gh-93649: Split memory and docstring tests from _testcapimodule.c (#99517)

7 files changed, 767 insertions, 671 deletions

diff --git a/Modules/Setup.stdlib.in b/Modules/Setup.stdlib.in
index e250f83..26e7ffc 100644
--- a/Modules/Setup.stdlib.in
+++ b/Modules/Setup.stdlib.in
@@ -169,7 +169,7 @@
 @MODULE__XXTESTFUZZ_TRUE@_xxtestfuzz _xxtestfuzz/_xxtestfuzz.c _xxtestfuzz/fuzzer.c
 @MODULE__TESTBUFFER_TRUE@_testbuffer _testbuffer.c
 @MODULE__TESTINTERNALCAPI_TRUE@_testinternalcapi _testinternalcapi.c
-@MODULE__TESTCAPI_TRUE@_testcapi _testcapimodule.c _testcapi/vectorcall.c _testcapi/vectorcall_limited.c _testcapi/heaptype.c _testcapi/unicode.c _testcapi/getargs.c _testcapi/pytime.c _testcapi/datetime.c
+@MODULE__TESTCAPI_TRUE@_testcapi _testcapimodule.c _testcapi/vectorcall.c _testcapi/vectorcall_limited.c _testcapi/heaptype.c _testcapi/unicode.c _testcapi/getargs.c _testcapi/pytime.c _testcapi/datetime.c _testcapi/docstring.c _testcapi/mem.c
 
 # Some testing modules MUST be built as shared libraries.
 *shared*
diff --git a/Modules/_testcapi/docstring.c b/Modules/_testcapi/docstring.c
new file mode 100644
index 0000000..a997c54
--- /dev/null
+++ b/Modules/_testcapi/docstring.c
@@ -0,0 +1,107 @@
+#include "parts.h"
+
+
+PyDoc_STRVAR(docstring_empty,
+""
+);
+
+PyDoc_STRVAR(docstring_no_signature,
+"This docstring has no signature."
+);
+
+PyDoc_STRVAR(docstring_with_invalid_signature,
+"docstring_with_invalid_signature($module, /, boo)\n"
+"\n"
+"This docstring has an invalid signature."
+);
+
+PyDoc_STRVAR(docstring_with_invalid_signature2,
+"docstring_with_invalid_signature2($module, /, boo)\n"
+"\n"
+"--\n"
+"\n"
+"This docstring also has an invalid signature."
+);
+
+PyDoc_STRVAR(docstring_with_signature,
+"docstring_with_signature($module, /, sig)\n"
+"--\n"
+"\n"
+"This docstring has a valid signature."
+);
+
+PyDoc_STRVAR(docstring_with_signature_but_no_doc,
+"docstring_with_signature_but_no_doc($module, /, sig)\n"
+"--\n"
+"\n"
+);
+
+PyDoc_STRVAR(docstring_with_signature_and_extra_newlines,
+"docstring_with_signature_and_extra_newlines($module, /, parameter)\n"
+"--\n"
+"\n"
+"\n"
+"This docstring has a valid signature and some extra newlines."
+);
+
+PyDoc_STRVAR(docstring_with_signature_with_defaults,
+"docstring_with_signature_with_defaults(module, s='avocado',\n"
+"        b=b'bytes', d=3.14, i=35, n=None, t=True, f=False,\n"
+"        local=the_number_three, sys=sys.maxsize,\n"
+"        exp=sys.maxsize - 1)\n"
+"--\n"
+"\n"
+"\n"
+"\n"
+"This docstring has a valid signature with parameters,\n"
+"and the parameters take defaults of varying types."
+);
+
+/* This is here to provide a docstring for test_descr. */
+static PyObject *
+test_with_docstring(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    Py_RETURN_NONE;
+}
+
+static PyMethodDef test_methods[] = {
+    {"docstring_empty",
+        (PyCFunction)test_with_docstring, METH_NOARGS,
+        docstring_empty},
+    {"docstring_no_signature",
+        (PyCFunction)test_with_docstring, METH_NOARGS,
+        docstring_no_signature},
+    {"docstring_with_invalid_signature",
+        (PyCFunction)test_with_docstring, METH_NOARGS,
+        docstring_with_invalid_signature},
+    {"docstring_with_invalid_signature2",
+        (PyCFunction)test_with_docstring, METH_NOARGS,
+        docstring_with_invalid_signature2},
+    {"docstring_with_signature",
+        (PyCFunction)test_with_docstring, METH_NOARGS,
+        docstring_with_signature},
+    {"docstring_with_signature_and_extra_newlines",
+        (PyCFunction)test_with_docstring, METH_NOARGS,
+        docstring_with_signature_and_extra_newlines},
+    {"docstring_with_signature_but_no_doc",
+        (PyCFunction)test_with_docstring, METH_NOARGS,
+        docstring_with_signature_but_no_doc},
+    {"docstring_with_signature_with_defaults",
+        (PyCFunction)test_with_docstring, METH_NOARGS,
+        docstring_with_signature_with_defaults},
+    {"no_docstring",
+        (PyCFunction)test_with_docstring, METH_NOARGS},
+    {"test_with_docstring",
+        test_with_docstring,              METH_NOARGS,
+        PyDoc_STR("This is a pretty normal docstring.")},
+    {NULL},
+};
+
+int
+_PyTestCapi_Init_Docstring(PyObject *mod)
+{
+    if (PyModule_AddFunctions(mod, test_methods) < 0) {
+        return -1;
+    }
+    return 0;
+}
diff --git a/Modules/_testcapi/mem.c b/Modules/_testcapi/mem.c
new file mode 100644
index 0000000..ef723bf
--- /dev/null
+++ b/Modules/_testcapi/mem.c
@@ -0,0 +1,643 @@
+#include "parts.h"
+
+#include <stddef.h>
+
+
+typedef struct {
+    PyMemAllocatorEx alloc;
+
+    size_t malloc_size;
+    size_t calloc_nelem;
+    size_t calloc_elsize;
+    void *realloc_ptr;
+    size_t realloc_new_size;
+    void *free_ptr;
+    void *ctx;
+} alloc_hook_t;
+
+static void *
+hook_malloc(void *ctx, size_t size)
+{
+    alloc_hook_t *hook = (alloc_hook_t *)ctx;
+    hook->ctx = ctx;
+    hook->malloc_size = size;
+    return hook->alloc.malloc(hook->alloc.ctx, size);
+}
+
+static void *
+hook_calloc(void *ctx, size_t nelem, size_t elsize)
+{
+    alloc_hook_t *hook = (alloc_hook_t *)ctx;
+    hook->ctx = ctx;
+    hook->calloc_nelem = nelem;
+    hook->calloc_elsize = elsize;
+    return hook->alloc.calloc(hook->alloc.ctx, nelem, elsize);
+}
+
+static void *
+hook_realloc(void *ctx, void *ptr, size_t new_size)
+{
+    alloc_hook_t *hook = (alloc_hook_t *)ctx;
+    hook->ctx = ctx;
+    hook->realloc_ptr = ptr;
+    hook->realloc_new_size = new_size;
+    return hook->alloc.realloc(hook->alloc.ctx, ptr, new_size);
+}
+
+static void
+hook_free(void *ctx, void *ptr)
+{
+    alloc_hook_t *hook = (alloc_hook_t *)ctx;
+    hook->ctx = ctx;
+    hook->free_ptr = ptr;
+    hook->alloc.free(hook->alloc.ctx, ptr);
+}
+
+/* Most part of the following code is inherited from the pyfailmalloc project
+ * written by Victor Stinner. */
+static struct {
+    int installed;
+    PyMemAllocatorEx raw;
+    PyMemAllocatorEx mem;
+    PyMemAllocatorEx obj;
+} FmHook;
+
+static struct {
+    int start;
+    int stop;
+    Py_ssize_t count;
+} FmData;
+
+static int
+fm_nomemory(void)
+{
+    FmData.count++;
+    if (FmData.count > FmData.start &&
+        (FmData.stop <= 0 || FmData.count <= FmData.stop))
+    {
+        return 1;
+    }
+    return 0;
+}
+
+static void *
+hook_fmalloc(void *ctx, size_t size)
+{
+    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+    if (fm_nomemory()) {
+        return NULL;
+    }
+    return alloc->malloc(alloc->ctx, size);
+}
+
+static void *
+hook_fcalloc(void *ctx, size_t nelem, size_t elsize)
+{
+    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+    if (fm_nomemory()) {
+        return NULL;
+    }
+    return alloc->calloc(alloc->ctx, nelem, elsize);
+}
+
+static void *
+hook_frealloc(void *ctx, void *ptr, size_t new_size)
+{
+    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+    if (fm_nomemory()) {
+        return NULL;
+    }
+    return alloc->realloc(alloc->ctx, ptr, new_size);
+}
+
+static void
+hook_ffree(void *ctx, void *ptr)
+{
+    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+    alloc->free(alloc->ctx, ptr);
+}
+
+static void
+fm_setup_hooks(void)
+{
+    if (FmHook.installed) {
+        return;
+    }
+    FmHook.installed = 1;
+
+    PyMemAllocatorEx alloc;
+    alloc.malloc = hook_fmalloc;
+    alloc.calloc = hook_fcalloc;
+    alloc.realloc = hook_frealloc;
+    alloc.free = hook_ffree;
+    PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &FmHook.raw);
+    PyMem_GetAllocator(PYMEM_DOMAIN_MEM, &FmHook.mem);
+    PyMem_GetAllocator(PYMEM_DOMAIN_OBJ, &FmHook.obj);
+
+    alloc.ctx = &FmHook.raw;
+    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &alloc);
+
+    alloc.ctx = &FmHook.mem;
+    PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &alloc);
+
+    alloc.ctx = &FmHook.obj;
+    PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &alloc);
+}
+
+static void
+fm_remove_hooks(void)
+{
+    if (FmHook.installed) {
+        FmHook.installed = 0;
+        PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &FmHook.raw);
+        PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &FmHook.mem);
+        PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &FmHook.obj);
+    }
+}
+
+static PyObject *
+set_nomemory(PyObject *self, PyObject *args)
+{
+    /* Memory allocation fails after 'start' allocation requests, and until
+     * 'stop' allocation requests except when 'stop' is negative or equal
+     * to 0 (default) in which case allocation failures never stop. */
+    FmData.count = 0;
+    FmData.stop = 0;
+    if (!PyArg_ParseTuple(args, "i|i", &FmData.start, &FmData.stop)) {
+        return NULL;
+    }
+    fm_setup_hooks();
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+remove_mem_hooks(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    fm_remove_hooks();
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+test_setallocators(PyMemAllocatorDomain domain)
+{
+    PyObject *res = NULL;
+    const char *error_msg;
+    alloc_hook_t hook;
+
+    memset(&hook, 0, sizeof(hook));
+
+    PyMemAllocatorEx alloc;
+    alloc.ctx = &hook;
+    alloc.malloc = &hook_malloc;
+    alloc.calloc = &hook_calloc;
+    alloc.realloc = &hook_realloc;
+    alloc.free = &hook_free;
+    PyMem_GetAllocator(domain, &hook.alloc);
+    PyMem_SetAllocator(domain, &alloc);
+
+    /* malloc, realloc, free */
+    size_t size = 42;
+    hook.ctx = NULL;
+    void *ptr;
+    switch(domain) {
+        case PYMEM_DOMAIN_RAW:
+            ptr = PyMem_RawMalloc(size);
+            break;
+        case PYMEM_DOMAIN_MEM:
+            ptr = PyMem_Malloc(size);
+            break;
+        case PYMEM_DOMAIN_OBJ:
+            ptr = PyObject_Malloc(size);
+            break;
+        default:
+            ptr = NULL;
+            break;
+    }
+
+#define CHECK_CTX(FUNC)                     \
+    if (hook.ctx != &hook) {                \
+        error_msg = FUNC " wrong context";  \
+        goto fail;                          \
+    }                                       \
+    hook.ctx = NULL;  /* reset for next check */
+
+    if (ptr == NULL) {
+        error_msg = "malloc failed";
+        goto fail;
+    }
+    CHECK_CTX("malloc");
+    if (hook.malloc_size != size) {
+        error_msg = "malloc invalid size";
+        goto fail;
+    }
+
+    size_t size2 = 200;
+    void *ptr2;
+    switch(domain) {
+        case PYMEM_DOMAIN_RAW:
+            ptr2 = PyMem_RawRealloc(ptr, size2);
+            break;
+        case PYMEM_DOMAIN_MEM:
+            ptr2 = PyMem_Realloc(ptr, size2);
+            break;
+        case PYMEM_DOMAIN_OBJ:
+            ptr2 = PyObject_Realloc(ptr, size2);
+            break;
+        default:
+            ptr2 = NULL;
+            break;
+    }
+
+    if (ptr2 == NULL) {
+        error_msg = "realloc failed";
+        goto fail;
+    }
+    CHECK_CTX("realloc");
+    if (hook.realloc_ptr != ptr || hook.realloc_new_size != size2) {
+        error_msg = "realloc invalid parameters";
+        goto fail;
+    }
+
+    switch(domain) {
+        case PYMEM_DOMAIN_RAW:
+            PyMem_RawFree(ptr2);
+            break;
+        case PYMEM_DOMAIN_MEM:
+            PyMem_Free(ptr2);
+            break;
+        case PYMEM_DOMAIN_OBJ:
+            PyObject_Free(ptr2);
+            break;
+    }
+
+    CHECK_CTX("free");
+    if (hook.free_ptr != ptr2) {
+        error_msg = "free invalid pointer";
+        goto fail;
+    }
+
+    /* calloc, free */
+    size_t nelem = 2;
+    size_t elsize = 5;
+    switch(domain) {
+        case PYMEM_DOMAIN_RAW:
+            ptr = PyMem_RawCalloc(nelem, elsize);
+            break;
+        case PYMEM_DOMAIN_MEM:
+            ptr = PyMem_Calloc(nelem, elsize);
+            break;
+        case PYMEM_DOMAIN_OBJ:
+            ptr = PyObject_Calloc(nelem, elsize);
+            break;
+        default:
+            ptr = NULL;
+            break;
+    }
+
+    if (ptr == NULL) {
+        error_msg = "calloc failed";
+        goto fail;
+    }
+    CHECK_CTX("calloc");
+    if (hook.calloc_nelem != nelem || hook.calloc_elsize != elsize) {
+        error_msg = "calloc invalid nelem or elsize";
+        goto fail;
+    }
+
+    hook.free_ptr = NULL;
+    switch(domain) {
+        case PYMEM_DOMAIN_RAW:
+            PyMem_RawFree(ptr);
+            break;
+        case PYMEM_DOMAIN_MEM:
+            PyMem_Free(ptr);
+            break;
+        case PYMEM_DOMAIN_OBJ:
+            PyObject_Free(ptr);
+            break;
+    }
+
+    CHECK_CTX("calloc free");
+    if (hook.free_ptr != ptr) {
+        error_msg = "calloc free invalid pointer";
+        goto fail;
+    }
+
+    res = Py_NewRef(Py_None);
+    goto finally;
+
+fail:
+    PyErr_SetString(PyExc_RuntimeError, error_msg);
+
+finally:
+    PyMem_SetAllocator(domain, &hook.alloc);
+    return res;
+
+#undef CHECK_CTX
+}
+
+static PyObject *
+test_pyobject_setallocators(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    return test_setallocators(PYMEM_DOMAIN_OBJ);
+}
+
+static PyObject *
+test_pyobject_new(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    PyObject *obj;
+    PyTypeObject *type = &PyBaseObject_Type;
+    PyTypeObject *var_type = &PyLong_Type;
+
+    // PyObject_New()
+    obj = PyObject_New(PyObject, type);
+    if (obj == NULL) {
+        goto alloc_failed;
+    }
+    Py_DECREF(obj);
+
+    // PyObject_NEW()
+    obj = PyObject_NEW(PyObject, type);
+    if (obj == NULL) {
+        goto alloc_failed;
+    }
+    Py_DECREF(obj);
+
+    // PyObject_NewVar()
+    obj = PyObject_NewVar(PyObject, var_type, 3);
+    if (obj == NULL) {
+        goto alloc_failed;
+    }
+    Py_DECREF(obj);
+
+    // PyObject_NEW_VAR()
+    obj = PyObject_NEW_VAR(PyObject, var_type, 3);
+    if (obj == NULL) {
+        goto alloc_failed;
+    }
+    Py_DECREF(obj);
+
+    Py_RETURN_NONE;
+
+alloc_failed:
+    PyErr_NoMemory();
+    return NULL;
+}
+
+static PyObject *
+test_pymem_alloc0(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    void *ptr;
+
+    ptr = PyMem_RawMalloc(0);
+    if (ptr == NULL) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "PyMem_RawMalloc(0) returns NULL");
+        return NULL;
+    }
+    PyMem_RawFree(ptr);
+
+    ptr = PyMem_RawCalloc(0, 0);
+    if (ptr == NULL) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "PyMem_RawCalloc(0, 0) returns NULL");
+        return NULL;
+    }
+    PyMem_RawFree(ptr);
+
+    ptr = PyMem_Malloc(0);
+    if (ptr == NULL) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "PyMem_Malloc(0) returns NULL");
+        return NULL;
+    }
+    PyMem_Free(ptr);
+
+    ptr = PyMem_Calloc(0, 0);
+    if (ptr == NULL) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "PyMem_Calloc(0, 0) returns NULL");
+        return NULL;
+    }
+    PyMem_Free(ptr);
+
+    ptr = PyObject_Malloc(0);
+    if (ptr == NULL) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "PyObject_Malloc(0) returns NULL");
+        return NULL;
+    }
+    PyObject_Free(ptr);
+
+    ptr = PyObject_Calloc(0, 0);
+    if (ptr == NULL) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "PyObject_Calloc(0, 0) returns NULL");
+        return NULL;
+    }
+    PyObject_Free(ptr);
+
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+test_pymem_getallocatorsname(PyObject *self, PyObject *args)
+{
+    const char *name = _PyMem_GetCurrentAllocatorName();
+    if (name == NULL) {
+        PyErr_SetString(PyExc_RuntimeError, "cannot get allocators name");
+        return NULL;
+    }
+    return PyUnicode_FromString(name);
+}
+
+static PyObject *
+test_pymem_setrawallocators(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    return test_setallocators(PYMEM_DOMAIN_RAW);
+}
+
+static PyObject *
+test_pymem_setallocators(PyObject *self, PyObject *Py_UNUSED(ignored))
+{
+    return test_setallocators(PYMEM_DOMAIN_MEM);
+}
+
+static PyObject *
+pyobject_malloc_without_gil(PyObject *self, PyObject *args)
+{
+    char *buffer;
+
+    /* Deliberate bug to test debug hooks on Python memory allocators:
+       call PyObject_Malloc() without holding the GIL */
+    Py_BEGIN_ALLOW_THREADS
+    buffer = PyObject_Malloc(10);
+    Py_END_ALLOW_THREADS
+
+    PyObject_Free(buffer);
+
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+pymem_buffer_overflow(PyObject *self, PyObject *args)
+{
+    char *buffer;
+
+    /* Deliberate buffer overflow to check that PyMem_Free() detects
+       the overflow when debug hooks are installed. */
+    buffer = PyMem_Malloc(16);
+    if (buffer == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+    buffer[16] = 'x';
+    PyMem_Free(buffer);
+
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+pymem_api_misuse(PyObject *self, PyObject *args)
+{
+    char *buffer;
+
+    /* Deliberate misusage of Python allocators:
+       allococate with PyMem but release with PyMem_Raw. */
+    buffer = PyMem_Malloc(16);
+    PyMem_RawFree(buffer);
+
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+pymem_malloc_without_gil(PyObject *self, PyObject *args)
+{
+    char *buffer;
+
+    /* Deliberate bug to test debug hooks on Python memory allocators:
+       call PyMem_Malloc() without holding the GIL */
+    Py_BEGIN_ALLOW_THREADS
+    buffer = PyMem_Malloc(10);
+    Py_END_ALLOW_THREADS
+
+    PyMem_Free(buffer);
+
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+test_pyobject_is_freed(const char *test_name, PyObject *op)
+{
+    if (!_PyObject_IsFreed(op)) {
+        PyErr_SetString(PyExc_AssertionError,
+                        "object is not seen as freed");
+        return NULL;
+    }
+    Py_RETURN_NONE;
+}
+
+static PyObject *
+check_pyobject_null_is_freed(PyObject *self, PyObject *Py_UNUSED(args))
+{
+    PyObject *op = NULL;
+    return test_pyobject_is_freed("check_pyobject_null_is_freed", op);
+}
+
+
+static PyObject *
+check_pyobject_uninitialized_is_freed(PyObject *self,
+                                      PyObject *Py_UNUSED(args))
+{
+    PyObject *op = (PyObject *)PyObject_Malloc(sizeof(PyObject));
+    if (op == NULL) {
+        return NULL;
+    }
+    /* Initialize reference count to avoid early crash in ceval or GC */
+    Py_SET_REFCNT(op, 1);
+    /* object fields like ob_type are uninitialized! */
+    return test_pyobject_is_freed("check_pyobject_uninitialized_is_freed", op);
+}
+
+
+static PyObject *
+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));
+    if (op == NULL) {
+        return NULL;
+    }
+    /* Initialize reference count to avoid early crash in ceval or GC */
+    Py_SET_REFCNT(op, 1);
+    /* ob_type field is after the memory block: part of "forbidden bytes"
+       when using debug hooks on memory allocators! */
+    return test_pyobject_is_freed("check_pyobject_forbidden_bytes_is_freed", op);
+}
+
+
+static PyObject *
+check_pyobject_freed_is_freed(PyObject *self, PyObject *Py_UNUSED(args))
+{
+    /* This test would fail if run with the address sanitizer */
+#ifdef _Py_ADDRESS_SANITIZER
+    Py_RETURN_NONE;
+#else
+    PyObject *op = PyObject_CallNoArgs((PyObject *)&PyBaseObject_Type);
+    if (op == NULL) {
+        return NULL;
+    }
+    Py_TYPE(op)->tp_dealloc(op);
+    /* Reset reference count to avoid early crash in ceval or GC */
+    Py_SET_REFCNT(op, 1);
+    /* object memory is freed! */
+    return test_pyobject_is_freed("check_pyobject_freed_is_freed", op);
+#endif
+}
+
+static PyMethodDef test_methods[] = {
+    {"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},
+    {"check_pyobject_null_is_freed",  check_pyobject_null_is_freed,  METH_NOARGS},
+    {"check_pyobject_uninitialized_is_freed",
+                              check_pyobject_uninitialized_is_freed, METH_NOARGS},
+    {"pymem_api_misuse",              pymem_api_misuse,              METH_NOARGS},
+    {"pymem_buffer_overflow",         pymem_buffer_overflow,         METH_NOARGS},
+    {"pymem_getallocatorsname",       test_pymem_getallocatorsname,  METH_NOARGS},
+    {"pymem_malloc_without_gil",      pymem_malloc_without_gil,      METH_NOARGS},
+    {"pyobject_malloc_without_gil",   pyobject_malloc_without_gil,   METH_NOARGS},
+    {"remove_mem_hooks",              remove_mem_hooks,              METH_NOARGS,
+        PyDoc_STR("Remove memory hooks.")},
+    {"set_nomemory",                  (PyCFunction)set_nomemory,     METH_VARARGS,
+        PyDoc_STR("set_nomemory(start:int, stop:int = 0)")},
+    {"test_pymem_alloc0",             test_pymem_alloc0,             METH_NOARGS},
+    {"test_pymem_setallocators",      test_pymem_setallocators,      METH_NOARGS},
+    {"test_pymem_setrawallocators",   test_pymem_setrawallocators,   METH_NOARGS},
+    {"test_pyobject_new",             test_pyobject_new,             METH_NOARGS},
+    {"test_pyobject_setallocators",   test_pyobject_setallocators,   METH_NOARGS},
+    {NULL},
+};
+
+int
+_PyTestCapi_Init_Mem(PyObject *mod)
+{
+    if (PyModule_AddFunctions(mod, test_methods) < 0) {
+        return -1;
+    }
+
+    PyObject *v;
+#ifdef WITH_PYMALLOC
+    v = Py_NewRef(Py_True);
+#else
+    v = Py_NewRef(Py_False);
+#endif
+    int rc = PyModule_AddObjectRef(mod, "WITH_PYMALLOC", v);
+    Py_DECREF(v);
+    if (rc < 0) {
+        return -1;
+    }
+
+    return 0;
+}
diff --git a/Modules/_testcapi/parts.h b/Modules/_testcapi/parts.h
index 2fa8dac..a39007b 100644
--- a/Modules/_testcapi/parts.h
+++ b/Modules/_testcapi/parts.h
@@ -30,6 +30,8 @@ int _PyTestCapi_Init_Unicode(PyObject *module);
 int _PyTestCapi_Init_GetArgs(PyObject *module);
 int _PyTestCapi_Init_PyTime(PyObject *module);
 int _PyTestCapi_Init_DateTime(PyObject *module);
+int _PyTestCapi_Init_Docstring(PyObject *module);
+int _PyTestCapi_Init_Mem(PyObject *module);
 
 #ifdef LIMITED_API_AVAILABLE
 int _PyTestCapi_Init_VectorcallLimited(PyObject *module);
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 79beb1c..2c21782 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -1438,13 +1438,6 @@ pending_threadfunc(PyObject *self, PyObject *arg)
     Py_RETURN_TRUE;
 }
 
-/* This is here to provide a docstring for test_descr. */
-static PyObject *
-test_with_docstring(PyObject *self, PyObject *Py_UNUSED(ignored))
-{
-    Py_RETURN_NONE;
-}
-
 /* Test PyOS_string_to_double. */
 static PyObject *
 test_string_to_double(PyObject *self, PyObject *Py_UNUSED(ignored)) {
@@ -2340,471 +2333,6 @@ test_incref_decref_API(PyObject *ob, PyObject *Py_UNUSED(ignored))
     Py_RETURN_NONE;
 }
 
-static PyObject *
-test_pymem_alloc0(PyObject *self, PyObject *Py_UNUSED(ignored))
-{
-    void *ptr;
-
-    ptr = PyMem_RawMalloc(0);
-    if (ptr == NULL) {
-        PyErr_SetString(PyExc_RuntimeError, "PyMem_RawMalloc(0) returns NULL");
-        return NULL;
-    }
-    PyMem_RawFree(ptr);
-
-    ptr = PyMem_RawCalloc(0, 0);
-    if (ptr == NULL) {
-        PyErr_SetString(PyExc_RuntimeError, "PyMem_RawCalloc(0, 0) returns NULL");
-        return NULL;
-    }
-    PyMem_RawFree(ptr);
-
-    ptr = PyMem_Malloc(0);
-    if (ptr == NULL) {
-        PyErr_SetString(PyExc_RuntimeError, "PyMem_Malloc(0) returns NULL");
-        return NULL;
-    }
-    PyMem_Free(ptr);
-
-    ptr = PyMem_Calloc(0, 0);
-    if (ptr == NULL) {
-        PyErr_SetString(PyExc_RuntimeError, "PyMem_Calloc(0, 0) returns NULL");
-        return NULL;
-    }
-    PyMem_Free(ptr);
-
-    ptr = PyObject_Malloc(0);
-    if (ptr == NULL) {
-        PyErr_SetString(PyExc_RuntimeError, "PyObject_Malloc(0) returns NULL");
-        return NULL;
-    }
-    PyObject_Free(ptr);
-
-    ptr = PyObject_Calloc(0, 0);
-    if (ptr == NULL) {
-        PyErr_SetString(PyExc_RuntimeError, "PyObject_Calloc(0, 0) returns NULL");
-        return NULL;
-    }
-    PyObject_Free(ptr);
-
-    Py_RETURN_NONE;
-}
-
-static PyObject *
-test_pyobject_new(PyObject *self, PyObject *Py_UNUSED(ignored))
-{
-    PyObject *obj;
-    PyTypeObject *type = &PyBaseObject_Type;
-    PyTypeObject *var_type = &PyLong_Type;
-
-    // PyObject_New()
-    obj = PyObject_New(PyObject, type);
-    if (obj == NULL) {
-        goto alloc_failed;
-    }
-    Py_DECREF(obj);
-
-    // PyObject_NEW()
-    obj = PyObject_NEW(PyObject, type);
-    if (obj == NULL) {
-        goto alloc_failed;
-    }
-    Py_DECREF(obj);
-
-    // PyObject_NewVar()
-    obj = PyObject_NewVar(PyObject, var_type, 3);
-    if (obj == NULL) {
-        goto alloc_failed;
-    }
-    Py_DECREF(obj);
-
-    // PyObject_NEW_VAR()
-    obj = PyObject_NEW_VAR(PyObject, var_type, 3);
-    if (obj == NULL) {
-        goto alloc_failed;
-    }
-    Py_DECREF(obj);
-
-    Py_RETURN_NONE;
-
-alloc_failed:
-    PyErr_NoMemory();
-    return NULL;
-}
-
-typedef struct {
-    PyMemAllocatorEx alloc;
-
-    size_t malloc_size;
-    size_t calloc_nelem;
-    size_t calloc_elsize;
-    void *realloc_ptr;
-    size_t realloc_new_size;
-    void *free_ptr;
-    void *ctx;
-} alloc_hook_t;
-
-static void* hook_malloc(void* ctx, size_t size)
-{
-    alloc_hook_t *hook = (alloc_hook_t *)ctx;
-    hook->ctx = ctx;
-    hook->malloc_size = size;
-    return hook->alloc.malloc(hook->alloc.ctx, size);
-}
-
-static void* hook_calloc(void* ctx, size_t nelem, size_t elsize)
-{
-    alloc_hook_t *hook = (alloc_hook_t *)ctx;
-    hook->ctx = ctx;
-    hook->calloc_nelem = nelem;
-    hook->calloc_elsize = elsize;
-    return hook->alloc.calloc(hook->alloc.ctx, nelem, elsize);
-}
-
-static void* hook_realloc(void* ctx, void* ptr, size_t new_size)
-{
-    alloc_hook_t *hook = (alloc_hook_t *)ctx;
-    hook->ctx = ctx;
-    hook->realloc_ptr = ptr;
-    hook->realloc_new_size = new_size;
-    return hook->alloc.realloc(hook->alloc.ctx, ptr, new_size);
-}
-
-static void hook_free(void *ctx, void *ptr)
-{
-    alloc_hook_t *hook = (alloc_hook_t *)ctx;
-    hook->ctx = ctx;
-    hook->free_ptr = ptr;
-    hook->alloc.free(hook->alloc.ctx, ptr);
-}
-
-static PyObject *
-test_setallocators(PyMemAllocatorDomain domain)
-{
-    PyObject *res = NULL;
-    const char *error_msg;
-    alloc_hook_t hook;
-    PyMemAllocatorEx alloc;
-    size_t size, size2, nelem, elsize;
-    void *ptr, *ptr2;
-
-    memset(&hook, 0, sizeof(hook));
-
-    alloc.ctx = &hook;
-    alloc.malloc = &hook_malloc;
-    alloc.calloc = &hook_calloc;
-    alloc.realloc = &hook_realloc;
-    alloc.free = &hook_free;
-    PyMem_GetAllocator(domain, &hook.alloc);
-    PyMem_SetAllocator(domain, &alloc);
-
-    /* malloc, realloc, free */
-    size = 42;
-    hook.ctx = NULL;
-    switch(domain)
-    {
-    case PYMEM_DOMAIN_RAW: ptr = PyMem_RawMalloc(size); break;
-    case PYMEM_DOMAIN_MEM: ptr = PyMem_Malloc(size); break;
-    case PYMEM_DOMAIN_OBJ: ptr = PyObject_Malloc(size); break;
-    default: ptr = NULL; break;
-    }
-
-#define CHECK_CTX(FUNC) \
-    if (hook.ctx != &hook) { \
-        error_msg = FUNC " wrong context"; \
-        goto fail; \
-    } \
-    hook.ctx = NULL;  /* reset for next check */
-
-    if (ptr == NULL) {
-        error_msg = "malloc failed";
-        goto fail;
-    }
-    CHECK_CTX("malloc");
-    if (hook.malloc_size != size) {
-        error_msg = "malloc invalid size";
-        goto fail;
-    }
-
-    size2 = 200;
-    switch(domain)
-    {
-    case PYMEM_DOMAIN_RAW: ptr2 = PyMem_RawRealloc(ptr, size2); break;
-    case PYMEM_DOMAIN_MEM: ptr2 = PyMem_Realloc(ptr, size2); break;
-    case PYMEM_DOMAIN_OBJ: ptr2 = PyObject_Realloc(ptr, size2); break;
-    default: ptr2 = NULL; break;
-    }
-
-    if (ptr2 == NULL) {
-        error_msg = "realloc failed";
-        goto fail;
-    }
-    CHECK_CTX("realloc");
-    if (hook.realloc_ptr != ptr
-        || hook.realloc_new_size != size2) {
-        error_msg = "realloc invalid parameters";
-        goto fail;
-    }
-
-    switch(domain)
-    {
-    case PYMEM_DOMAIN_RAW: PyMem_RawFree(ptr2); break;
-    case PYMEM_DOMAIN_MEM: PyMem_Free(ptr2); break;
-    case PYMEM_DOMAIN_OBJ: PyObject_Free(ptr2); break;
-    }
-
-    CHECK_CTX("free");
-    if (hook.free_ptr != ptr2) {
-        error_msg = "free invalid pointer";
-        goto fail;
-    }
-
-    /* calloc, free */
-    nelem = 2;
-    elsize = 5;
-    switch(domain)
-    {
-    case PYMEM_DOMAIN_RAW: ptr = PyMem_RawCalloc(nelem, elsize); break;
-    case PYMEM_DOMAIN_MEM: ptr = PyMem_Calloc(nelem, elsize); break;
-    case PYMEM_DOMAIN_OBJ: ptr = PyObject_Calloc(nelem, elsize); break;
-    default: ptr = NULL; break;
-    }
-
-    if (ptr == NULL) {
-        error_msg = "calloc failed";
-        goto fail;
-    }
-    CHECK_CTX("calloc");
-    if (hook.calloc_nelem != nelem || hook.calloc_elsize != elsize) {
-        error_msg = "calloc invalid nelem or elsize";
-        goto fail;
-    }
-
-    hook.free_ptr = NULL;
-    switch(domain)
-    {
-    case PYMEM_DOMAIN_RAW: PyMem_RawFree(ptr); break;
-    case PYMEM_DOMAIN_MEM: PyMem_Free(ptr); break;
-    case PYMEM_DOMAIN_OBJ: PyObject_Free(ptr); break;
-    }
-
-    CHECK_CTX("calloc free");
-    if (hook.free_ptr != ptr) {
-        error_msg = "calloc free invalid pointer";
-        goto fail;
-    }
-
-    res = Py_NewRef(Py_None);
-    goto finally;
-
-fail:
-    PyErr_SetString(PyExc_RuntimeError, error_msg);
-
-finally:
-    PyMem_SetAllocator(domain, &hook.alloc);
-    return res;
-
-#undef CHECK_CTX
-}
-
-static PyObject *
-test_pymem_setrawallocators(PyObject *self, PyObject *Py_UNUSED(ignored))
-{
-    return test_setallocators(PYMEM_DOMAIN_RAW);
-}
-
-static PyObject *
-test_pymem_setallocators(PyObject *self, PyObject *Py_UNUSED(ignored))
-{
-    return test_setallocators(PYMEM_DOMAIN_MEM);
-}
-
-static PyObject *
-test_pyobject_setallocators(PyObject *self, PyObject *Py_UNUSED(ignored))
-{
-    return test_setallocators(PYMEM_DOMAIN_OBJ);
-}
-
-/* Most part of the following code is inherited from the pyfailmalloc project
- * written by Victor Stinner. */
-static struct {
-    int installed;
-    PyMemAllocatorEx raw;
-    PyMemAllocatorEx mem;
-    PyMemAllocatorEx obj;
-} FmHook;
-
-static struct {
-    int start;
-    int stop;
-    Py_ssize_t count;
-} FmData;
-
-static int
-fm_nomemory(void)
-{
-    FmData.count++;
-    if (FmData.count > FmData.start &&
-            (FmData.stop <= 0 || FmData.count <= FmData.stop)) {
-        return 1;
-    }
-    return 0;
-}
-
-static void *
-hook_fmalloc(void *ctx, size_t size)
-{
-    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-    if (fm_nomemory()) {
-        return NULL;
-    }
-    return alloc->malloc(alloc->ctx, size);
-}
-
-static void *
-hook_fcalloc(void *ctx, size_t nelem, size_t elsize)
-{
-    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-    if (fm_nomemory()) {
-        return NULL;
-    }
-    return alloc->calloc(alloc->ctx, nelem, elsize);
-}
-
-static void *
-hook_frealloc(void *ctx, void *ptr, size_t new_size)
-{
-    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-    if (fm_nomemory()) {
-        return NULL;
-    }
-    return alloc->realloc(alloc->ctx, ptr, new_size);
-}
-
-static void
-hook_ffree(void *ctx, void *ptr)
-{
-    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-    alloc->free(alloc->ctx, ptr);
-}
-
-static void
-fm_setup_hooks(void)
-{
-    PyMemAllocatorEx alloc;
-
-    if (FmHook.installed) {
-        return;
-    }
-    FmHook.installed = 1;
-
-    alloc.malloc = hook_fmalloc;
-    alloc.calloc = hook_fcalloc;
-    alloc.realloc = hook_frealloc;
-    alloc.free = hook_ffree;
-    PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &FmHook.raw);
-    PyMem_GetAllocator(PYMEM_DOMAIN_MEM, &FmHook.mem);
-    PyMem_GetAllocator(PYMEM_DOMAIN_OBJ, &FmHook.obj);
-
-    alloc.ctx = &FmHook.raw;
-    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &alloc);
-
-    alloc.ctx = &FmHook.mem;
-    PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &alloc);
-
-    alloc.ctx = &FmHook.obj;
-    PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &alloc);
-}
-
-static void
-fm_remove_hooks(void)
-{
-    if (FmHook.installed) {
-        FmHook.installed = 0;
-        PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &FmHook.raw);
-        PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &FmHook.mem);
-        PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &FmHook.obj);
-    }
-}
-
-static PyObject*
-set_nomemory(PyObject *self, PyObject *args)
-{
-    /* Memory allocation fails after 'start' allocation requests, and until
-     * 'stop' allocation requests except when 'stop' is negative or equal
-     * to 0 (default) in which case allocation failures never stop. */
-    FmData.count = 0;
-    FmData.stop = 0;
-    if (!PyArg_ParseTuple(args, "i|i", &FmData.start, &FmData.stop)) {
-        return NULL;
-    }
-    fm_setup_hooks();
-    Py_RETURN_NONE;
-}
-
-static PyObject*
-remove_mem_hooks(PyObject *self, PyObject *Py_UNUSED(ignored))
-{
-    fm_remove_hooks();
-    Py_RETURN_NONE;
-}
-
-PyDoc_STRVAR(docstring_empty,
-""
-);
-
-PyDoc_STRVAR(docstring_no_signature,
-"This docstring has no signature."
-);
-
-PyDoc_STRVAR(docstring_with_invalid_signature,
-"docstring_with_invalid_signature($module, /, boo)\n"
-"\n"
-"This docstring has an invalid signature."
-);
-
-PyDoc_STRVAR(docstring_with_invalid_signature2,
-"docstring_with_invalid_signature2($module, /, boo)\n"
-"\n"
-"--\n"
-"\n"
-"This docstring also has an invalid signature."
-);
-
-PyDoc_STRVAR(docstring_with_signature,
-"docstring_with_signature($module, /, sig)\n"
-"--\n"
-"\n"
-"This docstring has a valid signature."
-);
-
-PyDoc_STRVAR(docstring_with_signature_but_no_doc,
-"docstring_with_signature_but_no_doc($module, /, sig)\n"
-"--\n"
-"\n"
-);
-
-PyDoc_STRVAR(docstring_with_signature_and_extra_newlines,
-"docstring_with_signature_and_extra_newlines($module, /, parameter)\n"
-"--\n"
-"\n"
-"\n"
-"This docstring has a valid signature and some extra newlines."
-);
-
-PyDoc_STRVAR(docstring_with_signature_with_defaults,
-"docstring_with_signature_with_defaults(module, s='avocado',\n"
-"        b=b'bytes', d=3.14, i=35, n=None, t=True, f=False,\n"
-"        local=the_number_three, sys=sys.maxsize,\n"
-"        exp=sys.maxsize - 1)\n"
-"--\n"
-"\n"
-"\n"
-"\n"
-"This docstring has a valid signature with parameters,\n"
-"and the parameters take defaults of varying types."
-);
-
 typedef struct {
     PyThread_type_lock start_event;
     PyThread_type_lock exit_event;
@@ -3069,150 +2597,6 @@ getitem_with_error(PyObject *self, PyObject *args)
     return PyObject_GetItem(map, key);
 }
 
-static PyObject*
-pymem_buffer_overflow(PyObject *self, PyObject *args)
-{
-    char *buffer;
-
-    /* Deliberate buffer overflow to check that PyMem_Free() detects
-       the overflow when debug hooks are installed. */
-    buffer = PyMem_Malloc(16);
-    if (buffer == NULL) {
-        PyErr_NoMemory();
-        return NULL;
-    }
-    buffer[16] = 'x';
-    PyMem_Free(buffer);
-
-    Py_RETURN_NONE;
-}
-
-static PyObject*
-pymem_api_misuse(PyObject *self, PyObject *args)
-{
-    char *buffer;
-
-    /* Deliberate misusage of Python allocators:
-       allococate with PyMem but release with PyMem_Raw. */
-    buffer = PyMem_Malloc(16);
-    PyMem_RawFree(buffer);
-
-    Py_RETURN_NONE;
-}
-
-static PyObject*
-pymem_malloc_without_gil(PyObject *self, PyObject *args)
-{
-    char *buffer;
-
-    /* Deliberate bug to test debug hooks on Python memory allocators:
-       call PyMem_Malloc() without holding the GIL */
-    Py_BEGIN_ALLOW_THREADS
-    buffer = PyMem_Malloc(10);
-    Py_END_ALLOW_THREADS
-
-    PyMem_Free(buffer);
-
-    Py_RETURN_NONE;
-}
-
-
-static PyObject*
-test_pymem_getallocatorsname(PyObject *self, PyObject *args)
-{
-    const char *name = _PyMem_GetCurrentAllocatorName();
-    if (name == NULL) {
-        PyErr_SetString(PyExc_RuntimeError, "cannot get allocators name");
-        return NULL;
-    }
-    return PyUnicode_FromString(name);
-}
-
-
-static PyObject*
-test_pyobject_is_freed(const char *test_name, PyObject *op)
-{
-    if (!_PyObject_IsFreed(op)) {
-        return raiseTestError(test_name, "object is not seen as freed");
-    }
-    Py_RETURN_NONE;
-}
-
-
-static PyObject*
-check_pyobject_null_is_freed(PyObject *self, PyObject *Py_UNUSED(args))
-{
-    PyObject *op = NULL;
-    return test_pyobject_is_freed("check_pyobject_null_is_freed", op);
-}
-
-
-static PyObject*
-check_pyobject_uninitialized_is_freed(PyObject *self, PyObject *Py_UNUSED(args))
-{
-    PyObject *op = (PyObject *)PyObject_Malloc(sizeof(PyObject));
-    if (op == NULL) {
-        return NULL;
-    }
-    /* Initialize reference count to avoid early crash in ceval or GC */
-    Py_SET_REFCNT(op, 1);
-    /* object fields like ob_type are uninitialized! */
-    return test_pyobject_is_freed("check_pyobject_uninitialized_is_freed", op);
-}
-
-
-static PyObject*
-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));
-    if (op == NULL) {
-        return NULL;
-    }
-    /* Initialize reference count to avoid early crash in ceval or GC */
-    Py_SET_REFCNT(op, 1);
-    /* ob_type field is after the memory block: part of "forbidden bytes"
-       when using debug hooks on memory allocators! */
-    return test_pyobject_is_freed("check_pyobject_forbidden_bytes_is_freed", op);
-}
-
-
-static PyObject*
-check_pyobject_freed_is_freed(PyObject *self, PyObject *Py_UNUSED(args))
-{
-    /* This test would fail if run with the address sanitizer */
-#ifdef _Py_ADDRESS_SANITIZER
-    Py_RETURN_NONE;
-#else
-    PyObject *op = PyObject_CallNoArgs((PyObject *)&PyBaseObject_Type);
-    if (op == NULL) {
-        return NULL;
-    }
-    Py_TYPE(op)->tp_dealloc(op);
-    /* Reset reference count to avoid early crash in ceval or GC */
-    Py_SET_REFCNT(op, 1);
-    /* object memory is freed! */
-    return test_pyobject_is_freed("check_pyobject_freed_is_freed", op);
-#endif
-}
-
-
-static PyObject*
-pyobject_malloc_without_gil(PyObject *self, PyObject *args)
-{
-    char *buffer;
-
-    /* Deliberate bug to test debug hooks on Python memory allocators:
-       call PyObject_Malloc() without holding the GIL */
-    Py_BEGIN_ALLOW_THREADS
-    buffer = PyObject_Malloc(10);
-    Py_END_ALLOW_THREADS
-
-    PyObject_Free(buffer);
-
-    Py_RETURN_NONE;
-}
-
 static PyObject *
 tracemalloc_track(PyObject *self, PyObject *args)
 {
@@ -4758,8 +4142,6 @@ static PyMethodDef TestMethods[] = {
     {"pyobject_repr_from_null", pyobject_repr_from_null, METH_NOARGS},
     {"pyobject_str_from_null",  pyobject_str_from_null, METH_NOARGS},
     {"pyobject_bytes_from_null", pyobject_bytes_from_null, METH_NOARGS},
-    {"test_with_docstring",     test_with_docstring,             METH_NOARGS,
-     PyDoc_STR("This is a pretty normal docstring.")},
     {"test_string_to_double",   test_string_to_double,           METH_NOARGS},
     {"test_capsule", (PyCFunction)test_capsule, METH_NOARGS},
     {"test_from_contiguous", (PyCFunction)test_from_contiguous, METH_NOARGS},
@@ -4797,41 +4179,6 @@ static PyMethodDef TestMethods[] = {
      METH_VARARGS | METH_KEYWORDS},
     {"with_tp_del",             with_tp_del,                     METH_VARARGS},
     {"create_cfunction",        create_cfunction,                METH_NOARGS},
-    {"test_pymem_alloc0",       test_pymem_alloc0,               METH_NOARGS},
-    {"test_pyobject_new",       test_pyobject_new,               METH_NOARGS},
-    {"test_pymem_setrawallocators",test_pymem_setrawallocators,  METH_NOARGS},
-    {"test_pymem_setallocators",test_pymem_setallocators,        METH_NOARGS},
-    {"test_pyobject_setallocators",test_pyobject_setallocators,  METH_NOARGS},
-    {"set_nomemory", (PyCFunction)set_nomemory, METH_VARARGS,
-     PyDoc_STR("set_nomemory(start:int, stop:int = 0)")},
-    {"remove_mem_hooks",        remove_mem_hooks,                METH_NOARGS,
-     PyDoc_STR("Remove memory hooks.")},
-    {"no_docstring",
-        (PyCFunction)test_with_docstring, METH_NOARGS},
-    {"docstring_empty",
-        (PyCFunction)test_with_docstring, METH_NOARGS,
-        docstring_empty},
-    {"docstring_no_signature",
-        (PyCFunction)test_with_docstring, METH_NOARGS,
-        docstring_no_signature},
-    {"docstring_with_invalid_signature",
-        (PyCFunction)test_with_docstring, METH_NOARGS,
-        docstring_with_invalid_signature},
-    {"docstring_with_invalid_signature2",
-        (PyCFunction)test_with_docstring, METH_NOARGS,
-        docstring_with_invalid_signature2},
-    {"docstring_with_signature",
-        (PyCFunction)test_with_docstring, METH_NOARGS,
-        docstring_with_signature},
-    {"docstring_with_signature_but_no_doc",
-        (PyCFunction)test_with_docstring, METH_NOARGS,
-        docstring_with_signature_but_no_doc},
-    {"docstring_with_signature_and_extra_newlines",
-        (PyCFunction)test_with_docstring, METH_NOARGS,
-        docstring_with_signature_and_extra_newlines},
-    {"docstring_with_signature_with_defaults",
-        (PyCFunction)test_with_docstring, METH_NOARGS,
-        docstring_with_signature_with_defaults},
     {"call_in_temporary_c_thread", call_in_temporary_c_thread, METH_O,
      PyDoc_STR("set_error_class(error_class) -> None")},
     {"pymarshal_write_long_to_file",
@@ -4850,15 +4197,6 @@ static PyMethodDef TestMethods[] = {
     {"return_result_with_error", return_result_with_error, METH_NOARGS},
     {"getitem_with_error", getitem_with_error, METH_VARARGS},
     {"Py_CompileString",     pycompilestring, METH_O},
-    {"pymem_buffer_overflow", pymem_buffer_overflow, METH_NOARGS},
-    {"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},
-    {"check_pyobject_null_is_freed", check_pyobject_null_is_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},
     {"tracemalloc_get_traceback", tracemalloc_get_traceback, METH_VARARGS},
@@ -5720,14 +5058,6 @@ PyInit__testcapi(void)
     PyModule_AddObject(m, "instancemethod", (PyObject *)&PyInstanceMethod_Type);
 
     PyModule_AddIntConstant(m, "the_number_three", 3);
-    PyObject *v;
-#ifdef WITH_PYMALLOC
-    v = Py_True;
-#else
-    v = Py_False;
-#endif
-    Py_INCREF(v);
-    PyModule_AddObject(m, "WITH_PYMALLOC", v);
 
     TestError = PyErr_NewException("_testcapi.error", NULL, NULL);
     Py_INCREF(TestError);
@@ -5760,6 +5090,12 @@ PyInit__testcapi(void)
     if (_PyTestCapi_Init_DateTime(m) < 0) {
         return NULL;
     }
+    if (_PyTestCapi_Init_Docstring(m) < 0) {
+        return NULL;
+    }
+    if (_PyTestCapi_Init_Mem(m) < 0) {
+        return NULL;
+    }
 
 #ifndef LIMITED_API_AVAILABLE
     PyModule_AddObjectRef(m, "LIMITED_API_AVAILABLE", Py_False);
diff --git a/PCbuild/_testcapi.vcxproj b/PCbuild/_testcapi.vcxproj
index 90b951c..0151d85 100644
--- a/PCbuild/_testcapi.vcxproj
+++ b/PCbuild/_testcapi.vcxproj
@@ -101,6 +101,8 @@
     <ClCompile Include="..\Modules\_testcapi\unicode.c" />
     <ClCompile Include="..\Modules\_testcapi\pytime.c" />
     <ClCompile Include="..\Modules\_testcapi\datetime.c" />
+    <ClCompile Include="..\Modules\_testcapi\docstring.c" />
+    <ClCompile Include="..\Modules\_testcapi\mem.c" />
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="..\PC\python_nt.rc" />
diff --git a/PCbuild/_testcapi.vcxproj.filters b/PCbuild/_testcapi.vcxproj.filters
index 504898d..c30c41b 100644
--- a/PCbuild/_testcapi.vcxproj.filters
+++ b/PCbuild/_testcapi.vcxproj.filters
@@ -33,6 +33,12 @@
     <ClCompile Include="..\Modules\_testcapi\datetime.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\Modules\_testcapi\docstring.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
+    <ClCompile Include="..\Modules\_testcapi\mem.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="..\PC\python_nt.rc">