cStringIO.StringIO is now METH_O

Module-level functions go through a slightly different code path than class-level
ones, so this commit adds the METH_O3/METH_D3 calling conventions to that as well.

from_cpython/Modules/cStringIO.c

@@ -685,11 +685,8 @@ newIobject(PyObject *s) {
   PyObject *args;
   int result;
 
-  args = Py_BuildValue("(O)", s);
-  if (args == NULL)
-      return NULL;
-  result = PyArg_ParseTuple(args, "s*:StringIO", &buf);
-  Py_DECREF(args);
+  // Pyston change:
+  result = PyArg_ParseSingle(s, 1, "StringIO", "s*", &buf);
   if (!result)
       return NULL;
 
@@ -714,11 +711,7 @@ PyDoc_STRVAR(IO_StringIO__doc__,
 "StringIO([s]) -- Return a StringIO-like stream for reading or writing");
 
 static PyObject *
-IO_StringIO(PyObject *self, PyObject *args) {
-  PyObject *s=0;
-
-  if (!PyArg_UnpackTuple(args, "StringIO", 0, 1, &s)) return NULL;
-
+IO_StringIO(PyObject *self, PyObject *s) {
   if (s) return newIobject(s);
   return newOobject(128);
 }
@@ -727,7 +720,7 @@ IO_StringIO(PyObject *self, PyObject *args) {
 
 static struct PyMethodDef IO_methods[] = {
   {"StringIO",  (PyCFunction)IO_StringIO,
-   METH_VARARGS,        IO_StringIO__doc__},
+   /* Pyston change: */ METH_O | METH_D1,        IO_StringIO__doc__},
   {NULL,                NULL}           /* sentinel */
 };
 

from_cpython/Python/getargs.c

@@ -161,12 +161,20 @@ cleanup_buffer(PyObject *self)
     }
 }
 
+// A special cleanup "list" that specifies that we don't need to keep track of cleanups.
+// This is useful for vgetsingle, where there are no partial-failure cases that require
+// keeping track of cleanups.
+#define NOCLEANUP ((PyObject**)1)
+
 static int
 addcleanup(void *ptr, PyObject **freelist, PyCapsule_Destructor destr)
 {
     PyObject *cobj;
     const char *name;
 
+    if (freelist == NOCLEANUP)
+        return 0;
+
     if (!*freelist) {
         *freelist = PyList_New(0);
         if (!*freelist) {
@@ -576,12 +584,8 @@ int vgetsingle(PyObject* obj, int arg_idx, const char* fname, const char* format
     assert(format[0] != '\0');
     assert(format[0] != '(');
     assert(format[0] != '|');
-    assert(format[0] != '|');
-
-    assert(format[1] != '*'); // would need to pass a non-null freelist
-    assert(format[0] != 'e'); // would need to pass a non-null freelist
 
-    msg = convertsimple(obj, &format, v_pa, flags, msgbuf, sizeof(msgbuf), NULL);
+    msg = convertsimple(obj, &format, v_pa, flags, msgbuf, sizeof(msgbuf), NOCLEANUP);
 
     if (msg) {
         int levels[1];

src/capi/modsupport.cpp

@@ -423,8 +423,6 @@ extern "C" PyObject* Py_InitModule4(const char* name, PyMethodDef* methods, cons
     Box* passthrough = static_cast<Box*>(self);
 
     while (methods && methods->ml_name) {
-        RELEASE_ASSERT((methods->ml_flags & (~(METH_VARARGS | METH_KEYWORDS | METH_NOARGS | METH_O))) == 0, "%d",
-                       methods->ml_flags);
         module->giveAttr(methods->ml_name, new BoxedCApiFunction(methods, passthrough, boxString(name)));
 
         methods++;

src/runtime/capi.cpp

@@ -1509,6 +1509,7 @@ Box* BoxedCApiFunction::tppCall(Box* _self, CallRewriteArgs* rewrite_args, ArgPa
     auto func = self->method_def->ml_meth;
 
     ParamReceiveSpec paramspec(0, 0, true, false);
+    Box** defaults = NULL;
     if (flags == METH_VARARGS) {
         paramspec = ParamReceiveSpec(0, 0, true, false);
     } else if (flags == (METH_VARARGS | METH_KEYWORDS)) {
@@ -1519,6 +1520,27 @@ Box* BoxedCApiFunction::tppCall(Box* _self, CallRewriteArgs* rewrite_args, ArgPa
         paramspec = ParamReceiveSpec(1, 0, false, false);
     } else if (flags == METH_OLDARGS) {
         paramspec = ParamReceiveSpec(1, 0, false, false);
+    } else if ((flags & ~(METH_O3 | METH_D3)) == 0) {
+        int num_args = 0;
+        if (flags & METH_O)
+            num_args++;
+        if (flags & METH_O2)
+            num_args += 2;
+
+        int num_defaults = 0;
+        if (flags & METH_D1)
+            num_defaults++;
+        if (flags & METH_D2)
+            num_defaults += 2;
+
+        paramspec = ParamReceiveSpec(num_args, num_defaults, false, false);
+        if (num_defaults) {
+            static Box* _defaults[] = { NULL, NULL, NULL };
+            assert(num_defaults <= 3);
+            defaults = _defaults;
+        }
+
+        assert(paramspec.totalReceived() <= 3); // would need to allocate oargs
     } else {
         RELEASE_ASSERT(0, "0x%x", flags);
     }
@@ -1549,8 +1571,8 @@ Box* BoxedCApiFunction::tppCall(Box* _self, CallRewriteArgs* rewrite_args, ArgPa
     }
 
     bool rewrite_success = false;
-    rearrangeArguments(paramspec, NULL, self->method_def->ml_name, NULL, rewrite_args, rewrite_success, argspec, arg1,
-                       arg2, arg3, args, oargs, keyword_names);
+    rearrangeArguments(paramspec, NULL, self->method_def->ml_name, defaults, rewrite_args, rewrite_success, argspec,
+                       arg1, arg2, arg3, args, oargs, keyword_names);
 
     if (!rewrite_success)
         rewrite_args = NULL;
@@ -1578,6 +1600,22 @@ Box* BoxedCApiFunction::tppCall(Box* _self, CallRewriteArgs* rewrite_args, ArgPa
         rtn = (Box*)func(self->passthrough, arg1);
         if (rewrite_args)
             rewrite_args->out_rtn = rewrite_args->rewriter->call(true, (void*)func, r_passthrough, rewrite_args->arg1);
+    } else if ((flags & ~(METH_O3 | METH_D3)) == 0) {
+        assert(paramspec.totalReceived() <= 3); // would need to pass through oargs
+        rtn = ((Box * (*)(Box*, Box*, Box*, Box*))func)(self->passthrough, arg1, arg2, arg3);
+        if (rewrite_args) {
+            if (paramspec.totalReceived() == 1)
+                rewrite_args->out_rtn
+                    = rewrite_args->rewriter->call(true, (void*)func, r_passthrough, rewrite_args->arg1);
+            else if (paramspec.totalReceived() == 2)
+                rewrite_args->out_rtn = rewrite_args->rewriter->call(true, (void*)func, r_passthrough,
+                                                                     rewrite_args->arg1, rewrite_args->arg2);
+            else if (paramspec.totalReceived() == 3)
+                rewrite_args->out_rtn = rewrite_args->rewriter->call(
+                    true, (void*)func, r_passthrough, rewrite_args->arg1, rewrite_args->arg2, rewrite_args->arg3);
+            else
+                abort();
+        }
     } else if (flags == METH_OLDARGS) {
         /* the really old style */