musl-cross-make: how to build target libraries with -fpic

musl-cross-make: how to build target libraries with -fpic

[Patrick Oppenlander]

Hi,

what is the the right way to build a toolchain with PIC libraries?

The best I've come up with is to add

GCC_CONFIG_FOR_TARGET = CFLAGS_FOR_TARGET="-g -O2 -fpic"
MUSL_CONFIG = CFLAGS="-fpic"

to my config. But that seems a little over complicated.

Is there a recommended/better way?

Patrick

Re: musl-cross-make: how to build target libraries with -fpic

[Rich Felker]

On Thu, Dec 21, 2017 at 09:51:21AM +1100, Patrick Oppenlander wrote:
> Hi,
> 
> what is the the right way to build a toolchain with PIC libraries?
> 
> The best I've come up with is to add
> 
> GCC_CONFIG_FOR_TARGET = CFLAGS_FOR_TARGET="-g -O2 -fpic"
> MUSL_CONFIG = CFLAGS="-fpic"
> 
> to my config. But that seems a little over complicated.
> 
> Is there a recommended/better way?

Are you specifically trying to get -fpic instead of -fPIC? As far as I
know, -fPIC is the default for all of the gcc target libraries anyway;
if not all, at least for libgcc (parts of which normally get linked
into most shared libraries and thus need to be pic). If you build gcc
with --enable-default-pie, musl libc.a will also end up as PIC by
default.

Aside from that, the above should work, but you should probably be
using GCC_CONFIG, not GCC_CONFIG_FOR_TARGET. The latter is intended
for the makefiles and your config.mak to automatically build based on
$(TARGET) to meet the ABI requirements of the target you specified,
and replacing it will definitely break some targets.

Rich