From patchwork Fri Oct  1 21:18:14 2010
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Subject: c++/42018 try to reject specialization re-declared in wrong namespace
From: Jonathan Wakely <jwakely.gcc@gmail.com>
X-Patchwork-Id: 66520
Message-Id: <AANLkTimZXYODVo2CHZnS=mCitoW_xrG4xia5in6tskg9@mail.gmail.com>
To: gcc-patches <gcc-patches@gcc.gnu.org>
Date: Fri, 1 Oct 2010 22:18:14 +0100

This patch is my attempt to fix PR c++/42018, but it's wrong, because
it also rejects some valid specializations, causing:

FAIL: g++.old-deja/g++.ns/template12.C (test for excess errors)
Excess errors:
/home/redi/src/gcc/gcc-4.x/gcc/testsuite/g++.old-deja/g++.ns/template12.C:18:47:
error: specialization of 'template<class T> const T bar::foo(const
T&)' in different namespace [-fpermissive]
/home/redi/src/gcc/gcc-4.x/gcc/testsuite/g++.old-deja/g++.ns/template12.C:13:20:
error:   from definition of 'template<class T> const T bar::foo(const
T&)' [-fpermissive]

FAIL: g++.old-deja/g++.pt/memtemp96.C (test for excess errors)
Excess errors:
/home/redi/src/gcc/gcc-4.x/gcc/testsuite/g++.old-deja/g++.pt/memtemp96.C:11:17:
error: specialization of 'template<class T> template<class U> int
A::f(U)' must appear at namespace scope

Can anyone point me in the right direction so that the new test in the
patch fails, but those don't?

Thanks,

Jonathan


Index: gcc/cp/pt.c
===================================================================
--- gcc/cp/pt.c	(revision 164893)
+++ gcc/cp/pt.c	(working copy)
@@ -1379,6 +1379,11 @@ register_specialization (tree spec, tree
 	}
       else if (DECL_TEMPLATE_SPECIALIZATION (fn))
 	{
+	  /* A specialization must be declared in the same namespace as the
+	     template it is specializing.  */
+	  if (!check_specialization_namespace (tmpl))
+	    return error_mark_node;
+
 	  if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
 	    /* Dup decl failed, but this is a new definition. Set the
 	       line number so any errors match this new
Index: gcc/testsuite/g++.dg/template/pr42018.C
===================================================================
--- gcc/testsuite/g++.dg/template/pr42018.C	(revision 0)
+++ gcc/testsuite/g++.dg/template/pr42018.C	(revision 0)
@@ -0,0 +1,14 @@
+// PR c++/42018
+// { dg-do compile }
+
+template<typename>
+  void foo(void);             // { dg-error "from definition of" }
+
+template<>
+  void foo<int>();
+
+namespace x {
+  template<>
+    void foo<int>() { return; } // { dg-error "in different namespace" }
+}
+