Merge from trunk revision 918a5b84a2c51dc9d011d39461cc276e6558069d

8 files changed, 248 insertions, 72 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 6728ea1..1bf50cd 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,70 @@
+2020-12-03  Jason Merrill  <jason@redhat.com>
+
+	* cp-tree.h (releasing_vec::operator[]): Change parameter type to
+	ptrdiff_t.
+
+2020-12-03  Nathan Sidwell  <nathan@acm.org>
+
+	* cp-tree.h (OVL_EXPORT): New.
+	(class ovl_iterator): Add get_using, exporting_p.
+	* tree.c (ovl_insert): Extend using_or_hidden meaning to include
+	an exported using.
+
+2020-12-03  Nathan Sidwell  <nathan@acm.org>
+
+	* cp-tree.h (DECL_UNINSTANTIATED_TEMPLATE_FRIEND): New.
+	* pt.c (push_template_decl): Set it.
+	(tsubst_friend_function): Clear it.
+
+2020-12-03  Nathan Sidwell  <nathan@acm.org>
+
+	* cp-tree.h (make_unbound_class_template_raw): Declare.
+	(canonical_type_parameter): Declare.
+	* decl.c (make_unbound_class_template_raw): Break out of ...
+	(make_unboud_class_template): ... here.  Call it.
+	* pt.c (canonical_type_parameter): Externalize.  Refactor & set
+	structural_equality for type parms.
+
+2020-12-03  Nathan Sidwell  <nathan@acm.org>
+
+	PR c++/98107
+	* tree.c (build_cplus_array_type): Mark dependency of new variant.
+	(cp_build_qualified_type_real, strip_typedefs): Assert
+	TYPE_DEPENDENT_P_VALID, or not a dependent type.
+
+2020-12-03  Jakub Jelinek  <jakub@redhat.com>
+
+	PR libstdc++/93121
+	* cp-tree.h (cp_build_bit_cast): Declare.
+	* cp-tree.def (BIT_CAST_EXPR): New tree code.
+	* cp-objcp-common.c (names_builtin_p): Handle RID_BUILTIN_BIT_CAST.
+	(cp_common_init_ts): Handle BIT_CAST_EXPR.
+	* cxx-pretty-print.c (cxx_pretty_printer::postfix_expression):
+	Likewise.
+	* parser.c (cp_parser_postfix_expression): Handle
+	RID_BUILTIN_BIT_CAST.
+	* semantics.c (cp_build_bit_cast): New function.
+	* tree.c (cp_tree_equal): Handle BIT_CAST_EXPR.
+	(cp_walk_subtrees): Likewise.
+	* pt.c (tsubst_copy): Likewise.
+	* constexpr.c (check_bit_cast_type, cxx_eval_bit_cast): New functions.
+	(cxx_eval_constant_expression): Handle BIT_CAST_EXPR.
+	(potential_constant_expression_1): Likewise.
+	* cp-gimplify.c (cp_genericize_r): Likewise.
+
+2020-12-03  Jason Merrill  <jason@redhat.com>
+
+	* parser.c (cp_parser_primary_expression): Distinguish
+	parms from vars in error.
+	(cp_parser_late_parsing_default_args): Pushdecl parms
+	as we go.
+
+2020-12-03  Jason Merrill  <jason@redhat.com>
+
+	* name-lookup.c (begin_scope): Set immediate_fn_ctx_p.
+	* parser.c (cp_parser_late_parsing_default_args): Push
+	sk_function_parms scope.
+
 2020-12-03  Peter Bergner  <bergner@linux.ibm.com>
 
 	PR c++/97947
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index bafcaf5..8bbcf01 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -3005,7 +3005,7 @@ fold_builtin_source_location (location_t loc)
 	      const char *name = "";
 
 	      if (current_function_decl)
-		name = cxx_printable_name (current_function_decl, 0);
+		name = cxx_printable_name (current_function_decl, 2);
 
 	      val = build_string_literal (strlen (name) + 1, name);
 	    }
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 69f8ed5..00901fe 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -488,10 +488,9 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
       CALL_EXPR_ORDERED_ARGS (in CALL_EXPR, AGGR_INIT_EXPR)
       DECLTYPE_FOR_REF_CAPTURE (in DECLTYPE_TYPE)
       CONSTRUCTOR_C99_COMPOUND_LITERAL (in CONSTRUCTOR)
-      DECL_MODULE_EXPORT_P (in _DECL)
       OVL_NESTED_P (in OVERLOAD)
       LAMBDA_EXPR_INSTANTIATED (in LAMBDA_EXPR)
-      Reserved for DECL_MODULE_EXPORT (in DECL_)
+      DECL_MODULE_EXPORT_P (in _DECL)
    4: IDENTIFIER_MARKED (IDENTIFIER_NODEs)
       TREE_HAS_CONSTRUCTOR (in INDIRECT_REF, SAVE_EXPR, CONSTRUCTOR,
 	  CALL_EXPR, or FIELD_DECL).
@@ -503,6 +502,7 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
       FUNCTION_RVALUE_QUALIFIED (in FUNCTION_TYPE, METHOD_TYPE)
       CALL_EXPR_REVERSE_ARGS (in CALL_EXPR, AGGR_INIT_EXPR)
       CONSTRUCTOR_PLACEHOLDER_BOUNDARY (in CONSTRUCTOR)
+      OVL_EXPORT_P (in OVERLOAD)
    6: TYPE_MARKED_P (in _TYPE)
       DECL_NONTRIVIALLY_INITIALIZED_P (in VAR_DECL)
       RANGE_FOR_IVDEP (in RANGE_FOR_STMT)
@@ -545,6 +545,7 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
       DECL_ANON_UNION_VAR_P (in a VAR_DECL)
       DECL_SELF_REFERENCE_P (in a TYPE_DECL)
       DECL_INVALID_OVERRIDER_P (in a FUNCTION_DECL)
+      DECL_UNINSTANIATED_TEMPLATE_FRIEND_P (in TEMPLATE_DECL)
    5: DECL_INTERFACE_KNOWN.
    6: DECL_THIS_STATIC (in VAR_DECL, FUNCTION_DECL or PARM_DECL)
       DECL_FIELD_IS_BASE (in FIELD_DECL)
@@ -779,6 +780,8 @@ typedef struct ptrmem_cst * ptrmem_cst_t;
 #define OVL_NESTED_P(NODE)	TREE_LANG_FLAG_3 (OVERLOAD_CHECK (NODE))
 /* If set, this overload was constructed during lookup.  */
 #define OVL_LOOKUP_P(NODE)	TREE_LANG_FLAG_4 (OVERLOAD_CHECK (NODE))
+/* If set, this OVL_USING_P overload is exported.  */
+#define OVL_EXPORT_P(NODE)	TREE_LANG_FLAG_5 (OVERLOAD_CHECK (NODE))
 
 /* The first decl of an overload.  */
 #define OVL_FIRST(NODE)	ovl_first (NODE)
@@ -838,6 +841,11 @@ class ovl_iterator {
 
     return fn;
   }
+  tree get_using () const
+  {
+    gcc_checking_assert (using_p ());
+    return ovl;
+  }
 
  public:
   /* Whether this overload was introduced by a using decl.  */
@@ -846,6 +854,12 @@ class ovl_iterator {
     return (TREE_CODE (ovl) == USING_DECL
 	    || (TREE_CODE (ovl) == OVERLOAD && OVL_USING_P (ovl)));
   }
+  /* Whether this using is being exported.  */
+  bool exporting_p () const
+  {
+    return OVL_EXPORT_P (get_using ());
+  }
+  
   bool hidden_p () const
   {
     return TREE_CODE (ovl) == OVERLOAD && OVL_HIDDEN_P (ovl);
@@ -961,8 +975,10 @@ public:
   operator vec_t *() const { return v; }
   vec_t ** operator& () { return &v; }
 
-  /* Breaks pointer/value consistency for convenience.  */
-  tree& operator[] (unsigned i) const { return (*v)[i]; }
+  /* Breaks pointer/value consistency for convenience.  This takes ptrdiff_t
+     rather than unsigned to avoid ambiguity with the built-in operator[]
+     (bootstrap/91828).  */
+  tree& operator[] (ptrdiff_t i) const { return (*v)[i]; }
 
   ~releasing_vec() { release_tree_vector (v); }
 private:
@@ -3161,6 +3177,13 @@ struct GTY(()) lang_decl {
   (DECL_LANG_SPECIFIC (FUNCTION_DECL_CHECK (NODE)) \
    ->u.base.friend_or_tls)
 
+/* True of a TEMPLATE_DECL that is a template class friend.  Such
+   decls are not pushed until instantiated (as they may depend on
+   parameters of the befriending class).  DECL_CHAIN is the
+   befriending class.  */
+#define DECL_UNINSTANTIATED_TEMPLATE_FRIEND_P(NODE) \
+  (DECL_LANG_FLAG_4 (TEMPLATE_DECL_CHECK (NODE)))
+
 /* Nonzero if the thread-local variable was declared with __thread as
    opposed to thread_local.  */
 #define DECL_GNU_TLS_P(NODE)				\
@@ -5399,10 +5422,6 @@ extern int function_depth;
    in structrual_comptypes.  */
 extern int comparing_specializations;
 
-/* Nonzero if we are inside eq_specializations, which affects
-   resolving of typenames in structural_comptypes.  */
-extern int comparing_typenames;
-
 /* In parser.c.  */
 
 /* Nonzero if we are parsing an unevaluated operand: an operand to
@@ -6863,6 +6882,103 @@ extern bool ctor_omit_inherited_parms		(tree);
 extern tree locate_ctor				(tree);
 extern tree implicitly_declare_fn               (special_function_kind, tree,
 						 bool, tree, tree);
+/* In module.cc  */
+class module_state; /* Forward declare.  */
+inline bool modules_p () { return flag_modules != 0; }
+
+/* The kind of module or part thereof that we're in.  */
+enum module_kind_bits
+{
+  MK_MODULE = 1 << 0,     /* This TU is a module.  */
+  MK_GLOBAL = 1 << 1,     /* Entities are in the global module.  */
+  MK_INTERFACE = 1 << 2,  /* This TU is an interface.  */
+  MK_PARTITION = 1 << 3,  /* This TU is a partition.  */
+  MK_EXPORTING = 1 << 4,  /* We are in an export region.  */
+};
+
+/* We do lots of bit-manipulation, so an unsigned is easier.  */
+extern unsigned module_kind;
+
+/*  MK_MODULE & MK_GLOBAL have the following combined meanings:
+ MODULE GLOBAL
+   0	  0	not a module
+   0	  1	GMF of named module (we've not yet seen module-decl)
+   1	  0	purview of named module
+   1	  1	header unit.   */
+
+inline bool module_purview_p ()
+{ return module_kind & MK_MODULE; }
+inline bool global_purview_p ()
+{ return module_kind & MK_GLOBAL; }
+
+inline bool not_module_p ()
+{ return (module_kind & (MK_MODULE | MK_GLOBAL)) == 0; }
+inline bool named_module_p ()
+{ /* This is a named module if exactly one of MODULE and GLOBAL is
+     set.  */
+  /* The divides are constant shifts!  */
+  return ((module_kind / MK_MODULE) ^ (module_kind / MK_GLOBAL)) & 1;
+}
+inline bool header_module_p ()
+{ return (module_kind & (MK_MODULE | MK_GLOBAL)) == (MK_MODULE | MK_GLOBAL); }
+inline bool named_module_purview_p ()
+{ return (module_kind & (MK_MODULE | MK_GLOBAL)) == MK_MODULE; }
+inline bool module_interface_p ()
+{ return module_kind & MK_INTERFACE; }
+inline bool module_partition_p ()
+{ return module_kind & MK_PARTITION; }
+inline bool module_has_cmi_p ()
+{ return module_kind & (MK_INTERFACE | MK_PARTITION); }
+
+/* We're currently exporting declarations.  */
+inline bool module_exporting_p ()
+{ return module_kind & MK_EXPORTING; }
+
+extern module_state *get_module (tree name, module_state *parent = NULL,
+				 bool partition = false);
+extern bool module_may_redeclare (tree decl);
+
+extern int module_initializer_kind ();
+extern void module_add_import_initializers ();
+
+/* Where the namespace-scope decl was originally declared.  */
+extern void set_originating_module (tree, bool friend_p = false);
+extern tree get_originating_module_decl (tree) ATTRIBUTE_PURE;
+extern int get_originating_module (tree, bool for_mangle = false) ATTRIBUTE_PURE;
+extern unsigned get_importing_module (tree, bool = false) ATTRIBUTE_PURE;
+
+/* Where current instance of the decl got declared/defined/instantiated.  */
+extern void set_instantiating_module (tree);
+extern void set_defining_module (tree);
+extern void maybe_attach_decl (tree ctx, tree decl);
+
+extern void mangle_module (int m, bool include_partition);
+extern void mangle_module_fini ();
+extern void lazy_load_binding (unsigned mod, tree ns, tree id,
+			       binding_slot *bslot);
+extern void lazy_load_specializations (tree tmpl);
+extern void lazy_load_members (tree decl);
+extern bool lazy_specializations_p (unsigned, bool, bool);
+extern module_state *preprocess_module (module_state *, location_t,
+					bool in_purview, 
+					bool is_import, bool export_p,
+					cpp_reader *reader);
+extern void preprocessed_module (cpp_reader *reader);
+extern void import_module (module_state *, location_t, bool export_p,
+			   tree attr, cpp_reader *);
+extern void declare_module (module_state *, location_t, bool export_p,
+			    tree attr, cpp_reader *);
+extern void init_modules (cpp_reader *);
+extern void fini_modules ();
+extern void maybe_check_all_macros (cpp_reader *);
+extern void finish_module_processing (cpp_reader *);
+extern char const *module_name (unsigned, bool header_ok);
+extern bitmap get_import_bitmap ();
+extern bitmap module_visible_instantiation_path (bitmap *);
+extern void module_begin_main_file (cpp_reader *, line_maps *,
+				    const line_map_ordinary *);
+extern void module_preprocess_options (cpp_reader *);
+extern bool handle_module_option (unsigned opt, const char *arg, int value);
 
 /* In optimize.c */
 extern bool maybe_clone_body			(tree);
@@ -7443,7 +7559,7 @@ extern bool is_local_temp			(tree);
 extern tree build_aggr_init_expr		(tree, tree);
 extern tree get_target_expr			(tree);
 extern tree get_target_expr_sfinae		(tree, tsubst_flags_t);
-extern tree build_cplus_array_type		(tree, tree, int is_dep = -1);
+extern tree build_cplus_array_type		(tree, tree);
 extern tree build_array_of_n_type		(tree, int);
 extern bool array_of_runtime_bound_p		(tree);
 extern bool vla_type_p				(tree);
diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 1bc7b7e..46069cb 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -1928,7 +1928,7 @@ static void
 clear_consteval_vfns (vec<tree> &consteval_vtables)
 {
   for (tree vtable : consteval_vtables)
-    for (constructor_elt &elt : *CONSTRUCTOR_ELTS (DECL_INITIAL (vtable)))
+    for (constructor_elt &elt : CONSTRUCTOR_ELTS (DECL_INITIAL (vtable)))
       {
 	tree fn = cp_get_fndecl_from_callee (elt.value, /*fold*/false);
 	if (fn && DECL_IMMEDIATE_FUNCTION_P (fn))
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 103567c..cc3da15 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -30611,9 +30611,6 @@ cp_parser_late_parsing_default_args (cp_parser *parser, tree fn)
     {
       tree default_arg = TREE_PURPOSE (parm);
       tree parsed_arg;
-      vec<tree, va_gc> *insts;
-      tree copy;
-      unsigned ix;
 
       tree parmdecl = parms[i];
       pushdecl (parmdecl);
@@ -30633,8 +30630,7 @@ cp_parser_late_parsing_default_args (cp_parser *parser, tree fn)
       TREE_PURPOSE (parm) = parsed_arg;
 
       /* Update any instantiations we've already created.  */
-      for (insts = DEFPARSE_INSTANTIATIONS (default_arg), ix = 0;
-	   vec_safe_iterate (insts, ix, &copy); ix++)
+      for (tree copy : DEFPARSE_INSTANTIATIONS (default_arg))
 	TREE_PURPOSE (copy) = parsed_arg;
     }
 
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 3ca2813..2d3ab92 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -22,7 +22,9 @@ along with GCC; see the file COPYING3.  If not see
 /* Known bugs or deficiencies include:
 
      all methods must be provided in header files; can't use a source
-     file that contains only the method templates and "just win".  */
+     file that contains only the method templates and "just win".
+
+     Fixed by: C++20 modules.  */
 
 #include "config.h"
 #include "system.h"
@@ -1702,19 +1704,16 @@ register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
   return spec;
 }
 
-/* Restricts tree and type comparisons.  */
-int comparing_specializations;
-int comparing_typenames;
-
 /* Returns true iff two spec_entry nodes are equivalent.  */
 
+int comparing_specializations;
+
 bool
 spec_hasher::equal (spec_entry *e1, spec_entry *e2)
 {
   int equal;
 
   ++comparing_specializations;
-  ++comparing_typenames;
   equal = (e1->tmpl == e2->tmpl
 	   && comp_template_args (e1->args, e2->args));
   if (equal && flag_concepts
@@ -1730,7 +1729,6 @@ spec_hasher::equal (spec_entry *e1, spec_entry *e2)
       equal = equivalent_constraints (c1, c2);
     }
   --comparing_specializations;
-  --comparing_typenames;
 
   return equal;
 }
@@ -6044,6 +6042,14 @@ push_template_decl (tree decl, bool is_friend)
 	      tmpl = NULL_TREE;
 	    }
 	}
+      else if (is_friend)
+	{
+	  /* Record this decl as belonging to the current class.  It's
+	     not chained onto anything else.  */
+	  DECL_UNINSTANTIATED_TEMPLATE_FRIEND_P (tmpl) = true;
+	  gcc_checking_assert (!DECL_CHAIN (tmpl));
+	  DECL_CHAIN (tmpl) = current_scope ();
+	}
     }
   else if (tmpl)
     /* The type may have been completed, or (erroneously) changed.  */
@@ -8260,7 +8266,7 @@ convert_template_argument (tree parm,
 
   /* When determining whether an argument pack expansion is a template,
      look at the pattern.  */
-  if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
+  if (PACK_EXPANSION_P (arg))
     arg = PACK_EXPANSION_PATTERN (arg);
 
   /* Deal with an injected-class-name used as a template template arg.  */
@@ -11053,6 +11059,7 @@ tsubst_friend_function (tree decl, tree args)
   DECL_USE_TEMPLATE (new_friend) = 0;
   if (TREE_CODE (new_friend) == TEMPLATE_DECL)
     {
+      DECL_UNINSTANTIATED_TEMPLATE_FRIEND_P (new_friend) = false;
       DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
       DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
 	= DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
@@ -29006,6 +29013,12 @@ do_class_deduction (tree ptype, tree tmpl, tree init,
   if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl))
     return ptype;
 
+  /* Initializing one placeholder from another.  */
+  if (init && TREE_CODE (init) == TEMPLATE_PARM_INDEX
+      && is_auto (TREE_TYPE (init))
+      && CLASS_PLACEHOLDER_TEMPLATE (TREE_TYPE (init)) == tmpl)
+    return cp_build_qualified_type (TREE_TYPE (init), cp_type_quals (ptype));
+
   /* Look through alias templates that just rename another template.  */
   tmpl = get_underlying_template (tmpl);
   if (!ctad_template_p (tmpl))
@@ -29022,10 +29035,6 @@ do_class_deduction (tree ptype, tree tmpl, tree init,
 		 "with %<-std=c++20%> or %<-std=gnu++20%>");
     }
 
-  if (init && TREE_TYPE (init) == ptype)
-    /* Using the template parm as its own argument.  */
-    return ptype;
-
   tree type = TREE_TYPE (tmpl);
 
   bool try_list_ctor = false;
@@ -29273,7 +29282,7 @@ do_auto_deduction (tree type, tree init, tree auto_node,
       /* We don't recurse here because we can't deduce from a nested
 	 initializer_list.  */
       if (CONSTRUCTOR_ELTS (init))
-	for (constructor_elt &elt : *CONSTRUCTOR_ELTS (init))
+	for (constructor_elt &elt : CONSTRUCTOR_ELTS (init))
 	  elt.value = resolve_nondeduced_context (elt.value, complain);
     }
   else
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 8d7df60..4e6bf9a 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -998,7 +998,7 @@ build_min_array_type (tree elt_type, tree index_type)
    build_cplus_array_type.  */
 
 static void
-set_array_type_canon (tree t, tree elt_type, tree index_type, bool dep)
+set_array_type_canon (tree t, tree elt_type, tree index_type)
 {
   /* Set the canonical type for this new node.  */
   if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
@@ -1009,33 +1009,30 @@ set_array_type_canon (tree t, tree elt_type, tree index_type, bool dep)
     TYPE_CANONICAL (t)
       = build_cplus_array_type (TYPE_CANONICAL (elt_type),
 				index_type
-				? TYPE_CANONICAL (index_type) : index_type,
-				dep);
+				? TYPE_CANONICAL (index_type) : index_type);
   else
     TYPE_CANONICAL (t) = t;
 }
 
 /* Like build_array_type, but handle special C++ semantics: an array of a
    variant element type is a variant of the array of the main variant of
-   the element type.  IS_DEPENDENT is -ve if we should determine the
-   dependency.  Otherwise its bool value indicates dependency.  */
+   the element type.  */
 
 tree
-build_cplus_array_type (tree elt_type, tree index_type, int dependent)
+build_cplus_array_type (tree elt_type, tree index_type)
 {
   tree t;
 
   if (elt_type == error_mark_node || index_type == error_mark_node)
     return error_mark_node;
 
-  if (dependent < 0)
-    dependent = (uses_template_parms (elt_type)
-		 || (index_type && uses_template_parms (index_type)));
+  bool dependent = (uses_template_parms (elt_type)
+		    || (index_type && uses_template_parms (index_type)));
 
   if (elt_type != TYPE_MAIN_VARIANT (elt_type))
     /* Start with an array of the TYPE_MAIN_VARIANT.  */
     t = build_cplus_array_type (TYPE_MAIN_VARIANT (elt_type),
-				index_type, dependent);
+				index_type);
   else if (dependent)
     {
       /* Since type_hash_canon calls layout_type, we need to use our own
@@ -1065,20 +1062,13 @@ build_cplus_array_type (tree elt_type, tree index_type, int dependent)
 	  *e = t;
 
 	  /* Set the canonical type for this new node.  */
-	  set_array_type_canon (t, elt_type, index_type, dependent);
-
-	  /* Mark it as dependent now, this saves time later.  */
-	  TYPE_DEPENDENT_P_VALID (t) = true;
-	  TYPE_DEPENDENT_P (t) = true;
+	  set_array_type_canon (t, elt_type, index_type);
 	}
     }
   else
     {
       bool typeless_storage = is_byte_access_type (elt_type);
       t = build_array_type (elt_type, index_type, typeless_storage);
-
-      /* Mark as non-dependenty now, this will save time later.  */
-      TYPE_DEPENDENT_P_VALID (t) = true;
     }
 
   /* Now check whether we already have this array variant.  */
@@ -1093,10 +1083,7 @@ build_cplus_array_type (tree elt_type, tree index_type, int dependent)
       if (!t)
 	{
 	  t = build_min_array_type (elt_type, index_type);
-	  /* Mark dependency now, this saves time later.  */
-	  TYPE_DEPENDENT_P_VALID (t) = true;
-	  TYPE_DEPENDENT_P (t) = dependent;
-	  set_array_type_canon (t, elt_type, index_type, dependent);
+	  set_array_type_canon (t, elt_type, index_type);
 	  if (!dependent)
 	    {
 	      layout_type (t);
@@ -1332,10 +1319,7 @@ cp_build_qualified_type_real (tree type,
 
       if (!t)
 	{
-	  gcc_checking_assert (TYPE_DEPENDENT_P_VALID (type)
-			       || !dependent_type_p (type));
-	  t = build_cplus_array_type (element_type, TYPE_DOMAIN (type),
-				      TYPE_DEPENDENT_P (type));
+	  t = build_cplus_array_type (element_type, TYPE_DOMAIN (type));
 
 	  /* Keep the typedef name.  */
 	  if (TYPE_NAME (t) != TYPE_NAME (type))
@@ -1571,9 +1555,7 @@ strip_typedefs (tree t, bool *remove_attributes, unsigned int flags)
     case ARRAY_TYPE:
       type = strip_typedefs (TREE_TYPE (t), remove_attributes, flags);
       t0  = strip_typedefs (TYPE_DOMAIN (t), remove_attributes, flags);
-      gcc_checking_assert (TYPE_DEPENDENT_P_VALID (t)
-			   || !dependent_type_p (t));
-      result = build_cplus_array_type (type, t0, TYPE_DEPENDENT_P (t));
+      result = build_cplus_array_type (type, t0);
       break;
     case FUNCTION_TYPE:
     case METHOD_TYPE:
@@ -2272,10 +2254,11 @@ ovl_make (tree fn, tree next)
   return result;
 }
 
-/* Add FN to the (potentially NULL) overload set OVL.  USING_OR_HIDDEN
-   is > 0, if FN is via a using declaration.  USING_OR_HIDDEN is < 0,
-   if FN is hidden.  (A decl cannot be both using and hidden.)  We
-   keep the hidden decls first, but remaining ones are unordered.  */
+/* Add FN to the (potentially NULL) overload set OVL.  USING_OR_HIDDEN is >
+   zero if this is a using-decl.  It is > 1 if we're exporting the
+   using decl.  USING_OR_HIDDEN is < 0, if FN is hidden.  (A decl
+   cannot be both using and hidden.)  We keep the hidden decls first,
+   but remaining ones are unordered.  */
 
 tree
 ovl_insert (tree fn, tree maybe_ovl, int using_or_hidden)
@@ -2299,7 +2282,11 @@ ovl_insert (tree fn, tree maybe_ovl, int using_or_hidden)
       if (using_or_hidden < 0)
 	OVL_HIDDEN_P (maybe_ovl) = true;
       if (using_or_hidden > 0)
-	OVL_DEDUP_P (maybe_ovl) = OVL_USING_P (maybe_ovl) = true;
+	{
+	  OVL_DEDUP_P (maybe_ovl) = OVL_USING_P (maybe_ovl) = true;
+	  if (using_or_hidden > 1)
+	    OVL_EXPORT_P (maybe_ovl) = true;
+	}
     }
   else
     maybe_ovl = fn;
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 6294a78..267b284 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -1256,15 +1256,16 @@ structural_comptypes (tree t1, tree t2, int strict)
 
   gcc_assert (TYPE_P (t1) && TYPE_P (t2));
 
-  /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
-     current instantiation, and we don't care about typename
-     structural equality.  The comparing_typenames check is after the
-     code check, in order to early-out the common case.  */
-  if (TREE_CODE (t1) == TYPENAME_TYPE && !comparing_typenames)
-    t1 = resolve_typename_type (t1, /*only_current_p=*/true);
-
-  if (TREE_CODE (t2) == TYPENAME_TYPE && !comparing_typenames)
-    t2 = resolve_typename_type (t2, /*only_current_p=*/true);
+  if (!comparing_specializations)
+    {
+      /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
+	 current instantiation.  */
+      if (TREE_CODE (t1) == TYPENAME_TYPE)
+	t1 = resolve_typename_type (t1, /*only_current_p=*/true);
+
+      if (TREE_CODE (t2) == TYPENAME_TYPE)
+	t2 = resolve_typename_type (t2, /*only_current_p=*/true);
+    }
 
   if (TYPE_PTRMEMFUNC_P (t1))
     t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);