bpo-20185: Convert the marshal module to Argument Clinic.

Based on patch by Vajrasky Kok.
serhiy-storchaka · Mar 12, 2017 · Mar 7, 2017 · Mar 12, 2017 · Mar 12, 2017 · Mar 7, 2017
commit 522587a122e9a5df07b79b9a00388690a1623ca0
diff --git a/Python/clinic/marshal.c.h b/Python/clinic/marshal.c.h
@@ -0,0 +1,146 @@
+/*[clinic input]
+preserve
+[clinic start generated code]*/
+
+PyDoc_STRVAR(marshal_dump__doc__,
+"dump($module, value, file, version=version, /)\n"
+"--\n"
+"\n"
+"Write the value on the open file.\n"
+"\n"
+"  value\n"
+"    Must be a supported type.\n"
+"  file\n"
+"    Must be an open file object such as sys.stdout or returned by open()\n"
+"    or os.popen().  It must be opened in binary mode (\'wb\' or \'w+b\').\n"
+"  version\n"
+"    Indicates the data format that dump should use.\n"
+"\n"
+"If the value has (or contains an object that has) an unsupported type, a\n"
+"ValueError exception is raised - but garbage data will also be written\n"
+"to the file. The object will not be properly read back by load().");
+
+#define MARSHAL_DUMP_METHODDEF    \
+    {"dump", (PyCFunction)marshal_dump, METH_FASTCALL, marshal_dump__doc__},
+
+static PyObject *
+marshal_dump_impl(PyObject *module, PyObject *value, PyObject *file,
+                  int version);
+
+static PyObject *
+marshal_dump(PyObject *module, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    PyObject *value;
+    PyObject *file;
+    int version = Py_MARSHAL_VERSION;
+
+    if (!_PyArg_ParseStack(args, nargs, "OO|i:dump",
+        &value, &file, &version)) {
+        goto exit;
+    }
+
+    if (!_PyArg_NoStackKeywords("dump", kwnames)) {
+        goto exit;
+    }
+    return_value = marshal_dump_impl(module, value, file, version);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(marshal_load__doc__,
+"load($module, file, /)\n"
+"--\n"
+"\n"
+"Read one value from the open file and return it.\n"
+"\n"
+"  file\n"
+"    Must be an open file object opened in binary mode (\'rb\' or \'r+b\')\n"
+"\n"
+"If no valid value is read (e.g. because the data has a different Python\n"
+"version\'s incompatible marshal format), raise EOFError, ValueError or\n"
+"TypeError.\n"
+"\n"
+"Note: If an object containing an unsupported type was marshalled with\n"
+"dump(), load() will substitute None for the unmarshallable type.");
+
+#define MARSHAL_LOAD_METHODDEF    \
+    {"load", (PyCFunction)marshal_load, METH_O, marshal_load__doc__},
+
+PyDoc_STRVAR(marshal_dumps__doc__,
+"dumps($module, value, version=version, /)\n"
+"--\n"
+"\n"
+"Return the string that would be written to a file by dump(value, file).\n"
+"\n"
+"  value\n"
+"    Must be a supported type.\n"
+"  version\n"
+"    Indicates the data format that dumps should use.\n"
+"\n"
+"Raise a ValueError exception if value has (or contains an object that has) an\n"
+"unsupported type.");
+
+#define MARSHAL_DUMPS_METHODDEF    \
+    {"dumps", (PyCFunction)marshal_dumps, METH_FASTCALL, marshal_dumps__doc__},
+
+static PyObject *
+marshal_dumps_impl(PyObject *module, PyObject *value, int version);
+
+static PyObject *
+marshal_dumps(PyObject *module, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    PyObject *value;
+    int version = Py_MARSHAL_VERSION;
+
+    if (!_PyArg_ParseStack(args, nargs, "O|i:dumps",
+        &value, &version)) {
+        goto exit;
+    }
+
+    if (!_PyArg_NoStackKeywords("dumps", kwnames)) {
+        goto exit;
+    }
+    return_value = marshal_dumps_impl(module, value, version);
+
+exit:
+    return return_value;
+}
+
+PyDoc_STRVAR(marshal_loads__doc__,
+"loads($module, bytes, /)\n"
+"--\n"
+"\n"
+"Convert the bytes object to a value.\n"
+"\n"
+"If no valid value is found, raise EOFError, ValueError or TypeError.  Extra\n"
+"characters in the input are ignored.");
+
+#define MARSHAL_LOADS_METHODDEF    \
+    {"loads", (PyCFunction)marshal_loads, METH_O, marshal_loads__doc__},
+
+static PyObject *
+marshal_loads_impl(PyObject *module, Py_buffer *bytes);
+
+static PyObject *
+marshal_loads(PyObject *module, PyObject *arg)
+{
+    PyObject *return_value = NULL;
+    Py_buffer bytes = {NULL, NULL};
+
+    if (!PyArg_Parse(arg, "y*:loads", &bytes)) {
+        goto exit;
+    }
+    return_value = marshal_loads_impl(module, &bytes);
+
+exit:
+    /* Cleanup for bytes */
+    if (bytes.obj) {
+       PyBuffer_Release(&bytes);
+    }
+
+    return return_value;
+}
+/*[clinic end generated code: output=c9a4fdb39afcd0c1 input=a9049054013a1b77]*/
diff --git a/Python/marshal.c b/Python/marshal.c
@@ -14,6 +14,13 @@
 #include "marshal.h"
 #include "../Modules/hashtable.h"
 
+/*[clinic input]
+module marshal
+[clinic start generated code]*/
+/*[clinic end generated code: output=da39a3ee5e6b4b0d input=c982b7930dee17db]*/
+
+#include "clinic/marshal.c.h"
+
 /* High water mark to determine when the marshalled object is dangerously deep
  * and risks coring the interpreter.  When the object stack gets this deep,
  * raise an exception instead of continuing.
@@ -1632,43 +1639,63 @@ PyMarshal_WriteObjectToString(PyObject *x, int version)
 }
 
 /* And an interface for Python programs... */
+/*[clinic input]
+marshal.dump
+
+    value: object
+        Must be a supported type.
+    file: object
+        Must be an open file object such as sys.stdout or returned by open()
+        or os.popen().  It must be opened in binary mode ('wb' or 'w+b').
+    version: int(c_default="Py_MARSHAL_VERSION") = version
+        Indicates the data format that dump should use.
+    /
+
+Write the value on the open file.
+
+If the value has (or contains an object that has) an unsupported type, a
+ValueError exception is raised - but garbage data will also be written
+to the file. The object will not be properly read back by load().
+[clinic start generated code]*/
 
 static PyObject *
-marshal_dump(PyObject *self, PyObject *args)
+marshal_dump_impl(PyObject *module, PyObject *value, PyObject *file,
+                  int version)
+/*[clinic end generated code: output=aaee62c7028a7cb2 input=dfc39428a577b3ed]*/
 {
     /* XXX Quick hack -- need to do this differently */
-    PyObject *x;
-    PyObject *f;
-    int version = Py_MARSHAL_VERSION;
     PyObject *s;
     PyObject *res;
     _Py_IDENTIFIER(write);
 
-    if (!PyArg_ParseTuple(args, "OO|i:dump", &x, &f, &version))
-        return NULL;
-    s = PyMarshal_WriteObjectToString(x, version);
+    s = PyMarshal_WriteObjectToString(value, version);
     if (s == NULL)
         return NULL;
-    res = _PyObject_CallMethodIdObjArgs(f, &PyId_write, s, NULL);
+    res = _PyObject_CallMethodIdObjArgs(file, &PyId_write, s, NULL);
     Py_DECREF(s);
     return res;
 }
 
-PyDoc_STRVAR(dump_doc,
-"dump(value, file[, version])\n\
-\n\
-Write the value on the open file. The value must be a supported type.\n\
-The file must be an open file object such as sys.stdout or returned by\n\
-open() or os.popen(). It must be opened in binary mode ('wb' or 'w+b').\n\
-\n\
-If the value has (or contains an object that has) an unsupported type, a\n\
-ValueError exception is raised - but garbage data will also be written\n\
-to the file. The object will not be properly read back by load()\n\
-\n\
-The version argument indicates the data format that dump should use.");
+/*[clinic input]
+marshal.load
+
+    file: object
+        Must be an open file object opened in binary mode ('rb' or 'r+b')
+    /
+
+Read one value from the open file and return it.
+
+If no valid value is read (e.g. because the data has a different Python
+version's incompatible marshal format), raise EOFError, ValueError or
+TypeError.
+
+Note: If an object containing an unsupported type was marshalled with
+dump(), load() will substitute None for the unmarshallable type.
+[clinic start generated code]*/
 
 static PyObject *
-marshal_load(PyObject *self, PyObject *f)
+marshal_load(PyObject *module, PyObject *file)
+/*[clinic end generated code: output=f8e5c33233566344 input=f66546e3051b25c0]*/
 {
     PyObject *data, *result;
     _Py_IDENTIFIER(read);
@@ -1681,19 +1708,19 @@ marshal_load(PyObject *self, PyObject *f)
      * This can be removed if we guarantee good error handling
      * for r_string()
      */
-    data = _PyObject_CallMethodId(f, &PyId_read, "i", 0);
+    data = _PyObject_CallMethodId(file, &PyId_read, "i", 0);
     if (data == NULL)
         return NULL;
     if (!PyBytes_Check(data)) {
         PyErr_Format(PyExc_TypeError,
-                     "f.read() returned not bytes but %.100s",
+                     "file.read() returned not bytes but %.100s",
                      data->ob_type->tp_name);
         result = NULL;
     }
     else {
         rf.depth = 0;
         rf.fp = NULL;
-        rf.readable = f;
+        rf.readable = file;
         rf.current_filename = NULL;
         rf.ptr = rf.end = NULL;
         rf.buf = NULL;
@@ -1709,51 +1736,48 @@ marshal_load(PyObject *self, PyObject *f)
     return result;
 }
 
-PyDoc_STRVAR(load_doc,
-"load(file)\n\
-\n\
-Read one value from the open file and return it. If no valid value is\n\
-read (e.g. because the data has a different Python version's\n\
-incompatible marshal format), raise EOFError, ValueError or TypeError.\n\
-The file must be an open file object opened in binary mode ('rb' or\n\
-'r+b').\n\
-\n\
-Note: If an object containing an unsupported type was marshalled with\n\
-dump(), load() will substitute None for the unmarshallable type.");
+/*[clinic input]
+marshal.dumps
+
+    value: object
+        Must be a supported type.
+    version: int(c_default="Py_MARSHAL_VERSION") = version
+        Indicates the data format that dumps should use.
+    /
 
+Return the string that would be written to a file by dump(value, file).
+
+Raise a ValueError exception if value has (or contains an object that has) an
+unsupported type.
+[clinic start generated code]*/
 
 static PyObject *
-marshal_dumps(PyObject *self, PyObject *args)
+marshal_dumps_impl(PyObject *module, PyObject *value, int version)
+/*[clinic end generated code: output=9c200f98d7256cad input=ef992725c9154d72]*/
 {
-    PyObject *x;
-    int version = Py_MARSHAL_VERSION;
-    if (!PyArg_ParseTuple(args, "O|i:dumps", &x, &version))
-        return NULL;
-    return PyMarshal_WriteObjectToString(x, version);
+    return PyMarshal_WriteObjectToString(value, version);
 }
 
-PyDoc_STRVAR(dumps_doc,
-"dumps(value[, version])\n\
-\n\
-Return the string that would be written to a file by dump(value, file).\n\
-The value must be a supported type. Raise a ValueError exception if\n\
-value has (or contains an object that has) an unsupported type.\n\
-\n\
-The version argument indicates the data format that dumps should use.");
+/*[clinic input]
+marshal.loads
+
+    bytes: Py_buffer
+    /
+
+Convert the bytes object to a value.
 
+If no valid value is found, raise EOFError, ValueError or TypeError.  Extra
+characters in the input are ignored.
+[clinic start generated code]*/
 
 static PyObject *
-marshal_loads(PyObject *self, PyObject *args)
+marshal_loads_impl(PyObject *module, Py_buffer *bytes)
+/*[clinic end generated code: output=9fc65985c93d1bb1 input=5090c2c130991b2f]*/
 {
     RFILE rf;
-    Py_buffer p;
-    char *s;
-    Py_ssize_t n;
+    char *s = bytes->buf;
+    Py_ssize_t n = bytes->len;
     PyObject* result;
-    if (!PyArg_ParseTuple(args, "y*:loads", &p))
-        return NULL;
-    s = p.buf;
-    n = p.len;
     rf.fp = NULL;
     rf.readable = NULL;
     rf.current_filename = NULL;
@@ -1763,23 +1787,15 @@ marshal_loads(PyObject *self, PyObject *args)
     if ((rf.refs = PyList_New(0)) == NULL)
         return NULL;
     result = read_object(&rf);
-    PyBuffer_Release(&p);
     Py_DECREF(rf.refs);
     return result;
 }
 
-PyDoc_STRVAR(loads_doc,
-"loads(bytes)\n\
-\n\
-Convert the bytes object to a value. If no valid value is found, raise\n\
-EOFError, ValueError or TypeError. Extra characters in the input are\n\
-ignored.");
-
 static PyMethodDef marshal_methods[] = {
-    {"dump",            marshal_dump,   METH_VARARGS,   dump_doc},
-    {"load",            marshal_load,   METH_O,         load_doc},
-    {"dumps",           marshal_dumps,  METH_VARARGS,   dumps_doc},
-    {"loads",           marshal_loads,  METH_VARARGS,   loads_doc},
+    MARSHAL_DUMP_METHODDEF
+    MARSHAL_LOAD_METHODDEF
+    MARSHAL_DUMPS_METHODDEF
+    MARSHAL_LOADS_METHODDEF
     {NULL,              NULL}           /* sentinel */
 };