oracular (1) lcov.1.gz

Provided by: lcov_2.1~beta2-1_all bug

NAME

       lcov - a graphical GCOV front-end

SYNOPSIS

       Capture coverage data tracefile (from compiler-generated data):

          lcov -c|--capture
              [-d|--directory directory] [-k|--kernel-directory directory]
              [-o|--output-file tracefile] [-t|--test-name testname]
              [-b|--base-directory directory]
              [--build-directory directory]
              [--source-directory directory]
              [-i|--initial]
              [--all]]
              [--gcov-tool tool]
              [--branch-coverage]
              [--demangle-cpp [param]]
              [--checksum] [--no-checksum] [--no-recursion] [-f|--follow]
              [--compat-libtool] [--no-compat-libtool]
              [--ignore-errors errors]
              [--preserve]   [--to-package   package]   [--from-package   package]  [--no-markers]  [--external]
              [--no-external]
              [--compat mode=on|off|auto]
              [--version-script script_file]
              [--resolv--script script_file]
              [--comment comment_string]

       Generate tracefile (from compiler-generated data) with all counter values set to zero:

          lcov -z|--zerocounters
              [-d|--directory directory] [--no-recursion] [-f|--follow]

       Show coverage counts recorded in previously generated tracefile:

          lcov -l|--list tracefile
              [--list-full-path] [--no-list-full-path]

       Aggregate multiple coverage tracefiles into one:

          lcov -a|--add-tracefile tracefile_pattern
              [-o|--output-file tracefile]
              [--prune-tests]
              [--forget-test-names]
              [--map-functions]
              [--branch-coverage]
              [--checksum] [--no-checksum]

          Depending on your use model, it may not be necessary to create aggregate  coverage  data  files.   For
          example,  if your regression tests are split into multiple suites, you may want to keep separate suite
          data and to compare both per-suite and aggregate  results  over  time.   genhtml  allows  you  specify
          tracefiles  via  one  or  more  glob  patterns  - which enables you generate aggregate reports without
          explicitly generating aggregated trace files.  See the genhtml man page.

       Generate new tracefile from existing tracefile, keeping only data from files matching pattern:

          lcov -e|--extract tracefile pattern
              [-o|--output-file tracefile] [--checksum] [--no-checksum]

       Generate new tracefile from existing tracefile, removing data from files matching pattern:

          lcov -r|--remove tracefile pattern
              [-o|--output-file tracefile] [--checksum] [--no-checksum]

       Generate new tracefile from existing tracefiles by performing set operations on coverage data:

          lcov --intersect rh_glob_pattern
              [-o|--output-file tracefile]
              lh_glob_pattern

              The output will reflect
                (union of files matching lh_glob_patterns) intersect (union of files matching rh_glob_patterns)
              such that coverpoints found in both sets are merged (summed) whereas coverpoints found in only one
              set are dropped.  Note that branch blocks are defined to be the same if and only if their block ID
              and the associated branch expressions list are identical.  Functions are defined to be the same if
              their name and location are identical.

          lcov --subtract rh_glob_pattern
              [-o|--output-file tracefile]
              lh_glob_pattern

              The output will reflect
                (union of files matching lh_glob_patterns) subtract (union of files matching rh_glob_patterns)
              such  that  coverpoints  found  only  in  the  set on the left will be retained and all others are
              dropped.

       Generate new tracefile from existing tracefile, modifying line numbers as indicated in diff file:

          lcov --diff tracefile diff
              [-o|--output-file tracefile] [--checksum] [--no-checksum]
              [--convert-filenames] [--strip depth] [--path path]

       Summarize tracefile content:

          lcov --summary tracefile
              [--fail-under-lines percentage]

       Print version or help message and exit:

          lcov [-h|--help] [--version]

       Common lcov options - supported by all the above use cases:

          lcov [--keep-going]
               [--filter type]
               [-q|--quiet]
               [-v|--verbose]
               [--comment comment_string]
               [--debug]
               [--parallel|-j [integer]]
               [--memory integer_num_Mb]
               [--tempdir dirname]
               [--branch-coverage]
               [--config-file config-file] [--rc keyword=value]
               [--include glob_pattern]
               [--exclude glob_pattern]
               [--erase-functions regexp_pattern]
               [--substitute regexp_pattern]
               [--omit-lines regexp_pattern]

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:  https://docs.kernel.org/dev-
              tools/gcov.html

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

       Also note that when printing percentages, 0% and 100% are only printed when the values are exactly 0% and
       100% respectively. Other values which would conventionally be rounded to 0% or 100% are  instead  printed
       as nearest non-boundary value. This behavior is in accordance with that of the gcov(1) tool.

       By  default, lcov and related tools generate and collect line and function coverage data.  Branch data is
       not collected or displayed by default; all tools support the --branch-coverage option  to  enable  branch
       coverage  -  or  you  can  permanently  enable branch coverage by adding the appropriate settings to your
       personal, group, or site lcov configuration file.  See man lcovrc(5) for details.

OPTIONS

       -a tracefile_pattern
       --add-tracefile tracefile_pattern
              Add contents of all files matching glob pattern tracefile_pattern.

              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.

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

       --build-directory build_directory
              search for .gcno data files from build_directory rather than adjacent to the  corresponding  .gcda
              file.

              See man geninfo(1)) for details.

       --source-directory dirname
              Add 'dirname' to the list of places to look for source files.

              For  relative  source file paths listed in e.g.  paths found in tracefile, or found in gcov output
              during --capture - possibly after substitutions have been applied - lcov
               will first look for the path from 'cwd' (where genhtml was invoked) and then from each  alternate
              directory name in the order specified.  The first location matching location is used.

              This option can be specified multiple times, to add more directories to the source search path.

       -c
       --capture
              Capture runtime 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.

              When combined with the --all flag, both runtime and compile-time coverage will be extracted in one
              step.  See the description of the --initial flag, below.

              See  man  geninfo(1))  for  more  details  about  the  capture  process  and available options and
              parameters.

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

       --branch-coverage
              Collect and/or retain branch coverage data.

              This is equivalent to using the option "--rc 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 and/or to verify matching
              checksums when combining 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 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 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
                     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 lcov 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, 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.

       --config-file config-file
              Specify a configuration file to use.  See man  lcovrc(5)  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  lcov  with  different
              configuration file options in parallel.

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

       --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, --diff or --summary 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.

       --exclude pattern
              Exclude source files matching pattern.

              Use this switch if you want to exclude coverage data for 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.  If you
              specify a pattern which does not seem to be correctly applied - files  that  you  expected  to  be
              excluded  still  appear  in  the output - you can look for warning messages in the log file.  lcov
              will emit a warning for every pattern which is not applied at least once.

              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.

       --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 or that you configure the tool  to  derive  the  required  dta  -  see  the
              derive_function_end_line discussion in man lcovrc(5).

       --substitute regexp_pattern
              Apply  Perl  regexp  regexp_pattern to source file names found during processing.  This is useful,
              for example, when the path name reported by gcov does not match your source layout and the file is
              not  found, or in more complicated environments where the build directory structure does not match
              the source code layout or the layout in the projects's revision control system.

              Use this option in situations where geninfo cannot find the correct path to source code files of a
              project. By providing a regexp_pattern in Perl regular expression format (see man perlre(1) ), you
              can instruct geninfo to remove or change parts  of  the  incorrect  source  path.   Also  see  the
              --resolve-script option.

              One  or  more  --substitution  patterns and/or a --resolve-script may be specified.  When multiple
              paterns are specified, they are  applied  in  the  order  specifed,  substitution  patterns  first
              followed by the resolve callback.  The file search order is:

                     1. Look for file name (unmodifed).
                        If the file exits: return it.

                     2. Apply  all  substitution  patterns in order - the result of the first pattern is used as
                        the input of the second pattern, and so forth.
                        If a file corresponding to the resulting name exists:  return it.

                     3. Apply the 'resolve' callback ot the final result of pattern substituions.
                        If a file corresponding to the resulting name exists:  return it.

                     4. Otherwise:  return original (unmodified) file name.
                        Depending on context, the unresolved file name may or may not result in an error.

              Substitutions are used in multiple contexts by lcov/genhtml/geninfo:

                     -  during --capture, applied to source file names found  in  gcov-generated  coverage  data
                        files (see man gcov(1) ).

                     -  during  --capture,  applied  to  alternate --build-dir paths, when looking for the .gcno
                        (compile time) data file corresponding to some .gcda (runtime) data file.

                     -  applied to file names found in lcov data files (".info" files) - e.g., during lcov  data
                        aggregation or HTML and text report generation.
                        For  example,  substituted  names are used to find source files for text-based filtering
                        (see the --filter section, below) and are passed to --version-script, --annotate-script,
                        and -criteria-script callbacks.

                     -  applied to file names found in the --diff-file passed to genhtml.

              Example:

              1. When geninfo reports that it cannot find source file

                  /path/to/src/.libs/file.c

              while the file is actually located in

                  /path/to/src/file.c

              use the following parameter:

                  --substitute 's#/.libs##g'

              This will remove all "/.libs" strings from the path.

              2. When geninfo reports that it cannot find source file

                  /tmp/build/file.c

              while the file is actually located in

                  /usr/src/file.c

              use the following parameter:

                  --substitute 's#/tmp/build#/usr/src#g'

              This will change all "/tmp/build" strings in the path to "/usr/src".

       --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).  Multiple patterns  can  be  specified  by
              using  multiple --omit-lines command line switches. The regexp will be interpreted as perl regular
              expressions (note that they may need to be escaped accordingly to prevent the shell from expanding
              them  first).  If you want the pattern to explicitly match from the start or end of the line, your
              regexp should start and/or end with "^" and/or "$".

              Note that the lcovrc config file setting lcov_excl_line  =  regexp  is  similar  to  --omit-lines.
              --omit-lines is useful if there are multiple teams each of which want to exclude certain patterns.
              --omit-lines is additive and can be specified across multiple config files whereas  each  call  to
              lcov_excl_line overrides the previous value - and thus teams must coordinate.

       --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.

       --forget-test-names
              If  non-zero,  ignore  testcase  names in .info file - 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.

       --prune-tests
              Determine list of unique tracefiles.

              Use  this  option  to  determine  a  list  of  unique  tracefiles  from  the  list  specified   by
              --add-tracefile.  A tracefile is considered to be unique if it is the only tracefile that:

                     1. contains data for a specific source file

                     2. contains data for a specific test case name

                     3. contains non-zero coverage data for a specific line, function or branch

              Note  that the list of retained files may depend on the order they are processed.  For example, if
              A and B contain identical coverage data, then the first one we see will be retained and the second
              will  be pruned.  The file processing order is nondeterministic when the --parallel option is used
              - implying that the pruned result may differ from one execution to the next in this case.

              --prune-testsmustbespecifiedtogetherwith --add-tracefile.  When specified, lcov will emit the list
              of unique files rather than combined tracefile data.

       --map-functions
              List tracefiles with non-zero coverage for each function.

              Use  this  option to determine the list of tracefiles that contain non-zero coverage data for each
              function from the list of tracefiles specified by --add-tracefile.

              This option must be specified together with --add-tracefile.  When specified, lcov will  emit  the
              list of functions and associated tracefiles rather than combined tracefile data.

       --version-script script

              Use  script  to  get  a source file's version ID from revision control when extracting data and to
              compare version IDs for the purpose of error checking when merging .info files.

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

       --resolve-script script
              Use script to find the file path for some source file which appears in an input data file  if  the
              file  is not found after applying --substitute patterns and searching the --source-directory list.
              This option is equivalent to the resolve_script config file option. See man lcovrc(5) for details.

       --comment comment_string

              Append comment_string to list of comments emitted into output result file.   This  option  may  be
              specified  multiple  times.   Comments  are printed at the top of the file, in the order they were
              specified.

              Comments may be useful to document the conditions under which the trace file was generated:  host,
              date, environment, etc.

              Note  that this option has no effect for lcov overations which do not write an output result file:
              --list --summary, --prune-tests, and --map-functions.

              See the geninfo man page for a description of the comment format in the result file.

       -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.

              Note: The pattern must be specified to match the absolute path of each source file.

              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.

       -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.

              See the geninfo man page for more details.

       -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).

              Note: The pattern must be specified to match the absolute path of each source file.

              If  you specify a pattern which does not seem to be correctly applied - files that you expected to
              be included in the output do not appear - lcov will generate an error message  of  type  'unused'.
              See the --ignore-errors option for how to make lcov ignore the error or turn it into a warning.

       --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.  Note that the tool will generate a warning (rather  than
              a fatal error) unless you ignore the error two (or more) times:
                     lcov ... --ignore-errors source,source ...

              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.

              child:
                 child  process  returned  non-zero  exit  code  during  --parallel  execution.   This typically
                 indicates that the child encountered an  error:   see  the  log  file  immediately  above  this
                 message.   In  contrast:  the parallel error indicates an unexpected/unhandled exception in the
                 child process - not a 'typical' lcov 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
                 man lcovrc(5).

              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.

              excessive:
                 your  coverage data contains a suspiciously large 'hit' count which is unlikely to be correct -
                 possibly indicating a bug in your toolchain.  See the excessive_count_threshold section in  man
                 lcovrc(5) for details.

              fork:
                 Unable to create child process during --parallel execution.
                 If  the  message is ignored ( --ignore-errors fork ), then genhtml will wait a brief period and
                 then retry the failed execution.
                 If you see continued errors, either turn off or reduce parallelism, set a memory limit, or find
                 a larger server to run the task.

              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.

              internal:
                 internal tool issue detected.  Please report this bug along with a testcase.

              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:...).

              missing:
                 File does not exist or is not readable.

              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 - i.e., a child process died due  to  an  error.
                 The corresponding error message appears in the log file immediately before the parallel error.

                 If  you see an error related to parallel execution that seems invalid, it may be a good idea to
                 remove the --parallel flag and try again.  If removing the flag leads to  a  different  result,
                 please report the issue (along with a testcase) so that the tool can be fixed.

              parent:
                 the  parent  process  exited  while child was active during --parallel execution.  This happens
                 when the parent has encountered a fatal error - e.g.  an error in some other  child  which  was
                 not ignored.  This child cannot continue working without its parent - and so will exit.

              range:
                 Coverage  data  refers  to a line number which is larger than the number of lines in the source
                 file.  This can be caused by a version mismatch or by an issue in the gcov data.

              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.

              usage:
                 unsupported usage detected - e.g. an unsupported option combination.

              utility:
                 a tool called during processing returned an error code (e.g., 'find' encountered an  unreadable
                 directory).

              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(5) 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 man  lcovrc(5)
              for more details.

       --preserve
              Preserve intermediate data files generated by various steps in the tool - e.g., for debugging.  By
              default, these 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++ function names.  See the genhtml man page for details.

       -i
       --initial
              Capture initial zero coverage data - i.e., from the compile-time '.gcno' data files.  Also see the
              --all flag, which tells the tool to capture both compile-time ('.gcno') and runtime ('.gcda') data
              at the same time.

              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

              The above 4 steps are equivalent to
                     # lcov --capture --all -o app_total.info -d appdir

              The combined compile- and runtime data will produce a different result than capturing runtime data
              alone if your project contains some compilation units which are not used in any of  your  testcase
              executables  or  shared libraries - that is, there are some '.gcno' (compile time) data files that
              do not have matching '.gcda' (runtime) data files.  In that case, the runtime-only report will not
              contain  any  coverpoints  from  the unused files, whereas those coverpoints will appear (with all
              zero 'hit' counts) in the combined report.

              The --initial flag is ignored except in  --capture  mode.   The  --all  flag  is  ignored  if  the
              --initial flag is specified.

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

       --list-full-path
       --no-list-full-path
              Specify whether to show full paths during list operation.

              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.

       --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.

       -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).
              Also see the memory,  memory_percentage,  max_fork_fails  and  fork_fail_timeout  entries  in  man
              lcovrc(5).

       --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.

              The configuration file memory_percentage option provided another way to  set  the  maximum  memory
              consumption.  See man lcovrc(5) for details.

       --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 man lcovrc(5) for a list of available
              keywords and their meaning.

       -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.

              Note: The pattern must be specified to match the absolute path of each source file.

              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.

       --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.

       --summary tracefile
              Show summary coverage information for the specified tracefile.

              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.

       --fail-under-lines percentage
              Use this option together with --summary to tell lcov to exit with a status of 1 if the total  line
              coverage is less than percentage.

       -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.

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

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

FILES

       /etc/lcovrc
              The system-wide configuration file.

       ~/.lcovrc
              The per-user configuration file.

AUTHOR

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

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

SEE ALSO

       lcovrc(5), genhtml(1), geninfo(1), genpng(1), gendesc(1), gcov(1)

       https://github.com/linux-test-project/lcov