Re: [PATCH] Add testcase for C++ placement new and the important difference between dtor clobbers and end of scope clobbers

[Michael Matz]

Hi,

On Mon, 28 Jan 2019, Richard Biener wrote:

> > -  MEM[(struct  &)&buf1] ={v} {CLOBBER};
> > +  buf1 ={v} {CLOBBER};
> 
> Eww :/  That means they are not semantically the same which IMHO is
> bad.

But they really are different.  One is saying "these bytes contain nothing 
anymore", the other says "these bytes are gone".  (in the original CLOBBER 
design there was only the latter, so perhaps both shouldn't have been 
conflated, but alas, afterwards it's always easy to say :) ).


Ciao,
Michael.