# gprof

## NAME



           gprof - display call graph profile data
    


## SYNOPSIS



           gprof [ -[abcDhilLrsTvwxyz] ] [ -[ABCeEfFJnNOpPqQRStZ][_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.
    
           "-B"
               The **-B** option causes "gprof" to print the call graph analysis.
    
           "-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.
    
           "-n _symspec_ "
           "--time=_symspec_ "
               The **-n** option causes "gprof", in its call graph analysis, to
               only propagate times for symbols matching _symspec_.
    
           "-N _symspec_ "
           "--no-time=_symspec_ "
               The **-n** option causes "gprof", in its call graph analysis, not
               to propagate times for symbols matching _symspec_.
    
           "-S _filename_ "
           "--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.
    
           "-O _name_ "
           "--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.
    


* * *