[cfe-commits] [PATCH] Array exception type decay to pointer automatically

[WenHan Gu (谷汶翰)]

Wrong file, sorry.
http://llvm.org/bugs/attachment.cgi?id=9602&action=diff

Thanks.

2012/11/28 WenHan Gu (谷汶翰) <wenhan.gu at gmail.com>

> Hi Richard,
>
> I've revised it again. I think this time all similar cases can run.
> Please have a look.
> http://llvm.org/bugs/attachment.cgi?id=9601&action=diff
> PR14388: http://llvm.org/bugs/show_bug.cgi?id=14388
>
> Thanks!
>
>
> 2012/11/22 Richard Smith <richard at metafoo.co.uk>
>
>> Hi,
>>
>> On Wed, Nov 21, 2012 at 11:58 PM, WenHan Gu (谷汶翰) <wenhan.gu at gmail.com>
>> wrote:
>> > Hi Richard,
>> >
>> > You're right. I've revised the patch.
>> > Patch url: http://llvm.org/bugs/attachment.cgi?id=9583
>> > (Sorry that my environment cannot upload it to GMail)
>> >
>> > I didn't put the logic inside CheckSpecifiedExceptionType, since the
>> > QualType is pass-by-value, instead, I found I should put it before it.
>> > I also made a test case.
>>
>> This still needs changes to handle the template instantiation case
>> (the other caller of CheckSpecifiedExceptionType):
>>
>> template<typename T> struct S {
>>   void f() throw(T);
>> };
>> S<int[10]> s;
>>
>> > 2012/11/21 Richard Smith <richard at metafoo.co.uk>
>> >>
>> >> On Tue, Nov 20, 2012 at 7:20 PM, WenHan Gu (谷汶翰) <wenhan.gu at gmail.com>
>> >> wrote:
>> >> > Hi Richard,
>> >> > Thanks your comments.
>> >> >
>> >> > However, I have no idea whether I should do this patch.
>> >> > I've tested by gcc, clang and searched C++ spec draft n3242, the
>> result
>> >> > is
>> >> > that both GCC and Clang failed on that and I cannot find any wording
>> on
>> >> > this
>> >> > issue.
>> >>
>> >> I suggest you switch to using n3485.
>> >>
>> >> 15.4/2:
>> >>
>> >> A type denoted in an exception-specification shall not denote an
>> >> incomplete type other than a class
>> >> currently being defined or an rvalue reference type. A type denoted in
>> >> an exception-specification shall not
>> >> denote a pointer or reference to an incomplete type, other than cv
>> >> void* or a pointer or reference to a
>> >> class currently being defined. A type cv T, “array of T”, or “function
>> >> returning T” denoted in an exception-
>> >> specification is adjusted to type T, “pointer to T”, or “pointer to
>> >> function returning T”, respectively.
>> >>
>> >> We are supposed to apply the decay from S[10] to S* before we check
>> >> whether it's an incomplete-or-being-defined type or a pointer to an
>> >> incomplete-or-being-defined type, so S[10] is OK.
>> >>
>> >> > Could you teach me more or could some else help?
>> >> > Thanks!
>> >> >
>> >> >   1 struct S {
>> >> >   2   void foo() throw (S[10])  { throw 0; }  // Both gcc and clang
>> >> > failed
>> >> > on this function
>> >> >   3   void bar() throw (S)  { throw 0; }
>> >> >   4 };
>> >> >   5
>> >> >   6 int main() {
>> >> >   7   S().foo();
>> >> >   8   S().bar();
>> >> >   9 }
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > 2012/11/21 Richard Smith <richard at metafoo.co.uk>
>> >> >>
>> >> >> Hi,
>> >> >>
>> >> >> On Tue, Nov 20, 2012 at 1:54 AM, WenHan Gu (谷汶翰) <
>> wenhan.gu at gmail.com>
>> >> >> wrote:
>> >> >> > Hi all,
>> >> >> >
>> >> >> > I've done the patch and testcase to fix PR14338.
>> >> >> > http://llvm.org/bugs/show_bug.cgi?id=14388
>> >> >> >
>> >> >> > Here's the patch, please review:
>> >> >> > http://llvm.org/bugs/attachment.cgi?id=9574&action=diff
>> >> >> >
>> >> >> >
>> >> >> > Is that okay to commit?
>> >> >>
>> >> >> A matching update is needed in SemaTemplateInstantiateDecl. Perhaps
>> >> >> you could put this logic into CheckSepcifiedExceptionType (and
>> either
>> >> >> return the modified type or pass it through by reference)? One of
>> the
>> >> >> checks in  CheckSpecifiedExceptionType also needs updating. With
>> your
>> >> >> patch, we still reject this:
>> >> >>
>> >> >> struct S {
>> >> >>   void f() throw (S[10]);
>> >> >> };
>> >> >>
>> >> >> ... but we should accept it, because the type 'S' is supposed to be
>> >> >> considered as complete in exception specifications inside its body.
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > Best regards,
>> >> > Wen-Han Gu (Nowar)
>> >> >
>> >
>> >
>> >
>> >
>> > --
>> > Best regards,
>> > Wen-Han Gu (Nowar)
>> >
>>
>
>
>
> --
> Best regards,
> Wen-Han Gu (Nowar)
>
>


-- 
Best regards,
Wen-Han Gu (Nowar)
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