Handle GNU-style Windows clang warnings

Author: allnes

CMakeLists.txt

@@ -162,11 +162,23 @@ if(MSVC)
     add_compile_options(/wd4267 /wd4244 /wd4127 /wd4324)
 endif()
 
-if(NOT WIN32
-    OR (DEFINED CMAKE_C_COMPILER_FRONTEND_VARIANT
-        AND DEFINED CMAKE_CXX_COMPILER_FRONTEND_VARIANT
-        AND NOT CMAKE_C_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC"
-        AND NOT CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC"))
+get_filename_component(ITLABAI_C_COMPILER_NAME "${CMAKE_C_COMPILER}" NAME)
+get_filename_component(ITLABAI_CXX_COMPILER_NAME "${CMAKE_CXX_COMPILER}" NAME)
+string(TOLOWER "${ITLABAI_C_COMPILER_NAME}" ITLABAI_C_COMPILER_NAME_LOWER)
+string(TOLOWER "${ITLABAI_CXX_COMPILER_NAME}" ITLABAI_CXX_COMPILER_NAME_LOWER)
+
+set(ITLABAI_WINDOWS_USES_MSVC_FRONTEND OFF)
+if(WIN32 AND (
+    ITLABAI_C_COMPILER_NAME_LOWER MATCHES "(^|-)cl(\\.exe)?$"
+    OR ITLABAI_C_COMPILER_NAME_LOWER MATCHES "clang-cl(\\.exe)?$"
+    OR ITLABAI_C_COMPILER_NAME_LOWER MATCHES "icx-cl(\\.exe)?$"
+    OR ITLABAI_CXX_COMPILER_NAME_LOWER MATCHES "(^|-)cl(\\.exe)?$"
+    OR ITLABAI_CXX_COMPILER_NAME_LOWER MATCHES "clang-cl(\\.exe)?$"
+    OR ITLABAI_CXX_COMPILER_NAME_LOWER MATCHES "icx-cl(\\.exe)?$"))
+    set(ITLABAI_WINDOWS_USES_MSVC_FRONTEND ON)
+endif()
+
+if(NOT WIN32 OR NOT ITLABAI_WINDOWS_USES_MSVC_FRONTEND)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Werror")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Werror")
 else()