1 // RUN: %clang_cc1 -analyze -analyzer-checker=core,unix.cstring,alpha.unix.cstring,debug.ExprInspection -analyzer-store=region -Wno-null-dereference -verify %s
2 // RUN: %clang_cc1 -analyze -DUSE_BUILTINS -analyzer-checker=core,unix.cstring,alpha.unix.cstring,debug.ExprInspection -analyzer-store=region -Wno-null-dereference -verify %s
3 // RUN: %clang_cc1 -analyze -DVARIANT -analyzer-checker=core,unix.cstring,alpha.unix.cstring,debug.ExprInspection -analyzer-store=region -Wno-null-dereference -verify %s
4 // RUN: %clang_cc1 -analyze -DUSE_BUILTINS -DVARIANT -analyzer-checker=alpha.security.taint,core,unix.cstring,alpha.unix.cstring,debug.ExprInspection -analyzer-store=region -Wno-null-dereference -verify %s
5 
6 //===----------------------------------------------------------------------===
7 // Declarations
8 //===----------------------------------------------------------------------===
9 
10 // Some functions are so similar to each other that they follow the same code
11 // path, such as memcpy and __memcpy_chk, or memcmp and bcmp. If VARIANT is
12 // defined, make sure to use the variants instead to make sure they are still
13 // checked by the analyzer.
14 
15 // Some functions are implemented as builtins. These should be #defined as
16 // BUILTIN(f), which will prepend "__builtin_" if USE_BUILTINS is defined.
17 
18 // Functions that have variants and are also available as builtins should be
19 // declared carefully! See memcpy() for an example.
20 
21 #ifdef USE_BUILTINS
22 # define BUILTIN(f) __builtin_ ## f
23 #else /* USE_BUILTINS */
24 # define BUILTIN(f) f
25 #endif /* USE_BUILTINS */
26 
27 #define NULL 0
28 typedef typeof(sizeof(int)) size_t;
29 
30 void clang_analyzer_eval(int);
31 
32 int scanf(const char *restrict format, ...);
33 
34 //===----------------------------------------------------------------------===
35 // strlen()
36 //===----------------------------------------------------------------------===
37 
38 #define strlen BUILTIN(strlen)
39 size_t strlen(const char *s);
40 
41 void strlen_constant0() {
42   clang_analyzer_eval(strlen("123") == 3); // expected-warning{{TRUE}}
43 }
44 
45 void strlen_constant1() {
46   const char *a = "123";
47   clang_analyzer_eval(strlen(a) == 3); // expected-warning{{TRUE}}
48 }
49 
50 void strlen_constant2(char x) {
51   char a[] = "123";
52   clang_analyzer_eval(strlen(a) == 3); // expected-warning{{TRUE}}
53 
54   a[0] = x;
55   clang_analyzer_eval(strlen(a) == 3); // expected-warning{{UNKNOWN}}
56 }
57 
58 size_t strlen_null() {
59   return strlen(0); // expected-warning{{Null pointer argument in call to string length function}}
60 }
61 
62 size_t strlen_fn() {
63   return strlen((char*)&strlen_fn); // expected-warning{{Argument to string length function is the address of the function 'strlen_fn', which is not a null-terminated string}}
64 }
65 
66 size_t strlen_nonloc() {
67 label:
68   return strlen((char*)&&label); // expected-warning{{Argument to string length function is the address of the label 'label', which is not a null-terminated string}}
69 }
70 
71 void strlen_subregion() {
72   struct two_strings { char a[2], b[2]; };
73   extern void use_two_strings(struct two_strings *);
74 
75   struct two_strings z;
76   use_two_strings(&z);
77 
78   size_t a = strlen(z.a);
79   z.b[0] = 5;
80   size_t b = strlen(z.a);
81   if (a == 0)
82     clang_analyzer_eval(b == 0); // expected-warning{{TRUE}}
83 
84   use_two_strings(&z);
85 
86   size_t c = strlen(z.a);
87   if (a == 0)
88     clang_analyzer_eval(c == 0); // expected-warning{{UNKNOWN}}
89 }
90 
91 extern void use_string(char *);
92 void strlen_argument(char *x) {
93   size_t a = strlen(x);
94   size_t b = strlen(x);
95   if (a == 0)
96     clang_analyzer_eval(b == 0); // expected-warning{{TRUE}}
97 
98   use_string(x);
99 
100   size_t c = strlen(x);
101   if (a == 0)
102     clang_analyzer_eval(c == 0); // expected-warning{{UNKNOWN}}
103 }
104 
105 extern char global_str[];
106 void strlen_global() {
107   size_t a = strlen(global_str);
108   size_t b = strlen(global_str);
109   if (a == 0) {
110     clang_analyzer_eval(b == 0); // expected-warning{{TRUE}}
111     // Make sure clang_analyzer_eval does not invalidate globals.
112     clang_analyzer_eval(strlen(global_str) == 0); // expected-warning{{TRUE}}
113   }
114 
115   // Call a function with unknown effects, which should invalidate globals.
116   use_string(0);
117 
118   size_t c = strlen(global_str);
119   if (a == 0)
120     clang_analyzer_eval(c == 0); // expected-warning{{UNKNOWN}}
121 }
122 
123 void strlen_indirect(char *x) {
124   size_t a = strlen(x);
125   char *p = x;
126   char **p2 = &p;
127   size_t b = strlen(x);
128   if (a == 0)
129     clang_analyzer_eval(b == 0); // expected-warning{{TRUE}}
130 
131   extern void use_string_ptr(char*const*);
132   use_string_ptr(p2);
133 
134   size_t c = strlen(x);
135   if (a == 0)
136     clang_analyzer_eval(c == 0); // expected-warning{{UNKNOWN}}
137 }
138 
139 void strlen_indirect2(char *x) {
140   size_t a = strlen(x);
141   char *p = x;
142   char **p2 = &p;
143   extern void use_string_ptr2(char**);
144   use_string_ptr2(p2);
145 
146   size_t c = strlen(x);
147   if (a == 0)
148     clang_analyzer_eval(c == 0); // expected-warning{{UNKNOWN}}
149 }
150 
151 void strlen_liveness(const char *x) {
152   if (strlen(x) < 5)
153     return;
154   clang_analyzer_eval(strlen(x) < 5); // expected-warning{{FALSE}}
155 }
156 
157 //===----------------------------------------------------------------------===
158 // strnlen()
159 //===----------------------------------------------------------------------===
160 
161 size_t strnlen(const char *s, size_t maxlen);
162 
163 void strnlen_constant0() {
164   clang_analyzer_eval(strnlen("123", 10) == 3); // expected-warning{{TRUE}}
165 }
166 
167 void strnlen_constant1() {
168   const char *a = "123";
169   clang_analyzer_eval(strnlen(a, 10) == 3); // expected-warning{{TRUE}}
170 }
171 
172 void strnlen_constant2(char x) {
173   char a[] = "123";
174   clang_analyzer_eval(strnlen(a, 10) == 3); // expected-warning{{TRUE}}
175   a[0] = x;
176   clang_analyzer_eval(strnlen(a, 10) == 3); // expected-warning{{UNKNOWN}}
177 }
178 
179 void strnlen_constant4() {
180   clang_analyzer_eval(strnlen("123456", 3) == 3); // expected-warning{{TRUE}}
181 }
182 
183 void strnlen_constant5() {
184   const char *a = "123456";
185   clang_analyzer_eval(strnlen(a, 3) == 3); // expected-warning{{TRUE}}
186 }
187 
188 void strnlen_constant6(char x) {
189   char a[] = "123456";
190   clang_analyzer_eval(strnlen(a, 3) == 3); // expected-warning{{TRUE}}
191   a[0] = x;
192   clang_analyzer_eval(strnlen(a, 3) == 3); // expected-warning{{UNKNOWN}}
193 }
194 
195 size_t strnlen_null() {
196   return strnlen(0, 3); // expected-warning{{Null pointer argument in call to string length function}}
197 }
198 
199 size_t strnlen_fn() {
200   return strnlen((char*)&strlen_fn, 3); // expected-warning{{Argument to string length function is the address of the function 'strlen_fn', which is not a null-terminated string}}
201 }
202 
203 size_t strnlen_nonloc() {
204 label:
205   return strnlen((char*)&&label, 3); // expected-warning{{Argument to string length function is the address of the label 'label', which is not a null-terminated string}}
206 }
207 
208 void strnlen_zero() {
209   clang_analyzer_eval(strnlen("abc", 0) == 0); // expected-warning{{TRUE}}
210   clang_analyzer_eval(strnlen(NULL, 0) == 0); // expected-warning{{TRUE}}
211 }
212 
213 size_t strnlen_compound_literal() {
214   // This used to crash because we don't model the string lengths of
215   // compound literals.
216   return strnlen((char[]) { 'a', 'b', 0 }, 1);
217 }
218 
219 size_t strnlen_unknown_limit(float f) {
220   // This used to crash because we don't model the integer values of floats.
221   return strnlen("abc", (int)f);
222 }
223 
224 void strnlen_is_not_strlen(char *x) {
225   clang_analyzer_eval(strnlen(x, 10) == strlen(x)); // expected-warning{{UNKNOWN}}
226 }
227 
228 void strnlen_at_limit(char *x) {
229   size_t len = strnlen(x, 10);
230   clang_analyzer_eval(len <= 10); // expected-warning{{TRUE}}
231   clang_analyzer_eval(len == 10); // expected-warning{{UNKNOWN}}
232   clang_analyzer_eval(len < 10); // expected-warning{{UNKNOWN}}
233 }
234 
235 void strnlen_at_actual(size_t limit) {
236   size_t len = strnlen("abc", limit);
237   clang_analyzer_eval(len <= 3); // expected-warning{{TRUE}}
238   // This is due to eager assertion in strnlen.
239   if (limit == 0) {
240     clang_analyzer_eval(len == 0); // expected-warning{{TRUE}}
241   } else {
242     clang_analyzer_eval(len == 3); // expected-warning{{UNKNOWN}}
243     clang_analyzer_eval(len < 3); // expected-warning{{UNKNOWN}}
244   }
245 }
246 
247 //===----------------------------------------------------------------------===
248 // strcpy()
249 //===----------------------------------------------------------------------===
250 
251 #ifdef VARIANT
252 
253 #define __strcpy_chk BUILTIN(__strcpy_chk)
254 char *__strcpy_chk(char *restrict s1, const char *restrict s2, size_t destlen);
255 
256 #define strcpy(a,b) __strcpy_chk(a,b,(size_t)-1)
257 
258 #else /* VARIANT */
259 
260 #define strcpy BUILTIN(strcpy)
261 char *strcpy(char *restrict s1, const char *restrict s2);
262 
263 #endif /* VARIANT */
264 
265 
266 void strcpy_null_dst(char *x) {
267   strcpy(NULL, x); // expected-warning{{Null pointer argument in call to string copy function}}
268 }
269 
270 void strcpy_null_src(char *x) {
271   strcpy(x, NULL); // expected-warning{{Null pointer argument in call to string copy function}}
272 }
273 
274 void strcpy_fn(char *x) {
275   strcpy(x, (char*)&strcpy_fn); // expected-warning{{Argument to string copy function is the address of the function 'strcpy_fn', which is not a null-terminated string}}
276 }
277 
278 void strcpy_fn_const(char *x) {
279   strcpy(x, (const char*)&strcpy_fn); // expected-warning{{Argument to string copy function is the address of the function 'strcpy_fn', which is not a null-terminated string}}
280 }
281 
282 extern int globalInt;
283 void strcpy_effects(char *x, char *y) {
284   char a = x[0];
285   if (globalInt != 42)
286     return;
287 
288   clang_analyzer_eval(strcpy(x, y) == x); // expected-warning{{TRUE}}
289   clang_analyzer_eval(strlen(x) == strlen(y)); // expected-warning{{TRUE}}
290   clang_analyzer_eval(a == x[0]); // expected-warning{{UNKNOWN}}
291   clang_analyzer_eval(globalInt == 42); // expected-warning{{TRUE}}
292 }
293 
294 void strcpy_overflow(char *y) {
295   char x[4];
296   if (strlen(y) == 4)
297     strcpy(x, y); // expected-warning{{String copy function overflows destination buffer}}
298 }
299 
300 void strcpy_no_overflow(char *y) {
301   char x[4];
302   if (strlen(y) == 3)
303     strcpy(x, y); // no-warning
304 }
305 
306 //===----------------------------------------------------------------------===
307 // stpcpy()
308 //===----------------------------------------------------------------------===
309 
310 #ifdef VARIANT
311 
312 #define __stpcpy_chk BUILTIN(__stpcpy_chk)
313 char *__stpcpy_chk(char *restrict s1, const char *restrict s2, size_t destlen);
314 
315 #define stpcpy(a,b) __stpcpy_chk(a,b,(size_t)-1)
316 
317 #else /* VARIANT */
318 
319 #define stpcpy BUILTIN(stpcpy)
320 char *stpcpy(char *restrict s1, const char *restrict s2);
321 
322 #endif /* VARIANT */
323 
324 
325 void stpcpy_effect(char *x, char *y) {
326   char a = x[0];
327 
328   clang_analyzer_eval(stpcpy(x, y) == &x[strlen(y)]); // expected-warning{{TRUE}}
329   clang_analyzer_eval(strlen(x) == strlen(y)); // expected-warning{{TRUE}}
330   clang_analyzer_eval(a == x[0]); // expected-warning{{UNKNOWN}}
331 }
332 
333 void stpcpy_overflow(char *y) {
334   char x[4];
335   if (strlen(y) == 4)
336     stpcpy(x, y); // expected-warning{{String copy function overflows destination buffer}}
337 }
338 
339 void stpcpy_no_overflow(char *y) {
340   char x[4];
341   if (strlen(y) == 3)
342     stpcpy(x, y); // no-warning
343 }
344 
345 //===----------------------------------------------------------------------===
346 // strcat()
347 //===----------------------------------------------------------------------===
348 
349 #ifdef VARIANT
350 
351 #define __strcat_chk BUILTIN(__strcat_chk)
352 char *__strcat_chk(char *restrict s1, const char *restrict s2, size_t destlen);
353 
354 #define strcat(a,b) __strcat_chk(a,b,(size_t)-1)
355 
356 #else /* VARIANT */
357 
358 #define strcat BUILTIN(strcat)
359 char *strcat(char *restrict s1, const char *restrict s2);
360 
361 #endif /* VARIANT */
362 
363 
364 void strcat_null_dst(char *x) {
365   strcat(NULL, x); // expected-warning{{Null pointer argument in call to string copy function}}
366 }
367 
368 void strcat_null_src(char *x) {
369   strcat(x, NULL); // expected-warning{{Null pointer argument in call to string copy function}}
370 }
371 
372 void strcat_fn(char *x) {
373   strcat(x, (char*)&strcat_fn); // expected-warning{{Argument to string copy function is the address of the function 'strcat_fn', which is not a null-terminated string}}
374 }
375 
376 void strcat_effects(char *y) {
377   char x[8] = "123";
378   size_t orig_len = strlen(x);
379   char a = x[0];
380 
381   if (strlen(y) != 4)
382     return;
383 
384   clang_analyzer_eval(strcat(x, y) == x); // expected-warning{{TRUE}}
385   clang_analyzer_eval((int)strlen(x) == (orig_len + strlen(y))); // expected-warning{{TRUE}}
386 }
387 
388 void strcat_overflow_0(char *y) {
389   char x[4] = "12";
390   if (strlen(y) == 4)
391     strcat(x, y); // expected-warning{{String copy function overflows destination buffer}}
392 }
393 
394 void strcat_overflow_1(char *y) {
395   char x[4] = "12";
396   if (strlen(y) == 3)
397     strcat(x, y); // expected-warning{{String copy function overflows destination buffer}}
398 }
399 
400 void strcat_overflow_2(char *y) {
401   char x[4] = "12";
402   if (strlen(y) == 2)
403     strcat(x, y); // expected-warning{{String copy function overflows destination buffer}}
404 }
405 
406 void strcat_no_overflow(char *y) {
407   char x[5] = "12";
408   if (strlen(y) == 2)
409     strcat(x, y); // no-warning
410 }
411 
412 void strcat_symbolic_dst_length(char *dst) {
413 	strcat(dst, "1234");
414   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
415 }
416 
417 void strcat_symbolic_dst_length_taint(char *dst) {
418   scanf("%s", dst); // Taint data.
419   strcat(dst, "1234");
420   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
421 }
422 
423 void strcat_unknown_src_length(char *src, int offset) {
424 	char dst[8] = "1234";
425 	strcat(dst, &src[offset]);
426   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
427 }
428 
429 // There is no strcat_unknown_dst_length because if we can't get a symbolic
430 // length for the "before" strlen, we won't be able to set one for "after".
431 
432 void strcat_too_big(char *dst, char *src) {
433   // We assume this can never actually happen, so we don't get a warning.
434 	if (strlen(dst) != (((size_t)0) - 2))
435 		return;
436 	if (strlen(src) != 2)
437 		return;
438 	strcat(dst, src);
439 }
440 
441 
442 //===----------------------------------------------------------------------===
443 // strncpy()
444 //===----------------------------------------------------------------------===
445 
446 #ifdef VARIANT
447 
448 #define __strncpy_chk BUILTIN(__strncpy_chk)
449 char *__strncpy_chk(char *restrict s1, const char *restrict s2, size_t n, size_t destlen);
450 
451 #define strncpy(a,b,n) __strncpy_chk(a,b,n,(size_t)-1)
452 
453 #else /* VARIANT */
454 
455 #define strncpy BUILTIN(strncpy)
456 char *strncpy(char *restrict s1, const char *restrict s2, size_t n);
457 
458 #endif /* VARIANT */
459 
460 
461 void strncpy_null_dst(char *x) {
462   strncpy(NULL, x, 5); // expected-warning{{Null pointer argument in call to string copy function}}
463 }
464 
465 void strncpy_null_src(char *x) {
466   strncpy(x, NULL, 5); // expected-warning{{Null pointer argument in call to string copy function}}
467 }
468 
469 void strncpy_fn(char *x) {
470   strncpy(x, (char*)&strcpy_fn, 5); // expected-warning{{Argument to string copy function is the address of the function 'strcpy_fn', which is not a null-terminated string}}
471 }
472 
473 void strncpy_effects(char *x, char *y) {
474   char a = x[0];
475 
476   clang_analyzer_eval(strncpy(x, y, 5) == x); // expected-warning{{TRUE}}
477   clang_analyzer_eval(strlen(x) == strlen(y)); // expected-warning{{UNKNOWN}}
478   clang_analyzer_eval(a == x[0]); // expected-warning{{UNKNOWN}}
479 }
480 
481 void strncpy_overflow(char *y) {
482   char x[4];
483   if (strlen(y) == 4)
484     strncpy(x, y, 5); // expected-warning{{Size argument is greater than the length of the destination buffer}}
485 }
486 
487 void strncpy_no_overflow(char *y) {
488   char x[4];
489   if (strlen(y) == 3)
490     strncpy(x, y, 5); // expected-warning{{Size argument is greater than the length of the destination buffer}}
491 }
492 
493 void strncpy_no_overflow2(char *y, int n) {
494 	if (n <= 4)
495 		return;
496 
497   char x[4];
498   if (strlen(y) == 3)
499     strncpy(x, y, n); // expected-warning{{Size argument is greater than the length of the destination buffer}}
500 }
501 
502 void strncpy_truncate(char *y) {
503   char x[4];
504   if (strlen(y) == 4)
505     strncpy(x, y, 3); // no-warning
506 }
507 
508 void strncpy_no_truncate(char *y) {
509   char x[4];
510   if (strlen(y) == 3)
511     strncpy(x, y, 3); // no-warning
512 }
513 
514 void strncpy_exactly_matching_buffer(char *y) {
515 	char x[4];
516 	strncpy(x, y, 4); // no-warning
517 
518 	// strncpy does not null-terminate, so we have no idea what the strlen is
519 	// after this.
520   clang_analyzer_eval(strlen(x) > 4); // expected-warning{{UNKNOWN}}
521 }
522 
523 void strncpy_zero(char *src) {
524   char dst[] = "123";
525   strncpy(dst, src, 0); // no-warning
526 }
527 
528 void strncpy_empty() {
529   char dst[] = "123";
530   char src[] = "";
531   strncpy(dst, src, 4); // no-warning
532 }
533 
534 //===----------------------------------------------------------------------===
535 // strncat()
536 //===----------------------------------------------------------------------===
537 
538 #ifdef VARIANT
539 
540 #define __strncat_chk BUILTIN(__strncat_chk)
541 char *__strncat_chk(char *restrict s1, const char *restrict s2, size_t n, size_t destlen);
542 
543 #define strncat(a,b,c) __strncat_chk(a,b,c, (size_t)-1)
544 
545 #else /* VARIANT */
546 
547 #define strncat BUILTIN(strncat)
548 char *strncat(char *restrict s1, const char *restrict s2, size_t n);
549 
550 #endif /* VARIANT */
551 
552 
553 void strncat_null_dst(char *x) {
554   strncat(NULL, x, 4); // expected-warning{{Null pointer argument in call to string copy function}}
555 }
556 
557 void strncat_null_src(char *x) {
558   strncat(x, NULL, 4); // expected-warning{{Null pointer argument in call to string copy function}}
559 }
560 
561 void strncat_fn(char *x) {
562   strncat(x, (char*)&strncat_fn, 4); // expected-warning{{Argument to string copy function is the address of the function 'strncat_fn', which is not a null-terminated string}}
563 }
564 
565 void strncat_effects(char *y) {
566   char x[8] = "123";
567   size_t orig_len = strlen(x);
568   char a = x[0];
569 
570   if (strlen(y) != 4)
571     return;
572 
573   clang_analyzer_eval(strncat(x, y, strlen(y)) == x); // expected-warning{{TRUE}}
574   clang_analyzer_eval(strlen(x) == (orig_len + strlen(y))); // expected-warning{{TRUE}}
575 }
576 
577 void strncat_overflow_0(char *y) {
578   char x[4] = "12";
579   if (strlen(y) == 4)
580     strncat(x, y, strlen(y)); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
581 }
582 
583 void strncat_overflow_1(char *y) {
584   char x[4] = "12";
585   if (strlen(y) == 3)
586     strncat(x, y, strlen(y)); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
587 }
588 
589 void strncat_overflow_2(char *y) {
590   char x[4] = "12";
591   if (strlen(y) == 2)
592     strncat(x, y, strlen(y)); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
593 }
594 
595 void strncat_overflow_3(char *y) {
596   char x[4] = "12";
597   if (strlen(y) == 4)
598     strncat(x, y, 2); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
599 }
600 void strncat_no_overflow_1(char *y) {
601   char x[5] = "12";
602   if (strlen(y) == 2)
603     strncat(x, y, strlen(y)); // no-warning
604 }
605 
606 void strncat_no_overflow_2(char *y) {
607   char x[4] = "12";
608   if (strlen(y) == 4)
609     strncat(x, y, 1); // no-warning
610 }
611 
612 void strncat_symbolic_dst_length(char *dst) {
613   strncat(dst, "1234", 5);
614   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
615 }
616 
617 void strncat_symbolic_src_length(char *src) {
618   char dst[8] = "1234";
619   strncat(dst, src, 3);
620   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
621 
622   char dst2[8] = "1234";
623   strncat(dst2, src, 4); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
624 }
625 
626 void strncat_unknown_src_length(char *src, int offset) {
627   char dst[8] = "1234";
628   strncat(dst, &src[offset], 3);
629   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
630 
631   char dst2[8] = "1234";
632   strncat(dst2, &src[offset], 4); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
633 }
634 
635 // There is no strncat_unknown_dst_length because if we can't get a symbolic
636 // length for the "before" strlen, we won't be able to set one for "after".
637 
638 void strncat_symbolic_limit(unsigned limit) {
639   char dst[6] = "1234";
640   char src[] = "567";
641   strncat(dst, src, limit); // no-warning
642 
643   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
644   clang_analyzer_eval(strlen(dst) == 4); // expected-warning{{UNKNOWN}}
645 }
646 
647 void strncat_unknown_limit(float limit) {
648   char dst[6] = "1234";
649   char src[] = "567";
650   strncat(dst, src, (size_t)limit); // no-warning
651 
652   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
653   clang_analyzer_eval(strlen(dst) == 4); // expected-warning{{UNKNOWN}}
654 }
655 
656 void strncat_too_big(char *dst, char *src) {
657   // We assume this will never actually happen, so we don't get a warning.
658   if (strlen(dst) != (((size_t)0) - 2))
659     return;
660   if (strlen(src) != 2)
661     return;
662   strncat(dst, src, 2);
663 }
664 
665 void strncat_zero(char *src) {
666   char dst[] = "123";
667   strncat(dst, src, 0); // no-warning
668 }
669 
670 void strncat_empty() {
671   char dst[8] = "123";
672   char src[] = "";
673   strncat(dst, src, 4); // no-warning
674 }
675 
676 //===----------------------------------------------------------------------===
677 // strcmp()
678 //===----------------------------------------------------------------------===
679 
680 #define strcmp BUILTIN(strcmp)
681 int strcmp(const char * s1, const char * s2);
682 
683 void strcmp_constant0() {
684   clang_analyzer_eval(strcmp("123", "123") == 0); // expected-warning{{TRUE}}
685 }
686 
687 void strcmp_constant_and_var_0() {
688   char *x = "123";
689   clang_analyzer_eval(strcmp(x, "123") == 0); // expected-warning{{TRUE}}
690 }
691 
692 void strcmp_constant_and_var_1() {
693   char *x = "123";
694   clang_analyzer_eval(strcmp("123", x) == 0); // expected-warning{{TRUE}}
695 }
696 
697 void strcmp_0() {
698   char *x = "123";
699   char *y = "123";
700   clang_analyzer_eval(strcmp(x, y) == 0); // expected-warning{{TRUE}}
701 }
702 
703 void strcmp_1() {
704   char *x = "234";
705   char *y = "123";
706   clang_analyzer_eval(strcmp(x, y) == 1); // expected-warning{{TRUE}}
707 }
708 
709 void strcmp_2() {
710   char *x = "123";
711   char *y = "234";
712   clang_analyzer_eval(strcmp(x, y) == -1); // expected-warning{{TRUE}}
713 }
714 
715 void strcmp_null_0() {
716   char *x = NULL;
717   char *y = "123";
718   strcmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
719 }
720 
721 void strcmp_null_1() {
722   char *x = "123";
723   char *y = NULL;
724   strcmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
725 }
726 
727 void strcmp_diff_length_0() {
728   char *x = "12345";
729   char *y = "234";
730   clang_analyzer_eval(strcmp(x, y) == -1); // expected-warning{{TRUE}}
731 }
732 
733 void strcmp_diff_length_1() {
734   char *x = "123";
735   char *y = "23456";
736   clang_analyzer_eval(strcmp(x, y) == -1); // expected-warning{{TRUE}}
737 }
738 
739 void strcmp_diff_length_2() {
740   char *x = "12345";
741   char *y = "123";
742   clang_analyzer_eval(strcmp(x, y) == 1); // expected-warning{{TRUE}}
743 }
744 
745 void strcmp_diff_length_3() {
746   char *x = "123";
747   char *y = "12345";
748   clang_analyzer_eval(strcmp(x, y) == -1); // expected-warning{{TRUE}}
749 }
750 
751 void strcmp_embedded_null () {
752 	clang_analyzer_eval(strcmp("\0z", "\0y") == 0); // expected-warning{{TRUE}}
753 }
754 
755 void strcmp_unknown_arg (char *unknown) {
756 	clang_analyzer_eval(strcmp(unknown, unknown) == 0); // expected-warning{{TRUE}}
757 }
758 
759 union argument {
760    char *f;
761 };
762 
763 void function_pointer_cast_helper(char **a) {
764   strcmp("Hi", *a); // PR24951 crash
765 }
766 
767 void strcmp_union_function_pointer_cast(union argument a) {
768   void (*fPtr)(union argument *) = (void (*)(union argument *))function_pointer_cast_helper;
769 
770   fPtr(&a);
771 }
772 
773 //===----------------------------------------------------------------------===
774 // strncmp()
775 //===----------------------------------------------------------------------===
776 
777 #define strncmp BUILTIN(strncmp)
778 int strncmp(const char *s1, const char *s2, size_t n);
779 
780 void strncmp_constant0() {
781   clang_analyzer_eval(strncmp("123", "123", 3) == 0); // expected-warning{{TRUE}}
782 }
783 
784 void strncmp_constant_and_var_0() {
785   char *x = "123";
786   clang_analyzer_eval(strncmp(x, "123", 3) == 0); // expected-warning{{TRUE}}
787 }
788 
789 void strncmp_constant_and_var_1() {
790   char *x = "123";
791   clang_analyzer_eval(strncmp("123", x, 3) == 0); // expected-warning{{TRUE}}
792 }
793 
794 void strncmp_0() {
795   char *x = "123";
796   char *y = "123";
797   clang_analyzer_eval(strncmp(x, y, 3) == 0); // expected-warning{{TRUE}}
798 }
799 
800 void strncmp_1() {
801   char *x = "234";
802   char *y = "123";
803   clang_analyzer_eval(strncmp(x, y, 3) == 1); // expected-warning{{TRUE}}
804 }
805 
806 void strncmp_2() {
807   char *x = "123";
808   char *y = "234";
809   clang_analyzer_eval(strncmp(x, y, 3) == -1); // expected-warning{{TRUE}}
810 }
811 
812 void strncmp_null_0() {
813   char *x = NULL;
814   char *y = "123";
815   strncmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
816 }
817 
818 void strncmp_null_1() {
819   char *x = "123";
820   char *y = NULL;
821   strncmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
822 }
823 
824 void strncmp_diff_length_0() {
825   char *x = "12345";
826   char *y = "234";
827   clang_analyzer_eval(strncmp(x, y, 5) == -1); // expected-warning{{TRUE}}
828 }
829 
830 void strncmp_diff_length_1() {
831   char *x = "123";
832   char *y = "23456";
833   clang_analyzer_eval(strncmp(x, y, 5) == -1); // expected-warning{{TRUE}}
834 }
835 
836 void strncmp_diff_length_2() {
837   char *x = "12345";
838   char *y = "123";
839   clang_analyzer_eval(strncmp(x, y, 5) == 1); // expected-warning{{TRUE}}
840 }
841 
842 void strncmp_diff_length_3() {
843   char *x = "123";
844   char *y = "12345";
845   clang_analyzer_eval(strncmp(x, y, 5) == -1); // expected-warning{{TRUE}}
846 }
847 
848 void strncmp_diff_length_4() {
849   char *x = "123";
850   char *y = "12345";
851   clang_analyzer_eval(strncmp(x, y, 3) == 0); // expected-warning{{TRUE}}
852 }
853 
854 void strncmp_diff_length_5() {
855   char *x = "012";
856   char *y = "12345";
857   clang_analyzer_eval(strncmp(x, y, 3) == -1); // expected-warning{{TRUE}}
858 }
859 
860 void strncmp_diff_length_6() {
861   char *x = "234";
862   char *y = "12345";
863   clang_analyzer_eval(strncmp(x, y, 3) == 1); // expected-warning{{TRUE}}
864 }
865 
866 void strncmp_embedded_null () {
867 	clang_analyzer_eval(strncmp("ab\0zz", "ab\0yy", 4) == 0); // expected-warning{{TRUE}}
868 }
869 
870 //===----------------------------------------------------------------------===
871 // strcasecmp()
872 //===----------------------------------------------------------------------===
873 
874 #define strcasecmp BUILTIN(strcasecmp)
875 int strcasecmp(const char *s1, const char *s2);
876 
877 void strcasecmp_constant0() {
878   clang_analyzer_eval(strcasecmp("abc", "Abc") == 0); // expected-warning{{TRUE}}
879 }
880 
881 void strcasecmp_constant_and_var_0() {
882   char *x = "abc";
883   clang_analyzer_eval(strcasecmp(x, "Abc") == 0); // expected-warning{{TRUE}}
884 }
885 
886 void strcasecmp_constant_and_var_1() {
887   char *x = "abc";
888   clang_analyzer_eval(strcasecmp("Abc", x) == 0); // expected-warning{{TRUE}}
889 }
890 
891 void strcasecmp_0() {
892   char *x = "abc";
893   char *y = "Abc";
894   clang_analyzer_eval(strcasecmp(x, y) == 0); // expected-warning{{TRUE}}
895 }
896 
897 void strcasecmp_1() {
898   char *x = "Bcd";
899   char *y = "abc";
900   clang_analyzer_eval(strcasecmp(x, y) == 1); // expected-warning{{TRUE}}
901 }
902 
903 void strcasecmp_2() {
904   char *x = "abc";
905   char *y = "Bcd";
906   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
907 }
908 
909 void strcasecmp_null_0() {
910   char *x = NULL;
911   char *y = "123";
912   strcasecmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
913 }
914 
915 void strcasecmp_null_1() {
916   char *x = "123";
917   char *y = NULL;
918   strcasecmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
919 }
920 
921 void strcasecmp_diff_length_0() {
922   char *x = "abcde";
923   char *y = "aBd";
924   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
925 }
926 
927 void strcasecmp_diff_length_1() {
928   char *x = "abc";
929   char *y = "aBdef";
930   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
931 }
932 
933 void strcasecmp_diff_length_2() {
934   char *x = "aBcDe";
935   char *y = "abc";
936   clang_analyzer_eval(strcasecmp(x, y) == 1); // expected-warning{{TRUE}}
937 }
938 
939 void strcasecmp_diff_length_3() {
940   char *x = "aBc";
941   char *y = "abcde";
942   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
943 }
944 
945 void strcasecmp_embedded_null () {
946 	clang_analyzer_eval(strcasecmp("ab\0zz", "ab\0yy") == 0); // expected-warning{{TRUE}}
947 }
948 
949 //===----------------------------------------------------------------------===
950 // strncasecmp()
951 //===----------------------------------------------------------------------===
952 
953 #define strncasecmp BUILTIN(strncasecmp)
954 int strncasecmp(const char *s1, const char *s2, size_t n);
955 
956 void strncasecmp_constant0() {
957   clang_analyzer_eval(strncasecmp("abc", "Abc", 3) == 0); // expected-warning{{TRUE}}
958 }
959 
960 void strncasecmp_constant_and_var_0() {
961   char *x = "abc";
962   clang_analyzer_eval(strncasecmp(x, "Abc", 3) == 0); // expected-warning{{TRUE}}
963 }
964 
965 void strncasecmp_constant_and_var_1() {
966   char *x = "abc";
967   clang_analyzer_eval(strncasecmp("Abc", x, 3) == 0); // expected-warning{{TRUE}}
968 }
969 
970 void strncasecmp_0() {
971   char *x = "abc";
972   char *y = "Abc";
973   clang_analyzer_eval(strncasecmp(x, y, 3) == 0); // expected-warning{{TRUE}}
974 }
975 
976 void strncasecmp_1() {
977   char *x = "Bcd";
978   char *y = "abc";
979   clang_analyzer_eval(strncasecmp(x, y, 3) == 1); // expected-warning{{TRUE}}
980 }
981 
982 void strncasecmp_2() {
983   char *x = "abc";
984   char *y = "Bcd";
985   clang_analyzer_eval(strncasecmp(x, y, 3) == -1); // expected-warning{{TRUE}}
986 }
987 
988 void strncasecmp_null_0() {
989   char *x = NULL;
990   char *y = "123";
991   strncasecmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
992 }
993 
994 void strncasecmp_null_1() {
995   char *x = "123";
996   char *y = NULL;
997   strncasecmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
998 }
999 
1000 void strncasecmp_diff_length_0() {
1001   char *x = "abcde";
1002   char *y = "aBd";
1003   clang_analyzer_eval(strncasecmp(x, y, 5) == -1); // expected-warning{{TRUE}}
1004 }
1005 
1006 void strncasecmp_diff_length_1() {
1007   char *x = "abc";
1008   char *y = "aBdef";
1009   clang_analyzer_eval(strncasecmp(x, y, 5) == -1); // expected-warning{{TRUE}}
1010 }
1011 
1012 void strncasecmp_diff_length_2() {
1013   char *x = "aBcDe";
1014   char *y = "abc";
1015   clang_analyzer_eval(strncasecmp(x, y, 5) == 1); // expected-warning{{TRUE}}
1016 }
1017 
1018 void strncasecmp_diff_length_3() {
1019   char *x = "aBc";
1020   char *y = "abcde";
1021   clang_analyzer_eval(strncasecmp(x, y, 5) == -1); // expected-warning{{TRUE}}
1022 }
1023 
1024 void strncasecmp_diff_length_4() {
1025   char *x = "abcde";
1026   char *y = "aBc";
1027   clang_analyzer_eval(strncasecmp(x, y, 3) == 0); // expected-warning{{TRUE}}
1028 }
1029 
1030 void strncasecmp_diff_length_5() {
1031   char *x = "abcde";
1032   char *y = "aBd";
1033   clang_analyzer_eval(strncasecmp(x, y, 3) == -1); // expected-warning{{TRUE}}
1034 }
1035 
1036 void strncasecmp_diff_length_6() {
1037   char *x = "aBDe";
1038   char *y = "abc";
1039   clang_analyzer_eval(strncasecmp(x, y, 3) == 1); // expected-warning{{TRUE}}
1040 }
1041 
1042 void strncasecmp_embedded_null () {
1043 	clang_analyzer_eval(strncasecmp("ab\0zz", "ab\0yy", 4) == 0); // expected-warning{{TRUE}}
1044 }
1045 
1046 //===----------------------------------------------------------------------===
1047 // strsep()
1048 //===----------------------------------------------------------------------===
1049 
1050 char *strsep(char **stringp, const char *delim);
1051 
1052 void strsep_null_delim(char *s) {
1053   strsep(&s, NULL); // expected-warning{{Null pointer argument in call to strsep()}}
1054 }
1055 
1056 void strsep_null_search() {
1057   strsep(NULL, ""); // expected-warning{{Null pointer argument in call to strsep()}}
1058 }
1059 
1060 void strsep_return_original_pointer(char *s) {
1061   char *original = s;
1062   char *result = strsep(&s, ""); // no-warning
1063   clang_analyzer_eval(original == result); // expected-warning{{TRUE}}
1064 }
1065 
1066 void strsep_null_string() {
1067   char *s = NULL;
1068   char *result = strsep(&s, ""); // no-warning
1069   clang_analyzer_eval(result == NULL); // expected-warning{{TRUE}}
1070 }
1071 
1072 void strsep_changes_input_pointer(char *s) {
1073   char *original = s;
1074   strsep(&s, ""); // no-warning
1075   clang_analyzer_eval(s == original); // expected-warning{{UNKNOWN}}
1076   clang_analyzer_eval(s == NULL); // expected-warning{{UNKNOWN}}
1077 
1078   // Check that the value is symbolic.
1079   if (s == NULL) {
1080     clang_analyzer_eval(s == NULL); // expected-warning{{TRUE}}
1081   }
1082 }
1083 
1084 void strsep_changes_input_string() {
1085   char str[] = "abc";
1086 
1087   clang_analyzer_eval(str[1] == 'b'); // expected-warning{{TRUE}}
1088 
1089   char *s = str;
1090   strsep(&s, "b"); // no-warning
1091 
1092   // The real strsep will change the first delimiter it finds into a NUL
1093   // character. For now, we just model the invalidation.
1094   clang_analyzer_eval(str[1] == 'b'); // expected-warning{{UNKNOWN}}
1095 }
1096 
1097 //===----------------------------------------------------------------------===
1098 // FIXMEs
1099 //===----------------------------------------------------------------------===
1100 
1101 // The analyzer_eval call below should evaluate to true. We are being too
1102 // aggressive in marking the (length of) src symbol dead. The length of dst
1103 // depends on src. This could be explicitely specified in the checker or the
1104 // logic for handling MetadataSymbol in SymbolManager needs to change.
1105 void strcat_symbolic_src_length(char *src) {
1106 	char dst[8] = "1234";
1107 	strcat(dst, src);
1108   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{UNKNOWN}}
1109 }
1110 
1111 // The analyzer_eval call below should evaluate to true. Most likely the same
1112 // issue as the test above.
1113 void strncpy_exactly_matching_buffer2(char *y) {
1114 	if (strlen(y) >= 4)
1115 		return;
1116 
1117 	char x[4];
1118 	strncpy(x, y, 4); // no-warning
1119 
1120 	// This time, we know that y fits in x anyway.
1121   clang_analyzer_eval(strlen(x) <= 3); // expected-warning{{UNKNOWN}}
1122 }
1123