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) 2014-2018 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-8 2021-05-14 GCOV-TOOL(1)