OK.
On Wed, Jun 20, 2018 at 11:34 AM, Marek Polacek wrote:
> The recent change introducing ABSU_EXPR neglected to also handle this code
> in cxx_eval_constant_expression so this patch puts it there. Also two
> other spots for good measure. It's possible we'll find out that we need
> to fix other spots too.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2018-06-20 Marek Polacek
>
> PR c++/86240
> * constexpr.c (cxx_eval_constant_expression): Handle ABSU_EXPR.
> (fold_simple_1): Likewise.
> * error.c (dump_expr): Likewise.
>
> * g++.dg/pr86240.C: New test.
>
> diff --git gcc/cp/constexpr.c gcc/cp/constexpr.c
> index 216eecd4b06..44f3093ab47 100644
> --- gcc/cp/constexpr.c
> +++ gcc/cp/constexpr.c
> @@ -4412,6 +4412,7 @@ cxx_eval_constant_expression (const constexpr_ctx *ctx,
> tree t,
> case FLOAT_EXPR:
> case NEGATE_EXPR:
> case ABS_EXPR:
> +case ABSU_EXPR:
> case BIT_NOT_EXPR:
> case TRUTH_NOT_EXPR:
> case FIXED_CONVERT_EXPR:
> @@ -5056,6 +5057,7 @@ fold_simple_1 (tree t)
>return fold_sizeof_expr (t);
>
> case ABS_EXPR:
> +case ABSU_EXPR:
> case CONJ_EXPR:
> case REALPART_EXPR:
> case IMAGPART_EXPR:
> diff --git gcc/cp/error.c gcc/cp/error.c
> index 6a261132afb..b0d8e322e65 100644
> --- gcc/cp/error.c
> +++ gcc/cp/error.c
> @@ -2764,6 +2764,7 @@ dump_expr (cxx_pretty_printer *pp, tree t, int flags)
> case VEC_DELETE_EXPR:
> case MODOP_EXPR:
> case ABS_EXPR:
> +case ABSU_EXPR:
> case CONJ_EXPR:
> case VECTOR_CST:
> case FIXED_CST:
> diff --git gcc/testsuite/g++.dg/pr86240.C gcc/testsuite/g++.dg/pr86240.C
> index e69de29bb2d..16ae89cccd1 100644
> --- gcc/testsuite/g++.dg/pr86240.C
> +++ gcc/testsuite/g++.dg/pr86240.C
> @@ -0,0 +1,12 @@
> +// { dg-do compile }
> +
> +extern "C" int abs (int);
> +struct a {
> + short b;
> +} e;
> +short c;
> +bool
> +foo ()
> +{
> + return abs(c) >= e.b;
> +}
