[Buildroot] Advice on buildroot implementation

Arnout Vandecappelle arnout at mind.be
Wed Feb 20 17:38:08 UTC 2013

On 20/02/13 12:08, Stefan Fröberg wrote:
> CFLAGS = -flto -fwhole-program
> LDFLAGS= -flto -fuse-linker-plugin
> It could be also possible to compile whole system to make it smaller but
> it is very delicate and experimental process and some packages
> don't like some flags at all (For example zlib 1.2.7 does not like
> -fwhole-program).
> So Im asking everyone here:
> How can I filter out flags-per-package ?

  For most gcc -f and -W options, there's a no- variant. So

ZLIB_CFLAGS = -fno-lto -fno-while-program
ZLIB_LDFLAGS = -fno-lto  -fno-use-linker-plugin

> And also enable flags-per-package?
> I would like to enable globally those LTO flags and filter some/all
> flags from problematic packages.

  You can only do that by changing the package .mk file. I don't think we 
want to add infrastructure for per-package CFLAGS configuration...

Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
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