1llvm-cov - emit coverage information
2====================================
3
4SYNOPSIS
5--------
6
7:program:`llvm-cov` *command* [*args...*]
8
9DESCRIPTION
10-----------
11
12The :program:`llvm-cov` tool shows code coverage information for
13programs that are instrumented to emit profile data. It can be used to
14work with ``gcov``\-style coverage or with ``clang``\'s instrumentation
15based profiling.
16
17If the program is invoked with a base name of ``gcov``, it will behave as if
18the :program:`llvm-cov gcov` command were called. Otherwise, a command should
19be provided.
20
21COMMANDS
22--------
23
24* :ref:`gcov <llvm-cov-gcov>`
25* :ref:`show <llvm-cov-show>`
26* :ref:`report <llvm-cov-report>`
27* :ref:`export <llvm-cov-export>`
28
29.. program:: llvm-cov gcov
30
31.. _llvm-cov-gcov:
32
33GCOV COMMAND
34------------
35
36SYNOPSIS
37^^^^^^^^
38
39:program:`llvm-cov gcov` [*options*] *SOURCEFILE*
40
41DESCRIPTION
42^^^^^^^^^^^
43
44The :program:`llvm-cov gcov` tool reads code coverage data files and displays
45the coverage information for a specified source file. It is compatible with the
46``gcov`` tool from version 4.2 of ``GCC`` and may also be compatible with some
47later versions of ``gcov``.
48
49To use :program:`llvm-cov gcov`, you must first build an instrumented version
50of your application that collects coverage data as it runs. Compile with the
51``-fprofile-arcs`` and ``-ftest-coverage`` options to add the
52instrumentation. (Alternatively, you can use the ``--coverage`` option, which
53includes both of those other options.) You should compile with debugging
54information (``-g``) and without optimization (``-O0``); otherwise, the
55coverage data cannot be accurately mapped back to the source code.
56
57At the time you compile the instrumented code, a ``.gcno`` data file will be
58generated for each object file. These ``.gcno`` files contain half of the
59coverage data. The other half of the data comes from ``.gcda`` files that are
60generated when you run the instrumented program, with a separate ``.gcda``
61file for each object file. Each time you run the program, the execution counts
62are summed into any existing ``.gcda`` files, so be sure to remove any old
63files if you do not want their contents to be included.
64
65By default, the ``.gcda`` files are written into the same directory as the
66object files, but you can override that by setting the ``GCOV_PREFIX`` and
67``GCOV_PREFIX_STRIP`` environment variables. The ``GCOV_PREFIX_STRIP``
68variable specifies a number of directory components to be removed from the
69start of the absolute path to the object file directory. After stripping those
70directories, the prefix from the ``GCOV_PREFIX`` variable is added. These
71environment variables allow you to run the instrumented program on a machine
72where the original object file directories are not accessible, but you will
73then need to copy the ``.gcda`` files back to the object file directories
74where :program:`llvm-cov gcov` expects to find them.
75
76Once you have generated the coverage data files, run :program:`llvm-cov gcov`
77for each main source file where you want to examine the coverage results. This
78should be run from the same directory where you previously ran the
79compiler. The results for the specified source file are written to a file named
80by appending a ``.gcov`` suffix. A separate output file is also created for
81each file included by the main source file, also with a ``.gcov`` suffix added.
82
83The basic content of an ``.gcov`` output file is a copy of the source file with
84an execution count and line number prepended to every line. The execution
85count is shown as ``-`` if a line does not contain any executable code. If
86a line contains code but that code was never executed, the count is displayed
87as ``#####``.
88
89OPTIONS
90^^^^^^^
91
92.. option:: -a, --all-blocks
93
94 Display all basic blocks. If there are multiple blocks for a single line of
95 source code, this option causes llvm-cov to show the count for each block
96 instead of just one count for the entire line.
97
98.. option:: -b, --branch-probabilities
99
100 Display conditional branch probabilities and a summary of branch information.
101
102.. option:: -c, --branch-counts
103
104 Display branch counts instead of probabilities (requires -b).
105
106.. option:: -f, --function-summaries
107
108 Show a summary of coverage for each function instead of just one summary for
109 an entire source file.
110
111.. option:: --help
112
113 Display available options (--help-hidden for more).
114
115.. option:: -l, --long-file-names
116
117 For coverage output of files included from the main source file, add the
118 main file name followed by ``##`` as a prefix to the output file names. This
119 can be combined with the --preserve-paths option to use complete paths for
120 both the main file and the included file.
121
122.. option:: -n, --no-output
123
124 Do not output any ``.gcov`` files. Summary information is still
125 displayed.
126
127.. option:: -o=<DIR|FILE>, --object-directory=<DIR>, --object-file=<FILE>
128
129 Find objects in DIR or based on FILE's path. If you specify a particular
130 object file, the coverage data files are expected to have the same base name
131 with ``.gcno`` and ``.gcda`` extensions. If you specify a directory, the
132 files are expected in that directory with the same base name as the source
133 file.
134
135.. option:: -p, --preserve-paths
136
137 Preserve path components when naming the coverage output files. In addition
138 to the source file name, include the directories from the path to that
139 file. The directories are separate by ``#`` characters, with ``.`` directories
140 removed and ``..`` directories replaced by ``^`` characters. When used with
141 the --long-file-names option, this applies to both the main file name and the
142 included file name.
143
144.. option:: -u, --unconditional-branches
145
146 Include unconditional branches in the output for the --branch-probabilities
147 option.
148
149.. option:: -version
150
151 Display the version of llvm-cov.
152
153EXIT STATUS
154^^^^^^^^^^^
155
156:program:`llvm-cov gcov` returns 1 if it cannot read input files.  Otherwise,
157it exits with zero.
158
159
160.. program:: llvm-cov show
161
162.. _llvm-cov-show:
163
164SHOW COMMAND
165------------
166
167SYNOPSIS
168^^^^^^^^
169
170:program:`llvm-cov show` [*options*] -instr-profile *PROFILE* *BIN* [*-object BIN,...*] [[*-object BIN*]] [*SOURCES*]
171
172DESCRIPTION
173^^^^^^^^^^^
174
175The :program:`llvm-cov show` command shows line by line coverage of the
176binaries *BIN*,...  using the profile data *PROFILE*. It can optionally be
177filtered to only show the coverage for the files listed in *SOURCES*.
178
179To use :program:`llvm-cov show`, you need a program that is compiled with
180instrumentation to emit profile and coverage data. To build such a program with
181``clang`` use the ``-fprofile-instr-generate`` and ``-fcoverage-mapping``
182flags. If linking with the ``clang`` driver, pass ``-fprofile-instr-generate``
183to the link stage to make sure the necessary runtime libraries are linked in.
184
185The coverage information is stored in the built executable or library itself,
186and this is what you should pass to :program:`llvm-cov show` as a *BIN*
187argument. The profile data is generated by running this instrumented program
188normally. When the program exits it will write out a raw profile file,
189typically called ``default.profraw``, which can be converted to a format that
190is suitable for the *PROFILE* argument using the :program:`llvm-profdata merge`
191tool.
192
193OPTIONS
194^^^^^^^
195
196.. option:: -show-line-counts
197
198 Show the execution counts for each line. This is enabled by default, unless
199 another ``-show`` option is used.
200
201.. option:: -show-expansions
202
203 Expand inclusions, such as preprocessor macros or textual inclusions, inline
204 in the display of the source file.
205
206.. option:: -show-instantiations
207
208 For source regions that are instantiated multiple times, such as templates in
209 ``C++``, show each instantiation separately as well as the combined summary.
210
211.. option:: -show-regions
212
213 Show the execution counts for each region by displaying a caret that points to
214 the character where the region starts.
215
216.. option:: -show-line-counts-or-regions
217
218 Show the execution counts for each line if there is only one region on the
219 line, but show the individual regions if there are multiple on the line.
220
221.. option:: -use-color[=VALUE]
222
223 Enable or disable color output. By default this is autodetected.
224
225.. option:: -arch=<name>
226
227 If the covered binary is a universal binary, select the architecture to use.
228 It is an error to specify an architecture that is not included in the
229 universal binary or to use an architecture that does not match a
230 non-universal binary.
231
232.. option:: -name=<NAME>
233
234 Show code coverage only for functions with the given name.
235
236.. option:: -name-regex=<PATTERN>
237
238 Show code coverage only for functions that match the given regular expression.
239
240.. option:: -format=<FORMAT>
241
242 Use the specified output format. The supported formats are: "text", "html".
243
244.. option:: -tab-size=<TABSIZE>
245
246 Replace tabs with <TABSIZE> spaces when preparing reports. Currently, this is
247 only supported for the html format.
248
249.. option:: -output-dir=PATH
250
251 Specify a directory to write coverage reports into. If the directory does not
252 exist, it is created. When used in function view mode (i.e when -name or
253 -name-regex are used to select specific functions), the report is written to
254 PATH/functions.EXTENSION. When used in file view mode, a report for each file
255 is written to PATH/REL_PATH_TO_FILE.EXTENSION.
256
257.. option:: -Xdemangler=<TOOL>|<TOOL-OPTION>
258
259 Specify a symbol demangler. This can be used to make reports more
260 human-readable. This option can be specified multiple times to supply
261 arguments to the demangler (e.g `-Xdemangler c++filt -Xdemangler -n` for C++).
262 The demangler is expected to read a newline-separated list of symbols from
263 stdin and write a newline-separated list of the same length to stdout.
264
265.. option:: -line-coverage-gt=<N>
266
267 Show code coverage only for functions with line coverage greater than the
268 given threshold.
269
270.. option:: -line-coverage-lt=<N>
271
272 Show code coverage only for functions with line coverage less than the given
273 threshold.
274
275.. option:: -region-coverage-gt=<N>
276
277 Show code coverage only for functions with region coverage greater than the
278 given threshold.
279
280.. option:: -region-coverage-lt=<N>
281
282 Show code coverage only for functions with region coverage less than the given
283 threshold.
284
285.. program:: llvm-cov report
286
287.. _llvm-cov-report:
288
289REPORT COMMAND
290--------------
291
292SYNOPSIS
293^^^^^^^^
294
295:program:`llvm-cov report` [*options*] -instr-profile *PROFILE* *BIN* [*-object BIN,...*] [[*-object BIN*]] [*SOURCES*]
296
297DESCRIPTION
298^^^^^^^^^^^
299
300The :program:`llvm-cov report` command displays a summary of the coverage of
301the binaries *BIN*,... using the profile data *PROFILE*. It can optionally be
302filtered to only show the coverage for the files listed in *SOURCES*.
303
304If no source files are provided, a summary line is printed for each file in the
305coverage data. If any files are provided, summaries are shown for each function
306in the listed files instead.
307
308For information on compiling programs for coverage and generating profile data,
309see :ref:`llvm-cov-show`.
310
311OPTIONS
312^^^^^^^
313
314.. option:: -use-color[=VALUE]
315
316 Enable or disable color output. By default this is autodetected.
317
318.. option:: -arch=<name>
319
320 If the covered binary is a universal binary, select the architecture to use.
321 It is an error to specify an architecture that is not included in the
322 universal binary or to use an architecture that does not match a
323 non-universal binary.
324
325.. program:: llvm-cov export
326
327.. _llvm-cov-export:
328
329EXPORT COMMAND
330--------------
331
332SYNOPSIS
333^^^^^^^^
334
335:program:`llvm-cov export` [*options*] -instr-profile *PROFILE* *BIN* [*-object BIN,...*] [[*-object BIN*]]
336
337DESCRIPTION
338^^^^^^^^^^^
339
340The :program:`llvm-cov export` command exports regions, functions, expansions,
341and summaries of the coverage of the binaries *BIN*,... using the profile data
342*PROFILE* as JSON.
343
344For information on compiling programs for coverage and generating profile data,
345see :ref:`llvm-cov-show`.
346
347OPTIONS
348^^^^^^^
349
350.. option:: -arch=<name>
351
352 If the covered binary is a universal binary, select the architecture to use.
353 It is an error to specify an architecture that is not included in the
354 universal binary or to use an architecture that does not match a
355 non-universal binary.
356