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1877 lines
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1877 lines
68 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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<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>
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<li><a href="#requirements">Requirements</a>
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<ol>
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<li><a href="#hardware">Hardware</a></li>
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<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>
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<li><a href="#starting">Getting Started with LLVM</a>
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<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="#installcf">Install the GCC Front End</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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<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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<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 llvm-gcc4</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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<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>
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</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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<div>
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<p>Welcome to LLVM! In order to get started, you first need to know some
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basic information.</p>
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<p>First, LLVM comes in three pieces. The first piece is the LLVM
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suite. This contains all of the tools, libraries, and header files
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needed to use the low level virtual machine. It contains an
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assembler, disassembler, bitcode analyzer and bitcode optimizer. It
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also contains basic regression tests that can be used to test the LLVM
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tools and the GCC front end.</p>
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<p>The second piece is the GCC front end. This component provides a version of
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GCC that compiles C and C++ code into LLVM bitcode. Currently, the GCC front
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end uses the GCC parser to convert code to LLVM. Once
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compiled into LLVM bitcode, a program can be manipulated with the LLVM tools
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from the LLVM suite.</p>
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<p>
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There is a third, optional piece called Test Suite. It is a suite of programs
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with a testing harness that can be used to further test LLVM's functionality
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and performance.
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</p>
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</div>
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<!-- *********************************************************************** -->
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<h2>
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<a name="quickstart">Getting Started Quickly (A Summary)</a>
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</h2>
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<!-- *********************************************************************** -->
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<div>
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<p>Here's the short story for getting up and running quickly with LLVM:</p>
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<ol>
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<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>
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<li>Install the llvm-gcc-4.2 front end if you intend to compile C or C++
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(see <a href="#installcf">Install the GCC Front End</a> for details):
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<ol>
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<li><tt>cd <i>where-you-want-the-C-front-end-to-live</i></tt></li>
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<li><tt>gunzip --stdout llvm-gcc-4.2-<i>version</i>-<i>platform</i>.tar.gz | tar -xvf -</tt></li>
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<li><tt><i>install-binutils-binary-from-MinGW</i></tt> (Windows only)</li>
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<li>Note: If the binary extension is "<tt>.bz</tt>" use <tt>bunzip2</tt> instead of <tt>gunzip</tt>.</li>
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<li>Note: On Windows, use <a href="http://www.7-zip.org/">7-Zip</a> or a similar archiving tool.</li>
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<li>Add <tt>llvm-gcc</tt>'s "<tt>bin</tt>" directory to your <tt>PATH</tt> environment variable.</li>
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</ol></li>
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<li>Get the LLVM Source Code
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<ul>
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<li>With the distributed files (or use <a href="#checkout">SVN</a>):
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<ol>
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<li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
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<li><tt>gunzip --stdout llvm-<i>version</i>.tar.gz | tar -xvf -</tt>
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</ol></li>
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</ul></li>
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<li><b>[Optional]</b> Get the Test Suite Source Code
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<ul>
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<li>With the distributed files (or use <a href="#checkout">SVN</a>):
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<ol>
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<li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
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<li><tt>cd llvm/projects</tt>
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<li><tt>gunzip --stdout llvm-test-<i>version</i>.tar.gz | tar -xvf -</tt>
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<li><tt>mv llvm-test-<i>version</i> test-suite</tt>
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</ol></li>
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</ul></li>
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<li>Configure the LLVM Build Environment
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<ol>
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<li><tt>cd <i>where-you-want-to-build-llvm</i></tt></li>
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<li><tt><i>/path/to/llvm/</i>configure [options]</tt><br>
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Some common options:
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<ul>
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<li><tt>--prefix=<i>directory</i></tt>
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<p>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>).</p></li>
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<li><tt>--with-llvmgccdir=<i>directory</i></tt>
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<p>Optionally, specify for <i>directory</i> the full pathname of the
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C/C++ front end installation to use with this LLVM configuration. If
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not specified, the PATH will be searched. This is only needed if you
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want to run test-suite or do some special kinds of LLVM builds.</p></li>
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<li><tt>--enable-spec2000=<i>directory</i></tt>
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<p>Enable the SPEC2000 benchmarks for testing. The SPEC2000
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benchmarks should be available in
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<tt><i>directory</i></tt>.</p></li>
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</ul>
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</ol></li>
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<li>Build the LLVM Suite:
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<ol>
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<li><tt>gmake -k |& tee gnumake.out
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# this is csh or tcsh syntax</tt></li>
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<li>If you get an "internal compiler error (ICE)" or test failures, see
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<a href="#brokengcc">below</a>.</li>
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</ol>
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</ol>
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<p>Consult the <a href="#starting">Getting Started with LLVM</a> section for
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detailed information on configuring and compiling LLVM. See <a
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href="#environment">Setting Up Your Environment</a> for tips that simplify
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working with the GCC front end and LLVM tools. Go to <a href="#layout">Program
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Layout</a> to learn about the layout of the source code tree.</p>
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</div>
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<!-- *********************************************************************** -->
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<h2>
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<a name="requirements">Requirements</a>
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</h2>
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<!-- *********************************************************************** -->
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<div>
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<p>Before you begin to use the LLVM system, review the requirements given below.
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This may save you some trouble by knowing ahead of time what hardware and
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software you will need.</p>
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<!-- ======================================================================= -->
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<h3>
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<a name="hardware">Hardware</a>
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</h3>
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<div>
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<p>LLVM is known to work on the following platforms:</p>
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<table cellpadding="3" summary="Known LLVM platforms">
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<tr>
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<th>OS</th>
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<th>Arch</th>
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<th>Compilers</th>
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</tr>
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<tr>
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<td>AuroraUX</td>
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<td>x86<sup><a href="#pf_1">1</a></sup></td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>Linux</td>
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<td>x86<sup><a href="#pf_1">1</a></sup></td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>Linux</td>
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<td>amd64</td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>Solaris</td>
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<td>V9 (Ultrasparc)</td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>FreeBSD</td>
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<td>x86<sup><a href="#pf_1">1</a></sup></td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>FreeBSD</td>
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<td>amd64</td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>MacOS X<sup><a href="#pf_2">2</a></sup></td>
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<td>PowerPC</td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>MacOS X<sup><a href="#pf_2">2</a>,<a href="#pf_9">9</a></sup></td>
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<td>x86</td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>Cygwin/Win32</td>
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<td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_8">8</a>,
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<a href="#pf_11">11</a></sup></td>
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<td>GCC 3.4.X, binutils 2.20</td>
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</tr>
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<tr>
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<td>MinGW/Win32</td>
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<td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_6">6</a>,
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<a href="#pf_8">8</a>, <a href="#pf_10">10</a>,
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<a href="#pf_11">11</a></sup></td>
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<td>GCC 3.4.X, binutils 2.20</td>
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</tr>
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</table>
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<p>LLVM has partial support for the following platforms:</p>
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<table summary="LLVM partial platform support">
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<tr>
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<th>OS</th>
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<th>Arch</th>
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<th>Compilers</th>
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</tr>
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<tr>
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<td>Windows</td>
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<td>x86<sup><a href="#pf_1">1</a></sup></td>
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<td>Visual Studio 2008 or higher<sup><a href="#pf_4">4</a>,<a href="#pf_5">5</a></sup></td>
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<tr>
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<td>AIX<sup><a href="#pf_3">3</a>,<a href="#pf_4">4</a></sup></td>
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<td>PowerPC</td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>Linux<sup><a href="#pf_3">3</a>,<a href="#pf_5">5</a></sup></td>
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<td>PowerPC</td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>Linux<sup><a href="#pf_7">7</a></sup></td>
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<td>Alpha</td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>Linux<sup><a href="#pf_7">7</a></sup></td>
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<td>Itanium (IA-64)</td>
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<td>GCC</td>
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</tr>
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<tr>
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<td>HP-UX<sup><a href="#pf_7">7</a></sup></td>
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<td>Itanium (IA-64)</td>
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<td>HP aCC</td>
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</tr>
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<tr>
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<td>Windows x64</td>
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<td>x86-64</td>
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<td>mingw-w64's GCC-4.5.x<sup><a href="#pf_12">12</a></sup></td>
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</tr>
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</table>
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<p><b>Notes:</b></p>
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<div class="doc_notes">
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<ol>
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<li><a name="pf_1">Code generation supported for Pentium processors and
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up</a></li>
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<li><a name="pf_2">Code generation supported for 32-bit ABI only</a></li>
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<li><a name="pf_3">No native code generation</a></li>
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<li><a name="pf_4">Build is not complete: one or more tools do not link or function</a></li>
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<li><a name="pf_5">The GCC-based C/C++ frontend does not build</a></li>
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<li><a name="pf_6">The port is done using the MSYS shell.</a></li>
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<li><a name="pf_7">Native code generation exists but is not complete.</a></li>
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<li><a name="pf_8">Binutils 2.20 or later is required to build the assembler
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generated by LLVM properly.</a></li>
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<li><a name="pf_9">XCode 2.5 and gcc 4.0.1</a> (Apple Build 5370) will trip
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internal LLVM assert messages when compiled for Release at optimization
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levels greater than 0 (i.e., <i>"-O1"</i> and higher).
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Add <i>OPTIMIZE_OPTION="-O0"</i> to the build command line
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if compiling for LLVM Release or bootstrapping the LLVM toolchain.</li>
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<li><a name="pf_10">For MSYS/MinGW on Windows, be sure to install the MSYS
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version of the perl package, and be sure it appears in your path
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before any Windows-based versions such as Strawberry Perl and
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ActivePerl, as these have Windows-specifics that will cause the
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build to fail.</a></li>
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<li><a name="pf_11">To use LLVM modules on Win32-based system,
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you may configure LLVM with <i>"--enable-shared"</i>.</a></li>
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<li><a name="pf_12">To compile SPU backend, you need to add
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<tt>"LDFLAGS=-Wl,--stack,16777216"</tt> to configure.</a></li>
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</ol>
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</div>
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<p>Note that you will need about 1-3 GB of space for a full LLVM build in Debug
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mode, depending on the system (it is so large because of all the debugging
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information and the fact that the libraries are statically linked into multiple
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tools). If you do not need many of the tools and you are space-conscious, you
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can pass <tt>ONLY_TOOLS="tools you need"</tt> to make. The Release build
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requires considerably less space.</p>
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<p>The LLVM suite <i>may</i> compile on other platforms, but it is not
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guaranteed to do so. If compilation is successful, the LLVM utilities should be
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able to assemble, disassemble, analyze, and optimize LLVM bitcode. Code
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generation should work as well, although the generated native code may not work
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on your platform.</p>
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<p>The GCC front end is not very portable at the moment. If you want to get it
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to work on another platform, you can download a copy of the source and <a
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href="GCCFEBuildInstrs.html">try to compile it</a> on your platform.</p>
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|
|
</div>
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|
|
<!-- ======================================================================= -->
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<h3>
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<a name="software">Software</a>
|
|
</h3>
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|
<div>
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|
<p>Compiling LLVM requires that you have several software packages
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installed. The table below lists those required packages. The Package column
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is the usual name for the software package that LLVM depends on. The Version
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column provides "known to work" versions of the package. The Notes column
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describes how LLVM uses the package and provides other details.</p>
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<table summary="Packages required to compile LLVM">
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<tr><th>Package</th><th>Version</th><th>Notes</th></tr>
|
|
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<tr>
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<td><a href="http://savannah.gnu.org/projects/make">GNU Make</a></td>
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<td>3.79, 3.79.1</td>
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<td>Makefile/build processor</td>
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</tr>
|
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|
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<tr>
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<td><a href="http://gcc.gnu.org/">GCC</a></td>
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<td>3.4.2</td>
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<td>C/C++ compiler<sup><a href="#sf1">1</a></sup></td>
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</tr>
|
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<tr>
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<td><a href="http://www.gnu.org/software/texinfo/">TeXinfo</a></td>
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<td>4.5</td>
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<td>For building the CFE</td>
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</tr>
|
|
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<tr>
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<td><a href="http://subversion.tigris.org/project_packages.html">SVN</a></td>
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<td>≥1.3</td>
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<td>Subversion access to LLVM<sup><a href="#sf2">2</a></sup></td>
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</tr>
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<!-- FIXME:
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Do we support dg?
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Are DejaGnu and expect obsolete?
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Shall we mention Python? -->
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<tr>
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<td><a href="http://savannah.gnu.org/projects/dejagnu">DejaGnu</a></td>
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<td>1.4.2</td>
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<td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
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</tr>
|
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<tr>
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<td><a href="http://www.tcl.tk/software/tcltk/">tcl</a></td>
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<td>8.3, 8.4</td>
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<td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
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</tr>
|
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<tr>
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<td><a href="http://expect.nist.gov/">expect</a></td>
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<td>5.38.0</td>
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<td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
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</tr>
|
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<tr>
|
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<td><a href="http://www.perl.com/download.csp">perl</a></td>
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<td>≥5.6.0</td>
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<td>Nightly tester, utilities</td>
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|
</tr>
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|
|
<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. Please <a href="GCCFEBuildInstrs.html#cygwin">upgrade
|
|
to a newer version</a> if possible.</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>
|
|
|
|
<dt>LLVMGCCDIR
|
|
<dd>
|
|
This is where the LLVM GCC Front End is installed.
|
|
<p>
|
|
For the pre-built GCC front end binaries, the LLVMGCCDIR is
|
|
<tt>llvm-gcc/<i>platform</i>/llvm-gcc</tt>.
|
|
</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>
|
|
|
|
<p>If you would like to get the GCC front end source code, you can also get it
|
|
and build it yourself. Please follow <a href="GCCFEBuildInstrs.html">these
|
|
instructions</a> to successfully get and build the LLVM GCC front-end.</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="installcf">Install the GCC Front End</a>
|
|
</h3>
|
|
|
|
<div>
|
|
|
|
<p>Before configuring and compiling the LLVM suite (or if you want to use just the LLVM
|
|
GCC front end) you can optionally extract the front end from the binary distribution.
|
|
It is used for running the LLVM test-suite and for compiling C/C++ programs. Note that
|
|
you can optionally <a href="GCCFEBuildInstrs.html">build llvm-gcc yourself</a> after building the
|
|
main LLVM repository.</p>
|
|
|
|
<p>To install the GCC front end, do the following (on Windows, use an archival tool
|
|
like <a href="http://www.7-zip.org/">7-zip</a> that understands gzipped tars):</p>
|
|
|
|
<ol>
|
|
<li><tt>cd <i>where-you-want-the-front-end-to-live</i></tt></li>
|
|
<li><tt>gunzip --stdout llvm-gcc-4.2-<i>version</i>-<i>platform</i>.tar.gz | tar -xvf
|
|
-</tt></li>
|
|
</ol>
|
|
|
|
<p>Once the binary is uncompressed, if you're using a *nix-based system, add a symlink for
|
|
<tt>llvm-gcc</tt> and <tt>llvm-g++</tt> to some directory in your path. If you're using a
|
|
Windows-based system, add the <tt>bin</tt> subdirectory of your front end installation directory
|
|
to your <tt>PATH</tt> environment variable. For example, if you uncompressed the binary to
|
|
<tt>c:\llvm-gcc</tt>, add <tt>c:\llvm-gcc\bin</tt> to your <tt>PATH</tt>.</p>
|
|
|
|
<p>If you now want to build LLVM from source, when you configure LLVM, it will
|
|
automatically detect <tt>llvm-gcc</tt>'s presence (if it is in your path) enabling its
|
|
use in test-suite. Note that you can always build or install <tt>llvm-gcc</tt> at any
|
|
point after building the main LLVM repository: just reconfigure llvm and
|
|
test-suite will pick it up.
|
|
</p>
|
|
|
|
<p>As a convenience for Windows users, the front end binaries for MinGW/x86 include
|
|
versions of the required w32api and mingw-runtime binaries. The last remaining step for
|
|
Windows users is to simply uncompress the binary binutils package from
|
|
<a href="http://mingw.org/">MinGW</a> into your front end installation directory. While the
|
|
front end installation steps are not quite the same as a typical manual MinGW installation,
|
|
they should be similar enough to those who have previously installed MinGW on Windows systems.</p>
|
|
|
|
<p>To install binutils on Windows:</p>
|
|
|
|
<ol>
|
|
<li><tt><i>download GNU Binutils from <a href="http://sourceforge.net/projects/mingw/files/">MinGW Downloads</a></i></tt></li>
|
|
<li><tt>cd <i>where-you-uncompressed-the-front-end</i></tt></li>
|
|
<li><tt><i>uncompress archived binutils directories (not the tar file) into the current directory</i></tt></li>
|
|
</ol>
|
|
|
|
<p>The binary versions of the LLVM GCC front end may not suit all of your needs. For
|
|
example, the binary distribution may include an old version of a system header
|
|
file, not "fix" a header file that needs to be fixed for GCC, or it may be linked with
|
|
libraries not available on your system. In cases like these, you may want to try
|
|
<a href="GCCFEBuildInstrs.html">building the GCC front end from source</a>. Thankfully,
|
|
this is much easier now than it was in the past.</p>
|
|
|
|
<p>We also do not currently support updating of the GCC front end by manually overlaying
|
|
newer versions of the w32api and mingw-runtime binary packages that may become available
|
|
from MinGW. At this time, it's best to think of the MinGW LLVM GCC front end binary as
|
|
a self-contained convenience package that requires Windows users to simply download and
|
|
uncompress the GNU Binutils binary package from the MinGW project.</p>
|
|
|
|
<p>Regardless of your platform, if you discover that installing the LLVM GCC front end
|
|
binaries is not as easy as previously described, or you would like to suggest improvements,
|
|
please let us know how you would like to see things improved by dropping us a note on our
|
|
<a href="http://llvm.org/docs/#maillist">mailing list</a>.</p>
|
|
|
|
</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>--with-llvmgccdir</i></dt>
|
|
<dd>Path to the LLVM C/C++ FrontEnd to be used with this LLVM configuration.
|
|
The value of this option should specify the full pathname of the C/C++ Front
|
|
End to be used. If this option is not provided, the PATH will be searched for
|
|
a program named <i>llvm-gcc</i> and the C/C++ FrontEnd install directory will
|
|
be inferred from the path found. If the option is not given, and no llvm-gcc
|
|
can be found in the path then a warning will be produced by
|
|
<tt>configure</tt> indicating this situation. LLVM may still be built with
|
|
the <tt>tools-only</tt> target but attempting to build the runtime libraries
|
|
will fail as these libraries require llvm-gcc and llvm-g++. See
|
|
<a href="#installcf">Install the GCC Front End</a> for details on installing
|
|
the C/C++ Front End. See
|
|
<a href="GCCFEBuildInstrs.html">Bootstrapping the LLVM C/C++ Front-End</a>
|
|
for details on building the C/C++ Front End.</dd>
|
|
<dt><i>--with-tclinclude</i></dt>
|
|
<dd>Path to the tcl include directory under which <tt>tclsh</tt> can be
|
|
found. Use this if you have multiple tcl installations on your machine and you
|
|
want to use a specific one (8.x) for LLVM. LLVM only uses tcl for running the
|
|
dejagnu based test suite in <tt>llvm/test</tt>. If you don't specify this
|
|
option, the LLVM configure script will search for the tcl 8.4 and 8.3
|
|
releases.
|
|
<br><br>
|
|
</dd>
|
|
<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>alpha, ia64, powerpc, skeleton, sparc, x86</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/CBackend</tt> implements the LLVM-to-C converter.</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 GCC 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>NewNightlyTest.pl</b></tt> and
|
|
<tt><b>NightlyTestTemplate.html</b></tt> <dd>These files are used in a
|
|
cron script to generate nightly status reports of the functionality of
|
|
tools, and the results can be seen by following the appropriate link on
|
|
the <a href="http://llvm.org/">LLVM homepage</a>.<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. llvm-gcc3 is now obsolete,
|
|
so we only include instructions for llvm-gcc4.
|
|
</p>
|
|
|
|
<p><b>Note:</b> The <i>gcc4</i> frontend's invocation is <b><i>considerably different</i></b>
|
|
from the previous <i>gcc3</i> frontend. In particular, the <i>gcc4</i> frontend <b><i>does not</i></b>
|
|
create bitcode by default: <i>gcc4</i> produces native code. As the example below illustrates,
|
|
the '--emit-llvm' flag is needed to produce LLVM bitcode output. For <i>makefiles</i> and
|
|
<i>configure</i> scripts, the CFLAGS variable needs '--emit-llvm' to produce bitcode
|
|
output.</p>
|
|
|
|
<!-- ======================================================================= -->
|
|
<h3>
|
|
<a name="tutorial4">Example with llvm-gcc4</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>% llvm-gcc hello.c -o hello</pre></div>
|
|
|
|
<p>Note that llvm-gcc 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>% llvm-gcc -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>
|
|
|
|
<p>Unlike llvm-gcc3, llvm-gcc4 correctly responds to -O[0123] arguments.
|
|
</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 llvm-gcc 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>
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|
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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>
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|
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<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: $Date$
|
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</address>
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</body>
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</html>
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