bpo-40744: Drop support for SQLite pre 3.7.3 (GH-20909)

Remove code required to support SQLite pre 3.7.3.

Co-written-by: Berker Peksag <berker.peksag@gmail.com>
Co-written-by: Sergey Fedoseev <fedoseev.sergey@gmail.com>

2 files changed, 16 insertions, 66 deletions

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 1bf9710..f765ba1 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -33,16 +33,6 @@
 #define ACTION_FINALIZE 1
 #define ACTION_RESET 2
 
-#if SQLITE_VERSION_NUMBER >= 3003008
-#ifndef SQLITE_OMIT_LOAD_EXTENSION
-#define HAVE_LOAD_EXTENSION
-#endif
-#endif
-
-#if SQLITE_VERSION_NUMBER >= 3006011
-#define HAVE_BACKUP_API
-#endif
-
 #if SQLITE_VERSION_NUMBER >= 3014000
 #define HAVE_TRACE_V2
 #endif
@@ -61,18 +51,6 @@ static int pysqlite_connection_set_isolation_level(pysqlite_Connection* self, Py
 static void _pysqlite_drop_unused_cursor_references(pysqlite_Connection* self);
 
 
-static void _sqlite3_result_error(sqlite3_context* ctx, const char* errmsg, int len)
-{
-    /* in older SQLite versions, calling sqlite3_result_error in callbacks
-     * triggers a bug in SQLite that leads either to irritating results or
-     * segfaults, depending on the SQLite version */
-#if SQLITE_VERSION_NUMBER >= 3003003
-    sqlite3_result_error(ctx, errmsg, len);
-#else
-    PyErr_SetString(pysqlite_OperationalError, errmsg);
-#endif
-}
-
 int pysqlite_connection_init(pysqlite_Connection* self, PyObject* args, PyObject* kwargs)
 {
     static char *kwlist[] = {
@@ -182,10 +160,6 @@ int pysqlite_connection_init(pysqlite_Connection* self, PyObject* args, PyObject
     self->timeout = timeout;
     (void)sqlite3_busy_timeout(self->db, (int)(timeout*1000));
     self->thread_ident = PyThread_get_thread_ident();
-    if (!check_same_thread && sqlite3_libversion_number() < 3003001) {
-        PyErr_SetString(pysqlite_NotSupportedError, "shared connections not available");
-        return -1;
-    }
     self->check_same_thread = check_same_thread;
 
     self->function_pinboard_trace_callback = NULL;
@@ -620,7 +594,7 @@ void _pysqlite_func_callback(sqlite3_context* context, int argc, sqlite3_value**
         } else {
             PyErr_Clear();
         }
-        _sqlite3_result_error(context, "user-defined function raised exception", -1);
+        sqlite3_result_error(context, "user-defined function raised exception", -1);
     }
 
     PyGILState_Release(threadstate);
@@ -652,7 +626,7 @@ static void _pysqlite_step_callback(sqlite3_context *context, int argc, sqlite3_
             } else {
                 PyErr_Clear();
             }
-            _sqlite3_result_error(context, "user-defined aggregate's '__init__' method raised error", -1);
+            sqlite3_result_error(context, "user-defined aggregate's '__init__' method raised error", -1);
             goto error;
         }
     }
@@ -676,7 +650,7 @@ static void _pysqlite_step_callback(sqlite3_context *context, int argc, sqlite3_
         } else {
             PyErr_Clear();
         }
-        _sqlite3_result_error(context, "user-defined aggregate's 'step' method raised error", -1);
+        sqlite3_result_error(context, "user-defined aggregate's 'step' method raised error", -1);
     }
 
 error:
@@ -693,7 +667,6 @@ void _pysqlite_final_callback(sqlite3_context* context)
     _Py_IDENTIFIER(finalize);
     int ok;
     PyObject *exception, *value, *tb;
-    int restore;
 
     PyGILState_STATE threadstate;
 
@@ -709,7 +682,6 @@ void _pysqlite_final_callback(sqlite3_context* context)
 
     /* Keep the exception (if any) of the last call to step() */
     PyErr_Fetch(&exception, &value, &tb);
-    restore = 1;
 
     function_result = _PyObject_CallMethodIdNoArgs(*aggregate_instance, &PyId_finalize);
 
@@ -726,19 +698,12 @@ void _pysqlite_final_callback(sqlite3_context* context)
         } else {
             PyErr_Clear();
         }
-        _sqlite3_result_error(context, "user-defined aggregate's 'finalize' method raised error", -1);
-#if SQLITE_VERSION_NUMBER < 3003003
-        /* with old SQLite versions, _sqlite3_result_error() sets a new Python
-           exception, so don't restore the previous exception */
-        restore = 0;
-#endif
+        sqlite3_result_error(context, "user-defined aggregate's 'finalize' method raised error", -1);
     }
 
-    if (restore) {
-        /* Restore the exception (if any) of the last call to step(),
-           but clear also the current exception if finalize() failed */
-        PyErr_Restore(exception, value, tb);
-    }
+    /* Restore the exception (if any) of the last call to step(),
+       but clear also the current exception if finalize() failed */
+    PyErr_Restore(exception, value, tb);
 
 error:
     PyGILState_Release(threadstate);
@@ -1110,7 +1075,7 @@ static PyObject* pysqlite_connection_set_trace_callback(pysqlite_Connection* sel
     Py_RETURN_NONE;
 }
 
-#ifdef HAVE_LOAD_EXTENSION
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
 static PyObject* pysqlite_enable_load_extension(pysqlite_Connection* self, PyObject* args)
 {
     int rc;
@@ -1513,7 +1478,6 @@ finally:
     return retval;
 }
 
-#ifdef HAVE_BACKUP_API
 static PyObject *
 pysqlite_connection_backup(pysqlite_Connection *self, PyObject *args, PyObject *kwds)
 {
@@ -1664,7 +1628,6 @@ pysqlite_connection_backup(pysqlite_Connection *self, PyObject *args, PyObject *
         return NULL;
     }
 }
-#endif
 
 static PyObject *
 pysqlite_connection_create_collation(pysqlite_Connection* self, PyObject* args)
@@ -1816,7 +1779,7 @@ static PyMethodDef connection_methods[] = {
         PyDoc_STR("Creates a new aggregate. Non-standard.")},
     {"set_authorizer", (PyCFunction)(void(*)(void))pysqlite_connection_set_authorizer, METH_VARARGS|METH_KEYWORDS,
         PyDoc_STR("Sets authorizer callback. Non-standard.")},
-    #ifdef HAVE_LOAD_EXTENSION
+    #ifndef SQLITE_OMIT_LOAD_EXTENSION
     {"enable_load_extension", (PyCFunction)pysqlite_enable_load_extension, METH_VARARGS,
         PyDoc_STR("Enable dynamic loading of SQLite extension modules. Non-standard.")},
     {"load_extension", (PyCFunction)pysqlite_load_extension, METH_VARARGS,
@@ -1838,10 +1801,8 @@ static PyMethodDef connection_methods[] = {
         PyDoc_STR("Abort any pending database operation. Non-standard.")},
     {"iterdump", (PyCFunction)pysqlite_connection_iterdump, METH_NOARGS,
         PyDoc_STR("Returns iterator to the dump of the database in an SQL text format. Non-standard.")},
-    #ifdef HAVE_BACKUP_API
     {"backup", (PyCFunction)(void(*)(void))pysqlite_connection_backup, METH_VARARGS | METH_KEYWORDS,
         PyDoc_STR("Makes a backup of the database. Non-standard.")},
-    #endif
     {"__enter__", (PyCFunction)pysqlite_connection_enter, METH_NOARGS,
         PyDoc_STR("For context manager. Non-standard.")},
     {"__exit__", (PyCFunction)pysqlite_connection_exit, METH_VARARGS,
diff --git a/Modules/_sqlite/module.c b/Modules/_sqlite/module.c
index 71d951e..82f58eb 100644
--- a/Modules/_sqlite/module.c
+++ b/Modules/_sqlite/module.c
@@ -29,8 +29,8 @@
 #include "microprotocols.h"
 #include "row.h"
 
-#if SQLITE_VERSION_NUMBER >= 3003003
-#define HAVE_SHARED_CACHE
+#if SQLITE_VERSION_NUMBER < 3007003
+#error "SQLite 3.7.3 or higher required"
 #endif
 
 /* static objects at module-level */
@@ -131,7 +131,6 @@ PyDoc_STRVAR(module_complete_doc,
 \n\
 Checks if a string contains a complete SQL statement. Non-standard.");
 
-#ifdef HAVE_SHARED_CACHE
 static PyObject* module_enable_shared_cache(PyObject* self, PyObject* args, PyObject*
         kwargs)
 {
@@ -159,7 +158,6 @@ PyDoc_STRVAR(module_enable_shared_cache_doc,
 \n\
 Enable or disable shared cache mode for the calling thread.\n\
 Experimental/Non-standard.");
-#endif /* HAVE_SHARED_CACHE */
 
 static PyObject* module_register_adapter(PyObject* self, PyObject* args)
 {
@@ -253,10 +251,8 @@ static PyMethodDef module_methods[] = {
      METH_VARARGS | METH_KEYWORDS, module_connect_doc},
     {"complete_statement",  (PyCFunction)(void(*)(void))module_complete,
      METH_VARARGS | METH_KEYWORDS, module_complete_doc},
-#ifdef HAVE_SHARED_CACHE
     {"enable_shared_cache",  (PyCFunction)(void(*)(void))module_enable_shared_cache,
      METH_VARARGS | METH_KEYWORDS, module_enable_shared_cache_doc},
-#endif
     {"register_adapter", (PyCFunction)module_register_adapter,
      METH_VARARGS, module_register_adapter_doc},
     {"register_converter", (PyCFunction)module_register_converter,
@@ -307,29 +303,17 @@ static const IntConstantPair _int_constants[] = {
     {"SQLITE_UPDATE", SQLITE_UPDATE},
     {"SQLITE_ATTACH", SQLITE_ATTACH},
     {"SQLITE_DETACH", SQLITE_DETACH},
-#if SQLITE_VERSION_NUMBER >= 3002001
     {"SQLITE_ALTER_TABLE", SQLITE_ALTER_TABLE},
     {"SQLITE_REINDEX", SQLITE_REINDEX},
-#endif
-#if SQLITE_VERSION_NUMBER >= 3003000
     {"SQLITE_ANALYZE", SQLITE_ANALYZE},
-#endif
-#if SQLITE_VERSION_NUMBER >= 3003007
     {"SQLITE_CREATE_VTABLE", SQLITE_CREATE_VTABLE},
     {"SQLITE_DROP_VTABLE", SQLITE_DROP_VTABLE},
-#endif
-#if SQLITE_VERSION_NUMBER >= 3003008
     {"SQLITE_FUNCTION", SQLITE_FUNCTION},
-#endif
-#if SQLITE_VERSION_NUMBER >= 3006008
     {"SQLITE_SAVEPOINT", SQLITE_SAVEPOINT},
-#endif
 #if SQLITE_VERSION_NUMBER >= 3008003
     {"SQLITE_RECURSIVE", SQLITE_RECURSIVE},
 #endif
-#if SQLITE_VERSION_NUMBER >= 3006011
     {"SQLITE_DONE", SQLITE_DONE},
-#endif
     {(char*)NULL, 0}
 };
 
@@ -360,6 +344,11 @@ PyMODINIT_FUNC PyInit__sqlite3(void)
     PyObject *tmp_obj;
     int i;
 
+    if (sqlite3_libversion_number() < 3007003) {
+        PyErr_SetString(PyExc_ImportError, MODULE_NAME ": SQLite 3.7.3 or higher required");
+        return NULL;
+    }
+
     module = PyModule_Create(&_sqlite3module);
 
     if (!module ||