string/test-strncmp.c

   1 /* Test strncmp and wcsncmp functions.
   2    Copyright (C) 1999-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #define TEST_MAIN
  20 #ifdef WIDE
  21 # define TEST_NAME "wcsncmp"
  22 #else
  23 # define TEST_NAME "strncmp"
  24 #endif
  25 #include "test-string.h"
  26
  27 #ifdef WIDE
  28 # include <wchar.h>
  29
  30 # define L(str) L##str
  31 # define STRNCMP wcsncmp
  32 # define STRCPY wcscpy
  33 # define STRDUP wcsdup
  34 # define MEMCPY wmemcpy
  35 # define SIMPLE_STRNCMP simple_wcsncmp
  36 # define STUPID_STRNCMP stupid_wcsncmp
  37 # define CHAR wchar_t
  38 # define UCHAR wchar_t
  39 # define CHARBYTES 4
  40 # define CHAR__MAX WCHAR_MAX
  41 # define CHAR__MIN WCHAR_MIN
  42
  43 /* Wcsncmp uses signed semantics for comparison, not unsigned.
  44    Avoid using substraction since possible overflow */
  45 int
  46 simple_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
  47 {
  48   wchar_t c1, c2;
  49
  50   while (n--)
  51     {
  52       c1 = *s1++;
  53       c2 = *s2++;
  54       if (c1 == L('\0') || c1 != c2)
  55         return c1 > c2 ? 1 : (c1 < c2 ? -1 : 0);
  56     }
  57   return 0;
  58 }
  59
  60 int
  61 stupid_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
  62 {
  63   wchar_t c1, c2;
  64   size_t ns1 = wcsnlen (s1, n) + 1, ns2 = wcsnlen (s2, n) + 1;
  65
  66   n = ns1 < n ? ns1 : n;
  67   n = ns2 < n ? ns2 : n;
  68
  69   while (n--)
  70     {
  71       c1 = *s1++;
  72       c2 = *s2++;
  73       if (c1 != c2)
  74         return c1 > c2 ? 1 : -1;
  75     }
  76   return 0;
  77 }
  78
  79 #else
  80 # define L(str) str
  81 # define STRNCMP strncmp
  82 # define STRCPY strcpy
  83 # define STRDUP strdup
  84 # define MEMCPY memcpy
  85 # define SIMPLE_STRNCMP simple_strncmp
  86 # define STUPID_STRNCMP stupid_strncmp
  87 # define CHAR char
  88 # define UCHAR unsigned char
  89 # define CHARBYTES 1
  90 # define CHAR__MAX CHAR_MAX
  91 # define CHAR__MIN CHAR_MIN
  92
  93 /* Strncmp uses unsigned semantics for comparison. */
  94 int
  95 simple_strncmp (const char *s1, const char *s2, size_t n)
  96 {
  97   int ret = 0;
  98
  99   while (n-- && (ret = *(unsigned char *) s1 - * (unsigned char *) s2++) == 0
 100          && *s1++);
 101   return ret;
 102 }
 103
 104 int
 105 stupid_strncmp (const char *s1, const char *s2, size_t n)
 106 {
 107   size_t ns1 = strnlen (s1, n) + 1, ns2 = strnlen (s2, n) + 1;
 108   int ret = 0;
 109
 110   n = ns1 < n ? ns1 : n;
 111   n = ns2 < n ? ns2 : n;
 112   while (n-- && (ret = *(unsigned char *) s1++ - * (unsigned char *) s2++) == 0);
 113   return ret;
 114 }
 115
 116 #endif
 117
 118 typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
 119
 120 IMPL (STUPID_STRNCMP, 0)
 121 IMPL (SIMPLE_STRNCMP, 0)
 122 IMPL (STRNCMP, 1)
 123
 124
 125 static int
 126 check_result (impl_t *impl, const CHAR *s1, const CHAR *s2, size_t n,
 127              int exp_result)
 128 {
 129   int result = CALL (impl, s1, s2, n);
 130   if ((exp_result == 0 && result != 0)
 131       || (exp_result < 0 && result >= 0)
 132       || (exp_result > 0 && result <= 0))
 133     {
 134       error (0, 0, "Wrong result in function %s %d %d", impl->name,
 135              result, exp_result);
 136       ret = 1;
 137       return -1;
 138     }
 139
 140   return 0;
 141 }
 142
 143 static void
 144 do_one_test (impl_t *impl, const CHAR *s1, const CHAR *s2, size_t n,
 145              int exp_result)
 146 {
 147   if (check_result (impl, s1, s2, n, exp_result) < 0)
 148     return;
 149 }
 150
 151 static void
 152 do_test_limit (size_t align1, size_t align2, size_t len, size_t n, int max_char,
 153          int exp_result)
 154 {
 155   size_t i, align_n;
 156   CHAR *s1, *s2;
 157
 158   align1 &= ~(CHARBYTES - 1);
 159   align2 &= ~(CHARBYTES - 1);
 160
 161   if (n == 0)
 162     {
 163       s1 = (CHAR *) (buf1 + page_size);
 164       s2 = (CHAR *) (buf2 + page_size);
 165
 166       FOR_EACH_IMPL (impl, 0)
 167         do_one_test (impl, s1, s2, n, 0);
 168
 169       return;
 170     }
 171
 172   align1 &= 15;
 173   align2 &= 15;
 174   align_n = (page_size - n * CHARBYTES) & 15;
 175
 176   s1 = (CHAR *) (buf1 + page_size - n * CHARBYTES);
 177   s2 = (CHAR *) (buf2 + page_size - n * CHARBYTES);
 178
 179   if (align1 < align_n)
 180     s1 = (CHAR *) ((char *) s1 - (align_n - align1));
 181
 182   if (align2 < align_n)
 183     s2 = (CHAR *) ((char *) s2 - (align_n - align2));
 184
 185   for (i = 0; i < n; i++)
 186     s1[i] = s2[i] = 1 + 23 * i % max_char;
 187
 188   if (len < n)
 189     {
 190       s1[len] = 0;
 191       s2[len] = 0;
 192       if (exp_result < 0)
 193         s2[len] = 32;
 194       else if (exp_result > 0)
 195         s1[len] = 64;
 196     }
 197
 198   FOR_EACH_IMPL (impl, 0)
 199     do_one_test (impl, s1, s2, n, exp_result);
 200 }
 201
 202 static void
 203 do_test (size_t align1, size_t align2, size_t len, size_t n, int max_char,
 204          int exp_result)
 205 {
 206   size_t i;
 207   CHAR *s1, *s2;
 208
 209   align1 &= ~(CHARBYTES - 1);
 210   align2 &= ~(CHARBYTES - 1);
 211
 212   if (n == 0)
 213     return;
 214
 215   align1 &= 63;
 216   if (align1 + (n + 1) * CHARBYTES >= page_size)
 217     return;
 218
 219   align2 &= 63;
 220   if (align2 + (n + 1) * CHARBYTES >= page_size)
 221     return;
 222
 223   s1 = (CHAR *) (buf1 + align1);
 224   s2 = (CHAR *) (buf2 + align2);
 225
 226   for (i = 0; i < n; i++)
 227     s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % max_char;
 228
 229   s1[n] = 24 + exp_result;
 230   s2[n] = 23;
 231   s1[len] = 0;
 232   s2[len] = 0;
 233   if (exp_result < 0)
 234     s2[len] = 32;
 235   else if (exp_result > 0)
 236     s1[len] = 64;
 237   if (len >= n)
 238     s2[n - 1] -= exp_result;
 239
 240   FOR_EACH_IMPL (impl, 0)
 241     do_one_test (impl, s1, s2, n, exp_result);
 242 }
 243
 244 static void
 245 do_page_test (size_t offset1, size_t offset2, CHAR *s2)
 246 {
 247   CHAR *s1;
 248   int exp_result;
 249
 250   if (offset1 * CHARBYTES  >= page_size || offset2 * CHARBYTES >= page_size)
 251     return;
 252
 253   s1 = (CHAR *) buf1;
 254   s1 += offset1;
 255   s2 += offset2;
 256
 257   exp_result= *s1;
 258
 259   FOR_EACH_IMPL (impl, 0)
 260     {
 261       check_result (impl, s1, s2, page_size, -exp_result);
 262       check_result (impl, s2, s1, page_size, exp_result);
 263     }
 264 }
 265
 266 static void
 267 do_random_tests (void)
 268 {
 269   size_t i, j, n, align1, align2, pos, len1, len2, size;
 270   int result;
 271   long r;
 272   UCHAR *p1 = (UCHAR *) (buf1 + page_size - 512 * CHARBYTES);
 273   UCHAR *p2 = (UCHAR *) (buf2 + page_size - 512 * CHARBYTES);
 274
 275   for (n = 0; n < ITERATIONS; n++)
 276     {
 277       align1 = random () & 31;
 278       if (random () & 1)
 279         align2 = random () & 31;
 280       else
 281         align2 = align1 + (random () & 24);
 282       pos = random () & 511;
 283       size = random () & 511;
 284       j = align1 > align2 ? align1 : align2;
 285       if (pos + j >= 511)
 286         pos = 510 - j - (random () & 7);
 287       len1 = random () & 511;
 288       if (pos >= len1 && (random () & 1))
 289         len1 = pos + (random () & 7);
 290       if (len1 + j >= 512)
 291         len1 = 511 - j - (random () & 7);
 292       if (pos >= len1)
 293         len2 = len1;
 294       else
 295         len2 = len1 + (len1 != 511 - j ? random () % (511 - j - len1) : 0);
 296       j = (pos > len2 ? pos : len2) + align1 + 64;
 297       if (j > 512)
 298         j = 512;
 299       for (i = 0; i < j; ++i)
 300         {
 301           p1[i] = random () & 255;
 302           if (i < len1 + align1 && !p1[i])
 303             {
 304               p1[i] = random () & 255;
 305               if (!p1[i])
 306                 p1[i] = 1 + (random () & 127);
 307             }
 308         }
 309       for (i = 0; i < j; ++i)
 310         {
 311           p2[i] = random () & 255;
 312           if (i < len2 + align2 && !p2[i])
 313             {
 314               p2[i] = random () & 255;
 315               if (!p2[i])
 316                 p2[i] = 1 + (random () & 127);
 317             }
 318         }
 319
 320       result = 0;
 321       MEMCPY (p2 + align2, p1 + align1, pos);
 322       if (pos < len1)
 323         {
 324           if (p2[align2 + pos] == p1[align1 + pos])
 325             {
 326               p2[align2 + pos] = random () & 255;
 327               if (p2[align2 + pos] == p1[align1 + pos])
 328                 p2[align2 + pos] = p1[align1 + pos] + 3 + (random () & 127);
 329             }
 330
 331           if (pos < size)
 332             {
 333               if (p1[align1 + pos] < p2[align2 + pos])
 334                 result = -1;
 335               else
 336                 result = 1;
 337             }
 338         }
 339       p1[len1 + align1] = 0;
 340       p2[len2 + align2] = 0;
 341
 342       FOR_EACH_IMPL (impl, 1)
 343         {
 344           r = CALL (impl, (CHAR *) (p1 + align1), (CHAR *) (p2 + align2), size);
 345           /* Test whether on 64-bit architectures where ABI requires
 346              callee to promote has the promotion been done.  */
 347           asm ("" : "=g" (r) : "0" (r));
 348           if ((r == 0 && result)
 349               || (r < 0 && result >= 0)
 350               || (r > 0 && result <= 0))
 351             {
 352               error (0, 0, "Iteration %zd - wrong result in function %s (%zd, %zd, %zd, %zd, %zd, %zd) %ld != %d, p1 %p p2 %p",
 353                      n, impl->name, align1, align2, len1, len2, pos, size, r, result, p1, p2);
 354               ret = 1;
 355             }
 356         }
 357     }
 358 }
 359
 360 static void
 361 check1 (void)
 362 {
 363   CHAR *s1 = (CHAR *) (buf1 + 0xb2c);
 364   CHAR *s2 = (CHAR *) (buf1 + 0xfd8);
 365   size_t i, offset;
 366   int exp_result;
 367
 368   STRCPY(s1, L("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrs"));
 369   STRCPY(s2, L("abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijkLMNOPQRSTUV"));
 370
 371   /* Check possible overflow bug for wcsncmp */
 372   s1[4] = CHAR__MAX;
 373   s2[4] = CHAR__MIN;
 374
 375   for (offset = 0; offset < 6; offset++)
 376     {
 377       for (i = 0; i < 80; i++)
 378         {
 379           exp_result = SIMPLE_STRNCMP (s1 + offset, s2 + offset, i);
 380           FOR_EACH_IMPL (impl, 0)
 381             check_result (impl, s1 + offset, s2 + offset, i, exp_result);
 382         }
 383     }
 384 }
 385
 386 static void
 387 check2 (void)
 388 {
 389   size_t i;
 390   CHAR *s1, *s2;
 391
 392   s1 = (CHAR *) buf1;
 393   for (i = 0; i < (page_size / CHARBYTES) - 1; i++)
 394     s1[i] = 23;
 395   s1[i] = 0;
 396
 397   s2 = STRDUP (s1);
 398
 399   for (i = 0; i < 64; ++i)
 400     do_page_test ((3988 / CHARBYTES) + i, (2636 / CHARBYTES), s2);
 401
 402   free (s2);
 403 }
 404
 405 static void
 406 check3 (void)
 407 {
 408   /* To trigger bug 25933, we need a size that is equal to the vector
 409      length times 4. In the case of AVX2 for Intel, we need 32 * 4.  We
 410      make this test generic and run it for all architectures as additional
 411      boundary testing for such related algorithms.  */
 412   size_t size = 32 * 4;
 413   CHAR *s1 = (CHAR *) (buf1 + (BUF1PAGES - 1) * page_size);
 414   CHAR *s2 = (CHAR *) (buf2 + (BUF1PAGES - 1) * page_size);
 415   int exp_result;
 416
 417   memset (s1, 'a', page_size);
 418   memset (s2, 'a', page_size);
 419   s1[(page_size / CHARBYTES) - 1] = (CHAR) 0;
 420
 421   /* Iterate over a size that is just below where we expect the bug to
 422      trigger up to the size we expect will trigger the bug e.g. [99-128].
 423      Likewise iterate the start of two strings between 30 and 31 bytes
 424      away from the boundary to simulate alignment changes.  */
 425   for (size_t s = 99; s <= size; s++)
 426     for (size_t s1a = 30; s1a < 32; s1a++)
 427       for (size_t s2a = 30; s2a < 32; s2a++)
 428         {
 429           CHAR *s1p = s1 + (page_size / CHARBYTES - s) - s1a;
 430           CHAR *s2p = s2 + (page_size / CHARBYTES - s) - s2a;
 431           exp_result = SIMPLE_STRNCMP (s1p, s2p, s);
 432           FOR_EACH_IMPL (impl, 0)
 433             check_result (impl, s1p, s2p, s, exp_result);
 434         }
 435 }
 436
 437 int
 438 test_main (void)
 439 {
 440   size_t i;
 441
 442   test_init ();
 443
 444   check1 ();
 445   check2 ();
 446   check3 ();
 447
 448   printf ("%23s", "");
 449   FOR_EACH_IMPL (impl, 0)
 450     printf ("\t%s", impl->name);
 451   putchar ('\n');
 452
 453   for (i =0; i < 16; ++i)
 454     {
 455       do_test (0, 0, 8, i, 127, 0);
 456       do_test (0, 0, 8, i, 127, -1);
 457       do_test (0, 0, 8, i, 127, 1);
 458       do_test (i, i, 8, i, 127, 0);
 459       do_test (i, i, 8, i, 127, 1);
 460       do_test (i, i, 8, i, 127, -1);
 461       do_test (i, 2 * i, 8, i, 127, 0);
 462       do_test (2 * i, i, 8, i, 127, 1);
 463       do_test (i, 3 * i, 8, i, 127, -1);
 464       do_test (0, 0, 8, i, 255, 0);
 465       do_test (0, 0, 8, i, 255, -1);
 466       do_test (0, 0, 8, i, 255, 1);
 467       do_test (i, i, 8, i, 255, 0);
 468       do_test (i, i, 8, i, 255, 1);
 469       do_test (i, i, 8, i, 255, -1);
 470       do_test (i, 2 * i, 8, i, 255, 0);
 471       do_test (2 * i, i, 8, i, 255, 1);
 472       do_test (i, 3 * i, 8, i, 255, -1);
 473     }
 474
 475   for (i = 1; i < 8; ++i)
 476     {
 477       do_test (0, 0, 8 << i, 16 << i, 127, 0);
 478       do_test (0, 0, 8 << i, 16 << i, 127, 1);
 479       do_test (0, 0, 8 << i, 16 << i, 127, -1);
 480       do_test (0, 0, 8 << i, 16 << i, 255, 0);
 481       do_test (0, 0, 8 << i, 16 << i, 255, 1);
 482       do_test (0, 0, 8 << i, 16 << i, 255, -1);
 483       do_test (8 - i, 2 * i, 8 << i, 16 << i, 127, 0);
 484       do_test (8 - i, 2 * i, 8 << i, 16 << i, 127, 1);
 485       do_test (2 * i, i, 8 << i, 16 << i, 255, 0);
 486       do_test (2 * i, i, 8 << i, 16 << i, 255, 1);
 487     }
 488
 489   do_test_limit (0, 0, 0, 0, 127, 0);
 490   do_test_limit (4, 0, 21, 20, 127, 0);
 491   do_test_limit (0, 4, 21, 20, 127, 0);
 492   do_test_limit (8, 0, 25, 24, 127, 0);
 493   do_test_limit (0, 8, 25, 24, 127, 0);
 494
 495   for (i = 0; i < 8; ++i)
 496     {
 497       do_test_limit (0, 0, 17 - i, 16 - i, 127, 0);
 498       do_test_limit (0, 0, 17 - i, 16 - i, 255, 0);
 499       do_test_limit (0, 0, 15 - i, 16 - i, 127, 0);
 500       do_test_limit (0, 0, 15 - i, 16 - i, 127, 1);
 501       do_test_limit (0, 0, 15 - i, 16 - i, 127, -1);
 502       do_test_limit (0, 0, 15 - i, 16 - i, 255, 0);
 503       do_test_limit (0, 0, 15 - i, 16 - i, 255, 1);
 504       do_test_limit (0, 0, 15 - i, 16 - i, 255, -1);
 505     }
 506
 507   do_random_tests ();
 508   return ret;
 509 }
 510
 511 #include <support/test-driver.c>