The MLKit

The MLKit is a compiler for the programming language Standard ML. The MLKit covers all of Standard ML, as defined in the 1997 edition of the Definition of Standard ML and supports most of the Standard ML Basis Library.

Statistics

Features

• Covers all of Standard ML. The MLKit compiles all of Standard ML, including Modules, as specified by the Definition of Standard ML. The MLKit also supports large parts of the Standard ML Basis Library.

• Supports ML Basis Files: The MLKit compiles large programs, including itself, around 80.000 lines of Standard ML plus the Standard ML Basis Library. The support for ML Basis Files makes it easy to compile a program with different Standard ML compilers. Currently, both MLton and the MLKit supports the concept of ML Basis Files.

• Region-Based Memory Management: Memory allocation directives (both allocation and deallocation) are inferred by the compiler, which uses a number of program analyses concerning lifetimes and storage layout. The MLKit compiler is unique among ML implementations in this respect.

• Reference-tracing Garbage Collection: The MLKit supports reference-tracing garbage collection in combination with region memory management.

• Native backend for the x86 architecture.

• Documentation. A comprehensive guide on programming with the MLKit is available. Documentation is also available in man-pages and from the MLKit home page.

License and Copyright

The MLKit compiler is distributed under the GNU Public License, version 2. See the file doc/license/MLKit-LICENSE for details. The runtime system (kit/src/Runtime/) and libraries (kit/basis/) is distributed under the more liberal MIT License.

Compilation Requirements

To compile, install, and use the MLKit, a Linux box running Ubuntu Linux, Debian, gentoo, or similar is needed. The MLKit also works on Mac OS and has also earlier been reported to run on the FreeBSD/x86 platform, with a little tweaking.

To compile the MLKit, a Standard ML compiler is needed, which needs to be one of the following:

MLton >= 20051202:

$ mlton
MLton 20051202 (built Sat Dec 03 04:20:11 2005 on pavilion)

A working MLKit compiler >= 4.3.0:

$ mlkit -V
MLKit version 4.3.0, Jan 25, 2006 [X86 Backend]

Moreover, gcc is needed for compiling the runtime system and related tools.

Compilation

After having checked out the sources from Github, execute the command:

$ ./autobuild

Now, cd to the toplevel directory of the repository and execute the appropriate set of commands:

Compile with MLton alone (Tested with 3Gb RAM):

$ ./configure 
$ make mlkit

Compile with existing MLKit (Tested with 1Gb RAM):

$ ./configure --with-compiler=mlkit
$ make mlkit

If you later want to install the MLKit in your own home directory, you should also pass the option --prefix=$HOME/mlkit to ./configure above.

For binary packages, we use

$ ./configure --sysconfdir=/etc --prefix=/usr

Bootstrapping (optional - works with 1Gb RAM)

This step is optional. If you want the resulting executable compiler to be bootstrapped (compiled with itself), execute the command:

$ make bootstrap

Be aware that this step takes some time.

Pre-compile Basis Library and Kit-Library

Execute the following command:

$ make mlkit_libs

Installation

For a system wide installation of the MLKit, installation including man-pages and tools, execute the command:

$ sudo make install

For a personal installation, with --prefix=$HOME/mlkit given to ./configure, execute the following command:

$ make install

Making a Binary Package

To build a binary package, execute the command

$ make mlkit_i386_tgz

This command leaves a package mlkit-X.Y.Z-i386.tgz in the dist/ directory. For building a binary package, the installation step above is not needed and the bootstrapping step is optional.

Try It

To test the installation, copy the directory /usr/share/mlkit/kitdemo to somewhere in your own directory, say $HOME/kitdemo:

$ cp -a /usr/share/mlkit/kitdemo $HOME/kitdemo
$ cd $HOME/kitdemo
$ mlkit helloworld.sml

The MLKit should produce an executable file run:

$ ./run
hello world

More Information

See the MLKit home page.

Documentation for the MLKit is located in the directories doc/mlkit and man/man1. License information is located in the file doc/license/MLKit-LICENSE.

Comments and Bug Reports

The MLKit has a number of known bugs and limitations. To file a bug-report, create an issue at the Github page.

Appendix A: Directory Structure of the Sources

kit/
   README
   configure
   Makefile.in        
   src/
   basis/
   doc/mlkit.pdf
      /license/MLKit-LICENSE                   
   man/man1/rp2ps.1                
   kitdemo/
   test/

Appendix B: Quick Compilation and Installation Guide

We assume that MLton >= 20051202 is installed on the system as described above.

After having checked out the sources from Github, execute the command:

$ ./autobuild

To compile and install the MLKit, execute the following commands:

$ ./configure
$ make mlkit
$ make bootstrap             
$ make mlkit_libs

To install the MLKit and related tools, execute:

$ sudo make install

See the section "Try It" above to test the installation.

Appendix C: Displaying Region Flow Graphs with VCG

The VCG tool can be used to show region flow graphs.