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Updated: Thursday, June 13, 2019

lit (1)


lit - LLVM Integrated Tester


lit [options] [tests]


LIT(1)                               LLVM                               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  com-
       mand line.  Tests can be either individual test files or directories to
       search for tests (see TEST DISCOVERY).

       Each specified test will be executed (potentially in parallel) and once
       all  tests have been run lit will print summary information on the num-
       ber 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.

       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, --threads=N
              Run N tests in parallel.  By default, this is automatically cho-
              sen to match the number of detected available CPUs.

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

       -D NAME, -D NAME=VALUE, --param NAME, --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 param-
              eters 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.

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

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

              Do not use curses based progress bar.

              Show the names of unsupported tests.

              Show the names of tests that were expected to fail.

              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 val-
              grind failures will cause the program to exit  with  a  non-zero

              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.

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

              When --vg is used, enable memory leak checks.  When this  option
              is enabled, lit will also automatically provide a "vg_leak" fea-
              ture that can be used to conditionally disable (or expect  fail-
              ure in) certain 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.  Note that this option is most useful with -j 1.

              Run at most N tests and then terminate.

              Spend at most N seconds (approximately) running tests  and  then

              Run the tests in a random order.

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

              List the discovered test suites and exit.

              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 con-
       venient and flexible support for out-of-tree builds.

       Each test ultimately produces one of the following six results:

          The test succeeded.

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

          The test succeeded, but it was expected to fail.  This is  used  for
          tests which were specified as expected to fail, but are now succeed-
          ing (generally because the feature they test was broken and has been

          The test failed.

          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.

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

       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  inter-
       ested  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.

       As  described in TEST DISCOVERY, tests are always located inside a test
       suite.  Test suites serve to define the format of the tests  they  con-
       tain, the logic for finding those tests, and any additional information
       to run the tests.

       lit  identifies  test  suites  as  directories  containing  lit.cfg  or
       lit.site.cfg  files  (see  also --config-prefix).  Test suites are ini-
       tially discovered by recursively searching up the  directory  hierarchy
       for  all  the  input  files  passed  on  the command line.  You can use
       --show-suites to display the discovered test suites at startup.

       Once a test suite is discovered, its config  file  is  loaded.   Config
       files  themselves  are Python modules which will be executed.  When the
       config file is executed, two important global variables are predefined:

          The global lit configuration object (a  LitConfig  instance),  which
          defines  the  builtin test formats, global configuration parameters,
          and other helper routines for implementing test configurations.

          This is the config object (a TestingConfig instance)  for  the  test
          suite, which the config file is expected to populate.  The following
          variables are also available on the config  object,  some  of  which
          must be set by the config and others are optional or predefined:

          name  [required]  The name of the test suite, for use in reports and

          test_format [required] The test format object which will be used  to
          discover  and run tests in the test suite.  Generally this will be a
          builtin test format available from the lit.formats module.

          test_source_root The filesystem path to the test  suite  root.   For
          out-of-dir  builds  this  is  the directory that will be scanned for

          test_exec_root For out-of-dir builds, the path  to  the  test  suite
          root  inside  the object directory.  This is where tests will be run
          and temporary output files placed.

          environment A dictionary representing the environment  to  use  when
          executing tests in the suite.

          suffixes For lit test formats which scan directories for tests, this
          variable is a list of suffixes to identify  test  files.   Used  by:

          substitutions For lit test formats which substitute variables into a
          test script, the list of substitutions to perform.  Used by: ShTest.

          unsupported Mark an unsupported directory, all tests within it  will
          be reported as unsupported.  Used by: ShTest.

          parent  The  parent configuration, this is the config object for the
          directory containing the test suite, or None.

          root The root configuration.  This is the top-most lit configuration
          in the project.

          pipefail Normally a test using a shell pipe fails if any of the com-
          mands on the pipe fail. If this is not desired, setting  this  vari-
          able  to  false  makes the test fail only if the last command in the
          pipe fails.

       Once test suites are located,  lit  recursively  traverses  the  source
       directory  (following  test_source_root)  looking  for tests.  When lit
       enters a sub-directory, it first checks to see if a nested  test  suite
       is  defined  in that directory.  If so, it loads that test suite recur-
       sively, otherwise it instantiates a local test config for the directory

       Tests  are  identified by the test suite they are contained within, and
       the relative path inside that suite.  Note that the relative  path  may
       not  refer  to  an  actual  file  on  disk;  some test formats (such as
       GoogleTest) define "virtual tests" which have a path that contains both
       the  path to the actual test file and a subpath to identify the virtual

       When lit loads a subdirectory in a test suite, it instantiates a  local
       test  configuration  by cloning the configuration for the parent direc-
       tory --- the root of this configuration chain will  always  be  a  test
       suite.   Once  the  test  configuration  is  cloned  lit  checks  for a
       lit.local.cfg file in the subdirectory.  If present, this file will  be
       loaded  and  can be used to specialize the configuration for each indi-
       vidual directory.  This facility can be used to  define  subdirectories
       of  optional tests, or to change other configuration parameters --- for
       example, to change the test format, or the suffixes which identify test

       The lit output for a test run conforms to the following schema, in both
       short and verbose modes (although in short mode no PASS lines  will  be
       shown).   This schema has been chosen to be relatively easy to reliably
       parse by a machine (for example in  buildbot  log  scraping),  and  for
       other tools to generate.

       Each test result is expected to appear on a line that matches:

          <result code>: <test name> (<progress info>)

       where  <result-code>  is  a  standard  test  result such as PASS, FAIL,
       XFAIL, XPASS, UNRESOLVED, or UNSUPPORTED.  The performance result codes
       of IMPROVED and REGRESSED are also allowed.

       The  <test name> field can consist of an arbitrary string containing no

       The <progress info> field can be used to  report  progress  information
       such  as  (1/300)  or can be empty, but even when empty the parentheses
       are required.

       Each test result may include additional (multiline) log information  in
       the following format:

          <log delineator> TEST '(<test name>)' <trailing delineator>
          ... log message ...
          <log delineator>

       where <test name> should be the name of a preceding reported test, <log
       delineator> is a string of "*" characters at least four characters long
       (the  recommended  length is 20), and <trailing delineator> is an arbi-
       trary (unparsed) string.

       The following is an example of a test run output which consists of four
       tests A, B, C, and D, and a log message for the failing test C:

          PASS: A (1 of 4)
          PASS: B (2 of 4)
          FAIL: C (3 of 4)
          ******************** TEST 'C' FAILED ********************
          Test 'C' failed as a result of exit code 1.
          PASS: D (4 of 4)

       The  lit  distribution contains several example implementations of test
       suites in the ExampleTests directory.

       See attributes(7) for descriptions of the following attributes:

       |Availability   | developer/llvm/llvm |
       |Stability      | Uncommitted         |

       Maintained by The LLVM Team (http://llvm.org/).

       2003-2016, LLVM Project

       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source                was                downloaded                from

       Further information about this software can be found on the open source
       community website at https://llvm.org/.

3.8                               2016-07-10                            LIT(1)