pascalecu/clang-objc2-gnustep repository overview

⁠Objective-C 2.0 Development Environment (Clang + libobjc2 + GNUstep)

This repository provides a Docker image for a modern Objective-C 2.0 toolchain based on:

• Clang (LLVM toolchain)
• GNUstep
• libobjc2 (modern Objective-C runtime)
• libdispatch (Swift corelibs GCD implementation)

It replaces legacy GCC-based Objective-C environments with a Clang-based toolchain using a modern Objective-C runtime (libobjc2).

⁠Features

This environment supports modern Objective-C features through Clang + libobjc2:

• Automatic Reference Counting (ARC)
• Blocks (closures)
• Grand Central Dispatch (libdispatch)
• Object literals
• Subscripting
• Properties and dot syntax
• Objective-C 2.0 runtime features

These features require the combination of:

• Clang compiler
• libobjc2 runtime
• GNUstep base libraries

⁠Why this image exists

Many Objective-C environments are:

• GCC-based with outdated runtime support
• Bundled with full GUI stacks when only CLI tools are needed
• Not aligned with modern Clang + libobjc2 development

This image focuses on a minimal, modern toolchain:

• Clang + libobjc2 runtime model
• Swift corelibs libdispatch (modern GCD)
• GNUstep base for Foundation-compatible APIs

⁠Usage

⁠Pull image

docker pull pascalecu/clang-objc2-gnustep:clang22-ubuntu26.04

⁠Build locally

git clone https://github.com/pascalecu/clang-objc2-gnustep
cd clang-objc2-gnustep
docker build -t clang-objc2-gnustep .

⁠Run container

$ docker run --rm -it -v $(pwd):/workdir pascalecu/clang-objc2-gnustep:clang22-ubuntu26.04 bash

⁠Compile a program

Inside the container:

objc -o foobar foobar.m
./foobar

For convenience, the image includes an objc wrapper script that configures the compiler and runtime environment.

#!/usr/bin/env bash
set -euo pipefail

export GNUSTEP_MAKEFILES=/opt/gnustep/share/GNUstep/Makefiles
source /opt/gnustep/share/GNUstep/Makefiles/GNUstep.sh

exec clang-X \
  -fobjc-runtime=gnustep-2.0 \
  -fobjc-arc \
  -fblocks \
  -fobjc-exceptions \
  -O2 \
  -I/opt/gnustep/include \
  -L/opt/gnustep/lib \
  -Wl,-rpath,/opt/gnustep/lib \
  "$@" \
  -lgnustep-base -lobjc -ldispatch -lpthread -ldl -lm

where clang-X depends on the tag.

This image is intended for CLI and systems programming use. As such, no GUI frameworks are included.

⁠Acknowledgments

• GNUstep project: https://github.com/gnustep⁠
• libobjc2: https://github.com/gnustep/libobjc2⁠
• libdispatch: https://github.com/apple/swift-corelibs-libdispatch⁠
• doraTeX/docker-clang9-objc2⁠
• rzuckerm/objective-c-docker-image⁠
• GNUstep tools-scripts⁠