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1.. _index:
2
3=======================
4libunwind LLVM Unwinder
5=======================
6
7Overview
8========
9
10libunwind is an implementation of the interface defined by the HP libunwind
11project. It was contributed by Apple as a way to enable clang++ to port to
12platforms that do not have a system unwinder. It is intended to be a small and
13fast implementation of the ABI, leaving off some features of HP's libunwind
14that never materialized (e.g. remote unwinding).
15
16The unwinder has two levels of API. The high level APIs are the `_Unwind_*`
17functions which implement functionality required by `__cxa_*` exception
18funcionts. The low level APIs are the `unw_*` functions which are an interface
19defined by the old HP libunwind project.
20
21Getting Started with libunwind
22------------------------------
23
24.. toctree::
25   :maxdepth: 2
26
27   BuildingLibunwind
28
29Current Status
30--------------
31
32libunwind is a production-quality unwinder, with platform support for DWARF
33unwind info, SjLj, and ARM EHABI.
34
35The low level libunwind API was designed to work either in-process (aka local)
36or to operate on another process (aka remote), but only the local path has been
37implemented. Remote unwinding remains as future work.
38
39Platform and Compiler Support
40-----------------------------
41
42libunwind is known to work on the following platforms:
43
44============ ==================== ============ ========================
45OS           Arch                 Compilers    Unwind Info
46============ ==================== ============ ========================
47Mac OS X     i386, x86_64         Clang, GCC   DWARF CFI
48iOS          ARM                  Clang        SjLj
49Linux        i386, x86_64         Clang, GCC   DWARF CFI
50Linux        ARM                  Clang, GCC   EHABI
51Bare Metal   ARM                  Clang, GCC   EHABI
52NetBSD       x86_64               Clang, GCC   DWARF CFI
53============ ==================== ============ ========================
54
55The following minimum compiler versions are strongly recommended.
56
57* Clang 3.5 and above
58* GCC 4.7 and above.
59
60Anything older *may* work.
61
62Notes and Known Issues
63----------------------
64
65* TODO
66
67
68Getting Involved
69================
70
71First please review our `Developer's Policy <http://llvm.org/docs/DeveloperPolicy.html>`__
72and `Getting started with LLVM <http://llvm.org/docs/GettingStarted.html>`__.
73
74**Bug Reports**
75
76If you think you've found a bug in libunwind, please report it using
77the `LLVM Bugzilla`_. If you're not sure, you
78can post a message to the `cfe-dev mailing list`_ or on IRC.
79Please include "libunwind" in your subject.
80
81**Patches**
82
83If you want to contribute a patch to libunwind, the best place for that is
84`Phabricator <http://llvm.org/docs/Phabricator.html>`_. Please include [libunwind] in the subject and
85add `cfe-commits` as a subscriber. Also make sure you are subscribed to the
86`cfe-commits mailing list <http://lists.llvm.org/mailman/listinfo/cfe-commits>`_.
87
88**Discussion and Questions**
89
90Send discussions and questions to the
91`cfe-dev mailing list <http://lists.llvm.org/mailman/listinfo/cfe-dev>`_.
92Please include [libunwind] in the subject.
93
94
95Quick Links
96===========
97* `LLVM Homepage <http://llvm.org/>`_
98* `LLVM Bugzilla <https://bugs.llvm.org/>`_
99* `cfe-commits Mailing List`_
100* `cfe-dev Mailing List`_
101* `Browse libunwind -- SVN <http://llvm.org/svn/llvm-project/libunwind/trunk/>`_
102* `Browse libunwind -- ViewVC <http://llvm.org/viewvc/llvm-project/libunwind/trunk/>`_
103