docs/GettingStartedVS.html

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   6   <title>Getting Started with LLVM System for Microsoft Visual Studio</title>
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  11 <div class="doc_title">
  12   Getting Started with the LLVM System using Microsoft Visual Studio
  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     </ol></li>
  23
  24   <li><a href="#starting">Getting Started with LLVM</a>
  25     <ol>
  26       <li><a href="#terminology">Terminology and Notation</a>
  27       <li><a href="#objfiles">The Location of LLVM Object Files</a>
  28     </ol></li>
  29
  30   <li><a href="#tutorial">An Example Using the LLVM Tool Chain</a>
  31   <li><a href="#problems">Common Problems</a>
  32   <li><a href="#links">Links</a>
  33 </ul>
  34
  35 <div class="doc_author">
  36   <p>Written by:
  37     <a href="mailto:jeffc@jolt-lang.org">Jeff Cohen</a>
  38   </p>
  39 </div>
  40
  41
  42 <!-- *********************************************************************** -->
  43 <div class="doc_section">
  44   <a name="overview"><b>Overview</b></a>
  45 </div>
  46 <!-- *********************************************************************** -->
  47
  48 <div class="doc_text">
  49
  50   <p>The Visual Studio port at this time is experimental.  It is suitable for
  51   use only if you are writing your own compiler front end or otherwise have a
  52   need to dynamically generate machine code.  The JIT and interpreter are
  53   functional, but it is currently not possible to generate assembly code which
  54   is then assembled into an executable.  You can indirectly create executables
  55   by using the C back end.</p>
  56
  57   <p>To emphasize, there is no C/C++ front end currently available.
  58   <tt>llvm-gcc</tt> is based on GCC, which cannot be bootstrapped using VC++.
  59   Eventually there should be a <tt>llvm-gcc</tt> based on Cygwin or MinGW that
  60   is usable.  There is also the option of generating bitcode files on Unix and
  61   copying them over to Windows.  But be aware the odds of linking C++ code
  62   compiled with <tt>llvm-gcc</tt> with code compiled with VC++ is essentially
  63   zero.</p>
  64
  65   <p>The LLVM test suite cannot be run on the Visual Studio port at this
  66   time.</p>
  67
  68   <p>Most of the tools build and work.  <tt>bugpoint</tt> does build, but does
  69   not work.  The other tools 'should' work, but have not been fully tested.</p>
  70
  71   <p>Additional information about the LLVM directory structure and tool chain
  72   can be found on the main <a href="GettingStarted.html">Getting Started</a>
  73   page.</p>
  74
  75 </div>
  76
  77 <!-- *********************************************************************** -->
  78 <div class="doc_section">
  79   <a name="quickstart"><b>Getting Started Quickly (A Summary)</b></a>
  80 </div>
  81 <!-- *********************************************************************** -->
  82
  83 <div class="doc_text">
  84
  85 <p>Here's the short story for getting up and running quickly with LLVM:</p>
  86
  87 <ol>
  88   <li>Read the documentation.</li>
  89   <li>Seriously, read the documentation.</li>
  90   <li>Remember that you were warned twice about reading the documentation.</li>
  91
  92   <li>Get the Source Code
  93   <ul>
  94     <li>With the distributed files:
  95     <ol>
  96       <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
  97       <li><tt>gunzip --stdout llvm-<i>version</i>.tar.gz | tar -xvf -</tt>
  98       <i>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;or use WinZip</i>
  99       <li><tt>cd llvm</tt></li>
 100     </ol></li>
 101
 102     <li>With anonymous Subversion access:
 103     <ol>
 104       <li><tt>cd <i>where-you-want-llvm-to-live</i></tt></li>
 105       <li><tt>svn co http://llvm.org/svn/llvm-project/llvm-top/trunk llvm-top
 106       </tt></li>
 107       <li><tt>make checkout MODULE=llvm</tt>
 108       <li><tt>cd llvm</tt></li>
 109     </ol></li>
 110   </ul></li>
 111
 112   <li> Use <a href="http://www.cmake.org/">CMake</a> to generate up-to-date
 113     project files:
 114     <ul><li>This step is currently optional as LLVM does still come with a
 115     normal Visual Studio solution file, but it is not always kept up-to-date
 116     and will soon be deprecated in favor of the multi-platform generator
 117     CMake.</li>
 118     <li>If CMake is installed then the most simple way is to just start the
 119     CMake GUI, select the directory where you have LLVM extracted to, and
 120     the default options should all be fine.  The one option you may really
 121     want to change, regardless of anything else, might be the
 122     CMAKE_INSTALL_PREFIX setting to select a directory to INSTALL to once
 123     compiling is complete.</li>
 124     <li>If you use CMake to generate the Visual Studio solution and project
 125     files, then the Solution will have a few extra options compared to the
 126     current included one.  The projects may still be built individually, but
 127     to build them all do not just select all of them in batch build (as some
 128     are meant as configuration projects), but rather select and build just
 129     the ALL_BUILD project to build everything, or the INSTALL project, which
 130     first builds the ALL_BUILD project, then installs the LLVM headers, libs,
 131     and other useful things to the directory set by the CMAKE_INSTALL_PREFIX
 132     setting when you first configured CMake.</li>
 133     </ul>
 134   </li>
 135
 136   <li>Start Visual Studio
 137   <ul>
 138     <li>If you did not use CMake, then simply double click on the solution
 139     file <tt>llvm/win32/llvm.sln</tt>.</li>
 140     <li>If you used CMake, then the directory you created the project files,
 141     the root directory will have an <tt>llvm.sln</tt> file, just
 142     double-click on that to open Visual Studio.</li>
 143   </ul></li>
 144
 145   <li>Build the LLVM Suite:
 146   <ul>
 147     <li>Simply build the solution.</li>
 148     <li>The Fibonacci project is a sample program that uses the JIT.  Modify
 149     the project's debugging properties to provide a numeric command line
 150     argument.  The program will print the corresponding fibonacci value.</li>
 151   </ul></li>
 152
 153 </ol>
 154
 155 <p>It is strongly encouraged that you get the latest version from Subversion as
 156 changes are continually making the VS support better.</p>
 157
 158 </div>
 159
 160 <!-- *********************************************************************** -->
 161 <div class="doc_section">
 162   <a name="requirements"><b>Requirements</b></a>
 163 </div>
 164 <!-- *********************************************************************** -->
 165
 166 <div class="doc_text">
 167
 168   <p>Before you begin to use the LLVM system, review the requirements given
 169   below.  This may save you some trouble by knowing ahead of time what hardware
 170   and software you will need.</p>
 171
 172 </div>
 173
 174 <!-- ======================================================================= -->
 175 <div class="doc_subsection">
 176   <a name="hardware"><b>Hardware</b></a>
 177 </div>
 178
 179 <div class="doc_text">
 180
 181   <p>Any system that can adequately run Visual Studio .NET 2005 SP1 is fine.
 182   The LLVM source tree and object files, libraries and executables will consume
 183   approximately 3GB.</p>
 184
 185 </div>
 186
 187 <!-- ======================================================================= -->
 188 <div class="doc_subsection"><a name="software"><b>Software</b></a></div>
 189 <div class="doc_text">
 190
 191   <p>You will need Visual Studio .NET 2005 SP1 or higher.  The VS2005 SP1
 192   beta and the normal VS2005 still have bugs that are not completely
 193   compatible. VS2003 would work except (at last check) it has a bug with
 194   friend classes that you can work-around with some minor code rewriting
 195   (and please submit a patch if you do).  Earlier versions of Visual Studio
 196   do not support the C++ standard well enough and will not work.</p>
 197
 198   <p>You will also need the <a href="http://www.cmake.org/">CMake</a> build
 199   system since it generates the project files you will use to build with.</p>
 200
 201   <p>
 202   Do not install the LLVM directory tree into a path containing spaces (e.g.
 203   C:\Documents and Settings\...) as the configure step will fail.</p>
 204
 205 </div>
 206
 207 <!-- *********************************************************************** -->
 208 <div class="doc_section">
 209   <a name="starting"><b>Getting Started with LLVM</b></a>
 210 </div>
 211 <!-- *********************************************************************** -->
 212
 213 <div class="doc_text">
 214
 215 <p>The remainder of this guide is meant to get you up and running with
 216 LLVM using Visual Studio and to give you some basic information about the LLVM
 217 environment.</p>
 218
 219 </div>
 220
 221 <!-- ======================================================================= -->
 222 <div class="doc_subsection">
 223   <a name="terminology">Terminology and Notation</a>
 224 </div>
 225
 226 <div class="doc_text">
 227
 228 <p>Throughout this manual, the following names are used to denote paths
 229 specific to the local system and working environment.  <i>These are not
 230 environment variables you need to set but just strings used in the rest
 231 of this document below</i>.  In any of the examples below, simply replace
 232 each of these names with the appropriate pathname on your local system.
 233 All these paths are absolute:</p>
 234
 235 <dl>
 236     <dt>SRC_ROOT</dt>
 237     <dd><p>This is the top level directory of the LLVM source tree.</p></dd>
 238
 239     <dt>OBJ_ROOT</dt>
 240     <dd><p>This is the top level directory of the LLVM object tree (i.e. the
 241         tree where object files and compiled programs will be placed.  It is
 242         fixed at SRC_ROOT/win32).</p></dd>
 243 </dl>
 244
 245 </div>
 246
 247 <!-- ======================================================================= -->
 248 <div class="doc_subsection">
 249   <a name="objfiles">The Location of LLVM Object Files</a>
 250 </div>
 251
 252 <div class="doc_text">
 253
 254   <p>The object files are placed under <tt>OBJ_ROOT/Debug</tt> for debug builds
 255   and <tt>OBJ_ROOT/Release</tt> for release (optimized) builds.  These include
 256   both executables and libararies that your application can link against.</p>
 257
 258   <p>The files that <tt>configure</tt> would create when building on Unix are
 259   created by the <tt>Configure</tt> project and placed in
 260   <tt>OBJ_ROOT/llvm</tt>.  You application must have OBJ_ROOT in its include
 261   search path just before <tt>SRC_ROOT/include</tt>.</p>
 262
 263 </div>
 264
 265 <!-- *********************************************************************** -->
 266 <div class="doc_section">
 267   <a name="tutorial">An Example Using the LLVM Tool Chain</a>
 268 </div>
 269 <!-- *********************************************************************** -->
 270
 271 <div class="doc_text">
 272
 273 <ol>
 274   <li><p>First, create a simple C file, name it 'hello.c':</p>
 275
 276 <div class="doc_code">
 277 <pre>
 278 #include &lt;stdio.h&gt;
 279 int main() {
 280   printf("hello world\n");
 281   return 0;
 282 }
 283 </pre></div></li>
 284
 285   <li><p>Next, compile the C file into a LLVM bitcode file:</p>
 286
 287 <div class="doc_code">
 288 <pre>
 289 % llvm-gcc -c hello.c -emit-llvm -o hello.bc
 290 </pre>
 291 </div>
 292
 293       <p>This will create the result file <tt>hello.bc</tt> which is the LLVM
 294          bitcode that corresponds the the compiled program and the library
 295          facilities that it required.  You can execute this file directly using
 296          <tt>lli</tt> tool, compile it to native assembly with the <tt>llc</tt>,
 297          optimize or analyze it further with the <tt>opt</tt> tool, etc.</p>
 298
 299       <p><b>Note: while you cannot do this step on Windows, you can do it on a
 300          Unix system and transfer <tt>hello.bc</tt> to Windows.  Important:
 301          transfer as a binary file!</b></p></li>
 302
 303   <li><p>Run the program using the just-in-time compiler:</p>
 304
 305 <div class="doc_code">
 306 <pre>
 307 % lli hello.bc
 308 </pre>
 309 </div>
 310
 311       <p>Note: this will only work for trivial C programs.  Non-trivial programs
 312          (and any C++ program) will have dependencies on the GCC runtime that
 313          won't be satisfied by the Microsoft runtime libraries.</p></li>
 314
 315   <li><p>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly
 316       code:</p>
 317
 318 <div class="doc_code">
 319 <pre>
 320 % llvm-dis &lt; hello.bc | more
 321 </pre>
 322 </div></li>
 323
 324   <li><p>Compile the program to C using the LLC code generator:</p>
 325
 326 <div class="doc_code">
 327 <pre>
 328 % llc -march=c hello.bc
 329 </pre>
 330 </div></li>
 331
 332   <li><p>Compile to binary using Microsoft C:</p>
 333
 334 <div class="doc_code">
 335 <pre>
 336 % cl hello.cbe.c
 337 </pre>
 338 </div>
 339
 340     <p>Note: this will only work for trivial C programs.  Non-trivial programs
 341       (and any C++ program) will have dependencies on the GCC runtime that won't
 342       be satisfied by the Microsoft runtime libraries.</p></li>
 343
 344   <li><p>Execute the native code program:</p>
 345
 346 <div class="doc_code">
 347 <pre>
 348 % hello.cbe.exe
 349 </pre>
 350 </div></li>
 351 </ol>
 352
 353 </div>
 354
 355 <!-- *********************************************************************** -->
 356 <div class="doc_section">
 357   <a name="problems">Common Problems</a>
 358 </div>
 359 <!-- *********************************************************************** -->
 360
 361 <div class="doc_text">
 362
 363   <ul>
 364     <li>In Visual C++, if you are linking with the x86 target statically, the
 365     linker will remove the x86 target library from your generated executable or
 366     shared library because there are no references to it. You can force the
 367     linker to include these references by using
 368     <tt>"/INCLUDE:_X86TargetMachineModule"</tt> when linking. In the Visual
 369     Studio IDE, this can be added in
 370 <tt>Project&nbsp;Properties->Linker->Input->Force&nbsp;Symbol&nbsp;References</tt>.
 371     </li>
 372   </ul>
 373
 374 <p>If you are having problems building or using LLVM, or if you have any other
 375 general questions about LLVM, please consult the <a href="FAQ.html">Frequently
 376 Asked Questions</a> page.</p>
 377
 378 </div>
 379
 380 <!-- *********************************************************************** -->
 381 <div class="doc_section">
 382   <a name="links">Links</a>
 383 </div>
 384 <!-- *********************************************************************** -->
 385
 386 <div class="doc_text">
 387
 388 <p>This document is just an <b>introduction</b> to how to use LLVM to do
 389 some simple things... there are many more interesting and complicated things
 390 that you can do that aren't documented here (but we'll gladly accept a patch
 391 if you want to write something up!).  For more information about LLVM, check
 392 out:</p>
 393
 394 <ul>
 395   <li><a href="http://llvm.org/">LLVM homepage</a></li>
 396   <li><a href="http://llvm.org/doxygen/">LLVM doxygen tree</a></li>
 397   <li><a href="http://llvm.org/docs/Projects.html">Starting a Project
 398       that Uses LLVM</a></li>
 399 </ul>
 400
 401 </div>
 402
 403 <!-- *********************************************************************** -->
 404
 405 <hr>
 406 <address>
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 411
 412   <a href="mailto:jeffc@jolt-lang.org">Jeff Cohen</a><br>
 413   <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
 414   Last modified: $Date$
 415 </address>
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