docs/CFEBuildInstrs.html - platform/external/llvm - Gitiles

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 </head>
 <body>

 <div class="doc_title">
   Bootstrapping the LLVM C/C++ Front-End
 </div>

 <ol>
   <li><a href="#cautionarynote">A Cautionary Note</a>
     <ul>
       <li><a href="#cygwin">Building under Cygwin</a></li>
       <li><a href="#aix">Building under AIX</a></li>
     </ul>
   </li>
   <li><a href="#instructions">llvm-gcc4 Instructions</a></li>
   <li><a href="#llvm-gcc3-instructions">llvm-gcc3 Instructions</a></li>
   <li><a href="#license">License Information</a></li>
 </ol>

 <div class="doc_author">
   <p>Written by Brian R. Gaeke and
      <a href="http://nondot.org/sabre">Chris Lattner</a></p>
 </div>

 <!-- *********************************************************************** -->
 <div class="doc_section">
   <a name="cautionarynote">A Cautionary Note</a>
 </div>
 <!-- *********************************************************************** -->

 <div class="doc_text">
 <p>This document is intended to explain the process of building the
 LLVM C/C++ front-end from its source code. You have to do this, for example, if
 you are porting LLVM to a new architecture or operating system, if you are
 working from Top-Of-Tree CVS/SVN, or if there is no precompiled snapshot
 available.</p>

 <p><b>NOTE:</b> This is currently a somewhat fragile, error-prone
 process, and you should <b>only</b> try to do it if:</p>

 <ol>
   <li>you really, really, really can't use the binaries we distribute</li>
   <li>you are an elite GCC hacker.</li>
   <li>you want to use the latest bits from CVS.</li>
 </ol>

 <p>We welcome patches to help make this process simpler.</p>
 </div>

 <!--=========================================================================-->
 <div class="doc_subsection">
   <a name="cygwin">Building under Cygwin</a>
 </div>
 <!--=========================================================================-->

 <div class="doc_text">
 <p>If you are building LLVM and the GCC front-end under Cygwin, please note that
 the LLVM and GCC makefiles do not correctly handle spaces in paths.  To deal
 with this issue, make sure that your LLVM and GCC source and build trees are
 located in a top-level directory (like <tt>/cygdrive/c/llvm</tt> and
 <tt>/cygdrive/c/llvm-cfrontend</tt>), not in a directory that contains a space
 (which includes your "home directory", because it lives under the "Documents
 and Settings" directory).  We welcome patches to fix this issue.
 </p>
 <p>It has been found that the GCC 3.3.3 compiler provided with recent Cygwin
 versions is incapable of compiling the LLVM GCC front-end correctly. If your
 Cygwin
 installation includes GCC 3.3.3, we <i>strongly</i> recommend that you download
 GCC 3.4.3, build it separately, and use it for compiling the LLVM GCC front-end.
  This has been
 shown to work correctly.</p>
 <p>Some versions of Cygwin utilize an experimental version of GNU binutils that
 will cause the GNU <tt>ld</tt> linker to fail an assertion when linking
 components of the libstdc++. It is recommended that you replace the entire
 binutils package with version 2.15 such that "<tt>ld --version</tt>" responds
 with</p>
 <pre>GNU ld version 2.15</pre>
 not with:<br/>
 <pre>GNU ld version 2.15.91 20040725</pre>
 </div>

 <!--=========================================================================-->
 <div class="doc_subsection"><a name="aix">Building under AIX</a></div>
 <div class="doc_text">
 <p>If you are building LLVM and the GCC front-end under AIX, do NOT use GNU
 Binutils.  They are not stable under AIX and may produce incorrect and/or
 invalid code.  Instead, use the system assembler and linker.
 </p>
 </div>

 <!-- *********************************************************************** -->
 <div class="doc_section">
   <a name="instructions">llvm-gcc4 Instructions</a>
 </div>
 <!-- *********************************************************************** -->

 <div class="doc_text">

 <p>This section describes how to aquire and build llvm-gcc4, which is based on
 the GCC 4.0.1 front-end.  This front-end supports C, C++, Objective-C, and
 Objective-C++.  Note that the instructions for building this front-end are
 completely different than those for building llvm-gcc3.
 </p>

 <ol>
 <li>
 <p>Retrieve the appropriate llvm-gcc4-x.y.source.tar.gz archive from the llvm
 web site.</p>
 <p>It is also possible to download the sources of the llvm-gcc4 front end from
 a read-only mirror using subversion.  To check out the code the first time use:
 </p>

 <tt>svn co svn://anonsvn.opensource.apple.com/svn/llvm/trunk
 <i>dst-directory</i></tt>

 <p>After that, the code can be be updated in the destination directory using;
 </p>

 <tt>svn update</tt>

 <p>The mirror is brought up to date every evening.</p>
 </li>

 <li>Follow the directions in the top-level README.LLVM file for up-to-date
     instructions on how to build llvm-gcc4.</li>
 </ol>
 </div>

 <!-- *********************************************************************** -->
 <div class="doc_section">
   <a name="llvm-gcc3-instructions">llvm-gcc3 Instructions</a>
 </div>
 <!-- *********************************************************************** -->

 <div class="doc_text">
 <ol>
 <li>Aquire llvm-gcc3 from <a href="GettingStarted.html#checkout">LLVM CVS</a> or
 from a <a href="http://llvm.org/releases/">release tarball</a>.</li>

 <li><p>Configure and build the LLVM libraries and tools. There are two ways to
 do this: either with <i>objdir</i> == <i>srcdir</i> or
 <i>objdir</i> != <i>srcdir</i>. It is recommended
 that <i>srcdir</i> be the same as <i>objdir</i> for your LLVM tree (but note
 that you should always use <i>srcdir</i> != <i>objdir</i> for llvm-gcc):</p>
 <ul>
   <li>With <i>objdir</i> != <i>srcdir</i>:<pre>
  % cd <i>objdir</i>
  % <i>srcdir</i>/configure --prefix=/some/path/you/can/install/to [options...]
  % gmake tools-only
   </pre></li>
   <li>With <i>objdir</i> == <i>srcdir</i>:<pre>
  % cd llvm
  % ./configure --prefix=/some/path/you/can/install/to [options...]
  % gmake tools-only
   </pre></li>
 </ul>
 <p>This will build all of the LLVM tools and libraries. The <tt>--prefix</tt>
 option defaults to /usr/local (per configure standards) but unless you are a
 system administrator, you probably won't be able to install LLVM there because
 of permissions. Specify a path into which LLVM can be installed (e.g.
 <tt>--prefix=/home/user/llvm</tt>).</p>
 </li>

 <li><p>Add the directory containing the tools to your PATH.</p>
 <pre>
  % set path = ( `cd llvm/Debug/bin &amp;&amp; pwd` $path )
 </pre></li>

 <li><p>Unpack the C/C++ front-end source into cfrontend/src, either by
        untar'ing a cfrontend.source.tar.gz file or checking out CVS into this
        directory.</p></li>

 <li><p>Make "build" and "install" directories as siblings of the "src" tree:</p>
 <pre>
  % pwd
  /usr/local/example/cfrontend/src
  % cd ..
  % mkdir build install
  % set CFEINSTALL = `pwd`/install
 </pre></li>


 <li><p>Configure, build, and install the GCC front-end:</p>

 <p>
 <b>Linux/x86:</b><br>
 <b>Linux/IA-64:</b><br>
 <b>MacOS X/PowerPC</b> (requires dlcompat library):<br>
 <b>AIX/PowerPC:</b>
 </p>

 <pre>
  % cd build
  % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
    --disable-shared --enable-languages=c,c++ --program-prefix=llvm-
  % gmake all; gmake install
 </pre>

 <p><b>Cygwin/x86:</b></p>

 <pre>
  % cd build
  % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
    --disable-shared --enable-languages=c,c++ --disable-c-mbchar \
    --program-prefix=llvm-
  % gmake all; gmake install
 </pre>

 <p><b>Solaris/SPARC:</b></p>

 <p>
 The GCC front-end can be configured for either SPARC V8 (32 bit) or SPARC V9 (64
 bit).  This changes, among other things, the sizes of integer types and the
 macros defined for conditional compilation.
 </p>

 <p>
 The SPARC V8 ABI support is more robust than the V9 ABI support and can generate
 SPARC V9 code.  It is highly recommended that you use the V8 ABI with LLVM, as
 shown below.  Also,
 note that Solaris has trouble with various wide (multibyte) character
 functions from C as referenced from C++, so we typically configure with
 --disable-c-mbchar (cf. <a href="http://llvm.org/PR206">Bug 206</a>).
 </p>

 <pre>
  % cd build
  % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
    --disable-shared --enable-languages=c,c++ --host=sparc-sun-solaris2.8 \
    --disable-c-mbchar --program-prefix=llvm-
  % gmake all; gmake install
 </pre>

  <p><b>Common Problem:</b> You may get error messages regarding the fact
  that LLVM does not support inline assembly. Here are two common
  fixes:</p>

  <ul>
   <li><p><b>Fix 1:</b> If you have system header files that include
    inline assembly, you may have to modify them to remove the inline
    assembly and install the modified versions in
    <code>$CFEINSTALL/lib/gcc/<i>target-triplet</i>/3.4-llvm/include</code>.</li>

   <li><b>Fix 2:</b> If you are building the C++ front-end on a CPU we
    haven't tried yet, you will probably have to edit the appropriate
    version of atomicity.h under
    <code>src/libstdc++-v3/config/cpu/<i>name-of-cpu</i>/atomicity.h</code>
    and apply a patch so that it does not use inline assembly.</li>
  </ul>

  <p><b>Porting to a new architecture:</b> If you are porting the front-end
  to a new architecture or compiling in a configuration that we have
  not tried previously, there are probably several changes you will have to make
  to the GCC target to get it to work correctly.  These include:<p>

  <ul>
   <li>Often targets include special assembler or linker flags which
       <tt>gccas</tt>/<tt>gccld</tt> does not understand.  In general, these can
       just be removed.</li>
   <li>LLVM currently does not support any floating point values other than
       32-bit and 64-bit IEEE floating point.  The primary effect of this is
       that you may have to map "long double" onto "double".</li>
   <li>The profiling hooks in GCC do not apply at all to the LLVM front-end.
       These may need to be disabled.</li>
   <li>No inline assembly for position independent code.  At the LLVM level,
       everything is position independent.</li>
   <li>We handle <tt>.init</tt> and <tt>.fini</tt> differently.</li>
   <li>You may have to disable multilib support in your target.  Using multilib
       support causes the GCC compiler driver to add a lot of "<tt>-L</tt>"
       options to the link line, which do not relate to LLVM and confuse
       <tt>gccld</tt>.  To disable multilibs, delete any
       <tt>MULTILIB_OPTIONS</tt> lines from your target files.</li>
   <li>Did we mention that we don't support inline assembly?  You'll probably
       have to add some fixinclude hacks to disable it in the system
       headers.</li>
  </ul>
 </li>

 <li><p>Put <tt>$CFEINSTALL/bin</tt> into your <tt>PATH</tt> environment
 variable.</p>
   <ul>
     <li>sh: <tt>export PATH=$CFEINSTALL/bin:$PATH</tt></li>
     <li>csh: <tt>setenv PATH $CFEINSTALL/bin:$PATH</tt></li>
   </ul>
 </li>

 <li><p>Go back into the LLVM source tree proper.  Rerun configure, using
 the same options as the last time. This will cause the configuration to now find
 the newly built llvm-gcc and llvm-g++ executables. </p></li>

 <li><p>Rebuild your CVS tree.  This shouldn't cause the whole thing to be
   rebuilt, but it should build the runtime libraries.  After the tree is
   built, install the runtime libraries into your GCC front-end build tree.
   These are the commands you need:</p>
 <pre>
  % gmake
  % gmake -C runtime install-bytecode
 </pre></li>

 <li><p>Optionally, build a symbol table for the newly installed runtime
 libraries. Although this step is optional, you are strongly encouraged to
 do this as the symbol tables will make a significant difference in your
 link times. Use the <tt>llvm-ranlib</tt> tool to do this, as follows:</p>
 <pre>
  % cd $CFEINSTALL/lib
  % llvm-ranlib libiberty.a
  % llvm-ranlib libstdc++.a
  % llvm-ranlib libsupc++.a
  % cd $CFEINSTALL/lib/gcc/<i>target-triplet</i>/3.4-llvm
  % llvm-ranlib libgcc.a
  % llvm-ranlib libgcov.a
 </pre>

 <li><p>Test the newly-installed C frontend by one or more of the
 following means:</p>
  <ul>
   <li> running the feature &amp; regression tests via <tt>make check</tt></li>
   <li> compiling and running a "hello, LLVM" program in C and C++.</li>
   <li> running the tests found in the <tt>llvm-test</tt> CVS module</li>
  </ul></li>
 </ol>
 </div>

 <!-- *********************************************************************** -->
 <div class="doc_section">
   <a name="license">License Information</a>
 </div>

 <div class="doc_text">
 <p>
 The LLVM GCC frontend is licensed to you under the GNU General Public License
 and the GNU Lesser General Public License.  Please see the files COPYING and
 COPYING.LIB for more details.
 </p>

 <p>
 More information is <a href="FAQ.html#license">available in the FAQ</a>.
 </p>
 </pre>
 </div>

 <!-- *********************************************************************** -->

 <hr>
 <address>
   <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
   src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
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   Brian Gaeke<br>
   <a href="http://llvm.org">LLVM Compiler Infrastructure</a><br>
   Last modified: $Date$
 </address>

 </body>
 </html>
	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
	"http://www.w3.org/TR/html4/strict.dtd">
	<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
	<link rel="stylesheet" href="llvm.css" type="text/css" media="screen">
	<title>Bootstrapping the LLVM C/C++ Front-End</title>
	</head>
	<body>

	<div class="doc_title">
	Bootstrapping the LLVM C/C++ Front-End
	</div>

	<ol>
	<li><a href="#cautionarynote">A Cautionary Note</a>
	<ul>
	<li><a href="#cygwin">Building under Cygwin</a></li>
	<li><a href="#aix">Building under AIX</a></li>
	</ul>
	</li>
	<li><a href="#instructions">llvm-gcc4 Instructions</a></li>
	<li><a href="#llvm-gcc3-instructions">llvm-gcc3 Instructions</a></li>
	<li><a href="#license">License Information</a></li>
	</ol>

	<div class="doc_author">
	<p>Written by Brian R. Gaeke and
	<a href="http://nondot.org/sabre">Chris Lattner</a></p>
	</div>

	<!-- *********************************************************************** -->
	<div class="doc_section">
	<a name="cautionarynote">A Cautionary Note</a>
	</div>
	<!-- *********************************************************************** -->

	<div class="doc_text">
	<p>This document is intended to explain the process of building the
	LLVM C/C++ front-end from its source code. You have to do this, for example, if
	you are porting LLVM to a new architecture or operating system, if you are
	working from Top-Of-Tree CVS/SVN, or if there is no precompiled snapshot
	available.</p>

	<p><b>NOTE:</b> This is currently a somewhat fragile, error-prone
	process, and you should <b>only</b> try to do it if:</p>

	<ol>
	<li>you really, really, really can't use the binaries we distribute</li>
	<li>you are an elite GCC hacker.</li>
	<li>you want to use the latest bits from CVS.</li>
	</ol>

	<p>We welcome patches to help make this process simpler.</p>
	</div>

	<!--=========================================================================-->
	<div class="doc_subsection">
	<a name="cygwin">Building under Cygwin</a>
	</div>
	<!--=========================================================================-->

	<div class="doc_text">
	<p>If you are building LLVM and the GCC front-end under Cygwin, please note that
	the LLVM and GCC makefiles do not correctly handle spaces in paths. To deal
	with this issue, make sure that your LLVM and GCC source and build trees are
	located in a top-level directory (like <tt>/cygdrive/c/llvm</tt> and
	<tt>/cygdrive/c/llvm-cfrontend</tt>), not in a directory that contains a space
	(which includes your "home directory", because it lives under the "Documents
	and Settings" directory). We welcome patches to fix this issue.
	</p>
	<p>It has been found that the GCC 3.3.3 compiler provided with recent Cygwin
	versions is incapable of compiling the LLVM GCC front-end correctly. If your
	Cygwin
	installation includes GCC 3.3.3, we <i>strongly</i> recommend that you download
	GCC 3.4.3, build it separately, and use it for compiling the LLVM GCC front-end.
	This has been
	shown to work correctly.</p>
	<p>Some versions of Cygwin utilize an experimental version of GNU binutils that
	will cause the GNU <tt>ld</tt> linker to fail an assertion when linking
	components of the libstdc++. It is recommended that you replace the entire
	binutils package with version 2.15 such that "<tt>ld --version</tt>" responds
	with</p>
	<pre>GNU ld version 2.15</pre>
	not with:<br/>
	<pre>GNU ld version 2.15.91 20040725</pre>
	</div>

	<!--=========================================================================-->
	<div class="doc_subsection"><a name="aix">Building under AIX</a></div>
	<div class="doc_text">
	<p>If you are building LLVM and the GCC front-end under AIX, do NOT use GNU
	Binutils. They are not stable under AIX and may produce incorrect and/or
	invalid code. Instead, use the system assembler and linker.
	</p>
	</div>

	<!-- *********************************************************************** -->
	<div class="doc_section">
	<a name="instructions">llvm-gcc4 Instructions</a>
	</div>
	<!-- *********************************************************************** -->

	<div class="doc_text">

	<p>This section describes how to aquire and build llvm-gcc4, which is based on
	the GCC 4.0.1 front-end. This front-end supports C, C++, Objective-C, and
	Objective-C++. Note that the instructions for building this front-end are
	completely different than those for building llvm-gcc3.
	</p>

	<ol>
	<li>
	<p>Retrieve the appropriate llvm-gcc4-x.y.source.tar.gz archive from the llvm
	web site.</p>
	<p>It is also possible to download the sources of the llvm-gcc4 front end from
	a read-only mirror using subversion. To check out the code the first time use:
	</p>

	<tt>svn co svn://anonsvn.opensource.apple.com/svn/llvm/trunk
	<i>dst-directory</i></tt>

	<p>After that, the code can be be updated in the destination directory using;
	</p>

	<tt>svn update</tt>

	<p>The mirror is brought up to date every evening.</p>
	</li>

	<li>Follow the directions in the top-level README.LLVM file for up-to-date
	instructions on how to build llvm-gcc4.</li>
	</ol>
	</div>

	<!-- *********************************************************************** -->
	<div class="doc_section">
	<a name="llvm-gcc3-instructions">llvm-gcc3 Instructions</a>
	</div>
	<!-- *********************************************************************** -->

	<div class="doc_text">
	<ol>
	<li>Aquire llvm-gcc3 from <a href="GettingStarted.html#checkout">LLVM CVS</a> or
	from a <a href="http://llvm.org/releases/">release tarball</a>.</li>

	<li><p>Configure and build the LLVM libraries and tools. There are two ways to
	do this: either with <i>objdir</i> == <i>srcdir</i> or
	<i>objdir</i> != <i>srcdir</i>. It is recommended
	that <i>srcdir</i> be the same as <i>objdir</i> for your LLVM tree (but note
	that you should always use <i>srcdir</i> != <i>objdir</i> for llvm-gcc):</p>
	<ul>
	<li>With <i>objdir</i> != <i>srcdir</i>:<pre>
	% cd <i>objdir</i>
	% <i>srcdir</i>/configure --prefix=/some/path/you/can/install/to [options...]
	% gmake tools-only
	</pre></li>
	<li>With <i>objdir</i> == <i>srcdir</i>:<pre>
	% cd llvm
	% ./configure --prefix=/some/path/you/can/install/to [options...]
	% gmake tools-only
	</pre></li>
	</ul>
	<p>This will build all of the LLVM tools and libraries. The <tt>--prefix</tt>
	option defaults to /usr/local (per configure standards) but unless you are a
	system administrator, you probably won't be able to install LLVM there because
	of permissions. Specify a path into which LLVM can be installed (e.g.
	<tt>--prefix=/home/user/llvm</tt>).</p>
	</li>

	<li><p>Add the directory containing the tools to your PATH.</p>
	<pre>
	% set path = ( `cd llvm/Debug/bin && pwd` $path )
	</pre></li>

	<li><p>Unpack the C/C++ front-end source into cfrontend/src, either by
	untar'ing a cfrontend.source.tar.gz file or checking out CVS into this
	directory.</p></li>

	<li><p>Make "build" and "install" directories as siblings of the "src" tree:</p>
	<pre>
	% pwd
	/usr/local/example/cfrontend/src
	% cd ..
	% mkdir build install
	% set CFEINSTALL = `pwd`/install
	</pre></li>


	<li><p>Configure, build, and install the GCC front-end:</p>

	<p>
	<b>Linux/x86:</b><br>
	<b>Linux/IA-64:</b><br>
	<b>MacOS X/PowerPC</b> (requires dlcompat library):<br>
	<b>AIX/PowerPC:</b>
	</p>

	<pre>
	% cd build
	% ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
	--disable-shared --enable-languages=c,c++ --program-prefix=llvm-
	% gmake all; gmake install
	</pre>

	<p><b>Cygwin/x86:</b></p>

	<pre>
	% cd build
	% ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
	--disable-shared --enable-languages=c,c++ --disable-c-mbchar \
	--program-prefix=llvm-
	% gmake all; gmake install
	</pre>

	<p><b>Solaris/SPARC:</b></p>

	<p>
	The GCC front-end can be configured for either SPARC V8 (32 bit) or SPARC V9 (64
	bit). This changes, among other things, the sizes of integer types and the
	macros defined for conditional compilation.
	</p>

	<p>
	The SPARC V8 ABI support is more robust than the V9 ABI support and can generate
	SPARC V9 code. It is highly recommended that you use the V8 ABI with LLVM, as
	shown below. Also,
	note that Solaris has trouble with various wide (multibyte) character
	functions from C as referenced from C++, so we typically configure with
	--disable-c-mbchar (cf. <a href="http://llvm.org/PR206">Bug 206</a>).
	</p>

	<pre>
	% cd build
	% ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
	--disable-shared --enable-languages=c,c++ --host=sparc-sun-solaris2.8 \
	--disable-c-mbchar --program-prefix=llvm-
	% gmake all; gmake install
	</pre>

	<p><b>Common Problem:</b> You may get error messages regarding the fact
	that LLVM does not support inline assembly. Here are two common
	fixes:</p>

	<ul>
	<li><p><b>Fix 1:</b> If you have system header files that include
	inline assembly, you may have to modify them to remove the inline
	assembly and install the modified versions in
	<code>$CFEINSTALL/lib/gcc/<i>target-triplet</i>/3.4-llvm/include</code>.</li>

	<li><b>Fix 2:</b> If you are building the C++ front-end on a CPU we
	haven't tried yet, you will probably have to edit the appropriate
	version of atomicity.h under
	<code>src/libstdc++-v3/config/cpu/<i>name-of-cpu</i>/atomicity.h</code>
	and apply a patch so that it does not use inline assembly.</li>
	</ul>

	<p><b>Porting to a new architecture:</b> If you are porting the front-end
	to a new architecture or compiling in a configuration that we have
	not tried previously, there are probably several changes you will have to make
	to the GCC target to get it to work correctly. These include:<p>

	<ul>
	<li>Often targets include special assembler or linker flags which
	<tt>gccas</tt>/<tt>gccld</tt> does not understand. In general, these can
	just be removed.</li>
	<li>LLVM currently does not support any floating point values other than
	32-bit and 64-bit IEEE floating point. The primary effect of this is
	that you may have to map "long double" onto "double".</li>
	<li>The profiling hooks in GCC do not apply at all to the LLVM front-end.
	These may need to be disabled.</li>
	<li>No inline assembly for position independent code. At the LLVM level,
	everything is position independent.</li>
	<li>We handle <tt>.init</tt> and <tt>.fini</tt> differently.</li>
	<li>You may have to disable multilib support in your target. Using multilib
	support causes the GCC compiler driver to add a lot of "<tt>-L</tt>"
	options to the link line, which do not relate to LLVM and confuse
	<tt>gccld</tt>. To disable multilibs, delete any
	<tt>MULTILIB_OPTIONS</tt> lines from your target files.</li>
	<li>Did we mention that we don't support inline assembly? You'll probably
	have to add some fixinclude hacks to disable it in the system
	headers.</li>
	</ul>
	</li>

	<li><p>Put <tt>$CFEINSTALL/bin</tt> into your <tt>PATH</tt> environment
	variable.</p>
	<ul>
	<li>sh: <tt>export PATH=$CFEINSTALL/bin:$PATH</tt></li>
	<li>csh: <tt>setenv PATH $CFEINSTALL/bin:$PATH</tt></li>
	</ul>
	</li>

	<li><p>Go back into the LLVM source tree proper. Rerun configure, using
	the same options as the last time. This will cause the configuration to now find
	the newly built llvm-gcc and llvm-g++ executables. </p></li>

	<li><p>Rebuild your CVS tree. This shouldn't cause the whole thing to be
	rebuilt, but it should build the runtime libraries. After the tree is
	built, install the runtime libraries into your GCC front-end build tree.
	These are the commands you need:</p>
	<pre>
	% gmake
	% gmake -C runtime install-bytecode
	</pre></li>

	<li><p>Optionally, build a symbol table for the newly installed runtime
	libraries. Although this step is optional, you are strongly encouraged to
	do this as the symbol tables will make a significant difference in your
	link times. Use the <tt>llvm-ranlib</tt> tool to do this, as follows:</p>
	<pre>
	% cd $CFEINSTALL/lib
	% llvm-ranlib libiberty.a
	% llvm-ranlib libstdc++.a
	% llvm-ranlib libsupc++.a
	% cd $CFEINSTALL/lib/gcc/<i>target-triplet</i>/3.4-llvm
	% llvm-ranlib libgcc.a
	% llvm-ranlib libgcov.a
	</pre>

	<li><p>Test the newly-installed C frontend by one or more of the
	following means:</p>
	<ul>
	<li> running the feature & regression tests via <tt>make check</tt></li>
	<li> compiling and running a "hello, LLVM" program in C and C++.</li>
	<li> running the tests found in the <tt>llvm-test</tt> CVS module</li>
	</ul></li>
	</ol>
	</div>

	<!-- *********************************************************************** -->
	<div class="doc_section">
	<a name="license">License Information</a>
	</div>

	<div class="doc_text">
	<p>
	The LLVM GCC frontend is licensed to you under the GNU General Public License
	and the GNU Lesser General Public License. Please see the files COPYING and
	COPYING.LIB for more details.
	</p>

	<p>
	More information is <a href="FAQ.html#license">available in the FAQ</a>.
	</p>
	</pre>
	</div>

	<!-- *********************************************************************** -->

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