gcc/gcov-io.h

   1 /* File format for coverage information
   2    Copyright (C) 1996-2014 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 #ifndef IN_LIBGCOV
 168 /* About the host */
 169
 170 typedef unsigned gcov_unsigned_t;
 171 typedef unsigned gcov_position_t;
 172 /* gcov_type is typedef'd elsewhere for the compiler */
 173 #if IN_GCOV
 174 #define GCOV_LINKAGE static
 175 typedef HOST_WIDEST_INT gcov_type;
 176 typedef unsigned HOST_WIDEST_INT gcov_type_unsigned;
 177 #if IN_GCOV > 0
 178 #include <sys/types.h>
 179 #endif
 180 #else /*!IN_GCOV */
 181 #define GCOV_TYPE_SIZE (LONG_LONG_TYPE_SIZE > 32 ? 64 : 32)
 182 #endif
 183
 184 #if defined (HOST_HAS_F_SETLKW)
 185 #define GCOV_LOCKED 1
 186 #else
 187 #define GCOV_LOCKED 0
 188 #endif
 189
 190 #define ATTRIBUTE_HIDDEN
 191
 192 #endif /* !IN_LIBGOCV */
 193
 194 #ifndef GCOV_LINKAGE
 195 #define GCOV_LINKAGE extern
 196 #endif
 197
 198 /* File suffixes.  */
 199 #define GCOV_DATA_SUFFIX ".gcda"
 200 #define GCOV_NOTE_SUFFIX ".gcno"
 201
 202 /* File magic. Must not be palindromes.  */
 203 #define GCOV_DATA_MAGIC ((gcov_unsigned_t)0x67636461) /* "gcda" */
 204 #define GCOV_NOTE_MAGIC ((gcov_unsigned_t)0x67636e6f) /* "gcno" */
 205
 206 /* gcov-iov.h is automatically generated by the makefile from
 207    version.c, it looks like
 208         #define GCOV_VERSION ((gcov_unsigned_t)0x89abcdef)
 209 */
 210 #include "gcov-iov.h"
 211
 212 /* Convert a magic or version number to a 4 character string.  */
 213 #define GCOV_UNSIGNED2STRING(ARRAY,VALUE)       \
 214   ((ARRAY)[0] = (char)((VALUE) >> 24),          \
 215    (ARRAY)[1] = (char)((VALUE) >> 16),          \
 216    (ARRAY)[2] = (char)((VALUE) >> 8),           \
 217    (ARRAY)[3] = (char)((VALUE) >> 0))
 218
 219 /* The record tags.  Values [1..3f] are for tags which may be in either
 220    file.  Values [41..9f] for those in the note file and [a1..ff] for
 221    the data file.  The tag value zero is used as an explicit end of
 222    file marker -- it is not required to be present.  */
 223
 224 #define GCOV_TAG_FUNCTION        ((gcov_unsigned_t)0x01000000)
 225 #define GCOV_TAG_FUNCTION_LENGTH (3)
 226 #define GCOV_TAG_BLOCKS          ((gcov_unsigned_t)0x01410000)
 227 #define GCOV_TAG_BLOCKS_LENGTH(NUM) (NUM)
 228 #define GCOV_TAG_BLOCKS_NUM(LENGTH) (LENGTH)
 229 #define GCOV_TAG_ARCS            ((gcov_unsigned_t)0x01430000)
 230 #define GCOV_TAG_ARCS_LENGTH(NUM)  (1 + (NUM) * 2)
 231 #define GCOV_TAG_ARCS_NUM(LENGTH)  (((LENGTH) - 1) / 2)
 232 #define GCOV_TAG_LINES           ((gcov_unsigned_t)0x01450000)
 233 #define GCOV_TAG_COUNTER_BASE    ((gcov_unsigned_t)0x01a10000)
 234 #define GCOV_TAG_COUNTER_LENGTH(NUM) ((NUM) * 2)
 235 #define GCOV_TAG_COUNTER_NUM(LENGTH) ((LENGTH) / 2)
 236 #define GCOV_TAG_OBJECT_SUMMARY  ((gcov_unsigned_t)0xa1000000) /* Obsolete */
 237 #define GCOV_TAG_PROGRAM_SUMMARY ((gcov_unsigned_t)0xa3000000)
 238 #define GCOV_TAG_SUMMARY_LENGTH(NUM)  \
 239         (1 + GCOV_COUNTERS_SUMMABLE * (10 + 3 * 2) + (NUM) * 5)
 240
 241
 242 /* Counters that are collected.  */
 243 #define GCOV_COUNTER_ARCS       0  /* Arc transitions.  */
 244 #define GCOV_COUNTERS_SUMMABLE  1  /* Counters which can be
 245                                       summaried.  */
 246 #define GCOV_FIRST_VALUE_COUNTER 1 /* The first of counters used for value
 247                                       profiling.  They must form a consecutive
 248                                       interval and their order must match
 249                                       the order of HIST_TYPEs in
 250                                       value-prof.h.  */
 251 #define GCOV_COUNTER_V_INTERVAL 1  /* Histogram of value inside an interval.  */
 252 #define GCOV_COUNTER_V_POW2     2  /* Histogram of exact power2 logarithm
 253                                       of a value.  */
 254 #define GCOV_COUNTER_V_SINGLE   3  /* The most common value of expression.  */
 255 #define GCOV_COUNTER_V_DELTA    4  /* The most common difference between
 256                                       consecutive values of expression.  */
 257
 258 #define GCOV_COUNTER_V_INDIR    5  /* The most common indirect address */
 259 #define GCOV_COUNTER_AVERAGE    6  /* Compute average value passed to the
 260                                       counter.  */
 261 #define GCOV_COUNTER_IOR        7  /* IOR of the all values passed to
 262                                       counter.  */
 263 #define GCOV_TIME_PROFILER  8 /* Time profile collecting first run of a function */
 264 #define GCOV_LAST_VALUE_COUNTER 8  /* The last of counters used for value
 265                                       profiling.  */
 266 #define GCOV_COUNTERS           9
 267
 268 /* Number of counters used for value profiling.  */
 269 #define GCOV_N_VALUE_COUNTERS \
 270   (GCOV_LAST_VALUE_COUNTER - GCOV_FIRST_VALUE_COUNTER + 1)
 271
 272   /* A list of human readable names of the counters */
 273 #define GCOV_COUNTER_NAMES      {"arcs", "interval", "pow2", "single", \
 274               "delta", "indirect_call", "average", "ior", "time_profiler"}
 275
 276   /* Names of merge functions for counters.  */
 277 #define GCOV_MERGE_FUNCTIONS    {"__gcov_merge_add",    \
 278                                  "__gcov_merge_add",    \
 279                                  "__gcov_merge_add",    \
 280                                  "__gcov_merge_single", \
 281                                  "__gcov_merge_delta",  \
 282                                  "__gcov_merge_single", \
 283                                  "__gcov_merge_add",    \
 284                                  "__gcov_merge_ior",  \
 285          "__gcov_merge_time_profile" }
 286
 287 /* Convert a counter index to a tag.  */
 288 #define GCOV_TAG_FOR_COUNTER(COUNT)                             \
 289         (GCOV_TAG_COUNTER_BASE + ((gcov_unsigned_t)(COUNT) << 17))
 290 /* Convert a tag to a counter.  */
 291 #define GCOV_COUNTER_FOR_TAG(TAG)                                       \
 292         ((unsigned)(((TAG) - GCOV_TAG_COUNTER_BASE) >> 17))
 293 /* Check whether a tag is a counter tag.  */
 294 #define GCOV_TAG_IS_COUNTER(TAG)                                \
 295         (!((TAG) & 0xFFFF) && GCOV_COUNTER_FOR_TAG (TAG) < GCOV_COUNTERS)
 296
 297 /* The tag level mask has 1's in the position of the inner levels, &
 298    the lsb of the current level, and zero on the current and outer
 299    levels.  */
 300 #define GCOV_TAG_MASK(TAG) (((TAG) - 1) ^ (TAG))
 301
 302 /* Return nonzero if SUB is an immediate subtag of TAG.  */
 303 #define GCOV_TAG_IS_SUBTAG(TAG,SUB)                             \
 304         (GCOV_TAG_MASK (TAG) >> 8 == GCOV_TAG_MASK (SUB)        \
 305          && !(((SUB) ^ (TAG)) & ~GCOV_TAG_MASK (TAG)))
 306
 307 /* Return nonzero if SUB is at a sublevel to TAG.  */
 308 #define GCOV_TAG_IS_SUBLEVEL(TAG,SUB)                           \
 309         (GCOV_TAG_MASK (TAG) > GCOV_TAG_MASK (SUB))
 310
 311 /* Basic block flags.  */
 312 #define GCOV_BLOCK_UNEXPECTED   (1 << 1)
 313
 314 /* Arc flags.  */
 315 #define GCOV_ARC_ON_TREE        (1 << 0)
 316 #define GCOV_ARC_FAKE           (1 << 1)
 317 #define GCOV_ARC_FALLTHROUGH    (1 << 2)
 318
 319 /* Structured records.  */
 320
 321 /* Structure used for each bucket of the log2 histogram of counter values.  */
 322 typedef struct
 323 {
 324   /* Number of counters whose profile count falls within the bucket.  */
 325   gcov_unsigned_t num_counters;
 326   /* Smallest profile count included in this bucket.  */
 327   gcov_type min_value;
 328   /* Cumulative value of the profile counts in this bucket.  */
 329   gcov_type cum_value;
 330 } gcov_bucket_type;
 331
 332 /* For a log2 scale histogram with each range split into 4
 333    linear sub-ranges, there will be at most 64 (max gcov_type bit size) - 1 log2
 334    ranges since the lowest 2 log2 values share the lowest 4 linear
 335    sub-range (values 0 - 3).  This is 252 total entries (63*4).  */
 336
 337 #define GCOV_HISTOGRAM_SIZE 252
 338
 339 /* How many unsigned ints are required to hold a bit vector of non-zero
 340    histogram entries when the histogram is written to the gcov file.
 341    This is essentially a ceiling divide by 32 bits.  */
 342 #define GCOV_HISTOGRAM_BITVECTOR_SIZE (GCOV_HISTOGRAM_SIZE + 31) / 32
 343
 344 /* Cumulative counter data.  */
 345 struct gcov_ctr_summary
 346 {
 347   gcov_unsigned_t num;          /* number of counters.  */
 348   gcov_unsigned_t runs;         /* number of program runs */
 349   gcov_type sum_all;            /* sum of all counters accumulated.  */
 350   gcov_type run_max;            /* maximum value on a single run.  */
 351   gcov_type sum_max;            /* sum of individual run max values.  */
 352   gcov_bucket_type histogram[GCOV_HISTOGRAM_SIZE]; /* histogram of
 353                                                       counter values.  */
 354 };
 355
 356 /* Object & program summary record.  */
 357 struct gcov_summary
 358 {
 359   gcov_unsigned_t checksum;     /* checksum of program */
 360   struct gcov_ctr_summary ctrs[GCOV_COUNTERS_SUMMABLE];
 361 };
 362
 363 #if !defined(inhibit_libc)
 364
 365 /* Functions for reading and writing gcov files. In libgcov you can
 366    open the file for reading then writing. Elsewhere you can open the
 367    file either for reading or for writing. When reading a file you may
 368    use the gcov_read_* functions, gcov_sync, gcov_position, &
 369    gcov_error. When writing a file you may use the gcov_write
 370    functions, gcov_seek & gcov_error. When a file is to be rewritten
 371    you use the functions for reading, then gcov_rewrite then the
 372    functions for writing.  Your file may become corrupted if you break
 373    these invariants.  */
 374
 375 #if !IN_LIBGCOV
 376 GCOV_LINKAGE int gcov_open (const char */*name*/, int /*direction*/);
 377 GCOV_LINKAGE int gcov_magic (gcov_unsigned_t, gcov_unsigned_t);
 378 #endif
 379
 380 /* Available everywhere.  */
 381 GCOV_LINKAGE int gcov_close (void) ATTRIBUTE_HIDDEN;
 382 GCOV_LINKAGE gcov_unsigned_t gcov_read_unsigned (void) ATTRIBUTE_HIDDEN;
 383 GCOV_LINKAGE gcov_type gcov_read_counter (void) ATTRIBUTE_HIDDEN;
 384 GCOV_LINKAGE void gcov_read_summary (struct gcov_summary *) ATTRIBUTE_HIDDEN;
 385 GCOV_LINKAGE const char *gcov_read_string (void);
 386 GCOV_LINKAGE void gcov_sync (gcov_position_t /*base*/,
 387                              gcov_unsigned_t /*length */);
 388
 389 #if !IN_GCOV
 390 /* Available outside gcov */
 391 GCOV_LINKAGE void gcov_write_unsigned (gcov_unsigned_t) ATTRIBUTE_HIDDEN;
 392 #endif
 393
 394 #if !IN_GCOV && !IN_LIBGCOV
 395 /* Available only in compiler */
 396 GCOV_LINKAGE unsigned gcov_histo_index (gcov_type value);
 397 GCOV_LINKAGE void gcov_write_string (const char *);
 398 GCOV_LINKAGE gcov_position_t gcov_write_tag (gcov_unsigned_t);
 399 GCOV_LINKAGE void gcov_write_length (gcov_position_t /*position*/);
 400 #endif
 401
 402 #if IN_GCOV <= 0 && !IN_LIBGCOV
 403 /* Available in gcov-dump and the compiler.  */
 404
 405 /* Number of data points in the working set summary array. Using 128
 406    provides information for at least every 1% increment of the total
 407    profile size. The last entry is hardwired to 99.9% of the total.  */
 408 #define NUM_GCOV_WORKING_SETS 128
 409
 410 /* Working set size statistics for a given percentage of the entire
 411    profile (sum_all from the counter summary).  */
 412 typedef struct gcov_working_set_info
 413 {
 414   /* Number of hot counters included in this working set.  */
 415   unsigned num_counters;
 416   /* Smallest counter included in this working set.  */
 417   gcov_type min_counter;
 418 } gcov_working_set_t;
 419
 420 GCOV_LINKAGE void compute_working_sets (const struct gcov_ctr_summary *summary,
 421                                         gcov_working_set_t *gcov_working_sets);
 422 #endif
 423
 424 #if IN_GCOV > 0
 425 /* Available in gcov */
 426 GCOV_LINKAGE time_t gcov_time (void);
 427 #endif
 428
 429 #endif /* !inhibit_libc  */
 430
 431 #endif /* GCC_GCOV_IO_H */