re PR c++/84330 ([concepts] ICE with broken constraint)

/cp
2018-02-15  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/84330
	* constraint.cc (tsubst_constraint_info): Handle an error_mark_node
	as first argument.

/testsuite
2018-02-15  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/84330
	* g++.dg/concepts/pr84330.C: New.

From-SVN: r257698

gcc/cp/ChangeLog

+2018-02-15  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/84330
+	* constraint.cc (tsubst_constraint_info): Handle an error_mark_node
+	as first argument.
+
 2018-02-14  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/84350

gcc/cp/constraint.cc

@@ -1918,7 +1918,7 @@ tsubst_constraint_info (tree t, tree args,
 tree
 tsubst_constraint (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 {
-  if (t == NULL_TREE)
+  if (t == NULL_TREE || t == error_mark_node)
     return t;
   switch (TREE_CODE (t))
   {

gcc/testsuite/ChangeLog

+2018-02-15  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/84330
+	* g++.dg/concepts/pr84330.C: New.
+
 2018-02-15  Tom de Vries  <tom@codesourcery.com>
 
 	* gcc.dg/Wstringop-overflow-3.c: Require effective target alloca.

gcc/testsuite/g++.dg/concepts/pr84330.C

+// PR c++/84330
+// { dg-options "-fconcepts" }
+
+struct A
+{
+  template<typename T> requires sizeof(T) >> 0 void foo(T);  // { dg-error "predicate constraint" }
+
+  void bar()
+  {
+    foo(0);  // { dg-error "no matching" }
+  }
+};