[dpdk-dev] [PATCH] mk: add EXTRA_CFLAGS to link step for shared library

[Thomas Monjalon]

05/11/2019 02:56, Stephen Hemminger:
> When doing a cross compiling it is common to use EXTRA_CFLAGS with
> --sysroot option to point to alternate root filesystem. This already
> works as expected for objects and executables, it just doesn't work
> correctly for shared libraries.
> 
> When a shared library is linked using CC this flag needs to
> be passed in order for libraries to be found.
> 
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
> ---
> --- a/mk/rte.shared.mk
> +++ b/mk/rte.shared.mk
> -O_TO_SO = $(CC) $(call linkerprefix,$(LDFLAGS)) $(LDFLAGS_$(@)) $(EXTRA_LDFLAGS) \
> +O_TO_SO = $(CC) $(EXTRA_CFLAGS) $(call linkerprefix,$(LDFLAGS)) $(LDFLAGS_$(@)) $(EXTRA_LDFLAGS) \
>  	-shared -o $@ $(OBJS-y) $(call linkerprefix,$(LDLIBS))

After several thoughts, I am afraid of the possible side effects
of such a change.
I think only LDFLAGS should be used when linking.
If you need the same parameters at compilation and linking,
you should pass the same parameters to CFLAGS and LDFLAGS.