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2<html>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]3 <head>
4 <title>Getting Started with LLVM System</title>
5 </head>
6
7 <body bgcolor=white>
8 <center><h1>Getting Started with the LLVM System<br><font size=3>By: <a
9 href="mailto:gshi1@uiuc.edu">Guochun Shi</a>,
John Criswellcb27f1e2003-07-01 21:55:57 +0000[diff] [blame]10 <a href="mailto:sabre@nondot.org">Chris Lattner</a>,
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]11 <a href="mailto:criswell@uiuc.edu">John Criswell</a>,
12 <a href="http://misha.brukman.net">Misha Brukman</a>, and
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]13 <a href="http://www.cs.uiuc.edu/~vadve">Vikram Adve</a>
14 </font></h1></center>
15
16 <!--=====================================================================-->
17 <h2><a name="Contents">Contents</a></h2>
18 <!--=====================================================================-->
19
20 <ul>
21 <li><a href="#overview">Overview</a>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]22 <li><a href="#quickstart">Getting Started Quickly (A Summary)</a>
John Criswell3ab71362003-10-20 16:39:52 +0000[diff] [blame]23 <li><a href="#requirements">Requirements</a>
24 <ol>
25 <li><a href="#hardware">Hardware</a>
26 <li><a href="#software">Software</a>
27 </ol>
28
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]29 <li><a href="#starting">Getting Started with LLVM</a>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]30 <ol>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]31 <li><a href="#terminology">Terminology and Notation</tt></a>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]32 <li><a href="#environment">Setting Up Your Environment</a>
John Criswell312a68c2003-07-07 19:27:35 +0000[diff] [blame]33 <li><a href="#unpack">Unpacking the LLVM Archives</a>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]34 <li><a href="#checkout">Checkout LLVM from CVS</a>
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]35 <li><a href="#installcf">Install the GCC Front End</a>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]36 <li><a href="#config">Local LLVM Configuration</tt></a>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]37 <li><a href="#compile">Compiling the LLVM Suite Source Code</a>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]38 <li><a href="#objfiles">The Location of LLVM Object Files</tt></a>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]39 </ol>
40 <li><a href="#layout">Program layout</a>
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]41 <ol>
42 <li><a href="#cvsdir"><tt>CVS</tt> directories</a>
43 <li><a href="#include"><tt>llvm/include</tt></a>
44 <li><a href="#lib"><tt>llvm/lib</tt></a>
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]45 <li><a href="#runtime"><tt>llvm/runtime</tt></a>
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]46 <li><a href="#test"><tt>llvm/test</tt></a>
47 <li><a href="#tools"><tt>llvm/tools</tt></a>
48 <li><a href="#utils"><tt>llvm/utils</tt></a>
49 </ol>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]50 <li><a href="#tutorial">An Example Using the LLVM Tool Chain</a>
51 <li><a href="#problems">Common Problems</a>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]52 <li><a href="#links">Links</a>
53 </ul>
54
55
56 <!--=====================================================================-->
57 <center>
58 <h2><a name="overview"><b>Overview</b></a></h2>
59 </center>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]60 <hr>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]61 <!--=====================================================================-->
62
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]63 Welcome to LLVM! In order to get started, you first need to know some
64 basic information.
65
66 <p>
67 First, LLVM comes in two pieces. The first piece is the LLVM suite. This
68 contains all of the tools, libraries, and header files needed to use the
John Criswell3ab71362003-10-20 16:39:52 +0000[diff] [blame]69 low level virtual machine. It contains an assembler, disassembler,
70 bytecode analyzer, and bytecode optimizer. It also contains a test suite
71 that can be used to test the LLVM tools and the GCC front end.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]72 <p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]73 The second piece is the GCC front end. This component provides a version
74 of GCC that compiles C and C++ code into LLVM bytecode. Currently, the
75 GCC front end is a modified version of GCC 3.4 (we track the GCC 3.4
76 development). Once compiled into LLVM bytecode, a program can be
77 manipulated with the LLVM tools from the LLVM suite.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]78
79 <!--=====================================================================-->
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]80 <center>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]81 <h2><a name="quickstart"><b>Getting Started Quickly (A Summary)</b></a></h2>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]82 </center>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]83 <hr>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]84 <!--=====================================================================-->
85
86 Here's the short story for getting up and running quickly with LLVM:
Chris Lattner96768ea2003-02-14 04:22:13 +0000[diff] [blame]87 <ol>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]88 <li>Install the GCC front end:
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]89 <ol>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]90 <li><tt>cd <i>where-you-want-the-C-front-end-to-live</i></tt>
91 <li><tt>gunzip --stdout cfrontend.<i>platform</i>.tar.gz | tar -xvf
92 -</tt>
John Criswell0f6d7c02003-10-27 18:18:16 +0000[diff] [blame^]93 <li><b>Sparc Only:</b><br>
94 <tt>
95 cd cfrontend/sparc<br>
96 ./fixheaders
97 </tt>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]98 </ol>
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]99
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]100 <p>
101
102 <li>Get the Source Code
103 <ul>
104 <li>With the distributed files:
105 <ol>
106 <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
107 <li><tt>gunzip --stdout llvm.tar.gz | tar -xvf -</tt>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]108 <li><tt>cd llvm</tt>
109 </ol>
110
111 <p>
112
113 <li>With anonymous CVS access:
114 <ol>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]115 <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
John Criswelle04c2632003-10-21 21:24:38 +0000[diff] [blame]116 <li><tt>cvs -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm login</tt>
117 <li>Hit the return key when prompted for the password.
Chris Lattner70bb09b2003-10-23 19:49:01 +0000[diff] [blame]118 <li><tt>cvs -z3 -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm co llvm</tt>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]119 <li><tt>cd llvm</tt>
120 </ol>
121 </ul>
122 </ul>
123
124 <p>
125
126 <li>Configure the LLVM Build Environment
127 <ol>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]128 <li>Change directory to where you want to store the LLVM object
129 files and run <tt>configure</tt> to configure the Makefiles and
130 header files for the default platform.
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]131 Useful options include:
132 <ul>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]133 <li><tt>--with-llvmgccdir=<i>directory</i></tt>
134 <br>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]135 Specify where the LLVM GCC frontend is installed.
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]136 <p>
137
138 <li><tt>--enable-spec2000=<i>directory</i></tt>
139 <br>
140 Enable the SPEC2000 benchmarks for testing. The SPEC2000
141 benchmarks should be available in <tt><i>directory</i></tt>.
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]142 </ul>
143 </ol>
144
145 <p>
146
147 <li>Build the LLVM Suite
148 <ol>
149 <li>Set your LLVM_LIB_SEARCH_PATH environment variable.
150 <li><tt>gmake -k |& tee gnumake.out
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]151 &nbsp;&nbsp;&nbsp;# this is csh or tcsh syntax</tt>
152 </ol>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]153
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]154 <p>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]155
Chris Lattner96768ea2003-02-14 04:22:13 +0000[diff] [blame]156 </ol>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]157
John Criswell3ab71362003-10-20 16:39:52 +0000[diff] [blame]158 <p>
159 Consult the <a href="starting">Getting Started with LLVM</a> section for
160 detailed information on configuring and compiling LLVM. See
161 <a href="#environment">Setting Up Your Environment</a> for tips that
162 simplify working with the GCC front end and LLVM tools. Go to
163 <a href="#layout">Program Layout</a> to learn about the layout of the
164 source code tree.
165
166 <!--=====================================================================-->
167 <center>
168 <h2><a name="requirements"><b>Requirements</b></a></h2>
169 </center>
170 <hr>
171 <!--=====================================================================-->
172
173 Before you begin to use the LLVM system, review the requirements given
174 below. This may save you some trouble by knowing ahead of time what
175 hardware and software you will need.
176
177 <!--=====================================================================-->
178 <h3><a name="hardware"><b>Hardware</b></a></h3>
179 <!--=====================================================================-->
180 LLVM is known to work on the following platforms:
181 <ul>
182 <li> Linux on x86 (Pentium and above)
183 <ul>
184 <li> Approximately 760 MB of Free Disk Space
185 <ul>
186 <li>Source code: 30 MB
187 <li>Object code: 670 MB
188 <li>GCC front end: 60 MB
189 </ul>
190 </ul>
191
192 <p>
193
194 <li> Solaris on SparcV9 (Ultrasparc)
195 <ul>
196 <li> Approximately 1.24 GB of Free Disk Space
197 <ul>
198 <li>Source code: 30 MB
199 <li>Object code: 1000 MB
200 <li>GCC front end: 210 MB
201 </ul>
202 </ul>
203 </ul>
204
205 The LLVM suite <i>may</i> compile on other platforms, but it is not
206 guaranteed to do so. If compilation is successful, the LLVM utilities
207 should be able to assemble, disassemble, analyze, and optimize LLVM
208 bytecode. Code generation should work as well, although the generated
209 native code may not work on your platform.
210 <p>
211 The GCC front end is not very portable at the moment. If you want to get
John Criswell0f6d7c02003-10-27 18:18:16 +0000[diff] [blame^]212 it to work on another platform, you can download a copy of the source
John Criswell3ab71362003-10-20 16:39:52 +0000[diff] [blame]213 and try to compile it on your platform.
214 </p>
215
216 <!--=====================================================================-->
217 <h3><a name="software"><b>Software</b></a></h3>
218 <!--=====================================================================-->
219 <p>
220
221 Compiling LLVM requires that you have several software packages installed:
222
223 <ul compact>
224 <li>
225 <a href="http://gcc.gnu.org">GCC 3.x with C and C++ language support</a>
226
227 <li>
228 <a href="http://savannah.gnu.org/projects/make">GNU Make</a>
229
230 <li>
231 <a href="http://www.gnu.org/software/flex">Flex</a>
232
233 <li>
234 <a href="http://www.gnu.org/software/bison/bison.html">Bison</a>
235 </ul>
236
237 <p>
238 There are some additional tools that you may want to have when working with
239 LLVM:
240 </p>
241
242 <ul>
243 <li><A href="http://www.gnu.org/software/autoconf">GNU Autoconf</A>
244 <li><A href="http://savannah.gnu.org/projects/m4">GNU M4</A>
245 <p>
246 If you want to make changes to the configure scripts, you will need
247 GNU autoconf (2.57 or higher), and consequently, GNU M4 (version 1.4
248 or higher).
249 </p>
250
251 <li><A href="http://www.codesourcery.com/qm/qmtest">QMTest</A>
252 <li><A href="http://www.python.org">Python</A>
253 <p>
254 These are needed to use the LLVM test suite.
255 </ul>
256
257
258 <p>The remainder of this guide is meant to get you up and running with
259 LLVM and to give you some basic information about the LLVM environment.
260 A <a href="#starting">complete guide to installation</a> is provided in the
261 next section.
262
263 <p>The later sections of this guide describe the <a
264 href="#layout">general layout</a> of the the LLVM source tree, a <a
265 href="#tutorial">simple example</a> using the LLVM tool chain, and <a
266 href="#links">links</a> to find more information about LLVM or to get
267 help via e-mail.
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]268
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]269 <!--=====================================================================-->
270 <center>
271 <h2><a name="starting"><b>Getting Started with LLVM</b></a></h2>
272 </center>
273 <hr>
274 <!--=====================================================================-->
275
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]276 <!------------------------------------------------------------------------->
277 <h3><a name="terminology">Terminology and Notation</a></h3>
278 <!------------------------------------------------------------------------->
279
280 <p>Throughout this manual, the following names are used to denote paths
281 specific to the local system and working environment. <i>These are not
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]282 environment variables you need to set but just strings used in the rest
283 of this document below</i>. In any of the examples below, simply replace
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]284 each of these names with the appropriate pathname on your local system.
Chris Lattner1db872d2002-09-06 16:26:13 +0000[diff] [blame]285 All these paths are absolute:</p>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]286 <dl compact>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]287 <dt>SRC_ROOT
288 <dd>
289 This is the top level directory of the LLVM source tree.
290 <p>
291
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]292 <dt>OBJ_ROOT
293 <dd>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]294 This is the top level directory of the LLVM object tree (i.e. the
295 tree where object files and compiled programs will be placed. It
296 can be the same as SRC_ROOT).
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]297 <p>
298
299 <dt>LLVMGCCDIR
300 <dd>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]301 This is the where the LLVM GCC Front End is installed.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]302 <p>
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]303 For the pre-built GCC front end binaries, the LLVMGCCDIR is
John Criswella27028b2003-07-03 16:49:40 +0000[diff] [blame]304 <tt>cfrontend/<i>platform</i>/llvm-gcc</tt>.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]305 </dl>
306
307 <!------------------------------------------------------------------------->
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]308 <h3><a name="environment">Setting Up Your Environment</a></h3>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]309 <!------------------------------------------------------------------------->
310
311 <p>
312 In order to compile and use LLVM, you will need to set some environment
313 variables. There are also some shell aliases which you may find useful.
314 You can set these on the command line, or better yet, set them in your
315 <tt>.cshrc</tt> or <tt>.profile</tt>.
316
317 <dl compact>
318 <dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt><i>LLVMGCCDIR</i>/llvm-gcc/bytecode-libs</tt>
319 <dd>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]320 This environment variable helps the LLVM GCC front end find bytecode
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]321 libraries that it will need for compilation.
322 <p>
323
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]324 <dt>alias llvmgcc <i>LLVMGCCDIR</i><tt>/llvm-gcc/bin/gcc</tt>
325 <dt>alias llvmg++ <i>LLVMGCCDIR</i><tt>/llvm-gcc/bin/g++</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]326 <dd>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]327 This alias allows you to use the LLVM C and C++ front ends without putting
328 them in your <tt>PATH</tt> or typing in their complete pathnames.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]329 </dl>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]330
331 <!------------------------------------------------------------------------->
John Criswell312a68c2003-07-07 19:27:35 +0000[diff] [blame]332 <h3><a name="unpack">Unpacking the LLVM Archives</a></h3>
333 <!------------------------------------------------------------------------->
334
335 <p>
336 If you have the LLVM distribution, you will need to unpack it before you
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]337 can begin to compile it. LLVM is distributed as a set of three files. Each
John Criswell312a68c2003-07-07 19:27:35 +0000[diff] [blame]338 file is a TAR archive that is compressed with the gzip program.
339 </p>
340
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]341 <p> The three files are as follows:
John Criswell312a68c2003-07-07 19:27:35 +0000[diff] [blame]342 <dl compact>
343 <dt>llvm.tar.gz
344 <dd>This is the source code to the LLVM suite.
345 <p>
346
347 <dt>cfrontend.sparc.tar.gz
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]348 <dd>This is the binary release of the GCC front end for Solaris/Sparc.
John Criswell312a68c2003-07-07 19:27:35 +0000[diff] [blame]349 <p>
350
351 <dt>cfrontend.x86.tar.gz
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]352 <dd>This is the binary release of the GCC front end for Linux/x86.
John Criswell312a68c2003-07-07 19:27:35 +0000[diff] [blame]353 </dl>
354
John Criswell312a68c2003-07-07 19:27:35 +0000[diff] [blame]355 <!------------------------------------------------------------------------->
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]356 <h3><a name="checkout">Checkout LLVM from CVS</a></h3>
357 <!------------------------------------------------------------------------->
358
John Criswell312a68c2003-07-07 19:27:35 +0000[diff] [blame]359 <p>If you have access to our CVS repository, you can get a fresh copy of
360 the entire source code. All you need to do is check it out from CVS as
361 follows:
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]362 <ul>
363 <li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
John Criswelle04c2632003-10-21 21:24:38 +0000[diff] [blame]364 <li><tt>cvs -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm login</tt>
365 <li>Hit the return key when prompted for the password.
Chris Lattner70bb09b2003-10-23 19:49:01 +0000[diff] [blame]366 <li><tt>cvs -z3 -d :pserver:anon@llvm-cvs.cs.uiuc.edu:/var/cvs/llvm co llvm</tt>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]367 </ul>
368
369 <p>This will create an '<tt>llvm</tt>' directory in the current
370 directory and fully populate it with the LLVM source code, Makefiles,
371 test directories, and local copies of documentation files.</p>
372
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]373 <p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]374 Note that the GCC front end is not included in the CVS repository. You
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]375 should have downloaded the binary distribution for your platform.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]376 </p>
377
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]378 <!------------------------------------------------------------------------->
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]379 <h3><a name="installcf">Install the GCC Front End</a></h3>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]380 <!------------------------------------------------------------------------->
381
382 <p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]383 Before configuring and compiling the LLVM suite, you need to extract the
John Criswell0f6d7c02003-10-27 18:18:16 +0000[diff] [blame^]384 LLVM GCC front end from the binary distribution. It is used for building
385 the
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]386 bytecode libraries later used by the GCC front end for linking programs, and
387 its location must be specified when the LLVM suite is configured.
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]388 </p>
389
390 <p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]391 To install the GCC front end, do the following:
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]392 <ol>
393 <li><tt>cd <i>where-you-want-the-front-end-to-live</i></tt>
394 <li><tt>gunzip --stdout cfrontend.<i>platform</i>.tar.gz | tar -xvf
395 -</tt>
396 </ol>
397
John Criswell0f6d7c02003-10-27 18:18:16 +0000[diff] [blame^]398 If you are on a Sparc/Solaris machine, you will need to fix the header
399 files:
400
401 <p>
402
403 <tt>
404 cd cfrontend/sparc
405 <br>
406 ./fixheaders
407 </tt>
408
409 <p>
410 The binary versions of the GCC front end may not suit all of your needs.
411 For example, the binary distribution may include an old version of a system
412 header file, not "fix" a header file that needs to be fixed for GCC, or it
413 may be linked with libraries not available on your system.
414 </p>
415
416 <p>
417 In cases like these, you may want to try
418 <a href="CFEBuildInstrs.html">building the GCC front end from source.</a>
419 This is not for the faint of heart, so be forewarned.
420 </p>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]421 <!------------------------------------------------------------------------->
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]422 <h3><a name="config">Local LLVM Configuration</a></h3>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]423 <!------------------------------------------------------------------------->
424
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]425 <p>Once checked out from the CVS repository, the LLVM suite source code
426 must be configured via the <tt>configure</tt> script. This script sets
427 variables in <tt>llvm/Makefile.config</tt> and
John Criswelle04c2632003-10-21 21:24:38 +0000[diff] [blame]428 <tt>llvm/include/Config/config.h</tt>. It also populates <i>OBJ_ROOT</i>
429 with the Makefiles needed to build LLVM.
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]430
431 <p>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]432 The following environment variables are used by the <tt>configure</tt>
433 script to configure the build system:
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]434 </p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]435
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]436 <table border=1>
437 <tr>
438 <th>Variable</th>
439 <th>
440 Purpose
441 </th>
442 </tr>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]443
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]444 <tr>
445 <td>CC</td>
446 <td>
447 Tells <tt>configure</tt> which C compiler to use. By default,
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]448 <tt>configure</tt> will look for the first GCC C compiler in
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]449 <tt>PATH</tt>. Use this variable to override
450 <tt>configure</tt>'s default behavior.
451 </td>
452 </tr>
453
454 <tr>
455 <td>CXX</td>
456 <td>
457 Tells <tt>configure</tt> which C++ compiler to use. By default,
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]458 <tt>configure</tt> will look for the first GCC C++ compiler in
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]459 <tt>PATH</tt>. Use this variable to override
460 <tt>configure</tt>'s default behavior.
461 </td>
462 </tr>
463 </table>
464
465 <p>
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]466 The following options can be used to set or enable LLVM specific options:
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]467 </p>
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]468
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]469 <dl compact>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]470 <dt><i>--with-llvmgccdir=LLVMGCCDIR</i>
471 <dd>
472 Path to the location where the LLVM C front end binaries and
473 associated libraries will be installed.
474 <p>
475 <dt><i>--enable-optimized</i>
476 <dd>
John Criswell623e5942003-10-10 18:51:11 +0000[diff] [blame]477 Enables optimized compilation by default (debugging symbols are removed
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]478 and GCC optimization flags are enabled). The default is to use an
479 unoptimized build (also known as a debug build).
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]480 <p>
481 <dt><i>--enable-jit</i>
482 <dd>
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]483 Compile the Just In Time (JIT) functionality. This is not available
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]484 on all platforms. The default is dependent on platform, so it is best
485 to explicitly enable it if you want it.
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]486 <p>
487 <dt><i>--enable-spec2000</i>
488 <dt><i>--enable-spec2000=&lt;<tt>directory</tt>&gt;</i>
489 <dd>
490 Enable the use of SPEC2000 when testing LLVM. This is disabled by default
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]491 (unless <tt>configure</tt> finds SPEC2000 installed). By specifying
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]492 <tt>directory</tt>, you can tell configure where to find the SPEC2000
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]493 benchmarks. If <tt>directory</tt> is left unspecified, <tt>configure</tt>
494 uses the default value
495 <tt>/home/vadve/shared/benchmarks/speccpu2000/benchspec</tt>.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]496 </dl>
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]497
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]498 <p>
499 To configure LLVM, follow these steps:
500 <ol>
501 <li>Change directory into the object root directory:
502 <br>
503 <tt>cd <i>OBJ_ROOT</i></tt>
504 <p>
505
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]506 <li>Run the <tt>configure</tt> script located in the LLVM source tree:
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]507 <br>
508 <tt><i>SRC_ROOT</i>/configure</tt>
509 <p>
510 </ol>
511 </p>
512
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]513 In addition to running <tt>configure</tt>, you must set the
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]514 <tt>LLVM_LIB_SEARCH_PATH</tt> environment variable in your startup scripts.
515 This environment variable is used to locate "system" libraries like
516 "<tt>-lc</tt>" and "<tt>-lm</tt>" when linking. This variable should be set
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]517 to the absolute path for the bytecode-libs subdirectory of the GCC front end
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]518 install, or <i>LLVMGCCDIR</i>/llvm-gcc/bytecode-libs. For example, one might
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]519 set <tt>LLVM_LIB_SEARCH_PATH</tt> to
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]520 <tt>/home/vadve/lattner/local/x86/llvm-gcc/bytecode-libs</tt> for the X86
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]521 version of the GCC front end on our research machines.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]522
523 <!------------------------------------------------------------------------->
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]524 <h3><a name="compile">Compiling the LLVM Suite Source Code</a></h3>
525 <!------------------------------------------------------------------------->
526
527 Once you have configured LLVM, you can build it. There are three types of
528 builds:
529
530 <dl compact>
531 <dt>Debug Builds
532 <dd>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]533 These builds are the default when one types <tt>gmake</tt> (unless the
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]534 <tt>--enable-optimized</tt> option was used during configuration). The
535 build system will compile the tools and libraries with debugging
536 information.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]537 <p>
538
539 <dt>Release (Optimized) Builds
540 <dd>
541 These builds are enabled with the <tt>--enable-optimized</tt> option to
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]542 <tt>configure</tt> or by specifying <tt>ENABLE_OPTIMIZED=1</tt> on the
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]543 <tt>gmake</tt> command line. For these builds, the build system will
544 compile the tools and libraries with GCC optimizations enabled and strip
545 debugging information from the libraries and executables it generates.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]546 <p>
547
548 <dt>Profile Builds
549 <dd>
550 These builds are for use with profiling. They compile profiling
551 information into the code for use with programs like <tt>gprof</tt>.
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]552 Profile builds must be started by specifying <tt>ENABLE_PROFILING=1</tt>
553 on the <tt>gmake</tt> command line.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]554 </dl>
555
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]556 Once you have LLVM configured, you can build it by entering the
557 <i>OBJ_ROOT</i> directory and issuing the following command:
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]558 <p>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]559 <tt>gmake</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]560
561 <p>
562 If you have multiple processors in your machine, you may wish to use some
563 of the parallel build options provided by GNU Make. For example, you could
564 use the command:
565 </p>
566
567 <p>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]568 <tt>gmake -j2</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]569
570 <p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]571 There are several special targets which are useful when working with the LLVM
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]572 source code:
573
574 <dl compact>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]575 <dt><tt>gmake clean</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]576 <dd>
577 Removes all files generated by the build. This includes object files,
578 generated C/C++ files, libraries, and executables.
579 <p>
580
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]581 <dt><tt>gmake distclean</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]582 <dd>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]583 Removes everything that <tt>gmake clean</tt> does, but also removes
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]584 files generated by <tt>configure</tt>. It attempts to return the
585 source tree to the original state in which it was shipped.
586 <p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]587
588 <dt><tt>gmake install</tt>
589 <dd>
590 Installs LLVM files into the proper location. For the most part,
591 this does nothing, but it does install bytecode libraries into the
592 GCC front end's bytecode library directory. If you need to update
593 your bytecode libraries, this is the target to use once you've built
594 them.
595 <p>
596
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]597 </dl>
598
599 It is also possible to override default values from <tt>configure</tt> by
600 declaring variables on the command line. The following are some examples:
601
602 <dl compact>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]603 <dt><tt>gmake ENABLE_OPTIMIZED=1</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]604 <dd>
605 Perform a Release (Optimized) build.
606 <p>
607
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]608 <dt><tt>gmake ENABLE_PROFILING=1</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]609 <dd>
610 Perform a Profiling build.
611 <p>
612
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]613 <dt><tt>gmake VERBOSE=1</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]614 <dd>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]615 Print what <tt>gmake</tt> is doing on standard output.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]616 <p>
617 </dl>
618
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]619 Every directory in the LLVM object tree includes a <tt>Makefile</tt> to
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]620 build it and any subdirectories that it contains. Entering any directory
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]621 inside the LLVM object tree and typing <tt>gmake</tt> should rebuild
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]622 anything in or below that directory that is out of date.
623
624 <!------------------------------------------------------------------------->
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]625 <h3><a name="objfiles">The Location of LLVM Object Files</a></h3>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]626 <!------------------------------------------------------------------------->
627
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]628 <p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]629 The LLVM build system is capable of sharing a single LLVM source tree among
630 several LLVM builds. Hence, it is possible to build LLVM for several
631 different platforms or configurations using the same source tree.
John Criswellef0096f2003-08-08 22:36:30 +0000[diff] [blame]632 <p>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]633 This is accomplished in the typical autoconf manner:
634 <ul>
635 <li>Change directory to where the LLVM object files should live:
636 <p>
637 <tt>cd <i>OBJ_ROOT</i></tt>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]638
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]639 <li>Run the <tt>configure</tt> script found in the LLVM source directory:
640 <p>
641 <tt><i>SRC_ROOT</i>/configure</tt>
642 </ul>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]643
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]644 <p>
645 The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories
646 named after the build type:
647 </p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]648
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]649 <dl compact>
650 <dt>Debug Builds
651 <dd>
652 <dl compact>
653 <dt>Tools
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]654 <dd><tt><i>OBJ_ROOT</i>/tools/Debug</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]655 <dt>Libraries
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]656 <dd><tt><i>OBJ_ROOT</i>/lib/Debug</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]657 </dl>
658 <p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]659
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]660 <dt>Release Builds
661 <dd>
662 <dl compact>
663 <dt>Tools
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]664 <dd><tt><i>OBJ_ROOT</i>/tools/Release</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]665 <dt>Libraries
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]666 <dd><tt><i>OBJ_ROOT</i>/lib/Release</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]667 </dl>
668 <p>
Chris Lattner7fe7f812002-07-24 19:51:14 +0000[diff] [blame]669
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]670 <dt>Profile Builds
671 <dd>
672 <dl compact>
673 <dt>Tools
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]674 <dd><tt><i>OBJ_ROOT</i>/tools/Profile</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]675 <dt>Libraries
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]676 <dd><tt><i>OBJ_ROOT</i>/lib/Profile</tt>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]677 </dl>
678 </dl>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]679
680 <!--=====================================================================-->
681 <center>
682 <h2><a name="layout"><b>Program Layout</b></a></h2>
683 </center>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]684 <hr>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]685 <!--=====================================================================-->
686
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]687 <p>
688 One useful source of information about the LLVM source base is the LLVM <a
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]689 href="http://www.doxygen.org">doxygen</a> documentation, available at <tt><a
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]690 href="http://llvm.cs.uiuc.edu/doxygen/">http://llvm.cs.uiuc.edu/doxygen/</a></tt>.
691 The following is a brief introduction to code layout:
692 </p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]693
694 <!------------------------------------------------------------------------->
695 <h3><a name="cvsdir"><tt>CVS</tt> directories</a></h3>
696 <!------------------------------------------------------------------------->
697
698 Every directory checked out of CVS will contain a <tt>CVS</tt> directory;
699 for the most part these can just be ignored.
700
701
702 <!------------------------------------------------------------------------->
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]703 <h3><a name="include"><tt>llvm/include</tt></a></h3>
704 <!------------------------------------------------------------------------->
705
706 This directory contains public header files exported from the LLVM
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]707 library. The three main subdirectories of this directory are:<p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]708
John Criswell8df90e02003-06-11 20:46:40 +0000[diff] [blame]709 <ol>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]710 <li><tt>llvm/include/llvm</tt> - This directory contains all of the LLVM
711 specific header files. This directory also has subdirectories for
712 different portions of LLVM: <tt>Analysis</tt>, <tt>CodeGen</tt>,
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]713 <tt>Target</tt>, <tt>Transforms</tt>, etc...
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]714
715 <li><tt>llvm/include/Support</tt> - This directory contains generic
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]716 support libraries that are independent of LLVM, but are used by LLVM.
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]717 For example, some C++ STL utilities and a Command Line option processing
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]718 library store their header files here.
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]719
720 <li><tt>llvm/include/Config</tt> - This directory contains header files
721 configured by the <tt>configure</tt> script. They wrap "standard" UNIX
722 and C header files. Source code can include these header files which
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]723 automatically take care of the conditional #includes that the
724 <tt>configure</tt> script generates.
Chris Lattner7fe7f812002-07-24 19:51:14 +0000[diff] [blame]725 </ol>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]726
727 <!------------------------------------------------------------------------->
728 <h3><a name="lib"><tt>llvm/lib</tt></a></h3>
729 <!------------------------------------------------------------------------->
730
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]731 This directory contains most of the source files of the LLVM system. In
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]732 LLVM, almost all
John Criswell7a73b802003-06-30 21:59:07 +0000[diff] [blame]733 code exists in libraries, making it very easy to share code among the
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]734 different <a href="#tools">tools</a>.<p>
735
736 <dl compact>
737 <dt><tt>llvm/lib/VMCore/</tt><dd> This directory holds the core LLVM
738 source files that implement core classes like Instruction and BasicBlock.
739
740 <dt><tt>llvm/lib/AsmParser/</tt><dd> This directory holds the source code
741 for the LLVM assembly language parser library.
742
743 <dt><tt>llvm/lib/ByteCode/</tt><dd> This directory holds code for reading
744 and write LLVM bytecode.
745
746 <dt><tt>llvm/lib/CWriter/</tt><dd> This directory implements the LLVM to C
747 converter.
748
749 <dt><tt>llvm/lib/Analysis/</tt><dd> This directory contains a variety of
750 different program analyses, such as Dominator Information, Call Graphs,
751 Induction Variables, Interval Identification, Natural Loop Identification,
752 etc...
753
754 <dt><tt>llvm/lib/Transforms/</tt><dd> This directory contains the source
755 code for the LLVM to LLVM program transformations, such as Aggressive Dead
756 Code Elimination, Sparse Conditional Constant Propagation, Inlining, Loop
John Criswell623e5942003-10-10 18:51:11 +0000[diff] [blame]757 Invariant Code Motion, Dead Global Elimination, and many others...
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]758
759 <dt><tt>llvm/lib/Target/</tt><dd> This directory contains files that
760 describe various target architectures for code generation. For example,
761 the llvm/lib/Target/Sparc directory holds the Sparc machine
762 description.<br>
763
764 <dt><tt>llvm/lib/CodeGen/</tt><dd> This directory contains the major parts
765 of the code generator: Instruction Selector, Instruction Scheduling, and
766 Register Allocation.
767
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]768 <dt><tt>llvm/lib/Support/</tt><dd> This directory contains the source code
769 that corresponds to the header files located in
770 <tt>llvm/include/Support/</tt>.
771 </dl>
772
773 <!------------------------------------------------------------------------->
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]774 <h3><a name="runtime"><tt>llvm/runtime</tt></a></h3>
775 <!------------------------------------------------------------------------->
776
777 <p>
778 This directory contains libraries which are compiled into LLVM bytecode and
779 used when linking programs with the GCC front end. Most of these libraries
780 are skeleton versions of real libraries; for example, libc is a stripped down
781 version of glibc.
782 </p>
783
784 <p>
785 Unlike the rest of the LLVM suite, this directory needs the LLVM GCC front end
786 to compile.
787 </p>
788
789 <!------------------------------------------------------------------------->
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]790 <h3><a name="test"><tt>llvm/test</tt></a></h3>
791 <!------------------------------------------------------------------------->
792
793 <p>This directory contains regression tests and source code that is used to
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]794 test the LLVM infrastructure.
795 </p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]796
797 <!------------------------------------------------------------------------->
798 <h3><a name="tools"><tt>llvm/tools</tt></a></h3>
799 <!------------------------------------------------------------------------->
800
801 <p>The <b>tools</b> directory contains the executables built out of the
802 libraries above, which form the main part of the user interface. You can
803 always get help for a tool by typing <tt>tool_name --help</tt>. The
804 following is a brief introduction to the most important tools.</p>
805
806 <dl compact>
Misha Brukmanef0ad412003-10-06 19:23:34 +0000[diff] [blame]807 <dt>
808
809 <dt><tt><b>analyze</b></tt><dd> <tt>analyze</tt> is used to run a specific
810 analysis on an input LLVM bytecode file and print out the results. It is
811 primarily useful for debugging analyses, or familiarizing yourself with
812 what an analysis does.<p>
813
814 <dt><tt><b>bugpoint</b></tt><dd> <tt>bugpoint</tt> is used to debug
815 optimization passes or code generation backends by narrowing down the
816 given test case to the minimum number of passes and/or instructions that
817 still cause a problem, whether it is a crash or miscompilation. See <a
818 href="HowToSubmitABug.html">HowToSubmitABug.html</a> for more information
819 on using <tt>bugpoint</tt>.<p>
820
821 <dt><tt><b>llvm-ar</b></tt><dd>The archiver produces an archive containing
822 the given LLVM bytecode files, optionally with an index for faster
823 lookup.<p>
824
Misha Brukmana0a0a032003-08-28 22:02:50 +0000[diff] [blame]825 <dt><tt><b>llvm-as</b></tt><dd>The assembler transforms the human readable
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]826 LLVM assembly to LLVM bytecode.<p>
827
Misha Brukmana0a0a032003-08-28 22:02:50 +0000[diff] [blame]828 <dt><tt><b>llvm-dis</b></tt><dd>The disassembler transforms the LLVM
Misha Brukmanef0ad412003-10-06 19:23:34 +0000[diff] [blame]829 bytecode to human readable LLVM assembly. Additionally, it can convert
Misha Brukmana0a0a032003-08-28 22:02:50 +0000[diff] [blame]830 LLVM bytecode to C, which is enabled with the <tt>-c</tt> option.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]831
Misha Brukmanef0ad412003-10-06 19:23:34 +0000[diff] [blame]832 <dt><tt><b>llvm-link</b></tt><dd> <tt>llvm-link</tt>, not surprisingly,
833 links multiple LLVM modules into a single program.<p>
834
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]835 <dt><tt><b>lli</b></tt><dd> <tt>lli</tt> is the LLVM interpreter, which
836 can directly execute LLVM bytecode (although very slowly...). In addition
Misha Brukmanef0ad412003-10-06 19:23:34 +0000[diff] [blame]837 to a simple interpreter, <tt>lli</tt> also has a tracing mode (entered by
838 specifying <tt>-trace</tt> on the command line). Finally, for
839 architectures that support it (currently only x86 and Sparc), by default,
840 <tt>lli</tt> will function as a Just-In-Time compiler (if the
841 functionality was compiled in), and will execute the code <i>much</i>
842 faster than the interpreter.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]843
844 <dt><tt><b>llc</b></tt><dd> <tt>llc</tt> is the LLVM backend compiler,
Misha Brukmanc56e5822003-07-03 16:29:36 +0000[diff] [blame]845 which translates LLVM bytecode to a SPARC or x86 assembly file.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]846
Misha Brukmanef0ad412003-10-06 19:23:34 +0000[diff] [blame]847 <dt><tt><b>llvmgcc</b></tt><dd> <tt>llvmgcc</tt> is a GCC-based C frontend
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]848 that has been retargeted to emit LLVM code as the machine code output. It
849 works just like any other GCC compiler, taking the typical <tt>-c, -S, -E,
850 -o</tt> options that are typically used. The source code for the
Chris Lattner70bb09b2003-10-23 19:49:01 +0000[diff] [blame]851 <tt>llvmgcc</tt> tool is currently not included in the LLVM CVS tree
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]852 because it is quite large and not very interesting.<p>
853
854 <ol>
855 <dt><tt><b>gccas</b></tt><dd> This tool is invoked by the
856 <tt>llvmgcc</tt> frontend as the "assembler" part of the compiler. This
857 tool actually assembles LLVM assembly to LLVM bytecode,
Misha Brukmanef0ad412003-10-06 19:23:34 +0000[diff] [blame]858 performs a variety of optimizations, and outputs LLVM bytecode. Thus
859 when you invoke <tt>llvmgcc -c x.c -o x.o</tt>, you are causing
860 <tt>gccas</tt> to be run, which writes the <tt>x.o</tt> file (which is
861 an LLVM bytecode file that can be disassembled or manipulated just like
862 any other bytecode file). The command line interface to <tt>gccas</tt>
863 is designed to be as close as possible to the <b>system</b>
864 `<tt>as</tt>' utility so that the gcc frontend itself did not have to be
865 modified to interface to a "weird" assembler.<p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]866
867 <dt><tt><b>gccld</b></tt><dd> <tt>gccld</tt> links together several LLVM
868 bytecode files into one bytecode file and does some optimization. It is
John Criswellabb1b582003-10-10 16:17:19 +0000[diff] [blame]869 the linker invoked by the GCC frontend when multiple .o files need to be
870 linked together. Like <tt>gccas</tt>, the command line interface of
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]871 <tt>gccld</tt> is designed to match the system linker, to aid
872 interfacing with the GCC frontend.<p>
873 </ol>
874
875 <dt><tt><b>opt</b></tt><dd> <tt>opt</tt> reads LLVM bytecode, applies a
876 series of LLVM to LLVM transformations (which are specified on the command
877 line), and then outputs the resultant bytecode. The '<tt>opt --help</tt>'
878 command is a good way to get a list of the program transformations
879 available in LLVM.<p>
880
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]881 </dl>
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]882
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]883 <!------------------------------------------------------------------------->
884 <h3><a name="utils"><tt>llvm/utils</tt></a></h3>
885 <!------------------------------------------------------------------------->
886
John Criswell623e5942003-10-10 18:51:11 +0000[diff] [blame]887 This directory contains utilities for working with LLVM source code, and some
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]888 of the utilities are actually required as part of the build process because
889 they are code generators for parts of LLVM infrastructure.
890
891 <dl compact>
Misha Brukmane0db8152003-08-11 19:13:12 +0000[diff] [blame]892 <td><tt><b>Burg/</b></tt><dd> <tt>Burg</tt> is an instruction selector
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]893 generator -- it builds trees on which it then performs pattern-matching to
894 select instructions according to the patterns the user has specified. Burg
895 is currently used in the Sparc V9 backend.<p>
896
897 <dt><tt><b>codegen-diff</b></tt><dd> <tt>codegen-diff</tt> is a script
898 that finds differences between code that LLC generates and code that LLI
899 generates. This is a useful tool if you are debugging one of them,
900 assuming that the other generates correct output. For the full user
901 manual, run <tt>`perldoc codegen-diff'</tt>.<p>
902
903 <dt><tt><b>cvsupdate</b></tt><dd> <tt>cvsupdate</tt> is a script that will
904 update your CVS tree, but produce a much cleaner and more organized output
Chris Lattner70bb09b2003-10-23 19:49:01 +0000[diff] [blame]905 than simply running <tt>`cvs -z3 up -dP'</tt> will. For example, it will group
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]906 together all the new and updated files and modified files in separate
907 sections, so you can see at a glance what has changed. If you are at the
908 top of your LLVM CVS tree, running <tt>utils/cvsupdate</tt> is the
909 preferred way of updating the tree.<p>
910
Misha Brukmane0db8152003-08-11 19:13:12 +0000[diff] [blame]911 <dt><tt><b>emacs/</b></tt><dd> The <tt>emacs</tt> directory contains
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]912 syntax-highlighting files which will work with Emacs and XEmacs editors,
913 providing syntax highlighting support for LLVM assembly files and TableGen
Misha Brukmane0db8152003-08-11 19:13:12 +0000[diff] [blame]914 description files. For information on how to use the syntax files, consult
915 the <tt>README</tt> file in that directory.<p>
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]916
917 <dt><tt><b>getsrcs.sh</b></tt><dd> The <tt>getsrcs.sh</tt> script finds
918 and outputs all non-generated source files, which is useful if one wishes
919 to do a lot of development across directories and does not want to
920 individually find each file. One way to use it is to run, for example:
921 <tt>xemacs `utils/getsources.sh`</tt> from the top of your LLVM source
922 tree.<p>
923
924 <dt><tt><b>makellvm</b></tt><dd> The <tt>makellvm</tt> script compiles all
925 files in the current directory and then compiles and links the tool that
926 is the first argument. For example, assuming you are in the directory
927 <tt>llvm/lib/Target/Sparc</tt>, if <tt>makellvm</tt> is in your path,
928 simply running <tt>makellvm llc</tt> will make a build of the current
929 directory, switch to directory <tt>llvm/tools/llc</tt> and build it,
930 causing a re-linking of LLC.<p>
931
932 <dt><tt><b>NightlyTest.pl</b></tt> and
933 <tt><b>NightlyTestTemplate.html</b></tt><dd> These files are used in a
934 cron script to generate nightly status reports of the functionality of
935 tools, and the results can be seen by following the appropriate link on
936 the <a href="http://llvm.cs.uiuc.edu/">LLVM homepage</a>.<p>
937
Misha Brukmane0db8152003-08-11 19:13:12 +0000[diff] [blame]938 <dt><tt><b>TableGen/</b></tt><dd> The <tt>TableGen</tt> directory contains
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]939 the tool used to generate register descriptions, instruction set
Chris Lattnera8f5de32003-08-11 18:53:14 +0000[diff] [blame]940 descriptions, and even assemblers from common TableGen description
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]941 files.<p>
942
Misha Brukmane0db8152003-08-11 19:13:12 +0000[diff] [blame]943 <dt><tt><b>vim/</b></tt><dd> The <tt>vim</tt> directory contains
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]944 syntax-highlighting files which will work with the VIM editor, providing
945 syntax highlighting support for LLVM assembly files and TableGen
Misha Brukmane0db8152003-08-11 19:13:12 +0000[diff] [blame]946 description files. For information on how to use the syntax files, consult
947 the <tt>README</tt> file in that directory.<p>
Misha Brukmanc103adf2003-08-11 18:45:46 +0000[diff] [blame]948
949 </dl>
950
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]951 <!--=====================================================================-->
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]952 <h2>
953 <center><a name="tutorial">An Example Using the LLVM Tool Chain</center>
954 </h2>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]955 <hr>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]956 <!--=====================================================================-->
957
958 <ol>
959 <li>First, create a simple C file, name it 'hello.c':
960 <pre>
961 #include &lt;stdio.h&gt;
962 int main() {
963 printf("hello world\n");
964 return 0;
965 }
966 </pre>
967
968 <li>Next, compile the C file into a LLVM bytecode file:<p>
969
970 <tt>% llvmgcc hello.c -o hello</tt><p>
971
972 This will create two result files: <tt>hello</tt> and
973 <tt>hello.bc</tt>. The <tt>hello.bc</tt> is the LLVM bytecode that
974 corresponds the the compiled program and the library facilities that it
975 required. <tt>hello</tt> is a simple shell script that runs the bytecode
976 file with <tt>lli</tt>, making the result directly executable.<p>
977
978 <li>Run the program. To make sure the program ran, execute one of the
979 following commands:<p>
John Criswell8df90e02003-06-11 20:46:40 +0000[diff] [blame]980
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]981 <tt>% ./hello</tt><p>
982
983 or<p>
984
985 <tt>% lli hello.bc</tt><p>
986
Misha Brukmana0a0a032003-08-28 22:02:50 +0000[diff] [blame]987 <li>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]988 code:<p>
989
Misha Brukmana0a0a032003-08-28 22:02:50 +0000[diff] [blame]990 <tt>% llvm-dis < hello.bc | less</tt><p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]991
992 <li>Compile the program to native Sparc assembly using the code
Misha Brukmanc56e5822003-07-03 16:29:36 +0000[diff] [blame]993 generator (assuming you are currently on a Sparc system):<p>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]994
995 <tt>% llc hello.bc -o hello.s</tt><p>
996
997 <li>Assemble the native sparc assemble file into a program:<p>
998
999 <tt>% /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.sparc</tt><p>
1000
1001 <li>Execute the native sparc program:<p>
1002
1003 <tt>% ./hello.sparc</tt><p>
1004
1005 </ol>
1006
1007
1008 <!--=====================================================================-->
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]1009 <h2>
1010 <center><a name="problems">Common Problems</a></center>
1011 </h2>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]1012 <hr>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]1013 <!--=====================================================================-->
1014
John Criswellb96646f2003-10-13 16:16:25 +0000[diff] [blame]1015 If you are having problems building or using LLVM, or if you have any other
1016 general questions about LLVM, please consult the
John Criswellb5ca43e2003-10-13 16:19:30 +0000[diff] [blame]1017 <a href="FAQ.html">Frequently Asked Questions</a> page.
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]1018
1019 <!--=====================================================================-->
John Criswell0b459202003-07-08 20:35:59 +0000[diff] [blame]1020 <h2><center><a name="links">Links</a></center></h2>
John Criswell20d2d3e2003-10-10 14:26:14 +0000[diff] [blame]1021 <hr>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]1022 <!--=====================================================================-->
1023
1024 <p>This document is just an <b>introduction</b> to how to use LLVM to do
1025 some simple things... there are many more interesting and complicated things
1026 that you can do that aren't documented here (but we'll gladly accept a patch
1027 if you want to write something up!). For more information about LLVM, check
1028 out:</p>
1029
1030 <ul>
1031 <li><a href="http://llvm.cs.uiuc.edu/">LLVM homepage</a></li>
1032 <li><a href="http://llvm.cs.uiuc.edu/doxygen/">LLVM doxygen tree</a></li>
John Criswellce760f62003-07-03 16:01:38 +0000[diff] [blame]1033 <li><a href="http://llvm.cs.uiuc.edu/docs/Projects.html">Starting a Project that Uses LLVM</a></li>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]1034 </ul>
1035
1036 <hr>
1037
1038 If you have any questions or run into any snags (or you have any
1039 additions...), please send an email to
1040 <a href="mailto:sabre@nondot.org">Chris Lattner</a>.</p>
John Criswell0f6d7c02003-10-27 18:18:16 +0000[diff] [blame^]1041 <a href="http://llvm.cs.uiuc.edu">The LLVM Compiler Infrastructure</a>
1042 <br>
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]1043
John Criswell0f6d7c02003-10-27 18:18:16 +0000[diff] [blame^]1044 <!-- Created: Mon Jul 1 02:29:02 CDT 2002 -->
1045 <!-- hhmts start -->
1046 Last modified: Mon Oct 27 12:00:00 CDT 2003
1047 <!-- hhmts end -->
John Criswell85ed3612003-06-12 19:34:44 +0000[diff] [blame]1048 </body>
Guochun Shif4688a82002-07-17 23:05:56 +0000[diff] [blame]1049</html>