Using SQLite custom functions with Qt

Luc4

Hi! I'm trying to create a custom function for a SQLite database I'm using with Qt. I found information on how to create the function and it seems to work correctly on a x86 system.

Instead, it seems to be failing with a segfault on an ARM device. This is the code I wrote:

@static bool createSQLiteFunctions(const QSqlDatabase& db)
{
// Get handle to the driver and check it is both valid and refers to SQLite3.
QVariant v = db.driver()->handle();
if (!v.isValid() || qstrcmp(v.typeName(), "sqlite3*") != 0) {
LOG_WARNING("Cannot get a sqlite3 handle to the driver.");
return false;
}

// Create a handler and attach functions.
sqlite3* handler = static_cast<sqlite3*>(v.data());
if (!handler) {
LOG_WARNING("Cannot get a sqlite3 handler.");
return false;
}

// Check validity of the state.
if (!db.isValid()) {
LOG_ERROR("Cannot create SQLite custom functions: db object is not valid.");
return false;
}

if (!db.isOpen()) {
LOG_ERROR("Cannot create SQLite custom functions: db object is not open.");
return false;
}

if (sqlite3_create_function(handler, "_deleteFile", 1, SQLITE_ANY, 0, &_sqlite3DeleteFile, 0, 0))
LOG_ERROR("Cannot create SQLite functions: sqlite3_create_function failed.");

return true;
}@

The db object is instantiated as a member of another object, which is calling this function in the constructor, where the connection to the db is estabilished:

@ ...
// Create the connection to the database. The connection has to be different
// for each thread requiring one.
db = QSqlDatabase::addDatabase("QSQLITE", connectionName);

// Setup the database to avoid lockings.
db.setConnectOptions("QSQLITE_BUSY_TIMEOUT=10000");

db.setDatabaseName(MEDIASTORE_DATABASE_FILENAME);
if (!db.open()) {
LOG_ERROR("Failed to open the database.");
// TODO: What to do in case of errors??
}

// Create custom defined functions.
if (!createSQLiteFunctions(db)) {
LOG_ERROR("Failed to create custom functions.");
// TODO: What to do in case of errors??
}
...@

It seems that no error log is printed and, but the sqlite3_create_function function gives a segfault. If I remove the call to createSQLiteFunctions everything works fine.

I suspect this may be related to http://bugreports.qt.nokia.com/browse/QTBUG-16586. Any idea how I can solve this?
Thanks!