1GPROF(1) GNU GPROF(1)
2
6 gprof - display call graph profile data
7
9 gprof [ -[abcDhilLrsTvwxyz] ] [ -[ACeEfFJnNOpPqQZ][name] ]
10 [ -I dirs ] [ -d[num] ] [ -k from/to ]
11 [ -m min-count ] [ -R map_file ] [ -t table-length ]
12 [ --[no-]annotated-source[=name] ]
13 [ --[no-]exec-counts[=name] ]
14 [ --[no-]flat-profile[=name] ] [ --[no-]graph[=name] ]
15 [ --[no-]time=name] [ --all-lines ] [ --brief ]
16 [ --debug[=level] ] [ --function-ordering ]
17 [ --file-ordering map_file ] [ --directory-path=dirs ]
18 [ --display-unused-functions ] [ --file-format=name ]
19 [ --file-info ] [ --help ] [ --line ] [ --min-count=n ]
20 [ --no-static ] [ --print-path ] [ --separate-files ]
21 [ --static-call-graph ] [ --sum ] [ --table-length=len ]
22 [ --traditional ] [ --version ] [ --width=n ]
23 [ --ignore-non-functions ] [ --demangle[=STYLE] ]
24 [ --no-demangle ] [ image-file ] [ profile-file ... ]
25
27 "gprof" produces an execution profile of C, Pascal, or Fortran77
28 programs. The effect of called routines is incorporated in the profile
29 of each caller. The profile data is taken from the call graph profile
30 file (gmon.out default) which is created by programs that are compiled
31 with the -pg option of "cc", "pc", and "f77". The -pg option also
32 links in versions of the library routines that are compiled for
33 profiling. "Gprof" reads the given object file (the default is
34 "a.out") and establishes the relation between its symbol table and the
35 call graph profile from gmon.out. If more than one profile file is
36 specified, the "gprof" output shows the sum of the profile information
37 in the given profile files.
38 "Gprof" calculates the amount of time spent in each routine. Next,
40 these times are propagated along the edges of the call graph. Cycles
41 are discovered, and calls into a cycle are made to share the time of
42 the cycle.
43 Several forms of output are available from the analysis.
45 The flat profile shows how much time your program spent in each
47 function, and how many times that function was called. If you simply
48 want to know which functions burn most of the cycles, it is stated
49 concisely here.
50 The call graph shows, for each function, which functions called it,
52 which other functions it called, and how many times. There is also an
53 estimate of how much time was spent in the subroutines of each
54 function. This can suggest places where you might try to eliminate
55 function calls that use a lot of time.
56 The annotated source listing is a copy of the program's source code,
58 labeled with the number of times each line of the program was executed.
59
61 These options specify which of several output formats "gprof" should
62 produce.
63 Many of these options take an optional symspec to specify functions to
65 be included or excluded. These options can be specified multiple
66 times, with different symspecs, to include or exclude sets of symbols.
67 Specifying any of these options overrides the default (-p -q), which
69 prints a flat profile and call graph analysis for all functions.
70 "-A[symspec]"
72 "--annotated-source[=symspec]"
73 The -A option causes "gprof" to print annotated source code. If
74 symspec is specified, print output only for matching symbols.
75 "-b"
77 "--brief"
78 If the -b option is given, "gprof" doesn't print the verbose blurbs
79 that try to explain the meaning of all of the fields in the tables.
80 This is useful if you intend to print out the output, or are tired
81 of seeing the blurbs.
82 "-C[symspec]"
84 "--exec-counts[=symspec]"
85 The -C option causes "gprof" to print a tally of functions and the
86 number of times each was called. If symspec is specified, print
87 tally only for matching symbols.
88 If the profile data file contains basic-block count records,
90 specifying the -l option, along with -C, will cause basic-block
91 execution counts to be tallied and displayed.
92 "-i"
94 "--file-info"
95 The -i option causes "gprof" to display summary information about
96 the profile data file(s) and then exit. The number of histogram,
97 call graph, and basic-block count records is displayed.
98 "-I dirs"
100 "--directory-path=dirs"
101 The -I option specifies a list of search directories in which to
102 find source files. Environment variable GPROF_PATH can also be
103 used to convey this information. Used mostly for annotated source
104 output.
105 "-J[symspec]"
107 "--no-annotated-source[=symspec]"
108 The -J option causes "gprof" not to print annotated source code.
109 If symspec is specified, "gprof" prints annotated source, but
110 excludes matching symbols.
111 "-L"
113 "--print-path"
114 Normally, source filenames are printed with the path component
115 suppressed. The -L option causes "gprof" to print the full
116 pathname of source filenames, which is determined from symbolic
117 debugging information in the image file and is relative to the
118 directory in which the compiler was invoked.
119 "-p[symspec]"
121 "--flat-profile[=symspec]"
122 The -p option causes "gprof" to print a flat profile. If symspec
123 is specified, print flat profile only for matching symbols.
124 "-P[symspec]"
126 "--no-flat-profile[=symspec]"
127 The -P option causes "gprof" to suppress printing a flat profile.
128 If symspec is specified, "gprof" prints a flat profile, but
129 excludes matching symbols.
130 "-q[symspec]"
132 "--graph[=symspec]"
133 The -q option causes "gprof" to print the call graph analysis. If
134 symspec is specified, print call graph only for matching symbols
135 and their children.
136 "-Q[symspec]"
138 "--no-graph[=symspec]"
139 The -Q option causes "gprof" to suppress printing the call graph.
140 If symspec is specified, "gprof" prints a call graph, but excludes
141 matching symbols.
142 "-t"
144 "--table-length=num"
145 The -t option causes the num most active source lines in each
146 source file to be listed when source annotation is enabled. The
147 default is 10.
148 "-y"
150 "--separate-files"
151 This option affects annotated source output only. Normally,
152 "gprof" prints annotated source files to standard-output. If this
153 option is specified, annotated source for a file named
154 path/filename is generated in the file filename-ann. If the
155 underlying file system would truncate filename-ann so that it
156 overwrites the original filename, "gprof" generates annotated
157 source in the file filename.ann instead (if the original file name
158 has an extension, that extension is replaced with .ann).
159 "-Z[symspec]"
161 "--no-exec-counts[=symspec]"
162 The -Z option causes "gprof" not to print a tally of functions and
163 the number of times each was called. If symspec is specified,
164 print tally, but exclude matching symbols.
165 "-r"
167 "--function-ordering"
168 The --function-ordering option causes "gprof" to print a suggested
169 function ordering for the program based on profiling data. This
170 option suggests an ordering which may improve paging, tlb and cache
171 behavior for the program on systems which support arbitrary
172 ordering of functions in an executable.
173 The exact details of how to force the linker to place functions in
175 a particular order is system dependent and out of the scope of this
176 manual.
177 "-R map_file"
179 "--file-ordering map_file"
180 The --file-ordering option causes "gprof" to print a suggested .o
181 link line ordering for the program based on profiling data. This
182 option suggests an ordering which may improve paging, tlb and cache
183 behavior for the program on systems which do not support arbitrary
184 ordering of functions in an executable.
185 Use of the -a argument is highly recommended with this option.
187 The map_file argument is a pathname to a file which provides
189 function name to object file mappings. The format of the file is
190 similar to the output of the program "nm".
191 c-parse.o:00000000 T yyparse
193 c-parse.o:00000004 C yyerrflag
194 c-lang.o:00000000 T maybe_objc_method_name
195 c-lang.o:00000000 T print_lang_statistics
196 c-lang.o:00000000 T recognize_objc_keyword
197 c-decl.o:00000000 T print_lang_identifier
198 c-decl.o:00000000 T print_lang_type
199 ...
200 To create a map_file with GNU "nm", type a command like "nm
202 --extern-only --defined-only -v --print-file-name program-name".
203 "-T"
205 "--traditional"
206 The -T option causes "gprof" to print its output in "traditional"
207 BSD style.
208 "-w width"
210 "--width=width"
211 Sets width of output lines to width. Currently only used when
212 printing the function index at the bottom of the call graph.
213 "-x"
215 "--all-lines"
216 This option affects annotated source output only. By default, only
217 the lines at the beginning of a basic-block are annotated. If this
218 option is specified, every line in a basic-block is annotated by
219 repeating the annotation for the first line. This behavior is
220 similar to "tcov"'s -a.
221 "--demangle[=style]"
223 "--no-demangle"
224 These options control whether C++ symbol names should be demangled
225 when printing output. The default is to demangle symbols. The
226 "--no-demangle" option may be used to turn off demangling.
227 Different compilers have different mangling styles. The optional
228 demangling style argument can be used to choose an appropriate
229 demangling style for your compiler.
230 Analysis Options
232 "-a"
234 "--no-static"
235 The -a option causes "gprof" to suppress the printing of statically
236 declared (private) functions. (These are functions whose names are
237 not listed as global, and which are not visible outside the
238 file/function/block where they were defined.) Time spent in these
239 functions, calls to/from them, etc., will all be attributed to the
240 function that was loaded directly before it in the executable file.
241 This option affects both the flat profile and the call graph.
242 "-c"
244 "--static-call-graph"
245 The -c option causes the call graph of the program to be augmented
246 by a heuristic which examines the text space of the object file and
247 identifies function calls in the binary machine code. Since normal
248 call graph records are only generated when functions are entered,
249 this option identifies children that could have been called, but
250 never were. Calls to functions that were not compiled with
251 profiling enabled are also identified, but only if symbol table
252 entries are present for them. Calls to dynamic library routines
253 are typically not found by this option. Parents or children
254 identified via this heuristic are indicated in the call graph with
255 call counts of 0.
256 "-D"
258 "--ignore-non-functions"
259 The -D option causes "gprof" to ignore symbols which are not known
260 to be functions. This option will give more accurate profile data
261 on systems where it is supported (Solaris and HPUX for example).
262 "-k from/to"
264 The -k option allows you to delete from the call graph any arcs
265 from symbols matching symspec from to those matching symspec to.
266 "-l"
268 "--line"
269 The -l option enables line-by-line profiling, which causes
270 histogram hits to be charged to individual source code lines,
271 instead of functions. This feature only works with programs
272 compiled by older versions of the "gcc" compiler. Newer versions
273 of "gcc" are designed to work with the "gcov" tool instead.
274 If the program was compiled with basic-block counting enabled, this
276 option will also identify how many times each line of code was
277 executed. While line-by-line profiling can help isolate where in a
278 large function a program is spending its time, it also
279 significantly increases the running time of "gprof", and magnifies
280 statistical inaccuracies.
281 "-m num"
283 "--min-count=num"
284 This option affects execution count output only. Symbols that are
285 executed less than num times are suppressed.
286 "-nsymspec"
288 "--time=symspec"
289 The -n option causes "gprof", in its call graph analysis, to only
290 propagate times for symbols matching symspec.
291 "-Nsymspec"
293 "--no-time=symspec"
294 The -n option causes "gprof", in its call graph analysis, not to
295 propagate times for symbols matching symspec.
296 "-z"
298 "--display-unused-functions"
299 If you give the -z option, "gprof" will mention all functions in
300 the flat profile, even those that were never called, and that had
301 no time spent in them. This is useful in conjunction with the -c
302 option for discovering which routines were never called.
303 Miscellaneous Options
305 "-d[num]"
307 "--debug[=num]"
308 The -d num option specifies debugging options. If num is not
309 specified, enable all debugging.
310 "-h"
312 "--help"
313 The -h option prints command line usage.
314 "-Oname"
316 "--file-format=name"
317 Selects the format of the profile data files. Recognized formats
318 are auto (the default), bsd, 4.4bsd, magic, and prof (not yet
319 supported).
320 "-s"
322 "--sum"
323 The -s option causes "gprof" to summarize the information in the
324 profile data files it read in, and write out a profile data file
325 called gmon.sum, which contains all the information from the
326 profile data files that "gprof" read in. The file gmon.sum may be
327 one of the specified input files; the effect of this is to merge
328 the data in the other input files into gmon.sum.
329 Eventually you can run "gprof" again without -s to analyze the
331 cumulative data in the file gmon.sum.
332 "-v"
334 "--version"
335 The -v flag causes "gprof" to print the current version number, and
336 then exit.
337 Deprecated Options
339 These options have been replaced with newer versions that use
341 symspecs.
342 "-e function_name"
344 The -e function option tells "gprof" to not print information about
346 the function function_name (and its children...) in the call graph.
347 The function will still be listed as a child of any functions that
348 call it, but its index number will be shown as [not printed]. More
349 than one -e option may be given; only one function_name may be
350 indicated with each -e option.
351 "-E function_name"
353 The "-E function" option works like the "-e" option, but time spent
355 in the function (and children who were not called from anywhere
356 else), will not be used to compute the percentages-of-time for the
357 call graph. More than one -E option may be given; only one
358 function_name may be indicated with each -E option.
359 "-f function_name"
361 The -f function option causes "gprof" to limit the call graph to
363 the function function_name and its children (and their
364 children...). More than one -f option may be given; only one
365 function_name may be indicated with each -f option.
366 "-F function_name"
368 The -F function option works like the "-f" option, but only time
370 spent in the function and its children (and their children...) will
371 be used to determine total-time and percentages-of-time for the
372 call graph. More than one -F option may be given; only one
373 function_name may be indicated with each -F option. The -F option
374 overrides the -E option.
375
377 "a.out"
378 the namelist and text space.
379 "gmon.out"
381 dynamic call graph and profile.
382 "gmon.sum"
384 summarized dynamic call graph and profile.
385
387 The granularity of the sampling is shown, but remains statistical at
388 best. We assume that the time for each execution of a function can be
389 expressed by the total time for the function divided by the number of
390 times the function is called. Thus the time propagated along the call
391 graph arcs to the function's parents is directly proportional to the
392 number of times that arc is traversed.
393 Parents that are not themselves profiled will have the time of their
395 profiled children propagated to them, but they will appear to be
396 spontaneously invoked in the call graph listing, and will not have
397 their time propagated further. Similarly, signal catchers, even though
398 profiled, will appear to be spontaneous (although for more obscure
399 reasons). Any profiled children of signal catchers should have their
400 times propagated properly, unless the signal catcher was invoked during
401 the execution of the profiling routine, in which case all is lost.
402 The profiled program must call "exit"(2) or return normally for the
404 profiling information to be saved in the gmon.out file.
405
407 monitor(3), profil(2), cc(1), prof(1), and the Info entry for gprof.
408 "An Execution Profiler for Modular Programs", by S. Graham, P. Kessler,
410 M. McKusick; Software - Practice and Experience, Vol. 13, pp. 671-685,
411 1983.
412 "gprof: A Call Graph Execution Profiler", by S. Graham, P. Kessler, M.
414 McKusick; Proceedings of the SIGPLAN '82 Symposium on Compiler
415 Construction, SIGPLAN Notices, Vol. 17, No 6, pp. 120-126, June 1982.
416
418 Copyright (c) 1988, 92, 97, 98, 99, 2000, 2001, 2003, 2007 Free
419 Software Foundation, Inc.
420 Permission is granted to copy, distribute and/or modify this document
422 under the terms of the GNU Free Documentation License, Version 1.1 or
423 any later version published by the Free Software Foundation; with no
424 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
425 Texts. A copy of the license is included in the section entitled "GNU
426 Free Documentation License".
427
429 Hey! The above document had some coding errors, which are explained
430 below:
431 Around line 527:
433 You can't have =items (as at line 533) unless the first thing after
434 the =over is an =item
435binutils-2.19.50.0.1 2009-07-28 GPROF(1)