1 // RUN: %clang_cc1 -fsyntax-only -Wuninitialized -Wconditional-uninitialized -fsyntax-only -fblocks %s -verify
2
3 typedef __typeof(sizeof(int)) size_t;
4 void *malloc(size_t);
5
test1()6 int test1() {
7 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
8 return x; // expected-warning{{variable 'x' is uninitialized when used here}}
9 }
10
test2()11 int test2() {
12 int x = 0;
13 return x; // no-warning
14 }
15
test3()16 int test3() {
17 int x;
18 x = 0;
19 return x; // no-warning
20 }
21
test4()22 int test4() {
23 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
24 ++x; // expected-warning{{variable 'x' is uninitialized when used here}}
25 return x;
26 }
27
test5()28 int test5() {
29 int x, y; // expected-note{{initialize the variable 'y' to silence this warning}}
30 x = y; // expected-warning{{variable 'y' is uninitialized when used here}}
31 return x;
32 }
33
test6()34 int test6() {
35 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
36 x += 2; // expected-warning{{variable 'x' is uninitialized when used here}}
37 return x;
38 }
39
test7(int y)40 int test7(int y) {
41 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
42 if (y) // expected-warning{{variable 'x' is used uninitialized whenever 'if' condition is false}} \
43 // expected-note{{remove the 'if' if its condition is always true}}
44 x = 1;
45 return x; // expected-note{{uninitialized use occurs here}}
46 }
47
test7b(int y)48 int test7b(int y) {
49 int x = x; // expected-note{{variable 'x' is declared here}}
50 if (y)
51 x = 1;
52 // Warn with "may be uninitialized" here (not "is sometimes uninitialized"),
53 // since the self-initialization is intended to suppress a -Wuninitialized
54 // warning.
55 return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
56 }
57
test8(int y)58 int test8(int y) {
59 int x;
60 if (y)
61 x = 1;
62 else
63 x = 0;
64 return x;
65 }
66
test9(int n)67 int test9(int n) {
68 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
69 for (unsigned i = 0 ; i < n; ++i) {
70 if (i == n - 1)
71 break;
72 x = 1;
73 }
74 return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
75 }
76
test10(unsigned n)77 int test10(unsigned n) {
78 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
79 for (unsigned i = 0 ; i < n; ++i) {
80 x = 1;
81 }
82 return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
83 }
84
test11(unsigned n)85 int test11(unsigned n) {
86 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
87 for (unsigned i = 0 ; i <= n; ++i) {
88 x = 1;
89 }
90 return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
91 }
92
test12(unsigned n)93 void test12(unsigned n) {
94 for (unsigned i ; n ; ++i) ; // expected-warning{{variable 'i' is uninitialized when used here}} expected-note{{initialize the variable 'i' to silence this warning}}
95 }
96
test13()97 int test13() {
98 static int i;
99 return i; // no-warning
100 }
101
102 // Simply don't crash on this test case.
test14()103 void test14() {
104 const char *p = 0;
105 for (;;) {}
106 }
107
test15()108 void test15() {
109 int x = x; // no-warning: signals intended lack of initialization.
110 }
111
test15b()112 int test15b() {
113 // Warn here with the self-init, since it does result in a use of
114 // an unintialized variable and this is the root cause.
115 int x = x; // expected-warning {{variable 'x' is uninitialized when used within its own initialization}}
116 return x;
117 }
118
119 // Don't warn in the following example; shows dataflow confluence.
120 char *test16_aux();
test16()121 void test16() {
122 char *p = test16_aux();
123 for (unsigned i = 0 ; i < 100 ; i++)
124 p[i] = 'a'; // no-warning
125 }
126
test17()127 void test17() {
128 // Don't warn multiple times about the same uninitialized variable
129 // along the same path.
130 int *x; // expected-note{{initialize the variable 'x' to silence this warning}}
131 *x = 1; // expected-warning{{variable 'x' is uninitialized when used here}}
132 *x = 1; // no-warning
133 }
134
test18(int x,int y)135 int test18(int x, int y) {
136 int z;
137 if (x && y && (z = 1)) {
138 return z; // no-warning
139 }
140 return 0;
141 }
142
143 int test19_aux1();
144 int test19_aux2();
145 int test19_aux3(int *x);
test19()146 int test19() {
147 int z;
148 if (test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z))
149 return z; // no-warning
150 return 0;
151 }
152
test20()153 int test20() {
154 int z; // expected-note{{initialize the variable 'z' to silence this warning}}
155 if ((test19_aux1() + test19_aux2() && test19_aux1()) || test19_aux3(&z)) // expected-warning {{variable 'z' is used uninitialized whenever '||' condition is true}} expected-note {{remove the '||' if its condition is always false}}
156 return z; // expected-note {{uninitialized use occurs here}}
157 return 0;
158 }
159
test21(int x,int y)160 int test21(int x, int y) {
161 int z; // expected-note{{initialize the variable 'z' to silence this warning}}
162 if ((x && y) || test19_aux3(&z) || test19_aux2()) // expected-warning {{variable 'z' is used uninitialized whenever '||' condition is true}} expected-note {{remove the '||' if its condition is always false}}
163 return z; // expected-note {{uninitialized use occurs here}}
164 return 0;
165 }
166
test22()167 int test22() {
168 int z;
169 while (test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z))
170 return z; // no-warning
171 return 0;
172 }
173
test23()174 int test23() {
175 int z;
176 for ( ; test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z) ; )
177 return z; // no-warning
178 return 0;
179 }
180
181 // The basic uninitialized value analysis doesn't have enough path-sensitivity
182 // to catch initializations relying on control-dependencies spanning multiple
183 // conditionals. This possibly can be handled by making the CFG itself
184 // represent such control-dependencies, but it is a niche case.
test24(int flag)185 int test24(int flag) {
186 unsigned val; // expected-note{{initialize the variable 'val' to silence this warning}}
187 if (flag)
188 val = 1;
189 if (!flag)
190 val = 1;
191 return val; // expected-warning{{variable 'val' may be uninitialized when used here}}
192 }
193
test25()194 float test25() {
195 float x; // expected-note{{initialize the variable 'x' to silence this warning}}
196 return x; // expected-warning{{variable 'x' is uninitialized when used here}}
197 }
198
199 typedef int MyInt;
test26()200 MyInt test26() {
201 MyInt x; // expected-note{{initialize the variable 'x' to silence this warning}}
202 return x; // expected-warning{{variable 'x' is uninitialized when used here}}
203 }
204
205 // Test handling of sizeof().
test27()206 int test27() {
207 struct test_27 { int x; } *y;
208 return sizeof(y->x); // no-warning
209 }
210
test28()211 int test28() {
212 int len; // expected-note{{initialize the variable 'len' to silence this warning}}
213 return sizeof(int[len]); // expected-warning{{variable 'len' is uninitialized when used here}}
214 }
215
test29()216 void test29() {
217 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
218 (void) ^{ (void) x; }; // expected-warning{{variable 'x' is uninitialized when captured by block}}
219 }
220
test30()221 void test30() {
222 static int x; // no-warning
223 (void) ^{ (void) x; };
224 }
225
test31()226 void test31() {
227 __block int x; // no-warning
228 (void) ^{ (void) x; };
229 }
230
231 int test32_x;
test32()232 void test32() {
233 (void) ^{ (void) test32_x; }; // no-warning
234 }
235
test_33()236 void test_33() {
237 int x; // no-warning
238 (void) x;
239 }
240
test_34()241 int test_34() {
242 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
243 (void) x;
244 return x; // expected-warning{{variable 'x' is uninitialized when used here}}
245 }
246
247 // Test that this case doesn't crash.
test35(int x)248 void test35(int x) {
249 __block int y = 0;
250 ^{ y = (x == 0); }();
251 }
252
253 // Test handling of indirect goto.
test36()254 void test36()
255 {
256 void **pc; // expected-note{{initialize the variable 'pc' to silence this warning}}
257 void *dummy[] = { &&L1, &&L2 };
258 L1:
259 goto *pc; // expected-warning{{variable 'pc' is uninitialized when used here}}
260 L2:
261 goto *pc;
262 }
263
264 // Test && nested in ||.
265 int test37_a();
266 int test37_b();
test37()267 int test37()
268 {
269 int identifier;
270 if ((test37_a() && (identifier = 1)) ||
271 (test37_b() && (identifier = 2))) {
272 return identifier; // no-warning
273 }
274 return 0;
275 }
276
277 // Test merging of path-specific dataflow values (without asserting).
test38(int r,int x,int y)278 int test38(int r, int x, int y)
279 {
280 int z;
281 return ((r < 0) || ((r == 0) && (x < y)));
282 }
283
test39(int x)284 int test39(int x) {
285 int y; // expected-note{{initialize the variable 'y' to silence this warning}}
286 int z = x + y; // expected-warning {{variable 'y' is uninitialized when used here}}
287 return z;
288 }
289
290
test40(int x)291 int test40(int x) {
292 int y; // expected-note{{initialize the variable 'y' to silence this warning}}
293 return x ? 1 : y; // expected-warning {{variable 'y' is uninitialized when used here}}
294 }
295
test41(int x)296 int test41(int x) {
297 int y; // expected-note{{initialize the variable 'y' to silence this warning}}
298 if (x) y = 1; // expected-warning{{variable 'y' is used uninitialized whenever 'if' condition is false}} \
299 // expected-note{{remove the 'if' if its condition is always true}}
300 return y; // expected-note{{uninitialized use occurs here}}
301 }
302
test42()303 void test42() {
304 int a;
305 a = 30; // no-warning
306 }
307
308 void test43_aux(int x);
test43(int i)309 void test43(int i) {
310 int x; // expected-note{{initialize the variable 'x' to silence this warning}}
311 for (i = 0 ; i < 10; i++)
312 test43_aux(x++); // expected-warning {{variable 'x' is uninitialized when used here}}
313 }
314
test44(int i)315 void test44(int i) {
316 int x = i;
317 int y; // expected-note{{initialize the variable 'y' to silence this warning}}
318 for (i = 0; i < 10; i++ ) {
319 test43_aux(x++); // no-warning
320 x += y; // expected-warning {{variable 'y' is uninitialized when used here}}
321 }
322 }
323
test45(int j)324 int test45(int j) {
325 int x = 1, y = x + 1;
326 if (y) // no-warning
327 return x;
328 return y;
329 }
330
test46()331 void test46()
332 {
333 int i; // expected-note{{initialize the variable 'i' to silence this warning}}
334 int j = i ? : 1; // expected-warning {{variable 'i' is uninitialized when used here}}
335 }
336
test47(int * i)337 void *test47(int *i)
338 {
339 return i ? : 0; // no-warning
340 }
341
test49(int * i)342 void *test49(int *i)
343 {
344 int a;
345 return &a ? : i; // no-warning
346 }
347
test50()348 void test50()
349 {
350 char c[1 ? : 2]; // no-warning
351 }
352
test51(void)353 int test51(void)
354 {
355 __block int a;
356 ^(void) {
357 a = 42;
358 }();
359 return a; // no-warning
360 }
361
362 // FIXME: This is a false positive, but it tests logical operations in switch statements.
test52(int a,int b)363 int test52(int a, int b) {
364 int x; // expected-note {{initialize the variable 'x' to silence this warning}}
365 switch (a || b) { // expected-warning {{switch condition has boolean value}}
366 case 0:
367 x = 1;
368 break;
369 case 1:
370 x = 2;
371 break;
372 }
373 return x; // expected-warning {{variable 'x' may be uninitialized when used here}}
374 }
375
test53()376 void test53() {
377 int x; // expected-note {{initialize the variable 'x' to silence this warning}}
378 int y = (x); // expected-warning {{variable 'x' is uninitialized when used here}}
379 }
380
381 // This CFG caused the uninitialized values warning to inf-loop.
382 extern int PR10379_g();
PR10379_f(int * len)383 void PR10379_f(int *len) {
384 int new_len; // expected-note{{initialize the variable 'new_len' to silence this warning}}
385 for (int i = 0; i < 42 && PR10379_g() == 0; i++) {
386 if (PR10379_g() == 1)
387 continue;
388 if (PR10379_g() == 2)
389 PR10379_f(&new_len);
390 else if (PR10379_g() == 3)
391 PR10379_f(&new_len);
392 *len += new_len; // expected-warning {{variable 'new_len' may be uninitialized when used here}}
393 }
394 }
395
396 // Test that sizeof(VLA) doesn't trigger a warning.
test_vla_sizeof(int x)397 void test_vla_sizeof(int x) {
398 double (*memory)[2][x] = malloc(sizeof(*memory)); // no-warning
399 }
400
401 // Test absurd case of deadcode + use of blocks. This previously was a false positive
402 // due to an analysis bug.
test_block_and_dead_code()403 int test_block_and_dead_code() {
404 __block int x;
405 ^{ x = 1; }();
406 if (0)
407 return x;
408 return x; // no-warning
409 }
410
411 // This previously triggered an infinite loop in the analysis.
PR11069(int a,int b)412 void PR11069(int a, int b) {
413 unsigned long flags;
414 for (;;) {
415 if (a && !b)
416 break;
417 }
418 for (;;) {
419 // This does not trigger a warning because it isn't a real use.
420 (void)(flags); // no-warning
421 }
422 }
423
424 // Test uninitialized value used in loop condition.
rdar9432305(float * P)425 void rdar9432305(float *P) {
426 int i; // expected-note {{initialize the variable 'i' to silence this warning}}
427 for (; i < 10000; ++i) // expected-warning {{variable 'i' is uninitialized when used here}}
428 P[i] = 0.0f;
429 }
430
431 // Test that fixits are not emitted inside macros.
432 #define UNINIT(T, x, y) T x; T y = x;
433 #define ASSIGN(T, x, y) T y = x;
test54()434 void test54() {
435 UNINIT(int, a, b); // expected-warning {{variable 'a' is uninitialized when used here}} \
436 // expected-note {{variable 'a' is declared here}}
437 int c; // expected-note {{initialize the variable 'c' to silence this warning}}
438 ASSIGN(int, c, d); // expected-warning {{variable 'c' is uninitialized when used here}}
439 }
440
441 // Taking the address is fine
442 struct { struct { void *p; } a; } test55 = { { &test55.a }}; // no-warning
443 struct { struct { void *p; } a; } test56 = { { &(test56.a) }}; // no-warning
444
uninit_in_loop()445 void uninit_in_loop() {
446 int produce(void);
447 void consume(int);
448 for (int n = 0; n < 100; ++n) {
449 int k; // expected-note {{initialize}}
450 consume(k); // expected-warning {{variable 'k' is uninitialized}}
451 k = produce();
452 }
453 }
454
uninit_in_loop_goto()455 void uninit_in_loop_goto() {
456 int produce(void);
457 void consume(int);
458 for (int n = 0; n < 100; ++n) {
459 goto skip_decl;
460 int k; // expected-note {{initialize}}
461 skip_decl:
462 // FIXME: This should produce the 'is uninitialized' diagnostic, but we
463 // don't have enough information in the CFG to easily tell that the
464 // variable's scope has been left and re-entered.
465 consume(k); // expected-warning {{variable 'k' may be uninitialized}}
466 k = produce();
467 }
468 }
469
470 typedef char jmp_buf[256];
471 extern int setjmp(jmp_buf env); // implicitly returns_twice
472
473 void do_stuff_and_longjmp(jmp_buf env, int *result) __attribute__((noreturn));
474
returns_twice()475 int returns_twice() {
476 int a; // expected-note {{initialize}}
477 if (!a) { // expected-warning {{variable 'a' is uninitialized}}
478 jmp_buf env;
479 int b;
480 if (setjmp(env) == 0) {
481 do_stuff_and_longjmp(env, &b);
482 } else {
483 a = b; // no warning
484 }
485 }
486 return a;
487 }
488
compound_assign(int * arr,int n)489 int compound_assign(int *arr, int n) {
490 int sum; // expected-note {{initialize}}
491 for (int i = 0; i < n; ++i)
492 sum += arr[i]; // expected-warning {{variable 'sum' is uninitialized}}
493 return sum / n;
494 }
495
compound_assign_2()496 int compound_assign_2() {
497 int x; // expected-note {{initialize}}
498 return x += 1; // expected-warning {{variable 'x' is uninitialized}}
499 }
500
compound_assign_3()501 int compound_assign_3() {
502 int x; // expected-note {{initialize}}
503 x *= 0; // expected-warning {{variable 'x' is uninitialized}}
504 return x;
505 }
506
self_init_in_cond(int * p)507 int self_init_in_cond(int *p) {
508 int n = ((p && (0 || 1)) && (n = *p)) ? n : -1; // ok
509 return n;
510 }
511
512 void test_analyzer_noreturn_aux() __attribute__((analyzer_noreturn));
513
test_analyzer_noreturn(int y)514 void test_analyzer_noreturn(int y) {
515 int x; // expected-note {{initialize the variable 'x' to silence this warning}}
516 if (y) {
517 test_analyzer_noreturn_aux();
518 ++x; // no-warning
519 }
520 else {
521 ++x; // expected-warning {{variable 'x' is uninitialized when used here}}
522 }
523 }
test_analyzer_noreturn_2(int y)524 void test_analyzer_noreturn_2(int y) {
525 int x;
526 if (y) {
527 test_analyzer_noreturn_aux();
528 }
529 else {
530 x = 1;
531 }
532 ++x; // no-warning
533 }
534