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<div class="doc_title">
- Bootstrapping the C/C++ Front-End
+ Bootstrapping the LLVM C/C++ Front-End
</div>
-<p>This document is intended to explain the process of building the LLVM
-C/C++ front-end, based on GCC 3.4, from source.</p>
+<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">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, 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 only try to do it if (A) you really, really,
-really can't use the binaries we distribute, and (B) you are a wicked
-good GCC hacker.</p>
+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 CFE 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 LLVM CFE. 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">
<div class="doc_text">
<p>
<ol>
-<li><p>Configure and build the LLVM libraries and tools using:</p>
-<pre>
+<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 not. It is recommended
+that <i>srcdir</i> not be the same as <i>objdir</i>:</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 [options...]
+ % ./configure --prefix=/some/path/you/can/install/to [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>
+ </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/tools/Debug && pwd` $path )
+ % set path = ( `cd llvm/Debug/bin && pwd` $path )
</pre></li>
-<li><p>Unpack the C/C++ front-end source into cfrontend/src.</p></li>
-
-<li><p>Edit src/configure. Change the first line (starting w/ #!) to
- contain the correct full pathname of sh.</p></li>
+<li><p>Unpack the C/C++ front-end source into cfrontend/src, either by
+ untar'ing an llvm-gcc.tar.gz file or checking out CVS into this
+ directory.</p></li>
-<li><p>Make "build" and "install" directories as siblings of the "src"
- tree.</p>
+<li><p>Make "build" and "install" directories as siblings of the "src" tree.</p>
<pre>
% pwd
/usr/local/example/cfrontend/src
% set CFEINSTALL = `pwd`/install
</pre></li>
-<li><p>Configure, build and install the C front-end:</p>
+
+<li><p>Configure, build, and install the GCC front-end:</p>
+
+<p>
+<b>Linux/x86:</b><br>
+<b>MacOS X/PowerPC</b> (requires dlcompat library):<br>
+<b>AIX/PowerPC:</b>
+</p>
+
+<pre>
+ % cd build
+ % ../src/configure --prefix=$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=$CFEINSTALL --disable-threads --disable-nls \
+ --disable-shared --enable-languages=c,c++ --disable-c-mbchar \
+ --program-prefix=llvm-
+ % gmake all; gmake install
+</pre>
+
+<p><b>Solaris/SPARC:</b></p>
+
+<p>
+For Solaris/SPARC, LLVM only supports the SPARC V9 architecture. Therefore,
+the configure command line should specify sparcv9, as shown below. Also,
+note that Solaris has trouble with various wide (multibyte) character
+functions from C as referenced from C++, so we typically configure with
+--disable-c-mbchar (cf. <a href="http://llvm.cs.uiuc.edu/PR206">Bug 206</a>).
+</p>
+
<pre>
% cd build
- % ../src/configure --prefix=$CFEINSTALL --disable-nls --disable-shared \
- --enable-languages=c,c++
- % gmake all-gcc
- % setenv LLVM_LIB_SEARCH_PATH `pwd`/gcc
+ % ../src/configure --prefix=$CFEINSTALL --disable-threads --disable-nls \
+ --disable-shared --enable-languages=c,c++ --host=sparcv9-sun-solaris2.8 \
+ --disable-c-mbchar --program-prefix=llvm-
% gmake all; gmake install
</pre>
<ul>
<li><p><b>Fix 1:</b> If you have system header files that include
inline assembly, you may have to modify them to remove the inline
- assembly, and install the modified versions in
- <code>$CFEINSTALL/<i>target-triplet</i>/sys-include</code>.</p></li>
+ 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.</p></li>
+ 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 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>
+ <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 or assembler linker flags which
+ <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
<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>$CFEINSTALL/bin/gcc --print-libgcc-file-name</code>.)</p></li>
-
-<li><p>Build and install the runtime (bytecode) libraries by running:</p>
+<li><p>Put <tt>$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 -C runtime
- % mkdir $CFEINSTALL/bytecode-libs
- % gmake -C runtime install
- % setenv LLVM_LIB_SEARCH_PATH $CFEINSTALL/bytecode-libs
+ % 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 under <tt>test/Programs</tt> using <code>gmake -C
- test/Programs</code></li>
- </ul>
- </p>
-</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>
+The software also has the following additional copyrights:
+</p>
+
+<pre>
+
+Copyright (c) 2003, 2004 University of Illinois at Urbana-Champaign.
+All rights reserved.
+
+Developed by:
+
+ LLVM Team
+
+ University of Illinois at Urbana-Champaign
+
+ http://llvm.cs.uiuc.edu
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
+SOFTWARE.
+
+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>
+<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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+ src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
-<hr><font size="-1">
-<address><a href="mailto:gaeke -at- uiuc.edu">Brian Gaeke</a></address>
-Last modified: $Date$
-</font>
+ Brian Gaeke<br>
+ <a href="http://llvm.cs.uiuc.edu">LLVM Compiler Infrastructure</a><br>
+ Last modified: $Date$
+</address>
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