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