Ping.
On Thu, Mar 30, 2017 at 08:26:55PM +0200, Marek Polacek wrote:
> This fix is similar to c++/79653: if something went wrong during
> make_pack_expansion, return error_mark instead of building up the attribute
> otherwise we end up with "gnu aligned <<<error>>>" and that would mean
> crashing
> later on at a lot of spots.
>
> Also, dump_expr wasn't able to print TREE_LISTs. It's easy to do so using
> dump_expr_list, so that we print '__alignof__ (A<T>)' instead of ugly
> '#'tree_list' not supported by dump_expr#<expression error>'.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2017-03-30 Marek Polacek <pola...@redhat.com>
>
> PR c++/80241 - ICE with alignas pack expansion.
> * error.c (dump_expr): Handle TREE_LIST.
> * parser.c (cp_parser_std_attribute_list): Return error_mark if
> make_pack_expansion returns an error.
>
> * g++.dg/cpp0x/alignas11.C: New test.
>
> diff --git gcc/cp/error.c gcc/cp/error.c
> index d8c5d5e..10af9d0 100644
> --- gcc/cp/error.c
> +++ gcc/cp/error.c
> @@ -2821,6 +2821,10 @@ dump_expr (cxx_pretty_printer *pp, tree t, int flags)
> pp_string (pp, M_("*this"));
> break;
>
> + case TREE_LIST:
> + dump_expr_list (pp, t, flags);
> + break;
> +
> /* This list is incomplete, but should suffice for now.
> It is very important that `sorry' does not call
> `report_error_function'. That could cause an infinite loop. */
> diff --git gcc/cp/parser.c gcc/cp/parser.c
> index c1b6496..efca2e1 100644
> --- gcc/cp/parser.c
> +++ gcc/cp/parser.c
> @@ -24842,8 +24842,12 @@ cp_parser_std_attribute_list (cp_parser *parser,
> tree attr_ns)
> error_at (token->location,
> "expected attribute before %<...%>");
> else
> - TREE_VALUE (attribute)
> - = make_pack_expansion (TREE_VALUE (attribute));
> + {
> + tree pack = make_pack_expansion (TREE_VALUE (attribute));
> + if (pack == error_mark_node)
> + return error_mark_node;
> + TREE_VALUE (attribute) = pack;
> + }
> token = cp_lexer_peek_token (parser->lexer);
> }
> if (token->type != CPP_COMMA)
> diff --git gcc/testsuite/g++.dg/cpp0x/alignas11.C
> gcc/testsuite/g++.dg/cpp0x/alignas11.C
> index e69de29..73c54da 100644
> --- gcc/testsuite/g++.dg/cpp0x/alignas11.C
> +++ gcc/testsuite/g++.dg/cpp0x/alignas11.C
> @@ -0,0 +1,10 @@
> +// PR c++/80241
> +// { dg-do compile { target c++11 } }
> +
> +template <typename... T>
> +struct A
> +{
> + [[gnu::aligned (alignof(A))...]] char c; // { dg-error "expansion pattern"
> }
> +};
> +
> +A<int> a;
>
> Marek
Marek
