bpo-45138: Expand traced SQL statements in sqlite3 trace callback

[erlend-aasland]

https://bugs.python.org/issue45138

[erlend-aasland]

I'll resolve the conflicting files after GH-29327 has been merged. Fixed.

[erlend-aasland]

Note to self: after GH-29356 has landed, add test for too long SQL statements. Done

[erlend-aasland]

Coverage for trace_callback() is now pretty good.

Details

 1056| |static int
1057| |trace_callback(unsigned int type, void *ctx, void *stmt, void *sql)
1058| |#else
1059| |static void
1060| |trace_callback(void *ctx, const char *sql)
1061| |#endif
1062| 20|{
1063| 20|#ifdef HAVE_TRACE_V2
1064| 20| if (type != SQLITE_TRACE_STMT) {
1065| 0| return 0;
1066| 0| }
1067| 20|#endif
1068| |
1069| 20| PyGILState_STATE gilstate = PyGILState_Ensure();
1070| |
1071| 20| assert(ctx != NULL);
1072| 20| PyObject *py_statement = NULL;
1073| 20|#ifdef HAVE_TRACE_V2
1074| 20| assert(stmt != NULL);
1075| 20| const char *expanded_sql = sqlite3_expanded_sql((sqlite3_stmt *)stmt);
1076| 20| if (expanded_sql == NULL) {
1077| 2| sqlite3 *db = sqlite3_db_handle((sqlite3_stmt *)stmt);
1078| 2| if (sqlite3_errcode(db) == SQLITE_NOMEM) {
1079| 0| (void)PyErr_NoMemory();
1080| 0| goto exit;
1081| 0| }
1082| |
1083| 2| pysqlite_state *state = ((callback_context *)ctx)->state;
1084| 2| assert(state != NULL);
1085| 2| PyErr_SetString(state->DataError,
1086| 2| "Expanded SQL string exceeds the maximum string "
1087| 2| "length");
1088| |
1089| | // Fall back to unexpanded sql
1090| 2| py_statement = PyUnicode_FromString((const char *)sql);
1091| 2| }
1092| 18| else {
1093| 18| py_statement = PyUnicode_FromString(expanded_sql);
1094| 18| sqlite3_free((void *)expanded_sql);
1095| 18| }
1096| |#else
1097| | py_statement = PyUnicode_FromString(sql);
1098| |#endif
1099| 20| if (py_statement) {
1100| 20| PyObject *exc, *val, *tb;
1101| 20| PyErr_Fetch(&exc, &val, &tb);
1102| |
1103| 20| PyObject *callable = ((callback_context *)ctx)->callable;
1104| 20| PyObject *ret = PyObject_CallOneArg(callable, py_statement);
1105| 20| Py_DECREF(py_statement);
1106| 20| Py_XDECREF(ret);
1107| |
1108| 20| _PyErr_ChainExceptions(exc, val, tb);
1109| 20| }
1110| |
1111| 20| if (PyErr_Occurred()) {
1112| 4| print_or_clear_traceback((callback_context *)ctx);
1113| 4| }
1114| |
1115| 20|exit:
1116| 20| PyGILState_Release(gilstate);
1117| 20|#ifdef HAVE_TRACE_V2
1118| 20| return 0;
1119| 20|#endif
1120| 20|}

[erlend-aasland]

I believe I've addressed everything here, @pablogsal. Let me know if you want further changes.

[JelleZijlstra]

Thanks, a few small comments

[JelleZijlstra]

Looks good! @gvanrossum I'm planning to merge this change, another SQLite enhancement by Erlend.

[erlend-aasland]

Thanks, @JelleZijlstra!

[kumaraditya303]

This change broke several buildbots See https://buildbot.python.org/all/#/builders/58/builds/1850

[erlend-aasland]

I'm aware, and I'm coming up with a fix for that test.