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 merge-stream [merge-stream-options] [file]
            [-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 a stream of profiles with associated filenames and merge it with a set 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.

       *   Collect profiles from target systems without a filesystem (freestanding environments).
           Merge the collected profiles with associated profiles present on the host system.  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.

       merge-stream
           Collect profiles with associated filenames from a gcfn and gcda data stream.  Read the
           stream from the file specified by file or from stdin.  Merge the profiles with
           associated profiles in the host filesystem.  Apply the optional weights while merging
           profiles.

           For the generation of a gcfn and gcda data stream on the target system, please have a
           look at the "__gcov_filename_to_gcfn()" and "__gcov_info_to_gcda()" functions declared
           in "#include <gcov.h>".

           -v
           --verbose
               Set the verbose mode.

           -w w1,w2
           --weight w1,w2
               Set the merge weights of the profiles from the gcfn and gcda data stream and the
               associated profiles in the host filesystem, 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) 2014-2023 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.