[cfe-commits] r164677 -

[Nico Weber]

On Fri, Sep 28, 2012 at 1:59 PM, Sean Silva <silvas at purdue.edu> wrote:
>>> Alternatively (and slightly more generally) how about teaching -verify to
>>> fail if it doesn't find any expected-* comments to check (like FileCheck
>>> does)?
>>
>> That wouldn't have helped in this case though, would it? there's no
>> expected- comment in this file.
>
> Wut? I think that what Richard was proposing elegantly addresses this
> case. Basically, it fails when it doesn't see an expected-* comment.

Right. This test here doesn't have an expected-* comment.

> Since stdin is empty, then there would be no expected-* comment, so
> the test would fail.

The fixed test would fail too.

>
> Richard, how do you suggest the diagnostic should be like? I fear that
> an error like "didn't see an expected-* comment" wouldn't be that
> helpful in diagnosing the issue at hand (missing input file,
> defaulting to stdin), even though it does accurately reflect the
> situation. As a hack, a note could be added, but that doesn't seem
> very in line with Clang style.
>
> Maybe it is worthwhile to require an explicit input file AND fail if
> no expected-* comments are found?
>
>> Sounds resonable. Wanna give it a shot? :-)
>
> Yeah, once we settle on a way to do this I'll prepare a patch (unless
> someone beats me to it).
>
> --Sean Silva
>
> On Thu, Sep 27, 2012 at 10:26 PM, Nico Weber <thakis at chromium.org> wrote:
>> On Fri, Sep 28, 2012 at 10:24 AM, Richard Smith <richard at metafoo.co.uk> wrote:
>>> On Thu, Sep 27, 2012 at 6:05 PM, Nico Weber <thakis at chromium.org> wrote:
>>>>
>>>> On Fri, Sep 28, 2012 at 1:31 AM, Sean Silva <silvas at purdue.edu> wrote:
>>>> >> I couldn't think of a great way. If no filename argument is present,
>>>> >> -cc1 -verify reads its input from stdin, which is a valid usecase. I
>>>> >> think lit closes stdin when it forks, which is why -cc1 doesn't just
>>>> >> wait for eof forever in this case.
>>>> >
>>>> > It is a valid use case, but how about just requiring that it be
>>>> > explicit (at least for -verify)? Forcing it to be explicit would
>>>> > preserve the use case but make the error case impossible.
>>>>
>>>> Sounds resonable. Wanna give it a shot? :-)
>>>
>>>
>>> Alternatively (and slightly more generally) how about teaching -verify to
>>> fail if it doesn't find any expected-* comments to check (like FileCheck
>>> does)?
>>
>> That wouldn't have helped in this case though, would it? there's no
>> expected- comment in this file.
>>
>>>
>>>>
>>>> >
>>>> > -- Sean Silva
>>>> >
>>>> > On Thu, Sep 27, 2012 at 6:22 AM, David Blaikie <dblaikie at gmail.com>
>>>> > wrote:
>>>> >>  /cfe/trunk/test/Sema/no-format-y2k-turnsoff-format.c
>>>> >> MIME-Version: 1.0
>>>> >> Content-Type: text/plain; charset="utf-8"
>>>> >> Content-Transfer-Encoding: 7bit
>>>> >>
>>>> >> If clang was going to read from stdin, wouldn't it need a -x to tell it
>>>> >> what kind of input it is? Even if it has a default, an empty file is
>>>> >> not a valid TU, at least in C++, though I guess if it has a default it
>>>> >> would be C and an empty file is probably valid C. Perhaps a warning
>>>> >> there at least could be handy
>>>> >> From: Nico Weber
>>>> >> Sent: 9/27/2012 7:43 AM
>>>> >> To: Sean Silva
>>>> >> Cc: Nico Weber; cfe-commits at cs.uiuc.edu
>>>> >> Subject: Re: [cfe-commits] r164677
>>>> >> - /cfe/trunk/test/Sema/no-format-y2k-turnsoff-format.c
>>>> >> On Thu, Sep 27, 2012 at 2:46 AM, Sean Silva <silvas at purdue.edu> wrote:
>>>> >>> Is there some way to ensure that this doesn't ever happen again? Like
>>>> >>> having -verify warn/fail if there is no input? That would allow fixing
>>>> >>> all of these cases in a single fell swoop and ensure that it never
>>>> >>> happens again.
>>>> >>
>>>> >> I couldn't think of a great way. If no filename argument is present,
>>>> >> -cc1 -verify reads its input from stdin, which is a valid usecase. I
>>>> >> think lit closes stdin when it forks, which is why -cc1 doesn't just
>>>> >> wait for eof forever in this case.
>>>> >>
>>>> >> I suppose lit could check if clang_cc1 is the first command on the run
>>>> >> line and then add a flag that tells cc1 to error out if it's reading
>>>> >> from stdin, but seems brittle.
>>>> >>
>>>> >> Do you have a good suggestion?
>>>> >>
>>>> >>>
>>>> >>> -- Sean Silva
>>>> >>>
>>>> >>> On Wed, Sep 26, 2012 at 5:02 AM, Nico Weber <nicolasweber at gmx.de>
>>>> >>> wrote:
>>>> >>>> Author: nico
>>>> >>>> Date: Wed Sep 26 04:02:07 2012
>>>> >>>> New Revision: 164677
>>>> >>>>
>>>> >>>> URL: http://llvm.org/viewvc/llvm-project?rev=164677&view=rev
>>>> >>>> Log:
>>>> >>>> Make this test actually test something
>>>> >>>>
>>>> >>>> Modified:
>>>> >>>>     cfe/trunk/test/Sema/no-format-y2k-turnsoff-format.c
>>>> >>>>
>>>> >>>> Modified: cfe/trunk/test/Sema/no-format-y2k-turnsoff-format.c
>>>> >>>> URL:
>>>> >>>> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/no-format-y2k-turnsoff-format.c?rev=164677&r1=164676&r2=164677&view=diff
>>>> >>>>
>>>> >>>> ==============================================================================
>>>> >>>> --- cfe/trunk/test/Sema/no-format-y2k-turnsoff-format.c (original)
>>>> >>>> +++ cfe/trunk/test/Sema/no-format-y2k-turnsoff-format.c Wed Sep 26
>>>> >>>> 04:02:07 2012
>>>> >>>> @@ -1,4 +1,4 @@
>>>> >>>> -// RUN: %clang_cc1 -verify -fsyntax-only -Wformat -Wno-format-y2k
>>>> >>>> +// RUN: %clang_cc1 -verify -fsyntax-only -Wformat -Wno-format-y2k %s
>>>> >>>>  // rdar://9504680
>>>> >>>>
>>>> >>>>  void foo(const char *, ...) __attribute__((__format__ (__printf__,
>>>> >>>> 1, 2)));
>>>> >>>>
>>>> >>>>
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