Ejemplo n.º 1
0
Archivo: ggen.go Proyecto: ckeyer/gosrc
// Called after regopt and peep have run.
// Expand CHECKNIL pseudo-op into actual nil pointer check.
func expandchecks(firstp *obj.Prog) {
	var p1 *obj.Prog
	var p2 *obj.Prog

	for p := firstp; p != nil; p = p.Link {
		if p.As != obj.ACHECKNIL {
			continue
		}
		if gc.Debug_checknil != 0 && p.Lineno > 1 { // p->lineno==1 in generated wrappers
			gc.Warnl(int(p.Lineno), "generated nil check")
		}

		// check is
		//	CMP arg, $0
		//	JNE 2(PC) (likely)
		//	MOV AX, 0
		p1 = gc.Ctxt.NewProg()

		p2 = gc.Ctxt.NewProg()
		gc.Clearp(p1)
		gc.Clearp(p2)
		p1.Link = p2
		p2.Link = p.Link
		p.Link = p1
		p1.Lineno = p.Lineno
		p2.Lineno = p.Lineno
		p1.Pc = 9999
		p2.Pc = 9999
		p.As = int16(cmpptr)
		p.To.Type = obj.TYPE_CONST
		p.To.Offset = 0
		p1.As = x86.AJNE
		p1.From.Type = obj.TYPE_CONST
		p1.From.Offset = 1 // likely
		p1.To.Type = obj.TYPE_BRANCH
		p1.To.Val = p2.Link

		// crash by write to memory address 0.
		// if possible, since we know arg is 0, use 0(arg),
		// which will be shorter to encode than plain 0.
		p2.As = x86.AMOVL

		p2.From.Type = obj.TYPE_REG
		p2.From.Reg = x86.REG_AX
		if regtyp(&p.From) {
			p2.To.Type = obj.TYPE_MEM
			p2.To.Reg = p.From.Reg
		} else {
			p2.To.Type = obj.TYPE_MEM
			p2.To.Reg = x86.REG_NONE
		}

		p2.To.Offset = 0
	}
}
Ejemplo n.º 2
0
Archivo: asm.go Proyecto: ckeyer/gosrc
// append adds the Prog to the end of the program-thus-far.
// If doLabel is set, it also defines the labels collect for this Prog.
func (p *Parser) append(prog *obj.Prog, cond string, doLabel bool) {
	if cond != "" {
		switch p.arch.Thechar {
		case '5':
			if !arch.ARMConditionCodes(prog, cond) {
				p.errorf("unrecognized condition code .%q", cond)
				return
			}

		case '7':
			if !arch.ARM64Suffix(prog, cond) {
				p.errorf("unrecognized suffix .%q", cond)
				return
			}

		default:
			p.errorf("unrecognized suffix .%q", cond)
			return
		}
	}
	if p.firstProg == nil {
		p.firstProg = prog
	} else {
		p.lastProg.Link = prog
	}
	p.lastProg = prog
	if doLabel {
		p.pc++
		for _, label := range p.pendingLabels {
			if p.labels[label] != nil {
				p.errorf("label %q multiply defined", label)
				return
			}
			p.labels[label] = prog
		}
		p.pendingLabels = p.pendingLabels[0:0]
	}
	prog.Pc = int64(p.pc)
	if *flags.Debug {
		fmt.Println(p.histLineNum, prog)
	}
	if testOut != nil {
		fmt.Fprintln(testOut, prog)
	}
}
Ejemplo n.º 3
0
Archivo: ggen.go Proyecto: ckeyer/gosrc
// Called after regopt and peep have run.
// Expand CHECKNIL pseudo-op into actual nil pointer check.
func expandchecks(firstp *obj.Prog) {
	var p1 *obj.Prog

	for p := (*obj.Prog)(firstp); p != nil; p = p.Link {
		if gc.Debug_checknil != 0 && gc.Ctxt.Debugvlog != 0 {
			fmt.Printf("expandchecks: %v\n", p)
		}
		if p.As != obj.ACHECKNIL {
			continue
		}
		if gc.Debug_checknil != 0 && p.Lineno > 1 { // p->lineno==1 in generated wrappers
			gc.Warnl(int(p.Lineno), "generated nil check")
		}
		if p.From.Type != obj.TYPE_REG {
			gc.Fatalf("invalid nil check %v\n", p)
		}

		// check is
		//	CBNZ arg, 2(PC)
		//	MOVD ZR, 0(arg)
		p1 = gc.Ctxt.NewProg()
		gc.Clearp(p1)
		p1.Link = p.Link
		p.Link = p1
		p1.Lineno = p.Lineno
		p1.Pc = 9999

		p.As = arm64.ACBNZ
		p.To.Type = obj.TYPE_BRANCH
		p.To.Val = p1.Link

		// crash by write to memory address 0.
		p1.As = arm64.AMOVD
		p1.From.Type = obj.TYPE_REG
		p1.From.Reg = arm64.REGZERO
		p1.To.Type = obj.TYPE_MEM
		p1.To.Reg = p.From.Reg
		p1.To.Offset = 0
	}
}
Ejemplo n.º 4
0
Archivo: ggen.go Proyecto: ckeyer/gosrc
// Called after regopt and peep have run.
// Expand CHECKNIL pseudo-op into actual nil pointer check.
func expandchecks(firstp *obj.Prog) {
	var reg int
	var p1 *obj.Prog

	for p := firstp; p != nil; p = p.Link {
		if p.As != obj.ACHECKNIL {
			continue
		}
		if gc.Debug_checknil != 0 && p.Lineno > 1 { // p->lineno==1 in generated wrappers
			gc.Warnl(int(p.Lineno), "generated nil check")
		}
		if p.From.Type != obj.TYPE_REG {
			gc.Fatalf("invalid nil check %v", p)
		}
		reg = int(p.From.Reg)

		// check is
		//	CMP arg, $0
		//	MOV.EQ arg, 0(arg)
		p1 = gc.Ctxt.NewProg()

		gc.Clearp(p1)
		p1.Link = p.Link
		p.Link = p1
		p1.Lineno = p.Lineno
		p1.Pc = 9999
		p1.As = arm.AMOVW
		p1.From.Type = obj.TYPE_REG
		p1.From.Reg = int16(reg)
		p1.To.Type = obj.TYPE_MEM
		p1.To.Reg = int16(reg)
		p1.To.Offset = 0
		p1.Scond = arm.C_SCOND_EQ
		p.As = arm.ACMP
		p.From.Type = obj.TYPE_CONST
		p.From.Reg = 0
		p.From.Offset = 0
		p.Reg = int16(reg)
	}
}
Ejemplo n.º 5
0
Archivo: ggen.go Proyecto: ckeyer/gosrc
// Called after regopt and peep have run.
// Expand CHECKNIL pseudo-op into actual nil pointer check.
func expandchecks(firstp *obj.Prog) {
	var p1 *obj.Prog
	var p2 *obj.Prog

	for p := (*obj.Prog)(firstp); p != nil; p = p.Link {
		if gc.Debug_checknil != 0 && gc.Ctxt.Debugvlog != 0 {
			fmt.Printf("expandchecks: %v\n", p)
		}
		if p.As != obj.ACHECKNIL {
			continue
		}
		if gc.Debug_checknil != 0 && p.Lineno > 1 { // p->lineno==1 in generated wrappers
			gc.Warnl(int(p.Lineno), "generated nil check")
		}
		if p.From.Type != obj.TYPE_REG {
			gc.Fatalf("invalid nil check %v\n", p)
		}

		/*
			// check is
			//	TD $4, R0, arg (R0 is always zero)
			// eqv. to:
			// 	tdeq r0, arg
			// NOTE: this needs special runtime support to make SIGTRAP recoverable.
			reg = p->from.reg;
			p->as = ATD;
			p->from = p->to = p->from3 = zprog.from;
			p->from.type = TYPE_CONST;
			p->from.offset = 4;
			p->from.reg = 0;
			p->reg = REGZERO;
			p->to.type = TYPE_REG;
			p->to.reg = reg;
		*/
		// check is
		//	CMP arg, R0
		//	BNE 2(PC) [likely]
		//	MOVD R0, 0(R0)
		p1 = gc.Ctxt.NewProg()

		p2 = gc.Ctxt.NewProg()
		gc.Clearp(p1)
		gc.Clearp(p2)
		p1.Link = p2
		p2.Link = p.Link
		p.Link = p1
		p1.Lineno = p.Lineno
		p2.Lineno = p.Lineno
		p1.Pc = 9999
		p2.Pc = 9999
		p.As = ppc64.ACMP
		p.To.Type = obj.TYPE_REG
		p.To.Reg = ppc64.REGZERO
		p1.As = ppc64.ABNE

		//p1->from.type = TYPE_CONST;
		//p1->from.offset = 1; // likely
		p1.To.Type = obj.TYPE_BRANCH

		p1.To.Val = p2.Link

		// crash by write to memory address 0.
		p2.As = ppc64.AMOVD

		p2.From.Type = obj.TYPE_REG
		p2.From.Reg = ppc64.REGZERO
		p2.To.Type = obj.TYPE_MEM
		p2.To.Reg = ppc64.REGZERO
		p2.To.Offset = 0
	}
}
Ejemplo n.º 6
0
func Clearp(p *obj.Prog) {
	obj.Nopout(p)
	p.As = obj.AEND
	p.Pc = int64(pcloc)
	pcloc++
}