}
// synthesizemaptypes is way too closely married to runtime/hashmap.c
const (
MaxKeySize = 128
MaxValSize = 128
BucketSize = 8
)
func mkinternaltype(ctxt *Link, abbrev int, typename, keyname, valname string, f func(*dwarf.DWDie)) *Symbol {
name := mkinternaltypename(typename, keyname, valname)
symname := dwarf.InfoPrefix + name
s := ctxt.Syms.ROLookup(symname, 0)
if s != nil && s.Type == SDWARFINFO {
return s
}
die := newdie(ctxt, &dwtypes, abbrev, name, 0)
f(die)
return dtolsym(die.Sym)
}
func synthesizemaptypes(ctxt *Link, die *dwarf.DWDie) {
hash := walktypedef(findprotodie(ctxt, "type.runtime.hmap"))
bucket := walktypedef(findprotodie(ctxt, "type.runtime.bmap"))
if hash == nil {
return
}
for ; die != nil; die = die.Link {
if die.Abbrev != dwarf.DW_ABRV_MAPTYPE {
continue
}
gotype := getattr(die, dwarf.DW_AT_type).Data.(*Symbol)
keytype := decodetypeMapKey(gotype)
valtype := decodetypeMapValue(gotype)
keysize, valsize := decodetypeSize(ctxt.Arch, keytype), decodetypeSize(ctxt.Arch, valtype)
keytype, valtype = walksymtypedef(ctxt, defgotype(ctxt, keytype)), walksymtypedef(ctxt, defgotype(ctxt, valtype))
// compute size info like hashmap.c does.
indirectKey, indirectVal := false, false
if keysize > MaxKeySize {
keysize = int64(SysArch.PtrSize)
indirectKey = true
}
if valsize > MaxValSize {
valsize = int64(SysArch.PtrSize)
indirectVal = true
}
// Construct type to represent an array of BucketSize keys
keyname := nameFromDIESym(keytype)
dwhks := mkinternaltype(ctxt, dwarf.DW_ABRV_ARRAYTYPE, "[]key", keyname, "", func(dwhk *dwarf.DWDie) {
newattr(dwhk, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, BucketSize*keysize, 0)
t := keytype
if indirectKey {
t = defptrto(ctxt, keytype)
}
newrefattr(dwhk, dwarf.DW_AT_type, t)
fld := newdie(ctxt, dwhk, dwarf.DW_ABRV_ARRAYRANGE, "size", 0)
newattr(fld, dwarf.DW_AT_count, dwarf.DW_CLS_CONSTANT, BucketSize, 0)
newrefattr(fld, dwarf.DW_AT_type, mustFind(ctxt, "uintptr"))
})
// Construct type to represent an array of BucketSize values
valname := nameFromDIESym(valtype)
dwhvs := mkinternaltype(ctxt, dwarf.DW_ABRV_ARRAYTYPE, "[]val", valname, "", func(dwhv *dwarf.DWDie) {
newattr(dwhv, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, BucketSize*valsize, 0)
t := valtype
if indirectVal {
t = defptrto(ctxt, valtype)
}
newrefattr(dwhv, dwarf.DW_AT_type, t)
fld := newdie(ctxt, dwhv, dwarf.DW_ABRV_ARRAYRANGE, "size", 0)
newattr(fld, dwarf.DW_AT_count, dwarf.DW_CLS_CONSTANT, BucketSize, 0)
newrefattr(fld, dwarf.DW_AT_type, mustFind(ctxt, "uintptr"))
})
// Construct bucket<K,V>
dwhbs := mkinternaltype(ctxt, dwarf.DW_ABRV_STRUCTTYPE, "bucket", keyname, valname, func(dwhb *dwarf.DWDie) {
// Copy over all fields except the field "data" from the generic
// bucket. "data" will be replaced with keys/values below.
copychildrenexcept(ctxt, dwhb, bucket, findchild(bucket, "data"))
fld := newdie(ctxt, dwhb, dwarf.DW_ABRV_STRUCTFIELD, "keys", 0)
newrefattr(fld, dwarf.DW_AT_type, dwhks)
newmemberoffsetattr(fld, BucketSize)
fld = newdie(ctxt, dwhb, dwarf.DW_ABRV_STRUCTFIELD, "values", 0)
newrefattr(fld, dwarf.DW_AT_type, dwhvs)
newmemberoffsetattr(fld, BucketSize+BucketSize*int32(keysize))
fld = newdie(ctxt, dwhb, dwarf.DW_ABRV_STRUCTFIELD, "overflow", 0)
newrefattr(fld, dwarf.DW_AT_type, defptrto(ctxt, dtolsym(dwhb.Sym)))
newmemberoffsetattr(fld, BucketSize+BucketSize*(int32(keysize)+int32(valsize)))
if SysArch.RegSize > SysArch.PtrSize {
fld = newdie(ctxt, dwhb, dwarf.DW_ABRV_STRUCTFIELD, "pad", 0)
newrefattr(fld, dwarf.DW_AT_type, mustFind(ctxt, "uintptr"))
newmemberoffsetattr(fld, BucketSize+BucketSize*(int32(keysize)+int32(valsize))+int32(SysArch.PtrSize))
}
newattr(dwhb, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, BucketSize+BucketSize*keysize+BucketSize*valsize+int64(SysArch.RegSize), 0)
})
// Construct hash<K,V>
dwhs := mkinternaltype(ctxt, dwarf.DW_ABRV_STRUCTTYPE, "hash", keyname, valname, func(dwh *dwarf.DWDie) {
copychildren(ctxt, dwh, hash)
substitutetype(dwh, "buckets", defptrto(ctxt, dwhbs))
substitutetype(dwh, "oldbuckets", defptrto(ctxt, dwhbs))
newattr(dwh, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, getattr(hash, dwarf.DW_AT_byte_size).Value, nil)
})
// make map type a pointer to hash<K,V>
newrefattr(die, dwarf.DW_AT_type, defptrto(ctxt, dwhs))
}
}
func synthesizechantypes(ctxt *Link, die *dwarf.DWDie) {
sudog := walktypedef(findprotodie(ctxt, "type.runtime.sudog"))
waitq := walktypedef(findprotodie(ctxt, "type.runtime.waitq"))
hchan := walktypedef(findprotodie(ctxt, "type.runtime.hchan"))
if sudog == nil || waitq == nil || hchan == nil {
return
}
sudogsize := int(getattr(sudog, dwarf.DW_AT_byte_size).Value)
for ; die != nil; die = die.Link {
if die.Abbrev != dwarf.DW_ABRV_CHANTYPE {
continue
}
elemgotype := getattr(die, dwarf.DW_AT_type).Data.(*Symbol)
elemname := elemgotype.Name[5:]
elemtype := walksymtypedef(ctxt, defgotype(ctxt, elemgotype))
// sudog<T>
dwss := mkinternaltype(ctxt, dwarf.DW_ABRV_STRUCTTYPE, "sudog", elemname, "", func(dws *dwarf.DWDie) {
copychildren(ctxt, dws, sudog)
substitutetype(dws, "elem", defptrto(ctxt, elemtype))
newattr(dws, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, int64(sudogsize), nil)
})
// waitq<T>
dwws := mkinternaltype(ctxt, dwarf.DW_ABRV_STRUCTTYPE, "waitq", elemname, "", func(dww *dwarf.DWDie) {
copychildren(ctxt, dww, waitq)
substitutetype(dww, "first", defptrto(ctxt, dwss))
substitutetype(dww, "last", defptrto(ctxt, dwss))
newattr(dww, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, getattr(waitq, dwarf.DW_AT_byte_size).Value, nil)
})
// hchan<T>
dwhs := mkinternaltype(ctxt, dwarf.DW_ABRV_STRUCTTYPE, "hchan", elemname, "", func(dwh *dwarf.DWDie) {
copychildren(ctxt, dwh, hchan)
substitutetype(dwh, "recvq", dwws)
substitutetype(dwh, "sendq", dwws)
newattr(dwh, dwarf.DW_AT_byte_size, dwarf.DW_CLS_CONSTANT, getattr(hchan, dwarf.DW_AT_byte_size).Value, nil)
})
newrefattr(die, dwarf.DW_AT_type, defptrto(ctxt, dwhs))
}
}
// For use with pass.c::genasmsym
func defdwsymb(ctxt *Link, sym *Symbol, s string, t SymbolType, v int64, gotype *Symbol) {
if strings.HasPrefix(s, "go.string.") {
return
}
if strings.HasPrefix(s, "runtime.gcbits.") {
return
}
if strings.HasPrefix(s, "type.") && s != "type.*" && !strings.HasPrefix(s, "type..") {
defgotype(ctxt, sym)
return
}
var dv *dwarf.DWDie
var dt *Symbol
switch t {
default:
return
case DataSym, BSSSym:
dv = newdie(ctxt, &dwglobals, dwarf.DW_ABRV_VARIABLE, s, int(sym.Version))
newabslocexprattr(dv, v, sym)
if sym.Version == 0 {
newattr(dv, dwarf.DW_AT_external, dwarf.DW_CLS_FLAG, 1, 0)
}
fallthrough
case AutoSym, ParamSym:
dt = defgotype(ctxt, gotype)
}
if dv != nil {
newrefattr(dv, dwarf.DW_AT_type, dt)
}
}
func movetomodule(parent *dwarf.DWDie) {
die := dwroot.Child.Child
if die == nil {
dwroot.Child.Child = parent.Child
return
}
for die.Link != nil {
die = die.Link
}
die.Link = parent.Child
}
// If the pcln table contains runtime/runtime.go, use that to set gdbscript path.
func finddebugruntimepath(s *Symbol) {
if gdbscript != "" {
return
}
for i := range s.FuncInfo.File {
f := s.FuncInfo.File[i]
if i := strings.Index(f.Name, "runtime/debug.go"); i >= 0 {
gdbscript = f.Name[:i] + "runtime/runtime-gdb.py"
break
}
}
}
/*
* Generate a sequence of opcodes that is as short as possible.
* See section 6.2.5
*/
const (
LINE_BASE = -4
LINE_RANGE = 10
PC_RANGE = (255 - OPCODE_BASE) / LINE_RANGE
OPCODE_BASE = 10
)
func putpclcdelta(linkctxt *Link, ctxt dwarf.Context, s *Symbol, deltaPC uint64, deltaLC int64) {
// Choose a special opcode that minimizes the number of bytes needed to
// encode the remaining PC delta and LC delta.
var opcode int64
if deltaLC < LINE_BASE {
if deltaPC >= PC_RANGE {
opcode = OPCODE_BASE + (LINE_RANGE * PC_RANGE)
} else {
opcode = OPCODE_BASE + (LINE_RANGE * int64(deltaPC))
}
} else if deltaLC < LINE_BASE+LINE_RANGE {
if deltaPC >= PC_RANGE {
opcode = OPCODE_BASE + (deltaLC - LINE_BASE) + (LINE_RANGE * PC_RANGE)
if opcode > 255 {
opcode -= LINE_RANGE
}
} else {
opcode = OPCODE_BASE + (deltaLC - LINE_BASE) + (LINE_RANGE * int64(deltaPC))
}
} else {
if deltaPC <= PC_RANGE {
opcode = OPCODE_BASE + (LINE_RANGE - 1) + (LINE_RANGE * int64(deltaPC))
if opcode > 255 {
opcode = 255
}
} else {
// Use opcode 249 (pc+=23, lc+=5) or 255 (pc+=24, lc+=1).
//
// Let x=deltaPC-PC_RANGE. If we use opcode 255, x will be the remaining
// deltaPC that we need to encode separately before emitting 255. If we
// use opcode 249, we will need to encode x+1. If x+1 takes one more
// byte to encode than x, then we use opcode 255.
//
// In all other cases x and x+1 take the same number of bytes to encode,
// so we use opcode 249, which may save us a byte in encoding deltaLC,
// for similar reasons.
switch deltaPC - PC_RANGE {
// PC_RANGE is the largest deltaPC we can encode in one byte, using
// DW_LNS_const_add_pc.
//
// (1<<16)-1 is the largest deltaPC we can encode in three bytes, using
// DW_LNS_fixed_advance_pc.
//
// (1<<(7n))-1 is the largest deltaPC we can encode in n+1 bytes for
// n=1,3,4,5,..., using DW_LNS_advance_pc.
case PC_RANGE, (1 << 7) - 1, (1 << 16) - 1, (1 << 21) - 1, (1 << 28) - 1,
(1 << 35) - 1, (1 << 42) - 1, (1 << 49) - 1, (1 << 56) - 1, (1 << 63) - 1:
opcode = 255
default:
opcode = OPCODE_BASE + LINE_RANGE*PC_RANGE - 1 // 249
}
}
}
if opcode < OPCODE_BASE || opcode > 255 {
panic(fmt.Sprintf("produced invalid special opcode %d", opcode))
}
// Subtract from deltaPC and deltaLC the amounts that the opcode will add.
deltaPC -= uint64((opcode - OPCODE_BASE) / LINE_RANGE)
deltaLC -= int64((opcode-OPCODE_BASE)%LINE_RANGE + LINE_BASE)
// Encode deltaPC.
if deltaPC != 0 {
if deltaPC <= PC_RANGE {
// Adjust the opcode so that we can use the 1-byte DW_LNS_const_add_pc
// instruction.
opcode -= LINE_RANGE * int64(PC_RANGE-deltaPC)
if opcode < OPCODE_BASE {
panic(fmt.Sprintf("produced invalid special opcode %d", opcode))
}
Adduint8(linkctxt, s, dwarf.DW_LNS_const_add_pc)
} else if (1<<14) <= deltaPC && deltaPC < (1<<16) {
Adduint8(linkctxt, s, dwarf.DW_LNS_fixed_advance_pc)
Adduint16(linkctxt, s, uint16(deltaPC))
} else {
Adduint8(linkctxt, s, dwarf.DW_LNS_advance_pc)
dwarf.Uleb128put(ctxt, s, int64(deltaPC))
}
}
// Encode deltaLC.
if deltaLC != 0 {
Adduint8(linkctxt, s, dwarf.DW_LNS_advance_line)
dwarf.Sleb128put(ctxt, s, deltaLC)
}
// Output the special opcode.
Adduint8(linkctxt, s, uint8(opcode))
}
/*
* Walk prog table, emit line program and build DIE tree.
*/
func getCompilationDir() string {
if dir, err := os.Getwd(); err == nil {
return dir
}
return "/"
}
func writelines(ctxt *Link, syms []*Symbol) ([]*Symbol, []*Symbol) {
var dwarfctxt dwarf.Context = dwctxt{ctxt}
ls := ctxt.Syms.Lookup(".debug_line", 0)
ls.Type = SDWARFSECT
ls.R = ls.R[:0]
syms = append(syms, ls)
var funcs []*Symbol
unitstart := int64(-1)
headerstart := int64(-1)
headerend := int64(-1)
epc := int64(0)
var epcs *Symbol
var dwinfo *dwarf.DWDie
lang := dwarf.DW_LANG_Go
s := ctxt.Textp[0]
if ctxt.DynlinkingGo() && Headtype == objabi.Hdarwin {
s = ctxt.Textp[1] // skip runtime.text
}