OS X Cross toolchain for Linux, FreeBSD and NetBSD

WHAT IS THE GOAL OF OSXCROSS?

The goal of OSXCross is to provide a well working OS X cross toolchain for Linux, FreeBSD and NetBSD.

HOW DOES IT WORK?

Clang/LLVM is a cross compiler by default and is now available on nearly every Linux distribution,
so we just need a proper port of the cctools (ld, lipo, ...) and the OS X SDK.

If you want, then you can build an up-to-date vanilla GCC as well.

WHAT IS NOT WORKING (YET)?

• GCC itself doesn't build with GCC, but builds fine when clang is used to build GCC.

WHAT CAN I BUILD WITH IT?

Basically everything you can build on OS X with clang/gcc should build with this cross toolchain as well.

INSTALLATION:

Move your packaged SDK to the tarball/ directory.

Then ensure you have the following installed on your Linux/FreeBSD box:

Clang 3.2+, llvm-devel, automake, autogen, libtool, patch,
libxml2-devel (<=10.5 only), uuid-devel, openssl-devel and the bash shell.

Hint 1: You can run 'sudo tools/get_dependencies.sh' to get these automatically.
Hint 2: On Ubuntu 12.04 LTS you can use llvm.org/apt to get a newer version of clang.

Then run ./build.sh to build the cross toolchain.
(It will search 'tarballs' for your SDK and then build in its own directory.)

Don't forget to add the printed `<path>/osxcross-env` to your ~/.profile or ~/.bashrc.
Then either run source ~/.profile or restart your shell session.

That's it. See usage examples below.

Building GCC:

If you want to build GCC as well, then you can do this by running ./build_gcc.sh.
But before you do this, make sure you have got the GCC build depedencies installed on your system,
on debian like systems you can run apt-get install libmpc-dev libmpfr-dev libgmp-dev to install them.

PACKAGING THE SDK:

1. Boot into OS X
2. [Download Xcode (used 5.1)]
3. [Mount Xcode.dmg (Open With -> DiskImageMounter)]
4. Run: ./tools/gen_sdk_package.sh (from the OSXCross package)
5. Copy the packaged SDK (*.tar.* or *.pkg) on a USB Stick
6. Reboot back into Linux
7. Copy or move the SDK into the tarball/ directory of OSXCross

Step 2. and 3. can be skipped if you have Xcode installed.

USAGE EXAMPLES:

Let's say you want to compile a file called test.cpp, then you can do this by running:

• Clang:

  • 32 bit: o32-clang++ test.cpp -O3 -o test OR i386-apple-darwinXX-clang++ test.cpp -O3 -o test
  • 64 bit: o64-clang++ test.cpp -O3 -o test OR x86_64-apple-darwinXX-clang++ test.cpp -O3 -o test

• GCC:

  • 32 bit: o32-g++ test.cpp -O3 -o test OR i386-apple-darwinXX-g++ test.cpp -O3 -o test
  • 64 bit: o64-g++ test.cpp -O3 -o test OR x86_64-apple-darwinXX-g++ test.cpp -O3 -o test

XX= the target version, you can find it out by running osxcross-conf and then see TARGET.

You can use the shortcut o32-... or i386-apple-darwin... what ever you like more.

I'll continue from now on with o32-clang, but remember, you can simply replace it with o32-gcc or i386-apple-darwin....

Building Makefile based projects:

• make CC=o32-clang CXX=o32-clang++

Building automake based projects:

• CC=o32-clang CXX=o32-clang++ ./configure --host=i386-apple-darwinXX

Building test.cpp with libc++:

Note: libc++ requires Mac OS X 10.7 or newer! If you really need C++11 for
an older OS X version, then you can do the following:

1. Build GCC so you have an up-to-date libstdc++
2. Build your source code with GCC or with clang and '-oc-use-gcc-libs'

Usage Examples:

• Clang:

  • C++98: o32-clang++ -stdlib=libc++ test.cpp -o test
  • C++11: o32-clang++ -stdlib=libc++ -std=c++11 tes1.cpp -o test
  • C++1y: o32-clang++ -stdlib=libc++ -std=c++1y test1.cpp -o test

• Clang (shortcut):

  • C++98: o32-clang++-libc++ test.cpp -o test
  • C++11: o32-clang++-libc++ -std=c++11 test.cpp -o test
  • C++1y: o32-clang++-libc++ -std=c++1y test.cpp -o test

• GCC (defaults to C++11 with libc++)

  • C++11: o32-g++-libc++ test.cpp
  • C++1y: o32-g++-libc++ -std=c++1y test.cpp -o test

Building test1.cpp and test2.cpp with LTO (Link Time Optimization):

• build the first object file: o32-clang++ test1.cpp -O3 -flto -c
• build the second object file: o32-clang++ test2.cpp -O3 -flto -c
• link them with LTO: o32-clang++ -O3 -flto test1.o test2.o -o test

Building a universal binary:

• Clang:
  • o64-clang++ test.cpp -O3 -arch i386 -arch x86_64 -o test
• GCC:
  • build the 32 bit binary: o32-g++ test.cpp -O3 -o test.i386
  • build the 64 bit binary: o64-g++ test.cpp -O3 -o test.x86_64
  • use lipo to generate the universal binary: x86_64-apple darwinXX-lipo -create test.i386 test.x86_64 -output test

DEPLOYMENT TARGET:

The default deployment target is Mac OS X 10.5.

However, there are several ways to override the default value:

1. by passing OSX_VERSION_MIN=10.x to ./build.sh
2. by passing -mmacosx-version-min=10.x to the compiler
3. by setting the MACOSX_DEPLOYMENT_TARGET environment variable

>= 10.9 also defaults to libc++ instead of libstdc++, this behavior
can be overriden by explicitly passing -stdlib=libstdc++ to clang.

LICENSE:

• scripts/wrapper: GPLv2
• cctools/ld64: APSL 2.0
• xar: New BSD
• bc: GPLv3

CREDITS:

• cjacker for the cctools linux port