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 {
ctxt.Diag("dwarf: bad def in dotypedef")
}
sym := Linklookup(ctxt, dtolsym(def.Sym).Name+"..def", 0)
sym.Attr |= AttrHidden
sym.Type = obj.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)
}
// 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 := Linklookup(ctxt, dwarf.InfoPrefix+name, version)
sym.Attr |= AttrHidden
sym.Type = obj.SDWARFINFO
die.Sym = sym
}
}
return die
}
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
}