Re: [PATCH] Fix PR 23402, ICE with zero sized structs

[Andrew Pinski <pinskia at physics dot uc dot edu>]

On Aug 25, 2005, at 6:38 PM, Alan Modra wrote:

> On Thu, Aug 25, 2005 at 01:14:54AM -0700, Richard Henderson wrote:
> > On Thu, Aug 25, 2005 at 02:29:38PM +0930, Alan Modra wrote:
> > > -  if (zero_sized_type (type))
> > > +  if (!TREE_SIDE_EFFECTS (*from_p) && zero_sized_type (type))
> > >      {
> > >        *expr_p = NULL_TREE;
> >
> > You can write
> >
> >   if (zero_sized_type (type))
> >     {
> >       *expr_p = (TREE_SIDE_EFFECTS (*from_p) ? *from_p : NULL);
>
> Um, this variation results in
> va-arg-22.c:46: internal compiler error: in gimplify_expr, at 
> gimplify.c:4441


Since this was caused by me and Alan did not know the gimplifier that
much, I was asked to fix this.  There were two problems with my original
patch.  First I put it in the wrong function;  I should have put the 
check
in gimplify_modify_expr but I put it in gimplify_modify_expr_rhs.  The 
second
issue is that I totally forgot about side effects, which I fixed by 
gimplifing
the left and right hand side as statements and then adding the result.  
I added
a new test to test that we don't remove the side effects.

OK? Bootstrapped and tested on both powerpc-linux-gnu and 
x86_64-linux-gnu
with no regressions and fixes va-arg-22.c on ppc-linux-gnu.

Thanks,
Andrew Pinski

ChangeLog:
	PR middle-end/23463
	* gimplify.c (gimplify_modify_expr_rhs): Remove check for zero sized 
types.
	(gimplify_modify_expr): Check for zero sized types and gimplify the 
rhs and
	lhs as statements.

testsuite/ChangeLog:
	PR middle-end/23463
	* gcc.c-torture/execute/zero-struct-1.c: New test.

Attachment: fixPR23463.diff.txt
Description: Text document