[MLton] Profiling...

[Stephen Weeks]

> If I run the mlton-compile.alloc that I
> find in the /mlton directory, I get the following:
> 
> > ../mlton/mlton-compile.alloc -prof-pass ssaSimplify test.sml
> unhandled exception: Fail: usage: exportMLton worldFile

By way of explanation, the "mlton-compile" executable runs in two
phases.  In the first phase, done at build time, it runs very quickly
and produces a saved world, world.mlton.  The bin/mlton script, which
is what people usually run, is the second phase, and starts with that
saved world.  See the use of @MLton load-world in that script.

So, when you try to directly run mlton-compile.alloc, you are doing
the first phase, which gives the error message above because the usual
MLton command-line arguments are intended for the second phase.

> If I don't give it the -prof-pass option it terminates too quickly
> to have done anything.

Right, here what is happening is it is actually running and creating
the world file (with the name of whatever file you supplied on the
command line).