Blame - docs/GettingStarted.html - fp2-dev/platform/external/llvm

blob: 4f8b28cf3b9b9b0d226cf367973dfd35ef1cb50e [file] [log] [blame]

Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
				2	"http://www.w3.org/TR/html4/strict.dtd">
				3	<html>
				4	<head>
				5	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				6	<title>Getting Started with LLVM System</title>
				7	<link rel="stylesheet" href="llvm.css" type="text/css">
				8	</head>
				9	<body>
				10
				11	<div class="doc_title">
				12	Getting Started with the LLVM System
				13	</div>
				14
				15	<ul>
				16	<li><a href="#overview">Overview</a>
				17	<li><a href="#quickstart">Getting Started Quickly (A Summary)</a>
				18	<li><a href="#requirements">Requirements</a>
				19	<ol>
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>
				229	<td>Solaris</td>
				230	<td>V9 (Ultrasparc)</td>
				231	<td>GCC</td>
				232	</tr>
				233	<tr>
				234	<td>FreeBSD</td>
				235	<td>x86<sup><a href="#pf_1">1</a></sup></td>
				236	<td>GCC</td>
				237	</tr>
				238	<tr>
				239	<td>MacOS X<sup><a href="#pf_2">2</a></sup></td>
				240	<td>PowerPC</td>
				241	<td>GCC</td>
				242	</tr>
				243	<tr>
Scott Michel	6de83ff	2008-03-18 23:13:26 +0000	[diff] [blame]	244	<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]	245	<td>x86</td>
				246	<td>GCC</td>
				247
				248	</tr>
				249	<tr>
				250	<td>Cygwin/Win32</td>
				251	<td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_8">8</a></sup></td>
				252	<td>GCC 3.4.X, binutils 2.15</td>
				253	</tr>
				254	<tr>
				255	<td>MinGW/Win32</td>
				256	<td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_6">6</a>,<a href="#pf_8">8</a></sup></td>
				257	<td>GCC 3.4.X, binutils 2.15</td>
				258	</tr>
				259	<tr>
				260	<td>Linux</td>
Dan Gohman	99fc244	2008-11-13 19:07:07 +0000	[diff] [blame]	261	<td>amd64</td>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	262	<td>GCC</td>
				263	</tr>
				264	</table>
				265
				266	<p>LLVM has partial support for the following platforms:</p>
				267
				268	<table summary="LLVM partial platform support">
				269	<tr>
				270	<th>OS</th>
				271	<th>Arch</th>
				272	<th>Compilers</th>
				273	</tr>
				274	<tr>
				275	<td>Windows</td>
				276	<td>x86<sup><a href="#pf_1">1</a></sup></td>
Nick Lewycky	18b90af	2008-12-08 00:45:02 +0000	[diff] [blame]	277	<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]	278	<tr>
				279	<td>AIX<sup><a href="#pf_3">3</a>,<a href="#pf_4">4</a></sup></td>
				280	<td>PowerPC</td>
				281	<td>GCC</td>
				282	</tr>
				283	<tr>
				284	<td>Linux<sup><a href="#pf_3">3</a>,<a href="#pf_5">5</a></sup></td>
				285	<td>PowerPC</td>
				286	<td>GCC</td>
				287	</tr>
				288
				289	<tr>
				290	<td>Linux<sup><a href="#pf_7">7</a></sup></td>
				291	<td>Alpha</td>
				292	<td>GCC</td>
				293	</tr>
				294	<tr>
				295	<td>Linux<sup><a href="#pf_7">7</a></sup></td>
				296	<td>Itanium (IA-64)</td>
				297	<td>GCC</td>
				298	</tr>
				299	<tr>
				300	<td>HP-UX<sup><a href="#pf_7">7</a></sup></td>
				301	<td>Itanium (IA-64)</td>
				302	<td>HP aCC</td>
				303	</tr>
				304	</table>
				305
				306	<p><b>Notes:</b></p>
				307
				308	<div class="doc_notes">
				309	<ol>
				310	<li><a name="pf_1">Code generation supported for Pentium processors and
				311	up</a></li>
				312	<li><a name="pf_2">Code generation supported for 32-bit ABI only</a></li>
				313	<li><a name="pf_3">No native code generation</a></li>
Nick Lewycky	18b90af	2008-12-08 00:45:02 +0000	[diff] [blame]	314	<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]	315	<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]	316	<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]	317	<li><a name="pf_7">Native code generation exists but is not complete.</a></li>
				318	<li><a name="pf_8">Binutils</a> up to post-2.17 has bug in bfd/cofflink.c
				319	preventing LLVM from building correctly. Several workarounds have been
				320	introduced into LLVM build system, but the bug can occur anytime in the
				321	future. We highly recommend that you rebuild your current binutils with the
				322	patch from <a href="http://sourceware.org/bugzilla/show_bug.cgi?id=2659">
				323	Binutils bugzilla</a>, if it wasn't already applied.</li>
Chris Lattner	fdae868	2008-11-09 17:19:14 +0000	[diff] [blame]	324	<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]	325	internal LLVM assert messages when compiled for Release at optimization
Chris Lattner	fdae868	2008-11-09 17:19:14 +0000	[diff] [blame]	326	levels greater than 0 (i.e., <i>"-O1"</i> and higher).
				327	Add <i>OPTIMIZE_OPTION="-O0"</i> to the build command line
Scott Michel	6de83ff	2008-03-18 23:13:26 +0000	[diff] [blame]	328	if compiling for LLVM Release or bootstrapping the LLVM toolchain.</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	329	</ol>
				330	</div>
				331
				332	<p>Note that you will need about 1-3 GB of space for a full LLVM build in Debug
				333	mode, depending on the system (it is so large because of all the debugging
				334	information and the fact that the libraries are statically linked into multiple
Chris Lattner	15aeb9a	2009-04-25 22:08:52 +0000	[diff] [blame]	335	tools). If you do not need many of the tools and you are space-conscious, you
				336	can pass <tt>ONLY_TOOLS="tools you need"</tt> to make. The Release build
				337	requires considerably less space.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	338
				339	<p>The LLVM suite <i>may</i> compile on other platforms, but it is not
				340	guaranteed to do so. If compilation is successful, the LLVM utilities should be
				341	able to assemble, disassemble, analyze, and optimize LLVM bitcode. Code
				342	generation should work as well, although the generated native code may not work
				343	on your platform.</p>
				344
				345	<p>The GCC front end is not very portable at the moment. If you want to get it
				346	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]	347	href="GCCFEBuildInstrs.html">try to compile it</a> on your platform.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	348
				349	</div>
				350
				351	<!-- ======================================================================= -->
				352	<div class="doc_subsection"><a name="software"><b>Software</b></a></div>
				353	<div class="doc_text">
				354	<p>Compiling LLVM requires that you have several software packages
				355	installed. The table below lists those required packages. The Package column
				356	is the usual name for the software package that LLVM depends on. The Version
				357	column provides "known to work" versions of the package. The Notes column
				358	describes how LLVM uses the package and provides other details.</p>
				359	<table summary="Packages required to compile LLVM">
				360	<tr><th>Package</th><th>Version</th><th>Notes</th></tr>
				361
				362	<tr>
				363	<td><a href="http://savannah.gnu.org/projects/make">GNU Make</a></td>
				364	<td>3.79, 3.79.1</td>
				365	<td>Makefile/build processor</td>
				366	</tr>
				367
				368	<tr>
				369	<td><a href="http://gcc.gnu.org">GCC</a></td>
				370	<td>3.4.2</td>
				371	<td>C/C++ compiler<sup><a href="#sf1">1</a></sup></td>
				372	</tr>
				373
				374	<tr>
				375	<td><a href="http://www.gnu.org/software/texinfo">TeXinfo</a></td>
				376	<td>4.5</td>
				377	<td>For building the CFE</td>
				378	</tr>
				379
				380	<tr>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	381	<td><a href="http://subversion.tigris.org/project_packages.html">SVN</a></td>
				382	<td>≥1.3</td>
				383	<td>Subversion access to LLVM<sup><a href="#sf2">2</a></sup></td>
				384	</tr>
				385
				386	<tr>
				387	<td><a href="http://savannah.gnu.org/projects/dejagnu">DejaGnu</a></td>
				388	<td>1.4.2</td>
				389	<td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
				390	</tr>
				391
				392	<tr>
				393	<td><a href="http://www.tcl.tk/software/tcltk/">tcl</a></td>
				394	<td>8.3, 8.4</td>
				395	<td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
				396	</tr>
				397
				398	<tr>
				399	<td><a href="http://expect.nist.gov/">expect</a></td>
				400	<td>5.38.0</td>
				401	<td>Automated test suite<sup><a href="#sf3">3</a></sup></td>
				402	</tr>
				403
				404	<tr>
				405	<td><a href="http://www.perl.com/download.csp">perl</a></td>
				406	<td>≥5.6.0</td>
				407	<td>Nightly tester, utilities</td>
				408	</tr>
				409
				410	<tr>
				411	<td><a href="http://savannah.gnu.org/projects/m4">GNU M4</a>
				412	<td>1.4</td>
				413	<td>Macro processor for configuration<sup><a href="#sf4">4</a></sup></td>
				414	</tr>
				415
				416	<tr>
				417	<td><a href="http://www.gnu.org/software/autoconf">GNU Autoconf</a></td>
				418	<td>2.59</td>
				419	<td>Configuration script builder<sup><a href="#sf4">4</a></sup></td>
				420	</tr>
				421
				422	<tr>
				423	<td><a href="http://www.gnu.org/software/automake">GNU Automake</a></td>
				424	<td>1.9.2</td>
				425	<td>aclocal macro generator<sup><a href="#sf4">4</a></sup></td>
				426	</tr>
				427
				428	<tr>
				429	<td><a href="http://savannah.gnu.org/projects/libtool">libtool</a></td>
				430	<td>1.5.10</td>
				431	<td>Shared library manager<sup><a href="#sf4">4</a></sup></td>
				432	</tr>
				433
				434	</table>
				435
				436	<p><b>Notes:</b></p>
				437	<div class="doc_notes">
				438	<ol>
				439	<li><a name="sf1">Only the C and C++ languages are needed so there's no
				440	need to build the other languages for LLVM's purposes.</a> See
				441	<a href="#brokengcc">below</a> for specific version info.</li>
				442	<li><a name="sf2">You only need Subversion if you intend to build from the
				443	latest LLVM sources. If you're working from a release distribution, you
				444	don't need Subversion.</a></li>
				445	<li><a name="sf3">Only needed if you want to run the automated test
				446	suite in the <tt>llvm/test</tt> directory.</a></li>
				447	<li><a name="sf4">If you want to make changes to the configure scripts,
				448	you will need GNU autoconf (2.59), and consequently, GNU M4 (version 1.4
				449	or higher). You will also need automake (1.9.2). We only use aclocal
				450	from that package.</a></li>
				451	</ol>
				452	</div>
				453
				454	<p>Additionally, your compilation host is expected to have the usual
				455	plethora of Unix utilities. Specifically:</p>
				456	<ul>
				457	<li><b>ar</b> - archive library builder</li>
				458	<li><b>bzip2*</b> - bzip2 command for distribution generation</li>
				459	<li><b>bunzip2*</b> - bunzip2 command for distribution checking</li>
				460	<li><b>chmod</b> - change permissions on a file</li>
				461	<li><b>cat</b> - output concatenation utility</li>
				462	<li><b>cp</b> - copy files</li>
				463	<li><b>date</b> - print the current date/time </li>
				464	<li><b>echo</b> - print to standard output</li>
				465	<li><b>egrep</b> - extended regular expression search utility</li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	466	<li><b>find</b> - find files/dirs in a file system</li>
				467	<li><b>grep</b> - regular expression search utility</li>
				468	<li><b>gzip*</b> - gzip command for distribution generation</li>
				469	<li><b>gunzip*</b> - gunzip command for distribution checking</li>
				470	<li><b>install</b> - install directories/files </li>
				471	<li><b>mkdir</b> - create a directory</li>
				472	<li><b>mv</b> - move (rename) files</li>
				473	<li><b>ranlib</b> - symbol table builder for archive libraries</li>
				474	<li><b>rm</b> - remove (delete) files and directories</li>
				475	<li><b>sed</b> - stream editor for transforming output</li>
				476	<li><b>sh</b> - Bourne shell for make build scripts</li>
				477	<li><b>tar</b> - tape archive for distribution generation</li>
				478	<li><b>test</b> - test things in file system</li>
				479	<li><b>unzip*</b> - unzip command for distribution checking</li>
				480	<li><b>zip*</b> - zip command for distribution generation</li>
				481	</ul>
				482	</div>
				483
				484	<!-- ======================================================================= -->
				485	<div class="doc_subsection">
				486	<a name="brokengcc">Broken versions of GCC and other tools</a>
				487	</div>
				488
				489	<div class="doc_text">
				490
				491	<p>LLVM is very demanding of the host C++ compiler, and as such tends to expose
				492	bugs in the compiler. In particular, several versions of GCC crash when trying
				493	to compile LLVM. We routinely use GCC 3.3.3, 3.4.0, and Apple 4.0.1
				494	successfully with them (however, see important notes below). Other versions
				495	of GCC will probably work as well. GCC versions listed
				496	here are known to not work. If you are using one of these versions, please try
				497	to upgrade your GCC to something more recent. If you run into a problem with a
				498	version of GCC not listed here, please <a href="mailto:llvmdev@cs.uiuc.edu">let
				499	us know</a>. Please use the "<tt>gcc -v</tt>" command to find out which version
				500	of GCC you are using.
				501	</p>
				502
				503	<p><b>GCC versions prior to 3.0</b>: GCC 2.96.x and before had several
				504	problems in the STL that effectively prevent it from compiling LLVM.
				505	</p>
				506
Chris Lattner	76bb530	2008-02-13 17:50:24 +0000	[diff] [blame]	507	<p><b>GCC 3.2.2 and 3.2.3</b>: These versions of GCC fails to compile LLVM with
				508	a bogus template error. This was fixed in later GCCs.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	509
				510	<p><b>GCC 3.3.2</b>: This version of GCC suffered from a <a
				511	href="http://gcc.gnu.org/PR13392">serious bug</a> which causes it to crash in
				512	the "<tt>convert_from_eh_region_ranges_1</tt>" GCC function.</p>
				513
				514	<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]	515	Cygwin does not work. Please <a href="GCCFEBuildInstrs.html#cygwin">upgrade
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	516	to a newer version</a> if possible.</p>
				517	<p><b>SuSE GCC 3.3.3</b>: The version of GCC 3.3.3 shipped with SuSE 9.1 (and
				518	possibly others) does not compile LLVM correctly (it appears that exception
				519	handling is broken in some cases). Please download the FSF 3.3.3 or upgrade
				520	to a newer version of GCC.</p>
				521	<p><b>GCC 3.4.0 on linux/x86 (32-bit)</b>: GCC miscompiles portions of the
				522	code generator, causing an infinite loop in the llvm-gcc build when built
				523	with optimizations enabled (i.e. a release build).</p>
				524	<p><b>GCC 3.4.2 on linux/x86 (32-bit)</b>: GCC miscompiles portions of the
				525	code generator at -O3, as with 3.4.0. However gcc 3.4.2 (unlike 3.4.0)
				526	correctly compiles LLVM at -O2. A work around is to build release LLVM
				527	builds with "make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2 ..."</p>
				528	<p><b>GCC 3.4.x on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1056">
				529	miscompiles portions of LLVM</a>.</p>
Chris Lattner	05300e4	2007-11-01 04:20:16 +0000	[diff] [blame]	530	<p><b>GCC 3.4.4 (CodeSourcery ARM 2005q3-2)</b>: this compiler miscompiles LLVM
				531	when building with optimizations enabled. It appears to work with
				532	"<tt>make ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O1</tt>" or build a debug
				533	build.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	534	<p><b>IA-64 GCC 4.0.0</b>: The IA-64 version of GCC 4.0.0 is known to
				535	miscompile LLVM.</p>
				536	<p><b>Apple Xcode 2.3</b>: GCC crashes when compiling LLVM at -O3 (which is the
				537	default with ENABLE_OPTIMIZED=1. To work around this, build with
				538	"ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2".</p>
				539	<p><b>GCC 4.1.1</b>: GCC fails to build LLVM with template concept check errors
				540	compiling some files. At the time of this writing, GCC mainline (4.2)
				541	did not share the problem.</p>
				542	<p><b>GCC 4.1.1 on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1063">
				543	miscompiles portions of LLVM</a> when compiling llvm itself into 64-bit
				544	code. LLVM will appear to mostly work but will be buggy, e.g. failing
				545	portions of its testsuite.</p>
				546	<p><b>GCC 4.1.2 on OpenSUSE</b>: Seg faults during libstdc++ build and on x86_64
				547	platforms compiling md5.c gets a mangled constant.</p>
Daniel Dunbar	597fdcd	2008-10-11 18:40:33 +0000	[diff] [blame]	548	<p><b>GCC 4.1.2 (20061115 (prerelease) (Debian 4.1.1-21)) on Debian</b>: Appears
				549	to miscompile parts of LLVM 2.4. One symptom is ValueSymbolTable complaining
				550	about symbols remaining in the table on destruction.</p>
Nuno Lopes	fc375a6	2008-12-10 16:11:10 +0000	[diff] [blame]	551	<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]	552	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]	553	<p><b>Cygwin GCC 4.3.2 20080827 (beta) 2</b>:
				554	Users <a href="http://llvm.org/PR4145">reported</a> various problems related
				555	with link errors when using this GCC version.</p>
Nick Lewycky	adb7b15	2009-07-17 06:32:10 +0000	[diff] [blame]	556	<p><b>GCC 4.3.3 (Debian 4.3.3-10) on ARM</b>: Miscompiles parts of LLVM 2.6
				557	when optimizations are turned on. The symptom is an infinite loop in
				558	FoldingSetImpl::RemoveNode while running the code generator.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	559	<p><b>GNU ld 2.16.X</b>. Some 2.16.X versions of the ld linker will produce very
				560	long warning messages complaining that some ".gnu.linkonce.t.*" symbol was
				561	defined in a discarded section. You can safely ignore these messages as they are
				562	erroneous and the linkage is correct. These messages disappear using ld
				563	2.17.</p>
				564
				565	<p><b>GNU binutils 2.17</b>: Binutils 2.17 contains <a
				566	href="http://sourceware.org/bugzilla/show_bug.cgi?id=3111">a bug</a> which
				567	causes huge link times (minutes instead of seconds) when building LLVM. We
				568	recommend upgrading to a newer version (2.17.50.0.4 or later).</p>
				569
Nick Lewycky	87da07c	2009-03-03 05:41:16 +0000	[diff] [blame]	570	<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]	571	<a href="http://sourceware.org/bugzilla/show_bug.cgi?id=9836">a bug</a>
				572	which causes intermittent failures when building LLVM with position independent
Nick Lewycky	87da07c	2009-03-03 05:41:16 +0000	[diff] [blame]	573	code. The symptom is an error about cyclic dependencies. We recommend
				574	upgrading to a newer version of Gold.</p>
Nick Lewycky	829108e	2009-02-25 06:29:47 +0000	[diff] [blame]	575
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	576	</div>
				577
				578
				579
				580	<!-- *********************************************************************** -->
				581	<div class="doc_section">
				582	<a name="starting"><b>Getting Started with LLVM</b></a>
				583	</div>
				584	<!-- *********************************************************************** -->
				585
				586	<div class="doc_text">
				587
				588	<p>The remainder of this guide is meant to get you up and running with
				589	LLVM and to give you some basic information about the LLVM environment.</p>
				590
				591	<p>The later sections of this guide describe the <a
				592	href="#layout">general layout</a> of the the LLVM source tree, a <a
				593	href="#tutorial">simple example</a> using the LLVM tool chain, and <a
				594	href="#links">links</a> to find more information about LLVM or to get
				595	help via e-mail.</p>
				596	</div>
				597
				598	<!-- ======================================================================= -->
				599	<div class="doc_subsection">
				600	<a name="terminology">Terminology and Notation</a>
				601	</div>
				602
				603	<div class="doc_text">
				604
				605	<p>Throughout this manual, the following names are used to denote paths
				606	specific to the local system and working environment. <i>These are not
				607	environment variables you need to set but just strings used in the rest
				608	of this document below</i>. In any of the examples below, simply replace
				609	each of these names with the appropriate pathname on your local system.
				610	All these paths are absolute:</p>
				611
				612	<dl>
				613	<dt>SRC_ROOT
				614	<dd>
				615	This is the top level directory of the LLVM source tree.
				616	<br><br>
				617
				618	<dt>OBJ_ROOT
				619	<dd>
				620	This is the top level directory of the LLVM object tree (i.e. the
				621	tree where object files and compiled programs will be placed. It
				622	can be the same as SRC_ROOT).
				623	<br><br>
				624
				625	<dt>LLVMGCCDIR
				626	<dd>
				627	This is where the LLVM GCC Front End is installed.
				628	<p>
				629	For the pre-built GCC front end binaries, the LLVMGCCDIR is
				630	<tt>llvm-gcc/<i>platform</i>/llvm-gcc</tt>.
				631	</dl>
				632
				633	</div>
				634
				635	<!-- ======================================================================= -->
				636	<div class="doc_subsection">
				637	<a name="environment">Setting Up Your Environment</a>
				638	</div>
				639
				640	<div class="doc_text">
				641
				642	<p>
				643	In order to compile and use LLVM, you may need to set some environment
				644	variables.
				645
				646	<dl>
				647	<dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt>/path/to/your/bitcode/libs</tt></dt>
				648	<dd>[Optional] This environment variable helps LLVM linking tools find the
				649	locations of your bitcode libraries. It is provided only as a
				650	convenience since you can specify the paths using the -L options of the
				651	tools and the C/C++ front-end will automatically use the bitcode files
				652	installed in its
				653	<tt>lib</tt> directory.</dd>
				654	</dl>
				655
				656	</div>
				657
				658	<!-- ======================================================================= -->
				659	<div class="doc_subsection">
				660	<a name="unpack">Unpacking the LLVM Archives</a>
				661	</div>
				662
				663	<div class="doc_text">
				664
				665	<p>
				666	If you have the LLVM distribution, you will need to unpack it before you
				667	can begin to compile it. LLVM is distributed as a set of two files: the LLVM
				668	suite and the LLVM GCC front end compiled for your platform. There is an
				669	additional test suite that is optional. Each file is a TAR archive that is
				670	compressed with the gzip program.
				671	</p>
				672
				673	<p>The files are as follows, with <em>x.y</em> marking the version number:
				674	<dl>
				675	<dt><tt>llvm-x.y.tar.gz</tt></dt>
Misha Brukman	5c1cc64	2008-12-11 18:23:24 +0000	[diff] [blame]	676	<dd>Source release for the LLVM libraries and tools.<br></dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	677
				678	<dt><tt>llvm-test-x.y.tar.gz</tt></dt>
				679	<dd>Source release for the LLVM test suite.</dd>
				680
Misha Brukman	313db03	2008-12-29 19:38:58 +0000	[diff] [blame]	681	<dt><tt>llvm-gcc-4.2-x.y.source.tar.gz</tt></dt>
				682	<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]	683	directory for build instructions.<br></dd>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	684
Misha Brukman	313db03	2008-12-29 19:38:58 +0000	[diff] [blame]	685	<dt><tt>llvm-gcc-4.2-x.y-platform.tar.gz</tt></dt>
				686	<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]	687
				688	</dl>
				689
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	690	</div>
				691
				692	<!-- ======================================================================= -->
				693	<div class="doc_subsection">
				694	<a name="checkout">Checkout LLVM from Subversion</a>
				695	</div>
				696
				697	<div class="doc_text">
				698
				699	<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]	700	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]	701	follows:</p>
				702
				703	<ul>
				704	<li><tt>cd <i>where-you-want-llvm-to-live</i></tt></li>
				705	<li>Read-Only: <tt>svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm</tt></li>
				706	<li>Read-Write:<tt>svn co https://user@llvm.org/svn/llvm-project/llvm/trunk
				707	llvm</tt></li>
				708	</ul>
				709
				710
				711	<p>This will create an '<tt>llvm</tt>' directory in the current
				712	directory and fully populate it with the LLVM source code, Makefiles,
				713	test directories, and local copies of documentation files.</p>
				714
				715	<p>If you want to get a specific release (as opposed to the most recent
				716	revision), you can checkout it from the '<tt>tags</tt>' directory (instead of
				717	'<tt>trunk</tt>'). The following releases are located in the following
Misha Brukman	8e73a47	2008-12-17 16:27:23 +0000	[diff] [blame]	718	subdirectories of the '<tt>tags</tt>' directory:</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	719
				720	<ul>
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	721	<li>Release 2.5: <b>RELEASE_25</b></li>
Misha Brukman	8e73a47	2008-12-17 16:27:23 +0000	[diff] [blame]	722	<li>Release 2.4: <b>RELEASE_24</b></li>
Tanya Lattner	9eb3be5	2008-06-09 06:02:09 +0000	[diff] [blame]	723	<li>Release 2.3: <b>RELEASE_23</b></li>
Tanya Lattner	6003078	2008-02-12 02:42:55 +0000	[diff] [blame]	724	<li>Release 2.2: <b>RELEASE_22</b></li>
Tanya Lattner	2fad5b0	2007-09-28 22:50:54 +0000	[diff] [blame]	725	<li>Release 2.1: <b>RELEASE_21</b></li>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	726	<li>Release 2.0: <b>RELEASE_20</b></li>
				727	<li>Release 1.9: <b>RELEASE_19</b></li>
				728	<li>Release 1.8: <b>RELEASE_18</b></li>
				729	<li>Release 1.7: <b>RELEASE_17</b></li>
				730	<li>Release 1.6: <b>RELEASE_16</b></li>
				731	<li>Release 1.5: <b>RELEASE_15</b></li>
				732	<li>Release 1.4: <b>RELEASE_14</b></li>
				733	<li>Release 1.3: <b>RELEASE_13</b></li>
				734	<li>Release 1.2: <b>RELEASE_12</b></li>
				735	<li>Release 1.1: <b>RELEASE_11</b></li>
				736	<li>Release 1.0: <b>RELEASE_1</b></li>
				737	</ul>
				738
				739	<p>If you would like to get the LLVM test suite (a separate package as of 1.4),
				740	you get it from the Subversion repository:</p>
				741
				742	<div class="doc_code">
				743	<pre>
				744	% cd llvm/projects
				745	% svn co http://llvm.org/svn/llvm-project/test-suite/trunk llvm-test
				746	</pre>
				747	</div>
				748
				749	<p>By placing it in the <tt>llvm/projects</tt>, it will be automatically
				750	configured by the LLVM configure script as well as automatically updated when
				751	you run <tt>svn update</tt>.</p>
				752
				753	<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]	754	and build it yourself. Please follow <a href="GCCFEBuildInstrs.html">these
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	755	instructions</a> to successfully get and build the LLVM GCC front-end.</p>
				756
				757	</div>
				758
				759	<!-- ======================================================================= -->
				760	<div class="doc_subsection">
				761	<a name="installcf">Install the GCC Front End</a>
				762	</div>
				763
				764	<div class="doc_text">
				765
				766	<p>Before configuring and compiling the LLVM suite, you can optionally extract the
				767	LLVM GCC front end from the binary distribution. It is used for running the
				768	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]	769	<a href="GCCFEBuildInstrs.html">build llvm-gcc yourself</a> after building the
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	770	main LLVM repository.</p>
				771
				772	<p>To install the GCC front end, do the following:</p>
				773
				774	<ol>
				775	<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]	776	<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]	777	-</tt></li>
				778	</ol>
				779
				780	<p>Once the binary is uncompressed, you should add a symlink for llvm-gcc and
				781	llvm-g++ to some directory in your path. When you configure LLVM, it will
				782	automatically detect llvm-gcc's presence (if it is in your path) enabling its
				783	use in llvm-test. Note that you can always build or install llvm-gcc at any
				784	pointer after building the main LLVM repository: just reconfigure llvm and
				785	llvm-test will pick it up.
				786	</p>
				787
				788	<p>The binary versions of the GCC front end may not suit all of your needs. For
				789	example, the binary distribution may include an old version of a system header
				790	file, not "fix" a header file that needs to be fixed for GCC, or it may be
				791	linked with libraries not available on your system.</p>
				792
				793	<p>In cases like these, you may want to try <a
Duncan Sands	e38f3dc	2008-02-14 17:53:22 +0000	[diff] [blame]	794	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]	795	much easier now than it was in the past.</p>
				796
				797	</div>
				798
				799	<!-- ======================================================================= -->
				800	<div class="doc_subsection">
				801	<a name="config">Local LLVM Configuration</a>
				802	</div>
				803
				804	<div class="doc_text">
				805
				806	<p>Once checked out from the Subversion repository, the LLVM suite source
				807	code must be
				808	configured via the <tt>configure</tt> script. This script sets variables in the
				809	various <tt>*.in</tt> files, most notably <tt>llvm/Makefile.config</tt> and
				810	<tt>llvm/include/Config/config.h</tt>. It also populates <i>OBJ_ROOT</i> with
				811	the Makefiles needed to begin building LLVM.</p>
				812
				813	<p>The following environment variables are used by the <tt>configure</tt>
				814	script to configure the build system:</p>
				815
				816	<table summary="LLVM configure script environment variables">
				817	<tr><th>Variable</th><th>Purpose</th></tr>
				818	<tr>
				819	<td>CC</td>
				820	<td>Tells <tt>configure</tt> which C compiler to use. By default,
				821	<tt>configure</tt> will look for the first GCC C compiler in
				822	<tt>PATH</tt>. Use this variable to override
				823	<tt>configure</tt>'s default behavior.</td>
				824	</tr>
				825	<tr>
				826	<td>CXX</td>
				827	<td>Tells <tt>configure</tt> which C++ compiler to use. By default,
				828	<tt>configure</tt> will look for the first GCC C++ compiler in
				829	<tt>PATH</tt>. Use this variable to override
				830	<tt>configure</tt>'s default behavior.</td>
				831	</tr>
				832	</table>
				833
				834	<p>The following options can be used to set or enable LLVM specific options:</p>
				835
				836	<dl>
				837	<dt><i>--with-llvmgccdir</i></dt>
				838	<dd>Path to the LLVM C/C++ FrontEnd to be used with this LLVM configuration.
				839	The value of this option should specify the full pathname of the C/C++ Front
				840	End to be used. If this option is not provided, the PATH will be searched for
				841	a program named <i>llvm-gcc</i> and the C/C++ FrontEnd install directory will
				842	be inferred from the path found. If the option is not given, and no llvm-gcc
				843	can be found in the path then a warning will be produced by
				844	<tt>configure</tt> indicating this situation. LLVM may still be built with
				845	the <tt>tools-only</tt> target but attempting to build the runtime libraries
				846	will fail as these libraries require llvm-gcc and llvm-g++. See
				847	<a href="#installcf">Install the GCC Front End</a> for details on installing
				848	the C/C++ Front End. See
Duncan Sands	e38f3dc	2008-02-14 17:53:22 +0000	[diff] [blame]	849	<a href="GCCFEBuildInstrs.html">Bootstrapping the LLVM C/C++ Front-End</a>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	850	for details on building the C/C++ Front End.</dd>
				851	<dt><i>--with-tclinclude</i></dt>
				852	<dd>Path to the tcl include directory under which <tt>tclsh</tt> can be
				853	found. Use this if you have multiple tcl installations on your machine and you
				854	want to use a specific one (8.x) for LLVM. LLVM only uses tcl for running the
				855	dejagnu based test suite in <tt>llvm/test</tt>. If you don't specify this
				856	option, the LLVM configure script will search for the tcl 8.4 and 8.3
				857	releases.
				858	<br><br>
				859	</dd>
				860	<dt><i>--enable-optimized</i></dt>
				861	<dd>
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	862	Enables optimized compilation (debugging symbols are removed
				863	and GCC optimization flags are enabled). Note that this is the default
				864	setting if you are using the LLVM distribution. The default behavior
				865	of an Subversion checkout is to use an unoptimized build (also known as a
				866	debug build).
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	867	<br><br>
				868	</dd>
				869	<dt><i>--enable-debug-runtime</i></dt>
				870	<dd>
				871	Enables debug symbols in the runtime libraries. The default is to strip
				872	debug symbols from the runtime libraries.
				873	</dd>
				874	<dt><i>--enable-jit</i></dt>
				875	<dd>
				876	Compile the Just In Time (JIT) compiler functionality. This is not
				877	available
				878	on all platforms. The default is dependent on platform, so it is best
				879	to explicitly enable it if you want it.
				880	<br><br>
				881	</dd>
				882	<dt><i>--enable-targets=</i><tt>target-option</tt></dt>
				883	<dd>Controls which targets will be built and linked into llc. The default
				884	value for <tt>target_options</tt> is "all" which builds and links all
				885	available targets. The value "host-only" can be specified to build only a
				886	native compiler (no cross-compiler targets available). The "native" target is
				887	selected as the target of the build host. You can also specify a comma
				888	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]	889	names use all lower case. The current set of targets is: <br>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	890	<tt>alpha, ia64, powerpc, skeleton, sparc, x86</tt>.
				891	<br><br></dd>
				892	<dt><i>--enable-doxygen</i></dt>
				893	<dd>Look for the doxygen program and enable construction of doxygen based
				894	documentation from the source code. This is disabled by default because
				895	generating the documentation can take a long time and producess 100s of
				896	megabytes of output.</dd>
				897	<dt><i>--with-udis86</i></dt>
				898	<dd>LLVM can use external disassembler library for various purposes (now it's
				899	used only for examining code produced by JIT). This option will enable usage
				900	of <a href="http://udis86.sourceforge.net/">udis86</a> x86 (both 32 and 64
				901	bits) disassembler library.</dd>
				902	</dl>
				903
				904	<p>To configure LLVM, follow these steps:</p>
				905
				906	<ol>
				907	<li><p>Change directory into the object root directory:</p>
				908
				909	<div class="doc_code"><pre>% cd <i>OBJ_ROOT</i></pre></div></li>
				910
				911	<li><p>Run the <tt>configure</tt> script located in the LLVM source
				912	tree:</p>
				913
				914	<div class="doc_code">
				915	<pre>% <i>SRC_ROOT</i>/configure --prefix=/install/path [other options]</pre>
				916	</div></li>
				917	</ol>
				918
				919	</div>
				920
				921	<!-- ======================================================================= -->
				922	<div class="doc_subsection">
				923	<a name="compile">Compiling the LLVM Suite Source Code</a>
				924	</div>
				925
				926	<div class="doc_text">
				927
				928	<p>Once you have configured LLVM, you can build it. There are three types of
				929	builds:</p>
				930
				931	<dl>
				932	<dt>Debug Builds
				933	<dd>
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	934	These builds are the default when one is using an Subversion checkout and
				935	types <tt>gmake</tt> (unless the <tt>--enable-optimized</tt> option was
				936	used during configuration). The build system will compile the tools and
				937	libraries with debugging information. To get a Debug Build using the
				938	LLVM distribution the <tt>--disable-optimized</tt> option must be passed
				939	to <tt>configure</tt>.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	940	<br><br>
				941
				942	<dt>Release (Optimized) Builds
				943	<dd>
				944	These builds are enabled with the <tt>--enable-optimized</tt> option to
				945	<tt>configure</tt> or by specifying <tt>ENABLE_OPTIMIZED=1</tt> on the
				946	<tt>gmake</tt> command line. For these builds, the build system will
				947	compile the tools and libraries with GCC optimizations enabled and strip
				948	debugging information from the libraries and executables it generates.
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	949	Note that Release Builds are default when using an LLVM distribution.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	950	<br><br>
				951
				952	<dt>Profile Builds
				953	<dd>
				954	These builds are for use with profiling. They compile profiling
				955	information into the code for use with programs like <tt>gprof</tt>.
				956	Profile builds must be started by specifying <tt>ENABLE_PROFILING=1</tt>
				957	on the <tt>gmake</tt> command line.
				958	</dl>
				959
				960	<p>Once you have LLVM configured, you can build it by entering the
				961	<i>OBJ_ROOT</i> directory and issuing the following command:</p>
				962
				963	<div class="doc_code"><pre>% gmake</pre></div>
				964
				965	<p>If the build fails, please <a href="#brokengcc">check here</a> to see if you
				966	are using a version of GCC that is known not to compile LLVM.</p>
				967
				968	<p>
				969	If you have multiple processors in your machine, you may wish to use some of
				970	the parallel build options provided by GNU Make. For example, you could use the
				971	command:</p>
				972
				973	<div class="doc_code"><pre>% gmake -j2</pre></div>
				974
				975	<p>There are several special targets which are useful when working with the LLVM
				976	source code:</p>
				977
				978	<dl>
				979	<dt><tt>gmake clean</tt>
				980	<dd>
				981	Removes all files generated by the build. This includes object files,
				982	generated C/C++ files, libraries, and executables.
				983	<br><br>
				984
				985	<dt><tt>gmake dist-clean</tt>
				986	<dd>
				987	Removes everything that <tt>gmake clean</tt> does, but also removes files
				988	generated by <tt>configure</tt>. It attempts to return the source tree to the
				989	original state in which it was shipped.
				990	<br><br>
				991
				992	<dt><tt>gmake install</tt>
				993	<dd>
				994	Installs LLVM header files, libraries, tools, and documentation in a
				995	hierarchy
				996	under $PREFIX, specified with <tt>./configure --prefix=[dir]</tt>, which
				997	defaults to <tt>/usr/local</tt>.
				998	<br><br>
				999
				1000	<dt><tt>gmake -C runtime install-bytecode</tt>
				1001	<dd>
				1002	Assuming you built LLVM into $OBJDIR, when this command is run, it will
				1003	install bitcode libraries into the GCC front end's bitcode library
				1004	directory. If you need to update your bitcode libraries,
				1005	this is the target to use once you've built them.
				1006	<br><br>
				1007	</dl>
				1008
				1009	<p>Please see the <a href="MakefileGuide.html">Makefile Guide</a> for further
				1010	details on these <tt>make</tt> targets and descriptions of other targets
				1011	available.</p>
				1012
				1013	<p>It is also possible to override default values from <tt>configure</tt> by
				1014	declaring variables on the command line. The following are some examples:</p>
				1015
				1016	<dl>
				1017	<dt><tt>gmake ENABLE_OPTIMIZED=1</tt>
				1018	<dd>
				1019	Perform a Release (Optimized) build.
				1020	<br><br>
				1021
				1022	<dt><tt>gmake ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1</tt>
				1023	<dd>
				1024	Perform a Release (Optimized) build without assertions enabled.
				1025	<br><br>
Chris Lattner	3d55fb9	2009-04-25 22:24:49 +0000	[diff] [blame]	1026
				1027	<dt><tt>gmake ENABLE_OPTIMIZED=0</tt>
				1028	<dd>
				1029	Perform a Debug build.
				1030	<br><br>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1031
				1032	<dt><tt>gmake ENABLE_PROFILING=1</tt>
				1033	<dd>
				1034	Perform a Profiling build.
				1035	<br><br>
				1036
				1037	<dt><tt>gmake VERBOSE=1</tt>
				1038	<dd>
				1039	Print what <tt>gmake</tt> is doing on standard output.
				1040	<br><br>
				1041
				1042	<dt><tt>gmake TOOL_VERBOSE=1</tt></dt>
				1043	<dd>Ask each tool invoked by the makefiles to print out what it is doing on
				1044	the standard output. This also implies <tt>VERBOSE=1</tt>.
				1045	<br><br></dd>
				1046	</dl>
				1047
				1048	<p>Every directory in the LLVM object tree includes a <tt>Makefile</tt> to build
				1049	it and any subdirectories that it contains. Entering any directory inside the
				1050	LLVM object tree and typing <tt>gmake</tt> should rebuild anything in or below
				1051	that directory that is out of date.</p>
				1052
				1053	</div>
				1054
				1055	<!-- ======================================================================= -->
				1056	<div class="doc_subsection">
				1057	<a name="cross-compile">Cross-Compiling LLVM</a>
				1058	</div>
				1059
				1060	<div class="doc_text">
Jim Grosbach	c8c7436	2009-04-17 17:25:16 +0000	[diff] [blame]	1061	<p>It is possible to cross-compile LLVM itself. That is, you can create LLVM
				1062	executables and libraries to be hosted on a platform different from the
				1063	platform where they are build (a Canadian Cross build). To configure a
				1064	cross-compile, supply the configure script with <tt>--build</tt> and
				1065	<tt>--host</tt> options that are different. The values of these options must
				1066	be legal target triples that your GCC compiler supports.</p>
				1067
				1068	<p>The result of such a build is executables that are not runnable on
				1069	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]	1070	(--host option).</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1071	</div>
				1072
				1073	<!-- ======================================================================= -->
				1074	<div class="doc_subsection">
				1075	<a name="objfiles">The Location of LLVM Object Files</a>
				1076	</div>
				1077
				1078	<div class="doc_text">
				1079
				1080	<p>The LLVM build system is capable of sharing a single LLVM source tree among
				1081	several LLVM builds. Hence, it is possible to build LLVM for several different
				1082	platforms or configurations using the same source tree.</p>
				1083
				1084	<p>This is accomplished in the typical autoconf manner:</p>
				1085
				1086	<ul>
				1087	<li><p>Change directory to where the LLVM object files should live:</p>
				1088
				1089	<div class="doc_code"><pre>% cd <i>OBJ_ROOT</i></pre></div></li>
				1090
				1091	<li><p>Run the <tt>configure</tt> script found in the LLVM source
				1092	directory:</p>
				1093
				1094	<div class="doc_code"><pre>% <i>SRC_ROOT</i>/configure</pre></div></li>
				1095	</ul>
				1096
				1097	<p>The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories
				1098	named after the build type:</p>
				1099
				1100	<dl>
				1101	<dt>Debug Builds
				1102	<dd>
				1103	<dl>
				1104	<dt>Tools
				1105	<dd><tt><i>OBJ_ROOT</i>/Debug/bin</tt>
				1106	<dt>Libraries
				1107	<dd><tt><i>OBJ_ROOT</i>/Debug/lib</tt>
				1108	</dl>
				1109	<br><br>
				1110
				1111	<dt>Release Builds
				1112	<dd>
				1113	<dl>
				1114	<dt>Tools
				1115	<dd><tt><i>OBJ_ROOT</i>/Release/bin</tt>
				1116	<dt>Libraries
				1117	<dd><tt><i>OBJ_ROOT</i>/Release/lib</tt>
				1118	</dl>
				1119	<br><br>
				1120
				1121	<dt>Profile Builds
				1122	<dd>
				1123	<dl>
				1124	<dt>Tools
				1125	<dd><tt><i>OBJ_ROOT</i>/Profile/bin</tt>
				1126	<dt>Libraries
				1127	<dd><tt><i>OBJ_ROOT</i>/Profile/lib</tt>
				1128	</dl>
				1129	</dl>
				1130
				1131	</div>
				1132
				1133	<!-- ======================================================================= -->
				1134	<div class="doc_subsection">
				1135	<a name="optionalconfig">Optional Configuration Items</a>
				1136	</div>
				1137
				1138	<div class="doc_text">
				1139
				1140	<p>
				1141	If you're running on a Linux system that supports the "<a
				1142	href="http://www.tat.physik.uni-tuebingen.de/~rguenth/linux/binfmt_misc.html">binfmt_misc</a>"
				1143	module, and you have root access on the system, you can set your system up to
				1144	execute LLVM bitcode files directly. To do this, use commands like this (the
				1145	first command may not be required if you are already using the module):</p>
				1146
				1147	<div class="doc_code">
				1148	<pre>
				1149	$ mount -t binfmt_misc none /proc/sys/fs/binfmt_misc
				1150	$ echo ':llvm:M::llvm::/path/to/lli:' > /proc/sys/fs/binfmt_misc/register
				1151	$ chmod u+x hello.bc (if needed)
				1152	$ ./hello.bc
				1153	</pre>
				1154	</div>
				1155
				1156	<p>
				1157	This allows you to execute LLVM bitcode files directly. Thanks to Jack
				1158	Cummings for pointing this out!
				1159	</p>
				1160
				1161	</div>
				1162
				1163
				1164	<!-- *********************************************************************** -->
				1165	<div class="doc_section">
				1166	<a name="layout"><b>Program Layout</b></a>
				1167	</div>
				1168	<!-- *********************************************************************** -->
				1169
				1170	<div class="doc_text">
				1171
				1172	<p>One useful source of information about the LLVM source base is the LLVM <a
				1173	href="http://www.doxygen.org">doxygen</a> documentation available at <tt><a
				1174	href="http://llvm.org/doxygen/">http://llvm.org/doxygen/</a></tt>.
				1175	The following is a brief introduction to code layout:</p>
				1176
				1177	</div>
				1178
				1179	<!-- ======================================================================= -->
				1180	<div class="doc_subsection"><a name="examples"><tt>llvm/examples</tt></a></div>
				1181	<div class="doc_text">
				1182	<p>This directory contains some simple examples of how to use the LLVM IR and
				1183	JIT.</p>
				1184	</div>
				1185
				1186	<!-- ======================================================================= -->
				1187	<div class="doc_subsection"><a name="include"><tt>llvm/include</tt></a></div>
				1188	<div class="doc_text">
				1189
				1190	<p>This directory contains public header files exported from the LLVM
				1191	library. The three main subdirectories of this directory are:</p>
				1192
				1193	<dl>
				1194	<dt><tt><b>llvm/include/llvm</b></tt></dt>
				1195	<dd>This directory contains all of the LLVM specific header files. This
				1196	directory also has subdirectories for different portions of LLVM:
				1197	<tt>Analysis</tt>, <tt>CodeGen</tt>, <tt>Target</tt>, <tt>Transforms</tt>,
				1198	etc...</dd>
				1199
				1200	<dt><tt><b>llvm/include/llvm/Support</b></tt></dt>
				1201	<dd>This directory contains generic support libraries that are provided with
				1202	LLVM but not necessarily specific to LLVM. For example, some C++ STL utilities
				1203	and a Command Line option processing library store their header files here.
				1204	</dd>
				1205
				1206	<dt><tt><b>llvm/include/llvm/Config</b></tt></dt>
				1207	<dd>This directory contains header files configured by the <tt>configure</tt>
				1208	script. They wrap "standard" UNIX and C header files. Source code can
				1209	include these header files which automatically take care of the conditional
				1210	#includes that the <tt>configure</tt> script generates.</dd>
				1211	</dl>
				1212	</div>
				1213
				1214	<!-- ======================================================================= -->
				1215	<div class="doc_subsection"><a name="lib"><tt>llvm/lib</tt></a></div>
				1216	<div class="doc_text">
				1217
				1218	<p>This directory contains most of the source files of the LLVM system. In LLVM,
				1219	almost all code exists in libraries, making it very easy to share code among the
				1220	different <a href="#tools">tools</a>.</p>
				1221
				1222	<dl>
				1223	<dt><tt><b>llvm/lib/VMCore/</b></tt></dt>
				1224	<dd> This directory holds the core LLVM source files that implement core
				1225	classes like Instruction and BasicBlock.</dd>
				1226
				1227	<dt><tt><b>llvm/lib/AsmParser/</b></tt></dt>
				1228	<dd>This directory holds the source code for the LLVM assembly language parser
				1229	library.</dd>
				1230
				1231	<dt><tt><b>llvm/lib/BitCode/</b></tt></dt>
				1232	<dd>This directory holds code for reading and write LLVM bitcode.</dd>
				1233
				1234	<dt><tt><b>llvm/lib/Analysis/</b></tt><dd>This directory contains a variety of
				1235	different program analyses, such as Dominator Information, Call Graphs,
				1236	Induction Variables, Interval Identification, Natural Loop Identification,
				1237	etc.</dd>
				1238
				1239	<dt><tt><b>llvm/lib/Transforms/</b></tt></dt>
				1240	<dd> This directory contains the source code for the LLVM to LLVM program
				1241	transformations, such as Aggressive Dead Code Elimination, Sparse Conditional
				1242	Constant Propagation, Inlining, Loop Invariant Code Motion, Dead Global
				1243	Elimination, and many others.</dd>
				1244
				1245	<dt><tt><b>llvm/lib/Target/</b></tt></dt>
				1246	<dd> This directory contains files that describe various target architectures
				1247	for code generation. For example, the <tt>llvm/lib/Target/X86</tt>
				1248	directory holds the X86 machine description while
				1249	<tt>llvm/lib/Target/CBackend</tt> implements the LLVM-to-C converter.</dd>
				1250
				1251	<dt><tt><b>llvm/lib/CodeGen/</b></tt></dt>
				1252	<dd> This directory contains the major parts of the code generator: Instruction
				1253	Selector, Instruction Scheduling, and Register Allocation.</dd>
				1254
				1255	<dt><tt><b>llvm/lib/Debugger/</b></tt></dt>
				1256	<dd> This directory contains the source level debugger library that makes
				1257	it possible to instrument LLVM programs so that a debugger could identify
				1258	source code locations at which the program is executing.</dd>
				1259
				1260	<dt><tt><b>llvm/lib/ExecutionEngine/</b></tt></dt>
				1261	<dd> This directory contains libraries for executing LLVM bitcode directly
				1262	at runtime in both interpreted and JIT compiled fashions.</dd>
				1263
				1264	<dt><tt><b>llvm/lib/Support/</b></tt></dt>
				1265	<dd> This directory contains the source code that corresponds to the header
				1266	files located in <tt>llvm/include/Support/</tt>.</dd>
				1267
				1268	<dt><tt><b>llvm/lib/System/</b></tt></dt>
				1269	<dd>This directory contains the operating system abstraction layer that
				1270	shields LLVM from platform-specific coding.</dd>
				1271	</dl>
				1272
				1273	</div>
				1274
				1275	<!-- ======================================================================= -->
				1276	<div class="doc_subsection"><a name="projects"><tt>llvm/projects</tt></a></div>
				1277	<div class="doc_text">
				1278	<p>This directory contains projects that are not strictly part of LLVM but are
				1279	shipped with LLVM. This is also the directory where you should create your own
				1280	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]	1281	to set up your own project.</p>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1282	</div>
				1283
				1284	<!-- ======================================================================= -->
				1285	<div class="doc_subsection"><a name="runtime"><tt>llvm/runtime</tt></a></div>
				1286	<div class="doc_text">
				1287
				1288	<p>This directory contains libraries which are compiled into LLVM bitcode and
				1289	used when linking programs with the GCC front end. Most of these libraries are
				1290	skeleton versions of real libraries; for example, libc is a stripped down
				1291	version of glibc.</p>
				1292
				1293	<p>Unlike the rest of the LLVM suite, this directory needs the LLVM GCC front
				1294	end to compile.</p>
				1295
				1296	</div>
				1297
				1298	<!-- ======================================================================= -->
				1299	<div class="doc_subsection"><a name="test"><tt>llvm/test</tt></a></div>
				1300	<div class="doc_text">
				1301	<p>This directory contains feature and regression tests and other basic sanity
				1302	checks on the LLVM infrastructure. These are intended to run quickly and cover
				1303	a lot of territory without being exhaustive.</p>
				1304	</div>
				1305
				1306	<!-- ======================================================================= -->
				1307	<div class="doc_subsection"><a name="llvmtest"><tt>test-suite</tt></a></div>
				1308	<div class="doc_text">
				1309	<p>This is not a directory in the normal llvm module; it is a separate
				1310	Subversion
				1311	module that must be checked out (usually to <tt>projects/test-suite</tt>).
				1312	This
				1313	module contains a comprehensive correctness, performance, and benchmarking
				1314	test
				1315	suite for LLVM. It is a separate Subversion module because not every LLVM
				1316	user is
				1317	interested in downloading or building such a comprehensive test suite. For
				1318	further details on this test suite, please see the
				1319	<a href="TestingGuide.html">Testing Guide</a> document.</p>
				1320	</div>
				1321
				1322	<!-- ======================================================================= -->
				1323	<div class="doc_subsection"><a name="tools"><tt>llvm/tools</tt></a></div>
				1324	<div class="doc_text">
				1325
				1326	<p>The <b>tools</b> directory contains the executables built out of the
				1327	libraries above, which form the main part of the user interface. You can
				1328	always get help for a tool by typing <tt>tool_name --help</tt>. The
				1329	following is a brief introduction to the most important tools. More detailed
				1330	information is in the <a href="CommandGuide/index.html">Command Guide</a>.</p>
				1331
				1332	<dl>
				1333
				1334	<dt><tt><b>bugpoint</b></tt></dt>
				1335	<dd><tt>bugpoint</tt> is used to debug
				1336	optimization passes or code generation backends by narrowing down the
				1337	given test case to the minimum number of passes and/or instructions that
				1338	still cause a problem, whether it is a crash or miscompilation. See <a
				1339	href="HowToSubmitABug.html">HowToSubmitABug.html</a> for more information
				1340	on using <tt>bugpoint</tt>.</dd>
				1341
				1342	<dt><tt><b>llvmc</b></tt></dt>
				1343	<dd>The LLVM Compiler Driver. This program can
				1344	be configured to utilize both LLVM and non-LLVM compilation tools to enable
				1345	pre-processing, translation, optimization, assembly, and linking of programs
				1346	all from one command line. <tt>llvmc</tt> also takes care of processing the
				1347	dependent libraries found in bitcode. This reduces the need to get the
				1348	traditional <tt>-l<name></tt> options right on the command line. Please
				1349	note that this tool, while functional, is still experimental and not feature
				1350	complete.</dd>
				1351
				1352	<dt><tt><b>llvm-ar</b></tt></dt>
				1353	<dd>The archiver produces an archive containing
				1354	the given LLVM bitcode files, optionally with an index for faster
				1355	lookup.</dd>
				1356
				1357	<dt><tt><b>llvm-as</b></tt></dt>
				1358	<dd>The assembler transforms the human readable LLVM assembly to LLVM
				1359	bitcode.</dd>
				1360
				1361	<dt><tt><b>llvm-dis</b></tt></dt>
				1362	<dd>The disassembler transforms the LLVM bitcode to human readable
				1363	LLVM assembly.</dd>
				1364
				1365	<dt><tt><b>llvm-ld</b></tt></dt>
				1366	<dd><tt>llvm-ld</tt> is a general purpose and extensible linker for LLVM.
				1367	This is the linker invoked by <tt>llvmc</tt>. It performsn standard link time
				1368	optimizations and allows optimization modules to be loaded and run so that
				1369	language specific optimizations can be applied at link time.</dd>
				1370
				1371	<dt><tt><b>llvm-link</b></tt></dt>
				1372	<dd><tt>llvm-link</tt>, not surprisingly, links multiple LLVM modules into
				1373	a single program.</dd>
				1374
				1375	<dt><tt><b>lli</b></tt></dt>
				1376	<dd><tt>lli</tt> is the LLVM interpreter, which
Nick Lewycky	32dc2a1	2007-12-03 01:58:01 +0000	[diff] [blame]	1377	can directly execute LLVM bitcode (although very slowly...). For architectures
				1378	that support it (currently x86, Sparc, and PowerPC), by default, <tt>lli</tt>
				1379	will function as a Just-In-Time compiler (if the functionality was compiled
				1380	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]	1381
				1382	<dt><tt><b>llc</b></tt></dt>
				1383	<dd> <tt>llc</tt> is the LLVM backend compiler, which
				1384	translates LLVM bitcode to a native code assembly file or to C code (with
				1385	the -march=c option).</dd>
				1386
				1387	<dt><tt><b>llvm-gcc</b></tt></dt>
				1388	<dd><tt>llvm-gcc</tt> is a GCC-based C frontend that has been retargeted to
				1389	use LLVM as its backend instead of GCC's RTL backend. It can also emit LLVM
				1390	bitcode or assembly (with the <tt>-emit-llvm</tt> option) instead of the
				1391	usual machine code output. It works just like any other GCC compiler,
				1392	taking the typical <tt>-c, -S, -E, -o</tt> options that are typically used.
				1393	Additionally, the the source code for <tt>llvm-gcc</tt> is available as a
				1394	separate Subversion module.</dd>
				1395
				1396	<dt><tt><b>opt</b></tt></dt>
				1397	<dd><tt>opt</tt> reads LLVM bitcode, applies a series of LLVM to LLVM
				1398	transformations (which are specified on the command line), and then outputs
				1399	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]	1400	get a list of the program transformations available in LLVM.<br>
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1401	<dd><tt>opt</tt> can also be used to run a specific analysis on an input
				1402	LLVM bitcode file and print out the results. It is primarily useful for
				1403	debugging analyses, or familiarizing yourself with what an analysis does.</dd>
				1404	</dl>
				1405	</div>
				1406
				1407	<!-- ======================================================================= -->
				1408	<div class="doc_subsection"><a name="utils"><tt>llvm/utils</tt></a></div>
				1409	<div class="doc_text">
				1410
				1411	<p>This directory contains utilities for working with LLVM source code, and some
				1412	of the utilities are actually required as part of the build process because they
				1413	are code generators for parts of LLVM infrastructure.</p>
				1414
				1415	<dl>
				1416	<dt><tt><b>codegen-diff</b></tt> <dd><tt>codegen-diff</tt> is a script
				1417	that finds differences between code that LLC generates and code that LLI
				1418	generates. This is a useful tool if you are debugging one of them,
				1419	assuming that the other generates correct output. For the full user
				1420	manual, run <tt>`perldoc codegen-diff'</tt>.<br><br>
				1421
				1422	<dt><tt><b>emacs/</b></tt> <dd>The <tt>emacs</tt> directory contains
				1423	syntax-highlighting files which will work with Emacs and XEmacs editors,
				1424	providing syntax highlighting support for LLVM assembly files and TableGen
				1425	description files. For information on how to use the syntax files, consult
				1426	the <tt>README</tt> file in that directory.<br><br>
				1427
				1428	<dt><tt><b>getsrcs.sh</b></tt> <dd>The <tt>getsrcs.sh</tt> script finds
				1429	and outputs all non-generated source files, which is useful if one wishes
				1430	to do a lot of development across directories and does not want to
				1431	individually find each file. One way to use it is to run, for example:
				1432	<tt>xemacs `utils/getsources.sh`</tt> from the top of your LLVM source
				1433	tree.<br><br>
				1434
				1435	<dt><tt><b>llvmgrep</b></tt></dt>
				1436	<dd>This little tool performs an "egrep -H -n" on each source file in LLVM and
				1437	passes to it a regular expression provided on <tt>llvmgrep</tt>'s command
				1438	line. This is a very efficient way of searching the source base for a
				1439	particular regular expression.</dd>
				1440
				1441	<dt><tt><b>makellvm</b></tt> <dd>The <tt>makellvm</tt> script compiles all
				1442	files in the current directory and then compiles and links the tool that
				1443	is the first argument. For example, assuming you are in the directory
				1444	<tt>llvm/lib/Target/Sparc</tt>, if <tt>makellvm</tt> is in your path,
				1445	simply running <tt>makellvm llc</tt> will make a build of the current
				1446	directory, switch to directory <tt>llvm/tools/llc</tt> and build it,
				1447	causing a re-linking of LLC.<br><br>
				1448
				1449	<dt><tt><b>NewNightlyTest.pl</b></tt> and
				1450	<tt><b>NightlyTestTemplate.html</b></tt> <dd>These files are used in a
				1451	cron script to generate nightly status reports of the functionality of
				1452	tools, and the results can be seen by following the appropriate link on
				1453	the <a href="http://llvm.org/">LLVM homepage</a>.<br><br>
				1454
				1455	<dt><tt><b>TableGen/</b></tt> <dd>The <tt>TableGen</tt> directory contains
				1456	the tool used to generate register descriptions, instruction set
				1457	descriptions, and even assemblers from common TableGen description
				1458	files.<br><br>
				1459
				1460	<dt><tt><b>vim/</b></tt> <dd>The <tt>vim</tt> directory contains
				1461	syntax-highlighting files which will work with the VIM editor, providing
				1462	syntax highlighting support for LLVM assembly files and TableGen
				1463	description files. For information on how to use the syntax files, consult
				1464	the <tt>README</tt> file in that directory.<br><br>
				1465
				1466	</dl>
				1467
				1468	</div>
				1469
				1470	<!-- ======================================================================= -->
				1471	<div class="doc_subsection"><a name="win32"><tt>llvm/win32</tt></a></div>
				1472	<div class="doc_text">
				1473	<p>This directory contains build scripts and project files for use with
				1474	Visual C++. This allows developers on Windows to build LLVM without the need
				1475	for Cygwin. The contents of this directory should be considered experimental
				1476	at this time.
				1477	</p>
				1478	</div>
				1479	<!-- *********************************************************************** -->
				1480	<div class="doc_section">
				1481	<a name="tutorial">An Example Using the LLVM Tool Chain</a>
				1482	</div>
				1483	<!-- *********************************************************************** -->
				1484
				1485	<div class="doc_text">
				1486	<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]	1487	so we only include instructions for llvm-gcc4.
Dan Gohman	f17a25c	2007-07-18 16:29:46 +0000	[diff] [blame]	1488	</p>
				1489
				1490	<p><b>Note:</b> The <i>gcc4</i> frontend's invocation is <b><i>considerably different</i></b>
				1491	from the previous <i>gcc3</i> frontend. In particular, the <i>gcc4</i> frontend <b><i>does not</i></b>
				1492	create bitcode by default: <i>gcc4</i> produces native code. As the example below illustrates,
				1493	the '--emit-llvm' flag is needed to produce LLVM bitcode output. For <i>makefiles</i> and
				1494	<i>configure</i> scripts, the CFLAGS variable needs '--emit-llvm' to produce bitcode
				1495	output.</p>
				1496	</div>
				1497
				1498	<!-- ======================================================================= -->
				1499	<div class="doc_subsection"><a name="tutorial4">Example with llvm-gcc4</a></div>
				1500
				1501	<div class="doc_text">
				1502
				1503	<ol>
				1504	<li><p>First, create a simple C file, name it 'hello.c':</p>
				1505
				1506	<div class="doc_code">
				1507	<pre>
				1508	#include <stdio.h>
				1509
				1510	int main() {
				1511	printf("hello world\n");
				1512	return 0;
				1513	}
				1514	</pre></div></li>
				1515
				1516	<li><p>Next, compile the C file into a native executable:</p>
				1517
				1518	<div class="doc_code"><pre>% llvm-gcc hello.c -o hello</pre></div>
				1519
				1520	<p>Note that llvm-gcc works just like GCC by default. The standard -S and
				1521	-c arguments work as usual (producing a native .s or .o file,
				1522	respectively).</p></li>
				1523
				1524	<li><p>Next, compile the C file into a LLVM bitcode file:</p>
				1525
				1526	<div class="doc_code">
				1527	<pre>% llvm-gcc -O3 -emit-llvm hello.c -c -o hello.bc</pre></div>
				1528
				1529	<p>The -emit-llvm option can be used with the -S or -c options to emit an
				1530	LLVM ".ll" or ".bc" file (respectively) for the code. This allows you
				1531	to use the <a href="CommandGuide/index.html">standard LLVM tools</a> on
				1532	the bitcode file.</p>
				1533
				1534	<p>Unlike llvm-gcc3, llvm-gcc4 correctly responds to -O[0123] arguments.
				1535	</p></li>
				1536
				1537	<li><p>Run the program in both forms. To run the program, use:</p>
				1538
				1539	<div class="doc_code"><pre>% ./hello</pre></div>
				1540
				1541	<p>and</p>
				1542
				1543	<div class="doc_code"><pre>% lli hello.bc</pre></div>
				1544
				1545	<p>The second examples shows how to invoke the LLVM JIT, <a
				1546	href="CommandGuide/html/lli.html">lli</a>.</p></li>
				1547
				1548	<li><p>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly
				1549	code:</p>
				1550
				1551	<div class="doc_code">
				1552	<pre>llvm-dis < hello.bc \| less</pre>
				1553	</div></li>
				1554
				1555	<li><p>Compile the program to native assembly using the LLC code
				1556	generator:</p>
				1557
				1558	<div class="doc_code"><pre>% llc hello.bc -o hello.s</pre></div></li>
				1559
				1560	<li><p>Assemble the native assembly language file into a program:</p>
				1561
				1562	<div class="doc_code">
				1563	<pre>
				1564	<b>Solaris:</b> % /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native
				1565
				1566	<b>Others:</b> % gcc hello.s -o hello.native
				1567	</pre>
				1568	</div></li>
				1569
				1570	<li><p>Execute the native code program:</p>
				1571
				1572	<div class="doc_code"><pre>% ./hello.native</pre></div>
				1573
				1574	<p>Note that using llvm-gcc to compile directly to native code (i.e. when
				1575	the -emit-llvm option is not present) does steps 6/7/8 for you.</p>
				1576	</li>
				1577
				1578	</ol>
				1579
				1580	</div>
				1581
				1582
				1583	<!-- *********************************************************************** -->
				1584	<div class="doc_section">
				1585	<a name="problems">Common Problems</a>
				1586	</div>
				1587	<!-- *********************************************************************** -->
				1588
				1589	<div class="doc_text">
				1590
				1591	<p>If you are having problems building or using LLVM, or if you have any other
				1592	general questions about LLVM, please consult the <a href="FAQ.html">Frequently
				1593	Asked Questions</a> page.</p>
				1594
				1595	</div>
				1596
				1597	<!-- *********************************************************************** -->
				1598	<div class="doc_section">
				1599	<a name="links">Links</a>
				1600	</div>
				1601	<!-- *********************************************************************** -->
				1602
				1603	<div class="doc_text">
				1604
Bill Wendling	08f49b9	2008-07-22 01:10:25 +0000	[diff] [blame]	1605	<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]	1606	some simple things... there are many more interesting and complicated things
				1607	that you can do that aren't documented here (but we'll gladly accept a patch
				1608	if you want to write something up!). For more information about LLVM, check
				1609	out:</p>
				1610
				1611	<ul>
				1612	<li><a href="http://llvm.org/">LLVM homepage</a></li>
				1613	<li><a href="http://llvm.org/doxygen/">LLVM doxygen tree</a></li>
				1614	<li><a href="http://llvm.org/docs/Projects.html">Starting a Project
				1615	that Uses LLVM</a></li>
				1616	</ul>
				1617
				1618	</div>
				1619
				1620	<!-- *********************************************************************** -->
				1621
				1622	<hr>
				1623	<address>
				1624	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	947321d	2008-12-11 17:34:48 +0000	[diff] [blame]	1625	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]	1626	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	5c1cc64	2008-12-11 18:23:24 +0000	[diff] [blame]	1627	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]	1628
				1629	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
				1630	<a href="http://llvm.x10sys.com/rspencer/">Reid Spencer</a><br>
				1631	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
				1632	Last modified: $Date$
				1633	</address>
				1634	</body>
				1635	</html>