On 18/03/18 15:55, Duy Nguyen wrote:

On Sun, Mar 18, 2018 at 9:18 AM, Nguyễn Thái Ngọc Duy [off-list ref] wrote:

quoted

+ifneq ($(or $(filter gcc6,$(COMPILER_FEATURES)),$(filter clang4,$(COMPILER_FEATURES))),)
+CFLAGS += -Wextra

Another thing we can add here is -Og instead of standard -O2 (or -O0
in my build), which is supported since gcc 4.8. clang seems to support
it too (mapped to -O1 at least for clang5) but I don't know what
version added that flag.

I've been doing a lot of compiling recently, using 10 'different'
versions of clang and gcc ('different' if you count 64-bit and 32-bit
compilers with the same version number as different!)

However, I can tell you that clang version 3.4 and 3.8.0 don't
support -Og, but clang version 5.0.1 does.

ATB,
Ramsay Jones