docs/GettingStartedVS.rst - platform/external/llvm - Git at Google

 ==================================================================
 Getting Started with the LLVM System using Microsoft Visual Studio
 ==================================================================

 .. contents::
    :local:


 Overview
 ========
 Welcome to LLVM on Windows! This document only covers LLVM on Windows using
 Visual Studio, not mingw or cygwin. In order to get started, you first need to
 know some basic information.

 There are many different projects that compose LLVM. The first is the LLVM
 suite. This contains all of the tools, libraries, and header files needed to
 use LLVM. It contains an assembler, disassembler,
 bitcode analyzer and bitcode optimizer. It also contains a test suite that can
 be used to test the LLVM tools.

 Another useful project on Windows is `Clang <http://clang.llvm.org/>`_.
 Clang is a C family ([Objective]C/C++) compiler. Clang mostly works on
 Windows, but does not currently understand all of the Microsoft extensions
 to C and C++. Because of this, clang cannot parse the C++ standard library
 included with Visual Studio, nor parts of the Windows Platform SDK. However,
 most standard C programs do compile. Clang can be used to emit bitcode,
 directly emit object files or even linked executables using Visual Studio's
 ``link.exe``.

 The large LLVM test suite cannot be run on the Visual Studio port at this
 time.

 Most of the tools build and work.  ``bugpoint`` does build, but does
 not work.

 Additional information about the LLVM directory structure and tool chain
 can be found on the main `Getting Started <GettingStarted.html>`_ page.


 Requirements
 ============
 Before you begin to use the LLVM system, review the requirements given
 below.  This may save you some trouble by knowing ahead of time what hardware
 and software you will need.

 Hardware
 --------
 Any system that can adequately run Visual Studio 2008 is fine. The LLVM
 source tree and object files, libraries and executables will consume
 approximately 3GB.

 Software
 --------
 You will need Visual Studio 2008 or higher.  Earlier versions of Visual
 Studio have bugs, are not completely compatible, or do not support the C++
 standard well enough.

 You will also need the `CMake <http://www.cmake.org/>`_ build system since it
 generates the project files you will use to build with.

 If you would like to run the LLVM tests you will need `Python
 <http://www.python.org/>`_. Versions 2.4-2.7 are known to work. You will need
 `GnuWin32 <http://gnuwin32.sourceforge.net/>`_ tools, too.

 Do not install the LLVM directory tree into a path containing spaces (e.g.
 ``C:\Documents and Settings\...``) as the configure step will fail.


 Getting Started
 ===============
 Here's the short story for getting up and running quickly with LLVM:

 1. Read the documentation.
 2. Seriously, read the documentation.
 3. Remember that you were warned twice about reading the documentation.
 4. Get the Source Code

    * With the distributed files:

       1. ``cd <where-you-want-llvm-to-live>``
       2. ``gunzip --stdout llvm-VERSION.tar.gz | tar -xvf -``
          (*or use WinZip*)
       3. ``cd llvm``

    * With anonymous Subversion access:

       1. ``cd <where-you-want-llvm-to-live>``
       2. ``svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm``
       3. ``cd llvm``

 5. Use `CMake <http://www.cmake.org/>`_ to generate up-to-date project files:

    * Once CMake is installed then the simplest way is to just start the
      CMake GUI, select the directory where you have LLVM extracted to, and
      the default options should all be fine.  One option you may really
      want to change, regardless of anything else, might be the
      ``CMAKE_INSTALL_PREFIX`` setting to select a directory to INSTALL to
      once compiling is complete, although installation is not mandatory for
      using LLVM.  Another important option is ``LLVM_TARGETS_TO_BUILD``,
      which controls the LLVM target architectures that are included on the
      build.
    * See the `LLVM CMake guide <CMake.html>`_ for detailed information about
      how to configure the LLVM build.

 6. Start Visual Studio

    * In the directory you created the project files will have an ``llvm.sln``
      file, just double-click on that to open Visual Studio.

 7. Build the LLVM Suite:

    * The projects may still be built individually, but to build them all do
      not just select all of them in batch build (as some are meant as
      configuration projects), but rather select and build just the
      ``ALL_BUILD`` project to build everything, or the ``INSTALL`` project,
      which first builds the ``ALL_BUILD`` project, then installs the LLVM
      headers, libs, and other useful things to the directory set by the
      ``CMAKE_INSTALL_PREFIX`` setting when you first configured CMake.
    * The Fibonacci project is a sample program that uses the JIT. Modify the
      project's debugging properties to provide a numeric command line argument
      or run it from the command line.  The program will print the
      corresponding fibonacci value.

 8. Test LLVM on Visual Studio:

    * If ``%PATH%`` does not contain GnuWin32, you may specify
      ``LLVM_LIT_TOOLS_DIR`` on CMake for the path to GnuWin32.
    * You can run LLVM tests by merely building the project "check". The test
      results will be shown in the VS output window.

 .. FIXME: Is it up-to-date?

 9. Test LLVM:

    * The LLVM tests can be run by changing directory to the llvm source
      directory and running:

      .. code-block:: bat

         C:\..\llvm> llvm-lit test

      Note that quite a few of these test will fail.

      A specific test or test directory can be run with:

      .. code-block:: bat

         C:\..\llvm> llvm-lit test/path/to/test


 An Example Using the LLVM Tool Chain
 ====================================

 1. First, create a simple C file, name it '``hello.c``':

    .. code-block:: c

       #include <stdio.h>
       int main() {
         printf("hello world\n");
         return 0;
       }

 2. Next, compile the C file into a LLVM bitcode file:

    .. code-block:: bat

       C:\..> clang -c hello.c -emit-llvm -o hello.bc

    This will create the result file ``hello.bc`` which is the LLVM bitcode
    that corresponds the compiled program and the library facilities that
    it required.  You can execute this file directly using ``lli`` tool,
    compile it to native assembly with the ``llc``, optimize or analyze it
    further with the ``opt`` tool, etc.

    Alternatively you can directly output an executable with clang with:

    .. code-block:: bat

       C:\..> clang hello.c -o hello.exe

    The ``-o hello.exe`` is required because clang currently outputs ``a.out``
    when neither ``-o`` nor ``-c`` are given.

 3. Run the program using the just-in-time compiler:

    .. code-block:: bat

       C:\..> lli hello.bc

 4. Use the ``llvm-dis`` utility to take a look at the LLVM assembly code:

    .. code-block:: bat

       C:\..> llvm-dis < hello.bc | more

 5. Compile the program to object code using the LLC code generator:

    .. code-block:: bat

       C:\..> llc -filetype=obj hello.bc

 6. Link to binary using Microsoft link:

    .. code-block:: bat

       C:\..> link hello.obj -defaultlib:libcmt

 7. Execute the native code program:

    .. code-block:: bat

       C:\..> hello.exe


 Common Problems
 ===============
 If you are having problems building or using LLVM, or if you have any other
 general questions about LLVM, please consult the `Frequently Asked Questions
 <FAQ.html>`_ page.


 Links
 =====
 This document is just an **introduction** to how to use LLVM to do some simple
 things... there are many more interesting and complicated things that you can
 do that aren't documented here (but we'll gladly accept a patch if you want to
 write something up!).  For more information about LLVM, check out:

 * `LLVM homepage <http://llvm.org/>`_
 * `LLVM doxygen tree <http://llvm.org/doxygen/>`_
	==================================================================
	Getting Started with the LLVM System using Microsoft Visual Studio
	==================================================================

	.. contents::
	:local:


	Overview
	========
	Welcome to LLVM on Windows! This document only covers LLVM on Windows using
	Visual Studio, not mingw or cygwin. In order to get started, you first need to
	know some basic information.

	There are many different projects that compose LLVM. The first is the LLVM
	suite. This contains all of the tools, libraries, and header files needed to
	use LLVM. It contains an assembler, disassembler,
	bitcode analyzer and bitcode optimizer. It also contains a test suite that can
	be used to test the LLVM tools.

	Another useful project on Windows is `Clang <http://clang.llvm.org/>`_.
	Clang is a C family ([Objective]C/C++) compiler. Clang mostly works on
	Windows, but does not currently understand all of the Microsoft extensions
	to C and C++. Because of this, clang cannot parse the C++ standard library
	included with Visual Studio, nor parts of the Windows Platform SDK. However,
	most standard C programs do compile. Clang can be used to emit bitcode,
	directly emit object files or even linked executables using Visual Studio's
	``link.exe``.

	The large LLVM test suite cannot be run on the Visual Studio port at this
	time.

	Most of the tools build and work. ``bugpoint`` does build, but does
	not work.

	Additional information about the LLVM directory structure and tool chain
	can be found on the main `Getting Started <GettingStarted.html>`_ page.


	Requirements
	============
	Before you begin to use the LLVM system, review the requirements given
	below. This may save you some trouble by knowing ahead of time what hardware
	and software you will need.

	Hardware
	--------
	Any system that can adequately run Visual Studio 2008 is fine. The LLVM
	source tree and object files, libraries and executables will consume
	approximately 3GB.

	Software
	--------
	You will need Visual Studio 2008 or higher. Earlier versions of Visual
	Studio have bugs, are not completely compatible, or do not support the C++
	standard well enough.

	You will also need the `CMake <http://www.cmake.org/>`_ build system since it
	generates the project files you will use to build with.

	If you would like to run the LLVM tests you will need `Python
	<http://www.python.org/>`_. Versions 2.4-2.7 are known to work. You will need
	`GnuWin32 <http://gnuwin32.sourceforge.net/>`_ tools, too.

	Do not install the LLVM directory tree into a path containing spaces (e.g.
	``C:\Documents and Settings\...``) as the configure step will fail.


	Getting Started
	===============
	Here's the short story for getting up and running quickly with LLVM:

	1. Read the documentation.
	2. Seriously, read the documentation.
	3. Remember that you were warned twice about reading the documentation.
	4. Get the Source Code

	* With the distributed files:

	1. ``cd <where-you-want-llvm-to-live>``
	2. ``gunzip --stdout llvm-VERSION.tar.gz \| tar -xvf -``
	(or use WinZip)
	3. ``cd llvm``

	* With anonymous Subversion access:

	1. ``cd <where-you-want-llvm-to-live>``
	2. ``svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm``
	3. ``cd llvm``

	5. Use `CMake <http://www.cmake.org/>`_ to generate up-to-date project files:

	* Once CMake is installed then the simplest way is to just start the
	CMake GUI, select the directory where you have LLVM extracted to, and
	the default options should all be fine. One option you may really
	want to change, regardless of anything else, might be the
	``CMAKE_INSTALL_PREFIX`` setting to select a directory to INSTALL to
	once compiling is complete, although installation is not mandatory for
	using LLVM. Another important option is ``LLVM_TARGETS_TO_BUILD``,
	which controls the LLVM target architectures that are included on the
	build.
	* See the `LLVM CMake guide <CMake.html>`_ for detailed information about
	how to configure the LLVM build.

	6. Start Visual Studio

	* In the directory you created the project files will have an ``llvm.sln``
	file, just double-click on that to open Visual Studio.

	7. Build the LLVM Suite:

	* The projects may still be built individually, but to build them all do
	not just select all of them in batch build (as some are meant as
	configuration projects), but rather select and build just the
	``ALL_BUILD`` project to build everything, or the ``INSTALL`` project,
	which first builds the ``ALL_BUILD`` project, then installs the LLVM
	headers, libs, and other useful things to the directory set by the
	``CMAKE_INSTALL_PREFIX`` setting when you first configured CMake.
	* The Fibonacci project is a sample program that uses the JIT. Modify the
	project's debugging properties to provide a numeric command line argument
	or run it from the command line. The program will print the
	corresponding fibonacci value.

	8. Test LLVM on Visual Studio:

	* If ``%PATH%`` does not contain GnuWin32, you may specify
	``LLVM_LIT_TOOLS_DIR`` on CMake for the path to GnuWin32.
	* You can run LLVM tests by merely building the project "check". The test
	results will be shown in the VS output window.

	.. FIXME: Is it up-to-date?

	9. Test LLVM:

	* The LLVM tests can be run by changing directory to the llvm source
	directory and running:

	.. code-block:: bat

	C:\..\llvm> llvm-lit test

	Note that quite a few of these test will fail.

	A specific test or test directory can be run with:

	.. code-block:: bat

	C:\..\llvm> llvm-lit test/path/to/test


	An Example Using the LLVM Tool Chain
	====================================

	1. First, create a simple C file, name it '``hello.c``':

	.. code-block:: c

	#include <stdio.h>
	int main() {
	printf("hello world\n");
	return 0;
	}

	2. Next, compile the C file into a LLVM bitcode file:

	.. code-block:: bat

	C:\..> clang -c hello.c -emit-llvm -o hello.bc

	This will create the result file ``hello.bc`` which is the LLVM bitcode
	that corresponds the compiled program and the library facilities that
	it required. You can execute this file directly using ``lli`` tool,
	compile it to native assembly with the ``llc``, optimize or analyze it
	further with the ``opt`` tool, etc.

	Alternatively you can directly output an executable with clang with:

	.. code-block:: bat

	C:\..> clang hello.c -o hello.exe

	The ``-o hello.exe`` is required because clang currently outputs ``a.out``
	when neither ``-o`` nor ``-c`` are given.

	3. Run the program using the just-in-time compiler:

	.. code-block:: bat

	C:\..> lli hello.bc

	4. Use the ``llvm-dis`` utility to take a look at the LLVM assembly code:

	.. code-block:: bat

	C:\..> llvm-dis < hello.bc \| more

	5. Compile the program to object code using the LLC code generator:

	.. code-block:: bat

	C:\..> llc -filetype=obj hello.bc

	6. Link to binary using Microsoft link:

	.. code-block:: bat

	C:\..> link hello.obj -defaultlib:libcmt

	7. Execute the native code program:

	.. code-block:: bat

	C:\..> hello.exe


	Common Problems
	===============
	If you are having problems building or using LLVM, or if you have any other
	general questions about LLVM, please consult the `Frequently Asked Questions
	<FAQ.html>`_ page.


	Links
	=====
	This document is just an introduction to how to use LLVM to do some simple
	things... there are many more interesting and complicated things that you can
	do that aren't documented here (but we'll gladly accept a patch if you want to
	write something up!). For more information about LLVM, check out:

	* `LLVM homepage <http://llvm.org/>`_
	* `LLVM doxygen tree <http://llvm.org/doxygen/>`_