## OS X Cross toolchain for Linux and FreeBSD ##

### WHAT IS THE GOAL OF OSXCROSS? ###

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

### HOW DOES IT WORK? ###

[Clang/LLVM is a cross compiler by default](http://clang.llvm.org/docs/CrossCompilation.html) and is now available on nearly every Linux distribution.  
Therefore we "just" need a proper
[port](https://github.com/tpoechtrager/cctools-port)
of the [cctools](http://www.opensource.apple.com/tarballs/cctools) (ld, lipo, ...) for Linux, 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)? ###

* Debug info is weak because of the [missing](https://github.com/tpoechtrager/osxcross/blob/master/patches/gcc-dsymutil.patch)
      [`dsymutil`](http://www.manpagez.com/man/1/dsymutil) (debugger shows only function names).  
  The source code of dsymutil is not publicly available, so it can't be ported to other platforms.  
  But you probably don't want debug symbols anyway if you build on a non OS X system.

* GCC itself [doesn't build with GCC](https://github.com/tpoechtrager/osxcross/commit/12f5dcdde4bc1000180d25ffda229f0a13cf723d),
      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: ###

Download the SDK version (links below) you want to the tarball/ (important!) directory.

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

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

Hint: On Ubuntu 12.04 LTS you can use [llvm.org/apt](http://llvm.org/apt) to get a newer version of clang.

Now edit the `SDK_VERSION` in `build.sh`, so it matches the version you have downloaded before.

Then run `./build.sh` to build the cross toolchain (It will build in it's 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 libc++: #####

If you want to build libc++ for modern C++11 with clang, then you can do this by running `./build_libcxx.sh`.  
The resulting library will be linked statically into the applications, to avoid troubles with different  
libc++.dylib versions on OS X.

See below in how to use libc++ as the standard library.

##### 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 mpc-dev mpfr-dev gmp-dev` to install them.

### SDK DOWNLOAD LINKS: ###

### 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++: #####

* 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`


### LICENSE: ####
  * bash scripts: GPLv2
  * cctools: APSL 2.0
  * xar: New BSD


### CREDITS: ####
 * [cjacker for the cctools linux port](https://code.google.com/p/ios-toolchain-based-on-clang-for-linux/source/browse/#svn%2Ftrunk%2Fcctools-porting%2Fpatches)