|  | .. _index: | 
|  |  | 
|  | ======================= | 
|  | libunwind LLVM Unwinder | 
|  | ======================= | 
|  |  | 
|  | Overview | 
|  | ======== | 
|  |  | 
|  | libunwind is an implementation of the interface defined by the HP libunwind | 
|  | project. It was contributed by Apple as a way to enable clang++ to port to | 
|  | platforms that do not have a system unwinder. It is intended to be a small and | 
|  | fast implementation of the ABI, leaving off some features of HP's libunwind | 
|  | that never materialized (e.g. remote unwinding). | 
|  |  | 
|  | The unwinder has two levels of API. The high level APIs are the `_Unwind_*` | 
|  | functions which implement functionality required by `__cxa_*` exception | 
|  | functions. The low level APIs are the `unw_*` functions which are an interface | 
|  | defined by the old HP libunwind project. | 
|  |  | 
|  | Getting Started with libunwind | 
|  | ------------------------------ | 
|  |  | 
|  | .. toctree:: | 
|  | :maxdepth: 2 | 
|  |  | 
|  | BuildingLibunwind | 
|  |  | 
|  | Current Status | 
|  | -------------- | 
|  |  | 
|  | libunwind is a production-quality unwinder, with platform support for DWARF | 
|  | unwind info, SjLj, and ARM EHABI. | 
|  |  | 
|  | The low level libunwind API was designed to work either in-process (aka local) | 
|  | or to operate on another process (aka remote), but only the local path has been | 
|  | implemented. Remote unwinding remains as future work. | 
|  |  | 
|  | Platform and Compiler Support | 
|  | ----------------------------- | 
|  |  | 
|  | libunwind is known to work on the following platforms: | 
|  |  | 
|  | ============ ======================== ============ ======================== | 
|  | OS           Arch                     Compilers    Unwind Info | 
|  | ============ ======================== ============ ======================== | 
|  | Any          i386, x86_64, ARM        Clang        SjLj | 
|  | Bare Metal   ARM                      Clang, GCC   EHABI | 
|  | FreeBSD      i386, x86_64, ARM64      Clang        DWARF CFI | 
|  | iOS          ARM                      Clang        SjLj | 
|  | Linux        ARM                      Clang, GCC   EHABI | 
|  | Linux        i386, x86_64, ARM64      Clang, GCC   DWARF CFI | 
|  | Mac OS X     i386, x86_64             Clang, GCC   DWARF CFI | 
|  | NetBSD       x86_64                   Clang, GCC   DWARF CFI | 
|  | Windows      i386, x86_64, ARM, ARM64 Clang        DWARF CFI | 
|  | ============ ======================== ============ ======================== | 
|  |  | 
|  | The following minimum compiler versions are strongly recommended. | 
|  |  | 
|  | * Clang 3.5 and above | 
|  | * GCC 4.7 and above. | 
|  |  | 
|  | Anything older *may* work. | 
|  |  | 
|  | Notes and Known Issues | 
|  | ---------------------- | 
|  |  | 
|  | * TODO | 
|  |  | 
|  |  | 
|  | Getting Involved | 
|  | ================ | 
|  |  | 
|  | First please review our `Developer's Policy <http://llvm.org/docs/DeveloperPolicy.html>`__ | 
|  | and `Getting started with LLVM <http://llvm.org/docs/GettingStarted.html>`__. | 
|  |  | 
|  | **Bug Reports** | 
|  |  | 
|  | If you think you've found a bug in libunwind, please report it using | 
|  | the `LLVM Bugzilla`_. If you're not sure, you | 
|  | can post a message to the `cfe-dev mailing list`_ or on IRC. | 
|  | Please include "libunwind" in your subject. | 
|  |  | 
|  | **Patches** | 
|  |  | 
|  | If you want to contribute a patch to libunwind, the best place for that is | 
|  | `Phabricator <http://llvm.org/docs/Phabricator.html>`_. Please include [libunwind] in the subject and | 
|  | add `cfe-commits` as a subscriber. Also make sure you are subscribed to the | 
|  | `cfe-commits mailing list <http://lists.llvm.org/mailman/listinfo/cfe-commits>`_. | 
|  |  | 
|  | **Discussion and Questions** | 
|  |  | 
|  | Send discussions and questions to the | 
|  | `cfe-dev mailing list <http://lists.llvm.org/mailman/listinfo/cfe-dev>`_. | 
|  | Please include [libunwind] in the subject. | 
|  |  | 
|  |  | 
|  | Quick Links | 
|  | =========== | 
|  | * `LLVM Homepage <http://llvm.org/>`_ | 
|  | * `LLVM Bugzilla <https://bugs.llvm.org/>`_ | 
|  | * `cfe-commits Mailing List`_ | 
|  | * `cfe-dev Mailing List`_ | 
|  | * `Browse libunwind -- SVN <http://llvm.org/svn/llvm-project/libunwind/trunk/>`_ | 
|  | * `Browse libunwind -- ViewVC <http://llvm.org/viewvc/llvm-project/libunwind/trunk/>`_ |