compiling glibc with a compiler flag

[Metuki Sabhe]

Hi Jakub and Thank You for the Help,

On 4/14/07, Jakub Jelinek <jakub@redhat.com> wrote:
> On Sat, Apr 14, 2007 at 11:54:40AM +0300, Metuki Sabhe wrote:
> > How can I compile glibc with some additional compiler flags ?
>
> Just tell it to configure, say:
> CC=gcc CXX=g++ CFLAGS="-g -O2 -mtune=generic -DNDEBUG=1" \
>  ../configure --prefix=/usr --enable-add-ons=nptl,libidn \
>  --without-cvs --enable-kernel=2.6.9 --with-headers=/usr/include \
>  --enable-bind-now --with-tls --with-__thread --build x86_64-redhat-linux \
>  --host x86_64-redhat-linux

If I understand correctly, doing so will override the CFLAGS that were meant
to be passed originally. How do I know I don't break things ? For example,
I tried:
CFLAGS="-g" ../glibc-2.5/configure
but during make it shouted it cannot be compiled without optimizations,
so now I'm trying:
CFLAGS="-O2 -g" ../glibc-2.5/configure

but how do I know I'm not breaking something else ? even worse, maybe some
parts of the glibc needs X flags and some other parts need Y flags ?
Ideally I would just *add* arbitrary flag, and not override them all..

But maybe I'm just over-paranoid here and the only problem is the missing -O2
flag.. ?

Thank You again !
metuki

>
>        Jakub
>