[CMake] Ensure CLANG_RESOURCE_DIR is respected.

re-commit of 39aa0f5c43 with missing file:
cmake/Modules/GetClangResourceDir.cmake.

clang/lib/Headers/CMakeLists.txt

@@ -298,7 +298,8 @@ set(openmp_wrapper_files
   openmp_wrappers/new
 )
 
-set(output_dir ${LLVM_LIBRARY_OUTPUT_INTDIR}/clang/${CLANG_VERSION_MAJOR}/include)
+include(GetClangResourceDir)
+get_clang_resource_dir(output_dir PREFIX ${LLVM_LIBRARY_OUTPUT_INTDIR}/.. SUBDIR include)
 set(out_files)
 set(generated_files)
 
@@ -456,7 +457,7 @@ add_header_target("openmp-resource-headers" ${openmp_wrapper_files})
 add_header_target("windows-resource-headers" ${windows_only_files})
 add_header_target("utility-resource-headers" ${utility_files})
 
-set(header_install_dir lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION_MAJOR}/include)
+get_clang_resource_dir(header_install_dir SUBDIR include)
 
 #############################################################
 # Install rules for the catch-all clang-resource-headers target

clang/lib/Tooling/CMakeLists.txt

@@ -53,6 +53,8 @@ else()
     list(APPEND implicitDirs -I ${implicitDir})
   endforeach()
 
+  include(GetClangResourceDir)
+  get_clang_resource_dir(resource_dir PREFIX ${LLVM_BINARY_DIR})
   add_custom_command(
       COMMENT Generate ASTNodeAPI.json
       OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/ASTNodeAPI.json
@@ -61,7 +63,7 @@ else()
       $<TARGET_FILE:clang-ast-dump>
         # Skip this in debug mode because parsing AST.h is too slow
         --skip-processing=${skip_expensive_processing}
-        -I ${LLVM_BINARY_DIR}/lib/clang/${CLANG_VERSION_MAJOR}/include
+        -I ${resource_dir}/include
         -I ${CLANG_SOURCE_DIR}/include
         -I ${LLVM_BINARY_DIR}/tools/clang/include
         -I ${LLVM_BINARY_DIR}/include

clang/runtime/CMakeLists.txt

@@ -66,6 +66,9 @@ if(LLVM_BUILD_EXTERNAL_COMPILER_RT AND EXISTS ${COMPILER_RT_SRC_ROOT}/)
     list(APPEND compiler_rt_configure_deps LLVMTestingSupport)
   endif()
 
+  include(GetClangResourceDir)
+  get_clang_resource_dir(output_resource_dir PREFIX ${LLVM_BINARY_DIR})
+  get_clang_resource_dir(install_resource_dir)
   ExternalProject_Add(compiler-rt
     DEPENDS llvm-config clang ${compiler_rt_configure_deps}
     PREFIX ${COMPILER_RT_PREFIX}
@@ -82,9 +85,9 @@ if(LLVM_BUILD_EXTERNAL_COMPILER_RT AND EXISTS ${COMPILER_RT_SRC_ROOT}/)
                -DCMAKE_CXX_COMPILER_LAUNCHER=${CMAKE_CXX_COMPILER_LAUNCHER}
                -DLLVM_CONFIG_PATH=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-config
                -DLLVM_LIT_ARGS=${LLVM_LIT_ARGS}
-               -DCOMPILER_RT_OUTPUT_DIR=${LLVM_LIBRARY_OUTPUT_INTDIR}/clang/${CLANG_VERSION_MAJOR}
+               -DCOMPILER_RT_OUTPUT_DIR=${output_resource_dir}
                -DCOMPILER_RT_EXEC_OUTPUT_DIR=${LLVM_RUNTIME_OUTPUT_INTDIR}
-               -DCOMPILER_RT_INSTALL_PATH:PATH=lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION_MAJOR}
+               -DCOMPILER_RT_INSTALL_PATH:PATH=${install_resource_dir}
                -DCOMPILER_RT_INCLUDE_TESTS=${LLVM_INCLUDE_TESTS}
                -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
                -DLLVM_LIBDIR_SUFFIX=${LLVM_LIBDIR_SUFFIX}

cmake/Modules/GetClangResourceDir.cmake

@@ -0,0 +1,27 @@
+# get clang resource directory
+#
+# usage:
+#  get_clang_resource_dir(out_var [PREFIX prefix] [SUBDIR subdirectory])
+#
+# user can use `PREFIX` to prepend some path to it or use `SUBDIR` to
+# get subdirectory under clang resource dir
+
+function(get_clang_resource_dir out_var)
+  cmake_parse_arguments(ARG "" "PREFIX;SUBDIR" "" ${ARGN})
+
+  if(DEFINED CLANG_RESOURCE_DIR AND NOT CLANG_RESOURCE_DIR STREQUAL "")
+    set(ret_dir bin/${CLANG_RESOURCE_DIR})
+  else()
+    string(REGEX MATCH "^[0-9]+" CLANG_VERSION_MAJOR ${PACKAGE_VERSION})
+    set(ret_dir lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION_MAJOR})
+  endif()
+
+  if(ARG_PREFIX)
+    set(ret_dir ${ARG_PREFIX}/${ret_dir})
+  endif()
+  if(ARG_SUBDIR)
+    set(ret_dir ${ret_dir}/${ARG_SUBDIR})
+  endif()
+
+  set(${out_var} ${ret_dir} PARENT_SCOPE)
+endfunction()

compiler-rt/cmake/base-config-ix.cmake

@@ -7,6 +7,7 @@ include(BuiltinTests)
 include(CheckIncludeFile)
 include(CheckCXXSourceCompiles)
 include(GNUInstallDirs)
+include(GetClangResourceDir)
 include(ExtendPath)
 include(CompilerRTDarwinUtils)
 
@@ -38,15 +39,10 @@ if (LLVM_LIBRARY_OUTPUT_INTDIR AND LLVM_RUNTIME_OUTPUT_INTDIR AND PACKAGE_VERSIO
 endif()
 
 if (LLVM_TREE_AVAILABLE)
-  # Compute the Clang version from the LLVM version.
-  # FIXME: We should be able to reuse CLANG_VERSION_MAJOR variable calculated
-  #        in Clang cmake files, instead of copying the rules here.
-  string(REGEX MATCH "^[0-9]+" CLANG_VERSION_MAJOR
-         ${PACKAGE_VERSION})
   # Setup the paths where compiler-rt runtimes and headers should be stored.
-  set(COMPILER_RT_OUTPUT_DIR ${LLVM_LIBRARY_OUTPUT_INTDIR}/clang/${CLANG_VERSION_MAJOR})
+  get_clang_resource_dir(COMPILER_RT_OUTPUT_DIR PREFIX ${LLVM_LIBRARY_OUTPUT_INTDIR}/..)
   set(COMPILER_RT_EXEC_OUTPUT_DIR ${LLVM_RUNTIME_OUTPUT_INTDIR})
-  set(COMPILER_RT_INSTALL_PATH lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION_MAJOR})
+  get_clang_resource_dir(COMPILER_RT_INSTALL_PATH)
   option(COMPILER_RT_INCLUDE_TESTS "Generate and build compiler-rt unit tests."
          ${LLVM_INCLUDE_TESTS})
   option(COMPILER_RT_ENABLE_WERROR "Fail and stop if warning is triggered"

lldb/source/Plugins/ExpressionParser/Clang/ClangHost.cpp

@@ -10,6 +10,7 @@
 
 #include "clang/Basic/Version.h"
 #include "clang/Config/config.h"
+#include "clang/Driver/Driver.h"
 
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Twine.h"
@@ -51,11 +52,14 @@ static bool DefaultComputeClangResourceDirectory(FileSpec &lldb_shlib_spec,
   Log *log = GetLog(LLDBLog::Host);
   std::string raw_path = lldb_shlib_spec.GetPath();
   llvm::StringRef parent_dir = llvm::sys::path::parent_path(raw_path);
+  const std::string clang_resource_path =
+      clang::driver::Driver::GetResourcesPath("bin/lldb", CLANG_RESOURCE_DIR);
 
   static const llvm::StringRef kResourceDirSuffixes[] = {
       // LLVM.org's build of LLDB uses the clang resource directory placed
-      // in $install_dir/lib{,64}/clang/$clang_version.
-      CLANG_INSTALL_LIBDIR_BASENAME "/clang/" CLANG_VERSION_MAJOR_STRING,
+      // in $install_dir/lib{,64}/clang/$clang_version or
+      // $install_dir/bin/$CLANG_RESOURCE_DIR
+      clang_resource_path,
       // swift-lldb uses the clang resource directory copied from swift, which
       // by default is placed in $install_dir/lib{,64}/lldb/clang. LLDB places
       // it there, so we use LLDB_INSTALL_LIBDIR_BASENAME.
@@ -82,7 +86,8 @@ static bool DefaultComputeClangResourceDirectory(FileSpec &lldb_shlib_spec,
 }
 
 bool lldb_private::ComputeClangResourceDirectory(FileSpec &lldb_shlib_spec,
-                                         FileSpec &file_spec, bool verify) {
+                                                 FileSpec &file_spec,
+                                                 bool verify) {
 #if !defined(__APPLE__)
   return DefaultComputeClangResourceDirectory(lldb_shlib_spec, file_spec,
                                               verify);

lldb/unittests/Expression/ClangParserTest.cpp

@@ -7,6 +7,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Basic/Version.h"
+#include "clang/Config/config.h"
+#include "clang/Driver/Driver.h"
 
 #include "Plugins/ExpressionParser/Clang/ClangHost.h"
 #include "TestingSupport/SubsystemRAII.h"
@@ -37,13 +39,11 @@ static std::string ComputeClangResourceDir(std::string lldb_shlib_path,
 TEST_F(ClangHostTest, ComputeClangResourceDirectory) {
 #if !defined(_WIN32)
   std::string path_to_liblldb = "/foo/bar/lib/";
-  std::string path_to_clang_dir =
-      "/foo/bar/" LLDB_INSTALL_LIBDIR_BASENAME "/clang/" CLANG_VERSION_MAJOR_STRING;
 #else
-  std::string path_to_liblldb = "C:\\foo\\bar\\lib";
-  std::string path_to_clang_dir =
-      "C:\\foo\\bar\\lib\\clang\\" CLANG_VERSION_MAJOR_STRING;
+  std::string path_to_liblldb = "C:\\foo\\bar\\lib\\";
 #endif
+  std::string path_to_clang_dir = clang::driver::Driver::GetResourcesPath(
+      path_to_liblldb + "liblldb", CLANG_RESOURCE_DIR);
   EXPECT_EQ(ComputeClangResourceDir(path_to_liblldb), path_to_clang_dir);
 
   // The path doesn't really exist, so setting verify to true should make

llvm/cmake/modules/LLVMExternalProjectUtils.cmake

@@ -280,7 +280,11 @@ function(llvm_ExternalProject_Add name source_dir)
     if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
       string(REGEX MATCH "^[0-9]+" CLANG_VERSION_MAJOR
              ${PACKAGE_VERSION})
-      set(resource_dir "${LLVM_LIBRARY_DIR}/clang/${CLANG_VERSION_MAJOR}")
+      if(DEFINED CLANG_RESOURCE_DIR AND NOT CLANG_RESOURCE_DIR STREQUAL "")
+        set(resource_dir ${LLVM_TOOLS_BINARY_DIR}/${CLANG_RESOURCE_DIR})
+      else()
+        set(resource_dir "${LLVM_LIBRARY_DIR}/clang/${CLANG_VERSION_MAJOR}")
+      endif()
       set(flag_types ASM C CXX MODULE_LINKER SHARED_LINKER EXE_LINKER)
       foreach(type ${flag_types})
         set(${type}_flag -DCMAKE_${type}_FLAGS=-resource-dir=${resource_dir})

openmp/CMakeLists.txt

@@ -90,8 +90,8 @@ option(OPENMP_ENABLE_LIBOMP_PROFILING "Enable time profiling for libomp." OFF)
 if(${OPENMP_STANDALONE_BUILD})
   set(LIBOMP_HEADERS_INSTALL_PATH "${CMAKE_INSTALL_INCLUDEDIR}")
 else()
-  string(REGEX MATCH "[0-9]+" CLANG_VERSION ${PACKAGE_VERSION})
-  set(LIBOMP_HEADERS_INSTALL_PATH "${OPENMP_INSTALL_LIBDIR}/clang/${CLANG_VERSION}/include")
+  include(GetClangResourceDir)
+  get_clang_resource_dir(LIBOMP_HEADERS_INSTALL_PATH SUBDIR include)
 endif()
 
 # Build host runtime library, after LIBOMPTARGET variables are set since they are needed