Re: [C++ PATCH] Fix ICE with SIZEOF_EXPR in default arg (PR c++/71822)

[Jason Merrill <jason at redhat dot com>]

OK.

On Mon, Jul 11, 2016 at 3:25 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> For SIZEOF_EXPR, we rely on cp_fold to fold it.
> But, for VEC_INIT_EXPR initialization, we actually just genericize it
> without ever folding the expressions, so e.g. if the ctor has default args
> and some complicated expressions in there, they will never be cp_folded.
> This is the only place that calls cp_genericize_tree other than when the
> whole function is genericized, the fix just adds similar folding of the
> expression that cp_fold_function does.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/6.2?
>
> 2016-07-11  Jakub Jelinek  <jakub@redhat.com>
>
>         PR c++/71822
>         * cp-gimplify.c (cp_gimplify_expr) <case VEC_INIT_EXPR>: Recursively
>         fold *expr_p before genericizing it.
>
>         * g++.dg/template/defarg21.C: New test.
>
> --- gcc/cp/cp-gimplify.c.jj     2016-07-11 11:14:28.000000000 +0200
> +++ gcc/cp/cp-gimplify.c        2016-07-11 11:24:30.554083084 +0200
> @@ -621,6 +621,8 @@ cp_gimplify_expr (tree *expr_p, gimple_s
>                                   init, VEC_INIT_EXPR_VALUE_INIT (*expr_p),
>                                   from_array,
>                                   tf_warning_or_error);
> +       hash_set<tree> pset;
> +       cp_walk_tree (expr_p, cp_fold_r, &pset, NULL);
>         cp_genericize_tree (expr_p);
>         ret = GS_OK;
>         input_location = loc;
> --- gcc/testsuite/g++.dg/template/defarg21.C.jj 2016-07-11 11:32:34.262266398 +0200
> +++ gcc/testsuite/g++.dg/template/defarg21.C    2016-07-11 11:31:21.000000000 +0200
> @@ -0,0 +1,21 @@
> +// PR c++/71822
> +// { dg-do compile }
> +
> +int bar (int);
> +
> +template <typename T>
> +struct A
> +{
> +  explicit A (int x = bar (sizeof (T)));
> +};
> +
> +struct B
> +{
> +  A <int> b[2];
> +};
> +
> +void
> +baz ()
> +{
> +  B b;
> +}
>
>         Jakub