[RFTesting] New POINTER_DIFF_EXPR

[David Malcolm]

On Sun, 2017-11-26 at 01:11 +0100, Gerald Pfeifer wrote:
> On Mon, 20 Nov 2017, Marc Glisse wrote:
> > new version, regtested on powerpc64le-unknown-linux-gnu. The front-
> > end 
> > parts are up for review.
> > 
> > 2017-10-28  Marc Glisse  <marc.glisse@inria.fr>
> > 
> > gcc/c/
> > 	* c-fold.c (c_fully_fold_internal): Handle POINTER_DIFF_EXPR.
> > 	* c-typeck.c (pointer_diff): Use POINTER_DIFF_EXPR.
> > 
> > gcc/c-family/
> > 	* c-pretty-print.c (pp_c_additive_expression,
> > 	c_pretty_printer::expression): Handle POINTER_DIFF_EXPR.
> > 
> > gcc/cp/
> > 	* constexpr.c (cxx_eval_constant_expression,
> > 	potential_constant_expression_1): Handle POINTER_DIFF_EXPR.
> > 	* cp-gimplify.c (cp_fold): Likewise.
> > 	* error.c (dump_expr): Likewise.
> > 	* typeck.c (pointer_diff): Use POINTER_DIFF_EXPR.
> 
> I'm afraid this broke building Wine.
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83164
> 
> 
> ddeml.c: In function ‘DDEML_AddThunk’:
> ddeml.c:181:28: error: type mismatch in pointer diff expression
>  static struct ddeml_thunk*      DDEML_AddThunk(DWORD instId, DWORD
> pfn16)
>                             ^~~~~~~~~~~~~~
> int
> 
> struct HDDEDATA__ * (*<T1c96>) (DWORD, UINT, UINT, struct HCONV__ *, 
> struct HSZ__ *, struct HSZ__ *, struct HDDEDATA__ *, ULONG_PTR,
> ULONG_PTR)
> 
> DWORD *
> 
> _6 = WDML_InvokeCallback16 - _5;
> ddeml.c:181:28: internal compiler error: verify_gimple failed
> 
> 
> David, in addition to the ICE diagnostics also looks, umm, 
> rather confusing?

Indeed.  I've added some comments about that to BZ.

Thanks
Dave