Iterative attribute nodes never return null

com.oracle.truffle.r.nodes/src/com/oracle/truffle/r/nodes/attributes/ArrayAttributeNode.java

@@ -24,23 +24,33 @@ package com.oracle.truffle.r.nodes.attributes;
 
 import java.util.List;
 
+import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.nodes.ExplodeLoop;
 import com.oracle.truffle.api.object.DynamicObject;
 import com.oracle.truffle.api.object.Property;
 import com.oracle.truffle.api.object.Shape;
+import com.oracle.truffle.api.profiles.BranchProfile;
+import com.oracle.truffle.api.profiles.ConditionProfile;
+import com.oracle.truffle.api.profiles.ValueProfile;
+import com.oracle.truffle.r.runtime.data.RAttributable;
+import com.oracle.truffle.r.runtime.data.RAttributeStorage;
 import com.oracle.truffle.r.runtime.data.RAttributesLayout;
 import com.oracle.truffle.r.runtime.data.RAttributesLayout.AttrsLayout;
 import com.oracle.truffle.r.runtime.data.RAttributesLayout.RAttribute;
 
 public abstract class ArrayAttributeNode extends AttributeIterativeAccessNode {
 
+    private static final RAttribute[] EMPTY = new RAttribute[0];
+
+    @Child private ArrayAttributeNode recursive;
+
     public static ArrayAttributeNode create() {
         return ArrayAttributeNodeGen.create();
     }
 
-    public abstract RAttribute[] execute(DynamicObject attrs);
+    public abstract RAttribute[] execute(Object attrs);
 
     @Specialization(limit = "CACHE_LIMIT", guards = {"attrsLayout != null", "attrsLayout.shape.check(attrs)"})
     @ExplodeLoop
@@ -69,7 +79,29 @@ public abstract class ArrayAttributeNode extends AttributeIterativeAccessNode {
         }
 
         return result;
-
     }
 
+    @Specialization
+    protected RAttribute[] getArrayFallback(RAttributable x,
+                    @Cached("create()") BranchProfile attrNullProfile,
+                    @Cached("createBinaryProfile()") ConditionProfile attrStorageProfile,
+                    @Cached("createClassProfile()") ValueProfile xTypeProfile) {
+        DynamicObject attributes;
+        if (attrStorageProfile.profile(x instanceof RAttributeStorage)) {
+            attributes = ((RAttributeStorage) x).getAttributes();
+        } else {
+            attributes = xTypeProfile.profile(x).getAttributes();
+        }
+
+        if (attributes == null) {
+            attrNullProfile.enter();
+            return EMPTY;
+        }
+        if (recursive == null) {
+            CompilerDirectives.transferToInterpreterAndInvalidate();
+            recursive = insert(create());
+        }
+
+        return recursive.execute(attributes);
+    }
 }

com.oracle.truffle.r.nodes/src/com/oracle/truffle/r/nodes/attributes/IterableAttributeNode.java

@@ -22,20 +22,28 @@
  */
 package com.oracle.truffle.r.nodes.attributes;
 
+import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.dsl.Cached;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.object.DynamicObject;
+import com.oracle.truffle.api.profiles.BranchProfile;
+import com.oracle.truffle.api.profiles.ConditionProfile;
+import com.oracle.truffle.api.profiles.ValueProfile;
+import com.oracle.truffle.r.runtime.data.RAttributable;
+import com.oracle.truffle.r.runtime.data.RAttributeStorage;
 import com.oracle.truffle.r.runtime.data.RAttributesLayout;
 import com.oracle.truffle.r.runtime.data.RAttributesLayout.AttrsLayout;
 
 public abstract class IterableAttributeNode extends AttributeIterativeAccessNode {
 
+    @Child private IterableAttributeNode recursive;
+
     public static IterableAttributeNode create() {
         return IterableAttributeNodeGen.create();
     }
 
-    public abstract RAttributesLayout.RAttributeIterable execute(DynamicObject attrs);
+    public abstract RAttributesLayout.RAttributeIterable execute(Object attr);
 
     @Specialization(limit = "CACHE_LIMIT", guards = {"attrsLayout != null", "shapeCheck(attrsLayout.shape, attrs)"})
     protected RAttributesLayout.RAttributeIterable getArrayFromConstantLayouts(DynamicObject attrs,
@@ -49,4 +57,27 @@ public abstract class IterableAttributeNode extends AttributeIterativeAccessNode
         return RAttributesLayout.asIterable(attrs);
     }
 
+    @Specialization
+    protected RAttributesLayout.RAttributeIterable getArrayFallback(RAttributable x,
+                    @Cached("create()") BranchProfile attrNullProfile,
+                    @Cached("createBinaryProfile()") ConditionProfile attrStorageProfile,
+                    @Cached("createClassProfile()") ValueProfile xTypeProfile) {
+        DynamicObject attributes;
+        if (attrStorageProfile.profile(x instanceof RAttributeStorage)) {
+            attributes = ((RAttributeStorage) x).getAttributes();
+        } else {
+            attributes = xTypeProfile.profile(x).getAttributes();
+        }
+
+        if (attributes == null) {
+            attrNullProfile.enter();
+            return RAttributesLayout.RAttributeIterable.EMPTY;
+        }
+        if (recursive == null) {
+            CompilerDirectives.transferToInterpreterAndInvalidate();
+            recursive = insert(create());
+        }
+
+        return recursive.execute(attributes);
+    }
 }

com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/data/RAttributesLayout.java

@@ -22,6 +22,7 @@
  */
 package com.oracle.truffle.r.runtime.data;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
@@ -257,6 +258,9 @@ public final class RAttributesLayout {
     }
 
     public static final class RAttributeIterable implements Iterable<RAttributesLayout.RAttribute> {
+
+        public static final RAttributeIterable EMPTY = new RAttributeIterable(null, null);
+
         private final DynamicObject attrs;
         private final List<Property> properties;
 
@@ -267,7 +271,11 @@ public final class RAttributesLayout {
 
         @Override
         public Iterator<RAttributesLayout.RAttribute> iterator() {
-            return new Iter(attrs, properties.iterator());
+            if (attrs == null || properties == null) {
+                return Collections.emptyIterator();
+            } else {
+                return new Iter(attrs, properties.iterator());
+            }
         }
 
     }