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<p class="MsoNormal">In an internal project, we build libcxx+libcxxabi with many settings configured in a cmake cache file. It gets invoked roughly like so:<o:p></o:p></p>
<p class="MsoNormal" style="text-indent:.5in"><o:p> </o:p></p>
<p class="MsoNormal" style="text-indent:.5in">cmake -DLLVM_ENABLE_PROJECTS=libcxx;libcxxabi;pstl -C./libcxx/xyz/target.cmake -DCMAKE_INSTALL_PREFIX=/target/install/path ../llvm-project/llvm<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">… I would prefer to include as many of the relevant build settings as possible in the ‘target.cmake’ file. Today we clobber “CMAKE_CXX_FLAGS” with the required target-specific flags in that file and it’s effective. But it doesn’t cooperate
well with the rest of the libcxx/libcxxabi cmake configuration. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This seems really simple but I’ve never quite been able to figure out how to append flags to the build configuration from the cmake cache. I’ve tried a few different ways of writing to LIBCXX_COMPILE_FLAGS (including with CACHE FORCE)
but even if the value in LIBCXX_COMPILE_FLAGS persists in the CMakeCache.txt they don’t seem to be reflected in the flags used to build. So it’s probably some cmake rules I don’t quite understand about the order or scope in which LIBCXX_COMPILE_FLAGS is defined.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’m sure I’m missing something simple – can anyone share a good way to accomplish my goal of adding/removing compile+link flags in the preloaded cmake cache file?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">-Brian<o:p></o:p></p>
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