re PR c++/53650 (large array causes huge memory use)

PR c++/53650
	* call.c (type_has_extended_temps): New.
	* cp-tree.h: Declare it.
	* decl.c (check_initializer): Use build_aggr_init for arrays
	if it is false.
	* init.c (build_vec_init): Avoid mixed signed/unsigned arithmetic.

From-SVN: r195380

gcc/cp/ChangeLog

@@ -1,5 +1,12 @@
 2013-01-22  Jason Merrill  <jason@redhat.com>
 
+	PR c++/53650
+	* call.c (type_has_extended_temps): New.
+	* cp-tree.h: Declare it.
+	* decl.c (check_initializer): Use build_aggr_init for arrays
+	if it is false.
+	* init.c (build_vec_init): Avoid mixed signed/unsigned arithmetic.
+
 	PR c++/56071
 	* pt.c (maybe_instantiate_noexcept): Don't defer access checks.
 

gcc/cp/call.c

@@ -8835,6 +8835,28 @@ extend_ref_init_temps (tree decl, tree init, VEC(tree,gc) **cleanups)
   return init;
 }
 
+/* Returns true iff an initializer for TYPE could contain temporaries that
+   need to be extended because they are bound to references or
+   std::initializer_list.  */
+
+bool
+type_has_extended_temps (tree type)
+{
+  type = strip_array_types (type);
+  if (TREE_CODE (type) == REFERENCE_TYPE)
+    return true;
+  if (CLASS_TYPE_P (type))
+    {
+      if (is_std_init_list (type))
+	return true;
+      for (tree f = next_initializable_field (TYPE_FIELDS (type));
+	   f; f = next_initializable_field (DECL_CHAIN (f)))
+	if (type_has_extended_temps (TREE_TYPE (f)))
+	  return true;
+    }
+  return false;
+}
+
 /* Returns true iff TYPE is some variant of std::initializer_list.  */
 
 bool

gcc/cp/cp-tree.h

@@ -4889,6 +4889,7 @@ extern tree initialize_reference		(tree, tree, int,
 						 tsubst_flags_t);
 extern tree extend_ref_init_temps		(tree, tree, VEC(tree,gc)**);
 extern tree make_temporary_var_for_ref_to_temp	(tree, tree);
+extern bool type_has_extended_temps		(tree);
 extern tree strip_top_quals			(tree);
 extern bool reference_related_p			(tree, tree);
 extern tree perform_implicit_conversion		(tree, tree, tsubst_flags_t);

gcc/cp/decl.c

@@ -5556,7 +5556,9 @@ check_initializer (tree decl, tree init, int flags, VEC(tree,gc) **cleanups)
       if ((type_build_ctor_call (type) || CLASS_TYPE_P (type))
 	  && !(flags & LOOKUP_ALREADY_DIGESTED)
 	  && !(init && BRACE_ENCLOSED_INITIALIZER_P (init)
-	       && CP_AGGREGATE_TYPE_P (type)))
+	       && CP_AGGREGATE_TYPE_P (type)
+	       && (CLASS_TYPE_P (type)
+		   || type_has_extended_temps (type))))
 	{
 	  init_code = build_aggr_init_full_exprs (decl, init, flags);
 

gcc/cp/init.c

@@ -3501,7 +3501,9 @@ build_vec_init (tree base, tree maxindex, tree init,
       if (TREE_CODE (type) == ARRAY_TYPE)
 	m = cp_build_binary_op (input_location,
 				MULT_EXPR, m,
-				array_type_nelts_total (type),
+				/* Force signed arithmetic.  */
+				convert (TREE_TYPE (m),
+					 array_type_nelts_total (type)),
 				complain);
 
       finish_cleanup_try_block (try_block);

gcc/testsuite/g++.dg/init/array34.C

@@ -0,0 +1,15 @@
+// PR c++/53650
+// We should loop over array inits if they don't involve temporaries
+// that need extending.
+// { dg-options "-fdump-tree-gimple" }
+// { dg-final { scan-tree-dump-times "Class::Class" 1 "gimple" } }
+// { dg-final { cleanup-tree-dump "gimple" } }
+
+struct Class {
+  Class();
+};
+
+int main() {
+  Class table [10] = {};
+  return 0;
+}