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32 Note that the following file format documentation might be outdated.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