* cp-tree.h (IDENTIFIER_TYPENAME_P): Use OPERATOR_TYPENAME_FORMAT

	here.
	(lang_type): Add is_partial_instantiation.  Decrease width of
	dummy.
	(PARTIAL_INSTANTIATION_P): New macro.
	(OPERATOR_TYPENAME_P): Remove.
	* decl.c (unary_op_p): Use IDENTIFIER_TYPENAME_P, not
	OPERATOR_TYPENAME_P.
	(grok_op_properties): Likewise.
	* friend.c (do_friend): Handle friends that are member functions
	correctly.
	* lex.c (init_parse): Use OPERATOR_TYPENAME_FORMAT.
	* pt.c (instantiate_class_template): Rework for clarity.  Avoid
	leaving TYPE_BEING_DEFINED set in obscure cases.  Don't do
	any more partial instantiation than is absolutely necessary for
	implicit typename.  Set PARTIAL_INSTANTIATION_P.
	(tsubst_decl): Use IDENTIFIER_TYPENAME_P.
	* semantics.c (begin_class_definition): Handle partial
	specializations of a type that was previously partially
	instantiated.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@24548 138bc75d-0d04-0410-961f-82ee72b054a4

7 files changed, 166 insertions, 73 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 7e1567b489c..478180ab80e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,26 @@
+1999-01-06  Mark Mitchell  <mark@markmitchell.com>
+
+	* cp-tree.h (IDENTIFIER_TYPENAME_P): Use OPERATOR_TYPENAME_FORMAT
+	here. 
+	(lang_type): Add is_partial_instantiation.  Decrease width of
+	dummy. 
+	(PARTIAL_INSTANTIATION_P): New macro.
+	(OPERATOR_TYPENAME_P): Remove.
+	* decl.c (unary_op_p): Use IDENTIFIER_TYPENAME_P, not
+	OPERATOR_TYPENAME_P. 
+	(grok_op_properties): Likewise.
+	* friend.c (do_friend): Handle friends that are member functions
+	correctly. 
+	* lex.c (init_parse): Use OPERATOR_TYPENAME_FORMAT.
+	* pt.c (instantiate_class_template): Rework for clarity.  Avoid
+	leaving TYPE_BEING_DEFINED set in obscure cases.  Don't do
+	any more partial instantiation than is absolutely necessary for
+	implicit typename.  Set PARTIAL_INSTANTIATION_P.
+	(tsubst_decl): Use IDENTIFIER_TYPENAME_P.
+	* semantics.c (begin_class_definition): Handle partial
+	specializations of a type that was previously partially
+	instantiated. 
+	
 Wed Jan  6 03:18:53 1999  Mark Elbrecht  <snowball3@usa.net.
 
 	* g++spec.c (LIBSTDCXX): Provide default definition.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index b255933a1ce..db6e2281577 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -1,5 +1,5 @@
 /* Definitions for C++ parsing and type checking.
-   Copyright (C) 1987, 92-97, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1987, 92-97, 1998, 1999 Free Software Foundation, Inc.
    Hacked by Michael Tiemann (tiemann@cygnus.com)
 
 This file is part of GNU CC.
@@ -293,10 +293,12 @@ struct tree_srcloc
 /* Nonzero if this identifier is the prefix for a mangled C++ operator name.  */
 #define IDENTIFIER_OPNAME_P(NODE) TREE_LANG_FLAG_2(NODE)
 
-#define IDENTIFIER_TYPENAME_P(NODE)	\
-  (! strncmp (IDENTIFIER_POINTER (NODE),			\
-	      IDENTIFIER_POINTER (ansi_opname[(int) TYPE_EXPR]),	\
-	      IDENTIFIER_LENGTH (ansi_opname[(int) TYPE_EXPR])))
+/* Nonzero if this identifier is the name of a type-conversion
+   operator.  */
+#define IDENTIFIER_TYPENAME_P(NODE)			\
+  (! strncmp (IDENTIFIER_POINTER (NODE),		\
+              OPERATOR_TYPENAME_FORMAT,			\
+	      strlen (OPERATOR_TYPENAME_FORMAT)))
 
 /* Nonzero means reject anything that ANSI standard C forbids.  */
 extern int pedantic;
@@ -723,11 +725,12 @@ struct lang_type
       unsigned has_complex_assign_ref : 1;
       unsigned has_abstract_assign_ref : 1;
       unsigned non_aggregate : 1;
+      unsigned is_partial_instantiation : 1;
 
       /* The MIPS compiler gets it wrong if this struct also
 	 does not fill out to a multiple of 4 bytes.  Add a
 	 member `dummy' with new bits if you go over the edge.  */
-      unsigned dummy : 12;
+      unsigned dummy : 11;
     } type_flags;
 
   int n_ancestors;
@@ -1913,6 +1916,12 @@ extern int flag_new_for_scope;
 #define DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION(DECL) \
   (DECL_TEMPLATE_INFO (DECL) && !DECL_USE_TEMPLATE (DECL))
 
+/* Non-zero if TYPE is a partial instantiation of a template class,
+   i.e., an instantiation whose instantiation arguments involve
+   template types.  */
+#define PARTIAL_INSTANTIATION_P(TYPE) \
+  (TYPE_LANG_SPECIFIC (TYPE)->type_flags.is_partial_instantiation)
+
 /* Non-zero iff we are currently processing a declaration for an
    entity with its own template parameter list, and which is not a
    full specialization.  */
@@ -2189,12 +2198,6 @@ extern int current_function_parms_stored;
 #define OPERATOR_ASSIGN_FORMAT "__a%s"
 #define OPERATOR_FORMAT "__%s"
 #define OPERATOR_TYPENAME_FORMAT "__op"
-#define OPERATOR_TYPENAME_P(ID_NODE) \
-  (IDENTIFIER_POINTER (ID_NODE)[0] == '_'	\
-   && IDENTIFIER_POINTER (ID_NODE)[1] == '_'	\
-   && IDENTIFIER_POINTER (ID_NODE)[2] == 'o'	\
-   && IDENTIFIER_POINTER (ID_NODE)[3] == 'p')
-
 
 /* Cannot use '$' up front, because this confuses gdb
    (names beginning with '$' are gdb-local identifiers).
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 8dc8008ba98..edad0a98097 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -11653,7 +11653,7 @@ unary_op_p (name)
   return (name == ansi_opname [(int) TRUTH_NOT_EXPR]
 	  || name == ansi_opname [(int) BIT_NOT_EXPR]
 	  || name == ansi_opname [(int) COMPONENT_REF]
-	  || OPERATOR_TYPENAME_P (name));
+	  || IDENTIFIER_TYPENAME_P (name));
 }
 
 /* Do a little sanity-checking on how they declared their operator.  */
@@ -11744,7 +11744,7 @@ grok_op_properties (decl, virtualp, friendp)
 	 an enumeration, or a reference to an enumeration.  13.4.0.6 */
       if (! methodp || DECL_STATIC_FUNCTION_P (decl))
 	{
-	  if (OPERATOR_TYPENAME_P (name)
+	  if (IDENTIFIER_TYPENAME_P (name)
 	      || name == ansi_opname[(int) CALL_EXPR]
 	      || name == ansi_opname[(int) MODIFY_EXPR]
 	      || name == ansi_opname[(int) COMPONENT_REF]
diff --git a/gcc/cp/friend.c b/gcc/cp/friend.c
index 98991ea452b..c26d6956c11 100644
--- a/gcc/cp/friend.c
+++ b/gcc/cp/friend.c
@@ -1,5 +1,5 @@
 /* Help friends in C++.
-   Copyright (C) 1997, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
 
 This file is part of GNU CC.
 
@@ -370,16 +370,20 @@ do_friend (ctype, declarator, decl, parmdecls, flags, quals, funcdef_flag)
 
 	  if (is_friend_template)
 	    decl = DECL_TI_TEMPLATE (push_template_decl (decl));
-
+	  else if (template_class_depth (current_class_type))
+	    decl = push_template_decl_real (decl, /*is_friend=*/1);
+
+	  /* We can't do lookup in a type that involves template
+	     parameters.  Instead, we rely on tsubst_friend_function
+	     to check the validity of the declaration later.  */
+	  if (uses_template_parms (ctype))
+	    add_friend (current_class_type, decl);
 	  /* A nested class may declare a member of an enclosing class
 	     to be a friend, so we do lookup here even if CTYPE is in
 	     the process of being defined.  */
-	  if (TYPE_SIZE (ctype) != 0 || TYPE_BEING_DEFINED (ctype))
+	  else if (TYPE_SIZE (ctype) != 0 || TYPE_BEING_DEFINED (ctype))
 	    {
-	      /* But, we defer looup in template specializations until
-		 they are fully specialized.  */
-	      if (template_class_depth (ctype) == 0)
-		decl = check_classfn (ctype, decl);
+	      decl = check_classfn (ctype, decl);
 
 	      if (decl)
 		add_friend (current_class_type, decl);
diff --git a/gcc/cp/lex.c b/gcc/cp/lex.c
index 0d8996f6eb2..505fbba5fed 100644
--- a/gcc/cp/lex.c
+++ b/gcc/cp/lex.c
@@ -1,5 +1,5 @@
 /* Separate lexical analyzer for GNU C++.
-   Copyright (C) 1987, 89, 92-97, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1987, 89, 92-97, 1998, 1999 Free Software Foundation, Inc.
    Hacked by Michael Tiemann (tiemann@cygnus.com)
 
 This file is part of GNU CC.
@@ -650,7 +650,7 @@ init_parse (filename)
   IDENTIFIER_OPNAME_P (ansi_opname[(int) VEC_NEW_EXPR]) = 1;
   ansi_opname[(int) VEC_DELETE_EXPR] = get_identifier ("__vd");
   IDENTIFIER_OPNAME_P (ansi_opname[(int) VEC_DELETE_EXPR]) = 1;
-  ansi_opname[(int) TYPE_EXPR] = get_identifier ("__op");
+  ansi_opname[(int) TYPE_EXPR] = get_identifier (OPERATOR_TYPENAME_FORMAT);
   IDENTIFIER_OPNAME_P (ansi_opname[(int) TYPE_EXPR]) = 1;
 
   /* This is not true: these operators are not defined in ANSI,
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index e27286789ba..9a0545ecd9f 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -1,5 +1,5 @@
 /* Handle parameterized types (templates) for GNU C++.
-   Copyright (C) 1992, 93-97, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1992, 93-97, 1998, 1999 Free Software Foundation, Inc.
    Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
    Rewritten by Jason Merrill (jason@cygnus.com).
 
@@ -4436,7 +4436,6 @@ instantiate_class_template (type)
 {
   tree template, args, pattern, t;
   tree typedecl;
-  int is_partial_instantiation;
 
   if (type == error_mark_node)
     return error_mark_node;
@@ -4457,9 +4456,33 @@ instantiate_class_template (type)
   /* Figure out which arguments are being used to do the
      instantiation.  */
   args = CLASSTYPE_TI_ARGS (type);
-  is_partial_instantiation = uses_template_parms (args);
+  PARTIAL_INSTANTIATION_P (type) = uses_template_parms (args);
 
-  if (is_partial_instantiation)
+  if (pedantic && PARTIAL_INSTANTIATION_P (type))
+    /* If this is a partial instantiation, then we can't instantiate
+       the type; there's no telling whether or not one of the
+       template parameters might eventually be instantiated to some
+       value that results in a specialization being used.  For
+       example, consider:
+
+         template <class T>
+         struct S {};
+
+         template <class U> 
+         void f(S<U>);
+	     
+         template <> 
+         struct S<int> {};
+
+       Now, the `S<U>' in `f<int>' is the specialization, not an
+       instantiation of the original template.  Mark the type as
+       complete, in the same way that we do for a definition of a
+       template class.  */
+    goto end;
+
+  /* Determine what specialization of the original template to
+     instantiate.  */
+  if (PARTIAL_INSTANTIATION_P (type))
     /* There's no telling which specialization is appropriate at this
        point.  Since all peeking at the innards of this partial
        instantiation are extensions (like the "implicit typename"
@@ -4500,9 +4523,39 @@ instantiate_class_template (type)
   else
     pattern = TREE_TYPE (template);
 
+  /* If the template we're instantiating is incomplete, then clearly
+     there's nothing we can do.  */
   if (TYPE_SIZE (pattern) == NULL_TREE)
     goto end;
 
+  /* If this is a partial instantiation, don't tsubst anything.  We will
+     only use this type for implicit typename, so the actual contents don't
+     matter.  All that matters is whether a particular name is a type.  */
+  if (PARTIAL_INSTANTIATION_P (type))
+    {
+      /* The fields set here must be kept in sync with those cleared
+	 in begin_class_definition.  */
+      TYPE_BINFO_BASETYPES (type) = TYPE_BINFO_BASETYPES (pattern);
+      TYPE_FIELDS (type) = TYPE_FIELDS (pattern);
+      TYPE_METHODS (type) = TYPE_METHODS (pattern);
+      CLASSTYPE_TAGS (type) = CLASSTYPE_TAGS (pattern);
+      /* Pretend that the type is complete, so that we will look
+	 inside it during name lookup and such.  */
+      TYPE_SIZE (type) = integer_zero_node;
+      goto end;
+    }
+
+  /* If we've recursively instantiated too many templates, stop.  */
+  if (! push_tinst_level (type))
+    goto end;
+
+  /* Now we're really doing the instantiation.  Mark the type as in
+     the process of being defined.  */
+  TYPE_BEING_DEFINED (type) = 1;
+
+  maybe_push_to_top_level (uses_template_parms (type));
+  pushclass (type, 0);
+
   if (t)
     {
       /* This TYPE is actually a instantiation of of a partial
@@ -4531,31 +4584,6 @@ instantiate_class_template (type)
 	args = inner_args;
     }
 
-  if (pedantic && is_partial_instantiation)
-    {
-      /* If this is a partial instantiation, then we can't instantiate
-	 the type; there's no telling whether or not one of the
-	 template parameters might eventually be instantiated to some
-	 value that results in a specialization being used.  We do
-	 mark the type as complete so that, for example, declaring one
-	 of its members to be a friend will not be rejected.  */
-      TYPE_SIZE (type) = integer_zero_node;
-      goto end;
-    }
-
-  TYPE_BEING_DEFINED (type) = 1;
-
-  if (! push_tinst_level (type))
-    goto end;
-
-  maybe_push_to_top_level (uses_template_parms (type));
-  pushclass (type, 0);
-
-  /* We must copy the arguments to the permanent obstack since
-     during the tsubst'ing below they may wind up in the
-     DECL_TI_ARGS of some instantiated member template.  */
-  args = copy_to_permanent (args);
-
   if (flag_external_templates)
     {
       if (flag_alt_external_templates)
@@ -4608,18 +4636,10 @@ instantiate_class_template (type)
   TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
   TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
 
-  /* If this is a partial instantiation, don't tsubst anything.  We will
-     only use this type for implicit typename, so the actual contents don't
-     matter.  All that matters is whether a particular name is a type.  */
-  if (is_partial_instantiation)
-    {
-      TYPE_BINFO_BASETYPES (type) = TYPE_BINFO_BASETYPES (pattern);
-      TYPE_FIELDS (type) = TYPE_FIELDS (pattern);
-      TYPE_METHODS (type) = TYPE_METHODS (pattern);
-      CLASSTYPE_TAGS (type) = CLASSTYPE_TAGS (pattern);
-      TYPE_SIZE (type) = integer_zero_node;
-      goto done_with_instantiation;
-    }
+  /* We must copy the arguments to the permanent obstack since
+     during the tsubst'ing below they may wind up in the
+     DECL_TI_ARGS of some instantiated member template.  */
+  args = copy_to_permanent (args);
 
   {
     tree binfo = TYPE_BINFO (type);
@@ -4850,10 +4870,7 @@ instantiate_class_template (type)
   TYPE_BEING_DEFINED (type) = 0;
   repo_template_used (type);
 
- done_with_instantiation:
-  TYPE_BEING_DEFINED (type) = 0;
   popclass (0);
-
   pop_from_top_level ();
   pop_tinst_level ();
 
@@ -5382,9 +5399,7 @@ tsubst_decl (t, args, type, in_decl)
 	  = tsubst_aggr_type (DECL_CONTEXT (t), args, t, /*entering_scope=*/1);
 	DECL_CLASS_CONTEXT (r) = ctx;
 
-	if (member && !strncmp (OPERATOR_TYPENAME_FORMAT,
-				IDENTIFIER_POINTER (DECL_NAME (r)),
-				sizeof (OPERATOR_TYPENAME_FORMAT) - 1))
+	if (member && IDENTIFIER_TYPENAME_P (DECL_NAME (r)))
 	  /* Type-conversion operator.  Reconstruct the name, in
 	     case it's the name of one of the template's parameters.  */
 	  DECL_NAME (r) = build_typename_overload (TREE_TYPE (type));
diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index b1278dcbb1d..4bd997df447 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -3,7 +3,7 @@
    building RTL.  These routines are used both during actual parsing
    and during the instantiation of template functions. 
 
-   Copyright (C) 1998 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999 Free Software Foundation, Inc.
    Written by Mark Mitchell (mmitchell@usa.net) based on code found
    formerly in parse.y and pt.c.  
 
@@ -1222,10 +1222,58 @@ begin_class_definition (t)
      implicit typename, a TYPENAME_TYPE with a type.  */
   if (TREE_CODE (t) == TYPENAME_TYPE)
     t = TREE_TYPE (t);
+  
+  /* If we generated a partial instantiation of this type, but now
+     we're seeing a real definition, we're actually looking at a
+     partial specialization.  Consider:
+
+       template <class T, class U>
+       struct Y {};
+
+       template <class T>
+       struct X {};
+
+       template <class T, class U>
+       void f()
+       {
+	 typename X<Y<T, U> >::A a;
+       }
+
+       template <class T, class U>
+       struct X<Y<T, U> >
+       {
+       };
+
+     We have to undo the effects of the previous partial
+     instantiation.  */
+  if (PARTIAL_INSTANTIATION_P (t))
+    {
+      if (!pedantic) 
+	{
+	  /* Unfortunately, when we're not in pedantic mode, we
+	     attempt to actually fill in some of the fields of the
+	     partial instantiation, in order to support the implicit
+	     typename extension.  Clear those fields now, in
+	     preparation for the definition here.  The fields cleared
+	     here must match those set in instantiate_class_template.
+	     Look for a comment mentioning begin_class_definition
+	     there.  */
+	  TYPE_BINFO_BASETYPES (t) = NULL_TREE;
+	  TYPE_FIELDS (t) = NULL_TREE;
+	  TYPE_METHODS (t) = NULL_TREE;
+	  CLASSTYPE_TAGS (t) = NULL_TREE;
+	  TYPE_SIZE (t) = NULL_TREE;
+	}
 
-  if (TYPE_SIZE (t))
+      /* This isn't a partial instantiation any more.  */
+      PARTIAL_INSTANTIATION_P (t) = 0;
+    }
+  /* If this type was already complete, and we see another definition,
+     that's an error.  */
+  else if (TYPE_SIZE (t))
     duplicate_tag_error (t);
-  if (TYPE_SIZE (t) || TYPE_BEING_DEFINED (t))
+
+  if (TYPE_BEING_DEFINED (t))
     {
       t = make_lang_type (TREE_CODE (t));
       pushtag (TYPE_IDENTIFIER (t), t, 0);