We were crashing on this invalid test because cp_parser_std_attribute_spec_seq
in cp_parser_statement returned error_mark_node, but the subsequent
attribute_fallthrough_p wasn't prepared for that.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2016-12-05 Marek Polacek <pola...@redhat.com>
PR c++/78647
* c-family/c-common.c (attribute_fallthrough_p): Return false for
error_mark_node.
* g++.dg/parse/error58.C: New.
diff --git gcc/c-family/c-common.c gcc/c-family/c-common.c
index 0749361..c8e1f0d 100644
--- gcc/c-family/c-common.c
+++ 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;
diff --git gcc/testsuite/g++.dg/parse/error58.C
gcc/testsuite/g++.dg/parse/error58.C
index e69de29..5ed6e1e 100644
--- gcc/testsuite/g++.dg/parse/error58.C
+++ gcc/testsuite/g++.dg/parse/error58.C
@@ -0,0 +1,7 @@
+// PR c++/78647
+// { dg-do compile { target c++11 } }
+// { dg-options "-w" }
+
+struct A;
+void foo ();
+void f() { alignas (foo (A)); } // { dg-error "expected" "" }
Marek
