[CMake] Install resource files into a share/ directory

[phosek]

Summary

Currently these files are being installed into a root installation
directory, but this triggers an error when the installation directory
is set to an empty string which is often the case when DESTDIR is
used to control the installation destination.

[fjricci]

Verified that this fixes my DESTDIR build of standalone compiler-rt.

[smeenai]

I like this idea, but will anything else need to be updated if these files are installed in this new location?

[smeenai]

Looks like the blacklist files are installed using add_compiler_rt_resource_file, so at the very least, this would require updating getDefaultBlacklist in clang to look in the new location?

[phosek]

I forgot about Clang driver, I've created D41706 to update the driver.

[compnerd]

This needs to be coordinated with D41706.

[hintonda]

compiler-rt/trunk/cmake/Modules/AddCompilerRT.cmake

434 ↗

(On Diff #129207)

I think you need to append "share" here too.

cmake/Modules/AddCompilerRT.cmake

macro(add_compiler_rt_resource_file target_name file_name component)
   set(dst_file "${COMPILER_RT_OUTPUT_DIR}/${file_name}")
   add_custom_command(OUTPUT ${dst_file}
     DEPENDS ${src_file}
     COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src_file} ${dst_file}
     COMMENT "Copying ${file_name}...")
   add_custom_target(${target_name} DEPENDS ${dst_file})
   # Install in Clang resource directory.
   install(FILES ${file_name}
-    DESTINATION ${COMPILER_RT_INSTALL_PATH}
+    DESTINATION ${COMPILER_RT_INSTALL_PATH}/share
     COMPONENT ${component})
   add_dependencies(${component} ${target_name})
 
   set_target_properties(${target_name} PROPERTIES FOLDER "Compiler-RT Misc")
 endmacro()
 
 macro(add_compiler_rt_script name)
   set(dst ${COMPILER_RT_EXEC_OUTPUT_DIR}/${name})

lib/dfsan/CMakeLists.txt

add_custom_command(OUTPUT ${dfsan_abilist_filename}
                    VERBATIM
                    COMMAND
                      cat ${CMAKE_CURRENT_SOURCE_DIR}/done_abilist.txt
                          ${CMAKE_CURRENT_SOURCE_DIR}/libc_ubuntu1404_abilist.txt
                          > ${dfsan_abilist_filename}
                    DEPENDS done_abilist.txt libc_ubuntu1404_abilist.txt)
 add_dependencies(dfsan dfsan_abilist)
 install(FILES ${dfsan_abilist_filename}
-        DESTINATION ${COMPILER_RT_INSTALL_PATH})
+        DESTINATION ${COMPILER_RT_INSTALL_PATH}/share)