bpo-38644: Add _PyObject_Call() (GH-17089)

* Add pycore_call.h internal header file.
* Add _PyObject_Call(): PyObject_Call() with tstate
* Add _PyObject_CallNoArgTstate(): _PyObject_CallNoArg() with tstate
* Add _PyObject_FastCallDictTstate(): _PyObject_FastCallDict()
  with tstate
* _PyObject_Call_Prepend() now takes tstate
* Replace _PyObject_FastCall() calls
  with _PyObject_VectorcallTstate() calls

1 files changed, 8 insertions, 7 deletions

diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index d79e254..4470310 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -4,6 +4,7 @@
 #include <ctype.h>
 #include "ast.h"
 #undef Yield   /* undefine macro conflicting with <winbase.h> */
+#include "pycore_pyerrors.h"
 #include "pycore_pystate.h"
 #include "pycore_tupleobject.h"
 
@@ -1254,23 +1255,23 @@ map_next(mapobject *lz)
 {
     PyObject *small_stack[_PY_FASTCALL_SMALL_STACK];
     PyObject **stack;
-    Py_ssize_t niters, nargs, i;
     PyObject *result = NULL;
+    PyThreadState *tstate = _PyThreadState_GET();
 
-    niters = PyTuple_GET_SIZE(lz->iters);
+    const Py_ssize_t niters = PyTuple_GET_SIZE(lz->iters);
     if (niters <= (Py_ssize_t)Py_ARRAY_LENGTH(small_stack)) {
         stack = small_stack;
     }
     else {
         stack = PyMem_Malloc(niters * sizeof(stack[0]));
         if (stack == NULL) {
-            PyErr_NoMemory();
+            _PyErr_NoMemory(tstate);
             return NULL;
         }
     }
 
-    nargs = 0;
-    for (i=0; i < niters; i++) {
+    Py_ssize_t nargs = 0;
+    for (Py_ssize_t i=0; i < niters; i++) {
         PyObject *it = PyTuple_GET_ITEM(lz->iters, i);
         PyObject *val = Py_TYPE(it)->tp_iternext(it);
         if (val == NULL) {
@@ -1280,10 +1281,10 @@ map_next(mapobject *lz)
         nargs++;
     }
 
-    result = _PyObject_FastCall(lz->func, stack, nargs);
+    result = _PyObject_VectorcallTstate(tstate, lz->func, stack, nargs, NULL);
 
 exit:
-    for (i=0; i < nargs; i++) {
+    for (Py_ssize_t i=0; i < nargs; i++) {
         Py_DECREF(stack[i]);
     }
     if (stack != small_stack) {