[MLton] deepFlatten exception
Tue, 13 Jun 2006 11:39:29 -0400 (EDT)
> While compiling a program using the command
> mlton -verbose 3 -runtime 'ram-slop 0.4' t.mlb
> quite a bit of output is produced (see attached log file) with this at the
> deepFlatten starting
> deepFlatten raised in 0.11 + 0.00 (0% GC)
> ssa2Simplify raised in 0.35 + 0.00 (0% GC)
> pre codegen raised in 28.94 + 5.17 (15% GC)
> Compile SML raised in 28.94 + 5.17 (15% GC)
> MLton raised in 28.94 + 5.17 (15% GC)
> DeepFlatten.replaceVar x_0
> Is this a compiler bug, or something wrong with my program?
It is a compiler bug. Any errors after the parseAndElaborate (i.e., SML
type-checking) phase are indicative of compiler bugs. (It might be a good
idea for us to change the exception printer to explicitly state that the
error should be reported to firstname.lastname@example.org as a compiler bug.)
> It compiles fine with Moscow ML. I've attached the t.mlb file to this
> email, but the t.sml program file is 608Kb, so I've put that up on my
> website at
You can also use http://mlton.org/TemporaryUpload as a place to post
files that are too large for the mailing list.
> I'm using the very latest version of MLton. I ran into this problem
> with a version I'd built a year ago, so today I did a cvs update and
> built the very latest version, with exactly the same results.
Indeed, the bug appears in my latest version. (BTW, MLton is now using
subversion for revision control; see http://mlton.org/Sources. The old
cvs repository is still accessible, but has been frozen for nearly a
Thanks for the report; we'll look into it.