re PR c++/47721 ([C++0x] Updated friendship rules?)

	PR c++/47721
	* parser.c (cp_parser_member_declaration): Allow friend T.
	* friend.c (make_friend_class): Ignore non-classes.
	* pt.c (instantiate_class_template_1): Handle TEMPLATE_TYPE_PARM.

From-SVN: r174319

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index d5ad50104464fe8ef5d593c350f06b7e4c0323ec..ed758c4e050b0b1f1f652e0d46abd539c55bf137 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,10 @@
 2011-05-26  Jason Merrill  <jason@redhat.com>
 
+       PR c++/47721
+       * parser.c (cp_parser_member_declaration): Allow friend T.
+       * friend.c (make_friend_class): Ignore non-classes.
+       * pt.c (instantiate_class_template_1): Handle TEMPLATE_TYPE_PARM.
+
        DR 1004
        * pt.c (convert_template_argument): Don't complain about using
        injected-class-name as template template argument.

diff --git a/gcc/cp/friend.c b/gcc/cp/friend.c
index b61611ad1ad8308f104616ae9308bbd9e9a897d3..36fcca4f737eca7a4937ee94ee8b844c1d096777 100644 (file)
--- a/gcc/cp/friend.c
+++ b/gcc/cp/friend.c
@@ -226,7 +226,14 @@ make_friend_class (tree type, tree friend_type, bool complain)
 
   if (! MAYBE_CLASS_TYPE_P (friend_type))
     {
-      error ("invalid type %qT declared %<friend%>", friend_type);
+      /* N1791: If the type specifier in a friend declaration designates a
+        (possibly cv-qualified) class type, that class is declared as a
+        friend; otherwise, the friend declaration is ignored.
+
+         So don't complain in C++0x mode.  */
+      if (cxx_dialect < cxx0x)
+       pedwarn (input_location, complain ? 0 : OPT_pedantic,
+                "invalid type %qT declared %<friend%>", friend_type);
       return;
     }
 

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 004ff05768beca1378f4ae8821eaf9ec2b4529d0..135ab145fb86989544acedbd061ec61ff467155c 100644 (file)
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -17758,9 +17758,10 @@ cp_parser_member_declaration (cp_parser* parser)
            {
              /* If the `friend' keyword was present, the friend must
                 be introduced with a class-key.  */
-              if (!declares_class_or_enum)
-                error_at (decl_spec_token_start->location,
-                          "a class-key must be used when declaring a friend");
+              if (!declares_class_or_enum && cxx_dialect < cxx0x)
+                pedwarn (decl_spec_token_start->location, OPT_pedantic,
+                         "in C++03 a class-key must be used "
+                         "when declaring a friend");
               /* In this case:
 
                    template <typename T> struct A {
@@ -17769,10 +17770,12 @@ cp_parser_member_declaration (cp_parser* parser)
 
                  A<T>::B will be represented by a TYPENAME_TYPE, and
                  therefore not recognized by check_tag_decl.  */
-              if (!type
-                  && decl_specifiers.type
-                  && TYPE_P (decl_specifiers.type))
-                type = decl_specifiers.type;
+              if (!type)
+                {
+                  type = decl_specifiers.type;
+                  if (type && TREE_CODE (type) == TYPE_DECL)
+                    type = TREE_TYPE (type);
+                }
               if (!type || !TYPE_P (type))
                 error_at (decl_spec_token_start->location,
                           "friend declaration does not name a class or "

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 28c82b80f4231fe2fbd19ddbf5fdd96b9131f448..767c4f6c584255154faaa701f81bf8c6749fc185 100644 (file)
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -8472,7 +8472,8 @@ instantiate_class_template_1 (tree type)
                    friend_type = TREE_TYPE (friend_type);
                  adjust_processing_template_decl = true;
                }
-             else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
+             else if (TREE_CODE (friend_type) == TYPENAME_TYPE
+                      || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
                {
                  /* This could be either
 

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8703117b5fee1904569ae4145ae7b65fdf73d76c..a6ce74b472aaa568b396310be6233a365313b618 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2011-05-26  Jason Merrill  <jason@redhat.com>
 
+       * g++.dg/cpp0x/friend1.C: New.
+       * g++.dg/cpp0x/friend2.C: New.
+
        * g++.dg/cpp0x/auto7.C: Update.
        * g++.dg/template/crash50.C: Adjust.
        * g++.dg/template/static9.C: Adjust.

diff --git a/gcc/testsuite/g++.dg/cpp0x/friend1.C b/gcc/testsuite/g++.dg/cpp0x/friend1.C
new file mode 100644 (file)
index 0000000..2cf4c3c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/friend1.C
@@ -0,0 +1,22 @@
+// From N1791
+// { dg-options -std=c++0x }
+
+class C;
+typedef C Ct;
+class X1 {
+  friend C;            // OK: class C is a friend
+};
+
+class X2
+{
+  friend Ct;           // OK: class C is a friend
+  friend D;            // { dg-error "" } no type-name D in scope
+  friend class D;      // OK: elaborated-type-specifier declares new class
+};
+
+template <typename T> class R {
+  friend T;
+};
+
+R<C> rc;               // class C is a friend of R<C>
+R<int> Ri;             // OK: "friend int;" is ignored

diff --git a/gcc/testsuite/g++.dg/cpp0x/friend2.C b/gcc/testsuite/g++.dg/cpp0x/friend2.C
new file mode 100644 (file)
index 0000000..39276a0
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/friend2.C
@@ -0,0 +1,40 @@
+// PR c++/47721
+// { dg-options -std=c++0x }
+
+// template type parameter friend:
+
+template<class W>
+class Q
+{
+  static const int I = 2;
+public:
+  friend W;
+};
+
+struct B
+{
+  int ar[Q<B>::I];
+};
+
+// bonus template template parameter friend:
+
+template <class T> struct A;
+
+template<template <class> class W>
+class P
+{
+  static const int I = 2;
+public:
+  // I'm not sure this is well-formed, but I can't find anything
+  // that says otherwise.
+  template <class T> friend class W;
+};
+
+template <class T>
+struct A
+{
+  int ar[P<A>::I];
+};
+
+A<int> a;
+