lzhangjianjunl / clang-as-ios-dylib

A workaround to build iOS dynamic libraries from Xcode.

Archived Repo

This is an archived project and is no longer supported or updated by Facebook. Please do not file issues or pull-requests against this repo. If you wish to continue to develop this code yourself, we recommend you fork it.

This hack was useful for convincing Xcode to make iOS dynamic libraries in the days of Xcode 5. With Xcode 6, Apple introduced Frameworks on iOS which are pretty much equivalent to dylibs but with a different packaging structure. Frameworks should satisfy all use cases for clang-as-ios-dylib.

clang-as-ios-dylib

clang-as-ios-dylib is a workaround for building iOS dynamic libraries from Xcode. Most importantly, it lets Xcode build iOS dylibs without requiring any modifications to the Xcode installation.

It works by tricking Xcode into building an OS X dynamic library as if it were an iOS dynamic library. By overriding CC and LD, we make Xcode call a wrapper script instead of directly calling clang, and our wrapper swaps the OS X compile flags for iOS flags.

Only iphonesimulator dylibs are supported now, but it would be possible to add device support if needed.

Usage

1. Copy the clang-as-ios-dylib code into your repo:

cd Vendor
mkdir clang-as-ios-dylib
cd clang-as-ios-dylib
curl -L https://github.com/facebook/clang-as-ios-dylib/archive/master.tar.gz | tar zxvf - --strip-components=1

1. In Xcode, create a new OS X Cocoa Library target.

2. In the project, create a new Configuration Settings File (.xcconfig) file with the following contents:

// The following can be one of 'latest', 'earliest', or a specific
// SDK version like '7.0', or '6.1'.
CAID_BASE_SDK_VERSION = latest
CAID_IPHONEOS_DEPLOYMENT_TARGET = latest

CAID_LINKS_PATH = $(PROJECT_DIR)/../Vendor/clang-as-ios-dylib/links

LD = $(CAID_LINKS_PATH)/ld-iphonesimulator-$(CAID_BASE_SDK_VERSION)-targeting-$(CAID_IPHONEOS_DEPLOYMENT_TARGET)
CC = $(CAID_LINKS_PATH)/cc-iphonesimulator-$(CAID_BASE_SDK_VERSION)-targeting-$(CAID_IPHONEOS_DEPLOYMENT_TARGET)

1. In your project’s Info settings panel, for each build configuration, select the xcconfig file created in #2 for your target.

2. Change references to Cocoa.framework to Foundation.framework:

• In your .pch file, change #import <Cocoa/Cocoa.h> to #import <Foundation/Foundation.h>.
• In your target's Build Phases panel, under Link Binary With Libraries, remove Cocoa.framework and add Foundation.framework.

Alternatives

The other possibility is modifying some of Xcode’s internal configuration files so that Xcode understands iOS dylibs again. Internally, Xcode already knows how to build iOS dylibs - it’s just that Apple strips some configuration items to prevent it.

See: http://sumgroup.wikispaces.com/iPhone_Dynamic_Library

The downside to this approach is that everyone on your team must also modify their Xcode installation.

License

BSD License

clang-as-ios-dylib
Copyright (c) 2013, Facebook, Inc.  All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
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* Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.

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