re PR c++/46803 (libstdc++ build errors on invalid OpenBSD system header attributes)

	PR c++/46803
	* c-common.c (attribute_takes_identifier_p): Assume that an
	unknown attribute takes an identifier.

From-SVN: r170885

gcc/c-family/ChangeLog

+2011-03-11  Jason Merrill  <jason@redhat.com>
+
+	PR c++/46803
+	* c-common.c (attribute_takes_identifier_p): Assume that an
+	unknown attribute takes an identifier.
+
 2011-03-07  Nathan Froyd  <froydnj@codesourcery.com>
 
 	PR c/47786

gcc/c-family/c-common.c

@@ -5665,9 +5665,14 @@ c_init_attributes (void)
 bool
 attribute_takes_identifier_p (const_tree attr_id)
 {
-  if (is_attribute_p ("mode", attr_id)
-      || is_attribute_p ("format", attr_id)
-      || is_attribute_p ("cleanup", attr_id))
+  struct attribute_spec *spec = lookup_attribute_spec (attr_id);
+  if (spec == NULL)
+    /* Unknown attribute that we'll end up ignoring, return true so we
+       don't complain about an identifier argument.  */
+    return true;
+  else if (!strcmp ("mode", spec->name)
+	   || !strcmp ("format", spec->name)
+	   || !strcmp ("cleanup", spec->name))
     return true;
   else
     return targetm.attribute_takes_identifier_p (attr_id);

gcc/testsuite/ChangeLog

 2011-03-11  Jason Merrill  <jason@redhat.com>
 
+	* g++.dg/ext/attrib40.C: New.
+
 	* g++.dg/cpp0x/regress/array1.C: New.
 
 2011-03-11  Richard Guenther  <rguenther@suse.de>

gcc/testsuite/g++.dg/ext/attrib40.C

+// PR c++/46803
+
+int strftime(char *, int, const char *, const struct tm *)
+        __attribute__ ((__bounded__(__string__,1,2))); // { dg-warning "ignored" }