On Fri, Sep 21, 2018 at 11:19:34AM -0400, Jason Merrill wrote:
> On Fri, Sep 21, 2018 at 11:04 AM, Marek Polacek <pola...@redhat.com> wrote:
> > On Fri, Sep 21, 2018 at 09:37:53AM +0200, Jakub Jelinek wrote:
> >> On Thu, Sep 20, 2018 at 11:56:37PM -0400, Marek Polacek wrote:
> >> > The patch for P0595R1 - is_constant_evaluated had this hunk:
> >> >
> >> > @@ -5279,7 +5315,9 @@ maybe_constant_init_1 (tree t, tree decl, bool
> >> > allow_non_constant)
> >> > else if (CONSTANT_CLASS_P (t) && allow_non_constant)
> >> > /* No evaluation needed. */;
> >> > else
> >> > - t = cxx_eval_outermost_constant_expr (t, allow_non_constant, false,
> >> > decl);
> >> > + t = cxx_eval_outermost_constant_expr (t, allow_non_constant,
> >> > + !allow_non_constant,
> >> > + pretend_const_required, decl);
> >> > if (TREE_CODE (t) == TARGET_EXPR)
> >> > {
> >> > tree init = TARGET_EXPR_INITIAL (t);
> >> >
> >> > the false -> !allow_non_constant change means that when calling
> >> > cxx_constant_init strict will be true because cxx_constant_init does not
> >> > allow
> >> > non constants. That means that for VAR_DECLs such as __func__ we'll call
> >> > decl_really_constant_value instead of decl_constant_value. But only the
> >> > latter
> >> > can evaluate __func__ to "foo()".
> >> >
> >> > Jakub, was there a specific reason for this change? Changing it back
> >> > still
> >> > regtests cleanly and the attached test compiles again.
> >>
> >> It just didn't feel right that cxx_constant_init which looks like a
> >> function
> >> that requires strict conformance still passes false as strict.
> >> If there is a reason to pass false, I think we need a comment that explains
> >> it.
> >
> > I think we use strict = true for *_constant_value, but *_constant_init
> > should
> > get strict = false.
>
> Right. In _init we try to get constant values for more than just C++
> constant expressions.
Is the patch OK then?
Marek
