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

[WenHan Gu (谷汶翰)]

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.

Please help review it.
Thanks!

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)
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