[GR-13574] Fix: 'CastToIndexNode' must not evaluate '__index__' twice.

PullRequest: graalpython/386

Author: fangerer

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

@@ -1,4 +1,4 @@
-# Copyright (c) 2018, Oracle and/or its affiliates.
+# Copyright (c) 2018, 2019, Oracle and/or its affiliates.
 # Copyright (C) 1996-2017 Python Software Foundation
 #
 # Licensed under the PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
@@ -138,6 +138,16 @@ class L(list): pass
     def test_getitem(self):
         l = [1, 2, 3]
         self.assertEqual(1, l[False])
+        
+        class IdxObj:
+            __cnt = 0
+            def __index__(self):
+                cur = self.__cnt
+                self.__cnt += 1
+                return cur
+        idxObj = IdxObj()
+        cpy = [l[idxObj], l[idxObj], l[idxObj]]
+        self.assertEqual(cpy, l)
 
     def pop_all_list(self, list):
         size = len(list)

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/util/CastToIndexNode.java

@@ -126,10 +126,7 @@ int doPIntOvf(PInt x) {
 
     @Specialization
     public int toInt(double x) {
-        if (typeErrorHandler != null) {
-            return typeErrorHandler.apply(x);
-        }
-        throw raise(TypeError, "'%p' object cannot be interpreted as an integer", x);
+        return handleError("'%p' object cannot be interpreted as an integer", x);
     }
 
     @Fallback
@@ -140,22 +137,23 @@ int doGeneric(Object x) {
                 callIndexNode = insert(LookupAndCallUnaryNode.create(__INDEX__));
             }
             Object result = callIndexNode.executeObject(x);
-            if (result == PNone.NONE) {
-                if (typeErrorHandler != null) {
-                    return typeErrorHandler.apply(x);
-                }
-                throw raise(TypeError, "'%p' object cannot be interpreted as an integer", x);
+            if (result == PNone.NO_VALUE) {
+                return handleError("'%p' object cannot be interpreted as an integer", x);
             }
             if (recursiveNode == null) {
                 CompilerDirectives.transferToInterpreterAndInvalidate();
                 recursiveNode = insert(CastToIndexNodeGen.create(errorType, false, typeErrorHandler));
             }
-            return recursiveNode.execute(callIndexNode.executeObject(x));
+            return recursiveNode.execute(result);
         }
+        return handleError("__index__ returned non-int (type %p)", x);
+    }
+
+    private int handleError(String fmt, Object x) {
         if (typeErrorHandler != null) {
             return typeErrorHandler.apply(x);
         }
-        throw raise(TypeError, "__index__ returned non-int (type %p)", x);
+        throw raise(TypeError, fmt, x);
     }
 
     public static CastToIndexNode create() {