[OpenMP] Install ompt-multiplex.h alongside omp.h

[serge-sans-paille]

Summary

The default install direction may not be in the compiler search path.

[serge-sans-paille]

This is affecting clang 15.0.0, see https://godbolt.org/z/78E1GvYn4

[protze.joachim]

Without testing, I would say the variable is not visible in this CMake scope, as it is defined in openmp/runtime/src/CMakeLists.txt. I would assume that you need to set it with PARENT_SCOPE in openmp/runtime/src/CMakeLists.txt and openmp/runtime/CMakeLists.txt. Similar to LIBOMP_LIBRARY_DIR or LIBOMP_INCLUDE_DIR.

[serge-sans-paille]

Indeed! Didn't use the PARENT_SCOPE option because the two directories only have root as common parent directory though.

[protze.joachim]

Lgtm

openmp/CMakeLists.txt

 if (APPLE OR WIN32 OR NOT OPENMP_HAVE_STD_CPP17_FLAG)
   set(ENABLE_LIBOMPTARGET OFF)
 endif()
 
 option(OPENMP_ENABLE_LIBOMPTARGET "Enable building libomptarget for offloading."
        ${ENABLE_LIBOMPTARGET})
 option(OPENMP_ENABLE_LIBOMP_PROFILING "Enable time profiling for libomp." OFF)
 
+# Header install location
+if(${OPENMP_STANDALONE_BUILD})
+  set(LIBOMP_HEADERS_INSTALL_PATH "${CMAKE_INSTALL_INCLUDEDIR}")
+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()
+
 # Build host runtime library, after LIBOMPTARGET variables are set since they are needed
 # to enable time profiling support in the OpenMP runtime.
 add_subdirectory(runtime)
 
 # Build libompd.so
 add_subdirectory(libompd)
 
 if (OPENMP_ENABLE_LIBOMPTARGET)

openmp/runtime/src/CMakeLists.txt

 if(${MIC})
   add_dependencies(libomp-micro-tests libomp-test-instr)
 endif()
 add_dependencies(libomp-micro-tests libomp-test-deps)
 
 # Install rules
 # We want to install libomp in ${DESTDIR}/${CMAKE_INSTALL_FULL_LIBDIR}
 # We want to install headers in ${DESTDIR}/${CMAKE_INSTALL_FULL_INCLUDEDIR}
-if(${OPENMP_STANDALONE_BUILD})
-  set(LIBOMP_HEADERS_INSTALL_PATH "${CMAKE_INSTALL_INCLUDEDIR}")
-else()
-  string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION ${PACKAGE_VERSION})
-  set(LIBOMP_HEADERS_INSTALL_PATH "${OPENMP_INSTALL_LIBDIR}/clang/${CLANG_VERSION}/include")
-endif()
 if(WIN32)
   install(TARGETS omp RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}")
   install(TARGETS ${LIBOMP_IMP_LIB_TARGET} ARCHIVE DESTINATION "${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_FULL_BINDIR}\")")

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 "${CMAKE_INSTALL_INCLUDEDIR}")
+  install(FILES ompt-multiplex.h DESTINATION "${LIBOMP_HEADERS_INSTALL_PATH}")
 
   add_subdirectory(tests)
 endif()