I've added some basic property-debugging support to FlightGear and SimGear. In FlightGear, the --trace-read option causes all read access for a property to be traced, and the --trace-write option causes all write access for a property to be traced, both through SG_LOG messages.
Tracing a popular property like /position/altitude will cause a lot of output and will slow down FlightGear, but presumably, you're debugging anyway so you won't mind. The neatest part of all this is that it allows you to debug properties and C++ code together in a regular debugger. The --trace-read property causes SGPropertyNode::trace_read to be invoked, and the --trace-write property causes SGPropertyNode::trace_write to be invoked. Let's say that you wanted to find out what parts of the C++ code are setting the /foo/bar property. You would load FlightGear into a debugger, set a breakpoint on SGPropertyNode::trace_write (in simgear/simgear/misc/props.cxx in the SimGear distro), then run the program with the following option: --trace-writes=/foo/bar Every time any code sets a new value for /foo/bar, you'll hit your breakpoint, and you can look at the backtrace to find out where it is being set. All the best, David -- David Megginson [EMAIL PROTECTED] _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
