1 ========================
2 Building LLVM with CMake
3 ========================
11 `CMake <http://www.cmake.org/>`_ is a cross-platform build-generator tool. CMake
12 does not build the project, it generates the files needed by your build tool
13 (GNU make, Visual Studio, etc.) for building LLVM.
15 If you are really anxious about getting a functional LLVM build, go to the
16 `Quick start`_ section. If you are a CMake novice, start with `Basic CMake usage`_
17 and then go back to the `Quick start`_ section once you know what you are doing. The
18 `Options and variables`_ section is a reference for customizing your build. If
19 you already have experience with CMake, this is the recommended starting point.
26 We use here the command-line, non-interactive CMake interface.
28 #. `Download <http://www.cmake.org/cmake/resources/software.html>`_ and install
29 CMake. Version 2.8.8 is the minimum required, but if you're using the Ninja
30 backend, CMake v3.2 or newer is required to `get interactive output
31 <http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20141117/244797.html>`_
32 when running :doc:`Lit <CommandGuide/lit>`.
34 #. Open a shell. Your development tools must be reachable from this shell
35 through the PATH environment variable.
37 #. Create a build directory. Building LLVM in the source
38 directory is not supported. cd to this directory:
40 .. code-block:: console
45 #. Execute this command in the shell replacing `path/to/llvm/source/root` with
46 the path to the root of your LLVM source tree:
48 .. code-block:: console
50 $ cmake path/to/llvm/source/root
52 CMake will detect your development environment, perform a series of tests, and
53 generate the files required for building LLVM. CMake will use default values
54 for all build parameters. See the `Options and variables`_ section for
55 a list of build parameters that you can modify.
57 This can fail if CMake can't detect your toolset, or if it thinks that the
58 environment is not sane enough. In this case, make sure that the toolset that
59 you intend to use is the only one reachable from the shell, and that the shell
60 itself is the correct one for your development environment. CMake will refuse
61 to build MinGW makefiles if you have a POSIX shell reachable through the PATH
62 environment variable, for instance. You can force CMake to use a given build
63 tool; for instructions, see the `Usage`_ section, below.
65 #. After CMake has finished running, proceed to use IDE project files, or start
66 the build from the build directory:
68 .. code-block:: console
72 The ``--build`` option tells ``cmake`` to invoke the underlying build
73 tool (``make``, ``ninja``, ``xcodebuild``, ``msbuild``, etc.)
75 The underlying build tool can be invoked directly, of course, but
76 the ``--build`` option is portable.
78 #. After LLVM has finished building, install it from the build directory:
80 .. code-block:: console
82 $ cmake --build . --target install
84 The ``--target`` option with ``install`` parameter in addition to
85 the ``--build`` option tells ``cmake`` to build the ``install`` target.
87 It is possible to set a different install prefix at installation time
88 by invoking the ``cmake_install.cmake`` script generated in the
91 .. code-block:: console
93 $ cmake -DCMAKE_INSTALL_PREFIX=/tmp/llvm -P cmake_install.cmake
95 .. _Basic CMake usage:
101 This section explains basic aspects of CMake
102 which you may need in your day-to-day usage.
104 CMake comes with extensive documentation, in the form of html files, and as
105 online help accessible via the ``cmake`` executable itself. Execute ``cmake
106 --help`` for further help options.
108 CMake allows you to specify a build tool (e.g., GNU make, Visual Studio,
109 or Xcode). If not specified on the command line, CMake tries to guess which
110 build tool to use, based on your environment. Once it has identified your
111 build tool, CMake uses the corresponding *Generator* to create files for your
112 build tool (e.g., Makefiles or Visual Studio or Xcode project files). You can
113 explicitly specify the generator with the command line option ``-G "Name of the
114 generator"``. To see a list of the available generators on your system, execute
116 .. code-block:: console
120 This will list the generator names at the end of the help text.
122 Generators' names are case-sensitive, and may contain spaces. For this reason,
123 you should enter them exactly as they are listed in the ``cmake --help``
124 output, in quotes. For example, to generate project files specifically for
125 Visual Studio 12, you can execute:
127 .. code-block:: console
129 $ cmake -G "Visual Studio 12" path/to/llvm/source/root
131 For a given development platform there can be more than one adequate
132 generator. If you use Visual Studio, "NMake Makefiles" is a generator you can use
133 for building with NMake. By default, CMake chooses the most specific generator
134 supported by your development environment. If you want an alternative generator,
135 you must tell this to CMake with the ``-G`` option.
139 Explain variables and cache. Move explanation here from #options section.
141 .. _Options and variables:
143 Options and variables
144 =====================
146 Variables customize how the build will be generated. Options are boolean
147 variables, with possible values ON/OFF. Options and variables are defined on the
148 CMake command line like this:
150 .. code-block:: console
152 $ cmake -DVARIABLE=value path/to/llvm/source
154 You can set a variable after the initial CMake invocation to change its
155 value. You can also undefine a variable:
157 .. code-block:: console
159 $ cmake -UVARIABLE path/to/llvm/source
161 Variables are stored in the CMake cache. This is a file named ``CMakeCache.txt``
162 stored at the root of your build directory that is generated by ``cmake``.
163 Editing it yourself is not recommended.
165 Variables are listed in the CMake cache and later in this document with
166 the variable name and type separated by a colon. You can also specify the
167 variable and type on the CMake command line:
169 .. code-block:: console
171 $ cmake -DVARIABLE:TYPE=value path/to/llvm/source
173 Frequently-used CMake variables
174 -------------------------------
176 Here are some of the CMake variables that are used often, along with a
177 brief explanation and LLVM-specific notes. For full documentation, consult the
178 CMake manual, or execute ``cmake --help-variable VARIABLE_NAME``.
180 **CMAKE_BUILD_TYPE**:STRING
181 Sets the build type for ``make``-based generators. Possible values are
182 Release, Debug, RelWithDebInfo and MinSizeRel. If you are using an IDE such as
183 Visual Studio, you should use the IDE settings to set the build type.
185 **CMAKE_INSTALL_PREFIX**:PATH
186 Path where LLVM will be installed if "make install" is invoked or the
187 "install" target is built.
189 **LLVM_LIBDIR_SUFFIX**:STRING
190 Extra suffix to append to the directory where libraries are to be
191 installed. On a 64-bit architecture, one could use ``-DLLVM_LIBDIR_SUFFIX=64``
192 to install libraries to ``/usr/lib64``.
194 **CMAKE_C_FLAGS**:STRING
195 Extra flags to use when compiling C source files.
197 **CMAKE_CXX_FLAGS**:STRING
198 Extra flags to use when compiling C++ source files.
200 **BUILD_SHARED_LIBS**:BOOL
201 Flag indicating if shared libraries will be built. Its default value is
202 OFF. This option is only recommended for use by LLVM developers.
203 On Windows, shared libraries may be used when building with MinGW, including
204 mingw-w64, but not when building with the Microsoft toolchain.
206 .. _LLVM-specific variables:
208 LLVM-specific variables
209 -----------------------
211 **LLVM_TARGETS_TO_BUILD**:STRING
212 Semicolon-separated list of targets to build, or *all* for building all
213 targets. Case-sensitive. Defaults to *all*. Example:
214 ``-DLLVM_TARGETS_TO_BUILD="X86;PowerPC"``.
216 **LLVM_BUILD_TOOLS**:BOOL
217 Build LLVM tools. Defaults to ON. Targets for building each tool are generated
218 in any case. You can build a tool separately by invoking its target. For
219 example, you can build *llvm-as* with a Makefile-based system by executing *make
220 llvm-as* at the root of your build directory.
222 **LLVM_INCLUDE_TOOLS**:BOOL
223 Generate build targets for the LLVM tools. Defaults to ON. You can use this
224 option to disable the generation of build targets for the LLVM tools.
226 **LLVM_BUILD_EXAMPLES**:BOOL
227 Build LLVM examples. Defaults to OFF. Targets for building each example are
228 generated in any case. See documentation for *LLVM_BUILD_TOOLS* above for more
231 **LLVM_INCLUDE_EXAMPLES**:BOOL
232 Generate build targets for the LLVM examples. Defaults to ON. You can use this
233 option to disable the generation of build targets for the LLVM examples.
235 **LLVM_BUILD_TESTS**:BOOL
236 Build LLVM unit tests. Defaults to OFF. Targets for building each unit test
237 are generated in any case. You can build a specific unit test using the
238 targets defined under *unittests*, such as ADTTests, IRTests, SupportTests,
239 etc. (Search for ``add_llvm_unittest`` in the subdirectories of *unittests*
240 for a complete list of unit tests.) It is possible to build all unit tests
241 with the target *UnitTests*.
243 **LLVM_INCLUDE_TESTS**:BOOL
244 Generate build targets for the LLVM unit tests. Defaults to ON. You can use
245 this option to disable the generation of build targets for the LLVM unit
248 **LLVM_APPEND_VC_REV**:BOOL
249 Append version control revision info (svn revision number or Git revision id)
250 to LLVM version string (stored in the PACKAGE_VERSION macro). For this to work
251 cmake must be invoked before the build. Defaults to OFF.
253 **LLVM_ENABLE_THREADS**:BOOL
254 Build with threads support, if available. Defaults to ON.
256 **LLVM_ENABLE_CXX1Y**:BOOL
257 Build in C++1y mode, if available. Defaults to OFF.
259 **LLVM_ENABLE_ASSERTIONS**:BOOL
260 Enables code assertions. Defaults to ON if and only if ``CMAKE_BUILD_TYPE``
263 **LLVM_ENABLE_EH**:BOOL
264 Build LLVM with exception-handling support. This is necessary if you wish to
265 link against LLVM libraries and make use of C++ exceptions in your own code
266 that need to propagate through LLVM code. Defaults to OFF.
268 **LLVM_ENABLE_PIC**:BOOL
269 Add the ``-fPIC`` flag to the compiler command-line, if the compiler supports
270 this flag. Some systems, like Windows, do not need this flag. Defaults to ON.
272 **LLVM_ENABLE_RTTI**:BOOL
273 Build LLVM with run-time type information. Defaults to OFF.
275 **LLVM_ENABLE_WARNINGS**:BOOL
276 Enable all compiler warnings. Defaults to ON.
278 **LLVM_ENABLE_PEDANTIC**:BOOL
279 Enable pedantic mode. This disables compiler-specific extensions, if
280 possible. Defaults to ON.
282 **LLVM_ENABLE_WERROR**:BOOL
283 Stop and fail the build, if a compiler warning is triggered. Defaults to OFF.
285 **LLVM_ABI_BREAKING_CHECKS**:STRING
286 Used to decide if LLVM should be built with ABI breaking checks or
287 not. Allowed values are `WITH_ASSERTS` (default), `FORCE_ON` and
288 `FORCE_OFF`. `WITH_ASSERTS` turns on ABI breaking checks in an
289 assertion enabled build. `FORCE_ON` (`FORCE_OFF`) turns them on
290 (off) irrespective of whether normal (`NDEBUG`-based) assertions are
291 enabled or not. A version of LLVM built with ABI breaking checks
292 is not ABI compatible with a version built without it.
294 **LLVM_BUILD_32_BITS**:BOOL
295 Build 32-bit executables and libraries on 64-bit systems. This option is
296 available only on some 64-bit Unix systems. Defaults to OFF.
298 **LLVM_TARGET_ARCH**:STRING
299 LLVM target to use for native code generation. This is required for JIT
300 generation. It defaults to "host", meaning that it shall pick the architecture
301 of the machine where LLVM is being built. If you are cross-compiling, set it
302 to the target architecture name.
304 **LLVM_TABLEGEN**:STRING
305 Full path to a native TableGen executable (usually named ``llvm-tblgen``). This is
306 intended for cross-compiling: if the user sets this variable, no native
307 TableGen will be created.
309 **LLVM_LIT_ARGS**:STRING
310 Arguments given to lit. ``make check`` and ``make clang-test`` are affected.
311 By default, ``'-sv --no-progress-bar'`` on Visual C++ and Xcode, ``'-sv'`` on
314 **LLVM_LIT_TOOLS_DIR**:PATH
315 The path to GnuWin32 tools for tests. Valid on Windows host. Defaults to
316 the empty string, in which case lit will look for tools needed for tests
317 (e.g. ``grep``, ``sort``, etc.) in your %PATH%. If GnuWin32 is not in your
318 %PATH%, then you can set this variable to the GnuWin32 directory so that
319 lit can find tools needed for tests in that directory.
321 **LLVM_ENABLE_FFI**:BOOL
322 Indicates whether the LLVM Interpreter will be linked with the Foreign Function
323 Interface library (libffi) in order to enable calling external functions.
324 If the library or its headers are installed in a custom
325 location, you can also set the variables FFI_INCLUDE_DIR and
326 FFI_LIBRARY_DIR to the directories where ffi.h and libffi.so can be found,
327 respectively. Defaults to OFF.
329 **LLVM_EXTERNAL_{CLANG,LLD,POLLY}_SOURCE_DIR**:PATH
330 These variables specify the path to the source directory for the external
331 LLVM projects Clang, lld, and Polly, respectively, relative to the top-level
332 source directory. If the in-tree subdirectory for an external project
333 exists (e.g., llvm/tools/clang for Clang), then the corresponding variable
334 will not be used. If the variable for an external project does not point
335 to a valid path, then that project will not be built.
337 **LLVM_USE_OPROFILE**:BOOL
338 Enable building OProfile JIT support. Defaults to OFF.
340 **LLVM_PROFDATA_FILE**:PATH
341 Path to a profdata file to pass into clang's -fprofile-instr-use flag. This
342 can only be specified if you're building with clang.
344 **LLVM_USE_INTEL_JITEVENTS**:BOOL
345 Enable building support for Intel JIT Events API. Defaults to OFF.
347 **LLVM_ENABLE_ZLIB**:BOOL
348 Enable building with zlib to support compression/uncompression in LLVM tools.
351 **LLVM_USE_SANITIZER**:STRING
352 Define the sanitizer used to build LLVM binaries and tests. Possible values
353 are ``Address``, ``Memory``, ``MemoryWithOrigins``, ``Undefined``, ``Thread``,
354 and ``Address;Undefined``. Defaults to empty string.
356 **LLVM_PARALLEL_COMPILE_JOBS**:STRING
357 Define the maximum number of concurrent compilation jobs.
359 **LLVM_PARALLEL_LINK_JOBS**:STRING
360 Define the maximum number of concurrent link jobs.
362 **LLVM_BUILD_DOCS**:BOOL
363 Enables all enabled documentation targets (i.e. Doxgyen and Sphinx targets) to
364 be built as part of the normal build. If the ``install`` target is run then
365 this also enables all built documentation targets to be installed. Defaults to
368 **LLVM_ENABLE_DOXYGEN**:BOOL
369 Enables the generation of browsable HTML documentation using doxygen.
372 **LLVM_ENABLE_DOXYGEN_QT_HELP**:BOOL
373 Enables the generation of a Qt Compressed Help file. Defaults to OFF.
374 This affects the make target ``doxygen-llvm``. When enabled, apart from
375 the normal HTML output generated by doxygen, this will produce a QCH file
376 named ``org.llvm.qch``. You can then load this file into Qt Creator.
377 This option is only useful in combination with ``-DLLVM_ENABLE_DOXYGEN=ON``;
378 otherwise this has no effect.
380 **LLVM_DOXYGEN_QCH_FILENAME**:STRING
381 The filename of the Qt Compressed Help file that will be generated when
382 ``-DLLVM_ENABLE_DOXYGEN=ON`` and
383 ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON`` are given. Defaults to
385 This option is only useful in combination with
386 ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``;
387 otherwise it has no effect.
389 **LLVM_DOXYGEN_QHP_NAMESPACE**:STRING
390 Namespace under which the intermediate Qt Help Project file lives. See `Qt
392 for more information. Defaults to "org.llvm". This option is only useful in
393 combination with ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``; otherwise
396 **LLVM_DOXYGEN_QHP_CUST_FILTER_NAME**:STRING
397 See `Qt Help Project`_ for
398 more information. Defaults to the CMake variable ``${PACKAGE_STRING}`` which
399 is a combination of the package name and version string. This filter can then
400 be used in Qt Creator to select only documentation from LLVM when browsing
401 through all the help files that you might have loaded. This option is only
402 useful in combination with ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``;
403 otherwise it has no effect.
405 .. _Qt Help Project: http://qt-project.org/doc/qt-4.8/qthelpproject.html#custom-filters
407 **LLVM_DOXYGEN_QHELPGENERATOR_PATH**:STRING
408 The path to the ``qhelpgenerator`` executable. Defaults to whatever CMake's
409 ``find_program()`` can find. This option is only useful in combination with
410 ``-DLLVM_ENABLE_DOXYGEN_QT_HELP=ON``; otherwise it has no
413 **LLVM_DOXYGEN_SVG**:BOOL
414 Uses .svg files instead of .png files for graphs in the Doxygen output.
417 **LLVM_ENABLE_SPHINX**:BOOL
418 If enabled CMake will search for the ``sphinx-build`` executable and will make
419 the ``SPHINX_OUTPUT_HTML`` and ``SPHINX_OUTPUT_MAN`` CMake options available.
422 **SPHINX_EXECUTABLE**:STRING
423 The path to the ``sphinx-build`` executable detected by CMake.
425 **SPHINX_OUTPUT_HTML**:BOOL
426 If enabled (and ``LLVM_ENABLE_SPHINX`` is enabled) then the targets for
427 building the documentation as html are added (but not built by default unless
428 ``LLVM_BUILD_DOCS`` is enabled). There is a target for each project in the
429 source tree that uses sphinx (e.g. ``docs-llvm-html``, ``docs-clang-html``
430 and ``docs-lld-html``). Defaults to ON.
432 **SPHINX_OUTPUT_MAN**:BOOL
433 If enabled (and ``LLVM_ENABLE_SPHINX`` is enabled) the targets for building
434 the man pages are added (but not built by default unless ``LLVM_BUILD_DOCS``
435 is enabled). Currently the only target added is ``docs-llvm-man``. Defaults
438 **SPHINX_WARNINGS_AS_ERRORS**:BOOL
439 If enabled then sphinx documentation warnings will be treated as
440 errors. Defaults to ON.
442 **LLVM_CREATE_XCODE_TOOLCHAIN**:BOOL
443 OS X Only: If enabled CMake will generate a target named
444 'install-xcode-toolchain'. This target will create a directory at
445 $CMAKE_INSTALL_PREFIX/Toolchains containing an xctoolchain directory which can
446 be used to override the default system tools.
448 Executing the test suite
449 ========================
451 Testing is performed when the *check-all* target is built. For instance, if you are
452 using Makefiles, execute this command in the root of your build directory:
454 .. code-block:: console
458 On Visual Studio, you may run tests by building the project "check-all".
459 For more information about testing, see the :doc:`TestingGuide`.
464 See `this wiki page <http://www.vtk.org/Wiki/CMake_Cross_Compiling>`_ for
465 generic instructions on how to cross-compile with CMake. It goes into detailed
466 explanations and may seem daunting, but it is not. On the wiki page there are
467 several examples including toolchain files. Go directly to `this section
468 <http://www.vtk.org/Wiki/CMake_Cross_Compiling#Information_how_to_set_up_various_cross_compiling_toolchains>`_
469 for a quick solution.
471 Also see the `LLVM-specific variables`_ section for variables used when
474 Embedding LLVM in your project
475 ==============================
477 From LLVM 3.5 onwards both the CMake and autoconf/Makefile build systems export
478 LLVM libraries as importable CMake targets. This means that clients of LLVM can
479 now reliably use CMake to develop their own LLVM-based projects against an
480 installed version of LLVM regardless of how it was built.
482 Here is a simple example of a CMakeLists.txt file that imports the LLVM libraries
483 and uses them to build a simple application ``simple-tool``.
485 .. code-block:: cmake
487 cmake_minimum_required(VERSION 2.8.8)
488 project(SimpleProject)
490 find_package(LLVM REQUIRED CONFIG)
492 message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")
493 message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")
495 # Set your project compile flags.
496 # E.g. if using the C++ header files
497 # you will need to enable C++11 support
500 include_directories(${LLVM_INCLUDE_DIRS})
501 add_definitions(${LLVM_DEFINITIONS})
503 # Now build our tools
504 add_executable(simple-tool tool.cpp)
506 # Find the libraries that correspond to the LLVM components
507 # that we wish to use
508 llvm_map_components_to_libnames(llvm_libs support core irreader)
510 # Link against LLVM libraries
511 target_link_libraries(simple-tool ${llvm_libs})
513 The ``find_package(...)`` directive when used in CONFIG mode (as in the above
514 example) will look for the ``LLVMConfig.cmake`` file in various locations (see
515 cmake manual for details). It creates a ``LLVM_DIR`` cache entry to save the
516 directory where ``LLVMConfig.cmake`` is found or allows the user to specify the
517 directory (e.g. by passing ``-DLLVM_DIR=/usr/share/llvm/cmake`` to
518 the ``cmake`` command or by setting it directly in ``ccmake`` or ``cmake-gui``).
520 This file is available in two different locations.
522 * ``<INSTALL_PREFIX>/share/llvm/cmake/LLVMConfig.cmake`` where
523 ``<INSTALL_PREFIX>`` is the install prefix of an installed version of LLVM.
524 On Linux typically this is ``/usr/share/llvm/cmake/LLVMConfig.cmake``.
526 * ``<LLVM_BUILD_ROOT>/share/llvm/cmake/LLVMConfig.cmake`` where
527 ``<LLVM_BUILD_ROOT>`` is the root of the LLVM build tree. **Note: this is only
528 available when building LLVM with CMake.**
530 If LLVM is installed in your operating system's normal installation prefix (e.g.
531 on Linux this is usually ``/usr/``) ``find_package(LLVM ...)`` will
532 automatically find LLVM if it is installed correctly. If LLVM is not installed
533 or you wish to build directly against the LLVM build tree you can use
534 ``LLVM_DIR`` as previously mentioned.
536 The ``LLVMConfig.cmake`` file sets various useful variables. Notable variables
540 The path to the LLVM CMake directory (i.e. the directory containing
544 A list of preprocessor defines that should be used when building against LLVM.
546 ``LLVM_ENABLE_ASSERTIONS``
547 This is set to ON if LLVM was built with assertions, otherwise OFF.
550 This is set to ON if LLVM was built with exception handling (EH) enabled,
554 This is set to ON if LLVM was built with run time type information (RTTI),
557 ``LLVM_INCLUDE_DIRS``
558 A list of include paths to directories containing LLVM header files.
560 ``LLVM_PACKAGE_VERSION``
561 The LLVM version. This string can be used with CMake conditionals, e.g., ``if
562 (${LLVM_PACKAGE_VERSION} VERSION_LESS "3.5")``.
564 ``LLVM_TOOLS_BINARY_DIR``
565 The path to the directory containing the LLVM tools (e.g. ``llvm-as``).
567 Notice that in the above example we link ``simple-tool`` against several LLVM
568 libraries. The list of libraries is determined by using the
569 ``llvm_map_components_to_libnames()`` CMake function. For a list of available
570 components look at the output of running ``llvm-config --components``.
572 Note that for LLVM < 3.5 ``llvm_map_components_to_libraries()`` was
573 used instead of ``llvm_map_components_to_libnames()``. This is now deprecated
574 and will be removed in a future version of LLVM.
576 .. _cmake-out-of-source-pass:
578 Developing LLVM passes out of source
579 ------------------------------------
581 It is possible to develop LLVM passes out of LLVM's source tree (i.e. against an
582 installed or built LLVM). An example of a project layout is provided below.
595 Contents of ``<project dir>/CMakeLists.txt``:
597 .. code-block:: cmake
599 find_package(LLVM REQUIRED CONFIG)
601 add_definitions(${LLVM_DEFINITIONS})
602 include_directories(${LLVM_INCLUDE_DIRS})
604 add_subdirectory(<pass name>)
606 Contents of ``<project dir>/<pass name>/CMakeLists.txt``:
608 .. code-block:: cmake
610 add_library(LLVMPassname MODULE Pass.cpp)
612 Note if you intend for this pass to be merged into the LLVM source tree at some
613 point in the future it might make more sense to use LLVM's internal
614 ``add_llvm_loadable_module`` function instead by...
617 Adding the following to ``<project dir>/CMakeLists.txt`` (after
618 ``find_package(LLVM ...)``)
620 .. code-block:: cmake
622 list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_DIR}")
625 And then changing ``<project dir>/<pass name>/CMakeLists.txt`` to
627 .. code-block:: cmake
629 add_llvm_loadable_module(LLVMPassname
633 When you are done developing your pass, you may wish to integrate it
634 into the LLVM source tree. You can achieve it in two easy steps:
636 #. Copying ``<pass name>`` folder into ``<LLVM root>/lib/Transform`` directory.
638 #. Adding ``add_subdirectory(<pass name>)`` line into
639 ``<LLVM root>/lib/Transform/CMakeLists.txt``.
641 Compiler/Platform-specific topics
642 =================================
644 Notes for specific compilers and/or platforms.
649 **LLVM_COMPILER_JOBS**:STRING
650 Specifies the maximum number of parallel compiler jobs to use per project
651 when building with msbuild or Visual Studio. Only supported for the Visual
652 Studio 2010 CMake generator. 0 means use all processors. Default is 0.