GCC Middle and Back End API Reference
gcov-io.h
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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
220 typedef unsigned HOST_WIDEST_INT gcov_type_unsigned;
221 #if IN_GCOV > 0
222 #include <sys/types.h>
223 #endif
224 #else
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
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)
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. */
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
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))
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. */
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;
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
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. */
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. */
433  counter values. */
434 };
435 
436 /* Object & program summary record. */
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 };
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
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);
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;
637 
638 GCOV_LINKAGE void compute_working_sets (const struct gcov_ctr_summary *summary,
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 */