gcc/gcov-io.h

   1 /* File format for coverage information
   2    Copyright (C) 1996, 1997, 1998, 2000, 2002,
   3    2003, 2004 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 2, 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 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING.  If not, write to the Free
  21 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  22 02111-1307, USA.  */
  23
  24 /* As a special exception, if you link this library with other files,
  25    some of which are compiled with GCC, to produce an executable,
  26    this library does not by itself cause the resulting executable
  27    to be covered by the GNU General Public License.
  28    This exception does not however invalidate any other reasons why
  29    the executable file might be covered by the GNU General Public License.  */
  30
  31 /* Coverage information is held in two files.  A notes file, which is
  32    generated by the compiler, and a data file, which is generated
  33    by the program under test.  Both files use a similar structure.  We
  34    do not attempt to make these files backwards compatible with
  35    previous versions, as you only need coverage information when
  36    developing a program.  We do hold version information, so that
  37    mismatches can be detected, and we use a format that allows tools
  38    to skip information they do not understand or are not interested
  39    in.
  40
  41    Numbers are recorded in the 32 bit unsigned binary form of the
  42    endianness of the machine generating the file. 64 bit numbers are
  43    stored as two 32 bit numbers, the low part first.  Strings are
  44    padded with 1 to 4 NUL bytes, to bring the length up to a multiple
  45    of 4. The number of 4 bytes is stored, followed by the padded
  46    string. Zero length and NULL strings are simply stored as
  47    a length of zero (they have no trailing NUL or padding).
  48
  49         int32:  byte3 byte2 byte1 byte0 | byte0 byte1 byte2 byte3
  50         int64:  int32:low int32:high
  51         string: int32:0 | int32:length char* char:0 padding
  52         padding: | char:0 | char:0 char:0 | char:0 char:0 char:0
  53         item: int32 | int64 | string
  54
  55    The basic format of the files is
  56
  57         file : int32:magic int32:version int32:stamp record*
  58
  59    The magic ident is different for the notes and the data files.  The
  60    magic ident is used to determine the endianness of the file, when
  61    reading.  The version is the same for both files and is derived
  62    from gcc's version number. The stamp value is used to synchronize
  63    note and data files and to synchronize merging within a data
  64    file. It need not be an absolute time stamp, merely a ticker that
  65    increments fast enough and cycles slow enough to distinguish
  66    different compile/run/compile cycles.
  67
  68    Although the ident and version are formally 32 bit numbers, they
  69    are derived from 4 character ASCII strings.  The version number
  70    consists of the single character major version number, a two
  71    character minor version number (leading zero for versions less than
  72    10), and a single character indicating the status of the release.
  73    That will be 'e' experimental, 'p' prerelease and 'r' for release.
  74    Because, by good fortune, these are in alphabetical order, string
  75    collating can be used to compare version strings.  Be aware that
  76    the 'e' designation will (naturally) be unstable and might be
  77    incompatible with itself.  For gcc 3.4 experimental, it would be
  78    '304e' (0x33303465).  When the major version reaches 10, the
  79    letters A-Z will be used.  Assuming minor increments releases every
  80    6 months, we have to make a major increment every 50 years.
  81    Assuming major increments releases every 5 years, we're ok for the
  82    next 155 years -- good enough for me.
  83
  84    A record has a tag, length and variable amount of data.
  85
  86         record: header data
  87         header: int32:tag int32:length
  88         data: item*
  89
  90    Records are not nested, but there is a record hierarchy.  Tag
  91    numbers reflect this hierarchy.  Tags are unique across note and
  92    data files.  Some record types have a varying amount of data.  The
  93    LENGTH is the number of 4bytes that follow and is usually used to
  94    determine how much data.  The tag value is split into 4 8-bit
  95    fields, one for each of four possible levels.  The most significant
  96    is allocated first.  Unused levels are zero.  Active levels are
  97    odd-valued, so that the LSB of the level is one.  A sub-level
  98    incorporates the values of its superlevels.  This formatting allows
  99    you to determine the tag hierarchy, without understanding the tags
 100    themselves, and is similar to the standard section numbering used
 101    in technical documents.  Level values [1..3f] are used for common
 102    tags, values [41..9f] for the notes file and [a1..ff] for the data
 103    file.
 104
 105    The basic block graph file contains the following records
 106         note: unit function-graph*
 107         unit: header int32:checksum string:source
 108         function-graph: announce_function basic_blocks {arcs | lines}*
 109         announce_function: header int32:ident int32:checksum
 110                 string:name string:source int32:lineno
 111         basic_block: header int32:flags*
 112         arcs: header int32:block_no arc*
 113         arc:  int32:dest_block int32:flags
 114         lines: header int32:block_no line*
 115                int32:0 string:NULL
 116         line:  int32:line_no | int32:0 string:filename
 117
 118    The BASIC_BLOCK record holds per-bb flags.  The number of blocks
 119    can be inferred from its data length.  There is one ARCS record per
 120    basic block.  The number of arcs from a bb is implicit from the
 121    data length.  It enumerates the destination bb and per-arc flags.
 122    There is one LINES record per basic block, it enumerates the source
 123    lines which belong to that basic block.  Source file names are
 124    introduced by a line number of 0, following lines are from the new
 125    source file.  The initial source file for the function is NULL, but
 126    the current source file should be remembered from one LINES record
 127    to the next.  The end of a block is indicated by an empty filename
 128    - this does not reset the current source file.  Note there is no
 129    ordering of the ARCS and LINES records: they may be in any order,
 130    interleaved in any manner.  The current filename follows the order
 131    the LINES records are stored in the file, *not* the ordering of the
 132    blocks they are for.
 133
 134    The data file contains the following records.
 135         data: {unit function-data* summary:object summary:program*}*
 136         unit: header int32:checksum
 137         function-data:  announce_function arc_counts
 138         announce_function: header int32:ident int32:checksum
 139         arc_counts: header int64:count*
 140         summary: int32:checksum {count-summary}GCOV_COUNTERS
 141         count-summary:  int32:num int32:runs int64:sum
 142                         int64:max int64:sum_max
 143
 144    The ANNOUNCE_FUNCTION record is the same as that in the note file,
 145    but without the source location.  The ARC_COUNTS gives the counter
 146    values for those arcs that are instrumented.  The SUMMARY records
 147    give information about the whole object file and about the whole
 148    program.  The checksum is used for whole program summaries, and
 149    disambiguates different programs which include the same
 150    instrumented object file.  There may be several program summaries,
 151    each with a unique checksum.  The object summary's checksum is zero.
 152    Note that the data file might contain information from several runs
 153    concatenated, or the data might be merged.
 154
 155    This file is included by both the compiler, gcov tools and the
 156    runtime support library libgcov. IN_LIBGCOV and IN_GCOV are used to
 157    distinguish which case is which.  If IN_LIBGCOV is nonzero,
 158    libgcov is being built. If IN_GCOV is nonzero, the gcov tools are
 159    being built. Otherwise the compiler is being built. IN_GCOV may be
 160    positive or negative. If positive, we are compiling a tool that
 161    requires additional functions (see the code for knowledge of what
 162    those functions are).  */
 163
 164 #ifndef GCC_GCOV_IO_H
 165 #define GCC_GCOV_IO_H
 166
 167 #if IN_LIBGCOV
 168 /* About the target */
 169
 170 #if BITS_PER_UNIT == 8
 171 typedef unsigned gcov_unsigned_t __attribute__ ((mode (SI)));
 172 typedef unsigned gcov_position_t __attribute__ ((mode (SI)));
 173 #if LONG_LONG_TYPE_SIZE > 32
 174 typedef signed gcov_type __attribute__ ((mode (DI)));
 175 #else
 176 typedef signed gcov_type __attribute__ ((mode (SI)));
 177 #endif
 178 #else
 179 #if BITS_PER_UNIT == 16
 180 typedef unsigned gcov_unsigned_t __attribute__ ((mode (HI)));
 181 typedef unsigned gcov_position_t __attribute__ ((mode (HI)));
 182 #if LONG_LONG_TYPE_SIZE > 32
 183 typedef signed gcov_type __attribute__ ((mode (SI)));
 184 #else
 185 typedef signed gcov_type __attribute__ ((mode (HI)));
 186 #endif
 187 #else
 188 typedef unsigned gcov_unsigned_t __attribute__ ((mode (QI)));
 189 typedef unsigned gcov_position_t __attribute__ ((mode (QI)));
 190 #if LONG_LONG_TYPE_SIZE > 32
 191 typedef signed gcov_type __attribute__ ((mode (HI)));
 192 #else
 193 typedef signed gcov_type __attribute__ ((mode (QI)));
 194 #endif
 195 #endif
 196 #endif
 197
 198
 199 #if defined (TARGET_HAS_F_SETLKW)
 200 #define GCOV_LOCKED 1
 201 #else
 202 #define GCOV_LOCKED 0
 203 #endif
 204
 205 #else /* !IN_LIBGCOV */
 206 /* About the host */
 207
 208 typedef unsigned gcov_unsigned_t;
 209 typedef unsigned gcov_position_t;
 210 /* gcov_type is typedef'd elsewhere for the compiler */
 211 #if IN_GCOV
 212 #define GCOV_LINKAGE static
 213 typedef HOST_WIDEST_INT gcov_type;
 214 #if IN_GCOV > 0
 215 #include <sys/types.h>
 216 #endif
 217 #else /*!IN_GCOV */
 218 #if LONG_LONG_TYPE_SIZE > 32
 219 #define GCOV_TYPE_NODE intDI_type_node
 220 #else
 221 #define GCOV_TYPE_NODE intSI_type_node
 222 #endif
 223 #endif
 224
 225 #if defined (HOST_HAS_F_SETLKW)
 226 #define GCOV_LOCKED 1
 227 #else
 228 #define GCOV_LOCKED 0
 229 #endif
 230
 231 #endif /* !IN_LIBGCOV */
 232
 233 /* In gcov we want function linkage to be static. In libgcov we need
 234    these functions to be extern, so prefix them with __gcov.  In the
 235    compiler we want it extern, so that they can be accessed from
 236    elsewhere.  */
 237 #if IN_LIBGCOV
 238 #define gcov_var __gcov_var
 239 #define gcov_open __gcov_open
 240 #define gcov_close __gcov_close
 241 #define gcov_write_tag_length __gcov_write_tag_length
 242 #define gcov_position __gcov_position
 243 #define gcov_seek __gcov_seek
 244 #define gcov_rewrite __gcov_rewrite
 245 #define gcov_is_error __gcov_is_error
 246 #define gcov_is_eof __gcov_is_eof
 247 #define gcov_write_unsigned __gcov_write_unsigned
 248 #define gcov_write_counter __gcov_write_counter
 249 #define gcov_write_summary __gcov_write_summary
 250 #define gcov_read_unsigned __gcov_read_unsigned
 251 #define gcov_read_counter __gcov_read_counter
 252 #define gcov_read_summary __gcov_read_summary
 253
 254 /* Poison these, so they don't accidentally slip in.  */
 255 #pragma GCC poison gcov_write_string gcov_write_tag gcov_write_length
 256 #pragma GCC poison gcov_read_string gcov_sync gcov_time gcov_magic
 257
 258 #endif
 259
 260 #ifndef GCOV_LINKAGE
 261 #define GCOV_LINKAGE extern
 262 #endif
 263
 264 /* File suffixes.  */
 265 #define GCOV_DATA_SUFFIX ".gcda"
 266 #define GCOV_NOTE_SUFFIX ".gcno"
 267
 268 /* File magic. Must not be palindromes.  */
 269 #define GCOV_DATA_MAGIC ((gcov_unsigned_t)0x67636461) /* "gcda" */
 270 #define GCOV_NOTE_MAGIC ((gcov_unsigned_t)0x67636e6f) /* "gcno" */
 271
 272 /* gcov-iov.h is automatically generated by the makefile from
 273    version.c, it looks like
 274         #define GCOV_VERSION ((gcov_unsigned_t)0x89abcdef)
 275 */
 276 #include "gcov-iov.h"
 277
 278 /* Convert a magic or version number to a 4 character string.  */
 279 #define GCOV_UNSIGNED2STRING(ARRAY,VALUE)       \
 280   ((ARRAY)[0] = (char)((VALUE) >> 24),          \
 281    (ARRAY)[1] = (char)((VALUE) >> 16),          \
 282    (ARRAY)[2] = (char)((VALUE) >> 8),           \
 283    (ARRAY)[3] = (char)((VALUE) >> 0))
 284
 285 /* The record tags.  Values [1..3f] are for tags which may be in either
 286    file.  Values [41..9f] for those in the note file and [a1..ff] for
 287    the data file.  */
 288
 289 #define GCOV_TAG_FUNCTION        ((gcov_unsigned_t)0x01000000)
 290 #define GCOV_TAG_FUNCTION_LENGTH (2)
 291 #define GCOV_TAG_BLOCKS          ((gcov_unsigned_t)0x01410000)
 292 #define GCOV_TAG_BLOCKS_LENGTH(NUM) (NUM)
 293 #define GCOV_TAG_BLOCKS_NUM(LENGTH) (LENGTH)
 294 #define GCOV_TAG_ARCS            ((gcov_unsigned_t)0x01430000)
 295 #define GCOV_TAG_ARCS_LENGTH(NUM)  (1 + (NUM) * 2)
 296 #define GCOV_TAG_ARCS_NUM(LENGTH)  (((LENGTH) - 1) / 2)
 297 #define GCOV_TAG_LINES           ((gcov_unsigned_t)0x01450000)
 298 #define GCOV_TAG_COUNTER_BASE    ((gcov_unsigned_t)0x01a10000)
 299 #define GCOV_TAG_COUNTER_LENGTH(NUM) ((NUM) * 2)
 300 #define GCOV_TAG_COUNTER_NUM(LENGTH) ((LENGTH) / 2)
 301 #define GCOV_TAG_OBJECT_SUMMARY  ((gcov_unsigned_t)0xa1000000)
 302 #define GCOV_TAG_PROGRAM_SUMMARY ((gcov_unsigned_t)0xa3000000)
 303 #define GCOV_TAG_SUMMARY_LENGTH  \
 304         (1 + GCOV_COUNTERS_SUMMABLE * (2 + 3 * 2))
 305
 306 /* Counters that are collected.  */
 307 #define GCOV_COUNTER_ARCS       0  /* Arc transitions.  */
 308 #define GCOV_COUNTERS_SUMMABLE  1  /* Counters which can be
 309                                       summaried.  */
 310 #define GCOV_FIRST_VALUE_COUNTER 1 /* The first of counters used for value
 311                                       profiling.  They must form a consecutive
 312                                       interval and their order must match
 313                                       the order of HIST_TYPEs in
 314                                       value-prof.h.  */
 315 #define GCOV_COUNTER_V_INTERVAL 1  /* Histogram of value inside an interval.  */
 316 #define GCOV_COUNTER_V_POW2     2  /* Histogram of exact power2 logarithm
 317                                       of a value.  */
 318 #define GCOV_COUNTER_V_SINGLE   3  /* The most common value of expression.  */
 319 #define GCOV_COUNTER_V_DELTA    4  /* The most common difference between
 320                                       consecutive values of expression.  */
 321 #define GCOV_LAST_VALUE_COUNTER 4  /* The last of counters used for value
 322                                       profiling.  */
 323 #define GCOV_COUNTERS           5
 324
 325 /* Number of counters used for value profiling.  */
 326 #define GCOV_N_VALUE_COUNTERS \
 327   (GCOV_LAST_VALUE_COUNTER - GCOV_FIRST_VALUE_COUNTER + 1)
 328
 329   /* A list of human readable names of the counters */
 330 #define GCOV_COUNTER_NAMES      {"arcs", "interval", "pow2", "single", "delta"}
 331
 332   /* Names of merge functions for counters.  */
 333 #define GCOV_MERGE_FUNCTIONS    {"__gcov_merge_add",    \
 334                                  "__gcov_merge_add",    \
 335                                  "__gcov_merge_add",    \
 336                                  "__gcov_merge_single", \
 337                                  "__gcov_merge_delta"}
 338
 339 /* Convert a counter index to a tag.  */
 340 #define GCOV_TAG_FOR_COUNTER(COUNT)                             \
 341         (GCOV_TAG_COUNTER_BASE + ((gcov_unsigned_t)(COUNT) << 17))
 342 /* Convert a tag to a counter.  */
 343 #define GCOV_COUNTER_FOR_TAG(TAG)                                       \
 344         ((unsigned)(((TAG) - GCOV_TAG_COUNTER_BASE) >> 17))
 345 /* Check whether a tag is a counter tag.  */
 346 #define GCOV_TAG_IS_COUNTER(TAG)                                \
 347         (!((TAG) & 0xFFFF) && GCOV_COUNTER_FOR_TAG (TAG) < GCOV_COUNTERS)
 348
 349 /* The tag level mask has 1's in the position of the inner levels, &
 350    the lsb of the current level, and zero on the current and outer
 351    levels.  */
 352 #define GCOV_TAG_MASK(TAG) (((TAG) - 1) ^ (TAG))
 353
 354 /* Return nonzero if SUB is an immediate subtag of TAG.  */
 355 #define GCOV_TAG_IS_SUBTAG(TAG,SUB)                             \
 356         (GCOV_TAG_MASK (TAG) >> 8 == GCOV_TAG_MASK (SUB)        \
 357          && !(((SUB) ^ (TAG)) & ~GCOV_TAG_MASK(TAG)))
 358
 359 /* Return nonzero if SUB is at a sublevel to TAG.  */
 360 #define GCOV_TAG_IS_SUBLEVEL(TAG,SUB)                           \
 361         (GCOV_TAG_MASK (TAG) > GCOV_TAG_MASK (SUB))
 362
 363 /* Basic block flags.  */
 364 #define GCOV_BLOCK_UNEXPECTED   (1 << 1)
 365
 366 /* Arc flags.  */
 367 #define GCOV_ARC_ON_TREE        (1 << 0)
 368 #define GCOV_ARC_FAKE           (1 << 1)
 369 #define GCOV_ARC_FALLTHROUGH    (1 << 2)
 370
 371 /* Structured records.  */
 372
 373 /* Cumulative counter data.  */
 374 struct gcov_ctr_summary
 375 {
 376   gcov_unsigned_t num;          /* number of counters.  */
 377   gcov_unsigned_t runs;         /* number of program runs */
 378   gcov_type sum_all;            /* sum of all counters accumulated.  */
 379   gcov_type run_max;            /* maximum value on a single run.  */
 380   gcov_type sum_max;            /* sum of individual run max values.  */
 381 };
 382
 383 /* Object & program summary record.  */
 384 struct gcov_summary
 385 {
 386   gcov_unsigned_t checksum;     /* checksum of program */
 387   struct gcov_ctr_summary ctrs[GCOV_COUNTERS_SUMMABLE];
 388 };
 389
 390 /* Structures embedded in coveraged program.  The structures generated
 391    by write_profile must match these.  */
 392
 393 #if IN_LIBGCOV
 394 /* Information about a single function.  This uses the trailing array
 395    idiom. The number of counters is determined from the counter_mask
 396    in gcov_info.  We hold an array of function info, so have to
 397    explicitly calculate the correct array stride.  */
 398 struct gcov_fn_info
 399 {
 400   gcov_unsigned_t ident;        /* unique ident of function */
 401   gcov_unsigned_t checksum;     /* function checksum */
 402   unsigned n_ctrs[0];           /* instrumented counters */
 403 };
 404
 405 /* Type of function used to merge counters.  */
 406 typedef void (*gcov_merge_fn) (gcov_type *, gcov_unsigned_t);
 407
 408 /* Information about counters.  */
 409 struct gcov_ctr_info
 410 {
 411   gcov_unsigned_t num;          /* number of counters.  */
 412   gcov_type *values;            /* their values.  */
 413   gcov_merge_fn merge;          /* The function used to merge them.  */
 414 };
 415
 416 /* Information about a single object file.  */
 417 struct gcov_info
 418 {
 419   gcov_unsigned_t version;      /* expected version number */
 420   struct gcov_info *next;       /* link to next, used by libgcov */
 421
 422   gcov_unsigned_t stamp;        /* uniquifying time stamp */
 423   const char *filename;         /* output file name */
 424
 425   unsigned n_functions;         /* number of functions */
 426   const struct gcov_fn_info *functions; /* table of functions */
 427
 428   unsigned ctr_mask;            /* mask of counters instrumented.  */
 429   struct gcov_ctr_info counts[0]; /* count data. The number of bits
 430                                      set in the ctr_mask field
 431                                      determines how big this array
 432                                      is.  */
 433 };
 434
 435 /* Register a new object file module.  */
 436 extern void __gcov_init (struct gcov_info *);
 437
 438 /* Called before fork, to avoid double counting.  */
 439 extern void __gcov_flush (void);
 440
 441 /* The merge function that just sums the counters.  */
 442 extern void __gcov_merge_add (gcov_type *, unsigned);
 443
 444 /* The merge function to choose the most common value.  */
 445 extern void __gcov_merge_single (gcov_type *, unsigned);
 446
 447 /* The merge function to choose the most common difference between
 448    consecutive values.  */
 449 extern void __gcov_merge_delta (gcov_type *, unsigned);
 450
 451 #ifndef inhibit_libc
 452 /* The wrappers around some library functions..  */
 453 extern pid_t __gcov_fork (void);
 454 extern int __gcov_execl (const char *, const char *, ...);
 455 extern int __gcov_execlp (const char *, const char *, ...);
 456 extern int __gcov_execle (const char *,  const char *, ...);
 457 extern int __gcov_execv (const char *, char *const []);
 458 extern int __gcov_execvp (const char *, char *const []);
 459 extern int __gcov_execve (const char *, char  *const [], char *const []);
 460 #endif
 461
 462 #endif /* IN_LIBGCOV */
 463
 464 #if IN_LIBGCOV >= 0
 465
 466 /* Optimum number of gcov_unsigned_t's read from or written to disk.  */
 467 #define GCOV_BLOCK_SIZE (1 << 10)
 468
 469 GCOV_LINKAGE struct gcov_var
 470 {
 471   FILE *file;
 472   gcov_position_t start;        /* Position of first byte of block */
 473   unsigned offset;              /* Read/write position within the block.  */
 474   unsigned length;              /* Read limit in the block.  */
 475   unsigned overread;            /* Number of words overread.  */
 476   int error;                    /* < 0 overflow, > 0 disk error.  */
 477   int mode;                     /* < 0 writing, > 0 reading */
 478 #if IN_LIBGCOV
 479   /* Holds one block plus 4 bytes, thus all coverage reads & writes
 480      fit within this buffer and we always can transfer GCOV_BLOCK_SIZE
 481      to and from the disk. libgcov never backtracks and only writes 4
 482      or 8 byte objects.  */
 483   gcov_unsigned_t buffer[GCOV_BLOCK_SIZE + 1];
 484 #else
 485   int endian;                   /* Swap endianness.  */
 486   /* Holds a variable length block, as the compiler can write
 487      strings and needs to backtrack.  */
 488   size_t alloc;
 489   gcov_unsigned_t *buffer;
 490 #endif
 491 } gcov_var;
 492
 493 /* Functions for reading and writing gcov files. In libgcov you can
 494    open the file for reading then writing. Elsewhere you can open the
 495    file either for reading or for writing. When reading a file you may
 496    use the gcov_read_* functions, gcov_sync, gcov_position, &
 497    gcov_error. When writing a file you may use the gcov_write
 498    functions, gcov_seek & gcov_error. When a file is to be rewritten
 499    you use the functions for reading, then gcov_rewrite then the
 500    functions for writing.  Your file may become corrupted if you break
 501    these invariants.  */
 502 #if IN_LIBGCOV
 503 GCOV_LINKAGE int gcov_open (const char */*name*/);
 504 #else
 505 GCOV_LINKAGE int gcov_open (const char */*name*/, int /*direction*/);
 506 GCOV_LINKAGE int gcov_magic (gcov_unsigned_t, gcov_unsigned_t);
 507 #endif
 508 GCOV_LINKAGE int gcov_close (void);
 509
 510 /* Available everywhere.  */
 511 static gcov_position_t gcov_position (void);
 512 static int gcov_is_error (void);
 513 static int gcov_is_eof (void);
 514
 515 GCOV_LINKAGE gcov_unsigned_t gcov_read_unsigned (void);
 516 GCOV_LINKAGE gcov_type gcov_read_counter (void);
 517 GCOV_LINKAGE void gcov_read_summary (struct gcov_summary *);
 518
 519 #if IN_LIBGCOV
 520 /* Available only in libgcov */
 521 GCOV_LINKAGE void gcov_write_counter (gcov_type);
 522 GCOV_LINKAGE void gcov_write_tag_length (gcov_unsigned_t, gcov_unsigned_t);
 523 GCOV_LINKAGE void gcov_write_summary (gcov_unsigned_t /*tag*/,
 524                                       const struct gcov_summary *);
 525 static void gcov_truncate (void);
 526 static void gcov_rewrite (void);
 527 GCOV_LINKAGE void gcov_seek (gcov_position_t /*position*/);
 528 #else
 529 /* Available outside libgcov */
 530 GCOV_LINKAGE const char *gcov_read_string (void);
 531 GCOV_LINKAGE void gcov_sync (gcov_position_t /*base*/,
 532                              gcov_unsigned_t /*length */);
 533 #endif
 534
 535 #if !IN_GCOV
 536 /* Available outside gcov */
 537 GCOV_LINKAGE void gcov_write_unsigned (gcov_unsigned_t);
 538 #endif
 539
 540 #if !IN_GCOV && !IN_LIBGCOV
 541 /* Available only in compiler */
 542 GCOV_LINKAGE void gcov_write_string (const char *);
 543 GCOV_LINKAGE gcov_position_t gcov_write_tag (gcov_unsigned_t);
 544 GCOV_LINKAGE void gcov_write_length (gcov_position_t /*position*/);
 545 #endif
 546
 547 #if IN_GCOV > 0
 548 /* Available in gcov */
 549 GCOV_LINKAGE time_t gcov_time (void);
 550 #endif
 551
 552 /* Make sure the library is used correctly.  */
 553 #if ENABLE_CHECKING
 554 #define GCOV_CHECK(expr) ((expr) ? (void)0 : (void)abort ())
 555 #else
 556 #define GCOV_CHECK(expr)
 557 #endif
 558 #define GCOV_CHECK_READING() GCOV_CHECK(gcov_var.mode > 0)
 559 #define GCOV_CHECK_WRITING() GCOV_CHECK(gcov_var.mode < 0)
 560
 561 /* Save the current position in the gcov file.  */
 562
 563 static inline gcov_position_t
 564 gcov_position (void)
 565 {
 566   GCOV_CHECK_READING ();
 567   return gcov_var.start + gcov_var.offset;
 568 }
 569
 570 /* Return nonzero if we read to end of file.  */
 571
 572 static inline int
 573 gcov_is_eof (void)
 574 {
 575   return !gcov_var.overread;
 576 }
 577
 578 /* Return nonzero if the error flag is set.  */
 579
 580 static inline int
 581 gcov_is_error (void)
 582 {
 583   return gcov_var.file ? gcov_var.error : 1;
 584 }
 585
 586 #if IN_LIBGCOV
 587 /* Move to beginning of file and initialize for writing.  */
 588
 589 static inline void
 590 gcov_rewrite (void)
 591 {
 592   GCOV_CHECK_READING ();
 593   gcov_var.mode = -1;
 594   gcov_var.start = 0;
 595   gcov_var.offset = 0;
 596   fseek (gcov_var.file, 0L, SEEK_SET);
 597 }
 598
 599 #ifdef __MINGW32__
 600 #define ftruncate _chsize
 601 #endif
 602 static inline void
 603 gcov_truncate (void)
 604 {
 605   ftruncate (fileno (gcov_var.file), 0L);
 606 }
 607 #endif
 608
 609 #endif /* IN_LIBGCOV >= 0 */
 610
 611 #endif /* GCC_GCOV_IO_H */