trace - sets trace flags and returns the old ones

int trace( int traceflags );

This efun is only available if TRACE and PACKAGE_DEVELOP are compiled in.

Sets the trace flags and returns the old trace flags. When tracing is on a lot of information is printed during execution.

The trace bits are:

1 - Trace all function calls to lfuns.
2 - Trace all calls to "call_other".
4 - Trace all function returns.
8 - Print arguments at function calls and return values.
16 - Print all executed stack machine instructions (produces a lot of output!).
32 - Enable trace in heart beat functions.
64 - Trace calls to apply.
128 - Show object name in tracing.