example use of -filter

[jtmoon79]

What is the syntax for passing -filter value for the magic-trace attach command?

In my case, I have a rust program myprogram. The attach command I use is:

magic-trace \
  -multi-thread \
  -full-execution \
  -working-directory ~/project/program/target/myprofile/myprogram \
  -p $(pgrep myprogram) \

I would like the magic-trace profiler to start profiling when function start_profile() is called from the function main(). magic-trace should profile until myprogram exits.

pub fn main() -> int {
  // ... setup things ...
  start_profile();
  // ... do important things ...
  return 0;
}

/// special function to instruct magic-trace start profiling
pub fn start_profile() {
  // ...
}

What string value would I pass to -filter for the magic-trace attach -filter ... command?