Handle builtins in identical(RFunction)

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

@@ -204,6 +204,17 @@ public abstract class Identical extends RBuiltinNode {
             // trivial case
             return RRuntime.LOGICAL_TRUE;
         } else {
+            boolean xb = x.isBuiltin();
+            boolean yb = y.isBuiltin();
+            if ((xb && !yb) || (yb && !xb)) {
+                return RRuntime.LOGICAL_FALSE;
+            }
+
+            if (xb && yb) {
+                // equal if the factories are
+                return RRuntime.asLogical(x.getRBuiltin() == y.getRBuiltin());
+            }
+
             // compare the structure
             if (!new IdenticalVisitor().accept((RSyntaxNode) x.getRootNode(), (RSyntaxNode) y.getRootNode())) {
                 return RRuntime.LOGICAL_FALSE;

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

@@ -217,7 +217,6 @@ public class TestBuiltin_identical extends TestBase {
 
         assertEval("{ identical(quote(if(x) 42), quote(if(x) 7)) }");
         assertEval("{ identical(quote(if(x) 42), quote(if(x) 42)) }");
-        assertEval("{ identical(function() 42, function() 42) }");
 
         assertEval("{ setClass(\"foo\", representation(j=\"numeric\")); x<-new(\"foo\", j=42); y<-new(\"foo\", j=42); identical(x,y) }");
         assertEval("{ setClass(\"foo\", representation(j=\"numeric\")); x<-new(\"foo\", j=42); y<-new(\"foo\", j=7); identical(x,y) }");
@@ -256,6 +255,7 @@ public class TestBuiltin_identical extends TestBase {
         // GnuR adds a srcref attribute, FastR does not, so we really can't do any comparative
         // tests.
         assertEval(Ignored.ImplementationError, "{ f1 <- function() {}; f2 <- function() {}; identical(f1, f2) }");
+        assertEval(Ignored.ImplementationError, "{ identical(function() 42, function() 42) }");
 
     }
 }