Re: [gentoo-science] sci-libs/mpir for the main tree

[Christopher Schwan <cschwan@students.uni-mainz.de>]

Hi,

On Friday 17 December 2010 14:00:16 Thomas Kahle wrote:
> Hi,
> 
> On 21:19 Tue 09 Nov     , François Bissey wrote:
> > > my next migration victim will be mpir, the friendly clone of gmp.  The
> > > current ebuild is the same in sage-on-gentoo and science.  It has this
> > > assembler stuff in it that I don't understand.  Who did this? What is
> > > the latest here, can we remove the fat TODO-banner (or DO it?).
> > > 
> > > Any other hints/objections?  (Yes, I know that there is a bump
> > > waiting...)
> > 
> > Hi Thomas,
> > 
> > Christopher did it. mpir like gmp suffer from executable stacks.
> > There are talk on sage-devel which is very close to mpir upstream
> > to take a different approach: using an m4 macro and a linker flag
> > to remove them -Wl,-z,noexecstack.
> > The motivation to fix this is fedora 14 which doesn't allow executable
> > stacks by default.
> 
> The changelog of mpir-2.2 shows:
> 
> -) Enable noexecstack for x86/x86_64 with GCC
> 
> So what should be done to use this in our ebuild.  I tried to simply
> append -Wl,-z,noexecstack to ldflags, but this did nothing.

Mpir's configure scripts looks like its adding "-Wl,-z,noexecstack" if it 
detects a gcc+x86/amd64 configuration - so I guess noexecstack should work out 
of the box. If it does not I would consider this as broken.

> 
> Cheers,
> Thomas

Cheers,

Christopher