Home | History | Annotate | Download | only in CommandGuide
      1 llvm-cov - emit coverage information
      2 ====================================
      3 
      4 SYNOPSIS
      5 --------
      6 
      7 :program:`llvm-cov` *command* [*args...*]
      8 
      9 DESCRIPTION
     10 -----------
     11 
     12 The :program:`llvm-cov` tool shows code coverage information for
     13 programs that are instrumented to emit profile data. It can be used to
     14 work with ``gcov``\-style coverage or with ``clang``\'s instrumentation
     15 based profiling.
     16 
     17 If the program is invoked with a base name of ``gcov``, it will behave as if
     18 the :program:`llvm-cov gcov` command were called. Otherwise, a command should
     19 be provided.
     20 
     21 COMMANDS
     22 --------
     23 
     24 * :ref:`gcov <llvm-cov-gcov>`
     25 * :ref:`show <llvm-cov-show>`
     26 * :ref:`report <llvm-cov-report>`
     27 
     28 .. program:: llvm-cov gcov
     29 
     30 .. _llvm-cov-gcov:
     31 
     32 GCOV COMMAND
     33 ------------
     34 
     35 SYNOPSIS
     36 ^^^^^^^^
     37 
     38 :program:`llvm-cov gcov` [*options*] *SOURCEFILE*
     39 
     40 DESCRIPTION
     41 ^^^^^^^^^^^
     42 
     43 The :program:`llvm-cov gcov` tool reads code coverage data files and displays
     44 the coverage information for a specified source file. It is compatible with the
     45 ``gcov`` tool from version 4.2 of ``GCC`` and may also be compatible with some
     46 later versions of ``gcov``.
     47 
     48 To use :program:`llvm-cov gcov`, you must first build an instrumented version
     49 of your application that collects coverage data as it runs. Compile with the
     50 ``-fprofile-arcs`` and ``-ftest-coverage`` options to add the
     51 instrumentation. (Alternatively, you can use the ``--coverage`` option, which
     52 includes both of those other options.) You should compile with debugging
     53 information (``-g``) and without optimization (``-O0``); otherwise, the
     54 coverage data cannot be accurately mapped back to the source code.
     55 
     56 At the time you compile the instrumented code, a ``.gcno`` data file will be
     57 generated for each object file. These ``.gcno`` files contain half of the
     58 coverage data. The other half of the data comes from ``.gcda`` files that are
     59 generated when you run the instrumented program, with a separate ``.gcda``
     60 file for each object file. Each time you run the program, the execution counts
     61 are summed into any existing ``.gcda`` files, so be sure to remove any old
     62 files if you do not want their contents to be included.
     63 
     64 By default, the ``.gcda`` files are written into the same directory as the
     65 object files, but you can override that by setting the ``GCOV_PREFIX`` and
     66 ``GCOV_PREFIX_STRIP`` environment variables. The ``GCOV_PREFIX_STRIP``
     67 variable specifies a number of directory components to be removed from the
     68 start of the absolute path to the object file directory. After stripping those
     69 directories, the prefix from the ``GCOV_PREFIX`` variable is added. These
     70 environment variables allow you to run the instrumented program on a machine
     71 where the original object file directories are not accessible, but you will
     72 then need to copy the ``.gcda`` files back to the object file directories
     73 where :program:`llvm-cov gcov` expects to find them.
     74 
     75 Once you have generated the coverage data files, run :program:`llvm-cov gcov`
     76 for each main source file where you want to examine the coverage results. This
     77 should be run from the same directory where you previously ran the
     78 compiler. The results for the specified source file are written to a file named
     79 by appending a ``.gcov`` suffix. A separate output file is also created for
     80 each file included by the main source file, also with a ``.gcov`` suffix added.
     81 
     82 The basic content of an ``.gcov`` output file is a copy of the source file with
     83 an execution count and line number prepended to every line. The execution
     84 count is shown as ``-`` if a line does not contain any executable code. If
     85 a line contains code but that code was never executed, the count is displayed
     86 as ``#####``.
     87 
     88 OPTIONS
     89 ^^^^^^^
     90 
     91 .. option:: -a, --all-blocks
     92 
     93  Display all basic blocks. If there are multiple blocks for a single line of
     94  source code, this option causes llvm-cov to show the count for each block
     95  instead of just one count for the entire line.
     96 
     97 .. option:: -b, --branch-probabilities
     98 
     99  Display conditional branch probabilities and a summary of branch information.
    100 
    101 .. option:: -c, --branch-counts
    102 
    103  Display branch counts instead of probabilities (requires -b).
    104 
    105 .. option:: -f, --function-summaries
    106 
    107  Show a summary of coverage for each function instead of just one summary for
    108  an entire source file.
    109 
    110 .. option:: --help
    111 
    112  Display available options (--help-hidden for more).
    113 
    114 .. option:: -l, --long-file-names
    115 
    116  For coverage output of files included from the main source file, add the
    117  main file name followed by ``##`` as a prefix to the output file names. This
    118  can be combined with the --preserve-paths option to use complete paths for
    119  both the main file and the included file.
    120 
    121 .. option:: -n, --no-output
    122 
    123  Do not output any ``.gcov`` files. Summary information is still
    124  displayed.
    125 
    126 .. option:: -o=<DIR|FILE>, --object-directory=<DIR>, --object-file=<FILE>
    127 
    128  Find objects in DIR or based on FILE's path. If you specify a particular
    129  object file, the coverage data files are expected to have the same base name
    130  with ``.gcno`` and ``.gcda`` extensions. If you specify a directory, the
    131  files are expected in that directory with the same base name as the source
    132  file.
    133 
    134 .. option:: -p, --preserve-paths
    135 
    136  Preserve path components when naming the coverage output files. In addition
    137  to the source file name, include the directories from the path to that
    138  file. The directories are separate by ``#`` characters, with ``.`` directories
    139  removed and ``..`` directories replaced by ``^`` characters. When used with
    140  the --long-file-names option, this applies to both the main file name and the
    141  included file name.
    142 
    143 .. option:: -u, --unconditional-branches
    144 
    145  Include unconditional branches in the output for the --branch-probabilities
    146  option.
    147 
    148 .. option:: -version
    149 
    150  Display the version of llvm-cov.
    151 
    152 EXIT STATUS
    153 ^^^^^^^^^^^
    154 
    155 :program:`llvm-cov gcov` returns 1 if it cannot read input files.  Otherwise,
    156 it exits with zero.
    157 
    158 
    159 .. program:: llvm-cov show
    160 
    161 .. _llvm-cov-show:
    162 
    163 SHOW COMMAND
    164 ------------
    165 
    166 SYNOPSIS
    167 ^^^^^^^^
    168 
    169 :program:`llvm-cov show` [*options*] -instr-profile *PROFILE* *BIN* [*SOURCES*]
    170 
    171 DESCRIPTION
    172 ^^^^^^^^^^^
    173 
    174 The :program:`llvm-cov show` command shows line by line coverage of a binary
    175 *BIN* using the profile data *PROFILE*. It can optionally be filtered to only
    176 show the coverage for the files listed in *SOURCES*.
    177 
    178 To use :program:`llvm-cov show`, you need a program that is compiled with
    179 instrumentation to emit profile and coverage data. To build such a program with
    180 ``clang`` use the ``-fprofile-instr-generate`` and ``-fcoverage-mapping``
    181 flags. If linking with the ``clang`` driver, pass ``-fprofile-instr-generate``
    182 to the link stage to make sure the necessary runtime libraries are linked in.
    183 
    184 The coverage information is stored in the built executable or library itself,
    185 and this is what you should pass to :program:`llvm-cov show` as the *BIN*
    186 argument. The profile data is generated by running this instrumented program
    187 normally. When the program exits it will write out a raw profile file,
    188 typically called ``default.profraw``, which can be converted to a format that
    189 is suitable for the *PROFILE* argument using the :program:`llvm-profdata merge`
    190 tool.
    191 
    192 OPTIONS
    193 ^^^^^^^
    194 
    195 .. option:: -show-line-counts
    196 
    197  Show the execution counts for each line. This is enabled by default, unless
    198  another ``-show`` option is used.
    199 
    200 .. option:: -show-expansions
    201 
    202  Expand inclusions, such as preprocessor macros or textual inclusions, inline
    203  in the display of the source file.
    204 
    205 .. option:: -show-instantiations
    206 
    207  For source regions that are instantiated multiple times, such as templates in
    208  ``C++``, show each instantiation separately as well as the combined summary.
    209 
    210 .. option:: -show-regions
    211 
    212  Show the execution counts for each region by displaying a caret that points to
    213  the character where the region starts.
    214 
    215 .. option:: -show-line-counts-or-regions
    216 
    217  Show the execution counts for each line if there is only one region on the
    218  line, but show the individual regions if there are multiple on the line.
    219 
    220 .. option:: -use-color[=VALUE]
    221 
    222  Enable or disable color output. By default this is autodetected.
    223 
    224 .. option:: -arch=<name>
    225 
    226  If the covered binary is a universal binary, select the architecture to use.
    227  It is an error to specify an architecture that is not included in the
    228  universal binary or to use an architecture that does not match a
    229  non-universal binary.
    230 
    231 .. option:: -name=<NAME>
    232 
    233  Show code coverage only for functions with the given name.
    234 
    235 .. option:: -name-regex=<PATTERN>
    236 
    237  Show code coverage only for functions that match the given regular expression.
    238 
    239 .. option:: -format=<FORMAT>
    240 
    241  Use the specified output format. The supported formats are: "text", "html".
    242 
    243 .. option:: -output-dir=PATH
    244 
    245  Specify a directory to write coverage reports into. If the directory does not
    246  exist, it is created. When used in function view mode (i.e when -name or
    247  -name-regex are used to select specific functions), the report is written to
    248  PATH/functions.EXTENSION. When used in file view mode, a report for each file
    249  is written to PATH/REL_PATH_TO_FILE.EXTENSION.
    250 
    251 .. option:: -line-coverage-gt=<N>
    252 
    253  Show code coverage only for functions with line coverage greater than the
    254  given threshold.
    255 
    256 .. option:: -line-coverage-lt=<N>
    257 
    258  Show code coverage only for functions with line coverage less than the given
    259  threshold.
    260 
    261 .. option:: -region-coverage-gt=<N>
    262 
    263  Show code coverage only for functions with region coverage greater than the
    264  given threshold.
    265 
    266 .. option:: -region-coverage-lt=<N>
    267 
    268  Show code coverage only for functions with region coverage less than the given
    269  threshold.
    270 
    271 .. program:: llvm-cov report
    272 
    273 .. _llvm-cov-report:
    274 
    275 REPORT COMMAND
    276 --------------
    277 
    278 SYNOPSIS
    279 ^^^^^^^^
    280 
    281 :program:`llvm-cov report` [*options*] -instr-profile *PROFILE* *BIN* [*SOURCES*]
    282 
    283 DESCRIPTION
    284 ^^^^^^^^^^^
    285 
    286 The :program:`llvm-cov report` command displays a summary of the coverage of a
    287 binary *BIN* using the profile data *PROFILE*. It can optionally be filtered to
    288 only show the coverage for the files listed in *SOURCES*.
    289 
    290 If no source files are provided, a summary line is printed for each file in the
    291 coverage data. If any files are provided, summaries are shown for each function
    292 in the listed files instead.
    293 
    294 For information on compiling programs for coverage and generating profile data,
    295 see :ref:`llvm-cov-show`.
    296 
    297 OPTIONS
    298 ^^^^^^^
    299 
    300 .. option:: -use-color[=VALUE]
    301 
    302  Enable or disable color output. By default this is autodetected.
    303 
    304 .. option:: -arch=<name>
    305 
    306  If the covered binary is a universal binary, select the architecture to use.
    307  It is an error to specify an architecture that is not included in the
    308  universal binary or to use an architecture that does not match a
    309  non-universal binary.
    310