[PATCH] Fallback to operator new for MSVC compatibility

[Richard Smith]

On Wed, May 29, 2013 at 1:01 PM, Aaron Ballman <aaron at aaronballman.com>wrote:

> On Wed, May 29, 2013 at 3:55 PM, Richard Smith <richard at metafoo.co.uk>
> wrote:
> > On Wed, May 29, 2013 at 7:49 AM, Aaron Ballman <aaron at aaronballman.com>
> > wrote:
> >>
> >> #include <stdio.h>
> >> #include <stdlib.h>
> >>
> >> struct arbitrary_t {} arbitrary;
> >>
> >> void *operator new[]( size_t s, arbitrary_t ) throw() { return
> ::malloc( s
> >> ); }
> >>
> >> struct S {
> >>   void *operator new( size_t s, arbitrary_t ) throw() { return
> ::malloc( s
> >> ); }
> >> };
> >>
> >> int main() {
> >>   S *s = new (arbitrary) S[2];
> >> }
> >>
> >> This will yield a call to the global operator new[] instead of the
> >> class-specific operator new.  Using new instead of new[] yields a call
> >> to the matching class-specific operator new still.  So I think my test
> >> will have to move down below the check for a global operator new:
> >>
> >>  <look for member operator new>
> >>  <look for global operator new>
> >> +if (not found && looking for array new && MS mode)
> >> +  <switch to looking for non-array new>
> >> +  <look for global operator new>
> >>
> >> If you agree, then I'll make the changes and add another test to
> >> CodeGenCXX to ensure we're calling the proper one.
> >
> >
> > What happens if you remove the global array new? Is the class-specific
> > non-array new used then?
>
> You get an error:
>
> F:\Aaron Ballman\Desktop\test6.cpp(13) : error C2660: 'operator new' :
> function
> does not take 2 arguments


Weird... well, OK then.

The indentation in SemaExprCXX.cpp in your latest patch looks a bit off
(maybe you ran diff with -b or -w?), otherwise LGTM.
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