Do not apply patches if sub non-git repo is located in a git repo. (#545)

follow up #539.
Also add an option to control patch apply which is default on. Pass
-DAPPLY_PATCHES=OFF will skip patch apply process.

Author: haonanya1

CMakeLists.txt

@@ -40,6 +40,10 @@ if(LLVM_USE_HOST_TOOLS AND OPENCL_CLANG_BUILD_EXTERNAL)
   llvm_create_cross_target(${PROJECT_NAME} NATIVE "" Release)
 endif()
 
+option(LLVMSPIRV_INCLUDED_IN_LLVM
+  "Set to ON if libLLVMSPIRVLib is linked into libLLVM" ON)
+option(APPLY_PATCHES "Apply local patches" ON)
+
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
     set(USE_PREBUILT_LLVM ON)
 
@@ -61,8 +65,6 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
     set(CMAKE_CXX_STANDARD 14)
     set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-    option(LLVMSPIRV_INCLUDED_IN_LLVM
-      "Set to ON if libLLVMSPIRVLib is linked into libLLVM" ON)
     if(LLVMSPIRV_INCLUDED_IN_LLVM)
         message(STATUS "[OPENCL-CLANG] Assuming that libLLVMSPIRVLib is linked into libLLVM")
     else(LLVMSPIRV_INCLUDED_IN_LLVM)
@@ -152,16 +154,19 @@ if(NOT USE_PREBUILT_LLVM)
     get_filename_component(LLVM_MONOREPO_DIR ${LLVM_SOURCE_DIR} DIRECTORY)
     set(LLVM_PATCHES_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/patches/llvm
                           ${CMAKE_CURRENT_SOURCE_DIR}/patches/clang)
-    apply_patches(${LLVM_MONOREPO_DIR}
-                  "${LLVM_PATCHES_DIRS}"
-                  ${LLVM_BASE_REVISION}
-                  ${TARGET_BRANCH}
-                  ret)
-    apply_patches(${SPIRV_SOURCE_DIR}
-                  ${CMAKE_CURRENT_SOURCE_DIR}/patches/spirv
-                  ${SPIRV_BASE_REVISION}
-                  ${TARGET_BRANCH}
-                  ret)
+    if(APPLY_PATCHES)
+      message(STATUS "APPLY_PATCHES is enabled.")
+      apply_patches(${LLVM_MONOREPO_DIR}
+                    "${LLVM_PATCHES_DIRS}"
+                    ${LLVM_BASE_REVISION}
+                    ${TARGET_BRANCH})
+      apply_patches(${SPIRV_SOURCE_DIR}
+                    ${CMAKE_CURRENT_SOURCE_DIR}/patches/spirv
+                    ${SPIRV_BASE_REVISION}
+                    ${TARGET_BRANCH})
+    else()
+      message(STATUS "APPLY_PATCHES is disabled, skip patch apply process.")
+    endif()
 endif(NOT USE_PREBUILT_LLVM)
 
 #

cmake/modules/CMakeFunctions.cmake

@@ -87,7 +87,7 @@ endfunction()
 # Then all patches from the `patches_dir` are committed to the `target_branch`.
 # Does nothing if the `target_branch` is already checked out in the `repo_dir`.
 #
-function(apply_patches repo_dir patches_dir base_revision target_branch ret)
+function(apply_patches repo_dir patches_dir base_revision target_branch)
     foreach(patches_dir ${patches_dir})
         file(GLOB patches_in_dir ${patches_dir}/*.patch)
         list(APPEND patches ${patches_in_dir})
@@ -97,19 +97,20 @@ function(apply_patches repo_dir patches_dir base_revision target_branch ret)
         return()
     endif()
 
-    message(STATUS "[OPENCL-CLANG] Patching repository ${repo_dir}")
+    # Check if it's a git repo
+    if(EXISTS "${repo_dir}/.git")
+      message(STATUS "[OPENCL-CLANG] Patching repository ${repo_dir}")
+    else()
+      message(STATUS "[OPENCL-CLANG][Warning] ${repo_dir} is not a git repository, therefore, local patches are not applied")
+      return()
+    endif()
     # Check if the target branch already exists
     execute_process(
         COMMAND ${GIT_EXECUTABLE} rev-parse --verify --no-revs -q ${target_branch}
         WORKING_DIRECTORY ${repo_dir}
         RESULT_VARIABLE patches_needed
         OUTPUT_QUIET
     )
-    if(patches_needed EQUAL 128) # not a git repo
-        set(${ret} True PARENT_SCOPE)
-        message(STATUS "[OPENCL-CLANG][Warning] ${repo_dir} is not a git repository, therefore, local patches are not applied")
-        return()
-    endif()
     if(patches_needed EQUAL 1) # The target branch doesn't exist
         list(SORT patches)
         is_valid_revision(${repo_dir} ${base_revision} exists_base_rev)
@@ -159,7 +160,7 @@ function(apply_patches repo_dir patches_dir base_revision target_branch ret)
         )
     endif()
     if (NOT (ret_check_out OR ret_apply_patch))
-        set(${ret} True PARENT_SCOPE)
+        message(STATUS "[OPENCL-CLANG] Applied patch successfully!")
     else()
         message(FATAL_ERROR "[OPENCL-CLANG] Failed to apply patch!")
     endif()