mokkang / gen-ir

Generates LLVM IR for Xcode Projects

Gen IR 🧞‍♂️

Generate LLVM IR from an Xcode Build Log

This tool was heavily inspired by: https://blog.digitalrickshaw.com/2016/03/14/dumping-the-swift-ast-for-an-ios-project-part-2.html ❤️

Prerequisites

To build the tool, you'll need Xcode 14 and macOS 12.5 or greater.

To install and run the tool, you'll need Homebrew, Xcode, and macOS 12 or greater.

Install

# If you don't have brew installed, install it: https://brew.sh/

# Add the brew tap to your local machine
brew tap NinjaLikesCheez/tap

# Install the tool
brew install gen-ir

🎉 Done!

All installed! You can now use gen-ir on your system - be sure to run gen-ir --help to check the available commands and options.

Usage

⚠️ Before you use

It's important to know that gen-ir requires that a full build log is provided.

This means a clean, fresh build of a project.

The compiler will not make a call for an object that doesn't need to be rebuilt, and we will not be able to parse what doesn't exist. Ensure you do a clean before your build otherwise gen-ir may miss some modules.

gen-ir takes a Xcode build log by two means, a path to a file or stdin:

# Path to build log (you can export from inside of Xcode too)
xcodebuild clean && \
xcodebuild build -project TestProject.xcodeproj -scheme TestProject -configuration Debug > build_log.txt

gen-ir build_log.txt ir_files/

# Stdin (you may need to redirect stderr to stdout here, Xcode is weird about writing to it sometimes)
xcodebuild clean && \
xcodebuild build -project TestProject.xcodeproj -scheme TestProject -configuration Debug | gen-ir - ir_files/

Building

gen-ir is implemented as a Swift Package, so you can either open Package.swift in Xcode, or build via the command line:

# Debug output: ./.build/debug/gen-ir
swift build

# Release output: ./.build/release/gen-ir
swift build -c release