cmake: Adjust diagnostic flags for clang-cl

Author: hebasto

CMakeLists.txt

@@ -242,17 +242,21 @@ endif()
 
 include(TryAppendCFlags)
 if(MSVC)
-  # Keep the following commands ordered lexicographically.
+  # For both cl and clang-cl compilers.
   try_append_c_flags(/W3) # Production quality warning level.
+  # Eliminate deprecation warnings for the older, less secure functions.
+  add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+else()
+  try_append_c_flags(-Wall) # GCC >= 2.95 and probably many other compilers.
+endif()  
+if(CMAKE_C_COMPILER_ID STREQUAL "MSVC")
+  # Keep the following commands ordered lexicographically.
   try_append_c_flags(/wd4146) # Disable warning C4146 "unary minus operator applied to unsigned type, result still unsigned".
   try_append_c_flags(/wd4244) # Disable warning C4244 "'conversion' conversion from 'type1' to 'type2', possible loss of data".
   try_append_c_flags(/wd4267) # Disable warning C4267 "'var' : conversion from 'size_t' to 'type', possible loss of data".
-  # Eliminate deprecation warnings for the older, less secure functions.
-  add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
 else()
   # Keep the following commands ordered lexicographically.
   try_append_c_flags(-pedantic)
-  try_append_c_flags(-Wall) # GCC >= 2.95 and probably many other compilers.
   try_append_c_flags(-Wcast-align) # GCC >= 2.95.
   try_append_c_flags(-Wcast-align=strict) # GCC >= 8.0.
   try_append_c_flags(-Wconditional-uninitialized) # Clang >= 3.0 only.