When using catch_discover_tests() with DISCOVERY_MODE PRE_TEST and a
multi-config generator (e.g. Ninja Multi-Config), if a test target has
zero discoverable tests (e.g. all tests tagged with [.]), ctest fails:
CMake Error: include could not find requested file:
.../test-hidden-b12d07c_tests-Release.cmake
The early return added in #2962 (76f70b14) correctly prevented a JSON
parsing crash for zero tests, but skipped writing the ctest file. The
PRE_TEST include script unconditionally includes this file, so the
missing file causes a hard error that aborts all test discovery.
Write an empty file before returning early so the include always
succeeds.
Classes will automatically inherit the virtual-ness of their base
class destructors. If the base class already has a virtual
destructor and the derived class needs default destructor semantics
then the derived class can omit defining the destructor in favor of
the compiler automatically defining it.
This has an additional benefit of reenabling move semantics. The
presence of a user-specified destructor automatically disables move
operations.
Introducing a new DISCOVERY_MODE mode option, which provides greater
control over when catch_discover_tests perforsm test discovery.
It has two supported modes:
* POST_BUILD: The default behavior, which adds a POST_BUILD command
to perform test discovery after the test has been built as was
always done so far.
* PRE_TEST: New mode, which delays test discovery until test execution.
The generated include file generates the appropriate CTest files at
runtime and regenerates the CTest files when the executable is
updated.
This mode can be used in build-environments that don't allow for
executing the linked binaries at build-time (like in a
cross-compilation environment).
DISCOVERY_MODE can be controlled in two ways:
1. Setting the DISCOVERY_MODE when calling catch_discover_tests.
2. Setting the global CMAKE_CATCH_DISCOVER_TESTS_DISCOVERY_MODE prior
to calling gtest_discover_tests.
Closes#2493
Move test discovery logic into new catch_discover_tests_impl method
and make CatchAddTests aware of whether it is being launched in
CMake's script mode.
When launched in script mode, catch_discover_tests_impl is called
passing arguments obtained from the definitions passed into the call
to cmake. This preserves the existing behavior assumed by Catch.cmake.
Looking ahead, it also allows CatchAddTests to be included in
generated files and call catch_discover_tests_impl to perform test
discovery at test runtime with the new PRE_TEST discovery mode
introduced later.
Manuel Knörle