NAME
lcov - a graphical GCOV front-end
SYNOPSIS
lcov -c|--capture
[-d|--directory directory] [-k|--kernel-directory directory]
[-o|--output-file tracefile] [-t|--test-name testname]
[-b|--base-directory directory] [-i|--initial] [--gcov-tool tool]
[--checksum] [--no-checksum] [--no-recursion] [-f|--follow]
[--compat-libtool] [--no-compat-libtool] [--ignore-errors errors]
[--to-package package] [--from-package package] [-q|--quiet]
[--no-markers]
lcov -z|--zerocounters
[-d|--directory directory] [--no-recursion] [-f|--follow]
[-q|--quiet]
lcov -l|--list tracefile
[-q|--quiet]
lcov -a|--add-tracefile tracefile
[-o|--output-file tracefile] [--checksum] [--no-checksum]
[-q|--quiet]
lcov -e|--extract tracefile pattern
[-o|--output-file tracefile] [--checksum] [--no-checksum]
[-q|--quiet]
lcov -r|--remove tracefile pattern
[-o|--output-file tracefile] [--checksum] [--no-checksum]
[-q|--quiet]
lcov --diff tracefile diff
[-o|--output-file tracefile] [--checksum] [--no-checksum]
[--convert-filenames] [--strip depth] [--path path] [-q|--quiet]
lcov [-h|--help] [-v|--version]
DESCRIPTION
lcov is a graphical front-end for GCC’s coverage testing tool gcov. It
collects line, function and branch coverage data for multiple source
files and creates HTML pages containing the source code annotated with
coverage information. It also adds overview pages for easy navigation
within the file structure.
Use lcov to collect coverage data and genhtml to create HTML pages.
Coverage data can either be collected from the currently running Linux
kernel or from a user space application. To do this, you have to
complete the following preparation steps:
For Linux kernel coverage:
Follow the setup instructions for the gcov-kernel
infrastructure: http://ltp.sourceforge.net/coverage/gcov.php
For user space application coverage:
Compile the application with GCC using the options
"-fprofile-arcs" and "-ftest-coverage".
Please note that this man page refers to the output format of lcov as
".info file" or "tracefile" and that the output of GCOV is called ".da
file".
OPTIONS
-a tracefile
--add-tracefile tracefile
Add contents of tracefile.
Specify several tracefiles using the -a switch to combine the
coverage data contained in these files by adding up execution
counts for matching test and filename combinations.
The result of the add operation will be written to stdout or the
tracefile specified with -o.
Only one of -z, -c, -a, -e, -r, -l and --diff may be specified
at a time.
-b directory
--base-directory directory
Use directory as base directory for relative paths.
Use this option to specify the base directory of a
build-environment when lcov produces error messages like:
ERROR: could not read source file
/home/user/project/subdir1/subdir2/subdir1/subdir2/file.c
In this example, use /home/user/project as base directory.
This option is required when using lcov on projects built with
libtool or similar build environments that work with a base
directory, i.e. environments, where the current working
directory when invoking the compiler is not the same directory
in which the source code file is located.
Note that this option will not work in environments where
multiple base directories are used. In that case repeat the lcov
call for each base directory while using the --ignore-errors
option to prevent lcov from exiting when the first source code
file could not be found. This way you can get partial coverage
information for each base directory which can then be combined
using the -a option.
-c
--capture
Capture coverage data.
By default captures the current kernel execution counts and
writes the resulting coverage data to the standard output. Use
the --directory option to capture counts for a user space
program.
The result of the capture operation will be written to stdout or
the tracefile specified with -o.
Only one of -z, -c, -a, -e, -r, -l and --diff may be specified
at a time.
--checksum
--no-checksum
Specify whether to generate checksum data when writing
tracefiles.
Use --checksum to enable checksum generation or --no-checksum to
disable it. Checksum generation is disabled by default.
When checksum generation is enabled, a checksum will be
generated for each source code line and stored along with the
coverage data. This checksum will be used to prevent attempts to
combine coverage data from different source code versions.
If you don’t work with different source code versions, disable
this option to speed up coverage data processing and to reduce
the size of tracefiles.
--compat-libtool
--no-compat-libtool
Specify whether to enable libtool compatibility mode.
Use --compat-libtool to enable libtool compatibility mode or
--no-compat-libtool to disable it. The libtool compatibility
mode is enabled by default.
When libtool compatibility mode is enabled, lcov will assume
that the source code relating to a .da file located in a
directory named ".libs" can be found in its parent directory.
If you have directories named ".libs" in your build environment
but don’t use libtool, disable this option to prevent problems
when capturing coverage data.
--convert-filenames
Convert filenames when applying diff.
Use this option together with --diff to rename the file names of
processed data sets according to the data provided by the diff.
--diff tracefile difffile
Convert coverage data in tracefile using source code diff file
difffile.
Use this option if you want to merge coverage data from
different source code levels of a program, e.g. when you have
data taken from an older version and want to combine it with
data from a more current version. lcov will try to map source
code lines between those versions and adjust the coverage data
respectively. difffile needs to be in unified format, i.e. it
has to be created using the "-u" option of the diff tool.
Note that lines which are not present in the old version will
not be counted as instrumented, therefore tracefiles resulting
from this operation should not be interpreted individually but
together with other tracefiles taken from the newer version.
Also keep in mind that converted coverage data should only be
used for overview purposes as the process itself introduces a
loss of accuracy.
The result of the diff operation will be written to stdout or
the tracefile specified with -o.
Only one of -z, -c, -a, -e, -r, -l and --diff may be specified
at a time.
-d directory
--directory directory
Use .da files in directory instead of kernel.
If you want to work on coverage data for a user space program,
use this option to specify the location where the program was
compiled (that’s where the counter files ending with .da will be
stored).
Note that you may specify this option more than once.
-e tracefile pattern
--extract tracefile pattern
Extract data from tracefile.
Use this switch if you want to extract coverage data for only a
particular set of files from a tracefile. Additional command
line parameters will be interpreted as shell wildcard patterns
(note that they may need to be escaped accordingly to prevent
the shell from expanding them first). Every file entry in
tracefile which matches at least one of those patterns will be
extracted.
The result of the extract operation will be written to stdout or
the tracefile specified with -o.
Only one of -z, -c, -a, -e, -r, -l and --diff may be specified
at a time.
-f
--follow
Follow links when searching for .da files.
--from-package package
Use .da files in package instead of kernel or directory.
Use this option if you have separate machines for build and test
and want to perform the .info file creation on the build
machine. See --to-package for more information.
--gcov-tool tool
Specify the location of the gcov tool.
-h
--help
Print a short help text, then exit.
--ignore-errors errors
Specify a list of errors after which to continue processing.
Use this option to specify a list of one or more classes of
errors after which lcov should continue processing instead of
aborting.
errors can be a comma-separated list of the following keywords:
gcov: the gcov tool returned with a non-zero return code.
source: the source code file for a data set could not be found.
-i
--initial
Capture initial zero coverage data.
Run lcov with -c and this option on the directories containing
.bb, .bbg or .gcno files before running any test case. The
result is a "baseline" coverage data file that contains zero
coverage for every instrumented line. Combine this data file
(using lcov -a) with coverage data files captured after a test
run to ensure that the percentage of total lines covered is
correct even when not all source code files were loaded during
the test.
Recommended procedure when capturing data for a test case:
1. create baseline coverage data file
# lcov -c -i -d appdir -o app_base.info
2. perform test
# appdir/test
3. create test coverage data file
# lcov -c -d appdir -o app_test.info
4. combine baseline and test coverage data
# lcov -a app_base.info -a app_test.info -o
app_total.info
-k subdirectory
--kernel-directory subdirectory
Capture kernel coverage data only from subdirectory.
Use this option if you don’t want to get coverage data for all
of the kernel, but only for specific subdirectories. This option
may be specified more than once.
Note that you may need to specify the full path to the kernel
subdirectory depending on the version of the kernel gcov
support.
-l tracefile
--list tracefile
List the contents of the tracefile.
Only one of -z, -c, -a, -e, -r, -l and --diff may be specified
at a time.
--no-markers
Use this option if you want to get coverage data without regard
to exclusion markers in the source code file. See geninfo (1)
for details on exclusion markers.
--no-recursion
Use this option if you want to get coverage data for the
specified directory only without processing subdirectories.
-o tracefile
--output-file tracefile
Write data to tracefile instead of stdout.
Specify "-" as a filename to use the standard output.
By convention, lcov-generated coverage data files are called
"tracefiles" and should have the filename extension ".info".
--path path
Strip path from filenames when applying diff.
Use this option together with --diff to tell lcov to disregard
the specified initial path component when matching between
tracefile and diff filenames.
-q
--quiet
Do not print progress messages.
This option is implied when no output filename is specified to
prevent progress messages to mess with coverage data which is
also printed to the standard output.
-r tracefile pattern
--remove tracefile pattern
Remove data from tracefile.
Use this switch if you want to remove coverage data for a
particular set of files from a tracefile. Additional command
line parameters will be interpreted as shell wildcard patterns
(note that they may need to be escaped accordingly to prevent
the shell from expanding them first). Every file entry in
tracefile which matches at least one of those patterns will be
removed.
The result of the remove operation will be written to stdout or
the tracefile specified with -o.
Only one of -z, -c, -a, -e, -r, -l and --diff may be specified
at a time.
--strip depth
Strip path components when applying diff.
Use this option together with --diff to tell lcov to disregard
the specified number of initial directories when matching
tracefile and diff filenames.
-t testname
--test-name testname
Specify test name to be stored in the tracefile.
This name identifies a coverage data set when more than one data
set is merged into a combined tracefile (see option -a).
Valid test names can consist of letters, decimal digits and the
underscore character ("_").
--to-package package
Store .da files for later processing.
Use this option if you have separate machines for build and test
and want to perform the .info file creation on the build
machine. To do this, follow these steps:
On the test machine:
- run the test
- run lcov -c [-d directory] --to-package file
- copy file to the build machine
On the build machine:
- run lcov -c --from-package file [-o and other options]
This works for both kernel and user space coverage data. Note
that you might have to specify the path to the build directory
using -b with either --to-package or --from-package. Note also
that the package data must be converted to a .info file before
recompiling the program or it will become invalid.
-v
--version
Print version number, then exit.
-z
--zerocounters
Reset all execution counts to zero.
By default tries to reset kernel execution counts. Use the
--directory option to reset all counters of a user space
program.
Only one of -z, -c, -a, -e, -r, -l and --diff may be specified
at a time.
FILES
/etc/lcovrc
The system-wide configuration file.
~/.lcovrc
The per-user configuration file.
AUTHOR
Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>
SEE ALSO
lcovrc(5), genhtml(1), geninfo(1), genpng(1), gendesc(1), gcov(1)