CCFLAGS is used by gcc and g++ compiler. So CFLAGS should be used for gcc to avoid passing gcc flags to g++.
2. Bsp stm32l452-st-nucleo has been tested with NUCLEO-L452RE board. 3. Modify the applications SConscript of bsp stm32f103-yf-ufun, using new method. 4. Modify README of bsp stm32f072-st-nucleo.