fix tuple.__getitem__ to be closer to the cpython implementation

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/tuple/TupleBuiltins.java

@@ -78,13 +78,15 @@
 import com.oracle.graal.python.builtins.objects.iterator.PSequenceIterator;
 import com.oracle.graal.python.builtins.objects.slice.PSlice;
 import com.oracle.graal.python.builtins.objects.tuple.TupleBuiltinsClinicProviders.IndexNodeClinicProviderGen;
+import com.oracle.graal.python.lib.PyIndexCheckNode;
 import com.oracle.graal.python.lib.PyNumberAsSizeNode;
 import com.oracle.graal.python.lib.PyObjectHashNode;
 import com.oracle.graal.python.lib.PyObjectReprAsTruffleStringNode;
 import com.oracle.graal.python.lib.PyObjectRichCompareBool;
 import com.oracle.graal.python.lib.PyTupleSizeNode;
 import com.oracle.graal.python.nodes.ErrorMessages;
 import com.oracle.graal.python.nodes.PGuards;
+import com.oracle.graal.python.nodes.PRaiseNode;
 import com.oracle.graal.python.nodes.function.PythonBuiltinBaseNode;
 import com.oracle.graal.python.nodes.function.PythonBuiltinNode;
 import com.oracle.graal.python.nodes.function.builtins.PythonBinaryBuiltinNode;
@@ -257,41 +259,48 @@ public static TruffleString repr(VirtualFrame frame, PTuple self,
     @GenerateNodeFactory
     public abstract static class GetItemNode extends PythonBinaryBuiltinNode {
 
-        private static final TruffleString TYPE_ERROR_MESSAGE = cat(T_TUPLE, T_SPACE, ErrorMessages.OBJ_INDEX_MUST_BE_INT_OR_SLICES);
-
         public abstract Object execute(VirtualFrame frame, PTuple tuple, Object index);
 
         @Specialization(guards = {"index >= 0", "index < tuple.getSequenceStorage().length()"})
-        protected Object doInBounds(PTuple tuple, int index,
+        static Object doInBounds(PTuple tuple, int index,
                         @Cached SequenceStorageNodes.GetItemScalarNode getItemNode) {
             return getItemNode.execute(tuple.getSequenceStorage(), index);
         }
 
         @InliningCutoff
-        @Specialization(guards = "!isPSlice(key)")
-        Object doPTuple(VirtualFrame frame, PTuple tuple, Object key,
+        @Specialization(guards = "indexCheck.execute(key)", limit = "1")
+        static Object doIndex(VirtualFrame frame, PTuple tuple, Object key,
+                        @SuppressWarnings("unused") @Cached PyIndexCheckNode indexCheck,
                         @Cached("createGetItemNode()") SequenceStorageNodes.GetItemNode getItemNode) {
             return getItemNode.execute(frame, tuple.getSequenceStorage(), key);
         }
 
         @InliningCutoff
         @Specialization
-        Object doPTuple(VirtualFrame frame, PTuple tuple, PSlice key,
+        static Object doSlice(VirtualFrame frame, PTuple tuple, PSlice key,
                         @Cached("createGetItemNode()") SequenceStorageNodes.GetItemNode getItemNode) {
             return getItemNode.execute(frame, tuple.getSequenceStorage(), key);
         }
 
         @InliningCutoff
         @Specialization
-        Object doNative(PythonNativeObject tuple, long key,
+        static Object doNative(PythonNativeObject tuple, long key,
                         @Cached PCallCapiFunction callSetItem,
                         @Cached CExtNodes.ToSulongNode toSulongNode,
                         @Cached CExtNodes.AsPythonObjectNode asPythonObjectNode) {
             return asPythonObjectNode.execute(callSetItem.call(NativeCAPISymbol.FUN_PY_TRUFFLE_TUPLE_GET_ITEM, toSulongNode.execute(tuple), key));
         }
 
+        @SuppressWarnings("unused")
+        @InliningCutoff
+        @Fallback
+        static Object doError(VirtualFrame frame, Object tuple, Object key,
+                        @Cached PRaiseNode raiseNode) {
+            throw raiseNode.raise(TypeError, ErrorMessages.OBJ_INDEX_MUST_BE_INT_OR_SLICES, "tuple", key);
+        }
+
         protected static SequenceStorageNodes.GetItemNode createGetItemNode() {
-            return SequenceStorageNodes.GetItemNode.create(NormalizeIndexNode.forTuple(), TYPE_ERROR_MESSAGE, (s, f) -> f.createTuple(s));
+            return SequenceStorageNodes.GetItemNode.create(NormalizeIndexNode.forTuple(), (s, f) -> f.createTuple(s));
         }
     }