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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 ] [ --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 ] [ 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.

       "-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.

       "-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,  92,  97,  98,  99,  2000,  2001, 2003, 2007 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".