GPROF 1 2005-03-08 binutils-2.15.96 GNU
NAME
gprof - display call graph profile data
SYNOPSIS
gprof [ -[abcDhilLrsTvwxyz] ] [ -[ACeEfFJnNOpPqQZ][_n_a_m_e] ]
[ -I _d_i_r_s ] [ -d[_n_u_m] ] [ -k _f_r_o_m_/_t_o ]
[ -m _m_i_n_-_c_o_u_n_t ] [ -R _m_a_p___f_i_l_e ] [ -t _t_a_b_l_e_-_l_e_n_g_t_h ]
[ --[no-]annotated-source[=_n_a_m_e] ]
[ --[no-]exec-counts[=_n_a_m_e] ]
[ --[no-]flat-profile[=_n_a_m_e] ] [ --[no-]graph[=_n_a_m_e] ]
[ --[no-]time=_n_a_m_e] [ --all-lines ] [ --brief ]
[ --debug[=_l_e_v_e_l] ] [ --function-ordering ]
[ --file-ordering ] [ --directory-path=_d_i_r_s ]
[ --display-unused-functions ] [ --file-format=_n_a_m_e ]
[ --file-info ] [ --help ] [ --line ] [ --min-count=_n ]
[ --no-static ] [ --print-path ] [ --separate-files ]
[ --static-call-graph ] [ --sum ] [ --table-length=_l_e_n ]
[ --traditional ] [ --version ] [ --width=_n ]
[ --ignore-non-functions ] [ --demangle[=_S_T_Y_L_E] ]
[ --no-demangle ] [ _i_m_a_g_e_-_f_i_l_e ] [ _p_r_o_f_i_l_e_-_f_i_l_e ... ]
DESCRIPTION
"gprof" produces an execution profile of C, Pascal, or Fortran77
programs. The effect of called routines is incorporated in the profile
of each caller. The profile data is taken from the call graph profile file
(_g_m_o_n_._o_u_t default) which is created by programs
that are compiled with the --ppgg option of
"cc", "pc", and "f77".
The --ppgg option also links in versions of the library routines
that are compiled for profiling. "Gprof" reads the given object
file (the default is "a.out") and establishes the relation between
its symbol table and the call graph profile from _g_m_o_n_._o_u_t.
If more than one profile file is specified, the "gprof"
output shows the sum of the profile information in the given profile files.
"Gprof" calculates the amount of time spent in each routine.
Next, these times are propagated along the edges of the call graph.
Cycles are discovered, and calls into a cycle are made to share the time
of the cycle.
Several forms of output are available from the analysis.
The _f_l_a_t _p_r_o_f_i_l_e shows how much time your program spent in each function,
and how many times that function was called. If you simply want to know
which functions burn most of the cycles, it is stated concisely here.
The _c_a_l_l _g_r_a_p_h shows, for each function, which functions called it, which
other functions it called, and how many times. There is also an estimate
of how much time was spent in the subroutines of each function. This can
suggest places where you might try to eliminate function calls that use a
lot of time.
The _a_n_n_o_t_a_t_e_d _s_o_u_r_c_e listing is a copy of the program's
source code, labeled with the number of times each line of the
program was executed.
OPTIONS
These options specify which of several output formats
"gprof" should produce.
Many of these options take an optional _s_y_m_s_p_e_c to specify
functions to be included or excluded. These options can be
specified multiple times, with different symspecs, to include
or exclude sets of symbols.
Specifying any of these options overrides the default (--pp --qq),
which prints a flat profile and call graph analysis
for all functions.
-
"-A[symspec]"
-
-
"--annotated-source[=symspec]"
The --AA option causes "gprof" to print annotated source code.
-
If _s_y_m_s_p_e_c is specified, print output only for matching symbols.
-
"-b"
-
-
"--brief"
If the --bb option is given, "gprof" doesn't print the
-
verbose blurbs that try to explain the meaning of all of the fields in
the tables. This is useful if you intend to print out the output, or
are tired of seeing the blurbs.
-
"-C[symspec]"
-
-
"--exec-counts[=symspec]"
The --CC option causes "gprof" to
-
print a tally of functions and the number of times each was called.
If _s_y_m_s_p_e_c is specified, print tally only for matching symbols.
If the profile data file contains basic-block count records, specifying
the --ll option, along with --CC, will cause basic-block
execution counts to be tallied and displayed.
-
"-i"
-
-
"--file-info"
The --ii option causes "gprof" to display summary information
-
about the profile data file(s) and then exit. The number of histogram,
call graph, and basic-block count records is displayed.
-
"-I dirs"
-
-
"--directory-path=dirs"
The --II option specifies a list of search directories in
-
which to find source files. Environment variable _G_P_R_O_F___P_A_T_H
can also be used to convey this information.
Used mostly for annotated source output.
-
"-J[symspec]"
-
-
"--no-annotated-source[=symspec]"
The --JJ option causes "gprof" not to
-
print annotated source code.
If _s_y_m_s_p_e_c is specified, "gprof" prints annotated source,
but excludes matching symbols.
-
"-L"
-
-
"--print-path"
Normally, source filenames are printed with the path
-
component suppressed. The --LL option causes "gprof"
to print the full pathname of
source filenames, which is determined
from symbolic debugging information in the image file
and is relative to the directory in which the compiler
was invoked.
-
"-p[symspec]"
-
-
"--flat-profile[=symspec]"
The --pp option causes "gprof" to print a flat profile.
-
If _s_y_m_s_p_e_c is specified, print flat profile only for matching symbols.
-
"-P[symspec]"
-
-
"--no-flat-profile[=symspec]"
The --PP option causes "gprof" to suppress printing a flat profile.
-
If _s_y_m_s_p_e_c is specified, "gprof" prints a flat profile,
but excludes matching symbols.
-
"-q[symspec]"
-
-
"--graph[=symspec]"
The --qq option causes "gprof" to print the call graph analysis.
-
If _s_y_m_s_p_e_c is specified, print call graph only for matching symbols
and their children.
-
"-Q[symspec]"
-
-
"--no-graph[=symspec]"
The --QQ option causes "gprof" to suppress printing the
-
call graph.
If _s_y_m_s_p_e_c is specified, "gprof" prints a call graph,
but excludes matching symbols.
-
"-t"
-
-
"--table-length=num"
The --tt option causes the _n_u_m most active source lines in
-
each source file to be listed when source annotation is enabled. The
default is 10.
-
"-y"
-
-
"--separate-files"
This option affects annotated source output only.
-
Normally, "gprof" prints annotated source files
to standard-output. If this option is specified,
annotated source for a file named _p_a_t_h_/_f_i_l_e_n_a_m_e
is generated in the file _f_i_l_e_n_a_m_e_-_a_n_n. If the underlying
filesystem would truncate _f_i_l_e_n_a_m_e_-_a_n_n so that it
overwrites the original _f_i_l_e_n_a_m_e, "gprof" generates
annotated source in the file _f_i_l_e_n_a_m_e_._a_n_n instead (if the
original file name has an extension, that extension is _r_e_p_l_a_c_e_d
with _._a_n_n).
-
"-Z[symspec]"
-
-
"--no-exec-counts[=symspec]"
The --ZZ option causes "gprof" not to
-
print a tally of functions and the number of times each was called.
If _s_y_m_s_p_e_c is specified, print tally, but exclude matching symbols.
-
"-r"
-
-
"--function-ordering"
The ----ffuunnccttiioonn--oorrddeerriinngg option causes "gprof" to print a
-
suggested function ordering for the program based on profiling data.
This option suggests an ordering which may improve paging, tlb and
cache behavior for the program on systems which support arbitrary
ordering of functions in an executable.
The exact details of how to force the linker to place functions
in a particular order is system dependent and out of the scope of this
manual.
-
"-R map_file"
-
-
"--file-ordering map_file"
The ----ffiillee--oorrddeerriinngg option causes "gprof" to print a
-
suggested .o link line ordering for the program based on profiling data.
This option suggests an ordering which may improve paging, tlb and
cache behavior for the program on systems which do not support arbitrary
ordering of functions in an executable.
Use of the --aa argument is highly recommended with this option.
The _m_a_p___f_i_l_e argument is a pathname to a file which provides
function name to object file mappings. The format of the file is similar to
the output of the program "nm".
c-parse.o:00000000 T yyparse
c-parse.o:00000004 C yyerrflag
c-lang.o:00000000 T maybe_objc_method_name
c-lang.o:00000000 T print_lang_statistics
c-lang.o:00000000 T recognize_objc_keyword
c-decl.o:00000000 T print_lang_identifier
c-decl.o:00000000 T print_lang_type
...
To create a _m_a_p___f_i_l_e with GNU "nm", type a command like
"nm --extern-only --defined-only -v --print-file-name program-name".
-
"-T"
-
-
"--traditional"
The --TT option causes "gprof" to print its output in
-
``traditional'' BSD style.
-
"-w width"
-
-
"--width=width"
Sets width of output lines to _w_i_d_t_h.
-
Currently only used when printing the function index at the bottom
of the call graph.
-
"-x"
-
-
"--all-lines"
This option affects annotated source output only.
-
By default, only the lines at the beginning of a basic-block
are annotated. If this option is specified, every line in
a basic-block is annotated by repeating the annotation for the
first line. This behavior is similar to "tcov"'s --aa.
-
"--demangle[=style]"
-
-
"--no-demangle"
These options control whether C++ symbol names should be demangled when
-
printing output. The default is to demangle symbols. The
"--no-demangle" option may be used to turn off demangling. Different
compilers have different mangling styles. The optional demangling style
argument can be used to choose an appropriate demangling style for your
compiler.
AAnnaallyyssiiss OOppttiioonnss
-
"-a"
-
-
"--no-static"
The --aa option causes "gprof" to suppress the printing of
-
statically declared (private) functions. (These are functions whose
names are not listed as global, and which are not visible outside the
file/function/block where they were defined.) Time spent in these
functions, calls to/from them, etc, will all be attributed to the
function that was loaded directly before it in the executable file.
This option affects both the flat profile and the call graph.
-
"-c"
-
-
"--static-call-graph"
The --cc option causes the call graph of the program to be
-
augmented by a heuristic which examines the text space of the object
file and identifies function calls in the binary machine code.
Since normal call graph records are only generated when functions are
entered, this option identifies children that could have been called,
but never were. Calls to functions that were not compiled with
profiling enabled are also identified, but only if symbol table
entries are present for them.
Calls to dynamic library routines are typically _n_o_t found
by this option.
Parents or children identified via this heuristic
are indicated in the call graph with call counts of 00.
-
"-D"
-
-
"--ignore-non-functions"
The --DD option causes "gprof" to ignore symbols which
-
are not known to be functions. This option will give more accurate
profile data on systems where it is supported (Solaris and HPUX for
example).
-
"-k from/to"
The --kk option allows you to delete from the call graph any arcs from
-
symbols matching symspec _f_r_o_m to those matching symspec _t_o.
-
"-l"
-
-
"--line"
The --ll option enables line-by-line profiling, which causes
-
histogram hits to be charged to individual source code lines,
instead of functions.
If the program was compiled with basic-block counting enabled,
this option will also identify how many times each line of
code was executed.
While line-by-line profiling can help isolate where in a large function
a program is spending its time, it also significantly increases
the running time of "gprof", and magnifies statistical
inaccuracies.
-
"-m num"
-
-
"--min-count=num"
This option affects execution count output only.
-
Symbols that are executed less than _n_u_m times are suppressed.
-
"-n[symspec]"
-
-
"--time[=symspec]"
The --nn option causes "gprof", in its call graph analysis,
-
to only propagate times for symbols matching _s_y_m_s_p_e_c.
-
"-N[symspec]"
-
-
"--no-time[=symspec]"
The --nn option causes "gprof", in its call graph analysis,
-
not to propagate times for symbols matching _s_y_m_s_p_e_c.
-
"-z"
-
-
"--display-unused-functions"
If you give the --zz option, "gprof" will mention all
-
functions in the flat profile, even those that were never called, and
that had no time spent in them. This is useful in conjunction with the
--cc option for discovering which routines were never called.
MMiisscceellllaanneeoouuss OOppttiioonnss
-
"-d[num]"
-
-
"--debug[=num]"
The --dd _n_u_m option specifies debugging options.
-
If _n_u_m is not specified, enable all debugging.
-
"-h"
-
-
"--help"
The --hh option prints command line usage.
-
-
"-Oname"
-
-
"--file-format=name"
Selects the format of the profile data files. Recognized formats are
-
aauuttoo (the default), bbssdd, 44..44bbssdd, mmaaggiicc, and
pprrooff (not yet supported).
-
"-s"
-
-
"--sum"
The --ss option causes "gprof" to summarize the information
-
in the profile data files it read in, and write out a profile data
file called _g_m_o_n_._s_u_m, which contains all the information from
the profile data files that "gprof" read in. The file _g_m_o_n_._s_u_m
may be one of the specified input files; the effect of this is to
merge the data in the other input files into _g_m_o_n_._s_u_m.
Eventually you can run "gprof" again without --ss to analyze the
cumulative data in the file _g_m_o_n_._s_u_m.
-
"-v"
-
-
"--version"
The --vv flag causes "gprof" to print the current version
-
number, and then exit.
DDeepprreeccaatteedd OOppttiioonnss
These options have been replaced with newer versions that use symspecs.
-
"-e function_name"
The --ee _f_u_n_c_t_i_o_n option tells "gprof" to not print
-
information about the function _f_u_n_c_t_i_o_n___n_a_m_e (and its
children...) in the call graph. The function will still be listed
as a child of any functions that call it, but its index number will be
shown as [[nnoott pprriinntteedd]]. More than one --ee option may be
given; only one _f_u_n_c_t_i_o_n___n_a_m_e may be indicated with each --ee
option.
-
"-E function_name"
The "-E function" option works like the "-e" option, but
-
time spent in the function (and children who were not called from
anywhere else), will not be used to compute the percentages-of-time for
the call graph. More than one --EE option may be given; only one
_f_u_n_c_t_i_o_n___n_a_m_e may be indicated with each --EE option.
-
"-f function_name"
The --ff _f_u_n_c_t_i_o_n option causes "gprof" to limit the
-
call graph to the function _f_u_n_c_t_i_o_n___n_a_m_e and its children (and
their children...). More than one --ff option may be given;
only one _f_u_n_c_t_i_o_n___n_a_m_e may be indicated with each --ff
option.
-
"-F function_name"
The --FF _f_u_n_c_t_i_o_n option works like the "-f" option, but
-
only time spent in the function and its children (and their
children...) will be used to determine total-time and
percentages-of-time for the call graph. More than one --FF option
may be given; only one _f_u_n_c_t_i_o_n___n_a_m_e may be indicated with each
--FF option. The --FF option overrides the --EE option.
FILES
-
"a.out"
the namelist and text space.
-
-
"gmon.out"
dynamic call graph and profile.
-
-
"gmon.sum"
summarized dynamic call graph and profile.
-
BUGS
The granularity of the sampling is shown, but remains
statistical at best.
We assume that the time for each execution of a function
can be expressed by the total time for the function divided
by the number of times the function is called.
Thus the time propagated along the call graph arcs to the function's
parents is directly proportional to the number of times that
arc is traversed.
Parents that are not themselves profiled will have the time of
their profiled children propagated to them, but they will appear
to be spontaneously invoked in the call graph listing, and will
not have their time propagated further.
Similarly, signal catchers, even though profiled, will appear
to be spontaneous (although for more obscure reasons).
Any profiled children of signal catchers should have their times
propagated properly, unless the signal catcher was invoked during
the execution of the profiling routine, in which case all is lost.
The profiled program must call "exit"(2)
or return normally for the profiling information to be saved
in the _g_m_o_n_._o_u_t file.
SEE ALSO
_m_o_n_i_t_o_r(3), _p_r_o_f_i_l(2), _c_c(1), _p_r_o_f(1), and the Info entry for _g_p_r_o_f.
``An Execution Profiler for Modular Programs'',
by S. Graham, P. Kessler, M. McKusick;
Software - Practice and Experience,
Vol. 13, pp. 671-685, 1983.
``gprof: A Call Graph Execution Profiler'',
by S. Graham, P. Kessler, M. McKusick;
Proceedings of the SIGPLAN '82 Symposium on Compiler Construction,
SIGPLAN Notices, Vol. 17, No 6, pp. 120-126, June 1982.
COPYRIGHT
Copyright (C) 1988, 92, 97, 98, 99, 2000, 2001, 2003 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1
or any later version published by the Free Software Foundation;
with no Invariant Sections, with no Front-Cover Texts, and with no
Back-Cover Texts. A copy of the license is included in the
section entitled "GNU Free Documentation License".