OK.
On Thu, Dec 15, 2016 at 11:44 AM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Thu, Dec 15, 2016 at 07:40:58AM -0500, Nathan Sidwell wrote:
>> On 12/15/2016 07:26 AM, Jakub Jelinek wrote:
>>
>> > I don't think so. complete_type (error_mark_node) returns error_mark_node,
>> > and COMPLETE_TYPE_P (error_mark_node) is invalid (should fail TYPE_CHECK in
>> > checking compiler).
>> >
>> > I can write it as
>> > inst = complete_type (inst);
>> > if (inst == error_mark_node || !COMPLETE_TYPE_P (inst))
>> > return NULL_TREE;
>>
>> that's probably better, because complete_type can return error_mark_node if
>> 'something goes horribly wrong'
>
> Ok, here is the updated patch (and also moving the diagnostics to
> get_tuple_size caller as written in the other mail as an option),
> bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
>
> 2016-12-15 Jakub Jelinek <ja...@redhat.com>
>
> P0490R0 GB 20: decomposition declaration should commit to tuple
> interpretation early
> * decl.c (get_tuple_size): Make static. If inst is error_mark_node
> or non-complete type, return NULL_TREE, otherwise if
> lookup_qualified_name fails or doesn't fold into INTEGER_CST, return
> error_mark_node.
> (get_tuple_element_type, get_tuple_decomp_init): Make static.
> (cp_finish_decomp): Pass LOC to get_tuple_size. If it returns
> error_mark_node, complain and fail.
>
> * g++.dg/cpp1z/decomp10.C (f1): Adjust expected diagnostics.
>
> --- gcc/cp/decl.c.jj 2016-12-08 23:17:57.256167066 +0100
> +++ gcc/cp/decl.c 2016-12-15 13:48:48.087424991 +0100
> @@ -7259,7 +7259,7 @@ find_decomp_class_base (location_t loc,
>
> /* Return std::tuple_size<TYPE>::value. */
>
> -tree
> +static tree
> get_tuple_size (tree type)
> {
> tree args = make_tree_vec (1);
> @@ -7268,6 +7268,9 @@ get_tuple_size (tree type)
> /*in_decl*/NULL_TREE,
> /*context*/std_node,
> /*entering_scope*/false, tf_none);
> + inst = complete_type (inst);
> + if (inst == error_mark_node || !COMPLETE_TYPE_P (inst))
> + return NULL_TREE;
> tree val = lookup_qualified_name (inst, get_identifier ("value"),
> /*type*/false, /*complain*/false);
> if (TREE_CODE (val) == VAR_DECL || TREE_CODE (val) == CONST_DECL)
> @@ -7275,12 +7278,12 @@ get_tuple_size (tree type)
> if (TREE_CODE (val) == INTEGER_CST)
> return val;
> else
> - return NULL_TREE;
> + return error_mark_node;
> }
>
> /* Return std::tuple_element<I,TYPE>::type. */
>
> -tree
> +static tree
> get_tuple_element_type (tree type, unsigned i)
> {
> tree args = make_tree_vec (2);
> @@ -7297,7 +7302,7 @@ get_tuple_element_type (tree type, unsig
>
> /* Return e.get<i>() or get<i>(e). */
>
> -tree
> +static tree
> get_tuple_decomp_init (tree decl, unsigned i)
> {
> tree get_id = get_identifier ("get");
> @@ -7342,6 +7347,7 @@ store_decomp_type (tree v, tree t)
> decomp_type_table = hash_map<tree,tree>::create_ggc (13);
> decomp_type_table->put (v, t);
> }
> +
> tree
> lookup_decomp_type (tree v)
> {
> @@ -7502,6 +7508,12 @@ cp_finish_decomp (tree decl, tree first,
> }
> else if (tree tsize = get_tuple_size (type))
> {
> + if (tsize == error_mark_node)
> + {
> + error_at (loc, "%<std::tuple_size<%T>::value%> is not an integral "
> + "constant expression", type);
> + goto error_out;
> + }
> eltscnt = tree_to_uhwi (tsize);
> if (count != eltscnt)
> goto cnt_mismatch;
> --- gcc/testsuite/g++.dg/cpp1z/decomp10.C.jj 2016-12-08 23:17:57.477164261
> +0100
> +++ gcc/testsuite/g++.dg/cpp1z/decomp10.C 2016-12-15 13:47:47.288240503
> +0100
> @@ -7,7 +7,7 @@ namespace std {
>
> struct A1 { int i,j; } a1;
> template<> struct std::tuple_size<A1> { };
> -void f1() { auto [ x ] = a1; } // { dg-error "decomposes into 2" }
> +void f1() { auto [ x ] = a1; } // { dg-error "is not an integral constant
> expression" }
>
> struct A2 { int i,j; } a2;
> template<> struct std::tuple_size<A2> { enum { value = 5 }; };
>
>
> Jakub
