Man1 - lit.1

lit - LLVM Integrated Tester

lit [/options/] [/tests/]

lit is a portable tool for executing LLVM and Clang style test suites, summarizing their results, and providing indication of failures. lit is designed to be a lightweight testing tool with as simple a user interface as possible.

lit should be run with one or more tests to run specified on the command line. Tests can be either individual test files or directories to search for tests (see TEST DISCOVERY).

Each specified test will be executed (potentially concurrently) and once all tests have been run lit will print summary information on the number of tests which passed or failed (see TEST STATUS RESULTS). The lit program will execute with a non-zero exit code if any tests fail.

By default lit will use a succinct progress display and will only print summary information for test failures. See OUTPUT OPTIONS for options controlling the lit progress display and output.

lit also includes a number of options for controlling how tests are executed (specific features may depend on the particular test format). See EXECUTION OPTIONS for more information.

Finally, lit also supports additional options for only running a subset of the options specified on the command line, see SELECTION OPTIONS for more information.

lit parses options from the environment variable LIT_OPTS after parsing options from the command line. LIT_OPTS is primarily useful for supplementing or overriding the command-line options supplied to lit by check targets defined by a project’s build system.

Users interested in the lit architecture or designing a lit testing implementation should see LIT INFRASTRUCTURE.

-h, –help

Show the lit help message.

-j N, –workers=N

Run N tests in parallel. By default, this is automatically chosen to match the number of detected available CPUs.

–config-prefix=NAME

Search for /NAME/*.cfg* and /NAME/*.site.cfg* when searching for test suites, instead of lit.cfg and lit.site.cfg.

-D NAME[=VALUE], –param NAME[=VALUE]

Add a user defined parameter NAME with the given VALUE (or the empty string if not given). The meaning and use of these parameters is test suite dependent.

-q, –quiet

Suppress any output except for test failures.

-s, –succinct

Show less output, for example don’t show information on tests that pass. Also show a progress bar, unless –no-progress-bar is specified.

-v, –verbose

Show more information on test failures, for example the entire test output instead of just the test result.

-vv, –echo-all-commands

Echo all commands to stdout, as they are being executed. This can be valuable for debugging test failures, as the last echoed command will be the one which has failed. lit normally inserts a no-op command (: in the case of bash) with argument ’RUN: at line N’ before each command pipeline, and this option also causes those no-op commands to be echoed to stdout to help you locate the source line of the failed command. This option implies –verbose.

-a, –show-all

Show more information about all tests, for example the entire test commandline and output.

–no-progress-bar

Do not use curses based progress bar.

–show-unsupported

Show the names of unsupported tests.

–show-xfail

Show the names of tests that were expected to fail.

–path=PATH

Specify an additional PATH to use when searching for executables in tests.

–vg

Run individual tests under valgrind (using the memcheck tool). The –error-exitcode argument for valgrind is used so that valgrind failures will cause the program to exit with a non-zero status.

When this option is enabled, lit will also automatically provide a “valgrind” feature that can be used to conditionally disable (or expect failure in) certain tests.

–vg-arg=ARG

When –vg is used, specify an additional argument to pass to valgrind itself.

–vg-leak

When –vg is used, enable memory leak checks. When this option is enabled, lit will also automatically provide a “vg_leak” feature that can be used to conditionally disable (or expect failure in) certain tests.

–time-tests

Track the wall time individual tests take to execute and includes the results in the summary output. This is useful for determining which tests in a test suite take the most time to execute.

–ignore-fail

Exit with status zero even if some tests fail.

–no-indirectly-run-check

Do not error if a test would not be run if the user had specified the containing directory instead of naming the test directly.

By default, lit will run failing tests first, then run tests in descending execution time order to optimize concurrency.

The timing data is stored in the test_exec_root in a file named .lit_test_times.txt. If this file does not exist, then lit checks the test_source_root for the file to optionally accelerate clean builds.

–shuffle

Run the tests in a random order, not failing/slowest first.

–max-failures N

Stop execution after the given number N of failures. An integer argument should be passed on the command line prior to execution.

–max-tests=N

Run at most N tests and then terminate.

–max-time=N

Spend at most N seconds (approximately) running tests and then terminate. Note that this is not an alias for –timeout; the two are different kinds of maximums.

–num-shards=M

Divide the set of selected tests into M equal-sized subsets or “shards”, and run only one of them. Must be used with the –run-shard=N option, which selects the shard to run. The environment variable LIT_NUM_SHARDS can also be used in place of this option. These two options provide a coarse mechanism for partitioning large testsuites, for parallel execution on separate machines (say in a large testing farm).

–run-shard=N

Select which shard to run, assuming the –num-shards=M option was provided. The two options must be used together, and the value of N must be in the range 1..M. The environment variable LIT_RUN_SHARD can also be used in place of this option.

–timeout=N

Spend at most N seconds (approximately) running each individual test. 0 means no time limit, and 0 is the default. Note that this is not an alias for –max-time; the two are different kinds of maximums.

–filter=REGEXP

Run only those tests whose name matches the regular expression specified in REGEXP. The environment variable LIT_FILTER can be also used in place of this option, which is especially useful in environments where the call to lit is issued indirectly.

–filter-out=REGEXP

Filter out those tests whose name matches the regular expression specified in REGEXP. The environment variable LIT_FILTER_OUT can be also used in place of this option, which is especially useful in environments where the call to lit is issued indirectly.

–xfail=LIST

Treat those tests whose name is in the semicolon separated list LIST as XFAIL. This can be helpful when one does not want to modify the test suite. The environment variable LIT_XFAIL can be also used in place of this option, which is especially useful in environments where the call to lit is issued indirectly.

A test name can specified as a file name relative to the test suite directory. For example:

#+begin_quote

#+begin_quote

        LIT_XFAIL="affinity/kmp-hw-subset.c;offloading/memory_manager.cpp"

#+end_quote

In this case, all of the following tests are treated as XFAIL:

#+begin_quote

        libomp :: affinity/kmp-hw-subset.c
        libomptarget :: nvptx64-nvidia-cuda :: offloading/memory_manager.cpp
        libomptarget :: x86_64-pc-linux-gnu :: offloading/memory_manager.cpp

#+end_quote

Alternatively, a test name can be specified as the full test name reported in LIT output. For example, we can adjust the previous example not to treat the nvptx64-nvidia-cuda version of offloading/memory_manager.cpp as XFAIL:

#+begin_quote

        LIT_XFAIL="affinity/kmp-hw-subset.c;libomptarget :: x86_64-pc-linux-gnu :: offloading/memory_manager.cpp"

#+end_quote #+end_quote

–xfail-not=LIST

Do not treat the specified tests as XFAIL. The environment variable LIT_XFAIL_NOT can also be used in place of this option. The syntax is the same as for –xfail and LIT_XFAIL. –xfail-not and LIT_XFAIL_NOT always override all other XFAIL specifications, including an –xfail appearing later on the command line. The primary purpose is to suppress an XPASS result without modifying a test case that uses the XFAIL directive.

–debug

Run lit in debug mode, for debugging configuration issues and lit itself.

–show-suites

List the discovered test suites and exit.

–show-tests

List all of the discovered tests and exit.

lit will exit with an exit code of 1 if there are any FAIL or XPASS results. Otherwise, it will exit with the status 0. Other exit codes are used for non-test related failures (for example a user error or an internal program error).

The inputs passed to lit can be either individual tests, or entire directories or hierarchies of tests to run. When lit starts up, the first thing it does is convert the inputs into a complete list of tests to run as part of test discovery.

In the lit model, every test must exist inside some test suite. lit resolves the inputs specified on the command line to test suites by searching upwards from the input path until it finds a lit.cfg or lit.site.cfg file. These files serve as both a marker of test suites and as configuration files which lit loads in order to understand how to find and run the tests inside the test suite.

Once lit has mapped the inputs into test suites it traverses the list of inputs adding tests for individual files and recursively searching for tests in directories.

This behavior makes it easy to specify a subset of tests to run, while still allowing the test suite configuration to control exactly how tests are interpreted. In addition, lit always identifies tests by the test suite they are in, and their relative path inside the test suite. For appropriately configured projects, this allows lit to provide convenient and flexible support for out-of-tree builds.

Each test ultimately produces one of the following eight results:

PASS

#+begin_quote The test succeeded.

#+end_quote

FLAKYPASS

#+begin_quote The test succeeded after being re-run more than once. This only applies to tests containing an ALLOW_RETRIES: annotation.

#+end_quote

XFAIL

#+begin_quote The test failed, but that is expected. This is used for test formats which allow specifying that a test does not currently work, but wish to leave it in the test suite.

#+end_quote

XPASS

#+begin_quote The test succeeded, but it was expected to fail. This is used for tests which were specified as expected to fail, but are now succeeding (generally because the feature they test was broken and has been fixed).

#+end_quote

FAIL

#+begin_quote The test failed.

#+end_quote

UNRESOLVED

#+begin_quote The test result could not be determined. For example, this occurs when the test could not be run, the test itself is invalid, or the test was interrupted.

#+end_quote

UNSUPPORTED

#+begin_quote The test is not supported in this environment. This is used by test formats which can report unsupported tests.

#+end_quote

TIMEOUT

#+begin_quote The test was run, but it timed out before it was able to complete. This is considered a failure.

#+end_quote

Depending on the test format tests may produce additional information about their status (generally only for failures). See the OUTPUT OPTIONS section for more information.

This section describes the lit testing architecture for users interested in creating a new lit testing implementation, or extending an existing one.

lit proper is primarily an infrastructure for discovering and running arbitrary tests, and to expose a single convenient interface to these tests. lit itself doesn’t know how to run tests, rather this logic is defined by test suites.

valgrind(1)

Maintained by the LLVM Team (https://llvm.org/).

2003-2021, LLVM Project