Re: [PATCH] Fix various tests to use -no-pie linker flag when needed

[Simon Marchi <simon dot marchi at polymtl dot ca>]

On 2018-10-14 05:59, Jan Vrany wrote:
> Hi,
>
> I'm sorry for a long delay, I've been very, very busy lately.
> Hopefully I'd have more time for GDB now...
>
>
> On Fri, 2018-09-07 at 23:18 +0100, Simon Marchi wrote:
> > On 2018-09-07 21:43, Tom Tromey wrote:
> > > > > > > > "Jan" == Jan Vrany <jan.vrany@fit.cvut.cz> writes:
> > >
> > > Jan> Various test use test code written in i385 / x86_64 assembly that
> > > cannot
> > > Jan> be used to create PIE executables. Therefore compilation of test
> > > programs
> > > Jan> failed on systems where the compiler default is to create PIE
> > > executable.
> > >
> > > Jan> To fix this, force -no-pie linker flag.
> > >
> > > I guess you're on an OS that enables PIE by default?
> >
> > I know recent-ish Ubuntus do that, I don't know if it's a patch 
> > specific
> > to that distro or if it's the default value in gcc that changed.
>
> Neither I know. I'm using Debian Buster which seems to have -no-pie
> by default too.
>
> > > These tests don't seem to be linux- or gcc-specific.
> > > Do you know how universal -no-pie is?  My worry is that this would fix
> > > the test for some people but break it for others.
> > >
>
> No, I don't know how universal -no-pie is. From what I have understood
> from Simon 
> (https://sourceware.org/ml/gdb-patches/2018-08/msg00662.html),
> out of the options available -no-pie is still the best bet.

gcc supports it, icc supports it [1], clang supports it starting at 
version 6 according to my testing.  I think this is universal enough 
that we can use it.  If somebody stumbles on a compiler that does not 
understand -no-pie and they really need to use it for their testing, 
they can quite easily add an option for gdb_compile.  But for now, I 
don't think it's worth the extra work.

[1] https://software.intel.com/en-us/node/523278

I tested the patch and amd64-disp-step.exp fails for me.  When you 
specify options to prepare_for_testing explicitly, you have to include 
the "debug" option (if you do want debug symbols).

With this fix the patch LGTM.

Simon