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				6	<title>Getting Started with LLVM System</title>
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				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>
Chris Lattner	05300e4	2007-11-01 04:20:16 +0000	[diff] [blame]	20	<li><a href="#hardware">Hardware</a></li>
				21	<li><a href="#software">Software</a></li>
				22	<li><a href="#brokengcc">Broken versions of GCC and other tools</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	23	</ol></li>
				24
				25	<li><a href="#starting">Getting Started with LLVM</a>
				26	<ol>
Chris Lattner	05300e4	2007-11-01 04:20:16 +0000	[diff] [blame]	27	<li><a href="#terminology">Terminology and Notation</a></li>
				28	<li><a href="#environment">Setting Up Your Environment</a></li>
				29	<li><a href="#unpack">Unpacking the LLVM Archives</a></li>
				30	<li><a href="#checkout">Checkout LLVM from Subversion</a></li>
				31	<li><a href="#installcf">Install the GCC Front End</a></li>
				32	<li><a href="#config">Local LLVM Configuration</a></li>
				33	<li><a href="#compile">Compiling the LLVM Suite Source Code</a></li>
				34	<li><a href="#cross-compile">Cross-Compiling LLVM</a></li>
				35	<li><a href="#objfiles">The Location of LLVM Object Files</a></li>
				36	<li><a href="#optionalconfig">Optional Configuration Items</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	37	</ol></li>
				38
				39	<li><a href="#layout">Program layout</a>
				40	<ol>
Chris Lattner	05300e4	2007-11-01 04:20:16 +0000	[diff] [blame]	41	<li><a href="#examples"><tt>llvm/examples</tt></a></li>
				42	<li><a href="#include"><tt>llvm/include</tt></a></li>
				43	<li><a href="#lib"><tt>llvm/lib</tt></a></li>
				44	<li><a href="#projects"><tt>llvm/projects</tt></a></li>
				45	<li><a href="#runtime"><tt>llvm/runtime</tt></a></li>
				46	<li><a href="#test"><tt>llvm/test</tt></a></li>
				47	<li><a href="#llvmtest"><tt>llvm-test</tt></a></li>
				48	<li><a href="#tools"><tt>llvm/tools</tt></a></li>
				49	<li><a href="#utils"><tt>llvm/utils</tt></a></li>
				50	<li><a href="#win32"><tt>llvm/win32</tt></a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	51	</ol></li>
				52
				53	<li><a href="#tutorial">An Example Using the LLVM Tool Chain</a>
				54	<ol>
				55	<li><a href="#tutorial4">Example with llvm-gcc4</a></li>
				56	</ol>
				57	<li><a href="#problems">Common Problems</a>
				58	<li><a href="#links">Links</a>
				59	</ul>
				60
				61	<div class="doc_author">
				62	<p>Written by:
				63	<a href="mailto:criswell@uiuc.edu">John Criswell</a>,
				64	<a href="mailto:sabre@nondot.org">Chris Lattner</a>,
				65	<a href="http://misha.brukman.net">Misha Brukman</a>,
				66	<a href="http://www.cs.uiuc.edu/~vadve">Vikram Adve</a>, and
				67	<a href="mailto:gshi1@uiuc.edu">Guochun Shi</a>.
				68	</p>
				69	</div>
				70
				71
				72	<!-- *********************************************************************** -->
				73	<div class="doc_section">
				74	<a name="overview"><b>Overview</b></a>
				75	</div>
				76	<!-- *********************************************************************** -->
				77
				78	<div class="doc_text">
				79
				80	<p>Welcome to LLVM! In order to get started, you first need to know some
				81	basic information.</p>
				82
				83	<p>First, LLVM comes in two pieces. The first piece is the LLVM suite. This
				84	contains all of the tools, libraries, and header files needed to use the low
				85	level virtual machine. It contains an assembler, disassembler, bitcode
				86	analyzer and bitcode optimizer. It also contains a test suite that can be
				87	used to test the LLVM tools and the GCC front end.</p>
				88
				89	<p>The second piece is the GCC front end. This component provides a version of
				90	GCC that compiles C and C++ code into LLVM bitcode. Currently, the GCC front
				91	end uses the GCC parser to convert code to LLVM. Once
				92	compiled into LLVM bitcode, a program can be manipulated with the LLVM tools
				93	from the LLVM suite.</p>
				94
				95	<p>
				96	There is a third, optional piece called llvm-test. It is a suite of programs
				97	with a testing harness that can be used to further test LLVM's functionality
				98	and performance.
				99	</p>
				100
				101	</div>
				102
				103	<!-- *********************************************************************** -->
				104	<div class="doc_section">
				105	<a name="quickstart"><b>Getting Started Quickly (A Summary)</b></a>
				106	</div>
				107	<!-- *********************************************************************** -->
				108
				109	<div class="doc_text">
				110
				111	<p>Here's the short story for getting up and running quickly with LLVM:</p>
				112
				113	<ol>
				114	<li>Read the documentation.</li>
				115	<li>Read the documentation.</li>
				116	<li>Remember that you were warned twice about reading the documentation.</li>
Misha Brukman	313db03	2008-12-29 19:38:58 +0000	[diff] [blame]	117	<li>Install the llvm-gcc-4.2 front end if you intend to compile C or C++:
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	118	<ol>
				119	<li><tt>cd <i>where-you-want-the-C-front-end-to-live</i></tt></li>
Misha Brukman	313db03	2008-12-29 19:38:58 +0000	[diff] [blame]	120	<li><tt>gunzip --stdout llvm-gcc-4.2-<i>version</i>-<i>platform</i>.tar.gz \| tar -xvf -</tt>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	121	</li>
Chris Lattner	fdae868	2008-11-09 17:19:14 +0000	[diff] [blame]	122	<li>Note: If the binary extension is ".bz" use bunzip2 instead of gunzip.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	123	<li>Add llvm-gcc's "bin" directory to your PATH variable.</li>
				124	</ol></li>
				125
				126	<li>Get the LLVM Source Code
				127	<ul>
				128	<li>With the distributed files (or use <a href="#checkout">SVN</a>):
				129	<ol>
				130	<li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
				131	<li><tt>gunzip --stdout llvm-<i>version</i>.tar.gz \| tar -xvf -</tt>
				132	</ol></li>
				133
				134	</ul></li>
				135
				136	<li><b>[Optional]</b> Get the Test Suite Source Code
				137	<ul>
				138	<li>With the distributed files (or use <a href="#checkout">SVN</a>):
				139	<ol>
				140	<li><tt>cd <i>where-you-want-llvm-to-live</i></tt>
				141	<li><tt>cd llvm/projects</tt>
				142	<li><tt>gunzip --stdout llvm-test-<i>version</i>.tar.gz \| tar -xvf -</tt>
				143	</ol></li>
				144
				145	</ul></li>
				146
				147
				148	<li>Configure the LLVM Build Environment
				149	<ol>
				150	<li><tt>cd <i>where-you-want-to-build-llvm</i></tt></li>
				151	<li><tt><i>/path/to/llvm/</i>configure [options]</tt><br>
				152	Some common options:
				153
				154	<ul>
				155	<li><tt>--prefix=<i>directory</i></tt>
				156	<p>Specify for <i>directory</i> the full pathname of where you
				157	want the LLVM tools and libraries to be installed (default
				158	<tt>/usr/local</tt>).</p></li>
				159	<li><tt>--with-llvmgccdir=<i>directory</i></tt>
				160	<p>Optionally, specify for <i>directory</i> the full pathname of the
				161	C/C++ front end installation to use with this LLVM configuration. If
Duncan Sands	cff3d04	2009-04-18 12:40:19 +0000	[diff] [blame]	162	not specified, the PATH will be searched. This is only needed if you
				163	want to run the testsuite or do some special kinds of LLVM builds.</p></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	164	<li><tt>--enable-spec2000=<i>directory</i></tt>
				165	<p>Enable the SPEC2000 benchmarks for testing. The SPEC2000
				166	benchmarks should be available in
				167	<tt><i>directory</i></tt>.</p></li>
				168	</ul>
				169	</ol></li>
				170
				171	<li>Build the LLVM Suite:
				172	<ol>
				173	<li><tt>gmake -k \|& tee gnumake.out
				174	# this is csh or tcsh syntax</tt></li>
				175	<li>If you get an "internal compiler error (ICE)" or test failures, see
				176	<a href="#brokengcc">below</a>.</li>
				177	</ol>
				178
				179	</ol>
				180
				181	<p>Consult the <a href="#starting">Getting Started with LLVM</a> section for
				182	detailed information on configuring and compiling LLVM. See <a
				183	href="#environment">Setting Up Your Environment</a> for tips that simplify
				184	working with the GCC front end and LLVM tools. Go to <a href="#layout">Program
				185	Layout</a> to learn about the layout of the source code tree.</p>
				186
				187	</div>
				188
				189	<!-- *********************************************************************** -->
				190	<div class="doc_section">
				191	<a name="requirements"><b>Requirements</b></a>
				192	</div>
				193	<!-- *********************************************************************** -->
				194
				195	<div class="doc_text">
				196
				197	<p>Before you begin to use the LLVM system, review the requirements given below.
				198	This may save you some trouble by knowing ahead of time what hardware and
				199	software you will need.</p>
				200
				201	</div>
				202
				203	<!-- ======================================================================= -->
				204	<div class="doc_subsection">
				205	<a name="hardware"><b>Hardware</b></a>
				206	</div>
				207
				208	<div class="doc_text">
				209
				210	<p>LLVM is known to work on the following platforms:</p>
				211
				212	<table cellpadding="3" summary="Known LLVM platforms">
				213	<tr>
				214	<th>OS</th>
				215	<th>Arch</th>
				216	<th>Compilers</th>
				217	</tr>
				218	<tr>
Chris Lattner	6abf676	2009-07-22 04:21:40 +0000	[diff] [blame]	219	<td>AuroraUX</td>
				220	<td>x86<sup><a href="#pf_1">1</a></sup></td>
				221	<td>GCC</td>
Chris Lattner	a8f2307	2009-07-21 22:47:03 +0000	[diff] [blame]	222	</tr>
				223	<tr>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	224	<td>Linux</td>
				225	<td>x86<sup><a href="#pf_1">1</a></sup></td>
				226	<td>GCC</td>
				227	</tr>
				228	<tr>
Edward O'Callaghan	82a57db	2009-08-04 05:24:28 +0000	[diff] [blame]	229	<td>Linux</td>
				230	<td>amd64</td>
				231	<td>GCC</td>
				232	</tr>
				233	<tr>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	234	<td>Solaris</td>
				235	<td>V9 (Ultrasparc)</td>
				236	<td>GCC</td>
				237	</tr>
				238	<tr>
				239	<td>FreeBSD</td>
				240	<td>x86<sup><a href="#pf_1">1</a></sup></td>
				241	<td>GCC</td>
				242	</tr>
				243	<tr>
				244	<td>MacOS X<sup><a href="#pf_2">2</a></sup></td>
				245	<td>PowerPC</td>
				246	<td>GCC</td>
				247	</tr>
				248	<tr>
Scott Michel	6de83ff	2008-03-18 23:13:26 +0000	[diff] [blame]	249	<td>MacOS X<sup><a href="#pf_2">2</a>,<a href="#pf_9">9</a></sup></td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	250	<td>x86</td>
				251	<td>GCC</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	252	</tr>
				253	<tr>
				254	<td>Cygwin/Win32</td>
Anton Korobeynikov	de76e8d	2009-12-09 17:26:02 +0000	[diff] [blame^]	255	<td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_8">8</a>,
				256	<a href="#pf_11">11</a></sup></td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	257	<td>GCC 3.4.X, binutils 2.15</td>
				258	</tr>
				259	<tr>
				260	<td>MinGW/Win32</td>
Anton Korobeynikov	bad20c3	2009-08-06 12:54:58 +0000	[diff] [blame]	261	<td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_6">6</a>,
				262	<a href="#pf_8">8</a>, <a href="#pf_10">10</a></sup></td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	263	<td>GCC 3.4.X, binutils 2.15</td>
				264	</tr>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	265	</table>
				266
				267	<p>LLVM has partial support for the following platforms:</p>
				268
				269	<table summary="LLVM partial platform support">
				270	<tr>
				271	<th>OS</th>
				272	<th>Arch</th>
				273	<th>Compilers</th>
				274	</tr>
				275	<tr>
				276	<td>Windows</td>
				277	<td>x86<sup><a href="#pf_1">1</a></sup></td>
Nick Lewycky	18b90af	2008-12-08 00:45:02 +0000	[diff] [blame]	278	<td>Visual Studio 2005 SP1 or higher<sup><a href="#pf_4">4</a>,<a href="#pf_5">5</a></sup></td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	279	<tr>
				280	<td>AIX<sup><a href="#pf_3">3</a>,<a href="#pf_4">4</a></sup></td>
				281	<td>PowerPC</td>
				282	<td>GCC</td>
				283	</tr>
				284	<tr>
				285	<td>Linux<sup><a href="#pf_3">3</a>,<a href="#pf_5">5</a></sup></td>
				286	<td>PowerPC</td>
				287	<td>GCC</td>
				288	</tr>
				289
				290	<tr>
				291	<td>Linux<sup><a href="#pf_7">7</a></sup></td>
				292	<td>Alpha</td>
				293	<td>GCC</td>
				294	</tr>
				295	<tr>
				296	<td>Linux<sup><a href="#pf_7">7</a></sup></td>
				297	<td>Itanium (IA-64)</td>
				298	<td>GCC</td>
				299	</tr>
				300	<tr>
				301	<td>HP-UX<sup><a href="#pf_7">7</a></sup></td>
				302	<td>Itanium (IA-64)</td>
				303	<td>HP aCC</td>
				304	</tr>
				305	</table>
				306
				307	<p><b>Notes:</b></p>
				308
				309	<div class="doc_notes">
				310	<ol>
				311	<li><a name="pf_1">Code generation supported for Pentium processors and
				312	up</a></li>
				313	<li><a name="pf_2">Code generation supported for 32-bit ABI only</a></li>
				314	<li><a name="pf_3">No native code generation</a></li>
Nick Lewycky	18b90af	2008-12-08 00:45:02 +0000	[diff] [blame]	315	<li><a name="pf_4">Build is not complete: one or more tools do not link or function</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	316	<li><a name="pf_5">The GCC-based C/C++ frontend does not build</a></li>
Chris Lattner	789ce3a	2009-01-02 07:10:51 +0000	[diff] [blame]	317	<li><a name="pf_6">The port is done using the MSYS shell.</a></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	318	<li><a name="pf_7">Native code generation exists but is not complete.</a></li>
				319	<li><a name="pf_8">Binutils</a> up to post-2.17 has bug in bfd/cofflink.c
				320	preventing LLVM from building correctly. Several workarounds have been
				321	introduced into LLVM build system, but the bug can occur anytime in the
				322	future. We highly recommend that you rebuild your current binutils with the
				323	patch from <a href="http://sourceware.org/bugzilla/show_bug.cgi?id=2659">
				324	Binutils bugzilla</a>, if it wasn't already applied.</li>
Chris Lattner	fdae868	2008-11-09 17:19:14 +0000	[diff] [blame]	325	<li><a name="pf_9">XCode 2.5 and gcc 4.0.1</a> (Apple Build 5370) will trip
Scott Michel	6de83ff	2008-03-18 23:13:26 +0000	[diff] [blame]	326	internal LLVM assert messages when compiled for Release at optimization
Chris Lattner	fdae868	2008-11-09 17:19:14 +0000	[diff] [blame]	327	levels greater than 0 (i.e., <i>"-O1"</i> and higher).
				328	Add <i>OPTIMIZE_OPTION="-O0"</i> to the build command line
Scott Michel	6de83ff	2008-03-18 23:13:26 +0000	[diff] [blame]	329	if compiling for LLVM Release or bootstrapping the LLVM toolchain.</li>
Anton Korobeynikov	bad20c3	2009-08-06 12:54:58 +0000	[diff] [blame]	330	<li><a name="pf_10">For MSYS/MinGW on Windows, be sure to install the MSYS
				331	version of the perl package, and be sure it appears in your path
				332	before any Windows-based versions such as Strawberry Perl and
				333	ActivePerl, as these have Windows-specifics that will cause the
				334	build to fail.</a></li>
Anton Korobeynikov	de76e8d	2009-12-09 17:26:02 +0000	[diff] [blame^]	335	<li><a name="pf_11">In general, LLVM modules requiring dynamic linking can
				336	not be built on Windows. However, you can build LLVM tools using
				337	<i>"make tools-only"</i>.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	338	</ol>
				339	</div>
				340
				341	<p>Note that you will need about 1-3 GB of space for a full LLVM build in Debug
				342	mode, depending on the system (it is so large because of all the debugging
				343	information and the fact that the libraries are statically linked into multiple
Chris Lattner	15aeb9a	2009-04-25 22:08:52 +0000	[diff] [blame]	344	tools). If you do not need many of the tools and you are space-conscious, you
				345	can pass <tt>ONLY_TOOLS="tools you need"</tt> to make. The Release build
				346	requires considerably less space.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	347
				348	<p>The LLVM suite <i>may</i> compile on other platforms, but it is not
				349	guaranteed to do so. If compilation is successful, the LLVM utilities should be
				350	able to assemble, disassemble, analyze, and optimize LLVM bitcode. Code
				351	generation should work as well, although the generated native code may not work
				352	on your platform.</p>
				353
				354	<p>The GCC front end is not very portable at the moment. If you want to get it
				355	to work on another platform, you can download a copy of the source and <a
Duncan Sands	e38f3dc	2008-02-14 17:53:22 +0000	[diff] [blame]	356	href="GCCFEBuildInstrs.html">try to compile it</a> on your platform.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	357
				358	</div>
				359
				360	<!-- ======================================================================= -->
				361	<div class="doc_subsection"><a name="software"><b>Software</b></a></div>
				362	<div class="doc_text">
				363	<p>Compiling LLVM requires that you have several software packages
				364	installed. The table below lists those required packages. The Package column
				365	is the usual name for the software package that LLVM depends on. The Version
				366	column provides "known to work" versions of the package. The Notes column
				367	describes how LLVM uses the package and provides other details.</p>
				368	<table summary="Packages required to compile LLVM">
				369	<tr><th>Package</th><th>Version</th><th>Notes</th></tr>
				370
				371	<tr>
				372	<td><a href="http://savannah.gnu.org/projects/make">GNU Make</a></td>
				373	<td>3.79, 3.79.1</td>
				374	<td>Makefile/build processor</td>
				375	</tr>
				376
				377	<tr>
				378	<td><a href="http://gcc.gnu.org">GCC</a></td>
				379	<td>3.4.2</td>
				380	<td>C/C++ compiler<sup><a href="#sf1">1</a></sup></td>
				381	</tr>
				382
				383	<tr>
				384	<td><a href="http://www.gnu.org/software/texinfo">TeXinfo</a></td>
				385	<td>4.5</td>
				386	<td>For building the CFE</td>
				387	</tr>
				388
				389	<tr>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	390	<td><a href="http://subversion.tigris.org/project_packages.html">SVN</a></td>
				391	<td>≥1.3</td>
				392	<td>Subversion access to LLVM<sup><a href="#sf2">2</a></sup></td>
				393	</tr>
				394
				395	<tr>
				396	<td><a href="http://savannah.gnu.org/projects/dejagnu">DejaGnu</a></td>
				397	<td>1.4.2</td>
				398	<td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
				399	</tr>
				400
				401	<tr>
				402	<td><a href="http://www.tcl.tk/software/tcltk/">tcl</a></td>
				403	<td>8.3, 8.4</td>
				404	<td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
				405	</tr>
				406
				407	<tr>
				408	<td><a href="http://expect.nist.gov/">expect</a></td>
				409	<td>5.38.0</td>
				410	<td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
				411	</tr>
				412
				413	<tr>
				414	<td><a href="http://www.perl.com/download.csp">perl</a></td>
				415	<td>≥5.6.0</td>
				416	<td>Nightly tester, utilities</td>
				417	</tr>
				418
				419	<tr>
				420	<td><a href="http://savannah.gnu.org/projects/m4">GNU M4</a>
				421	<td>1.4</td>
				422	<td>Macro processor for configuration<sup><a href="#sf4">4</a></sup></td>
				423	</tr>
				424
				425	<tr>
				426	<td><a href="http://www.gnu.org/software/autoconf">GNU Autoconf</a></td>
Nick Lewycky	985d6d1	2009-09-27 04:56:27 +0000	[diff] [blame]	427	<td>2.60</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	428	<td>Configuration script builder<sup><a href="#sf4">4</a></sup></td>
				429	</tr>
				430
				431	<tr>
				432	<td><a href="http://www.gnu.org/software/automake">GNU Automake</a></td>
Nick Lewycky	985d6d1	2009-09-27 04:56:27 +0000	[diff] [blame]	433	<td>1.9.6</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	434	<td>aclocal macro generator<sup><a href="#sf4">4</a></sup></td>
				435	</tr>
				436
				437	<tr>
				438	<td><a href="http://savannah.gnu.org/projects/libtool">libtool</a></td>
Nick Lewycky	985d6d1	2009-09-27 04:56:27 +0000	[diff] [blame]	439	<td>1.5.22</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	440	<td>Shared library manager<sup><a href="#sf4">4</a></sup></td>
				441	</tr>
				442
				443	</table>
				444
				445	<p><b>Notes:</b></p>
				446	<div class="doc_notes">
				447	<ol>
				448	<li><a name="sf1">Only the C and C++ languages are needed so there's no
				449	need to build the other languages for LLVM's purposes.</a> See
				450	<a href="#brokengcc">below</a> for specific version info.</li>
				451	<li><a name="sf2">You only need Subversion if you intend to build from the
				452	latest LLVM sources. If you're working from a release distribution, you
				453	don't need Subversion.</a></li>
				454	<li><a name="sf3">Only needed if you want to run the automated test
				455	suite in the <tt>llvm/test</tt> directory.</a></li>
				456	<li><a name="sf4">If you want to make changes to the configure scripts,
				457	you will need GNU autoconf (2.59), and consequently, GNU M4 (version 1.4
				458	or higher). You will also need automake (1.9.2). We only use aclocal
				459	from that package.</a></li>
				460	</ol>
				461	</div>
				462
				463	<p>Additionally, your compilation host is expected to have the usual
				464	plethora of Unix utilities. Specifically:</p>
				465	<ul>
				466	<li><b>ar</b> - archive library builder</li>
				467	<li><b>bzip2*</b> - bzip2 command for distribution generation</li>
				468	<li><b>bunzip2*</b> - bunzip2 command for distribution checking</li>
				469	<li><b>chmod</b> - change permissions on a file</li>
				470	<li><b>cat</b> - output concatenation utility</li>
				471	<li><b>cp</b> - copy files</li>
				472	<li><b>date</b> - print the current date/time </li>
				473	<li><b>echo</b> - print to standard output</li>
				474	<li><b>egrep</b> - extended regular expression search utility</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	475	<li><b>find</b> - find files/dirs in a file system</li>
				476	<li><b>grep</b> - regular expression search utility</li>
				477	<li><b>gzip*</b> - gzip command for distribution generation</li>
				478	<li><b>gunzip*</b> - gunzip command for distribution checking</li>
				479	<li><b>install</b> - install directories/files </li>
				480	<li><b>mkdir</b> - create a directory</li>
				481	<li><b>mv</b> - move (rename) files</li>
				482	<li><b>ranlib</b> - symbol table builder for archive libraries</li>
				483	<li><b>rm</b> - remove (delete) files and directories</li>
				484	<li><b>sed</b> - stream editor for transforming output</li>
				485	<li><b>sh</b> - Bourne shell for make build scripts</li>
				486	<li><b>tar</b> - tape archive for distribution generation</li>
				487	<li><b>test</b> - test things in file system</li>
				488	<li><b>unzip*</b> - unzip command for distribution checking</li>
				489	<li><b>zip*</b> - zip command for distribution generation</li>
				490	</ul>
				491	</div>
				492
				493	<!-- ======================================================================= -->
				494	<div class="doc_subsection">
				495	<a name="brokengcc">Broken versions of GCC and other tools</a>
				496	</div>
				497
				498	<div class="doc_text">
				499
				500	<p>LLVM is very demanding of the host C++ compiler, and as such tends to expose
				501	bugs in the compiler. In particular, several versions of GCC crash when trying
				502	to compile LLVM. We routinely use GCC 3.3.3, 3.4.0, and Apple 4.0.1
				503	successfully with them (however, see important notes below). Other versions
				504	of GCC will probably work as well. GCC versions listed
				505	here are known to not work. If you are using one of these versions, please try
				506	to upgrade your GCC to something more recent. If you run into a problem with a
				507	version of GCC not listed here, please <a href="mailto:llvmdev@cs.uiuc.edu">let
				508	us know</a>. Please use the "<tt>gcc -v</tt>" command to find out which version
				509	of GCC you are using.
				510	</p>
				511
				512	<p><b>GCC versions prior to 3.0</b>: GCC 2.96.x and before had several
				513	problems in the STL that effectively prevent it from compiling LLVM.
				514	</p>
				515
Chris Lattner	76bb530	2008-02-13 17:50:24 +0000	[diff] [blame]	516	<p><b>GCC 3.2.2 and 3.2.3</b>: These versions of GCC fails to compile LLVM with
				517	a bogus template error. This was fixed in later GCCs.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	518
				519	<p><b>GCC 3.3.2</b>: This version of GCC suffered from a <a
				520	href="http://gcc.gnu.org/PR13392">serious bug</a> which causes it to crash in
				521	the "<tt>convert_from_eh_region_ranges_1</tt>" GCC function.</p>
				522
				523	<p><b>Cygwin GCC 3.3.3</b>: The version of GCC 3.3.3 commonly shipped with
Duncan Sands	e38f3dc	2008-02-14 17:53:22 +0000	[diff] [blame]	524	Cygwin does not work. Please <a href="GCCFEBuildInstrs.html#cygwin">upgrade
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	525	to a newer version</a> if possible.</p>
				526	<p><b>SuSE GCC 3.3.3</b>: The version of GCC 3.3.3 shipped with SuSE 9.1 (and
				527	possibly others) does not compile LLVM correctly (it appears that exception
				528	handling is broken in some cases). Please download the FSF 3.3.3 or upgrade
				529	to a newer version of GCC.</p>
				530	<p><b>GCC 3.4.0 on linux/x86 (32-bit)</b>: GCC miscompiles portions of the
				531	code generator, causing an infinite loop in the llvm-gcc build when built
				532	with optimizations enabled (i.e. a release build).</p>
				533	<p><b>GCC 3.4.2 on linux/x86 (32-bit)</b>: GCC miscompiles portions of the
				534	code generator at -O3, as with 3.4.0. However gcc 3.4.2 (unlike 3.4.0)
				535	correctly compiles LLVM at -O2. A work around is to build release LLVM
				536	builds with "make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2 ..."</p>
				537	<p><b>GCC 3.4.x on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1056">
				538	miscompiles portions of LLVM</a>.</p>
Chris Lattner	05300e4	2007-11-01 04:20:16 +0000	[diff] [blame]	539	<p><b>GCC 3.4.4 (CodeSourcery ARM 2005q3-2)</b>: this compiler miscompiles LLVM
				540	when building with optimizations enabled. It appears to work with
				541	"<tt>make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O1</tt>" or build a debug
				542	build.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	543	<p><b>IA-64 GCC 4.0.0</b>: The IA-64 version of GCC 4.0.0 is known to
				544	miscompile LLVM.</p>
				545	<p><b>Apple Xcode 2.3</b>: GCC crashes when compiling LLVM at -O3 (which is the
				546	default with ENABLE_OPTIMIZED=1. To work around this, build with
				547	"ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2".</p>
				548	<p><b>GCC 4.1.1</b>: GCC fails to build LLVM with template concept check errors
				549	compiling some files. At the time of this writing, GCC mainline (4.2)
				550	did not share the problem.</p>
				551	<p><b>GCC 4.1.1 on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1063">
				552	miscompiles portions of LLVM</a> when compiling llvm itself into 64-bit
				553	code. LLVM will appear to mostly work but will be buggy, e.g. failing
				554	portions of its testsuite.</p>
				555	<p><b>GCC 4.1.2 on OpenSUSE</b>: Seg faults during libstdc++ build and on x86_64
				556	platforms compiling md5.c gets a mangled constant.</p>
Daniel Dunbar	597fdcd	2008-10-11 18:40:33 +0000	[diff] [blame]	557	<p><b>GCC 4.1.2 (20061115 (prerelease) (Debian 4.1.1-21)) on Debian</b>: Appears
				558	to miscompile parts of LLVM 2.4. One symptom is ValueSymbolTable complaining
				559	about symbols remaining in the table on destruction.</p>
Nuno Lopes	fc375a6	2008-12-10 16:11:10 +0000	[diff] [blame]	560	<p><b>GCC 4.1.2 20071124 (Red Hat 4.1.2-42)</b>: Suffers from the same symptoms
Nuno Lopes	c36ac04	2008-12-10 16:01:22 +0000	[diff] [blame]	561	as the previous one. It appears to work with ENABLE_OPTIMIZED=0 (the default).</p>
Anton Korobeynikov	30403a0	2009-05-04 10:24:46 +0000	[diff] [blame]	562	<p><b>Cygwin GCC 4.3.2 20080827 (beta) 2</b>:
				563	Users <a href="http://llvm.org/PR4145">reported</a> various problems related
				564	with link errors when using this GCC version.</p>
Chris Lattner	5d83433	2009-09-10 16:25:02 +0000	[diff] [blame]	565	<p><b>Debian GCC 4.3.2 on X86</b>: Crashes building some files in LLVM 2.6.</p>
Nick Lewycky	adb7b15	2009-07-17 06:32:10 +0000	[diff] [blame]	566	<p><b>GCC 4.3.3 (Debian 4.3.3-10) on ARM</b>: Miscompiles parts of LLVM 2.6
				567	when optimizations are turned on. The symptom is an infinite loop in
Chris Lattner	5d83433	2009-09-10 16:25:02 +0000	[diff] [blame]	568	FoldingSetImpl::RemoveNode while running the code generator.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	569	<p><b>GNU ld 2.16.X</b>. Some 2.16.X versions of the ld linker will produce very
				570	long warning messages complaining that some ".gnu.linkonce.t.*" symbol was
				571	defined in a discarded section. You can safely ignore these messages as they are
				572	erroneous and the linkage is correct. These messages disappear using ld
				573	2.17.</p>
				574
				575	<p><b>GNU binutils 2.17</b>: Binutils 2.17 contains <a
				576	href="http://sourceware.org/bugzilla/show_bug.cgi?id=3111">a bug</a> which
				577	causes huge link times (minutes instead of seconds) when building LLVM. We
				578	recommend upgrading to a newer version (2.17.50.0.4 or later).</p>
				579
Nick Lewycky	87da07c	2009-03-03 05:41:16 +0000	[diff] [blame]	580	<p><b>GNU Binutils 2.19.1 Gold</b>: This version of Gold contained
Nick Lewycky	829108e	2009-02-25 06:29:47 +0000	[diff] [blame]	581	<a href="http://sourceware.org/bugzilla/show_bug.cgi?id=9836">a bug</a>
				582	which causes intermittent failures when building LLVM with position independent
Nick Lewycky	87da07c	2009-03-03 05:41:16 +0000	[diff] [blame]	583	code. The symptom is an error about cyclic dependencies. We recommend
				584	upgrading to a newer version of Gold.</p>
Nick Lewycky	829108e	2009-02-25 06:29:47 +0000	[diff] [blame]	585
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	586	</div>
				587
				588
				589
				590	<!-- *********************************************************************** -->
				591	<div class="doc_section">
				592	<a name="starting"><b>Getting Started with LLVM</b></a>
				593	</div>
				594	<!-- *********************************************************************** -->
				595
				596	<div class="doc_text">
				597
				598	<p>The remainder of this guide is meant to get you up and running with
				599	LLVM and to give you some basic information about the LLVM environment.</p>
				600
				601	<p>The later sections of this guide describe the <a
				602	href="#layout">general layout</a> of the the LLVM source tree, a <a
				603	href="#tutorial">simple example</a> using the LLVM tool chain, and <a
				604	href="#links">links</a> to find more information about LLVM or to get
				605	help via e-mail.</p>
				606	</div>
				607
				608	<!-- ======================================================================= -->
				609	<div class="doc_subsection">
				610	<a name="terminology">Terminology and Notation</a>
				611	</div>
				612
				613	<div class="doc_text">
				614
				615	<p>Throughout this manual, the following names are used to denote paths
				616	specific to the local system and working environment. <i>These are not
				617	environment variables you need to set but just strings used in the rest
				618	of this document below</i>. In any of the examples below, simply replace
				619	each of these names with the appropriate pathname on your local system.
				620	All these paths are absolute:</p>
				621
				622	<dl>
				623	<dt>SRC_ROOT
				624	<dd>
				625	This is the top level directory of the LLVM source tree.
				626	<br><br>
				627
				628	<dt>OBJ_ROOT
				629	<dd>
				630	This is the top level directory of the LLVM object tree (i.e. the
				631	tree where object files and compiled programs will be placed. It
				632	can be the same as SRC_ROOT).
				633	<br><br>
				634
				635	<dt>LLVMGCCDIR
				636	<dd>
				637	This is where the LLVM GCC Front End is installed.
				638	<p>
				639	For the pre-built GCC front end binaries, the LLVMGCCDIR is
				640	<tt>llvm-gcc/<i>platform</i>/llvm-gcc</tt>.
				641	</dl>
				642
				643	</div>
				644
				645	<!-- ======================================================================= -->
				646	<div class="doc_subsection">
				647	<a name="environment">Setting Up Your Environment</a>
				648	</div>
				649
				650	<div class="doc_text">
				651
				652	<p>
				653	In order to compile and use LLVM, you may need to set some environment
				654	variables.
				655
				656	<dl>
				657	<dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt>/path/to/your/bitcode/libs</tt></dt>
				658	<dd>[Optional] This environment variable helps LLVM linking tools find the
				659	locations of your bitcode libraries. It is provided only as a
				660	convenience since you can specify the paths using the -L options of the
				661	tools and the C/C++ front-end will automatically use the bitcode files
				662	installed in its
				663	<tt>lib</tt> directory.</dd>
				664	</dl>
				665
				666	</div>
				667
				668	<!-- ======================================================================= -->
				669	<div class="doc_subsection">
				670	<a name="unpack">Unpacking the LLVM Archives</a>
				671	</div>
				672
				673	<div class="doc_text">
				674
				675	<p>
				676	If you have the LLVM distribution, you will need to unpack it before you
				677	can begin to compile it. LLVM is distributed as a set of two files: the LLVM
				678	suite and the LLVM GCC front end compiled for your platform. There is an
				679	additional test suite that is optional. Each file is a TAR archive that is
				680	compressed with the gzip program.
				681	</p>
				682
				683	<p>The files are as follows, with <em>x.y</em> marking the version number:
				684	<dl>
				685	<dt><tt>llvm-x.y.tar.gz</tt></dt>
Misha Brukman	5c1cc64	2008-12-11 18:23:24 +0000	[diff] [blame]	686	<dd>Source release for the LLVM libraries and tools.<br></dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	687
				688	<dt><tt>llvm-test-x.y.tar.gz</tt></dt>
				689	<dd>Source release for the LLVM test suite.</dd>
				690
Misha Brukman	313db03	2008-12-29 19:38:58 +0000	[diff] [blame]	691	<dt><tt>llvm-gcc-4.2-x.y.source.tar.gz</tt></dt>
				692	<dd>Source release of the llvm-gcc-4.2 front end. See README.LLVM in the root
Misha Brukman	5c1cc64	2008-12-11 18:23:24 +0000	[diff] [blame]	693	directory for build instructions.<br></dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	694
Misha Brukman	313db03	2008-12-29 19:38:58 +0000	[diff] [blame]	695	<dt><tt>llvm-gcc-4.2-x.y-platform.tar.gz</tt></dt>
				696	<dd>Binary release of the llvm-gcc-4.2 front end for a specific platform.<br></dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	697
				698	</dl>
				699
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	700	</div>
				701
				702	<!-- ======================================================================= -->
				703	<div class="doc_subsection">
				704	<a name="checkout">Checkout LLVM from Subversion</a>
				705	</div>
				706
				707	<div class="doc_text">
				708
				709	<p>If you have access to our Subversion repository, you can get a fresh copy of
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	710	the entire source code. All you need to do is check it out from Subversion as
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	711	follows:</p>
				712
				713	<ul>
				714	<li><tt>cd <i>where-you-want-llvm-to-live</i></tt></li>
				715	<li>Read-Only: <tt>svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm</tt></li>
				716	<li>Read-Write:<tt>svn co https://user@llvm.org/svn/llvm-project/llvm/trunk
				717	llvm</tt></li>
				718	</ul>
				719
				720
				721	<p>This will create an '<tt>llvm</tt>' directory in the current
				722	directory and fully populate it with the LLVM source code, Makefiles,
				723	test directories, and local copies of documentation files.</p>
				724
				725	<p>If you want to get a specific release (as opposed to the most recent
				726	revision), you can checkout it from the '<tt>tags</tt>' directory (instead of
				727	'<tt>trunk</tt>'). The following releases are located in the following
Misha Brukman	8e73a47	2008-12-17 16:27:23 +0000	[diff] [blame]	728	subdirectories of the '<tt>tags</tt>' directory:</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	729
				730	<ul>
Tanya Lattner	221f9d4	2009-10-23 06:20:06 +0000	[diff] [blame]	731	<li>Release 2.6: <b>RELEASE_26</b></li>
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	732	<li>Release 2.5: <b>RELEASE_25</b></li>
Misha Brukman	8e73a47	2008-12-17 16:27:23 +0000	[diff] [blame]	733	<li>Release 2.4: <b>RELEASE_24</b></li>
Tanya Lattner	9eb3be5	2008-06-09 06:02:09 +0000	[diff] [blame]	734	<li>Release 2.3: <b>RELEASE_23</b></li>
Tanya Lattner	6003078	2008-02-12 02:42:55 +0000	[diff] [blame]	735	<li>Release 2.2: <b>RELEASE_22</b></li>
Tanya Lattner	2fad5b0	2007-09-28 22:50:54 +0000	[diff] [blame]	736	<li>Release 2.1: <b>RELEASE_21</b></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	737	<li>Release 2.0: <b>RELEASE_20</b></li>
				738	<li>Release 1.9: <b>RELEASE_19</b></li>
				739	<li>Release 1.8: <b>RELEASE_18</b></li>
				740	<li>Release 1.7: <b>RELEASE_17</b></li>
				741	<li>Release 1.6: <b>RELEASE_16</b></li>
				742	<li>Release 1.5: <b>RELEASE_15</b></li>
				743	<li>Release 1.4: <b>RELEASE_14</b></li>
				744	<li>Release 1.3: <b>RELEASE_13</b></li>
				745	<li>Release 1.2: <b>RELEASE_12</b></li>
				746	<li>Release 1.1: <b>RELEASE_11</b></li>
				747	<li>Release 1.0: <b>RELEASE_1</b></li>
				748	</ul>
				749
				750	<p>If you would like to get the LLVM test suite (a separate package as of 1.4),
				751	you get it from the Subversion repository:</p>
				752
				753	<div class="doc_code">
				754	<pre>
				755	% cd llvm/projects
				756	% svn co http://llvm.org/svn/llvm-project/test-suite/trunk llvm-test
				757	</pre>
				758	</div>
				759
				760	<p>By placing it in the <tt>llvm/projects</tt>, it will be automatically
				761	configured by the LLVM configure script as well as automatically updated when
				762	you run <tt>svn update</tt>.</p>
				763
				764	<p>If you would like to get the GCC front end source code, you can also get it
Duncan Sands	e38f3dc	2008-02-14 17:53:22 +0000	[diff] [blame]	765	and build it yourself. Please follow <a href="GCCFEBuildInstrs.html">these
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	766	instructions</a> to successfully get and build the LLVM GCC front-end.</p>
				767
				768	</div>
				769
				770	<!-- ======================================================================= -->
				771	<div class="doc_subsection">
				772	<a name="installcf">Install the GCC Front End</a>
				773	</div>
				774
				775	<div class="doc_text">
				776
				777	<p>Before configuring and compiling the LLVM suite, you can optionally extract the
				778	LLVM GCC front end from the binary distribution. It is used for running the
				779	llvm-test testsuite and for compiling C/C++ programs. Note that you can optionally
Duncan Sands	e38f3dc	2008-02-14 17:53:22 +0000	[diff] [blame]	780	<a href="GCCFEBuildInstrs.html">build llvm-gcc yourself</a> after building the
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	781	main LLVM repository.</p>
				782
				783	<p>To install the GCC front end, do the following:</p>
				784
				785	<ol>
				786	<li><tt>cd <i>where-you-want-the-front-end-to-live</i></tt></li>
Misha Brukman	313db03	2008-12-29 19:38:58 +0000	[diff] [blame]	787	<li><tt>gunzip --stdout llvm-gcc-4.2-<i>version</i>-<i>platform</i>.tar.gz \| tar -xvf
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	788	-</tt></li>
				789	</ol>
				790
				791	<p>Once the binary is uncompressed, you should add a symlink for llvm-gcc and
				792	llvm-g++ to some directory in your path. When you configure LLVM, it will
				793	automatically detect llvm-gcc's presence (if it is in your path) enabling its
				794	use in llvm-test. Note that you can always build or install llvm-gcc at any
				795	pointer after building the main LLVM repository: just reconfigure llvm and
				796	llvm-test will pick it up.
				797	</p>
				798
				799	<p>The binary versions of the GCC front end may not suit all of your needs. For
				800	example, the binary distribution may include an old version of a system header
				801	file, not "fix" a header file that needs to be fixed for GCC, or it may be
				802	linked with libraries not available on your system.</p>
				803
				804	<p>In cases like these, you may want to try <a
Duncan Sands	e38f3dc	2008-02-14 17:53:22 +0000	[diff] [blame]	805	href="GCCFEBuildInstrs.html">building the GCC front end from source.</a> This is
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	806	much easier now than it was in the past.</p>
				807
				808	</div>
				809
				810	<!-- ======================================================================= -->
				811	<div class="doc_subsection">
				812	<a name="config">Local LLVM Configuration</a>
				813	</div>
				814
				815	<div class="doc_text">
				816
				817	<p>Once checked out from the Subversion repository, the LLVM suite source
				818	code must be
				819	configured via the <tt>configure</tt> script. This script sets variables in the
				820	various <tt>*.in</tt> files, most notably <tt>llvm/Makefile.config</tt> and
				821	<tt>llvm/include/Config/config.h</tt>. It also populates <i>OBJ_ROOT</i> with
				822	the Makefiles needed to begin building LLVM.</p>
				823
				824	<p>The following environment variables are used by the <tt>configure</tt>
				825	script to configure the build system:</p>
				826
				827	<table summary="LLVM configure script environment variables">
				828	<tr><th>Variable</th><th>Purpose</th></tr>
				829	<tr>
				830	<td>CC</td>
				831	<td>Tells <tt>configure</tt> which C compiler to use. By default,
				832	<tt>configure</tt> will look for the first GCC C compiler in
				833	<tt>PATH</tt>. Use this variable to override
				834	<tt>configure</tt>'s default behavior.</td>
				835	</tr>
				836	<tr>
				837	<td>CXX</td>
				838	<td>Tells <tt>configure</tt> which C++ compiler to use. By default,
				839	<tt>configure</tt> will look for the first GCC C++ compiler in
				840	<tt>PATH</tt>. Use this variable to override
				841	<tt>configure</tt>'s default behavior.</td>
				842	</tr>
				843	</table>
				844
				845	<p>The following options can be used to set or enable LLVM specific options:</p>
				846
				847	<dl>
				848	<dt><i>--with-llvmgccdir</i></dt>
				849	<dd>Path to the LLVM C/C++ FrontEnd to be used with this LLVM configuration.
				850	The value of this option should specify the full pathname of the C/C++ Front
				851	End to be used. If this option is not provided, the PATH will be searched for
				852	a program named <i>llvm-gcc</i> and the C/C++ FrontEnd install directory will
				853	be inferred from the path found. If the option is not given, and no llvm-gcc
				854	can be found in the path then a warning will be produced by
				855	<tt>configure</tt> indicating this situation. LLVM may still be built with
				856	the <tt>tools-only</tt> target but attempting to build the runtime libraries
				857	will fail as these libraries require llvm-gcc and llvm-g++. See
				858	<a href="#installcf">Install the GCC Front End</a> for details on installing
				859	the C/C++ Front End. See
Duncan Sands	e38f3dc	2008-02-14 17:53:22 +0000	[diff] [blame]	860	<a href="GCCFEBuildInstrs.html">Bootstrapping the LLVM C/C++ Front-End</a>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	861	for details on building the C/C++ Front End.</dd>
				862	<dt><i>--with-tclinclude</i></dt>
				863	<dd>Path to the tcl include directory under which <tt>tclsh</tt> can be
				864	found. Use this if you have multiple tcl installations on your machine and you
				865	want to use a specific one (8.x) for LLVM. LLVM only uses tcl for running the
				866	dejagnu based test suite in <tt>llvm/test</tt>. If you don't specify this
				867	option, the LLVM configure script will search for the tcl 8.4 and 8.3
				868	releases.
				869	<br><br>
				870	</dd>
				871	<dt><i>--enable-optimized</i></dt>
				872	<dd>
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	873	Enables optimized compilation (debugging symbols are removed
				874	and GCC optimization flags are enabled). Note that this is the default
				875	setting if you are using the LLVM distribution. The default behavior
				876	of an Subversion checkout is to use an unoptimized build (also known as a
				877	debug build).
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	878	<br><br>
				879	</dd>
				880	<dt><i>--enable-debug-runtime</i></dt>
				881	<dd>
				882	Enables debug symbols in the runtime libraries. The default is to strip
				883	debug symbols from the runtime libraries.
				884	</dd>
				885	<dt><i>--enable-jit</i></dt>
				886	<dd>
				887	Compile the Just In Time (JIT) compiler functionality. This is not
				888	available
				889	on all platforms. The default is dependent on platform, so it is best
				890	to explicitly enable it if you want it.
				891	<br><br>
				892	</dd>
				893	<dt><i>--enable-targets=</i><tt>target-option</tt></dt>
				894	<dd>Controls which targets will be built and linked into llc. The default
				895	value for <tt>target_options</tt> is "all" which builds and links all
				896	available targets. The value "host-only" can be specified to build only a
				897	native compiler (no cross-compiler targets available). The "native" target is
				898	selected as the target of the build host. You can also specify a comma
				899	separated list of target names that you want available in llc. The target
Misha Brukman	5c1cc64	2008-12-11 18:23:24 +0000	[diff] [blame]	900	names use all lower case. The current set of targets is: <br>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	901	<tt>alpha, ia64, powerpc, skeleton, sparc, x86</tt>.
				902	<br><br></dd>
				903	<dt><i>--enable-doxygen</i></dt>
				904	<dd>Look for the doxygen program and enable construction of doxygen based
				905	documentation from the source code. This is disabled by default because
				906	generating the documentation can take a long time and producess 100s of
				907	megabytes of output.</dd>
				908	<dt><i>--with-udis86</i></dt>
				909	<dd>LLVM can use external disassembler library for various purposes (now it's
				910	used only for examining code produced by JIT). This option will enable usage
				911	of <a href="http://udis86.sourceforge.net/">udis86</a> x86 (both 32 and 64
				912	bits) disassembler library.</dd>
				913	</dl>
				914
				915	<p>To configure LLVM, follow these steps:</p>
				916
				917	<ol>
				918	<li><p>Change directory into the object root directory:</p>
				919
				920	<div class="doc_code"><pre>% cd <i>OBJ_ROOT</i></pre></div></li>
				921
				922	<li><p>Run the <tt>configure</tt> script located in the LLVM source
				923	tree:</p>
				924
				925	<div class="doc_code">
				926	<pre>% <i>SRC_ROOT</i>/configure --prefix=/install/path [other options]</pre>
				927	</div></li>
				928	</ol>
				929
				930	</div>
				931
				932	<!-- ======================================================================= -->
				933	<div class="doc_subsection">
				934	<a name="compile">Compiling the LLVM Suite Source Code</a>
				935	</div>
				936
				937	<div class="doc_text">
				938
				939	<p>Once you have configured LLVM, you can build it. There are three types of
				940	builds:</p>
				941
				942	<dl>
				943	<dt>Debug Builds
				944	<dd>
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	945	These builds are the default when one is using an Subversion checkout and
				946	types <tt>gmake</tt> (unless the <tt>--enable-optimized</tt> option was
				947	used during configuration). The build system will compile the tools and
				948	libraries with debugging information. To get a Debug Build using the
				949	LLVM distribution the <tt>--disable-optimized</tt> option must be passed
				950	to <tt>configure</tt>.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	951	<br><br>
				952
				953	<dt>Release (Optimized) Builds
				954	<dd>
				955	These builds are enabled with the <tt>--enable-optimized</tt> option to
				956	<tt>configure</tt> or by specifying <tt>ENABLE_OPTIMIZED=1</tt> on the
				957	<tt>gmake</tt> command line. For these builds, the build system will
				958	compile the tools and libraries with GCC optimizations enabled and strip
				959	debugging information from the libraries and executables it generates.
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	960	Note that Release Builds are default when using an LLVM distribution.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	961	<br><br>
				962
				963	<dt>Profile Builds
				964	<dd>
				965	These builds are for use with profiling. They compile profiling
				966	information into the code for use with programs like <tt>gprof</tt>.
				967	Profile builds must be started by specifying <tt>ENABLE_PROFILING=1</tt>
				968	on the <tt>gmake</tt> command line.
				969	</dl>
				970
				971	<p>Once you have LLVM configured, you can build it by entering the
				972	<i>OBJ_ROOT</i> directory and issuing the following command:</p>
				973
				974	<div class="doc_code"><pre>% gmake</pre></div>
				975
				976	<p>If the build fails, please <a href="#brokengcc">check here</a> to see if you
				977	are using a version of GCC that is known not to compile LLVM.</p>
				978
				979	<p>
				980	If you have multiple processors in your machine, you may wish to use some of
				981	the parallel build options provided by GNU Make. For example, you could use the
				982	command:</p>
				983
				984	<div class="doc_code"><pre>% gmake -j2</pre></div>
				985
				986	<p>There are several special targets which are useful when working with the LLVM
				987	source code:</p>
				988
				989	<dl>
				990	<dt><tt>gmake clean</tt>
				991	<dd>
				992	Removes all files generated by the build. This includes object files,
				993	generated C/C++ files, libraries, and executables.
				994	<br><br>
				995
				996	<dt><tt>gmake dist-clean</tt>
				997	<dd>
				998	Removes everything that <tt>gmake clean</tt> does, but also removes files
				999	generated by <tt>configure</tt>. It attempts to return the source tree to the
				1000	original state in which it was shipped.
				1001	<br><br>
				1002
				1003	<dt><tt>gmake install</tt>
				1004	<dd>
				1005	Installs LLVM header files, libraries, tools, and documentation in a
				1006	hierarchy
				1007	under $PREFIX, specified with <tt>./configure --prefix=[dir]</tt>, which
				1008	defaults to <tt>/usr/local</tt>.
				1009	<br><br>
				1010
				1011	<dt><tt>gmake -C runtime install-bytecode</tt>
				1012	<dd>
				1013	Assuming you built LLVM into $OBJDIR, when this command is run, it will
				1014	install bitcode libraries into the GCC front end's bitcode library
				1015	directory. If you need to update your bitcode libraries,
				1016	this is the target to use once you've built them.
				1017	<br><br>
				1018	</dl>
				1019
				1020	<p>Please see the <a href="MakefileGuide.html">Makefile Guide</a> for further
				1021	details on these <tt>make</tt> targets and descriptions of other targets
				1022	available.</p>
				1023
				1024	<p>It is also possible to override default values from <tt>configure</tt> by
				1025	declaring variables on the command line. The following are some examples:</p>
				1026
				1027	<dl>
				1028	<dt><tt>gmake ENABLE_OPTIMIZED=1</tt>
				1029	<dd>
				1030	Perform a Release (Optimized) build.
				1031	<br><br>
				1032
				1033	<dt><tt>gmake ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1</tt>
				1034	<dd>
				1035	Perform a Release (Optimized) build without assertions enabled.
				1036	<br><br>
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	1037
				1038	<dt><tt>gmake ENABLE_OPTIMIZED=0</tt>
				1039	<dd>
				1040	Perform a Debug build.
				1041	<br><br>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1042
				1043	<dt><tt>gmake ENABLE_PROFILING=1</tt>
				1044	<dd>
				1045	Perform a Profiling build.
				1046	<br><br>
				1047
				1048	<dt><tt>gmake VERBOSE=1</tt>
				1049	<dd>
				1050	Print what <tt>gmake</tt> is doing on standard output.
				1051	<br><br>
				1052
				1053	<dt><tt>gmake TOOL_VERBOSE=1</tt></dt>
				1054	<dd>Ask each tool invoked by the makefiles to print out what it is doing on
				1055	the standard output. This also implies <tt>VERBOSE=1</tt>.
				1056	<br><br></dd>
				1057	</dl>
				1058
				1059	<p>Every directory in the LLVM object tree includes a <tt>Makefile</tt> to build
				1060	it and any subdirectories that it contains. Entering any directory inside the
				1061	LLVM object tree and typing <tt>gmake</tt> should rebuild anything in or below
				1062	that directory that is out of date.</p>
				1063
				1064	</div>
				1065
				1066	<!-- ======================================================================= -->
				1067	<div class="doc_subsection">
				1068	<a name="cross-compile">Cross-Compiling LLVM</a>
				1069	</div>
				1070
				1071	<div class="doc_text">
Jim Grosbach	c8c7436	2009-04-17 17:25:16 +0000	[diff] [blame]	1072	<p>It is possible to cross-compile LLVM itself. That is, you can create LLVM
				1073	executables and libraries to be hosted on a platform different from the
				1074	platform where they are build (a Canadian Cross build). To configure a
				1075	cross-compile, supply the configure script with <tt>--build</tt> and
				1076	<tt>--host</tt> options that are different. The values of these options must
				1077	be legal target triples that your GCC compiler supports.</p>
				1078
				1079	<p>The result of such a build is executables that are not runnable on
				1080	on the build host (--build option) but can be executed on the compile host
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1081	(--host option).</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1082	</div>
				1083
				1084	<!-- ======================================================================= -->
				1085	<div class="doc_subsection">
				1086	<a name="objfiles">The Location of LLVM Object Files</a>
				1087	</div>
				1088
				1089	<div class="doc_text">
				1090
				1091	<p>The LLVM build system is capable of sharing a single LLVM source tree among
				1092	several LLVM builds. Hence, it is possible to build LLVM for several different
				1093	platforms or configurations using the same source tree.</p>
				1094
				1095	<p>This is accomplished in the typical autoconf manner:</p>
				1096
				1097	<ul>
				1098	<li><p>Change directory to where the LLVM object files should live:</p>
				1099
				1100	<div class="doc_code"><pre>% cd <i>OBJ_ROOT</i></pre></div></li>
				1101
				1102	<li><p>Run the <tt>configure</tt> script found in the LLVM source
				1103	directory:</p>
				1104
				1105	<div class="doc_code"><pre>% <i>SRC_ROOT</i>/configure</pre></div></li>
				1106	</ul>
				1107
				1108	<p>The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories
				1109	named after the build type:</p>
				1110
				1111	<dl>
				1112	<dt>Debug Builds
				1113	<dd>
				1114	<dl>
				1115	<dt>Tools
				1116	<dd><tt><i>OBJ_ROOT</i>/Debug/bin</tt>
				1117	<dt>Libraries
				1118	<dd><tt><i>OBJ_ROOT</i>/Debug/lib</tt>
				1119	</dl>
				1120	<br><br>
				1121
				1122	<dt>Release Builds
				1123	<dd>
				1124	<dl>
				1125	<dt>Tools
				1126	<dd><tt><i>OBJ_ROOT</i>/Release/bin</tt>
				1127	<dt>Libraries
				1128	<dd><tt><i>OBJ_ROOT</i>/Release/lib</tt>
				1129	</dl>
				1130	<br><br>
				1131
				1132	<dt>Profile Builds
				1133	<dd>
				1134	<dl>
				1135	<dt>Tools
				1136	<dd><tt><i>OBJ_ROOT</i>/Profile/bin</tt>
				1137	<dt>Libraries
				1138	<dd><tt><i>OBJ_ROOT</i>/Profile/lib</tt>
				1139	</dl>
				1140	</dl>
				1141
				1142	</div>
				1143
				1144	<!-- ======================================================================= -->
				1145	<div class="doc_subsection">
				1146	<a name="optionalconfig">Optional Configuration Items</a>
				1147	</div>
				1148
				1149	<div class="doc_text">
				1150
				1151	<p>
				1152	If you're running on a Linux system that supports the "<a
				1153	href="http://www.tat.physik.uni-tuebingen.de/~rguenth/linux/binfmt_misc.html">binfmt_misc</a>"
				1154	module, and you have root access on the system, you can set your system up to
				1155	execute LLVM bitcode files directly. To do this, use commands like this (the
				1156	first command may not be required if you are already using the module):</p>
				1157
				1158	<div class="doc_code">
				1159	<pre>
				1160	$ mount -t binfmt_misc none /proc/sys/fs/binfmt_misc
Nick Lewycky	b367380	2009-11-04 06:15:28 +0000	[diff] [blame]	1161	$ echo ':llvm:M::BC::/path/to/lli:' > /proc/sys/fs/binfmt_misc/register
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1162	$ chmod u+x hello.bc (if needed)
				1163	$ ./hello.bc
				1164	</pre>
				1165	</div>
				1166
				1167	<p>
				1168	This allows you to execute LLVM bitcode files directly. Thanks to Jack
				1169	Cummings for pointing this out!
				1170	</p>
				1171
				1172	</div>
				1173
				1174
				1175	<!-- *********************************************************************** -->
				1176	<div class="doc_section">
				1177	<a name="layout"><b>Program Layout</b></a>
				1178	</div>
				1179	<!-- *********************************************************************** -->
				1180
				1181	<div class="doc_text">
				1182
				1183	<p>One useful source of information about the LLVM source base is the LLVM <a
				1184	href="http://www.doxygen.org">doxygen</a> documentation available at <tt><a
				1185	href="http://llvm.org/doxygen/">http://llvm.org/doxygen/</a></tt>.
				1186	The following is a brief introduction to code layout:</p>
				1187
				1188	</div>
				1189
				1190	<!-- ======================================================================= -->
				1191	<div class="doc_subsection"><a name="examples"><tt>llvm/examples</tt></a></div>
				1192	<div class="doc_text">
				1193	<p>This directory contains some simple examples of how to use the LLVM IR and
				1194	JIT.</p>
				1195	</div>
				1196
				1197	<!-- ======================================================================= -->
				1198	<div class="doc_subsection"><a name="include"><tt>llvm/include</tt></a></div>
				1199	<div class="doc_text">
				1200
				1201	<p>This directory contains public header files exported from the LLVM
				1202	library. The three main subdirectories of this directory are:</p>
				1203
				1204	<dl>
				1205	<dt><tt><b>llvm/include/llvm</b></tt></dt>
				1206	<dd>This directory contains all of the LLVM specific header files. This
				1207	directory also has subdirectories for different portions of LLVM:
				1208	<tt>Analysis</tt>, <tt>CodeGen</tt>, <tt>Target</tt>, <tt>Transforms</tt>,
				1209	etc...</dd>
				1210
				1211	<dt><tt><b>llvm/include/llvm/Support</b></tt></dt>
				1212	<dd>This directory contains generic support libraries that are provided with
				1213	LLVM but not necessarily specific to LLVM. For example, some C++ STL utilities
				1214	and a Command Line option processing library store their header files here.
				1215	</dd>
				1216
				1217	<dt><tt><b>llvm/include/llvm/Config</b></tt></dt>
				1218	<dd>This directory contains header files configured by the <tt>configure</tt>
				1219	script. They wrap "standard" UNIX and C header files. Source code can
				1220	include these header files which automatically take care of the conditional
				1221	#includes that the <tt>configure</tt> script generates.</dd>
				1222	</dl>
				1223	</div>
				1224
				1225	<!-- ======================================================================= -->
				1226	<div class="doc_subsection"><a name="lib"><tt>llvm/lib</tt></a></div>
				1227	<div class="doc_text">
				1228
				1229	<p>This directory contains most of the source files of the LLVM system. In LLVM,
				1230	almost all code exists in libraries, making it very easy to share code among the
				1231	different <a href="#tools">tools</a>.</p>
				1232
				1233	<dl>
				1234	<dt><tt><b>llvm/lib/VMCore/</b></tt></dt>
				1235	<dd> This directory holds the core LLVM source files that implement core
				1236	classes like Instruction and BasicBlock.</dd>
				1237
				1238	<dt><tt><b>llvm/lib/AsmParser/</b></tt></dt>
				1239	<dd>This directory holds the source code for the LLVM assembly language parser
				1240	library.</dd>
				1241
				1242	<dt><tt><b>llvm/lib/BitCode/</b></tt></dt>
				1243	<dd>This directory holds code for reading and write LLVM bitcode.</dd>
				1244
				1245	<dt><tt><b>llvm/lib/Analysis/</b></tt><dd>This directory contains a variety of
				1246	different program analyses, such as Dominator Information, Call Graphs,
				1247	Induction Variables, Interval Identification, Natural Loop Identification,
				1248	etc.</dd>
				1249
				1250	<dt><tt><b>llvm/lib/Transforms/</b></tt></dt>
				1251	<dd> This directory contains the source code for the LLVM to LLVM program
				1252	transformations, such as Aggressive Dead Code Elimination, Sparse Conditional
				1253	Constant Propagation, Inlining, Loop Invariant Code Motion, Dead Global
				1254	Elimination, and many others.</dd>
				1255
				1256	<dt><tt><b>llvm/lib/Target/</b></tt></dt>
				1257	<dd> This directory contains files that describe various target architectures
				1258	for code generation. For example, the <tt>llvm/lib/Target/X86</tt>
				1259	directory holds the X86 machine description while
				1260	<tt>llvm/lib/Target/CBackend</tt> implements the LLVM-to-C converter.</dd>
				1261
				1262	<dt><tt><b>llvm/lib/CodeGen/</b></tt></dt>
				1263	<dd> This directory contains the major parts of the code generator: Instruction
				1264	Selector, Instruction Scheduling, and Register Allocation.</dd>
				1265
				1266	<dt><tt><b>llvm/lib/Debugger/</b></tt></dt>
				1267	<dd> This directory contains the source level debugger library that makes
				1268	it possible to instrument LLVM programs so that a debugger could identify
				1269	source code locations at which the program is executing.</dd>
				1270
				1271	<dt><tt><b>llvm/lib/ExecutionEngine/</b></tt></dt>
				1272	<dd> This directory contains libraries for executing LLVM bitcode directly
				1273	at runtime in both interpreted and JIT compiled fashions.</dd>
				1274
				1275	<dt><tt><b>llvm/lib/Support/</b></tt></dt>
				1276	<dd> This directory contains the source code that corresponds to the header
				1277	files located in <tt>llvm/include/Support/</tt>.</dd>
				1278
				1279	<dt><tt><b>llvm/lib/System/</b></tt></dt>
				1280	<dd>This directory contains the operating system abstraction layer that
				1281	shields LLVM from platform-specific coding.</dd>
				1282	</dl>
				1283
				1284	</div>
				1285
				1286	<!-- ======================================================================= -->
				1287	<div class="doc_subsection"><a name="projects"><tt>llvm/projects</tt></a></div>
				1288	<div class="doc_text">
				1289	<p>This directory contains projects that are not strictly part of LLVM but are
				1290	shipped with LLVM. This is also the directory where you should create your own
				1291	LLVM-based projects. See <tt>llvm/projects/sample</tt> for an example of how
Chris Lattner	af1df78	2008-08-11 06:13:31 +0000	[diff] [blame]	1292	to set up your own project.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1293	</div>
				1294
				1295	<!-- ======================================================================= -->
				1296	<div class="doc_subsection"><a name="runtime"><tt>llvm/runtime</tt></a></div>
				1297	<div class="doc_text">
				1298
				1299	<p>This directory contains libraries which are compiled into LLVM bitcode and
				1300	used when linking programs with the GCC front end. Most of these libraries are
				1301	skeleton versions of real libraries; for example, libc is a stripped down
				1302	version of glibc.</p>
				1303
				1304	<p>Unlike the rest of the LLVM suite, this directory needs the LLVM GCC front
				1305	end to compile.</p>
				1306
				1307	</div>
				1308
				1309	<!-- ======================================================================= -->
				1310	<div class="doc_subsection"><a name="test"><tt>llvm/test</tt></a></div>
				1311	<div class="doc_text">
				1312	<p>This directory contains feature and regression tests and other basic sanity
				1313	checks on the LLVM infrastructure. These are intended to run quickly and cover
				1314	a lot of territory without being exhaustive.</p>
				1315	</div>
				1316
				1317	<!-- ======================================================================= -->
				1318	<div class="doc_subsection"><a name="llvmtest"><tt>test-suite</tt></a></div>
				1319	<div class="doc_text">
				1320	<p>This is not a directory in the normal llvm module; it is a separate
				1321	Subversion
				1322	module that must be checked out (usually to <tt>projects/test-suite</tt>).
				1323	This
				1324	module contains a comprehensive correctness, performance, and benchmarking
				1325	test
				1326	suite for LLVM. It is a separate Subversion module because not every LLVM
				1327	user is
				1328	interested in downloading or building such a comprehensive test suite. For
				1329	further details on this test suite, please see the
				1330	<a href="TestingGuide.html">Testing Guide</a> document.</p>
				1331	</div>
				1332
				1333	<!-- ======================================================================= -->
				1334	<div class="doc_subsection"><a name="tools"><tt>llvm/tools</tt></a></div>
				1335	<div class="doc_text">
				1336
				1337	<p>The <b>tools</b> directory contains the executables built out of the
				1338	libraries above, which form the main part of the user interface. You can
				1339	always get help for a tool by typing <tt>tool_name --help</tt>. The
				1340	following is a brief introduction to the most important tools. More detailed
				1341	information is in the <a href="CommandGuide/index.html">Command Guide</a>.</p>
				1342
				1343	<dl>
				1344
				1345	<dt><tt><b>bugpoint</b></tt></dt>
				1346	<dd><tt>bugpoint</tt> is used to debug
				1347	optimization passes or code generation backends by narrowing down the
				1348	given test case to the minimum number of passes and/or instructions that
				1349	still cause a problem, whether it is a crash or miscompilation. See <a
				1350	href="HowToSubmitABug.html">HowToSubmitABug.html</a> for more information
				1351	on using <tt>bugpoint</tt>.</dd>
				1352
				1353	<dt><tt><b>llvmc</b></tt></dt>
				1354	<dd>The LLVM Compiler Driver. This program can
				1355	be configured to utilize both LLVM and non-LLVM compilation tools to enable
				1356	pre-processing, translation, optimization, assembly, and linking of programs
				1357	all from one command line. <tt>llvmc</tt> also takes care of processing the
				1358	dependent libraries found in bitcode. This reduces the need to get the
				1359	traditional <tt>-l<name></tt> options right on the command line. Please
				1360	note that this tool, while functional, is still experimental and not feature
				1361	complete.</dd>
				1362
				1363	<dt><tt><b>llvm-ar</b></tt></dt>
				1364	<dd>The archiver produces an archive containing
				1365	the given LLVM bitcode files, optionally with an index for faster
				1366	lookup.</dd>
				1367
				1368	<dt><tt><b>llvm-as</b></tt></dt>
				1369	<dd>The assembler transforms the human readable LLVM assembly to LLVM
				1370	bitcode.</dd>
				1371
				1372	<dt><tt><b>llvm-dis</b></tt></dt>
				1373	<dd>The disassembler transforms the LLVM bitcode to human readable
				1374	LLVM assembly.</dd>
				1375
				1376	<dt><tt><b>llvm-ld</b></tt></dt>
				1377	<dd><tt>llvm-ld</tt> is a general purpose and extensible linker for LLVM.
				1378	This is the linker invoked by <tt>llvmc</tt>. It performsn standard link time
				1379	optimizations and allows optimization modules to be loaded and run so that
				1380	language specific optimizations can be applied at link time.</dd>
				1381
				1382	<dt><tt><b>llvm-link</b></tt></dt>
				1383	<dd><tt>llvm-link</tt>, not surprisingly, links multiple LLVM modules into
				1384	a single program.</dd>
				1385
				1386	<dt><tt><b>lli</b></tt></dt>
				1387	<dd><tt>lli</tt> is the LLVM interpreter, which
Nick Lewycky	32dc2a1	2007-12-03 01:58:01 +0000	[diff] [blame]	1388	can directly execute LLVM bitcode (although very slowly...). For architectures
				1389	that support it (currently x86, Sparc, and PowerPC), by default, <tt>lli</tt>
				1390	will function as a Just-In-Time compiler (if the functionality was compiled
				1391	in), and will execute the code <i>much</i> faster than the interpreter.</dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1392
				1393	<dt><tt><b>llc</b></tt></dt>
				1394	<dd> <tt>llc</tt> is the LLVM backend compiler, which
				1395	translates LLVM bitcode to a native code assembly file or to C code (with
				1396	the -march=c option).</dd>
				1397
				1398	<dt><tt><b>llvm-gcc</b></tt></dt>
				1399	<dd><tt>llvm-gcc</tt> is a GCC-based C frontend that has been retargeted to
				1400	use LLVM as its backend instead of GCC's RTL backend. It can also emit LLVM
				1401	bitcode or assembly (with the <tt>-emit-llvm</tt> option) instead of the
				1402	usual machine code output. It works just like any other GCC compiler,
				1403	taking the typical <tt>-c, -S, -E, -o</tt> options that are typically used.
				1404	Additionally, the the source code for <tt>llvm-gcc</tt> is available as a
				1405	separate Subversion module.</dd>
				1406
				1407	<dt><tt><b>opt</b></tt></dt>
				1408	<dd><tt>opt</tt> reads LLVM bitcode, applies a series of LLVM to LLVM
				1409	transformations (which are specified on the command line), and then outputs
				1410	the resultant bitcode. The '<tt>opt --help</tt>' command is a good way to
Misha Brukman	5c1cc64	2008-12-11 18:23:24 +0000	[diff] [blame]	1411	get a list of the program transformations available in LLVM.<br>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1412	<dd><tt>opt</tt> can also be used to run a specific analysis on an input
				1413	LLVM bitcode file and print out the results. It is primarily useful for
				1414	debugging analyses, or familiarizing yourself with what an analysis does.</dd>
				1415	</dl>
				1416	</div>
				1417
				1418	<!-- ======================================================================= -->
				1419	<div class="doc_subsection"><a name="utils"><tt>llvm/utils</tt></a></div>
				1420	<div class="doc_text">
				1421
				1422	<p>This directory contains utilities for working with LLVM source code, and some
				1423	of the utilities are actually required as part of the build process because they
				1424	are code generators for parts of LLVM infrastructure.</p>
				1425
				1426	<dl>
				1427	<dt><tt><b>codegen-diff</b></tt> <dd><tt>codegen-diff</tt> is a script
				1428	that finds differences between code that LLC generates and code that LLI
				1429	generates. This is a useful tool if you are debugging one of them,
				1430	assuming that the other generates correct output. For the full user
				1431	manual, run <tt>`perldoc codegen-diff'</tt>.<br><br>
				1432
				1433	<dt><tt><b>emacs/</b></tt> <dd>The <tt>emacs</tt> directory contains
				1434	syntax-highlighting files which will work with Emacs and XEmacs editors,
				1435	providing syntax highlighting support for LLVM assembly files and TableGen
				1436	description files. For information on how to use the syntax files, consult
				1437	the <tt>README</tt> file in that directory.<br><br>
				1438
				1439	<dt><tt><b>getsrcs.sh</b></tt> <dd>The <tt>getsrcs.sh</tt> script finds
				1440	and outputs all non-generated source files, which is useful if one wishes
				1441	to do a lot of development across directories and does not want to
				1442	individually find each file. One way to use it is to run, for example:
				1443	<tt>xemacs `utils/getsources.sh`</tt> from the top of your LLVM source
				1444	tree.<br><br>
				1445
				1446	<dt><tt><b>llvmgrep</b></tt></dt>
				1447	<dd>This little tool performs an "egrep -H -n" on each source file in LLVM and
				1448	passes to it a regular expression provided on <tt>llvmgrep</tt>'s command
				1449	line. This is a very efficient way of searching the source base for a
				1450	particular regular expression.</dd>
				1451
				1452	<dt><tt><b>makellvm</b></tt> <dd>The <tt>makellvm</tt> script compiles all
				1453	files in the current directory and then compiles and links the tool that
				1454	is the first argument. For example, assuming you are in the directory
				1455	<tt>llvm/lib/Target/Sparc</tt>, if <tt>makellvm</tt> is in your path,
				1456	simply running <tt>makellvm llc</tt> will make a build of the current
				1457	directory, switch to directory <tt>llvm/tools/llc</tt> and build it,
				1458	causing a re-linking of LLC.<br><br>
				1459
				1460	<dt><tt><b>NewNightlyTest.pl</b></tt> and
				1461	<tt><b>NightlyTestTemplate.html</b></tt> <dd>These files are used in a
				1462	cron script to generate nightly status reports of the functionality of
				1463	tools, and the results can be seen by following the appropriate link on
				1464	the <a href="http://llvm.org/">LLVM homepage</a>.<br><br>
				1465
				1466	<dt><tt><b>TableGen/</b></tt> <dd>The <tt>TableGen</tt> directory contains
				1467	the tool used to generate register descriptions, instruction set
				1468	descriptions, and even assemblers from common TableGen description
				1469	files.<br><br>
				1470
				1471	<dt><tt><b>vim/</b></tt> <dd>The <tt>vim</tt> directory contains
				1472	syntax-highlighting files which will work with the VIM editor, providing
				1473	syntax highlighting support for LLVM assembly files and TableGen
				1474	description files. For information on how to use the syntax files, consult
				1475	the <tt>README</tt> file in that directory.<br><br>
				1476
				1477	</dl>
				1478
				1479	</div>
				1480
				1481	<!-- ======================================================================= -->
				1482	<div class="doc_subsection"><a name="win32"><tt>llvm/win32</tt></a></div>
				1483	<div class="doc_text">
				1484	<p>This directory contains build scripts and project files for use with
				1485	Visual C++. This allows developers on Windows to build LLVM without the need
				1486	for Cygwin. The contents of this directory should be considered experimental
				1487	at this time.
				1488	</p>
				1489	</div>
				1490	<!-- *********************************************************************** -->
				1491	<div class="doc_section">
				1492	<a name="tutorial">An Example Using the LLVM Tool Chain</a>
				1493	</div>
				1494	<!-- *********************************************************************** -->
				1495
				1496	<div class="doc_text">
				1497	<p>This section gives an example of using LLVM. llvm-gcc3 is now obsolete,
Chris Lattner	e609964	2009-04-10 15:38:51 +0000	[diff] [blame]	1498	so we only include instructions for llvm-gcc4.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1499	</p>
				1500
				1501	<p><b>Note:</b> The <i>gcc4</i> frontend's invocation is <b><i>considerably different</i></b>
				1502	from the previous <i>gcc3</i> frontend. In particular, the <i>gcc4</i> frontend <b><i>does not</i></b>
				1503	create bitcode by default: <i>gcc4</i> produces native code. As the example below illustrates,
				1504	the '--emit-llvm' flag is needed to produce LLVM bitcode output. For <i>makefiles</i> and
				1505	<i>configure</i> scripts, the CFLAGS variable needs '--emit-llvm' to produce bitcode
				1506	output.</p>
				1507	</div>
				1508
				1509	<!-- ======================================================================= -->
				1510	<div class="doc_subsection"><a name="tutorial4">Example with llvm-gcc4</a></div>
				1511
				1512	<div class="doc_text">
				1513
				1514	<ol>
				1515	<li><p>First, create a simple C file, name it 'hello.c':</p>
				1516
				1517	<div class="doc_code">
				1518	<pre>
				1519	#include <stdio.h>
				1520
				1521	int main() {
				1522	printf("hello world\n");
				1523	return 0;
				1524	}
				1525	</pre></div></li>
				1526
				1527	<li><p>Next, compile the C file into a native executable:</p>
				1528
				1529	<div class="doc_code"><pre>% llvm-gcc hello.c -o hello</pre></div>
				1530
				1531	<p>Note that llvm-gcc works just like GCC by default. The standard -S and
				1532	-c arguments work as usual (producing a native .s or .o file,
				1533	respectively).</p></li>
				1534
				1535	<li><p>Next, compile the C file into a LLVM bitcode file:</p>
				1536
				1537	<div class="doc_code">
				1538	<pre>% llvm-gcc -O3 -emit-llvm hello.c -c -o hello.bc</pre></div>
				1539
				1540	<p>The -emit-llvm option can be used with the -S or -c options to emit an
				1541	LLVM ".ll" or ".bc" file (respectively) for the code. This allows you
				1542	to use the <a href="CommandGuide/index.html">standard LLVM tools</a> on
				1543	the bitcode file.</p>
				1544
				1545	<p>Unlike llvm-gcc3, llvm-gcc4 correctly responds to -O[0123] arguments.
				1546	</p></li>
				1547
				1548	<li><p>Run the program in both forms. To run the program, use:</p>
				1549
				1550	<div class="doc_code"><pre>% ./hello</pre></div>
				1551
				1552	<p>and</p>
				1553
				1554	<div class="doc_code"><pre>% lli hello.bc</pre></div>
				1555
				1556	<p>The second examples shows how to invoke the LLVM JIT, <a
				1557	href="CommandGuide/html/lli.html">lli</a>.</p></li>
				1558
				1559	<li><p>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly
				1560	code:</p>
				1561
				1562	<div class="doc_code">
				1563	<pre>llvm-dis < hello.bc \| less</pre>
				1564	</div></li>
				1565
				1566	<li><p>Compile the program to native assembly using the LLC code
				1567	generator:</p>
				1568
				1569	<div class="doc_code"><pre>% llc hello.bc -o hello.s</pre></div></li>
				1570
				1571	<li><p>Assemble the native assembly language file into a program:</p>
				1572
				1573	<div class="doc_code">
				1574	<pre>
				1575	<b>Solaris:</b> % /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native
				1576
				1577	<b>Others:</b> % gcc hello.s -o hello.native
				1578	</pre>
				1579	</div></li>
				1580
				1581	<li><p>Execute the native code program:</p>
				1582
				1583	<div class="doc_code"><pre>% ./hello.native</pre></div>
				1584
				1585	<p>Note that using llvm-gcc to compile directly to native code (i.e. when
				1586	the -emit-llvm option is not present) does steps 6/7/8 for you.</p>
				1587	</li>
				1588
				1589	</ol>
				1590
				1591	</div>
				1592
				1593
				1594	<!-- *********************************************************************** -->
				1595	<div class="doc_section">
				1596	<a name="problems">Common Problems</a>
				1597	</div>
				1598	<!-- *********************************************************************** -->
				1599
				1600	<div class="doc_text">
				1601
				1602	<p>If you are having problems building or using LLVM, or if you have any other
				1603	general questions about LLVM, please consult the <a href="FAQ.html">Frequently
				1604	Asked Questions</a> page.</p>
				1605
				1606	</div>
				1607
				1608	<!-- *********************************************************************** -->
				1609	<div class="doc_section">
				1610	<a name="links">Links</a>
				1611	</div>
				1612	<!-- *********************************************************************** -->
				1613
				1614	<div class="doc_text">
				1615
Bill Wendling	08f49b9	2008-07-22 01:10:25 +0000	[diff] [blame]	1616	<p>This document is just an <b>introduction</b> on how to use LLVM to do
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1617	some simple things... there are many more interesting and complicated things
				1618	that you can do that aren't documented here (but we'll gladly accept a patch
				1619	if you want to write something up!). For more information about LLVM, check
				1620	out:</p>
				1621
				1622	<ul>
				1623	<li><a href="http://llvm.org/">LLVM homepage</a></li>
				1624	<li><a href="http://llvm.org/doxygen/">LLVM doxygen tree</a></li>
				1625	<li><a href="http://llvm.org/docs/Projects.html">Starting a Project
				1626	that Uses LLVM</a></li>
				1627	</ul>
				1628
				1629	</div>
				1630
				1631	<!-- *********************************************************************** -->
				1632
				1633	<hr>
				1634	<address>
				1635	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	947321d	2008-12-11 17:34:48 +0000	[diff] [blame]	1636	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1637	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	5c1cc64	2008-12-11 18:23:24 +0000	[diff] [blame]	1638	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1639
				1640	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
				1641	<a href="http://llvm.x10sys.com/rspencer/">Reid Spencer</a><br>
				1642	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
				1643	Last modified: $Date$
				1644	</address>
				1645	</body>
				1646	</html>