From: INADA Naoki <methane@users.noreply.github.com>
Date: Thu, 23 Feb 2017 17:48:17 +0000 (+0900)
Subject: bpo-29622: Make AST constructor to accept less than enough number of positional argum... 
X-Git-Tag: v3.7.0a1~1295
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4c78c527d215c37472145152cb0e95f196cdddc9;p=thirdparty%2FPython%2Fcpython.git

bpo-29622: Make AST constructor to accept less than enough number of positional arguments (GH-249)

bpo-29463 added optional "docstring" field to 4 AST types.
While it is optional, it breaks backward compatibility because AST constructor
requires number of positional argument is same to number of fields.

AST types accepts empty arguments, and incomplete keyword arguments.
But it's not big problem because field can be filled after creation, and checked when compiling.
So stop requiring complete set of fields for positional arguments too.
---

diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index ac79989796d6..366269fe405a 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -373,12 +373,8 @@ class AST_Tests(unittest.TestCase):
         self.assertEqual(x.right, 3)
         self.assertEqual(x.lineno, 0)
 
-        # node raises exception when not given enough arguments
-        self.assertRaises(TypeError, ast.BinOp, 1, 2)
         # node raises exception when given too many arguments
         self.assertRaises(TypeError, ast.BinOp, 1, 2, 3, 4)
-        # node raises exception when not given enough arguments
-        self.assertRaises(TypeError, ast.BinOp, 1, 2, lineno=0)
         # node raises exception when given too many arguments
         self.assertRaises(TypeError, ast.BinOp, 1, 2, 3, 4, lineno=0)
 
diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index 444cdea341d7..096f5f8c7494 100644
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -664,29 +664,27 @@ ast_type_init(PyObject *self, PyObject *args, PyObject *kw)
         if (numfields == -1)
             goto cleanup;
     }
+
     res = 0; /* if no error occurs, this stays 0 to the end */
-    if (PyTuple_GET_SIZE(args) > 0) {
-        if (numfields != PyTuple_GET_SIZE(args)) {
-            PyErr_Format(PyExc_TypeError, "%.400s constructor takes %s"
-                         "%zd positional argument%s",
-                         Py_TYPE(self)->tp_name,
-                         numfields == 0 ? "" : "either 0 or ",
-                         numfields, numfields == 1 ? "" : "s");
+    if (numfields < PyTuple_GET_SIZE(args)) {
+        PyErr_Format(PyExc_TypeError, "%.400s constructor takes at most "
+                     "%zd positional argument%s",
+                     Py_TYPE(self)->tp_name,
+                     numfields, numfields == 1 ? "" : "s");
+        res = -1;
+        goto cleanup;
+    }
+    for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
+        /* cannot be reached when fields is NULL */
+        PyObject *name = PySequence_GetItem(fields, i);
+        if (!name) {
             res = -1;
             goto cleanup;
         }
-        for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
-            /* cannot be reached when fields is NULL */
-            PyObject *name = PySequence_GetItem(fields, i);
-            if (!name) {
-                res = -1;
-                goto cleanup;
-            }
-            res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
-            Py_DECREF(name);
-            if (res < 0)
-                goto cleanup;
-        }
+        res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
+        Py_DECREF(name);
+        if (res < 0)
+            goto cleanup;
     }
     if (kw) {
         i = 0;  /* needed by PyDict_Next */
diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index a6a49f78b1e2..2759b2fe9c4b 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -551,29 +551,27 @@ ast_type_init(PyObject *self, PyObject *args, PyObject *kw)
         if (numfields == -1)
             goto cleanup;
     }
+
     res = 0; /* if no error occurs, this stays 0 to the end */
-    if (PyTuple_GET_SIZE(args) > 0) {
-        if (numfields != PyTuple_GET_SIZE(args)) {
-            PyErr_Format(PyExc_TypeError, "%.400s constructor takes %s"
-                         "%zd positional argument%s",
-                         Py_TYPE(self)->tp_name,
-                         numfields == 0 ? "" : "either 0 or ",
-                         numfields, numfields == 1 ? "" : "s");
+    if (numfields < PyTuple_GET_SIZE(args)) {
+        PyErr_Format(PyExc_TypeError, "%.400s constructor takes at most "
+                     "%zd positional argument%s",
+                     Py_TYPE(self)->tp_name,
+                     numfields, numfields == 1 ? "" : "s");
+        res = -1;
+        goto cleanup;
+    }
+    for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
+        /* cannot be reached when fields is NULL */
+        PyObject *name = PySequence_GetItem(fields, i);
+        if (!name) {
             res = -1;
             goto cleanup;
         }
-        for (i = 0; i < PyTuple_GET_SIZE(args); i++) {
-            /* cannot be reached when fields is NULL */
-            PyObject *name = PySequence_GetItem(fields, i);
-            if (!name) {
-                res = -1;
-                goto cleanup;
-            }
-            res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
-            Py_DECREF(name);
-            if (res < 0)
-                goto cleanup;
-        }
+        res = PyObject_SetAttr(self, name, PyTuple_GET_ITEM(args, i));
+        Py_DECREF(name);
+        if (res < 0)
+            goto cleanup;
     }
     if (kw) {
         i = 0;  /* needed by PyDict_Next */