[OpenMP][Tool] Fix install directory of ompt-multiplex.h

[protze.joachim]

Summary

As raised in https://reviews.llvm.org/D76012, the header is currently installed to $CMAKE_INSTALL_PREFIX/include.
This patch changes the install destination to install next to the other OpenMP headers.

[Hahnfeld]

LIBOMP_HEADERS_INSTALL_PATH is the internal compiler where for example omp.h. I think the header tool is of relevance outside of Clang, so IMO it should go the general include/ directory.

[protze.joachim]

With the same argument, omp-tools.h should not go to ${CMAKE_INSTALL_PREFIX}/lib/clang/11.0.0/include/omp-tools.h, but ${CMAKE_INSTALL_PREFIX}/include.
Other than omp.h, the header is not used for code compiled with -fopenmp flag.

openmp/runtime/CMakeLists.txt

 endif()
 
 add_subdirectory(src)
 add_subdirectory(test)
 
 # make these variables available for tools:
 set(LIBOMP_LIBRARY_DIR ${LIBOMP_LIBRARY_DIR} PARENT_SCOPE)
 set(LIBOMP_INCLUDE_DIR ${LIBOMP_INCLUDE_DIR} PARENT_SCOPE)
+set(LIBOMP_HEADERS_INSTALL_PATH ${LIBOMP_HEADERS_INSTALL_PATH} PARENT_SCOPE)
 No newline at end of file

openmp/runtime/src/CMakeLists.txt

 # We want to install libomp in DESTDIR/CMAKE_INSTALL_PREFIX/lib
 # We want to install headers in DESTDIR/CMAKE_INSTALL_PREFIX/include
 if(${OPENMP_STANDALONE_BUILD})
   set(LIBOMP_HEADERS_INSTALL_PATH include)
 else()
   string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION ${PACKAGE_VERSION})
   set(LIBOMP_HEADERS_INSTALL_PATH "${OPENMP_INSTALL_LIBDIR}/clang/${CLANG_VERSION}/include")
 endif()
+set(LIBOMP_HEADERS_INSTALL_PATH ${LIBOMP_HEADERS_INSTALL_PATH} PARENT_SCOPE)
 if(WIN32)
   install(TARGETS omp RUNTIME DESTINATION bin)
   install(TARGETS ompimp ARCHIVE DESTINATION "${OPENMP_INSTALL_LIBDIR}")
   # Create aliases (regular copies) of the library for backwards compatibility
   set(LIBOMP_ALIASES "libiomp5md")
   foreach(alias IN LISTS LIBOMP_ALIASES)
     install(CODE "execute_process(COMMAND \"\${CMAKE_COMMAND}\" -E copy \"${LIBOMP_LIB_FILE}\"
       \"${alias}${LIBOMP_LIBRARY_SUFFIX}\" WORKING_DIRECTORY \${CMAKE_INSTALL_PREFIX}/bin)")

openmp/tools/multiplex/CMakeLists.txt

 if(LIBOMP_OMPT_SUPPORT)
   include_directories(${LIBOMP_INCLUDE_DIR})
 
   add_library(ompt-multiplex INTERFACE)
   target_include_directories(ompt-multiplex INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
 
-  install(FILES ompt-multiplex.h DESTINATION include)
+  install(FILES ompt-multiplex.h DESTINATION ${LIBOMP_HEADERS_INSTALL_PATH})
 
   add_subdirectory(tests)
 endif()