[Buildroot] [PATCH] open2300: fix build failure

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Samuel Martin,

On Wed,  5 Feb 2014 22:09:22 +0100, Samuel Martin wrote:

> +- allow to extend CFLAGS and CC_LDFLAGS

[...]

> +-CFLAGS = -Wall -O3 -DVERSION=\"$(VERSION)\"
> +-CC_LDFLAGS = -lm
> +-CC_WINFLAG = 
> ++CFLAGS += -Wall -O3 -DVERSION=\"$(VERSION)\"
> ++CC_LDFLAGS += -lm
> ++CC_WINFLAG =

This doesn't allow to extend CFLAGS if the CFLAGS is passed on the
right hand side of the "make" call.

I.e, with your patch, if you do:

	make CFLAGS=-something

Then the CFLAGS will only contain "-something", not "-something -Wall
-O3 -DVERSION...". However, with your patch, it works if you do:

	CFLAGS=-something make

In Buildroot, we indeed often do $(TARGET_CONFIGURE_OPTS) $(MAKE),
which means CFLAGS is passed on the left side of make. But this
specific package does not do this:

	$(MAKE) CC=... LD=... -C $(@D)

So it doesn't pass CFLAGS, so there is no problem for now, but if it
started to pass CFLAGS on the right side of make, then your patch
wouldn't work.

Instead, if you want it to work in all cases, it should be:

override CFLAGS += -Wall -O3 ...

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com