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 //===----------------------------------------------------------------------===
760 // strncmp()
761 //===----------------------------------------------------------------------===
762 
763 #define strncmp BUILTIN(strncmp)
764 int strncmp(const char *s1, const char *s2, size_t n);
765 
766 void strncmp_constant0() {
767   clang_analyzer_eval(strncmp("123", "123", 3) == 0); // expected-warning{{TRUE}}
768 }
769 
770 void strncmp_constant_and_var_0() {
771   char *x = "123";
772   clang_analyzer_eval(strncmp(x, "123", 3) == 0); // expected-warning{{TRUE}}
773 }
774 
775 void strncmp_constant_and_var_1() {
776   char *x = "123";
777   clang_analyzer_eval(strncmp("123", x, 3) == 0); // expected-warning{{TRUE}}
778 }
779 
780 void strncmp_0() {
781   char *x = "123";
782   char *y = "123";
783   clang_analyzer_eval(strncmp(x, y, 3) == 0); // expected-warning{{TRUE}}
784 }
785 
786 void strncmp_1() {
787   char *x = "234";
788   char *y = "123";
789   clang_analyzer_eval(strncmp(x, y, 3) == 1); // expected-warning{{TRUE}}
790 }
791 
792 void strncmp_2() {
793   char *x = "123";
794   char *y = "234";
795   clang_analyzer_eval(strncmp(x, y, 3) == -1); // expected-warning{{TRUE}}
796 }
797 
798 void strncmp_null_0() {
799   char *x = NULL;
800   char *y = "123";
801   strncmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
802 }
803 
804 void strncmp_null_1() {
805   char *x = "123";
806   char *y = NULL;
807   strncmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
808 }
809 
810 void strncmp_diff_length_0() {
811   char *x = "12345";
812   char *y = "234";
813   clang_analyzer_eval(strncmp(x, y, 5) == -1); // expected-warning{{TRUE}}
814 }
815 
816 void strncmp_diff_length_1() {
817   char *x = "123";
818   char *y = "23456";
819   clang_analyzer_eval(strncmp(x, y, 5) == -1); // expected-warning{{TRUE}}
820 }
821 
822 void strncmp_diff_length_2() {
823   char *x = "12345";
824   char *y = "123";
825   clang_analyzer_eval(strncmp(x, y, 5) == 1); // expected-warning{{TRUE}}
826 }
827 
828 void strncmp_diff_length_3() {
829   char *x = "123";
830   char *y = "12345";
831   clang_analyzer_eval(strncmp(x, y, 5) == -1); // expected-warning{{TRUE}}
832 }
833 
834 void strncmp_diff_length_4() {
835   char *x = "123";
836   char *y = "12345";
837   clang_analyzer_eval(strncmp(x, y, 3) == 0); // expected-warning{{TRUE}}
838 }
839 
840 void strncmp_diff_length_5() {
841   char *x = "012";
842   char *y = "12345";
843   clang_analyzer_eval(strncmp(x, y, 3) == -1); // expected-warning{{TRUE}}
844 }
845 
846 void strncmp_diff_length_6() {
847   char *x = "234";
848   char *y = "12345";
849   clang_analyzer_eval(strncmp(x, y, 3) == 1); // expected-warning{{TRUE}}
850 }
851 
852 void strncmp_embedded_null () {
853 	clang_analyzer_eval(strncmp("ab\0zz", "ab\0yy", 4) == 0); // expected-warning{{TRUE}}
854 }
855 
856 //===----------------------------------------------------------------------===
857 // strcasecmp()
858 //===----------------------------------------------------------------------===
859 
860 #define strcasecmp BUILTIN(strcasecmp)
861 int strcasecmp(const char *s1, const char *s2);
862 
863 void strcasecmp_constant0() {
864   clang_analyzer_eval(strcasecmp("abc", "Abc") == 0); // expected-warning{{TRUE}}
865 }
866 
867 void strcasecmp_constant_and_var_0() {
868   char *x = "abc";
869   clang_analyzer_eval(strcasecmp(x, "Abc") == 0); // expected-warning{{TRUE}}
870 }
871 
872 void strcasecmp_constant_and_var_1() {
873   char *x = "abc";
874   clang_analyzer_eval(strcasecmp("Abc", x) == 0); // expected-warning{{TRUE}}
875 }
876 
877 void strcasecmp_0() {
878   char *x = "abc";
879   char *y = "Abc";
880   clang_analyzer_eval(strcasecmp(x, y) == 0); // expected-warning{{TRUE}}
881 }
882 
883 void strcasecmp_1() {
884   char *x = "Bcd";
885   char *y = "abc";
886   clang_analyzer_eval(strcasecmp(x, y) == 1); // expected-warning{{TRUE}}
887 }
888 
889 void strcasecmp_2() {
890   char *x = "abc";
891   char *y = "Bcd";
892   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
893 }
894 
895 void strcasecmp_null_0() {
896   char *x = NULL;
897   char *y = "123";
898   strcasecmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
899 }
900 
901 void strcasecmp_null_1() {
902   char *x = "123";
903   char *y = NULL;
904   strcasecmp(x, y); // expected-warning{{Null pointer argument in call to string comparison function}}
905 }
906 
907 void strcasecmp_diff_length_0() {
908   char *x = "abcde";
909   char *y = "aBd";
910   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
911 }
912 
913 void strcasecmp_diff_length_1() {
914   char *x = "abc";
915   char *y = "aBdef";
916   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
917 }
918 
919 void strcasecmp_diff_length_2() {
920   char *x = "aBcDe";
921   char *y = "abc";
922   clang_analyzer_eval(strcasecmp(x, y) == 1); // expected-warning{{TRUE}}
923 }
924 
925 void strcasecmp_diff_length_3() {
926   char *x = "aBc";
927   char *y = "abcde";
928   clang_analyzer_eval(strcasecmp(x, y) == -1); // expected-warning{{TRUE}}
929 }
930 
931 void strcasecmp_embedded_null () {
932 	clang_analyzer_eval(strcasecmp("ab\0zz", "ab\0yy") == 0); // expected-warning{{TRUE}}
933 }
934 
935 //===----------------------------------------------------------------------===
936 // strncasecmp()
937 //===----------------------------------------------------------------------===
938 
939 #define strncasecmp BUILTIN(strncasecmp)
940 int strncasecmp(const char *s1, const char *s2, size_t n);
941 
942 void strncasecmp_constant0() {
943   clang_analyzer_eval(strncasecmp("abc", "Abc", 3) == 0); // expected-warning{{TRUE}}
944 }
945 
946 void strncasecmp_constant_and_var_0() {
947   char *x = "abc";
948   clang_analyzer_eval(strncasecmp(x, "Abc", 3) == 0); // expected-warning{{TRUE}}
949 }
950 
951 void strncasecmp_constant_and_var_1() {
952   char *x = "abc";
953   clang_analyzer_eval(strncasecmp("Abc", x, 3) == 0); // expected-warning{{TRUE}}
954 }
955 
956 void strncasecmp_0() {
957   char *x = "abc";
958   char *y = "Abc";
959   clang_analyzer_eval(strncasecmp(x, y, 3) == 0); // expected-warning{{TRUE}}
960 }
961 
962 void strncasecmp_1() {
963   char *x = "Bcd";
964   char *y = "abc";
965   clang_analyzer_eval(strncasecmp(x, y, 3) == 1); // expected-warning{{TRUE}}
966 }
967 
968 void strncasecmp_2() {
969   char *x = "abc";
970   char *y = "Bcd";
971   clang_analyzer_eval(strncasecmp(x, y, 3) == -1); // expected-warning{{TRUE}}
972 }
973 
974 void strncasecmp_null_0() {
975   char *x = NULL;
976   char *y = "123";
977   strncasecmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
978 }
979 
980 void strncasecmp_null_1() {
981   char *x = "123";
982   char *y = NULL;
983   strncasecmp(x, y, 3); // expected-warning{{Null pointer argument in call to string comparison function}}
984 }
985 
986 void strncasecmp_diff_length_0() {
987   char *x = "abcde";
988   char *y = "aBd";
989   clang_analyzer_eval(strncasecmp(x, y, 5) == -1); // expected-warning{{TRUE}}
990 }
991 
992 void strncasecmp_diff_length_1() {
993   char *x = "abc";
994   char *y = "aBdef";
995   clang_analyzer_eval(strncasecmp(x, y, 5) == -1); // expected-warning{{TRUE}}
996 }
997 
998 void strncasecmp_diff_length_2() {
999   char *x = "aBcDe";
1000   char *y = "abc";
1001   clang_analyzer_eval(strncasecmp(x, y, 5) == 1); // expected-warning{{TRUE}}
1002 }
1003 
1004 void strncasecmp_diff_length_3() {
1005   char *x = "aBc";
1006   char *y = "abcde";
1007   clang_analyzer_eval(strncasecmp(x, y, 5) == -1); // expected-warning{{TRUE}}
1008 }
1009 
1010 void strncasecmp_diff_length_4() {
1011   char *x = "abcde";
1012   char *y = "aBc";
1013   clang_analyzer_eval(strncasecmp(x, y, 3) == 0); // expected-warning{{TRUE}}
1014 }
1015 
1016 void strncasecmp_diff_length_5() {
1017   char *x = "abcde";
1018   char *y = "aBd";
1019   clang_analyzer_eval(strncasecmp(x, y, 3) == -1); // expected-warning{{TRUE}}
1020 }
1021 
1022 void strncasecmp_diff_length_6() {
1023   char *x = "aBDe";
1024   char *y = "abc";
1025   clang_analyzer_eval(strncasecmp(x, y, 3) == 1); // expected-warning{{TRUE}}
1026 }
1027 
1028 void strncasecmp_embedded_null () {
1029 	clang_analyzer_eval(strncasecmp("ab\0zz", "ab\0yy", 4) == 0); // expected-warning{{TRUE}}
1030 }
1031 
1032 //===----------------------------------------------------------------------===
1033 // strsep()
1034 //===----------------------------------------------------------------------===
1035 
1036 char *strsep(char **stringp, const char *delim);
1037 
1038 void strsep_null_delim(char *s) {
1039   strsep(&s, NULL); // expected-warning{{Null pointer argument in call to strsep()}}
1040 }
1041 
1042 void strsep_null_search() {
1043   strsep(NULL, ""); // expected-warning{{Null pointer argument in call to strsep()}}
1044 }
1045 
1046 void strsep_return_original_pointer(char *s) {
1047   char *original = s;
1048   char *result = strsep(&s, ""); // no-warning
1049   clang_analyzer_eval(original == result); // expected-warning{{TRUE}}
1050 }
1051 
1052 void strsep_null_string() {
1053   char *s = NULL;
1054   char *result = strsep(&s, ""); // no-warning
1055   clang_analyzer_eval(result == NULL); // expected-warning{{TRUE}}
1056 }
1057 
1058 void strsep_changes_input_pointer(char *s) {
1059   char *original = s;
1060   strsep(&s, ""); // no-warning
1061   clang_analyzer_eval(s == original); // expected-warning{{UNKNOWN}}
1062   clang_analyzer_eval(s == NULL); // expected-warning{{UNKNOWN}}
1063 
1064   // Check that the value is symbolic.
1065   if (s == NULL) {
1066     clang_analyzer_eval(s == NULL); // expected-warning{{TRUE}}
1067   }
1068 }
1069 
1070 void strsep_changes_input_string() {
1071   char str[] = "abc";
1072 
1073   clang_analyzer_eval(str[1] == 'b'); // expected-warning{{TRUE}}
1074 
1075   char *s = str;
1076   strsep(&s, "b"); // no-warning
1077 
1078   // The real strsep will change the first delimiter it finds into a NUL
1079   // character. For now, we just model the invalidation.
1080   clang_analyzer_eval(str[1] == 'b'); // expected-warning{{UNKNOWN}}
1081 }
1082 
1083 //===----------------------------------------------------------------------===
1084 // FIXMEs
1085 //===----------------------------------------------------------------------===
1086 
1087 // The analyzer_eval call below should evaluate to true. We are being too
1088 // aggressive in marking the (length of) src symbol dead. The length of dst
1089 // depends on src. This could be explicitely specified in the checker or the
1090 // logic for handling MetadataSymbol in SymbolManager needs to change.
1091 void strcat_symbolic_src_length(char *src) {
1092 	char dst[8] = "1234";
1093 	strcat(dst, src);
1094   clang_analyzer_eval(strlen(dst) >= 4); // expected-warning{{UNKNOWN}}
1095 }
1096 
1097 // The analyzer_eval call below should evaluate to true. Most likely the same
1098 // issue as the test above.
1099 void strncpy_exactly_matching_buffer2(char *y) {
1100 	if (strlen(y) >= 4)
1101 		return;
1102 
1103 	char x[4];
1104 	strncpy(x, y, 4); // no-warning
1105 
1106 	// This time, we know that y fits in x anyway.
1107   clang_analyzer_eval(strlen(x) <= 3); // expected-warning{{UNKNOWN}}
1108 }
1109