Golang dwarf.DWDie類代碼示例

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
}