Added frozen_utils module

frozen_utils is a module that exposes the modules (& submodules,
essentially all frozen python files) that were freezed with
the Python interpreter, including ones that have not been imported.

Author: roddyrap

Modules/Setup.stdlib.in

@@ -44,6 +44,7 @@
 @MODULE__XXSUBINTERPRETERS_TRUE@_xxsubinterpreters _xxsubinterpretersmodule.c
 @MODULE__XXINTERPCHANNELS_TRUE@_xxinterpchannels _xxinterpchannelsmodule.c
 @MODULE__ZONEINFO_TRUE@_zoneinfo _zoneinfo.c
+@MODULE_FROZEN_UTILS_TRUE@frozen_utils frozen_utils.c
 
 # needs libm
 @MODULE_AUDIOOP_TRUE@audioop audioop.c

Modules/frozen_utils.c

@@ -0,0 +1,77 @@
+#include "Python.h"
+#include "pycore_import.h"
+
+#include <string.h>
+
+PyDoc_STRVAR(frozen_utils__doc__,
+"Expose the modules that were frozen together with the Python interpreter");
+
+static int
+frozen_utils_exec(PyObject *module)
+{
+    return 0;
+}
+
+PyDoc_STRVAR(frozen_utils_get_frozen_modules__doc__,
+"get_frozen_modules() -> List[str]\n\nReturn all of the Python modules & submodules that have \
+been frozen with the Python interpreter.");
+
+int
+is_frozen_modules_end(const struct _frozen* current_frozen)
+{
+    // The array end in a _frozen instance that is completely zeroed out.
+    struct _frozen empty_frozen;
+    memset(&empty_frozen, 0, sizeof(struct _frozen));
+
+    return current_frozen == NULL || memcmp(&empty_frozen, current_frozen, sizeof(struct _frozen)) == 0;
+}
+
+void
+add_modules(PyObject *frozen_list, const struct _frozen* frozen_modules_start)
+{
+    const struct _frozen *current_frozen = NULL;
+    for (current_frozen = frozen_modules_start; !is_frozen_modules_end(current_frozen); current_frozen++)
+    {
+        PyObject *name_str = PyUnicode_FromString(current_frozen->name);
+        PyList_Append(frozen_list, name_str);
+    }
+}
+
+static PyObject *
+get_frozen_modules(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
+{
+    PyObject *frozen_modules_list = PyList_New(0);
+
+    add_modules(frozen_modules_list, _PyImport_FrozenBootstrap);
+    add_modules(frozen_modules_list, _PyImport_FrozenStdlib);
+    add_modules(frozen_modules_list, PyImport_FrozenModules);
+    add_modules(frozen_modules_list, _PyImport_FrozenTest);
+
+    return frozen_modules_list;
+}
+
+static PyMethodDef frozen_utils_methods[] = {
+    {"get_frozen_modules", _PyCFunction_CAST(get_frozen_modules), METH_FASTCALL, frozen_utils_get_frozen_modules__doc__},
+    {NULL, NULL}
+};
+
+static PyModuleDef_Slot frozen_utils_slots[] = {
+    {Py_mod_exec, frozen_utils_exec},
+    {Py_mod_multiple_interpreters, Py_MOD_PER_INTERPRETER_GIL_SUPPORTED},
+    {0, NULL}
+};
+
+static struct PyModuleDef frozen_utils_module = {
+    PyModuleDef_HEAD_INIT,
+    .m_name = "frozen_utils",
+    .m_doc = frozen_utils__doc__,
+    .m_size = 0,
+    .m_methods = frozen_utils_methods,
+    .m_slots = frozen_utils_slots,
+};
+
+PyMODINIT_FUNC
+PyInit_frozen_utils(void)
+{
+    return PyModuleDef_Init(&frozen_utils_module);
+}

PC/config.c

@@ -76,6 +76,7 @@ extern PyObject* PyInit__stat(void);
 extern PyObject* PyInit__opcode(void);
 extern PyObject* PyInit__contextvars(void);
 extern PyObject* PyInit__tokenize(void);
+extern PyObject* PyInit_frozen_utils(void);
 
 /* tools/freeze/makeconfig.py marker for additional "extern" */
 /* -- ADDMODULE MARKER 1 -- */
@@ -175,6 +176,7 @@ struct _inittab _PyImport_Inittab[] = {
     {"_opcode", PyInit__opcode},
 
     {"_contextvars", PyInit__contextvars},
+    {"frozen_utils", PyInit_frozen_utils},
 
     /* Sentinel */
     {0, 0}

configure

@@ -7410,6 +7410,7 @@ PY_STDLIB_MOD_SIMPLE([_typing])
 PY_STDLIB_MOD_SIMPLE([_xxsubinterpreters])
 PY_STDLIB_MOD_SIMPLE([_xxinterpchannels])
 PY_STDLIB_MOD_SIMPLE([_zoneinfo])
+PY_STDLIB_MOD_SIMPLE([frozen_utils])
 
 dnl multiprocessing modules
 PY_STDLIB_MOD([_multiprocessing],