Fix passing NULL modulus from 2-argument pow

Fixes #551

Author: msimacek

graalpython/com.oracle.graal.python.test/src/tests/cpyext/test_tp_slots.py

@@ -1076,6 +1076,10 @@ def test_nb_slot_calls():
                 }
             #define proxy_nb_ternary_slot(slot) \
                 static PyObject* proxy_##slot(PyObject *a, PyObject *b, PyObject* c) { \
+                    if (c == NULL) { \
+                        PyErr_SetString(PyExc_AssertionError, "modulus in NULL"); \
+                        return NULL; \
+                    } \
                     if (Py_TYPE(a) == &NativeNbSlotProxyType) { \
                         PyObject* delegate = get_delegate(a); \
                         return Py_TYPE(delegate)->tp_as_number->slot(delegate, b, c); \
@@ -1089,6 +1093,10 @@ def test_nb_slot_calls():
                 }
             #define proxy_nb_ternary_inplace_slot(slot) \
                 static PyObject* proxy_##slot(PyObject *self, PyObject *b, PyObject* c) { \
+                    if (c == NULL) { \
+                        PyErr_SetString(PyExc_AssertionError, "modulus in NULL"); \
+                        return NULL; \
+                    } \
                     PyObject* delegate = get_delegate(self); \
                     PyObject* result = Py_TYPE(delegate)->tp_as_number->slot(delegate, b, c); \
                     if (!result) \
@@ -1176,6 +1184,8 @@ def __rmatmul__(self, other):
         assert divmod(2, obj) == (0, 2)
         assert obj ** 2 == 9
         assert 2 ** obj == 8
+        assert pow(obj, 2) == 9
+        assert pow(2, obj) == 8
         assert pow(obj, 2, 2) == 1
         if isinstance(obj.delegate, int):  # pow doesn't call __rpow__
             assert pow(2, obj, 2) == 0

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/BuiltinFunctions.java

@@ -237,6 +237,7 @@
 import com.oracle.graal.python.nodes.function.builtins.PythonBinaryBuiltinNode;
 import com.oracle.graal.python.nodes.function.builtins.PythonClinicBuiltinNode;
 import com.oracle.graal.python.nodes.function.builtins.PythonTernaryBuiltinNode;
+import com.oracle.graal.python.nodes.function.builtins.PythonTernaryClinicBuiltinNode;
 import com.oracle.graal.python.nodes.function.builtins.PythonUnaryBuiltinNode;
 import com.oracle.graal.python.nodes.function.builtins.PythonUnaryClinicBuiltinNode;
 import com.oracle.graal.python.nodes.function.builtins.PythonVarargsBuiltinNode;
@@ -2029,14 +2030,20 @@ private int getDebuggerSessionCount() {
     }
 
     @Builtin(name = J_POW, minNumOfPositionalArgs = 2, numOfPositionalOnlyArgs = 0, parameterNames = {"base", "exp", "mod"})
+    @ArgumentClinic(name = "mod", defaultValue = "PNone.NONE")
     @GenerateNodeFactory
-    public abstract static class PowNode extends PythonTernaryBuiltinNode {
+    public abstract static class PowNode extends PythonTernaryClinicBuiltinNode {
 
         @Specialization
         Object ternary(VirtualFrame frame, Object x, Object y, Object z,
                         @Cached PyNumberPowerNode power) {
             return power.execute(frame, x, y, z);
         }
+
+        @Override
+        protected ArgumentClinicProvider getArgumentClinic() {
+            return BuiltinFunctionsClinicProviders.PowNodeClinicProviderGen.INSTANCE;
+        }
     }
 
     // sum(iterable[, start])

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/lib/PyNumberPowerNode.java

@@ -81,6 +81,7 @@ public static Object doIt(VirtualFrame frame, Object v, Object w, Object z,
                     @Cached GetCachedTpSlotsNode getWSlots,
                     @Cached CallTernaryOpNode callTernaryOpNode,
                     @Cached PRaiseNode raiseNode) {
+        assert z != PNone.NO_VALUE;
         Object classV = getVClass.execute(inliningTarget, v);
         Object classW = getWClass.execute(inliningTarget, w);
         TpSlot slotV = getVSlots.execute(inliningTarget, classV).nb_power();