lcov(1) User Manuals lcov(1)
NAME
lcov - GCOV coverage tool extension
SYNOPSIS
lcov [-h|--help] [-v|--version] [-q|--quiet]
[-z|--zerocounters] [-c|--capture]
[-a|--add-tracefile tracefile]
[-e|--extract tracefile]
[-r|--remove tracefile]
[-l|--list tracefile]
[--diff tracefile diff]
[-i|--initial] [-t|--test-name testname]
[-o|--output-file filename]
[-d|--directory directory]
[-f|--follow]
[-k|--kernel-directory directory]
[-b|--base-directory directory]
[--convert-filenames] [--strip depth] [--path path]
[--checksum] [--no-checksum]
[--compat-libtool] [--no-compat-libtool]
[--gcov-tool tool] [--ignore-errors errors]
DESCRIPTION
lcov is an extension of GCOV, a GNU tool which provides information
about what parts of a program are actually executed (i.e. "covered")
during a particular test case. The extension consists of a set of PERL
scripts which build on the textual GCOV output to implement HTML out-
put and support for large projects.
Use lcov to collect coverage data from either 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:
Download and install the "gcov-kernel" package from
http://sourceforge.net/projects/ltp
The resulting kernel module has to be installed either in the
system wide kernel modules directory or in the same directory
as the LCOV tool. Note that you will need root privileges to
access kernel coverage data.
For user space application coverage:
Compile the application with GCC using the options "-fpro-
file-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-envi-
ronment when lcov produces error messages like:
ERROR: could not read source file
/home/user/project/subdir1/subdir2/subdir1/sub-
dir2/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 direc-
tory 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 mul-
tiple 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 pro-
gram.
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 trace-
files.
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 gener-
ated for each source code line and stored along with the cover-
age 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 direc-
tory 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 differ-
ent 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.
--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.
Note that you may specify this option more than once.
-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.
-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 par-
ticular 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 trace-
file 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 ("_").
-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 pro-
gram.
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)
2007-08-20 lcov 1.6 lcov(1)
