This allows for setting EXCLUDE_FROM_ALL, conditional on the build
configuration. However, only the Ninja Multi-Config generator supports
different property values per config. All other multi-config
generators will yield an error in that situation.
Fixes: #20923
In commit a653ca9504 (Tests: Update CUDA tests to work with Clang,
2020-03-27) some tests were conditioned using `CMAKE_CUDA_COMPILER_ID`.
That is not defined when configuring CMake itself, so it accidentally
turned off NVCC-specific CUDA tests altogether. Convert the conditions
to check `CMake_TEST_CUDA` for `Clang` instead. That option is added
explicitly to builds where we want the tests to run, so we can set it to
a value indicating the CUDA compiler vendor.
In commit a653ca9504 (Tests: Update CUDA tests to work with Clang,
2020-03-27) the NVCC-specific `CudaOnly.GPUDebugFlag` test was
accidentally broken by removing a space when appending `-G` to the CUDA
flags. This was covered by the test not running. Restore the space.
Fixes: #20727
Also rename `..._DEFAULT_BUILD_FILE_CONFIG` to `..._DEFAULT_BUILD_TYPE`.
These name changes make the variables meaningful for future use by other
generators.
Prior to this fix, CMAKE_NMC_DEFAULT_CONFIGS would inherit "all" from
the union of CMAKE_NMC_DEFAULT_BUILD_FILE_CONFIG and
CMAKE_NMC_CROSS_CONFIGS. This is inconsistent with the behavior of the
"all" target signifying CMAKE_NMC_CROSS_CONFIGS. Update "all" in
CMAKE_NMC_DEFAULT_CONFIGS to inherit only from CMAKE_NMC_CROSS_CONFIGS.
Fix an issue where CMAKE_NMC_DEFAULT_BUILD_FILE_CONFIG is specified
and CMAKE_NMC_CROSS_CONFIGS is not, which results in a false error
with CMAKE_NMC_DEFAULT_CONFIGS.
Many users will want to use the Ninja Multi-Config generator like a
traditional Visual Studio-style multi-config generator, which doesn't
mix configurations - custom commands are built using target executables
of the same configuration the command is for. We do not want to force
these people to generate an N*N build matrix when they only need N*1,
especially if they have lots of targets. Add a new variable,
CMAKE_NINJA_CROSS_CONFIG_ENABLE, to opt-in to the cross-config build
matrix.
