1LIT(1) LLVM Command Guide LIT(1)
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6 lit - LLVM Integrated Tester
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9 lit [options] [tests]
10
12 lit is a portable tool for executing LLVM and Clang style test suites,
13 summarizing their results, and providing indication of failures. lit is
14 designed to be a lightweight testing tool with as simple a user
15 interface as possible.
16 lit should be run with one or more tests to run specified on the
18 command line. Tests can be either individual test files or directories
19 to search for tests (see "TEST DISCOVERY").
20 Each specified test will be executed (potentially in parallel) and once
22 all tests have been run lit will print summary information on the
23 number of tests which passed or failed (see "TEST STATUS RESULTS"). The
24 lit program will execute with a non-zero exit code if any tests fail.
25 By default lit will use a succinct progress display and will only print
27 summary information for test failures. See "OUTPUT OPTIONS" for options
28 controlling the lit progress display and output.
29 lit also includes a number of options for controlling how tests are
31 exected (specific features may depend on the particular test format).
32 See "EXECUTION OPTIONS" for more information.
33 Finally, lit also supports additional options for only running a subset
35 of the options specified on the command line, see "SELECTION OPTIONS"
36 for more information.
37 Users interested in the lit architecture or designing a lit testing
39 implementation should see "LIT ARCHITECTURE"
40
42 -h, --help
43 Show the lit help message.
44 -j N, --threads=N
46 Run N tests in parallel. By default, this is automatically chosen
47 to match the number of detected available CPUs.
48 --config-prefix=NAME
50 Search for NAME.cfg and NAME.site.cfg when searching for test
51 suites, instead of lit.cfg and lit.site.cfg.
52 --param NAME, --param NAME=VALUE
54 Add a user defined parameter NAME with the given VALUE (or the
55 empty string if not given). The meaning and use of these parameters
56 is test suite dependent.
57
59 -q, --quiet
60 Suppress any output except for test failures.
61 -s, --succinct
63 Show less output, for example don't show information on tests that
64 pass.
65 -v, --verbose
67 Show more information on test failures, for example the entire test
68 output instead of just the test result.
69 --no-progress-bar
71 Do not use curses based progress bar.
72
74 --path=PATH
75 Specify an addition PATH to use when searching for executables in
76 tests.
77 --vg
79 Run individual tests under valgrind (using the memcheck tool). The
80 --error-exitcode argument for valgrind is used so that valgrind
81 failures will cause the program to exit with a non-zero status.
82 --vg-arg=ARG
84 When --vg is used, specify an additional argument to pass to
85 valgrind itself.
86 --time-tests
88 Track the wall time individual tests take to execute and includes
89 the results in the summary output. This is useful for determining
90 which tests in a test suite take the most time to execute. Note
91 that this option is most useful with -j 1.
92
94 --max-tests=N
95 Run at most N tests and then terminate.
96 --max-time=N
98 Spend at most N seconds (approximately) running tests and then
99 terminate.
100 --shuffle
102 Run the tests in a random order.
103
105 --debug
106 Run lit in debug mode, for debugging configuration issues and lit
107 itself.
108 --show-suites
110 List the discovered test suites as part of the standard output.
111 --no-tcl-as-sh
113 Run Tcl scripts internally (instead of converting to shell
114 scripts).
115 --repeat=N
117 Run each test N times. Currently this is primarily useful for
118 timing tests, other results are not collated in any reasonable
119 fashion.
120
122 lit will exit with an exit code of 1 if there are any FAIL or XPASS
123 results. Otherwise, it will exit with the status 0. Other exit codes
124 used for non-test related failures (for example a user error or an
125 internal program error).
126
128 The inputs passed to lit can be either individual tests, or entire
129 directories or hierarchies of tests to run. When lit starts up, the
130 first thing it does is convert the inputs into a complete list of tests
131 to run as part of test discovery.
132 In the lit model, every test must exist inside some test suite. lit
134 resolves the inputs specified on the command line to test suites by
135 searching upwards from the input path until it finds a lit.cfg or
136 lit.site.cfg file. These files serve as both a marker of test suites
137 and as configuration files which lit loads in order to understand how
138 to find and run the tests inside the test suite.
139 Once lit has mapped the inputs into test suites it traverses the list
141 of inputs adding tests for individual files and recursively searching
142 for tests in directories.
143 This behavior makes it easy to specify a subset of tests to run, while
145 still allowing the test suite configuration to control exactly how
146 tests are interpreted. In addition, lit always identifies tests by the
147 test suite they are in, and their relative path inside the test suite.
148 For appropriately configured projects, this allows lit to provide
149 convenient and flexible support for out-of-tree builds.
150
152 Each test ultimately produces one of the following six results:
153 PASS
155 The test succeeded.
156 XFAIL
158 The test failed, but that is expected. This is used for test
159 formats which allow specifying that a test does not currently work,
160 but wish to leave it in the test suite.
161 XPASS
163 The test succeeded, but it was expected to fail. This is used for
164 tests which were specified as expected to fail, but are now
165 succeeding (generally because the feautre they test was broken and
166 has been fixed).
167 FAIL
169 The test failed.
170 UNRESOLVED
172 The test result could not be determined. For example, this occurs
173 when the test could not be run, the test itself is invalid, or the
174 test was interrupted.
175 UNSUPPORTED
177 The test is not supported in this environment. This is used by test
178 formats which can report unsupported tests.
179 Depending on the test format tests may produce additional information
181 about their status (generally only for failures). See the Output
182 section for more information.
183
185 This section describes the lit testing architecture for users
186 interested in creating a new lit testing implementation, or extending
187 an existing one.
188 lit proper is primarily an infrastructure for discovering and running
190 arbitrary tests, and to expose a single convenient interface to these
191 tests. lit itself doesn't know how to run tests, rather this logic is
192 defined by test suites.
193 TEST SUITES
195 As described in "TEST DISCOVERY", tests are always located inside a
196 test suite. Test suites serve to define the format of the tests they
197 contain, the logic for finding those tests, and any additional
198 information to run the tests.
199 lit identifies test suites as directories containing lit.cfg or
201 lit.site.cfg files (see also --config-prefix. Test suites are initially
202 discovered by recursively searching up the directory hierarchy for all
203 the input files passed on the command line. You can use --show-suites
204 to display the discovered test suites at startup.
205 Once a test suite is discovered, its config file is loaded. Config
207 files themselves are Python modules which will be executed. When the
208 config file is executed, two important global variables are predefined:
209 lit The global lit configuration object (a LitConfig instance), which
211 defines the builtin test formats, global configuration parameters,
212 and other helper routines for implementing test configurations.
213 config
215 This is the config object (a TestingConfig instance) for the test
216 suite, which the config file is expected to populate. The following
217 variables are also available on the config object, some of which
218 must be set by the config and others are optional or predefined:
219 name [required] The name of the test suite, for use in reports and
221 diagnostics.
222 test_format [required] The test format object which will be used to
224 discover and run tests in the test suite. Generally this will be a
225 builtin test format available from the lit.formats module.
226 test_src_root The filesystem path to the test suite root. For out-
228 of-dir builds this is the directory that will be scanned for tests.
229 test_exec_root For out-of-dir builds, the path to the test suite
231 root inside the object directory. This is where tests will be run
232 and temporary output files places.
233 environment A dictionary representing the environment to use when
235 executing tests in the suite.
236 suffixes For lit test formats which scan directories for tests,
238 this variable as a list of suffixes to identify test files. Used
239 by: ShTest, TclTest.
240 substitutions For lit test formats which substitute variables into
242 a test script, the list of substitutions to perform. Used by:
243 ShTest, TclTest.
244 unsupported Mark an unsupported directory, all tests within it will
246 be reported as unsupported. Used by: ShTest, TclTest.
247 parent The parent configuration, this is the config object for the
249 directory containing the test suite, or None.
250 on_clone The config is actually cloned for every subdirectory
252 inside a test suite, to allow local configuration on a per-
253 directory basis. The on_clone variable can be set to a Python
254 function which will be called whenever a configuration is cloned
255 (for a subdirectory). The function should takes three arguments:
256 (1) the parent configuration, (2) the new configuration (which the
257 on_clone function will generally modify), and (3) the test path to
258 the new directory being scanned.
259 TEST DISCOVERY
261 Once test suites are located, lit recursively traverses the source
262 directory (following test_src_root) looking for tests. When lit enters
263 a sub-directory, it first checks to see if a nest test suite is defined
264 in that directory. If so, it loads that test suite recursively,
265 otherwise it instantiates a local test config for the directory (see
266 "LOCAL CONFIGURATION FILES").
267 Tests are identified by the test suite they are contained within, and
269 the relative path inside that suite. Note that the relative path may
270 not refer to an actual file on disk; some test formats (such as
271 GoogleTest) define "virtual tests" which have a path that contains both
272 the path to the actual test file and a subpath to identify the virtual
273 test.
274 LOCAL CONFIGURATION FILES
276 When lit loads a subdirectory in a test suite, it instantiates a local
277 test configuration by cloning the configuration for the parent
278 direction -- the root of this configuration chain will always be a test
279 suite. Once the test configuration is cloned lit checks for a
280 lit.local.cfg file in the subdirectory. If present, this file will be
281 loaded and can be used to specialize the configuration for each
282 individual directory. This facility can be used to define
283 subdirectories of optional tests, or to change other configuration
284 parameters -- for example, to change the test format, or the suffixes
285 which identify test files.
286 LIT EXAMPLE TESTS
288 The lit distribution contains several example implementations of test
289 suites in the ExampleTests directory.
290
292 valgrind(1)
293
295 Written by Daniel Dunbar and maintained by the LLVM Team
296 (<http://llvm.org>).
297CVS 2010-05-11 LIT(1)