Implement C++0x unrestricted unions (N2544)

	Implement C++0x unrestricted unions (N2544)
	* class.c (check_field_decl): Loosen union handling in C++0x.
	* method.c (walk_field_subobs): Split out from...
	(synthesized_method_walk): ...here.  Set msg before loops.
	(process_subob_fn): Check for triviality in union members.
	* init.c (sort_mem_initializers): Splice out uninitialized
	anonymous unions and union members.
	(push_base_cleanups): Don't automatically destroy anonymous unions
	and union members.

From-SVN: r162187

1 files changed, 140 insertions, 108 deletions

diff --git a/gcc/cp/method.c b/gcc/cp/method.c
index b09064b..9876af2 100644
--- a/gcc/cp/method.c
+++ b/gcc/cp/method.c
@@ -545,7 +545,8 @@ do_build_copy_constructor (tree fndecl)
 	    }
 	  else if (ANON_AGGR_TYPE_P (expr_type) && TYPE_FIELDS (expr_type))
 	    /* Just use the field; anonymous types can't have
-	       nontrivial copy ctors or assignment ops.  */;
+	       nontrivial copy ctors or assignment ops or this
+	       function would be deleted.  */;
 	  else
 	    continue;
 
@@ -663,7 +664,8 @@ do_build_copy_assign (tree fndecl)
 	  else if (ANON_AGGR_TYPE_P (expr_type)
 		   && TYPE_FIELDS (expr_type) != NULL_TREE)
 	    /* Just use the field; anonymous types can't have
-	       nontrivial copy ctors or assignment ops.  */;
+	       nontrivial copy ctors or assignment ops or this
+	       function would be deleted.  */;
 	  else
 	    continue;
 
@@ -912,8 +914,19 @@ process_subob_fn (tree fn, bool move_p, tree *spec_p, bool *trivial_p,
       *spec_p = merge_exception_specifiers (*spec_p, raises);
     }
 
-  if (trivial_p && !trivial_fn_p (fn))
-    *trivial_p = false;
+  if (!trivial_fn_p (fn))
+    {
+      if (trivial_p)
+	*trivial_p = false;
+      if (TREE_CODE (arg) == FIELD_DECL
+	  && TREE_CODE (DECL_CONTEXT (arg)) == UNION_TYPE)
+	{
+	  if (deleted_p)
+	    *deleted_p = true;
+	  if (msg)
+	    error ("union member %q+D with non-trivial %qD", arg, fn);
+	}
+    }
 
   if (move_p && !move_fn_p (fn) && !trivial_fn_p (fn))
     {
@@ -929,6 +942,99 @@ process_subob_fn (tree fn, bool move_p, tree *spec_p, bool *trivial_p,
     *deleted_p = true;
 }
 
+/* Subroutine of synthesized_method_walk to allow recursion into anonymous
+   aggregates.  */
+
+static void
+walk_field_subobs (tree fields, tree fnname, special_function_kind sfk,
+		   int quals, bool copy_arg_p, bool move_p,
+		   bool assign_p, tree *spec_p, bool *trivial_p,
+		   bool *deleted_p, const char *msg,
+		   int flags, tsubst_flags_t complain)
+{
+  tree field;
+  for (field = fields; field; field = TREE_CHAIN (field))
+    {
+      tree mem_type, argtype, rval;
+
+      if (TREE_CODE (field) != FIELD_DECL
+	  || DECL_ARTIFICIAL (field))
+	continue;
+
+      mem_type = strip_array_types (TREE_TYPE (field));
+      if (assign_p)
+	{
+	  bool bad = true;
+	  if (CP_TYPE_CONST_P (mem_type) && !CLASS_TYPE_P (mem_type))
+	    {
+	      if (msg)
+		error ("non-static const member %q#D, can't use default "
+		       "assignment operator", field);
+	    }
+	  else if (TREE_CODE (mem_type) == REFERENCE_TYPE)
+	    {
+	      if (msg)
+		error ("non-static reference member %q#D, can't use "
+		       "default assignment operator", field);
+	    }
+	  else
+	    bad = false;
+
+	  if (bad && deleted_p)
+	    *deleted_p = true;
+	}
+      else if (sfk == sfk_constructor)
+	{
+	  bool bad = true;
+	  if (CP_TYPE_CONST_P (mem_type)
+	      && (!CLASS_TYPE_P (mem_type)
+		  || !type_has_user_provided_default_constructor (mem_type)))
+	    {
+	      if (msg)
+		error ("uninitialized non-static const member %q#D",
+		       field);
+	    }
+	  else if (TREE_CODE (mem_type) == REFERENCE_TYPE)
+	    {
+	      if (msg)
+		error ("uninitialized non-static reference member %q#D",
+		       field);
+	    }
+	  else
+	    bad = false;
+
+	  if (bad && deleted_p)
+	    *deleted_p = true;
+	}
+
+      if (!CLASS_TYPE_P (mem_type))
+	continue;
+
+      if (ANON_AGGR_TYPE_P (mem_type))
+	{
+	  walk_field_subobs (TYPE_FIELDS (mem_type), fnname, sfk, quals,
+			     copy_arg_p, move_p, assign_p, spec_p, trivial_p,
+			     deleted_p, msg, flags, complain);
+	  continue;
+	}
+
+      if (copy_arg_p)
+	{
+	  int mem_quals = cp_type_quals (mem_type) | quals;
+	  if (DECL_MUTABLE_P (field))
+	    mem_quals &= ~TYPE_QUAL_CONST;
+	  argtype = build_stub_type (mem_type, mem_quals, move_p);
+	}
+      else
+	argtype = NULL_TREE;
+
+      rval = locate_fn_flags (mem_type, fnname, argtype, flags, complain);
+
+      process_subob_fn (rval, move_p, spec_p, trivial_p, deleted_p,
+			msg, field);
+    }
+}
+
 /* The caller wants to generate an implicit declaration of SFK for CTYPE
    which is const if relevant and CONST_P is set.  If spec_p, trivial_p and
    deleted_p are non-null, set their referent appropriately.  If diag is
@@ -940,7 +1046,7 @@ synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p,
 			 tree *spec_p, bool *trivial_p, bool *deleted_p,
 			 bool diag)
 {
-  tree binfo, base_binfo, field, scope, fnname, rval, argtype;
+  tree binfo, base_binfo, scope, fnname, rval, argtype;
   bool move_p, copy_arg_p, assign_p, expected_trivial, check_vdtor;
   VEC(tree,gc) *vbases;
   int i, quals, flags;
@@ -1052,6 +1158,15 @@ synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p,
     quals = TYPE_UNQUALIFIED;
   argtype = NULL_TREE;
 
+  if (!diag)
+    msg = NULL;
+  else if (assign_p)
+    msg = ("base %qT does not have a move assignment operator or trivial "
+	   "copy assignment operator");
+  else
+    msg = ("base %qT does not have a move constructor or trivial "
+	   "copy constructor");
+
   for (binfo = TYPE_BINFO (ctype), i = 0;
        BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
     {
@@ -1060,15 +1175,6 @@ synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p,
 	argtype = build_stub_type (basetype, quals, move_p);
       rval = locate_fn_flags (base_binfo, fnname, argtype, flags, complain);
 
-      if (!diag)
-	msg = NULL;
-      else if (assign_p)
-	msg = ("base %qT does not have a move assignment operator or trivial "
-	       "copy assignment operator");
-      else
-	msg = ("base %qT does not have a move constructor or trivial "
-	       "copy constructor");
-
       process_subob_fn (rval, move_p, spec_p, trivial_p, deleted_p,
 			msg, BINFO_TYPE (base_binfo));
 
@@ -1094,105 +1200,31 @@ synthesized_method_walk (tree ctype, special_function_kind sfk, bool const_p,
 	*deleted_p = true;
     }
   else if (!assign_p)
-    for (i = 0; VEC_iterate (tree, vbases, i, base_binfo); ++i)
-      {
-	if (copy_arg_p)
-	  argtype = build_stub_type (BINFO_TYPE (base_binfo), quals, move_p);
-	rval = locate_fn_flags (base_binfo, fnname, argtype, flags, complain);
-
-	if (!diag)
-	  msg = NULL;
-	else if (assign_p)
-	  msg = ("virtual base %qT does not have a move assignment "
-		 "operator or trivial copy assignment operator");
-	else
-	  msg = ("virtual base %qT does not have a move constructor "
-		 "or trivial copy constructor");
-
-	process_subob_fn (rval, move_p, spec_p, trivial_p, deleted_p,
-			  msg, BINFO_TYPE (base_binfo));
-      }
-
-  for (field = TYPE_FIELDS (ctype); field; field = TREE_CHAIN (field))
     {
-      tree mem_type;
-
-      if (TREE_CODE (field) != FIELD_DECL
-	  || DECL_ARTIFICIAL (field))
-	continue;
-
-      mem_type = strip_array_types (TREE_TYPE (field));
-      if (assign_p)
+      if (diag)
+	msg = ("virtual base %qT does not have a move constructor "
+	       "or trivial copy constructor");
+      for (i = 0; VEC_iterate (tree, vbases, i, base_binfo); ++i)
 	{
-	  bool bad = true;
-	  if (CP_TYPE_CONST_P (mem_type) && !CLASS_TYPE_P (mem_type))
-	    {
-	      if (diag)
-		error ("non-static const member %q#D, can't use default "
-		       "assignment operator", field);
-	    }
-	  else if (TREE_CODE (mem_type) == REFERENCE_TYPE)
-	    {
-	      if (diag)
-		error ("non-static reference member %q#D, can't use "
-		       "default assignment operator", field);
-	    }
-	  else
-	    bad = false;
+	  if (copy_arg_p)
+	    argtype = build_stub_type (BINFO_TYPE (base_binfo), quals, move_p);
+	  rval = locate_fn_flags (base_binfo, fnname, argtype, flags, complain);
 
-	  if (bad && deleted_p)
-	    *deleted_p = true;
+	  process_subob_fn (rval, move_p, spec_p, trivial_p, deleted_p,
+			    msg, BINFO_TYPE (base_binfo));
 	}
-      else if (sfk == sfk_constructor)
-	{
-	  bool bad = true;
-	  if (CP_TYPE_CONST_P (mem_type)
-	      && (!CLASS_TYPE_P (mem_type)
-		  || !type_has_user_provided_default_constructor (mem_type)))
-	    {
-	      if (diag)
-		error ("uninitialized non-static const member %q#D",
-		       field);
-	    }
-	  else if (TREE_CODE (mem_type) == REFERENCE_TYPE)
-	    {
-	      if (diag)
-		error ("uninitialized non-static reference member %q#D",
-		       field);
-	    }
-	  else
-	    bad = false;
-
-	  if (bad && deleted_p)
-	    *deleted_p = true;
-	}
-
-      if (!CLASS_TYPE_P (mem_type)
-	  || ANON_AGGR_TYPE_P (mem_type))
-	continue;
-
-      if (copy_arg_p)
-	{
-	  int mem_quals = cp_type_quals (mem_type) | quals;
-	  if (DECL_MUTABLE_P (field))
-	    mem_quals &= ~TYPE_QUAL_CONST;
-	  argtype = build_stub_type (mem_type, mem_quals, move_p);
-	}
-
-      rval = locate_fn_flags (mem_type, fnname, argtype, flags, complain);
-
-      if (!diag)
-	msg = NULL;
-      else if (assign_p)
-	msg = ("non-static data member %qD does not have a move "
-	       "assignment operator or trivial copy assignment operator");
-      else
-	msg = ("non-static data member %qD does not have a move "
-	       "constructor or trivial copy constructor");
-
-      process_subob_fn (rval, move_p, spec_p, trivial_p, deleted_p,
-			msg, field);
     }
+  if (!diag)
+    /* Leave msg null. */;
+  else if (assign_p)
+    msg = ("non-static data member %qD does not have a move "
+	   "assignment operator or trivial copy assignment operator");
+  else
+    msg = ("non-static data member %qD does not have a move "
+	   "constructor or trivial copy constructor");
+  walk_field_subobs (TYPE_FIELDS (ctype), fnname, sfk, quals,
+		     copy_arg_p, move_p, assign_p, spec_p, trivial_p,
+		     deleted_p, msg, flags, complain);
 
   pop_scope (scope);