MDEV-34408: Facilitate the addition of warnings into the build system

Create a MY_WARNING_FLAGS_NON_FATAL for testing warnings

Add -Weffc++ as no-error espect, disabling from rocksdb due
to excessive errors that will be corrected later.

cmake/maintainer.cmake

@@ -40,11 +40,21 @@ SET(MY_WARNING_FLAGS
   -Wwrite-strings
   )
 
+# Warning flags that are in testing before moving
+# to MY_WARNING_FLAGS if stable.
+SET(MY_WARNING_FLAGS_NON_FATAL
+  effc++
+  )
+
 FOREACH(F ${MY_WARNING_FLAGS})
   MY_CHECK_AND_SET_COMPILER_FLAG(${F} DEBUG RELWITHDEBINFO)
 ENDFOREACH()
 
-SET(MY_ERROR_FLAGS -Werror)
+FOREACH(F ${MY_WARNING_FLAGS_NON_FATAL})
+  MY_CHECK_AND_SET_COMPILER_FLAG(-Wno-error=${F} DEBUG RELWITHDEBINFO)
+ENDFOREACH()
+
+SET(MY_ERROR_FLAGS -Werror -fno-operator-names)
 
 IF(CMAKE_COMPILER_IS_GNUCC AND CMAKE_C_COMPILER_VERSION VERSION_LESS "6.0.0")
   SET(MY_ERROR_FLAGS ${MY_ERROR_FLAGS} -Wno-error=maybe-uninitialized)

storage/rocksdb/CMakeLists.txt

@@ -10,6 +10,7 @@ SET(CPACK_RPM_rocksdb-engine_PACKAGE_DESCRIPTION "The RocksDB storage engine is
 at maximising storage efficiency while maintaining InnoDB-like performance." PARENT_SCOPE)
 
 MY_CHECK_AND_SET_COMPILER_FLAG(-Wno-range-loop-construct)
+MY_CHECK_AND_SET_COMPILER_FLAG(-Wno-effc++ DEBUG RELWITHDEBINFO)
 
 MACRO(SKIP_ROCKSDB_PLUGIN msg)
   MESSAGE_ONCE(SKIP_ROCKSDB_PLUGIN "Can't build rocksdb engine - ${msg}")