`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.
#. 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
+#. 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).
+ tool (``make``, ``ninja``, ``xcodebuild``, ``msbuild``, etc.)
- The underlying build tool can be invoked directly either of course, but
+ 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:
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 11" 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
-------------------------------
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``.
+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
**BUILD_SHARED_LIBS**:BOOL
Flag indicating if shared libraries will be built. Its default value is
- OFF. Shared libraries are not supported on Windows and not recommended on the
- other OSes.
+ OFF. This option is only recommended for use by LLVM developers.
+ On Windows, shared libraries may be used when building with MinGW, including
+ mingw-w64, but not when building with the Microsoft toolchain.
.. _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
is *Debug*.
**LLVM_ENABLE_EH**:BOOL
- Build LLVM with exception handling support. This is necessary if you wish to
+ 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.
+ 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 disables compiler specific extensions, if
+ 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
+ (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_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
``org.llvm.qch``.
This option is only useful in combination with
``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``;
- otherwise this has no effect.
+ 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
- this has no effect.
+ it has no effect.
**LLVM_DOXYGEN_QHP_CUST_FILTER_NAME**:STRING
See `Qt Help Project`_ for
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 this has no effect.
+ 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 this has no
+ ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``; otherwise it has no
effect.
**LLVM_DOXYGEN_SVG**:BOOL
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
===============
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
+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 CMakeLists.txt file that imports the LLVM libraries
+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
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 only
- available when building LLVM with CMake**
+ ``<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
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
+ 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``
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...
+``add_llvm_loadable_module`` function instead by...
Adding the following to ``<project dir>/CMakeLists.txt`` (after
)
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.
--------------------
**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