The current testing workflow had quite a few major flaws and it was no
longer possible after the move of Any* plugins to core. Among the flaws
is:
* Every plugin was basically built twice, once as the real plugin and
once as a static testing library. Most of the build shared common
object files, but nevertheless it inflated build times and made the
buildsystem extremely complex.
* Because the actual plugin binary was never actually loaded during the
test, it couldn't spot problems like:
- undefined references
- errors in metadata files
- mismatched plugin interface/version, missing entry points
- broken static plugin import files
* Tests that made use of independent plugins (such as TgaImageConverter
test using TgaImporter to verify the output) had a hardcoded
dependency on such plugins, making a minimal setup very hard.
* Dynamic loading of plugins from the Any* proxies was always directed
to the install location on the filesystem with no possibility to
load these directly from the build tree. That caused random ABI
mismatch crashes, or, on the other hand, if no plugins were
installed, particular portions of the codebase weren't tested at all.
Now the workflow is the following:
* Every plugin is built exactly once, either as dynamic or as static.
* The test always loads it via the plugin manager. If it's dynamic,
it's loaded straight from the build directory; if it's static, it
gets linked to the test executable directly.
* Plugins used indirectly are always served from the build directory
(if enabled) to ensure reproducibility and independence on what's
installed on the filesystem. Missing presence of these plugins causes
particular tests to be simply skipped.
* Plugins that have extensive tests for internal functionality that's
not exposed through the plugin interface are still built in two
parts, but the internal tests are simply consuming the OBJECT files
directly instead of linking to a static library.
There will be numerous additions to this one so it made sense to make it
a static library instead of a header-only library. That also allows
CMake users to just link to Magnum::OpenGLTester instead of going
through the pain of a huge branching in order to find a correct
windowless application just to run their tests. It could have been done
even without the static library using a INTERFACE target, but that
wouldn't work on CMake < 3.0 (which, unfortunately, quite a few people
are still stuck with).
Unfortunately it's already heavily used elsewhere so I had to go through
the pain of deprecating the old implementation. The old implementation
was header-only so it can't be just typedef'd to the new one as there
would be linker failures. So the old header is just kept as it was, with
only the macros reduced.
As with Corrade, this is not exactly backwards compatible, but for
common use case without OBJECT libraries this should not be a problem.
In any case, recreate the build dir and update your copy of all
Find*.cmake modules to avoid weird things happening.
User-facing changes:
* Documentation of all Find*.cmake modules converted to
reStructuredText to follow official CMake guidelines.
* The newfangled way to use the libraries is to link to Magnum::Shaders
instead of adding ${MAGNUM_SHADERS_INCLUDE_DIRS} to include path and
linking to ${MAGNUM_SHADERS_LIBRARIES}.
* The old ${MAGNUM_*_LIBRARIES} are deprecated and now just expand to
Magnum::* target. Use the target directly. These are also enabled
only when building with MAGNUM_BUILD_DEPRECATED.
* The old ${MAGNUM_*_INCLUDE_DIRS} are removed as the Magnum::* targets
cover these too.
Internal changes:
* Global state such as include_directories() was replaced with
target-specific settings.
I wanted to preserve the parameter-less constructor of tests, but WINAPI
requires fairly ugly entagled set of functions, passing HWND around,
which required storing it in a global var and hoping it is properly
initialized when querying it for it to be passed to application
constructor.
When this was done, it was now fairly easy to support passing also
argv/argc to application constructor, which in the future will enable
selective disabling of extensions for even better test coverage.
This however needed slightly different main() function and thus we now
have MAGNUM_GL_TEST_MAIN() instead of CORRADE_TEST_MAIN(). Using the
latter will result in an assert inside std::optional.
They need to be installed into possibly system-wide location on Windows
and thus we need to avoid name clashes (or at least explicitly show that
e.g. TgaImporterTestLib.dll belongs to Magnum and is not any OMG virus).
As we are now using absolute includes, there is no need to prefix
everything with "magnum<Namespace>" etc. All generated configuration
files are renamed to configure.h and their path is included _before_
everything else to avoid accidental collisions.
The only places where they aren't absolute are:
- when header is included from corresponding source file
- when including headers which are not part of final installation (e.g.
test-specific configuration, headers from Implementation/)
Everything what was in src/ is now in src/Corrade, everything from
src/Plugins is now in src/MagnumPlugins, everything from external/ is in
src/MagnumExternal. Added new CMakeLists.txt file and updated the other
ones for the moves, no other change was made. If MAGNUM_BUILD_DEPRECATED
is set, everything compiles and installs like previously except for the
plugins, which are now in MagnumPlugins and not in Magnum/Plugins.
Vladimír Vondruš