Use hash tables for template specialization lookup.

	* pt.c (struct spec_entry): New type.
	(decl_specializations, type_specializations): New hash tables.
	(register_specialization, retrieve_specialization): Use them.
	(reregister_specialization, lookup_template_class): Use them.
	(eq_specializations, hash_tmpl_and_args, hash_specialization): New.
	(iterative_hash_template_arg): New.
	(init_template_processing): New
	(process_partial_specialization): Don't look to see if we already
	have this partial specialization.
	(maybe_process_partial_specialization): Handle reassigning
	full specializations when we get an explicit specialization
	of the partial instantiation.
	(tsubst_friend_function): Adjust specialization reassignment code.
	(instantiate_template): Only do one lookup.
	(instantiate_decl): Don't do any lookup.
	* cp-tree.h: Declare init_template_processing.
	* decl.c (duplicate_decls): Pass args to reregister_specialization.

From-SVN: r149188

gcc/cp/ChangeLog

+2009-07-02  Jason Merrill  <jason@redhat.com>
+
+	Use hash tables for template specialization lookup.
+	* pt.c (struct spec_entry): New type.
+	(decl_specializations, type_specializations): New hash tables.
+	(register_specialization, retrieve_specialization): Use them.
+	(reregister_specialization, lookup_template_class): Use them.
+	(eq_specializations, hash_tmpl_and_args, hash_specialization): New.
+	(iterative_hash_template_arg): New.
+	(init_template_processing): New
+	(process_partial_specialization): Don't look to see if we already
+	have this partial specialization.
+	(maybe_process_partial_specialization): Handle reassigning
+	full specializations when we get an explicit specialization
+	of the partial instantiation.
+	(tsubst_friend_function): Adjust specialization reassignment code.
+	(instantiate_template): Only do one lookup.
+	(instantiate_decl): Don't do any lookup.
+	* cp-tree.h: Declare init_template_processing.
+	* decl.c (duplicate_decls): Pass args to reregister_specialization.
+
 2009-07-01  Jason Merrill  <jason@redhat.com>
 
 	* cp-tree.h (DECL_CLASS_TEMPLATE_P): Use DECL_IMPLICIT_TYPEDEF_P.

gcc/cp/cp-tree.h

@@ -3072,15 +3072,18 @@ more_aggr_init_expr_args_p (const aggr_init_expr_arg_iterator *iter)
    TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (NODE))
 /* For function, method, class-data templates.  */
 #define DECL_TEMPLATE_RESULT(NODE)      DECL_RESULT_FLD (NODE)
-/* For a static member variable template, the
-   DECL_TEMPLATE_INSTANTIATIONS list contains the explicitly and
-   implicitly generated instantiations of the variable.  There are no
-   partial instantiations of static member variables, so all of these
-   will be full instantiations.
+/* For a function template at namespace scope, DECL_TEMPLATE_INSTANTIATIONS
+   lists all instantiations and specializations of the function so that
+   tsubst_friend_function can reassign them to another template if we find
+   that the namespace-scope template is really a partial instantiation of a
+   friend template.
 
    For a class template the DECL_TEMPLATE_INSTANTIATIONS lists holds
    all instantiations and specializations of the class type, including
-   partial instantiations and partial specializations.
+   partial instantiations and partial specializations, so that if we
+   explicitly specialize a partial instantiation we can walk the list
+   in maybe_process_partial_specialization and reassign them or complain
+   as appropriate.
 
    In both cases, the TREE_PURPOSE of each node contains the arguments
    used; the TREE_VALUE contains the generated variable.  The template
@@ -3096,29 +3099,9 @@ more_aggr_init_expr_args_p (const aggr_init_expr_arg_iterator *iter)
    DECL_TEMPLATE_INSTANTIATIONS list for `template <class T> template
    <class U> struct S1<T>::S2'.
 
-   This list is not used for function templates.  */
+   This list is not used for other templates.  */
 #define DECL_TEMPLATE_INSTANTIATIONS(NODE) DECL_VINDEX (NODE)
-/* For a function template, the DECL_TEMPLATE_SPECIALIZATIONS lists
-   contains all instantiations and specializations of the function,
-   including partial instantiations.  For a partial instantiation
-   which is a specialization, this list holds only full
-   specializations of the template that are instantiations of the
-   partial instantiation.  For example, given:
-
-      template <class T> struct S {
-	template <class U> void f(U);
-	template <> void f(T);
-      };
-
-   the `S<int>::f<int>(int)' function will appear on the
-   DECL_TEMPLATE_SPECIALIZATIONS list for both `template <class T>
-   template <class U> void S<T>::f(U)' and `template <class T> void
-   S<int>::f(T)'.  In the latter case, however, it will have only the
-   innermost set of arguments (T, in this case).  The DECL_TI_TEMPLATE
-   for the function declaration will point at the specialization, not
-   the fully general template.
-
-   For a class template, this list contains the partial
+/* For a class template, this list contains the partial
    specializations of this template.  (Full specializations are not
    recorded on this list.)  The TREE_PURPOSE holds the arguments used
    in the partial specialization (e.g., for `template <class T> struct
@@ -3128,7 +3111,7 @@ more_aggr_init_expr_args_p (const aggr_init_expr_arg_iterator *iter)
    example above.)  The TREE_TYPE is the _TYPE node for the partial
    specialization.
 
-   This list is not used for static variable templates.  */
+   This list is not used for other templates.  */
 #define DECL_TEMPLATE_SPECIALIZATIONS(NODE)     DECL_SIZE (NODE)
 
 /* Nonzero for a DECL which is actually a template parameter.  Keep
@@ -4619,6 +4602,7 @@ extern tree fold_non_dependent_expr		(tree);
 extern bool explicit_class_specialization_p     (tree);
 extern struct tinst_level *outermost_tinst_level(void);
 extern bool parameter_of_template_p		(tree, tree);
+extern void init_template_processing		(void);
 
 /* in repo.c */
 extern void init_repo				(void);

gcc/cp/decl.c

@@ -1109,7 +1109,7 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
   unsigned olddecl_uid = DECL_UID (olddecl);
   int olddecl_friend = 0, types_match = 0, hidden_friend = 0;
   int new_defines_function = 0;
-  tree new_template;
+  tree new_template_info;
 
   if (newdecl == olddecl)
     return olddecl;
@@ -1855,7 +1855,7 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
   if (! DECL_EXTERNAL (olddecl))
     DECL_EXTERNAL (newdecl) = 0;
 
-  new_template = NULL_TREE;
+  new_template_info = NULL_TREE;
   if (DECL_LANG_SPECIFIC (newdecl) && DECL_LANG_SPECIFIC (olddecl))
     {
       bool new_redefines_gnu_inline = false;
@@ -1899,7 +1899,7 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
       DECL_NONCONVERTING_P (newdecl) = DECL_NONCONVERTING_P (olddecl);
       DECL_REPO_AVAILABLE_P (newdecl) = DECL_REPO_AVAILABLE_P (olddecl);
       if (DECL_TEMPLATE_INFO (newdecl))
-	new_template = DECL_TI_TEMPLATE (newdecl);
+	new_template_info = DECL_TEMPLATE_INFO (newdecl);
       DECL_TEMPLATE_INFO (newdecl) = DECL_TEMPLATE_INFO (olddecl);
       DECL_INITIALIZED_IN_CLASS_P (newdecl)
 	|= DECL_INITIALIZED_IN_CLASS_P (olddecl);
@@ -2097,7 +2097,7 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
       memcpy ((char *) olddecl + sizeof (struct tree_decl_common),
 	      (char *) newdecl + sizeof (struct tree_decl_common),
 	      sizeof (struct tree_function_decl) - sizeof (struct tree_decl_common));
-      if (new_template)
+      if (new_template_info)
 	/* If newdecl is a template instantiation, it is possible that
 	   the following sequence of events has occurred:
 
@@ -2120,7 +2120,7 @@ duplicate_decls (tree newdecl, tree olddecl, bool newdecl_is_friend)
 	   instantiations so that if we try to do the instantiation
 	   again we won't get the clobbered declaration.  */
 	reregister_specialization (newdecl,
-				   new_template,
+				   new_template_info,
 				   olddecl);
     }
   else
@@ -3459,6 +3459,7 @@ cxx_init_decl_processing (void)
   /* Perform other language dependent initializations.  */
   init_class_processing ();
   init_rtti_processing ();
+  init_template_processing ();
 
   if (flag_exceptions)
     init_exception_processing ();

gcc/testsuite/ChangeLog

+2009-07-02  Jason Merrill  <jason@redhat.com>
+
+	* g++.dg/template/spec8.C: Fix.
+
 2009-07-02  Michael Matz  <matz@suse.de>
 
 	PR fortran/32131

gcc/testsuite/g++.dg/template/spec8.C

@@ -5,7 +5,12 @@
 template<class T1> struct A
 {
   template<class T2> struct B {};
+  template<class T2> struct C {};
 }; 
 
-template <> template <> struct A<int>::B<int> {};
-template <> template <class U> struct A<int>::B {}; // { dg-error "specialization" }
+template <> template <> struct A<int>::B<int>;
+template <> template <class U> struct A<int>::B {};
+A<int>::B<int> ab;		// { dg-error "incomplete" }
+
+A<int>::C<char> ac;
+template <> template <class U> struct A<int>::C {}; // { dg-error "specialization" }