Make BUILD_HIPIFY_CLANG a cmake option

Instead of deciding whether to build hipify-clang based on
the presence of an LLVM path on the command line, have an
explicit option.

Do we want this default-on or default-off? I've defaulted it to
on for now, but maybe we want the opposite?

CMakeLists.txt

@@ -1,6 +1,11 @@
 cmake_minimum_required(VERSION 2.8.3)
 project(hip)
 
+#############################
+# Options
+#############################
+option(BUILD_HIPIFY_CLANG "Enable building the CUDA->HIP converter" OFF)
+
 #############################
 # Setup config generation
 #############################
@@ -142,7 +147,9 @@ add_to_config(_buildInfo COMPILE_HIP_ATP_MARKER)
 # Build steps
 #############################
 # Build clang hipify if enabled
-add_subdirectory(hipify-clang)
+if (BUILD_HIPIFY_CLANG)
+    add_subdirectory(hipify-clang)
+endif()
 
 # Build hip_hcc if platform is hcc
 if(HIP_PLATFORM STREQUAL "hcc")

hipify-clang/CMakeLists.txt

@@ -1,8 +1,6 @@
 cmake_minimum_required(VERSION 2.8.8)
 project(hipify-clang)
 
-set(BUILD_HIPIFY_CLANG 0 CACHE INTERNAL "")
-
 if (HIPIFY_CLANG_LLVM_DIR)
     find_package(LLVM PATHS ${HIPIFY_CLANG_LLVM_DIR} REQUIRED NO_DEFAULT_PATH)
 else()
@@ -10,7 +8,7 @@ else()
     return()
 endif()
 
-option(HIPIFY_CLANG_TESTS "Build the tests for hipify-clang, if lit is installed" ON)
+option(HIPIFY_CLANG_TESTS "Build the tests for hipify-clang, if lit is installed" OFF)
 
 # Disable the tests if `lit` or `FileCheck` is not installed.
 find_program(LIT_COMMAND lit)
@@ -102,5 +100,3 @@ if (HIPIFY_CLANG_TESTS)
     add_dependencies(test-hipify-clang test-hipify)
     set_target_properties(test-hipify-clang PROPERTIES FOLDER "Tests")
 endif()
-
-set(BUILD_HIPIFY_CLANG 1 CACHE INTERNAL "")