iOS Prebuild Scripts Documentation

This folder contains scripts for creating precompiled XCFrameworks for React Native's dependencies. These scripts automate the process of downloading, building, and packaging third-party libraries into distributable XCFramework bundles for iOS.

Overview

The iOS prebuild system creates precompiled frameworks to reduce build times for React Native iOS apps. Instead of compiling dependencies from source during every build, these scripts package them as ready-to-use XCFrameworks.

The prebuild process creates a Swift package that builds frameworks for the following 3rd party libraries:

boost
folly
glog
fmt
double-conversion
socketrocket
fast-float

Main Scripts

`cli.js`

Command-line interface for the prebuild system.

bash

node scripts/releases/prepare-ios-prebuilds.js

If no options are passed, the script executes all the steps in this order:

setup dependencies and prepares them
creates Swift package file
builds for all platforms and configurations
creates xcframeworks

Options:

Option	Short	Description
`--setup`	`-s`	Download and setup dependencies
`--build`	`-b`	Build dependencies for target platforms
`--compose`	`-c`	Compose XCFrameworks from built artifacts
`--swiftpackage`	`-w`	Generate `Package.swift` file
`--platforms`	`-p`	Target platforms (ios, macos, catalyst, tvos, visionos)
`--configurations`	`-g`	Build configurations (Debug, Release)
`--dependencies`	`-d`	Specific dependencies to process
`--clean`	—	Clean build folder before building
`--identity`	`-i`	Signing identity for frameworks

Integrating in your project with Cocoapods

To use the prebuilt React Native Dependencies XCFrameworks in your iOS project, run pod install with the environment variable RCT_USE_RN_DEP set to 1:

bash

RCT_USE_RN_DEP=1 bundle exec pod install

This can be combined with RCT_USE_RN_DEP=1 to use both React Native and its dependencies as prebuilt frameworks.

For debugging and troubleshooting the Cocoapods scripts, you can use the following environment variables:

RCT_USE_RN_DEP: If set to 1, it will use the release tarball from Maven instead of building from source.
RCT_USE_LOCAL_RN_DEP: TEST ONLY If set, it will use a local tarball of ReactNativeDependencies if it exists.
RCT_DEPS_VERSION: TEST ONLY If set, it will override the version of ReactNativeDependencies to be used.