Home | History | Annotate | Download | only in www
      1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
      2 <html xmlns="http://www.w3.org/1999/xhtml">
      3 <head>
      4 <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
      5 <link href="style.css" rel="stylesheet" type="text/css" />
      6 <title>LLDB Homepage</title>
      7 </head>
      8 
      9 <body>
     10     <div class="www_title">
     11       The <strong>LLDB</strong> Debugger
     12     </div>
     13     
     14 <div id="container">
     15 	<div id="content">
     16         
     17         <!--#include virtual="sidebar.incl"-->
     18 
     19 		<div id="middle">
     20 			<div class="post">
     21 				<h1 class ="postheader">What is LLDB?</h1>
     22 				<div class="postcontent">
     23                     <p>LLDB is a next generation, high-performance debugger. It is built as a set
     24                         of reusable components which highly leverage existing libraries in the
     25                         larger LLVM Project, such as the Clang expression parser and LLVM
     26                         disassembler.</p>
     27                     <p>LLDB is the default debugger in Xcode on Mac OS X and supports
     28                         debugging C, Objective-C and C++ on the desktop and iOS devices and simulator.</p>
     29 
     30                     <p>All of the code in the LLDB project is available under the standard
     31                         <a href="http://llvm.org/docs/DeveloperPolicy.html#license">LLVM
     32                         License</a>, an open source "BSD-style" license.</p>
     33                 </div>
     34     			<div class="postfooter"></div>
     35 			</div>
     36 
     37 			<div class="post">
     38 				<h1 class ="postheader">Why a new debugger?</h1>
     39 				<div class="postcontent">
     40 					  <p>In order to achieve our goals we decided to start with a fresh architecture
     41 					     that would support modern multi-threaded programs, handle debugging symbols
     42 					     in an efficient manner, use compiler based code knowledge and have plug-in
     43 					     support for functionality and extensions. Additionally we want the debugger
     44 					     capabilities to be available to other analysis tools, be they scripts or
     45 					     compiled programs, without requiring them to be GPL.</p>
     46 				</div>
     47 				<div class="postfooter"></div>
     48 			</div>
     49 
     50 			<div class="post">
     51 				<h1 class ="postheader">Compiler Integration Benefits</h1>
     52 				<div class="postcontent">
     53 						<p>LLDB currently converts debug information into clang types so that
     54 						it can leverage the clang compiler infrastructure.
     55 						This allows LLDB to support the latest C, C++, Objective C and Objective C++
     56 						language features and runtimes in expressions without having to reimplement <b>any</b> 
     57 						of this functionality. It also leverages the compiler to take care of all ABI
     58 						details when making functions calls for expressions, when disassembling
     59 						instructions and extracting instruciton details, and much more. 
     60 				   	<p>The major benefits include:</p>
     61 				   	<ul>
     62 					   	<li>Up to date language support for C, C++, Objective C</li>
     63 					   	<li>Multi-line expressions that can declare local variables and types</li>
     64 					   	<li>Utilitize the JIT for expressions when supported</li>
     65 					   	<li>Evaluate expression Intermediate Representation (IR) when JIT can't be used</li>
     66 				    </ul>
     67 				</div>
     68 			</div>
     69 
     70 			<div class="post">
     71 				<h1 class ="postheader">Reusability</h1>
     72 				<div class="postcontent">
     73 				   	<p>The LLDB debugger APIs are exposed as a C++ object oriented interface in a shared library. 
     74 					The <b>lldb</b> command line tool links to, and uses this public API. On Mac OS X the shared library
     75 					is exposed as a framework named <b>LLDB.framework</b>, and unix systems expose it as <b>lldb.so</b>.
     76 					The entire API is also then exposed through Python script bindings which allow the API to be used
     77 					within the LLDB embedded script interpreter, and also in any python script that loads the <b>lldb.py</b>
     78 					module in standard python script files. See the <a href="python-reference.html">Python Reference</a> page for more details on how 
     79 					and where Python can be used with the LLDB API.</p>
     80 					<p>Sharing the LLDB API allows LLDB to not only be used for debugging, but also for symbolication,
     81 						disassembly, object and symbol file introspection, and much more.
     82 				</div>
     83 			</div>
     84 
     85 			<div class="post">
     86 				<h1 class ="postheader">Platform Support</h1>
     87 				<div class="postcontent">
     88 
     89 				   	<p>LLDB is known to work on the following platforms, but ports to new
     90 				       platforms are welcome:</p>
     91 				   	<ul>
     92 					   	<li>Mac OS X desktop user space debugging for i386 and x86-64</li>
     93 					   	<li>iOS simulator debugging on i386</li>
     94 					   	<li>iOS device debugging on ARM</li>
     95 					   	<li>Linux local user-space debugging for i386 and x86-64</li>
     96 					   	<li>FreeBSD local user-space debugging for i386 and x86-64</li>
     97 				    </ul>
     98 				</div>
     99 				<div class="postfooter"></div>
    100 			</div>
    101 
    102 
    103 			<div class="post">
    104 				<h1 class ="postheader">Get it and get involved!</h1>
    105 				<div class="postcontent">
    106 
    107 				    <p>To check out the code, use:</p>
    108 
    109 				    <ul>
    110 				        <li>svn co http://llvm.org/svn/llvm-project/lldb/trunk lldb</li>
    111 				    </ul>
    112 
    113 				    <p>Note that LLDB generally builds from top-of-trunk on Mac OS X with
    114 				        Xcode and on Linux (with clang and libstdc++/libc++). </p>
    115 
    116 				    <p>Discussions about LLDB should go to the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev">lldb-dev</a> mailing
    117 				        list.  Commit messages for the lldb SVN module are automatically sent to the
    118 				        <a  href="http://lists.cs.uiuc.edu/mailman/listinfo/lldb-commits">lldb-commits</a>
    119 				        mailing list, and this is also the preferred mailing list for patch
    120 				        submissions.</p>
    121 			    </div>
    122 				<div class="postfooter"></div>
    123 			</div>
    124 		</div>
    125 	</div>
    126 </div>
    127 </body>
    128 </html>
    129