[MLton] self-compiling failed

[Matthew Fluet]

On Fri, May 21, 2010 at 2:37 AM, Baojian Hua <huabj at mail.ustc.edu.cn> wrote:
>> Actually, you would need to install it in /usr/lib/mlton/.  Also, note
>> that you can't generally replace the mlton-compile executable (or
>> mlton-smlnj.x86-linux heap) from one version of the compiler with
>> another version, since the runtime library, basis library, etc. may
>> have also changed.  If /usr/bin/mlton and /usr/lib/mlton correspond to
>> mlton-20070826 (as might be the case if you installed them from your
>> Linux distribution's package manager or if you installed it from
>> mlton-20070826-1.x86-linux.tgz from mlton.org), then this will almost
>> certainly not work.
>>
>> Generally, the best thing to do when self-compiling is to run the
>> resulting compiler directly from build/bin/mlton.
>>
> The installed MLton is 20100504, so the problem you mentioned hasn't been
> observed. In fact, I tried to build MLton (by MLton) from the source
> root, and after I copied the generated "mlton-compile" to /usr/lib/mlton,
> it works fine. :-)

You are asking for trouble.  There are (implicit) dependencies between
the mlton-compile executable and the libmlton.a runtime library.
While mlton-compile might correctly execute when invoked from the
mlton-2001504 /usr/bin/mlton script, the executables it creates will
likely have problems --- they are compiled with a mlton-compile that
assumes one thing about the runtime, but linked against a runtime that
provides a different thing.

>> Looks like something got corrupted in your mlton script.  Has it been
>> altered from that in SVN HEAD?
> Maybe we've not decribe our difficulty clear. We followd these
> steps to try to build an smlnj heap image (just as you mentioned in a
> previous post):
> 1. run "make" at the source root;
> 2. run "make smlnj-mlton"
> 3. copy the generated "mlton-smlnj.x86-linux" to "build/lib/"

This step is not necessary; the "make smlnj-mlton" will copy
mlton/mlton-smlnj.x86-linux to build/lib/.

> 4. remove "mlton-compile" in the "build/lib/"
> 5. run the script "mlton" in the "build/bin"

> but we got the error message:
> "unknown switch: -fno-common:
> just as in the previous post.
>
> Is there something we forgot?

No.  But your error message says that "-fno-common" is being
interpreted as an argument to mlton-compile, rather than being
interpreted as an argument to the -cc-opt argument to mlton-compile.
This would happen if, for example, you modified bin/mlton-script and
deleted the quotes around the '-O1 -fno-common' on line 101.  The fact
that your were getting additional output means that you changed the
"set -e" to "set -ex" as suggested by Wesley earlier in the thread.
Perhaps you accidentally modified something else.  Try running "svn
diff bin/mlton-script" to see if you have any other edits.