src/lib/gcov-io.c

   1 /* File format for coverage information
   2    Copyright (C) 1996, 1997, 1998, 2000, 2002, 2003, 2004, 2005, 2007,
   3    2008  Free Software Foundation, Inc.
   4    Contributed by Bob Manson <manson@cygnus.com>.
   5    Completely remangled by Nathan Sidwell <nathan@codesourcery.com>.
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify it under
  10 the terms of the GNU General Public License as published by the Free
  11 Software Foundation; either version 3, or (at your option) any later
  12 version.
  13
  14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17 for more details.
  18
  19 Under Section 7 of GPL version 3, you are granted additional
  20 permissions described in the GCC Runtime Library Exception, version
  21 3.1, as published by the Free Software Foundation.
  22 */
  23
  24 /* Routines declared in gcov-io.h.  This file should be #included by
  25    another source file, after having #included gcov-io.h.  */
  26
  27 #if !IN_GCOV
  28 static void gcov_write_block (unsigned);
  29 static gcov_unsigned_t *gcov_write_words (unsigned);
  30 #endif
  31 static const gcov_unsigned_t *gcov_read_words (unsigned);
  32 #if !IN_LIBGCOV
  33 static void gcov_allocate (unsigned);
  34 #endif
  35
  36 static inline gcov_unsigned_t from_file (gcov_unsigned_t value)
  37 {
  38 #if !IN_LIBGCOV
  39   if (gcov_var.endian)
  40     {
  41       value = (value >> 16) | (value << 16);
  42       value = ((value & 0xff00ff) << 8) | ((value >> 8) & 0xff00ff);
  43     }
  44 #endif
  45   return value;
  46 }
  47
  48 /* Open a gcov file. NAME is the name of the file to open and MODE
  49    indicates whether a new file should be created, or an existing file
  50    opened. If MODE is >= 0 an existing file will be opened, if
  51    possible, and if MODE is <= 0, a new file will be created. Use
  52    MODE=0 to attempt to reopen an existing file and then fall back on
  53    creating a new one.  If MODE < 0, the file will be opened in
  54    read-only mode.  Otherwise it will be opened for modification.
  55    Return zero on failure, >0 on opening an existing file and <0 on
  56    creating a new one.  */
  57
  58 GCOV_LINKAGE int
  59 #if IN_LIBGCOV
  60 gcov_open (const char *name)
  61 #else
  62 gcov_open (const char *name, int mode)
  63 #endif
  64 {
  65 #if IN_LIBGCOV
  66   const int mode = 0;
  67 #endif
  68 #if GCOV_LOCKED
  69   struct flock s_flock;
  70   int fd;
  71
  72   s_flock.l_whence = SEEK_SET;
  73   s_flock.l_start = 0;
  74   s_flock.l_len = 0; /* Until EOF.  */
  75   s_flock.l_pid = getpid ();
  76 #endif
  77
  78   gcc_assert (!gcov_var.file);
  79   gcov_var.start = 0;
  80   gcov_var.offset = gcov_var.length = 0;
  81   gcov_var.overread = -1u;
  82   gcov_var.error = 0;
  83 #if !IN_LIBGCOV
  84   gcov_var.endian = 0;
  85 #endif
  86 #if GCOV_LOCKED
  87   if (mode > 0)
  88     {
  89       /* Read-only mode - acquire a read-lock.  */
  90       s_flock.l_type = F_RDLCK;
  91       fd = open (name, O_RDONLY);
  92     }
  93   else
  94     {
  95       /* Write mode - acquire a write-lock.  */
  96       s_flock.l_type = F_WRLCK;
  97       fd = open (name, O_RDWR | O_CREAT, 0666);
  98     }
  99   if (fd < 0)
 100     return 0;
 101
 102   while (fcntl (fd, F_SETLKW, &s_flock) && errno == EINTR)
 103     continue;
 104
 105   gcov_var.file = fdopen (fd, (mode > 0) ? "rb" : "r+b");
 106
 107   if (!gcov_var.file)
 108     {
 109       close (fd);
 110       return 0;
 111     }
 112
 113   if (mode > 0)
 114     gcov_var.mode = 1;
 115   else if (mode == 0)
 116     {
 117       struct stat st;
 118
 119       if (fstat (fd, &st) < 0)
 120         {
 121           fclose (gcov_var.file);
 122           gcov_var.file = 0;
 123           return 0;
 124         }
 125       if (st.st_size != 0)
 126         gcov_var.mode = 1;
 127       else
 128         gcov_var.mode = mode * 2 + 1;
 129     }
 130   else
 131     gcov_var.mode = mode * 2 + 1;
 132 #else
 133   if (mode >= 0)
 134     gcov_var.file = fopen (name, (mode > 0) ? "rb" : "r+b");
 135
 136   if (gcov_var.file)
 137     gcov_var.mode = 1;
 138   else if (mode <= 0)
 139     {
 140       gcov_var.file = fopen (name, "w+b");
 141       if (gcov_var.file)
 142         gcov_var.mode = mode * 2 + 1;
 143     }
 144   if (!gcov_var.file)
 145     return 0;
 146 #endif
 147
 148   setbuf (gcov_var.file, (char *)0);
 149
 150   return 1;
 151 }
 152
 153 /* Close the current gcov file. Flushes data to disk. Returns nonzero
 154    on failure or error flag set.  */
 155
 156 GCOV_LINKAGE int
 157 gcov_close (void)
 158 {
 159   if (gcov_var.file)
 160     {
 161 #if !IN_GCOV
 162       if (gcov_var.offset && gcov_var.mode < 0)
 163         gcov_write_block (gcov_var.offset);
 164 #endif
 165       fclose (gcov_var.file);
 166       gcov_var.file = 0;
 167       gcov_var.length = 0;
 168     }
 169 #if !IN_LIBGCOV
 170   free (gcov_var.buffer);
 171   gcov_var.alloc = 0;
 172   gcov_var.buffer = 0;
 173 #endif
 174   gcov_var.mode = 0;
 175   return gcov_var.error;
 176 }
 177
 178 #if !IN_LIBGCOV
 179 /* Check if MAGIC is EXPECTED. Use it to determine endianness of the
 180    file. Returns +1 for same endian, -1 for other endian and zero for
 181    not EXPECTED.  */
 182
 183 GCOV_LINKAGE int
 184 gcov_magic (gcov_unsigned_t magic, gcov_unsigned_t expected)
 185 {
 186   if (magic == expected)
 187     return 1;
 188   magic = (magic >> 16) | (magic << 16);
 189   magic = ((magic & 0xff00ff) << 8) | ((magic >> 8) & 0xff00ff);
 190   if (magic == expected)
 191     {
 192       gcov_var.endian = 1;
 193       return -1;
 194     }
 195   return 0;
 196 }
 197 #endif
 198
 199 #if !IN_LIBGCOV
 200 static void
 201 gcov_allocate (unsigned length)
 202 {
 203   size_t new_size = gcov_var.alloc;
 204
 205   if (!new_size)
 206     new_size = GCOV_BLOCK_SIZE;
 207   new_size += length;
 208   new_size *= 2;
 209
 210   gcov_var.alloc = new_size;
 211   gcov_var.buffer = XRESIZEVAR (gcov_unsigned_t, gcov_var.buffer, new_size << 2);
 212 }
 213 #endif
 214
 215 #if !IN_GCOV
 216 /* Write out the current block, if needs be.  */
 217
 218 static void
 219 gcov_write_block (unsigned size)
 220 {
 221   if (fwrite (gcov_var.buffer, size << 2, 1, gcov_var.file) != 1)
 222     gcov_var.error = 1;
 223   gcov_var.start += size;
 224   gcov_var.offset -= size;
 225 }
 226
 227 /* Allocate space to write BYTES bytes to the gcov file. Return a
 228    pointer to those bytes, or NULL on failure.  */
 229
 230 static gcov_unsigned_t *
 231 gcov_write_words (unsigned words)
 232 {
 233   gcov_unsigned_t *result;
 234
 235   gcc_assert (gcov_var.mode < 0);
 236 #if IN_LIBGCOV
 237   if (gcov_var.offset >= GCOV_BLOCK_SIZE)
 238     {
 239       gcov_write_block (GCOV_BLOCK_SIZE);
 240       if (gcov_var.offset)
 241         {
 242           gcc_assert (gcov_var.offset == 1);
 243           memcpy (gcov_var.buffer, gcov_var.buffer + GCOV_BLOCK_SIZE, 4);
 244         }
 245     }
 246 #else
 247   if (gcov_var.offset + words > gcov_var.alloc)
 248     gcov_allocate (gcov_var.offset + words);
 249 #endif
 250   result = &gcov_var.buffer[gcov_var.offset];
 251   gcov_var.offset += words;
 252
 253   return result;
 254 }
 255
 256 /* Write unsigned VALUE to coverage file.  Sets error flag
 257    appropriately.  */
 258
 259 GCOV_LINKAGE void
 260 gcov_write_unsigned (gcov_unsigned_t value)
 261 {
 262   gcov_unsigned_t *buffer = gcov_write_words (1);
 263
 264   buffer[0] = value;
 265 }
 266
 267 /* Write counter VALUE to coverage file.  Sets error flag
 268    appropriately.  */
 269
 270 #if IN_LIBGCOV
 271 GCOV_LINKAGE void
 272 gcov_write_counter (gcov_type value)
 273 {
 274   gcov_unsigned_t *buffer = gcov_write_words (2);
 275
 276   buffer[0] = (gcov_unsigned_t) value;
 277   if (sizeof (value) > sizeof (gcov_unsigned_t))
 278     buffer[1] = (gcov_unsigned_t) (value >> 32);
 279   else
 280     buffer[1] = 0;
 281 }
 282 #endif /* IN_LIBGCOV */
 283
 284 #if !IN_LIBGCOV
 285 /* Write STRING to coverage file.  Sets error flag on file
 286    error, overflow flag on overflow */
 287
 288 GCOV_LINKAGE void
 289 gcov_write_string (const char *string)
 290 {
 291   unsigned length = 0;
 292   unsigned alloc = 0;
 293   gcov_unsigned_t *buffer;
 294
 295   if (string)
 296     {
 297       length = strlen (string);
 298       alloc = (length + 4) >> 2;
 299     }
 300
 301   buffer = gcov_write_words (1 + alloc);
 302
 303   buffer[0] = alloc;
 304   buffer[alloc] = 0;
 305   memcpy (&buffer[1], string, length);
 306 }
 307 #endif
 308
 309 #if !IN_LIBGCOV
 310 /* Write a tag TAG and reserve space for the record length. Return a
 311    value to be used for gcov_write_length.  */
 312
 313 GCOV_LINKAGE gcov_position_t
 314 gcov_write_tag (gcov_unsigned_t tag)
 315 {
 316   gcov_position_t result = gcov_var.start + gcov_var.offset;
 317   gcov_unsigned_t *buffer = gcov_write_words (2);
 318
 319   buffer[0] = tag;
 320   buffer[1] = 0;
 321
 322   return result;
 323 }
 324
 325 /* Write a record length using POSITION, which was returned by
 326    gcov_write_tag.  The current file position is the end of the
 327    record, and is restored before returning.  Returns nonzero on
 328    overflow.  */
 329
 330 GCOV_LINKAGE void
 331 gcov_write_length (gcov_position_t position)
 332 {
 333   unsigned offset;
 334   gcov_unsigned_t length;
 335   gcov_unsigned_t *buffer;
 336
 337   gcc_assert (gcov_var.mode < 0);
 338   gcc_assert (position + 2 <= gcov_var.start + gcov_var.offset);
 339   gcc_assert (position >= gcov_var.start);
 340   offset = position - gcov_var.start;
 341   length = gcov_var.offset - offset - 2;
 342   buffer = (gcov_unsigned_t *) &gcov_var.buffer[offset];
 343   buffer[1] = length;
 344   if (gcov_var.offset >= GCOV_BLOCK_SIZE)
 345     gcov_write_block (gcov_var.offset);
 346 }
 347
 348 #else /* IN_LIBGCOV */
 349
 350 /* Write a tag TAG and length LENGTH.  */
 351
 352 GCOV_LINKAGE void
 353 gcov_write_tag_length (gcov_unsigned_t tag, gcov_unsigned_t length)
 354 {
 355   gcov_unsigned_t *buffer = gcov_write_words (2);
 356
 357   buffer[0] = tag;
 358   buffer[1] = length;
 359 }
 360
 361 /* Write a summary structure to the gcov file.  Return nonzero on
 362    overflow.  */
 363
 364 GCOV_LINKAGE void
 365 gcov_write_summary (gcov_unsigned_t tag, const struct gcov_summary *summary)
 366 {
 367   unsigned ix;
 368   const struct gcov_ctr_summary *csum;
 369
 370   gcov_write_tag_length (tag, GCOV_TAG_SUMMARY_LENGTH);
 371   gcov_write_unsigned (summary->checksum);
 372   for (csum = summary->ctrs, ix = GCOV_COUNTERS_SUMMABLE; ix--; csum++)
 373     {
 374       gcov_write_unsigned (csum->num);
 375       gcov_write_unsigned (csum->runs);
 376       gcov_write_counter (csum->sum_all);
 377       gcov_write_counter (csum->run_max);
 378       gcov_write_counter (csum->sum_max);
 379     }
 380 }
 381 #endif /* IN_LIBGCOV */
 382
 383 #endif /*!IN_GCOV */
 384
 385 /* Return a pointer to read BYTES bytes from the gcov file. Returns
 386    NULL on failure (read past EOF).  */
 387
 388 static const gcov_unsigned_t *
 389 gcov_read_words (unsigned words)
 390 {
 391   const gcov_unsigned_t *result;
 392   unsigned excess = gcov_var.length - gcov_var.offset;
 393
 394   gcc_assert (gcov_var.mode > 0);
 395   if (excess < words)
 396     {
 397       gcov_var.start += gcov_var.offset;
 398 #if IN_LIBGCOV
 399       if (excess)
 400         {
 401           gcc_assert (excess == 1);
 402           memcpy (gcov_var.buffer, gcov_var.buffer + gcov_var.offset, 4);
 403         }
 404 #else
 405       memmove (gcov_var.buffer, gcov_var.buffer + gcov_var.offset, excess * 4);
 406 #endif
 407       gcov_var.offset = 0;
 408       gcov_var.length = excess;
 409 #if IN_LIBGCOV
 410       gcc_assert (!gcov_var.length || gcov_var.length == 1);
 411       excess = GCOV_BLOCK_SIZE;
 412 #else
 413       if (gcov_var.length + words > gcov_var.alloc)
 414         gcov_allocate (gcov_var.length + words);
 415       excess = gcov_var.alloc - gcov_var.length;
 416 #endif
 417       excess = fread (gcov_var.buffer + gcov_var.length,
 418                       1, excess << 2, gcov_var.file) >> 2;
 419       gcov_var.length += excess;
 420       if (gcov_var.length < words)
 421         {
 422           gcov_var.overread += words - gcov_var.length;
 423           gcov_var.length = 0;
 424           return 0;
 425         }
 426     }
 427   result = &gcov_var.buffer[gcov_var.offset];
 428   gcov_var.offset += words;
 429   return result;
 430 }
 431
 432 /* Read unsigned value from a coverage file. Sets error flag on file
 433    error, overflow flag on overflow */
 434
 435 GCOV_LINKAGE gcov_unsigned_t
 436 gcov_read_unsigned (void)
 437 {
 438   gcov_unsigned_t value;
 439   const gcov_unsigned_t *buffer = gcov_read_words (1);
 440
 441   if (!buffer)
 442     return 0;
 443   value = from_file (buffer[0]);
 444   return value;
 445 }
 446
 447 /* Read counter value from a coverage file. Sets error flag on file
 448    error, overflow flag on overflow */
 449
 450 GCOV_LINKAGE gcov_type
 451 gcov_read_counter (void)
 452 {
 453   gcov_type value;
 454   const gcov_unsigned_t *buffer = gcov_read_words (2);
 455
 456   if (!buffer)
 457     return 0;
 458   value = from_file (buffer[0]);
 459   if (sizeof (value) > sizeof (gcov_unsigned_t))
 460     value |= ((gcov_type) from_file (buffer[1])) << 32;
 461   else if (buffer[1])
 462     gcov_var.error = -1;
 463
 464   return value;
 465 }
 466
 467 /* Read string from coverage file. Returns a pointer to a static
 468    buffer, or NULL on empty string. You must copy the string before
 469    calling another gcov function.  */
 470
 471 #if !IN_LIBGCOV
 472 GCOV_LINKAGE const char *
 473 gcov_read_string (void)
 474 {
 475   unsigned length = gcov_read_unsigned ();
 476
 477   if (!length)
 478     return 0;
 479
 480   return (const char *) gcov_read_words (length);
 481 }
 482 #endif
 483
 484 GCOV_LINKAGE void
 485 gcov_read_summary (struct gcov_summary *summary)
 486 {
 487   unsigned ix;
 488   struct gcov_ctr_summary *csum;
 489
 490   summary->checksum = gcov_read_unsigned ();
 491   for (csum = summary->ctrs, ix = GCOV_COUNTERS_SUMMABLE; ix--; csum++)
 492     {
 493       csum->num = gcov_read_unsigned ();
 494       csum->runs = gcov_read_unsigned ();
 495       csum->sum_all = gcov_read_counter ();
 496       csum->run_max = gcov_read_counter ();
 497       csum->sum_max = gcov_read_counter ();
 498     }
 499 }
 500
 501 #if !IN_LIBGCOV
 502 /* Reset to a known position.  BASE should have been obtained from
 503    gcov_position, LENGTH should be a record length.  */
 504
 505 GCOV_LINKAGE void
 506 gcov_sync (gcov_position_t base, gcov_unsigned_t length)
 507 {
 508   gcc_assert (gcov_var.mode > 0);
 509   base += length;
 510   if (base - gcov_var.start <= gcov_var.length)
 511     gcov_var.offset = base - gcov_var.start;
 512   else
 513     {
 514       gcov_var.offset = gcov_var.length = 0;
 515       fseek (gcov_var.file, base << 2, SEEK_SET);
 516       gcov_var.start = ftell (gcov_var.file) >> 2;
 517     }
 518 }
 519 #endif
 520
 521 #if IN_LIBGCOV
 522 /* Move to a given position in a gcov file.  */
 523
 524 GCOV_LINKAGE void
 525 gcov_seek (gcov_position_t base)
 526 {
 527   gcc_assert (gcov_var.mode < 0);
 528   if (gcov_var.offset)
 529     gcov_write_block (gcov_var.offset);
 530   fseek (gcov_var.file, base << 2, SEEK_SET);
 531   gcov_var.start = ftell (gcov_var.file) >> 2;
 532 }
 533 #endif
 534
 535 #if IN_GCOV > 0
 536 /* Return the modification time of the current gcov file.  */
 537
 538 GCOV_LINKAGE time_t
 539 gcov_time (void)
 540 {
 541   struct stat status;
 542
 543   if (fstat (fileno (gcov_var.file), &status))
 544     return 0;
 545   else
 546     return status.st_mtime;
 547 }
 548 #endif /* IN_GCOV */