GPROF(1)			      GNU			      GPROF(1)



NAME
       gprof - display call graph profile data

SYNOPSIS
       gprof [ -[abcDhilLrsTvwxyz] ] [ -[ACeEfFJnNOpPqQZ][name] ]
	[ -I dirs ] [ -d[num] ] [ -k from/to ]
	[ -m min-count ] [ -R map_file ] [ -t table-length ]
	[ --[no-]annotated-source[=name] ]
	[ --[no-]exec-counts[=name] ]
	[ --[no-]flat-profile[=name] ] [ --[no-]graph[=name] ]
	[ --[no-]time=name] [ --all-lines ] [ --brief ]
	[ --debug[=level] ] [ --function-ordering ]
	[ --file-ordering map_file ] [ --directory-path=dirs ]
	[ --display-unused-functions ] [ --file-format=name ]
	[ --file-info ] [ --help ] [ --line ] [ --inline-file-names ]
	[ --min-count=n ] [ --no-static ] [ --print-path ]
	[ --separate-files ] [ --static-call-graph ] [ --sum ]
	[ --table-length=len ] [ --traditional ] [ --version ]
	[ --width=n ] [ --ignore-non-functions ]
	[ --demangle[=STYLE] ] [ --no-demangle ]
	[--external-symbol-table=name]
	[ image-file ] [ profile-file ... ]

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 (gmon.out default) which is created by programs that are compiled
       with the -pg option of "cc", "pc", and "f77".  The -pg 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 gmon.out.  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 flat profile 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 call graph 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 annotated source 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 symspec 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 (-p -q), which
       prints a flat profile and call graph analysis for all functions.

       "-A[symspec]"
       "--annotated-source[=symspec]"
	   The -A option causes "gprof" to print annotated source code.	 If
	   symspec is specified, print output only for matching symbols.

       "-b"
       "--brief"
	   If the -b 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 -C option causes "gprof" to print a tally of functions and the
	   number of times each was called.  If symspec is specified, print
	   tally only for matching symbols.

	   If the profile data file contains basic-block count records,
	   specifying the -l option, along with -C, will cause basic-block
	   execution counts to be tallied and displayed.

       "-i"
       "--file-info"
	   The -i 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 -I option specifies a list of search directories in which to
	   find source files.  Environment variable GPROF_PATH can also be
	   used to convey this information.  Used mostly for annotated source
	   output.

       "-J[symspec]"
       "--no-annotated-source[=symspec]"
	   The -J option causes "gprof" not to print annotated source code.
	   If symspec is specified, "gprof" prints annotated source, but
	   excludes matching symbols.

       "-L"
       "--print-path"
	   Normally, source filenames are printed with the path component
	   suppressed.	The -L 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 -p option causes "gprof" to print a flat profile.  If symspec
	   is specified, print flat profile only for matching symbols.

       "-P[symspec]"
       "--no-flat-profile[=symspec]"
	   The -P option causes "gprof" to suppress printing a flat profile.
	   If symspec is specified, "gprof" prints a flat profile, but
	   excludes matching symbols.

       "-q[symspec]"
       "--graph[=symspec]"
	   The -q option causes "gprof" to print the call graph analysis.  If
	   symspec is specified, print call graph only for matching symbols
	   and their children.

       "-Q[symspec]"
       "--no-graph[=symspec]"
	   The -Q option causes "gprof" to suppress printing the call graph.
	   If symspec is specified, "gprof" prints a call graph, but excludes
	   matching symbols.

       "-t"
       "--table-length=num"
	   The -t option causes the num 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
	   path/filename is generated in the file filename-ann.	 If the
	   underlying file system would truncate filename-ann so that it
	   overwrites the original filename, "gprof" generates annotated
	   source in the file filename.ann instead (if the original file name
	   has an extension, that extension is replaced with .ann).

       "-Z[symspec]"
       "--no-exec-counts[=symspec]"
	   The -Z option causes "gprof" not to print a tally of functions and
	   the number of times each was called.	 If symspec is specified,
	   print tally, but exclude matching symbols.

       "-r"
       "--function-ordering"
	   The --function-ordering 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 --file-ordering 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 -a argument is highly recommended with this option.

	   The map_file 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 map_file with GNU "nm", type a command like "nm
	   --extern-only --defined-only -v --print-file-name program-name".

       "-T"
       "--traditional"
	   The -T option causes "gprof" to print its output in "traditional"
	   BSD style.

       "-w width"
       "--width=width"
	   Sets width of output lines to width.	 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 -a.

       "--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.

   Analysis Options
       "-a"
       "--no-static"
	   The -a 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 -c 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 not found by this option.  Parents or children
	   identified via this heuristic are indicated in the call graph with
	   call counts of 0.

       "-D"
       "--ignore-non-functions"
	   The -D 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 -k option allows you to delete from the call graph any arcs
	   from symbols matching symspec from to those matching symspec to.

       "-l"
       "--line"
	   The -l option enables line-by-line profiling, which causes
	   histogram hits to be charged to individual source code lines,
	   instead of functions.  This feature only works with programs
	   compiled by older versions of the "gcc" compiler.  Newer versions
	   of "gcc" are designed to work with the "gcov" tool instead.

	   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.

       "--inline-file-names"
	   This option causes "gprof" to print the source file after each
	   symbol in both the flat profile and the call graph. The full path
	   to the file is printed if used with the -L option.

       "-m num"
       "--min-count=num"
	   This option affects execution count output only.  Symbols that are
	   executed less than num times are suppressed.

       "-nsymspec"
       "--time=symspec"
	   The -n option causes "gprof", in its call graph analysis, to only
	   propagate times for symbols matching symspec.

       "-Nsymspec"
       "--no-time=symspec"
	   The -n option causes "gprof", in its call graph analysis, not to
	   propagate times for symbols matching symspec.

       "-Sfilename"
       "--external-symbol-table=filename"
	   The -S option causes "gprof" to read an external symbol table file,
	   such as /proc/kallsyms, rather than read the symbol table from the
	   given object file (the default is "a.out"). This is useful for
	   profiling kernel modules.

       "-z"
       "--display-unused-functions"
	   If you give the -z 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 -c
	   option for discovering which routines were never called.

   Miscellaneous Options
       "-d[num]"
       "--debug[=num]"
	   The -d num option specifies debugging options.  If num is not
	   specified, enable all debugging.

       "-h"
       "--help"
	   The -h option prints command line usage.

       "-Oname"
       "--file-format=name"
	   Selects the format of the profile data files.  Recognized formats
	   are auto (the default), bsd, 4.4bsd, magic, and prof (not yet
	   supported).

       "-s"
       "--sum"
	   The -s option causes "gprof" to summarize the information in the
	   profile data files it read in, and write out a profile data file
	   called gmon.sum, which contains all the information from the
	   profile data files that "gprof" read in.  The file gmon.sum may be
	   one of the specified input files; the effect of this is to merge
	   the data in the other input files into gmon.sum.

	   Eventually you can run "gprof" again without -s to analyze the
	   cumulative data in the file gmon.sum.

       "-v"
       "--version"
	   The -v flag causes "gprof" to print the current version number, and
	   then exit.

   Deprecated Options
       These options have been replaced with newer versions that use symspecs.

       "-e function_name"
	   The -e function option tells "gprof" to not print information about
	   the function function_name (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 [not printed].  More
	   than one -e option may be given; only one function_name may be
	   indicated with each -e 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 -E option may be given; only one
	   function_name may be indicated with each -E option.

       "-f function_name"
	   The -f function option causes "gprof" to limit the call graph to
	   the function function_name and its children (and their
	   children...).  More than one -f option may be given; only one
	   function_name may be indicated with each -f option.

       "-F function_name"
	   The -F function 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 -F option may be given; only one
	   function_name may be indicated with each -F option.	The -F option
	   overrides the -E 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 gmon.out file.

SEE ALSO
       monitor(3), profil(2), cc(1), prof(1), and the Info entry for gprof.

       "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) 1988-2016 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 1.3 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".



binutils-2.27			  2023-09-13			      GPROF(1)