[build] Check if SPIRV-LLVM-Translator is already patched (#4314)

Author: AndreyPavlenko

third_party/intel/cmake/FindSPIRVToLLVMTranslator.cmake

@@ -20,21 +20,35 @@ if (NOT SPIRVToLLVMTranslator_FOUND)
 
     FetchContent_GetProperties(spirv-llvm-translator)
     if(NOT spirv-llvm-translator_POPULATED)
+            set(LLVM_CONFIG ${LLVM_LIBRARY_DIR}/../bin/llvm-config)
+            set(LLVM_DIR "${LLVM_LIBRARY_DIR}/cmake/llvm" CACHE PATH "Path to LLVM build dir " FORCE)
+            set(LLVM_SPIRV_BUILD_EXTERNAL YES CACHE BOOL "Build SPIRV-LLVM Translator as external" FORCE)
+
             FetchContent_MakeAvailable(spirv-llvm-translator)
 
             # FIXME: Don't apply patch when Agama driver is updated.
             execute_process(
-                COMMAND git apply ${CMAKE_CURRENT_LIST_DIR}/3122.patch
+                COMMAND git apply --check ${CMAKE_CURRENT_LIST_DIR}/3122.patch
                 WORKING_DIRECTORY ${spirv-llvm-translator_SOURCE_DIR}
+                ERROR_QUIET
                 RESULT_VARIABLE PATCH_RESULT
             )
+            if(PATCH_RESULT EQUAL 0)
+                execute_process(
+                        COMMAND git apply ${CMAKE_CURRENT_LIST_DIR}/3122.patch
+                        WORKING_DIRECTORY ${spirv-llvm-translator_SOURCE_DIR}
+                        RESULT_VARIABLE PATCH_RESULT
+                )
+            else()
+                execute_process( # Check if the patch is already applied
+                        COMMAND git apply --reverse --check ${CMAKE_CURRENT_LIST_DIR}/3122.patch
+                        WORKING_DIRECTORY ${spirv-llvm-translator_SOURCE_DIR}
+                        RESULT_VARIABLE PATCH_RESULT
+                )
+            endif()
             if(NOT PATCH_RESULT EQUAL 0)
                 message(FATAL_ERROR "Failed to apply 3122.patch to SPIRV-LLVM-Translator")
             endif()
-
-            set(LLVM_CONFIG ${LLVM_LIBRARY_DIR}/../bin/llvm-config)
-            set(LLVM_DIR "${LLVM_LIBRARY_DIR}/cmake/llvm" CACHE PATH "Path to LLVM build dir " FORCE)
-            set(LLVM_SPIRV_BUILD_EXTERNAL YES CACHE BOOL "Build SPIRV-LLVM Translator as external" FORCE)
     endif()
 
     set(SPIRVToLLVMTranslator_INCLUDE_DIR "${SPIRVToLLVMTranslator_SOURCE_DIR}/include"