-<!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" />
+ <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>
<ol>
<li><a href="#cautionarynote">A Cautionary Note</a>
- <li><a href="#instructions">Instructions</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_text">
- <p><b>Written by Brian R. Gaeke</b></p>
+<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_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 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 need GCC to fix some of the header files on your system</li>
+ <li>you really, <em>really</em>, <b><em>really</em></b> 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 <em>strongly</em> 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>
+
+<div class="doc_code">
+<pre>GNU ld version 2.15</pre>
+</div>
+
+<p>not with:</p>
+
+<div class="doc_code">
+<pre>GNU ld version 2.15.91 20040725</pre>
+</div>
+
+</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">Instructions</a>
+ <a name="instructions">llvm-gcc4 Instructions</a>
</div>
<!-- *********************************************************************** -->
<div class="doc_text">
-<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 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>
+
+<div class="doc_code">
+<pre>
+svn co svn://anonsvn.opensource.apple.com/svn/llvm/trunk <i>dst-directory</i>
+</pre>
+</div>
+
+ <p>After that, the code can be be updated in the destination directory
+ using:</p>
+
+<div class="doc_code">
+<pre>svn update</pre>
+</div>
+
+ <p>The mirror is brought up to date every evening.</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 class="doc_section">
+ <a name="llvm-gcc3-instructions">llvm-gcc3 Instructions</a>
+</div>
+<!-- *********************************************************************** -->
+
+<div class="doc_text">
+
<ol>
-<li><p>Configure and build the LLVM libraries and tools using:</p>
+ <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 <tt><i>objdir</i> == <i>srcdir</i></tt> or
+ <tt><i>objdir</i> != <i>srcdir</i></tt>. It is recommended that
+ <tt><i>srcdir</i></tt> be the same as <tt><i>objdir</i></tt> for your
+ LLVM tree (but note that you should always use <tt><i>srcdir</i> !=
+ <i>objdir</i></tt> for llvm-gcc):</p>
+
+ <ul>
+ <li><p>With <tt><i>objdir</i> != <i>srcdir</i></tt>:</p>
+
+<div class="doc_code">
+<pre>
+% cd <i>objdir</i>
+% <i>srcdir</i>/configure --prefix=/some/path/you/can/install/to [options...]
+% gmake tools-only
+</pre>
+</div>
+ </li>
+ <li><p>With <tt><i>objdir</i> == <i>srcdir</i></tt>:</p>
+
+<div class="doc_code">
+<pre>
+% cd llvm
+% ./configure --prefix=/some/path/you/can/install/to [options...]
+% gmake tools-only
+</pre>
+</div>
+ </li>
+ </ul>
+
+ <p>This will build all of the LLVM tools and libraries. The
+ <tt>--prefix</tt> option defaults to <tt>/usr/local</tt> (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>
+
+<div class="doc_code">
+csh:
+<pre>
+ % set path = ( `cd llvm/Debug/bin && pwd` $path )
+</pre>
+sh:
<pre>
- % cd llvm
- % ./configure [options...]
- % gmake tools-only
+ % export PATH=`cd llvm/Debug/bin && pwd`:$PATH
</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>
+</div>
+ </li>
+
+ <li><p>Unpack the C/C++ front-end source, either by
+ untar'ing/unzipping a 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>
-<li><p>Add the directory containing the tools to your PATH.</p>
+<div class="doc_code">
+csh:
<pre>
- % set path = ( `cd llvm/tools/Debug && pwd` $path )
-</pre></li>
+ % pwd
+ /usr/local/example/llvm-gcc3.4/src
+ % cd ..
+ % mkdir build install
+ % set CFEINSTALL = `pwd`/install
+</pre>
+sh:
+<pre>
+ % pwd
+ /usr/local/example/llvm-gcc3.4/src
+ % cd ..
+ % mkdir build install
+ % export CFEINSTALL=`pwd`/install
+</pre>
+</div>
+ </li>
-<li><p>Unpack the C/C++ front-end source into cfrontend/src.</p></li>
+ <li><p>Configure, build, and install the GCC front-end:</p>
-<li><p>Edit src/configure. Change the first line (starting w/ #!) to
- contain the correct full pathname of sh.</p></li>
+ <p>
+ <b>Linux/x86:</b><br>
+ <b>Linux/IA-64:</b><br>
+ <b>MacOS X/PowerPC</b> (requires dlcompat library):<br>
+ <b>AIX/PowerPC:</b>
+ </p>
-<li><p>Make "build" and "install" directories as siblings of the "src"
- tree.</p>
+<div class="doc_code">
<pre>
- % pwd
- /usr/local/example/cfrontend/src
- % cd ..
- % mkdir build install
- % set CFEINSTALL = `pwd`/install
-</pre></li>
+% cd build
+% ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
+ --disable-shared --enable-languages=c,c++ --program-prefix=llvm-
+% gmake all; gmake install
+</pre>
+</div>
-<li><p>Configure, build and install the C front-end:</p>
+ <p><b>Cygwin/x86:</b></p>
-<p>
-<b>Linux/x86:</b>
-</p>
+<div class="doc_code">
+<pre>
+% cd build
+% ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
+ --disable-shared --enable-languages=c,c++ --disable-c-mbchar \
+ --program-prefix=llvm-
+% gmake all; gmake install
+</pre>
+</div>
+
+ <p><b>Solaris/SPARC:</b></p>
+
+ <p>The GCC front-end can be configured for either SPARC V8 (32 bit) or
+ SPARC V9 (64 bit). This changes, among other things, the sizes of
+ integer types and the macros defined for conditional compilation.</p>
+
+ <p>The SPARC V8 ABI support is more robust than the V9 ABI support and can
+ generate SPARC V9 code. It is highly recommended that you use the V8
+ ABI with LLVM, as shown below. Also, note that Solaris has trouble
+ with various wide (multibyte) character functions from C as referenced
+ from C++, so we typically configure with --disable-c-mbchar (cf. <a
+ href="http://llvm.org/PR206">Bug 206</a>).</p>
+<div class="doc_code">
<pre>
- % cd build
- % ../src/configure --prefix=$CFEINSTALL --disable-nls --disable-shared \
- --enable-languages=c,c++
- % gmake all-gcc
- % setenv LLVM_LIB_SEARCH_PATH `pwd`/gcc
- % gmake all; gmake install
+% cd build
+% ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
+ --disable-shared --enable-languages=c,c++ --host=sparc-sun-solaris2.8 \
+ --disable-c-mbchar --program-prefix=llvm-
+% gmake all; gmake install
</pre>
+</div>
-<p>
-<b>Solaris/Sparc:</b>
-</p>
+ <p><b>Common Problem:</b> You may get error messages regarding the fact
+ that LLVM does not support inline assembly. Here are two common
+ fixes:</p>
+
+ <ul>
+ <li><p><b>Fix 1:</b> If you have system header files that include inline
+ assembly, you may have to modify them to remove the inline assembly
+ and install the modified versions in
+ <code>$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>
+
+<div class="doc_code">
+csh:
+<pre>
+ % setenv PATH $CFEINSTALL/bin:$PATH
+</pre>
+sh:
+<pre>
+ % export PATH=$CFEINSTALL/bin:$PATH
+</pre>
+</div>
+ </li>
-<p>
-For Solaris/Sparc, LLVM only supports SparcV9. Therefore, the configure
-command line should like something like this:
-</p>
+ <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>
+
+<div class="doc_code">
<pre>
- % cd build
- % ../src/configure --prefix=$CFEINSTALL --disable-nls --disable-shared \
- --enable-languages=c,c++ --host=sparcv9-sun-solaris2.8
- % gmake all-gcc
- % setenv LLVM_LIB_SEARCH_PATH `pwd`/gcc
- % gmake all; gmake install
+% gmake
+% gmake -C runtime install-bytecode
</pre>
+</div>
+ </li>
+
+ <li><p>Optionally, build a symbol table for the newly installed runtime
+ libraries. Although this step is optional, you are strongly encouraged to
+ do this as the symbol tables will make a significant difference in your
+ link times. Use the <tt>llvm-ranlib</tt> tool to do this, as follows:</p>
- <p><b>Common Problem:</b> You may get error messages regarding the fact
- that LLVM does not support inline assembly. Here are two common
- fixes:</p>
-
- <ul>
- <li><p><b>Fix 1:</b> If you have system header files that include
- inline assembly, you may have to modify them to remove the inline
- assembly, and install the modified versions in
- <code>$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>$CFEINSTALL</code> directory, which is the directory you just
-installed the C front-end into. (The ./configure script is likely to
-have set this to a directory which does not exist on your system.)</p></li>
-
-<li><p>If you edited header files during the C/C++ front-end build as
-described in "Fix 1" above, you must now copy those header files from
-<code>$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>
-
-<li><p>Build and install the runtime (bytecode) libraries by running:</p>
+<div class="doc_code">
<pre>
- % gmake -C runtime
- % mkdir $CFEINSTALL/bytecode-libs
- % gmake -C runtime install
- % setenv LLVM_LIB_SEARCH_PATH $CFEINSTALL/bytecode-libs
-</pre></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>
+% 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>
+</div>
+ </li>
+
+ <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>
<!-- *********************************************************************** -->
<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>
+
+ Brian Gaeke<br>
+ <a href="http://llvm.org">LLVM Compiler Infrastructure</a><br>
Last modified: $Date$
-</div>
+</address>
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