Fix: as.call could not handle language.

com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/AsCall.java

@@ -32,6 +32,7 @@ import com.oracle.truffle.api.profiles.ConditionProfile;
 import com.oracle.truffle.r.nodes.RASTUtils;
 import com.oracle.truffle.r.nodes.attributes.SpecialAttributesFunctions.GetNamesAttributeNode;
 import com.oracle.truffle.r.nodes.builtin.RBuiltinNode;
+import com.oracle.truffle.r.nodes.function.RCallBaseNode;
 import com.oracle.truffle.r.runtime.ArgumentsSignature;
 import com.oracle.truffle.r.runtime.RError;
 import com.oracle.truffle.r.runtime.RError.Message;
@@ -87,6 +88,15 @@ public abstract class AsCall extends RBuiltinNode.Arg1 {
         }
     }
 
+    protected boolean containsCall(RLanguage l) {
+        return l.getRep() instanceof RCallBaseNode;
+    }
+
+    @Specialization(guards = "containsCall(l)")
+    protected RLanguage asCall(RLanguage l) {
+        return l;
+    }
+
     @Fallback
     protected Object asCallFunction(@SuppressWarnings("unused") Object x) {
         throw error(RError.Message.GENERIC, "invalid argument list");

com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_ascall.java

@@ -78,5 +78,7 @@ public class TestBuiltin_ascall extends TestBase {
         assertEval(Output.IgnoreWhitespace, "as.call(list(as.symbol('function'), pairlist(a=1)))");
         assertEval(Output.IgnoreWhitespace, "as.call(list(as.symbol('function')))");
         assertEval(Output.IgnoreWhitespace, "call('function')");
+
+        assertEval(Output.IgnoreWhitespace, "{ cl <- quote(fun(3)); as.call(cl) }");
     }
 }