Modifying gb_C(XX)FLAGS in solenv/gbuild/LINUX_*_GCC.mk?

[Michael Stahl]

On 16.09.2016 15:55, Stephan Bergmann wrote:
> Various of the solenv/gbuild/LINUX_*_GCC.mk (namely ARM, AXP, M86K, 
> POWERPC64, S390, S390X) have lines
> 
>    gb_CFLAGS += ...
>    gb_CXXFLAGS += ...
> 
> to add additional flags before including linux.mk.  However, these 
> additions appear to not be effective, as unxgcc.mk (included from 
> linux.mk) unconditionally resets those variables via
> 
>    gb_CFLAGS := ...
>    gb_CXXFLAGS := ...
> 
> (Also, moving the additions in the LINUX_*_GCC.mk files after including 
> linux.mk wouldn't appear to help, either, as the ultimate use of these 
> two variables is in
> 
>    gb_LinkTarget_CFLAGS := $(gb_CFLAGS)
>    gb_LinkTarget_CXXFLAGS := $(gb_CXXFLAGS)
> 
> in unxgcc.mk, so the latter variables would still not get the additions. 
>   The only correct way appears to be to have
> 
>    gb_LinkTarget_CFLAGS += ...
>    gb_LinkTarget_CXXFLAGS += ...
> 
> in the LINUX_*_GCC.mk files after including linux.mk.  Similar problems 
> may be present in other $(OS)_$(CPUNAME)_$(COM) files, too)
> 
> Or what am I missing?

yes that appears quite pointless.

it would be better to assign these values to gb_COMPILEROPTFLAGS which
is checked in com_GCC_defs.mk.

most of the unused ones are set to -fno-omit-frame-pointer anyway which
i guess isn't that important; there is just one where i have no idea
what it does:

solenv/gbuild/platform/LINUX_POWERPC64_GCC.mk:gb_CXXFLAGS += -mminimal-toc