1 /* File format for coverage information
2 Copyright (C) 1996-2020 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32 Note that the following file format documentation might be outdated.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. Strings are
46 padded with 1 to 4 NUL bytes, to bring the length up to a multiple
47 of 4. The number of 4 bytes is stored, followed by the padded
48 string. Zero length and NULL strings are simply stored as a length
49 of zero (they have no trailing NUL or padding).
51 int32: byte3 byte2 byte1 byte0 | byte0 byte1 byte2 byte3
52 int64: int32:low int32:high
53 string: int32:0 | int32:length char* char:0 padding
54 padding: | char:0 | char:0 char:0 | char:0 char:0 char:0
55 item: int32 | int64 | string
57 The basic format of the notes file is
59 file : int32:magic int32:version int32:stamp int32:support_unexecuted_blocks record*
61 The basic format of the data file is
63 file : int32:magic int32:version int32:stamp record*
65 The magic ident is different for the notes and the data files. The
66 magic ident is used to determine the endianness of the file, when
67 reading. The version is the same for both files and is derived
68 from gcc's version number. The stamp value is used to synchronize
69 note and data files and to synchronize merging within a data
70 file. It need not be an absolute time stamp, merely a ticker that
71 increments fast enough and cycles slow enough to distinguish
72 different compile/run/compile cycles.
74 Although the ident and version are formally 32 bit numbers, they
75 are derived from 4 character ASCII strings. The version number
76 consists of a two character major version number
77 (first digit starts from 'A' letter to not to clash with the older
78 numbering scheme), the single character minor version number,
79 and a single character indicating the status of the release.
80 That will be 'e' experimental, 'p' prerelease and 'r' for release.
81 Because, by good fortune, these are in alphabetical order, string
82 collating can be used to compare version strings. Be aware that
83 the 'e' designation will (naturally) be unstable and might be
84 incompatible with itself. For gcc 17.0 experimental, it would be
85 'B70e' (0x42373065). As we currently do not release more than 5 minor
86 releases, the single character should be always fine. Major number
87 is currently changed roughly every year, which gives us space
88 for next 250 years (maximum allowed number would be 259.9).
90 A record has a tag, length and variable amount of data.
93 header: int32:tag int32:length
96 Records are not nested, but there is a record hierarchy. Tag
97 numbers reflect this hierarchy. Tags are unique across note and
98 data files. Some record types have a varying amount of data. The
99 LENGTH is the number of 4bytes that follow and is usually used to
100 determine how much data. The tag value is split into 4 8-bit
101 fields, one for each of four possible levels. The most significant
102 is allocated first. Unused levels are zero. Active levels are
103 odd-valued, so that the LSB of the level is one. A sub-level
104 incorporates the values of its superlevels. This formatting allows
105 you to determine the tag hierarchy, without understanding the tags
106 themselves, and is similar to the standard section numbering used
107 in technical documents. Level values [1..3f] are used for common
108 tags, values [41..9f] for the notes file and [a1..ff] for the data
111 The notes file contains the following records
112 note: unit function-graph*
113 unit: header int32:checksum string:source
114 function-graph: announce_function basic_blocks {arcs | lines}*
115 announce_function: header int32:ident
116 int32:lineno_checksum int32:cfg_checksum
117 string:name string:source int32:start_lineno int32:start_column int32:end_lineno
118 basic_block: header int32:flags*
119 arcs: header int32:block_no arc*
120 arc: int32:dest_block int32:flags
121 lines: header int32:block_no line*
123 line: int32:line_no | int32:0 string:filename
125 The BASIC_BLOCK record holds per-bb flags. The number of blocks
126 can be inferred from its data length. There is one ARCS record per
127 basic block. The number of arcs from a bb is implicit from the
128 data length. It enumerates the destination bb and per-arc flags.
129 There is one LINES record per basic block, it enumerates the source
130 lines which belong to that basic block. Source file names are
131 introduced by a line number of 0, following lines are from the new
132 source file. The initial source file for the function is NULL, but
133 the current source file should be remembered from one LINES record
134 to the next. The end of a block is indicated by an empty filename
135 - this does not reset the current source file. Note there is no
136 ordering of the ARCS and LINES records: they may be in any order,
137 interleaved in any manner. The current filename follows the order
138 the LINES records are stored in the file, *not* the ordering of the
141 The data file contains the following records.
142 data: {unit summary:object function-data*}*
143 unit: header int32:checksum
144 function-data: announce_function present counts
145 announce_function: header int32:ident
146 int32:lineno_checksum int32:cfg_checksum
147 present: header int32:present
148 counts: header int64:count*
149 summary: int32:checksum int32:runs int32:sum_max
151 The ANNOUNCE_FUNCTION record is the same as that in the note file,
152 but without the source location. The COUNTS gives the
153 counter values for instrumented features. The about the whole
154 program. The checksum is used for whole program summaries, and
155 disambiguates different programs which include the same
156 instrumented object file. There may be several program summaries,
157 each with a unique checksum. The object summary's checksum is
158 zero. Note that the data file might contain information from
159 several runs concatenated, or the data might be merged.
161 This file is included by both the compiler, gcov tools and the
162 runtime support library libgcov. IN_LIBGCOV and IN_GCOV are used to
163 distinguish which case is which. If IN_LIBGCOV is nonzero,
164 libgcov is being built. If IN_GCOV is nonzero, the gcov tools are
165 being built. Otherwise the compiler is being built. IN_GCOV may be
166 positive or negative. If positive, we are compiling a tool that
167 requires additional functions (see the code for knowledge of what
168 those functions are). */
170 #ifndef GCC_GCOV_IO_H
171 #define GCC_GCOV_IO_H
173 /* GCOV key-value pair linked list type. */
181 struct gcov_kvp
*next
;
187 typedef unsigned gcov_unsigned_t
;
188 typedef unsigned gcov_position_t
;
189 /* gcov_type is typedef'd elsewhere for the compiler */
191 #define GCOV_LINKAGE static
192 typedef int64_t gcov_type
;
193 typedef uint64_t gcov_type_unsigned
;
195 #include <sys/types.h>
199 #if defined (HOST_HAS_F_SETLKW)
200 #define GCOV_LOCKED 1
202 #define GCOV_LOCKED 0
205 #define ATTRIBUTE_HIDDEN
207 #endif /* !IN_LIBGCOV */
210 #define GCOV_LINKAGE extern
214 #define gcov_nonruntime_assert(EXPR) ((void)(0 && (EXPR)))
216 #define gcov_nonruntime_assert(EXPR) gcc_assert (EXPR)
217 #define gcov_error(...) fatal_error (input_location, __VA_ARGS__)
221 #define GCOV_DATA_SUFFIX ".gcda"
222 #define GCOV_NOTE_SUFFIX ".gcno"
224 /* File magic. Must not be palindromes. */
225 #define GCOV_DATA_MAGIC ((gcov_unsigned_t)0x67636461) /* "gcda" */
226 #define GCOV_NOTE_MAGIC ((gcov_unsigned_t)0x67636e6f) /* "gcno" */
228 /* gcov-iov.h is automatically generated by the makefile from
229 version.c, it looks like
230 #define GCOV_VERSION ((gcov_unsigned_t)0x89abcdef)
232 #include "gcov-iov.h"
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))
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. */
246 #define GCOV_TAG_FUNCTION ((gcov_unsigned_t)0x01000000)
247 #define GCOV_TAG_FUNCTION_LENGTH (3)
248 #define GCOV_TAG_BLOCKS ((gcov_unsigned_t)0x01410000)
249 #define GCOV_TAG_BLOCKS_LENGTH(NUM) (NUM)
250 #define GCOV_TAG_ARCS ((gcov_unsigned_t)0x01430000)
251 #define GCOV_TAG_ARCS_LENGTH(NUM) (1 + (NUM) * 2)
252 #define GCOV_TAG_ARCS_NUM(LENGTH) (((LENGTH) - 1) / 2)
253 #define GCOV_TAG_LINES ((gcov_unsigned_t)0x01450000)
254 #define GCOV_TAG_COUNTER_BASE ((gcov_unsigned_t)0x01a10000)
255 #define GCOV_TAG_COUNTER_LENGTH(NUM) ((NUM) * 2)
256 #define GCOV_TAG_COUNTER_NUM(LENGTH) ((LENGTH) / 2)
257 #define GCOV_TAG_OBJECT_SUMMARY ((gcov_unsigned_t)0xa1000000)
258 #define GCOV_TAG_PROGRAM_SUMMARY ((gcov_unsigned_t)0xa3000000) /* Obsolete */
259 #define GCOV_TAG_SUMMARY_LENGTH (2)
260 #define GCOV_TAG_AFDO_FILE_NAMES ((gcov_unsigned_t)0xaa000000)
261 #define GCOV_TAG_AFDO_FUNCTION ((gcov_unsigned_t)0xac000000)
262 #define GCOV_TAG_AFDO_WORKING_SET ((gcov_unsigned_t)0xaf000000)
265 /* Counters that are collected. */
267 #define DEF_GCOV_COUNTER(COUNTER, NAME, MERGE_FN) COUNTER,
269 #include "gcov-counter.def"
272 #undef DEF_GCOV_COUNTER
274 /* The first of counters used for value profiling. They must form a
275 consecutive interval and their order must match the order of
276 HIST_TYPEs in value-prof.h. */
277 #define GCOV_FIRST_VALUE_COUNTER GCOV_COUNTER_V_INTERVAL
279 /* The last of counters used for value profiling. */
280 #define GCOV_LAST_VALUE_COUNTER (GCOV_COUNTERS - 1)
282 /* Number of counters used for value profiling. */
283 #define GCOV_N_VALUE_COUNTERS \
284 (GCOV_LAST_VALUE_COUNTER - GCOV_FIRST_VALUE_COUNTER + 1)
286 /* Number of top N counters when being in memory. */
287 #define GCOV_TOPN_MEM_COUNTERS 3
289 /* Number of top N counters in disk representation. */
290 #define GCOV_TOPN_DISK_COUNTERS 2
292 /* Maximum number of tracked TOP N value profiles. */
293 #define GCOV_TOPN_MAXIMUM_TRACKED_VALUES 32
295 /* Number of pre-allocated gcov_kvp structures. */
296 #define GCOV_PREALLOCATED_KVP 16
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)
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
311 #define GCOV_TAG_MASK(TAG) (((TAG) - 1) ^ (TAG))
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)))
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))
322 /* Basic block flags. */
323 #define GCOV_BLOCK_UNEXPECTED (1 << 1)
326 #define GCOV_ARC_ON_TREE (1 << 0)
327 #define GCOV_ARC_FAKE (1 << 1)
328 #define GCOV_ARC_FALLTHROUGH (1 << 2)
330 /* Object & program summary record. */
334 gcov_unsigned_t runs
; /* Number of program runs. */
335 gcov_type sum_max
; /* Sum of individual run max values. */
338 #if !defined(inhibit_libc)
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
351 GCOV_LINKAGE
int gcov_open (const char */
*name*/
, int /*direction*/);
354 #if !IN_LIBGCOV || defined (IN_GCOV_TOOL)
355 GCOV_LINKAGE
int gcov_magic (gcov_unsigned_t
, gcov_unsigned_t
);
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
);
369 /* Available outside gcov */
370 GCOV_LINKAGE
void gcov_write_unsigned (gcov_unsigned_t
) ATTRIBUTE_HIDDEN
;
373 #if !IN_GCOV && !IN_LIBGCOV
374 /* Available only in compiler */
375 GCOV_LINKAGE
void gcov_write_string (const char *);
376 GCOV_LINKAGE
void gcov_write_filename (const char *);
377 GCOV_LINKAGE gcov_position_t
gcov_write_tag (gcov_unsigned_t
);
378 GCOV_LINKAGE
void gcov_write_length (gcov_position_t
/*position*/);
382 /* Available in gcov */
383 GCOV_LINKAGE
time_t gcov_time (void);
386 #endif /* !inhibit_libc */
388 #endif /* GCC_GCOV_IO_H */