[PATCH][GIMPLE FE] Add parsing of MEM_REFs

[Richard Biener]

On Wed, 11 Jan 2017, Joseph Myers wrote:

> On Wed, 11 Jan 2017, Richard Biener wrote:
> 
> > As you can see I adjusted dumping of pointer constants (we can't
> > parse the B suffix and large unsigned numbers get a warning so
> > add 'U').  There's the general issue that we dump
> > 
> >   short x;
> >   x = 1;
> > 
> > and then lex the '1' as type int and there's no suffixes for integer
> > types smaller than int which means we can't write those constants
> > type correct :/  Suggestions welcome (currently we ICE with type
> > mismatches in those cases, we can avoid that by auto-fixing during
> > parsing but I'd like to be explicit somehow).
> 
> You could always dump as ((short) 1); that's valid C.

Indeed.  It makes parsing a little more awkward as (short) 1 is not
a postfix expression.

I suppose adding additional suffixes for char/short conditional on
-fgimple would be another way (either via setting user_literals option
or teaching libcpp about those itself).  's' and 'ss' (CPP_N_SMALL_SMALL
and CPP_N_SMALL_SMALL_SMALL?) would be my choice...

I'll give the (short) 1 parsing a try though to see how awkward it
really gets.

Thanks,
Richard.