Golang Addr.Sym方法代碼示例

// symbolReference parses a symbol that is known not to be a register.
func (p *Parser) symbolReference(a *obj.Addr, name string, prefix rune) {
	// Identifier is a name.
	switch prefix {
	case 0:
		a.Type = obj.TYPE_MEM
	case '$':
		a.Type = obj.TYPE_ADDR
	case '*':
		a.Type = obj.TYPE_INDIR
	}
	// Weirdness with statics: Might now have "<>".
	isStatic := 0 // TODO: Really a boolean, but Linklookup wants a "version" integer.
	if p.peek() == '<' {
		isStatic = 1
		p.next()
		p.get('>')
	}
	if p.peek() == '+' || p.peek() == '-' {
		a.Offset = int64(p.expr())
	}
	a.Sym = obj.Linklookup(p.ctxt, name, isStatic)
	if p.peek() == scanner.EOF {
		if prefix == 0 && p.isJump {
			// Symbols without prefix or suffix are jump labels.
			return
		}
		p.errorf("illegal or missing addressing mode for symbol %s", name)
		return
	}
	// Expect (SB), (FP), (PC), or (SP)
	p.get('(')
	reg := p.get(scanner.Ident).String()
	p.get(')')
	p.setPseudoRegister(a, reg, isStatic != 0, prefix)
}

func datagostring(sval string, a *obj.Addr) {
	symhdr, _ := stringsym(sval)
	a.Type = obj.TYPE_MEM
	a.Name = obj.NAME_EXTERN
	a.Sym = Linksym(symhdr)
	a.Node = symhdr.Def
	a.Offset = 0
	a.Etype = uint8(TSTRING)
}

func Datastring(s string, a *obj.Addr) {
	_, symdata := stringsym(s)
	a.Type = obj.TYPE_MEM
	a.Name = obj.NAME_EXTERN
	a.Sym = Linksym(symdata)
	a.Node = symdata.Def
	a.Offset = 0
	a.Etype = uint8(Simtype[TINT])
}

func addreg(a *obj.Addr, rn int) {
	a.Sym = nil
	a.Node = nil
	a.Offset = 0
	a.Type = obj.TYPE_REG
	a.Reg = int16(rn)
	a.Name = 0

	Ostats.Ncvtreg++
}

// Naddr rewrites a to refer to n.
// It assumes that a is zeroed on entry.
func Naddr(a *obj.Addr, n *Node) {
	if n == nil {
		return
	}

	if n.Type != nil && n.Type.Etype != TIDEAL {
		// TODO(rsc): This is undone by the selective clearing of width below,
		// to match architectures that were not as aggressive in setting width
		// during naddr. Those widths must be cleared to avoid triggering
		// failures in gins when it detects real but heretofore latent (and one
		// hopes innocuous) type mismatches.
		// The type mismatches should be fixed and the clearing below removed.
		dowidth(n.Type)

		a.Width = n.Type.Width
	}

	switch n.Op {
	default:
		a := a // copy to let escape into Ctxt.Dconv
		Debug['h'] = 1
		Dump("naddr", n)
		Fatalf("naddr: bad %v %v", Oconv(int(n.Op), 0), Ctxt.Dconv(a))

	case OREGISTER:
		a.Type = obj.TYPE_REG
		a.Reg = n.Reg
		a.Sym = nil
		if Thearch.Thechar == '8' { // TODO(rsc): Never clear a->width.
			a.Width = 0
		}

	case OINDREG:
		a.Type = obj.TYPE_MEM
		a.Reg = n.Reg
		a.Sym = Linksym(n.Sym)
		a.Offset = n.Xoffset
		if a.Offset != int64(int32(a.Offset)) {
			Yyerror("offset %d too large for OINDREG", a.Offset)
		}
		if Thearch.Thechar == '8' { // TODO(rsc): Never clear a->width.
			a.Width = 0
		}

		// n->left is PHEAP ONAME for stack parameter.
	// compute address of actual parameter on stack.
	case OPARAM:
		a.Etype = uint8(Simtype[n.Left.Type.Etype])

		a.Width = n.Left.Type.Width
		a.Offset = n.Xoffset
		a.Sym = Linksym(n.Left.Sym)
		a.Type = obj.TYPE_MEM
		a.Name = obj.NAME_PARAM
		a.Node = n.Left.Orig

	case OCLOSUREVAR:
		if !Curfn.Func.Needctxt {
			Fatalf("closurevar without needctxt")
		}
		a.Type = obj.TYPE_MEM
		a.Reg = int16(Thearch.REGCTXT)
		a.Sym = nil
		a.Offset = n.Xoffset

	case OCFUNC:
		Naddr(a, n.Left)
		a.Sym = Linksym(n.Left.Sym)

	case ONAME:
		a.Etype = 0
		if n.Type != nil {
			a.Etype = uint8(Simtype[n.Type.Etype])
		}
		a.Offset = n.Xoffset
		s := n.Sym
		a.Node = n.Orig

		//if(a->node >= (Node*)&n)
		//	fatal("stack node");
		if s == nil {
			s = Lookup(".noname")
		}
		if n.Name.Method {
			if n.Type != nil {
				if n.Type.Sym != nil {
					if n.Type.Sym.Pkg != nil {
						s = Pkglookup(s.Name, n.Type.Sym.Pkg)
					}
				}
			}
		}

		a.Type = obj.TYPE_MEM
		switch n.Class {
		default:
			Fatalf("naddr: ONAME class %v %d\n", n.Sym, n.Class)

//.........這裏部分代碼省略.........

func Afunclit(a *obj.Addr, n *Node) {
	if a.Type == obj.TYPE_ADDR && a.Name == obj.NAME_EXTERN {
		a.Type = obj.TYPE_MEM
		a.Sym = Linksym(n.Sym)
	}
}