1// errorcheck -0 -m -l
2
3// Copyright 2015 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7// Test escape analysis for struct function parameters.
8// Note companion strict_param1 checks *struct function parameters with similar tests.
9
10package notmain
11
12var Ssink *string
13
14type U struct {
15	_sp  *string
16	_spp **string
17}
18
19type V struct {
20	_u   U
21	_up  *U
22	_upp **U
23}
24
25func (u U) SP() *string { // ERROR "leaking param: u to result ~r0 level=0$"
26	return u._sp
27}
28
29func (u U) SPP() **string { // ERROR "leaking param: u to result ~r0 level=0$"
30	return u._spp
31}
32
33func (u U) SPPi() *string { // ERROR "leaking param: u to result ~r0 level=1$"
34	return *u._spp
35}
36
37func tSPPi() {
38	s := "cat" // ERROR "moved to heap: s$"
39	ps := &s
40	pps := &ps
41	pu := &U{ps, pps} // ERROR "&U{...} does not escape$"
42	Ssink = pu.SPPi()
43}
44
45func tiSPP() {
46	s := "cat" // ERROR "moved to heap: s$"
47	ps := &s
48	pps := &ps
49	pu := &U{ps, pps} // ERROR "&U{...} does not escape$"
50	Ssink = *pu.SPP()
51}
52
53// BAD: need fine-grained analysis to avoid spurious escape of ps
54func tSP() {
55	s := "cat" // ERROR "moved to heap: s$"
56	ps := &s   // ERROR "moved to heap: ps$"
57	pps := &ps
58	pu := &U{ps, pps} // ERROR "&U{...} does not escape$"
59	Ssink = pu.SP()
60}
61
62func (v V) u() U { // ERROR "leaking param: v to result ~r0 level=0$"
63	return v._u
64}
65
66func (v V) UP() *U { // ERROR "leaking param: v to result ~r0 level=0$"
67	return v._up
68}
69
70func (v V) UPP() **U { // ERROR "leaking param: v to result ~r0 level=0$"
71	return v._upp
72}
73
74func (v V) UPPia() *U { // ERROR "leaking param: v to result ~r0 level=1$"
75	return *v._upp
76}
77
78func (v V) UPPib() *U { // ERROR "leaking param: v to result ~r0 level=1$"
79	return *v.UPP()
80}
81
82func (v V) USPa() *string { // ERROR "leaking param: v to result ~r0 level=0$"
83	return v._u._sp
84}
85
86func (v V) USPb() *string { // ERROR "leaking param: v to result ~r0 level=0$"
87	return v.u()._sp
88}
89
90func (v V) USPPia() *string { // ERROR "leaking param: v to result ~r0 level=1$"
91	return *v._u._spp
92}
93
94func (v V) USPPib() *string { // ERROR "leaking param: v to result ~r0 level=1$"
95	return v._u.SPPi()
96}
97
98func (v V) UPiSPa() *string { // ERROR "leaking param: v to result ~r0 level=1$"
99	return v._up._sp
100}
101
102func (v V) UPiSPb() *string { // ERROR "leaking param: v to result ~r0 level=1$"
103	return v._up.SP()
104}
105
106func (v V) UPiSPc() *string { // ERROR "leaking param: v to result ~r0 level=1$"
107	return v.UP()._sp
108}
109
110func (v V) UPiSPd() *string { // ERROR "leaking param: v to result ~r0 level=1$"
111	return v.UP().SP()
112}
113
114// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3
115func tUPiSPa() {
116	s1 := "ant"
117	s2 := "bat" // ERROR "moved to heap: s2$"
118	s3 := "cat" // ERROR "moved to heap: s3$"
119	s4 := "dog" // ERROR "moved to heap: s4$"
120	s5 := "emu" // ERROR "moved to heap: s5$"
121	s6 := "fox" // ERROR "moved to heap: s6$"
122	ps2 := &s2
123	ps4 := &s4 // ERROR "moved to heap: ps4$"
124	ps6 := &s6 // ERROR "moved to heap: ps6$"
125	u1 := U{&s1, &ps2}
126	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$"
127	u3 := &U{&s5, &ps6}  // ERROR "&U{...} escapes to heap$"
128	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$"
129	Ssink = v.UPiSPa()   // Ssink = &s3 (only &s3 really escapes)
130}
131
132// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3
133func tUPiSPb() {
134	s1 := "ant"
135	s2 := "bat" // ERROR "moved to heap: s2$"
136	s3 := "cat" // ERROR "moved to heap: s3$"
137	s4 := "dog" // ERROR "moved to heap: s4$"
138	s5 := "emu" // ERROR "moved to heap: s5$"
139	s6 := "fox" // ERROR "moved to heap: s6$"
140	ps2 := &s2
141	ps4 := &s4 // ERROR "moved to heap: ps4$"
142	ps6 := &s6 // ERROR "moved to heap: ps6$"
143	u1 := U{&s1, &ps2}
144	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$"
145	u3 := &U{&s5, &ps6}  // ERROR "&U{...} escapes to heap$"
146	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$"
147	Ssink = v.UPiSPb()   // Ssink = &s3 (only &s3 really escapes)
148}
149
150// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3
151func tUPiSPc() {
152	s1 := "ant"
153	s2 := "bat" // ERROR "moved to heap: s2$"
154	s3 := "cat" // ERROR "moved to heap: s3$"
155	s4 := "dog" // ERROR "moved to heap: s4$"
156	s5 := "emu" // ERROR "moved to heap: s5$"
157	s6 := "fox" // ERROR "moved to heap: s6$"
158	ps2 := &s2
159	ps4 := &s4 // ERROR "moved to heap: ps4$"
160	ps6 := &s6 // ERROR "moved to heap: ps6$"
161	u1 := U{&s1, &ps2}
162	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$"
163	u3 := &U{&s5, &ps6}  // ERROR "&U{...} escapes to heap$"
164	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$"
165	Ssink = v.UPiSPc()   // Ssink = &s3 (only &s3 really escapes)
166}
167
168// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s3
169func tUPiSPd() {
170	s1 := "ant"
171	s2 := "bat" // ERROR "moved to heap: s2$"
172	s3 := "cat" // ERROR "moved to heap: s3$"
173	s4 := "dog" // ERROR "moved to heap: s4$"
174	s5 := "emu" // ERROR "moved to heap: s5$"
175	s6 := "fox" // ERROR "moved to heap: s6$"
176	ps2 := &s2
177	ps4 := &s4 // ERROR "moved to heap: ps4$"
178	ps6 := &s6 // ERROR "moved to heap: ps6$"
179	u1 := U{&s1, &ps2}
180	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$"
181	u3 := &U{&s5, &ps6}  // ERROR "&U{...} escapes to heap$"
182	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$"
183	Ssink = v.UPiSPd()   // Ssink = &s3 (only &s3 really escapes)
184}
185
186func (v V) UPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=2$"
187	return *v._up._spp
188}
189
190func (v V) UPiSPPib() *string { // ERROR "leaking param: v to result ~r0 level=2$"
191	return v._up.SPPi()
192}
193
194func (v V) UPiSPPic() *string { // ERROR "leaking param: v to result ~r0 level=2$"
195	return *v.UP()._spp
196}
197
198func (v V) UPiSPPid() *string { // ERROR "leaking param: v to result ~r0 level=2$"
199	return v.UP().SPPi()
200}
201
202// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4
203func tUPiSPPia() {
204	s1 := "ant"
205	s2 := "bat"
206	s3 := "cat"
207	s4 := "dog" // ERROR "moved to heap: s4$"
208	s5 := "emu" // ERROR "moved to heap: s5$"
209	s6 := "fox" // ERROR "moved to heap: s6$"
210	ps2 := &s2
211	ps4 := &s4
212	ps6 := &s6 // ERROR "moved to heap: ps6$"
213	u1 := U{&s1, &ps2}
214	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$"
215	u3 := &U{&s5, &ps6}  // ERROR "&U{...} does not escape$"
216	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$"
217	Ssink = v.UPiSPPia() // Ssink = *&ps4 = &s4 (only &s4 really escapes)
218}
219
220// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4
221func tUPiSPPib() {
222	s1 := "ant"
223	s2 := "bat"
224	s3 := "cat"
225	s4 := "dog" // ERROR "moved to heap: s4$"
226	s5 := "emu" // ERROR "moved to heap: s5$"
227	s6 := "fox" // ERROR "moved to heap: s6$"
228	ps2 := &s2
229	ps4 := &s4
230	ps6 := &s6 // ERROR "moved to heap: ps6$"
231	u1 := U{&s1, &ps2}
232	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$"
233	u3 := &U{&s5, &ps6}  // ERROR "&U{...} does not escape$"
234	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$"
235	Ssink = v.UPiSPPib() // Ssink = *&ps4 = &s4 (only &s4 really escapes)
236}
237
238// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4
239func tUPiSPPic() {
240	s1 := "ant"
241	s2 := "bat"
242	s3 := "cat"
243	s4 := "dog" // ERROR "moved to heap: s4$"
244	s5 := "emu" // ERROR "moved to heap: s5$"
245	s6 := "fox" // ERROR "moved to heap: s6$"
246	ps2 := &s2
247	ps4 := &s4
248	ps6 := &s6 // ERROR "moved to heap: ps6$"
249	u1 := U{&s1, &ps2}
250	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$"
251	u3 := &U{&s5, &ps6}  // ERROR "&U{...} does not escape$"
252	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$"
253	Ssink = v.UPiSPPic() // Ssink = *&ps4 = &s4 (only &s4 really escapes)
254}
255
256// BAD: need fine-grained (field-sensitive) analysis to avoid spurious escape of all but &s4
257func tUPiSPPid() {
258	s1 := "ant"
259	s2 := "bat"
260	s3 := "cat"
261	s4 := "dog" // ERROR "moved to heap: s4$"
262	s5 := "emu" // ERROR "moved to heap: s5$"
263	s6 := "fox" // ERROR "moved to heap: s6$"
264	ps2 := &s2
265	ps4 := &s4
266	ps6 := &s6 // ERROR "moved to heap: ps6$"
267	u1 := U{&s1, &ps2}
268	u2 := &U{&s3, &ps4}  // ERROR "&U{...} does not escape$"
269	u3 := &U{&s5, &ps6}  // ERROR "&U{...} does not escape$"
270	v := &V{u1, u2, &u3} // ERROR "&V{...} does not escape$"
271	Ssink = v.UPiSPPid() // Ssink = *&ps4 = &s4 (only &s4 really escapes)
272}
273
274func (v V) UPPiSPPia() *string { // ERROR "leaking param: v to result ~r0 level=3$"
275	return *(*v._upp)._spp
276}
277
278// This test isolates the one value that needs to escape, not because
279// it distinguishes fields but because it knows that &s6 is the only
280// value reachable by two indirects from v.
281// The test depends on the level cap in the escape analysis tags
282// being able to encode that fact.
283func tUPPiSPPia() { // This test is sensitive to the level cap in function summary results.
284	s1 := "ant"
285	s2 := "bat"
286	s3 := "cat"
287	s4 := "dog"
288	s5 := "emu"
289	s6 := "fox" // ERROR "moved to heap: s6$"
290	ps2 := &s2
291	ps4 := &s4
292	ps6 := &s6
293	u1 := U{&s1, &ps2}
294	u2 := &U{&s3, &ps4}   // ERROR "&U{...} does not escape$"
295	u3 := &U{&s5, &ps6}   // ERROR "&U{...} does not escape$"
296	v := &V{u1, u2, &u3}  // ERROR "&V{...} does not escape$"
297	Ssink = v.UPPiSPPia() // Ssink = *&ps6 = &s6 (only &s6 really escapes)
298}
299