helper to flamegraph a command

flamegraph.fish

# macos fix to run dtrace
# https://apple.stackexchange.com/questions/208762/now-that-el-capitan-is-rootless-is-there-any-way-to-get-dtrace-working
# https://github.com/brendangregg/FlameGraph
# http://www.brendangregg.com/DTrace/DTrace-cheatsheet.pdf

function flamegraph
    if test (count $argv) -eq 0
        echo usage: flamegraph command [args]
        return 1
    end
    
    set stacks /tmp/out.stacks
    sudo rm -f $stacks 2>/dev/null
    set program (basename "$argv[1]")
    set pdtrace 'profile-99 /execname == "'$program'" && arg1/ { @[ustack()] = count(); }'
    sudo dtrace -x ustackframes=100 -n "$pdtrace" -o $stacks -c "$argv"

    if test $status -eq 0
        # git clone https://github.com/brendangregg/FlameGraph in your ~/dev/ or adjust the path
        ~/dev/FlameGraph/stackcollapse.pl $stacks > /tmp/out.folded
        ~/dev/FlameGraph/flamegraph.pl /tmp/out.folded > ./flamegraph.svg
    end

end