man/lcov.1

.TH lcov 1 "LCOV 1.7" 2008\-11\-17 "User Manuals"
.SH NAME
lcov \- a graphical GCOV front\-end
.SH SYNOPSIS
.B lcov
.RB [ \-h | \-\-help ]
.RB [ \-v | \-\-version ]
.RB [ \-q | \-\-quiet ]
.RS 5
.br
.RB [ \-z | \-\-zerocounters ]
.RB [ \-c | \-\-capture ]
.br
.RB [ \-a | \-\-add\-tracefile
.IR tracefile ]
.br
.RB [ \-e | \-\-extract
.IR tracefile ]
.br
.RB [ \-r | \-\-remove
.IR tracefile ]
.br
.RB [ \-l | \-\-list
.IR tracefile ]
.br
.RB [ \-\-diff
.IR "tracefile diff" ]
.br
.RB [ \-i | \-\-initial ]
.RB [ \-t | \-\-test\-name
.IR testname ]
.br
.RB [ \-o | \-\-output\-file
.IR filename ]
.br
.RB [ \-d | \-\-directory
.IR directory ]
.br
.RB [ \-f | \-\-follow ]
.br
.RB [ \-k | \-\-kernel\-directory
.IR directory ]
.br
.RB [ \-b | \-\-base\-directory
.IR directory ]
.br
.RB [ \-\-convert\-filenames ]
.RB [ \-\-strip
.IR depth ]
.RB [ \-\-path
.IR path ]
.br
.RB [ \-\-checksum ]
.RB [ \-\-no\-checksum ]
.br
.RB [ \-\-compat\-libtool ]
.RB [ \-\-no\-compat\-libtool ]
.br
.RB [ \-\-gcov\-tool
.IR tool ]
.RB [ \-\-ignore\-errors
.IR errors ]
.br
.RB [ \-\-no\-recursion ]
.SH DESCRIPTION
.B lcov
is a graphical front\-end for GCC's coverage testing tool gcov. It collects
gcov 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
.B lcov
to collect coverage data and
.B 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:
.RS
Follow the installation instructions for the gcov\-kernel patch:
.I http://ltp.sourceforge.net/coverage/gcov.php

.RE
For user space application coverage:
.RS
Compile the application with GCC using the options
"\-fprofile\-arcs" and "\-ftest\-coverage".
.RE

Please note that this man page refers to the output format of
.B lcov
as ".info file" or "tracefile" and that the output of GCOV
is called ".da file".
.SH OPTIONS


.B \-a
.I tracefile
.br
.B \-\-add\-tracefile
.I tracefile
.br
.RS
Add contents of
.IR 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.

.RE

.B \-b
.I directory
.br
.B \-\-base\-directory
.I directory
.br
.RS
.RI "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:

.RS
ERROR: could not read source file /home/user/project/subdir1/subdir2/subdir1/subdir2/file.c
.RE

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.
.RE

.B \-c
.br
.B \-\-capture
.br
.RS
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.
.RE

.B \-\-checksum
.br
.B \-\-no\-checksum
.br
.RS
Specify whether to generate checksum data when writing tracefiles.

Use \-\-checksum to enable checksum generation or \-\-no\-checksum to
disable it. Checksum generation is
.B 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.
.RE

.B \-\-compat\-libtool
.br
.B \-\-no\-compat\-libtool
.br
.RS
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
.B 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.
.RE

.B \-\-convert\-filenames
.br
.RS
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.
.RE

.B \-\-diff
.I tracefile
.I difffile
.br
.RS
Convert coverage data in
.I tracefile
using source code diff file
.IR 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.
.B lcov
will try to map source code lines between those versions and adjust the coverage
data respectively.
.I difffile
needs to be in unified format, i.e. it has to be created using the "\-u" option
of the
.B 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.
.RE

.B \-d
.I directory
.br
.B \-\-directory
.I  directory
.br
.RS
Use .da files in
.I 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.
.RE

.B \-e
.I tracefile
.I pattern
.br
.B \-\-extract
.I tracefile
.I pattern
.br
.RS
Extract data from
.IR 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
.I 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.
.RE

.B \-f
.br
.B \-\-follow
.br
.RS
Follow links when searching for .da files.
.RE

.B \-\-gcov\-tool
.I tool
.br
.RS
Specify the location of the gcov tool.
.RE

.B \-h
.br
.B \-\-help
.br
.RS
Print a short help text, then exit.
.RE

.B \-\-ignore\-errors
.I errors
.br
.RS
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.

.I errors
can be a comma\-separated list of the following keywords:

.B gcov:
the gcov tool returned with a non\-zero return code.

.B source:
the source code file for a data set could not be found.
.RE

.B \-i
.br
.B \-\-initial
.RS
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
.RS
# lcov \-c \-i \-d appdir \-o app_base.info
.br

.RE
2. perform test
.RS
# appdir/test
.br

.RE
3. create test coverage data file
.RS
# lcov \-c \-d appdir \-o app_test.info
.br

.RE
4. combine baseline and test coverage data
.RS
# lcov \-a app_base.info \-a app_test.info \-o app_total.info
.br

.RE
.RE

.B \-k
.I subdirectory
.br
.B \-\-kernel\-directory
.I subdirectory
.br
.RS
Capture kernel coverage data only from
.IR 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.
.RE

.B \-l
.I tracefile
.br
.B \-\-list
.I tracefile
.br
.RS
List the contents of the
.IR tracefile .

Only one of  \-z, \-c, \-a, \-e, \-r, \-l and \-\-diff may be specified
at a time.
.RE

.B \-\-no\-recursion
.br
.RS
Use this option if you want to get coverage data for the specified directory
only without processing subdirectories.
.RE

.B \-o
.I tracefile
.br
.B \-\-output\-file
.I tracefile
.br
.RS
Write data to
.I 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".
.RE

.B \-\-path
.I path
.br
.RS
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.
.RE

.B \-q
.br
.B \-\-quiet
.br
.RS
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.
.RE

.B \-r
.I tracefile
.I pattern
.br
.B \-\-remove
.I tracefile
.I pattern
.br
.RS
Remove data from
.IR 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
.I 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.
.RE

.B \-\-strip
.I depth
.br
.RS
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.
.RE

.B \-t
.I testname
.br
.B \-\-test\-name
.I testname
.br
.RS
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 ("_").
.RE

.B \-v
.br
.B \-\-version
.br
.RS
Print version number, then exit.
.RE

.B \-z
.br
.B \-\-zerocounters
.br
.RS
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.
.RE

.SH FILES

.I /etc/lcovrc
.RS
The system\-wide configuration file.
.RE

.I ~/.lcovrc
.RS
The per\-user configuration file.
.RE

.SH AUTHOR
Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>

.SH SEE ALSO
.BR lcovrc (5),
.BR genhtml (1),
.BR geninfo (1),
.BR genpng (1),
.BR gendesc (1),
.BR gcov (1)