10 .. _build instructions:
15 On Mac OS, the easiest way to get this library is to link with -lSystem.
16 However if you want to build tip-of-trunk from here (getting the bleeding
19 The basic steps needed to build libc++ are:
21 #. Checkout LLVM, libunwind, and related projects:
23 * ``cd where-you-want-llvm-to-live``
24 * ``git clone https://github.com/llvm/llvm-project.git``
26 #. Configure and build libunwind:
28 CMake is the only supported configuration system.
30 Clang is the preferred compiler when building and using libunwind.
32 * ``cd where you want to build llvm``
35 * ``cmake -G <generator> -DLLVM_ENABLE_RUNTIMES=libunwind [options] <llvm-monorepo>/runtimes``
37 For more information about configuring libunwind see :ref:`CMake Options`.
39 * ``make unwind`` --- will build libunwind.
40 * ``make check-unwind`` --- will run the test suite.
42 Shared and static libraries for libunwind should now be present in llvm/build/lib.
44 #. **Optional**: Install libunwind
46 If your system already provides an unwinder, it is important to be careful
47 not to replace it. Remember Use the CMake option ``CMAKE_INSTALL_PREFIX`` to
48 select a safe place to install libunwind.
50 * ``make install-unwind`` --- Will install the libraries and the headers
53 It is sometimes beneficial to build outside of the LLVM tree. An out-of-tree
54 build would look like this:
58 $ cd where-you-want-libunwind-to-live
59 $ # Check out llvm, and libunwind
60 $ ``svn co https://llvm.org/svn/llvm-project/llvm/trunk llvm``
61 $ ``svn co https://llvm.org/svn/llvm-project/libunwind/trunk libunwind``
62 $ cd where-you-want-to-build
63 $ mkdir build && cd build
64 $ export CC=clang CXX=clang++
65 $ cmake -DLLVM_PATH=path/to/llvm \
75 Here are some of the CMake variables that are used often, along with a
76 brief explanation and LLVM-specific notes. For full documentation, check the
77 CMake docs or execute ``cmake --help-variable VARIABLE_NAME``.
79 **CMAKE_BUILD_TYPE**:STRING
80 Sets the build type for ``make`` based generators. Possible values are
81 Release, Debug, RelWithDebInfo and MinSizeRel. On systems like Visual Studio
82 the user sets the build type with the IDE settings.
84 **CMAKE_INSTALL_PREFIX**:PATH
85 Path where LLVM will be installed if "make install" is invoked or the
86 "INSTALL" target is built.
88 **CMAKE_CXX_COMPILER**:STRING
89 The C++ compiler to use when building and testing libunwind.
92 .. _libunwind-specific options:
94 libunwind specific options
95 --------------------------
97 .. option:: LIBUNWIND_ENABLE_ASSERTIONS:BOOL
101 Toggle assertions independent of the build mode.
103 .. option:: LIBUNWIND_ENABLE_PEDANTIC:BOOL
107 Compile with -Wpedantic.
109 .. option:: LIBUNWIND_ENABLE_WERROR:BOOL
115 .. option:: LIBUNWIND_ENABLE_SHARED:BOOL
119 Build libunwind as a shared library.
121 .. option:: LIBUNWIND_ENABLE_STATIC:BOOL
125 Build libunwind as a static archive.
127 .. option:: LIBUNWIND_ENABLE_CROSS_UNWINDING:BOOL
131 Enable cross-platform unwinding support.
133 .. option:: LIBUNWIND_ENABLE_ARM_WMMX:BOOL
137 Enable unwinding support for ARM WMMX registers.
139 .. option:: LIBUNWIND_ENABLE_THREADS:BOOL
143 Build libunwind with threading support.
145 .. option:: LIBUNWIND_INSTALL_LIBRARY_DIR:PATH
147 **Default**: ``lib${LIBUNWIND_LIBDIR_SUFFIX}``
149 Path where built libunwind libraries should be installed. If a relative path,
150 relative to ``CMAKE_INSTALL_PREFIX``.