gcc/gcov-io.h

   1 /* File format for coverage information
   2    Copyright (C) 1996-2013 Free Software Foundation, Inc.
   3    Contributed by Bob Manson <manson@cygnus.com>.
   4    Completely remangled by Nathan Sidwell <nathan@codesourcery.com>.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  */
  26
  27
  28 /* Coverage information is held in two files.  A notes file, which is
  29    generated by the compiler, and a data file, which is generated by
  30    the program under test.  Both files use a similar structure.  We do
  31    not attempt to make these files backwards compatible with previous
  32    versions, as you only need coverage information when developing a
  33    program.  We do hold version information, so that mismatches can be
  34    detected, and we use a format that allows tools to skip information
  35    they do not understand or are not interested in.
  36
  37    Numbers are recorded in the 32 bit unsigned binary form of the
  38    endianness of the machine generating the file. 64 bit numbers are
  39    stored as two 32 bit numbers, the low part first.  Strings are
  40    padded with 1 to 4 NUL bytes, to bring the length up to a multiple
  41    of 4. The number of 4 bytes is stored, followed by the padded
  42    string. Zero length and NULL strings are simply stored as a length
  43    of zero (they have no trailing NUL or padding).
  44
  45         int32:  byte3 byte2 byte1 byte0 | byte0 byte1 byte2 byte3
  46         int64:  int32:low int32:high
  47         string: int32:0 | int32:length char* char:0 padding
  48         padding: | char:0 | char:0 char:0 | char:0 char:0 char:0
  49         item: int32 | int64 | string
  50
  51    The basic format of the files is
  52
  53         file : int32:magic int32:version int32:stamp record*
  54
  55    The magic ident is different for the notes and the data files.  The
  56    magic ident is used to determine the endianness of the file, when
  57    reading.  The version is the same for both files and is derived
  58    from gcc's version number. The stamp value is used to synchronize
  59    note and data files and to synchronize merging within a data
  60    file. It need not be an absolute time stamp, merely a ticker that
  61    increments fast enough and cycles slow enough to distinguish
  62    different compile/run/compile cycles.
  63
  64    Although the ident and version are formally 32 bit numbers, they
  65    are derived from 4 character ASCII strings.  The version number
  66    consists of the single character major version number, a two
  67    character minor version number (leading zero for versions less than
  68    10), and a single character indicating the status of the release.
  69    That will be 'e' experimental, 'p' prerelease and 'r' for release.
  70    Because, by good fortune, these are in alphabetical order, string
  71    collating can be used to compare version strings.  Be aware that
  72    the 'e' designation will (naturally) be unstable and might be
  73    incompatible with itself.  For gcc 3.4 experimental, it would be
  74    '304e' (0x33303465).  When the major version reaches 10, the
  75    letters A-Z will be used.  Assuming minor increments releases every
  76    6 months, we have to make a major increment every 50 years.
  77    Assuming major increments releases every 5 years, we're ok for the
  78    next 155 years -- good enough for me.
  79
  80    A record has a tag, length and variable amount of data.
  81
  82         record: header data
  83         header: int32:tag int32:length
  84         data: item*
  85
  86    Records are not nested, but there is a record hierarchy.  Tag
  87    numbers reflect this hierarchy.  Tags are unique across note and
  88    data files.  Some record types have a varying amount of data.  The
  89    LENGTH is the number of 4bytes that follow and is usually used to
  90    determine how much data.  The tag value is split into 4 8-bit
  91    fields, one for each of four possible levels.  The most significant
  92    is allocated first.  Unused levels are zero.  Active levels are
  93    odd-valued, so that the LSB of the level is one.  A sub-level
  94    incorporates the values of its superlevels.  This formatting allows
  95    you to determine the tag hierarchy, without understanding the tags
  96    themselves, and is similar to the standard section numbering used
  97    in technical documents.  Level values [1..3f] are used for common
  98    tags, values [41..9f] for the notes file and [a1..ff] for the data
  99    file.
 100
 101    The notes file contains the following records
 102         note: unit function-graph*
 103         unit: header int32:checksum string:source
 104         function-graph: announce_function basic_blocks {arcs | lines}*
 105         announce_function: header int32:ident
 106                 int32:lineno_checksum int32:cfg_checksum
 107                 string:name string:source int32:lineno
 108         basic_block: header int32:flags*
 109         arcs: header int32:block_no arc*
 110         arc:  int32:dest_block int32:flags
 111         lines: header int32:block_no line*
 112                int32:0 string:NULL
 113         line:  int32:line_no | int32:0 string:filename
 114
 115    The BASIC_BLOCK record holds per-bb flags.  The number of blocks
 116    can be inferred from its data length.  There is one ARCS record per
 117    basic block.  The number of arcs from a bb is implicit from the
 118    data length.  It enumerates the destination bb and per-arc flags.
 119    There is one LINES record per basic block, it enumerates the source
 120    lines which belong to that basic block.  Source file names are
 121    introduced by a line number of 0, following lines are from the new
 122    source file.  The initial source file for the function is NULL, but
 123    the current source file should be remembered from one LINES record
 124    to the next.  The end of a block is indicated by an empty filename
 125    - this does not reset the current source file.  Note there is no
 126    ordering of the ARCS and LINES records: they may be in any order,
 127    interleaved in any manner.  The current filename follows the order
 128    the LINES records are stored in the file, *not* the ordering of the
 129    blocks they are for.
 130
 131    The data file contains the following records.
 132         data: {unit summary:object summary:program* function-data*}*
 133         unit: header int32:checksum
 134         function-data:  announce_function present counts
 135         announce_function: header int32:ident
 136                 int32:lineno_checksum int32:cfg_checksum
 137         present: header int32:present
 138         counts: header int64:count*
 139         summary: int32:checksum {count-summary}GCOV_COUNTERS_SUMMABLE
 140         count-summary:  int32:num int32:runs int64:sum
 141                         int64:max int64:sum_max histogram
 142         histogram: {int32:bitvector}8 histogram-buckets*
 143         histogram-buckets: int32:num int64:min int64:sum
 144
 145    The ANNOUNCE_FUNCTION record is the same as that in the note file,
 146    but without the source location.  The COUNTS gives the
 147    counter values for instrumented features.  The 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
 152    zero.  Note that the data file might contain information from
 153    several runs 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 typedef unsigned gcov_type_unsigned __attribute__ ((mode (DI)));
 176 #else
 177 typedef signed gcov_type __attribute__ ((mode (SI)));
 178 typedef unsigned gcov_type_unsigned __attribute__ ((mode (SI)));
 179 #endif
 180 #else
 181 #if BITS_PER_UNIT == 16
 182 typedef unsigned gcov_unsigned_t __attribute__ ((mode (HI)));
 183 typedef unsigned gcov_position_t __attribute__ ((mode (HI)));
 184 #if LONG_LONG_TYPE_SIZE > 32
 185 typedef signed gcov_type __attribute__ ((mode (SI)));
 186 typedef unsigned gcov_type_unsigned __attribute__ ((mode (SI)));
 187 #else
 188 typedef signed gcov_type __attribute__ ((mode (HI)));
 189 typedef unsigned gcov_type_unsigned __attribute__ ((mode (HI)));
 190 #endif
 191 #else
 192 typedef unsigned gcov_unsigned_t __attribute__ ((mode (QI)));
 193 typedef unsigned gcov_position_t __attribute__ ((mode (QI)));
 194 #if LONG_LONG_TYPE_SIZE > 32
 195 typedef signed gcov_type __attribute__ ((mode (HI)));
 196 typedef unsigned gcov_type_unsigned __attribute__ ((mode (HI)));
 197 #else
 198 typedef signed gcov_type __attribute__ ((mode (QI)));
 199 typedef unsigned gcov_type_unsigned __attribute__ ((mode (QI)));
 200 #endif
 201 #endif
 202 #endif
 203
 204
 205 #if defined (TARGET_POSIX_IO)
 206 #define GCOV_LOCKED 1
 207 #else
 208 #define GCOV_LOCKED 0
 209 #endif
 210
 211 #else /* !IN_LIBGCOV */
 212 /* About the host */
 213
 214 typedef unsigned gcov_unsigned_t;
 215 typedef unsigned gcov_position_t;
 216 /* gcov_type is typedef'd elsewhere for the compiler */
 217 #if IN_GCOV
 218 #define GCOV_LINKAGE static
 219 typedef HOST_WIDEST_INT gcov_type;
 220 typedef unsigned HOST_WIDEST_INT gcov_type_unsigned;
 221 #if IN_GCOV > 0
 222 #include <sys/types.h>
 223 #endif
 224 #else /*!IN_GCOV */
 225 #define GCOV_TYPE_SIZE (LONG_LONG_TYPE_SIZE > 32 ? 64 : 32)
 226 #endif
 227
 228 #if defined (HOST_HAS_F_SETLKW)
 229 #define GCOV_LOCKED 1
 230 #else
 231 #define GCOV_LOCKED 0
 232 #endif
 233
 234 #endif /* !IN_LIBGCOV */
 235
 236 /* In gcov we want function linkage to be static.  In the compiler we want
 237    it extern, so that they can be accessed from elsewhere.  In libgcov we
 238    need these functions to be extern, so prefix them with __gcov.  In
 239    libgcov they must also be hidden so that the instance in the executable
 240    is not also used in a DSO.  */
 241 #if IN_LIBGCOV
 242
 243 #include "tconfig.h"
 244
 245 #define gcov_var __gcov_var
 246 #define gcov_open __gcov_open
 247 #define gcov_close __gcov_close
 248 #define gcov_write_tag_length __gcov_write_tag_length
 249 #define gcov_position __gcov_position
 250 #define gcov_seek __gcov_seek
 251 #define gcov_rewrite __gcov_rewrite
 252 #define gcov_is_error __gcov_is_error
 253 #define gcov_write_unsigned __gcov_write_unsigned
 254 #define gcov_write_counter __gcov_write_counter
 255 #define gcov_write_summary __gcov_write_summary
 256 #define gcov_read_unsigned __gcov_read_unsigned
 257 #define gcov_read_counter __gcov_read_counter
 258 #define gcov_read_summary __gcov_read_summary
 259
 260 /* Poison these, so they don't accidentally slip in.  */
 261 #pragma GCC poison gcov_write_string gcov_write_tag gcov_write_length
 262 #pragma GCC poison gcov_read_string gcov_sync gcov_time gcov_magic
 263
 264 #ifdef HAVE_GAS_HIDDEN
 265 #define ATTRIBUTE_HIDDEN  __attribute__ ((__visibility__ ("hidden")))
 266 #else
 267 #define ATTRIBUTE_HIDDEN
 268 #endif
 269
 270 #else
 271
 272 #define ATTRIBUTE_HIDDEN
 273
 274 #endif
 275
 276 #ifndef GCOV_LINKAGE
 277 #define GCOV_LINKAGE extern
 278 #endif
 279
 280 /* File suffixes.  */
 281 #define GCOV_DATA_SUFFIX ".gcda"
 282 #define GCOV_NOTE_SUFFIX ".gcno"
 283
 284 /* File magic. Must not be palindromes.  */
 285 #define GCOV_DATA_MAGIC ((gcov_unsigned_t)0x67636461) /* "gcda" */
 286 #define GCOV_NOTE_MAGIC ((gcov_unsigned_t)0x67636e6f) /* "gcno" */
 287
 288 /* gcov-iov.h is automatically generated by the makefile from
 289    version.c, it looks like
 290         #define GCOV_VERSION ((gcov_unsigned_t)0x89abcdef)
 291 */
 292 #include "gcov-iov.h"
 293
 294 /* Convert a magic or version number to a 4 character string.  */
 295 #define GCOV_UNSIGNED2STRING(ARRAY,VALUE)       \
 296   ((ARRAY)[0] = (char)((VALUE) >> 24),          \
 297    (ARRAY)[1] = (char)((VALUE) >> 16),          \
 298    (ARRAY)[2] = (char)((VALUE) >> 8),           \
 299    (ARRAY)[3] = (char)((VALUE) >> 0))
 300
 301 /* The record tags.  Values [1..3f] are for tags which may be in either
 302    file.  Values [41..9f] for those in the note file and [a1..ff] for
 303    the data file.  The tag value zero is used as an explicit end of
 304    file marker -- it is not required to be present.  */
 305
 306 #define GCOV_TAG_FUNCTION        ((gcov_unsigned_t)0x01000000)
 307 #define GCOV_TAG_FUNCTION_LENGTH (3)
 308 #define GCOV_TAG_BLOCKS          ((gcov_unsigned_t)0x01410000)
 309 #define GCOV_TAG_BLOCKS_LENGTH(NUM) (NUM)
 310 #define GCOV_TAG_BLOCKS_NUM(LENGTH) (LENGTH)
 311 #define GCOV_TAG_ARCS            ((gcov_unsigned_t)0x01430000)
 312 #define GCOV_TAG_ARCS_LENGTH(NUM)  (1 + (NUM) * 2)
 313 #define GCOV_TAG_ARCS_NUM(LENGTH)  (((LENGTH) - 1) / 2)
 314 #define GCOV_TAG_LINES           ((gcov_unsigned_t)0x01450000)
 315 #define GCOV_TAG_COUNTER_BASE    ((gcov_unsigned_t)0x01a10000)
 316 #define GCOV_TAG_COUNTER_LENGTH(NUM) ((NUM) * 2)
 317 #define GCOV_TAG_COUNTER_NUM(LENGTH) ((LENGTH) / 2)
 318 #define GCOV_TAG_OBJECT_SUMMARY  ((gcov_unsigned_t)0xa1000000) /* Obsolete */
 319 #define GCOV_TAG_PROGRAM_SUMMARY ((gcov_unsigned_t)0xa3000000)
 320 #define GCOV_TAG_SUMMARY_LENGTH(NUM)  \
 321         (1 + GCOV_COUNTERS_SUMMABLE * (10 + 3 * 2) + (NUM) * 5)
 322
 323
 324 /* Counters that are collected.  */
 325 #define GCOV_COUNTER_ARCS       0  /* Arc transitions.  */
 326 #define GCOV_COUNTERS_SUMMABLE  1  /* Counters which can be
 327                                       summaried.  */
 328 #define GCOV_FIRST_VALUE_COUNTER 1 /* The first of counters used for value
 329                                       profiling.  They must form a consecutive
 330                                       interval and their order must match
 331                                       the order of HIST_TYPEs in
 332                                       value-prof.h.  */
 333 #define GCOV_COUNTER_V_INTERVAL 1  /* Histogram of value inside an interval.  */
 334 #define GCOV_COUNTER_V_POW2     2  /* Histogram of exact power2 logarithm
 335                                       of a value.  */
 336 #define GCOV_COUNTER_V_SINGLE   3  /* The most common value of expression.  */
 337 #define GCOV_COUNTER_V_DELTA    4  /* The most common difference between
 338                                       consecutive values of expression.  */
 339
 340 #define GCOV_COUNTER_V_INDIR    5  /* The most common indirect address */
 341 #define GCOV_COUNTER_AVERAGE    6  /* Compute average value passed to the
 342                                       counter.  */
 343 #define GCOV_COUNTER_IOR        7  /* IOR of the all values passed to
 344                                       counter.  */
 345 #define GCOV_LAST_VALUE_COUNTER 7  /* The last of counters used for value
 346                                       profiling.  */
 347 #define GCOV_COUNTERS           8
 348
 349 /* Number of counters used for value profiling.  */
 350 #define GCOV_N_VALUE_COUNTERS \
 351   (GCOV_LAST_VALUE_COUNTER - GCOV_FIRST_VALUE_COUNTER + 1)
 352
 353   /* A list of human readable names of the counters */
 354 #define GCOV_COUNTER_NAMES      {"arcs", "interval", "pow2", "single", \
 355                                  "delta", "indirect_call", "average", "ior"}
 356
 357   /* Names of merge functions for counters.  */
 358 #define GCOV_MERGE_FUNCTIONS    {"__gcov_merge_add",    \
 359                                  "__gcov_merge_add",    \
 360                                  "__gcov_merge_add",    \
 361                                  "__gcov_merge_single", \
 362                                  "__gcov_merge_delta",  \
 363                                  "__gcov_merge_single", \
 364                                  "__gcov_merge_add",    \
 365                                  "__gcov_merge_ior"}
 366
 367 /* Convert a counter index to a tag.  */
 368 #define GCOV_TAG_FOR_COUNTER(COUNT)                             \
 369         (GCOV_TAG_COUNTER_BASE + ((gcov_unsigned_t)(COUNT) << 17))
 370 /* Convert a tag to a counter.  */
 371 #define GCOV_COUNTER_FOR_TAG(TAG)                                       \
 372         ((unsigned)(((TAG) - GCOV_TAG_COUNTER_BASE) >> 17))
 373 /* Check whether a tag is a counter tag.  */
 374 #define GCOV_TAG_IS_COUNTER(TAG)                                \
 375         (!((TAG) & 0xFFFF) && GCOV_COUNTER_FOR_TAG (TAG) < GCOV_COUNTERS)
 376
 377 /* The tag level mask has 1's in the position of the inner levels, &
 378    the lsb of the current level, and zero on the current and outer
 379    levels.  */
 380 #define GCOV_TAG_MASK(TAG) (((TAG) - 1) ^ (TAG))
 381
 382 /* Return nonzero if SUB is an immediate subtag of TAG.  */
 383 #define GCOV_TAG_IS_SUBTAG(TAG,SUB)                             \
 384         (GCOV_TAG_MASK (TAG) >> 8 == GCOV_TAG_MASK (SUB)        \
 385          && !(((SUB) ^ (TAG)) & ~GCOV_TAG_MASK(TAG)))
 386
 387 /* Return nonzero if SUB is at a sublevel to TAG.  */
 388 #define GCOV_TAG_IS_SUBLEVEL(TAG,SUB)                           \
 389         (GCOV_TAG_MASK (TAG) > GCOV_TAG_MASK (SUB))
 390
 391 /* Basic block flags.  */
 392 #define GCOV_BLOCK_UNEXPECTED   (1 << 1)
 393
 394 /* Arc flags.  */
 395 #define GCOV_ARC_ON_TREE        (1 << 0)
 396 #define GCOV_ARC_FAKE           (1 << 1)
 397 #define GCOV_ARC_FALLTHROUGH    (1 << 2)
 398
 399 /* Structured records.  */
 400
 401 /* Structure used for each bucket of the log2 histogram of counter values.  */
 402 typedef struct
 403 {
 404   /* Number of counters whose profile count falls within the bucket.  */
 405   gcov_unsigned_t num_counters;
 406   /* Smallest profile count included in this bucket.  */
 407   gcov_type min_value;
 408   /* Cumulative value of the profile counts in this bucket.  */
 409   gcov_type cum_value;
 410 } gcov_bucket_type;
 411
 412 /* For a log2 scale histogram with each range split into 4
 413    linear sub-ranges, there will be at most 64 (max gcov_type bit size) - 1 log2
 414    ranges since the lowest 2 log2 values share the lowest 4 linear
 415    sub-range (values 0 - 3).  This is 252 total entries (63*4).  */
 416
 417 #define GCOV_HISTOGRAM_SIZE 252
 418
 419 /* How many unsigned ints are required to hold a bit vector of non-zero
 420    histogram entries when the histogram is written to the gcov file.
 421    This is essentially a ceiling divide by 32 bits.  */
 422 #define GCOV_HISTOGRAM_BITVECTOR_SIZE (GCOV_HISTOGRAM_SIZE + 31) / 32
 423
 424 /* Cumulative counter data.  */
 425 struct gcov_ctr_summary
 426 {
 427   gcov_unsigned_t num;          /* number of counters.  */
 428   gcov_unsigned_t runs;         /* number of program runs */
 429   gcov_type sum_all;            /* sum of all counters accumulated.  */
 430   gcov_type run_max;            /* maximum value on a single run.  */
 431   gcov_type sum_max;            /* sum of individual run max values.  */
 432   gcov_bucket_type histogram[GCOV_HISTOGRAM_SIZE]; /* histogram of
 433                                                       counter values.  */
 434 };
 435
 436 /* Object & program summary record.  */
 437 struct gcov_summary
 438 {
 439   gcov_unsigned_t checksum;     /* checksum of program */
 440   struct gcov_ctr_summary ctrs[GCOV_COUNTERS_SUMMABLE];
 441 };
 442
 443 /* Structures embedded in coveraged program.  The structures generated
 444    by write_profile must match these.  */
 445
 446 #if IN_LIBGCOV
 447 /* Information about counters for a single function.  */
 448 struct gcov_ctr_info
 449 {
 450   gcov_unsigned_t num;          /* number of counters.  */
 451   gcov_type *values;            /* their values.  */
 452 };
 453
 454 /* Information about a single function.  This uses the trailing array
 455    idiom. The number of counters is determined from the merge pointer
 456    array in gcov_info.  The key is used to detect which of a set of
 457    comdat functions was selected -- it points to the gcov_info object
 458    of the object file containing the selected comdat function.  */
 459
 460 struct gcov_fn_info
 461 {
 462   const struct gcov_info *key;          /* comdat key */
 463   gcov_unsigned_t ident;                /* unique ident of function */
 464   gcov_unsigned_t lineno_checksum;      /* function lineo_checksum */
 465   gcov_unsigned_t cfg_checksum;         /* function cfg checksum */
 466   struct gcov_ctr_info ctrs[0];         /* instrumented counters */
 467 };
 468
 469 /* Type of function used to merge counters.  */
 470 typedef void (*gcov_merge_fn) (gcov_type *, gcov_unsigned_t);
 471
 472 /* Information about a single object file.  */
 473 struct gcov_info
 474 {
 475   gcov_unsigned_t version;      /* expected version number */
 476   struct gcov_info *next;       /* link to next, used by libgcov */
 477
 478   gcov_unsigned_t stamp;        /* uniquifying time stamp */
 479   const char *filename;         /* output file name */
 480
 481   gcov_merge_fn merge[GCOV_COUNTERS];  /* merge functions (null for
 482                                           unused) */
 483
 484   unsigned n_functions;         /* number of functions */
 485   const struct gcov_fn_info *const *functions; /* pointer to pointers
 486                                                   to function information  */
 487 };
 488
 489 /* Register a new object file module.  */
 490 extern void __gcov_init (struct gcov_info *) ATTRIBUTE_HIDDEN;
 491
 492 /* Called before fork, to avoid double counting.  */
 493 extern void __gcov_flush (void) ATTRIBUTE_HIDDEN;
 494
 495 /* Function to reset all counters to 0.  */
 496 extern void __gcov_reset (void);
 497
 498 /* Function to enable early write of profile information so far.  */
 499 extern void __gcov_dump (void);
 500
 501 /* The merge function that just sums the counters.  */
 502 extern void __gcov_merge_add (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;
 503
 504 /* The merge function to choose the most common value.  */
 505 extern void __gcov_merge_single (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;
 506
 507 /* The merge function to choose the most common difference between
 508    consecutive values.  */
 509 extern void __gcov_merge_delta (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;
 510
 511 /* The merge function that just ors the counters together.  */
 512 extern void __gcov_merge_ior (gcov_type *, unsigned) ATTRIBUTE_HIDDEN;
 513
 514 /* The profiler functions.  */
 515 extern void __gcov_interval_profiler (gcov_type *, gcov_type, int, unsigned);
 516 extern void __gcov_pow2_profiler (gcov_type *, gcov_type);
 517 extern void __gcov_one_value_profiler (gcov_type *, gcov_type);
 518 extern void __gcov_indirect_call_profiler_v2 (gcov_type, void *);
 519 extern void __gcov_average_profiler (gcov_type *, gcov_type);
 520 extern void __gcov_ior_profiler (gcov_type *, gcov_type);
 521
 522 #ifndef inhibit_libc
 523 /* The wrappers around some library functions..  */
 524 extern pid_t __gcov_fork (void) ATTRIBUTE_HIDDEN;
 525 extern int __gcov_execl (const char *, char *, ...) ATTRIBUTE_HIDDEN;
 526 extern int __gcov_execlp (const char *, char *, ...) ATTRIBUTE_HIDDEN;
 527 extern int __gcov_execle (const char *, char *, ...) ATTRIBUTE_HIDDEN;
 528 extern int __gcov_execv (const char *, char *const []) ATTRIBUTE_HIDDEN;
 529 extern int __gcov_execvp (const char *, char *const []) ATTRIBUTE_HIDDEN;
 530 extern int __gcov_execve (const char *, char  *const [], char *const [])
 531   ATTRIBUTE_HIDDEN;
 532 #endif
 533
 534 #endif /* IN_LIBGCOV */
 535
 536 #if IN_LIBGCOV >= 0
 537
 538 /* Optimum number of gcov_unsigned_t's read from or written to disk.  */
 539 #define GCOV_BLOCK_SIZE (1 << 10)
 540
 541 GCOV_LINKAGE struct gcov_var
 542 {
 543   FILE *file;
 544   gcov_position_t start;        /* Position of first byte of block */
 545   unsigned offset;              /* Read/write position within the block.  */
 546   unsigned length;              /* Read limit in the block.  */
 547   unsigned overread;            /* Number of words overread.  */
 548   int error;                    /* < 0 overflow, > 0 disk error.  */
 549   int mode;                     /* < 0 writing, > 0 reading */
 550 #if IN_LIBGCOV
 551   /* Holds one block plus 4 bytes, thus all coverage reads & writes
 552      fit within this buffer and we always can transfer GCOV_BLOCK_SIZE
 553      to and from the disk. libgcov never backtracks and only writes 4
 554      or 8 byte objects.  */
 555   gcov_unsigned_t buffer[GCOV_BLOCK_SIZE + 1];
 556 #else
 557   int endian;                   /* Swap endianness.  */
 558   /* Holds a variable length block, as the compiler can write
 559      strings and needs to backtrack.  */
 560   size_t alloc;
 561   gcov_unsigned_t *buffer;
 562 #endif
 563 } gcov_var ATTRIBUTE_HIDDEN;
 564
 565 /* Functions for reading and writing gcov files. In libgcov you can
 566    open the file for reading then writing. Elsewhere you can open the
 567    file either for reading or for writing. When reading a file you may
 568    use the gcov_read_* functions, gcov_sync, gcov_position, &
 569    gcov_error. When writing a file you may use the gcov_write
 570    functions, gcov_seek & gcov_error. When a file is to be rewritten
 571    you use the functions for reading, then gcov_rewrite then the
 572    functions for writing.  Your file may become corrupted if you break
 573    these invariants.  */
 574 #if IN_LIBGCOV
 575 GCOV_LINKAGE int gcov_open (const char */*name*/) ATTRIBUTE_HIDDEN;
 576 #else
 577 GCOV_LINKAGE int gcov_open (const char */*name*/, int /*direction*/);
 578 GCOV_LINKAGE int gcov_magic (gcov_unsigned_t, gcov_unsigned_t);
 579 #endif
 580 GCOV_LINKAGE int gcov_close (void) ATTRIBUTE_HIDDEN;
 581
 582 /* Available everywhere.  */
 583 static gcov_position_t gcov_position (void);
 584 static int gcov_is_error (void);
 585
 586 GCOV_LINKAGE gcov_unsigned_t gcov_read_unsigned (void) ATTRIBUTE_HIDDEN;
 587 GCOV_LINKAGE gcov_type gcov_read_counter (void) ATTRIBUTE_HIDDEN;
 588 GCOV_LINKAGE void gcov_read_summary (struct gcov_summary *) ATTRIBUTE_HIDDEN;
 589
 590 #if IN_LIBGCOV
 591 /* Available only in libgcov */
 592 GCOV_LINKAGE void gcov_write_counter (gcov_type) ATTRIBUTE_HIDDEN;
 593 GCOV_LINKAGE void gcov_write_tag_length (gcov_unsigned_t, gcov_unsigned_t)
 594     ATTRIBUTE_HIDDEN;
 595 GCOV_LINKAGE void gcov_write_summary (gcov_unsigned_t /*tag*/,
 596                                       const struct gcov_summary *)
 597     ATTRIBUTE_HIDDEN;
 598 static void gcov_rewrite (void);
 599 GCOV_LINKAGE void gcov_seek (gcov_position_t /*position*/) ATTRIBUTE_HIDDEN;
 600 #else
 601 /* Available outside libgcov */
 602 GCOV_LINKAGE const char *gcov_read_string (void);
 603 GCOV_LINKAGE void gcov_sync (gcov_position_t /*base*/,
 604                              gcov_unsigned_t /*length */);
 605 #endif
 606
 607 #if !IN_GCOV
 608 /* Available outside gcov */
 609 GCOV_LINKAGE void gcov_write_unsigned (gcov_unsigned_t) ATTRIBUTE_HIDDEN;
 610 #endif
 611
 612 #if !IN_GCOV && !IN_LIBGCOV
 613 /* Available only in compiler */
 614 GCOV_LINKAGE unsigned gcov_histo_index (gcov_type value);
 615 GCOV_LINKAGE void gcov_write_string (const char *);
 616 GCOV_LINKAGE gcov_position_t gcov_write_tag (gcov_unsigned_t);
 617 GCOV_LINKAGE void gcov_write_length (gcov_position_t /*position*/);
 618 #endif
 619
 620 #if IN_GCOV <= 0 && !IN_LIBGCOV
 621 /* Available in gcov-dump and the compiler.  */
 622
 623 /* Number of data points in the working set summary array. Using 128
 624    provides information for at least every 1% increment of the total
 625    profile size. The last entry is hardwired to 99.9% of the total.  */
 626 #define NUM_GCOV_WORKING_SETS 128
 627
 628 /* Working set size statistics for a given percentage of the entire
 629    profile (sum_all from the counter summary).  */
 630 typedef struct gcov_working_set_info
 631 {
 632   /* Number of hot counters included in this working set.  */
 633   unsigned num_counters;
 634   /* Smallest counter included in this working set.  */
 635   gcov_type min_counter;
 636 } gcov_working_set_t;
 637
 638 GCOV_LINKAGE void compute_working_sets (const struct gcov_ctr_summary *summary,
 639                                         gcov_working_set_t *gcov_working_sets);
 640 #endif
 641
 642 #if IN_GCOV > 0
 643 /* Available in gcov */
 644 GCOV_LINKAGE time_t gcov_time (void);
 645 #endif
 646
 647 /* Save the current position in the gcov file.  */
 648
 649 static inline gcov_position_t
 650 gcov_position (void)
 651 {
 652   gcc_assert (gcov_var.mode > 0);
 653   return gcov_var.start + gcov_var.offset;
 654 }
 655
 656 /* Return nonzero if the error flag is set.  */
 657
 658 static inline int
 659 gcov_is_error (void)
 660 {
 661   return gcov_var.file ? gcov_var.error : 1;
 662 }
 663
 664 #if IN_LIBGCOV
 665 /* Move to beginning of file and initialize for writing.  */
 666
 667 static inline void
 668 gcov_rewrite (void)
 669 {
 670   gcc_assert (gcov_var.mode > 0);
 671   gcov_var.mode = -1;
 672   gcov_var.start = 0;
 673   gcov_var.offset = 0;
 674   fseek (gcov_var.file, 0L, SEEK_SET);
 675 }
 676 #endif
 677
 678 #endif /* IN_LIBGCOV >= 0 */
 679
 680 #endif /* GCC_GCOV_IO_H */