Compatibility for AdaCore's legacy testsuites ============================================= Although all the default behaviors in ``e3.testsuite`` presented in this documentation should be fine for most new projects, it is not realistic to require existing big testsuites to migrate to them. A lot of testsuites at AdaCore use similar formalisms (atomic testcases, dedicated test directories, ...), but different formats: no ``test.yaml`` file, custom files for test execution control, etc. These testsuites contain a huge number of testcases, and thus it is a better investment of time to introduce compatible settings in testsuite scripts rather than reformat all testcases. This section presents compatibility helpers for legacy AdaCore testsuites. Test finder ----------- The ``e3.testsuite.testcase_finder.AdaCoreLegacyTestFinder`` class can act as a drop-in test finder for legacy AdaCore testsuites: all directories whose name matches a TN (Ticket Number), i.e. matching the ``[0-9A-Z]{2}[0-9]{2}-[A-Z0-9]{3}`` regular expression, are considered as containing a testcase. Legacy AdaCore testsuites have only one driver, so this test finder always use the same driver. For instance: .. code-block:: python @property def test_finders(self): # This will create a testcase for all directories whose name matches a # TN, using the MyDriver test driver. return [AdaCoreLegacyTestFinder(MyDriver)] Test control ------------ AdaCore legacy testsuites rely on a custom file format to lead testcase execution control: ``test.opt`` files. Similarly to the :ref:`YAML-based control descriptions `, this format provides a declarative formalism to describe settings depending on the environment, and more precisely on a set of *discriminants* ("the configuration"): simple case insensitive names for environment specificities. For instance: ``linux`` on a Linux system, ``windows`` on a Windows one, ``x86`` on Intel 32 bits architecture, ``vxworks`` when targetting a VxWorks is involved, etc. The set of discriminants for a given testsuite run is stored in testsuite reports, and visible in GAIA's ``Discriminants`` testsuite report section. A parser for such files is included in ``e3.testsuite`` (see the ``optfileparser`` module), and most importantly, a ``TestControlCreator`` subclass binds it to the rest of the testsuite framework: ``AdaCoreLegacyTestControlCreator``, from the ``e3.testsuite.control`` module. Its constructor requires the list of discriminants used to selectively evaluate ``test.opt`` directives. The ``e3.env.Env`` class provides a `discriminants `_ method to compute a basic set of discriminants based on the current context (build/host/target platforms, ...), then testsuites are free to add more discriminants as they see fit. This file format not only controls test execution with its ``DEAD``, ``XFAIL`` and ``SKIP`` commands: it also allows to control the name of the script file to run (``CMD`` command), the name of the output baseline file (``OUT``), the time limit for the script (``RLIMIT``), etc. For this reason, ``AdaCoreLegacyTestControlCreator`` works best with the AdaCore legacy test driver: see the next section. Test driver ----------- All legacy AdaCore testsuites use actual/expected test output comparisons to determine if a test passes, so the reference test driver for them derives from ``DiffTestDriver``: ``e3.testsuite.driver.adacore.AdaCoreLegacyTestDriver``. This driver is coupled with a custom test execution control mechanism: ``test.opt`` files (see the previous section), and thus overrides the ``test_control_creator`` property accordingly. This driver has two requirements for ``Testsuite`` subclasses using it: * Put a process environment (string dictionary) for subprocesses in ``self.env.test_environ``. By default they can just put a copy of the testsuite's own environment: ``dict(os.environ)``. * Put the list of discriminants (list of strings) in ``self.env.discs``. For the latter, starting from the result of the ``e3.env.AbstractEnv.discriminants`` property can help, as it computes standard discriminants based on the current host/build/target platforms. Testsuites can then add more discriminants as needed. For instance, imagine a testsuite that wants standard dircriminants plus the ``valgrind`` discriminant if the ``--valgrind`` command-line option is passed to the testsuite: .. code-block:: python class MyTestsuite(Testsuite): def add_options(self, parser): parser.add_argument("--valgrind", action="store_true", help="Run tests under Valgrind") def set_up(self): super(MyTestsuite, self).set_up() self.env.test_environ = dict(os.environ) self.env.discs = self.env.discriminants if self.env.options.valgrind: self.env.discs.append("valgrind") There is little point describing precisely the convoluted behavior for this driver, so we will stick here to a summary, with a few pointers to go further: * All testcases must provide a script to run. Depending on testsuite defaults (``AdaCoreLegacyTestControlCreator.default_script`` property) and the content of each ``test.opt`` testcase file, this script can be a Windows batch script (``*.cmd``), a Bourne-compatible shell script (``*.sh``) or a Python script (``*.py``). * It is the output of this script that is compared against the output baseline. To hide environment-specific differences, output refiners turn backslashes into forward slashes, remove ``.exe`` extensions and also remove occurences of the working directory. * On Unix systems, this driver has a very crude conversion of Windows batch script to Bourne-compatible scripts: text substitution remove some ``.exe`` extensions, replaces ``%VAR%`` environment variable references with ``$VAR``, etc. See ``AdaCoreLegacyTestDriver.get_script_command_line``. Note that subclasses can override this method to automatically generate a test script. Curious readers are invited to read the sources to know the details: doing so is necessary anyway to override specific behaviors so that this driver fits the precise need of some testsuite. Hopefully, this documentation and inline comments have made this process easier. ``test.opt`` syntax ------------------- The ``test.opt`` syntax allows users to add Ada-style comments anywhere in the ``test.opt`` file. When ``--`` is encountered every character until the next line break will be ignored. The ``test.opt`` grammar is the following: .. code-block:: text testopt : testopt line | line ; line : flag_list ASCII.LF | flag_list command ASCII.LF | flag_list command argument ASCII.LF | ASCII.LF ; flag_list : flag_list ',' expr /* no space is allowed between flags */ | expr expr : !FLAG | FLAG command : CMD|OUT|DEAD|REQUIRED|XFAIL|SKIP|RLIMIT Basically, each line of a ``test.opt`` file is composed of three fields separated by white spaces (the number of white spaces between each fields is not fixed): * The first field is either a single flag or a list of flags separated by commas (without spaces between them). Flags can prefixed by a ``!`` which behave as a boolean ``NOT``. * The second field is the command. * The last is the argument of the command. Notice that the argument can contain spaces as the parser will take every character from the end of the command field up to the next newline (or comment). Notice that the ``test.opt`` parser is case insensitive. ``test.opt`` semantics ---------------------- For each line in the ``test.opt`` file, the ``test.opt`` parser/interpreter compares the list of flags on the line to those defined for the current configuration. If all flags on the current line belong to the list of configuration flags (or absent from it in the case of an exclamation sign in front of the flag) then the line is taken into account. When this occurs, all subsequent lines with the same command type (``CMD``, ``OUT``, ..) are ignored, except if the current line only contains the ``ALL`` flag. Here is an example: .. code-block:: text Linux CMD linux.cmd Linux,PowerPC CMD linuxppc.cmd ALL CMD default.cmd AIX CMD aix.cmd Depending on the configuration the following lines will be matched: * ``Linux,x86``: first line matches. * ``Linux,PowerPC``: first line matches. If you want the second line to match as well, then you need to swap first and second line of the ``test.opt``. * ``AIX,PowerPC``: last line matches. * ``VMS,Alpha``: third line matches. Each type of command is handled independently except for the ``DEAD`` command. When a given configuration matches a line with the ``DEAD`` command, the ``DEAD`` command will be taken into account only if the current configuration does not match any line with another type of command. If a line containing no command is matched, the main effect is to disable subsequent ``DEAD`` commands. ``test.opt`` commands manual ---------------------------- ``CMD`` On Microsoft Windows systems, the default script file is ``test.cmd`` (and ``test.sh`` if ``test.cmd`` does not exist). Note that ``test.cmd`` is processed by the Windows command interpreter. On other systems the default script file is ``test.sh`` (and ``test.cmd`` if ``test.sh`` does not exist). If you want to override the default, use ``CMD``. In this case the third field will be the filename of the script to be used. Note that when you override the defaults, if the script has a ``.sh`` extension then ``sh`` will be used. Otherwise, the default system shell is used (``cmd`` on Windows, ``sh`` on Unixes). ``OUT`` By default, when a test is executed, its output is compared to a file called ``test.out``. If the contents are the same then the test is marked as passed. If there is no ``test.out`` then a null output is expected from the test. In order to override this default you can use ``OUT`` command and set the third argument to a file that contains the expected output. Notice that even if the output differs between two platforms, you can often use the same ``test.out`` for both. Indeed test drivers often perform some filtering/processing of both the output and the ``test.out`` file in order to remove differences like ``/`` and ``\`` in paths. ``DEAD`` Do not run this test on the specified configuration, with the aforementioned provision about the interaction with other commands. If it is honored, the status of the test will be ``SKIPPED`` (``DEAD`` on GAIA); in this case, if a third field is specified, it will be added as a comment to the report. Example: .. code-block:: text AIX DEAD this feature is not supported on AIX ``REQUIRED`` Do not run a test if the current configuration does not contain the specified discriminant. The ``REQUIRED`` command is a variant of the ``DEAD`` command. Its main difference is that it cannot be cancelled by other matching lines. Currently it's mainly used in the GPRbuild testsuite in order to simplify the ``test.opt``: .. code-block:: text Ada,C REQUIRED Linux test-linux.cmd Aix DEAD In this example, running the testcase requires at least Ada and C discriminants to be present. Other lines are not considered if not. ``XFAIL`` Expect a test failure on specified target. The mandatory third field is the comment explaining why we expect a failure for this test. Example: .. code-block:: text IA64 XFAIL currently this test is failing on IA64 If the test fails for the specified target(s) the status will be ``XFAIL``. If the test passes then its status will be ``XPASS`` (for unexpected passed, ``UOK`` on GAIA). ``XFAIL`` should be used instead of ``DEAD`` if we intend to make the test pass on this configuration someday. ``SKIP`` Expect a test failure on specified target. The difference with the ``XFAIL`` command is that there is no attempt to run the test. This is useful for tests that are for example affecting machine stability, or for tests that sometimes pass "by accident". As for the ``XFAIL`` command, the test is marked as ``XFAIL`` with an annotation added to the comment signaling that the test has not been run. As for the ``XFAIL`` command the mandatory third field is a short comment explaining why we expect the failure. ``RLIMIT `` Override the default time limit (780s) for this test on the specified configuration (as passed to e3's ``rlimit`` program). Do run this test on specified target if not already explicitly cancelled. This is not a command; in particular, it will not override a previous ``DEAD`` command that is explicitly matched (i.e. a non-``ALL`` ``DEAD`` command). But it will override a previous ``ALL DEAD`` command, as well as disable all subsequent ``DEAD`` commands that would have otherwise matched. ``test.opt`` important advice ----------------------------- When you need to create a ``test.opt`` file, you should think twice when choosing the characteristic(s) that will be used to make the distinction between two configurations. Here are two examples: First let's say that a new functionality is available only on Linux and Windows. The more evident ``test.opt`` will be: .. code-block:: text ALL DEAD NT Linux This approach is **very bad**. Indeed when the functionality is added on more exotic platforms, the test won't be executed... except if the famous "someone" updates all the tests related to that functionality. The good approach in this is to open an issue and ask testsuite maintainers maintainers to add a new tag that describes this functionality: .. code-block:: text ALL DEAD great-functionality This way when the functionality is implemented on a new platform, the test will be automatically activated. The second advice concerns differences between versions of GCC. For example assume we have currently the default output for GCC 3.4.x builds and we introduce the builds for GCC 4.1.x. If the test output differs it's better to write the ``test.opt`` this way: .. code-block:: text GCC34 OUT test_gcc34.out Than this way: .. code-block:: text GCC41 OUT test_gcc41.out Indeed if you introduce afterward the builds for GCC 4.2.x, there is more chance that the new output match the GCC 4.1.x one than the GCC 3.4.x one. So when there is a difference trigerred by different GCC versions, use the last GCC version as the default. Testing a test.opt file ----------------------- In order to test a ``test.opt`` file you can use the following script provided by ``e3-testsuite``: .. code-block:: sh $ cat test.opt Linux CMD linux.cmd Linux,PowerPC CMD linuxppc.cmd ALL CMD default.cmd AIX CMD aix.cmd $ e3-opt-parser ALL,Linux ./test.opt cmd="linux.cmd" $ e3-opt-parser ALL,AIX ./test.opt cmd="aix.cmd"