gprof - display call graph profile data
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 ... ]
"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.
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.
  - "-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.
  - "-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.
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.
  - "a.out"
- the namelist and text space.
- "gmon.out"
- dynamic call graph and profile.
- "gmon.sum"
- summarized dynamic call graph and profile.
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.
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 (c) 1988-2018 Free Software Foundation, Inc.
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    A copy of the license is included in the section entitled "GNU Free
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