gcc/gcov-io.h

   1 /* File format for coverage information
   2    Copyright (C) 1996-2021 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 /* CAVEAT: Coverage information files should not be parsed directly,
  29    instead use `gcov --json-format`, which provides
  30    machine-readable coverage information.
  31
  32    Note that the following file format documentation might be outdated.
  33
  34    Coverage information is held in two files.  A notes file, which is
  35    generated by the compiler, and a data file, which is generated by
  36    the program under test.  Both files use a similar structure.  We do
  37    not attempt to make these files backwards compatible with previous
  38    versions, as you only need coverage information when developing a
  39    program.  We do hold version information, so that mismatches can be
  40    detected, and we use a format that allows tools to skip information
  41    they do not understand or are not interested in.
  42
  43    Numbers are recorded in the 32 bit unsigned binary form of the
  44    endianness of the machine generating the file. 64 bit numbers are
  45    stored as two 32 bit numbers, the low part first.
  46    The number of bytes is stored, followed by the
  47    string. Zero length and NULL strings are simply stored as a length
  48    of zero (they have no trailing NUL).
  49
  50         int32:  byte3 byte2 byte1 byte0 | byte0 byte1 byte2 byte3
  51         int64:  int32:low int32:high
  52         string: int32:0 | int32:length char* char:0
  53         item: int32 | int64 | string
  54
  55    The basic format of the notes file is
  56
  57         file : int32:magic int32:version int32:stamp int32:support_unexecuted_blocks record*
  58
  59    The basic format of the data file is
  60
  61         file : int32:magic int32:version int32:stamp record*
  62
  63    The magic ident is different for the notes and the data files.  The
  64    magic ident is used to determine the endianness of the file, when
  65    reading.  The version is the same for both files and is derived
  66    from gcc's version number. The stamp value is used to synchronize
  67    note and data files and to synchronize merging within a data
  68    file. It need not be an absolute time stamp, merely a ticker that
  69    increments fast enough and cycles slow enough to distinguish
  70    different compile/run/compile cycles.
  71
  72    Although the ident and version are formally 32 bit numbers, they
  73    are derived from 4 character ASCII strings.  The version number
  74    consists of a two character major version number
  75    (first digit starts from 'A' letter to not to clash with the older
  76    numbering scheme), the single character minor version number,
  77    and a single character indicating the status of the release.
  78    That will be 'e' experimental, 'p' prerelease and 'r' for release.
  79    Because, by good fortune, these are in alphabetical order, string
  80    collating can be used to compare version strings.  Be aware that
  81    the 'e' designation will (naturally) be unstable and might be
  82    incompatible with itself.  For gcc 17.0 experimental, it would be
  83    'B70e' (0x42373065).  As we currently do not release more than 5 minor
  84    releases, the single character should be always fine.  Major number
  85    is currently changed roughly every year, which gives us space
  86    for next 250 years (maximum allowed number would be 259.9).
  87
  88    A record has a tag, length and variable amount of data.
  89
  90         record: header data
  91         header: int32:tag int32:length
  92         data: item*
  93
  94    Records are not nested, but there is a record hierarchy.  Tag
  95    numbers reflect this hierarchy.  Tags are unique across note and
  96    data files.  Some record types have a varying amount of data.  The
  97    LENGTH is the number of 4bytes that follow and is usually used to
  98    determine how much data.  The tag value is split into 4 8-bit
  99    fields, one for each of four possible levels.  The most significant
 100    is allocated first.  Unused levels are zero.  Active levels are
 101    odd-valued, so that the LSB of the level is one.  A sub-level
 102    incorporates the values of its superlevels.  This formatting allows
 103    you to determine the tag hierarchy, without understanding the tags
 104    themselves, and is similar to the standard section numbering used
 105    in technical documents.  Level values [1..3f] are used for common
 106    tags, values [41..9f] for the notes file and [a1..ff] for the data
 107    file.
 108
 109    The notes file contains the following records
 110         note: unit function-graph*
 111         unit: header int32:checksum string:source
 112         function-graph: announce_function basic_blocks {arcs | lines}*
 113         announce_function: header int32:ident
 114                 int32:lineno_checksum int32:cfg_checksum
 115                 string:name string:source int32:start_lineno int32:start_column int32:end_lineno
 116         basic_block: header int32:flags*
 117         arcs: header int32:block_no arc*
 118         arc:  int32:dest_block int32:flags
 119         lines: header int32:block_no line*
 120                int32:0 string:NULL
 121         line:  int32:line_no | int32:0 string:filename
 122
 123    The BASIC_BLOCK record holds per-bb flags.  The number of blocks
 124    can be inferred from its data length.  There is one ARCS record per
 125    basic block.  The number of arcs from a bb is implicit from the
 126    data length.  It enumerates the destination bb and per-arc flags.
 127    There is one LINES record per basic block, it enumerates the source
 128    lines which belong to that basic block.  Source file names are
 129    introduced by a line number of 0, following lines are from the new
 130    source file.  The initial source file for the function is NULL, but
 131    the current source file should be remembered from one LINES record
 132    to the next.  The end of a block is indicated by an empty filename
 133    - this does not reset the current source file.  Note there is no
 134    ordering of the ARCS and LINES records: they may be in any order,
 135    interleaved in any manner.  The current filename follows the order
 136    the LINES records are stored in the file, *not* the ordering of the
 137    blocks they are for.
 138
 139    The data file contains the following records.
 140         data: {unit summary:object function-data*}*
 141         unit: header int32:checksum
 142         function-data:  announce_function present counts
 143         announce_function: header int32:ident
 144                 int32:lineno_checksum int32:cfg_checksum
 145         present: header int32:present
 146         counts: header int64:count*
 147         summary: int32:checksum int32:runs int32:sum_max
 148
 149    The ANNOUNCE_FUNCTION record is the same as that in the note file,
 150    but without the source location.  The COUNTS gives the
 151    counter values for instrumented features.  The about the whole
 152    program.  The checksum is used for whole program summaries, and
 153    disambiguates different programs which include the same
 154    instrumented object file.  There may be several program summaries,
 155    each with a unique checksum.  The object summary's checksum is
 156    zero.  Note that the data file might contain information from
 157    several runs concatenated, or the data might be merged.
 158
 159    This file is included by both the compiler, gcov tools and the
 160    runtime support library libgcov. IN_LIBGCOV and IN_GCOV are used to
 161    distinguish which case is which.  If IN_LIBGCOV is nonzero,
 162    libgcov is being built. If IN_GCOV is nonzero, the gcov tools are
 163    being built. Otherwise the compiler is being built. IN_GCOV may be
 164    positive or negative. If positive, we are compiling a tool that
 165    requires additional functions (see the code for knowledge of what
 166    those functions are).  */
 167
 168 #ifndef GCC_GCOV_IO_H
 169 #define GCC_GCOV_IO_H
 170
 171 /* GCOV key-value pair linked list type.  */
 172
 173 struct gcov_kvp;
 174
 175 struct gcov_kvp
 176 {
 177   gcov_type value;
 178   gcov_type count;
 179   struct gcov_kvp *next;
 180 };
 181
 182 #ifndef IN_LIBGCOV
 183 /* About the host */
 184
 185 typedef unsigned gcov_unsigned_t;
 186 typedef unsigned gcov_position_t;
 187 /* gcov_type is typedef'd elsewhere for the compiler */
 188 #if IN_GCOV
 189 #define GCOV_LINKAGE static
 190 typedef int64_t gcov_type;
 191 typedef uint64_t gcov_type_unsigned;
 192 #if IN_GCOV > 0
 193 #include <sys/types.h>
 194 #endif
 195 #endif
 196
 197 #if defined (HOST_HAS_F_SETLKW)
 198 #define GCOV_LOCKED 1
 199 #else
 200 #define GCOV_LOCKED 0
 201 #endif
 202
 203 #if defined (HOST_HAS_LK_LOCK)
 204 #define GCOV_LOCKED_WITH_LOCKING 1
 205 #else
 206 #define GCOV_LOCKED_WITH_LOCKING 0
 207 #endif
 208
 209 #define ATTRIBUTE_HIDDEN
 210
 211 #endif /* !IN_LIBGCOV */
 212
 213 #ifndef GCOV_LINKAGE
 214 #define GCOV_LINKAGE extern
 215 #endif
 216
 217 #if IN_LIBGCOV
 218 #define gcov_nonruntime_assert(EXPR) ((void)(0 && (EXPR)))
 219 #else
 220 #define gcov_nonruntime_assert(EXPR) gcc_assert (EXPR)
 221 #define gcov_error(...) fatal_error (input_location, __VA_ARGS__)
 222 #endif
 223
 224 /* File suffixes.  */
 225 #define GCOV_DATA_SUFFIX ".gcda"
 226 #define GCOV_NOTE_SUFFIX ".gcno"
 227
 228 /* File magic. Must not be palindromes.  */
 229 #define GCOV_DATA_MAGIC ((gcov_unsigned_t)0x67636461) /* "gcda" */
 230 #define GCOV_NOTE_MAGIC ((gcov_unsigned_t)0x67636e6f) /* "gcno" */
 231
 232 #include "version.h"
 233
 234 /* Convert a magic or version number to a 4 character string.  */
 235 #define GCOV_UNSIGNED2STRING(ARRAY,VALUE)       \
 236   ((ARRAY)[0] = (char)((VALUE) >> 24),          \
 237    (ARRAY)[1] = (char)((VALUE) >> 16),          \
 238    (ARRAY)[2] = (char)((VALUE) >> 8),           \
 239    (ARRAY)[3] = (char)((VALUE) >> 0))
 240
 241 /* The record tags.  Values [1..3f] are for tags which may be in either
 242    file.  Values [41..9f] for those in the note file and [a1..ff] for
 243    the data file.  The tag value zero is used as an explicit end of
 244    file marker -- it is not required to be present.
 245    All length values are in bytes.  */
 246
 247 #define GCOV_WORD_SIZE          4
 248
 249 #define GCOV_TAG_FUNCTION        ((gcov_unsigned_t)0x01000000)
 250 #define GCOV_TAG_FUNCTION_LENGTH (3 * GCOV_WORD_SIZE)
 251 #define GCOV_TAG_BLOCKS          ((gcov_unsigned_t)0x01410000)
 252 #define GCOV_TAG_BLOCKS_LENGTH(NUM) (NUM)
 253 #define GCOV_TAG_ARCS            ((gcov_unsigned_t)0x01430000)
 254 #define GCOV_TAG_ARCS_LENGTH(NUM)  (1 + (NUM) * 2 * GCOV_WORD_SIZE)
 255 #define GCOV_TAG_ARCS_NUM(LENGTH)  (((LENGTH / GCOV_WORD_SIZE) - 1) / 2)
 256 #define GCOV_TAG_LINES           ((gcov_unsigned_t)0x01450000)
 257 #define GCOV_TAG_COUNTER_BASE    ((gcov_unsigned_t)0x01a10000)
 258 #define GCOV_TAG_COUNTER_LENGTH(NUM) ((NUM) * 2 * GCOV_WORD_SIZE)
 259 #define GCOV_TAG_COUNTER_NUM(LENGTH) ((LENGTH / GCOV_WORD_SIZE) / 2)
 260 #define GCOV_TAG_OBJECT_SUMMARY  ((gcov_unsigned_t)0xa1000000)
 261 #define GCOV_TAG_PROGRAM_SUMMARY ((gcov_unsigned_t)0xa3000000) /* Obsolete */
 262 #define GCOV_TAG_SUMMARY_LENGTH (2 * GCOV_WORD_SIZE)
 263 #define GCOV_TAG_AFDO_FILE_NAMES ((gcov_unsigned_t)0xaa000000)
 264 #define GCOV_TAG_AFDO_FUNCTION ((gcov_unsigned_t)0xac000000)
 265 #define GCOV_TAG_AFDO_WORKING_SET ((gcov_unsigned_t)0xaf000000)
 266
 267
 268 /* Counters that are collected.  */
 269
 270 #define DEF_GCOV_COUNTER(COUNTER, NAME, MERGE_FN) COUNTER,
 271 enum {
 272 #include "gcov-counter.def"
 273 GCOV_COUNTERS
 274 };
 275 #undef DEF_GCOV_COUNTER
 276
 277 /* The first of counters used for value profiling.  They must form a
 278    consecutive interval and their order must match the order of
 279    HIST_TYPEs in value-prof.h.  */
 280 #define GCOV_FIRST_VALUE_COUNTER GCOV_COUNTER_V_INTERVAL
 281
 282 /* The last of counters used for value profiling.  */
 283 #define GCOV_LAST_VALUE_COUNTER (GCOV_COUNTERS - 1)
 284
 285 /* Number of counters used for value profiling.  */
 286 #define GCOV_N_VALUE_COUNTERS \
 287   (GCOV_LAST_VALUE_COUNTER - GCOV_FIRST_VALUE_COUNTER + 1)
 288
 289 /* Number of top N counters when being in memory.  */
 290 #define GCOV_TOPN_MEM_COUNTERS 3
 291
 292 /* Number of top N counters in disk representation.  */
 293 #define GCOV_TOPN_DISK_COUNTERS 2
 294
 295 /* Maximum number of tracked TOP N value profiles.  */
 296 #define GCOV_TOPN_MAXIMUM_TRACKED_VALUES 32
 297
 298 /* Convert a counter index to a tag.  */
 299 #define GCOV_TAG_FOR_COUNTER(COUNT)                             \
 300         (GCOV_TAG_COUNTER_BASE + ((gcov_unsigned_t)(COUNT) << 17))
 301 /* Convert a tag to a counter.  */
 302 #define GCOV_COUNTER_FOR_TAG(TAG)                                       \
 303         ((unsigned)(((TAG) - GCOV_TAG_COUNTER_BASE) >> 17))
 304 /* Check whether a tag is a counter tag.  */
 305 #define GCOV_TAG_IS_COUNTER(TAG)                                \
 306         (!((TAG) & 0xFFFF) && GCOV_COUNTER_FOR_TAG (TAG) < GCOV_COUNTERS)
 307
 308 /* The tag level mask has 1's in the position of the inner levels, &
 309    the lsb of the current level, and zero on the current and outer
 310    levels.  */
 311 #define GCOV_TAG_MASK(TAG) (((TAG) - 1) ^ (TAG))
 312
 313 /* Return nonzero if SUB is an immediate subtag of TAG.  */
 314 #define GCOV_TAG_IS_SUBTAG(TAG,SUB)                             \
 315         (GCOV_TAG_MASK (TAG) >> 8 == GCOV_TAG_MASK (SUB)        \
 316          && !(((SUB) ^ (TAG)) & ~GCOV_TAG_MASK (TAG)))
 317
 318 /* Return nonzero if SUB is at a sublevel to TAG.  */
 319 #define GCOV_TAG_IS_SUBLEVEL(TAG,SUB)                           \
 320         (GCOV_TAG_MASK (TAG) > GCOV_TAG_MASK (SUB))
 321
 322 /* Basic block flags.  */
 323 #define GCOV_BLOCK_UNEXPECTED   (1 << 1)
 324
 325 /* Arc flags.  */
 326 #define GCOV_ARC_ON_TREE        (1 << 0)
 327 #define GCOV_ARC_FAKE           (1 << 1)
 328 #define GCOV_ARC_FALLTHROUGH    (1 << 2)
 329
 330 /* Object & program summary record.  */
 331
 332 struct gcov_summary
 333 {
 334   gcov_unsigned_t runs;         /* Number of program runs.  */
 335   gcov_type sum_max;            /* Sum of individual run max values.  */
 336 };
 337
 338 #if !defined(inhibit_libc)
 339
 340 /* Functions for reading and writing gcov files. In libgcov you can
 341    open the file for reading then writing. Elsewhere you can open the
 342    file either for reading or for writing. When reading a file you may
 343    use the gcov_read_* functions, gcov_sync, gcov_position, &
 344    gcov_error. When writing a file you may use the gcov_write
 345    functions, gcov_seek & gcov_error. When a file is to be rewritten
 346    you use the functions for reading, then gcov_rewrite then the
 347    functions for writing.  Your file may become corrupted if you break
 348    these invariants.  */
 349
 350 #if !IN_LIBGCOV
 351 GCOV_LINKAGE int gcov_open (const char */*name*/, int /*direction*/);
 352 #endif
 353
 354 #if !IN_LIBGCOV || defined (IN_GCOV_TOOL)
 355 GCOV_LINKAGE int gcov_magic (gcov_unsigned_t, gcov_unsigned_t);
 356 #endif
 357
 358 /* Available everywhere.  */
 359 GCOV_LINKAGE int gcov_close (void) ATTRIBUTE_HIDDEN;
 360 GCOV_LINKAGE gcov_unsigned_t gcov_read_unsigned (void) ATTRIBUTE_HIDDEN;
 361 GCOV_LINKAGE gcov_type gcov_read_counter (void) ATTRIBUTE_HIDDEN;
 362 GCOV_LINKAGE void gcov_read_summary (struct gcov_summary *) ATTRIBUTE_HIDDEN;
 363 GCOV_LINKAGE const char *gcov_read_string (void);
 364 GCOV_LINKAGE void gcov_sync (gcov_position_t /*base*/,
 365                              gcov_unsigned_t /*length */);
 366 char *mangle_path (char const *base);
 367
 368 #if !IN_GCOV
 369 /* Available outside gcov */
 370 GCOV_LINKAGE void gcov_write (const void *, unsigned) ATTRIBUTE_HIDDEN;
 371 GCOV_LINKAGE void gcov_write_unsigned (gcov_unsigned_t) ATTRIBUTE_HIDDEN;
 372 #endif
 373
 374 #if !IN_GCOV && !IN_LIBGCOV
 375 /* Available only in compiler */
 376 GCOV_LINKAGE void gcov_write_string (const char *);
 377 GCOV_LINKAGE void gcov_write_filename (const char *);
 378 GCOV_LINKAGE gcov_position_t gcov_write_tag (gcov_unsigned_t);
 379 GCOV_LINKAGE void gcov_write_length (gcov_position_t /*position*/);
 380 #endif
 381
 382 #if IN_GCOV > 0
 383 /* Available in gcov */
 384 GCOV_LINKAGE time_t gcov_time (void);
 385 #endif
 386
 387 #endif /* !inhibit_libc  */
 388
 389 #endif /* GCC_GCOV_IO_H */