re PR c++/78647 (ICE on invalid C++ code on x86_64-linux-gnu (internal compiler…

re PR c++/78647 (ICE on invalid C++ code on x86_64-linux-gnu (internal compiler error: tree check: expected tree_list, have error_mark in get_attribute_name, at attribs.c:664))

	PR c++/78647
	* c-common.c (attribute_fallthrough_p): Return false for
	error_mark_node.

	* g++.dg/parse/error58.C: New.

From-SVN: r243575

gcc/c-family/ChangeLog

+2016-12-12  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/78647
+	* c-common.c (attribute_fallthrough_p): Return false for
+	error_mark_node.
+
 2016-12-08  Martin Sebor  <msebor@redhat.com>
 
 	PR c/78284

gcc/c-family/c-common.c

@@ -5558,6 +5558,8 @@ parse_optimize_options (tree args, bool attr_p)
 bool
 attribute_fallthrough_p (tree attr)
 {
+  if (attr == error_mark_node)
+   return false;
   tree t = lookup_attribute ("fallthrough", attr);
   if (t == NULL_TREE)
     return false;

gcc/testsuite/ChangeLog

+2016-12-12  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/78647
+	* g++.dg/parse/error58.C: New.
+
 2016-12-12  David Malcolm  <dmalcolm@redhat.com>
 
 	PR preprocessor/78680

gcc/testsuite/g++.dg/parse/error58.C

+// PR c++/78647
+// { dg-do compile { target c++11 } }
+// { dg-options "-w" }
+
+struct A;
+void foo ();
+void f() { alignas (foo (A)); } // { dg-error "expected" "" }