forked from OSchip/llvm-project
546 lines
16 KiB
ReStructuredText
546 lines
16 KiB
ReStructuredText
.. _BuildingLibcxx:
|
|
|
|
===============
|
|
Building libc++
|
|
===============
|
|
|
|
.. contents::
|
|
:local:
|
|
|
|
.. _build instructions:
|
|
|
|
Getting Started
|
|
===============
|
|
|
|
On Mac OS 10.7 (Lion) and later, the easiest way to get this library is to install
|
|
Xcode 4.2 or later. However if you want to install tip-of-trunk from here
|
|
(getting the bleeding edge), read on.
|
|
|
|
The basic steps needed to build libc++ are:
|
|
|
|
#. Checkout LLVM:
|
|
|
|
* ``cd where-you-want-llvm-to-live``
|
|
* ``svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm``
|
|
|
|
#. Checkout libc++:
|
|
|
|
* ``cd where-you-want-llvm-to-live``
|
|
* ``cd llvm/projects``
|
|
* ``svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx``
|
|
|
|
#. Checkout libc++abi:
|
|
|
|
* ``cd where-you-want-llvm-to-live``
|
|
* ``cd llvm/projects``
|
|
* ``svn co http://llvm.org/svn/llvm-project/libcxxabi/trunk libcxxabi``
|
|
|
|
#. Configure and build libc++ with libc++abi:
|
|
|
|
CMake is the only supported configuration system.
|
|
|
|
Clang is the preferred compiler when building and using libc++.
|
|
|
|
* ``cd where you want to build llvm``
|
|
* ``mkdir build``
|
|
* ``cd build``
|
|
* ``cmake -G <generator> [options] <path to llvm sources>``
|
|
|
|
For more information about configuring libc++ see :ref:`CMake Options`.
|
|
|
|
* ``make cxx`` --- will build libc++ and libc++abi.
|
|
* ``make check-cxx check-cxxabi`` --- will run the test suites.
|
|
|
|
Shared libraries for libc++ and libc++ abi should now be present in llvm/build/lib.
|
|
See :ref:`using an alternate libc++ installation <alternate libcxx>`
|
|
|
|
#. **Optional**: Install libc++ and libc++abi
|
|
|
|
If your system already provides a libc++ installation it is important to be
|
|
careful not to replace it. Remember Use the CMake option ``CMAKE_INSTALL_PREFIX`` to
|
|
select a safe place to install libc++.
|
|
|
|
* ``make install-cxx install-cxxabi`` --- Will install the libraries and the headers
|
|
|
|
.. warning::
|
|
* Replacing your systems libc++ installation could render the system non-functional.
|
|
* Mac OS X will not boot without a valid copy of ``libc++.1.dylib`` in ``/usr/lib``.
|
|
|
|
|
|
The instructions are for building libc++ on
|
|
FreeBSD, Linux, or Mac using `libc++abi`_ as the C++ ABI library.
|
|
On Linux, it is also possible to use :ref:`libsupc++ <libsupcxx>` or libcxxrt.
|
|
|
|
It is sometimes beneficial to build outside of the LLVM tree. An out-of-tree
|
|
build would look like this:
|
|
|
|
.. code-block:: bash
|
|
|
|
$ cd where-you-want-libcxx-to-live
|
|
$ # Check out llvm, libc++ and libc++abi.
|
|
$ ``svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm``
|
|
$ ``svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx``
|
|
$ ``svn co http://llvm.org/svn/llvm-project/libcxxabi/trunk libcxxabi``
|
|
$ cd where-you-want-to-build
|
|
$ mkdir build && cd build
|
|
$ export CC=clang CXX=clang++
|
|
$ cmake -DLLVM_PATH=path/to/llvm \
|
|
-DLIBCXX_CXX_ABI=libcxxabi \
|
|
-DLIBCXX_CXX_ABI_INCLUDE_PATHS=path/to/libcxxabi/include \
|
|
path/to/libcxx
|
|
$ make
|
|
$ make check-libcxx # optional
|
|
|
|
|
|
Experimental Support for Windows
|
|
--------------------------------
|
|
|
|
The Windows support requires building with clang-cl as cl does not support one
|
|
required extension: `#include_next`. Furthermore, VS 2015 or newer (19.00) is
|
|
required. In the case of clang-cl, we need to specify the "MS Compatibility
|
|
Version" as it defaults to 2014 (18.00).
|
|
|
|
CMake + Visual Studio
|
|
~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Building with Visual Studio currently does not permit running tests. However,
|
|
it is the simplest way to build.
|
|
|
|
.. code-block:: batch
|
|
|
|
> cmake -G "Visual Studio 14 2015" ^
|
|
-T "LLVM-vs2014" ^
|
|
-DLIBCXX_ENABLE_SHARED=YES ^
|
|
-DLIBCXX_ENABLE_STATIC=NO ^
|
|
-DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=NO ^
|
|
\path\to\libcxx
|
|
> cmake --build .
|
|
|
|
CMake + ninja
|
|
~~~~~~~~~~~~~
|
|
|
|
Building with ninja is required for development to enable tests.
|
|
Unfortunately, doing so requires additional configuration as we cannot
|
|
just specify a toolset.
|
|
|
|
.. code-block:: batch
|
|
|
|
> cmake -G Ninja ^
|
|
-DCMAKE_MAKE_PROGRAM=/path/to/ninja ^
|
|
-DCMAKE_SYSTEM_NAME=Windows ^
|
|
-DCMAKE_C_COMPILER=clang-cl ^
|
|
-DCMAKE_C_FLAGS="-fms-compatibility-version=19.00 --target=i686--windows" ^
|
|
-DCMAKE_CXX_COMPILER=clang-cl ^
|
|
-DCMAKE_CXX_FLAGS="-fms-compatibility-version=19.00 --target=i686--windows" ^
|
|
-DLLVM_PATH=/path/to/llvm/tree ^
|
|
-DLIBCXX_ENABLE_SHARED=YES ^
|
|
-DLIBCXX_ENABLE_STATIC=NO ^
|
|
-DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=NO ^
|
|
\path\to\libcxx
|
|
> /path/to/ninja cxx
|
|
> /path/to/ninja check-cxx
|
|
|
|
Note that the paths specified with backward slashes must use the `\\` as the
|
|
directory separator as clang-cl may otherwise parse the path as an argument.
|
|
|
|
.. _`libc++abi`: http://libcxxabi.llvm.org/
|
|
|
|
|
|
.. _CMake Options:
|
|
|
|
CMake Options
|
|
=============
|
|
|
|
Here are some of the CMake variables that are used often, along with a
|
|
brief explanation and LLVM-specific notes. For full documentation, check the
|
|
CMake docs or execute ``cmake --help-variable VARIABLE_NAME``.
|
|
|
|
**CMAKE_BUILD_TYPE**:STRING
|
|
Sets the build type for ``make`` based generators. Possible values are
|
|
Release, Debug, RelWithDebInfo and MinSizeRel. On systems like Visual Studio
|
|
the user sets the build type with the IDE settings.
|
|
|
|
**CMAKE_INSTALL_PREFIX**:PATH
|
|
Path where LLVM will be installed if "make install" is invoked or the
|
|
"INSTALL" target is built.
|
|
|
|
**CMAKE_CXX_COMPILER**:STRING
|
|
The C++ compiler to use when building and testing libc++.
|
|
|
|
|
|
.. _libcxx-specific options:
|
|
|
|
libc++ specific options
|
|
-----------------------
|
|
|
|
.. option:: LIBCXX_INSTALL_LIBRARY:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Toggle the installation of the library portion of libc++.
|
|
|
|
.. option:: LIBCXX_INSTALL_HEADERS:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Toggle the installation of the libc++ headers.
|
|
|
|
.. option:: LIBCXX_ENABLE_ASSERTIONS:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Build libc++ with assertions enabled.
|
|
|
|
.. option:: LIBCXX_BUILD_32_BITS:BOOL
|
|
|
|
**Default**: ``OFF``
|
|
|
|
Build libc++ as a 32 bit library. Also see `LLVM_BUILD_32_BITS`.
|
|
|
|
.. option:: LIBCXX_ENABLE_SHARED:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Build libc++ as a shared library. Either `LIBCXX_ENABLE_SHARED` or
|
|
`LIBCXX_ENABLE_STATIC` has to be enabled.
|
|
|
|
.. option:: LIBCXX_ENABLE_STATIC:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Build libc++ as a static library. Either `LIBCXX_ENABLE_SHARED` or
|
|
`LIBCXX_ENABLE_STATIC` has to be enabled.
|
|
|
|
.. option:: LIBCXX_LIBDIR_SUFFIX:STRING
|
|
|
|
Extra suffix to append to the directory where libraries are to be installed.
|
|
This option overrides `LLVM_LIBDIR_SUFFIX`.
|
|
|
|
.. option:: LIBCXX_INSTALL_PREFIX:STRING
|
|
|
|
**Default**: ``""``
|
|
|
|
Define libc++ destination prefix.
|
|
|
|
.. _libc++experimental options:
|
|
|
|
libc++experimental Specific Options
|
|
------------------------------------
|
|
|
|
.. option:: LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Build and test libc++experimental.a.
|
|
|
|
.. option:: LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY:BOOL
|
|
|
|
**Default**: ``LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY AND LIBCXX_INSTALL_LIBRARY``
|
|
|
|
Install libc++experimental.a alongside libc++.
|
|
|
|
|
|
.. option:: LIBCXX_ENABLE_FILESYSTEM:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Build filesystem as a standalone library libc++fs.a.
|
|
|
|
.. option:: LIBCXX_INSTALL_FILESYSTEM_LIBRARY:BOOL
|
|
|
|
**Default**: ``LIBCXX_ENABLE_FILESYSTEM AND LIBCXX_INSTALL_LIBRARY``
|
|
|
|
Install libc++fs.a alongside libc++.
|
|
|
|
.. _ABI Library Specific Options:
|
|
|
|
ABI Library Specific Options
|
|
----------------------------
|
|
|
|
.. option:: LIBCXX_CXX_ABI:STRING
|
|
|
|
**Values**: ``none``, ``libcxxabi``, ``libcxxrt``, ``libstdc++``, ``libsupc++``.
|
|
|
|
Select the ABI library to build libc++ against.
|
|
|
|
.. option:: LIBCXX_CXX_ABI_INCLUDE_PATHS:PATHS
|
|
|
|
Provide additional search paths for the ABI library headers.
|
|
|
|
.. option:: LIBCXX_CXX_ABI_LIBRARY_PATH:PATH
|
|
|
|
Provide the path to the ABI library that libc++ should link against.
|
|
|
|
.. option:: LIBCXX_ENABLE_STATIC_ABI_LIBRARY:BOOL
|
|
|
|
**Default**: ``OFF``
|
|
|
|
If this option is enabled, libc++ will try and link the selected ABI library
|
|
statically.
|
|
|
|
.. option:: LIBCXX_ENABLE_ABI_LINKER_SCRIPT:BOOL
|
|
|
|
**Default**: ``ON`` by default on UNIX platforms other than Apple unless
|
|
'LIBCXX_ENABLE_STATIC_ABI_LIBRARY' is ON. Otherwise the default value is ``OFF``.
|
|
|
|
This option generate and installs a linker script as ``libc++.so`` which
|
|
links the correct ABI library.
|
|
|
|
.. option:: LIBCXXABI_USE_LLVM_UNWINDER:BOOL
|
|
|
|
**Default**: ``OFF``
|
|
|
|
Build and use the LLVM unwinder. Note: This option can only be used when
|
|
libc++abi is the C++ ABI library used.
|
|
|
|
|
|
libc++ Feature Options
|
|
----------------------
|
|
|
|
.. option:: LIBCXX_ENABLE_EXCEPTIONS:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Build libc++ with exception support.
|
|
|
|
.. option:: LIBCXX_ENABLE_RTTI:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Build libc++ with run time type information.
|
|
|
|
.. option:: LIBCXX_INCLUDE_BENCHMARKS:BOOL
|
|
|
|
**Default**: ``ON``
|
|
|
|
Build the libc++ benchmark tests and the Google Benchmark library needed
|
|
to support them.
|
|
|
|
.. option:: LIBCXX_BENCHMARK_TEST_ARGS:STRING
|
|
|
|
**Default**: ``--benchmark_min_time=0.01``
|
|
|
|
A semicolon list of arguments to pass when running the libc++ benchmarks using the
|
|
``check-cxx-benchmarks`` rule. By default we run the benchmarks for a very short amount of time,
|
|
since the primary use of ``check-cxx-benchmarks`` is to get test and sanitizer coverage, not to
|
|
get accurate measurements.
|
|
|
|
.. option:: LIBCXX_BENCHMARK_NATIVE_STDLIB:STRING
|
|
|
|
**Default**:: ``""``
|
|
|
|
**Values**:: ``libc++``, ``libstdc++``
|
|
|
|
Build the libc++ benchmark tests and Google Benchmark library against the
|
|
specified standard library on the platform. On linux this can be used to
|
|
compare libc++ to libstdc++ by building the benchmark tests against both
|
|
standard libraries.
|
|
|
|
.. option:: LIBCXX_BENCHMARK_NATIVE_GCC_TOOLCHAIN:STRING
|
|
|
|
Use the specified GCC toolchain and standard library when building the native
|
|
stdlib benchmark tests.
|
|
|
|
.. option:: LIBCXX_HIDE_FROM_ABI_PER_TU_BY_DEFAULT:BOOL
|
|
|
|
**Default**: ``OFF``
|
|
|
|
Pick the default for whether to constrain ABI-unstable symbols to
|
|
each individual translation unit. This setting controls whether
|
|
`_LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT` is defined by default --
|
|
see the documentation of that macro for details.
|
|
|
|
|
|
libc++ ABI Feature Options
|
|
--------------------------
|
|
|
|
The following options allow building libc++ for a different ABI version.
|
|
|
|
.. option:: LIBCXX_ABI_VERSION:STRING
|
|
|
|
**Default**: ``1``
|
|
|
|
Defines the target ABI version of libc++.
|
|
|
|
.. option:: LIBCXX_ABI_UNSTABLE:BOOL
|
|
|
|
**Default**: ``OFF``
|
|
|
|
Build the "unstable" ABI version of libc++. Includes all ABI changing features
|
|
on top of the current stable version.
|
|
|
|
.. option:: LIBCXX_ABI_NAMESPACE:STRING
|
|
|
|
**Default**: ``__n`` where ``n`` is the current ABI version.
|
|
|
|
This option defines the name of the inline ABI versioning namespace. It can be used for building
|
|
custom versions of libc++ with unique symbol names in order to prevent conflicts or ODR issues
|
|
with other libc++ versions.
|
|
|
|
.. warning::
|
|
When providing a custom namespace, it's the users responsibility to ensure the name won't cause
|
|
conflicts with other names defined by libc++, both now and in the future. In particular, inline
|
|
namespaces of the form ``__[0-9]+`` are strictly reserved by libc++ and may not be used by users.
|
|
Doing otherwise could cause conflicts and hinder libc++ ABI evolution.
|
|
|
|
.. option:: LIBCXX_ABI_DEFINES:STRING
|
|
|
|
**Default**: ``""``
|
|
|
|
A semicolon-separated list of ABI macros to persist in the site config header.
|
|
See ``include/__config`` for the list of ABI macros.
|
|
|
|
.. _LLVM-specific variables:
|
|
|
|
LLVM-specific options
|
|
---------------------
|
|
|
|
.. option:: LLVM_LIBDIR_SUFFIX:STRING
|
|
|
|
Extra suffix to append to the directory where libraries are to be
|
|
installed. On a 64-bit architecture, one could use ``-DLLVM_LIBDIR_SUFFIX=64``
|
|
to install libraries to ``/usr/lib64``.
|
|
|
|
.. option:: LLVM_BUILD_32_BITS:BOOL
|
|
|
|
Build 32-bits executables and libraries on 64-bits systems. This option is
|
|
available only on some 64-bits unix systems. Defaults to OFF.
|
|
|
|
.. option:: LLVM_LIT_ARGS:STRING
|
|
|
|
Arguments given to lit. ``make check`` and ``make clang-test`` are affected.
|
|
By default, ``'-sv --no-progress-bar'`` on Visual C++ and Xcode, ``'-sv'`` on
|
|
others.
|
|
|
|
|
|
Using Alternate ABI libraries
|
|
=============================
|
|
|
|
|
|
.. _libsupcxx:
|
|
|
|
Using libsupc++ on Linux
|
|
------------------------
|
|
|
|
You will need libstdc++ in order to provide libsupc++.
|
|
|
|
Figure out where the libsupc++ headers are on your system. On Ubuntu this
|
|
is ``/usr/include/c++/<version>`` and ``/usr/include/c++/<version>/<target-triple>``
|
|
|
|
You can also figure this out by running
|
|
|
|
.. code-block:: bash
|
|
|
|
$ echo | g++ -Wp,-v -x c++ - -fsyntax-only
|
|
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
|
|
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../x86_64-linux-gnu/include"
|
|
#include "..." search starts here:
|
|
#include <...> search starts here:
|
|
/usr/include/c++/4.7
|
|
/usr/include/c++/4.7/x86_64-linux-gnu
|
|
/usr/include/c++/4.7/backward
|
|
/usr/lib/gcc/x86_64-linux-gnu/4.7/include
|
|
/usr/local/include
|
|
/usr/lib/gcc/x86_64-linux-gnu/4.7/include-fixed
|
|
/usr/include/x86_64-linux-gnu
|
|
/usr/include
|
|
End of search list.
|
|
|
|
Note that the first two entries happen to be what we are looking for. This
|
|
may not be correct on other platforms.
|
|
|
|
We can now run CMake:
|
|
|
|
.. code-block:: bash
|
|
|
|
$ CC=clang CXX=clang++ cmake -G "Unix Makefiles" \
|
|
-DLIBCXX_CXX_ABI=libstdc++ \
|
|
-DLIBCXX_CXX_ABI_INCLUDE_PATHS="/usr/include/c++/4.7/;/usr/include/c++/4.7/x86_64-linux-gnu/" \
|
|
-DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/usr \
|
|
<libc++-source-dir>
|
|
|
|
|
|
You can also substitute ``-DLIBCXX_CXX_ABI=libsupc++``
|
|
above, which will cause the library to be linked to libsupc++ instead
|
|
of libstdc++, but this is only recommended if you know that you will
|
|
never need to link against libstdc++ in the same executable as libc++.
|
|
GCC ships libsupc++ separately but only as a static library. If a
|
|
program also needs to link against libstdc++, it will provide its
|
|
own copy of libsupc++ and this can lead to subtle problems.
|
|
|
|
.. code-block:: bash
|
|
|
|
$ make cxx
|
|
$ make install
|
|
|
|
You can now run clang with -stdlib=libc++.
|
|
|
|
|
|
.. _libcxxrt_ref:
|
|
|
|
Using libcxxrt on Linux
|
|
------------------------
|
|
|
|
You will need to keep the source tree of `libcxxrt`_ available
|
|
on your build machine and your copy of the libcxxrt shared library must
|
|
be placed where your linker will find it.
|
|
|
|
We can now run CMake like:
|
|
|
|
.. code-block:: bash
|
|
|
|
$ CC=clang CXX=clang++ cmake -G "Unix Makefiles" \
|
|
-DLIBCXX_CXX_ABI=libcxxrt \
|
|
-DLIBCXX_CXX_ABI_INCLUDE_PATHS=path/to/libcxxrt-sources/src \
|
|
-DCMAKE_BUILD_TYPE=Release \
|
|
-DCMAKE_INSTALL_PREFIX=/usr \
|
|
<libc++-source-directory>
|
|
$ make cxx
|
|
$ make install
|
|
|
|
Unfortunately you can't simply run clang with "-stdlib=libc++" at this point, as
|
|
clang is set up to link for libc++ linked to libsupc++. To get around this
|
|
you'll have to set up your linker yourself (or patch clang). For example,
|
|
|
|
.. code-block:: bash
|
|
|
|
$ clang++ -stdlib=libc++ helloworld.cpp \
|
|
-nodefaultlibs -lc++ -lcxxrt -lm -lc -lgcc_s -lgcc
|
|
|
|
Alternately, you could just add libcxxrt to your libraries list, which in most
|
|
situations will give the same result:
|
|
|
|
.. code-block:: bash
|
|
|
|
$ clang++ -stdlib=libc++ helloworld.cpp -lcxxrt
|
|
|
|
.. _`libcxxrt`: https://github.com/pathscale/libcxxrt/
|
|
|
|
|
|
Using a local ABI library installation
|
|
---------------------------------------
|
|
|
|
.. warning::
|
|
This is not recommended in almost all cases.
|
|
|
|
These instructions should only be used when you can't install your ABI library.
|
|
|
|
Normally you must link libc++ against a ABI shared library that the
|
|
linker can find. If you want to build and test libc++ against an ABI
|
|
library not in the linker's path you needq to set
|
|
``-DLIBCXX_CXX_ABI_LIBRARY_PATH=/path/to/abi/lib`` when configuring CMake.
|
|
|
|
An example build using libc++abi would look like:
|
|
|
|
.. code-block:: bash
|
|
|
|
$ CC=clang CXX=clang++ cmake \
|
|
-DLIBCXX_CXX_ABI=libc++abi \
|
|
-DLIBCXX_CXX_ABI_INCLUDE_PATHS="/path/to/libcxxabi/include" \
|
|
-DLIBCXX_CXX_ABI_LIBRARY_PATH="/path/to/libcxxabi-build/lib" \
|
|
path/to/libcxx
|
|
$ make
|
|
|
|
When testing libc++ LIT will automatically link against the proper ABI
|
|
library.
|