`CMake <http://www.cmake.org/>`_ is a cross-platform build-generator tool. CMake
does not build the project, it generates the files needed by your build tool
-(GNU make, Visual Studio, etc) for building LLVM.
+(GNU make, Visual Studio, etc.) for building LLVM.
If you are really anxious about getting a functional LLVM build, go to the
-`Quick start`_ section. If you are a CMake novice, start on `Basic CMake usage`_
-and then go back to the `Quick start`_ once you know what you are doing. The
+`Quick start`_ section. If you are a CMake novice, start with `Basic CMake usage`_
+and then go back to the `Quick start`_ section once you know what you are doing. The
`Options and variables`_ section is a reference for customizing your build. If
you already have experience with CMake, this is the recommended starting point.
We use here the command-line, non-interactive CMake interface.
#. `Download <http://www.cmake.org/cmake/resources/software.html>`_ and install
- CMake. Version 2.8 is the minimum required.
+ CMake. Version 2.8.8 is the minimum required, but if you're using the Ninja
+ backend, CMake v3.2 or newer is required to `get interactive output
+ <http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20141117/244797.html>`_
+ when running :doc:`Lit <CommandGuide/lit>`.
#. Open a shell. Your development tools must be reachable from this shell
through the PATH environment variable.
-#. Create a directory for containing the build. It is not supported to build
- LLVM on the source directory. cd to this directory:
+#. Create a build directory. Building LLVM in the source
+ directory is not supported. cd to this directory:
.. code-block:: console
$ mkdir mybuilddir
$ cd mybuilddir
-#. Execute this command on the shell replacing `path/to/llvm/source/root` with
+#. Execute this command in the shell replacing `path/to/llvm/source/root` with
the path to the root of your LLVM source tree:
.. code-block:: console
$ cmake path/to/llvm/source/root
- CMake will detect your development environment, perform a series of test and
+ CMake will detect your development environment, perform a series of tests, and
generate the files required for building LLVM. CMake will use default values
for all build parameters. See the `Options and variables`_ section for
- fine-tuning your build
+ a list of build parameters that you can modify.
This can fail if CMake can't detect your toolset, or if it thinks that the
- environment is not sane enough. On this case make sure that the toolset that
- you intend to use is the only one reachable from the shell and that the shell
- itself is the correct one for you development environment. CMake will refuse
+ environment is not sane enough. In this case, make sure that the toolset that
+ you intend to use is the only one reachable from the shell, and that the shell
+ itself is the correct one for your development environment. CMake will refuse
to build MinGW makefiles if you have a POSIX shell reachable through the PATH
environment variable, for instance. You can force CMake to use a given build
- tool, see the `Usage`_ section.
+ tool; for instructions, see the `Usage`_ section, below.
+
+#. After CMake has finished running, proceed to use IDE project files, or start
+ the build from the build directory:
+
+ .. code-block:: console
+
+ $ cmake --build .
+
+ The ``--build`` option tells ``cmake`` to invoke the underlying build
+ tool (``make``, ``ninja``, ``xcodebuild``, ``msbuild``, etc.)
+
+ The underlying build tool can be invoked directly, of course, but
+ the ``--build`` option is portable.
+
+#. After LLVM has finished building, install it from the build directory:
+
+ .. code-block:: console
+
+ $ cmake --build . --target install
+
+ The ``--target`` option with ``install`` parameter in addition to
+ the ``--build`` option tells ``cmake`` to build the ``install`` target.
+
+ It is possible to set a different install prefix at installation time
+ by invoking the ``cmake_install.cmake`` script generated in the
+ build directory:
+
+ .. code-block:: console
+
+ $ cmake -DCMAKE_INSTALL_PREFIX=/tmp/llvm -P cmake_install.cmake
.. _Basic CMake usage:
.. _Usage:
Basic CMake usage
=================
-This section explains basic aspects of CMake, mostly for explaining those
-options which you may need on your day-to-day usage.
+This section explains basic aspects of CMake
+which you may need in your day-to-day usage.
-CMake comes with extensive documentation in the form of html files and on the
-cmake executable itself. Execute ``cmake --help`` for further help options.
+CMake comes with extensive documentation, in the form of html files, and as
+online help accessible via the ``cmake`` executable itself. Execute ``cmake
+--help`` for further help options.
-CMake requires to know for which build tool it shall generate files (GNU make,
-Visual Studio, Xcode, etc). If not specified on the command line, it tries to
-guess it based on you environment. Once identified the build tool, CMake uses
-the corresponding *Generator* for creating files for your build tool. You can
+CMake allows you to specify a build tool (e.g., GNU make, Visual Studio,
+or Xcode). If not specified on the command line, CMake tries to guess which
+build tool to use, based on your environment. Once it has identified your
+build tool, CMake uses the corresponding *Generator* to create files for your
+build tool (e.g., Makefiles or Visual Studio or Xcode project files). You can
explicitly specify the generator with the command line option ``-G "Name of the
-generator"``. For knowing the available generators on your platform, execute
+generator"``. To see a list of the available generators on your system, execute
.. code-block:: console
$ cmake --help
-This will list the generator's names at the end of the help text. Generator's
-names are case-sensitive. Example:
+This will list the generator names at the end of the help text.
+
+Generators' names are case-sensitive, and may contain spaces. For this reason,
+you should enter them exactly as they are listed in the ``cmake --help``
+output, in quotes. For example, to generate project files specifically for
+Visual Studio 12, you can execute:
.. code-block:: console
- $ cmake -G "Visual Studio 10" path/to/llvm/source/root
+ $ cmake -G "Visual Studio 12" path/to/llvm/source/root
For a given development platform there can be more than one adequate
-generator. If you use Visual Studio "NMake Makefiles" is a generator you can use
-for building with NMake. By default, CMake chooses the more specific generator
+generator. If you use Visual Studio, "NMake Makefiles" is a generator you can use
+for building with NMake. By default, CMake chooses the most specific generator
supported by your development environment. If you want an alternative generator,
you must tell this to CMake with the ``-G`` option.
$ cmake -DVARIABLE=value path/to/llvm/source
-You can set a variable after the initial CMake invocation for changing its
+You can set a variable after the initial CMake invocation to change its
value. You can also undefine a variable:
.. code-block:: console
$ cmake -UVARIABLE path/to/llvm/source
-Variables are stored on the CMake cache. This is a file named ``CMakeCache.txt``
-on the root of the build directory. Do not hand-edit it.
+Variables are stored in the CMake cache. This is a file named ``CMakeCache.txt``
+stored at the root of your build directory that is generated by ``cmake``.
+Editing it yourself is not recommended.
-Variables are listed here appending its type after a colon. It is correct to
-write the variable and the type on the CMake command line:
+Variables are listed in the CMake cache and later in this document with
+the variable name and type separated by a colon. You can also specify the
+variable and type on the CMake command line:
.. code-block:: console
Frequently-used CMake variables
-------------------------------
-Here are listed 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``.
+Here are some of the CMake variables that are used often, along with a
+brief explanation and LLVM-specific notes. For full documentation, consult the
+CMake manual, 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.
+ Sets the build type for ``make``-based generators. Possible values are
+ Release, Debug, RelWithDebInfo and MinSizeRel. If you are using an IDE such as
+ Visual Studio, you should use the IDE settings to set the build type.
**CMAKE_INSTALL_PREFIX**:PATH
Path where LLVM will be installed if "make install" is invoked or the
- "INSTALL" target is built.
+ "install" target is built.
**LLVM_LIBDIR_SUFFIX**:STRING
Extra suffix to append to the directory where libraries are to be
**CMAKE_CXX_FLAGS**:STRING
Extra flags to use when compiling C++ source files.
-**BUILD_SHARED_LIBS**:BOOL
- Flag indicating is shared libraries will be built. Its default value is
- OFF. Shared libraries are not supported on Windows and not recommended in the
- other OSes.
-
.. _LLVM-specific variables:
LLVM-specific variables
**LLVM_BUILD_TOOLS**:BOOL
Build LLVM tools. Defaults to ON. Targets for building each tool are generated
- in any case. You can build an tool separately by invoking its target. For
- example, you can build *llvm-as* with a makefile-based system executing *make
- llvm-as* on the root of your build directory.
+ in any case. You can build a tool separately by invoking its target. For
+ example, you can build *llvm-as* with a Makefile-based system by executing *make
+ llvm-as* at the root of your build directory.
**LLVM_INCLUDE_TOOLS**:BOOL
- Generate build targets for the LLVM tools. Defaults to ON. You can use that
- option for disabling the generation of build targets for the LLVM tools.
+ Generate build targets for the LLVM tools. Defaults to ON. You can use this
+ option to disable the generation of build targets for the LLVM tools.
**LLVM_BUILD_EXAMPLES**:BOOL
Build LLVM examples. Defaults to OFF. Targets for building each example are
details.
**LLVM_INCLUDE_EXAMPLES**:BOOL
- Generate build targets for the LLVM examples. Defaults to ON. You can use that
- option for disabling the generation of build targets for the LLVM examples.
+ Generate build targets for the LLVM examples. Defaults to ON. You can use this
+ option to disable the generation of build targets for the LLVM examples.
**LLVM_BUILD_TESTS**:BOOL
Build LLVM unit tests. Defaults to OFF. Targets for building each unit test
- are generated in any case. You can build a specific unit test with the target
- *UnitTestNameTests* (where at this time *UnitTestName* can be ADT, Analysis,
- ExecutionEngine, JIT, Support, Transform, VMCore; see the subdirectories of
- *unittests* for an updated list.) It is possible to build all unit tests with
- the target *UnitTests*.
+ are generated in any case. You can build a specific unit test using the
+ targets defined under *unittests*, such as ADTTests, IRTests, SupportTests,
+ etc. (Search for ``add_llvm_unittest`` in the subdirectories of *unittests*
+ for a complete list of unit tests.) It is possible to build all unit tests
+ with the target *UnitTests*.
**LLVM_INCLUDE_TESTS**:BOOL
Generate build targets for the LLVM unit tests. Defaults to ON. You can use
- that option for disabling the generation of build targets for the LLVM unit
+ this option to disable the generation of build targets for the LLVM unit
tests.
**LLVM_APPEND_VC_REV**:BOOL
**LLVM_ENABLE_THREADS**:BOOL
Build with threads support, if available. Defaults to ON.
-**LLVM_ENABLE_CXX11**:BOOL
- Build in C++11 mode, if available. Defaults to OFF.
+**LLVM_ENABLE_CXX1Y**:BOOL
+ Build in C++1y mode, if available. Defaults to OFF.
**LLVM_ENABLE_ASSERTIONS**:BOOL
- Enables code assertions. Defaults to OFF if and only if ``CMAKE_BUILD_TYPE``
- is *Release*.
+ Enables code assertions. Defaults to ON if and only if ``CMAKE_BUILD_TYPE``
+ is *Debug*.
+
+**LLVM_ENABLE_EH**:BOOL
+ Build LLVM with exception-handling support. This is necessary if you wish to
+ link against LLVM libraries and make use of C++ exceptions in your own code
+ that need to propagate through LLVM code. Defaults to OFF.
**LLVM_ENABLE_PIC**:BOOL
- Add the ``-fPIC`` flag for the compiler command-line, if the compiler supports
+ Add the ``-fPIC`` flag to the compiler command-line, if the compiler supports
this flag. Some systems, like Windows, do not need this flag. Defaults to ON.
+**LLVM_ENABLE_RTTI**:BOOL
+ Build LLVM with run-time type information. Defaults to OFF.
+
**LLVM_ENABLE_WARNINGS**:BOOL
Enable all compiler warnings. Defaults to ON.
**LLVM_ENABLE_PEDANTIC**:BOOL
- Enable pedantic mode. This disable compiler specific extensions, is
+ Enable pedantic mode. This disables compiler-specific extensions, if
possible. Defaults to ON.
**LLVM_ENABLE_WERROR**:BOOL
- Stop and fail build, if a compiler warning is triggered. Defaults to OFF.
+ Stop and fail the build, if a compiler warning is triggered. Defaults to OFF.
+
+**LLVM_ABI_BREAKING_CHECKS**:STRING
+ Used to decide if LLVM should be built with ABI breaking checks or
+ not. Allowed values are `WITH_ASSERTS` (default), `FORCE_ON` and
+ `FORCE_OFF`. `WITH_ASSERTS` turns on ABI breaking checks in an
+ assertion enabled build. `FORCE_ON` (`FORCE_OFF`) turns them on
+ (off) irrespective of whether normal (`NDEBUG`-based) assertions are
+ enabled or not. A version of LLVM built with ABI breaking checks
+ is not ABI compatible with a version built without it.
**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.
+ Build 32-bit executables and libraries on 64-bit systems. This option is
+ available only on some 64-bit Unix systems. Defaults to OFF.
**LLVM_TARGET_ARCH**:STRING
LLVM target to use for native code generation. This is required for JIT
to the target architecture name.
**LLVM_TABLEGEN**:STRING
- Full path to a native TableGen executable (usually named ``tblgen``). This is
+ Full path to a native TableGen executable (usually named ``llvm-tblgen``). This is
intended for cross-compiling: if the user sets this variable, no native
TableGen will be created.
others.
**LLVM_LIT_TOOLS_DIR**:PATH
- The path to GnuWin32 tools for tests. Valid on Windows host. Defaults to "",
- then Lit seeks tools according to %PATH%. Lit can find tools(eg. grep, sort,
- &c) on LLVM_LIT_TOOLS_DIR at first, without specifying GnuWin32 to %PATH%.
+ The path to GnuWin32 tools for tests. Valid on Windows host. Defaults to
+ the empty string, in which case lit will look for tools needed for tests
+ (e.g. ``grep``, ``sort``, etc.) in your %PATH%. If GnuWin32 is not in your
+ %PATH%, then you can set this variable to the GnuWin32 directory so that
+ lit can find tools needed for tests in that directory.
**LLVM_ENABLE_FFI**:BOOL
- Indicates whether LLVM Interpreter will be linked with Foreign Function
- Interface library. If the library or its headers are installed on a custom
- location, you can set the variables FFI_INCLUDE_DIR and
- FFI_LIBRARY_DIR. Defaults to OFF.
+ Indicates whether the LLVM Interpreter will be linked with the Foreign Function
+ Interface library (libffi) in order to enable calling external functions.
+ If the library or its headers are installed in a custom
+ location, you can also set the variables FFI_INCLUDE_DIR and
+ FFI_LIBRARY_DIR to the directories where ffi.h and libffi.so can be found,
+ respectively. Defaults to OFF.
**LLVM_EXTERNAL_{CLANG,LLD,POLLY}_SOURCE_DIR**:PATH
- Path to ``{Clang,lld,Polly}``\'s source directory. Defaults to
- ``tools/{clang,lld,polly}``. ``{Clang,lld,Polly}`` will not be built when it
- is empty or it does not point to a valid path.
+ These variables specify the path to the source directory for the external
+ LLVM projects Clang, lld, and Polly, respectively, relative to the top-level
+ source directory. If the in-tree subdirectory for an external project
+ exists (e.g., llvm/tools/clang for Clang), then the corresponding variable
+ will not be used. If the variable for an external project does not point
+ to a valid path, then that project will not be built.
**LLVM_USE_OPROFILE**:BOOL
- Enable building OProfile JIT support. Defaults to OFF
+ Enable building OProfile JIT support. Defaults to OFF.
+
+**LLVM_PROFDATA_FILE**:PATH
+ Path to a profdata file to pass into clang's -fprofile-instr-use flag. This
+ can only be specified if you're building with clang.
**LLVM_USE_INTEL_JITEVENTS**:BOOL
- Enable building support for Intel JIT Events API. Defaults to OFF
+ Enable building support for Intel JIT Events API. Defaults to OFF.
**LLVM_ENABLE_ZLIB**:BOOL
- Build with zlib to support compression/uncompression in LLVM tools.
+ Enable building with zlib to support compression/uncompression in LLVM tools.
Defaults to ON.
**LLVM_USE_SANITIZER**:STRING
Define the sanitizer used to build LLVM binaries and tests. Possible values
- are ``Address``, ``Memory`` and ``MemoryWithOrigins``. Defaults to empty
- string.
+ are ``Address``, ``Memory``, ``MemoryWithOrigins``, ``Undefined``, ``Thread``,
+ and ``Address;Undefined``. Defaults to empty string.
+
+**LLVM_PARALLEL_COMPILE_JOBS**:STRING
+ Define the maximum number of concurrent compilation jobs.
+
+**LLVM_PARALLEL_LINK_JOBS**:STRING
+ Define the maximum number of concurrent link jobs.
+
+**LLVM_BUILD_DOCS**:BOOL
+ Enables all enabled documentation targets (i.e. Doxgyen and Sphinx targets) to
+ be built as part of the normal build. If the ``install`` target is run then
+ this also enables all built documentation targets to be installed. Defaults to
+ OFF.
+
+**LLVM_ENABLE_DOXYGEN**:BOOL
+ Enables the generation of browsable HTML documentation using doxygen.
+ Defaults to OFF.
+
+**LLVM_ENABLE_DOXYGEN_QT_HELP**:BOOL
+ Enables the generation of a Qt Compressed Help file. Defaults to OFF.
+ This affects the make target ``doxygen-llvm``. When enabled, apart from
+ the normal HTML output generated by doxygen, this will produce a QCH file
+ named ``org.llvm.qch``. You can then load this file into Qt Creator.
+ This option is only useful in combination with ``-DLLVM_ENABLE_DOXYGEN=ON``;
+ otherwise this has no effect.
+
+**LLVM_DOXYGEN_QCH_FILENAME**:STRING
+ The filename of the Qt Compressed Help file that will be generated when
+ ``-DLLVM_ENABLE_DOXYGEN=ON`` and
+ ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON`` are given. Defaults to
+ ``org.llvm.qch``.
+ This option is only useful in combination with
+ ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``;
+ otherwise it has no effect.
+
+**LLVM_DOXYGEN_QHP_NAMESPACE**:STRING
+ Namespace under which the intermediate Qt Help Project file lives. See `Qt
+ Help Project`_
+ for more information. Defaults to "org.llvm". This option is only useful in
+ combination with ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``; otherwise
+ it has no effect.
+
+**LLVM_DOXYGEN_QHP_CUST_FILTER_NAME**:STRING
+ See `Qt Help Project`_ for
+ more information. Defaults to the CMake variable ``${PACKAGE_STRING}`` which
+ is a combination of the package name and version string. This filter can then
+ be used in Qt Creator to select only documentation from LLVM when browsing
+ through all the help files that you might have loaded. This option is only
+ useful in combination with ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``;
+ otherwise it has no effect.
+
+.. _Qt Help Project: http://qt-project.org/doc/qt-4.8/qthelpproject.html#custom-filters
+
+**LLVM_DOXYGEN_QHELPGENERATOR_PATH**:STRING
+ The path to the ``qhelpgenerator`` executable. Defaults to whatever CMake's
+ ``find_program()`` can find. This option is only useful in combination with
+ ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``; otherwise it has no
+ effect.
+
+**LLVM_DOXYGEN_SVG**:BOOL
+ Uses .svg files instead of .png files for graphs in the Doxygen output.
+ Defaults to OFF.
+
+**LLVM_ENABLE_SPHINX**:BOOL
+ If enabled CMake will search for the ``sphinx-build`` executable and will make
+ the ``SPHINX_OUTPUT_HTML`` and ``SPHINX_OUTPUT_MAN`` CMake options available.
+ Defaults to OFF.
+
+**SPHINX_EXECUTABLE**:STRING
+ The path to the ``sphinx-build`` executable detected by CMake.
+
+**SPHINX_OUTPUT_HTML**:BOOL
+ If enabled (and ``LLVM_ENABLE_SPHINX`` is enabled) then the targets for
+ building the documentation as html are added (but not built by default unless
+ ``LLVM_BUILD_DOCS`` is enabled). There is a target for each project in the
+ source tree that uses sphinx (e.g. ``docs-llvm-html``, ``docs-clang-html``
+ and ``docs-lld-html``). Defaults to ON.
+
+**SPHINX_OUTPUT_MAN**:BOOL
+ If enabled (and ``LLVM_ENABLE_SPHINX`` is enabled) the targets for building
+ the man pages are added (but not built by default unless ``LLVM_BUILD_DOCS``
+ is enabled). Currently the only target added is ``docs-llvm-man``. Defaults
+ to ON.
+
+**SPHINX_WARNINGS_AS_ERRORS**:BOOL
+ If enabled then sphinx documentation warnings will be treated as
+ errors. Defaults to ON.
+
+**LLVM_CREATE_XCODE_TOOLCHAIN**:BOOL
+ OS X Only: If enabled CMake will generate a target named
+ 'install-xcode-toolchain'. This target will create a directory at
+ $CMAKE_INSTALL_PREFIX/Toolchains containing an xctoolchain directory which can
+ be used to override the default system tools.
+
+**LLVM_BUILD_LLVM_DYLIB**:BOOL
+ If enabled, the target for building the libLLVM shared library is added.
+ This library contains all of LLVM's components in a single shared library.
+ Defaults to OFF. This cannot be used in conjunction with BUILD_SHARED_LIBS.
+ Tools will only be linked to the libLLVM shared library if LLVM_LINK_LLVM_DYLIB
+ is also ON.
+ The components in the library can be customised by setting LLVM_DYLIB_COMPONENTS
+ to a list of the desired components.
+
+**LLVM_LINK_LLVM_DYLIB**:BOOL
+ If enabled, tools will be linked with the libLLVM shared library. Defaults
+ to OFF. Setting LLVM_LINK_LLVM_DYLIB to ON also sets LLVM_BUILD_LLVM_DYLIB
+ to ON.
+
+**BUILD_SHARED_LIBS**:BOOL
+ Flag indicating if each LLVM component (e.g. Support) is built as a shared
+ library (ON) or as a static library (OFF). Its default value is OFF. On
+ Windows, shared libraries may be used when building with MinGW, including
+ mingw-w64, but not when building with the Microsoft toolchain.
+
+ .. note:: BUILD_SHARED_LIBS is only recommended for use by LLVM developers.
+ If you want to build LLVM as a shared library, you should use the
+ ``LLVM_BUILD_LLVM_DYLIB`` option.
Executing the test suite
========================
-Testing is performed when the *check* target is built. For instance, if you are
-using makefiles, execute this command while on the top level of your build
-directory:
+Testing is performed when the *check-all* target is built. For instance, if you are
+using Makefiles, execute this command in the root of your build directory:
.. code-block:: console
- $ make check
+ $ make check-all
-On Visual Studio, you may run tests to build the project "check".
+On Visual Studio, you may run tests by building the project "check-all".
+For more information about testing, see the :doc:`TestingGuide`.
Cross compiling
===============
Embedding LLVM in your project
==============================
-The most difficult part of adding LLVM to the build of a project is to determine
-the set of LLVM libraries corresponding to the set of required LLVM
-features. What follows is an example of how to obtain this information:
+From LLVM 3.5 onwards both the CMake and autoconf/Makefile build systems export
+LLVM libraries as importable CMake targets. This means that clients of LLVM can
+now reliably use CMake to develop their own LLVM-based projects against an
+installed version of LLVM regardless of how it was built.
+
+Here is a simple example of a CMakeLists.txt file that imports the LLVM libraries
+and uses them to build a simple application ``simple-tool``.
.. code-block:: cmake
- # A convenience variable:
- set(LLVM_ROOT "" CACHE PATH "Root of LLVM install.")
+ cmake_minimum_required(VERSION 2.8.8)
+ project(SimpleProject)
- # A bit of a sanity check:
- if( NOT EXISTS ${LLVM_ROOT}/include/llvm )
- message(FATAL_ERROR "LLVM_ROOT (${LLVM_ROOT}) is not a valid LLVM install")
- endif()
+ find_package(LLVM REQUIRED CONFIG)
- # We incorporate the CMake features provided by LLVM:
- set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${LLVM_ROOT}/share/llvm/cmake")
- include(LLVMConfig)
+ message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
+ message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")
- # Now set the header and library paths:
- include_directories( ${LLVM_INCLUDE_DIRS} )
- link_directories( ${LLVM_LIBRARY_DIRS} )
- add_definitions( ${LLVM_DEFINITIONS} )
+ # Set your project compile flags.
+ # E.g. if using the C++ header files
+ # you will need to enable C++11 support
+ # for your compiler.
- # Let's suppose we want to build a JIT compiler with support for
- # binary code (no interpreter):
- llvm_map_components_to_libraries(REQ_LLVM_LIBRARIES jit native)
+ include_directories(${LLVM_INCLUDE_DIRS})
+ add_definitions(${LLVM_DEFINITIONS})
- # Finally, we link the LLVM libraries to our executable:
- target_link_libraries(mycompiler ${REQ_LLVM_LIBRARIES})
+ # Now build our tools
+ add_executable(simple-tool tool.cpp)
-This assumes that LLVM_ROOT points to an install of LLVM. The procedure works
-too for uninstalled builds although we need to take care to add an
-`include_directories` for the location of the headers on the LLVM source
-directory (if we are building out-of-source.)
+ # Find the libraries that correspond to the LLVM components
+ # that we wish to use
+ llvm_map_components_to_libnames(llvm_libs support core irreader)
-Alternativaly, you can utilize CMake's ``find_package`` functionality. Here is
-an equivalent variant of snippet shown above:
+ # Link against LLVM libraries
+ target_link_libraries(simple-tool ${llvm_libs})
-.. code-block:: cmake
+The ``find_package(...)`` directive when used in CONFIG mode (as in the above
+example) will look for the ``LLVMConfig.cmake`` file in various locations (see
+cmake manual for details). It creates a ``LLVM_DIR`` cache entry to save the
+directory where ``LLVMConfig.cmake`` is found or allows the user to specify the
+directory (e.g. by passing ``-DLLVM_DIR=/usr/share/llvm/cmake`` to
+the ``cmake`` command or by setting it directly in ``ccmake`` or ``cmake-gui``).
+
+This file is available in two different locations.
+
+* ``<INSTALL_PREFIX>/share/llvm/cmake/LLVMConfig.cmake`` where
+ ``<INSTALL_PREFIX>`` is the install prefix of an installed version of LLVM.
+ On Linux typically this is ``/usr/share/llvm/cmake/LLVMConfig.cmake``.
+
+* ``<LLVM_BUILD_ROOT>/share/llvm/cmake/LLVMConfig.cmake`` where
+ ``<LLVM_BUILD_ROOT>`` is the root of the LLVM build tree. **Note: this is only
+ available when building LLVM with CMake.**
+
+If LLVM is installed in your operating system's normal installation prefix (e.g.
+on Linux this is usually ``/usr/``) ``find_package(LLVM ...)`` will
+automatically find LLVM if it is installed correctly. If LLVM is not installed
+or you wish to build directly against the LLVM build tree you can use
+``LLVM_DIR`` as previously mentioned.
+
+The ``LLVMConfig.cmake`` file sets various useful variables. Notable variables
+include
- find_package(LLVM)
+``LLVM_CMAKE_DIR``
+ The path to the LLVM CMake directory (i.e. the directory containing
+ LLVMConfig.cmake).
- if( NOT LLVM_FOUND )
- message(FATAL_ERROR "LLVM package can't be found. Set CMAKE_PREFIX_PATH variable to LLVM's installation prefix.")
- endif()
+``LLVM_DEFINITIONS``
+ A list of preprocessor defines that should be used when building against LLVM.
- include_directories( ${LLVM_INCLUDE_DIRS} )
- link_directories( ${LLVM_LIBRARY_DIRS} )
+``LLVM_ENABLE_ASSERTIONS``
+ This is set to ON if LLVM was built with assertions, otherwise OFF.
- llvm_map_components_to_libraries(REQ_LLVM_LIBRARIES jit native)
+``LLVM_ENABLE_EH``
+ This is set to ON if LLVM was built with exception handling (EH) enabled,
+ otherwise OFF.
- target_link_libraries(mycompiler ${REQ_LLVM_LIBRARIES})
+``LLVM_ENABLE_RTTI``
+ This is set to ON if LLVM was built with run time type information (RTTI),
+ otherwise OFF.
+
+``LLVM_INCLUDE_DIRS``
+ A list of include paths to directories containing LLVM header files.
+
+``LLVM_PACKAGE_VERSION``
+ The LLVM version. This string can be used with CMake conditionals, e.g., ``if
+ (${LLVM_PACKAGE_VERSION} VERSION_LESS "3.5")``.
+
+``LLVM_TOOLS_BINARY_DIR``
+ The path to the directory containing the LLVM tools (e.g. ``llvm-as``).
+
+Notice that in the above example we link ``simple-tool`` against several LLVM
+libraries. The list of libraries is determined by using the
+``llvm_map_components_to_libnames()`` CMake function. For a list of available
+components look at the output of running ``llvm-config --components``.
+
+Note that for LLVM < 3.5 ``llvm_map_components_to_libraries()`` was
+used instead of ``llvm_map_components_to_libnames()``. This is now deprecated
+and will be removed in a future version of LLVM.
.. _cmake-out-of-source-pass:
-Developing LLVM pass out of source
-----------------------------------
+Developing LLVM passes out of source
+------------------------------------
-It is possible to develop LLVM passes against installed LLVM. An example of
-project layout provided below:
+It is possible to develop LLVM passes out of LLVM's source tree (i.e. against an
+installed or built LLVM). An example of a project layout is provided below.
.. code-block:: none
.. code-block:: cmake
- find_package(LLVM)
-
- # Define add_llvm_* macro's.
- include(AddLLVM)
+ find_package(LLVM REQUIRED CONFIG)
add_definitions(${LLVM_DEFINITIONS})
include_directories(${LLVM_INCLUDE_DIRS})
- link_directories(${LLVM_LIBRARY_DIRS})
add_subdirectory(<pass name>)
Contents of ``<project dir>/<pass name>/CMakeLists.txt``:
+.. code-block:: cmake
+
+ add_library(LLVMPassname MODULE Pass.cpp)
+
+Note if you intend for this pass to be merged into the LLVM source tree at some
+point in the future it might make more sense to use LLVM's internal
+``add_llvm_loadable_module`` function instead by...
+
+
+Adding the following to ``<project dir>/CMakeLists.txt`` (after
+``find_package(LLVM ...)``)
+
+.. code-block:: cmake
+
+ list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_DIR}")
+ include(AddLLVM)
+
+And then changing ``<project dir>/<pass name>/CMakeLists.txt`` to
+
.. code-block:: cmake
add_llvm_loadable_module(LLVMPassname
)
When you are done developing your pass, you may wish to integrate it
-into LLVM source tree. You can achieve it in two easy steps:
+into the LLVM source tree. You can achieve it in two easy steps:
#. Copying ``<pass name>`` folder into ``<LLVM root>/lib/Transform`` directory.
#. Adding ``add_subdirectory(<pass name>)`` line into
``<LLVM root>/lib/Transform/CMakeLists.txt``.
-Compiler/Platform specific topics
+Compiler/Platform-specific topics
=================================
Notes for specific compilers and/or platforms.
--------------------
**LLVM_COMPILER_JOBS**:STRING
- Specifies the maximum number of parallell compiler jobs to use per project
+ Specifies the maximum number of parallel compiler jobs to use per project
when building with msbuild or Visual Studio. Only supported for the Visual
Studio 2010 CMake generator. 0 means use all processors. Default is 0.
projects / oota-llvm.git / blobdiff