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			1764 lines
		
	
	
		
			61 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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|                       "http://www.w3.org/TR/html4/strict.dtd">
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| <html>
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| <head>
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|   <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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|   <title>Getting Started with LLVM System</title>
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|   <link rel="stylesheet" href="llvm.css" type="text/css">
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| </head>
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| <body>
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| 
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| <h1>
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|   Getting Started with the LLVM System  
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| </h1>
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| 
 | |
| <ul>
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|   <li><a href="#overview">Overview</a>
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|   <li><a href="#quickstart">Getting Started Quickly (A Summary)</a>
 | |
|   <li><a href="#requirements">Requirements</a>
 | |
|     <ol>
 | |
|       <li><a href="#hardware">Hardware</a></li>
 | |
|       <li><a href="#software">Software</a></li>
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|       <li><a href="#brokengcc">Broken versions of GCC and other tools</a></li>
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|     </ol></li>
 | |
| 
 | |
|   <li><a href="#starting">Getting Started with LLVM</a>
 | |
|     <ol>
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|       <li><a href="#terminology">Terminology and Notation</a></li>
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|       <li><a href="#environment">Setting Up Your Environment</a></li>
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|       <li><a href="#unpack">Unpacking the LLVM Archives</a></li>
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|       <li><a href="#checkout">Checkout LLVM from Subversion</a></li>
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|       <li><a href="#git_mirror">LLVM GIT mirror</a></li>
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|       <li><a href="#config">Local LLVM Configuration</a></li>
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|       <li><a href="#compile">Compiling the LLVM Suite Source Code</a></li>
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|       <li><a href="#cross-compile">Cross-Compiling LLVM</a></li>
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|       <li><a href="#objfiles">The Location of LLVM Object Files</a></li>
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|       <li><a href="#optionalconfig">Optional Configuration Items</a></li>
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|     </ol></li>
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| 
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|   <li><a href="#layout">Program layout</a>
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|     <ol>
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|       <li><a href="#examples"><tt>llvm/examples</tt></a></li>
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|       <li><a href="#include"><tt>llvm/include</tt></a></li>
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|       <li><a href="#lib"><tt>llvm/lib</tt></a></li>
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|       <li><a href="#projects"><tt>llvm/projects</tt></a></li>
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|       <li><a href="#runtime"><tt>llvm/runtime</tt></a></li>
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|       <li><a href="#test"><tt>llvm/test</tt></a></li>
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|       <li><a href="#test-suite"><tt>test-suite</tt></a></li>
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|       <li><a href="#tools"><tt>llvm/tools</tt></a></li>
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|       <li><a href="#utils"><tt>llvm/utils</tt></a></li>
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|     </ol></li>
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| 
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|   <li><a href="#tutorial">An Example Using the LLVM Tool Chain</a>
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|       <ol>
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|          <li><a href="#tutorial4">Example with Clang</a></li>
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|       </ol>
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|   <li><a href="#problems">Common Problems</a>
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|   <li><a href="#links">Links</a>
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| </ul>
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| 
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| <div class="doc_author">
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|   <p>Written by: 
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|     <a href="mailto:criswell@uiuc.edu">John Criswell</a>, 
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|     <a href="mailto:sabre@nondot.org">Chris Lattner</a>,
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|     <a href="http://misha.brukman.net/">Misha Brukman</a>, 
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|     <a href="http://www.cs.uiuc.edu/~vadve">Vikram Adve</a>, and
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|     <a href="mailto:gshi1@uiuc.edu">Guochun Shi</a>.
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|   </p>
 | |
| </div>
 | |
| 
 | |
| 
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| <!-- *********************************************************************** -->
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| <h2>
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|   <a name="overview">Overview</a>
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| </h2>
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| <!-- *********************************************************************** -->
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| 
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| <div>
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| 
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| <p>Welcome to LLVM! In order to get started, you first need to know some
 | |
| basic information.</p>
 | |
| 
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| <p>First, LLVM comes in three pieces. The first piece is the LLVM
 | |
| suite. This contains all of the tools, libraries, and header files
 | |
| needed to use LLVM.  It contains an assembler, disassembler, bitcode
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| analyzer and bitcode optimizer.  It also contains basic regression tests that
 | |
| can be used to test the LLVM tools and the Clang front end.</p>
 | |
| 
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| <p>The second piece is the <a href="http://clang.llvm.org/">Clang</a> front end.
 | |
| This component compiles C, C++, Objective C, and Objective C++ code into LLVM
 | |
| bitcode. Once compiled into LLVM bitcode, a program can be manipulated with the
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| LLVM tools from the LLVM suite.
 | |
| </p>
 | |
| 
 | |
| <p>
 | |
| There is a third, optional piece called Test Suite.  It is a suite of programs
 | |
| with a testing harness that can be used to further test LLVM's functionality
 | |
| and performance.
 | |
| </p>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- *********************************************************************** -->
 | |
| <h2>
 | |
|   <a name="quickstart">Getting Started Quickly (A Summary)</a>
 | |
| </h2>
 | |
| <!-- *********************************************************************** -->
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>The LLVM Getting Started documentation may be out of date.  So, the Clang 
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| <a href="http://clang.llvm.org/get_started.html">Getting Started</a> page might 
 | |
| also be a good place to start.</p>
 | |
| 
 | |
| <p>Here's the short story for getting up and running quickly with LLVM:</p>
 | |
| 
 | |
| <ol>
 | |
|   <li>Read the documentation.</li>
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|   <li>Read the documentation.</li>
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|   <li>Remember that you were warned twice about reading the documentation.</li>
 | |
| 
 | |
|   <li>Checkout LLVM:
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|   <ul>
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|     <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
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|     <li><tt>svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm</tt></li>
 | |
|   </ul>
 | |
|   </li>
 | |
| 
 | |
|   <li>Checkout Clang:
 | |
|   <ul>
 | |
|     <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
 | |
|     <li><tt>cd llvm/tools</tt>
 | |
|     <li><tt>svn co http://llvm.org/svn/llvm-project/cfe/trunk clang</tt></li>
 | |
|   </ul>
 | |
|   </li>
 | |
| 
 | |
|   <li>Checkout Compiler-RT:
 | |
|   <ul>
 | |
|     <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
 | |
|     <li><tt>cd llvm/projects</tt>
 | |
|     <li><tt>svn co http://llvm.org/svn/llvm-project/compiler-rt/trunk
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|         compiler-rt</tt></li>
 | |
|   </ul>
 | |
|   </li>
 | |
| 
 | |
|   <li>Get the Test Suite Source Code <b>[Optional]</b>
 | |
|   <ul>
 | |
|     <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
 | |
|     <li><tt>cd llvm/projects</tt>
 | |
|     <li><tt>svn co http://llvm.org/svn/llvm-project/test-suite/trunk test-suite</tt></li>
 | |
|   </ul>
 | |
|   </li>
 | |
| 
 | |
|   <li>Configure and build LLVM and Clang:
 | |
|   <ul>
 | |
|     <li><tt>cd <i>where-you-want-to-build-llvm</i></tt></li>
 | |
|     <li><tt>mkdir build</tt> (for building without polluting the source dir)</li>
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|     <li><tt>cd build</tt></li>
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|     <li><tt>../llvm/configure [options]</tt>
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|     <br>Some common options:
 | |
| 
 | |
|       <ul>
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|         <li><tt>--prefix=<i>directory</i></tt> -
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|         Specify for <i>directory</i> the full pathname of where you
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|         want the LLVM tools and libraries to be installed (default
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|         <tt>/usr/local</tt>).</li>
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|       </ul>
 | |
| 
 | |
|       <ul>
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|         <li><tt>--enable-optimized</tt> -
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|         Compile with optimizations enabled (default is NO).</li>
 | |
|       </ul>
 | |
| 
 | |
|       <ul>
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|         <li><tt>--enable-assertions</tt> -
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|         Compile with assertion checks enabled (default is YES).</li>
 | |
|       </ul>
 | |
|    </li>
 | |
|     <li><tt>make [-j]</tt> - The -j specifies the number of jobs (commands) to 
 | |
|     run simultaneously.  This builds both LLVM and Clang for Debug+Asserts mode.
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|     The --enabled-optimized configure option is used to specify a Release build.</li>
 | |
|     <li><tt>make check-all</tt> -
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|     This run the regression tests to ensure everything is in working order.</li>
 | |
|     <li><tt>make update</tt> -
 | |
|     This command is used to update all the svn repositories at once, rather then
 | |
|     having to <tt>cd</tt> into the individual repositories and running
 | |
|     <tt>svn update</tt>.</li>
 | |
|     <li>It is also possible to use CMake instead of the makefiles. With CMake
 | |
|     it is also possible to generate project files for several IDEs: Eclipse
 | |
|     CDT4, CodeBlocks, Qt-Creator (use the CodeBlocks generator), KDevelop3.</li>
 | |
|     <li>If you get an "internal compiler error (ICE)" or test failures, see 
 | |
|         <a href="#brokengcc">below</a>.</li>
 | |
| 
 | |
|   </ul>
 | |
|   </li>
 | |
| 
 | |
| </ol>
 | |
| 
 | |
| <p>Consult the <a href="#starting">Getting Started with LLVM</a> section for
 | |
| detailed information on configuring and compiling LLVM.  See <a
 | |
| href="#environment">Setting Up Your Environment</a> for tips that simplify
 | |
| working with the Clang front end and LLVM tools.  Go to <a href="#layout">Program
 | |
| Layout</a> to learn about the layout of the source code tree.</p>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- *********************************************************************** -->
 | |
| <h2>
 | |
|   <a name="requirements">Requirements</a>
 | |
| </h2>
 | |
| <!-- *********************************************************************** -->
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>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.</p>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="hardware">Hardware</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>LLVM is known to work on the following platforms:</p>
 | |
| 
 | |
| <table cellpadding="3" summary="Known LLVM platforms">
 | |
| <tr>
 | |
|   <th>OS</th>
 | |
|   <th>Arch</th>
 | |
|   <th>Compilers</th>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>AuroraUX</td>
 | |
|   <td>x86<sup><a href="#pf_1">1</a></sup></td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>Linux</td>
 | |
|   <td>x86<sup><a href="#pf_1">1</a></sup></td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>Linux</td>
 | |
|   <td>amd64</td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>Solaris</td>
 | |
|   <td>V9 (Ultrasparc)</td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>FreeBSD</td>
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|   <td>x86<sup><a href="#pf_1">1</a></sup></td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>FreeBSD</td>
 | |
|   <td>amd64</td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>MacOS X<sup><a href="#pf_2">2</a></sup></td>
 | |
|   <td>PowerPC</td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>MacOS X<sup><a href="#pf_2">2</a>,<a href="#pf_9">9</a></sup></td>
 | |
|   <td>x86</td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>Cygwin/Win32</td>
 | |
|   <td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_8">8</a>,
 | |
|      <a href="#pf_11">11</a></sup></td>
 | |
|   <td>GCC 3.4.X, binutils 2.20</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>MinGW/Win32</td>
 | |
|   <td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_6">6</a>,
 | |
|      <a href="#pf_8">8</a>, <a href="#pf_10">10</a>,
 | |
|      <a href="#pf_11">11</a></sup></td>
 | |
|   <td>GCC 3.4.X, binutils 2.20</td>
 | |
| </tr>
 | |
| </table>
 | |
| 
 | |
| <p>LLVM has partial support for the following platforms:</p>
 | |
| 
 | |
| <table summary="LLVM partial platform support">
 | |
| <tr>
 | |
|   <th>OS</th>
 | |
|   <th>Arch</th>
 | |
|   <th>Compilers</th>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>Windows</td>
 | |
|   <td>x86<sup><a href="#pf_1">1</a></sup></td>
 | |
|   <td>Visual Studio 2008 or higher<sup><a href="#pf_4">4</a>,<a href="#pf_5">5</a></sup></td>
 | |
| <tr>
 | |
|   <td>AIX<sup><a href="#pf_3">3</a>,<a href="#pf_4">4</a></sup></td>
 | |
|   <td>PowerPC</td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>Linux<sup><a href="#pf_3">3</a>,<a href="#pf_5">5</a></sup></td>
 | |
|   <td>PowerPC</td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| 
 | |
| <tr>
 | |
|   <td>Linux<sup><a href="#pf_7">7</a></sup></td>
 | |
|   <td>Alpha</td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>Linux<sup><a href="#pf_7">7</a></sup></td>
 | |
|   <td>Itanium (IA-64)</td>
 | |
|   <td>GCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>HP-UX<sup><a href="#pf_7">7</a></sup></td>
 | |
|   <td>Itanium (IA-64)</td>
 | |
|   <td>HP aCC</td>
 | |
| </tr>
 | |
| <tr>
 | |
|   <td>Windows x64</td>
 | |
|   <td>x86-64</td>
 | |
|   <td>mingw-w64's GCC-4.5.x<sup><a href="#pf_12">12</a></sup></td>
 | |
| </tr>
 | |
| </table>
 | |
| 
 | |
| <p><b>Notes:</b></p>
 | |
| 
 | |
| <div class="doc_notes">
 | |
| <ol>
 | |
| <li><a name="pf_1">Code generation supported for Pentium processors and
 | |
| up</a></li>
 | |
| <li><a name="pf_2">Code generation supported for 32-bit ABI only</a></li>
 | |
| <li><a name="pf_3">No native code generation</a></li>
 | |
| <li><a name="pf_4">Build is not complete: one or more tools do not link or function</a></li>
 | |
| <li><a name="pf_5">The GCC-based C/C++ frontend does not build</a></li>
 | |
| <li><a name="pf_6">The port is done using the MSYS shell.</a></li>
 | |
| <li><a name="pf_7">Native code generation exists but is not complete.</a></li>
 | |
| <li><a name="pf_8">Binutils 2.20 or later is required to build the assembler
 | |
|     generated by LLVM properly.</a></li>
 | |
| <li><a name="pf_9">XCode 2.5 and gcc 4.0.1</a> (Apple Build 5370) will trip
 | |
|     internal LLVM assert messages when compiled for Release at optimization
 | |
|     levels greater than 0 (i.e., <i>"-O1"</i> and higher).
 | |
|     Add <i>OPTIMIZE_OPTION="-O0"</i> to the build command line
 | |
|     if compiling for LLVM Release or bootstrapping the LLVM toolchain.</li>
 | |
| <li><a name="pf_10">For MSYS/MinGW on Windows, be sure to install the MSYS
 | |
|     version of the perl package, and be sure it appears in your path
 | |
|     before any Windows-based versions such as Strawberry Perl and
 | |
|     ActivePerl, as these have Windows-specifics that will cause the
 | |
|     build to fail.</a></li>
 | |
| <li><a name="pf_11">To use LLVM modules on Win32-based system,
 | |
|     you may configure LLVM with <i>"--enable-shared"</i>.</a></li>
 | |
| <li><a name="pf_12">To compile SPU backend, you need to add
 | |
|     <tt>"LDFLAGS=-Wl,--stack,16777216"</tt> to configure.</a></li>
 | |
| </ol>
 | |
| </div>
 | |
| 
 | |
| <p>Note that you will need about 1-3 GB of space for a full LLVM build in Debug
 | |
| mode, depending on the system (it is so large because of all the debugging
 | |
| information and the fact that the libraries are statically linked into multiple
 | |
| tools).  If you do not need many of the tools and you are space-conscious, you
 | |
| can pass <tt>ONLY_TOOLS="tools you need"</tt> to make.  The Release build
 | |
| requires considerably less space.</p>
 | |
| 
 | |
| <p>The LLVM suite <i>may</i> compile on other platforms, but it is not
 | |
| guaranteed to do so.  If compilation is successful, the LLVM utilities should be
 | |
| able to assemble, disassemble, analyze, and optimize LLVM bitcode.  Code
 | |
| generation should work as well, although the generated native code may not work
 | |
| on your platform.</p>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="software">Software</a>
 | |
| </h3>
 | |
| <div>
 | |
|   <p>Compiling LLVM requires that you have several software packages 
 | |
|   installed. The table below lists those required packages. The Package column
 | |
|   is the usual name for the software package that LLVM depends on. The Version
 | |
|   column provides "known to work" versions of the package. The Notes column
 | |
|   describes how LLVM uses the package and provides other details.</p>
 | |
|   <table summary="Packages required to compile LLVM">
 | |
|     <tr><th>Package</th><th>Version</th><th>Notes</th></tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://savannah.gnu.org/projects/make">GNU Make</a></td>
 | |
|       <td>3.79, 3.79.1</td>
 | |
|       <td>Makefile/build processor</td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://gcc.gnu.org/">GCC</a></td>
 | |
|       <td>3.4.2</td>
 | |
|       <td>C/C++ compiler<sup><a href="#sf1">1</a></sup></td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://www.gnu.org/software/texinfo/">TeXinfo</a></td>
 | |
|       <td>4.5</td>
 | |
|       <td>For building the CFE</td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://subversion.tigris.org/project_packages.html">SVN</a></td>
 | |
|       <td>≥1.3</td>
 | |
|       <td>Subversion access to LLVM<sup><a href="#sf2">2</a></sup></td>
 | |
|     </tr>
 | |
| 
 | |
|     <!-- FIXME:
 | |
|     Do we support dg?
 | |
|     Are DejaGnu and expect obsolete?
 | |
|     Shall we mention Python? -->
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://savannah.gnu.org/projects/dejagnu">DejaGnu</a></td>
 | |
|       <td>1.4.2</td>
 | |
|       <td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://www.tcl.tk/software/tcltk/">tcl</a></td>
 | |
|       <td>8.3, 8.4</td>
 | |
|       <td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://expect.nist.gov/">expect</a></td>
 | |
|       <td>5.38.0</td>
 | |
|       <td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://www.perl.com/download.csp">perl</a></td>
 | |
|       <td>≥5.6.0</td>
 | |
|       <td>Utilities</td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://savannah.gnu.org/projects/m4">GNU M4</a>
 | |
|       <td>1.4</td>
 | |
|       <td>Macro processor for configuration<sup><a href="#sf4">4</a></sup></td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://www.gnu.org/software/autoconf/">GNU Autoconf</a></td>
 | |
|       <td>2.60</td>
 | |
|       <td>Configuration script builder<sup><a href="#sf4">4</a></sup></td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://www.gnu.org/software/automake/">GNU Automake</a></td>
 | |
|       <td>1.9.6</td>
 | |
|       <td>aclocal macro generator<sup><a href="#sf4">4</a></sup></td>
 | |
|     </tr>
 | |
| 
 | |
|     <tr>
 | |
|       <td><a href="http://savannah.gnu.org/projects/libtool">libtool</a></td>
 | |
|       <td>1.5.22</td>
 | |
|       <td>Shared library manager<sup><a href="#sf4">4</a></sup></td>
 | |
|     </tr>
 | |
| 
 | |
|   </table>
 | |
| 
 | |
|   <p><b>Notes:</b></p>
 | |
|   <div class="doc_notes">
 | |
|   <ol>
 | |
|     <li><a name="sf1">Only the C and C++ languages are needed so there's no
 | |
|       need to build the other languages for LLVM's purposes.</a> See 
 | |
|       <a href="#brokengcc">below</a> for specific version info.</li>
 | |
|     <li><a name="sf2">You only need Subversion if you intend to build from the 
 | |
|       latest LLVM sources. If you're working from a release distribution, you
 | |
|       don't need Subversion.</a></li>
 | |
|     <li><a name="sf3">Only needed if you want to run the automated test 
 | |
|       suite in the <tt>llvm/test</tt> directory.</a></li>
 | |
|     <li><a name="sf4">If you want to make changes to the configure scripts, 
 | |
|       you will need GNU autoconf (2.60), and consequently, GNU M4 (version 1.4 
 | |
|       or higher). You will also need automake (1.9.6). We only use aclocal 
 | |
|       from that package.</a></li>
 | |
|   </ol>
 | |
|   </div>
 | |
|   
 | |
|   <p>Additionally, your compilation host is expected to have the usual 
 | |
|   plethora of Unix utilities. Specifically:</p>
 | |
|   <ul>
 | |
|     <li><b>ar</b> - archive library builder</li>
 | |
|     <li><b>bzip2*</b> - bzip2 command for distribution generation</li>
 | |
|     <li><b>bunzip2*</b> - bunzip2 command for distribution checking</li>
 | |
|     <li><b>chmod</b> - change permissions on a file</li>
 | |
|     <li><b>cat</b> - output concatenation utility</li>
 | |
|     <li><b>cp</b> - copy files</li>
 | |
|     <li><b>date</b> - print the current date/time </li>
 | |
|     <li><b>echo</b> - print to standard output</li>
 | |
|     <li><b>egrep</b> - extended regular expression search utility</li>
 | |
|     <li><b>find</b> - find files/dirs in a file system</li>
 | |
|     <li><b>grep</b> - regular expression search utility</li>
 | |
|     <li><b>gzip*</b> - gzip command for distribution generation</li>
 | |
|     <li><b>gunzip*</b> - gunzip command for distribution checking</li>
 | |
|     <li><b>install</b> - install directories/files </li>
 | |
|     <li><b>mkdir</b> - create a directory</li>
 | |
|     <li><b>mv</b> - move (rename) files</li>
 | |
|     <li><b>ranlib</b> - symbol table builder for archive libraries</li>
 | |
|     <li><b>rm</b> - remove (delete) files and directories</li>
 | |
|     <li><b>sed</b> - stream editor for transforming output</li>
 | |
|     <li><b>sh</b> - Bourne shell for make build scripts</li>
 | |
|     <li><b>tar</b> - tape archive for distribution generation</li>
 | |
|     <li><b>test</b> - test things in file system</li>
 | |
|     <li><b>unzip*</b> - unzip command for distribution checking</li>
 | |
|     <li><b>zip*</b> - zip command for distribution generation</li>
 | |
|   </ul>
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="brokengcc">Broken versions of GCC and other tools</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>LLVM is very demanding of the host C++ compiler, and as such tends to expose
 | |
| bugs in the compiler.  In particular, several versions of GCC crash when trying
 | |
| to compile LLVM.  We routinely use GCC 4.2 (and higher) or Clang.  
 | |
| Other versions of GCC will probably work as well.  GCC versions listed
 | |
| here are known to not work.  If you are using one of these versions, please try
 | |
| to upgrade your GCC to something more recent.  If you run into a problem with a
 | |
| version of GCC not listed here, please <a href="mailto:llvmdev@cs.uiuc.edu">let
 | |
| us know</a>.  Please use the "<tt>gcc -v</tt>" command to find out which version
 | |
| of GCC you are using.
 | |
| </p>
 | |
| 
 | |
| <p><b>GCC versions prior to 3.0</b>: GCC 2.96.x and before had several
 | |
| problems in the STL that effectively prevent it from compiling LLVM.
 | |
| </p>
 | |
| 
 | |
| <p><b>GCC 3.2.2 and 3.2.3</b>: These versions of GCC fails to compile LLVM with
 | |
| a bogus template error.  This was fixed in later GCCs.</p>
 | |
| 
 | |
| <p><b>GCC 3.3.2</b>: This version of GCC suffered from a <a 
 | |
| href="http://gcc.gnu.org/PR13392">serious bug</a> which causes it to crash in
 | |
| the "<tt>convert_from_eh_region_ranges_1</tt>" GCC function.</p>
 | |
| 
 | |
| <p><b>Cygwin GCC 3.3.3</b>: The version of GCC 3.3.3 commonly shipped with 
 | |
|    Cygwin does not work.</p>
 | |
| <p><b>SuSE GCC 3.3.3</b>: The version of GCC 3.3.3 shipped with SuSE 9.1 (and 
 | |
|    possibly others) does not compile LLVM correctly (it appears that exception 
 | |
|    handling is broken in some cases).  Please download the FSF 3.3.3 or upgrade
 | |
|    to a newer version of GCC.</p>
 | |
| <p><b>GCC 3.4.0 on linux/x86 (32-bit)</b>: GCC miscompiles portions of the 
 | |
|    code generator, causing an infinite loop in the llvm-gcc build when built
 | |
|    with optimizations enabled (i.e. a release build).</p>
 | |
| <p><b>GCC 3.4.2 on linux/x86 (32-bit)</b>: GCC miscompiles portions of the 
 | |
|    code generator at -O3, as with 3.4.0.  However gcc 3.4.2 (unlike 3.4.0)
 | |
|    correctly compiles LLVM at -O2.  A work around is to build release LLVM
 | |
|    builds with "make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2 ..."</p>
 | |
| <p><b>GCC 3.4.x on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1056">
 | |
|    miscompiles portions of LLVM</a>.</p>
 | |
| <p><b>GCC 3.4.4 (CodeSourcery ARM 2005q3-2)</b>: this compiler miscompiles LLVM
 | |
|    when building with optimizations enabled.  It appears to work with 
 | |
|    "<tt>make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O1</tt>" or build a debug
 | |
|    build.</p>
 | |
| <p><b>IA-64 GCC 4.0.0</b>: The IA-64 version of GCC 4.0.0 is known to
 | |
|    miscompile LLVM.</p>
 | |
| <p><b>Apple Xcode 2.3</b>: GCC crashes when compiling LLVM at -O3 (which is the
 | |
|    default with ENABLE_OPTIMIZED=1.  To work around this, build with 
 | |
|    "ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2".</p>
 | |
| <p><b>GCC 4.1.1</b>: GCC fails to build LLVM with template concept check errors
 | |
|       compiling some files.  At the time of this writing, GCC mainline (4.2)
 | |
|       did not share the problem.</p>
 | |
| <p><b>GCC 4.1.1 on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1063">
 | |
|    miscompiles portions of LLVM</a> when compiling llvm itself into 64-bit 
 | |
|    code.  LLVM will appear to mostly work but will be buggy, e.g. failing 
 | |
|    portions of its testsuite.</p>
 | |
| <p><b>GCC 4.1.2 on OpenSUSE</b>: Seg faults during libstdc++ build and on x86_64
 | |
| platforms compiling md5.c gets a mangled constant.</p>
 | |
| <p><b>GCC 4.1.2 (20061115 (prerelease) (Debian 4.1.1-21)) on Debian</b>: Appears
 | |
| to miscompile parts of LLVM 2.4. One symptom is ValueSymbolTable complaining
 | |
| about symbols remaining in the table on destruction.</p>
 | |
| <p><b>GCC 4.1.2 20071124 (Red Hat 4.1.2-42)</b>: Suffers from the same symptoms
 | |
| as the previous one. It appears to work with ENABLE_OPTIMIZED=0 (the default).</p>
 | |
| <p><b>Cygwin GCC 4.3.2 20080827 (beta) 2</b>:
 | |
|   Users <a href="http://llvm.org/PR4145">reported</a> various problems related
 | |
|   with link errors when using this GCC version.</p>
 | |
| <p><b>Debian GCC 4.3.2 on X86</b>: Crashes building some files in LLVM 2.6.</p>
 | |
| <p><b>GCC 4.3.3 (Debian 4.3.3-10) on ARM</b>: Miscompiles parts of LLVM 2.6
 | |
| when optimizations are turned on. The symptom is an infinite loop in
 | |
| FoldingSetImpl::RemoveNode while running the code generator.</p>
 | |
| <p><b>GCC 4.3.5 and GCC 4.4.5 on ARM</b>: These can miscompile <tt>value >>
 | |
| 1</tt> even at -O0. A test failure in <tt>test/Assembler/alignstack.ll</tt> is
 | |
| one symptom of the problem.
 | |
| <p><b>GNU ld 2.16.X</b>. Some 2.16.X versions of the ld linker will produce very
 | |
| long warning messages complaining that some ".gnu.linkonce.t.*" symbol was
 | |
| defined in a discarded section. You can safely ignore these messages as they are
 | |
| erroneous and the linkage is correct.  These messages disappear using ld
 | |
| 2.17.</p>
 | |
| 
 | |
| <p><b>GNU binutils 2.17</b>: Binutils 2.17 contains <a 
 | |
| href="http://sourceware.org/bugzilla/show_bug.cgi?id=3111">a bug</a> which
 | |
| causes huge link times (minutes instead of seconds) when building LLVM.  We
 | |
| recommend upgrading to a newer version (2.17.50.0.4 or later).</p>
 | |
| 
 | |
| <p><b>GNU Binutils 2.19.1 Gold</b>: This version of Gold contained
 | |
| <a href="http://sourceware.org/bugzilla/show_bug.cgi?id=9836">a bug</a>
 | |
| which causes intermittent failures when building LLVM with position independent
 | |
| code.  The symptom is an error about cyclic dependencies.  We recommend
 | |
| upgrading to a newer version of Gold.</p>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- *********************************************************************** -->
 | |
| <h2>
 | |
|   <a name="starting">Getting Started with LLVM</a>
 | |
| </h2>
 | |
| <!-- *********************************************************************** -->
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>The remainder of this guide is meant to get you up and running with
 | |
| LLVM and to give you some basic information about the LLVM environment.</p>
 | |
| 
 | |
| <p>The later sections of this guide describe the <a
 | |
| href="#layout">general layout</a> of the the LLVM source tree, a <a
 | |
| href="#tutorial">simple example</a> using the LLVM tool chain, and <a
 | |
| href="#links">links</a> to find more information about LLVM or to get
 | |
| help via e-mail.</p>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="terminology">Terminology and Notation</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>Throughout this manual, the following names are used to denote paths
 | |
| specific to the local system and working environment.  <i>These are not
 | |
| environment variables you need to set but just strings used in the rest
 | |
| of this document below</i>.  In any of the examples below, simply replace
 | |
| each of these names with the appropriate pathname on your local system.
 | |
| All these paths are absolute:</p>
 | |
| 
 | |
| <dl>
 | |
|     <dt>SRC_ROOT
 | |
|     <dd>
 | |
|     This is the top level directory of the LLVM source tree.
 | |
|     <br><br>
 | |
| 
 | |
|     <dt>OBJ_ROOT
 | |
|     <dd>
 | |
|     This is the top level directory of the LLVM object tree (i.e. the
 | |
|     tree where object files and compiled programs will be placed.  It
 | |
|     can be the same as SRC_ROOT).
 | |
|     <br><br>
 | |
| 
 | |
| </dl>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="environment">Setting Up Your Environment</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>
 | |
| In order to compile and use LLVM, you may need to set some environment
 | |
| variables.
 | |
| 
 | |
| <dl>
 | |
|   <dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt>/path/to/your/bitcode/libs</tt></dt>
 | |
|   <dd>[Optional] This environment variable helps LLVM linking tools find the
 | |
|   locations of your bitcode libraries. It is provided only as a
 | |
|   convenience since you can specify the paths using the -L options of the
 | |
|   tools and the C/C++ front-end will automatically use the bitcode files
 | |
|   installed in its
 | |
|   <tt>lib</tt> directory.</dd>
 | |
| </dl>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="unpack">Unpacking the LLVM Archives</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>
 | |
| If you have the LLVM distribution, you will need to unpack it before you
 | |
| can begin to compile it.  LLVM is distributed as a set of two files: the LLVM
 | |
| suite and the LLVM GCC front end compiled for your platform.  There is an
 | |
| additional test suite that is optional.  Each file is a TAR archive that is
 | |
| compressed with the gzip program.
 | |
| </p>
 | |
| 
 | |
| <p>The files are as follows, with <em>x.y</em> marking the version number:
 | |
| <dl>
 | |
|   <dt><tt>llvm-x.y.tar.gz</tt></dt>
 | |
|   <dd>Source release for the LLVM libraries and tools.<br></dd>
 | |
| 
 | |
|   <dt><tt>llvm-test-x.y.tar.gz</tt></dt>
 | |
|   <dd>Source release for the LLVM test-suite.</dd>
 | |
| 
 | |
|   <dt><tt>llvm-gcc-4.2-x.y.source.tar.gz</tt></dt>
 | |
|   <dd>Source release of the llvm-gcc-4.2 front end.  See README.LLVM in the root
 | |
|       directory for build instructions.<br></dd>
 | |
| 
 | |
|   <dt><tt>llvm-gcc-4.2-x.y-platform.tar.gz</tt></dt>
 | |
|   <dd>Binary release of the llvm-gcc-4.2 front end for a specific platform.<br></dd>
 | |
| 
 | |
| </dl>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="checkout">Checkout LLVM from Subversion</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>If you have access to our Subversion repository, you can get a fresh copy of
 | |
| the entire source code.  All you need to do is check it out from Subversion as
 | |
| follows:</p>
 | |
| 
 | |
| <ul>
 | |
|   <li><tt>cd <i>where-you-want-llvm-to-live</i></tt></li>
 | |
|   <li>Read-Only: <tt>svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm</tt></li>
 | |
|   <li>Read-Write:<tt>svn co https://user@llvm.org/svn/llvm-project/llvm/trunk
 | |
|     llvm</tt></li>
 | |
| </ul>
 | |
| 
 | |
| 
 | |
| <p>This will create an '<tt>llvm</tt>' directory in the current
 | |
| directory and fully populate it with the LLVM source code, Makefiles,
 | |
| test directories, and local copies of documentation files.</p>
 | |
| 
 | |
| <p>If you want to get a specific release (as opposed to the most recent
 | |
| revision), you can checkout it from the '<tt>tags</tt>' directory (instead of
 | |
| '<tt>trunk</tt>'). The following releases are located in the following
 | |
| subdirectories of the '<tt>tags</tt>' directory:</p>
 | |
| 
 | |
| <ul>
 | |
| <li>Release 2.9: <b>RELEASE_29/final</b></li>
 | |
| <li>Release 2.8: <b>RELEASE_28</b></li>
 | |
| <li>Release 2.7: <b>RELEASE_27</b></li>
 | |
| <li>Release 2.6: <b>RELEASE_26</b></li>
 | |
| <li>Release 2.5: <b>RELEASE_25</b></li>
 | |
| <li>Release 2.4: <b>RELEASE_24</b></li>
 | |
| <li>Release 2.3: <b>RELEASE_23</b></li>
 | |
| <li>Release 2.2: <b>RELEASE_22</b></li>
 | |
| <li>Release 2.1: <b>RELEASE_21</b></li>
 | |
| <li>Release 2.0: <b>RELEASE_20</b></li>
 | |
| <li>Release 1.9: <b>RELEASE_19</b></li>
 | |
| <li>Release 1.8: <b>RELEASE_18</b></li>
 | |
| <li>Release 1.7: <b>RELEASE_17</b></li>
 | |
| <li>Release 1.6: <b>RELEASE_16</b></li>
 | |
| <li>Release 1.5: <b>RELEASE_15</b></li>
 | |
| <li>Release 1.4: <b>RELEASE_14</b></li>
 | |
| <li>Release 1.3: <b>RELEASE_13</b></li>
 | |
| <li>Release 1.2: <b>RELEASE_12</b></li>
 | |
| <li>Release 1.1: <b>RELEASE_11</b></li>
 | |
| <li>Release 1.0: <b>RELEASE_1</b></li>
 | |
| </ul>
 | |
| 
 | |
| <p>If you would like to get the LLVM test suite (a separate package as of 1.4),
 | |
| you get it from the Subversion repository:</p>
 | |
| 
 | |
| <div class="doc_code">
 | |
| <pre>
 | |
| % cd llvm/projects
 | |
| % svn co http://llvm.org/svn/llvm-project/test-suite/trunk test-suite
 | |
| </pre>
 | |
| </div>
 | |
| 
 | |
| <p>By placing it in the <tt>llvm/projects</tt>, it will be automatically
 | |
| configured by the LLVM configure script as well as automatically updated when
 | |
| you run <tt>svn update</tt>.</p>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="git_mirror">GIT mirror</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>GIT mirrors are available for a number of LLVM subprojects. These mirrors
 | |
|   sync automatically with each Subversion commit and contain all necessary
 | |
|   git-svn marks (so, you can recreate git-svn metadata locally). Note that right
 | |
|   now mirrors reflect only <tt>trunk</tt> for each project. You can do the
 | |
|   read-only GIT clone of LLVM via:</p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| git clone http://llvm.org/git/llvm.git
 | |
| </pre>
 | |
| 
 | |
| <p>If you want to check out clang too, run:</p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| git clone http://llvm.org/git/llvm.git
 | |
| cd llvm/tools
 | |
| git clone http://llvm.org/git/clang.git
 | |
| </pre>
 | |
| 
 | |
| <p>
 | |
| Since the upstream repository is in Subversion, you should use
 | |
| <tt>"git pull --rebase"</tt>
 | |
| instead of <tt>"git pull"</tt> to avoid generating a non-linear
 | |
| history in your clone.
 | |
| To configure <tt>"git pull"</tt> to pass <tt>--rebase</tt> by default
 | |
| on the master branch, run the following command:
 | |
| </p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| git config branch.master.rebase true
 | |
| </pre>
 | |
| 
 | |
| <h4>Sending patches with Git</h4>
 | |
| <div>
 | |
| <p>
 | |
| Please read <a href="DeveloperPolicy.html#patches">Developer Policy</a>, too.
 | |
| </p>
 | |
| 
 | |
| <p>
 | |
| Assume <tt>master</tt> points the upstream and <tt>mybranch</tt> points your
 | |
| working branch, and <tt>mybranch</tt> is rebased onto <tt>master</tt>.
 | |
| At first you may check sanity of whitespaces:
 | |
| </p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| git diff --check master..mybranch
 | |
| </pre>
 | |
| 
 | |
| <p>
 | |
| The easiest way to generate a patch is as below:
 | |
| </p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| git diff master..mybranch > /path/to/mybranch.diff
 | |
| </pre>
 | |
| 
 | |
| <p>
 | |
| It is a little different from svn-generated diff. git-diff-generated diff has
 | |
| prefixes like <tt>a/</tt> and <tt>b/</tt>. Don't worry, most developers might
 | |
| know it could be accepted with <tt>patch -p1 -N</tt>.
 | |
| </p>
 | |
| 
 | |
| <p>
 | |
| But you may generate patchset with git-format-patch. It generates
 | |
| by-each-commit patchset. To generate patch files to attach to your article:
 | |
| </p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| git format-patch --no-attach master..mybranch -o /path/to/your/patchset
 | |
| </pre>
 | |
| 
 | |
| <p>
 | |
| If you would like to send patches directly, you may use git-send-email or
 | |
| git-imap-send. Here is an example to generate the patchset in Gmail's [Drafts].
 | |
| </p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| git format-patch --attach master..mybranch --stdout | git imap-send
 | |
| </pre>
 | |
| 
 | |
| <p>
 | |
| Then, your .git/config should have [imap] sections.
 | |
| </p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| [imap]
 | |
|         host = imaps://imap.gmail.com
 | |
|         user = <em>your.gmail.account</em>@gmail.com
 | |
|         pass = <em>himitsu!</em>
 | |
|         port = 993
 | |
|         sslverify = false
 | |
| ; in English
 | |
|         folder = "[Gmail]/Drafts"
 | |
| ; example for Japanese, "Modified UTF-7" encoded.
 | |
|         folder = "[Gmail]/&Tgtm+DBN-"
 | |
| ; example for Traditional Chinese
 | |
|         folder = "[Gmail]/&g0l6Pw-"
 | |
| </pre>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <h4>For developers to work with git-svn</h4>
 | |
| <div>
 | |
| 
 | |
| <p>To set up clone from which you can submit code using
 | |
|    <tt>git-svn</tt>, run:</p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| git clone http://llvm.org/git/llvm.git
 | |
| cd llvm
 | |
| git svn init https://llvm.org/svn/llvm-project/llvm/trunk --username=<username>
 | |
| git config svn-remote.svn.fetch :refs/remotes/origin/master
 | |
| git svn rebase -l  # -l avoids fetching ahead of the git mirror.
 | |
| 
 | |
| # If you have clang too:
 | |
| cd tools
 | |
| git clone http://llvm.org/git/clang.git
 | |
| cd clang
 | |
| git svn init https://llvm.org/svn/llvm-project/cfe/trunk --username=<username>
 | |
| git config svn-remote.svn.fetch :refs/remotes/origin/master
 | |
| git svn rebase -l
 | |
| </pre>
 | |
| 
 | |
| <p>To update this clone without generating git-svn tags that conflict
 | |
| with the upstream git repo, run:</p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| git fetch && (cd tools/clang && git fetch)  # Get matching revisions of both trees.
 | |
| git checkout master
 | |
| git svn rebase -l
 | |
| (cd tools/clang &&
 | |
|  git checkout master &&
 | |
|  git svn rebase -l)
 | |
| </pre>
 | |
| 
 | |
| <p>This leaves your working directories on their master branches, so
 | |
| you'll need to <tt>checkout</tt> each working branch individually and
 | |
| <tt>rebase</tt> it on top of its parent branch.  (Note: This script is
 | |
| intended for relative newbies to git.  If you have more experience,
 | |
| you can likely improve on it.)</p>
 | |
| 
 | |
| <p>The git-svn metadata can get out of sync after you mess around with
 | |
| branches and <code>dcommit</code>. When that happens, <code>git svn
 | |
| dcommit</code> stops working, complaining about files with uncommitted
 | |
| changes. The fix is to rebuild the metadata:</p>
 | |
| 
 | |
| <pre class="doc_code">
 | |
| rm -rf .git/svn
 | |
| git svn rebase -l
 | |
| </pre>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="config">Local LLVM Configuration</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
|   <p>Once checked out from the Subversion repository, the LLVM suite source 
 | |
|   code must be
 | |
| configured via the <tt>configure</tt> script.  This script sets variables in the
 | |
| various <tt>*.in</tt> files, most notably <tt>llvm/Makefile.config</tt> and 
 | |
| <tt>llvm/include/Config/config.h</tt>.  It also populates <i>OBJ_ROOT</i> with 
 | |
| the Makefiles needed to begin building LLVM.</p>
 | |
| 
 | |
| <p>The following environment variables are used by the <tt>configure</tt>
 | |
| script to configure the build system:</p>
 | |
| 
 | |
| <table summary="LLVM configure script environment variables">
 | |
|   <tr><th>Variable</th><th>Purpose</th></tr>
 | |
|   <tr>
 | |
|     <td>CC</td>
 | |
|     <td>Tells <tt>configure</tt> which C compiler to use.  By default,
 | |
|         <tt>configure</tt> will look for the first GCC C compiler in
 | |
|         <tt>PATH</tt>.  Use this variable to override
 | |
|         <tt>configure</tt>'s default behavior.</td>
 | |
|   </tr>
 | |
|   <tr>
 | |
|     <td>CXX</td>
 | |
|     <td>Tells <tt>configure</tt> which C++ compiler to use.  By default,
 | |
|        <tt>configure</tt> will look for the first GCC C++ compiler in
 | |
|        <tt>PATH</tt>.  Use this variable to override
 | |
|        <tt>configure</tt>'s default behavior.</td>
 | |
|   </tr>
 | |
| </table>
 | |
| 
 | |
| <p>The following options can be used to set or enable LLVM specific options:</p>
 | |
| 
 | |
| <dl>
 | |
|   <dt><i>--enable-optimized</i></dt>
 | |
|   <dd>
 | |
|     Enables optimized compilation (debugging symbols are removed
 | |
|     and GCC optimization flags are enabled). Note that this is the default 
 | |
|     setting     if you are using the LLVM distribution. The default behavior 
 | |
|     of an Subversion checkout is to use an unoptimized build (also known as a 
 | |
|     debug build).
 | |
|     <br><br>
 | |
|   </dd>
 | |
|   <dt><i>--enable-debug-runtime</i></dt>
 | |
|   <dd>
 | |
|     Enables debug symbols in the runtime libraries. The default is to strip
 | |
|     debug symbols from the runtime libraries. 
 | |
|   </dd>
 | |
|   <dt><i>--enable-jit</i></dt>
 | |
|   <dd>
 | |
|     Compile the Just In Time (JIT) compiler functionality.  This is not
 | |
|     available
 | |
|     on all platforms.  The default is dependent on platform, so it is best
 | |
|     to explicitly enable it if you want it.
 | |
|     <br><br>
 | |
|   </dd>
 | |
|   <dt><i>--enable-targets=</i><tt>target-option</tt></dt>
 | |
|   <dd>Controls which targets will be built and linked into llc. The default 
 | |
|   value for <tt>target_options</tt> is "all" which builds and links all 
 | |
|   available targets.  The value "host-only" can be specified to build only a 
 | |
|   native compiler (no cross-compiler targets available). The "native" target is 
 | |
|   selected as the target of the build host. You can also specify a comma 
 | |
|   separated list of target names that you want available in llc. The target 
 | |
|   names use all lower case. The current set of targets is: <br>
 | |
|   <tt>arm, cbe, cpp, hexagon, mblaze, mips, mipsel, msp430, powerpc, ptx, sparc, spu, x86, x86_64, xcore</tt>.
 | |
|   <br><br></dd>
 | |
|   <dt><i>--enable-doxygen</i></dt>
 | |
|   <dd>Look for the doxygen program and enable construction of doxygen based
 | |
|   documentation from the source code. This is disabled by default because 
 | |
|   generating the documentation can take a long time and producess 100s of 
 | |
|   megabytes of output.</dd>
 | |
|   <dt><i>--with-udis86</i></dt>
 | |
|   <dd>LLVM can use external disassembler library for various purposes (now it's
 | |
|   used only for examining code produced by JIT). This option will enable usage
 | |
|   of <a href="http://udis86.sourceforge.net/">udis86</a> x86 (both 32 and 64
 | |
|   bits) disassembler library.</dd>
 | |
| </dl>
 | |
| 
 | |
| <p>To configure LLVM, follow these steps:</p>
 | |
| 
 | |
| <ol>
 | |
|     <li><p>Change directory into the object root directory:</p>
 | |
| 
 | |
|     <div class="doc_code"><pre>% cd <i>OBJ_ROOT</i></pre></div></li>
 | |
| 
 | |
|     <li><p>Run the <tt>configure</tt> script located in the LLVM source
 | |
|     tree:</p>
 | |
| 
 | |
|     <div class="doc_code">
 | |
|     <pre>% <i>SRC_ROOT</i>/configure --prefix=/install/path [other options]</pre>
 | |
|     </div></li>
 | |
| </ol>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="compile">Compiling the LLVM Suite Source Code</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>Once you have configured LLVM, you can build it.  There are three types of
 | |
| builds:</p>
 | |
| 
 | |
| <dl>
 | |
|     <dt>Debug Builds
 | |
|     <dd>
 | |
|     These builds are the default when one is using an Subversion checkout and 
 | |
|     types <tt>gmake</tt> (unless the <tt>--enable-optimized</tt> option was 
 | |
|     used during configuration).  The build system will compile the tools and 
 | |
|     libraries with debugging information.  To get a Debug Build using the
 | |
|     LLVM distribution the <tt>--disable-optimized</tt> option must be passed
 | |
|     to <tt>configure</tt>.
 | |
|     <br><br>
 | |
| 
 | |
|     <dt>Release (Optimized) Builds
 | |
|     <dd>
 | |
|     These builds are enabled with the <tt>--enable-optimized</tt> option to
 | |
|     <tt>configure</tt> or by specifying <tt>ENABLE_OPTIMIZED=1</tt> on the
 | |
|     <tt>gmake</tt> command line.  For these builds, the build system will
 | |
|     compile the tools and libraries with GCC optimizations enabled and strip
 | |
|     debugging information from the libraries and executables it generates. 
 | |
|     Note that Release Builds are default when using an LLVM distribution.
 | |
|     <br><br>
 | |
| 
 | |
|     <dt>Profile Builds
 | |
|     <dd>
 | |
|     These builds are for use with profiling.  They compile profiling
 | |
|     information into the code for use with programs like <tt>gprof</tt>.
 | |
|     Profile builds must be started by specifying <tt>ENABLE_PROFILING=1</tt>
 | |
|     on the <tt>gmake</tt> command line.
 | |
| </dl>
 | |
| 
 | |
| <p>Once you have LLVM configured, you can build it by entering the
 | |
| <i>OBJ_ROOT</i> directory and issuing the following command:</p>
 | |
| 
 | |
| <div class="doc_code"><pre>% gmake</pre></div>
 | |
| 
 | |
| <p>If the build fails, please <a href="#brokengcc">check here</a> to see if you
 | |
| are using a version of GCC that is known not to compile LLVM.</p>
 | |
| 
 | |
| <p>
 | |
| If you have multiple processors in your machine, you may wish to use some of
 | |
| the parallel build options provided by GNU Make.  For example, you could use the
 | |
| command:</p>
 | |
| 
 | |
| <div class="doc_code"><pre>% gmake -j2</pre></div>
 | |
| 
 | |
| <p>There are several special targets which are useful when working with the LLVM
 | |
| source code:</p>
 | |
| 
 | |
| <dl>
 | |
|   <dt><tt>gmake clean</tt>
 | |
|   <dd>
 | |
|   Removes all files generated by the build.  This includes object files,
 | |
|   generated C/C++ files, libraries, and executables.
 | |
|   <br><br>
 | |
| 
 | |
|   <dt><tt>gmake dist-clean</tt>
 | |
|   <dd>
 | |
|   Removes everything that <tt>gmake clean</tt> does, but also removes files
 | |
|   generated by <tt>configure</tt>.  It attempts to return the source tree to the
 | |
|   original state in which it was shipped.
 | |
|   <br><br>
 | |
| 
 | |
|   <dt><tt>gmake install</tt>
 | |
|   <dd>
 | |
|   Installs LLVM header files, libraries, tools, and documentation in a
 | |
|   hierarchy 
 | |
|   under $PREFIX, specified with <tt>./configure --prefix=[dir]</tt>, which 
 | |
|   defaults to <tt>/usr/local</tt>.
 | |
|   <br><br>
 | |
| 
 | |
|   <dt><tt>gmake -C runtime install-bytecode</tt>
 | |
|   <dd>
 | |
|   Assuming you built LLVM into $OBJDIR, when this command is run, it will 
 | |
|   install bitcode libraries into the GCC front end's bitcode library 
 | |
|   directory.  If you need to update your bitcode libraries,
 | |
|   this is the target to use once you've built them.
 | |
|   <br><br>
 | |
| </dl>
 | |
| 
 | |
| <p>Please see the <a href="MakefileGuide.html">Makefile Guide</a> for further
 | |
| details on these <tt>make</tt> targets and descriptions of other targets
 | |
| available.</p>
 | |
| 
 | |
| <p>It is also possible to override default values from <tt>configure</tt> by
 | |
| declaring variables on the command line.  The following are some examples:</p>
 | |
| 
 | |
| <dl>
 | |
|   <dt><tt>gmake ENABLE_OPTIMIZED=1</tt>
 | |
|   <dd>
 | |
|   Perform a Release (Optimized) build.
 | |
|   <br><br>
 | |
| 
 | |
|   <dt><tt>gmake ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1</tt>
 | |
|   <dd>
 | |
|   Perform a Release (Optimized) build without assertions enabled.
 | |
|   <br><br>
 | |
|  
 | |
|   <dt><tt>gmake ENABLE_OPTIMIZED=0</tt>
 | |
|   <dd>
 | |
|   Perform a Debug build.
 | |
|   <br><br>
 | |
| 
 | |
|   <dt><tt>gmake ENABLE_PROFILING=1</tt>
 | |
|   <dd>
 | |
|   Perform a Profiling build.
 | |
|   <br><br>
 | |
| 
 | |
|   <dt><tt>gmake VERBOSE=1</tt>
 | |
|   <dd>
 | |
|   Print what <tt>gmake</tt> is doing on standard output.
 | |
|   <br><br>
 | |
| 
 | |
|   <dt><tt>gmake TOOL_VERBOSE=1</tt></dt>
 | |
|   <dd>Ask each tool invoked by the makefiles to print out what it is doing on 
 | |
|   the standard output. This also implies <tt>VERBOSE=1</tt>.
 | |
|   <br><br></dd>
 | |
| </dl>
 | |
| 
 | |
| <p>Every directory in the LLVM object tree includes a <tt>Makefile</tt> to build
 | |
| it and any subdirectories that it contains.  Entering any directory inside the
 | |
| LLVM object tree and typing <tt>gmake</tt> should rebuild anything in or below
 | |
| that directory that is out of date.</p>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="cross-compile">Cross-Compiling LLVM</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
|   <p>It is possible to cross-compile LLVM itself. That is, you can create LLVM
 | |
|   executables and libraries to be hosted on a platform different from the
 | |
|   platform where they are build (a Canadian Cross build). To configure a
 | |
|   cross-compile, supply the configure script with <tt>--build</tt> and
 | |
|   <tt>--host</tt> options that are different. The values of these options must
 | |
|   be legal target triples that your GCC compiler supports.</p>
 | |
| 
 | |
|   <p>The result of such a build is executables that are not runnable on
 | |
|   on the build host (--build option) but can be executed on the compile host
 | |
|   (--host option).</p>
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="objfiles">The Location of LLVM Object Files</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>The LLVM build system is capable of sharing a single LLVM source tree among
 | |
| several LLVM builds.  Hence, it is possible to build LLVM for several different
 | |
| platforms or configurations using the same source tree.</p>
 | |
| 
 | |
| <p>This is accomplished in the typical autoconf manner:</p>
 | |
| 
 | |
| <ul>
 | |
|   <li><p>Change directory to where the LLVM object files should live:</p>
 | |
| 
 | |
|       <div class="doc_code"><pre>% cd <i>OBJ_ROOT</i></pre></div></li>
 | |
| 
 | |
|   <li><p>Run the <tt>configure</tt> script found in the LLVM source
 | |
|       directory:</p>
 | |
| 
 | |
|       <div class="doc_code"><pre>% <i>SRC_ROOT</i>/configure</pre></div></li>
 | |
| </ul>
 | |
| 
 | |
| <p>The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories
 | |
| named after the build type:</p>
 | |
| 
 | |
| <dl>
 | |
|   <dt>Debug Builds with assertions enabled (the default)
 | |
|   <dd>
 | |
|   <dl>
 | |
|     <dt>Tools
 | |
|     <dd><tt><i>OBJ_ROOT</i>/Debug+Asserts/bin</tt>
 | |
|     <dt>Libraries
 | |
|     <dd><tt><i>OBJ_ROOT</i>/Debug+Asserts/lib</tt>
 | |
|   </dl>
 | |
|   <br><br>
 | |
| 
 | |
|   <dt>Release Builds
 | |
|   <dd>
 | |
|   <dl>
 | |
|     <dt>Tools
 | |
|     <dd><tt><i>OBJ_ROOT</i>/Release/bin</tt>
 | |
|     <dt>Libraries
 | |
|     <dd><tt><i>OBJ_ROOT</i>/Release/lib</tt>
 | |
|   </dl>
 | |
|   <br><br>
 | |
| 
 | |
|   <dt>Profile Builds
 | |
|   <dd>
 | |
|   <dl>
 | |
|     <dt>Tools
 | |
|     <dd><tt><i>OBJ_ROOT</i>/Profile/bin</tt>
 | |
|     <dt>Libraries
 | |
|     <dd><tt><i>OBJ_ROOT</i>/Profile/lib</tt>
 | |
|   </dl>
 | |
| </dl>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="optionalconfig">Optional Configuration Items</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>
 | |
| If you're running on a Linux system that supports the "<a
 | |
| href="http://www.tat.physik.uni-tuebingen.de/~rguenth/linux/binfmt_misc.html">binfmt_misc</a>"
 | |
| module, and you have root access on the system, you can set your system up to
 | |
| execute LLVM bitcode files directly. To do this, use commands like this (the
 | |
| first command may not be required if you are already using the module):</p>
 | |
| 
 | |
| <div class="doc_code">
 | |
| <pre>
 | |
| $ mount -t binfmt_misc none /proc/sys/fs/binfmt_misc
 | |
| $ echo ':llvm:M::BC::/path/to/lli:' > /proc/sys/fs/binfmt_misc/register
 | |
| $ chmod u+x hello.bc   (if needed)
 | |
| $ ./hello.bc
 | |
| </pre>
 | |
| </div>
 | |
| 
 | |
| <p>
 | |
| This allows you to execute LLVM bitcode files directly.  On Debian, you 
 | |
| can also use this command instead of the 'echo' command above:
 | |
| </p>
 | |
| 
 | |
| <div class="doc_code">
 | |
| <pre>
 | |
| $ sudo update-binfmts --install llvm /path/to/lli --magic 'BC'
 | |
| </pre>
 | |
| </div>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- *********************************************************************** -->
 | |
| <h2>
 | |
|   <a name="layout">Program Layout</a>
 | |
| </h2>
 | |
| <!-- *********************************************************************** -->
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>One useful source of information about the LLVM source base is the LLVM <a
 | |
| href="http://www.doxygen.org/">doxygen</a> documentation available at <tt><a
 | |
| href="http://llvm.org/doxygen/">http://llvm.org/doxygen/</a></tt>.
 | |
| The following is a brief introduction to code layout:</p>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="examples"><tt>llvm/examples</tt></a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
|   <p>This directory contains some simple examples of how to use the LLVM IR and
 | |
|   JIT.</p>
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="include"><tt>llvm/include</tt></a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>This directory contains public header files exported from the LLVM
 | |
| library. The three main subdirectories of this directory are:</p>
 | |
| 
 | |
| <dl>
 | |
|   <dt><tt><b>llvm/include/llvm</b></tt></dt>
 | |
|   <dd>This directory contains all of the LLVM specific header files.  This 
 | |
|   directory also has subdirectories for different portions of LLVM: 
 | |
|   <tt>Analysis</tt>, <tt>CodeGen</tt>, <tt>Target</tt>, <tt>Transforms</tt>, 
 | |
|   etc...</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/include/llvm/Support</b></tt></dt>
 | |
|   <dd>This directory contains generic support libraries that are provided with 
 | |
|   LLVM but not necessarily specific to LLVM. For example, some C++ STL utilities 
 | |
|   and a Command Line option processing library store their header files here.
 | |
|   </dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/include/llvm/Config</b></tt></dt>
 | |
|   <dd>This directory contains header files configured by the <tt>configure</tt> 
 | |
|   script.  They wrap "standard" UNIX and C header files.  Source code can 
 | |
|   include these header files which automatically take care of the conditional 
 | |
|   #includes that the <tt>configure</tt> script generates.</dd>
 | |
| </dl>
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="lib"><tt>llvm/lib</tt></a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>This directory contains most of the source files of the LLVM system. In LLVM,
 | |
| almost all code exists in libraries, making it very easy to share code among the
 | |
| different <a href="#tools">tools</a>.</p>
 | |
| 
 | |
| <dl>
 | |
|   <dt><tt><b>llvm/lib/VMCore/</b></tt></dt>
 | |
|   <dd> This directory holds the core LLVM source files that implement core 
 | |
|   classes like Instruction and BasicBlock.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/lib/AsmParser/</b></tt></dt>
 | |
|   <dd>This directory holds the source code for the LLVM assembly language parser 
 | |
|   library.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/lib/BitCode/</b></tt></dt>
 | |
|   <dd>This directory holds code for reading and write LLVM bitcode.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/lib/Analysis/</b></tt><dd>This directory contains a variety of
 | |
|   different program analyses, such as Dominator Information, Call Graphs,
 | |
|   Induction Variables, Interval Identification, Natural Loop Identification,
 | |
|   etc.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/lib/Transforms/</b></tt></dt>
 | |
|   <dd> This directory contains the source code for the LLVM to LLVM program 
 | |
|   transformations, such as Aggressive Dead Code Elimination, Sparse Conditional 
 | |
|   Constant Propagation, Inlining, Loop Invariant Code Motion, Dead Global 
 | |
|   Elimination, and many others.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/lib/Target/</b></tt></dt>
 | |
|   <dd> This directory contains files that describe various target architectures
 | |
|   for code generation.  For example, the <tt>llvm/lib/Target/X86</tt> 
 | |
|   directory holds the X86 machine description while
 | |
|   <tt>llvm/lib/Target/ARM</tt> implements the ARM backend.</dd>
 | |
|     
 | |
|   <dt><tt><b>llvm/lib/CodeGen/</b></tt></dt>
 | |
|   <dd> This directory contains the major parts of the code generator: Instruction 
 | |
|   Selector, Instruction Scheduling, and Register Allocation.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/lib/MC/</b></tt></dt>
 | |
|   <dd>(FIXME: T.B.D.)</dd>
 | |
| 
 | |
|   <!--FIXME: obsoleted -->
 | |
|   <dt><tt><b>llvm/lib/Debugger/</b></tt></dt>
 | |
|   <dd> This directory contains the source level debugger library that makes 
 | |
|   it possible to instrument LLVM programs so that a debugger could identify 
 | |
|   source code locations at which the program is executing.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/lib/ExecutionEngine/</b></tt></dt>
 | |
|   <dd> This directory contains libraries for executing LLVM bitcode directly 
 | |
|   at runtime in both interpreted and JIT compiled fashions.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm/lib/Support/</b></tt></dt>
 | |
|   <dd> This directory contains the source code that corresponds to the header
 | |
|   files located in <tt>llvm/include/ADT/</tt>
 | |
|   and <tt>llvm/include/Support/</tt>.</dd>
 | |
| </dl>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="projects"><tt>llvm/projects</tt></a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
|   <p>This directory contains projects that are not strictly part of LLVM but are
 | |
|   shipped with LLVM. This is also the directory where you should create your own
 | |
|   LLVM-based projects. See <tt>llvm/projects/sample</tt> for an example of how
 | |
|   to set up your own project.</p>
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="runtime"><tt>llvm/runtime</tt></a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>This directory contains libraries which are compiled into LLVM bitcode and
 | |
| used when linking programs with the Clang front end.  Most of these libraries are
 | |
| skeleton versions of real libraries; for example, libc is a stripped down
 | |
| version of glibc.</p>
 | |
| 
 | |
| <p>Unlike the rest of the LLVM suite, this directory needs the LLVM GCC front
 | |
| end to compile.</p>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="test"><tt>llvm/test</tt></a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
|   <p>This directory contains feature and regression tests and other basic sanity
 | |
|   checks on the LLVM infrastructure. These are intended to run quickly and cover
 | |
|   a lot of territory without being exhaustive.</p>
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="test-suite"><tt>test-suite</tt></a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
|   <p>This is not a directory in the normal llvm module; it is a separate
 | |
|   Subversion
 | |
|   module that must be checked out (usually to <tt>projects/test-suite</tt>). 
 | |
|   This
 | |
|   module contains a comprehensive correctness, performance, and benchmarking
 | |
|   test
 | |
|   suite for LLVM. It is a separate Subversion module because not every LLVM 
 | |
|   user is
 | |
|   interested in downloading or building such a comprehensive test suite. For
 | |
|   further details on this test suite, please see the 
 | |
|   <a href="TestingGuide.html">Testing Guide</a> document.</p>
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="tools"><tt>llvm/tools</tt></a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>The <b>tools</b> directory contains the executables built out of the
 | |
| libraries above, which form the main part of the user interface.  You can
 | |
| always get help for a tool by typing <tt>tool_name -help</tt>.  The
 | |
| following is a brief introduction to the most important tools.  More detailed
 | |
| information is in the <a href="CommandGuide/index.html">Command Guide</a>.</p>
 | |
| 
 | |
| <dl>
 | |
| 
 | |
|   <dt><tt><b>bugpoint</b></tt></dt>
 | |
|   <dd><tt>bugpoint</tt> is used to debug
 | |
|   optimization passes or code generation backends by narrowing down the
 | |
|   given test case to the minimum number of passes and/or instructions that
 | |
|   still cause a problem, whether it is a crash or miscompilation. See <a
 | |
|   href="HowToSubmitABug.html">HowToSubmitABug.html</a> for more information
 | |
|   on using <tt>bugpoint</tt>.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm-ar</b></tt></dt>
 | |
|   <dd>The archiver produces an archive containing
 | |
|   the given LLVM bitcode files, optionally with an index for faster
 | |
|   lookup.</dd>
 | |
|   
 | |
|   <dt><tt><b>llvm-as</b></tt></dt>
 | |
|   <dd>The assembler transforms the human readable LLVM assembly to LLVM 
 | |
|   bitcode.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm-dis</b></tt></dt>
 | |
|   <dd>The disassembler transforms the LLVM bitcode to human readable 
 | |
|   LLVM assembly.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm-ld</b></tt></dt>
 | |
|   <dd><tt>llvm-ld</tt> is a general purpose and extensible linker for LLVM. 
 | |
|   It performs standard link time optimizations and allows optimization
 | |
|   modules to be loaded and run so that language specific optimizations can 
 | |
|   be applied at link time.</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm-link</b></tt></dt>
 | |
|   <dd><tt>llvm-link</tt>, not surprisingly, links multiple LLVM modules into 
 | |
|   a single program.</dd>
 | |
|   
 | |
|   <dt><tt><b>lli</b></tt></dt>
 | |
|   <dd><tt>lli</tt> is the LLVM interpreter, which
 | |
|   can directly execute LLVM bitcode (although very slowly...). For architectures
 | |
|   that support it (currently x86, Sparc, and PowerPC), by default, <tt>lli</tt>
 | |
|   will function as a Just-In-Time compiler (if the functionality was compiled
 | |
|   in), and will execute the code <i>much</i> faster than the interpreter.</dd>
 | |
| 
 | |
|   <dt><tt><b>llc</b></tt></dt>
 | |
|   <dd> <tt>llc</tt> is the LLVM backend compiler, which
 | |
|   translates LLVM bitcode to a native code assembly file or to C code (with
 | |
|   the -march=c option).</dd>
 | |
| 
 | |
|   <dt><tt><b>llvm-gcc</b></tt></dt>
 | |
|   <dd><tt>llvm-gcc</tt> is a GCC-based C frontend that has been retargeted to 
 | |
|   use LLVM as its backend instead of GCC's RTL backend. It can also emit LLVM 
 | |
|   bitcode or assembly (with the <tt>-emit-llvm</tt> option) instead of the
 | |
|   usual machine code output.  It works just like any other GCC compiler, 
 | |
|   taking the typical <tt>-c, -S, -E, -o</tt> options that are typically used.  
 | |
|   Additionally, the the source code for <tt>llvm-gcc</tt> is available as a 
 | |
|   separate Subversion module.</dd>
 | |
| 
 | |
|   <dt><tt><b>opt</b></tt></dt>
 | |
|   <dd><tt>opt</tt> reads LLVM bitcode, applies a series of LLVM to LLVM 
 | |
|   transformations (which are specified on the command line), and then outputs 
 | |
|   the resultant bitcode.  The '<tt>opt -help</tt>' command is a good way to 
 | |
|   get a list of the program transformations available in LLVM.<br>
 | |
|   <dd><tt>opt</tt> can also be used to run a specific analysis on an input 
 | |
|   LLVM bitcode file and print out the results.  It is primarily useful for 
 | |
|   debugging analyses, or familiarizing yourself with what an analysis does.</dd>
 | |
| </dl>
 | |
| </div>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="utils"><tt>llvm/utils</tt></a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>This directory contains utilities for working with LLVM source code, and some
 | |
| of the utilities are actually required as part of the build process because they
 | |
| are code generators for parts of LLVM infrastructure.</p>
 | |
| 
 | |
| <dl>
 | |
|   <dt><tt><b>codegen-diff</b></tt> <dd><tt>codegen-diff</tt> is a script
 | |
|   that finds differences between code that LLC generates and code that LLI
 | |
|   generates. This is a useful tool if you are debugging one of them,
 | |
|   assuming that the other generates correct output. For the full user
 | |
|   manual, run <tt>`perldoc codegen-diff'</tt>.<br><br>
 | |
| 
 | |
|   <dt><tt><b>emacs/</b></tt> <dd>The <tt>emacs</tt> directory contains
 | |
|   syntax-highlighting files which will work with Emacs and XEmacs editors,
 | |
|   providing syntax highlighting support for LLVM assembly files and TableGen
 | |
|   description files. For information on how to use the syntax files, consult
 | |
|   the <tt>README</tt> file in that directory.<br><br>
 | |
| 
 | |
|   <dt><tt><b>getsrcs.sh</b></tt> <dd>The <tt>getsrcs.sh</tt> script finds
 | |
|   and outputs all non-generated source files, which is useful if one wishes
 | |
|   to do a lot of development across directories and does not want to
 | |
|   individually find each file. One way to use it is to run, for example:
 | |
|   <tt>xemacs `utils/getsources.sh`</tt> from the top of your LLVM source
 | |
|   tree.<br><br>
 | |
| 
 | |
|   <dt><tt><b>llvmgrep</b></tt></dt>
 | |
|   <dd>This little tool performs an "egrep -H -n" on each source file in LLVM and
 | |
|   passes to it a regular expression provided on <tt>llvmgrep</tt>'s command
 | |
|   line. This is a very efficient way of searching the source base for a
 | |
|   particular regular expression.</dd>
 | |
| 
 | |
|   <dt><tt><b>makellvm</b></tt> <dd>The <tt>makellvm</tt> script compiles all
 | |
|   files in the current directory and then compiles and links the tool that
 | |
|   is the first argument. For example, assuming you are in the directory
 | |
|   <tt>llvm/lib/Target/Sparc</tt>, if <tt>makellvm</tt> is in your path,
 | |
|   simply running <tt>makellvm llc</tt> will make a build of the current
 | |
|   directory, switch to directory <tt>llvm/tools/llc</tt> and build it,
 | |
|   causing a re-linking of LLC.<br><br>
 | |
| 
 | |
|   <dt><tt><b>TableGen/</b></tt> <dd>The <tt>TableGen</tt> directory contains
 | |
|   the tool used to generate register descriptions, instruction set
 | |
|   descriptions, and even assemblers from common TableGen description
 | |
|   files.<br><br>
 | |
| 
 | |
|   <dt><tt><b>vim/</b></tt> <dd>The <tt>vim</tt> directory contains
 | |
|   syntax-highlighting files which will work with the VIM editor, providing
 | |
|   syntax highlighting support for LLVM assembly files and TableGen
 | |
|   description files. For information on how to use the syntax files, consult
 | |
|   the <tt>README</tt> file in that directory.<br><br>
 | |
| 
 | |
| </dl>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- *********************************************************************** -->
 | |
| <h2>
 | |
|   <a name="tutorial">An Example Using the LLVM Tool Chain</a>
 | |
| </h2>
 | |
| <!-- *********************************************************************** -->
 | |
| 
 | |
| <div>
 | |
| <p>This section gives an example of using LLVM with the Clang front end.</p>
 | |
| 
 | |
| <!-- ======================================================================= -->
 | |
| <h3>
 | |
|   <a name="tutorial4">Example with clang</a>
 | |
| </h3>
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <ol>
 | |
|   <li><p>First, create a simple C file, name it 'hello.c':</p>
 | |
| 
 | |
| <div class="doc_code">
 | |
| <pre>
 | |
| #include <stdio.h>
 | |
| 
 | |
| int main() {
 | |
|   printf("hello world\n");
 | |
|   return 0;
 | |
| }
 | |
| </pre></div></li>
 | |
| 
 | |
|   <li><p>Next, compile the C file into a native executable:</p>
 | |
| 
 | |
|       <div class="doc_code"><pre>% clang hello.c -o hello</pre></div>
 | |
| 
 | |
|       <p>Note that clang works just like GCC by default.  The standard -S and
 | |
|         -c arguments work as usual (producing a native .s or .o file,
 | |
|         respectively).</p></li>
 | |
| 
 | |
|   <li><p>Next, compile the C file into a LLVM bitcode file:</p>
 | |
| 
 | |
|       <div class="doc_code">
 | |
|       <pre>% clang -O3 -emit-llvm hello.c -c -o hello.bc</pre></div>
 | |
| 
 | |
|       <p>The -emit-llvm option can be used with the -S or -c options to emit an
 | |
|          LLVM ".ll" or ".bc" file (respectively) for the code.  This allows you
 | |
|          to use the <a href="CommandGuide/index.html">standard LLVM tools</a> on
 | |
|          the bitcode file.</p></li>
 | |
| 
 | |
|   <li><p>Run the program in both forms. To run the program, use:</p>
 | |
|       
 | |
|       <div class="doc_code"><pre>% ./hello</pre></div>
 | |
|  
 | |
|       <p>and</p>
 | |
| 
 | |
|       <div class="doc_code"><pre>% lli hello.bc</pre></div>
 | |
| 
 | |
|       <p>The second examples shows how to invoke the LLVM JIT, <a
 | |
|        href="CommandGuide/html/lli.html">lli</a>.</p></li>
 | |
| 
 | |
|   <li><p>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly
 | |
|       code:</p>
 | |
| 
 | |
| <div class="doc_code">
 | |
| <pre>llvm-dis < hello.bc | less</pre>
 | |
| </div></li>
 | |
| 
 | |
|   <li><p>Compile the program to native assembly using the LLC code
 | |
|       generator:</p>
 | |
| 
 | |
|       <div class="doc_code"><pre>% llc hello.bc -o hello.s</pre></div></li>
 | |
| 
 | |
|   <li><p>Assemble the native assembly language file into a program:</p>
 | |
| 
 | |
| <div class="doc_code">
 | |
| <pre>
 | |
| <b>Solaris:</b> % /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native
 | |
| 
 | |
| <b>Others:</b>  % gcc hello.s -o hello.native
 | |
| </pre>
 | |
| </div></li>
 | |
| 
 | |
|   <li><p>Execute the native code program:</p>
 | |
| 
 | |
|       <div class="doc_code"><pre>% ./hello.native</pre></div>
 | |
| 
 | |
|       <p>Note that using clang to compile directly to native code (i.e. when
 | |
|          the -emit-llvm option is not present) does steps 6/7/8 for you.</p>
 | |
|         </li>
 | |
| 
 | |
| </ol>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- *********************************************************************** -->
 | |
| <h2>
 | |
|   <a name="problems">Common Problems</a>
 | |
| </h2>
 | |
| <!-- *********************************************************************** -->
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>If you are having problems building or using LLVM, or if you have any other
 | |
| general questions about LLVM, please consult the <a href="FAQ.html">Frequently
 | |
| Asked Questions</a> page.</p>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- *********************************************************************** -->
 | |
| <h2>
 | |
|   <a name="links">Links</a>
 | |
| </h2>
 | |
| <!-- *********************************************************************** -->
 | |
| 
 | |
| <div>
 | |
| 
 | |
| <p>This document is just an <b>introduction</b> on 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:</p>
 | |
| 
 | |
| <ul>
 | |
|   <li><a href="http://llvm.org/">LLVM homepage</a></li>
 | |
|   <li><a href="http://llvm.org/doxygen/">LLVM doxygen tree</a></li>
 | |
|   <li><a href="http://llvm.org/docs/Projects.html">Starting a Project
 | |
|   that Uses LLVM</a></li>
 | |
| </ul>
 | |
| 
 | |
| </div>
 | |
| 
 | |
| <!-- *********************************************************************** -->
 | |
| 
 | |
| <hr>
 | |
| <address>
 | |
|   <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
 | |
|   src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
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|   src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
 | |
| 
 | |
|   <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
 | |
|   <a href="http://llvm.x10sys.com/rspencer/">Reid Spencer</a><br>
 | |
|   <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
 | |
|   Last modified: $Date$
 | |
| </address>
 | |
| </body>
 | |
| </html>
 |