1LIT(1) LLVM LIT(1)
2
6 lit - LLVM Integrated Tester
7
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
14 is designed to be a lightweight testing tool with as simple a user in‐
15 terface as possible.
16 lit should be run with one or more tests to run specified on the com‐
18 mand line. Tests can be either individual test files or directories to
19 search for tests (see TEST DISCOVERY).
20 Each specified test will be executed (potentially concurrently) and
22 once 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 ex‐
31 ecuted (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 for
36 more information.
37 lit parses options from the environment variable LIT_OPTS after parsing
39 options from the command line. LIT_OPTS is primarily useful for sup‐
40 plementing or overriding the command-line options supplied to lit by
41 check targets defined by a project's build system.
42 Users interested in the lit architecture or designing a lit testing im‐
44 plementation should see LIT INFRASTRUCTURE.
45
47 -h, --help
48 Show the lit help message.
49 -j N, --workers=N
51 Run N tests in parallel. By default, this is automatically cho‐
52 sen to match the number of detected available CPUs.
53 --config-prefix=NAME
55 Search for NAME.cfg and NAME.site.cfg when searching for test
56 suites, instead of lit.cfg and lit.site.cfg.
57 -D NAME[=VALUE], --param NAME[=VALUE]
59 Add a user defined parameter NAME with the given VALUE (or the
60 empty string if not given). The meaning and use of these param‐
61 eters is test suite dependent.
62
64 -q, --quiet
65 Suppress any output except for test failures.
66 -s, --succinct
68 Show less output, for example don't show information on tests
69 that pass. Also show a progress bar, unless --no-progress-bar
70 is specified.
71 -v, --verbose
73 Show more information on test failures, for example the entire
74 test output instead of just the test result.
75 -vv, --echo-all-commands
77 Echo all commands to stdout, as they are being executed. This
78 can be valuable for debugging test failures, as the last echoed
79 command will be the one which has failed. lit normally inserts
80 a no-op command (: in the case of bash) with argument 'RUN: at
81 line N' before each command pipeline, and this option also
82 causes those no-op commands to be echoed to stdout to help you
83 locate the source line of the failed command. This option im‐
84 plies --verbose.
85 -a, --show-all
87 Show more information about all tests, for example the entire
88 test commandline and output.
89 --no-progress-bar
91 Do not use curses based progress bar.
92 --show-unsupported
94 Show the names of unsupported tests.
95 --show-xfail
97 Show the names of tests that were expected to fail.
98
100 --path=PATH
101 Specify an additional PATH to use when searching for executables
102 in tests.
103 --vg Run individual tests under valgrind (using the memcheck tool).
105 The --error-exitcode argument for valgrind is used so that val‐
106 grind failures will cause the program to exit with a non-zero
107 status.
108 When this option is enabled, lit will also automatically provide
110 a "valgrind" feature that can be used to conditionally disable
111 (or expect failure in) certain tests.
112 --vg-arg=ARG
114 When --vg is used, specify an additional argument to pass to
115 valgrind itself.
116 --vg-leak
118 When --vg is used, enable memory leak checks. When this option
119 is enabled, lit will also automatically provide a "vg_leak" fea‐
120 ture that can be used to conditionally disable (or expect fail‐
121 ure in) certain tests.
122 --time-tests
124 Track the wall time individual tests take to execute and in‐
125 cludes the results in the summary output. This is useful for
126 determining which tests in a test suite take the most time to
127 execute.
128 --ignore-fail
130 Exit with status zero even if some tests fail.
131 --no-indirectly-run-check
133 Do not error if a test would not be run if the user had speci‐
134 fied the containing directory instead of naming the test di‐
135 rectly.
136
138 By default, lit will run failing tests first, then run tests in de‐
139 scending execution time order to optimize concurrency.
140 The timing data is stored in the test_exec_root in a file named
142 .lit_test_times.txt. If this file does not exist, then lit checks the
143 test_source_root for the file to optionally accelerate clean builds.
144 --shuffle
146 Run the tests in a random order, not failing/slowest first.
147 --max-failures N
149 Stop execution after the given number N of failures. An integer
150 argument should be passed on the command line prior to execu‐
151 tion.
152 --max-tests=N
154 Run at most N tests and then terminate.
155 --max-time=N
157 Spend at most N seconds (approximately) running tests and then
158 terminate. Note that this is not an alias for --timeout; the
159 two are different kinds of maximums.
160 --num-shards=M
162 Divide the set of selected tests into M equal-sized subsets or
163 "shards", and run only one of them. Must be used with the
164 --run-shard=N option, which selects the shard to run. The envi‐
165 ronment variable LIT_NUM_SHARDS can also be used in place of
166 this option. These two options provide a coarse mechanism for
167 partitioning large testsuites, for parallel execution on sepa‐
168 rate machines (say in a large testing farm).
169 --run-shard=N
171 Select which shard to run, assuming the --num-shards=M option
172 was provided. The two options must be used together, and the
173 value of N must be in the range 1..M. The environment variable
174 LIT_RUN_SHARD can also be used in place of this option.
175 --timeout=N
177 Spend at most N seconds (approximately) running each individual
178 test. 0 means no time limit, and 0 is the default. Note that
179 this is not an alias for --max-time; the two are different kinds
180 of maximums.
181 --filter=REGEXP
183 Run only those tests whose name matches the regular expression
184 specified in REGEXP. The environment variable LIT_FILTER can be
185 also used in place of this option, which is especially useful in
186 environments where the call to lit is issued indirectly.
187 --filter-out=REGEXP
189 Filter out those tests whose name matches the regular expression
190 specified in REGEXP. The environment variable LIT_FILTER_OUT can
191 be also used in place of this option, which is especially useful
192 in environments where the call to lit is issued indirectly.
193 --xfail=LIST
195 Treat those tests whose name is in the semicolon separated list
196 LIST as XFAIL. This can be helpful when one does not want to
197 modify the test suite. The environment variable LIT_XFAIL can be
198 also used in place of this option, which is especially useful in
199 environments where the call to lit is issued indirectly.
200 A test name can specified as a file name relative to the test
202 suite directory. For example:
203 LIT_XFAIL="affinity/kmp-hw-subset.c;offloading/memory_manager.cpp"
205 In this case, all of the following tests are treated as XFAIL:
207 libomp :: affinity/kmp-hw-subset.c
209 libomptarget :: nvptx64-nvidia-cuda :: offloading/memory_manager.cpp
210 libomptarget :: x86_64-pc-linux-gnu :: offloading/memory_manager.cpp
211 Alternatively, a test name can be specified as the full test
213 name reported in LIT output. For example, we can adjust the
214 previous example not to treat the nvptx64-nvidia-cuda version of
215 offloading/memory_manager.cpp as XFAIL:
216 LIT_XFAIL="affinity/kmp-hw-subset.c;libomptarget :: x86_64-pc-linux-gnu :: offloading/memory_manager.cpp"
218 --xfail-not=LIST
220 Do not treat the specified tests as XFAIL. The environment
221 variable LIT_XFAIL_NOT can also be used in place of this option.
222 The syntax is the same as for --xfail and LIT_XFAIL.
223 --xfail-not and LIT_XFAIL_NOT always override all other XFAIL
224 specifications, including an --xfail appearing later on the com‐
225 mand line. The primary purpose is to suppress an XPASS result
226 without modifying a test case that uses the XFAIL directive.
227
229 --debug
230 Run lit in debug mode, for debugging configuration issues and
231 lit itself.
232 --show-suites
234 List the discovered test suites and exit.
235 --show-tests
237 List all of the discovered tests and exit.
238
240 lit will exit with an exit code of 1 if there are any FAIL or XPASS re‐
241 sults. Otherwise, it will exit with the status 0. Other exit codes
242 are used for non-test related failures (for example a user error or an
243 internal program error).
244
246 The inputs passed to lit can be either individual tests, or entire di‐
247 rectories or hierarchies of tests to run. When lit starts up, the
248 first thing it does is convert the inputs into a complete list of tests
249 to run as part of test discovery.
250 In the lit model, every test must exist inside some test suite. lit
252 resolves the inputs specified on the command line to test suites by
253 searching upwards from the input path until it finds a lit.cfg or
254 lit.site.cfg file. These files serve as both a marker of test suites
255 and as configuration files which lit loads in order to understand how
256 to find and run the tests inside the test suite.
257 Once lit has mapped the inputs into test suites it traverses the list
259 of inputs adding tests for individual files and recursively searching
260 for tests in directories.
261 This behavior makes it easy to specify a subset of tests to run, while
263 still allowing the test suite configuration to control exactly how
264 tests are interpreted. In addition, lit always identifies tests by the
265 test suite they are in, and their relative path inside the test suite.
266 For appropriately configured projects, this allows lit to provide con‐
267 venient and flexible support for out-of-tree builds.
268
270 Each test ultimately produces one of the following eight results:
271 PASS
273 The test succeeded.
274 FLAKYPASS
276 The test succeeded after being re-run more than once. This only ap‐
277 plies to tests containing an ALLOW_RETRIES: annotation.
278 XFAIL
280 The test failed, but that is expected. This is used for test for‐
281 mats which allow specifying that a test does not currently work, but
282 wish to leave it in the test suite.
283 XPASS
285 The test succeeded, but it was expected to fail. This is used for
286 tests which were specified as expected to fail, but are now succeed‐
287 ing (generally because the feature they test was broken and has been
288 fixed).
289 FAIL
291 The test failed.
292 UNRESOLVED
294 The test result could not be determined. For example, this occurs
295 when the test could not be run, the test itself is invalid, or the
296 test was interrupted.
297 UNSUPPORTED
299 The test is not supported in this environment. This is used by test
300 formats which can report unsupported tests.
301 TIMEOUT
303 The test was run, but it timed out before it was able to complete.
304 This is considered a failure.
305 Depending on the test format tests may produce additional information
307 about their status (generally only for failures). See the OUTPUT OP‐
308 TIONS section for more information.
309
311 This section describes the lit testing architecture for users inter‐
312 ested in creating a new lit testing implementation, or extending an ex‐
313 isting one.
314 lit proper is primarily an infrastructure for discovering and running
316 arbitrary tests, and to expose a single convenient interface to these
317 tests. lit itself doesn't know how to run tests, rather this logic is
318 defined by test suites.
319 TEST SUITES
321 As described in TEST DISCOVERY, tests are always located inside a test
322 suite. Test suites serve to define the format of the tests they con‐
323 tain, the logic for finding those tests, and any additional information
324 to run the tests.
325 lit identifies test suites as directories containing lit.cfg or
327 lit.site.cfg files (see also --config-prefix). Test suites are ini‐
328 tially discovered by recursively searching up the directory hierarchy
329 for all the input files passed on the command line. You can use
330 --show-suites to display the discovered test suites at startup.
331 Once a test suite is discovered, its config file is loaded. Config
333 files themselves are Python modules which will be executed. When the
334 config file is executed, two important global variables are predefined:
335 lit_config
337 The global lit configuration object (a LitConfig instance), which
338 defines the builtin test formats, global configuration parameters,
339 and other helper routines for implementing test configurations.
340 config
342 This is the config object (a TestingConfig instance) for the test
343 suite, which the config file is expected to populate. The following
344 variables are also available on the config object, some of which
345 must be set by the config and others are optional or predefined:
346 name [required] The name of the test suite, for use in reports and
348 diagnostics.
349 test_format [required] The test format object which will be used to
351 discover and run tests in the test suite. Generally this will be a
352 builtin test format available from the lit.formats module.
353 test_source_root The filesystem path to the test suite root. For
355 out-of-dir builds this is the directory that will be scanned for
356 tests.
357 test_exec_root For out-of-dir builds, the path to the test suite
359 root inside the object directory. This is where tests will be run
360 and temporary output files placed.
361 environment A dictionary representing the environment to use when
363 executing tests in the suite.
364 standalone_tests When true, mark a directory with tests expected to
366 be run standalone. Test discovery is disabled for that directory and
367 --no-indirectly-run-check is in effect. lit.suffixes and lit.ex‐
368 cludes must be empty when this variable is true.
369 suffixes For lit test formats which scan directories for tests, this
371 variable is a list of suffixes to identify test files. Used by:
372 ShTest.
373 substitutions For lit test formats which substitute variables into a
375 test script, the list of substitutions to perform. Used by: ShTest.
376 unsupported Mark an unsupported directory, all tests within it will
378 be reported as unsupported. Used by: ShTest.
379 parent The parent configuration, this is the config object for the
381 directory containing the test suite, or None.
382 root The root configuration. This is the top-most lit configuration
384 in the project.
385 pipefail Normally a test using a shell pipe fails if any of the com‐
387 mands on the pipe fail. If this is not desired, setting this vari‐
388 able to false makes the test fail only if the last command in the
389 pipe fails.
390 available_features A set of features that can be used in XFAIL, RE‐
392 QUIRES, and UNSUPPORTED directives.
393 TEST DISCOVERY
395 Once test suites are located, lit recursively traverses the source di‐
396 rectory (following test_source_root) looking for tests. When lit en‐
397 ters a sub-directory, it first checks to see if a nested test suite is
398 defined in that directory. If so, it loads that test suite recur‐
399 sively, otherwise it instantiates a local test config for the directory
400 (see LOCAL CONFIGURATION FILES).
401 Tests are identified by the test suite they are contained within, and
403 the relative path inside that suite. Note that the relative path may
404 not refer to an actual file on disk; some test formats (such as
405 GoogleTest) define "virtual tests" which have a path that contains both
406 the path to the actual test file and a subpath to identify the virtual
407 test.
408 LOCAL CONFIGURATION FILES
410 When lit loads a subdirectory in a test suite, it instantiates a local
411 test configuration by cloning the configuration for the parent direc‐
412 tory --- the root of this configuration chain will always be a test
413 suite. Once the test configuration is cloned lit checks for a lit.lo‐
414 cal.cfg file in the subdirectory. If present, this file will be loaded
415 and can be used to specialize the configuration for each individual di‐
416 rectory. This facility can be used to define subdirectories of op‐
417 tional tests, or to change other configuration parameters --- for exam‐
418 ple, to change the test format, or the suffixes which identify test
419 files.
420 SUBSTITUTIONS
422 lit allows patterns to be substituted inside RUN commands. It also pro‐
423 vides the following base set of substitutions, which are defined in
424 TestRunner.py:
425 ┌────────────────────────┬────────────────────────────┐
427 │Macro │ Substitution │
428 ├────────────────────────┼────────────────────────────┤
429 │%s │ source path (path to the │
430 │ │ file currently being run) │
431 ├────────────────────────┼────────────────────────────┤
432 │%S │ source dir (directory of │
433 │ │ the file currently being │
434 │ │ run) │
435 ├────────────────────────┼────────────────────────────┤
436 │%p │ same as %S │
437 ├────────────────────────┼────────────────────────────┤
438 │%{pathsep} │ path separator │
439 ├────────────────────────┼────────────────────────────┤
440 │%t │ temporary file name unique │
441 │ │ to the test │
442 ├────────────────────────┼────────────────────────────┤
443 │%basename_t │ The last path component of │
444 │ │ %t but without the .tmp │
445 │ │ extension │
446 ├────────────────────────┼────────────────────────────┤
447 │%T │ parent directory of %t │
448 │ │ (not unique, deprecated, │
449 │ │ do not use) │
450 ├────────────────────────┼────────────────────────────┤
451 │%% │ % │
452 ├────────────────────────┼────────────────────────────┤
453 │%/s │ %s but \ is replaced by / │
454 ├────────────────────────┼────────────────────────────┤
455 │%/S │ %S but \ is replaced by / │
456 ├────────────────────────┼────────────────────────────┤
457 │%/p │ %p but \ is replaced by / │
458 ├────────────────────────┼────────────────────────────┤
459 │%/t │ %t but \ is replaced by / │
460 ├────────────────────────┼────────────────────────────┤
461 │%/T │ %T but \ is replaced by / │
462 ├────────────────────────┼────────────────────────────┤
463 │%{/s:regex_replacement} │ %/s but escaped for use in │
464 │ │ the replacement of a s@@@ │
465 │ │ command in sed │
466 ├────────────────────────┼────────────────────────────┤
467 │%{/S:regex_replacement} │ %/S but escaped for use in │
468 │ │ the replacement of a s@@@ │
469 │ │ command in sed │
470 ├────────────────────────┼────────────────────────────┤
471 │%{/p:regex_replacement} │ %/p but escaped for use in │
472 │ │ the replacement of a s@@@ │
473 │ │ command in sed │
474 ├────────────────────────┼────────────────────────────┤
475 │%{/t:regex_replacement} │ %/t but escaped for use in │
476 │ │ the replacement of a s@@@ │
477 │ │ command in sed │
478 └────────────────────────┴────────────────────────────┘
479 │%{/T:regex_replacement} │ %/T but escaped for use in │
484 │ │ the replacement of a s@@@ │
485 │ │ command in sed │
486 ├────────────────────────┼────────────────────────────┤
487 │%:s │ On Windows, %/s but a : is │
488 │ │ removed if its the second │
489 │ │ character. Otherwise, %s │
490 │ │ but with a single leading │
491 │ │ / removed. │
492 ├────────────────────────┼────────────────────────────┤
493 │%:S │ On Windows, %/S but a : is │
494 │ │ removed if its the second │
495 │ │ character. Otherwise, %S │
496 │ │ but with a single leading │
497 │ │ / removed. │
498 ├────────────────────────┼────────────────────────────┤
499 │%:p │ On Windows, %/p but a : is │
500 │ │ removed if its the second │
501 │ │ character. Otherwise, %p │
502 │ │ but with a single leading │
503 │ │ / removed. │
504 ├────────────────────────┼────────────────────────────┤
505 │%:t │ On Windows, %/t but a : is │
506 │ │ removed if its the second │
507 │ │ character. Otherwise, %t │
508 │ │ but with a single leading │
509 │ │ / removed. │
510 ├────────────────────────┼────────────────────────────┤
511 │%:T │ On Windows, %/T but a : is │
512 │ │ removed if its the second │
513 │ │ character. Otherwise, %T │
514 │ │ but with a single leading │
515 │ │ / removed. │
516 └────────────────────────┴────────────────────────────┘
517 Other substitutions are provided that are variations on this base set
519 and further substitution patterns can be defined by each test module.
520 See the modules LOCAL CONFIGURATION FILES.
521 By default, substitutions are expanded exactly once, so that if e.g. a
523 substitution %build is defined in top of another substitution %cxx,
524 %build will expand to %cxx textually, not to what %cxx expands to.
525 However, if the recursiveExpansionLimit property of the TestingConfig
526 is set to a non-negative integer, substitutions will be expanded recur‐
527 sively until that limit is reached. It is an error if the limit is
528 reached and expanding substitutions again would yield a different re‐
529 sult.
530 More detailed information on substitutions can be found in the LLVM
532 Testing Infrastructure Guide.
533 TEST RUN OUTPUT FORMAT
535 The lit output for a test run conforms to the following schema, in both
536 short and verbose modes (although in short mode no PASS lines will be
537 shown). This schema has been chosen to be relatively easy to reliably
538 parse by a machine (for example in buildbot log scraping), and for
539 other tools to generate.
540 Each test result is expected to appear on a line that matches:
542 <result code>: <test name> (<progress info>)
544 where <result-code> is a standard test result such as PASS, FAIL,
546 XFAIL, XPASS, UNRESOLVED, or UNSUPPORTED. The performance result codes
547 of IMPROVED and REGRESSED are also allowed.
548 The <test name> field can consist of an arbitrary string containing no
550 newline.
551 The <progress info> field can be used to report progress information
553 such as (1/300) or can be empty, but even when empty the parentheses
554 are required.
555 Each test result may include additional (multiline) log information in
557 the following format:
558 <log delineator> TEST '(<test name>)' <trailing delineator>
560 ... log message ...
561 <log delineator>
562 where <test name> should be the name of a preceding reported test, <log
564 delineator> is a string of "*" characters at least four characters long
565 (the recommended length is 20), and <trailing delineator> is an arbi‐
566 trary (unparsed) string.
567 The following is an example of a test run output which consists of four
569 tests A, B, C, and D, and a log message for the failing test C:
570 PASS: A (1 of 4)
572 PASS: B (2 of 4)
573 FAIL: C (3 of 4)
574 ******************** TEST 'C' FAILED ********************
575 Test 'C' failed as a result of exit code 1.
576 ********************
577 PASS: D (4 of 4)
578 LIT EXAMPLE TESTS
580 The lit distribution contains several example implementations of test
581 suites in the ExampleTests directory.
582
584 valgrind(1)
585
587 Maintained by the LLVM Team (https://llvm.org/).
588
590 2003-2022, LLVM Project
59113 2022-07-21 LIT(1)