build libclc as part of llvm (#1417)

It should help with cross-compiling target like android

CMakeLists.txt

@@ -109,12 +109,7 @@ if (${EXTERNAL_LLVM} EQUAL 1)
     message(FATAL_ERROR "External LLVM requires CLSPV_LLVM_BINARY_DIR to be specified")
   endif()
   if (NOT DEFINED CLSPV_EXTERNAL_LIBCLC_DIR)
-    if (NOT DEFINED CLSPV_LIBCLC_SOURCE_DIR)
-      message(FATAL_ERROR "External LLVM requires CLSPV_LIBCLC_SOURCE_DIR to be specified")
-    endif()
-    if (NOT DEFINED CLSPV_LLVM_CMAKE_MODULES_DIR)
-      message(FATAL_ERROR "External LLVM requires CLSPV_LLVM_CMAKE_MODULES_DIR to be specified")
-    endif()
+    message(FATAL_ERROR "External LLVM requires CLSPV_EXTERNAL_LIBCLC_DIR to be specified")
   endif()
 else()
   # Setup to use the LLVM monorepo.
@@ -126,16 +121,6 @@ else()
     set(CLSPV_CLANG_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/llvm/clang)
   endif()
 
-  if (NOT DEFINED CLSPV_EXTERNAL_LIBCLC_DIR)
-    if (NOT DEFINED CLSPV_LIBCLC_SOURCE_DIR)
-      set(CLSPV_LIBCLC_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/llvm/libclc)
-    endif()
-
-    if (NOT DEFINED CLSPV_LLVM_CMAKE_MODULES_DIR)
-      set(CLSPV_LLVM_CMAKE_MODULES_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/llvm/cmake/Modules)
-    endif()
-  endif()
-
   use_component(${CLSPV_LLVM_SOURCE_DIR})
   use_component(${CLSPV_CLANG_SOURCE_DIR})
 
@@ -145,7 +130,19 @@ else()
 
   # First tell LLVM where to find clang.
   set(LLVM_EXTERNAL_CLANG_SOURCE_DIR ${CLSPV_CLANG_SOURCE_DIR})
-  set(LLVM_ENABLE_PROJECTS clang)
+  set(LLVM_ENABLE_PROJECTS clang CACHE STRING "LLVM enabled projects for clspv")
+
+  # Also tell LLVM where to find libclc if required.
+  if (NOT DEFINED CLSPV_EXTERNAL_LIBCLC_DIR)
+    if (NOT DEFINED CLSPV_LIBCLC_SOURCE_DIR)
+      set(CLSPV_LIBCLC_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/llvm/libclc)
+    endif()
+    use_component(${CLSPV_LIBCLC_SOURCE_DIR})
+
+    set(LLVM_ENABLE_PROJECTS "${LLVM_ENABLE_PROJECTS};libclc")
+    set(LIBCLC_TARGETS_TO_BUILD clspv--;clspv64--)
+    set(LLVM_EXTERNAL_LIBCLC_SOURCE_DIR ${CLSPV_LIBCLC_SOURCE_DIR})
+  endif()
 
   # Tell LLVM not to build any targets.
   set(LLVM_TARGETS_TO_BUILD ""
@@ -159,11 +156,6 @@ else()
   include(HandleLLVMOptions)
 endif()
 
-if (NOT DEFINED CLSPV_EXTERNAL_LIBCLC_DIR)
-  include(${CLSPV_LLVM_CMAKE_MODULES_DIR}/LLVMVersion.cmake)
-  set(LLVM_VERSION ${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH})
-endif()
-
 set(CLSPV_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 
 set(CLSPV_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/include
@@ -198,12 +190,6 @@ elseif(${CMAKE_CXX_COMPILER_ID} MATCHES "Clang")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror-unused-variable -Werror-switch")
 endif()
 
-if (NOT DEFINED CLSPV_EXTERNAL_LIBCLC_DIR)
-  set(LIBCLC_TARGETS_TO_BUILD clspv--;clspv64--)
-  string(REPLACE "${CMAKE_CURRENT_SOURCE_DIR}" "" CLSPV_LIBCLC_SUFFIX "${CLSPV_LIBCLC_SOURCE_DIR}")
-  add_subdirectory(${CLSPV_LIBCLC_SOURCE_DIR} EXCLUDE_FROM_ALL)
-endif()
-
 # Bring in our cmake folder
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/cmake)
 

cmake/CMakeLists.txt

@@ -116,8 +116,8 @@ add_custom_target(clspv64_builtin_library
   DEPENDS ${CLSPV64_LIBRARY_OUTPUT_FILE})
 
 if (NOT DEFINED CLSPV_EXTERNAL_LIBCLC_DIR)
-  set(CLSPV_LIBRARY_INPUT_FILE ${CLSPV_BINARY_DIR}/${CLSPV_LIBCLC_SUFFIX}/clspv--.bc)
-  set(CLSPV64_LIBRARY_INPUT_FILE ${CLSPV_BINARY_DIR}/${CLSPV_LIBCLC_SUFFIX}/clspv64--.bc)
+  set(CLSPV_LIBRARY_INPUT_FILE ${CLSPV_LLVM_BINARY_DIR}/tools/libclc/clspv--.bc)
+  set(CLSPV64_LIBRARY_INPUT_FILE ${CLSPV_LLVM_BINARY_DIR}/tools/libclc/clspv64--.bc)
   set(CLSPV_LIBRARY_INPUT_DEP prepare-clspv--.bc)
   set(CLSPV64_LIBRARY_INPUT_DEP prepare-clspv64--.bc)
 else()