[GR-21159] 'Is' operation should threat hosted null object as None in Jython emulation mode.

Author: ppisl

graalpython/com.oracle.graal.python.test/src/tests/test_interop.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # The Universal Permissive License (UPL), Version 1.0
@@ -449,3 +449,44 @@ def test_java_import_star():
             exec("from java.util.logging.Logger import *", globals=d, locals=d)
             assert "getGlobal" in d
             assert d["getGlobal"]().getName() == d["GLOBAL_LOGGER_NAME"]
+
+    def test_java_null_is_none():
+        import java.lang.Integer as Integer
+        x = Integer.getInteger("something_what_does_not_exists")
+        y = Integer.getInteger("something_what_does_not_exists2")
+        z = None
+
+        if sys.graal_python_jython_emulation_enabled:
+
+            assert x == None
+            assert (x != None) == False
+            assert x is None
+            assert (x is not None) == False
+                        
+            assert x == y
+            assert (x != y) == False
+            assert x is y
+            assert (x is not y) == False
+
+            assert x == z
+            assert (x != z) == False
+            assert x is z
+            assert (x is not z) == False
+
+        else:
+
+            assert x == None
+            assert (x != None) == False
+            assert (x is None) == False
+            assert x is not None
+
+            assert (x == y) == False
+            assert x != y
+            assert x is y
+            assert (x is not y) == False
+
+            assert x == z
+            assert (x != z) == False
+            assert (x is z) == False
+            assert x is not z
+

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/expression/IsExpressionNode.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -40,18 +40,25 @@
  */
 package com.oracle.graal.python.nodes.expression;
 
+import com.oracle.graal.python.PythonLanguage;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__EQ__;
 
 import com.oracle.graal.python.builtins.PythonBuiltinClassType;
+import com.oracle.graal.python.builtins.objects.PNone;
 import com.oracle.graal.python.builtins.objects.cext.CExtNodes;
 import com.oracle.graal.python.builtins.objects.cext.PythonAbstractNativeObject;
 import com.oracle.graal.python.builtins.objects.code.PCode;
 import com.oracle.graal.python.builtins.objects.ints.PInt;
 import com.oracle.graal.python.builtins.objects.type.PythonBuiltinClass;
+import com.oracle.graal.python.nodes.PGuards;
+import com.oracle.graal.python.runtime.PythonContext;
+import com.oracle.graal.python.runtime.PythonOptions;
 import com.oracle.truffle.api.RootCallTarget;
 import com.oracle.truffle.api.dsl.Cached;
+import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.dsl.Fallback;
 import com.oracle.truffle.api.dsl.GenerateUncached;
+import com.oracle.truffle.api.dsl.ImportStatic;
 import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.nodes.Node;
 
@@ -67,6 +74,7 @@ boolean doIt(Object left, Object right,
     }
 
     @GenerateUncached
+    @ImportStatic({PGuards.class})
     public abstract static class IsNode extends Node {
 
         public abstract boolean execute(Object left, Object right);
@@ -210,6 +218,22 @@ boolean doCode(PCode left, PCode right) {
             return left == right;
         }
 
+        @Specialization
+        boolean doObjectPNone(Object left, PNone right,
+                        @CachedContext(PythonLanguage.class) PythonContext ctxt) {
+            if (PythonOptions.getFlag(ctxt, PythonOptions.EmulateJython) && ctxt.getEnv().isHostObject(left) && ctxt.getEnv().asHostObject(left) == null &&
+                            right == PNone.NONE) {
+                return true;
+            }
+            return doGeneric(left, right);
+        }
+
+        @Specialization
+        boolean doPNoneObject(PNone left, Object right,
+                        @CachedContext(PythonLanguage.class) PythonContext ctxt) {
+            return doObjectPNone(right, left, ctxt);
+        }
+
         @Fallback
         boolean doGeneric(Object left, Object right) {
             return left == right;