gh-85283: Build resource extension with limited C API (#110989)

* Replace PyStructSequence_SET_ITEM() with
  PyStructSequence_SetItem().
* Replace PyTuple_GET_SIZE() with PyTuple_Size().
* Replace PyTuple_GET_ITEM() with PyTuple_GetItem().

2 files changed, 32 insertions, 30 deletions

diff --git a/Modules/clinic/resource.c.h b/Modules/clinic/resource.c.h
index e4ef939..9eda7de 100644
--- a/Modules/clinic/resource.c.h
+++ b/Modules/clinic/resource.c.h
@@ -2,8 +2,6 @@
 preserve
 [clinic start generated code]*/
 
-#include "pycore_modsupport.h"    // _PyArg_CheckPositional()
-
 #if defined(HAVE_GETRUSAGE)
 
 PyDoc_STRVAR(resource_getrusage__doc__,
@@ -68,7 +66,7 @@ PyDoc_STRVAR(resource_setrlimit__doc__,
 "\n");
 
 #define RESOURCE_SETRLIMIT_METHODDEF    \
-    {"setrlimit", _PyCFunction_CAST(resource_setrlimit), METH_FASTCALL, resource_setrlimit__doc__},
+    {"setrlimit", (PyCFunction)(void(*)(void))resource_setrlimit, METH_FASTCALL, resource_setrlimit__doc__},
 
 static PyObject *
 resource_setrlimit_impl(PyObject *module, int resource, PyObject *limits);
@@ -80,7 +78,8 @@ resource_setrlimit(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
     int resource;
     PyObject *limits;
 
-    if (!_PyArg_CheckPositional("setrlimit", nargs, 2, 2)) {
+    if (nargs != 2) {
+        PyErr_Format(PyExc_TypeError, "setrlimit expected 2 arguments, got %zd", nargs);
         goto exit;
     }
     resource = PyLong_AsInt(args[0]);
@@ -102,7 +101,7 @@ PyDoc_STRVAR(resource_prlimit__doc__,
 "\n");
 
 #define RESOURCE_PRLIMIT_METHODDEF    \
-    {"prlimit", _PyCFunction_CAST(resource_prlimit), METH_FASTCALL, resource_prlimit__doc__},
+    {"prlimit", (PyCFunction)(void(*)(void))resource_prlimit, METH_FASTCALL, resource_prlimit__doc__},
 
 static PyObject *
 resource_prlimit_impl(PyObject *module, pid_t pid, int resource,
@@ -116,7 +115,12 @@ resource_prlimit(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
     int resource;
     PyObject *limits = Py_None;
 
-    if (!_PyArg_CheckPositional("prlimit", nargs, 2, 3)) {
+    if (nargs < 2) {
+        PyErr_Format(PyExc_TypeError, "prlimit expected at least 2 arguments, got %zd", nargs);
+        goto exit;
+    }
+    if (nargs > 3) {
+        PyErr_Format(PyExc_TypeError, "prlimit expected at most 3 arguments, got %zd", nargs);
         goto exit;
     }
     pid = PyLong_AsPid(args[0]);
@@ -174,4 +178,4 @@ exit:
 #ifndef RESOURCE_PRLIMIT_METHODDEF
     #define RESOURCE_PRLIMIT_METHODDEF
 #endif /* !defined(RESOURCE_PRLIMIT_METHODDEF) */
-/*[clinic end generated code: output=8e905b2f5c35170e input=a9049054013a1b77]*/
+/*[clinic end generated code: output=e45883ace510414a input=a9049054013a1b77]*/
diff --git a/Modules/resource.c b/Modules/resource.c
index 22ac31a..c973008 100644
--- a/Modules/resource.c
+++ b/Modules/resource.c
@@ -1,7 +1,5 @@
-// clinic/resource.c.h uses internal pycore_modsupport.h API
-#ifndef Py_BUILD_CORE_BUILTIN
-#  define Py_BUILD_CORE_MODULE 1
-#endif
+// Need limited C API version 3.13 for Py_MOD_PER_INTERPRETER_GIL_SUPPORTED
+#define Py_LIMITED_API 0x030d0000
 
 #include "Python.h"
 #include <errno.h>                // errno
@@ -121,24 +119,24 @@ resource_getrusage_impl(PyObject *module, int who)
     if (!result)
         return NULL;
 
-    PyStructSequence_SET_ITEM(result, 0,
+    PyStructSequence_SetItem(result, 0,
                     PyFloat_FromDouble(doubletime(ru.ru_utime)));
-    PyStructSequence_SET_ITEM(result, 1,
+    PyStructSequence_SetItem(result, 1,
                     PyFloat_FromDouble(doubletime(ru.ru_stime)));
-    PyStructSequence_SET_ITEM(result, 2, PyLong_FromLong(ru.ru_maxrss));
-    PyStructSequence_SET_ITEM(result, 3, PyLong_FromLong(ru.ru_ixrss));
-    PyStructSequence_SET_ITEM(result, 4, PyLong_FromLong(ru.ru_idrss));
-    PyStructSequence_SET_ITEM(result, 5, PyLong_FromLong(ru.ru_isrss));
-    PyStructSequence_SET_ITEM(result, 6, PyLong_FromLong(ru.ru_minflt));
-    PyStructSequence_SET_ITEM(result, 7, PyLong_FromLong(ru.ru_majflt));
-    PyStructSequence_SET_ITEM(result, 8, PyLong_FromLong(ru.ru_nswap));
-    PyStructSequence_SET_ITEM(result, 9, PyLong_FromLong(ru.ru_inblock));
-    PyStructSequence_SET_ITEM(result, 10, PyLong_FromLong(ru.ru_oublock));
-    PyStructSequence_SET_ITEM(result, 11, PyLong_FromLong(ru.ru_msgsnd));
-    PyStructSequence_SET_ITEM(result, 12, PyLong_FromLong(ru.ru_msgrcv));
-    PyStructSequence_SET_ITEM(result, 13, PyLong_FromLong(ru.ru_nsignals));
-    PyStructSequence_SET_ITEM(result, 14, PyLong_FromLong(ru.ru_nvcsw));
-    PyStructSequence_SET_ITEM(result, 15, PyLong_FromLong(ru.ru_nivcsw));
+    PyStructSequence_SetItem(result, 2, PyLong_FromLong(ru.ru_maxrss));
+    PyStructSequence_SetItem(result, 3, PyLong_FromLong(ru.ru_ixrss));
+    PyStructSequence_SetItem(result, 4, PyLong_FromLong(ru.ru_idrss));
+    PyStructSequence_SetItem(result, 5, PyLong_FromLong(ru.ru_isrss));
+    PyStructSequence_SetItem(result, 6, PyLong_FromLong(ru.ru_minflt));
+    PyStructSequence_SetItem(result, 7, PyLong_FromLong(ru.ru_majflt));
+    PyStructSequence_SetItem(result, 8, PyLong_FromLong(ru.ru_nswap));
+    PyStructSequence_SetItem(result, 9, PyLong_FromLong(ru.ru_inblock));
+    PyStructSequence_SetItem(result, 10, PyLong_FromLong(ru.ru_oublock));
+    PyStructSequence_SetItem(result, 11, PyLong_FromLong(ru.ru_msgsnd));
+    PyStructSequence_SetItem(result, 12, PyLong_FromLong(ru.ru_msgrcv));
+    PyStructSequence_SetItem(result, 13, PyLong_FromLong(ru.ru_nsignals));
+    PyStructSequence_SetItem(result, 14, PyLong_FromLong(ru.ru_nvcsw));
+    PyStructSequence_SetItem(result, 15, PyLong_FromLong(ru.ru_nivcsw));
 
     if (PyErr_Occurred()) {
         Py_DECREF(result);
@@ -158,13 +156,13 @@ py2rlimit(PyObject *limits, struct rlimit *rl_out)
         /* Here limits is a borrowed reference */
         return -1;
 
-    if (PyTuple_GET_SIZE(limits) != 2) {
+    if (PyTuple_Size(limits) != 2) {
         PyErr_SetString(PyExc_ValueError,
                         "expected a tuple of 2 integers");
         goto error;
     }
-    curobj = PyTuple_GET_ITEM(limits, 0);
-    maxobj = PyTuple_GET_ITEM(limits, 1);
+    curobj = PyTuple_GetItem(limits, 0);  // borrowed
+    maxobj = PyTuple_GetItem(limits, 1);  // borrowed
 #if !defined(HAVE_LARGEFILE_SUPPORT)
     rl_out->rlim_cur = PyLong_AsLong(curobj);
     if (rl_out->rlim_cur == (rlim_t)-1 && PyErr_Occurred())