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From: Thomas Koenig <tkoenig@netcologne.de>
To: Mikael Morin <mikael.morin@sfr.fr>, fortran@gcc.gnu.org
Cc: gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: [Patch, Fortran] Simplify lbound
Date: Tue, 12 May 2015 07:08:00 -0000	[thread overview]
Message-ID: <5551A10A.6080707@netcologne.de> (raw)
In-Reply-To: <5550ABEC.8050909@sfr.fr>

Hi Mikael,


> To be honest, both patches look fragile to me. Yours because it leaves
> gfc_current_ns to its value, leaving the door open to other problems.
> Mine, well, because it's playing with a global variable, with the
> possible side-effects this could have.
> However, without a better idea, I'm OK with either patch (or both).

I have found that playing around with gfc_current_ns can be quite
dangerous and can cause regressions in unexpected places.  Specifically,
I tried wrapping the callers to create_var and insert_block in
save/restore wrappers for gfc_current_ns, and that caused quite
a few very strange regressions.

So, working on the theory that a fix that may leave unknown problems
open is better than a fix that may introduce unknown problems, and
in order to get the regression out of the way, I have committed the
patch preventing multiple resolution of an array spec.

Maybe we should open a PR for auditing the use of gfc_current_ns
in front-end optmiization.

Regards

	Thomas


  reply	other threads:[~2015-05-12  6:43 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-25 11:34 Thomas Koenig
2015-04-25 18:13 ` Mikael Morin
2015-04-27 18:45   ` Thomas Koenig
2015-04-27 19:22     ` Thomas Koenig
2015-04-30 18:46     ` Mikael Morin
2015-05-01 21:04       ` Mikael Morin
2015-05-03 20:38         ` Thomas Koenig
2015-05-10 13:59           ` Mikael Morin
2015-05-10 20:43             ` H.J. Lu
2015-05-10 22:08               ` Thomas Koenig
2015-05-11 13:17                 ` Mikael Morin
2015-05-12  7:08                   ` Thomas Koenig [this message]
2015-05-12 10:04                     ` Mikael Morin
2015-05-02 10:50     ` H.J. Lu

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