Update function parameter types to always be PyObject *

Standard Python dev practice has been to use the "subclass" C type
for the self parameter.  The methods are called with PyObject * as the
type.  This does not cause any problems.

Except control flow integrity is now available.  It requires that
the types and parameters of a called function match exactly, and if
not will fail.  clangs undefined sanitizer warns about these.

CPython fixed their own calls in 3.14 - see
python/cpython#111178

This large change corrects the self parameter to PyObject * and
then casts to the useful type in the body.  It also adds the various
unused closure parameters.  It won't cause any code generation changes.

Refs #498

Author: rogerbinns

src/apsw.c

@@ -273,7 +273,7 @@ static int allow_missing_dict_bindings = 0;
 */
 
 static PyObject *
-get_sqlite_version(void)
+get_sqlite_version(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(unused))
 {
   return PyUnicode_FromString(sqlite3_libversion());
 }
@@ -287,7 +287,7 @@ get_sqlite_version(void)
 */
 
 static PyObject *
-get_sqlite3_sourceid(void)
+get_sqlite3_sourceid(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(unused))
 {
   return PyUnicode_FromString(sqlite3_sourceid());
 }
@@ -297,7 +297,7 @@ get_sqlite3_sourceid(void)
   Returns the APSW version.
 */
 static PyObject *
-get_apsw_version(void)
+get_apsw_version(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(unused))
 {
   return PyUnicode_FromString(APSW_VERSION);
 }
@@ -340,7 +340,7 @@ enable_shared_cache(PyObject *Py_UNUSED(self), PyObject *const *fast_args, Py_ss
 */
 static PyObject *the_connections;
 static PyObject *
-apsw_connections(PyObject *Py_UNUSED(self))
+apsw_connections(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(unused))
 {
   Py_ssize_t i;
   PyObject *res = PyList_New(0), *item = NULL;
@@ -408,7 +408,7 @@ apsw_connection_add(Connection *con)
 */
 
 static PyObject *
-initialize(void)
+initialize(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(unused))
 {
   int res;
 
@@ -435,7 +435,7 @@ static void free_fork_checker(void);
 #endif
 
 static PyObject *
-sqliteshutdown(void)
+sqliteshutdown(PyObject *Py_UNUSED(unused1), PyObject *Py_UNUSED(unused2))
 {
   int res;
 
@@ -623,7 +623,7 @@ apsw_config(PyObject *Py_UNUSED(self), PyObject *args)
   -* sqlite3_memory_used
 */
 static PyObject *
-memory_used(void)
+memory_used(PyObject *Py_UNUSED(unused1), PyObject *Py_UNUSED(unused2))
 {
   return PyLong_FromLongLong(sqlite3_memory_used());
 }
@@ -805,7 +805,7 @@ status(PyObject *Py_UNUSED(self), PyObject *const *fast_args, Py_ssize_t fast_na
   -* sqlite3_vfs_find
 */
 static PyObject *
-vfs_names(PyObject *Py_UNUSED(self))
+vfs_names(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(unused))
 {
   PyObject *result = NULL, *str = NULL;
   int res;
@@ -866,7 +866,7 @@ Pointers are converted using :c:func:`PyLong_FromVoidPtr`.
 -* sqlite3_vfs_find
 */
 static PyObject *
-vfs_details(PyObject *Py_UNUSED(self))
+vfs_details(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(unused))
 {
   PyObject *result, *dict;
   sqlite3_vfs *vfs = sqlite3_vfs_find(0);
@@ -1008,7 +1008,7 @@ apswcomplete(PyObject *Py_UNUSED(self), PyObject *const *fast_args, Py_ssize_t f
 
 #if defined(APSW_DEBUG) || defined(APSW_FAULT_INJECT)
 static PyObject *
-apsw_fini(PyObject *Py_UNUSED(self))
+apsw_fini(PyObject *Py_UNUSED(self), PyObject *Py_UNUSED(unused))
 {
   fini_apsw_strings();
   Py_RETURN_NONE;
@@ -1811,13 +1811,13 @@ apsw_getattr(PyObject *Py_UNUSED(module), PyObject *name)
 
 static PyMethodDef module_methods[] = {
   { "sqlite3_sourceid", (PyCFunction)get_sqlite3_sourceid, METH_NOARGS, Apsw_sqlite3_sourceid_DOC },
-  { "sqlite_lib_version", (PyCFunction)get_sqlite_version, METH_NOARGS, Apsw_sqlite_lib_version_DOC },
-  { "apsw_version", (PyCFunction)get_apsw_version, METH_NOARGS, Apsw_apsw_version_DOC },
+  { "sqlite_lib_version", get_sqlite_version, METH_NOARGS, Apsw_sqlite_lib_version_DOC },
+  { "apsw_version", get_apsw_version, METH_NOARGS, Apsw_apsw_version_DOC },
   { "vfs_names", (PyCFunction)vfs_names, METH_NOARGS, Apsw_vfs_names_DOC },
   { "vfs_details", (PyCFunction)vfs_details, METH_NOARGS, Apsw_vfs_details_DOC },
   { "enable_shared_cache", (PyCFunction)enable_shared_cache, METH_FASTCALL | METH_KEYWORDS,
     Apsw_enable_shared_cache_DOC },
-  { "initialize", (PyCFunction)initialize, METH_NOARGS, Apsw_initialize_DOC },
+  { "initialize", initialize, METH_NOARGS, Apsw_initialize_DOC },
   { "shutdown", (PyCFunction)sqliteshutdown, METH_NOARGS, Apsw_shutdown_DOC },
   { "format_sql_value", (PyCFunction)formatsqlvalue, METH_O, Apsw_format_sql_value_DOC },
   { "config", (PyCFunction)apsw_config, METH_VARARGS, Apsw_config_DOC },
@@ -1900,11 +1900,11 @@ PyInit_apsw(void)
       || PyType_Ready(&APSWFTS5TokenizerType) < 0 || PyType_Ready(&APSWFTS5ExtensionAPIType) < 0
       || PyType_Ready(&PyObjectBindType) < 0
 #ifdef SQLITE_ENABLE_SESSION
-      || PyType_Ready(&APSWSessionType) <0  || PyType_Ready(&APSWTableChangeType) <0
-      || PyType_Ready(&APSWChangesetType) <0 || PyType_Ready(&APSWChangesetBuilderType) <0
-      || PyType_Ready(&APSWChangesetIteratorType) <0  || PyType_Ready(&APSWRebaserType) <0
+      || PyType_Ready(&APSWSessionType) < 0 || PyType_Ready(&APSWTableChangeType) < 0
+      || PyType_Ready(&APSWChangesetType) < 0 || PyType_Ready(&APSWChangesetBuilderType) < 0
+      || PyType_Ready(&APSWChangesetIteratorType) < 0 || PyType_Ready(&APSWRebaserType) < 0
 #endif
-      )
+  )
     goto fail;
 
   /* PyStructSequence_NewType is broken in some Pythons

src/apsw.docstrings

@@ -3666,6 +3666,13 @@
 "\n" \
 "Calls: `sqlite3session_changeset <https://sqlite.org/session/sqlite3session_changeset.html>`__\n" 
 
+#define Session_changeset_KWNAMES NULL
+#define Session_changeset_USAGE "Session.changeset() -> bytes"
+
+#define Session_changeset_CHECK do { \
+} while(0)
+
+
 #define  Session_changeset_size_DOC ":type: int\n" \
 "\n" \
 "Returns upper limit on changeset size, but only if :meth:`Session.config`\n" \
@@ -3783,6 +3790,13 @@
 "\n" \
 "Calls: `sqlite3session_patchset <https://sqlite.org/session/sqlite3session_patchset.html>`__\n" 
 
+#define Session_patchset_KWNAMES NULL
+#define Session_patchset_USAGE "Session.patchset() -> bytes"
+
+#define Session_patchset_CHECK do { \
+} while(0)
+
+
 #define  Session_patchset_stream_DOC "patchset_stream($self,output)\n--\n\nSession.patchset_stream(output: SessionStreamOutput) -> None\n\n" \
 "Produces a patchset of the session so far in a stream\n" \
 "\n" \

src/backup.c

@@ -118,8 +118,9 @@ APSWBackup_close_internal(APSWBackup *self, int force)
 }
 
 static void
-APSWBackup_dealloc(APSWBackup *self)
+APSWBackup_dealloc(PyObject *self_)
 {
+  APSWBackup *self = (APSWBackup *)self_;
   APSW_CLEAR_WEAKREFS;
 
   if (self->backup)
@@ -152,8 +153,9 @@ APSWBackup_dealloc(APSWBackup *self)
   -* sqlite3_backup_step
 */
 static PyObject *
-APSWBackup_step(APSWBackup *self, PyObject *const *fast_args, Py_ssize_t fast_nargs, PyObject *fast_kwnames)
+APSWBackup_step(PyObject *self_, PyObject *const *fast_args, Py_ssize_t fast_nargs, PyObject *fast_kwnames)
 {
+  APSWBackup *self = (APSWBackup *)self_;
   int npages = -1, res;
 
   CHECK_BACKUP_CLOSED(NULL);
@@ -206,8 +208,9 @@ APSWBackup_step(APSWBackup *self, PyObject *const *fast_args, Py_ssize_t fast_na
   -* sqlite3_backup_finish
 */
 static PyObject *
-APSWBackup_finish(APSWBackup *self)
+APSWBackup_finish(PyObject *self_, PyObject *Py_UNUSED(unused))
 {
+  APSWBackup *self = (APSWBackup *)self_;
   int setexc;
 
   /* We handle CHECK_BACKUP_CLOSED internally */
@@ -233,8 +236,9 @@ APSWBackup_finish(APSWBackup *self)
   :param force: If true then any exceptions are ignored.
 */
 static PyObject *
-APSWBackup_close(APSWBackup *self, PyObject *const *fast_args, Py_ssize_t fast_nargs, PyObject *fast_kwnames)
+APSWBackup_close(PyObject *self_, PyObject *const *fast_args, Py_ssize_t fast_nargs, PyObject *fast_kwnames)
 {
+  APSWBackup *self = (APSWBackup *)self_;
   int force = 0, setexc;
 
   /* We handle CHECK_BACKUP_CLOSED internally */
@@ -266,9 +270,9 @@ APSWBackup_close(APSWBackup *self, PyObject *const *fast_args, Py_ssize_t fast_n
   -* sqlite3_backup_remaining
 */
 static PyObject *
-APSWBackup_get_remaining(APSWBackup *self, void *Py_UNUSED(ignored))
+APSWBackup_get_remaining(PyObject *self_, void *Py_UNUSED(ignored))
 {
-
+  APSWBackup *self = (APSWBackup *)self_;
   return PyLong_FromLong(self->backup ? sqlite3_backup_remaining(self->backup) : 0);
 }
 
@@ -283,9 +287,9 @@ APSWBackup_get_remaining(APSWBackup *self, void *Py_UNUSED(ignored))
   -* sqlite3_backup_pagecount
 */
 static PyObject *
-APSWBackup_get_page_count(APSWBackup *self, void *Py_UNUSED(ignored))
+APSWBackup_get_page_count(PyObject *self_, void *Py_UNUSED(ignored))
 {
-
+  APSWBackup *self = (APSWBackup *)self_;
   return PyLong_FromLong(self->backup ? sqlite3_backup_pagecount(self->backup) : 0);
 }
 
@@ -297,12 +301,12 @@ APSWBackup_get_page_count(APSWBackup *self, void *Py_UNUSED(ignored))
   is :meth:`finished <Backup.finish>`.
 */
 static PyObject *
-APSWBackup_enter(APSWBackup *self)
+APSWBackup_enter(PyObject *self_, PyObject *Py_UNUSED(ignored))
 {
-
+  APSWBackup *self = (APSWBackup *)self_;
   CHECK_BACKUP_CLOSED(NULL);
 
-  return Py_NewRef((PyObject *)self);
+  return Py_NewRef(self_);
 }
 
 /** .. method:: __exit__(etype: Optional[type[BaseException]], evalue: Optional[BaseException], etraceback: Optional[types.TracebackType]) -> Optional[bool]
@@ -311,8 +315,9 @@ APSWBackup_enter(APSWBackup *self)
   that the copy is :meth:`finished <Backup.finish>`.
 */
 static PyObject *
-APSWBackup_exit(APSWBackup *self, PyObject *const *fast_args, Py_ssize_t fast_nargs, PyObject *fast_kwnames)
+APSWBackup_exit(PyObject *self_, PyObject *const *fast_args, Py_ssize_t fast_nargs, PyObject *fast_kwnames)
 {
+  APSWBackup *self = (APSWBackup *)self_;
   PyObject *etype, *evalue, *etraceback;
   int setexc;
 
@@ -347,8 +352,9 @@ APSWBackup_exit(APSWBackup *self, PyObject *const *fast_args, Py_ssize_t fast_na
 }
 
 static PyObject *
-APSWBackup_tp_str(APSWBackup *self)
+APSWBackup_tp_str(PyObject *self_)
 {
+  APSWBackup *self = (APSWBackup *)self_;
   return PyUnicode_FromFormat("<apsw.Backup object from %S to %S at %p>",
                               self->source ? (PyObject *)self->source : apst.closed,
                               self->dest ? (PyObject *)self->dest : apst.closed, self);