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 void strcpy_effects(char *x, char *y) {
283   char a = x[0];
284 
285   clang_analyzer_eval(strcpy(x, y) == x); // expected-warning{{TRUE}}
286   clang_analyzer_eval(strlen(x) == strlen(y)); // expected-warning{{TRUE}}
287   clang_analyzer_eval(a == x[0]); // expected-warning{{UNKNOWN}}
288 }
289 
290 void strcpy_overflow(char *y) {
291   char x[4];
292   if (strlen(y) == 4)
293     strcpy(x, y); // expected-warning{{String copy function overflows destination buffer}}
294 }
295 
296 void strcpy_no_overflow(char *y) {
297   char x[4];
298   if (strlen(y) == 3)
299     strcpy(x, y); // no-warning
300 }
301 
302 //===----------------------------------------------------------------------===
303 // stpcpy()
304 //===----------------------------------------------------------------------===
305 
306 #ifdef VARIANT
307 
308 #define __stpcpy_chk BUILTIN(__stpcpy_chk)
309 char *__stpcpy_chk(char *restrict s1, const char *restrict s2, size_t destlen);
310 
311 #define stpcpy(a,b) __stpcpy_chk(a,b,(size_t)-1)
312 
313 #else /* VARIANT */
314 
315 #define stpcpy BUILTIN(stpcpy)
316 char *stpcpy(char *restrict s1, const char *restrict s2);
317 
318 #endif /* VARIANT */
319 
320 
321 void stpcpy_effect(char *x, char *y) {
322   char a = x[0];
323 
324   clang_analyzer_eval(stpcpy(x, y) == &x[strlen(y)]); // expected-warning{{TRUE}}
325   clang_analyzer_eval(strlen(x) == strlen(y)); // expected-warning{{TRUE}}
326   clang_analyzer_eval(a == x[0]); // expected-warning{{UNKNOWN}}
327 }
328 
329 void stpcpy_overflow(char *y) {
330   char x[4];
331   if (strlen(y) == 4)
332     stpcpy(x, y); // expected-warning{{String copy function overflows destination buffer}}
333 }
334 
335 void stpcpy_no_overflow(char *y) {
336   char x[4];
337   if (strlen(y) == 3)
338     stpcpy(x, y); // no-warning
339 }
340 
341 //===----------------------------------------------------------------------===
342 // strcat()
343 //===----------------------------------------------------------------------===
344 
345 #ifdef VARIANT
346 
347 #define __strcat_chk BUILTIN(__strcat_chk)
348 char *__strcat_chk(char *restrict s1, const char *restrict s2, size_t destlen);
349 
350 #define strcat(a,b) __strcat_chk(a,b,(size_t)-1)
351 
352 #else /* VARIANT */
353 
354 #define strcat BUILTIN(strcat)
355 char *strcat(char *restrict s1, const char *restrict s2);
356 
357 #endif /* VARIANT */
358 
359 
360 void strcat_null_dst(char *x) {
361   strcat(NULL, x); // expected-warning{{Null pointer argument in call to string copy function}}
362 }
363 
364 void strcat_null_src(char *x) {
365   strcat(x, NULL); // expected-warning{{Null pointer argument in call to string copy function}}
366 }
367 
368 void strcat_fn(char *x) {
369   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}}
370 }
371 
372 void strcat_effects(char *y) {
373   char x[8] = "123";
374   size_t orig_len = strlen(x);
375   char a = x[0];
376 
377   if (strlen(y) != 4)
378     return;
379 
380   clang_analyzer_eval(strcat(x, y) == x); // expected-warning{{TRUE}}
381   clang_analyzer_eval((int)strlen(x) == (orig_len + strlen(y))); // expected-warning{{TRUE}}
382 }
383 
384 void strcat_overflow_0(char *y) {
385   char x[4] = "12";
386   if (strlen(y) == 4)
387     strcat(x, y); // expected-warning{{String copy function overflows destination buffer}}
388 }
389 
390 void strcat_overflow_1(char *y) {
391   char x[4] = "12";
392   if (strlen(y) == 3)
393     strcat(x, y); // expected-warning{{String copy function overflows destination buffer}}
394 }
395 
396 void strcat_overflow_2(char *y) {
397   char x[4] = "12";
398   if (strlen(y) == 2)
399     strcat(x, y); // expected-warning{{String copy function overflows destination buffer}}
400 }
401 
402 void strcat_no_overflow(char *y) {
403   char x[5] = "12";
404   if (strlen(y) == 2)
405     strcat(x, y); // no-warning
406 }
407 
408 void strcat_symbolic_dst_length(char *dst) {
409 	strcat(dst, "1234");
410   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
411 }
412 
413 void strcat_symbolic_src_length(char *src) {
414 	char dst[8] = "1234";
415 	strcat(dst, src);
416   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
417 }
418 
419 void strcat_symbolic_dst_length_taint(char *dst) {
420   scanf("%s", dst); // Taint data.
421   strcat(dst, "1234");
422   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
423 }
424 
425 void strcat_unknown_src_length(char *src, int offset) {
426 	char dst[8] = "1234";
427 	strcat(dst, &src[offset]);
428   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
429 }
430 
431 // There is no strcat_unknown_dst_length because if we can't get a symbolic
432 // length for the "before" strlen, we won't be able to set one for "after".
433 
434 void strcat_too_big(char *dst, char *src) {
435 	if (strlen(dst) != (((size_t)0) - 2))
436 		return;
437 	if (strlen(src) != 2)
438 		return;
439 	strcat(dst, src); // expected-warning{{This expression will create a string whose length is too big to be represented as a size_t}}
440 }
441 
442 
443 //===----------------------------------------------------------------------===
444 // strncpy()
445 //===----------------------------------------------------------------------===
446 
447 #ifdef VARIANT
448 
449 #define __strncpy_chk BUILTIN(__strncpy_chk)
450 char *__strncpy_chk(char *restrict s1, const char *restrict s2, size_t n, size_t destlen);
451 
452 #define strncpy(a,b,n) __strncpy_chk(a,b,n,(size_t)-1)
453 
454 #else /* VARIANT */
455 
456 #define strncpy BUILTIN(strncpy)
457 char *strncpy(char *restrict s1, const char *restrict s2, size_t n);
458 
459 #endif /* VARIANT */
460 
461 
462 void strncpy_null_dst(char *x) {
463   strncpy(NULL, x, 5); // expected-warning{{Null pointer argument in call to string copy function}}
464 }
465 
466 void strncpy_null_src(char *x) {
467   strncpy(x, NULL, 5); // expected-warning{{Null pointer argument in call to string copy function}}
468 }
469 
470 void strncpy_fn(char *x) {
471   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}}
472 }
473 
474 void strncpy_effects(char *x, char *y) {
475   char a = x[0];
476 
477   clang_analyzer_eval(strncpy(x, y, 5) == x); // expected-warning{{TRUE}}
478   clang_analyzer_eval(strlen(x) == strlen(y)); // expected-warning{{UNKNOWN}}
479   clang_analyzer_eval(a == x[0]); // expected-warning{{UNKNOWN}}
480 }
481 
482 void strncpy_overflow(char *y) {
483   char x[4];
484   if (strlen(y) == 4)
485     strncpy(x, y, 5); // expected-warning{{Size argument is greater than the length of the destination buffer}}
486 }
487 
488 void strncpy_no_overflow(char *y) {
489   char x[4];
490   if (strlen(y) == 3)
491     strncpy(x, y, 5); // expected-warning{{Size argument is greater than the length of the destination buffer}}
492 }
493 
494 void strncpy_no_overflow2(char *y, int n) {
495 	if (n <= 4)
496 		return;
497 
498   char x[4];
499   if (strlen(y) == 3)
500     strncpy(x, y, n); // expected-warning{{Size argument is greater than the length of the destination buffer}}
501 }
502 
503 void strncpy_truncate(char *y) {
504   char x[4];
505   if (strlen(y) == 4)
506     strncpy(x, y, 3); // no-warning
507 }
508 
509 void strncpy_no_truncate(char *y) {
510   char x[4];
511   if (strlen(y) == 3)
512     strncpy(x, y, 3); // no-warning
513 }
514 
515 void strncpy_exactly_matching_buffer(char *y) {
516 	char x[4];
517 	strncpy(x, y, 4); // no-warning
518 
519 	// strncpy does not null-terminate, so we have no idea what the strlen is
520 	// after this.
521   clang_analyzer_eval(strlen(x) > 4); // expected-warning{{UNKNOWN}}
522 }
523 
524 void strncpy_exactly_matching_buffer2(char *y) {
525 	if (strlen(y) >= 4)
526 		return;
527 
528 	char x[4];
529 	strncpy(x, y, 4); // no-warning
530 
531 	// This time, we know that y fits in x anyway.
532   clang_analyzer_eval(strlen(x) <= 3); // expected-warning{{TRUE}}
533 }
534 
535 void strncpy_zero(char *src) {
536   char dst[] = "123";
537   strncpy(dst, src, 0); // no-warning
538 }
539 
540 void strncpy_empty() {
541   char dst[] = "123";
542   char src[] = "";
543   strncpy(dst, src, 4); // no-warning
544 }
545 
546 //===----------------------------------------------------------------------===
547 // strncat()
548 //===----------------------------------------------------------------------===
549 
550 #ifdef VARIANT
551 
552 #define __strncat_chk BUILTIN(__strncat_chk)
553 char *__strncat_chk(char *restrict s1, const char *restrict s2, size_t n, size_t destlen);
554 
555 #define strncat(a,b,c) __strncat_chk(a,b,c, (size_t)-1)
556 
557 #else /* VARIANT */
558 
559 #define strncat BUILTIN(strncat)
560 char *strncat(char *restrict s1, const char *restrict s2, size_t n);
561 
562 #endif /* VARIANT */
563 
564 
565 void strncat_null_dst(char *x) {
566   strncat(NULL, x, 4); // expected-warning{{Null pointer argument in call to string copy function}}
567 }
568 
569 void strncat_null_src(char *x) {
570   strncat(x, NULL, 4); // expected-warning{{Null pointer argument in call to string copy function}}
571 }
572 
573 void strncat_fn(char *x) {
574   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}}
575 }
576 
577 void strncat_effects(char *y) {
578   char x[8] = "123";
579   size_t orig_len = strlen(x);
580   char a = x[0];
581 
582   if (strlen(y) != 4)
583     return;
584 
585   clang_analyzer_eval(strncat(x, y, strlen(y)) == x); // expected-warning{{TRUE}}
586   clang_analyzer_eval(strlen(x) == (orig_len + strlen(y))); // expected-warning{{TRUE}}
587 }
588 
589 void strncat_overflow_0(char *y) {
590   char x[4] = "12";
591   if (strlen(y) == 4)
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_1(char *y) {
596   char x[4] = "12";
597   if (strlen(y) == 3)
598     strncat(x, y, strlen(y)); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
599 }
600 
601 void strncat_overflow_2(char *y) {
602   char x[4] = "12";
603   if (strlen(y) == 2)
604     strncat(x, y, strlen(y)); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
605 }
606 
607 void strncat_overflow_3(char *y) {
608   char x[4] = "12";
609   if (strlen(y) == 4)
610     strncat(x, y, 2); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
611 }
612 void strncat_no_overflow_1(char *y) {
613   char x[5] = "12";
614   if (strlen(y) == 2)
615     strncat(x, y, strlen(y)); // no-warning
616 }
617 
618 void strncat_no_overflow_2(char *y) {
619   char x[4] = "12";
620   if (strlen(y) == 4)
621     strncat(x, y, 1); // no-warning
622 }
623 
624 void strncat_symbolic_dst_length(char *dst) {
625   strncat(dst, "1234", 5);
626   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
627 }
628 
629 void strncat_symbolic_src_length(char *src) {
630   char dst[8] = "1234";
631   strncat(dst, src, 3);
632   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
633 
634   char dst2[8] = "1234";
635   strncat(dst2, src, 4); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
636 }
637 
638 void strncat_unknown_src_length(char *src, int offset) {
639   char dst[8] = "1234";
640   strncat(dst, &src[offset], 3);
641   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
642 
643   char dst2[8] = "1234";
644   strncat(dst2, &src[offset], 4); // expected-warning{{Size argument is greater than the free space in the destination buffer}}
645 }
646 
647 // There is no strncat_unknown_dst_length because if we can't get a symbolic
648 // length for the "before" strlen, we won't be able to set one for "after".
649 
650 void strncat_symbolic_limit(unsigned limit) {
651   char dst[6] = "1234";
652   char src[] = "567";
653   strncat(dst, src, limit); // no-warning
654 
655   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
656   clang_analyzer_eval(strlen(dst) == 4); // expected-warning{{UNKNOWN}}
657 }
658 
659 void strncat_unknown_limit(float limit) {
660   char dst[6] = "1234";
661   char src[] = "567";
662   strncat(dst, src, (size_t)limit); // no-warning
663 
664   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{TRUE}}
665   clang_analyzer_eval(strlen(dst) == 4); // expected-warning{{UNKNOWN}}
666 }
667 
668 void strncat_too_big(char *dst, char *src) {
669   if (strlen(dst) != (((size_t)0) - 2))
670     return;
671   if (strlen(src) != 2)
672     return;
673   strncat(dst, src, 2); // expected-warning{{This expression will create a string whose length is too big to be represented as a size_t}}
674 }
675 
676 void strncat_zero(char *src) {
677   char dst[] = "123";
678   strncat(dst, src, 0); // no-warning
679 }
680 
681 void strncat_empty() {
682   char dst[8] = "123";
683   char src[] = "";
684   strncat(dst, src, 4); // no-warning
685 }
686 
687 //===----------------------------------------------------------------------===
688 // strcmp()
689 //===----------------------------------------------------------------------===
690 
691 #define strcmp BUILTIN(strcmp)
692 int strcmp(const char * s1, const char * s2);
693 
694 void strcmp_constant0() {
695   clang_analyzer_eval(strcmp("123", "123") == 0); // expected-warning{{TRUE}}
696 }
697 
698 void strcmp_constant_and_var_0() {
699   char *x = "123";
700   clang_analyzer_eval(strcmp(x, "123") == 0); // expected-warning{{TRUE}}
701 }
702 
703 void strcmp_constant_and_var_1() {
704   char *x = "123";
705   clang_analyzer_eval(strcmp("123", x) == 0); // expected-warning{{TRUE}}
706 }
707 
708 void strcmp_0() {
709   char *x = "123";
710   char *y = "123";
711   clang_analyzer_eval(strcmp(x, y) == 0); // expected-warning{{TRUE}}
712 }
713 
714 void strcmp_1() {
715   char *x = "234";
716   char *y = "123";
717   clang_analyzer_eval(strcmp(x, y) == 1); // expected-warning{{TRUE}}
718 }
719 
720 void strcmp_2() {
721   char *x = "123";
722   char *y = "234";
723   clang_analyzer_eval(strcmp(x, y) == -1); // expected-warning{{TRUE}}
724 }
725 
726 void strcmp_null_0() {
727   char *x = NULL;
728   char *y = "123";
729   strcmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
730 }
731 
732 void strcmp_null_1() {
733   char *x = "123";
734   char *y = NULL;
735   strcmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
736 }
737 
738 void strcmp_diff_length_0() {
739   char *x = "12345";
740   char *y = "234";
741   clang_analyzer_eval(strcmp(x, y) == -1); // expected-warning{{TRUE}}
742 }
743 
744 void strcmp_diff_length_1() {
745   char *x = "123";
746   char *y = "23456";
747   clang_analyzer_eval(strcmp(x, y) == -1); // expected-warning{{TRUE}}
748 }
749 
750 void strcmp_diff_length_2() {
751   char *x = "12345";
752   char *y = "123";
753   clang_analyzer_eval(strcmp(x, y) == 1); // expected-warning{{TRUE}}
754 }
755 
756 void strcmp_diff_length_3() {
757   char *x = "123";
758   char *y = "12345";
759   clang_analyzer_eval(strcmp(x, y) == -1); // expected-warning{{TRUE}}
760 }
761 
762 void strcmp_embedded_null () {
763 	clang_analyzer_eval(strcmp("\0z", "\0y") == 0); // expected-warning{{TRUE}}
764 }
765 
766 void strcmp_unknown_arg (char *unknown) {
767 	clang_analyzer_eval(strcmp(unknown, unknown) == 0); // expected-warning{{TRUE}}
768 }
769 
770 //===----------------------------------------------------------------------===
771 // strncmp()
772 //===----------------------------------------------------------------------===
773 
774 #define strncmp BUILTIN(strncmp)
775 int strncmp(const char *s1, const char *s2, size_t n);
776 
777 void strncmp_constant0() {
778   clang_analyzer_eval(strncmp("123", "123", 3) == 0); // expected-warning{{TRUE}}
779 }
780 
781 void strncmp_constant_and_var_0() {
782   char *x = "123";
783   clang_analyzer_eval(strncmp(x, "123", 3) == 0); // expected-warning{{TRUE}}
784 }
785 
786 void strncmp_constant_and_var_1() {
787   char *x = "123";
788   clang_analyzer_eval(strncmp("123", x, 3) == 0); // expected-warning{{TRUE}}
789 }
790 
791 void strncmp_0() {
792   char *x = "123";
793   char *y = "123";
794   clang_analyzer_eval(strncmp(x, y, 3) == 0); // expected-warning{{TRUE}}
795 }
796 
797 void strncmp_1() {
798   char *x = "234";
799   char *y = "123";
800   clang_analyzer_eval(strncmp(x, y, 3) == 1); // expected-warning{{TRUE}}
801 }
802 
803 void strncmp_2() {
804   char *x = "123";
805   char *y = "234";
806   clang_analyzer_eval(strncmp(x, y, 3) == -1); // expected-warning{{TRUE}}
807 }
808 
809 void strncmp_null_0() {
810   char *x = NULL;
811   char *y = "123";
812   strncmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
813 }
814 
815 void strncmp_null_1() {
816   char *x = "123";
817   char *y = NULL;
818   strncmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
819 }
820 
821 void strncmp_diff_length_0() {
822   char *x = "12345";
823   char *y = "234";
824   clang_analyzer_eval(strncmp(x, y, 5) == -1); // expected-warning{{TRUE}}
825 }
826 
827 void strncmp_diff_length_1() {
828   char *x = "123";
829   char *y = "23456";
830   clang_analyzer_eval(strncmp(x, y, 5) == -1); // expected-warning{{TRUE}}
831 }
832 
833 void strncmp_diff_length_2() {
834   char *x = "12345";
835   char *y = "123";
836   clang_analyzer_eval(strncmp(x, y, 5) == 1); // expected-warning{{TRUE}}
837 }
838 
839 void strncmp_diff_length_3() {
840   char *x = "123";
841   char *y = "12345";
842   clang_analyzer_eval(strncmp(x, y, 5) == -1); // expected-warning{{TRUE}}
843 }
844 
845 void strncmp_diff_length_4() {
846   char *x = "123";
847   char *y = "12345";
848   clang_analyzer_eval(strncmp(x, y, 3) == 0); // expected-warning{{TRUE}}
849 }
850 
851 void strncmp_diff_length_5() {
852   char *x = "012";
853   char *y = "12345";
854   clang_analyzer_eval(strncmp(x, y, 3) == -1); // expected-warning{{TRUE}}
855 }
856 
857 void strncmp_diff_length_6() {
858   char *x = "234";
859   char *y = "12345";
860   clang_analyzer_eval(strncmp(x, y, 3) == 1); // expected-warning{{TRUE}}
861 }
862 
863 void strncmp_embedded_null () {
864 	clang_analyzer_eval(strncmp("ab\0zz", "ab\0yy", 4) == 0); // expected-warning{{TRUE}}
865 }
866 
867 //===----------------------------------------------------------------------===
868 // strcasecmp()
869 //===----------------------------------------------------------------------===
870 
871 #define strcasecmp BUILTIN(strcasecmp)
872 int strcasecmp(const char *s1, const char *s2);
873 
874 void strcasecmp_constant0() {
875   clang_analyzer_eval(strcasecmp("abc", "Abc") == 0); // expected-warning{{TRUE}}
876 }
877 
878 void strcasecmp_constant_and_var_0() {
879   char *x = "abc";
880   clang_analyzer_eval(strcasecmp(x, "Abc") == 0); // expected-warning{{TRUE}}
881 }
882 
883 void strcasecmp_constant_and_var_1() {
884   char *x = "abc";
885   clang_analyzer_eval(strcasecmp("Abc", x) == 0); // expected-warning{{TRUE}}
886 }
887 
888 void strcasecmp_0() {
889   char *x = "abc";
890   char *y = "Abc";
891   clang_analyzer_eval(strcasecmp(x, y) == 0); // expected-warning{{TRUE}}
892 }
893 
894 void strcasecmp_1() {
895   char *x = "Bcd";
896   char *y = "abc";
897   clang_analyzer_eval(strcasecmp(x, y) == 1); // expected-warning{{TRUE}}
898 }
899 
900 void strcasecmp_2() {
901   char *x = "abc";
902   char *y = "Bcd";
903   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
904 }
905 
906 void strcasecmp_null_0() {
907   char *x = NULL;
908   char *y = "123";
909   strcasecmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
910 }
911 
912 void strcasecmp_null_1() {
913   char *x = "123";
914   char *y = NULL;
915   strcasecmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
916 }
917 
918 void strcasecmp_diff_length_0() {
919   char *x = "abcde";
920   char *y = "aBd";
921   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
922 }
923 
924 void strcasecmp_diff_length_1() {
925   char *x = "abc";
926   char *y = "aBdef";
927   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
928 }
929 
930 void strcasecmp_diff_length_2() {
931   char *x = "aBcDe";
932   char *y = "abc";
933   clang_analyzer_eval(strcasecmp(x, y) == 1); // expected-warning{{TRUE}}
934 }
935 
936 void strcasecmp_diff_length_3() {
937   char *x = "aBc";
938   char *y = "abcde";
939   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
940 }
941 
942 void strcasecmp_embedded_null () {
943 	clang_analyzer_eval(strcasecmp("ab\0zz", "ab\0yy") == 0); // expected-warning{{TRUE}}
944 }
945 
946 //===----------------------------------------------------------------------===
947 // strncasecmp()
948 //===----------------------------------------------------------------------===
949 
950 #define strncasecmp BUILTIN(strncasecmp)
951 int strncasecmp(const char *s1, const char *s2, size_t n);
952 
953 void strncasecmp_constant0() {
954   clang_analyzer_eval(strncasecmp("abc", "Abc", 3) == 0); // expected-warning{{TRUE}}
955 }
956 
957 void strncasecmp_constant_and_var_0() {
958   char *x = "abc";
959   clang_analyzer_eval(strncasecmp(x, "Abc", 3) == 0); // expected-warning{{TRUE}}
960 }
961 
962 void strncasecmp_constant_and_var_1() {
963   char *x = "abc";
964   clang_analyzer_eval(strncasecmp("Abc", x, 3) == 0); // expected-warning{{TRUE}}
965 }
966 
967 void strncasecmp_0() {
968   char *x = "abc";
969   char *y = "Abc";
970   clang_analyzer_eval(strncasecmp(x, y, 3) == 0); // expected-warning{{TRUE}}
971 }
972 
973 void strncasecmp_1() {
974   char *x = "Bcd";
975   char *y = "abc";
976   clang_analyzer_eval(strncasecmp(x, y, 3) == 1); // expected-warning{{TRUE}}
977 }
978 
979 void strncasecmp_2() {
980   char *x = "abc";
981   char *y = "Bcd";
982   clang_analyzer_eval(strncasecmp(x, y, 3) == -1); // expected-warning{{TRUE}}
983 }
984 
985 void strncasecmp_null_0() {
986   char *x = NULL;
987   char *y = "123";
988   strncasecmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
989 }
990 
991 void strncasecmp_null_1() {
992   char *x = "123";
993   char *y = NULL;
994   strncasecmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
995 }
996 
997 void strncasecmp_diff_length_0() {
998   char *x = "abcde";
999   char *y = "aBd";
1000   clang_analyzer_eval(strncasecmp(x, y, 5) == -1); // expected-warning{{TRUE}}
1001 }
1002 
1003 void strncasecmp_diff_length_1() {
1004   char *x = "abc";
1005   char *y = "aBdef";
1006   clang_analyzer_eval(strncasecmp(x, y, 5) == -1); // expected-warning{{TRUE}}
1007 }
1008 
1009 void strncasecmp_diff_length_2() {
1010   char *x = "aBcDe";
1011   char *y = "abc";
1012   clang_analyzer_eval(strncasecmp(x, y, 5) == 1); // expected-warning{{TRUE}}
1013 }
1014 
1015 void strncasecmp_diff_length_3() {
1016   char *x = "aBc";
1017   char *y = "abcde";
1018   clang_analyzer_eval(strncasecmp(x, y, 5) == -1); // expected-warning{{TRUE}}
1019 }
1020 
1021 void strncasecmp_diff_length_4() {
1022   char *x = "abcde";
1023   char *y = "aBc";
1024   clang_analyzer_eval(strncasecmp(x, y, 3) == 0); // expected-warning{{TRUE}}
1025 }
1026 
1027 void strncasecmp_diff_length_5() {
1028   char *x = "abcde";
1029   char *y = "aBd";
1030   clang_analyzer_eval(strncasecmp(x, y, 3) == -1); // expected-warning{{TRUE}}
1031 }
1032 
1033 void strncasecmp_diff_length_6() {
1034   char *x = "aBDe";
1035   char *y = "abc";
1036   clang_analyzer_eval(strncasecmp(x, y, 3) == 1); // expected-warning{{TRUE}}
1037 }
1038 
1039 void strncasecmp_embedded_null () {
1040 	clang_analyzer_eval(strncasecmp("ab\0zz", "ab\0yy", 4) == 0); // expected-warning{{TRUE}}
1041 }
1042