M2BSK Modula-2 Bootstrap Kernel Project

Welcome to the M2BSK Modula-2 Bootstrap Kernel Project

Objective

The objective of this project is to develop a bootstrap compiler for the revised Modula-2 language described in

Modula-2 Revision 2010, Language Report for the Bootstrap Kernel Subset (BSK), by Kowarsch and Sutcliffe, July 2020.

Grammar

The grammar of the compiler's command line interface is in the project repository

https://github.com/m2sf/m2bsk/blob/master/grammar/m2cli-grammar.gll

The grammar of the compiler's input language is in the project repository

https://github.com/m2sf/m2bsk/blob/master/grammar/m2bsk-grammar.gll

For a graphical representation of the grammar, see section Syntax Diagrams.

Language Specification

An online version of the language specification is here:

https://github.com/m2sf/m2bsk/wiki/Language-Specification

The authoritative language specification (PDF) is available for download:

https://github.com/m2sf/PDFs/blob/master/M2BSK%20Language%20Description.pdf

Scope

The compiler supports the Bootstrap Kernel (BSK) subset of Modula-2 R10. It does not support earlier PIM or ISO dialects.

For a list of facilities that have been omitted in the subset, see Omissions

Targets

The compiler will generate classic Modula-2 sources that can be compiled with any Modula-2 compiler that meets the prerequisites for compiling M2BSK itself. An LLVM backend will be added later to generate LLVM IR.

License

M2BSK is licensed under the GNU Lesser General Public License (LGPL) both v.2.1 and v.3.

Prerequisites

M2BSK is written in a subset of the third and fourth editions of Niklaus Wirth's "Programming in Modula-2" that represents an intersection with ISO Modula-2 (IS 10514-1) in order to facilitate compilation with any classic Modula-2 compiler, regardless of dialect and platform.

Nevertheless, the host compiler needs to support one of the following memory models:

• 16-bit CARDINAL type and 32-bit LONGINT type
• 32-bit CARDINAL type and 32-bit LONGINT type
• 32-bit CARDINAL type and 64-bit LONGINT type

Furthermore, the following libraries from Wirth's "Programming in Modula-2" are required.

• Storage
• Terminal
• FileSystem

These libraries should be part of any PIM Modula-2 compiler's library. For use with ISO Modula-2 compilers, M2BSK provides shim libraries for adaptation to ISO Modula-2 libraries.

There are no dependencies on any third party libraries.

OS support

M2BSK will run on any operating system with target support by the host-compiler.

Development Languages

• M2BSK itself is written in classic Modula-2
• The syntax diagram generator script is written in TCL/TK (not required to build M2BSK)
• Build configuration scripts are written in the prevalent shell language of the hosting platform

Contact

If you have questions or would like to contribute to the project, get in touch via

• Modula2 Telegram group chat

• email to the project maintainer

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