}

type ContextStub struct {
	context
}

func (c ContextStub) GetPC() uintptr {
	return c.ip()
}

func NewContextStub() *ContextStub {
	var ctx context
	ctx.set_ip(getcallerpc())
	ctx.set_sp(getcallersp())
	ctx.set_fp(getcallerfp())
	return &ContextStub{ctx}

// 386 does not have link register, so this returns 0.
func (c *context) lr() uintptr      { return 0 }
func (c *context) set_lr(x uintptr) {}

func (c *context) set_ip(x uintptr) { c.eip = uint32(x) }
func (c *context) set_sp(x uintptr) { c.esp = uint32(x) }

// 386 does not have frame pointer register.
func (c *context) set_fp(x uintptr) {}

func prepareContextForSigResume(c *context) {
	c.edx = c.esp
	c.ecx = c.eip
}

func (c *context) lr() uintptr { return uintptr(c.lrr) }

func (c *context) set_ip(x uintptr) { c.pc = uint32(x) }
func (c *context) set_sp(x uintptr) { c.spr = uint32(x) }
func (c *context) set_lr(x uintptr) { c.lrr = uint32(x) }

// arm does not have frame pointer register.
func (c *context) set_fp(x uintptr) {}

func prepareContextForSigResume(c *context) {
	c.r0 = c.spr
	c.r1 = c.pc
}

// AMD64 does not have link register, so this returns 0.
func (c *context) lr() uintptr      { return 0 }
func (c *context) set_lr(x uintptr) {}

func (c *context) set_ip(x uintptr) { c.rip = uint64(x) }
func (c *context) set_sp(x uintptr) { c.rsp = uint64(x) }
func (c *context) set_fp(x uintptr) { c.rbp = uint64(x) }

func prepareContextForSigResume(c *context) {
	c.r8 = c.rsp
	c.r9 = c.rip
}

func (c *context) sp() uintptr { return uintptr(c.xsp) }
func (c *context) lr() uintptr { return uintptr(c.x[30]) }

func (c *context) set_ip(x uintptr) { c.pc = uint64(x) }
func (c *context) set_sp(x uintptr) { c.xsp = uint64(x) }
func (c *context) set_lr(x uintptr) { c.x[30] = uint64(x) }
func (c *context) set_fp(x uintptr) { c.x[29] = uint64(x) }

func prepareContextForSigResume(c *context) {
	c.x[0] = c.xsp
	c.x[1] = c.pc
}

func (c *sigctxt) sigaddr() uint64 { return c.info.si_addr }

func (c *sigctxt) set_pc(x uint64) { c.regs().sc_regs.pc = x }
func (c *sigctxt) set_ra(x uint64) { c.regs().sc_regs.ra = x }
func (c *sigctxt) set_sp(x uint64) { c.regs().sc_regs.sp = x }
func (c *sigctxt) set_gp(x uint64) { c.regs().sc_regs.gp = x }

func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }

func (c *sigctxt) sigaddr() uint64 { return c.info.si_addr }

func (c *sigctxt) set_pc(x uint64) { c.regs().mc_gpregs.gp_sepc = x }
func (c *sigctxt) set_ra(x uint64) { c.regs().mc_gpregs.gp_ra = x }
func (c *sigctxt) set_sp(x uint64) { c.regs().mc_gpregs.gp_sp = x }
func (c *sigctxt) set_gp(x uint64) { c.regs().mc_gpregs.gp_gp = x }

func (c *sigctxt) set_sigcode(x uint64) { c.info.si_code = int32(x) }

	reason := *(*string)(unsafe.Pointer(uintptr(sp) + 8))
	h.err = plainError(reason)
	ctxt.set_pc(ctxt.pc() + 4)
}

// case 16
func (h *debugCallHandler) restoreSigContext(ctxt *sigctxt) {
	// Restore all registers except for pc and sp
	pc, sp := ctxt.pc(), ctxt.sp()
	*ctxt.regs() = h.sigCtxt.savedRegs
	ctxt.set_pc(pc + 4)
	ctxt.set_sp(sp)
}

// storeRegArgs sets up argument registers in the signal

	// anyway.
	sp := c.sp() - 4
	c.set_sp(sp)
	*(*uint32)(unsafe.Pointer(uintptr(sp))) = c.lr()

	pc := gp.sigpc

	if shouldPushSigpanic(gp, pc, uintptr(c.lr())) {
		// Make it look the like faulting PC called sigpanic.
		c.set_lr(uint32(pc))
	}

	// In case we are panicking from external C code
	c.set_r10(uint32(uintptr(unsafe.Pointer(gp))))
	c.set_pc(uint32(abi.FuncPCABIInternal(sigpanic)))
}

func (c *sigctxt) sigaddr() uint64 {
	return *(*uint64)(add(unsafe.Pointer(c.info), 2*goarch.PtrSize))
}

func (c *sigctxt) set_pc(x uint64) { c.regs().sc_sepc = uintptr(x) }
func (c *sigctxt) set_ra(x uint64) { c.regs().sc_ra = uintptr(x) }
func (c *sigctxt) set_sp(x uint64) { c.regs().sc_sp = uintptr(x) }
func (c *sigctxt) set_gp(x uint64) { c.regs().sc_gp = uintptr(x) }

func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }