On Wed, Apr 4, 2018 at 5:28 AM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Tue, Apr 03, 2018 at 12:23:11PM -0400, Jason Merrill wrote:
>> On Tue, Apr 3, 2018 at 12:06 PM, Jakub Jelinek <ja...@redhat.com> wrote:
>>
>> > From N2965 it is unclear to me what should the trait do on classes with
>> > incomplete types, but given that __bases already returns an empty pack,
>> > this patch does the same for __direct_bases.
>> >
>>
>> I think it should be ill-formed, i.e. call complete_type_or_maybe_complain
>> from tsubst_pack_expansion.
>
> calculate_*bases already calls complete_type, so it seems better to me
> to just pass complain down to those and handle it there.
>
> Ok for trunk if it passes bootstrap/regtest?
>
> I've also double-checked that it works with stuff like
> va_list ap;
> B<__typeof (*ap)> b;
> where __va_list_tag is RECORD_TYPE but not CLASS_TYPE_P.
>
> 2018-04-04 Jakub Jelinek <ja...@redhat.com>
>
> PR c++/85146
> * cp-tree.h (calculate_bases, calculate_direct_bases): Add complain
> argument.
> * semantics.c (calculate_direct_bases, calculate_bases): Add complain
> argument. Use complete_type_or_maybe_complain instead of just
> complete_type and return an empty vector if it fails. Formatting
> fixes.
> (dfs_calculate_bases_post, calculate_bases_helper): Formatting fixes.
> * pt.c (tsubst_pack_expansion): Adjust calculate_bases and
> calculate_direct_bases callers, formatting fixes.
>
> * g++.dg/ext/bases2.C: Expect extra error diagnostics.
> * g++.dg/ext/bases3.C: New test.
>
> --- gcc/cp/cp-tree.h.jj 2018-04-03 23:39:16.601665294 +0200
> +++ gcc/cp/cp-tree.h 2018-04-04 10:34:20.451307112 +0200
> @@ -6870,9 +6870,9 @@ extern cp_expr finish_id_expression (tr
> location_t);
> extern tree finish_typeof (tree);
> extern tree finish_underlying_type (tree);
> -extern tree calculate_bases (tree);
> +extern tree calculate_bases (tree, tsubst_flags_t);
> extern tree finish_bases (tree, bool);
> -extern tree calculate_direct_bases (tree);
> +extern tree calculate_direct_bases (tree, tsubst_flags_t);
> extern tree finish_offsetof (tree, tree, location_t);
> extern void finish_decl_cleanup (tree, tree);
> extern void finish_eh_cleanup (tree);
> --- gcc/cp/semantics.c.jj 2018-04-03 23:39:16.559665288 +0200
> +++ gcc/cp/semantics.c 2018-04-04 11:17:47.455507857 +0200
> @@ -3885,49 +3885,38 @@ finish_underlying_type (tree type)
> }
>
> /* Implement the __direct_bases keyword: Return the direct base classes
> - of type */
> + of type. */
>
> tree
> -calculate_direct_bases (tree type)
> +calculate_direct_bases (tree type, tsubst_flags_t complain)
> {
> - vec<tree, va_gc> *vector = make_tree_vector();
> + vec<tree, va_gc> *vector = make_tree_vector ();
> tree bases_vec = NULL_TREE;
> vec<tree, va_gc> *base_binfos;
> tree binfo;
> unsigned i;
>
> - complete_type (type);
> -
> - if (!NON_UNION_CLASS_TYPE_P (type))
> + if (!complete_type_or_maybe_complain (type, NULL_TREE, complain)
> + || !NON_UNION_CLASS_TYPE_P (type))
> return make_tree_vec (0);
>
> base_binfos = BINFO_BASE_BINFOS (TYPE_BINFO (type));
>
> /* Virtual bases are initialized first */
> for (i = 0; base_binfos->iterate (i, &binfo); i++)
> - {
> - if (BINFO_VIRTUAL_P (binfo))
> - {
> - vec_safe_push (vector, binfo);
> - }
> - }
> + if (BINFO_VIRTUAL_P (binfo))
> + vec_safe_push (vector, binfo);
>
> /* Now non-virtuals */
> for (i = 0; base_binfos->iterate (i, &binfo); i++)
> - {
> - if (!BINFO_VIRTUAL_P (binfo))
> - {
> - vec_safe_push (vector, binfo);
> - }
> - }
> -
> + if (!BINFO_VIRTUAL_P (binfo))
> + vec_safe_push (vector, binfo);
>
> bases_vec = make_tree_vec (vector->length ());
>
> for (i = 0; i < vector->length (); ++i)
> - {
> - TREE_VEC_ELT (bases_vec, i) = BINFO_TYPE ((*vector)[i]);
> - }
> + TREE_VEC_ELT (bases_vec, i) = BINFO_TYPE ((*vector)[i]);
> +
> return bases_vec;
> }
>
> @@ -3949,9 +3938,7 @@ dfs_calculate_bases_post (tree binfo, vo
> {
> vec<tree, va_gc> **data = ((vec<tree, va_gc> **) data_);
> if (!BINFO_VIRTUAL_P (binfo))
> - {
> - vec_safe_push (*data, BINFO_TYPE (binfo));
> - }
> + vec_safe_push (*data, BINFO_TYPE (binfo));
> return NULL_TREE;
> }
>
> @@ -3959,7 +3946,7 @@ dfs_calculate_bases_post (tree binfo, vo
> static vec<tree, va_gc> *
> calculate_bases_helper (tree type)
> {
> - vec<tree, va_gc> *vector = make_tree_vector();
> + vec<tree, va_gc> *vector = make_tree_vector ();
>
> /* Now add non-virtual base classes in order of construction */
> if (TYPE_BINFO (type))
> @@ -3969,18 +3956,17 @@ calculate_bases_helper (tree type)
> }
>
> tree
> -calculate_bases (tree type)
> +calculate_bases (tree type, tsubst_flags_t complain)
> {
> - vec<tree, va_gc> *vector = make_tree_vector();
> + vec<tree, va_gc> *vector = make_tree_vector ();
While we're touching this line, let's move it down below the early
return so we don't allocate a vec we aren't going to use. OK with
that change.
> tree bases_vec = NULL_TREE;
> unsigned i;
> vec<tree, va_gc> *vbases;
> vec<tree, va_gc> *nonvbases;
> tree binfo;
>
> - complete_type (type);
> -
> - if (!NON_UNION_CLASS_TYPE_P (type))
> + if (!complete_type_or_maybe_complain (type, NULL_TREE, complain)
> + || !NON_UNION_CLASS_TYPE_P (type))
> return make_tree_vec (0);
>
> /* First go through virtual base classes */
> --- gcc/cp/pt.c.jj 2018-04-03 23:39:16.487665280 +0200
> +++ gcc/cp/pt.c 2018-04-04 10:36:03.086316790 +0200
> @@ -11743,15 +11743,18 @@ tsubst_pack_expansion (tree t, tree args
> int level = 0;
>
> if (TREE_CODE (parm_pack) == BASES)
> - {
> - gcc_assert (parm_pack == pattern);
> - if (BASES_DIRECT (parm_pack))
> - return calculate_direct_bases (tsubst_expr (BASES_TYPE
> (parm_pack),
> - args, complain,
> in_decl, false));
> - else
> - return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
> - args, complain, in_decl,
> false));
> - }
> + {
> + gcc_assert (parm_pack == pattern);
> + if (BASES_DIRECT (parm_pack))
> + return calculate_direct_bases (tsubst_expr (BASES_TYPE
> (parm_pack),
> + args, complain,
> + in_decl, false),
> + complain);
> + else
> + return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
> + args, complain, in_decl,
> + false), complain);
> + }
> else if (builtin_pack_call_p (parm_pack))
> {
> /* ??? Support use in other patterns. */
> --- gcc/testsuite/g++.dg/ext/bases2.C.jj 2015-12-10 09:48:29.228598346
> +0100
> +++ gcc/testsuite/g++.dg/ext/bases2.C 2018-04-04 10:47:57.401384092 +0200
> @@ -5,7 +5,7 @@ template<typename...> struct A {};
>
> template<typename T> struct B
> {
> - typedef A<__bases(T)...> C;
> + typedef A<__bases(T)...> C; // { dg-error "incomplete type" }
> };
>
> struct X {};
> --- gcc/testsuite/g++.dg/ext/bases3.C.jj 2018-04-04 10:32:46.841305015
> +0200
> +++ gcc/testsuite/g++.dg/ext/bases3.C 2018-04-04 10:48:11.646385434 +0200
> @@ -0,0 +1,13 @@
> +// PR c++/85146
> +// { dg-do compile { target c++11 } }
> +
> +template<typename...> struct A {};
> +
> +template<typename T> struct B
> +{
> + typedef A<__direct_bases(T)...> C; // { dg-error "incomplete type" }
> +};
> +
> +struct X;
> +
> +B<X> b;
>
>
> Jakub
