-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<!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>
+ <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
+ <link rel="stylesheet" href="llvm.css" type="text/css" media="screen">
+ <title>Building the LLVM C/C++ Front-End</title>
</head>
<body>
<div class="doc_title">
- Bootstrapping the LLVM C/C++ Front-End
+ Building the LLVM C/C++ Front-End
</div>
<ol>
- <li><a href="#cautionarynote">A Cautionary Note</a>
- <li><a href="#instructions">Instructions</a>
- <li><a href="#license">License Information</a>
+ <li><a href="#instructions">Building llvm-gcc 4 from Source</a></li>
+ <li><a href="#license">License Information</a></li>
</ol>
-<div class="doc_text">
- <p><b>Written by Brian R. Gaeke</b></p>
+<div class="doc_author">
+ <p>Written by the LLVM Team</p>
</div>
<!-- *********************************************************************** -->
<div class="doc_section">
- <a name="cautionarynote">A Cautionary Note</a>
+ <a name="instructions">Building llvm-gcc 4 from Source</a>
</div>
<!-- *********************************************************************** -->
<div class="doc_text">
-<p>This document is intended to explain the process of building the
-LLVM C/C++ front-end, based on GCC 3.4, from its source code. You
-would have to do this, for example, if you are porting LLVM to a new
-architecture or operating system.</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>
+<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 (and much easier!) than those for building llvm-gcc3 in
+the past.</p>
<ol>
- <li>you really, really, really can't use the binaries we distribute</li>
- <li>you need GCC to fix some of the header files on your system</li>
- <li>you are an elite GCC hacker.</li>
-</ol>
-
-<p>We welcome patches to help make this process simpler.</p>
-</div>
-
-<!-- *********************************************************************** -->
-<div class="doc_section">
- <a name="instructions">Instructions</a>
-</div>
-<!-- *********************************************************************** -->
-
-<div class="doc_text">
-<p>
-<ol>
-<li><p>Configure and build the LLVM libraries and tools using:</p>
-<pre>
- % cd llvm
- % ./configure [options...]
- % gmake tools-only
-</pre>
- <p>The use of the non-default target "tools-only" means that the
- LLVM tools and libraries will build, and the binaries will be
- deposited in llvm/tools/Debug, but the runtime (bytecode)
- libraries will not build.</p></li>
-
-<li><p>Add the directory containing the tools to your PATH.</p>
-<pre>
- % set path = ( `cd llvm/tools/Debug && pwd` $path )
-</pre></li>
-
-<li><p>Unpack the C/C++ front-end source into cfrontend/src.</p></li>
-
-<li><p>Edit src/configure. Change the first line (starting w/ #!) to
- contain the correct full pathname of sh.</p></li>
-
-<li><p>Make "build" and "install" directories as siblings of the "src"
- tree.</p>
-<pre>
- % pwd
- /usr/local/example/cfrontend/src
- % cd ..
- % mkdir build install
- % set CFEINSTALL = `pwd`/install
-</pre></li>
-
-<li><p>Configure, build, and install the C front-end:</p>
-
-<p>
-<b>Linux/x86:</b>
-</p>
-
-<pre>
- % cd build
- % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls --disable-shared \
- --enable-languages=c,c++
- % gmake all-gcc
- % setenv LLVM_LIB_SEARCH_PATH `pwd`/gcc
- % gmake all; gmake install
-</pre>
-
-<p>
-<b>Solaris/Sparc:</b>
-</p>
+ <li><p>Retrieve the appropriate llvm-gcc4-x.y.source.tar.gz archive from the
+ <a href="http://llvm.org/releases/">llvm web site</a>.</p>
-<p>
-For Solaris/Sparc, LLVM only supports SparcV9. Therefore, the configure
-command line should like something like this:
-</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>
+<div class="doc_code">
<pre>
- % cd build
- % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls --disable-shared \
- --enable-languages=c,c++ --host=sparcv9-sun-solaris2.8
- % gmake all-gcc
- % setenv LLVM_LIB_SEARCH_PATH `pwd`/gcc
- % gmake all
+svn co svn://anonsvn.opensource.apple.com/svn/llvm/trunk <i>dst-directory</i>
</pre>
+</div>
-<p>
-At this point, libstdc++ may fail to build because of wchar errors (look for
-errors that reference <tt>vfwscanf</tt> or <tt>wcstof</tt>). If that happens,
-edit <tt>sparcv9-sun-solaris2.8/libstdc++-v3/config.h</tt> and comment out the
-line that defines <tt>_GLIBCXX_USE_WCHAR_T</tt>.
-</p>
-
-<p>
-Then, continue as below:
-</p>
-
-<pre>
- % gmake all
- % gmake install
-</pre>
-
- <p><b>Common Problem:</b> You may get error messages regarding the fact
- that LLVM does not support inline assembly. Here are two common
- fixes:</p>
-
- <ul>
- <li><p><b>Fix 1:</b> If you have system header files that include
- inline assembly, you may have to modify them to remove the inline
- assembly, and install the modified versions in
- <code>$CFEINSTALL/<i>target-triplet</i>/sys-include</code>.</p></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.</p></li>
- </ul>
-
- <p><b>Porting to a new architecture:</b> If you are porting the new front-end
- to a new architecture, or compiling in a different configuration that we have
- 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 or assembler 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>Go back into the LLVM source tree proper. Edit Makefile.config
-to redefine <code>LLVMGCCDIR</code> to the full pathname of the
-<code>$CFEINSTALL</code> directory, which is the directory you just
-installed the C front-end into. (The ./configure script is likely to
-have set this to a directory which does not exist on your system.)</p></li>
+ <p>After that, the code can be be updated in the destination directory
+ using:</p>
-<li><p>If you edited header files during the C/C++ front-end build as
-described in "Fix 1" above, you must now copy those header files from
-<code>$CFEINSTALL/<i>target-triplet</i>/sys-include</code> to
-<code>$CFEINSTALL/lib/gcc/<i>target-triplet</i>/3.4-llvm/include</code>.
-(This should be the "include" directory in the same directory as the
-libgcc.a library, which you can find by running
-<code>$CFEINSTALL/bin/gcc --print-libgcc-file-name</code>.)</p></li>
+<div class="doc_code">
+<pre>svn update</pre>
+</div>
-<li><p>Build and install the runtime (bytecode) libraries by running:</p>
-<pre>
- % gmake -C runtime
- % mkdir $CFEINSTALL/bytecode-libs
- % gmake -C runtime install
- % setenv LLVM_LIB_SEARCH_PATH $CFEINSTALL/bytecode-libs
-</pre></li>
+ <p>The mirror is brought up to date every evening.</p></li>
-<li><p>Test the newly-installed C frontend by one or more of the
-following means:</p>
- <ul>
- <li> compiling and running a "hello, LLVM" program in C and C++.</li>
- <li> running the tests under <tt>test/Programs</tt> using <code>gmake -C
- test/Programs</code></li>
- </ul>
- </p>
-</li>
+ <li>Follow the directions in the top-level <tt>README.LLVM</tt> file for
+ up-to-date instructions on how to build llvm-gcc4.</li>
</ol>
-</div>
+</div>
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="license">License Information</a>
</p>
<p>
-The software also has the following additional copyrights:
+More information is <a href="FAQ.html#license">available in the FAQ</a>.
</p>
-
-<pre>
-Copyright (c) 1994
-Hewlett-Packard Company
-
-Permission to use, copy, modify, distribute and sell this software
-and its documentation for any purpose is hereby granted without fee,
-provided that the above copyright notice appear in all copies and
-that both that copyright notice and this permission notice appear
-in supporting documentation. Hewlett-Packard Company makes no
-representations about the suitability of this software for any
-purpose. It is provided "as is" without express or implied warranty.
-
-Copyright (c) 1996, 1997, 1998, 1999
-Silicon Graphics Computer Systems, Inc.
-
-Permission to use, copy, modify, distribute and sell this software
-and its documentation for any purpose is hereby granted without fee,
-provided that the above copyright notice appear in all copies and
-that both that copyright notice and this permission notice appear
-in supporting documentation. Silicon Graphics makes no
-representations about the suitability of this software for any
-purpose. It is provided "as is" without express or implied warranty.
-</pre>
</div>
-<!-- *********************************************************************** -->
<!-- *********************************************************************** -->
<hr>
-<div class="doc_footer">
- <address>Brian Gaeke</address>
- <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a>
- <br>
+<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>
+ <a href="http://validator.w3.org/check/referer"><img
+ src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
+
+ <a href="http://llvm.org">LLVM Compiler Infrastructure</a><br>
Last modified: $Date$
-</div>
+</address>
</body>
</html>