When setting default CUDA_HOST_COMPILER we must dereference CMAKE_C_COMPILER,
i.e. /usr/bin/clang should be used instead /usr/bin/cc which is symlink.
Otherwise CUDA thinks it is GCC and issues -dumpspecs which is unknown option
to Clang.
Also in case neither CMAKE_C_COMPILER is defined (project does not use C
language) nor CUDA_HOST_COMPILER is specified manually we should skip -ccbin
and let nvcc use its own default C compiler.
The matches have already been calculated and can simply be taken from
CMAKE_MATCH_n variables. This avoids multiple compilations of the same or very
similar regular expressions.
Added a new CUDA variable for specifying the CUDA_HOST_COMPILER. This will allow users to
be able to specify which host compiler to use for invoking NVCC with. By default it will
use the compiler used for host compilation. This is convenient for when you want to
specify a different compiler than the default compiler. You end up using the same
compiler for both the NVCC compilation and the host compilation instead of using the
default compiler in the path for NVCC.
Ancient versions of CMake required else(), endif(), and similar block
termination commands to have arguments matching the command starting the
block. This is no longer the preferred style.
Run the following shell code:
for c in else endif endforeach endfunction endmacro endwhile; do
echo 's/\b'"$c"'\(\s*\)(.\+)/'"$c"'\1()/'
done >convert.sed &&
git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' |
egrep -z -v '^(Utilities/cm|Source/kwsys/)' |
egrep -z -v 'Tests/CMakeTests/While-Endwhile-' |
xargs -0 sed -i -f convert.sed &&
rm convert.sed
Nvcc can emit '/path' instead of '//path' which can cause a lot of grief later. We test
to see if the file exists, if it doesn't then we see if the file exists with '/'
prepended. Files that don't exist won't be added to the list.