Ubuntu Manpage: geninfo - Generate tracefiles from GCOV coverage data files

NAME

       geninfo - Generate tracefiles from GCOV coverage data files

SYNOPSIS

       geninfo [-h|--help] [--version] [-q|--quiet] [-v|--verbose] [--debug]
               [-i|--initial] [-t|--test-name test-name]
               [-o|--output-filename filename] [-f|--follow]
               [-b|--base-directory directory]
               [--build-directory directory]
               [--branch-coverage]
               [--checksum] [--no-checksum]
               [--compat-libtool] [--no-compat-libtool]
               [--gcov-tool tool]
               [--parallel|-j [integer]]
               [--memory integer_num_Mb]
               [--ignore-errors errors]
               [--keep-going]
               [--preserve]
               [--filter type]
               [--demangle-cpp[param]]
               [--no-recursion] [--external] [--no-external]
               [--config-file config-file] [--no-markers]
               [--derive-func-data] [--compat mode=on|off|auto]
               [--rc keyword=value]
               [--include glob_pattern]
               [--exclude glob_pattern]
               [--erase-functions regexp_pattern]
               [--substitute regexp_pattern]
               [--omit-lines regexp_pattern]
               [--forget-test-names]
               [--version-script script_file]
               [--tempdir dirname]
               directory

DESCRIPTION

Use geninfo to create LCOV tracefiles from GCC and LLVM/Clang coverage data files (see --gcov-tool for
considerations when working with LLVM). You can use genhtml to create an HTML report from a tracefile.

Note that geninfo is called by lcov --capture, so there is typically no need to call it directly.

Unless the --output-filename option is specified geninfo writes its output to one file with .info
filename extension per input file.

Note also that the current user needs write access to both directory as well as to the original source
code location. This is necessary because some temporary files have to be created there during the
conversion process.

File types
A tracefile is a coverage data file in the format used by all LCOV tools such as geninfo, lcov, and
genhtml. By convention, tracefiles have a .info filename extension. See "Tracefile format" below for a
description of the file format.

A .gcda file is a compiler-specific file containing run-time coverage data. It is created and updated
when a program compiled with GCC/LLVM's --coverage option is run to completion. geninfo reads .gcda
files in its default mode of operation. Note: earlier compiler versions used the .da filename extension
for this file type.

A .gcno file is a compiler-specific file containing static, compile-time coverage data. It is created
when source code is compiled with GCC/LLVM's --coverage option. geninfo reads .gcno files when option
--initial is specified. Note: earlier compiler versions used .bb and .bbg filename extensions for this
file type.

A .gcov file is a textual or JSON representation of the data found in .gcda and .gcno files. It is
created by the gcov tools that is part of GCC (see --gcov-tool for LLVM considerations). There are
multiple gcov file format versions, including textual, intermediate, and JSON format. geninfo internally
uses gcov to extract coverage data from .gcda and .gcno files using the best supported gcov file format.

See the gcov man page for more information on .gcda, .gcno and .gcov output formats.

Exclusion markers
To exclude specific lines of code from a tracefile, you can add exclusion markers to the source code.
Additionally you can exclude specific branches from branch coverage without excluding the involved lines
from line and function coverage. Exclusion markers are keywords which can for example be added in the
form of a comment. See lcovrc(5) how to override some of them.

The following markers are recognized by geninfo:

LCOV_EXCL_LINE
Lines containing this marker will be excluded.

LCOV_EXCL_START
Marks the beginning of an excluded section. The current line is part of this section.

LCOV_EXCL_STOP
Marks the end of an excluded section. The current line not part of this section.

LCOV_EXCL_BR_LINE
Lines containing this marker will be excluded from branch coverage.

LCOV_EXCL_BR_START
Marks the beginning of a section which is excluded from branch coverage. The current line is part
of this section.

LCOV_EXCL_BR_STOP
Marks the end of a section which is excluded from branch coverage. The current line not part of
this section.

LCOV_EXCL_EXCEPTION_BR_LINE
Lines containing this marker will be excluded from exception branch coverage: Exception branches
will be ignored, but non-exception branches will not be affected.

LCOV_EXCL_EXCEPTION_BR_START
Marks the beginning of a section which is excluded from exception branch coverage. The current
line is part of this section.

LCOV_EXCL_EXCEPTION_BR_STOP
Marks the end of a section which is excluded from exception branch coverage. The current line not
part of this section

OPTIONS

-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 geninfo 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 geninfo 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)).

--build-directory build_dir
Search for .gcno data files from build_dir rather finding them only adjacent to the corresponding
.o and/or .gcda file.

By default, geninfo expects to find the .gcno and .gcda files (compile- and run-time data,
respectively) in the same directory.

When this option is used:

geninfo path1 --build-directory path2 ...

then geninfo will look for .gcno file

path2/relative/path/to/da_base.gcno

when it finds .gcda file

path1/relative/path/to/da_base.gcda.

Use this option when you have used the GCOV_PREFIX environment variable to direct the gcc or llvm
runtime environment to write coverage data files to somewhere other than the directory where the
code was originally compiled. See gcc(1) and/or search for GCOV_PREFIX and GCOV_PREFIX_STRIP.

This option can be used several times to specify multiple alternate directories to look for .gcno
files. This may be useful if your application uses code which is compiled in many separate
locations - for example, common libraries that are shared between teams.

--branch-coverage
Collect retain branch coverage data.

This is equivalent to using the option "--rc lcov_branch_coverage=1"; the option was added to
better match the genhml interface.

--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.

Note that this options is somewhat subsumed by the --version-script option - which does something
similar, but at the 'whole file' level.

--compat mode=value[,mode=value,...]
Set compatibility mode.

Use --compat to specify that geninfo 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
Enable compatibility mode.
off
Disable compatibility mode.
auto
Apply auto-detection to determine if compatibility mode is required. Note that auto-
detection is not available for all compatibility modes.

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

Valid modes are:

libtool
Enable this mode if you are capturing coverage data for a project that was built using the
libtool mechanism. See also --compat-libtool.

The default value for this setting is 'on'.

hammer
Enable this mode if you are capturing coverage data for a project that was built using a
version of GCC 3.3 that contains a modification (hammer patch) of later GCC versions. You
can identify a modified GCC 3.3 by checking the build directory of your project for files
ending in the extension .bbg. Unmodified versions of GCC 3.3 name these files .bb.

The default value for this setting is 'auto'.

split_crc
Enable this mode if you are capturing coverage data for a project that was built using a
version of GCC 4.6 that contains a modification (split function checksums) of later GCC
versions. Typical error messages when running geninfo on coverage data produced by such GCC
versions are ´out of memory' and 'reached unexpected end of file'.

The default value for this setting is 'auto'

--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, geninfo will assume that the source code relating to a
.gcda 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.

--config-file config-file
Specify a configuration file to use. See the lcovrc man page for details of the file format and
options.

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 geninfo with different
configuration file options in parallel.

Note that this option must be specified in full - abbreviations are not supported.

--derive-func-data
Calculate function coverage data from line coverage data.

Use this option to collect function coverage data, even if the version of the gcov tool installed
on the test system does not provide this data. lcov will instead derive function coverage data
from line coverage data and information about which lines belong to a function.

--external
--no-external
Specify whether to capture coverage data for external source files.

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.

-f
--follow
Follow links when searching .gcda files.

--gcov-tool tool
Specify the location of the gcov tool.

If the --gcov-tool option is used multiple times, then the arguments are concatenated when the
callback is executed - similar to how the gcc -Xlinker parameter works. This provides a possibly
easier way to pass arguments to your tool, without requiring a wrapper script. In that case, your
callback will be executed as: tool-0 'tool-1; ... 'filename'. Note that the second and subsequent
arguments are quoted when passed to the shell, in order to handle parameters which contain spaces.

A common use for this option is to enable LLVM:

geninfo --gcov-tool llvm-cov --gcov-tool gcov ...

Note: 'llvm-cov gcov da_file_name' will generate output in gcov-compatible format as required by
lcov.

If not specified, 'gcov' is used by default.

-h
--help
Print a short help text, then exit.

--include pattern
Include source files matching pattern.

Use this switch if you want to include coverage data for only a particular set of source files
matching any of the given patterns. Multiple patterns can be specified by using multiple --include
command line switches. The patterns will be interpreted as shell wildcard patterns (note that they
may need to be escaped accordingly to prevent the shell from expanding them first).

See the lcov man page for details

--exclude pattern
Exclude source files matching pattern.

Use this switch if you want to exclude coverage data from a particular set of source files
matching any of the given patterns. Multiple patterns can be specified by using multiple --exclude
command line switches. The patterns will be interpreted as shell wildcard patterns (note that they
may need to be escaped accordingly to prevent the shell from expanding them first). Note: The
pattern must be specified to match the absolute path of each source file.

Can be combined with the --include command line switch. If a given file matches both the include
pattern and the exclude pattern, the exclude pattern will take precedence.

See the lcov man page for details.

--erase-functions regexp
Exclude coverage data from lines which fall within a function whose name matches the supplied
regexp. Note that this is a mangled or demangled name, depending on whether the --demangle-cpp
option is used or not.

Note that this option requires that you use a gcc version which is new enough to support function
begin/end line reports.

--substitute regexp_pattern
Apply Perl regexp regexp_pattern to source file names found during processing. This is useful
when the path name reported by gcov does not match your source layout and the file is not found.
See the lcov man page for more details.

--omit-lines regexp
Exclude coverage data from lines whose content matches regexp.

Use this switch if you want to exclude line and branch coverage data for some particular
constructs in your code (e.g., some complicated macro). See the lcov man page for details.

--forget-test-names
If non-zero, ignore testcase names in tracefile - i.e., treat all coverage data as if it came from
the same testcase. This may improve performance and reduce memory consumption if user does not
need per-testcase coverage summary in coverage reports.

This option can also be configured permanently using the configuration file option
forget_testcase_names.

--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 geninfo should
continue processing instead of aborting. Note that the tool will generate a warning (rather than
a fatal error) unless you ignore the error two (or more) times:
geninfo ... --ignore-errors unused,unused

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

branch: branch ID (2nd field in the .info file 'BRDA' entry) does not follow expected integer
sequence.

callback: Version script error.

corrupt: corrupt/unreadable file found.

count: An excessive number of messages of some class have been reported - subsequent messages of
that type will be suppressed. The limit can be controlled by the 'max_message_count' variable.
See the lcovrc man page.

deprecated: You are using a deprecated option. This option will be removed in an upcoming release
- so you should change your scripts now.

empty: the .info data file is empty (e.g., because all the code was 'removed' or excluded.

format: unexpected syntax found in .info file.

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

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

mismatch: Inconsistent entries found in trace file:

• branch expression (3rd field in the .info file 'BRDA' entry) of merge data does not match, or

• function execution count (FNDA:...) but no function declaration (FN:...).

negative: negative 'hit' count found.

Note that negative counts may be caused by a known GCC bug - see

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68080

and try compiling with "-fprofile-update=atomic". You will need to recompile, re-run your tests,
and re-capture coverage data.

package: a required perl package is not installed on your system. In some cases, it is possible
to ignore this message and continue - however, certain features will be disabled in that case.

parallel: various types of errors related to parallelism - e.g., child process died due to some
error. If you see an error related to parallel execution, it may be a good idea to remove the
--parallel flag and try again.

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

unsupported: the requested feature is not supported for this tool configuration. For example,
function begin/end line range exclusions use some GCOV features that are not available in older
GCC releases.

unused: the include/exclude/erase/omit/substitute pattern did not match any file pathnames.

version: revision control IDs of the file which we are trying to merge are not the same - line
numbering and other information may be incorrect.

Also see man lcovrc for a discussion of the 'max_message_count' parameter which can be used to
control the number of warnings which are emitted before all subsequent messages are suppressed.
This can be used to reduce log file volume.

--keep-going
Do not stop if error occurs: attempt to generate a result, however flawed.

This command line option corresponds to the stop_on_error [0|1] lcovrc option. See the lcovrc
man page for more details.

--preserve
Preserve intermediate data files (e.g., for debugging).

By default, intermediate files are deleted.

--filter filters
Specify a list of coverpoint filters to apply to input data. See the genhtml man page for
details.

--demangle-cpp [param]
Demangle C++ method and function names in captured output. See the genhtml man page for details.

-i
--initial
Capture initial zero coverage data.

Run geninfo with 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 and function. 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 object code files were loaded during the test.

Note: currently, the --initial option does not generate branch coverage information.

--no-markers
Use this option if you want to get coverage data without regard to exclusion markers in the source
code file.

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

-o output-filename
--output-filename output-filename
Write all data to output-filename.

If you want to have all data written to a single file (for easier handling), use this option to
specify the respective filename. By default, one tracefile will be created for each processed
.gcda file.

--version-script script
Use script to get a source file's version ID from revision control when extracting data. The ID is
used for error checking when merging .info files.

See the genhtml man page for more details on the version script.

-v
--verbose
Increment informational message verbosity. This is mainly used for script and/or flow debugging -
e.g., to figure out which data file are found, where. Also see the --quiet flag.

Messages are sent to stdout unless there is no output file (i.e., if the coverage data is written
to stdout rather than to a file) and to stderr otherwise.

-q
--quiet
Decrement informational message verbosity.

Decreased verbosity will suppress 'progress' messages for example - while error and warning
messages will continue to be printed.

--debug
Increment 'debug messages' verbosity. This is useful primarily to developers who want to enhance
the lcov tool suite.

--parallel [ integer ]
-j [ integer ]
Specify parallelism to use during processing (maximum number of forked child processes). If the
optional integer parallelism parameter is zero or is missing, then use to use up the number of
cores on the machine. Default is not to use a single process (no parallelism).

--memory integer
Specify the maximum amount of memory to use during parallel processing, in Mb. Effectively, the
process will not fork() if this limit would be exceeded. Default is 0 (zero) - which means that
there is no limit.

This option may be useful if the compute farm environment imposes strict limits on resource
utilization such that the job will be killed if it tries to use too many parallel children - but
the user does now know a priori what the permissible maximum is. This option enables the tool to
use maximum parallelism - up to the limit imposed by the memory restriction.

--rc keyword=value
Override a configuration directive.

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.

-t testname
--test-name testname
Use test case name testname for resulting data. Valid test case names can consist of letters,
decimal digits and the underscore character ('_').

This proves useful when data from several test cases is merged (i.e. by simply concatenating the
respective tracefiles) in which case a test name can be used to differentiate between data from
each test case.

--version
Print version number, then exit.

--tempdir dirname
Write temporary and intermediate data to indicated directory. Default is "/tmp".

TRACEFILE FORMAT

       Following is a quick description of the tracefile format as used by genhtml, geninfo and lcov.

       A  tracefile  is  made up of several human-readable lines of text, divided into sections. If available, a
       tracefile begins with the testname which is stored in the following format:

         TN:<test name>

       For each source file referenced in the .gcda file, there is a section containing  filename  and  coverage
       data:

         SF:<absolute path to the source file>

       An optional source code version ID follows:

         VER:<version ID>

       If  present,  the  version ID is compared before file entries are merged (see lcov --add-tracefile ), and
       before the 'source detail' view is  generated  by  genhtml.   See  the  --version-script  callback_script
       documentation and the sample usage in the lcov regression test examples.

       Following is a list of line numbers for each function name found in the source file:

         FN:<line number of function start>,(<line number of function end>,)?<function name>

       The  'end'  line  number  is  optional, and is generated only if the compiler/toolchain version is recent
       enough to generate the data (e.g., gcc 9 or newer).  This data is used to support  the  --erase-functions
       and --show-proportions options.  If the function end line data is not available, then these features will
       not work.

       Next, there is a list of execution counts for each instrumented function:

         FNDA:<execution count>,<function name>

       This list is followed by two lines containing the number of functions found and hit:

         FNF:<number of functions found>
         FNH:<number of function hit>

       Branch coverage information is stored which one line per branch:

         BRDA:<exception tag><line number>,<block number>,<branch number>,<taken>

       Block  number  and  branch  number  are gcc internal IDs for the branch. Taken is either '-' if the basic
       block containing the branch was never executed or a number indicating how often that  branch  was  taken.
       'exception  tag'  is  'e'  if  this is a branch related to exception handling - and is not present if the
       branch is not related to exceptions.

       Branch coverage summaries are stored in two lines:

         BRF:<number of branches found>
         BRH:<number of branches hit>

       Then there is a list of execution counts for each instrumented  line  (i.e.  a  line  which  resulted  in
       executable code):

         DA:<line number>,<execution count>[,<checksum>]

       Note  that  there  may  be  an  optional checksum present for each instrumented line. The current geninfo
       implementation uses an MD5 hash as checksumming algorithm.

       At the end of a section, there is a summary about how many lines were found and how  many  were  actually
       instrumented:

         LH:<number of lines with a non-zero execution count>
         LF:<number of instrumented lines>

       Each sections ends with:

         end_of_record

       In  addition  to  the main source code file there are sections for all #included files which also contain
       executable code.

       Note that the absolute path of a source file is generated by interpreting the contents of the  respective
       .gcno  file  (see  gcov (1) for more information on this file type). Relative filenames are prefixed with
       the directory in which the .gcno file is found.

       Note also that symbolic links to the .gcno file will be resolved so that the actual  file  path  is  used
       instead  of  the path to a link. This approach is necessary for the mechanism to work with the /proc/gcov
       files.

FILES

       /etc/lcovrc
              The system-wide configuration file.

       ~/.lcovrc
              The per-user configuration file.

       /usr/share/lcov/support-scripts/getp4version
              Sample script for use with --version-script that obtains version IDs via Perforce.

       /usr/share/lcov/support-scripts/get_signature
              Sample script for use with --version-script that uses md5hash as version IDs.

AUTHOR

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

       Henry Cox <henry.cox@mediatek.com>
              Filtering, error management, parallel execution sections.