https://gcc.gnu.org/g:48c3e5a4f935d6b8cd9ef7c51995e3b29ceb8be7
commit r15-1000-g48c3e5a4f935d6b8cd9ef7c51995e3b29ceb8be7
Author: Jakub Jelinek <ja...@redhat.com>
Date: Mon Jun 3 23:07:08 2024 +0200
c++: Fix parsing of abstract-declarator starting with ... followed by
opening paren [PR115012]
The C++26 P2662R3 Pack indexing paper mentions that both GCC
and MSVC don't handle T...[10] parameter declaration when T
is a pack. And apparently neither T...(args).
While the former will change meaning in C++26, T...(args) is still
valid even in C++26.
The following patch handles just the T...(args) case in
cp_parser_direct_declarator.
2024-06-03 Jakub Jelinek <ja...@redhat.com>
PR c++/115012
* parser.cc (cp_parser_direct_declarator): Handle
abstract declarator starting with ... followed by opening paren.
* g++.dg/cpp0x/variadic185.C: New test.
Diff:
---
gcc/cp/parser.cc | 15 +++++++++--
gcc/testsuite/g++.dg/cpp0x/variadic185.C | 43 ++++++++++++++++++++++++++++++++
2 files changed, 56 insertions(+), 2 deletions(-)
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 779625144db..3b2ad25af9f 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -23991,7 +23991,12 @@ cp_parser_direct_declarator (cp_parser* parser,
{
/* Peek at the next token. */
token = cp_lexer_peek_token (parser->lexer);
- if (token->type == CPP_OPEN_PAREN)
+ if (token->type == CPP_OPEN_PAREN
+ || (first
+ && dcl_kind != CP_PARSER_DECLARATOR_NAMED
+ && token->type == CPP_ELLIPSIS
+ && cxx_dialect > cxx98
+ && cp_lexer_nth_token_is (parser->lexer, 2, CPP_OPEN_PAREN)))
{
/* This is either a parameter-declaration-clause, or a
parenthesized declarator. When we know we are parsing a
@@ -24030,6 +24035,11 @@ cp_parser_direct_declarator (cp_parser* parser,
Thus again, we try a parameter-declaration-clause, and if
that fails, we back out and return. */
+ bool pack_expansion_p = token->type == CPP_ELLIPSIS;
+
+ if (pack_expansion_p)
+ /* Consume the `...' */
+ cp_lexer_consume_token (parser->lexer);
if (!first || dcl_kind != CP_PARSER_DECLARATOR_NAMED)
{
@@ -24173,6 +24183,7 @@ cp_parser_direct_declarator (cp_parser* parser,
attrs,
parens_loc);
declarator->attributes = gnu_attrs;
+ declarator->parameter_pack_p |= pack_expansion_p;
/* Any subsequent parameter lists are to do with
return type, so are not those of the declared
function. */
@@ -24196,7 +24207,7 @@ cp_parser_direct_declarator (cp_parser* parser,
/* If this is the first, we can try a parenthesized
declarator. */
- if (first)
+ if (first && !pack_expansion_p)
{
bool saved_in_type_id_in_expr_p;
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic185.C
b/gcc/testsuite/g++.dg/cpp0x/variadic185.C
new file mode 100644
index 00000000000..2c04afeda00
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic185.C
@@ -0,0 +1,43 @@
+// PR c++/115012
+// { dg-do compile { target { c++11 } } }
+// { dg-final { scan-assembler "_Z3fooIJidEEvDpFT_iE" } }
+// { dg-final { scan-assembler "_Z3barIiEvPFT_iE" } }
+// { dg-final { scan-assembler "_Z3bazIJidEEvDpFT_iE" } }
+
+template <typename ...T>
+void
+foo (T... x (int))
+{
+}
+
+template <typename T>
+void
+bar (T (int))
+{
+}
+
+template <typename ...T>
+void
+baz (T... (int))
+{
+}
+
+int
+f1 (int)
+{
+ return 0;
+}
+
+double
+f2 (int)
+{
+ return 0;
+}
+
+void
+corge ()
+{
+ foo <int, double> (f1, f2);
+ bar <int> (f1);
+ baz <int, double> (f1, f2);
+}
