docs/GettingStarted.html

   1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
   2                       "http://www.w3.org/TR/html4/strict.dtd">
   3 <html>
   4 <head>
   5   <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
   6   <title>Getting Started with LLVM System</title>
   7   <link rel="stylesheet" href="llvm.css" type="text/css">
   8 </head>
   9 <body>
  10
  11 <div class="doc_title">
  12   Getting Started with the LLVM System
  13 </div>
  14
  15 <ul>
  16   <li><a href="#overview">Overview</a>
  17   <li><a href="#quickstart">Getting Started Quickly (A Summary)</a>
  18   <li><a href="#requirements">Requirements</a>
  19     <ol>
  20       <li><a href="#hardware">Hardware</a>
  21       <li><a href="#software">Software</a>
  22       <li><a href="#brokengcc">Broken versions of GCC</a>
  23     </ol></li>
  24
  25   <li><a href="#starting">Getting Started with LLVM</a>
  26     <ol>
  27       <li><a href="#terminology">Terminology and Notation</a>
  28       <li><a href="#environment">Setting Up Your Environment</a>
  29       <li><a href="#unpack">Unpacking the LLVM Archives</a>
  30       <li><a href="#checkout">Checkout LLVM from CVS</a>
  31       <li><a href="#installcf">Install the GCC Front End</a>
  32       <li><a href="#config">Local LLVM Configuration</a>
  33       <li><a href="#compile">Compiling the LLVM Suite Source Code</a>
  34       <li><a href="#cross-compile">Cross-Compiling LLVM</a>
  35       <li><a href="#objfiles">The Location of LLVM Object Files</a>
  36       <li><a href="#optionalconfig">Optional Configuration Items</a>
  37     </ol></li>
  38
  39   <li><a href="#layout">Program layout</a>
  40     <ol>
  41       <li><a href="#cvsdir"><tt>CVS</tt> directories</a>
  42       <li><a href="#examples"><tt>llvm/examples</tt></a>
  43       <li><a href="#include"><tt>llvm/include</tt></a>
  44       <li><a href="#lib"><tt>llvm/lib</tt></a>
  45       <li><a href="#projects"><tt>llvm/projects</tt></a>
  46       <li><a href="#runtime"><tt>llvm/runtime</tt></a>
  47       <li><a href="#test"><tt>llvm/test</tt></a>
  48       <li><a href="#llvmtest"><tt>llvm-test</tt></a>
  49       <li><a href="#tools"><tt>llvm/tools</tt></a>
  50       <li><a href="#utils"><tt>llvm/utils</tt></a>
  51       <li><a href="#win32"><tt>llvm/win32</tt></a>
  52     </ol></li>
  53
  54   <li><a href="#tutorial">An Example Using the LLVM Tool Chain</a>
  55       <ol>
  56          <li><a href="#tutorial4">Example with llvm-gcc4</a></li>
  57       </ol>
  58   <li><a href="#problems">Common Problems</a>
  59   <li><a href="#links">Links</a>
  60 </ul>
  61
  62 <div class="doc_author">
  63   <p>Written by:
  64     <a href="mailto:criswell@uiuc.edu">John Criswell</a>,
  65     <a href="mailto:sabre@nondot.org">Chris Lattner</a>,
  66     <a href="http://misha.brukman.net">Misha Brukman</a>,
  67     <a href="http://www.cs.uiuc.edu/~vadve">Vikram Adve</a>, and
  68     <a href="mailto:gshi1@uiuc.edu">Guochun Shi</a>.
  69   </p>
  70 </div>
  71
  72
  73 <!-- *********************************************************************** -->
  74 <div class="doc_section">
  75   <a name="overview"><b>Overview</b></a>
  76 </div>
  77 <!-- *********************************************************************** -->
  78
  79 <div class="doc_text">
  80
  81 <p>Welcome to LLVM! In order to get started, you first need to know some
  82 basic information.</p>
  83
  84 <p>First, LLVM comes in two pieces. The first piece is the LLVM suite. This
  85 contains all of the tools, libraries, and header files needed to use the low
  86 level virtual machine.  It contains an assembler, disassembler, bytecode
  87 analyzer and bytecode optimizer.  It also contains a test suite that can be
  88 used to test the LLVM tools and the GCC front end.</p>
  89
  90 <p>The second piece is the GCC front end.  This component provides a version of
  91 GCC that compiles C and C++ code into LLVM bytecode.  Currently, the GCC front
  92 end uses the GCC parser to convert code to LLVM.  Once
  93 compiled into LLVM bytecode, a program can be manipulated with the LLVM tools
  94 from the LLVM suite.</p>
  95
  96 <p>
  97 There is a third, optional piece called llvm-test.  It is a suite of programs
  98 with a testing harness that can be used to further test LLVM's functionality
  99 and performance.
 100 </p>
 101
 102 </div>
 103
 104 <!-- *********************************************************************** -->
 105 <div class="doc_section">
 106   <a name="quickstart"><b>Getting Started Quickly (A Summary)</b></a>
 107 </div>
 108 <!-- *********************************************************************** -->
 109
 110 <div class="doc_text">
 111
 112 <p>Here's the short story for getting up and running quickly with LLVM:</p>
 113
 114 <ol>
 115   <li>Read the documentation.</li>
 116   <li>Read the documentation.</li>
 117   <li>Remember that you were warned twice about reading the documentation.</li>
 118   <li>Install the GCC front end if you intend to compile C or C++:
 119     <ol>
 120       <li><tt>cd <i>where-you-want-the-C-front-end-to-live</i></tt></li>
 121       <li><tt>gunzip --stdout llvm-gcc.<i>platform</i>.tar.gz | tar -xvf -</tt>
 122       </li>
 123       <li><tt>cd llvm-gcc3.4/<i>platform</i> (llvm-gcc3.4 only)<br>
 124         ./fixheaders</tt></li>
 125       <li>Add llvm-gcc's "bin" directory to your PATH variable.</li>
 126     </ol></li>
 127
 128   <li>Get the LLVM Source Code
 129   <ul>
 130     <li>With the distributed files (or use <a href="#checkout">CVS</a>):
 131     <ol>
 132       <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
 133       <li><tt>gunzip --stdout llvm-<i>version</i>.tar.gz | tar -xvf -</tt>
 134     </ol></li>
 135
 136   </ul></li>
 137
 138   <li><b>[Optional]</b> Get the Test Suite Source Code
 139   <ul>
 140     <li>With the distributed files (or use <a href="#checkout">CVS</a>):
 141     <ol>
 142       <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
 143       <li><tt>cd llvm/projects</tt>
 144       <li><tt>gunzip --stdout llvm-test-<i>version</i>.tar.gz | tar -xvf -</tt>
 145     </ol></li>
 146
 147   </ul></li>
 148
 149
 150   <li>Configure the LLVM Build Environment
 151   <ol>
 152     <li><tt>cd <i>where-you-want-to-build-llvm</i></tt></li>
 153     <li><tt><i>/path/to/llvm/</i>configure [options]</tt><br>
 154     Some common options:
 155
 156       <ul>
 157         <li><tt>--prefix=<i>directory</i></tt>
 158         <p>Specify for <i>directory</i> the full pathname of where you
 159         want the LLVM tools and libraries to be installed (default
 160         <tt>/usr/local</tt>).</p></li>
 161         <li><tt>--with-llvmgccdir=<i>directory</i></tt>
 162         <p>Optionally, specify for <i>directory</i> the full pathname of the
 163         C/C++ front end installation to use with this LLVM configuration. If
 164         not specified, the PATH will be searched.</p></li>
 165         <li><tt>--enable-spec2000=<i>directory</i></tt>
 166             <p>Enable the SPEC2000 benchmarks for testing.  The SPEC2000
 167             benchmarks should be available in
 168             <tt><i>directory</i></tt>.</p></li>
 169       </ul>
 170   </ol></li>
 171
 172   <li>Build the LLVM Suite:
 173   <ol>
 174       <li><tt>gmake -k |&amp; tee gnumake.out
 175       &nbsp;&nbsp;&nbsp;# this is csh or tcsh syntax</tt></li>
 176       <li>If you get an "internal compiler error (ICE)" or test failures, see
 177           <a href="#brokengcc">below</a>.</li>
 178   </ol>
 179
 180 </ol>
 181
 182 <p>Consult the <a href="#starting">Getting Started with LLVM</a> section for
 183 detailed information on configuring and compiling LLVM.  See <a
 184 href="#environment">Setting Up Your Environment</a> for tips that simplify
 185 working with the GCC front end and LLVM tools.  Go to <a href="#layout">Program
 186 Layout</a> to learn about the layout of the source code tree.</p>
 187
 188 </div>
 189
 190 <!-- *********************************************************************** -->
 191 <div class="doc_section">
 192   <a name="requirements"><b>Requirements</b></a>
 193 </div>
 194 <!-- *********************************************************************** -->
 195
 196 <div class="doc_text">
 197
 198 <p>Before you begin to use the LLVM system, review the requirements given below.
 199 This may save you some trouble by knowing ahead of time what hardware and
 200 software you will need.</p>
 201
 202 </div>
 203
 204 <!-- ======================================================================= -->
 205 <div class="doc_subsection">
 206   <a name="hardware"><b>Hardware</b></a>
 207 </div>
 208
 209 <div class="doc_text">
 210
 211 <p>LLVM is known to work on the following platforms:</p>
 212
 213 <table cellpadding="3" summary="Known LLVM platforms">
 214 <tr>
 215   <th>OS</th>
 216   <th>Arch</th>
 217   <th>Compilers</th>
 218 </tr>
 219 <tr>
 220   <td>Linux</td>
 221   <td>x86<sup><a href="#pf_1">1</a></sup></td>
 222   <td>GCC</td>
 223 </tr>
 224 <tr>
 225   <td>Solaris</td>
 226   <td>V9 (Ultrasparc)</td>
 227   <td>GCC</td>
 228 </tr>
 229 <tr>
 230   <td>FreeBSD</td>
 231   <td>x86<sup><a href="#pf_1">1</a></sup></td>
 232   <td>GCC</td>
 233 </tr>
 234 <tr>
 235   <td>MacOS X<sup><a href="#pf_2">2</a></sup></td>
 236   <td>PowerPC</td>
 237   <td>GCC</td>
 238 </tr>
 239 <tr>
 240   <td>MacOS X<sup><a href="#pf_2">2</a></sup></td>
 241   <td>x86</td>
 242   <td>GCC</td>
 243
 244 </tr>
 245 <tr>
 246   <td>Cygwin/Win32</td>
 247   <td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_8">8</a></sup></td>
 248   <td>GCC 3.4.X, binutils 2.15</td>
 249 </tr>
 250 <tr>
 251   <td>MinGW/Win32</td>
 252   <td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_6">6</a>,<a href="#pf_8">8</a></sup></td>
 253   <td>GCC 3.4.X, binutils 2.15</td>
 254 </tr>
 255 <tr>
 256   <td>Linux</td>
 257   <td>amd64<sup><a href="#pf_3">3</a></sup></td>
 258   <td>GCC</td>
 259 </tr>
 260 </table>
 261
 262 <p>LLVM has partial support for the following platforms:</p>
 263
 264 <table summary="LLVM partial platform support">
 265 <tr>
 266   <th>OS</th>
 267   <th>Arch</th>
 268   <th>Compilers</th>
 269 </tr>
 270 <tr>
 271   <td>Windows</td>
 272   <td>x86<sup><a href="#pf_1">1</a></sup></td>
 273   <td>Visual Studio .NET<sup><a href="#pf_4">4</a>,<a href="#pf_5">5</a></sup></td>
 274 <tr>
 275   <td>AIX<sup><a href="#pf_3">3</a>,<a href="#pf_4">4</a></sup></td>
 276   <td>PowerPC</td>
 277   <td>GCC</td>
 278 </tr>
 279 <tr>
 280   <td>Linux<sup><a href="#pf_3">3</a>,<a href="#pf_5">5</a></sup></td>
 281   <td>PowerPC</td>
 282   <td>GCC</td>
 283 </tr>
 284
 285 <tr>
 286   <td>Linux<sup><a href="#pf_7">7</a></sup></td>
 287   <td>Alpha</td>
 288   <td>GCC</td>
 289 </tr>
 290 <tr>
 291   <td>Linux<sup><a href="#pf_7">7</a></sup></td>
 292   <td>Itanium (IA-64)</td>
 293   <td>GCC</td>
 294 </tr>
 295 <tr>
 296   <td>HP-UX<sup><a href="#pf_7">7</a></sup></td>
 297   <td>Itanium (IA-64)</td>
 298   <td>HP aCC</td>
 299 </tr>
 300 </table>
 301
 302 <p><b>Notes:</b></p>
 303
 304 <div class="doc_notes">
 305 <ol>
 306 <li><a name="pf_1">Code generation supported for Pentium processors and
 307 up</a></li>
 308 <li><a name="pf_2">Code generation supported for 32-bit ABI only</a></li>
 309 <li><a name="pf_3">No native code generation</a></li>
 310 <li><a name="pf_4">Build is not complete: one or more tools don't link</a></li>
 311 <li><a name="pf_5">The GCC-based C/C++ frontend does not build</a></li>
 312 <li><a name="pf_6">The port is done using the MSYS shell.</a>
 313 <a href="http://www.mingw.org/MinGWiki/">Download</a> and install
 314 bison (excl. M4.exe) and flex in that order. Build binutils-2.15 from source,
 315 if necessary. Bison &amp; flex can be also grabbed from GNUWin32 sf.net
 316 project.</li>
 317 <li><a name="pf_7">Native code generation exists but is not complete.</a></li>
 318 <li><a name="pf_8">Binutils</a> up to post-2.17 has bug in bfd/cofflink.c
 319     preventing LLVM from building correctly. Several workarounds have been
 320     introduced into LLVM build system, but the bug can occur anytime in the
 321     future. We highly recommend that you rebuild your current binutils with the
 322     patch from <a href="http://sourceware.org/bugzilla/show_bug.cgi?id=2659">
 323     Binutils bugzilla</a>, if it wasn't already applied.</li>
 324 </ol>
 325 </div>
 326
 327 <p>Note that you will need about 1-3 GB of space for a full LLVM build in Debug
 328 mode, depending on the system (it is so large because of all the debugging
 329 information and the fact that the libraries are statically linked into multiple
 330 tools).  If you do not need many of the tools and you are space-conscious,
 331 you can disable them individually in <tt>llvm/tools/Makefile</tt>.  The Release
 332 build requires considerably less space.</p>
 333
 334 <p>The LLVM suite <i>may</i> compile on other platforms, but it is not
 335 guaranteed to do so.  If compilation is successful, the LLVM utilities should be
 336 able to assemble, disassemble, analyze, and optimize LLVM bytecode.  Code
 337 generation should work as well, although the generated native code may not work
 338 on your platform.</p>
 339
 340 <p>The GCC front end is not very portable at the moment.  If you want to get it
 341 to work on another platform, you can download a copy of the source and <a
 342 href="CFEBuildInstrs.html">try to compile it</a> on your platform.</p>
 343
 344 </div>
 345
 346 <!-- ======================================================================= -->
 347 <div class="doc_subsection"><a name="software"><b>Software</b></a></div>
 348 <div class="doc_text">
 349   <p>Compiling LLVM requires that you have several software packages
 350   installed. The table below lists those required packages. The Package column
 351   is the usual name for the software package that LLVM depends on. The Version
 352   column provides "known to work" versions of the package. The Notes column
 353   describes how LLVM uses the package and provides other details.</p>
 354   <table summary="Packages required to compile LLVM">
 355     <tr><th>Package</th><th>Version</th><th>Notes</th></tr>
 356
 357     <tr>
 358       <td><a href="http://savannah.gnu.org/projects/make">GNU Make</a></td>
 359       <td>3.79, 3.79.1</td>
 360       <td>Makefile/build processor</td>
 361     </tr>
 362
 363     <tr>
 364       <td><a href="http://gcc.gnu.org">GCC</a></td>
 365       <td>3.4.2</td>
 366       <td>C/C++ compiler<sup><a href="#sf1">1</a></sup></td>
 367     </tr>
 368
 369     <tr>
 370       <td><a href="http://www.gnu.org/software/texinfo">TeXinfo</a></td>
 371       <td>4.5</td>
 372       <td>For building the CFE</td>
 373     </tr>
 374
 375     <tr>
 376       <td><a href="http://www.gnu.org/software/flex">Flex</a></td>
 377       <td>2.5.4</td>
 378       <td>LEX compiler</td>
 379     </tr>
 380
 381     <tr>
 382       <td><a href="http://www.gnu.org/software/bison/bison.html">Bison</a></td>
 383       <td>1.28, 1.35, 1.75, 1.875d, 2.0, or 2.1<br>(not 1.85 or 1.875)</td>
 384       <td>YACC compiler</td>
 385     </tr>
 386
 387     <tr>
 388       <td><a href="https://www.cvshome.org/downloads.html">CVS</a></td>
 389       <td>&ge;1.11</td>
 390       <td>CVS access to LLVM<sup><a href="#sf2">2</a></sup></td>
 391     </tr>
 392
 393     <tr>
 394       <td><a href="http://savannah.gnu.org/projects/dejagnu">DejaGnu</a></td>
 395       <td>1.4.2</td>
 396       <td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
 397     </tr>
 398
 399     <tr>
 400       <td><a href="http://www.tcl.tk/software/tcltk/">tcl</a></td>
 401       <td>8.3, 8.4</td>
 402       <td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
 403     </tr>
 404
 405     <tr>
 406       <td><a href="http://expect.nist.gov/">expect</a></td>
 407       <td>5.38.0</td>
 408       <td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
 409     </tr>
 410
 411     <tr>
 412       <td><a href="http://www.perl.com/download.csp">perl</a></td>
 413       <td>&ge;5.6.0</td>
 414       <td>Nightly tester, utilities</td>
 415     </tr>
 416
 417     <tr>
 418       <td><a href="http://savannah.gnu.org/projects/m4">GNU M4</a>
 419       <td>1.4</td>
 420       <td>Macro processor for configuration<sup><a href="#sf4">4</a></sup></td>
 421     </tr>
 422
 423     <tr>
 424       <td><a href="http://www.gnu.org/software/autoconf">GNU Autoconf</a></td>
 425       <td>2.59</td>
 426       <td>Configuration script builder<sup><a href="#sf4">4</a></sup></td>
 427     </tr>
 428
 429     <tr>
 430       <td><a href="http://www.gnu.org/software/automake">GNU Automake</a></td>
 431       <td>1.9.2</td>
 432       <td>aclocal macro generator<sup><a href="#sf4">4</a></sup></td>
 433     </tr>
 434
 435     <tr>
 436       <td><a href="http://savannah.gnu.org/projects/libtool">libtool</a></td>
 437       <td>1.5.10</td>
 438       <td>Shared library manager<sup><a href="#sf4">4</a></sup></td>
 439     </tr>
 440
 441   </table>
 442
 443   <p><b>Notes:</b></p>
 444   <div class="doc_notes">
 445   <ol>
 446     <li><a name="sf1">Only the C and C++ languages are needed so there's no
 447       need to build the other languages for LLVM's purposes.</a> See
 448       <a href="#brokengcc">below</a> for specific version info.</li>
 449     <li><a name="sf2">You only need CVS if you intend to build from the
 450       latest LLVM sources. If you're working from a release distribution, you
 451       don't need CVS.</a></li>
 452     <li><a name="sf3">Only needed if you want to run the automated test
 453       suite in the <tt>llvm/test</tt> directory.</a></li>
 454     <li><a name="sf4">If you want to make changes to the configure scripts,
 455       you will need GNU autoconf (2.59), and consequently, GNU M4 (version 1.4
 456       or higher). You will also need automake (1.9.2). We only use aclocal
 457       from that package.</a></li>
 458   </ol>
 459   </div>
 460
 461   <p>Additionally, your compilation host is expected to have the usual
 462   plethora of Unix utilities. Specifically:</p>
 463   <ul>
 464     <li><b>ar</b> - archive library builder</li>
 465     <li><b>bzip2*</b> - bzip2 command for distribution generation</li>
 466     <li><b>bunzip2*</b> - bunzip2 command for distribution checking</li>
 467     <li><b>chmod</b> - change permissions on a file</li>
 468     <li><b>cat</b> - output concatenation utility</li>
 469     <li><b>cp</b> - copy files</li>
 470     <li><b>date</b> - print the current date/time </li>
 471     <li><b>echo</b> - print to standard output</li>
 472     <li><b>egrep</b> - extended regular expression search utility</li>
 473     <li><b>etags</b> - C/C++ tag file creator for vim/emacs</li>
 474     <li><b>find</b> - find files/dirs in a file system</li>
 475     <li><b>grep</b> - regular expression search utility</li>
 476     <li><b>gzip*</b> - gzip command for distribution generation</li>
 477     <li><b>gunzip*</b> - gunzip command for distribution checking</li>
 478     <li><b>install</b> - install directories/files </li>
 479     <li><b>mkdir</b> - create a directory</li>
 480     <li><b>mv</b> - move (rename) files</li>
 481     <li><b>ranlib</b> - symbol table builder for archive libraries</li>
 482     <li><b>rm</b> - remove (delete) files and directories</li>
 483     <li><b>sed</b> - stream editor for transforming output</li>
 484     <li><b>sh</b> - Bourne shell for make build scripts</li>
 485     <li><b>tar</b> - tape archive for distribution generation</li>
 486     <li><b>test</b> - test things in file system</li>
 487     <li><b>unzip*</b> - unzip command for distribution checking</li>
 488     <li><b>zip*</b> - zip command for distribution generation</li>
 489   </ul>
 490 </div>
 491
 492 <!-- ======================================================================= -->
 493 <div class="doc_subsection">
 494   <a name="brokengcc">Broken versions of GCC</a>
 495 </div>
 496
 497 <div class="doc_text">
 498
 499 <p>LLVM is very demanding of the host C++ compiler, and as such tends to expose
 500 bugs in the compiler.  In particular, several versions of GCC crash when trying
 501 to compile LLVM.  We routinely use GCC 3.3.3, 3.4.0, and Apple 4.0.1
 502 successfully with them (however, see important notes below).  Other versions
 503 of GCC will probably work as well.  GCC versions listed
 504 here are known to not work.  If you are using one of these versions, please try
 505 to upgrade your GCC to something more recent.  If you run into a problem with a
 506 version of GCC not listed here, please <a href="mailto:llvmdev@cs.uiuc.edu">let
 507 us know</a>.  Please use the "<tt>gcc -v</tt>" command to find out which version
 508 of GCC you are using.
 509 </p>
 510
 511 <p><b>GCC versions prior to 3.0</b>: GCC 2.96.x and before had several
 512 problems in the STL that effectively prevent it from compiling LLVM.
 513 </p>
 514
 515 <p><b>GCC 3.2.2</b>: This version of GCC fails to compile LLVM.</p>
 516
 517 <p><b>GCC 3.3.2</b>: This version of GCC suffered from a <a
 518 href="http://gcc.gnu.org/PR13392">serious bug</a> which causes it to crash in
 519 the "<tt>convert_from_eh_region_ranges_1</tt>" GCC function.</p>
 520
 521 <p><b>Cygwin GCC 3.3.3</b>: The version of GCC 3.3.3 commonly shipped with
 522    Cygwin does not work.  Please <a href="CFEBuildInstrs.html#cygwin">upgrade
 523    to a newer version</a> if possible.</p>
 524 <p><b>SuSE GCC 3.3.3</b>: The version of GCC 3.3.3 shipped with SuSE 9.1 (and
 525    possibly others) does not compile LLVM correctly (it appears that exception
 526    handling is broken in some cases).  Please download the FSF 3.3.3 or upgrade
 527    to a newer version of GCC.</p>
 528 <p><b>GCC 3.4.0</b> on linux/x86 (32-bit)</b>: GCC miscompiles portions of the
 529    code generator, causing an infinite loop in the llvm-gcc build when built
 530    with optimizations enabled (i.e. a release build).</p>
 531 <p><b>GCC 3.4.2</b> on linux/x86 (32-bit)</b>: GCC miscompiles portions of the
 532    code generator at -O3, as with 3.4.0.  However gcc 3.4.2 (unlike 3.4.0)
 533    correctly compiles LLVM at -O2.  A work around is to build release LLVM
 534    builds with "make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2 ..."</p>
 535 <p><b>GCC 3.4.x</b> on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1056">
 536    miscompiles portions of LLVM</a>.</p>
 537 <p><b>IA-64 GCC 4.0.0</b>: The IA-64 version of GCC 4.0.0 is known to
 538    miscompile LLVM.</p>
 539 <p><b>Apple Xcode 2.3</b>: GCC crashes when compiling LLVM at -O3 (which is the
 540    default with ENABLE_OPTIMIZED=1.  To work around this, build with
 541    "ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2".</p>
 542 <p><b>GCC 4.1.1</b>: GCC fails to build LLVM with template concept check errors
 543       compiling some files.  At the time of this writing, GCC mainline (4.2)
 544       did not share the problem.</p>
 545 <p><b>GCC 4.1.1 on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1063">
 546    miscompiles portions of LLVM</a> when compiling llvm itself into 64-bit
 547    code.  LLVM will appear to mostly work but will be buggy, e.g. failing
 548    portions of its testsuite.</p>
 549 <p><b>GCC 4.1.2 on OpenSUSE</b>: Seg faults during libstdc++ build and on x86_64
 550 platforms compiling md5.c gets a mangled constant.</p>
 551 <p><b>GNU ld 2.16.X</b>. Some 2.16.X versions of the ld linker will produce very
 552 long warning messages complaining that some ".gnu.linkonce.t.*" symbol was
 553 defined in a discarded section. You can safely ignore these messages as they are
 554 erroneous and the linkage is correct.  These messages disappear using ld
 555 2.17.</p>
 556 </div>
 557
 558
 559
 560 <!-- *********************************************************************** -->
 561 <div class="doc_section">
 562   <a name="starting"><b>Getting Started with LLVM</b></a>
 563 </div>
 564 <!-- *********************************************************************** -->
 565
 566 <div class="doc_text">
 567
 568 <p>The remainder of this guide is meant to get you up and running with
 569 LLVM and to give you some basic information about the LLVM environment.</p>
 570
 571 <p>The later sections of this guide describe the <a
 572 href="#layout">general layout</a> of the the LLVM source tree, a <a
 573 href="#tutorial">simple example</a> using the LLVM tool chain, and <a
 574 href="#links">links</a> to find more information about LLVM or to get
 575 help via e-mail.</p>
 576 </div>
 577
 578 <!-- ======================================================================= -->
 579 <div class="doc_subsection">
 580   <a name="terminology">Terminology and Notation</a>
 581 </div>
 582
 583 <div class="doc_text">
 584
 585 <p>Throughout this manual, the following names are used to denote paths
 586 specific to the local system and working environment.  <i>These are not
 587 environment variables you need to set but just strings used in the rest
 588 of this document below</i>.  In any of the examples below, simply replace
 589 each of these names with the appropriate pathname on your local system.
 590 All these paths are absolute:</p>
 591
 592 <dl>
 593     <dt>SRC_ROOT
 594     <dd>
 595     This is the top level directory of the LLVM source tree.
 596     <br><br>
 597
 598     <dt>OBJ_ROOT
 599     <dd>
 600     This is the top level directory of the LLVM object tree (i.e. the
 601     tree where object files and compiled programs will be placed.  It
 602     can be the same as SRC_ROOT).
 603     <br><br>
 604
 605     <dt>LLVMGCCDIR
 606     <dd>
 607     This is where the LLVM GCC Front End is installed.
 608     <p>
 609     For the pre-built GCC front end binaries, the LLVMGCCDIR is
 610     <tt>llvm-gcc/<i>platform</i>/llvm-gcc</tt>.
 611 </dl>
 612
 613 </div>
 614
 615 <!-- ======================================================================= -->
 616 <div class="doc_subsection">
 617   <a name="environment">Setting Up Your Environment</a>
 618 </div>
 619
 620 <div class="doc_text">
 621
 622 <p>
 623 In order to compile and use LLVM, you may need to set some environment
 624 variables.
 625
 626 <dl>
 627   <dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt>/path/to/your/bytecode/libs</tt></dt>
 628   <dd>[Optional] This environment variable helps LLVM linking tools find the
 629   locations of your bytecode libraries. It is provided only as a
 630   convenience since you can specify the paths using the -L options of the
 631   tools and the C/C++ front-end will automatically use the bytecode files
 632   installed in its
 633   <tt>lib</tt> directory.</dd>
 634 </dl>
 635
 636 </div>
 637
 638 <!-- ======================================================================= -->
 639 <div class="doc_subsection">
 640   <a name="unpack">Unpacking the LLVM Archives</a>
 641 </div>
 642
 643 <div class="doc_text">
 644
 645 <p>
 646 If you have the LLVM distribution, you will need to unpack it before you
 647 can begin to compile it.  LLVM is distributed as a set of two files: the LLVM
 648 suite and the LLVM GCC front end compiled for your platform.  There is an
 649 additional test suite that is optional.  Each file is a TAR archive that is
 650 compressed with the gzip program.
 651 </p>
 652
 653 <p>The files are as follows, with <em>x.y</em> marking the version number:
 654 <dl>
 655   <dt><tt>llvm-x.y.tar.gz</tt></dt>
 656   <dd>Source release for the LLVM libraries and tools.<br/></dd>
 657
 658   <dt><tt>llvm-test-x.y.tar.gz</tt></dt>
 659   <dd>Source release for the LLVM test suite.</dd>
 660
 661   <dt><tt>llvm-gcc4-x.y.source.tar.gz</tt></dt>
 662   <dd>Source release of the llvm-gcc4 front end.  See README.LLVM in the root
 663       directory for build instructions.<br/></dd>
 664
 665   <dt><tt>llvm-gcc4-x.y-platform.tar.gz</tt></dt>
 666   <dd>Binary release of the llvm-gcc4 front end for a specific platform.<br/></dd>
 667
 668 </dl>
 669
 670 <p>It is also possible to download the sources of the llvm-gcc4 front end from a
 671 read-only subversion mirror at
 672 svn://anonsvn.opensource.apple.com/svn/llvm/trunk. </p>
 673
 674 </div>
 675
 676 <!-- ======================================================================= -->
 677 <div class="doc_subsection">
 678   <a name="checkout">Checkout LLVM from CVS</a>
 679 </div>
 680
 681 <div class="doc_text">
 682
 683 <p>If you have access to our CVS repository, you can get a fresh copy of
 684 the entire source code.  All you need to do is check it out from CVS as
 685 follows:</p>
 686
 687 <ul>
 688 <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
 689   <li><tt>cvs -d :pserver:anon@llvm.org:/var/cvs/llvm login</tt>
 690   <li>Hit the return key when prompted for the password.
 691   <li><tt>cvs -z3 -d :pserver:anon@llvm.org:/var/cvs/llvm co
 692       llvm</tt>
 693 </ul>
 694
 695 <p>This will create an '<tt>llvm</tt>' directory in the current
 696 directory and fully populate it with the LLVM source code, Makefiles,
 697 test directories, and local copies of documentation files.</p>
 698
 699 <p>If you want to get a specific release (as opposed to the most recent
 700 revision), you can specify a label.  The following releases have the following
 701 labels:</p>
 702
 703 <ul>
 704 <li>Release 2.0: <b>RELEASE_20</b></li>
 705 <li>Release 1.9: <b>RELEASE_19</b></li>
 706 <li>Release 1.8: <b>RELEASE_18</b></li>
 707 <li>Release 1.7: <b>RELEASE_17</b></li>
 708 <li>Release 1.6: <b>RELEASE_16</b></li>
 709 <li>Release 1.5: <b>RELEASE_15</b></li>
 710 <li>Release 1.4: <b>RELEASE_14</b></li>
 711 <li>Release 1.3: <b>RELEASE_13</b></li>
 712 <li>Release 1.2: <b>RELEASE_12</b></li>
 713 <li>Release 1.1: <b>RELEASE_11</b></li>
 714 <li>Release 1.0: <b>RELEASE_1</b></li>
 715 </ul>
 716
 717 <p>If you would like to get the LLVM test suite (a separate package as of 1.4),
 718 you get it from the CVS repository:</p>
 719 <pre>
 720   cd llvm/projects
 721   cvs -z3 -d :pserver:anon@llvm.org:/var/cvs/llvm co llvm-test
 722 </pre>
 723 <p>By placing it in the <tt>llvm/projects</tt>, it will be automatically
 724 configured by the LLVM configure script as well as automatically updated when
 725 you run <tt>cvs update</tt>.</p>
 726
 727 <p>If you would like to get the GCC front end source code, you can also get it
 728 and build it yourself.  Please follow <a href="CFEBuildInstrs.html">these
 729 instructions</a> to successfully get and build the LLVM GCC front-end.</p>
 730
 731 </div>
 732
 733 <!-- ======================================================================= -->
 734 <div class="doc_subsection">
 735   <a name="installcf">Install the GCC Front End</a>
 736 </div>
 737
 738 <div class="doc_text">
 739
 740 <p>Before configuring and compiling the LLVM suite, you can optionally extract the
 741 LLVM GCC front end from the binary distribution.  It is used for running the
 742 llvm-test testsuite and for compiling C/C++ programs.  Note that you can optionally
 743 <a href="CFEBuildInstrs.html">build llvm-gcc yourself</a> after building the
 744 main LLVM repository.</p>
 745
 746 <p>To install the GCC front end, do the following:</p>
 747
 748 <ol>
 749   <li><tt>cd <i>where-you-want-the-front-end-to-live</i></tt></li>
 750   <li><tt>gunzip --stdout llvmgcc-<i>version</i>.<i>platform</i>.tar.gz | tar -xvf
 751       -</tt></li>
 752 </ol>
 753
 754 <p>Once the binary is uncompressed, you should add a symlink for llvm-gcc and
 755 llvm-g++ to some directory in your path.  When you configure LLVM, it will
 756 automatically detect llvm-gcc's presence (if it is in your path) enabling its
 757 use in llvm-test.  Note that you can always build or install llvm-gcc at any
 758 pointer after building the main LLVM repository: just reconfigure llvm and
 759 llvm-test will pick it up.
 760 </p>
 761
 762 <p>The binary versions of the GCC front end may not suit all of your needs.  For
 763 example, the binary distribution may include an old version of a system header
 764 file, not "fix" a header file that needs to be fixed for GCC, or it may be
 765 linked with libraries not available on your system.</p>
 766
 767 <p>In cases like these, you may want to try <a
 768 href="CFEBuildInstrs.html">building the GCC front end from source.</a> This is
 769 much easier now than it was in the past.</p>
 770
 771 </div>
 772
 773 <!-- ======================================================================= -->
 774 <div class="doc_subsection">
 775   <a name="config">Local LLVM Configuration</a>
 776 </div>
 777
 778 <div class="doc_text">
 779
 780 <p>Once checked out from the CVS repository, the LLVM suite source code must be
 781 configured via the <tt>configure</tt> script.  This script sets variables in the
 782 various <tt>*.in</tt> files, most notably <tt>llvm/Makefile.config</tt> and
 783 <tt>llvm/include/Config/config.h</tt>.  It also populates <i>OBJ_ROOT</i> with
 784 the Makefiles needed to begin building LLVM.</p>
 785
 786 <p>The following environment variables are used by the <tt>configure</tt>
 787 script to configure the build system:</p>
 788
 789 <table summary="LLVM configure script environment variables">
 790   <tr><th>Variable</th><th>Purpose</th></tr>
 791   <tr>
 792     <td>CC</td>
 793     <td>Tells <tt>configure</tt> which C compiler to use.  By default,
 794         <tt>configure</tt> will look for the first GCC C compiler in
 795         <tt>PATH</tt>.  Use this variable to override
 796         <tt>configure</tt>'s default behavior.</td>
 797   </tr>
 798   <tr>
 799     <td>CXX</td>
 800     <td>Tells <tt>configure</tt> which C++ compiler to use.  By default,
 801        <tt>configure</tt> will look for the first GCC C++ compiler in
 802        <tt>PATH</tt>.  Use this variable to override
 803        <tt>configure</tt>'s default behavior.</td>
 804   </tr>
 805 </table>
 806
 807 <p>The following options can be used to set or enable LLVM specific options:</p>
 808
 809 <dl>
 810   <dt><i>--with-llvmgccdir</i></dt>
 811   <dd>Path to the LLVM C/C++ FrontEnd to be used with this LLVM configuration.
 812   The value of this option should specify the full pathname of the C/C++ Front
 813   End to be used. If this option is not provided, the PATH will be searched for
 814   a program named <i>llvm-gcc</i> and the C/C++ FrontEnd install directory will
 815   be inferred from the path found. If the option is not given, and no llvm-gcc
 816   can be found in the path then a warning will be produced by
 817   <tt>configure</tt> indicating this situation. LLVM may still be built with
 818   the <tt>tools-only</tt> target but attempting to build the runtime libraries
 819   will fail as these libraries require llvm-gcc and llvm-g++. See
 820   <a href="#installcf">Install the GCC Front End</a> for details on installing
 821   the C/C++ Front End. See
 822   <a href="CFEBuildInstrs.html">Bootstrapping the LLVM C/C++ Front-End</a>
 823   for details on building the C/C++ Front End.</dd>
 824   <dt><i>--with-tclinclude</i></dt>
 825   <dd>Path to the tcl include directory under which <tt>tclsh</tt> can be
 826   found. Use this if you have multiple tcl installations on your machine and you
 827   want to use a specific one (8.x) for LLVM. LLVM only uses tcl for running the
 828   dejagnu based test suite in <tt>llvm/test</tt>. If you don't specify this
 829   option, the LLVM configure script will search for the tcl 8.4 and 8.3
 830   releases.
 831   <br><br>
 832   </dd>
 833   <dt><i>--enable-optimized</i></dt>
 834   <dd>
 835     Enables optimized compilation by default (debugging symbols are removed
 836     and GCC optimization flags are enabled).  The default is to use an
 837     unoptimized build (also known as a debug build).
 838     <br><br>
 839   </dd>
 840   <dt><i>--enable-debug-runtime</i></dt>
 841   <dd>
 842     Enables debug symbols in the runtime libraries. The default is to strip
 843     debug symbols from the runtime libraries.
 844   </dd>
 845   <dt><i>--enable-jit</i></dt>
 846   <dd>
 847     Compile the Just In Time (JIT) compiler functionality.  This is not
 848     available
 849     on all platforms.  The default is dependent on platform, so it is best
 850     to explicitly enable it if you want it.
 851     <br><br>
 852   </dd>
 853   <dt><i>--enable-targets=</i><tt>target-option</tt></dt>
 854   <dd>Controls which targets will be built and linked into llc. The default
 855   value for <tt>target_options</tt> is "all" which builds and links all
 856   available targets.  The value "host-only" can be specified to build only a
 857   native compiler (no cross-compiler targets available). The "native" target is
 858   selected as the target of the build host. You can also specify a comma
 859   separated list of target names that you want available in llc. The target
 860   names use all lower case. The current set of targets is: <br/>
 861   <tt>alpha, ia64, powerpc, skeleton, sparc, x86</tt>.
 862   <br><br></dd>
 863   <dt><i>--enable-doxygen</i></dt>
 864   <dd>Look for the doxygen program and enable construction of doxygen based
 865   documentation from the source code. This is disabled by default because
 866   generating the documentation can take a long time and producess 100s of
 867   megabytes of output.</dd>
 868   <dt><i>--with-udis86</i></dt>
 869   <dd>LLVM can use external disassembler library for various purposes (now it's
 870   used only for examining code produced by JIT). This option will enable usage
 871   of <a href="http://udis86.sourceforge.net/">udis86</a> x86 (both 32 and 64
 872   bits) disassembler library.</dd>
 873 </dl>
 874
 875 <p>To configure LLVM, follow these steps:</p>
 876
 877 <ol>
 878     <li>Change directory into the object root directory:
 879     <br>
 880     <tt>cd <i>OBJ_ROOT</i></tt>
 881     <br><br>
 882
 883     <li>Run the <tt>configure</tt> script located in the LLVM source tree:
 884     <br>
 885     <tt><i>SRC_ROOT</i>/configure --prefix=/install/path [other options]</tt>
 886     <br><br>
 887 </ol>
 888
 889 </div>
 890
 891 <!-- ======================================================================= -->
 892 <div class="doc_subsection">
 893   <a name="compile">Compiling the LLVM Suite Source Code</a>
 894 </div>
 895
 896 <div class="doc_text">
 897
 898 <p>Once you have configured LLVM, you can build it.  There are three types of
 899 builds:</p>
 900
 901 <dl>
 902     <dt>Debug Builds
 903     <dd>
 904     These builds are the default when one types <tt>gmake</tt> (unless the
 905     <tt>--enable-optimized</tt> option was used during configuration).  The
 906     build system will compile the tools and libraries with debugging
 907     information.
 908     <br><br>
 909
 910     <dt>Release (Optimized) Builds
 911     <dd>
 912     These builds are enabled with the <tt>--enable-optimized</tt> option to
 913     <tt>configure</tt> or by specifying <tt>ENABLE_OPTIMIZED=1</tt> on the
 914     <tt>gmake</tt> command line.  For these builds, the build system will
 915     compile the tools and libraries with GCC optimizations enabled and strip
 916     debugging information from the libraries and executables it generates.
 917     <br><br>
 918
 919     <dt>Profile Builds
 920     <dd>
 921     These builds are for use with profiling.  They compile profiling
 922     information into the code for use with programs like <tt>gprof</tt>.
 923     Profile builds must be started by specifying <tt>ENABLE_PROFILING=1</tt>
 924     on the <tt>gmake</tt> command line.
 925 </dl>
 926
 927 <p>Once you have LLVM configured, you can build it by entering the
 928 <i>OBJ_ROOT</i> directory and issuing the following command:</p>
 929
 930 <p><tt>gmake</tt></p>
 931
 932 <p>If the build fails, please <a href="#brokengcc">check here</a> to see if you
 933 are using a version of GCC that is known not to compile LLVM.</p>
 934
 935 <p>
 936 If you have multiple processors in your machine, you may wish to use some of
 937 the parallel build options provided by GNU Make.  For example, you could use the
 938 command:</p>
 939
 940 <p><tt>gmake -j2</tt></p>
 941
 942 <p>There are several special targets which are useful when working with the LLVM
 943 source code:</p>
 944
 945 <dl>
 946   <dt><tt>gmake clean</tt>
 947   <dd>
 948   Removes all files generated by the build.  This includes object files,
 949   generated C/C++ files, libraries, and executables.
 950   <br><br>
 951
 952   <dt><tt>gmake dist-clean</tt>
 953   <dd>
 954   Removes everything that <tt>gmake clean</tt> does, but also removes files
 955   generated by <tt>configure</tt>.  It attempts to return the source tree to the
 956   original state in which it was shipped.
 957   <br><br>
 958
 959   <dt><tt>gmake install</tt>
 960   <dd>
 961   Installs LLVM header files, libraries, tools, and documentation in a
 962   hierarchy
 963   under $PREFIX, specified with <tt>./configure --prefix=[dir]</tt>, which
 964   defaults to <tt>/usr/local</tt>.
 965   <br><br>
 966
 967   <dt><tt>gmake -C runtime install-bytecode</tt>
 968   <dd>
 969   Assuming you built LLVM into $OBJDIR, when this command is run, it will
 970   install bytecode libraries into the GCC front end's bytecode library
 971   directory.  If you need to update your bytecode libraries,
 972   this is the target to use once you've built them.
 973   <br><br>
 974 </dl>
 975
 976 <p>Please see the <a href="MakefileGuide.html">Makefile Guide</a> for further
 977 details on these <tt>make</tt> targets and descriptions of other targets
 978 available.</p>
 979
 980 <p>It is also possible to override default values from <tt>configure</tt> by
 981 declaring variables on the command line.  The following are some examples:</p>
 982
 983 <dl>
 984   <dt><tt>gmake ENABLE_OPTIMIZED=1</tt>
 985   <dd>
 986   Perform a Release (Optimized) build.
 987   <br><br>
 988
 989   <dt><tt>gmake ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1</tt>
 990   <dd>
 991   Perform a Release (Optimized) build without assertions enabled.
 992   <br><br>
 993
 994   <dt><tt>gmake ENABLE_PROFILING=1</tt>
 995   <dd>
 996   Perform a Profiling build.
 997   <br><br>
 998
 999   <dt><tt>gmake VERBOSE=1</tt>
1000   <dd>
1001   Print what <tt>gmake</tt> is doing on standard output.
1002   <br><br>
1003
1004   <dt><tt>gmake TOOL_VERBOSE=1</tt></dt>
1005   <dd>Ask each tool invoked by the makefiles to print out what it is doing on
1006   the standard output. This also implies <tt>VERBOSE=1</tt>.
1007   <br><br></dd>
1008 </dl>
1009
1010 <p>Every directory in the LLVM object tree includes a <tt>Makefile</tt> to build
1011 it and any subdirectories that it contains.  Entering any directory inside the
1012 LLVM object tree and typing <tt>gmake</tt> should rebuild anything in or below
1013 that directory that is out of date.</p>
1014
1015 </div>
1016
1017 <!-- ======================================================================= -->
1018 <div class="doc_subsection">
1019   <a name="cross-compile">Cross-Compiling LLVM</a>
1020 </div>
1021
1022 <div class="doc_text">
1023   <p>It is possible to cross-compile LLVM. That is, you can create LLVM
1024   executables and libraries for a platform different than the one one which you
1025   are compiling.  To do this, a few additional steps are
1026   required. <sup><a href="#ccn_1">1</a></sup> To cross-compile LLVM, use
1027   these instructions:</p>
1028   <ol>
1029     <li>Configure and build LLVM as a native compiler. You will need
1030     just <tt>TableGen</tt> from that build.
1031       <ul>
1032         <li>If you have <tt>$LLVM_OBJ_ROOT=$LLVM_SRC_ROOT</tt> just execute
1033           <tt>make -C utils/TableGen</tt> after configuring.</li>
1034         <li>Otherwise you will need to monitor building process and terminate
1035           it just after <tt>TableGen</tt> was built.</li>
1036       </ul>
1037     </li>
1038     <li>Copy the TableGen binary to somewhere safe (out of your build tree).
1039     </li>
1040     <li>Configure LLVM to build with a cross-compiler. To do this, supply the
1041     configure script with <tt>--build</tt> and <tt>--host</tt> options that
1042     are different. The values of these options must be legal target triples
1043     that your GCC compiler supports.</li>
1044     <li>Put the saved <tt>TableGen</tt> executable into the
1045     into <tt>$LLVM_OBJ_ROOT/{BUILD_TYPE}/bin</tt> directory (e.g. into
1046     <tt>.../Release/bin</tt> for a Release build).</li>
1047     <li>Build LLVM  as usual.</li>
1048   </ol>
1049   <p>The result of such a build will produce executables that are not executable
1050   on your build host (--build option) but can be executed on your compile host
1051   (--host option).</p>
1052   <p><b>Notes:</b></p>
1053   <div class="doc_notes">
1054     <ol>
1055       <li><a name="ccn_1">Cross-compiling</a> was tested only with Linux as
1056       build platform and Windows as host using mingw32 cross-compiler. Other
1057       combinations have not been tested.</li>
1058     </ol>
1059   </div>
1060 </div>
1061
1062 <!-- ======================================================================= -->
1063 <div class="doc_subsection">
1064   <a name="objfiles">The Location of LLVM Object Files</a>
1065 </div>
1066
1067 <div class="doc_text">
1068
1069 <p>The LLVM build system is capable of sharing a single LLVM source tree among
1070 several LLVM builds.  Hence, it is possible to build LLVM for several different
1071 platforms or configurations using the same source tree.</p>
1072
1073 <p>This is accomplished in the typical autoconf manner:</p>
1074
1075 <ul>
1076   <li><p>Change directory to where the LLVM object files should live:</p>
1077
1078       <p><tt>cd <i>OBJ_ROOT</i></tt></p></li>
1079
1080   <li><p>Run the <tt>configure</tt> script found in the LLVM source
1081       directory:</p>
1082
1083       <p><tt><i>SRC_ROOT</i>/configure</tt></p></li>
1084 </ul>
1085
1086 <p>The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories
1087 named after the build type:</p>
1088
1089 <dl>
1090   <dt>Debug Builds
1091   <dd>
1092   <dl>
1093     <dt>Tools
1094     <dd><tt><i>OBJ_ROOT</i>/Debug/bin</tt>
1095     <dt>Libraries
1096     <dd><tt><i>OBJ_ROOT</i>/Debug/lib</tt>
1097   </dl>
1098   <br><br>
1099
1100   <dt>Release Builds
1101   <dd>
1102   <dl>
1103     <dt>Tools
1104     <dd><tt><i>OBJ_ROOT</i>/Release/bin</tt>
1105     <dt>Libraries
1106     <dd><tt><i>OBJ_ROOT</i>/Release/lib</tt>
1107   </dl>
1108   <br><br>
1109
1110   <dt>Profile Builds
1111   <dd>
1112   <dl>
1113     <dt>Tools
1114     <dd><tt><i>OBJ_ROOT</i>/Profile/bin</tt>
1115     <dt>Libraries
1116     <dd><tt><i>OBJ_ROOT</i>/Profile/lib</tt>
1117   </dl>
1118 </dl>
1119
1120 </div>
1121
1122 <!-- ======================================================================= -->
1123 <div class="doc_subsection">
1124   <a name="optionalconfig">Optional Configuration Items</a>
1125 </div>
1126
1127 <div class="doc_text">
1128
1129 <p>
1130 If you're running on a Linux system that supports the "<a
1131   href="http://www.tat.physik.uni-tuebingen.de/~rguenth/linux/binfmt_misc.html">
1132   binfmt_misc</a>"
1133 module, and you have root access on the system, you can set your system up to
1134 execute LLVM bytecode files directly.  To do this, use commands like this (the
1135 first command may not be required if you are already using the module):</p>
1136
1137 <div class="doc_code">
1138 <pre>
1139    $ mount -t binfmt_misc none /proc/sys/fs/binfmt_misc
1140    $ echo ':llvm:M::llvm::/path/to/lli:' &gt; /proc/sys/fs/binfmt_misc/register
1141    $ chmod u+x hello.bc                (if needed)
1142    $ ./hello.bc
1143 </pre>
1144 </div>
1145
1146 <p>
1147 This allows you to execute LLVM bytecode files directly.  Thanks to Jack
1148 Cummings for pointing this out!
1149 </p>
1150
1151 </div>
1152
1153
1154 <!-- *********************************************************************** -->
1155 <div class="doc_section">
1156   <a name="layout"><b>Program Layout</b></a>
1157 </div>
1158 <!-- *********************************************************************** -->
1159
1160 <div class="doc_text">
1161
1162 <p>One useful source of information about the LLVM source base is the LLVM <a
1163 href="http://www.doxygen.org">doxygen</a> documentation available at <tt><a
1164 href="http://llvm.org/doxygen/">http://llvm.org/doxygen/</a></tt>.
1165 The following is a brief introduction to code layout:</p>
1166
1167 </div>
1168
1169 <!-- ======================================================================= -->
1170 <div class="doc_subsection"><a name="cvsdir"><tt>CVS</tt> directories</a></div>
1171 <div class="doc_text">
1172 <p>Every directory checked out of CVS will contain a <tt>CVS</tt> directory; for
1173 the most part these can just be ignored.</p>
1174 </div>
1175
1176 <!-- ======================================================================= -->
1177 <div class="doc_subsection"><a name="examples"><tt>llvm/examples</tt></a></div>
1178 <div class="doc_text">
1179   <p>This directory contains some simple examples of how to use the LLVM IR and
1180   JIT.</p>
1181 </div>
1182
1183 <!-- ======================================================================= -->
1184 <div class="doc_subsection"><a name="include"><tt>llvm/include</tt></a></div>
1185 <div class="doc_text">
1186
1187 <p>This directory contains public header files exported from the LLVM
1188 library. The three main subdirectories of this directory are:</p>
1189
1190 <dl>
1191   <dt><tt><b>llvm/include/llvm</b></tt></dt>
1192   <dd>This directory contains all of the LLVM specific header files.  This
1193   directory also has subdirectories for different portions of LLVM:
1194   <tt>Analysis</tt>, <tt>CodeGen</tt>, <tt>Target</tt>, <tt>Transforms</tt>,
1195   etc...</dd>
1196
1197   <dt><tt><b>llvm/include/llvm/Support</b></tt></dt>
1198   <dd>This directory contains generic support libraries that are provided with
1199   LLVM but not necessarily specific to LLVM. For example, some C++ STL utilities
1200   and a Command Line option processing library store their header files here.
1201   </dd>
1202
1203   <dt><tt><b>llvm/include/llvm/Config</b></tt></dt>
1204   <dd>This directory contains header files configured by the <tt>configure</tt>
1205   script.  They wrap "standard" UNIX and C header files.  Source code can
1206   include these header files which automatically take care of the conditional
1207   #includes that the <tt>configure</tt> script generates.</dd>
1208 </dl>
1209 </div>
1210
1211 <!-- ======================================================================= -->
1212 <div class="doc_subsection"><a name="lib"><tt>llvm/lib</tt></a></div>
1213 <div class="doc_text">
1214
1215 <p>This directory contains most of the source files of the LLVM system. In LLVM,
1216 almost all code exists in libraries, making it very easy to share code among the
1217 different <a href="#tools">tools</a>.</p>
1218
1219 <dl>
1220   <dt><tt><b>llvm/lib/VMCore/</b></tt></dt>
1221   <dd> This directory holds the core LLVM source files that implement core
1222   classes like Instruction and BasicBlock.</dd>
1223
1224   <dt><tt><b>llvm/lib/AsmParser/</b></tt></dt>
1225   <dd>This directory holds the source code for the LLVM assembly language parser
1226   library.</dd>
1227
1228   <dt><tt><b>llvm/lib/ByteCode/</b></tt></dt>
1229   <dd>This directory holds code for reading and write LLVM bytecode.</dd>
1230
1231   <dt><tt><b>llvm/lib/Analysis/</b></tt><dd>This directory contains a variety of
1232   different program analyses, such as Dominator Information, Call Graphs,
1233   Induction Variables, Interval Identification, Natural Loop Identification,
1234   etc.</dd>
1235
1236   <dt><tt><b>llvm/lib/Transforms/</b></tt></dt>
1237   <dd> This directory contains the source code for the LLVM to LLVM program
1238   transformations, such as Aggressive Dead Code Elimination, Sparse Conditional
1239   Constant Propagation, Inlining, Loop Invariant Code Motion, Dead Global
1240   Elimination, and many others.</dd>
1241
1242   <dt><tt><b>llvm/lib/Target/</b></tt></dt>
1243   <dd> This directory contains files that describe various target architectures
1244   for code generation.  For example, the <tt>llvm/lib/Target/X86</tt>
1245   directory holds the X86 machine description while
1246   <tt>llvm/lib/Target/CBackend</tt> implements the LLVM-to-C converter.</dd>
1247
1248   <dt><tt><b>llvm/lib/CodeGen/</b></tt></dt>
1249   <dd> This directory contains the major parts of the code generator: Instruction
1250   Selector, Instruction Scheduling, and Register Allocation.</dd>
1251
1252   <dt><tt><b>llvm/lib/Debugger/</b></tt></dt>
1253   <dd> This directory contains the source level debugger library that makes
1254   it possible to instrument LLVM programs so that a debugger could identify
1255   source code locations at which the program is executing.</dd>
1256
1257   <dt><tt><b>llvm/lib/ExecutionEngine/</b></tt></dt>
1258   <dd> This directory contains libraries for executing LLVM bytecode directly
1259   at runtime in both interpreted and JIT compiled fashions.</dd>
1260
1261   <dt><tt><b>llvm/lib/Support/</b></tt></dt>
1262   <dd> This directory contains the source code that corresponds to the header
1263   files located in <tt>llvm/include/Support/</tt>.</dd>
1264
1265   <dt><tt><b>llvm/lib/System/</b></tt></dt>
1266   <dd>This directory contains the operating system abstraction layer that
1267   shields LLVM from platform-specific coding.</dd>
1268 </dl>
1269
1270 </div>
1271
1272 <!-- ======================================================================= -->
1273 <div class="doc_subsection"><a name="projects"><tt>llvm/projects</tt></a></div>
1274 <div class="doc_text">
1275   <p>This directory contains projects that are not strictly part of LLVM but are
1276   shipped with LLVM. This is also the directory where you should create your own
1277   LLVM-based projects. See <tt>llvm/projects/sample</tt> for an example of how
1278   to set up your own project. See <tt>llvm/projects/Stacker</tt> for a fully
1279   functional example of a compiler front end.</p>
1280 </div>
1281
1282 <!-- ======================================================================= -->
1283 <div class="doc_subsection"><a name="runtime"><tt>llvm/runtime</tt></a></div>
1284 <div class="doc_text">
1285
1286 <p>This directory contains libraries which are compiled into LLVM bytecode and
1287 used when linking programs with the GCC front end.  Most of these libraries are
1288 skeleton versions of real libraries; for example, libc is a stripped down
1289 version of glibc.</p>
1290
1291 <p>Unlike the rest of the LLVM suite, this directory needs the LLVM GCC front
1292 end to compile.</p>
1293
1294 </div>
1295
1296 <!-- ======================================================================= -->
1297 <div class="doc_subsection"><a name="test"><tt>llvm/test</tt></a></div>
1298 <div class="doc_text">
1299   <p>This directory contains feature and regression tests and other basic sanity
1300   checks on the LLVM infrastructure. These are intended to run quickly and cover
1301   a lot of territory without being exhaustive.</p>
1302 </div>
1303
1304 <!-- ======================================================================= -->
1305 <div class="doc_subsection"><a name="llvmtest"><tt>llvm-test</tt></a></div>
1306 <div class="doc_text">
1307   <p>This is not a directory in the normal llvm module; it is a separate CVS
1308   module that must be checked out (usually to <tt>projects/llvm-test</tt>). This
1309   module contains a comprehensive correctness, performance, and benchmarking
1310   test
1311   suite for LLVM. It is a separate CVS module because not every LLVM user is
1312   interested in downloading or building such a comprehensive test suite. For
1313   further details on this test suite, please see the
1314   <a href="TestingGuide.html">Testing Guide</a> document.</p>
1315 </div>
1316
1317 <!-- ======================================================================= -->
1318 <div class="doc_subsection"><a name="tools"><tt>llvm/tools</tt></a></div>
1319 <div class="doc_text">
1320
1321 <p>The <b>tools</b> directory contains the executables built out of the
1322 libraries above, which form the main part of the user interface.  You can
1323 always get help for a tool by typing <tt>tool_name --help</tt>.  The
1324 following is a brief introduction to the most important tools.  More detailed
1325 information is in the <a href="CommandGuide/index.html">Command Guide</a>.</p>
1326
1327 <dl>
1328
1329   <dt><tt><b>bugpoint</b></tt></dt>
1330   <dd><tt>bugpoint</tt> is used to debug
1331   optimization passes or code generation backends by narrowing down the
1332   given test case to the minimum number of passes and/or instructions that
1333   still cause a problem, whether it is a crash or miscompilation. See <a
1334   href="HowToSubmitABug.html">HowToSubmitABug.html</a> for more information
1335   on using <tt>bugpoint</tt>.</dd>
1336
1337   <dt><tt><b>llvmc</b></tt></dt>
1338   <dd>The LLVM Compiler Driver. This program can
1339   be configured to utilize both LLVM and non-LLVM compilation tools to enable
1340   pre-processing, translation, optimization, assembly, and linking of programs
1341   all from one command line. <tt>llvmc</tt> also takes care of processing the
1342   dependent libraries found in bytecode. This reduces the need to get the
1343   traditional <tt>-l&lt;name&gt;</tt> options right on the command line. Please
1344   note that this tool, while functional, is still experimental and not feature
1345   complete.</dd>
1346
1347   <dt><tt><b>llvm-ar</b></tt></dt>
1348   <dd>The archiver produces an archive containing
1349   the given LLVM bytecode files, optionally with an index for faster
1350   lookup.</dd>
1351
1352   <dt><tt><b>llvm-as</b></tt></dt>
1353   <dd>The assembler transforms the human readable LLVM assembly to LLVM
1354   bytecode.</dd>
1355
1356   <dt><tt><b>llvm-dis</b></tt></dt>
1357   <dd>The disassembler transforms the LLVM bytecode to human readable
1358   LLVM assembly.</dd>
1359
1360   <dt><tt><b>llvm-ld</b></tt></dt>
1361   <dd><tt>llvm-ld</tt> is a general purpose and extensible linker for LLVM.
1362   This is the linker invoked by <tt>llvmc</tt>. It performsn standard link time
1363   optimizations and allows optimization modules to be loaded and run so that
1364   language specific optimizations can be applied at link time.</dd>
1365
1366   <dt><tt><b>llvm-link</b></tt></dt>
1367   <dd><tt>llvm-link</tt>, not surprisingly, links multiple LLVM modules into
1368   a single program.</dd>
1369
1370   <dt><tt><b>lli</b></tt></dt>
1371   <dd><tt>lli</tt> is the LLVM interpreter, which
1372   can directly execute LLVM bytecode (although very slowly...). In addition
1373   to a simple interpreter, <tt>lli</tt> also has a tracing mode (entered by
1374   specifying <tt>-trace</tt> on the command line). Finally, for
1375   architectures that support it (currently x86, Sparc, and PowerPC), by default,
1376   <tt>lli</tt> will function as a Just-In-Time compiler (if the
1377   functionality was compiled in), and will execute the code <i>much</i>
1378   faster than the interpreter.</dd>
1379
1380   <dt><tt><b>llc</b></tt></dt>
1381   <dd> <tt>llc</tt> is the LLVM backend compiler, which
1382   translates LLVM bytecode to a native code assembly file or to C code (with
1383   the -march=c option).</dd>
1384
1385   <dt><tt><b>llvm-gcc</b></tt></dt>
1386   <dd><tt>llvm-gcc</tt> is a GCC-based C frontend that has been retargeted to
1387   use LLVM as its backend instead of GCC's RTL backend. It can also emit LLVM
1388   byte code or assembly (with the <tt>-emit-llvm</tt> option) instead of the
1389   usual machine code output.  It works just like any other GCC compiler,
1390   taking the typical <tt>-c, -S, -E, -o</tt> options that are typically used.
1391   Additionally, the the source code for <tt>llvm-gcc</tt> is available as a
1392   separate CVS module.</dd>
1393
1394   <dt><tt><b>opt</b></tt></dt>
1395   <dd><tt>opt</tt> reads LLVM bytecode, applies a series of LLVM to LLVM
1396   transformations (which are specified on the command line), and then outputs
1397   the resultant bytecode.  The '<tt>opt --help</tt>' command is a good way to
1398   get a list of the program transformations available in LLVM.<br/>
1399   <dd><tt>opt</tt> can also be used to run a specific analysis on an input
1400   LLVM bytecode file and print out the results.  It is primarily useful for
1401   debugging analyses, or familiarizing yourself with what an analysis does.</dd>
1402 </dl>
1403 </div>
1404
1405 <!-- ======================================================================= -->
1406 <div class="doc_subsection"><a name="utils"><tt>llvm/utils</tt></a></div>
1407 <div class="doc_text">
1408
1409 <p>This directory contains utilities for working with LLVM source code, and some
1410 of the utilities are actually required as part of the build process because they
1411 are code generators for parts of LLVM infrastructure.</p>
1412
1413 <dl>
1414   <dt><tt><b>codegen-diff</b></tt> <dd><tt>codegen-diff</tt> is a script
1415   that finds differences between code that LLC generates and code that LLI
1416   generates. This is a useful tool if you are debugging one of them,
1417   assuming that the other generates correct output. For the full user
1418   manual, run <tt>`perldoc codegen-diff'</tt>.<br><br>
1419
1420   <dt><tt><b>cvsupdate</b></tt> <dd><tt>cvsupdate</tt> is a script that will
1421   update your CVS tree, but produce a much cleaner and more organized output
1422   than simply running <tt>`cvs -z3 up -dP'</tt> will. For example, it will group
1423   together all the new and updated files and modified files in separate
1424   sections, so you can see at a glance what has changed. If you are at the
1425   top of your LLVM CVS tree, running <tt>utils/cvsupdate</tt> is the
1426   preferred way of updating the tree.<br><br>
1427
1428   <dt><tt><b>emacs/</b></tt> <dd>The <tt>emacs</tt> directory contains
1429   syntax-highlighting files which will work with Emacs and XEmacs editors,
1430   providing syntax highlighting support for LLVM assembly files and TableGen
1431   description files. For information on how to use the syntax files, consult
1432   the <tt>README</tt> file in that directory.<br><br>
1433
1434   <dt><tt><b>getsrcs.sh</b></tt> <dd>The <tt>getsrcs.sh</tt> script finds
1435   and outputs all non-generated source files, which is useful if one wishes
1436   to do a lot of development across directories and does not want to
1437   individually find each file. One way to use it is to run, for example:
1438   <tt>xemacs `utils/getsources.sh`</tt> from the top of your LLVM source
1439   tree.<br><br>
1440
1441   <dt><tt><b>llvmgrep</b></tt></dt>
1442   <dd>This little tool performs an "egrep -H -n" on each source file in LLVM and
1443   passes to it a regular expression provided on <tt>llvmgrep</tt>'s command
1444   line. This is a very efficient way of searching the source base for a
1445   particular regular expression.</dd>
1446
1447   <dt><tt><b>makellvm</b></tt> <dd>The <tt>makellvm</tt> script compiles all
1448   files in the current directory and then compiles and links the tool that
1449   is the first argument. For example, assuming you are in the directory
1450   <tt>llvm/lib/Target/Sparc</tt>, if <tt>makellvm</tt> is in your path,
1451   simply running <tt>makellvm llc</tt> will make a build of the current
1452   directory, switch to directory <tt>llvm/tools/llc</tt> and build it,
1453   causing a re-linking of LLC.<br><br>
1454
1455   <dt><tt><b>NewNightlyTest.pl</b></tt> and
1456   <tt><b>NightlyTestTemplate.html</b></tt> <dd>These files are used in a
1457   cron script to generate nightly status reports of the functionality of
1458   tools, and the results can be seen by following the appropriate link on
1459   the <a href="http://llvm.org/">LLVM homepage</a>.<br><br>
1460
1461   <dt><tt><b>TableGen/</b></tt> <dd>The <tt>TableGen</tt> directory contains
1462   the tool used to generate register descriptions, instruction set
1463   descriptions, and even assemblers from common TableGen description
1464   files.<br><br>
1465
1466   <dt><tt><b>vim/</b></tt> <dd>The <tt>vim</tt> directory contains
1467   syntax-highlighting files which will work with the VIM editor, providing
1468   syntax highlighting support for LLVM assembly files and TableGen
1469   description files. For information on how to use the syntax files, consult
1470   the <tt>README</tt> file in that directory.<br><br>
1471
1472 </dl>
1473
1474 </div>
1475
1476 <!-- ======================================================================= -->
1477 <div class="doc_subsection"><a name="win32"><tt>llvm/win32</tt></a></div>
1478 <div class="doc_text">
1479   <p>This directory contains build scripts and project files for use with
1480   Visual C++. This allows developers on Windows to build LLVM without the need
1481   for Cygwin. The contents of this directory should be considered experimental
1482   at this time.
1483   </p>
1484 </div>
1485 <!-- *********************************************************************** -->
1486 <div class="doc_section">
1487   <a name="tutorial">An Example Using the LLVM Tool Chain</a>
1488 </div>
1489 <!-- *********************************************************************** -->
1490
1491 <div class="doc_text">
1492 <p>This section gives an example of using LLVM.  llvm-gcc3 is now obsolete,
1493 so we only include instructiosn for llvm-gcc4.
1494 </p>
1495
1496 <p><b>Note:</b> The <i>gcc4</i> frontend's invocation is <b><i>considerably different</i></b>
1497 from the previous <i>gcc3</i> frontend. In particular, the <i>gcc4</i> frontend <b><i>does not</i></b>
1498 create bytecode by default: <i>gcc4</i> produces native code. As the example below illustrates,
1499 the '--emit-llvm' flag is needed to produce LLVM bytecode output. For <i>makefiles</i> and
1500 <i>configure</i> scripts, the CFLAGS variable needs '--emit-llvm' to produce bytecode
1501 output.</p>
1502 </div>
1503
1504 <!-- ======================================================================= -->
1505 <div class="doc_subsection"><a name="tutorial4">Example with llvm-gcc4</a></div>
1506
1507 <div class="doc_text">
1508
1509 <ol>
1510   <li>First, create a simple C file, name it 'hello.c':
1511        <pre>
1512    #include &lt;stdio.h&gt;
1513    int main() {
1514      printf("hello world\n");
1515      return 0;
1516    }
1517        </pre></li>
1518
1519   <li><p>Next, compile the C file into a native executable:</p>
1520
1521       <p><tt>% llvm-gcc hello.c -o hello</tt></p>
1522
1523       <p>Note that llvm-gcc works just like GCC by default.  The standard -S and
1524         -c arguments work as usual (producing a native .s or .o file,
1525         respectively). </p>
1526
1527   <li><p>Next, compile the C file into a LLVM bytecode file:</p>
1528       <p><tt>% llvm-gcc -O3 -emit-llvm hello.c -c -o hello.bc</tt></p>
1529
1530       <p>The -emit-llvm option can be used with the -S or -c options to emit an
1531          LLVM ".ll" or ".bc" file (respectively) for the code.  This allows you
1532          to use the <a href="CommandGuide/index.html">standard LLVM tools</a> on
1533          the bytecode file.</p>
1534
1535       <p>Unlike llvm-gcc3, llvm-gcc4 correctly responds to -O[0123] arguments.
1536          </p></li>
1537
1538   <li><p>Run the program in both forms. To run the program, use:</p>
1539
1540       <p><tt>% ./hello</tt></p>
1541
1542       <p>and</p>
1543
1544       <p><tt>% lli hello.bc</tt></p>
1545
1546       <p>The second examples shows how to invoke the LLVM JIT, <a
1547        href="CommandGuide/html/lli.html">lli</a>.</p></li>
1548
1549   <li><p>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly
1550       code:</p>
1551
1552       <p><tt>% llvm-dis &lt; hello.bc | less</tt><br><br></li>
1553
1554   <li><p>Compile the program to native assembly using the LLC code
1555       generator:</p>
1556
1557       <p><tt>% llc hello.bc -o hello.s</tt></p>
1558
1559   <li><p>Assemble the native assembly language file into a program:</p>
1560
1561       <p><b>Solaris:</b><tt>% /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native</tt></p>
1562       <p><b>Others:</b><tt>% gcc hello.s -o hello.native</tt></p>
1563
1564   <li><p>Execute the native code program:</p>
1565
1566       <p><tt>% ./hello.native</tt></p>
1567
1568       <p>Note that using llvm-gcc to compile directly to native code (i.e. when
1569          the -emit-llvm option is not present) does steps 6/7/8 for you.</p>
1570         </li>
1571
1572 </ol>
1573
1574 </div>
1575
1576
1577 <!-- *********************************************************************** -->
1578 <div class="doc_section">
1579   <a name="problems">Common Problems</a>
1580 </div>
1581 <!-- *********************************************************************** -->
1582
1583 <div class="doc_text">
1584
1585 <p>If you are having problems building or using LLVM, or if you have any other
1586 general questions about LLVM, please consult the <a href="FAQ.html">Frequently
1587 Asked Questions</a> page.</p>
1588
1589 </div>
1590
1591 <!-- *********************************************************************** -->
1592 <div class="doc_section">
1593   <a name="links">Links</a>
1594 </div>
1595 <!-- *********************************************************************** -->
1596
1597 <div class="doc_text">
1598
1599 <p>This document is just an <b>introduction</b> to how to use LLVM to do
1600 some simple things... there are many more interesting and complicated things
1601 that you can do that aren't documented here (but we'll gladly accept a patch
1602 if you want to write something up!).  For more information about LLVM, check
1603 out:</p>
1604
1605 <ul>
1606   <li><a href="http://llvm.org/">LLVM homepage</a></li>
1607   <li><a href="http://llvm.org/doxygen/">LLVM doxygen tree</a></li>
1608   <li><a href="http://llvm.org/docs/Projects.html">Starting a Project
1609   that Uses LLVM</a></li>
1610 </ul>
1611
1612 </div>
1613
1614 <!-- *********************************************************************** -->
1615
1616 <hr>
1617 <address>
1618   <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
1619   src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
1620   <a href="http://validator.w3.org/check/referer"><img
1621   src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
1622
1623   <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
1624   <a href="http://llvm.x10sys.com/rspencer/">Reid Spencer</a><br>
1625   <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
1626   Last modified: $Date$
1627 </address>
1628 </body>
1629 </html>