Implement '__kwdefaults__' attribute for function objects.

Author: fangerer

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

@@ -72,6 +72,10 @@ def f2(a=f(1, 2), b=10):
     return a, b
 
 
+def f3(a, b=f(1,2), c=10, *args, d="hello", e="world"):
+    return a, b, c, args, d, e
+
+
 class MyClass(object):
     def __init__(self, x = 10):
         pass
@@ -82,6 +86,12 @@ def test_defaults():
     assert f2.__defaults__ == ((1, 2, 10, (), {}), 10)
 
 
+def test_kwdefaults():
+    assert f.__kwdefaults__ == None
+    assert f2.__kwdefaults__ == None
+    assert f3.__kwdefaults__ == { "d": "hello", "e": "world"}
+
+
 def test_defaults_method():
     obj = MyClass()
     assert obj.__init__.__defaults__ == (10,)

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/function/FunctionBuiltins.java

@@ -27,6 +27,7 @@
 package com.oracle.graal.python.builtins.objects.function;
 
 import static com.oracle.graal.python.nodes.SpecialAttributeNames.__DEFAULTS__;
+import static com.oracle.graal.python.nodes.SpecialAttributeNames.__KWDEFAULTS__;
 import static com.oracle.graal.python.nodes.SpecialAttributeNames.__NAME__;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__REDUCE__;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__REPR__;
@@ -41,6 +42,7 @@
 import com.oracle.graal.python.builtins.PythonBuiltins;
 import com.oracle.graal.python.builtins.objects.PNone;
 import com.oracle.graal.python.builtins.objects.function.FunctionBuiltinsFactory.GetFunctionDefaultsNodeFactory;
+import com.oracle.graal.python.builtins.objects.function.FunctionBuiltinsFactory.GetFunctionKeywordDefaultsNodeFactory;
 import com.oracle.graal.python.builtins.objects.str.PString;
 import com.oracle.graal.python.builtins.objects.tuple.PTuple;
 import com.oracle.graal.python.nodes.argument.ReadKeywordNode;
@@ -140,7 +142,7 @@ Object setName(Object self, Object value) {
     @Builtin(name = __DEFAULTS__, minNumOfPositionalArgs = 1, maxNumOfPositionalArgs = 2, isGetter = true, isSetter = true)
     @GenerateNodeFactory
     public abstract static class GetFunctionDefaultsNode extends PythonBinaryBuiltinNode {
-        protected final ConditionProfile nullDefaultsProfile = ConditionProfile.createBinaryProfile();
+        private final ConditionProfile nullDefaultsProfile = ConditionProfile.createBinaryProfile();
 
         @TruffleBoundary
         private static Object[] extractDefaults(PFunction function) {
@@ -181,10 +183,52 @@ public static GetFunctionDefaultsNode create() {
         }
     }
 
+    @Builtin(name = __KWDEFAULTS__, fixedNumOfPositionalArgs = 1, isGetter = true)
+    @GenerateNodeFactory
+    public abstract static class GetFunctionKeywordDefaultsNode extends PythonUnaryBuiltinNode {
+        @TruffleBoundary
+        private static PKeyword[] extractDefaults(PFunction function) {
+            ArrayList<PKeyword> kwdefaults = new ArrayList<>();
+            List<ReadKeywordNode> readKeywordNodes = NodeUtil.findAllNodeInstances(function.getFunctionRootNode(), ReadKeywordNode.class);
+            for (ReadKeywordNode readKeywordNode : readKeywordNodes) {
+                if (!readKeywordNode.canBePositional()) {
+                    Object defaultValue = readKeywordNode.getDefaultValue();
+                    if (defaultValue != null) {
+                        kwdefaults.add(new PKeyword(readKeywordNode.getName(), defaultValue));
+                    }
+                }
+            }
+
+            return kwdefaults.toArray(new PKeyword[0]);
+        }
+
+        @Specialization(guards = "!takesVarargs(self)")
+        Object doNoKeywordOnlyArgs(@SuppressWarnings("unused") PFunction self) {
+            return PNone.NONE;
+        }
+
+        @Specialization(guards = "takesVarargs(self)")
+        Object doGeneric(PFunction self) {
+            PKeyword[] kwdefaults = extractDefaults(self);
+            if (kwdefaults.length > 0) {
+                return factory().createDict(kwdefaults);
+            }
+            return PNone.NONE;
+        }
+
+        protected static boolean takesVarargs(PFunction self) {
+            return self.getArity().takesVarArgs();
+        }
+
+        public static GetFunctionKeywordDefaultsNode create() {
+            return GetFunctionKeywordDefaultsNodeFactory.create();
+        }
+    }
+
     @Builtin(name = __REDUCE__, fixedNumOfPositionalArgs = 1)
     @GenerateNodeFactory
     public abstract static class ReduceNode extends PythonUnaryBuiltinNode {
-        @Specialization
+        @Fallback
         Object doGeneric(@SuppressWarnings("unused") Object obj) {
             throw raise(TypeError, "can't pickle function objects");
         }

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/method/MethodBuiltins.java

@@ -29,6 +29,7 @@
 import static com.oracle.graal.python.nodes.SpecialAttributeNames.__CODE__;
 import static com.oracle.graal.python.nodes.SpecialAttributeNames.__DEFAULTS__;
 import static com.oracle.graal.python.nodes.SpecialAttributeNames.__FUNC__;
+import static com.oracle.graal.python.nodes.SpecialAttributeNames.__KWDEFAULTS__;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__REDUCE__;
 import static com.oracle.graal.python.nodes.SpecialMethodNames.__REPR__;
 import static com.oracle.graal.python.runtime.exception.PythonErrorType.TypeError;
@@ -108,6 +109,16 @@ Object defaults(PMethod self,
         }
     }
 
+    @Builtin(name = __KWDEFAULTS__, fixedNumOfPositionalArgs = 1, isGetter = true)
+    @GenerateNodeFactory
+    public abstract static class GetMethodKwdefaultsNode extends PythonUnaryBuiltinNode {
+        @Specialization
+        Object defaults(PMethod self,
+                        @Cached("create()") FunctionBuiltins.GetFunctionKeywordDefaultsNode getFunctionKwdefaultsNode) {
+            return getFunctionKwdefaultsNode.execute(self.getFunction());
+        }
+    }
+
     @Builtin(name = __REDUCE__, fixedNumOfPositionalArgs = 1)
     @GenerateNodeFactory
     public abstract static class ReduceNode extends PythonUnaryBuiltinNode {