[OpenMP][CMake] Clean up the CMake variable `LIBOMPTARGET_LLVM_INCLUDE_DIRS`

[tianshilei1992]

Summary

LIBOMPTARGET_LLVM_INCLUDE_DIRS is currently checked and included for
multiple times redundantly. This patch is simply a clean up.

[jhuber6]

LG

[JonChesterfield]

Nice, thanks!

openmp/libomptarget/CMakeLists.txt

 # Get dependencies for the different components of the project.
 include(LibomptargetGetDependencies)
 
 # LLVM source tree is required at build time for libomptarget
 if (NOT LIBOMPTARGET_LLVM_INCLUDE_DIRS)
   message(FATAL_ERROR "Missing definition for LIBOMPTARGET_LLVM_INCLUDE_DIRS")
 endif()
 
+include_directories(${LIBOMPTARGET_LLVM_INCLUDE_DIRS})
+
 # This is a list of all the targets that are supported/tested right now.
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} aarch64-unknown-linux-gnu")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} aarch64-unknown-linux-gnu-newDriver")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} amdgcn-amd-amdhsa")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} amdgcn-amd-amdhsa-newDriver")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} powerpc64le-ibm-linux-gnu")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} powerpc64le-ibm-linux-gnu-newDriver")
 set (LIBOMPTARGET_ALL_TARGETS "${LIBOMPTARGET_ALL_TARGETS} powerpc64-ibm-linux-gnu")

openmp/libomptarget/DeviceRTL/CMakeLists.txt

 set(LIBOMPTARGET_BUILD_DEVICERTL_BCLIB TRUE CACHE BOOL
   "Can be set to false to disable building this library.")
 
 if (NOT LIBOMPTARGET_BUILD_DEVICERTL_BCLIB)
   libomptarget_say("Not building DeviceRTL: Disabled by LIBOMPTARGET_BUILD_DEVICERTL_BCLIB")
   return()
 endif()
 
-if (NOT LIBOMPTARGET_LLVM_INCLUDE_DIRS)
-  libomptarget_say("Not building DeviceRTL: Missing definition for LIBOMPTARGET_LLVM_INCLUDE_DIRS")
-  return()
-endif()
-
 if (LLVM_DIR)
   # Builds that use pre-installed LLVM have LLVM_DIR set.
   find_program(CLANG_TOOL clang PATHS ${LLVM_TOOLS_BINARY_DIR} NO_DEFAULT_PATH)
   find_program(LINK_TOOL llvm-link PATHS ${LLVM_TOOLS_BINARY_DIR}
     NO_DEFAULT_PATH)
   find_program(OPT_TOOL opt PATHS ${LLVM_TOOLS_BINARY_DIR} NO_DEFAULT_PATH)
   if ((NOT CLANG_TOOL) OR (NOT LINK_TOOL) OR (NOT OPT_TOOL))
     libomptarget_say("Not building DeviceRTL. Missing clang: ${CLANG_TOOL}, llvm-link: ${LINK_TOOL} or opt: ${OPT_TOOL}")

openmp/libomptarget/plugins/amdgpu/CMakeLists.txt

if(NOT LIBOMPTARGET_DEP_LIBELF_FOUND)
   return()
 endif()
 
 if(NOT CMAKE_SYSTEM_PROCESSOR MATCHES "(x86_64)|(ppc64le)|(aarch64)$" AND CMAKE_SYSTEM_NAME MATCHES "Linux")
   libomptarget_say("Not building AMDGPU plugin: only support AMDGPU in Linux x86_64, ppc64le, or aarch64 hosts")
   return()
 endif()
 
-if (NOT LIBOMPTARGET_LLVM_INCLUDE_DIRS)
-  libomptarget_say("Not building AMDGPU plugin: Missing definition for LIBOMPTARGET_LLVM_INCLUDE_DIRS")
-  return()
-endif()
-
 ################################################################################
 # Define the suffix for the runtime messaging dumps.
 add_definitions(-DTARGET_NAME=AMDGPU)
 if(CMAKE_SYSTEM_PROCESSOR MATCHES "(ppc64le)|(aarch64)$")
    add_definitions(-DLITTLEENDIAN_CPU=1)
 endif()
 
 if(CMAKE_BUILD_TYPE MATCHES Debug)
   add_definitions(-DDEBUG)
 endif()
 
 include_directories(
   ${CMAKE_CURRENT_SOURCE_DIR}/impl
-  ${LIBOMPTARGET_LLVM_INCLUDE_DIRS}
 )
 
 set(LIBOMPTARGET_DLOPEN_LIBHSA OFF)
 option(LIBOMPTARGET_FORCE_DLOPEN_LIBHSA "Build with dlopened libhsa" ${LIBOMPTARGET_DLOPEN_LIBHSA})
 
 if (${hsa-runtime64_FOUND} AND NOT LIBOMPTARGET_FORCE_DLOPEN_LIBHSA)
   libomptarget_say("Building AMDGPU plugin linked against libhsa")
   set(LIBOMPTARGET_EXTRA_SOURCE)

openmp/libomptarget/plugins/common/elf_common/CMakeLists.txt

 # Build elf_common with PIC to be able to link it with plugin shared libraries.
 set_property(TARGET elf_common PROPERTY POSITION_INDEPENDENT_CODE ON)
 llvm_update_compile_flags(elf_common)
 set(LINK_LLVM_LIBS LLVMBinaryFormat LLVMObject LLVMSupport)
 if (LLVM_LINK_LLVM_DYLIB)
   set(LINK_LLVM_LIBS LLVM)
 endif()
 target_link_libraries(elf_common INTERFACE ${LINK_LLVM_LIBS})
-include_directories(${LIBOMPTARGET_LLVM_INCLUDE_DIRS})
 add_dependencies(elf_common ${LINK_LLVM_LIBS})
 
 # The code uses Debug.h, which requires threads support.
 target_link_libraries(elf_common INTERFACE ${OPENMP_PTHREAD_LIB})
 
 # Expose elf_common.h directory to the users of this library.
 target_include_directories(elf_common INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})

openmp/libomptarget/plugins/cuda/CMakeLists.txt

 
 libomptarget_say("Building CUDA offloading plugin.")
 
 # Define the suffix for the runtime messaging dumps.
 add_definitions(-DTARGET_NAME=CUDA)
 
 include_directories(
   ${LIBOMPTARGET_DEP_LIBELF_INCLUDE_DIRS}
-  ${LIBOMPTARGET_LLVM_INCLUDE_DIRS}
 )
 
 set(LIBOMPTARGET_DLOPEN_LIBCUDA OFF)
 option(LIBOMPTARGET_FORCE_DLOPEN_LIBCUDA "Build with dlopened libcuda" ${LIBOMPTARGET_DLOPEN_LIBCUDA})
 
 set(LIBOMPTARGET_CAN_LINK_LIBCUDA FALSE)
 if (LIBOMPTARGET_DEP_CUDA_FOUND AND LIBOMPTARGET_DEP_CUDA_DRIVER_FOUND)
   set(LIBOMPTARGET_CAN_LINK_LIBCUDA TRUE)

openmp/libomptarget/src/CMakeLists.txt

set(LIBOMPTARGET_SRC_FILES
   ${CMAKE_CURRENT_SOURCE_DIR}/interface.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/interop.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/omptarget.cpp
   ${CMAKE_CURRENT_SOURCE_DIR}/rtl.cpp
 )
 
 set(LIBOMPTARGET_SRC_FILES ${LIBOMPTARGET_SRC_FILES} PARENT_SCOPE)
 
-include_directories(${LIBOMPTARGET_LLVM_INCLUDE_DIRS})
-
 # Build libomptarget library with libdl dependency.
 add_library(omptarget SHARED ${LIBOMPTARGET_SRC_FILES})
 set_target_properties(omptarget PROPERTIES INSTALL_RPATH "$ORIGIN" BUILD_RPATH "$ORIGIN")
 if (OPENMP_ENABLE_LIBOMPTARGET_PROFILING)
   # Add LLVMSupport dependency if profiling is enabled.
   # Linking with LLVM component libraries also requires
   # aligning the compile flags.
   llvm_update_compile_flags(omptarget)