re PR c++/775 (2.97 error declaring nested class a friend)

cp:
	PR c++/775
	* cp-tree.h (handle_class_head): Adjust prototype.
	* decl2.c (handle_class_head): Add DEFN_P and NEW_TYPE_P
	parameters. Use for all class heads.
	* parse.y (named_class_head_sans_basetype, named_class_head,
	named_complex_class_head_sans_basetype,
	named_class_head_sans_basetype_defn,
	unnamed_class_head): Remove.
	(class_head, class_head_apparent_template): Recognize class heads
	(class_head_decl, class_head_defn): New reductions. Process class
	heads.
	(structsp): Adjust class definition and class declaration
	reductions.
	(maybe_base_class_list): Give diagnostic on empty list.
testsuite:
	* g++.dg/template/friend2.C: New test.
	* g++.old-deja/g++/brendan/crash8.C: Adjust location of error.

From-SVN: r48466

7 files changed, 234 insertions, 185 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 14194c7..3f05cb7 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,22 @@
 2002-01-02  Nathan Sidwell  <nathan@codesourcery.com>
 
+	PR c++/775
+	* cp-tree.h (handle_class_head): Adjust prototype.
+	* decl2.c (handle_class_head): Add DEFN_P and NEW_TYPE_P
+	parameters. Use for all class heads.
+	* parse.y (named_class_head_sans_basetype, named_class_head,
+	named_complex_class_head_sans_basetype,
+	named_class_head_sans_basetype_defn,
+	unnamed_class_head): Remove.
+	(class_head, class_head_apparent_template): Recognize class heads
+	(class_head_decl, class_head_defn): New reductions. Process class
+	heads.
+	(structsp): Adjust class definition and class declaration
+	reductions.
+	(maybe_base_class_list): Give diagnostic on empty list.
+
+2002-01-02  Nathan Sidwell  <nathan@codesourcery.com>
+
 	PR c++/4379
 	* typeck.c (build_x_unary_op): Don't destroy the OFFSET_REF on a
 	single non-static member.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 5069648..45b8fbf 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -1,6 +1,6 @@
 /* Definitions for C++ parsing and type checking.
    Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-   2000, 2001 Free Software Foundation, Inc.
+   2000, 2001, 2002 Free Software Foundation, Inc.
    Contributed by Michael Tiemann (tiemann@cygnus.com)
 
 This file is part of GNU CC.
@@ -3769,7 +3769,7 @@ extern tree do_class_using_decl			PARAMS ((tree));
 extern void do_using_directive			PARAMS ((tree));
 extern void check_default_args			PARAMS ((tree));
 extern void mark_used				PARAMS ((tree));
-extern tree handle_class_head			PARAMS ((tree, tree, tree));
+extern tree handle_class_head			PARAMS ((tree, tree, tree, int, int *));
 extern tree lookup_arg_dependent                PARAMS ((tree, tree, tree));
 extern void finish_static_data_member_decl      PARAMS ((tree, tree, tree, int));
 extern tree build_artificial_parm               PARAMS ((tree, tree));
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 401ccbf..3ff1ccc 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -5162,70 +5162,90 @@ mark_used (decl)
     instantiate_decl (decl, /*defer_ok=*/1);
 }
 
-/* Helper function for named_class_head_sans_basetype nonterminal.  We
-   have just seen something of the form `AGGR SCOPE::ID'.  Return a
-   TYPE_DECL for the type declared by ID in SCOPE.  */
+/* Helper function for class_head_decl and class_head_defn
+   nonterminals. AGGR is the class, union or struct tag. SCOPE is the
+   explicit scope used (NULL for no scope resolution). ID is the
+   name. DEFN_P is true, if this is a definition of the class and
+   NEW_TYPE_P is set to non-zero, if we push into the scope containing
+   the to be defined aggregate.
+   
+   Return a TYPE_DECL for the type declared by ID in SCOPE.  */
 
 tree
-handle_class_head (aggr, scope, id)
+handle_class_head (aggr, scope, id, defn_p, new_type_p)
      tree aggr, scope, id;
+     int defn_p;
+     int *new_type_p;
 {
   tree decl = NULL_TREE;
-
-  if (TREE_CODE (id) == TYPE_DECL)
-    /* We must bash typedefs back to the main decl of the type. Otherwise
-       we become confused about scopes.  */
-    decl = TYPE_MAIN_DECL (TREE_TYPE (id));
-  else if (DECL_CLASS_TEMPLATE_P (id))
-    decl = DECL_TEMPLATE_RESULT (id);
-  else 
-    {
-      tree current = current_scope ();
+  tree current = current_scope ();
+  bool xrefd_p = false;
   
-      if (current == NULL_TREE)
-        current = current_namespace;
-      if (scope == NULL_TREE)
-        scope = global_namespace;
+  if (current == NULL_TREE)
+    current = current_namespace;
 
-      if (TYPE_P (scope))
+  *new_type_p = 0;
+  
+  if (scope)
+    {
+      if (TREE_CODE (id) == TYPE_DECL)
+	/* We must bash typedefs back to the main decl of the
+       	   type. Otherwise we become confused about scopes.  */
+	decl = TYPE_MAIN_DECL (TREE_TYPE (id));
+      else if (DECL_CLASS_TEMPLATE_P (id))
+	decl = DECL_TEMPLATE_RESULT (id);
+      else
 	{
-	  /* According to the suggested resolution of core issue 180,
-	     'typename' is assumed after a class-key.  */
-	  decl = make_typename_type (scope, id, 1);
-	  if (decl != error_mark_node)
-	    decl = TYPE_MAIN_DECL (decl);
+	  if (TYPE_P (scope))
+	    {
+	      /* According to the suggested resolution of core issue
+	     	 180, 'typename' is assumed after a class-key.  */
+	      decl = make_typename_type (scope, id, 1);
+	      if (decl != error_mark_node)
+		decl = TYPE_MAIN_DECL (decl);
+	      else
+		decl = NULL_TREE;
+	    }
+	  else if (scope == current)
+	    {
+	      /* We've been given AGGR SCOPE::ID, when we're already
+             	 inside SCOPE.  Be nice about it.  */
+	      if (pedantic)
+		pedwarn ("extra qualification `%T::' on member `%D' ignored",
+			 scope, id);
+	    }
 	  else
-	    decl = NULL_TREE;
+	    error ("`%T' does not have a class or union named `%D'",
+		   scope, id);
 	}
-      else if (scope == current)
-        {
-          /* We've been given AGGR SCOPE::ID, when we're already inside SCOPE.
-             Be nice about it.  */
-          if (pedantic)
-            pedwarn ("extra qualification `%T::' on member `%D' ignored",
-                        FROB_CONTEXT (scope), id);
-        }
-      else if (scope != global_namespace)
-	error ("`%T' does not have a nested type named `%D'", scope, id);
-      else
-	error ("no file-scope type named `%D'", id);
-      
-      /* Inject it at the current scope.  */
-      if (! decl)
-	decl = TYPE_MAIN_DECL (xref_tag (aggr, id, 1));
     }
- 
-  /* Enter the SCOPE.  If this turns out not to be a definition, the
-     parser must leave the scope.  */
-  push_scope (CP_DECL_CONTEXT (decl));
-
-  /* If we see something like:
+  
+  if (!decl)
+    {
+      decl = TYPE_MAIN_DECL (xref_tag (aggr, id, !defn_p));
+      xrefd_p = true;
+    }
 
-       template <typename T> struct S::I ....
-       
-     we must create a TEMPLATE_DECL for the nested type.  */
-  if (PROCESSING_REAL_TEMPLATE_DECL_P ())
-    decl = push_template_decl (decl);
+  if (!TYPE_BINFO (TREE_TYPE (decl)))
+    {
+      error ("`%T' is not a class or union type", decl);
+      return error_mark_node;
+    }
+  
+  if (defn_p)
+    {
+      /* For a definition, we want to enter the containing scope
+	 before looking up any base classes etc. Only do so, if this
+	 is different to the current scope.  */
+      tree context = CP_DECL_CONTEXT (decl);
+
+      *new_type_p = current != context;
+      if (*new_type_p)
+	push_scope (context);
+  
+      if (!xrefd_p && PROCESSING_REAL_TEMPLATE_DECL_P ())
+	decl = push_template_decl (decl);
+    }
 
   return decl;
 }
diff --git a/gcc/cp/parse.y b/gcc/cp/parse.y
index 7339fe3..64f3dc1 100644
--- a/gcc/cp/parse.y
+++ b/gcc/cp/parse.y
@@ -1,6 +1,6 @@
 /* YACC parser for C++ syntax.
    Copyright (C) 1988, 1989, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001 Free Software Foundation, Inc.
+   1999, 2000, 2001, 2002 Free Software Foundation, Inc.
    Hacked by Michael Tiemann (tiemann@cygnus.com)
 
 This file is part of GNU CC.
@@ -386,10 +386,8 @@ cp_parse_init ()
 %type <ttype> component_constructor_declarator
 %type <ttype> fn.def2 return_id constructor_declarator
 %type <ttype> .begin_function_body
-%type <ttype> named_class_head_sans_basetype
-%type <ftype> class_head named_class_head 
-%type <ftype> named_complex_class_head_sans_basetype 
-%type <ttype> unnamed_class_head
+%type <ttype> class_head class_head_apparent_template
+%type <ftype> class_head_decl class_head_defn
 %type <ttype> base_class_list
 %type <ttype> base_class_access_list
 %type <ttype> base_class maybe_base_class_list base_class.1
@@ -418,7 +416,6 @@ cp_parse_init ()
 %type <ttype> explicit_template_type
 /* in order to recognize aggr tags as defining and thus shadowing.  */
 %token TYPENAME_DEFN IDENTIFIER_DEFN PTYPENAME_DEFN
-%type <ttype> named_class_head_sans_basetype_defn
 %type <ttype> identifier_defn IDENTIFIER_DEFN TYPENAME_DEFN PTYPENAME_DEFN
 %type <ttype> handler_args
 %type <ttype> self_template_type .finish_template_type
@@ -2277,8 +2274,21 @@ structsp:
 		  if (!processing_template_decl)
 		    pedwarn ("using `typename' outside of template"); }
 	/* C++ extensions, merged with C to avoid shift/reduce conflicts */
-	| class_head '{'
-                { $1.t = begin_class_definition ($1.t); 
+	| class_head_defn maybe_base_class_list '{'
+		{
+		  if ($2 && $1.t != error_mark_node)
+		    {
+		      tree type = TREE_TYPE ($1.t);
+		  
+		      if (TREE_CODE (type) == TYPENAME_TYPE)
+			/* In a definition of a member class template,
+                           we will get here with an implicit typename,
+                           a TYPENAME_TYPE with a type. */
+			type = TREE_TYPE (type);
+		      maybe_process_partial_specialization (type);
+		      xref_basetypes (current_aggr, $1.t, type, $2);
+		    }
+		  $1.t = begin_class_definition (TREE_TYPE ($1.t)); 
                   current_aggr = NULL_TREE; }
           opt.component_decl_list '}' maybe_attribute
 		{ 
@@ -2289,8 +2299,7 @@ structsp:
 		    yychar = YYLEX;
 		  semi = yychar == ';';
 
-		  t = finish_class_definition ($1.t, $6, semi,
-					       $1.new_type_flag); 
+		  t = finish_class_definition ($1.t, $7, semi, $1.new_type_flag);
 		  $<ttype>$ = t;
 
 		  /* restore current_aggr */
@@ -2307,32 +2316,13 @@ structsp:
 	  pending_inlines
                 {
 		  finish_inline_definitions ();
-		  $$.t = $<ttype>7;
+		  $$.t = $<ttype>8;
 		  $$.new_type_flag = 1; 
 		}
-	| class_head  %prec EMPTY
+	| class_head_decl
 		{
-		  if ($1.new_type_flag && $1.t != error_mark_node)
-		    pop_scope (CP_DECL_CONTEXT (TYPE_MAIN_DECL ($1.t)));
-		  $$.new_type_flag = 0;
-		  if ($1.t == error_mark_node)
-		    $$.t = $1.t;
-		  else if (TYPE_BINFO ($1.t) == NULL_TREE)
-		    {
-		      error ("%T is not a class type", $1.t);
-		      $$.t = error_mark_node;
-		    } 
-		  else
-		    {
-		      $$.t = $1.t;
-		      /* struct B: public A; is not accepted by the standard grammar.  */
-		      if (CLASS_TYPE_P ($$.t)
-			  && TYPE_BINFO_BASETYPES ($$.t) 
-			  && !COMPLETE_TYPE_P ($$.t)
-			  && ! TYPE_BEING_DEFINED ($$.t))
-			error ("base clause without member specification for `%#T'",
-				  $$.t);
-		    }
+		  $$.t = TREE_TYPE ($1.t);
+		  $$.new_type_flag = $1.new_type_flag;
 		}
 	;
 
@@ -2362,140 +2352,126 @@ aggr:
 		{ $$ = build_tree_list ($2, $1); }
 	;
 
-named_class_head_sans_basetype:
+class_head:
 	  aggr identifier
-		{ 
-		  current_aggr = $1; 
-		  $$ = $2; 
+		{
+		  current_aggr = $1;
+		  $$ = build_tree_list (NULL_TREE, $2);
 		}
-	;
-
-named_class_head_sans_basetype_defn:
-	  aggr identifier_defn  %prec EMPTY
-		{ current_aggr = $$; $$ = $2; }
-	| named_class_head_sans_basetype '{'
-		{ yyungetc ('{', 1); }
-	| named_class_head_sans_basetype ':'
-		{ yyungetc (':', 1); }
-	;
-
-named_complex_class_head_sans_basetype:
-	  aggr nested_name_specifier identifier
+	| aggr nested_name_specifier identifier
 		{
 		  current_aggr = $1;
-		  $$.t = handle_class_head ($1, $2, $3);
-		  $$.new_type_flag = 1;
+		  $$ = build_tree_list ($2, $3);
 		}
 	| aggr global_scope nested_name_specifier identifier
 		{
 		  current_aggr = $1;
-		  $$.t = handle_class_head ($1, $3, $4);
-		  $$.new_type_flag = 1;
+		  $$ = build_tree_list ($3, $4);
 		}
 	| aggr global_scope identifier
 		{
 		  current_aggr = $1;
-		  $$.t = handle_class_head ($1, NULL_TREE, $3);
-		  $$.new_type_flag = 1;
+		  $$ = build_tree_list (global_namespace, $3);
 		}
-	| aggr apparent_template_type
+	;
+
+class_head_apparent_template:
+	  aggr apparent_template_type
 		{ 
 		  current_aggr = $1; 
-		  $$.t = $2;
-		  $$.new_type_flag = 0;
+		  $$ = $2;
 		}
 	| aggr nested_name_specifier apparent_template_type
 		{ 
 		  current_aggr = $1; 
-		  $$.t = $3;
-		  push_scope (CP_DECL_CONTEXT ($$.t));
-		  $$.new_type_flag = 1;
+		  $$ = $3;
 		}
 	| aggr global_scope nested_name_specifier apparent_template_type
 		{ 
 		  current_aggr = $1; 
-		  $$.t = $4;
-		  push_scope (CP_DECL_CONTEXT ($$.t));
-		  $$.new_type_flag = 1;
+		  $$ = $4;
 		}
 	;
 
-named_class_head:
-	  named_class_head_sans_basetype  %prec EMPTY
-		{ 
-		  $$.t = xref_tag (current_aggr, $1, 1); 
-		  $$.new_type_flag = 0;
+class_head_decl:
+	  class_head %prec EMPTY
+		{
+		  $$.t = handle_class_head (current_aggr,
+					    TREE_PURPOSE ($1), TREE_VALUE ($1),
+					    0, &$$.new_type_flag);
 		}
-	| named_class_head_sans_basetype_defn 
-                { $<ttype>$ = xref_tag (current_aggr, $1, 0); }
-          /* Class name is unqualified, so we look for base classes
-             in the current scope.  */
-          maybe_base_class_list  %prec EMPTY
-		{ 
-		  $$.t = $<ttype>2;
-		  $$.new_type_flag = 0;
-		  if ($3)
-                    xref_basetypes (current_aggr, $1, $<ttype>2, $3); 
+	| aggr identifier_defn %prec EMPTY
+		{
+		  current_aggr = $1;
+		  $$.t = TYPE_MAIN_DECL (xref_tag (current_aggr, $2, 0));
+		  $$.new_type_flag = 1;
 		}
-	| named_complex_class_head_sans_basetype 
-	  maybe_base_class_list
-		{ 
-		  if ($1.t != error_mark_node)
-		    {
-		      tree type = TREE_TYPE ($1.t);
-
-		      $$.t = type;
-		      $$.new_type_flag = $1.new_type_flag;
-		      if ((current_aggr == union_type_node)
-			  != (TREE_CODE (type) == UNION_TYPE))
-			pedwarn (current_aggr == union_type_node
-	                            ? "`union' tag used in declaring `%#T'"
-	                            : "non-`union' tag used in declaring `%#T'", 
-				    type);
-		      else if (TREE_CODE (type) == RECORD_TYPE)
-			/* We might be specializing a template with a different
-			   class-key; deal.  */
-			CLASSTYPE_DECLARED_CLASS (type) 
-			  = (current_aggr == class_type_node);
-		      if ($2)
-			{
-                          if (TREE_CODE (type) == TYPENAME_TYPE)
-                            /* In a definition of a member class template, we
-                               will get here with an implicit typename, a
-                               TYPENAME_TYPE with a type. */
-                            type = TREE_TYPE (type);
-			  maybe_process_partial_specialization (type);
-			  xref_basetypes (current_aggr, $1.t, type, $2); 
-			}
-		    }
+	| class_head_apparent_template %prec EMPTY
+		{
+		  $$.t = $1;
+		  $$.new_type_flag = 0;
 		}
 	;
 
-unnamed_class_head:
-	  aggr '{'
-		{ $$ = xref_tag ($$, make_anon_name (), 0);
-		  yyungetc ('{', 1); }
-	;
-
-/* The tree output of this nonterminal a declarationf or the type
-   named.  If NEW_TYPE_FLAG is set, then the name used in this
-   class-head was explicitly qualified, e.g.:  `struct X::Y'.  We have
-   already called push_scope for X.  */
-class_head:
-	  unnamed_class_head
-                {
+class_head_defn:
+	  class_head '{'
+		{
+		  yyungetc ('{', 1);
+		  $$.t = handle_class_head (current_aggr,
+					    TREE_PURPOSE ($1), TREE_VALUE ($1),
+					    1, &$$.new_type_flag);
+		}
+	| class_head ':'
+		{
+		  yyungetc (':', 1);
+		  $$.t = handle_class_head (current_aggr,
+					    TREE_PURPOSE ($1), TREE_VALUE ($1),
+					    1, &$$.new_type_flag);
+		}
+	| class_head_apparent_template '{'
+		{
+		  yyungetc ('{', 1);
+		  $$.t = $1;
+		  $$.new_type_flag = 0;
+		}
+	| class_head_apparent_template ':'
+		{
+		  yyungetc (':', 1);
 		  $$.t = $1;
 		  $$.new_type_flag = 0;
 		}
-	| named_class_head
+	| aggr identifier_defn '{'
+		{
+		  yyungetc ('{', 1);
+		  current_aggr = $1;
+		  $$.t = handle_class_head (current_aggr,
+					    NULL_TREE, $2,
+					    1, &$$.new_type_flag);
+		}
+	| aggr identifier_defn ':'
+		{
+		  yyungetc (':', 1);
+		  current_aggr = $1;
+		  $$.t = handle_class_head (current_aggr,
+					    NULL_TREE, $2,
+					    1, &$$.new_type_flag);
+		}
+        | aggr '{'
+		{
+		  current_aggr = $1;
+		  $$.t = TYPE_MAIN_DECL (xref_tag ($1, make_anon_name (), 0));
+		  $$.new_type_flag = 0;
+		  yyungetc ('{', 1);
+		}
 	;
 
 maybe_base_class_list:
-	  /* empty */  %prec EMPTY
+	  /* empty */
 		{ $$ = NULL_TREE; }
-	| ':' see_typename  %prec EMPTY
-		{ yyungetc(':', 1); $$ = NULL_TREE; }
-	| ':' see_typename base_class_list  %prec EMPTY
+	| ':' see_typename
+		{ error ("no bases given following `:'");
+		  $$ = NULL_TREE; }
+	| ':' see_typename base_class_list
 		{ $$ = $3; }
 	;
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e75984c..96c503d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2002-01-02  Nathan Sidwell  <nathan@codesourcery.com>
 
+	* g++.dg/template/friend2.C: New test.
+	* g++.old-deja/g++/brendan/crash8.C: Adjust location of error.
+
+2002-01-02  Nathan Sidwell  <nathan@codesourcery.com>
+
 	* g++.dg/other/ptrmem1.C: New test.
 	* g++.dg/other/ptrmem2.C: New test.
 
diff --git a/gcc/testsuite/g++.dg/template/friend3.C b/gcc/testsuite/g++.dg/template/friend3.C
new file mode 100644
index 0000000..7400534
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/friend3.C
@@ -0,0 +1,31 @@
+// { dg-do compile }
+
+// Copyright (C) 2001 Free Software Foundation, Inc.
+// Contributed by Nathan Sidwell 28 Dec 2001 <nathan@codesourcery.com>
+
+// PR 775 friend classes with qualified names inside template classes.
+
+struct A
+{
+  struct B {
+    B () { }
+  };
+};
+
+template <class T>
+struct C: A {
+  friend A::B::B (); // 2.95.2 ICE
+  friend struct A;
+  friend struct A::B; // 2.97 error
+};
+
+template class C<char>;
+
+template <typename T> class TPL
+{
+  class nested;
+};
+
+template <typename T> class TPL<T>::nested 
+{
+};
diff --git a/gcc/testsuite/g++.old-deja/g++.brendan/crash8.C b/gcc/testsuite/g++.old-deja/g++.brendan/crash8.C
index 4de66c6..46cc16f 100644
--- a/gcc/testsuite/g++.old-deja/g++.brendan/crash8.C
+++ b/gcc/testsuite/g++.old-deja/g++.brendan/crash8.C
@@ -1,8 +1,8 @@
 // Build don't link: 
 // GROUPS passed old-abort
 template<int a, int b>
-class Elvis // ERROR - in template.*
-{
+class Elvis
+{ // ERROR - in template.*
 } ;
 
 template<int a>