From 71506d4107f7cf3eef78bb9fa9743b7765e43fd9 Mon Sep 17 00:00:00 2001
From: Paolo Carlini <paolo.carlini@oracle.com>
Date: Mon, 29 Jun 2015 22:02:08 +0000
Subject: [PATCH] re PR c++/65977 (Constexpr should be allowed in declaration
 of friend template specialization)

/cp
2015-06-29  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/65977
	* decl.c (grokfndecl): Allow constexpr declarations of friend
	template specializations.

/testsuite
2015-06-29  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/65977
	* g++.dg/cpp0x/constexpr-friend-3.C: New.
	* g++.dg/cpp0x/constexpr-friend-2.C: Adjust.

From-SVN: r225148
---
 gcc/cp/ChangeLog                              |  6 ++++++
 gcc/cp/decl.c                                 | 15 ++++++-------
 gcc/testsuite/ChangeLog                       |  6 ++++++
 .../g++.dg/cpp0x/constexpr-friend-2.C         |  2 +-
 .../g++.dg/cpp0x/constexpr-friend-3.C         | 21 +++++++++++++++++++
 5 files changed, 40 insertions(+), 10 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/constexpr-friend-3.C

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index aad780f6aea..843b7eda176 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2015-06-29  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/65977
+	* decl.c (grokfndecl): Allow constexpr declarations of friend
+	template specializations.
+
 2015-06-29  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	PR fortran/66605
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 3f1cd340e16..5a644d7e2f4 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -7738,15 +7738,12 @@ grokfndecl (tree ctype,
 	    }
 
 	  if (inlinep & 1)
-	    error ("%<inline%> is not allowed in declaration of friend "
-		   "template specialization %qD",
-		   decl);
-	  if (inlinep & 2)
-	    error ("%<constexpr%> is not allowed in declaration of friend "
-		   "template specialization %qD",
-		   decl);
-	  if (inlinep)
-	    return NULL_TREE;
+	    {
+	      error ("%<inline%> is not allowed in declaration of friend "
+		     "template specialization %qD",
+		     decl);
+	      return NULL_TREE;
+	    }
 	}
     }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b4e9732fc0b..9c2f20b2c72 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-06-29  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/65977
+	* g++.dg/cpp0x/constexpr-friend-3.C: New.
+	* g++.dg/cpp0x/constexpr-friend-2.C: Adjust.
+
 2015-06-29  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	PR fortran/66605
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-friend-2.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-friend-2.C
index 36799b43587..b2ddc218d4a 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-friend-2.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-friend-2.C
@@ -3,5 +3,5 @@
 template<typename T> void f(T);
 
 template <class T> class A {
-  friend constexpr void f<>(int);  // { dg-error "'constexpr' is not allowed" }
+  friend constexpr void f<>(int);
 };
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-friend-3.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-friend-3.C
new file mode 100644
index 00000000000..aec38eb68ff
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-friend-3.C
@@ -0,0 +1,21 @@
+// PR c++/65977
+// { dg-do compile { target c++11 } }
+
+template<__SIZE_TYPE__>
+class bitset;
+
+template<__SIZE_TYPE__ N>
+constexpr bool operator==(const bitset<N>&, const bitset<N>&) noexcept;
+
+template<__SIZE_TYPE__ N>
+class bitset
+{
+  friend constexpr bool operator== <>(const bitset<N>&,
+				      const bitset<N>&) noexcept;
+};
+
+template<__SIZE_TYPE__ N>
+constexpr bool operator==(const bitset<N>&, const bitset<N>&) noexcept
+{
+  return true;
+}
-- 
2.30.2