C++ PATCH for c++/90736 - bogus error with alignof

[Jason Merrill]

On 6/9/19 8:45 PM, Marek Polacek wrote:
> The problem here is that we're getting "requested alignment is not an
> integer constant" since r261971, because of this part of the patch:
> 
> @ -4676,7 +4685,11 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t,
>           conversion.  */
>        return fold (t);
> 
> -   if (tcode == UNARY_PLUS_EXPR)
> +   /* Handle an array's bounds having been deduced after we built
> +      the wrapping expression.  */
> +   if (same_type_ignoring_tlq_and_bounds_p (type, TREE_TYPE (op)))
> +     r = op;
> +   else if (tcode == UNARY_PLUS_EXPR)
>        r = fold_convert (TREE_TYPE (t), op);
>      else
>        r = fold_build1 (tcode, type, op);
> 
> where type was "int" and TREE_TYPE (op) was "const int", so we just used OP
> which was an INTEGER_CST of type "const int".  That resulted in a NOP_EXPR
> causing the error above.  Previously, we'd fold_build, returning an INTEGER_CST
> with type "int".
> 
> It seems weird to me to have an INTEGER_CST with a cv-qual type, so the
> following patch handles that case in adjust_temp_type.
> 
> Bootstrapped/regtested on x86_64-linux, ok for trunk and 9?

OK.

Jason