support warnings in float tests

Author: timfel

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

@@ -106,6 +106,7 @@
 import com.oracle.graal.python.builtins.CoreFunctions;
 import com.oracle.graal.python.builtins.PythonBuiltinClassType;
 import com.oracle.graal.python.builtins.PythonBuiltins;
+import com.oracle.graal.python.builtins.modules.WarningsModuleBuiltins.WarnNode;
 import com.oracle.graal.python.builtins.modules.WeakRefModuleBuiltins.GetWeakRefsNode;
 import com.oracle.graal.python.builtins.objects.PEllipsis;
 import com.oracle.graal.python.builtins.objects.PNone;
@@ -966,6 +967,7 @@ static boolean isHandledType(PythonObjectLibrary lib, Object o) {
         @Specialization(guards = {"isPrimitiveFloat(cls)", "!isHandledType(objectLib, obj)"}, limit = "1")
         double doubleFromObject(VirtualFrame frame, @SuppressWarnings("unused") Object cls, Object obj,
                         @CachedLibrary("obj") PythonObjectLibrary objectLib,
+                        @Cached WarnNode warnNode,
                         @CachedLibrary(limit = "1") PythonObjectLibrary methodLib,
                         @CachedLibrary(limit = "1") PythonObjectLibrary indexLib) {
             // Follows logic from PyNumber_Float:
@@ -981,7 +983,9 @@ static boolean isHandledType(PythonObjectLibrary lib, Object o) {
                     }
                     if (PGuards.isPFloat(result)) {
                         if (!isPrimitiveProfile.profileObject(result, PythonBuiltinClassType.PFloat)) {
-                            // TODO deprecation warning
+                            warnNode.warnFormat(frame, null, PythonBuiltinClassType.DeprecationWarning, 1,
+                                            ErrorMessages.P_RETURNED_NON_P,
+                                            obj, "__float__", "float", result, "float");
                         }
                         return ((PFloat) result).getValue();
                     }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/nodes/ErrorMessages.java

@@ -619,4 +619,8 @@ public abstract class ErrorMessages {
     public static final String EXPECTED_BYTES_P_FOUND = "expected bytes, %p found";
     public static final String EMBEDDED_NULL_BYTE = "embedded null byte";
     public static final String CANNOT_INTERN_P = "can't intern %p";
+
+    public static final String P_RETURNED_NON_P = "%p.%s returned non-%s (type %p). " +
+        "The ability to return an instance of a strict subclass of %s " +
+        "is deprecated, and may be removed in a future version of Python.";
 }

graalpython/lib-python/3/test/test_float.py

@@ -198,13 +198,10 @@ class FooStr(str):
             def __float__(self):
                 return float(str(self)) + 1
 
-        # Assertions that check DeprecationWarnings have been temporarily disabled since
-        # graalvm does not support warnings yet.
-
         self.assertEqual(float(Foo1()), 42.)
         self.assertEqual(float(Foo2()), 42.)
-#        with self.assertWarns(DeprecationWarning):
-        self.assertEqual(float(Foo3(21)), 42.)
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(float(Foo3(21)), 42.)
         self.assertRaises(TypeError, float, Foo4(42))
         self.assertEqual(float(FooStr('8')), 9.)
 
@@ -217,14 +214,14 @@ def __float__(self):
         class F:
             def __float__(self):
                 return OtherFloatSubclass(42.)
-#        with self.assertWarns(DeprecationWarning):
-        self.assertEqual(float(F()), 42.)
-#        with self.assertWarns(DeprecationWarning):
-        self.assertIs(type(float(F())), float)
-#        with self.assertWarns(DeprecationWarning):
-        self.assertEqual(FloatSubclass(F()), 42.)
-#        with self.assertWarns(DeprecationWarning):
-        self.assertIs(type(FloatSubclass(F())), FloatSubclass)
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(float(F()), 42.)
+        with self.assertWarns(DeprecationWarning):
+            self.assertIs(type(float(F())), float)
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(FloatSubclass(F()), 42.)
+        with self.assertWarns(DeprecationWarning):
+            self.assertIs(type(FloatSubclass(F())), FloatSubclass)
 
         class MyIndex:
             def __init__(self, value):