Set default optimization flags less intrusively

CMakeLists.txt

@@ -8,6 +8,7 @@ endif()
 set(CMAKE_POLICY_DEFAULT_CMP0069 NEW)
 
 set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})
+set(CMAKE_USER_MAKE_RULES_OVERRIDE "${CMAKE_SOURCE_DIR}/cmake/DefaultBuildFlags.cmake")
 
 option(USE_VCPKG "Use vcpkg for dependency packages" OFF)
 if (USE_VCPKG)
@@ -78,14 +79,6 @@ if (ENABLE_LTO)
     set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
 endif()
 
-if (CMAKE_CXX_COMPILER_ID STREQUAL GNU)
-    set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -Og")
-    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Og")
-endif()
-
-string(REPLACE "-O2" "-O3" CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE}")
-string(REPLACE "-O2" "-O3" CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}")
-
 if (NOT APPLE)
     set(CMAKE_EXE_LINKER_FLAGS_RELEASE "${CMAKE_EXE_LINKER_FLAGS_RELEASE} -s")
 endif()