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| <title>Bootstrapping the LLVM C/C++ Front-End</title> |
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| |
| <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">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 <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">Instructions</a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| <p> |
| <ol> |
| <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=$CFEINSTALL --disable-threads --disable-nls \ |
| --disable-shared --enable-languages=c,c++ --disable-c-mbchar \ |
| --program-prefix=llvm- |
| % gmake all; gmake install |
| </pre> |
| |
| <p><b>Solaris/SPARC:</b></p> |
| |
| <p> |
| The GCC front-end can be configured for either SPARC V8 (32 bit) or SPARC V9 (64 |
| bit). This changes, among other things, the sizes of integer types and the |
| macros defined for conditional compilation. |
| </p> |
| |
| <p> |
| The SPARC V8 backend is still beta quality software. Unless you are working on |
| the SPARC V8 backend, you should specify sparcv9 on the configure command line, |
| as shown below. Also, |
| note that Solaris has trouble with various wide (multibyte) character |
| functions from C as referenced from C++, so we typically configure with |
| --disable-c-mbchar (cf. <a href="http://llvm.cs.uiuc.edu/PR206">Bug 206</a>). |
| </p> |
| |
| <pre> |
| % cd build |
| % ../src/configure --prefix=$CFEINSTALL --disable-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> |
| |
| <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> |
| The software also has the following additional copyrights: |
| </p> |
| |
| <pre> |
| |
| Copyright (c) 2003, 2004, 2005 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> |
| |
| <!-- *********************************************************************** --> |
| |
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| <address> |
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| <a href="http://llvm.cs.uiuc.edu">LLVM Compiler Infrastructure</a><br> |
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