osxcross/README.md

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 CAN I BUILD WITH IT?

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

PACKET MANAGERS

OSXCross comes with a minimalistic MacPorts Packet Manager.
Please see README.MACPORTS for more.

INSTALLATION:

Move your packaged SDK to the tarballs/ directory.

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

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

--
You can run 'sudo tools/get_dependencies.sh' to get these automatically.

'[INSTALLPREFIX=...] ./build_clang.sh' can be used to build a recent clang version
from source (requires gcc and g++).

On debian like systems you can also use llvm.org/apt to get a newer version of clang.
But be careful, that repository is known to cause troubles.
--

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

Do not forget to add <path>/target/bin to your PATH variable.

That's it. See usage examples below.

Building GCC:

If you want to build GCC as well, then you can do this by running:
[GCC_VERSION=5.1.0] [ENABLE_FORTRAN=1] ./build_gcc.sh.

A gfortran usage example can be found [here](https://github.com/tpoechtrager/osxcross/issues/28#issuecomment-67047134)]

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:

`[sudo] apt-get install gcc g++ zlib1g-dev libmpc-dev libmpfr-dev libgmp-dev`  

to install them.

ATTENTION:

OSXCross links libgcc and libstdc++ statically by default (this affects `-oc-use-gcc-libs` too).  
You can turn this behavior off with `OSXCROSS_GCC_NO_STATIC_RUNTIME=1` (env).

### PACKAGING THE SDK: ###

If you need a recent SDK, then you must do the SDK packaging on OS X.  
Recent Xcode images are compressed, but the Linux kernel does not  
support HFS+ compression.

##### Packaging the SDK on Mac OS X: #####

1. [Download [Xcode](https://developer.apple.com/downloads/index.action?name=Xcode%205.1.1) \*\*]
2. [Mount Xcode.dmg (Open With -> DiskImageMounter) \*\*\*]
3. Run: `./tools/gen_sdk_package.sh` (from the OSXCross package)
4. Copy the packaged SDK (\*.tar.\* or \*.pkg) on a USB Stick
5. (On Linux/BSD) Copy or move the SDK into the tarballs/ directory of OSXCross

\*\* Xcode 4.6, 5.0+, 6.0, and the 6.1 Betas are known to work.  
\*\*\* If you get a dialog with a crossed circle, ignore it, you don't need to install Xcode.

Step 1. and 2. can be skipped if you have Xcode installed.

##### Packing the SDK on Linux, Method 1 (does *NOT* work with Xcode 4.3 or later!): #####

1. Download
   [Xcode 4.2](https://startpage.com/do/search?q=stackoverflow+xcode+4.2+download+snow+leopard)
   for Snow Leopard \*\*
2. Ensure you are downloading the "Snow Leopard" version
3. Install `dmg2img`
4. Run (as root): `./tools/mount_xcode_image.sh /path/to/xcode.dmg`
5. Follow the instructions printed by `./tools/mount_xcode_image.sh`
6. Copy or move the SDK into the tarballs/ directory

\*\* SHA1 Sum: 1a06882638996dfbff65ea6b4c6625842903ead3.

##### Packing the SDK on Linux, Method 2 (*UNSUPPORTED* - but works with Xcode >= 4.3): #####

1. Download Xcode like described in 'Packaging the SDK on Mac OS X'
2. Download and build [HFSExplorer](http://www.catacombae.org/hfsexplorer/)
   (you will need `openjdk` and `ant`)
3. Open the HFSExplorer GUI (do *NOT* use the command line utility)
4. Open the Xcode image
5. Right click on the Xcode (not Xcode.app) folder and choose 'extract data'
6. Answer the 'Follow Symlinks' dialog with 'No'
7. Click on '>>' and choose 'Quiet mode'
8. Click away all the annoying Java errors
9. Run: `XCODEDIR=/path/to/extracted-xcode/Xcode ./tools/gen_sdk_package.sh`
10. Copy or move the SDK into the tarballs/ directory

### 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.

x86\_64h defaults to `Mac OS X 10.8` and requires clang 3.5+.  
x86\_64h = x86\_64 with optimizations for the Intel Haswell Architecture.

### LICENSE: ####
  * scripts/wrapper: GPLv2
  * cctools/ld64: 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)