bpo-36290: Fix keytword collision handling in AST node constructors (GH-12382)
diff --git a/Lib/ast.py b/Lib/ast.py
index 52e51b4..6a5b39e 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -524,6 +524,13 @@
return type.__instancecheck__(cls, inst)
def _new(cls, *args, **kwargs):
+ for key in kwargs:
+ if key not in cls._fields:
+ # arbitrary keyword arguments are accepted
+ continue
+ pos = cls._fields.index(key)
+ if pos < len(args):
+ raise TypeError(f"{cls.__name__} got multiple values for argument {key!r}")
if cls in _const_types:
return Constant(*args, **kwargs)
return Constant.__new__(cls, *args, **kwargs)
diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index e55d10b..3e9c8b5 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -402,6 +402,15 @@
self.assertRaises(TypeError, ast.Num, 1, None, 2)
self.assertRaises(TypeError, ast.Num, 1, None, 2, lineno=0)
+ # Arbitrary keyword arguments are supported
+ self.assertEqual(ast.Constant(1, foo='bar').foo, 'bar')
+ self.assertEqual(ast.Num(1, foo='bar').foo, 'bar')
+
+ with self.assertRaisesRegex(TypeError, "Num got multiple values for argument 'n'"):
+ ast.Num(1, n=2)
+ with self.assertRaisesRegex(TypeError, "Constant got multiple values for argument 'value'"):
+ ast.Constant(1, value=2)
+
self.assertEqual(ast.Num(42).n, 42)
self.assertEqual(ast.Num(4.25).n, 4.25)
self.assertEqual(ast.Num(4.25j).n, 4.25j)
diff --git a/Misc/NEWS.d/next/Library/2019-03-17-19-01-53.bpo-36290.7VXo_K.rst b/Misc/NEWS.d/next/Library/2019-03-17-19-01-53.bpo-36290.7VXo_K.rst
new file mode 100644
index 0000000..a9afe62
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-03-17-19-01-53.bpo-36290.7VXo_K.rst
@@ -0,0 +1,2 @@
+AST nodes are now raising :exc:`TypeError` on conflicting keyword arguments.
+Patch contributed by Rémi Lapeyre.
diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index 6d57275..f8729cd 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -695,8 +695,9 @@
}
if (fields) {
numfields = PySequence_Size(fields);
- if (numfields == -1)
+ if (numfields == -1) {
goto cleanup;
+ }
}
res = 0; /* if no error occurs, this stays 0 to the end */
@@ -717,15 +718,35 @@
}
res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
Py_DECREF(name);
- if (res < 0)
+ if (res < 0) {
goto cleanup;
+ }
}
if (kw) {
i = 0; /* needed by PyDict_Next */
while (PyDict_Next(kw, &i, &key, &value)) {
- res = PyObject_SetAttr(self, key, value);
- if (res < 0)
+ int contains = PySequence_Contains(fields, key);
+ if (contains == -1) {
+ res = -1;
goto cleanup;
+ } else if (contains == 1) {
+ Py_ssize_t p = PySequence_Index(fields, key);
+ if (p == -1) {
+ res = -1;
+ goto cleanup;
+ }
+ if (p < PyTuple_GET_SIZE(args)) {
+ PyErr_Format(PyExc_TypeError,
+ "%.400s got multiple values for argument '%U'",
+ Py_TYPE(self)->tp_name, key);
+ res = -1;
+ goto cleanup;
+ }
+ }
+ res = PyObject_SetAttr(self, key, value);
+ if (res < 0) {
+ goto cleanup;
+ }
}
}
cleanup:
diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index f34b145..d2edf74 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -1131,8 +1131,9 @@
}
if (fields) {
numfields = PySequence_Size(fields);
- if (numfields == -1)
+ if (numfields == -1) {
goto cleanup;
+ }
}
res = 0; /* if no error occurs, this stays 0 to the end */
@@ -1153,15 +1154,35 @@
}
res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
Py_DECREF(name);
- if (res < 0)
+ if (res < 0) {
goto cleanup;
+ }
}
if (kw) {
i = 0; /* needed by PyDict_Next */
while (PyDict_Next(kw, &i, &key, &value)) {
- res = PyObject_SetAttr(self, key, value);
- if (res < 0)
+ int contains = PySequence_Contains(fields, key);
+ if (contains == -1) {
+ res = -1;
goto cleanup;
+ } else if (contains == 1) {
+ Py_ssize_t p = PySequence_Index(fields, key);
+ if (p == -1) {
+ res = -1;
+ goto cleanup;
+ }
+ if (p < PyTuple_GET_SIZE(args)) {
+ PyErr_Format(PyExc_TypeError,
+ "%.400s got multiple values for argument '%U'",
+ Py_TYPE(self)->tp_name, key);
+ res = -1;
+ goto cleanup;
+ }
+ }
+ res = PyObject_SetAttr(self, key, value);
+ if (res < 0) {
+ goto cleanup;
+ }
}
}
cleanup: