Skip to content

README.md

Latest commit

 

History

History
136 lines (95 loc) · 5.32 KB

README.md

File metadata and controls

136 lines (95 loc) · 5.32 KB

iOS Prebuild Scripts

This directory contains scripts for prebuilding React Native itself into XCFrameworks for iOS and related platforms.

Overview

These scripts automate the process of building React Native as a Swift Package and packaging it into XCFrameworks that can be distributed and consumed by iOS applications. The build process creates optimized frameworks for multiple architectures and platforms.

Purpose

The prebuild scripts are used to:

  • Build React Native itself (not its dependencies) as XCFrameworks
  • Create distributable binaries for iOS, iOS Simulator, Catalyst.
  • Support both Debug and Release build configurations
  • Generate Debug Symbol (dSYM) files for debugging

Usage

Run the prebuild script from the command line:

cd packages/react-native
node scripts/ios-prebuild

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

  • setup the codebase for all platforms and flavors
  • build for all platforms and flavors
  • compose xcframeworks
  • sign (if an identity is passed)

Options

Option Alias Type Default Description
--setup -s boolean - Download and setup dependencies
--build -b boolean - Build dependencies/platforms
--compose -c boolean - Compose XCFramework from built dependencies
--platforms -p array ['ios', 'ios-simulator', 'mac-catalyst'] Specify one or more platforms to build for
--flavor -f string Debug Specify the flavor to build: Debug or Release
--identity -i string - Specify the code signing identity to use for signing the frameworks
--help - boolean - Show help information

Output Structure

The build produces:

  • XCFrameworks in the specified output directory
  • Debug symbols (dSYM files) for debugging
  • Build products organized by platform and configuration

Architecture

The build system consists of several components:

cli.js

The main entry point that orchestrates the build process. It:

  • Parses command-line arguments
  • Validates build parameters
  • Coordinates the build, archiving, and XCFramework creation steps

build.js

Handles the Swift Package build process. It:

  • Executes xcodebuild commands with appropriate flags
  • Builds for specific platforms and build types (Debug/Release)
  • Locates and validates the generated framework artifacts
  • Uses build settings like BUILD_LIBRARY_FOR_DISTRIBUTION=YES for binary compatibility

types.js

Defines TypeScript/Flow type definitions for:

  • BuildFlavor: Debug or Release configurations
  • Destination: Target platforms (iOS, iOS Simulator, Catalyst, Vision, visionOS)
  • ArchiveOptions: Configuration options for the build process

utils.js

Provides utility functions including:

  • Logging functionality with prefixed output
  • Common helper functions used across scripts

Build Flags

The build process uses specific xcodebuild flags:

  • BUILD_LIBRARY_FOR_DISTRIBUTION=YES: Enables module stability
  • SKIP_INSTALL=NO: Ensures frameworks are properly installed
  • DEBUG_INFORMATION_FORMAT="dwarf-with-dsym": Generates debug symbols
  • OTHER_SWIFT_FLAGS="-no-verify-emitted-module-interface": Skips interface verification (useful for React Native modules due to the header structure not beeing modular)

Notes

  • These scripts build React Native itself, not third-party dependencies
  • The build process requires significant disk space for derived data
  • Build times vary depending on the target platform and configuration
  • XCFrameworks support multiple architectures in a single bundle

Known Issues

The generated XCFrameworks currently use CocoaPods-style header structures rather than standard framework header conventions. This may cause modularity issues when:

  • Consuming the XCFrameworks in projects that expect standard framework headers
  • Building dependent frameworks that rely on proper module boundaries
  • Integrating with Swift Package Manager projects expecting modular headers

Integrating in your project with Cocoapods

For consuming, debugging or troubleshooting when using Cocoapods scripts, you can use the following environment variables:

  • RCT_USE_PREBUILT_RNCORE: If set to 1, it will use the release tarball from Maven instead of building from source.
  • RCT_TESTONLY_RNCORE_TARBALL_PATH: TEST ONLY If set, it will use a local tarball of RNCore if it exists.
  • RCT_TESTONLY_RNCORE_VERSION: TEST ONLY If set, it will override the version of RNCore to be used.
  • RCT_SYMBOLICATE_PREBUILT_FRAMEWORKS: If set to 1, it will download the dSYMs for the prebuilt RNCore frameworks and install these in the framework folders