From 426c1e2ec7b42902a80a20cb3965a69061b8345b Mon Sep 17 00:00:00 2001
From: Jason Merrill <jason@redhat.com>
Date: Tue, 13 Mar 2018 11:55:07 -0400
Subject: [PATCH] PR c++/84798 - ICE with auto in abstract function declarator.

	* parser.c (cp_parser_parameter_declaration_clause): Check
	parser->default_arg_ok_p.

From-SVN: r258493
---
 gcc/cp/ChangeLog                     | 6 ++++++
 gcc/cp/parser.c                      | 5 ++++-
 gcc/testsuite/g++.dg/cpp0x/auto51.C  | 9 +++++++++
 gcc/testsuite/g++.dg/cpp1y/pr60393.C | 3 +--
 4 files changed, 20 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/auto51.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 9b5f0c36663..d480c1bafba 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2018-03-13  Jason Merrill  <jason@redhat.com>
+
+	PR c++/84798 - ICE with auto in abstract function declarator.
+	* parser.c (cp_parser_parameter_declaration_clause): Check
+	parser->default_arg_ok_p.
+
 2018-03-13  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/84808
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index cdc62388973..8e8ebceb0d5 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -21198,7 +21198,10 @@ cp_parser_parameter_declaration_clause (cp_parser* parser)
 
   if (!processing_specialization
       && !processing_template_parmlist
-      && !processing_explicit_instantiation)
+      && !processing_explicit_instantiation
+      /* default_arg_ok_p tracks whether this is a parameter-clause for an
+         actual function or a random abstract declarator.  */
+      && parser->default_arg_ok_p)
     if (!current_function_decl
 	|| (current_class_type && LAMBDA_TYPE_P (current_class_type)))
       parser->auto_is_implicit_function_template_parm_p = true;
diff --git a/gcc/testsuite/g++.dg/cpp0x/auto51.C b/gcc/testsuite/g++.dg/cpp0x/auto51.C
new file mode 100644
index 00000000000..dfb08336b53
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/auto51.C
@@ -0,0 +1,9 @@
+// PR c++/84798
+// { dg-do compile { target c++11 } }
+
+template<typename T>
+struct S {
+    static constexpr T value = 0;
+};
+
+constexpr auto x = S<void(*)(auto)>::value; // { dg-error "auto" }
diff --git a/gcc/testsuite/g++.dg/cpp1y/pr60393.C b/gcc/testsuite/g++.dg/cpp1y/pr60393.C
index 27fe2b72296..2ae21ed1147 100644
--- a/gcc/testsuite/g++.dg/cpp1y/pr60393.C
+++ b/gcc/testsuite/g++.dg/cpp1y/pr60393.C
@@ -1,8 +1,7 @@
 // PR c++/60393
 // { dg-do compile { target c++14 } }
-// { dg-options "" }
 
-void (*f)(auto) + 0; // { dg-error "expected" }
+void (*f)(auto) + 0; // { dg-error "auto|expected" }
 
 struct A
 {
-- 
2.30.2