Disable source fortification under Clang

Disable source fortification under Clang on Linux.
Right now source fortification isn't supported by Clang (http://llvm.org/bugs/show_bug.cgi?id=16821)
It may also prevent the sanitizer tools from catching some bugs.

BUG=162783, 341809
R=hans@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=251868

[Alexander Potapenko, 2014-02-11 09:06:42]

PTAL

[Alexander Potapenko, 2014-02-11 09:08:06]

s/Nico(away)/Hans

Hans, can you please take a look?

[hans, 2014-02-11 16:26:17]

On 2014/02/11 09:08:06, Alexander Potapenko wrote:
> s/Nico(away)/Hans
> 
> Hans, can you please take a look?

Is PR16821 causing problems on Mac as well? If it's just Linux, maybe we can
disable Linux only?

[Alexander Potapenko, 2014-02-17 11:42:04]

On 2014/02/11 16:26:17, hans wrote:
> On 2014/02/11 09:08:06, Alexander Potapenko wrote:
> > s/Nico(away)/Hans
> > 
> > Hans, can you please take a look?
> 
> Is PR16821 causing problems on Mac as well? If it's just Linux, maybe we can
> disable Linux only?

It doesn't cause problems on Mac with Clang, but source fortification may still
prevent the sanitizers from catching bugs.
Since ASan is the only sanitizer available on Mac, and it undefines
_FORTIFY_SOURCE right in the driver, it's ok to just disable Linux only for now.

[Alexander Potapenko, 2014-02-18 15:59:27]

On 2014/02/17 11:42:04, Alexander Potapenko wrote:
> On 2014/02/11 16:26:17, hans wrote:
> > On 2014/02/11 09:08:06, Alexander Potapenko wrote:
> > > s/Nico(away)/Hans
> > > 
> > > Hans, can you please take a look?
> > 
> > Is PR16821 causing problems on Mac as well? If it's just Linux, maybe we can
> > disable Linux only?
> 
> It doesn't cause problems on Mac with Clang, but source fortification may
still
> prevent the sanitizers from catching bugs.
> Since ASan is the only sanitizer available on Mac, and it undefines
> _FORTIFY_SOURCE right in the driver, it's ok to just disable Linux only for
now.
Forgot to mention I've uploaded the new patch.

[hans, 2014-02-18 16:59:40]

On 2014/02/18 15:59:27, Alexander Potapenko wrote:
> On 2014/02/17 11:42:04, Alexander Potapenko wrote:
> > On 2014/02/11 16:26:17, hans wrote:
> > > On 2014/02/11 09:08:06, Alexander Potapenko wrote:
> > > > s/Nico(away)/Hans
> > > > 
> > > > Hans, can you please take a look?
> > > 
> > > Is PR16821 causing problems on Mac as well? If it's just Linux, maybe we
can
> > > disable Linux only?
> > 
> > It doesn't cause problems on Mac with Clang, but source fortification may
> still
> > prevent the sanitizers from catching bugs.
> > Since ASan is the only sanitizer available on Mac, and it undefines
> > _FORTIFY_SOURCE right in the driver, it's ok to just disable Linux only for
> now.
> Forgot to mention I've uploaded the new patch.

ok, lgtm.

[Alexander Potapenko, 2014-02-18 19:14:46]

The CQ bit was checked by glider@chromium.org

[commit-bot: I haz the power, 2014-02-18 19:15:16]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/glider@chromium.org/138913015/290001

[commit-bot: I haz the power, 2014-02-18 20:30:19]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-02-18 20:30:19]

Retried try job too often on win_rel for step(s) content_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[hans, 2014-02-18 21:12:52]

The CQ bit was checked by hans@chromium.org

[commit-bot: I haz the power, 2014-02-18 21:12:56]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/glider@chromium.org/138913015/290001

[commit-bot: I haz the power, 2014-02-18 22:54:50]

Change committed as 251868

[Nico, 2014-07-09 23:35:49]

(fwiw, https://codereview.chromium.org/377383004/ turns this back on unless
you're building for sanitizers. This is what this CL should've done in the first
place I feel, given that the bug only repros with -O1, not -O2 as far as I
understand?)