Jam build system on Python

This is a Python reimplementation of the Jam build system (link).

Supported platforms: Linux (Unix), OpenVMS, Windows (ninja 1.14), MacOS

What is Jam

Jam is a build system (similar to meson, cmake, etc.). The key difference is that its core is essentially an interpreter for its internal language, with all building functionality written in this language.

The raw Jam language doesn't know how to build anything by itself, but it allows you to define rules and dependencies which construct the actual command sequence to build projects using a dependency tree.

Jam includes Jambase, which is a collection of generic rules to build C, C++ and Fortran projects. It can be easily extended (or modified) to support other types of projects.

Differences from the original Jam

• Uses ninja, samurai or other ninja-compatible builders for the actual building of executables.
• mkdir is a built-in command that collects all created directories to the dirs target.
• Built-in rules are case-insensitive (Echo and ECHO are the same).
• Regular expressions are Python-based.
• Clean actions are ignored in favor of ninja -t clean.

Quick Start

Install:

# Using uv (easiest and recommmended) from PyPI
uv tool install jam-build@latest

# Install jamp with the system pip
pip3 install jam-build

# Or from the latest main branch.
pip3 install git+https://github.com/ildus/jamp

# Using pypy3 provides approximately twice the performance
# pypy3 -m pip install jam-build

Install ninja using your package manager

dnf install ninja
# or pacman -Syu ninja
# etc.

Example project structure with a library and a main executable that uses math functions:

src
    main.c
lib
    print.c
include
    common.h

Jamfile

Corresponding Jamfile:

HDRS = include ;                    # common includes, affects all sources
Library libprint : lib/print.c ;    # on Unix this will create libprint.a
Main app : src/main.c ;             # executable
LinkLibraries app : libprint ;      # linking the executable with our library
LINKLIBS on app = -lm ;             # extra libraries using paths

To build the executable, simply run:

jamp && ninja

For more complex examples, look at the tests directory. When dealing with subdirectories, it's recommended to use the SubDir rule. Note that this example will not work on VMS.

Contributing

git clone git@github.com:ildus/jamp.git

# To run without installing
export PYTHONPATH=$PYTHONPATH:<current_dir>/jamp/src
python3 -m jamp

# Testing changes
pip install pytest
cd <jamp root folder>
pytest

Documentation

See the docs directory.

OpenVMS Notes

Use my github.com/ildus/samurai fork for compilation. It supports the additional '$^' escape sequence for newlines, allowing you to add full scripts to build.ninja.