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| <title>Building the LLVM GCC Front-End</title> |
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| |
| <div class="doc_title"> |
| Building the LLVM GCC Front-End |
| </div> |
| |
| <ol> |
| <li><a href="#instructions">Building llvm-gcc from Source</a></li> |
| <li><a href="#license">License Information</a></li> |
| </ol> |
| |
| <div class="doc_author"> |
| <p>Written by the LLVM Team</p> |
| </div> |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="instructions">Building llvm-gcc from Source</a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| |
| <p>This section describes how to acquire and build llvm-gcc 4.0 and 4.2, which are |
| based on the GCC 4.0.1/4.2.1 front-ends respectively. Both front-ends support C, |
| C++, Objective-C and Objective-C++. The 4.2 front-end also supports Ada and |
| Fortran to some extent. Note that the instructions for building these front-ends |
| are completely different (and much easier!) than those for building llvm-gcc3 in |
| the past.</p> |
| |
| <ol> |
| <li><p>Retrieve the appropriate llvm-gcc4.x-y.z.source.tar.gz archive from the |
| <a href="http://llvm.org/releases/">llvm web site</a>.</p> |
| |
| <p>It is also possible to download the sources of the llvm-gcc front end |
| from a read-only mirror using subversion. To check out the 4.0 code |
| for first time use:</p> |
| |
| <div class="doc_code"> |
| <pre> |
| svn co http://llvm.org/svn/llvm-project/llvm-gcc-4.0/trunk <i>dst-directory</i> |
| </pre> |
| </div> |
| |
| <p>To check out the 4.2 code use:</p> |
| |
| <div class="doc_code"> |
| <pre> |
| svn co http://llvm.org/svn/llvm-project/llvm-gcc-4.2/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-gcc. See below for building |
| with support for Ada or Fortran. |
| </ol> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="license">Building the Ada front-end</a> |
| </div> |
| |
| <div class="doc_text"> |
| <p>Building with support for Ada amounts to following the directions in the |
| top-level <tt>README.LLVM</tt> file, adding ",ada" to EXTRALANGS, for example: |
| <tt>EXTRALANGS=,ada</tt></p> |
| |
| <p>There are some complications however:</p> |
| |
| <ol> |
| <li><p>The only platform for which the Ada front-end is known to build is |
| 32 bit intel x86 running linux. It is unlikely to build for other |
| systems without some work.</p></li> |
| <li><p>The build requires having a compiler that supports Ada, C and C++. |
| The Ada front-end is written in Ada so an Ada compiler is needed to |
| build it. Compilers known to work with the |
| <a href="http://llvm.org/releases/download.html">LLVM 2.2 release</a> |
| are <a href="http://gcc.gnu.org/releases.html">gcc-4.2</a> and the |
| <a href="http://libre.adacore.com/">2005 GNAT GPL Edition</a>. |
| <a href="GettingStarted.html#checkout">LLVM from subversion</a> |
| also works with the |
| <a href="http://libre.adacore.com/">2006 and 2007 GNAT GPL Editions</a>. |
| The LLVM parts of llvm-gcc are written in C++ so a C++ compiler is |
| needed to build them. The rest of gcc is written in C. |
| Some linux distributions provide a version of gcc that supports all |
| three languages (the Ada part often comes as an add-on package to |
| the rest of gcc). Otherwise it is possible to combine two versions |
| of gcc, one that supports Ada and C (such as the |
| <a href="http://libre.adacore.com/">2005 GNAT GPL Edition</a>) |
| and another which supports C++, see below.</p></li> |
| <li><p>Because the Ada front-end is experimental, it is wise to build the |
| compiler with checking enabled. This causes it to run much slower, but |
| helps catch mistakes in the compiler (please report any problems using |
| <a href="http://llvm.org/bugs">LLVM bugzilla</a>).</p></li> |
| </ol> |
| |
| <p>Supposing appropriate compilers are available, llvm-gcc with Ada support can |
| be built on an x86-32 linux box using the following recipe:</p> |
| |
| <ol> |
| <li><p>Download the <a href="http://llvm.org/releases/download.html">LLVM source</a> |
| and unpack it:</p> |
| |
| <div class="doc_code"> |
| <pre>wget http://llvm.org/releases/2.2/llvm-2.2.tar.gz |
| tar xzf llvm-2.2.tar.gz |
| mv llvm-2.2 llvm</pre> |
| </div> |
| |
| <p>or <a href="GettingStarted.html#checkout">check out the |
| latest version from subversion</a>:</p> |
| |
| <div class="doc_code"> |
| <pre>svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm</pre> |
| </div> |
| </li> |
| |
| <li><p>Download the |
| <a href="http://llvm.org/releases/download.html">llvm-gcc-4.2 source</a> |
| and unpack it:</p> |
| |
| <div class="doc_code"> |
| <pre>wget http://llvm.org/releases/2.2/llvm-gcc4.2-2.2.source.tar.gz |
| tar xzf llvm-gcc4.2-2.2.source.tar.gz |
| mv llvm-gcc4.2-2.2.source llvm-gcc-4.2</pre> |
| </div> |
| |
| <p>or <a href="GettingStarted.html#checkout">check out the |
| latest version from subversion</a>:</p> |
| |
| <div class="doc_code"> |
| <pre>svn co http://llvm.org/svn/llvm-project/llvm-gcc-4.2/trunk llvm-gcc-4.2</pre> |
| </div> |
| </li> |
| |
| <li><p>Make a build directory <tt>llvm-objects</tt> for llvm and make it the |
| current directory:</p> |
| |
| <div class="doc_code"> |
| <pre>mkdir llvm-objects |
| cd llvm-objects</pre> |
| </div> |
| </li> |
| |
| <li><p>Configure LLVM (here it is configured to install into <tt>/usr/local</tt>):</p> |
| |
| <div class="doc_code"> |
| <pre>../llvm/configure --prefix=<b>/usr/local</b></pre> |
| </div> |
| |
| <p>If you have a multi-compiler setup and the C++ compiler is not the |
| default, then you can configure like this:</p> |
| |
| <div class="doc_code"> |
| <pre>CXX=<b>PATH_TO_C++_COMPILER</b> ../llvm/configure --prefix=<b>/usr/local</b></pre> |
| </div> |
| </li> |
| |
| <li><p>Build LLVM with checking enabled (use <tt>ENABLE_OPTIMIZED=1</tt> to |
| build without checking):</p> |
| |
| <div class="doc_code"> |
| <pre>make ENABLE_OPTIMIZED=0</pre> |
| </div> |
| </li> |
| |
| <li><p>Install LLVM (optional):</p> |
| |
| <div class="doc_code"> |
| <pre>make install</pre> |
| </div> |
| </li> |
| |
| <li><p>Make a build directory <tt>llvm-gcc-4.2-objects</tt> for llvm-gcc and make it the |
| current directory:</p> |
| |
| <div class="doc_code"> |
| <pre> |
| cd .. |
| mkdir llvm-gcc-4.2-objects |
| cd llvm-gcc-4.2-objects</pre> |
| </div> |
| </li> |
| |
| <li><p>Configure llvm-gcc (here it is configured to install into <tt>/usr/local</tt>). |
| The <tt>--enable-checking</tt> flag turns on sanity checks inside the compiler. |
| If you omit it then LLVM must be built with <tt>make ENABLE_OPTIMIZED=1</tt>. |
| Additional languages can be appended to the --enable-languages switch, |
| for example <tt>--enable-languages=ada,c,c++</tt>.</p> |
| |
| <div class="doc_code"> |
| <pre>../llvm-gcc-4.2/configure --prefix=<b>/usr/local</b> --enable-languages=ada,c --enable-checking --enable-llvm=$PWD/../llvm-objects --disable-shared --disable-bootstrap --disable-multilib</pre> |
| </div> |
| |
| <p>If you have a multi-compiler setup, then you can configure like this:</p> |
| <div class="doc_code"> |
| |
| <pre> |
| export CC=<b>PATH_TO_C_AND_ADA_COMPILER</b> |
| export CXX=<b>PATH_TO_C++_COMPILER</b> |
| ../llvm-gcc-4.2/configure --prefix=<b>/usr/local</b> --enable-languages=ada,c --enable-checking --enable-llvm=$PWD/../llvm-objects --disable-shared --disable-bootstrap --disable-multilib</pre> |
| </div> |
| </li> |
| |
| <li><p>Build and install the compiler:</p> |
| |
| <div class="doc_code"> |
| <pre>make |
| make install</pre> |
| </div> |
| </li> |
| </ol> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="license">Building the Fortran front-end</a> |
| </div> |
| |
| <div class="doc_text"> |
| <p> |
| To build with support for Fortran, follow the directions in the top-level |
| <tt>README.LLVM</tt> file, adding ",fortran" to EXTRALANGS, for example:</p> |
| |
| <div class="doc_code"> |
| <pre> |
| EXTRALANGS=,fortran |
| </pre> |
| </div> |
| |
| </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> |
| </div> |
| |
| <!-- *********************************************************************** --> |
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