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:
@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 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 thee3.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:
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 eachtest.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. SeeAdaCoreLegacyTestDriver.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:
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 booleanNOT
.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:
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 thetest.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
(andtest.sh
iftest.cmd
does not exist). Note thattest.cmd
is processed by the Windows command interpreter. On other systems the default script file istest.sh
(andtest.cmd
iftest.sh
does not exist). If you want to override the default, useCMD
. 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 thensh
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 notest.out
then a null output is expected from the test. In order to override this default you can useOUT
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 sametest.out
for both. Indeed test drivers often perform some filtering/processing of both the output and thetest.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:
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 theDEAD
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 thetest.opt
: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:
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 beXPASS
(for unexpected passed,UOK
on GAIA).XFAIL
should be used instead ofDEAD
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 theXFAIL
command, the test is marked asXFAIL
with an annotation added to the comment signaling that the test has not been run. As for theXFAIL
command the mandatory third field is a short comment explaining why we expect the failure.RLIMIT <duration in seconds>
Override the default time limit (780s) for this test on the specified configuration (as passed to e3’s
rlimit
program).- <empty>
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 previousALL DEAD
command, as well as disable all subsequentDEAD
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:
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:
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:
GCC34 OUT test_gcc34.out
Than this way:
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
:
$ 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"