gcov-tool

GCOV-TOOL(1)                          GNU                         GCOV-TOOL(1)

NAME
       gcov-tool - offline gcda profile processing tool

SYNOPSIS
       gcov-tool [-v|--version] [-h|--help]

       gcov-tool merge [merge-options] directory1 directory2
            [-o|--output directory]
            [-v|--verbose]
            [-w|--weight w1,w2]

       gcov-tool rewrite [rewrite-options] directory
            [-n|--normalize long_long_value]
            [-o|--output directory]
            [-s|--scale float_or_simple-frac_value]
            [-v|--verbose]

       gcov-tool overlap [overlap-options] directory1 directory2
            [-f|--function]
            [-F|--fullname]
            [-h|--hotonly]
            [-o|--object]
            [-t|--hot_threshold] float
            [-v|--verbose]

DESCRIPTION
       gcov-tool is an offline tool to process gcc's gcda profile files.

       Current gcov-tool supports the following functionalities:

       *   merge two sets of profiles with weights.

       *   read one set of profile and rewrite profile contents. One can scale
           or normalize the count values.

       Examples of the use cases for this tool are:

       *   Collect the profiles for different set of inputs, and use this tool
           to merge them. One can specify the weight to factor in the relative
           importance of each input.

       *   Rewrite the profile after removing a subset of the gcda files,
           while maintaining the consistency of the summary and the histogram.

       *   It can also be used to debug or libgcov code as the tools shares
           the majority code as the runtime library.

       Note that for the merging operation, this profile generated offline may
       contain slight different values from the online merged profile. Here
       are a list of typical differences:

       *   histogram difference: This offline tool recomputes the histogram
           after merging the counters. The resulting histogram, therefore, is
           precise. The online merging does not have this capability -- the
           histogram is merged from two histograms and the result is an
           approximation.

       *   summary checksum difference: Summary checksum uses a CRC32
           operation. The value depends on the link list order of gcov-info
           objects. This order is different in gcov-tool from that in the
           online merge. It's expected to have different summary checksums. It
           does not really matter as the compiler does not use this checksum
           anywhere.

       *   value profile counter values difference: Some counter values for
           value profile are runtime dependent, like heap addresses. It's
           normal to see some difference in these kind of counters.

OPTIONS
       -h
       --help
           Display help about using gcov-tool (on the standard output), and
           exit without doing any further processing.

       -v
       --version
           Display the gcov-tool version number (on the standard output), and
           exit without doing any further processing.

       merge
           Merge two profile directories.

           -o directory
           --output directory
               Set the output profile directory. Default output directory name
               is merged_profile.

           -v
           --verbose
               Set the verbose mode.

           -w w1,w2
           --weight w1,w2
               Set the merge weights of the directory1 and directory2,
               respectively. The default weights are 1 for both.

       rewrite
           Read the specified profile directory and rewrite to a new
           directory.

           -n long_long_value
           --normalize <long_long_value>
               Normalize the profile. The specified value is the max counter
               value in the new profile.

           -o directory
           --output directory
               Set the output profile directory. Default output name is
               rewrite_profile.

           -s float_or_simple-frac_value
           --scale float_or_simple-frac_value
               Scale the profile counters. The specified value can be in
               floating point value, or simple fraction value form, such 1, 2,
               2/3, and 5/3.

           -v
           --verbose
               Set the verbose mode.

       overlap
           Compute the overlap score between the two specified profile
           directories.  The overlap score is computed based on the arc
           profiles. It is defined as the sum of min (p1_counter[i] /
           p1_sum_all, p2_counter[i] / p2_sum_all), for all arc counter i,
           where p1_counter[i] and p2_counter[i] are two matched counters and
           p1_sum_all and p2_sum_all are the sum of counter values in profile
           1 and profile 2, respectively.

           -f
           --function
               Print function level overlap score.

           -F
           --fullname
               Print full gcda filename.

           -h
           --hotonly
               Only print info for hot objects/functions.

           -o
           --object
               Print object level overlap score.

           -t float
           --hot_threshold <float>
               Set the threshold for hot counter value.

           -v
           --verbose
               Set the verbose mode.

SEE ALSO
       gpl(7), gfdl(7), fsf-funding(7), gcc(1), gcov(1) and the Info entry for
       gcc.

COPYRIGHT
       Copyright (c) 2014-2019 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 the
       Invariant Sections being "GNU General Public License" and "Funding Free
       Software", the Front-Cover texts being (a) (see below), and with the
       Back-Cover Texts being (b) (see below).  A copy of the license is
       included in the gfdl(7) man page.

       (a) The FSF's Front-Cover Text is:

            A GNU Manual

       (b) The FSF's Back-Cover Text is:

            You have freedom to copy and modify this GNU Manual, like GNU
            software.  Copies published by the Free Software Foundation raise
            funds for GNU development.

gcc-9.4.0                         2021-06-01                      GCOV-TOOL(1)