| // errorcheck -0 -m -l | 
 |  | 
 | // Copyright 2015 The Go Authors. All rights reserved. | 
 | // Use of this source code is governed by a BSD-style | 
 | // license that can be found in the LICENSE file. | 
 |  | 
 | // Test escape analysis for struct function parameters. | 
 | // Note companion strict_param1 checks *struct function parameters with similar tests. | 
 |  | 
 | package notmain | 
 |  | 
 | var Ssink *string | 
 |  | 
 | type U struct { | 
 | 	_sp  *string | 
 | 	_spp **string | 
 | } | 
 |  | 
 | type V struct { | 
 | 	_u   U | 
 | 	_up  *U | 
 | 	_upp **U | 
 | } | 
 |  | 
 | func (u U) SP() *string { // ERROR "leaking param: u to result ~r0 level=0$" | 
 | 	return u._sp | 
 | } | 
 |  | 
 | func (u U) SPP() **string { // ERROR "leaking param: u to result ~r0 level=0$" | 
 | 	return u._spp | 
 | } | 
 |  | 
 | func (u U) SPPi() *string { // ERROR "leaking param: u to result ~r0 level=1$" | 
 | 	return *u._spp | 
 | } | 
 |  | 
 | func tSPPi() { | 
 | 	s := "cat" // ERROR "moved to heap: s$" | 
 | 	ps := &s | 
 | 	pps := &ps | 
 | 	pu := &U{ps, pps} // ERROR "&U{...} does not escape$" | 
 | 	Ssink = pu.SPPi() | 
 | } | 
 |  | 
 | func tiSPP() { | 
 | 	s := "cat" // ERROR "moved to heap: s$" | 
 | 	ps := &s | 
 | 	pps := &ps | 
 | 	pu := &U{ps, pps} // ERROR "&U{...} does not escape$" | 
 | 	Ssink = *pu.SPP() | 
 | } | 
 |  | 
 | // BAD: need fine-grained analysis to avoid spurious escape of ps | 
 | func tSP() { | 
 | 	s := "cat" // ERROR "moved to heap: s$" | 
 | 	ps := &s   // ERROR "moved to heap: ps$" | 
 | 	pps := &ps | 
 | 	pu := &U{ps, pps} // ERROR "&U{...} does not escape$" | 
 | 	Ssink = pu.SP() | 
 | } | 
 |  | 
 | func (v V) u() U { // ERROR "leaking param: v to result ~r0 level=0$" | 
 | 	return v._u | 
 | } | 
 |  | 
 | func (v V) UP() *U { // ERROR "leaking param: v to result ~r0 level=0$" | 
 | 	return v._up | 
 | } | 
 |  | 
 | func (v V) UPP() **U { // ERROR "leaking param: v to result ~r0 level=0$" | 
 | 	return v._upp | 
 | } | 
 |  | 
 | func (v V) UPPia() *U { // ERROR "leaking param: v to result ~r0 level=1$" | 
 | 	return *v._upp | 
 | } | 
 |  | 
 | func (v V) UPPib() *U { // ERROR "leaking param: v to result ~r0 level=1$" | 
 | 	return *v.UPP() | 
 | } | 
 |  | 
 | func (v V) USPa() *string { // ERROR "leaking param: v to result ~r0 level=0$" | 
 | 	return v._u._sp | 
 | } | 
 |  | 
 | func (v V) USPb() *string { // ERROR "leaking param: v to result ~r0 level=0$" | 
 | 	return v.u()._sp | 
 | } | 
 |  | 
 | func (v V) USPPia() *string { // ERROR "leaking param: v to result ~r0 level=1$" | 
 | 	return *v._u._spp | 
 | } | 
 |  | 
 | func (v V) USPPib() *string { // ERROR "leaking param: v to result ~r0 level=1$" | 
 | 	return v._u.SPPi() | 
 | } | 
 |  | 
 | func (v V) UPiSPa() *string { // ERROR "leaking param: v to result ~r0 level=1$" | 
 | 	return v._up._sp | 
 | } | 
 |  | 
 | func (v V) UPiSPb() *string { // ERROR "leaking param: v to result ~r0 level=1$" | 
 | 	return v._up.SP() | 
 | } | 
 |  | 
 | func (v V) UPiSPc() *string { // ERROR "leaking param: v to result ~r0 level=1$" | 
 | 	return v.UP()._sp | 
 | } | 
 |  | 
 | func (v V) UPiSPd() *string { // ERROR "leaking param: v to result ~r0 level=1$" | 
 | 	return v.UP().SP() | 
 | } | 
 |  | 
 | // BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 | 
 | func tUPiSPa() { | 
 | 	s1 := "ant" | 
 | 	s2 := "bat" // ERROR "moved to heap: s2$" | 
 | 	s3 := "cat" // ERROR "moved to heap: s3$" | 
 | 	s4 := "dog" // ERROR "moved to heap: s4$" | 
 | 	s5 := "emu" // ERROR "moved to heap: s5$" | 
 | 	s6 := "fox" // ERROR "moved to heap: s6$" | 
 | 	ps2 := &s2 | 
 | 	ps4 := &s4 // ERROR "moved to heap: ps4$" | 
 | 	ps6 := &s6 // ERROR "moved to heap: ps6$" | 
 | 	u1 := U{&s1, &ps2} | 
 | 	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$" | 
 | 	u3 := &U{&s5, &ps6}  // ERROR "&U{...} escapes to heap$" | 
 | 	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$" | 
 | 	Ssink = v.UPiSPa()   // Ssink = &s3 (only &s3 really escapes) | 
 | } | 
 |  | 
 | // BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 | 
 | func tUPiSPb() { | 
 | 	s1 := "ant" | 
 | 	s2 := "bat" // ERROR "moved to heap: s2$" | 
 | 	s3 := "cat" // ERROR "moved to heap: s3$" | 
 | 	s4 := "dog" // ERROR "moved to heap: s4$" | 
 | 	s5 := "emu" // ERROR "moved to heap: s5$" | 
 | 	s6 := "fox" // ERROR "moved to heap: s6$" | 
 | 	ps2 := &s2 | 
 | 	ps4 := &s4 // ERROR "moved to heap: ps4$" | 
 | 	ps6 := &s6 // ERROR "moved to heap: ps6$" | 
 | 	u1 := U{&s1, &ps2} | 
 | 	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$" | 
 | 	u3 := &U{&s5, &ps6}  // ERROR "&U{...} escapes to heap$" | 
 | 	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$" | 
 | 	Ssink = v.UPiSPb()   // Ssink = &s3 (only &s3 really escapes) | 
 | } | 
 |  | 
 | // BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 | 
 | func tUPiSPc() { | 
 | 	s1 := "ant" | 
 | 	s2 := "bat" // ERROR "moved to heap: s2$" | 
 | 	s3 := "cat" // ERROR "moved to heap: s3$" | 
 | 	s4 := "dog" // ERROR "moved to heap: s4$" | 
 | 	s5 := "emu" // ERROR "moved to heap: s5$" | 
 | 	s6 := "fox" // ERROR "moved to heap: s6$" | 
 | 	ps2 := &s2 | 
 | 	ps4 := &s4 // ERROR "moved to heap: ps4$" | 
 | 	ps6 := &s6 // ERROR "moved to heap: ps6$" | 
 | 	u1 := U{&s1, &ps2} | 
 | 	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$" | 
 | 	u3 := &U{&s5, &ps6}  // ERROR "&U{...} escapes to heap$" | 
 | 	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$" | 
 | 	Ssink = v.UPiSPc()   // Ssink = &s3 (only &s3 really escapes) | 
 | } | 
 |  | 
 | // BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3 | 
 | func tUPiSPd() { | 
 | 	s1 := "ant" | 
 | 	s2 := "bat" // ERROR "moved to heap: s2$" | 
 | 	s3 := "cat" // ERROR "moved to heap: s3$" | 
 | 	s4 := "dog" // ERROR "moved to heap: s4$" | 
 | 	s5 := "emu" // ERROR "moved to heap: s5$" | 
 | 	s6 := "fox" // ERROR "moved to heap: s6$" | 
 | 	ps2 := &s2 | 
 | 	ps4 := &s4 // ERROR "moved to heap: ps4$" | 
 | 	ps6 := &s6 // ERROR "moved to heap: ps6$" | 
 | 	u1 := U{&s1, &ps2} | 
 | 	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$" | 
 | 	u3 := &U{&s5, &ps6}  // ERROR "&U{...} escapes to heap$" | 
 | 	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$" | 
 | 	Ssink = v.UPiSPd()   // Ssink = &s3 (only &s3 really escapes) | 
 | } | 
 |  | 
 | func (v V) UPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=2$" | 
 | 	return *v._up._spp | 
 | } | 
 |  | 
 | func (v V) UPiSPPib() *string { // ERROR "leaking param: v to result ~r0 level=2$" | 
 | 	return v._up.SPPi() | 
 | } | 
 |  | 
 | func (v V) UPiSPPic() *string { // ERROR "leaking param: v to result ~r0 level=2$" | 
 | 	return *v.UP()._spp | 
 | } | 
 |  | 
 | func (v V) UPiSPPid() *string { // ERROR "leaking param: v to result ~r0 level=2$" | 
 | 	return v.UP().SPPi() | 
 | } | 
 |  | 
 | // BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 | 
 | func tUPiSPPia() { | 
 | 	s1 := "ant" | 
 | 	s2 := "bat" | 
 | 	s3 := "cat" | 
 | 	s4 := "dog" // ERROR "moved to heap: s4$" | 
 | 	s5 := "emu" // ERROR "moved to heap: s5$" | 
 | 	s6 := "fox" // ERROR "moved to heap: s6$" | 
 | 	ps2 := &s2 | 
 | 	ps4 := &s4 | 
 | 	ps6 := &s6 // ERROR "moved to heap: ps6$" | 
 | 	u1 := U{&s1, &ps2} | 
 | 	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$" | 
 | 	u3 := &U{&s5, &ps6}  // ERROR "&U{...} does not escape$" | 
 | 	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$" | 
 | 	Ssink = v.UPiSPPia() // Ssink = *&ps4 = &s4 (only &s4 really escapes) | 
 | } | 
 |  | 
 | // BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 | 
 | func tUPiSPPib() { | 
 | 	s1 := "ant" | 
 | 	s2 := "bat" | 
 | 	s3 := "cat" | 
 | 	s4 := "dog" // ERROR "moved to heap: s4$" | 
 | 	s5 := "emu" // ERROR "moved to heap: s5$" | 
 | 	s6 := "fox" // ERROR "moved to heap: s6$" | 
 | 	ps2 := &s2 | 
 | 	ps4 := &s4 | 
 | 	ps6 := &s6 // ERROR "moved to heap: ps6$" | 
 | 	u1 := U{&s1, &ps2} | 
 | 	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$" | 
 | 	u3 := &U{&s5, &ps6}  // ERROR "&U{...} does not escape$" | 
 | 	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$" | 
 | 	Ssink = v.UPiSPPib() // Ssink = *&ps4 = &s4 (only &s4 really escapes) | 
 | } | 
 |  | 
 | // BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 | 
 | func tUPiSPPic() { | 
 | 	s1 := "ant" | 
 | 	s2 := "bat" | 
 | 	s3 := "cat" | 
 | 	s4 := "dog" // ERROR "moved to heap: s4$" | 
 | 	s5 := "emu" // ERROR "moved to heap: s5$" | 
 | 	s6 := "fox" // ERROR "moved to heap: s6$" | 
 | 	ps2 := &s2 | 
 | 	ps4 := &s4 | 
 | 	ps6 := &s6 // ERROR "moved to heap: ps6$" | 
 | 	u1 := U{&s1, &ps2} | 
 | 	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$" | 
 | 	u3 := &U{&s5, &ps6}  // ERROR "&U{...} does not escape$" | 
 | 	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$" | 
 | 	Ssink = v.UPiSPPic() // Ssink = *&ps4 = &s4 (only &s4 really escapes) | 
 | } | 
 |  | 
 | // BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4 | 
 | func tUPiSPPid() { | 
 | 	s1 := "ant" | 
 | 	s2 := "bat" | 
 | 	s3 := "cat" | 
 | 	s4 := "dog" // ERROR "moved to heap: s4$" | 
 | 	s5 := "emu" // ERROR "moved to heap: s5$" | 
 | 	s6 := "fox" // ERROR "moved to heap: s6$" | 
 | 	ps2 := &s2 | 
 | 	ps4 := &s4 | 
 | 	ps6 := &s6 // ERROR "moved to heap: ps6$" | 
 | 	u1 := U{&s1, &ps2} | 
 | 	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$" | 
 | 	u3 := &U{&s5, &ps6}  // ERROR "&U{...} does not escape$" | 
 | 	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$" | 
 | 	Ssink = v.UPiSPPid() // Ssink = *&ps4 = &s4 (only &s4 really escapes) | 
 | } | 
 |  | 
 | func (v V) UPPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=3$" | 
 | 	return *(*v._upp)._spp | 
 | } | 
 |  | 
 | // This test isolates the one value that needs to escape, not because | 
 | // it distinguishes fields but because it knows that &s6 is the only | 
 | // value reachable by two indirects from v. | 
 | // The test depends on the level cap in the escape analysis tags | 
 | // being able to encode that fact. | 
 | func tUPPiSPPia() { // This test is sensitive to the level cap in function summary results. | 
 | 	s1 := "ant" | 
 | 	s2 := "bat" | 
 | 	s3 := "cat" | 
 | 	s4 := "dog" | 
 | 	s5 := "emu" | 
 | 	s6 := "fox" // ERROR "moved to heap: s6$" | 
 | 	ps2 := &s2 | 
 | 	ps4 := &s4 | 
 | 	ps6 := &s6 | 
 | 	u1 := U{&s1, &ps2} | 
 | 	u2 := &U{&s3, &ps4}   // ERROR "&U{...} does not escape$" | 
 | 	u3 := &U{&s5, &ps6}   // ERROR "&U{...} does not escape$" | 
 | 	v := &V{u1, u2, &u3}  // ERROR "&V{...} does not escape$" | 
 | 	Ssink = v.UPPiSPPia() // Ssink = *&ps6 = &s6 (only &s6 really escapes) | 
 | } |