Replaces ScriptFunc top-level bodies Stmts with a Stmt class that diverts execution
through a trampoline (minimal JITing) and produces /tmp/perf-<pid>.map files.
Not enabled by default. Run with:
perf record -g zeek -r ./trace.pcap PerfSupport::enable=T
or
ZEEKPERFSUPPORT=1 perf record -g zeek -r ./trace.pcap
To prefix the functions in the map file "ZEEK:", can redef PerfSupport::prefix="ZEEK:".
There's an artificial _Zeek_PerfSupport_stmt_exec function in the callbacks, filter
out with grep ;-)
perf script | grep -v '_Zeek_PerfSupport' | stackcollapse-perf.pl | flamegraph.pl > flame.svg
The assembly code used in src/Trampoline.s can be determined by:
make print-trampoline