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| <title>Getting Started with LLVM System</title> |
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| |
| <div class="doc_title"> |
| Getting Started with the LLVM System |
| </div> |
| |
| <ul> |
| <li><a href="#overview">Overview</a> |
| <li><a href="#quickstart">Getting Started Quickly (A Summary)</a> |
| <li><a href="#requirements">Requirements</a> |
| <ol> |
| <li><a href="#hardware">Hardware</a> |
| <li><a href="#software">Software</a> |
| <li><a href="#brokengcc">Broken versions of GCC</a> |
| </ol></li> |
| |
| <li><a href="#starting">Getting Started with LLVM</a> |
| <ol> |
| <li><a href="#terminology">Terminology and Notation</a> |
| <li><a href="#environment">Setting Up Your Environment</a> |
| <li><a href="#unpack">Unpacking the LLVM Archives</a> |
| <li><a href="#checkout">Checkout LLVM from CVS</a> |
| <li><a href="#installcf">Install the GCC Front End</a> |
| <li><a href="#config">Local LLVM Configuration</a> |
| <li><a href="#compile">Compiling the LLVM Suite Source Code</a> |
| <li><a href="#cross-compile">Cross-Compiling LLVM</a> |
| <li><a href="#objfiles">The Location of LLVM Object Files</a> |
| <li><a href="#optionalconfig">Optional Configuration Items</a> |
| </ol></li> |
| |
| <li><a href="#layout">Program layout</a> |
| <ol> |
| <li><a href="#cvsdir"><tt>CVS</tt> directories</a> |
| <li><a href="#examples"><tt>llvm/examples</tt></a> |
| <li><a href="#include"><tt>llvm/include</tt></a> |
| <li><a href="#lib"><tt>llvm/lib</tt></a> |
| <li><a href="#projects"><tt>llvm/projects</tt></a> |
| <li><a href="#runtime"><tt>llvm/runtime</tt></a> |
| <li><a href="#test"><tt>llvm/test</tt></a> |
| <li><a href="#llvmtest"><tt>llvm-test</tt></a> |
| <li><a href="#tools"><tt>llvm/tools</tt></a> |
| <li><a href="#utils"><tt>llvm/utils</tt></a> |
| <li><a href="#win32"><tt>llvm/win32</tt></a> |
| </ol></li> |
| |
| <li><a href="#tutorial">An Example Using the LLVM Tool Chain</a> |
| <ol> |
| <li><a href="#tutorial4">Example with llvm-gcc4</a></li> |
| </ol> |
| <li><a href="#problems">Common Problems</a> |
| <li><a href="#links">Links</a> |
| </ul> |
| |
| <div class="doc_author"> |
| <p>Written by: |
| <a href="mailto:criswell@uiuc.edu">John Criswell</a>, |
| <a href="mailto:sabre@nondot.org">Chris Lattner</a>, |
| <a href="http://misha.brukman.net">Misha Brukman</a>, |
| <a href="http://www.cs.uiuc.edu/~vadve">Vikram Adve</a>, and |
| <a href="mailto:gshi1@uiuc.edu">Guochun Shi</a>. |
| </p> |
| </div> |
| |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="overview"><b>Overview</b></a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| |
| <p>Welcome to LLVM! In order to get started, you first need to know some |
| basic information.</p> |
| |
| <p>First, LLVM comes in two pieces. The first piece is the LLVM suite. This |
| contains all of the tools, libraries, and header files needed to use the low |
| level virtual machine. It contains an assembler, disassembler, bytecode |
| analyzer and bytecode optimizer. It also contains a test suite that can be |
| used to test the LLVM tools and the GCC front end.</p> |
| |
| <p>The second piece is the GCC front end. This component provides a version of |
| GCC that compiles C and C++ code into LLVM bytecode. Currently, the GCC front |
| end is a modified version of GCC 3.4 (we track the GCC 3.4 development). Once |
| compiled into LLVM bytecode, a program can be manipulated with the LLVM tools |
| from the LLVM suite.</p> |
| |
| <p> |
| There is a third, optional piece called llvm-test. It is a suite of programs |
| with a testing harness that can be used to further test LLVM's functionality |
| and performance. |
| </p> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="quickstart"><b>Getting Started Quickly (A Summary)</b></a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| |
| <p>Here's the short story for getting up and running quickly with LLVM:</p> |
| |
| <ol> |
| <li>Read the documentation.</li> |
| <li>Read the documentation.</li> |
| <li>Remember that you were warned twice about reading the documentation.</li> |
| <li>Install the GCC front end if you intend to compile C or C++: |
| <ol> |
| <li><tt>cd <i>where-you-want-the-C-front-end-to-live</i></tt></li> |
| <li><tt>gunzip --stdout llvm-gcc.<i>platform</i>.tar.gz | tar -xvf -</tt> |
| </li> |
| <li><tt>cd llvm-gcc3.4/<i>platform</i> (llvm-gcc3.4 only)<br> |
| ./fixheaders</tt></li> |
| <li>Add llvm-gcc's "bin" directory to your PATH variable.</li> |
| </ol></li> |
| |
| <li>Get the LLVM Source Code |
| <ul> |
| <li>With the distributed files (or use <a href="#checkout">CVS</a>): |
| <ol> |
| <li><tt>cd <i>where-you-want-llvm-to-live</i></tt> |
| <li><tt>gunzip --stdout llvm-<i>version</i>.tar.gz | tar -xvf -</tt> |
| </ol></li> |
| |
| </ul></li> |
| |
| <li><b>[Optional]</b> Get the Test Suite Source Code |
| <ul> |
| <li>With the distributed files (or use <a href="#checkout">CVS</a>): |
| <ol> |
| <li><tt>cd <i>where-you-want-llvm-to-live</i></tt> |
| <li><tt>cd llvm/projects</tt> |
| <li><tt>gunzip --stdout llvm-test-<i>version</i>.tar.gz | tar -xvf -</tt> |
| </ol></li> |
| |
| </ul></li> |
| |
| |
| <li>Configure the LLVM Build Environment |
| <ol> |
| <li><tt>cd <i>where-you-want-to-build-llvm</i></tt></li> |
| <li><tt><i>/path/to/llvm/</i>configure [options]</tt><br> |
| Some common options: |
| |
| <ul> |
| <li><tt>--prefix=<i>directory</i></tt> |
| <p>Specify for <i>directory</i> the full pathname of where you |
| want the LLVM tools and libraries to be installed (default |
| <tt>/usr/local</tt>).</p></li> |
| <li><tt>--with-llvmgccdir=<i>directory</i></tt> |
| <p>Optionally, specify for <i>directory</i> the full pathname of the |
| C/C++ front end installation to use with this LLVM configuration. If |
| not specified, the PATH will be searched.</p></li> |
| <li><tt>--enable-spec2000=<i>directory</i></tt> |
| <p>Enable the SPEC2000 benchmarks for testing. The SPEC2000 |
| benchmarks should be available in |
| <tt><i>directory</i></tt>.</p></li> |
| </ul> |
| </ol></li> |
| |
| <li>Build the LLVM Suite: |
| <ol> |
| <li><tt>gmake -k |& tee gnumake.out |
| # this is csh or tcsh syntax</tt></li> |
| <li>If you get an "internal compiler error (ICE)" or test failures, see |
| <a href="#brokengcc">below</a>.</li> |
| </ol> |
| |
| </ol> |
| |
| <p>Consult the <a href="#starting">Getting Started with LLVM</a> section for |
| detailed information on configuring and compiling LLVM. See <a |
| href="#environment">Setting Up Your Environment</a> for tips that simplify |
| working with the GCC front end and LLVM tools. Go to <a href="#layout">Program |
| Layout</a> to learn about the layout of the source code tree.</p> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="requirements"><b>Requirements</b></a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| |
| <p>Before you begin to use the LLVM system, review the requirements given below. |
| This may save you some trouble by knowing ahead of time what hardware and |
| software you will need.</p> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="hardware"><b>Hardware</b></a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p>LLVM is known to work on the following platforms:</p> |
| |
| <table cellpadding="3" summary="Known LLVM platforms"> |
| <tr> |
| <th>OS</th> |
| <th>Arch</th> |
| <th>Compilers</th> |
| </tr> |
| <tr> |
| <td>Linux</td> |
| <td>x86<sup><a href="#pf_1">1</a></sup></td> |
| <td>GCC</td> |
| </tr> |
| <tr> |
| <td>Solaris</td> |
| <td>V9 (Ultrasparc)</td> |
| <td>GCC</td> |
| </tr> |
| <tr> |
| <td>FreeBSD</td> |
| <td>x86<sup><a href="#pf_1">1</a></sup></td> |
| <td>GCC</td> |
| </tr> |
| <tr> |
| <td>MacOS X<sup><a href="#pf_2">2</a></sup></td> |
| <td>PowerPC</td> |
| <td>GCC</td> |
| </tr> |
| <tr> |
| <td>MacOS X<sup><a href="#pf_2">2</a></sup></td> |
| <td>x86</td> |
| <td>GCC</td> |
| |
| </tr> |
| <tr> |
| <td>Cygwin/Win32</td> |
| <td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_8">8</a></sup></td> |
| <td>GCC 3.4.X, binutils 2.15</td> |
| </tr> |
| <tr> |
| <td>MinGW/Win32</td> |
| <td>x86<sup><a href="#pf_1">1</a>,<a href="#pf_6">6</a>,<a href="#pf_8">8</a></sup></td> |
| <td>GCC 3.4.X, binutils 2.15</td> |
| </tr> |
| <tr> |
| <td>Linux</td> |
| <td>amd64<sup><a href="#pf_3">3</a></sup></td> |
| <td>GCC</td> |
| </tr> |
| </table> |
| |
| <p>LLVM has partial support for the following platforms:</p> |
| |
| <table summary="LLVM partial platform support"> |
| <tr> |
| <th>OS</th> |
| <th>Arch</th> |
| <th>Compilers</th> |
| </tr> |
| <tr> |
| <td>Windows</td> |
| <td>x86<sup><a href="#pf_1">1</a></sup></td> |
| <td>Visual Studio .NET<sup><a href="#pf_4">4</a>,<a href="#pf_5">5</a></sup></td> |
| <tr> |
| <td>AIX<sup><a href="#pf_3">3</a>,<a href="#pf_4">4</a></sup></td> |
| <td>PowerPC</td> |
| <td>GCC</td> |
| </tr> |
| <tr> |
| <td>Linux<sup><a href="#pf_3">3</a>,<a href="#pf_5">5</a></sup></td> |
| <td>PowerPC</td> |
| <td>GCC</td> |
| </tr> |
| |
| <tr> |
| <td>Linux<sup><a href="#pf_7">7</a></sup></td> |
| <td>Alpha</td> |
| <td>GCC</td> |
| </tr> |
| <tr> |
| <td>Linux<sup><a href="#pf_7">7</a></sup></td> |
| <td>Itanium (IA-64)</td> |
| <td>GCC</td> |
| </tr> |
| <tr> |
| <td>HP-UX<sup><a href="#pf_7">7</a></sup></td> |
| <td>Itanium (IA-64)</td> |
| <td>HP aCC</td> |
| </tr> |
| </table> |
| |
| <p><b>Notes:</b></p> |
| |
| <div class="doc_notes"> |
| <ol> |
| <li><a name="pf_1">Code generation supported for Pentium processors and |
| up</a></li> |
| <li><a name="pf_2">Code generation supported for 32-bit ABI only</a></li> |
| <li><a name="pf_3">No native code generation</a></li> |
| <li><a name="pf_4">Build is not complete: one or more tools don't link</a></li> |
| <li><a name="pf_5">The GCC-based C/C++ frontend does not build</a></li> |
| <li><a name="pf_6">The port is done using the MSYS shell.</a> |
| <a href="http://www.mingw.org/MinGWiki/">Download</a> and install |
| bison (excl. M4.exe) and flex in that order. Build binutils-2.15 from source, |
| if necessary. Bison & flex can be also grabbed from GNUWin32 sf.net |
| project.</li> |
| <li><a name="pf_7">Native code generation exists but is not complete.</a></li> |
| <li><a name="pf_8">Binutils</a> up to post-2.17 has bug in bfd/cofflink.c |
| preventing LLVM from building correctly. Several workarounds have been |
| introduced into LLVM build system, but the bug can occur anytime in the |
| future. We highly recommend that you rebuild your current binutils with the |
| patch from <a href="http://sourceware.org/bugzilla/show_bug.cgi?id=2659"> |
| Binutils bugzilla</a>, if it wasn't already applied.</li> |
| </ol> |
| </div> |
| |
| <p>Note that you will need about 1-3 GB of space for a full LLVM build in Debug |
| mode, depending on the system (it is so large because of all the debugging |
| information and the fact that the libraries are statically linked into multiple |
| tools). If you do not need many of the tools and you are space-conscious, |
| you can disable them individually in <tt>llvm/tools/Makefile</tt>. The Release |
| build requires considerably less space.</p> |
| |
| <p>The LLVM suite <i>may</i> compile on other platforms, but it is not |
| guaranteed to do so. If compilation is successful, the LLVM utilities should be |
| able to assemble, disassemble, analyze, and optimize LLVM bytecode. Code |
| generation should work as well, although the generated native code may not work |
| on your platform.</p> |
| |
| <p>The GCC front end is not very portable at the moment. If you want to get it |
| to work on another platform, you can download a copy of the source and <a |
| href="CFEBuildInstrs.html">try to compile it</a> on your platform.</p> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="software"><b>Software</b></a></div> |
| <div class="doc_text"> |
| <p>Compiling LLVM requires that you have several software packages |
| installed. The table below lists those required packages. The Package column |
| is the usual name for the software package that LLVM depends on. The Version |
| column provides "known to work" versions of the package. The Notes column |
| describes how LLVM uses the package and provides other details.</p> |
| <table summary="Packages required to compile LLVM"> |
| <tr><th>Package</th><th>Version</th><th>Notes</th></tr> |
| |
| <tr> |
| <td><a href="http://savannah.gnu.org/projects/make">GNU Make</a></td> |
| <td>3.79, 3.79.1</td> |
| <td>Makefile/build processor</td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://gcc.gnu.org">GCC</a></td> |
| <td>3.4.2</td> |
| <td>C/C++ compiler<sup><a href="#sf1">1</a></sup></td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://www.gnu.org/software/texinfo">TeXinfo</a></td> |
| <td>4.5</td> |
| <td>For building the CFE</td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://www.gnu.org/software/flex">Flex</a></td> |
| <td>2.5.4</td> |
| <td>LEX compiler</td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://www.gnu.org/software/bison/bison.html">Bison</a></td> |
| <td>1.28, 1.35, 1.75, 1.875d, 2.0, or 2.1<br>(not 1.85 or 1.875)</td> |
| <td>YACC compiler</td> |
| </tr> |
| |
| <tr> |
| <td><a href="https://www.cvshome.org/downloads.html">CVS</a></td> |
| <td>≥1.11</td> |
| <td>CVS access to LLVM<sup><a href="#sf2">2</a></sup></td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://savannah.gnu.org/projects/dejagnu">DejaGnu</a></td> |
| <td>1.4.2</td> |
| <td>Automated test suite<sup><a href="#sf3">3</a></sup></td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://www.tcl.tk/software/tcltk/">tcl</a></td> |
| <td>8.3, 8.4</td> |
| <td>Automated test suite<sup><a href="#sf3">3</a></sup></td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://expect.nist.gov/">expect</a></td> |
| <td>5.38.0</td> |
| <td>Automated test suite<sup><a href="#sf3">3</a></sup></td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://www.perl.com/download.csp">perl</a></td> |
| <td>≥5.6.0</td> |
| <td>Nightly tester, utilities</td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://savannah.gnu.org/projects/m4">GNU M4</a> |
| <td>1.4</td> |
| <td>Macro processor for configuration<sup><a href="#sf4">4</a></sup></td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://www.gnu.org/software/autoconf">GNU Autoconf</a></td> |
| <td>2.59</td> |
| <td>Configuration script builder<sup><a href="#sf4">4</a></sup></td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://www.gnu.org/software/automake">GNU Automake</a></td> |
| <td>1.9.2</td> |
| <td>aclocal macro generator<sup><a href="#sf4">4</a></sup></td> |
| </tr> |
| |
| <tr> |
| <td><a href="http://savannah.gnu.org/projects/libtool">libtool</a></td> |
| <td>1.5.10</td> |
| <td>Shared library manager<sup><a href="#sf4">4</a></sup></td> |
| </tr> |
| |
| </table> |
| |
| <p><b>Notes:</b></p> |
| <div class="doc_notes"> |
| <ol> |
| <li><a name="sf1">Only the C and C++ languages are needed so there's no |
| need to build the other languages for LLVM's purposes.</a> See |
| <a href="#brokengcc">below</a> for specific version info.</li> |
| <li><a name="sf2">You only need CVS if you intend to build from the |
| latest LLVM sources. If you're working from a release distribution, you |
| don't need CVS.</a></li> |
| <li><a name="sf3">Only needed if you want to run the automated test |
| suite in the <tt>llvm/test</tt> directory.</a></li> |
| <li><a name="sf4">If you want to make changes to the configure scripts, |
| you will need GNU autoconf (2.59), and consequently, GNU M4 (version 1.4 |
| or higher). You will also need automake (1.9.2). We only use aclocal |
| from that package.</a></li> |
| </ol> |
| </div> |
| |
| <p>Additionally, your compilation host is expected to have the usual |
| plethora of Unix utilities. Specifically:</p> |
| <ul> |
| <li><b>ar</b> - archive library builder</li> |
| <li><b>bzip2*</b> - bzip2 command for distribution generation</li> |
| <li><b>bunzip2*</b> - bunzip2 command for distribution checking</li> |
| <li><b>chmod</b> - change permissions on a file</li> |
| <li><b>cat</b> - output concatenation utility</li> |
| <li><b>cp</b> - copy files</li> |
| <li><b>date</b> - print the current date/time </li> |
| <li><b>echo</b> - print to standard output</li> |
| <li><b>egrep</b> - extended regular expression search utility</li> |
| <li><b>etags</b> - C/C++ tag file creator for vim/emacs</li> |
| <li><b>find</b> - find files/dirs in a file system</li> |
| <li><b>grep</b> - regular expression search utility</li> |
| <li><b>gzip*</b> - gzip command for distribution generation</li> |
| <li><b>gunzip*</b> - gunzip command for distribution checking</li> |
| <li><b>install</b> - install directories/files </li> |
| <li><b>mkdir</b> - create a directory</li> |
| <li><b>mv</b> - move (rename) files</li> |
| <li><b>ranlib</b> - symbol table builder for archive libraries</li> |
| <li><b>rm</b> - remove (delete) files and directories</li> |
| <li><b>sed</b> - stream editor for transforming output</li> |
| <li><b>sh</b> - Bourne shell for make build scripts</li> |
| <li><b>tar</b> - tape archive for distribution generation</li> |
| <li><b>test</b> - test things in file system</li> |
| <li><b>unzip*</b> - unzip command for distribution checking</li> |
| <li><b>zip*</b> - zip command for distribution generation</li> |
| </ul> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="brokengcc">Broken versions of GCC</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p>LLVM is very demanding of the host C++ compiler, and as such tends to expose |
| bugs in the compiler. In particular, several versions of GCC crash when trying |
| to compile LLVM. We routinely use GCC 3.3.3, 3.4.0, and Apple 4.0.1 |
| successfully with them (however, see below). Other versions of GCC will |
| probably work as well. GCC versions listed |
| here are known to not work. If you are using one of these versions, please try |
| to upgrade your GCC to something more recent. If you run into a problem with a |
| version of GCC not listed here, please <a href="mailto:llvmdev@cs.uiuc.edu">let |
| us know</a>. Please use the "<tt>gcc -v</tt>" command to find out which version |
| of GCC you are using. |
| </p> |
| |
| <p><b>GCC versions prior to 3.0</b>: GCC 2.96.x and before had several |
| problems in the STL that effectively prevent it from compiling LLVM. |
| </p> |
| |
| <p><b>GCC 3.2.2</b>: This version of GCC fails to compile LLVM.</p> |
| |
| <p><b>GCC 3.3.2</b>: This version of GCC suffered from a <a |
| href="http://gcc.gnu.org/PR13392">serious bug</a> which causes it to crash in |
| the "<tt>convert_from_eh_region_ranges_1</tt>" GCC function.</p> |
| |
| <p><b>Cygwin GCC 3.3.3</b>: The version of GCC 3.3.3 commonly shipped with |
| Cygwin does not work. Please <a href="CFEBuildInstrs.html#cygwin">upgrade |
| to a newer version</a> if possible.</p> |
| <p><b>SuSE GCC 3.3.3</b>: The version of GCC 3.3.3 shipped with SuSE 9.1 (and |
| possibly others) does not compile LLVM correctly (it appears that exception |
| handling is broken in some cases). Please download the FSF 3.3.3 or upgrade |
| to a newer version of GCC.</p> |
| <p><b>IA-64 GCC 4.0.0</b>: The IA-64 version of GCC 4.0.0 is known to |
| miscompile LLVM.</p> |
| <p><b>Apple Xcode 2.3</b>: GCC crashes when compiling LLVM at -O3 (which is the |
| default with ENABLE_OPTIMIZED=1. To work around this, build with |
| "ENABLE_OPTIMIZED=1 OPTIMIZE_OPTION=-O2".</p> |
| <p><b>GCC 4.1.1</b>: GCC fails to build LLVM with template concept check errors |
| compiling some files. At the time of this writing, GCC mainline (4.2) |
| did not share the problem.</p> |
| <p><b>GCC 4.1.1 on X86-64/amd64</b>: GCC <a href="http://llvm.org/PR1063"> |
| miscompiles portions of LLVM</a> when compiling llvm itself into 64-bit |
| code. LLVM will appear to mostly work but will be buggy, e.g. failing |
| portions of its testsuite.</p> |
| <p><b>GNU ld 2.16.X</b>. Some 2.16.X versions of the ld linker will produce very |
| long warning messages complaining that some ".gnu.linkonce.t.*" symbol was |
| defined in a discarded section. You can safely ignore these messages as they are |
| erroneous and the linkage is correct. These messages disappear using ld |
| 2.17.</p> |
| </div> |
| |
| |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="starting"><b>Getting Started with LLVM</b></a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| |
| <p>The remainder of this guide is meant to get you up and running with |
| LLVM and to give you some basic information about the LLVM environment.</p> |
| |
| <p>The later sections of this guide describe the <a |
| href="#layout">general layout</a> of the the LLVM source tree, a <a |
| href="#tutorial">simple example</a> using the LLVM tool chain, and <a |
| href="#links">links</a> to find more information about LLVM or to get |
| help via e-mail.</p> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="terminology">Terminology and Notation</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p>Throughout this manual, the following names are used to denote paths |
| specific to the local system and working environment. <i>These are not |
| environment variables you need to set but just strings used in the rest |
| of this document below</i>. In any of the examples below, simply replace |
| each of these names with the appropriate pathname on your local system. |
| All these paths are absolute:</p> |
| |
| <dl> |
| <dt>SRC_ROOT |
| <dd> |
| This is the top level directory of the LLVM source tree. |
| <br><br> |
| |
| <dt>OBJ_ROOT |
| <dd> |
| This is the top level directory of the LLVM object tree (i.e. the |
| tree where object files and compiled programs will be placed. It |
| can be the same as SRC_ROOT). |
| <br><br> |
| |
| <dt>LLVMGCCDIR |
| <dd> |
| This is where the LLVM GCC Front End is installed. |
| <p> |
| For the pre-built GCC front end binaries, the LLVMGCCDIR is |
| <tt>llvm-gcc/<i>platform</i>/llvm-gcc</tt>. |
| </dl> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="environment">Setting Up Your Environment</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p> |
| In order to compile and use LLVM, you may need to set some environment |
| variables. |
| |
| <dl> |
| <dt><tt>LLVM_LIB_SEARCH_PATH</tt>=<tt>/path/to/your/bytecode/libs</tt></dt> |
| <dd>[Optional] This environment variable helps LLVM linking tools find the |
| locations of your bytecode libraries. It is provided only as a |
| convenience since you can specify the paths using the -L options of the |
| tools and the C/C++ front-end will automatically use the bytecode files |
| installed in its |
| <tt>lib</tt> directory.</dd> |
| </dl> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="unpack">Unpacking the LLVM Archives</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p> |
| If you have the LLVM distribution, you will need to unpack it before you |
| can begin to compile it. LLVM is distributed as a set of two files: the LLVM |
| suite and the LLVM GCC front end compiled for your platform. There is an |
| additional test suite that is optional. Each file is a TAR archive that is |
| compressed with the gzip program. |
| </p> |
| |
| <p>The files are as follows, with <em>x.y</em> marking the version number: |
| <dl> |
| <dt><tt>llvm-x.y.tar.gz</tt></dt> |
| <dd>Source release for the LLVM libraries and tools.<br/></dd> |
| |
| <dt><tt>llvm-test-x.y.tar.gz</tt></dt> |
| <dd>Source release for the LLVM test suite.</dd> |
| |
| <dt><tt>llvm-gcc4-x.y.source.tar.gz</tt></dt> |
| <dd>Source release of the llvm-gcc4 front end. See README.LLVM in the root |
| directory for build instructions.<br/></dd> |
| |
| <dt><tt>llvm-gcc4-x.y-platform.tar.gz</tt></dt> |
| <dd>Binary release of the llvm-gcc4 front end for a specific platform.<br/></dd> |
| |
| </dl> |
| |
| <p>It is also possible to download the sources of the llvm-gcc4 front end from a |
| read-only subversion mirror at |
| svn://anonsvn.opensource.apple.com/svn/llvm/trunk. </p> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="checkout">Checkout LLVM from CVS</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p>If you have access to our CVS repository, you can get a fresh copy of |
| the entire source code. All you need to do is check it out from CVS as |
| follows:</p> |
| |
| <ul> |
| <li><tt>cd <i>where-you-want-llvm-to-live</i></tt> |
| <li><tt>cvs -d :pserver:anon@llvm.org:/var/cvs/llvm login</tt> |
| <li>Hit the return key when prompted for the password. |
| <li><tt>cvs -z3 -d :pserver:anon@llvm.org:/var/cvs/llvm co |
| llvm</tt> |
| </ul> |
| |
| <p>This will create an '<tt>llvm</tt>' directory in the current |
| directory and fully populate it with the LLVM source code, Makefiles, |
| test directories, and local copies of documentation files.</p> |
| |
| <p>If you want to get a specific release (as opposed to the most recent |
| revision), you can specify a label. The following releases have the following |
| labels:</p> |
| |
| <ul> |
| <li>Release 1.9: <b>RELEASE_19</b></li> |
| <li>Release 1.8: <b>RELEASE_18</b></li> |
| <li>Release 1.7: <b>RELEASE_17</b></li> |
| <li>Release 1.6: <b>RELEASE_16</b></li> |
| <li>Release 1.5: <b>RELEASE_15</b></li> |
| <li>Release 1.4: <b>RELEASE_14</b></li> |
| <li>Release 1.3: <b>RELEASE_13</b></li> |
| <li>Release 1.2: <b>RELEASE_12</b></li> |
| <li>Release 1.1: <b>RELEASE_11</b></li> |
| <li>Release 1.0: <b>RELEASE_1</b></li> |
| </ul> |
| |
| <p>If you would like to get the LLVM test suite (a separate package as of 1.4), |
| you get it from the CVS repository:</p> |
| <pre> |
| cd llvm/projects |
| cvs -z3 -d :pserver:anon@llvm.org:/var/cvs/llvm co llvm-test |
| </pre> |
| <p>By placing it in the <tt>llvm/projects</tt>, it will be automatically |
| configured by the LLVM configure script as well as automatically updated when |
| you run <tt>cvs update</tt>.</p> |
| |
| <p>If you would like to get the GCC 3.4 front end source code, you can also get it from the CVS repository:</p> |
| |
| <pre> |
| cvs -z3 -d :pserver:anon@llvm.org:/var/cvs/llvm co llvm-gcc |
| </pre> |
| |
| <p>Please note that you must follow <a href="CFEBuildInstrs.html">these |
| instructions</a> to successfully build the LLVM GCC front-end.</p> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="installcf">Install the GCC Front End</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p>Before configuring and compiling the LLVM suite, you need to extract the LLVM |
| GCC front end from the binary distribution. It is used for building the |
| bytecode libraries later used by the GCC front end for linking programs, and its |
| location must be specified when the LLVM suite is configured.</p> |
| |
| <p>To install the GCC front end, do the following:</p> |
| |
| <ol> |
| <li><tt>cd <i>where-you-want-the-front-end-to-live</i></tt></li> |
| <li><tt>gunzip --stdout llvmgcc-<i>version</i>.<i>platform</i>.tar.gz | tar -xvf |
| -</tt></li> |
| </ol> |
| |
| <p>The binary versions of the GCC front end may not suit all of your needs. For |
| example, the binary distribution may include an old version of a system header |
| file, not "fix" a header file that needs to be fixed for GCC, or it may be |
| linked with libraries not available on your system.</p> |
| |
| <p>In cases like these, you may want to try <a |
| href="CFEBuildInstrs.html">building the GCC front end from source.</a> This is |
| not for the faint of heart, so be forewarned.</p> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="config">Local LLVM Configuration</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p>Once checked out from the CVS repository, the LLVM suite source code must be |
| configured via the <tt>configure</tt> script. This script sets variables in the |
| various <tt>*.in</tt> files, most notably <tt>llvm/Makefile.config</tt> and |
| <tt>llvm/include/Config/config.h</tt>. It also populates <i>OBJ_ROOT</i> with |
| the Makefiles needed to begin building LLVM.</p> |
| |
| <p>The following environment variables are used by the <tt>configure</tt> |
| script to configure the build system:</p> |
| |
| <table summary="LLVM configure script environment variables"> |
| <tr><th>Variable</th><th>Purpose</th></tr> |
| <tr> |
| <td>CC</td> |
| <td>Tells <tt>configure</tt> which C compiler to use. By default, |
| <tt>configure</tt> will look for the first GCC C compiler in |
| <tt>PATH</tt>. Use this variable to override |
| <tt>configure</tt>'s default behavior.</td> |
| </tr> |
| <tr> |
| <td>CXX</td> |
| <td>Tells <tt>configure</tt> which C++ compiler to use. By default, |
| <tt>configure</tt> will look for the first GCC C++ compiler in |
| <tt>PATH</tt>. Use this variable to override |
| <tt>configure</tt>'s default behavior.</td> |
| </tr> |
| </table> |
| |
| <p>The following options can be used to set or enable LLVM specific options:</p> |
| |
| <dl> |
| <dt><i>--with-llvmgccdir</i></dt> |
| <dd>Path to the LLVM C/C++ FrontEnd to be used with this LLVM configuration. |
| The value of this option should specify the full pathname of the C/C++ Front |
| End to be used. If this option is not provided, the PATH will be searched for |
| a program named <i>llvm-gcc</i> and the C/C++ FrontEnd install directory will |
| be inferred from the path found. If the option is not given, and no llvm-gcc |
| can be found in the path then a warning will be produced by |
| <tt>configure</tt> indicating this situation. LLVM may still be built with |
| the <tt>tools-only</tt> target but attempting to build the runtime libraries |
| will fail as these libraries require llvm-gcc and llvm-g++. See |
| <a href="#installcf">Install the GCC Front End</a> for details on installing |
| the C/C++ Front End. See |
| <a href="CFEBuildInstrs.html">Bootstrapping the LLVM C/C++ Front-End</a> |
| for details on building the C/C++ Front End.</dd> |
| <dt><i>--with-tclinclude</i></dt> |
| <dd>Path to the tcl include directory under which <tt>tclsh</tt> can be |
| found. Use this if you have multiple tcl installations on your machine and you |
| want to use a specific one (8.x) for LLVM. LLVM only uses tcl for running the |
| dejagnu based test suite in <tt>llvm/test</tt>. If you don't specify this |
| option, the LLVM configure script will search for the tcl 8.4 and 8.3 |
| releases. |
| <br><br> |
| </dd> |
| <dt><i>--enable-optimized</i></dt> |
| <dd> |
| Enables optimized compilation by default (debugging symbols are removed |
| and GCC optimization flags are enabled). The default is to use an |
| unoptimized build (also known as a debug build). |
| <br><br> |
| </dd> |
| <dt><i>--enable-debug-runtime</i></dt> |
| <dd> |
| Enables debug symbols in the runtime libraries. The default is to strip |
| debug symbols from the runtime libraries. |
| </dd> |
| <dt><i>--enable-jit</i></dt> |
| <dd> |
| Compile the Just In Time (JIT) compiler functionality. This is not |
| available |
| on all platforms. The default is dependent on platform, so it is best |
| to explicitly enable it if you want it. |
| <br><br> |
| </dd> |
| <dt><i>--enable-targets=</i><tt>target-option</tt></dt> |
| <dd>Controls which targets will be built and linked into llc. The default |
| value for <tt>target_options</tt> is "all" which builds and links all |
| available targets. The value "host-only" can be specified to build only a |
| native compiler (no cross-compiler targets available). The "native" target is |
| selected as the target of the build host. You can also specify a comma |
| separated list of target names that you want available in llc. The target |
| names use all lower case. The current set of targets is: <br/> |
| <tt>alpha, ia64, powerpc, skeleton, sparc, x86</tt>. |
| <br><br></dd> |
| <dt><i>--enable-doxygen</i></dt> |
| <dd>Look for the doxygen program and enable construction of doxygen based |
| documentation from the source code. This is disabled by default because |
| generating the documentation can take a long time and producess 100s of |
| megabytes of output.</dd> |
| </dl> |
| |
| <p>To configure LLVM, follow these steps:</p> |
| |
| <ol> |
| <li>Change directory into the object root directory: |
| <br> |
| <tt>cd <i>OBJ_ROOT</i></tt> |
| <br><br> |
| |
| <li>Run the <tt>configure</tt> script located in the LLVM source tree: |
| <br> |
| <tt><i>SRC_ROOT</i>/configure --prefix=/install/path [other options]</tt> |
| <br><br> |
| </ol> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="compile">Compiling the LLVM Suite Source Code</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p>Once you have configured LLVM, you can build it. There are three types of |
| builds:</p> |
| |
| <dl> |
| <dt>Debug Builds |
| <dd> |
| These builds are the default when one types <tt>gmake</tt> (unless the |
| <tt>--enable-optimized</tt> option was used during configuration). The |
| build system will compile the tools and libraries with debugging |
| information. |
| <br><br> |
| |
| <dt>Release (Optimized) Builds |
| <dd> |
| These builds are enabled with the <tt>--enable-optimized</tt> option to |
| <tt>configure</tt> or by specifying <tt>ENABLE_OPTIMIZED=1</tt> on the |
| <tt>gmake</tt> command line. For these builds, the build system will |
| compile the tools and libraries with GCC optimizations enabled and strip |
| debugging information from the libraries and executables it generates. |
| <br><br> |
| |
| <dt>Profile Builds |
| <dd> |
| These builds are for use with profiling. They compile profiling |
| information into the code for use with programs like <tt>gprof</tt>. |
| Profile builds must be started by specifying <tt>ENABLE_PROFILING=1</tt> |
| on the <tt>gmake</tt> command line. |
| </dl> |
| |
| <p>Once you have LLVM configured, you can build it by entering the |
| <i>OBJ_ROOT</i> directory and issuing the following command:</p> |
| |
| <p><tt>gmake</tt></p> |
| |
| <p>If the build fails, please <a href="#brokengcc">check here</a> to see if you |
| are using a version of GCC that is known not to compile LLVM.</p> |
| |
| <p> |
| If you have multiple processors in your machine, you may wish to use some of |
| the parallel build options provided by GNU Make. For example, you could use the |
| command:</p> |
| |
| <p><tt>gmake -j2</tt></p> |
| |
| <p>There are several special targets which are useful when working with the LLVM |
| source code:</p> |
| |
| <dl> |
| <dt><tt>gmake clean</tt> |
| <dd> |
| Removes all files generated by the build. This includes object files, |
| generated C/C++ files, libraries, and executables. |
| <br><br> |
| |
| <dt><tt>gmake dist-clean</tt> |
| <dd> |
| Removes everything that <tt>gmake clean</tt> does, but also removes files |
| generated by <tt>configure</tt>. It attempts to return the source tree to the |
| original state in which it was shipped. |
| <br><br> |
| |
| <dt><tt>gmake install</tt> |
| <dd> |
| Installs LLVM header files, libraries, tools, and documentation in a |
| hierarchy |
| under $PREFIX, specified with <tt>./configure --prefix=[dir]</tt>, which |
| defaults to <tt>/usr/local</tt>. |
| <br><br> |
| |
| <dt><tt>gmake -C runtime install-bytecode</tt> |
| <dd> |
| Assuming you built LLVM into $OBJDIR, when this command is run, it will |
| install bytecode libraries into the GCC front end's bytecode library |
| directory. If you need to update your bytecode libraries, |
| this is the target to use once you've built them. |
| <br><br> |
| </dl> |
| |
| <p>Please see the <a href="MakefileGuide.html">Makefile Guide</a> for further |
| details on these <tt>make</tt> targets and descriptions of other targets |
| available.</p> |
| |
| <p>It is also possible to override default values from <tt>configure</tt> by |
| declaring variables on the command line. The following are some examples:</p> |
| |
| <dl> |
| <dt><tt>gmake ENABLE_OPTIMIZED=1</tt> |
| <dd> |
| Perform a Release (Optimized) build. |
| <br><br> |
| |
| <dt><tt>gmake ENABLE_OPTIMIZED=1 DISABLE_ASSERTIONS=1</tt> |
| <dd> |
| Perform a Release (Optimized) build without assertions enabled. |
| <br><br> |
| |
| <dt><tt>gmake ENABLE_PROFILING=1</tt> |
| <dd> |
| Perform a Profiling build. |
| <br><br> |
| |
| <dt><tt>gmake VERBOSE=1</tt> |
| <dd> |
| Print what <tt>gmake</tt> is doing on standard output. |
| <br><br> |
| |
| <dt><tt>gmake TOOL_VERBOSE=1</tt></dt> |
| <dd>Ask each tool invoked by the makefiles to print out what it is doing on |
| the standard output. This also implies <tt>VERBOSE=1</tt>. |
| <br><br></dd> |
| </dl> |
| |
| <p>Every directory in the LLVM object tree includes a <tt>Makefile</tt> to build |
| it and any subdirectories that it contains. Entering any directory inside the |
| LLVM object tree and typing <tt>gmake</tt> should rebuild anything in or below |
| that directory that is out of date.</p> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="cross-compile">Cross-Compiling LLVM</a> |
| </div> |
| |
| <div class="doc_text"> |
| <p>It is possible to cross-compile LLVM. That is, you can create LLVM |
| executables and libraries for a platform different than the one one which you |
| are compiling. To do this, a few additional steps are |
| required. <sup><a href="#ccn_1">1</a></sup> To cross-compile LLVM, use |
| these instructions:</p> |
| <ol> |
| <li>Configure and build LLVM as a native compiler. You will need |
| just <tt>TableGen</tt> from that build. |
| <ul> |
| <li>If you have <tt>$LLVM_OBJ_ROOT=$LLVM_SRC_ROOT</tt> just execute |
| <tt>make -C utils/TableGen</tt> after configuring.</li> |
| <li>Otherwise you will need to monitor building process and terminate |
| it just after <tt>TableGen</tt> was built.</li> |
| </ul> |
| </li> |
| <li>Copy the TableGen binary to somewhere safe (out of your build tree). |
| </li> |
| <li>Configure LLVM to build with a cross-compiler. To do this, supply the |
| configure script with <tt>--build</tt> and <tt>--host</tt> options that |
| are different. The values of these options must be legal target triples |
| that your GCC compiler supports.</li> |
| <li>Put the saved <tt>TableGen</tt> executable into the |
| into <tt>$LLVM_OBJ_ROOT/{BUILD_TYPE}/bin</tt> directory (e.g. into |
| <tt>.../Release/bin</tt> for a Release build).</li> |
| <li>Build LLVM as usual.</li> |
| </ol> |
| <p>The result of such a build will produce executables that are not executable |
| on your build host (--build option) but can be executed on your compile host |
| (--host option).</p> |
| <p><b>Notes:</b></p> |
| <div class="doc_notes"> |
| <ol> |
| <li><a name="ccn_1">Cross-compiling</a> was tested only with Linux as |
| build platform and Windows as host using mingw32 cross-compiler. Other |
| combinations have not been tested.</li> |
| </ol> |
| </div> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="objfiles">The Location of LLVM Object Files</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p>The LLVM build system is capable of sharing a single LLVM source tree among |
| several LLVM builds. Hence, it is possible to build LLVM for several different |
| platforms or configurations using the same source tree.</p> |
| |
| <p>This is accomplished in the typical autoconf manner:</p> |
| |
| <ul> |
| <li><p>Change directory to where the LLVM object files should live:</p> |
| |
| <p><tt>cd <i>OBJ_ROOT</i></tt></p></li> |
| |
| <li><p>Run the <tt>configure</tt> script found in the LLVM source |
| directory:</p> |
| |
| <p><tt><i>SRC_ROOT</i>/configure</tt></p></li> |
| </ul> |
| |
| <p>The LLVM build will place files underneath <i>OBJ_ROOT</i> in directories |
| named after the build type:</p> |
| |
| <dl> |
| <dt>Debug Builds |
| <dd> |
| <dl> |
| <dt>Tools |
| <dd><tt><i>OBJ_ROOT</i>/Debug/bin</tt> |
| <dt>Libraries |
| <dd><tt><i>OBJ_ROOT</i>/Debug/lib</tt> |
| </dl> |
| <br><br> |
| |
| <dt>Release Builds |
| <dd> |
| <dl> |
| <dt>Tools |
| <dd><tt><i>OBJ_ROOT</i>/Release/bin</tt> |
| <dt>Libraries |
| <dd><tt><i>OBJ_ROOT</i>/Release/lib</tt> |
| </dl> |
| <br><br> |
| |
| <dt>Profile Builds |
| <dd> |
| <dl> |
| <dt>Tools |
| <dd><tt><i>OBJ_ROOT</i>/Profile/bin</tt> |
| <dt>Libraries |
| <dd><tt><i>OBJ_ROOT</i>/Profile/lib</tt> |
| </dl> |
| </dl> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"> |
| <a name="optionalconfig">Optional Configuration Items</a> |
| </div> |
| |
| <div class="doc_text"> |
| |
| <p> |
| If you're running on a Linux system that supports the "<a |
| href="http://www.tat.physik.uni-tuebingen.de/~rguenth/linux/binfmt_misc.html"> |
| binfmt_misc</a>" |
| module, and you have root access on the system, you can set your system up to |
| execute LLVM bytecode files directly. To do this, use commands like this (the |
| first command may not be required if you are already using the module):</p> |
| |
| <div class="doc_code"> |
| <pre> |
| $ mount -t binfmt_misc none /proc/sys/fs/binfmt_misc |
| $ echo ':llvm:M::llvm::/path/to/lli:' > /proc/sys/fs/binfmt_misc/register |
| $ chmod u+x hello.bc (if needed) |
| $ ./hello.bc |
| </pre> |
| </div> |
| |
| <p> |
| This allows you to execute LLVM bytecode files directly. Thanks to Jack |
| Cummings for pointing this out! |
| </p> |
| |
| </div> |
| |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="layout"><b>Program Layout</b></a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| |
| <p>One useful source of information about the LLVM source base is the LLVM <a |
| href="http://www.doxygen.org">doxygen</a> documentation available at <tt><a |
| href="http://llvm.org/doxygen/">http://llvm.org/doxygen/</a></tt>. |
| The following is a brief introduction to code layout:</p> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="cvsdir"><tt>CVS</tt> directories</a></div> |
| <div class="doc_text"> |
| <p>Every directory checked out of CVS will contain a <tt>CVS</tt> directory; for |
| the most part these can just be ignored.</p> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="examples"><tt>llvm/examples</tt></a></div> |
| <div class="doc_text"> |
| <p>This directory contains some simple examples of how to use the LLVM IR and |
| JIT.</p> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="include"><tt>llvm/include</tt></a></div> |
| <div class="doc_text"> |
| |
| <p>This directory contains public header files exported from the LLVM |
| library. The three main subdirectories of this directory are:</p> |
| |
| <dl> |
| <dt><tt><b>llvm/include/llvm</b></tt></dt> |
| <dd>This directory contains all of the LLVM specific header files. This |
| directory also has subdirectories for different portions of LLVM: |
| <tt>Analysis</tt>, <tt>CodeGen</tt>, <tt>Target</tt>, <tt>Transforms</tt>, |
| etc...</dd> |
| |
| <dt><tt><b>llvm/include/llvm/Support</b></tt></dt> |
| <dd>This directory contains generic support libraries that are provided with |
| LLVM but not necessarily specific to LLVM. For example, some C++ STL utilities |
| and a Command Line option processing library store their header files here. |
| </dd> |
| |
| <dt><tt><b>llvm/include/llvm/Config</b></tt></dt> |
| <dd>This directory contains header files configured by the <tt>configure</tt> |
| script. They wrap "standard" UNIX and C header files. Source code can |
| include these header files which automatically take care of the conditional |
| #includes that the <tt>configure</tt> script generates.</dd> |
| </dl> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="lib"><tt>llvm/lib</tt></a></div> |
| <div class="doc_text"> |
| |
| <p>This directory contains most of the source files of the LLVM system. In LLVM, |
| almost all code exists in libraries, making it very easy to share code among the |
| different <a href="#tools">tools</a>.</p> |
| |
| <dl> |
| <dt><tt><b>llvm/lib/VMCore/</b></tt></dt> |
| <dd> This directory holds the core LLVM source files that implement core |
| classes like Instruction and BasicBlock.</dd> |
| |
| <dt><tt><b>llvm/lib/AsmParser/</b></tt></dt> |
| <dd>This directory holds the source code for the LLVM assembly language parser |
| library.</dd> |
| |
| <dt><tt><b>llvm/lib/ByteCode/</b></tt></dt> |
| <dd>This directory holds code for reading and write LLVM bytecode.</dd> |
| |
| <dt><tt><b>llvm/lib/Analysis/</b></tt><dd>This directory contains a variety of |
| different program analyses, such as Dominator Information, Call Graphs, |
| Induction Variables, Interval Identification, Natural Loop Identification, |
| etc.</dd> |
| |
| <dt><tt><b>llvm/lib/Transforms/</b></tt></dt> |
| <dd> This directory contains the source code for the LLVM to LLVM program |
| transformations, such as Aggressive Dead Code Elimination, Sparse Conditional |
| Constant Propagation, Inlining, Loop Invariant Code Motion, Dead Global |
| Elimination, and many others.</dd> |
| |
| <dt><tt><b>llvm/lib/Target/</b></tt></dt> |
| <dd> This directory contains files that describe various target architectures |
| for code generation. For example, the <tt>llvm/lib/Target/X86</tt> |
| directory holds the X86 machine description while |
| <tt>llvm/lib/Target/CBackend</tt> implements the LLVM-to-C converter.</dd> |
| |
| <dt><tt><b>llvm/lib/CodeGen/</b></tt></dt> |
| <dd> This directory contains the major parts of the code generator: Instruction |
| Selector, Instruction Scheduling, and Register Allocation.</dd> |
| |
| <dt><tt><b>llvm/lib/Debugger/</b></tt></dt> |
| <dd> This directory contains the source level debugger library that makes |
| it possible to instrument LLVM programs so that a debugger could identify |
| source code locations at which the program is executing.</dd> |
| |
| <dt><tt><b>llvm/lib/ExecutionEngine/</b></tt></dt> |
| <dd> This directory contains libraries for executing LLVM bytecode directly |
| at runtime in both interpreted and JIT compiled fashions.</dd> |
| |
| <dt><tt><b>llvm/lib/Support/</b></tt></dt> |
| <dd> This directory contains the source code that corresponds to the header |
| files located in <tt>llvm/include/Support/</tt>.</dd> |
| |
| <dt><tt><b>llvm/lib/System/</b></tt></dt> |
| <dd>This directory contains the operating system abstraction layer that |
| shields LLVM from platform-specific coding.</dd> |
| </dl> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="projects"><tt>llvm/projects</tt></a></div> |
| <div class="doc_text"> |
| <p>This directory contains projects that are not strictly part of LLVM but are |
| shipped with LLVM. This is also the directory where you should create your own |
| LLVM-based projects. See <tt>llvm/projects/sample</tt> for an example of how |
| to set up your own project. See <tt>llvm/projects/Stacker</tt> for a fully |
| functional example of a compiler front end.</p> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="runtime"><tt>llvm/runtime</tt></a></div> |
| <div class="doc_text"> |
| |
| <p>This directory contains libraries which are compiled into LLVM bytecode and |
| used when linking programs with the GCC front end. Most of these libraries are |
| skeleton versions of real libraries; for example, libc is a stripped down |
| version of glibc.</p> |
| |
| <p>Unlike the rest of the LLVM suite, this directory needs the LLVM GCC front |
| end to compile.</p> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="test"><tt>llvm/test</tt></a></div> |
| <div class="doc_text"> |
| <p>This directory contains feature and regression tests and other basic sanity |
| checks on the LLVM infrastructure. These are intended to run quickly and cover |
| a lot of territory without being exhaustive.</p> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="llvmtest"><tt>llvm-test</tt></a></div> |
| <div class="doc_text"> |
| <p>This is not a directory in the normal llvm module; it is a separate CVS |
| module that must be checked out (usually to <tt>projects/llvm-test</tt>). This |
| module contains a comprehensive correctness, performance, and benchmarking |
| test |
| suite for LLVM. It is a separate CVS module because not every LLVM user is |
| interested in downloading or building such a comprehensive test suite. For |
| further details on this test suite, please see the |
| <a href="TestingGuide.html">Testing Guide</a> document.</p> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="tools"><tt>llvm/tools</tt></a></div> |
| <div class="doc_text"> |
| |
| <p>The <b>tools</b> directory contains the executables built out of the |
| libraries above, which form the main part of the user interface. You can |
| always get help for a tool by typing <tt>tool_name --help</tt>. The |
| following is a brief introduction to the most important tools. More detailed |
| information is in the <a href="CommandGuide/index.html">Command Guide</a>.</p> |
| |
| <dl> |
| |
| <dt><tt><b>bugpoint</b></tt></dt> |
| <dd><tt>bugpoint</tt> is used to debug |
| optimization passes or code generation backends by narrowing down the |
| given test case to the minimum number of passes and/or instructions that |
| still cause a problem, whether it is a crash or miscompilation. See <a |
| href="HowToSubmitABug.html">HowToSubmitABug.html</a> for more information |
| on using <tt>bugpoint</tt>.</dd> |
| |
| <dt><tt><b>llvmc</b></tt></dt> |
| <dd>The LLVM Compiler Driver. This program can |
| be configured to utilize both LLVM and non-LLVM compilation tools to enable |
| pre-processing, translation, optimization, assembly, and linking of programs |
| all from one command line. <tt>llvmc</tt> also takes care of processing the |
| dependent libraries found in bytecode. This reduces the need to get the |
| traditional <tt>-l<name></tt> options right on the command line. Please |
| note that this tool, while functional, is still experimental and not feature |
| complete.</dd> |
| |
| <dt><tt><b>llvm-ar</b></tt></dt> |
| <dd>The archiver produces an archive containing |
| the given LLVM bytecode files, optionally with an index for faster |
| lookup.</dd> |
| |
| <dt><tt><b>llvm-as</b></tt></dt> |
| <dd>The assembler transforms the human readable LLVM assembly to LLVM |
| bytecode.</dd> |
| |
| <dt><tt><b>llvm-dis</b></tt></dt> |
| <dd>The disassembler transforms the LLVM bytecode to human readable |
| LLVM assembly.</dd> |
| |
| <dt><tt><b>llvm-ld</b></tt></dt> |
| <dd><tt>llvm-ld</tt> is very similar to gccld and provides a general purpose |
| and extensible linker for LLVM. This is the linker invoked by <tt>llvmc</tt>. |
| It allows optimization modules to be loaded so that language specific |
| optimizations can be applied at link time. This tool is considered |
| experimental.</dd> |
| |
| <dt><tt><b>llvm-link</b></tt></dt> |
| <dd><tt>llvm-link</tt>, not surprisingly, links multiple LLVM modules into |
| a single program.</dd> |
| |
| <dt><tt><b>lli</b></tt></dt> |
| <dd><tt>lli</tt> is the LLVM interpreter, which |
| can directly execute LLVM bytecode (although very slowly...). In addition |
| to a simple interpreter, <tt>lli</tt> also has a tracing mode (entered by |
| specifying <tt>-trace</tt> on the command line). Finally, for |
| architectures that support it (currently x86, Sparc, and PowerPC), by default, |
| <tt>lli</tt> will function as a Just-In-Time compiler (if the |
| functionality was compiled in), and will execute the code <i>much</i> |
| faster than the interpreter.</dd> |
| |
| <dt><tt><b>llc</b></tt></dt> |
| <dd> <tt>llc</tt> is the LLVM backend compiler, which |
| translates LLVM bytecode to a native code assembly file or to C code (with |
| the -march=c option).</dd> |
| |
| <dt><tt><b>llvm-gcc</b></tt></dt> |
| <dd><tt>llvm-gcc</tt> is a GCC-based C frontend |
| that has been retargeted to emit LLVM code as the machine code output. It |
| works just like any other GCC compiler, taking the typical <tt>-c, -S, -E, |
| -o</tt> options that are typically used. The source code for the |
| <tt>llvm-gcc</tt> tool is available as a separate CVS module. |
| <blockquote> |
| <dl> |
| <dt><tt><b>gccas</b></tt></dt> |
| <dd>This tool is invoked by the <tt>llvm-gcc</tt> frontend as the |
| "assembler" part of the compiler. This tool actually assembles LLVM |
| assembly to LLVM bytecode, performs a variety of optimizations, and |
| outputs LLVM bytecode. Thus when you invoke |
| <tt>llvm-gcc -c x.c -o x.o</tt>, you are causing <tt>gccas</tt> to be |
| run, which writes the <tt>x.o</tt> file (which is an LLVM bytecode file |
| that can be disassembled or manipulated just like any other bytecode |
| file). The command line interface to <tt>gccas</tt> is designed to be |
| as close as possible to the <b>system</b> `<tt>as</tt>' utility so that |
| the gcc frontend itself did not have to be modified to interface to |
| a "weird" assembler.</dd> |
| |
| <dt><tt><b>gccld</b></tt></dt> |
| <dd><tt>gccld</tt> links together several LLVM bytecode files into one |
| bytecode file and does some optimization. It is the linker invoked by |
| the GCC frontend when multiple .o files need to be linked together. |
| Like <tt>gccas</tt>, the command line interface of <tt>gccld</tt> is |
| designed to match the system linker, to aid interfacing with the GCC |
| frontend.</dd> |
| </dl> |
| </blockquote> |
| </dd> |
| |
| <dt><tt><b>opt</b></tt></dt> |
| <dd><tt>opt</tt> reads LLVM bytecode, applies a series of LLVM to LLVM |
| transformations (which are specified on the command line), and then outputs |
| the resultant bytecode. The '<tt>opt --help</tt>' command is a good way to |
| get a list of the program transformations available in LLVM.<br/> |
| <dd><tt>opt</tt> can also be used to run a specific analysis on an input |
| LLVM bytecode file and print out the results. It is primarily useful for |
| debugging analyses, or familiarizing yourself with what an analysis does.</dd> |
| </dl> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="utils"><tt>llvm/utils</tt></a></div> |
| <div class="doc_text"> |
| |
| <p>This directory contains utilities for working with LLVM source code, and some |
| of the utilities are actually required as part of the build process because they |
| are code generators for parts of LLVM infrastructure.</p> |
| |
| <dl> |
| <dt><tt><b>codegen-diff</b></tt> <dd><tt>codegen-diff</tt> is a script |
| that finds differences between code that LLC generates and code that LLI |
| generates. This is a useful tool if you are debugging one of them, |
| assuming that the other generates correct output. For the full user |
| manual, run <tt>`perldoc codegen-diff'</tt>.<br><br> |
| |
| <dt><tt><b>cvsupdate</b></tt> <dd><tt>cvsupdate</tt> is a script that will |
| update your CVS tree, but produce a much cleaner and more organized output |
| than simply running <tt>`cvs -z3 up -dP'</tt> will. For example, it will group |
| together all the new and updated files and modified files in separate |
| sections, so you can see at a glance what has changed. If you are at the |
| top of your LLVM CVS tree, running <tt>utils/cvsupdate</tt> is the |
| preferred way of updating the tree.<br><br> |
| |
| <dt><tt><b>emacs/</b></tt> <dd>The <tt>emacs</tt> directory contains |
| syntax-highlighting files which will work with Emacs and XEmacs editors, |
| providing syntax highlighting support for LLVM assembly files and TableGen |
| description files. For information on how to use the syntax files, consult |
| the <tt>README</tt> file in that directory.<br><br> |
| |
| <dt><tt><b>getsrcs.sh</b></tt> <dd>The <tt>getsrcs.sh</tt> script finds |
| and outputs all non-generated source files, which is useful if one wishes |
| to do a lot of development across directories and does not want to |
| individually find each file. One way to use it is to run, for example: |
| <tt>xemacs `utils/getsources.sh`</tt> from the top of your LLVM source |
| tree.<br><br> |
| |
| <dt><tt><b>llvmgrep</b></tt></dt> |
| <dd>This little tool performs an "egrep -H -n" on each source file in LLVM and |
| passes to it a regular expression provided on <tt>llvmgrep</tt>'s command |
| line. This is a very efficient way of searching the source base for a |
| particular regular expression.</dd> |
| |
| <dt><tt><b>makellvm</b></tt> <dd>The <tt>makellvm</tt> script compiles all |
| files in the current directory and then compiles and links the tool that |
| is the first argument. For example, assuming you are in the directory |
| <tt>llvm/lib/Target/Sparc</tt>, if <tt>makellvm</tt> is in your path, |
| simply running <tt>makellvm llc</tt> will make a build of the current |
| directory, switch to directory <tt>llvm/tools/llc</tt> and build it, |
| causing a re-linking of LLC.<br><br> |
| |
| <dt><tt><b>NightlyTest.pl</b></tt> and |
| <tt><b>NightlyTestTemplate.html</b></tt> <dd>These files are used in a |
| cron script to generate nightly status reports of the functionality of |
| tools, and the results can be seen by following the appropriate link on |
| the <a href="http://llvm.org/">LLVM homepage</a>.<br><br> |
| |
| <dt><tt><b>TableGen/</b></tt> <dd>The <tt>TableGen</tt> directory contains |
| the tool used to generate register descriptions, instruction set |
| descriptions, and even assemblers from common TableGen description |
| files.<br><br> |
| |
| <dt><tt><b>vim/</b></tt> <dd>The <tt>vim</tt> directory contains |
| syntax-highlighting files which will work with the VIM editor, providing |
| syntax highlighting support for LLVM assembly files and TableGen |
| description files. For information on how to use the syntax files, consult |
| the <tt>README</tt> file in that directory.<br><br> |
| |
| </dl> |
| |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="win32"><tt>llvm/win32</tt></a></div> |
| <div class="doc_text"> |
| <p>This directory contains build scripts and project files for use with |
| Visual C++. This allows developers on Windows to build LLVM without the need |
| for Cygwin. The contents of this directory should be considered experimental |
| at this time. |
| </p> |
| </div> |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="tutorial">An Example Using the LLVM Tool Chain</a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| <p>This section gives an example of using LLVM. llvm-gcc3 is now obsolete, |
| so we only include instructiosn for llvm-gcc4. |
| </p> |
| |
| <p><b>Note:</b> The <i>gcc4</i> frontend's invocation is <b><i>considerably different</i></b> |
| from the previous <i>gcc3</i> frontend. In particular, the <i>gcc4</i> frontend <b><i>does not</i></b> |
| create bytecode by default: <i>gcc4</i> produces native code. As the example below illustrates, |
| the '--emit-llvm' flag is needed to produce LLVM bytecode output. For <i>makefiles</i> and |
| <i>configure</i> scripts, the CFLAGS variable needs '--emit-llvm' to produce bytecode |
| output.</p> |
| </div> |
| |
| <!-- ======================================================================= --> |
| <div class="doc_subsection"><a name="tutorial4">Example with llvm-gcc4</a></div> |
| |
| <div class="doc_text"> |
| |
| <ol> |
| <li>First, create a simple C file, name it 'hello.c': |
| <pre> |
| #include <stdio.h> |
| int main() { |
| printf("hello world\n"); |
| return 0; |
| } |
| </pre></li> |
| |
| <li><p>Next, compile the C file into a native executable:</p> |
| |
| <p><tt>% llvm-gcc hello.c -o hello</tt></p> |
| |
| <p>Note that llvm-gcc works just like GCC by default. The standard -S and |
| -c arguments work as usual (producing a native .s or .o file, |
| respectively). </p> |
| |
| <li><p>Next, compile the C file into a LLVM bytecode file:</p> |
| <p><tt>% llvm-gcc -O3 -emit-llvm hello.c -c -o hello.bc</tt></p> |
| |
| <p>The -emit-llvm option can be used with the -S or -c options to emit an |
| LLVM ".ll" or ".bc" file (respectively) for the code. This allows you |
| to use the <a href="CommandGuide/index.html">standard LLVM tools</a> on |
| the bytecode file.</p> |
| |
| <p>Unlike llvm-gcc3, llvm-gcc4 correctly responds to -O[0123] arguments. |
| </p></li> |
| |
| <li><p>Run the program in both forms. To run the program, use:</p> |
| |
| <p><tt>% ./hello</tt></p> |
| |
| <p>and</p> |
| |
| <p><tt>% lli hello.bc</tt></p> |
| |
| <p>The second examples shows how to invoke the LLVM JIT, <a |
| href="CommandGuide/html/lli.html">lli</a>.</p></li> |
| |
| <li><p>Use the <tt>llvm-dis</tt> utility to take a look at the LLVM assembly |
| code:</p> |
| |
| <p><tt>% llvm-dis < hello.bc | less</tt><br><br></li> |
| |
| <li><p>Compile the program to native assembly using the LLC code |
| generator:</p> |
| |
| <p><tt>% llc hello.bc -o hello.s</tt></p> |
| |
| <li><p>Assemble the native assembly language file into a program:</p> |
| |
| <p><b>Solaris:</b><tt>% /opt/SUNWspro/bin/cc -xarch=v9 hello.s -o hello.native</tt></p> |
| <p><b>Others:</b><tt>% gcc hello.s -o hello.native</tt></p> |
| |
| <li><p>Execute the native code program:</p> |
| |
| <p><tt>% ./hello.native</tt></p> |
| |
| <p>Note that using llvm-gcc to compile directly to native code (i.e. when |
| the -emit-llvm option is not present) does steps 6/7/8 for you.</p> |
| </li> |
| |
| </ol> |
| |
| </div> |
| |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="problems">Common Problems</a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| |
| <p>If you are having problems building or using LLVM, or if you have any other |
| general questions about LLVM, please consult the <a href="FAQ.html">Frequently |
| Asked Questions</a> page.</p> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
| <div class="doc_section"> |
| <a name="links">Links</a> |
| </div> |
| <!-- *********************************************************************** --> |
| |
| <div class="doc_text"> |
| |
| <p>This document is just an <b>introduction</b> to how to use LLVM to do |
| some simple things... there are many more interesting and complicated things |
| that you can do that aren't documented here (but we'll gladly accept a patch |
| if you want to write something up!). For more information about LLVM, check |
| out:</p> |
| |
| <ul> |
| <li><a href="http://llvm.org/">LLVM homepage</a></li> |
| <li><a href="http://llvm.org/doxygen/">LLVM doxygen tree</a></li> |
| <li><a href="http://llvm.org/docs/Projects.html">Starting a Project |
| that Uses LLVM</a></li> |
| </ul> |
| |
| </div> |
| |
| <!-- *********************************************************************** --> |
| |
| <hr> |
| <address> |
| <a href="http://jigsaw.w3.org/css-validator/check/referer"><img |
| src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a> |
| <a href="http://validator.w3.org/check/referer"><img |
| src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a> |
| |
| <a href="mailto:sabre@nondot.org">Chris Lattner</a><br> |
| <a href="http://llvm.x10sys.com/rspencer/">Reid Spencer</a><br> |
| <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br> |
| Last modified: $Date$ |
| </address> |
| </body> |
| </html> |