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 */
432