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 18functions. 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============ ======================== ============ ======================== 47Any i386, x86_64, ARM Clang SjLj 48Bare Metal ARM Clang, GCC EHABI 49FreeBSD i386, x86_64, ARM64 Clang DWARF CFI 50iOS ARM Clang SjLj 51Linux ARM Clang, GCC EHABI 52Linux i386, x86_64, ARM64 Clang, GCC DWARF CFI 53macOS i386, x86_64 Clang, GCC DWARF CFI 54NetBSD x86_64 Clang, GCC DWARF CFI 55Windows i386, x86_64, ARM, ARM64 Clang DWARF CFI 56============ ======================== ============ ======================== 57 58The following minimum compiler versions are strongly recommended. 59 60* Clang 3.5 and above 61* GCC 4.7 and above. 62 63Anything older *may* work. 64 65Notes and Known Issues 66---------------------- 67 68* TODO 69 70 71Getting Involved 72================ 73 74First please review our `Developer's Policy <https://llvm.org/docs/DeveloperPolicy.html>`__ 75and `Getting started with LLVM <https://llvm.org/docs/GettingStarted.html>`__. 76 77**Bug Reports** 78 79If you think you've found a bug in libunwind, please report it using 80the `LLVM bug tracker`_. If you're not sure, you 81can ask for support on the `Runtimes forum`_ or on Discord. 82Please use the tag "libunwind" for new threads. 83 84**Patches** 85 86If you want to contribute a patch to libunwind, please start by reading the LLVM 87`documentation about contributing <https://www.llvm.org/docs/Contributing.html>`__. 88 89**Discussion and Questions** 90 91Send discussions and questions to the `Runtimes forum`_. Please add the tag "libunwind" to your post. 92 93 94Quick Links 95=========== 96* `LLVM Homepage <https://llvm.org/>`_ 97* `LLVM Bug Tracker <https://github.com/llvm/llvm-project/labels/libunwind/>`_ 98* `Clang Discourse Forums <https://discourse.llvm.org/c/clang/6>`_ 99* `cfe-commits Mailing List <http://lists.llvm.org/mailman/listinfo/cfe-commits>`_ 100* `Runtimes Forum <https://discourse.llvm.org/tags/c/runtimes>`_ 101* `Browse libunwind Sources <https://github.com/llvm/llvm-project/blob/main/libunwind/>`_ 102