From 875225301e356759982573d5578ed7ca54f81f86 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 3 Nov 2020 21:42:51 +0100
Subject: [PATCH] c++: Don't try to parse a function declaration as deduction
 guide [PR97663]

While these function declarations have NULL decl_specifiers->type,
they have still type specifiers specified from which the default int
in the return type is added, so we shouldn't try to parse those as
deduction guides.

2020-11-03  Jakub Jelinek  <jakub@redhat.com>

	PR c++/97663
	* parser.c (cp_parser_init_declarator): Don't try to parse
	C++17 deduction guides if there are any type specifiers even when
	type is NULL.

	* g++.dg/cpp1z/class-deduction75.C: New test.
---
 gcc/cp/parser.c                                |  1 +
 gcc/testsuite/g++.dg/cpp1z/class-deduction75.C | 15 +++++++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp1z/class-deduction75.C

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 274797f1879..b0d5c69f1d6 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -20790,6 +20790,7 @@ cp_parser_init_declarator (cp_parser* parser,
     {
       /* Handle C++17 deduction guides.  */
       if (!decl_specifiers->type
+	  && !decl_specifiers->any_type_specifiers_p
 	  && ctor_dtor_or_conv_p <= 0
 	  && cxx_dialect >= cxx17)
 	{
diff --git a/gcc/testsuite/g++.dg/cpp1z/class-deduction75.C b/gcc/testsuite/g++.dg/cpp1z/class-deduction75.C
new file mode 100644
index 00000000000..52e6131c7b5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/class-deduction75.C
@@ -0,0 +1,15 @@
+// PR c++/97663
+
+template <class T> struct foo {};
+template <class T> struct bar {};
+template <class T> struct baz {};
+template <class T> struct qux {};
+template <class T> struct corge {};
+
+namespace N {
+  unsigned foo ();
+  signed bar ();
+  long baz ();
+  long long qux ();
+  short corge (); 
+}
-- 
2.30.2