bpo-37169: Rewrite _PyObject_IsFreed() unit tests (GH-13888) (GH-13895)

Replace two Python function calls with a single one to ensure that no
memory allocation is done between the invalid object is created and
when _PyObject_IsFreed() is called.

(cherry picked from commit 3bf0f3ad2046ac674d8e8a2c074a5a8b3327797d)

1 files changed, 14 insertions, 13 deletions

diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index c1ae237..07aadea 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -4489,15 +4489,17 @@ test_pymem_getallocatorsname(PyObject *self, PyObject *args)
 
 
 static PyObject*
-pyobject_is_freed(PyObject *self, PyObject *op)
+test_pyobject_is_freed(const char *test_name, PyObject *op)
 {
-    int res = _PyObject_IsFreed(op);
-    return PyBool_FromLong(res);
+    if (!_PyObject_IsFreed(op)) {
+        return raiseTestError(test_name, "object is not seen as freed");
+    }
+    Py_RETURN_NONE;
 }
 
 
 static PyObject*
-pyobject_uninitialized(PyObject *self, PyObject *args)
+check_pyobject_uninitialized_is_freed(PyObject *self, PyObject *Py_UNUSED(args))
 {
     PyObject *op = (PyObject *)PyObject_Malloc(sizeof(PyObject));
     if (op == NULL) {
@@ -4506,12 +4508,12 @@ pyobject_uninitialized(PyObject *self, PyObject *args)
     /* Initialize reference count to avoid early crash in ceval or GC */
     Py_REFCNT(op) = 1;
     /* object fields like ob_type are uninitialized! */
-    return op;
+    return test_pyobject_is_freed("check_pyobject_uninitialized_is_freed", op);
 }
 
 
 static PyObject*
-pyobject_forbidden_bytes(PyObject *self, PyObject *args)
+check_pyobject_forbidden_bytes_is_freed(PyObject *self, PyObject *Py_UNUSED(args))
 {
     /* Allocate an incomplete PyObject structure: truncate 'ob_type' field */
     PyObject *op = (PyObject *)PyObject_Malloc(offsetof(PyObject, ob_type));
@@ -4522,12 +4524,12 @@ pyobject_forbidden_bytes(PyObject *self, PyObject *args)
     Py_REFCNT(op) = 1;
     /* ob_type field is after the memory block: part of "forbidden bytes"
        when using debug hooks on memory allocatrs! */
-    return op;
+    return test_pyobject_is_freed("check_pyobject_forbidden_bytes_is_freed", op);
 }
 
 
 static PyObject*
-pyobject_freed(PyObject *self, PyObject *args)
+check_pyobject_freed_is_freed(PyObject *self, PyObject *Py_UNUSED(args))
 {
     PyObject *op = _PyObject_CallNoArg((PyObject *)&PyBaseObject_Type);
     if (op == NULL) {
@@ -4537,7 +4539,7 @@ pyobject_freed(PyObject *self, PyObject *args)
     /* Reset reference count to avoid early crash in ceval or GC */
     Py_REFCNT(op) = 1;
     /* object memory is freed! */
-    return op;
+    return test_pyobject_is_freed("check_pyobject_freed_is_freed", op);
 }
 
 
@@ -5264,10 +5266,9 @@ static PyMethodDef TestMethods[] = {
     {"pymem_api_misuse", pymem_api_misuse, METH_NOARGS},
     {"pymem_malloc_without_gil", pymem_malloc_without_gil, METH_NOARGS},
     {"pymem_getallocatorsname", test_pymem_getallocatorsname, METH_NOARGS},
-    {"pyobject_is_freed", (PyCFunction)(void(*)(void))pyobject_is_freed, METH_O},
-    {"pyobject_uninitialized", pyobject_uninitialized, METH_NOARGS},
-    {"pyobject_forbidden_bytes", pyobject_forbidden_bytes, METH_NOARGS},
-    {"pyobject_freed", pyobject_freed, METH_NOARGS},
+    {"check_pyobject_uninitialized_is_freed", check_pyobject_uninitialized_is_freed, METH_NOARGS},
+    {"check_pyobject_forbidden_bytes_is_freed", check_pyobject_forbidden_bytes_is_freed, METH_NOARGS},
+    {"check_pyobject_freed_is_freed", check_pyobject_freed_is_freed, METH_NOARGS},
     {"pyobject_malloc_without_gil", pyobject_malloc_without_gil, METH_NOARGS},
     {"tracemalloc_track", tracemalloc_track, METH_VARARGS},
     {"tracemalloc_untrack", tracemalloc_untrack, METH_VARARGS},