llvm/docs/UsingLibraries.html - toolchain/llvm-project - Gitiles

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 <body>
 <div class="doc_title">Using The LLVM Libraries</div>
 <ol>
   <li><a href="#abstract">Abstract</a></li>
   <li><a href="#introduction">Introduction</a></li>
   <li><a href="#descriptions">Library Descriptions</a></li>
   <li><a href="#dependencies">Library Dependencies</a></li>
   <li><a href="#rot">Linkage Rules Of Thumb</a>
 	  <ol>
       <li><a href="#always">Always link LLVMCore, LLVMSupport, LLVMSystem</a>
 			<li><a href="#onlyone">Never link both archive and re-linked</a>
 		</ol>
 	</li>
 </ol>

 <div class="doc_author">
   <p>Written by <a href="mailto:rspencer@x10sys.com">Reid Spencer</a></p>
 </div>

 <p class="doc_warning">Warning: This document is out of date, please see <a href="CommandGuide/html/llvm-config.html">llvm-config</a> for more information.</p>

 <!-- ======================================================================= -->
 <div class="doc_section"><a name="abstract">Abstract</a></div>
 <div class="doc_text">
   <p>Amongst other things, LLVM is a toolkit for building compilers, linkers,
   runtime executives, virtual machines, and other program execution related
   tools. In addition to the LLVM tool set, the functionality of LLVM is
   available through a set of libraries.  To use LLVM as a toolkit for
   constructing tools, a developer needs to understand what is contained in the
   various libraries, what they depend on, and how to use them.  Fortunately,
   there is a tool, <tt>llvm-config</tt> to aid with this. This document
   describes the contents of the libraries and how to use <tt>llvm-config</tt>
   to generate command line options.
 </p>
 </div>

 <!-- ======================================================================= -->
 <div class="doc_section"> <a name="introduction">Introduction</a></div>
 <div class="doc_text">
   <p>If you're writing a compiler, virtual machine, or any other utility based
   on LLVM, you'll need to figure out which of the many libraries files you will
   need to link with to be successful. An understanding of the contents of these
   libraries will be useful in coming up with an optimal specification for the
   libraries to link with. The purpose of this document is to reduce some of
   the trial and error that the author experienced in using LLVM.</p>
   <p>LLVM produces two types of libraries: archives (ending in <tt>.a</tt>) and
   objects (ending in <tt>.o</tt>). However, both are libraries. Libraries ending
   in <tt>.o</tt> are known as re-linked libraries because they contain all the
   compilation units of the library linked together as a single <tt>.o</tt> file.
   Furthermore, several of the libraries have <em>both</em> forms of library. The
   re-linked libraries are used whenever you want to include all symbols from the
   library. The archive libraries are used whenever you want to only resolve
   outstanding symbols at that point in the link without including everything in
   the library. </p>
   <p>If you're using the LLVM Makefile system to link your tools,you will use
   the <tt>LLVMLIBS</tt> make variable.
   (see the <a href="MakefileGuide.html#LLVMLIBS">Makefile Guide</a> for
   details). This variable specifies which LLVM libraries to link into your tool
   and the order in which they will be linked. You specify re-linked libraries by
   naming the library without a suffix. You specify archive libraries by naming
   the library with a <tt>.a</tt> suffix but without the <tt>lib</tt> prefix. The
   order in which the libraries appear in the <tt>LLVMLIBS</tt> variable
   definition is the order in which they will be linked. Getting this order
   correct for your tool can sometimes be challenging.
 </div>
 <!-- ======================================================================= -->
 <div class="doc_section"><a name="descriptions"></a>Library Descriptions</div>
 <div class="doc_text">
   <p>The table below categorizes each library
 <table style="text-align:left">
   <tr><th>Library</th><th>Forms</th><th>Description</th></tr>
   <tr><th colspan="3">Core Libraries</th></tr>
   <tr><td>LLVMArchive</td><td><tt>.a</tt></td>
     <td>LLVM archive reading and writing</td></tr>
   <tr><td>LLVMAsmParser</td><td><tt>.a</tt></td>
     <td>LLVM assembly parsing</td></tr>
   <tr><td>LLVMBCReader</td><td><tt>.a</tt></td>
     <td>LLVM bitcode reading</td></tr>
   <tr><td>LLVMBCWriter</td><td><tt>.a</tt></td>
     <td>LLVM bitcode writing</td></tr>
   <tr><td>LLVMCore</td><td><tt>.a</tt></td>
     <td>LLVM core intermediate representation</td></tr>
   <tr><td>LLVMDebugger</td><td><tt>.a</tt></td>
     <td>Source level debugging support</td></tr>
   <tr><td>LLVMLinker</td><td><tt>.a</tt></td>
     <td>Bitcode and archive linking interface</td></tr>
   <tr><td>LLVMSupport</td><td><tt>.a</tt></td>
     <td>General support utilities</td></tr>
   <tr><td>LLVMSystem</td><td><tt>.a</tt></td>
     <td>Operating system abstraction layer</td></tr>
   <tr><td>LLVMbzip2</td><td><tt>.a</tt></td>
     <td>BZip2 compression library</td></tr>

   <tr><th colspan="3">Analysis Libraries</th></tr>
   <tr><td>LLVMAnalysis</td><td><tt>.a</tt></td>
     <td>Various analysis passes.</td></tr>
   <tr><td>LLVMDataStructure</td><td><tt>.o</tt></td>
     <td>Data structure analysis passes.</td></tr>
   <tr><td>LLVMipa</td><td><tt>.a</tt></td>
     <td>Inter-procedural analysis passes.</td></tr>

   <tr><th colspan="3">Transformation Libraries</th></tr>
   <tr><td>LLVMInstrumentation</td><td><tt>.a</tt></td>
     <td>Instrumentation passes.</td></tr>
   <tr><td>LLVMipo</td><td><tt>.a</tt></td>
     <td>All inter-procedural optimization passes.</td></tr>
   <tr><td>LLVMScalarOpts</td><td><tt>.a</tt></td>
     <td>All scalar optimization passes.</td></tr>
   <tr><td>LLVMTransformUtils</td><td><tt>.a</tt></td>
     <td>Transformation utilities used by many passes.</td></tr>

   <tr><th colspan="3">Code Generation Libraries </th></tr>
   <tr><td>LLVMCodeGen</td><td><tt>.o</tt></td>
     <td>Native code generation infrastructure</td></tr>
   <tr><td>LLVMSelectionDAG</td><td><tt>.o</tt></td>
     <td>Aggressive instruction selector for directed acyclic graphs</td></tr>

   <tr><th colspan="3">Target Libraries</th></tr>
   <tr><td>LLVMAlpha</td><td><tt>.o</tt></td>
     <td>Code generation for Alpha architecture</td></tr>
   <tr><td>LLVMARM</td><td><tt>.o</tt></td>
     <td>Code generation for ARM architecture</td></tr>
   <tr><td>LLVMCBackend</td><td><tt>.o</tt></td>
     <td>'C' language code generator.</td></tr>
   <tr><td>LLVMPowerPC</td><td><tt>.o</tt></td>
     <td>Code generation for PowerPC architecture</td></tr>
   <tr><td>LLVMSparc</td><td><tt>.o</tt></td>
     <td>Code generation for Sparc architecture</td></tr>
   <tr><td>LLVMTarget</td><td><tt>.a</tt></td>
     <td>Generic code generation utilities.</td></tr>
   <tr><td>LLVMX86</td><td><tt>.o</tt></td>
     <td>Code generation for Intel x86 architecture</td></tr>

   <tr><th colspan="3">Runtime Libraries</th></tr>
   <tr><td>LLVMInterpreter</td><td><tt>.o</tt></td>
     <td>Bitcode Interpreter</td></tr>
   <tr><td>LLVMJIT</td><td><tt>.o</tt></td>
     <td>Bitcode JIT Compiler</td></tr>
   <tr><td>LLVMExecutionEngine</td><td><tt>.o</tt></td>
     <td>Virtual machine engine</td></tr>
 </table>
 </div>

 <!-- ======================================================================= -->
 <div class="doc_section"><a name="dependencies"></a>Using llvm-config</div>
 <div class="doc_text">
   <p>The <tt>llvm-config</tt> tool is a perl script that produces on its output
   various kinds of information. For example, the source or object directories
   used to build LLVM can be accessed by passing options to <tt>llvm-config</tt>.
   For complete details on this tool, please see the
   <a href="CommandGuide/html/llvm-config.html">manual page</a>.</p>
   <p>To understand the relationships between libraries, the <tt>llvm-config</tt>
   can be very useful. If all you know is that you want certain libraries to
   be available, you can generate the complete set of libraries to link with
   using one of four options, as below:</p>
   <ol>
     <li><tt>--ldflags</tt>. This generates the command line options necessary to
     be passed to the <tt>ld</tt> tool in order to link with LLVM. Most notably,
     the <tt>-L</tt> option is provided to specify a library search directory
     that contains the LLVM libraries.</li>
     <li><tt>--libs</tt>. This generates command line options suitable for
     use with a gcc-style linker. That is, libraries are given with a -l option
     and object files are given with a full path.</li>
     <li><tt>--libnames</tt>. This generates a list of just the library file
     names. If you know the directory in which these files reside (see --ldflags)
     then you can find the libraries there.</li>
     <li><tt>--libfiles</tt>. This generates the full path names of the
     LLVM library files.</li>
   </ol>
   <p>If you wish to delve further into how <tt>llvm-config</tt> generates the
   correct order (based on library dependencies), please see the tool named
   <tt>GenLibDeps.pl</tt> in the <tt>utils</tt> source directory of LLVM.</p>

   <!-- =======NOTE: =========================================================-->
   <!-- === The following graphs and <dl> list are generated automatically ===-->
   <!-- === by the util named GenLibDeps.pl in the llvm/utils directory.   ===-->
   <!-- === This should be updated whenever new libraries are added,       ===-->
   <!-- === removed, or changed                                            ===-->
   <!-- =======NOTE: =========================================================-->
   <h2>Dependency Relationships Of Libraries</h2>
   <p>This graph shows the dependency of archive libraries on other archive
   libraries or objects. Where a library has both archive and object forms, only
   the archive form is shown.</p>
   <img src="img/libdeps.gif" alt="Library Dependencies"/>
   <h2>Dependency Relationships Of Object Files</h2>
   <p>This graph shows the dependency of object files on archive libraries or
   other objects. Where a library has both object and archive forms, only the
   dependency to the archive form is shown.</p>
   <img src="img/objdeps.gif" alt="Object File Dependencies"/>
   <p>The following list shows the dependency relationships between libraries in
   textual form. The information is the same as shown on the graphs but arranged
   alphabetically.</p>
 <dl>
   <dt><b>libLLVMAnalysis.a</b></dt><dd><ul>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
   </ul></dd>
   <dt><b>libLLVMArchive.a</b></dt><dd><ul>
     <li>libLLVMBCReader.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
   </ul></dd>
   <dt><b>libLLVMAsmParser.a</b></dt><dd><ul>
     <li>libLLVMCore.a</li>
     <li>libLLVMSystem.a</li>
   </ul></dd>
   <dt><b>libLLVMBCReader.a</b></dt><dd><ul>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
   </ul></dd>
   <dt><b>libLLVMBCWriter.a</b></dt><dd><ul>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
   </ul></dd>
   <dt><b>libLLVMCodeGen.a</b></dt><dd><ul>
     <li>libLLVMAnalysis.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMScalarOpts.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
     <li>libLLVMTransformUtils.a</li>
   </ul></dd>
   <dt><b>libLLVMCore.a</b></dt><dd><ul>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
   </ul></dd>
   <dt><b>libLLVMDebugger.a</b></dt><dd><ul>
     <li>libLLVMBCReader.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
   </ul></dd>
   <dt><b>libLLVMInstrumentation.a</b></dt><dd><ul>
     <li>libLLVMCore.a</li>
     <li>libLLVMScalarOpts.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMTransformUtils.a</li>
   </ul></dd>
   <dt><b>libLLVMLinker.a</b></dt><dd><ul>
     <li>libLLVMArchive.a</li>
     <li>libLLVMBCReader.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
   </ul></dd>
   <dt><b>libLLVMScalarOpts.a</b></dt><dd><ul>
     <li>libLLVMAnalysis.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
     <li>libLLVMTransformUtils.a</li>
   </ul></dd>
   <dt><b>libLLVMSelectionDAG.a</b></dt><dd><ul>
     <li>libLLVMAnalysis.a</li>
     <li>libLLVMCodeGen.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
     <li>libLLVMTransformUtils.a</li>
   </ul></dd>
   <dt><b>libLLVMSupport.a</b></dt><dd><ul>
     <li>libLLVMSystem.a</li>
     <li>libLLVMbzip2.a</li>
   </ul></dd>
   <dt><b>libLLVMSystem.a</b></dt><dd><ul>
   </ul></dd>
   <dt><b>libLLVMTarget.a</b></dt><dd><ul>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
   </ul></dd>
   <dt><b>libLLVMTransformUtils.a</b></dt><dd><ul>
     <li>libLLVMAnalysis.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
     <li>libLLVMipa.a</li>
   </ul></dd>
   <dt><b>libLLVMbzip2.a</b></dt><dd><ul>
   </ul></dd>
   <dt><b>libLLVMipa.a</b></dt><dd><ul>
     <li>libLLVMAnalysis.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
   </ul></dd>
   <dt><b>libLLVMipo.a</b></dt><dd><ul>
     <li>libLLVMAnalysis.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
     <li>libLLVMTransformUtils.a</li>
     <li>libLLVMipa.a</li>
   </ul></dd>
   <dt><b>libLLVMlto.a</b></dt><dd><ul>
     <li>libLLVMAnalysis.a</li>
     <li>libLLVMBCReader.a</li>
     <li>libLLVMBCWriter.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMLinker.a</li>
     <li>libLLVMScalarOpts.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
     <li>libLLVMipa.a</li>
     <li>libLLVMipo.a</li>
   </ul></dd>
   <dt><b>LLVMARM.o</b></dt><dd><ul>
     <li>libLLVMCodeGen.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSelectionDAG.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
   </ul></dd>
   <dt><b>LLVMAlpha.o</b></dt><dd><ul>
     <li>libLLVMCodeGen.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSelectionDAG.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
   </ul></dd>
   <dt><b>LLVMCBackend.o</b></dt><dd><ul>
     <li>libLLVMAnalysis.a</li>
     <li>libLLVMCodeGen.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMScalarOpts.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
     <li>libLLVMTransformUtils.a</li>
     <li>libLLVMipa.a</li>
   </ul></dd>
   <dt><b>LLVMExecutionEngine.o</b></dt><dd><ul>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
   </ul></dd>
   <dt><b>LLVMInterpreter.o</b></dt><dd><ul>
     <li>LLVMExecutionEngine.o</li>
     <li>libLLVMCodeGen.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
   </ul></dd>
   <dt><b>LLVMJIT.o</b></dt><dd><ul>
     <li>LLVMExecutionEngine.o</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
   </ul></dd>
   <dt><b>LLVMPowerPC.o</b></dt><dd><ul>
     <li>libLLVMCodeGen.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSelectionDAG.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
   </ul></dd>
   <dt><b>LLVMSparc.o</b></dt><dd><ul>
     <li>libLLVMCodeGen.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSelectionDAG.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
   </ul></dd>
   <dt><b>LLVMX86.o</b></dt><dd><ul>
     <li>libLLVMCodeGen.a</li>
     <li>libLLVMCore.a</li>
     <li>libLLVMSelectionDAG.a</li>
     <li>libLLVMSupport.a</li>
     <li>libLLVMSystem.a</li>
     <li>libLLVMTarget.a</li>
   </ul></dd>
 </dl>
 </div>

 <!-- ======================================================================= -->
 <div class="doc_section"><a name="rot">Linkage Rules Of Thumb</a></div>
 <div class="doc_text">
 	<p>This section contains various "rules of thumb" about what files you
 	should link into your programs.</p>
 </div>
 <!-- ======================================================================= -->
 <div class="doc_subsection"><a name="always">Always Link LLVMCore, LLVMSupport,
     and LLVMSystem</a></div>
 <div class="doc_text">
   <p>No matter what you do with LLVM, the last three entries in the value of
   your LLVMLIBS make variable should always be:
   <tt>LLVMCore LLVMSupport.a LLVMSystem.a</tt>. There are no <tt>LLVM</tt>
   programs that don't depend on these three.</p>
 </div>
 <!-- ======================================================================= -->
 <div class="doc_subsection"><a name="onlyone">Never link both archive and
     re-linked library</a></div>
 <div class="doc_text">
   <p>There is never any point to linking both the re-linked (<tt>.o</tt>) and
   the archive (<tt>.a</tt>) versions of a library. Since the re-linked version
   includes the entire library, the archive version will not resolve any symbols.
   You could even end up with link error if you place the archive version before
   the re-linked version on the linker's command line.</p>
 </div>
 <!-- ======================================================================= -->
 <hr>
 <div class="doc_footer">
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   <a href="mailto:rspencer@x10sys.com">Reid Spencer</a>
 </address>
 <a href="http://llvm.org">The LLVM Compiler Infrastructure</a>
 <br>Last modified: $Date$ </div>
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 <!-- vim: sw=2 ts=2 ai
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	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
	<html>
	<head>
	<title>Using The LLVM Libraries</title>
	<link rel="stylesheet" href="llvm.css" type="text/css">
	</head>
	<body>
	<div class="doc_title">Using The LLVM Libraries</div>
	<ol>
	<li><a href="#abstract">Abstract</a></li>
	<li><a href="#introduction">Introduction</a></li>
	<li><a href="#descriptions">Library Descriptions</a></li>
	<li><a href="#dependencies">Library Dependencies</a></li>
	<li><a href="#rot">Linkage Rules Of Thumb</a>
	<ol>
	<li><a href="#always">Always link LLVMCore, LLVMSupport, LLVMSystem</a>
	<li><a href="#onlyone">Never link both archive and re-linked</a>
	</ol>
	</li>
	</ol>

	<div class="doc_author">
	<p>Written by <a href="mailto:rspencer@x10sys.com">Reid Spencer</a></p>
	</div>

	<p class="doc_warning">Warning: This document is out of date, please see <a href="CommandGuide/html/llvm-config.html">llvm-config</a> for more information.</p>

	<!-- ======================================================================= -->
	<div class="doc_section"><a name="abstract">Abstract</a></div>
	<div class="doc_text">
	<p>Amongst other things, LLVM is a toolkit for building compilers, linkers,
	runtime executives, virtual machines, and other program execution related
	tools. In addition to the LLVM tool set, the functionality of LLVM is
	available through a set of libraries. To use LLVM as a toolkit for
	constructing tools, a developer needs to understand what is contained in the
	various libraries, what they depend on, and how to use them. Fortunately,
	there is a tool, <tt>llvm-config</tt> to aid with this. This document
	describes the contents of the libraries and how to use <tt>llvm-config</tt>
	to generate command line options.
	</p>
	</div>

	<!-- ======================================================================= -->
	<div class="doc_section"> <a name="introduction">Introduction</a></div>
	<div class="doc_text">
	<p>If you're writing a compiler, virtual machine, or any other utility based
	on LLVM, you'll need to figure out which of the many libraries files you will
	need to link with to be successful. An understanding of the contents of these
	libraries will be useful in coming up with an optimal specification for the
	libraries to link with. The purpose of this document is to reduce some of
	the trial and error that the author experienced in using LLVM.</p>
	<p>LLVM produces two types of libraries: archives (ending in <tt>.a</tt>) and
	objects (ending in <tt>.o</tt>). However, both are libraries. Libraries ending
	in <tt>.o</tt> are known as re-linked libraries because they contain all the
	compilation units of the library linked together as a single <tt>.o</tt> file.
	Furthermore, several of the libraries have <em>both</em> forms of library. The
	re-linked libraries are used whenever you want to include all symbols from the
	library. The archive libraries are used whenever you want to only resolve
	outstanding symbols at that point in the link without including everything in
	the library. </p>
	<p>If you're using the LLVM Makefile system to link your tools,you will use
	the <tt>LLVMLIBS</tt> make variable.
	(see the <a href="MakefileGuide.html#LLVMLIBS">Makefile Guide</a> for
	details). This variable specifies which LLVM libraries to link into your tool
	and the order in which they will be linked. You specify re-linked libraries by
	naming the library without a suffix. You specify archive libraries by naming
	the library with a <tt>.a</tt> suffix but without the <tt>lib</tt> prefix. The
	order in which the libraries appear in the <tt>LLVMLIBS</tt> variable
	definition is the order in which they will be linked. Getting this order
	correct for your tool can sometimes be challenging.
	</div>
	<!-- ======================================================================= -->
	<div class="doc_section"><a name="descriptions"></a>Library Descriptions</div>
	<div class="doc_text">
	<p>The table below categorizes each library
	<table style="text-align:left">
	<tr><th>Library</th><th>Forms</th><th>Description</th></tr>
	<tr><th colspan="3">Core Libraries</th></tr>
	<tr><td>LLVMArchive</td><td><tt>.a</tt></td>
	<td>LLVM archive reading and writing</td></tr>
	<tr><td>LLVMAsmParser</td><td><tt>.a</tt></td>
	<td>LLVM assembly parsing</td></tr>
	<tr><td>LLVMBCReader</td><td><tt>.a</tt></td>
	<td>LLVM bitcode reading</td></tr>
	<tr><td>LLVMBCWriter</td><td><tt>.a</tt></td>
	<td>LLVM bitcode writing</td></tr>
	<tr><td>LLVMCore</td><td><tt>.a</tt></td>
	<td>LLVM core intermediate representation</td></tr>
	<tr><td>LLVMDebugger</td><td><tt>.a</tt></td>
	<td>Source level debugging support</td></tr>
	<tr><td>LLVMLinker</td><td><tt>.a</tt></td>
	<td>Bitcode and archive linking interface</td></tr>
	<tr><td>LLVMSupport</td><td><tt>.a</tt></td>
	<td>General support utilities</td></tr>
	<tr><td>LLVMSystem</td><td><tt>.a</tt></td>
	<td>Operating system abstraction layer</td></tr>
	<tr><td>LLVMbzip2</td><td><tt>.a</tt></td>
	<td>BZip2 compression library</td></tr>

	<tr><th colspan="3">Analysis Libraries</th></tr>
	<tr><td>LLVMAnalysis</td><td><tt>.a</tt></td>
	<td>Various analysis passes.</td></tr>
	<tr><td>LLVMDataStructure</td><td><tt>.o</tt></td>
	<td>Data structure analysis passes.</td></tr>
	<tr><td>LLVMipa</td><td><tt>.a</tt></td>
	<td>Inter-procedural analysis passes.</td></tr>

	<tr><th colspan="3">Transformation Libraries</th></tr>
	<tr><td>LLVMInstrumentation</td><td><tt>.a</tt></td>
	<td>Instrumentation passes.</td></tr>
	<tr><td>LLVMipo</td><td><tt>.a</tt></td>
	<td>All inter-procedural optimization passes.</td></tr>
	<tr><td>LLVMScalarOpts</td><td><tt>.a</tt></td>
	<td>All scalar optimization passes.</td></tr>
	<tr><td>LLVMTransformUtils</td><td><tt>.a</tt></td>
	<td>Transformation utilities used by many passes.</td></tr>

	<tr><th colspan="3">Code Generation Libraries </th></tr>
	<tr><td>LLVMCodeGen</td><td><tt>.o</tt></td>
	<td>Native code generation infrastructure</td></tr>
	<tr><td>LLVMSelectionDAG</td><td><tt>.o</tt></td>
	<td>Aggressive instruction selector for directed acyclic graphs</td></tr>

	<tr><th colspan="3">Target Libraries</th></tr>
	<tr><td>LLVMAlpha</td><td><tt>.o</tt></td>
	<td>Code generation for Alpha architecture</td></tr>
	<tr><td>LLVMARM</td><td><tt>.o</tt></td>
	<td>Code generation for ARM architecture</td></tr>
	<tr><td>LLVMCBackend</td><td><tt>.o</tt></td>
	<td>'C' language code generator.</td></tr>
	<tr><td>LLVMPowerPC</td><td><tt>.o</tt></td>
	<td>Code generation for PowerPC architecture</td></tr>
	<tr><td>LLVMSparc</td><td><tt>.o</tt></td>
	<td>Code generation for Sparc architecture</td></tr>
	<tr><td>LLVMTarget</td><td><tt>.a</tt></td>
	<td>Generic code generation utilities.</td></tr>
	<tr><td>LLVMX86</td><td><tt>.o</tt></td>
	<td>Code generation for Intel x86 architecture</td></tr>

	<tr><th colspan="3">Runtime Libraries</th></tr>
	<tr><td>LLVMInterpreter</td><td><tt>.o</tt></td>
	<td>Bitcode Interpreter</td></tr>
	<tr><td>LLVMJIT</td><td><tt>.o</tt></td>
	<td>Bitcode JIT Compiler</td></tr>
	<tr><td>LLVMExecutionEngine</td><td><tt>.o</tt></td>
	<td>Virtual machine engine</td></tr>
	</table>
	</div>

	<!-- ======================================================================= -->
	<div class="doc_section"><a name="dependencies"></a>Using llvm-config</div>
	<div class="doc_text">
	<p>The <tt>llvm-config</tt> tool is a perl script that produces on its output
	various kinds of information. For example, the source or object directories
	used to build LLVM can be accessed by passing options to <tt>llvm-config</tt>.
	For complete details on this tool, please see the
	<a href="CommandGuide/html/llvm-config.html">manual page</a>.</p>
	<p>To understand the relationships between libraries, the <tt>llvm-config</tt>
	can be very useful. If all you know is that you want certain libraries to
	be available, you can generate the complete set of libraries to link with
	using one of four options, as below:</p>
	<ol>
	<li><tt>--ldflags</tt>. This generates the command line options necessary to
	be passed to the <tt>ld</tt> tool in order to link with LLVM. Most notably,
	the <tt>-L</tt> option is provided to specify a library search directory
	that contains the LLVM libraries.</li>
	<li><tt>--libs</tt>. This generates command line options suitable for
	use with a gcc-style linker. That is, libraries are given with a -l option
	and object files are given with a full path.</li>
	<li><tt>--libnames</tt>. This generates a list of just the library file
	names. If you know the directory in which these files reside (see --ldflags)
	then you can find the libraries there.</li>
	<li><tt>--libfiles</tt>. This generates the full path names of the
	LLVM library files.</li>
	</ol>
	<p>If you wish to delve further into how <tt>llvm-config</tt> generates the
	correct order (based on library dependencies), please see the tool named
	<tt>GenLibDeps.pl</tt> in the <tt>utils</tt> source directory of LLVM.</p>

	<!-- =======NOTE: =========================================================-->
	<!-- === The following graphs and <dl> list are generated automatically ===-->
	<!-- === by the util named GenLibDeps.pl in the llvm/utils directory. ===-->
	<!-- === This should be updated whenever new libraries are added, ===-->
	<!-- === removed, or changed ===-->
	<!-- =======NOTE: =========================================================-->
	<h2>Dependency Relationships Of Libraries</h2>
	<p>This graph shows the dependency of archive libraries on other archive
	libraries or objects. Where a library has both archive and object forms, only
	the archive form is shown.</p>
	<img src="img/libdeps.gif" alt="Library Dependencies"/>
	<h2>Dependency Relationships Of Object Files</h2>
	<p>This graph shows the dependency of object files on archive libraries or
	other objects. Where a library has both object and archive forms, only the
	dependency to the archive form is shown.</p>
	<img src="img/objdeps.gif" alt="Object File Dependencies"/>
	<p>The following list shows the dependency relationships between libraries in
	textual form. The information is the same as shown on the graphs but arranged
	alphabetically.</p>
	<dl>
	<dt><b>libLLVMAnalysis.a</b></dt><dd><ul>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	</ul></dd>
	<dt><b>libLLVMArchive.a</b></dt><dd><ul>
	<li>libLLVMBCReader.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	</ul></dd>
	<dt><b>libLLVMAsmParser.a</b></dt><dd><ul>
	<li>libLLVMCore.a</li>
	<li>libLLVMSystem.a</li>
	</ul></dd>
	<dt><b>libLLVMBCReader.a</b></dt><dd><ul>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	</ul></dd>
	<dt><b>libLLVMBCWriter.a</b></dt><dd><ul>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	</ul></dd>
	<dt><b>libLLVMCodeGen.a</b></dt><dd><ul>
	<li>libLLVMAnalysis.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMScalarOpts.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	<li>libLLVMTransformUtils.a</li>
	</ul></dd>
	<dt><b>libLLVMCore.a</b></dt><dd><ul>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	</ul></dd>
	<dt><b>libLLVMDebugger.a</b></dt><dd><ul>
	<li>libLLVMBCReader.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	</ul></dd>
	<dt><b>libLLVMInstrumentation.a</b></dt><dd><ul>
	<li>libLLVMCore.a</li>
	<li>libLLVMScalarOpts.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMTransformUtils.a</li>
	</ul></dd>
	<dt><b>libLLVMLinker.a</b></dt><dd><ul>
	<li>libLLVMArchive.a</li>
	<li>libLLVMBCReader.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	</ul></dd>
	<dt><b>libLLVMScalarOpts.a</b></dt><dd><ul>
	<li>libLLVMAnalysis.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	<li>libLLVMTransformUtils.a</li>
	</ul></dd>
	<dt><b>libLLVMSelectionDAG.a</b></dt><dd><ul>
	<li>libLLVMAnalysis.a</li>
	<li>libLLVMCodeGen.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	<li>libLLVMTransformUtils.a</li>
	</ul></dd>
	<dt><b>libLLVMSupport.a</b></dt><dd><ul>
	<li>libLLVMSystem.a</li>
	<li>libLLVMbzip2.a</li>
	</ul></dd>
	<dt><b>libLLVMSystem.a</b></dt><dd><ul>
	</ul></dd>
	<dt><b>libLLVMTarget.a</b></dt><dd><ul>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	</ul></dd>
	<dt><b>libLLVMTransformUtils.a</b></dt><dd><ul>
	<li>libLLVMAnalysis.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	<li>libLLVMipa.a</li>
	</ul></dd>
	<dt><b>libLLVMbzip2.a</b></dt><dd><ul>
	</ul></dd>
	<dt><b>libLLVMipa.a</b></dt><dd><ul>
	<li>libLLVMAnalysis.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	</ul></dd>
	<dt><b>libLLVMipo.a</b></dt><dd><ul>
	<li>libLLVMAnalysis.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	<li>libLLVMTransformUtils.a</li>
	<li>libLLVMipa.a</li>
	</ul></dd>
	<dt><b>libLLVMlto.a</b></dt><dd><ul>
	<li>libLLVMAnalysis.a</li>
	<li>libLLVMBCReader.a</li>
	<li>libLLVMBCWriter.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMLinker.a</li>
	<li>libLLVMScalarOpts.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	<li>libLLVMipa.a</li>
	<li>libLLVMipo.a</li>
	</ul></dd>
	<dt><b>LLVMARM.o</b></dt><dd><ul>
	<li>libLLVMCodeGen.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSelectionDAG.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	</ul></dd>
	<dt><b>LLVMAlpha.o</b></dt><dd><ul>
	<li>libLLVMCodeGen.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSelectionDAG.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	</ul></dd>
	<dt><b>LLVMCBackend.o</b></dt><dd><ul>
	<li>libLLVMAnalysis.a</li>
	<li>libLLVMCodeGen.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMScalarOpts.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	<li>libLLVMTransformUtils.a</li>
	<li>libLLVMipa.a</li>
	</ul></dd>
	<dt><b>LLVMExecutionEngine.o</b></dt><dd><ul>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	</ul></dd>
	<dt><b>LLVMInterpreter.o</b></dt><dd><ul>
	<li>LLVMExecutionEngine.o</li>
	<li>libLLVMCodeGen.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	</ul></dd>
	<dt><b>LLVMJIT.o</b></dt><dd><ul>
	<li>LLVMExecutionEngine.o</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	</ul></dd>
	<dt><b>LLVMPowerPC.o</b></dt><dd><ul>
	<li>libLLVMCodeGen.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSelectionDAG.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	</ul></dd>
	<dt><b>LLVMSparc.o</b></dt><dd><ul>
	<li>libLLVMCodeGen.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSelectionDAG.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	</ul></dd>
	<dt><b>LLVMX86.o</b></dt><dd><ul>
	<li>libLLVMCodeGen.a</li>
	<li>libLLVMCore.a</li>
	<li>libLLVMSelectionDAG.a</li>
	<li>libLLVMSupport.a</li>
	<li>libLLVMSystem.a</li>
	<li>libLLVMTarget.a</li>
	</ul></dd>
	</dl>
	</div>

	<!-- ======================================================================= -->
	<div class="doc_section"><a name="rot">Linkage Rules Of Thumb</a></div>
	<div class="doc_text">
	<p>This section contains various "rules of thumb" about what files you
	should link into your programs.</p>
	</div>
	<!-- ======================================================================= -->
	<div class="doc_subsection"><a name="always">Always Link LLVMCore, LLVMSupport,
	and LLVMSystem</a></div>
	<div class="doc_text">
	<p>No matter what you do with LLVM, the last three entries in the value of
	your LLVMLIBS make variable should always be:
	<tt>LLVMCore LLVMSupport.a LLVMSystem.a</tt>. There are no <tt>LLVM</tt>
	programs that don't depend on these three.</p>
	</div>
	<!-- ======================================================================= -->
	<div class="doc_subsection"><a name="onlyone">Never link both archive and
	re-linked library</a></div>
	<div class="doc_text">
	<p>There is never any point to linking both the re-linked (<tt>.o</tt>) and
	the archive (<tt>.a</tt>) versions of a library. Since the re-linked version
	includes the entire library, the archive version will not resolve any symbols.
	You could even end up with link error if you place the archive version before
	the re-linked version on the linker's command line.</p>
	</div>
	<!-- ======================================================================= -->
	<hr>
	<div class="doc_footer">
	<address>
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	<a href="mailto:rspencer@x10sys.com">Reid Spencer</a>
	</address>
	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a>
	<br>Last modified: $Date$ </div>
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