* lambda-switch regression
@ 2017-11-15 13:08 Nathan Sidwell
2017-11-15 17:10 ` David Malcolm
2017-11-15 17:38 ` Martin Sebor
0 siblings, 2 replies; 6+ messages in thread
From: Nathan Sidwell @ 2017-11-15 13:08 UTC (permalink / raw)
To: GCC Patches; +Cc: David Malcolm
g++.dg/lambda/lambda-switch.C Has recently regressed. It appears the
location of a warning message has moved.
l = []() // { dg-warning "statement will never be executed" }
{
case 3: // { dg-error "case" }
break; // { dg-error "break" }
}; <--- warning now here
We seem to be diagnosing the last line of the statement, not the first.
That seems not a useful.
I've not investigated what patch may have caused this, on the chance
someone might already know?
nathan
--
Nathan Sidwell
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lambda-switch regression
2017-11-15 13:08 lambda-switch regression Nathan Sidwell
@ 2017-11-15 17:10 ` David Malcolm
2017-11-15 17:38 ` David Malcolm
2017-11-15 17:38 ` Martin Sebor
1 sibling, 1 reply; 6+ messages in thread
From: David Malcolm @ 2017-11-15 17:10 UTC (permalink / raw)
To: Nathan Sidwell, GCC Patches, polacek
On Wed, 2017-11-15 at 08:03 -0500, Nathan Sidwell wrote:
> g++.dg/lambda/lambda-switch.C Has recently regressed.
g++.dg/cpp0x/lambda/lambda-switch.C
> It appears the
> location of a warning message has moved.
>
> l = []() // { dg-warning "statement will never
> be executed" }
> {
> case 3: // { dg-error "case" }
> break; // { dg-error "break" }
> }; <--- warning now here
>
> We seem to be diagnosing the last line of the statement, not the
> first.
> That seems not a useful.
>
> I've not investigated what patch may have caused this, on the chance
> someone might already know?
>
> nathan
The warning was added in r236597 (aka
1398da0f786e120bb0b407e84f412aa9fc6d80ee):
+2016-05-23 Marek Polacek <polacek@redhat.com>
+
+ PR c/49859
+ * common.opt (Wswitch-unreachable): New option.
+ * doc/invoke.texi: Document -Wswitch-unreachable.
+ * gimplify.c (gimplify_switch_expr): Implement the -Wswitch-unreachable
+ warning.
which had it at there (23:7).
r244705 (aka 3ef7eab185e1463c7dbfa2a8d1af5d0120cf9f76) moved the
warning from 23:7 up to the "[] ()" at 19:6 in:
+2017-01-20 Marek Polacek <polacek@redhat.com>
+
+ PR c/64279
[...snip...]
+ * g++.dg/cpp0x/lambda/lambda-switch.C: Move dg-warning.
I tried it with some working copies I have to hand:
- works for me with r254387 (2017-11-03)
- fails for me with r254700 (2017-11-13)
so hopefully that helps track it down.
Dave
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lambda-switch regression
2017-11-15 13:08 lambda-switch regression Nathan Sidwell
2017-11-15 17:10 ` David Malcolm
@ 2017-11-15 17:38 ` Martin Sebor
1 sibling, 0 replies; 6+ messages in thread
From: Martin Sebor @ 2017-11-15 17:38 UTC (permalink / raw)
To: Nathan Sidwell, GCC Patches; +Cc: David Malcolm
On 11/15/2017 06:03 AM, Nathan Sidwell wrote:
> g++.dg/lambda/lambda-switch.C Has recently regressed. It appears the
> location of a warning message has moved.
>
> l = []() // { dg-warning "statement will never be executed" }
> {
> case 3: // { dg-error "case" }
> break; // { dg-error "break" }
> }; <--- warning now here
>
> We seem to be diagnosing the last line of the statement, not the first.
> That seems not a useful.
>
> I've not investigated what patch may have caused this, on the chance
> someone might already know?
Bug 82988 points to my r254630 as the commit that triggered it.
I haven't yet looked into it. There some small chance that it
was caused by bug 82977 that Jakub just fixed.
Martin
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lambda-switch regression
2017-11-15 17:10 ` David Malcolm
@ 2017-11-15 17:38 ` David Malcolm
2017-11-15 17:51 ` David Malcolm
0 siblings, 1 reply; 6+ messages in thread
From: David Malcolm @ 2017-11-15 17:38 UTC (permalink / raw)
To: Nathan Sidwell, GCC Patches, polacek
On Wed, 2017-11-15 at 12:06 -0500, David Malcolm wrote:
> On Wed, 2017-11-15 at 08:03 -0500, Nathan Sidwell wrote:
> > g++.dg/lambda/lambda-switch.C Has recently regressed.
>
> g++.dg/cpp0x/lambda/lambda-switch.C
>
> > It appears the
> > location of a warning message has moved.
> >
> > l = []() // { dg-warning "statement will never
> > be executed" }
> > {
> > case 3: // { dg-error "case" }
> > break; // { dg-error "break" }
> > }; <--- warning now here
> >
> > We seem to be diagnosing the last line of the statement, not the
> > first.
> > That seems not a useful.
> >
> > I've not investigated what patch may have caused this, on the
> > chance
> > someone might already know?
> >
> > nathan
>
> The warning was added in r236597 (aka
> 1398da0f786e120bb0b407e84f412aa9fc6d80ee):
>
> +2016-05-23 Marek Polacek <polacek@redhat.com>
> +
> + PR c/49859
> + * common.opt (Wswitch-unreachable): New option.
> + * doc/invoke.texi: Document -Wswitch-unreachable.
> + * gimplify.c (gimplify_switch_expr): Implement the -Wswitch-
> unreachable
> + warning.
>
> which had it at there (23:7).
>
> r244705 (aka 3ef7eab185e1463c7dbfa2a8d1af5d0120cf9f76) moved the
> warning from 23:7 up to the "[] ()" at 19:6 in:
>
> +2017-01-20 Marek Polacek <polacek@redhat.com>
> +
> + PR c/64279
> [...snip...]
> + * g++.dg/cpp0x/lambda/lambda-switch.C: Move dg-warning.
>
> I tried it with some working copies I have to hand:
> - works for me with r254387 (2017-11-03)
> - fails for me with r254700 (2017-11-13)
>
> so hopefully that helps track it down.
>
> Dave
Searching in the November archives of the gcc-regression ML for
"lambda-switch.c":
https://gcc.gnu.org/cgi-bin/search.cgi?wm=wrd&form=extended&m=all&s=D&q=lambda-switch.c&ul=%2Fml%2Fgcc-regression%2F2017-11%2F%25
showed e.g.:
https://gcc.gnu.org/ml/gcc-regression/2017-11/msg00173.html
"Regressions on trunk at revision 254648 vs revision 254623"
which says this is a new failure somewhere in that range; so it
presumably happened sometime on 2017-11-10 after r254623 and up to
(maybe ==) r254648.
Looking at:
svn log -r r254623:r254648 |less
nothing jumps out at me as being related.
Hope this is helpful
Dave
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lambda-switch regression
2017-11-15 17:38 ` David Malcolm
@ 2017-11-15 17:51 ` David Malcolm
2017-11-15 21:31 ` Martin Sebor
0 siblings, 1 reply; 6+ messages in thread
From: David Malcolm @ 2017-11-15 17:51 UTC (permalink / raw)
To: Nathan Sidwell, GCC Patches, polacek; +Cc: msebor
On Wed, 2017-11-15 at 12:25 -0500, David Malcolm wrote:
> On Wed, 2017-11-15 at 12:06 -0500, David Malcolm wrote:
> > On Wed, 2017-11-15 at 08:03 -0500, Nathan Sidwell wrote:
> > > g++.dg/lambda/lambda-switch.C Has recently regressed.
> >
> > g++.dg/cpp0x/lambda/lambda-switch.C
> >
> > > It appears the
> > > location of a warning message has moved.
> > >
> > > l = []() // { dg-warning "statement will never
> > > be executed" }
> > > {
> > > case 3: // { dg-error "case" }
> > > break; // { dg-error "break" }
> > > }; <--- warning now here
> > >
> > > We seem to be diagnosing the last line of the statement, not the
> > > first.
> > > That seems not a useful.
> > >
> > > I've not investigated what patch may have caused this, on the
> > > chance
> > > someone might already know?
> > >
> > > nathan
> >
> > The warning was added in r236597 (aka
> > 1398da0f786e120bb0b407e84f412aa9fc6d80ee):
> >
> > +2016-05-23 Marek Polacek <polacek@redhat.com>
> > +
> > + PR c/49859
> > + * common.opt (Wswitch-unreachable): New option.
> > + * doc/invoke.texi: Document -Wswitch-unreachable.
> > + * gimplify.c (gimplify_switch_expr): Implement the
> > -Wswitch-
> > unreachable
> > + warning.
> >
> > which had it at there (23:7).
> >
> > r244705 (aka 3ef7eab185e1463c7dbfa2a8d1af5d0120cf9f76) moved the
> > warning from 23:7 up to the "[] ()" at 19:6 in:
> >
> > +2017-01-20 Marek Polacek <polacek@redhat.com>
> > +
> > + PR c/64279
> > [...snip...]
> > + * g++.dg/cpp0x/lambda/lambda-switch.C: Move dg-warning.
> >
> > I tried it with some working copies I have to hand:
> > - works for me with r254387 (2017-11-03)
> > - fails for me with r254700 (2017-11-13)
> >
> > so hopefully that helps track it down.
> >
> > Dave
>
> Searching in the November archives of the gcc-regression ML for
> "lambda-switch.c":
>
> https://gcc.gnu.org/cgi-bin/search.cgi?wm=wrd&form=extended&m=all&s=D
> &q=lambda-switch.c&ul=%2Fml%2Fgcc-regression%2F2017-11%2F%25
>
> showed e.g.:
> https://gcc.gnu.org/ml/gcc-regression/2017-11/msg00173.html
> "Regressions on trunk at revision 254648 vs revision 254623"
>
> which says this is a new failure somewhere in that range; so it
> presumably happened sometime on 2017-11-10 after r254623 and up to
> (maybe ==) r254648.
>
> Looking at:
> svn log -r r254623:r254648 |less
> nothing jumps out at me as being related.
>
> Hope this is helpful
> Dave
Actually, https://gcc.gnu.org/ml/gcc-regression/2017-11/msg00157.html
has a tighter range: r254628 vs r254635.
Looking at:
svn log -r r254628:r254635 |less
I see msebor's r254630 ("PR c/81117 - Improve buffer overflow checking
in strncpy") has:
* gimple.c (gimple_build_call_from_tree): Set call location.
with:
+ gimple_set_location (call, EXPR_LOCATION (t));
Maybe that's it? (nothing else in that commit range seems to affect
locations).
Dave
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: lambda-switch regression
2017-11-15 17:51 ` David Malcolm
@ 2017-11-15 21:31 ` Martin Sebor
0 siblings, 0 replies; 6+ messages in thread
From: Martin Sebor @ 2017-11-15 21:31 UTC (permalink / raw)
To: David Malcolm, Nathan Sidwell, GCC Patches, polacek; +Cc: msebor
On 11/15/2017 10:38 AM, David Malcolm wrote:
> On Wed, 2017-11-15 at 12:25 -0500, David Malcolm wrote:
>> On Wed, 2017-11-15 at 12:06 -0500, David Malcolm wrote:
>>> On Wed, 2017-11-15 at 08:03 -0500, Nathan Sidwell wrote:
>>>> g++.dg/lambda/lambda-switch.C Has recently regressed.
>>>
>>> g++.dg/cpp0x/lambda/lambda-switch.C
>>>
>>>> It appears the
>>>> location of a warning message has moved.
>>>>
>>>> l = []() // { dg-warning "statement will never
>>>> be executed" }
>>>> {
>>>> case 3: // { dg-error "case" }
>>>> break; // { dg-error "break" }
>>>> }; <--- warning now here
>>>>
>>>> We seem to be diagnosing the last line of the statement, not the
>>>> first.
>>>> That seems not a useful.
>>>>
>>>> I've not investigated what patch may have caused this, on the
>>>> chance
>>>> someone might already know?
>>>>
>>>> nathan
>>>
>>> The warning was added in r236597 (aka
>>> 1398da0f786e120bb0b407e84f412aa9fc6d80ee):
>>>
>>> +2016-05-23 Marek Polacek <polacek@redhat.com>
>>> +
>>> + PR c/49859
>>> + * common.opt (Wswitch-unreachable): New option.
>>> + * doc/invoke.texi: Document -Wswitch-unreachable.
>>> + * gimplify.c (gimplify_switch_expr): Implement the
>>> -Wswitch-
>>> unreachable
>>> + warning.
>>>
>>> which had it at there (23:7).
>>>
>>> r244705 (aka 3ef7eab185e1463c7dbfa2a8d1af5d0120cf9f76) moved the
>>> warning from 23:7 up to the "[] ()" at 19:6 in:
>>>
>>> +2017-01-20 Marek Polacek <polacek@redhat.com>
>>> +
>>> + PR c/64279
>>> [...snip...]
>>> + * g++.dg/cpp0x/lambda/lambda-switch.C: Move dg-warning.
>>>
>>> I tried it with some working copies I have to hand:
>>> - works for me with r254387 (2017-11-03)
>>> - fails for me with r254700 (2017-11-13)
>>>
>>> so hopefully that helps track it down.
>>>
>>> Dave
>>
>> Searching in the November archives of the gcc-regression ML for
>> "lambda-switch.c":
>>
>> https://gcc.gnu.org/cgi-bin/search.cgi?wm=wrd&form=extended&m=all&s=D
>> &q=lambda-switch.c&ul=%2Fml%2Fgcc-regression%2F2017-11%2F%25
>>
>> showed e.g.:
>> https://gcc.gnu.org/ml/gcc-regression/2017-11/msg00173.html
>> "Regressions on trunk at revision 254648 vs revision 254623"
>>
>> which says this is a new failure somewhere in that range; so it
>> presumably happened sometime on 2017-11-10 after r254623 and up to
>> (maybe ==) r254648.
>>
>> Looking at:
>> svn log -r r254623:r254648 |less
>> nothing jumps out at me as being related.
>>
>> Hope this is helpful
>> Dave
>
> Actually, https://gcc.gnu.org/ml/gcc-regression/2017-11/msg00157.html
> has a tighter range: r254628 vs r254635.
>
> Looking at:
> svn log -r r254628:r254635 |less
> I see msebor's r254630 ("PR c/81117 - Improve buffer overflow checking
> in strncpy") has:
>
> * gimple.c (gimple_build_call_from_tree): Set call location.
>
> with:
> + gimple_set_location (call, EXPR_LOCATION (t));
>
> Maybe that's it? (nothing else in that commit range seems to affect
> locations).
Yes, that's it. Before the change there would be no location
associated with a GIMPLE call seen in gimple-fold. The location
would only get added later, after folding.
The purpose of the lambda-switch.C test is to verify GCC doesn't
ICE on the ill-formed code. The warning is incidental to the test
case so I've adjusted it to filter it out.
Martin
^ permalink raw reply [flat|nested] 6+ messages in thread
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2017-11-15 13:08 lambda-switch regression Nathan Sidwell
2017-11-15 17:10 ` David Malcolm
2017-11-15 17:38 ` David Malcolm
2017-11-15 17:51 ` David Malcolm
2017-11-15 21:31 ` Martin Sebor
2017-11-15 17:38 ` Martin Sebor
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