clang/test/Analysis/bstring.c

   1 // RUN: %clang_analyze_cc1 -verify %s \
   2 // RUN:   -analyzer-checker=core \
   3 // RUN:   -analyzer-checker=unix.cstring \
   4 // RUN:   -analyzer-checker=alpha.unix.cstring \
   5 // RUN:   -analyzer-disable-checker=alpha.unix.cstring.UninitializedRead \
   6 // RUN:   -analyzer-checker=debug.ExprInspection \
   7 // RUN:   -analyzer-config eagerly-assume=false
   8 //
   9 // RUN: %clang_analyze_cc1 -verify %s -DUSE_BUILTINS \
  10 // RUN:   -analyzer-checker=core \
  11 // RUN:   -analyzer-checker=unix.cstring \
  12 // RUN:   -analyzer-checker=alpha.unix.cstring \
  13 // RUN:   -analyzer-disable-checker=alpha.unix.cstring.UninitializedRead \
  14 // RUN:   -analyzer-checker=debug.ExprInspection \
  15 // RUN:   -analyzer-config eagerly-assume=false
  16 //
  17 // RUN: %clang_analyze_cc1 -verify %s -DVARIANT \
  18 // RUN:   -analyzer-checker=core \
  19 // RUN:   -analyzer-checker=unix.cstring \
  20 // RUN:   -analyzer-checker=alpha.unix.cstring \
  21 // RUN:   -analyzer-disable-checker=alpha.unix.cstring.UninitializedRead \
  22 // RUN:   -analyzer-checker=debug.ExprInspection \
  23 // RUN:   -analyzer-config eagerly-assume=false
  24 //
  25 // RUN: %clang_analyze_cc1 -verify %s -DUSE_BUILTINS -DVARIANT \
  26 // RUN:   -analyzer-checker=core \
  27 // RUN:   -analyzer-checker=unix.cstring \
  28 // RUN:   -analyzer-checker=alpha.unix.cstring \
  29 // RUN:   -analyzer-disable-checker=alpha.unix.cstring.UninitializedRead \
  30 // RUN:   -analyzer-checker=debug.ExprInspection \
  31 // RUN:   -analyzer-config eagerly-assume=false
  32
  33 //===----------------------------------------------------------------------===
  34 // Declarations
  35 //===----------------------------------------------------------------------===
  36
  37 // Some functions are so similar to each other that they follow the same code
  38 // path, such as memcpy and __memcpy_chk, or memcmp and bcmp. If VARIANT is
  39 // defined, make sure to use the variants instead to make sure they are still
  40 // checked by the analyzer.
  41
  42 // Some functions are implemented as builtins. These should be #defined as
  43 // BUILTIN(f), which will prepend "__builtin_" if USE_BUILTINS is defined.
  44
  45 // Functions that have variants and are also available as builtins should be
  46 // declared carefully! See memcpy() for an example.
  47
  48 #ifdef USE_BUILTINS
  49 # define BUILTIN(f) __builtin_ ## f
  50 #else /* USE_BUILTINS */
  51 # define BUILTIN(f) f
  52 #endif /* USE_BUILTINS */
  53
  54 typedef typeof(sizeof(int)) size_t;
  55
  56 void clang_analyzer_eval(int);
  57
  58 //===----------------------------------------------------------------------===
  59 // memcpy()
  60 //===----------------------------------------------------------------------===
  61
  62 #ifdef VARIANT
  63
  64 #define __memcpy_chk BUILTIN(__memcpy_chk)
  65 void *__memcpy_chk(void *restrict s1, const void *restrict s2, size_t n,
  66                    size_t destlen);
  67
  68 #define memcpy(a,b,c) __memcpy_chk(a,b,c,(size_t)-1)
  69
  70 #else /* VARIANT */
  71
  72 #define memcpy BUILTIN(memcpy)
  73 void *memcpy(void *restrict s1, const void *restrict s2, size_t n);
  74
  75 #endif /* VARIANT */
  76
  77
  78 void memcpy0 (void) {
  79   char src[] = {1, 2, 3, 4};
  80   char dst[4] = {0};
  81
  82   memcpy(dst, src, 4); // no-warning
  83
  84   clang_analyzer_eval(memcpy(dst, src, 4) == dst); // expected-warning{{TRUE}}
  85
  86   // If we actually model the copy, we can make this known.
  87   // The important thing for now is that the old value has been invalidated.
  88   clang_analyzer_eval(dst[0] != 0); // expected-warning{{UNKNOWN}}
  89 }
  90
  91 void memcpy1 (void) {
  92   char src[] = {1, 2, 3, 4};
  93   char dst[10];
  94
  95   memcpy(dst, src, 5); // expected-warning{{Memory copy function accesses out-of-bound array element}}
  96 }
  97
  98 void memcpy2 (void) {
  99   char src[] = {1, 2, 3, 4};
 100   char dst[1];
 101
 102   memcpy(dst, src, 4); // expected-warning {{Memory copy function overflows the destination buffer}}
 103 #ifndef VARIANT
 104   // expected-warning@-2 {{memcpy' will always overflow; destination buffer has size 1, but size argument is 4}}
 105 #endif
 106 }
 107
 108 void memcpy3 (void) {
 109   char src[] = {1, 2, 3, 4};
 110   char dst[3];
 111
 112   memcpy(dst+1, src+2, 2); // no-warning
 113 }
 114
 115 void memcpy4 (void) {
 116   char src[] = {1, 2, 3, 4};
 117   char dst[10];
 118
 119   memcpy(dst+2, src+2, 3); // expected-warning{{Memory copy function accesses out-of-bound array element}}
 120 }
 121
 122 void memcpy5(void) {
 123   char src[] = {1, 2, 3, 4};
 124   char dst[3];
 125
 126   memcpy(dst + 2, src + 2, 2); // expected-warning{{Memory copy function overflows the destination buffer}}
 127 #ifndef VARIANT
 128   // expected-warning@-2{{memcpy' will always overflow; destination buffer has size 1, but size argument is 2}}
 129 #endif
 130 }
 131
 132 void memcpy6(void) {
 133   int a[4] = {0};
 134   memcpy(a, a, 8); // expected-warning{{overlapping}}
 135 }
 136
 137 void memcpy7(void) {
 138   int a[4] = {0};
 139   memcpy(a+2, a+1, 8); // expected-warning{{overlapping}}
 140 }
 141
 142 void memcpy8(void) {
 143   int a[4] = {0};
 144   memcpy(a+1, a+2, 8); // expected-warning{{overlapping}}
 145 }
 146
 147 void memcpy9(void) {
 148   int a[4] = {0};
 149   memcpy(a+2, a+1, 4); // no-warning
 150   memcpy(a+1, a+2, 4); // no-warning
 151 }
 152
 153 void memcpy10(void) {
 154   char a[4] = {0};
 155   memcpy(0, a, 4); // expected-warning{{Null pointer passed as 1st argument to memory copy function}}
 156 }
 157
 158 void memcpy11(void) {
 159   char a[4] = {0};
 160   memcpy(a, 0, 4); // expected-warning{{Null pointer passed as 2nd argument to memory copy function}}
 161 }
 162
 163 void memcpy12(void) {
 164   char a[4] = {0};
 165   memcpy(0, a, 0); // no-warning
 166 }
 167
 168 void memcpy13(void) {
 169   char a[4] = {0};
 170   memcpy(a, 0, 0); // no-warning
 171 }
 172
 173 void memcpy_unknown_size (size_t n) {
 174   char a[4], b[4] = {1};
 175   clang_analyzer_eval(memcpy(a, b, n) == a); // expected-warning{{TRUE}}
 176 }
 177
 178 void memcpy_unknown_size_warn (size_t n) {
 179   char a[4];
 180   void *result = memcpy(a, 0, n); // expected-warning{{Null pointer passed as 2nd argument to memory copy function}}
 181   clang_analyzer_eval(result == a); // no-warning (above is fatal)
 182 }
 183
 184 //===----------------------------------------------------------------------===
 185 // mempcpy()
 186 //===----------------------------------------------------------------------===
 187
 188 #ifdef VARIANT
 189
 190 #define __mempcpy_chk BUILTIN(__mempcpy_chk)
 191 void *__mempcpy_chk(void *restrict s1, const void *restrict s2, size_t n,
 192                    size_t destlen);
 193
 194 #define mempcpy(a,b,c) __mempcpy_chk(a,b,c,(size_t)-1)
 195
 196 #else /* VARIANT */
 197
 198 #define mempcpy BUILTIN(mempcpy)
 199 void *mempcpy(void *restrict s1, const void *restrict s2, size_t n);
 200
 201 #endif /* VARIANT */
 202
 203
 204 void mempcpy0 (void) {
 205   char src[] = {1, 2, 3, 4};
 206   char dst[5] = {0};
 207
 208   mempcpy(dst, src, 4); // no-warning
 209
 210   clang_analyzer_eval(mempcpy(dst, src, 4) == &dst[4]); // expected-warning{{TRUE}}
 211
 212   // If we actually model the copy, we can make this known.
 213   // The important thing for now is that the old value has been invalidated.
 214   clang_analyzer_eval(dst[0] != 0); // expected-warning{{UNKNOWN}}
 215 }
 216
 217 void mempcpy1 (void) {
 218   char src[] = {1, 2, 3, 4};
 219   char dst[10];
 220
 221   mempcpy(dst, src, 5); // expected-warning{{Memory copy function accesses out-of-bound array element}}
 222 }
 223
 224 void mempcpy2 (void) {
 225   char src[] = {1, 2, 3, 4};
 226   char dst[1];
 227
 228   mempcpy(dst, src, 4); // expected-warning{{Memory copy function overflows the destination buffer}}
 229 #ifndef VARIANT
 230 // expected-warning@-2{{'mempcpy' will always overflow; destination buffer has size 1, but size argument is 4}}
 231 #endif
 232 }
 233
 234 void mempcpy3 (void) {
 235   char src[] = {1, 2, 3, 4};
 236   char dst[3];
 237
 238   mempcpy(dst+1, src+2, 2); // no-warning
 239 }
 240
 241 void mempcpy4 (void) {
 242   char src[] = {1, 2, 3, 4};
 243   char dst[10];
 244
 245   mempcpy(dst+2, src+2, 3); // expected-warning{{Memory copy function accesses out-of-bound array element}}
 246 }
 247
 248 void mempcpy5(void) {
 249   char src[] = {1, 2, 3, 4};
 250   char dst[3];
 251
 252   mempcpy(dst + 2, src + 2, 2); // expected-warning{{Memory copy function overflows the destination buffer}}
 253 #ifndef VARIANT
 254 // expected-warning@-2{{'mempcpy' will always overflow; destination buffer has size 1, but size argument is 2}}
 255 #endif
 256 }
 257
 258 void mempcpy6(void) {
 259   int a[4] = {0};
 260   mempcpy(a, a, 8); // expected-warning{{overlapping}}
 261 }
 262
 263 void mempcpy7(void) {
 264   int a[4] = {0};
 265   mempcpy(a+2, a+1, 8); // expected-warning{{overlapping}}
 266 }
 267
 268 void mempcpy8(void) {
 269   int a[4] = {0};
 270   mempcpy(a+1, a+2, 8); // expected-warning{{overlapping}}
 271 }
 272
 273 void mempcpy9(void) {
 274   int a[4] = {0};
 275   mempcpy(a+2, a+1, 4); // no-warning
 276   mempcpy(a+1, a+2, 4); // no-warning
 277 }
 278
 279 void mempcpy10(void) {
 280   char a[4] = {0};
 281   mempcpy(0, a, 4); // expected-warning{{Null pointer passed as 1st argument to memory copy function}}
 282 }
 283
 284 void mempcpy11(void) {
 285   char a[4] = {0};
 286   mempcpy(a, 0, 4); // expected-warning{{Null pointer passed as 2nd argument to memory copy function}}
 287 }
 288
 289 void mempcpy12(void) {
 290   char a[4] = {0};
 291   mempcpy(0, a, 0); // no-warning
 292 }
 293
 294 void mempcpy13(void) {
 295   char a[4] = {0};
 296   mempcpy(a, 0, 0); // no-warning
 297 }
 298
 299 void mempcpy14(void) {
 300   int src[] = {1, 2, 3, 4};
 301   int dst[5] = {0};
 302   int *p;
 303
 304   p = mempcpy(dst, src, 4 * sizeof(int));
 305
 306   clang_analyzer_eval(p == &dst[4]); // expected-warning{{TRUE}}
 307 }
 308
 309 struct st {
 310   int i;
 311   int j;
 312 };
 313
 314 void mempcpy15(void) {
 315   struct st s1 = {0};
 316   struct st s2;
 317   struct st *p1;
 318   struct st *p2;
 319
 320   p1 = (&s2) + 1;
 321   p2 = mempcpy(&s2, &s1, sizeof(struct st));
 322
 323   clang_analyzer_eval(p1 == p2); // expected-warning{{TRUE}}
 324 }
 325
 326 void mempcpy16(void) {
 327   struct st s1[10] = {{0}};
 328   struct st s2[10];
 329   struct st *p1;
 330   struct st *p2;
 331
 332   p1 = (&s2[0]) + 5;
 333   p2 = mempcpy(&s2[0], &s1[0], 5 * sizeof(struct st));
 334
 335   clang_analyzer_eval(p1 == p2); // expected-warning{{TRUE}}
 336 }
 337
 338 void mempcpy_unknown_size_warn (size_t n) {
 339   char a[4];
 340   void *result = mempcpy(a, 0, n); // expected-warning{{Null pointer passed as 2nd argument to memory copy function}}
 341   clang_analyzer_eval(result == a); // no-warning (above is fatal)
 342 }
 343
 344 void mempcpy_unknownable_size (char *src, float n) {
 345   char a[4];
 346   // This used to crash because we don't model floats.
 347   mempcpy(a, src, (size_t)n);
 348 }
 349
 350 //===----------------------------------------------------------------------===
 351 // memmove()
 352 //===----------------------------------------------------------------------===
 353
 354 #ifdef VARIANT
 355
 356 #define __memmove_chk BUILTIN(__memmove_chk)
 357 void *__memmove_chk(void *s1, const void *s2, size_t n, size_t destlen);
 358
 359 #define memmove(a,b,c) __memmove_chk(a,b,c,(size_t)-1)
 360
 361 #else /* VARIANT */
 362
 363 #define memmove BUILTIN(memmove)
 364 void *memmove(void *s1, const void *s2, size_t n);
 365
 366 #endif /* VARIANT */
 367
 368
 369 void memmove0 (void) {
 370   char src[] = {1, 2, 3, 4};
 371   char dst[4] = {0};
 372
 373   memmove(dst, src, 4); // no-warning
 374
 375   clang_analyzer_eval(memmove(dst, src, 4) == dst); // expected-warning{{TRUE}}
 376
 377   // If we actually model the copy, we can make this known.
 378   // The important thing for now is that the old value has been invalidated.
 379   clang_analyzer_eval(dst[0] != 0); // expected-warning{{UNKNOWN}}
 380 }
 381
 382 void memmove1 (void) {
 383   char src[] = {1, 2, 3, 4};
 384   char dst[10];
 385
 386   memmove(dst, src, 5); // expected-warning{{out-of-bound}}
 387 }
 388
 389 void memmove2 (void) {
 390   char src[] = {1, 2, 3, 4};
 391   char dst[1];
 392
 393   memmove(dst, src, 4); // expected-warning{{Memory copy function overflows the destination buffer}}
 394 #ifndef VARIANT
 395   // expected-warning@-2{{memmove' will always overflow; destination buffer has size 1, but size argument is 4}}
 396 #endif
 397 }
 398
 399 //===----------------------------------------------------------------------===
 400 // memcmp()
 401 //===----------------------------------------------------------------------===
 402
 403 #ifdef VARIANT
 404
 405 #define bcmp BUILTIN(bcmp)
 406 int bcmp(const void *s1, const void *s2, size_t n);
 407 #define memcmp bcmp
 408 //
 409 #else /* VARIANT */
 410
 411 #define memcmp BUILTIN(memcmp)
 412 int memcmp(const void *s1, const void *s2, size_t n);
 413
 414 #endif /* VARIANT */
 415
 416
 417 void memcmp0 (void) {
 418   char a[] = {1, 2, 3, 4};
 419   char b[4] = { 0 };
 420
 421   memcmp(a, b, 4); // no-warning
 422 }
 423
 424 void memcmp1 (void) {
 425   char a[] = {1, 2, 3, 4};
 426   char b[10] = { 0 };
 427
 428   memcmp(a, b, 5); // expected-warning{{out-of-bound}}
 429 }
 430
 431 void memcmp2 (void) {
 432   char a[] = {1, 2, 3, 4};
 433   char b[1] = { 0 };
 434
 435   memcmp(a, b, 4); // expected-warning{{out-of-bound}}
 436 }
 437
 438 void memcmp3 (void) {
 439   char a[] = {1, 2, 3, 4};
 440
 441   clang_analyzer_eval(memcmp(a, a, 4) == 0); // expected-warning{{TRUE}}
 442 }
 443
 444 void memcmp4 (char *input) {
 445   char a[] = {1, 2, 3, 4};
 446
 447   clang_analyzer_eval(memcmp(a, input, 4) == 0); // expected-warning{{UNKNOWN}}
 448 }
 449
 450 void memcmp5 (char *input) {
 451   char a[] = {1, 2, 3, 4};
 452
 453   clang_analyzer_eval(memcmp(a, 0, 0) == 0); // expected-warning{{TRUE}}
 454   clang_analyzer_eval(memcmp(0, a, 0) == 0); // expected-warning{{TRUE}}
 455   clang_analyzer_eval(memcmp(a, input, 0) == 0); // expected-warning{{TRUE}}
 456 }
 457
 458 void memcmp6 (char *a, char *b, size_t n) {
 459   int result = memcmp(a, b, n);
 460   if (result != 0)
 461     clang_analyzer_eval(n != 0); // expected-warning{{TRUE}}
 462   // else
 463   //   analyzer_assert_unknown(n == 0);
 464
 465   // We can't do the above comparison because n has already been constrained.
 466   // On one path n == 0, on the other n != 0.
 467 }
 468
 469 int memcmp7 (char *a, size_t x, size_t y, size_t n) {
 470   // We used to crash when either of the arguments was unknown.
 471   return memcmp(a, &a[x*y], n) +
 472          memcmp(&a[x*y], a, n);
 473 }
 474
 475 int memcmp8(char *a, size_t n) {
 476   char *b = 0;
 477   // Do not warn about the first argument!
 478   return memcmp(a, b, n); // expected-warning{{Null pointer passed as 2nd argument to memory comparison function}}
 479 }
 480
 481 //===----------------------------------------------------------------------===
 482 // bcopy()
 483 //===----------------------------------------------------------------------===
 484
 485 #define bcopy BUILTIN(bcopy)
 486 // __builtin_bcopy is not defined with const in Builtins.def.
 487 void bcopy(/*const*/ void *s1, void *s2, size_t n);
 488
 489
 490 void bcopy0 (void) {
 491   char src[] = {1, 2, 3, 4};
 492   char dst[4] = {0};
 493
 494   bcopy(src, dst, 4); // no-warning
 495
 496   // If we actually model the copy, we can make this known.
 497   // The important thing for now is that the old value has been invalidated.
 498   clang_analyzer_eval(dst[0] != 0); // expected-warning{{UNKNOWN}}
 499 }
 500
 501 void bcopy1 (void) {
 502   char src[] = {1, 2, 3, 4};
 503   char dst[10];
 504
 505   bcopy(src, dst, 5); // expected-warning{{out-of-bound}}
 506 }
 507
 508 void bcopy2 (void) {
 509   char src[] = {1, 2, 3, 4};
 510   char dst[1];
 511
 512   bcopy(src, dst, 4); // expected-warning{{overflow}}
 513 }
 514
 515 void *malloc(size_t);
 516 void free(void *);
 517 char radar_11125445_memcopythenlogfirstbyte(const char *input, size_t length) {
 518   char *bytes = malloc(sizeof(char) * (length + 1));
 519   memcpy(bytes, input, length);
 520   char x = bytes[0]; // no warning
 521   free(bytes);
 522   return x;
 523 }
 524
 525 struct S {
 526   char f;
 527 };
 528
 529 void nocrash_on_locint_offset(void *addr, void* from, struct S s) {
 530   size_t iAdd = (size_t) addr;
 531   memcpy(((void *) &(s.f)), from, iAdd);
 532 }