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, --diff or --summary may be specified at a time.

Use this option to specify the base directory of a build-environment when lcov produces error messages like:

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 use configuration file setting geninfo_auto_base=1 (see lcovrc(5)).

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, --diff or --summary may be specified at a time.

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.

Use --compat to specify that lcov should enable one or more compatibility modes when capturing coverage data. You can provide a comma-separated list of mode=value pairs to specify the values for multiple modes.

Valid values are:

on

If no value is specified, 'on' is assumed as default value.

Valid modes are:

libtool

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.

When this option is specified, neither the system-wide configuration file /etc/lcovrc, nor the per-user configuration file ~/.lcovrc is read.

This option may be useful when there is a need to run several instances of lcov with different configuration file options in parallel.

Use this option together with --diff to rename the file names of processed data sets according to the data provided by the diff.

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, --diff or --summary may be specified at a time.

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.

External source files are files which are not located in one of the directories specified by --directory or --base-directory. Use --external to include external source files while capturing coverage data or --no-external to ignore this data.

Data for external source files is included by default.

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, --diff or --summary may be specified at a time.

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.

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.

graph: the graph file could not be found or is corrupted.

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

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.

Only one of -z, -c, -a, -e, -r, -l, --diff or --summary may be specified at a time.

Use --list-full-path to show full paths during list operation or --no-list-full-path to show shortened paths. Paths are shortened by default.

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".

Use this option together with --diff to tell lcov to disregard the specified initial path component when matching between tracefile and diff filenames.

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.

Use this option to specify a keyword=value statement which overrides the corresponding configuration statement in the lcovrc configuration file. You can specify this option more than once to override multiple configuration statements. See lcovrc(5) for a list of available keywords and their meaning.

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, --diff or --summary may be specified at a time.

Use this option together with --diff to tell lcov to disregard the specified number of initial directories when matching tracefile and diff filenames.

Note that you may specify this option more than once.

Only one of -z, -c, -a, -e, -r, -l, --diff or --summary may be specified at a time.

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 ("_").

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:

On the build machine:

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.

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, --diff or --summary may be specified at a time.