blob: 52edd482087be30f7182c9d42d7ce0f10ee4ad30 [file] [log] [blame]
Howard Hinnant3e1b0422010-08-22 01:04:38 +00001<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
Howard Hinnantc51e1022010-05-11 19:42:16 +00002 "http://www.w3.org/TR/html4/strict.dtd">
3<!-- Material used from: HTML 4.01 specs: http://www.w3.org/TR/html401/ -->
4<html>
5<head>
6 <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
7 <title>"libc++" C++ Standard Library</title>
8 <link type="text/css" rel="stylesheet" href="menu.css">
9 <link type="text/css" rel="stylesheet" href="content.css">
10</head>
11
12<body>
13<div id="menu">
14 <div>
15 <a href="http://llvm.org/">LLVM Home</a>
16 </div>
Howard Hinnant3e1b0422010-08-22 01:04:38 +000017
Howard Hinnantc51e1022010-05-11 19:42:16 +000018 <div class="submenu">
19 <label>libc++ Info</label>
20 <a href="/index.html">About</a>
21 </div>
22
23 <div class="submenu">
24 <label>Quick Links</label>
Chris Lattner3c9af342010-05-11 20:53:16 +000025 <a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">cfe-dev</a>
26 <a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits">cfe-commits</a>
Howard Hinnantc51e1022010-05-11 19:42:16 +000027 <a href="http://llvm.org/bugs/">Bug Reports</a>
Howard Hinnant00171852010-05-11 20:51:20 +000028 <a href="http://llvm.org/svn/llvm-project/libcxx/trunk/">Browse SVN</a>
29 <a href="http://llvm.org/viewvc/llvm-project/libcxx/trunk/">Browse ViewVC</a>
Howard Hinnantc51e1022010-05-11 19:42:16 +000030 </div>
31</div>
32
33<div id="content">
34 <!--*********************************************************************-->
35 <h1>"libc++" C++ Standard Library</h1>
36 <!--*********************************************************************-->
Howard Hinnant3e1b0422010-08-22 01:04:38 +000037
Howard Hinnantc51e1022010-05-11 19:42:16 +000038 <p>libc++ is a new implementation of the C++ standard library, targeting
Howard Hinnantd04724c2012-07-19 15:57:51 +000039 C++11.</p>
Howard Hinnantc51e1022010-05-11 19:42:16 +000040
Chris Lattner7b2aacc2010-11-16 21:40:19 +000041 <p>All of the code in libc++ is <a
42 href="http://llvm.org/docs/DeveloperPolicy.html#license">dual licensed</a>
43 under the MIT license and the UIUC License (a BSD-like license).</p>
Howard Hinnant3e1b0422010-08-22 01:04:38 +000044
Howard Hinnantc51e1022010-05-11 19:42:16 +000045 <!--=====================================================================-->
46 <h2 id="goals">Features and Goals</h2>
47 <!--=====================================================================-->
Howard Hinnant3e1b0422010-08-22 01:04:38 +000048
Howard Hinnantc51e1022010-05-11 19:42:16 +000049 <ul>
Howard Hinnantd04724c2012-07-19 15:57:51 +000050 <li>Correctness as defined by the C++11 standard.</li>
Howard Hinnantc51e1022010-05-11 19:42:16 +000051 <li>Fast execution.</li>
52 <li>Minimal memory use.</li>
53 <li>Fast compile times.</li>
54 <li>ABI compatibility with gcc's libstdc++ for some low-level features
55 such as exception objects, rtti and memory allocation.</li>
56 <li>Extensive unit tests.</li>
57 </ul>
58
59 <!--=====================================================================-->
Marshall Clowb6a04fe2012-11-14 16:31:15 +000060 <h2 id="why">Why a new C++ Standard Library for C++11?</h2>
Chris Lattnere2b07272010-05-12 22:21:15 +000061 <!--=====================================================================-->
Howard Hinnant3e1b0422010-08-22 01:04:38 +000062
Chris Lattnere2b07272010-05-12 22:21:15 +000063 <p>After its initial introduction, many people have asked "why start a new
64 library instead of contributing to an existing library?" (like Apache's
65 libstdcxx, GNU's libstdc++, STLport, etc). There are many contributing
66 reasons, but some of the major ones are:</p>
Howard Hinnant3e1b0422010-08-22 01:04:38 +000067
Chris Lattnere2b07272010-05-12 22:21:15 +000068 <ul>
69 <li><p>From years of experience (including having implemented the standard
70 library before), we've learned many things about implementing
71 the standard containers which require ABI breakage and fundamental changes
72 to how they are implemented. For example, it is generally accepted that
73 building std::string using the "short string optimization" instead of
74 using Copy On Write (COW) is a superior approach for multicore
Marshall Clowb6a04fe2012-11-14 16:31:15 +000075 machines (particularly in C++11, which has rvalue references). Breaking
Chris Lattnerc67061b2010-05-12 22:30:22 +000076 ABI compatibility with old versions of the library was
Chris Lattnere2b07272010-05-12 22:21:15 +000077 determined to be critical to achieving the performance goals of
78 libc++.</p></li>
Howard Hinnant3e1b0422010-08-22 01:04:38 +000079
Chris Lattnere2b07272010-05-12 22:21:15 +000080 <li><p>Mainline libstdc++ has switched to GPL3, a license which the developers
81 of libc++ cannot use. libstdc++ 4.2 (the last GPL2 version) could be
Marshall Clowb6a04fe2012-11-14 16:31:15 +000082 independently extended to support C++11, but this would be a fork of the
Chris Lattnere7bdfe62010-05-12 22:33:00 +000083 codebase (which is often seen as worse for a project than starting a new
84 independent one). Another problem with libstdc++ is that it is tightly
85 integrated with G++ development, tending to be tied fairly closely to the
86 matching version of G++.</p>
Chris Lattnere2b07272010-05-12 22:21:15 +000087 </li>
88
89 <li><p>STLport and the Apache libstdcxx library are two other popular
Marshall Clowb6a04fe2012-11-14 16:31:15 +000090 candidates, but both lack C++11 support. Our experience (and the
Howard Hinnantd04724c2012-07-19 15:57:51 +000091 experience of libstdc++ developers) is that adding support for C++11 (in
Chris Lattnere2b07272010-05-12 22:21:15 +000092 particular rvalue references and move-only types) requires changes to
93 almost every class and function, essentially amounting to a rewrite.
Chris Lattner48035ce2010-05-12 22:34:21 +000094 Faced with a rewrite, we decided to start from scratch and evaluate every
95 design decision from first principles based on experience.</p>
Howard Hinnant3e1b0422010-08-22 01:04:38 +000096
Chris Lattnere2b07272010-05-12 22:21:15 +000097 <p>Further, both projects are apparently abandoned: STLport 5.2.1 was
98 released in Oct'08, and STDCXX 4.2.1 in May'08.</p>
99
100 </ul>
101
102 <!--=====================================================================-->
Howard Hinnantc51e1022010-05-11 19:42:16 +0000103 <h2 id="requirements">Platform Support</h2>
104 <!--=====================================================================-->
105
Dan Albertce369362014-08-11 15:12:46 +0000106 <p>
107 libc++ is known to work on the following platforms, using g++-4.2 and
108 clang (lack of C++11 language support disables some functionality). Note
109 that functionality provided by &lt;atomic&gt; is only functional with
110 clang.
111 </p>
Howard Hinnantc51e1022010-05-11 19:42:16 +0000112
Dan Albertce369362014-08-11 15:12:46 +0000113 <ul>
114 <li>Mac OS X i386</li>
115 <li>Mac OS X x86_64</li>
116 <li>FreeBSD 10+ i386</li>
117 <li>FreeBSD 10+ x86_64</li>
118 <li>FreeBSD 10+ ARM</li>
119 </ul>
Howard Hinnantc51e1022010-05-11 19:42:16 +0000120
121 <!--=====================================================================-->
122 <h2 id="dir-structure">Current Status</h2>
123 <!--=====================================================================-->
124
Howard Hinnant09ce6822012-11-27 18:52:32 +0000125 <p>libc++ is a 100% complete C++11 implementation on Apple's OS X. </p>
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000126 <p>LLVM and Clang can self host in C++ and C++11 mode with libc++ on Linux.</p>
Marshall Clow979d36a2014-04-03 02:38:12 +0000127 <p>libc++ is also a 100% complete C++14 implementation. A list of new features and changes for
Marshall Clow6d44d712014-04-03 02:35:29 +0000128 C++14 can be found <a href="cxx1y_status.html">here</a>.</p>
Marshall Clow5ac35df2014-11-10 15:43:20 +0000129 <p>A list of features and changes for the next C++ standard, known here as
130 "C++1z" (probably to be C++17) can be found <a href="cxx1z_status.html">here</a>.</p>
Marshall Clowbbec82d2014-06-02 23:37:13 +0000131 <p>Implementation of the post-c++14 Technical Specifications is in progress. A list of features and
132 the current status of these features can be found <a href="ts1z_status.html">here</a>.</p>
Howard Hinnant2347d2f2011-09-28 15:44:39 +0000133 <p>
Howard Hinnante1a0abb2012-07-31 21:30:28 +0000134 Ports to other platforms are underway. Here are recent test
135 results for <a href="results.Windows.html">Windows</a>
136 and <a href="results.Linux.html">Linux</a>.
Howard Hinnant2347d2f2011-09-28 15:44:39 +0000137 </p>
138
Eric Fiselierdc770102014-08-18 05:25:04 +0000139 <!--======================================================================-->
140 <h2 id="dir-structure">Build Bots</h2>
141 <!--======================================================================-->
Eric Fiselierf4e7fc22014-12-09 22:53:21 +0000142 <p>The latest libc++ build results can be found at the following locations.</p>
Eric Fiselierdc770102014-08-18 05:25:04 +0000143 <ul>
Eric Fiselierf4e7fc22014-12-09 22:53:21 +0000144 <li><a href="http://lab.llvm.org:8011/console">
145 Buildbot libc++ builders
Eric Fiselierdc770102014-08-18 05:25:04 +0000146 </a></li>
Eric Fiselierf4e7fc22014-12-09 22:53:21 +0000147 <li><a href="http://lab.llvm.org:8080/green/view/Libcxx/">
148 Jenkins libc++ builders
Eric Fiselier7b7ef162014-10-16 02:48:59 +0000149 </a></li>
Eric Fiselierdc770102014-08-18 05:25:04 +0000150 </ul>
151
Howard Hinnantc51e1022010-05-11 19:42:16 +0000152 <!--=====================================================================-->
153 <h2>Get it and get involved!</h2>
154 <!--=====================================================================-->
Howard Hinnant3e1b0422010-08-22 01:04:38 +0000155
Howard Hinnantf0721aa2011-09-30 16:58:02 +0000156 <p>First please review our
157 <a href="http://llvm.org/docs/DeveloperPolicy.html">Developer's Policy</a>.
158
Howard Hinnantbec2fd52011-11-17 17:14:16 +0000159 <p>
Howard Hinnant79d6bcc2012-11-06 21:31:37 +0000160 On Mac OS 10.7 (Lion) and later, the easiest way to get this library is to install
Howard Hinnantbec2fd52011-11-17 17:14:16 +0000161 Xcode 4.2 or later. However if you want to install tip-of-trunk from here
Howard Hinnant961a7352012-04-03 15:08:42 +0000162 (getting the bleeding edge), read on. However, be warned that Mac OS
163 10.7 will not boot without a valid copy of <code>libc++.1.dylib</code> in
164 <code>/usr/lib</code>.
Howard Hinnantbec2fd52011-11-17 17:14:16 +0000165 </p>
166
Dan Albertce369362014-08-11 15:12:46 +0000167 <p>To check out the code, use:</p>
168
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000169 <ul>
Dan Albertce369362014-08-11 15:12:46 +0000170 <li><code>svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx</code></li>
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000171 </ul>
Dan Albertce369362014-08-11 15:12:46 +0000172
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000173 <p>
Dan Albertce369362014-08-11 15:12:46 +0000174 Note that for an in-tree build, you should check out libcxx to
175 llvm/projects.
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000176 </p>
177
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000178 <p>
Dan Albertce369362014-08-11 15:12:46 +0000179 The following instructions are for building libc++ on FreeBSD, Linux, or Mac
180 using <a href="http://libcxxabi.llvm.org/">libc++abi</a> as the C++ ABI
181 library. On Linux, it is also possible to use
182 <a href="#libsupcxx">libsupc++</a> or <a href="#libcxxrt">libcxxrt</a>.
183 </p>
184
185 <p>In-tree build:</p>
186 <ul>
187 <li>Check out libcxx and <a href="http://libcxxabi.llvm.org/">libcxxabi</a>
188 into llvm/projects</li>
189 <li><code>cd llvm</code></li>
190 <li><code>mkdir build &amp;&amp; cd build</code></li>
191 <li><code>cmake .. # Linux may require -DCMAKE_C_COMPILER=clang
192 -DCMAKE_CXX_COMPILER=clang++</code></li>
193 <li><code>make cxx</code></li>
194 </ul>
195
196 <p>Out-of-tree build:</p>
197 <ul>
198 <li>Check out libcxx</li>
199 <li>If not on a Mac, also check out
200 <a href="http://libcxxabi.llvm.org/">libcxxabi</a></li>
201 <li><code>cd libcxx</code></li>
202 <li><code>mkdir build &amp;&amp; cd build</code></li>
203 <li><code>cmake -DLIBCXX_CXX_ABI=libcxxabi
204 -DLIBCXX_LIBCXXABI_INCLUDE_PATHS=path/to/libcxxabi/include
205 -DLIT_EXECUTABLE=path/to/llvm/utils/lit/lit.py .. # Linux may require
206 -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++</code></li>
207 <li><code>make</code></li>
208 </ul>
209
210 <p>To run the tests:</p>
211 <ul>
212 <li><code>make check-libcxx</code></li>
213 </ul>
214
215 <p>If you wish to run a subset of the test suite:</p>
216 <ul>
217 <li><code>cd path/to/libcxx/libcxx</code></li>
218 <li><code>alias lit='python path/to/llvm/utils/lit/lit.py'</code></li>
219 <li><code>ln -s path/to/build/dir/projects/libcxx/test/lit.site.cfg
220 test/lit.site.cfg</code></li>
221 <li><code>lit -sv test/re/ # or whichever subset of tests you're interested
222 in</code></li>
223 </ul>
224 <p>The above is currently quite inconvenient. Sorry! We're working on it!</p>
225
226 <p>More information on using LIT can be found
227 <a href="http://llvm.org/docs/CommandGuide/lit.html">here</a>. For more
228 general information about the LLVM testing infrastructure, see the
229 <a href="http://llvm.org/docs/TestingGuide.html">LLVM Testing Infrastructure
230 Guide</a>
231 </p>
232
233 <p>
234 Shared libraries for libc++ should now be present in llvm/build/lib. Note
235 that it is safest to use this from its current location rather than
236 replacing your system's libc++ (if it has one, if not, go right ahead).
237 </p>
238
239 <p>
240 Mac users, remember to be careful when replacing the system's libc++.
241 <strong>Your system will not be able to boot without a funcioning
242 libc++.</strong>
243 </p>
244
245 <!--=====================================================================-->
246 <h3>Notes</h3>
247 <!--=====================================================================-->
248
249 <p>
250 Building libc++ with <code>-fno-rtti</code> is not supported. However
251 linking against it with <code>-fno-rtti</code> is supported.
252 </p>
253
254 <p>Send discussions to the
255 <a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">clang mailing list</a>.</p>
256
257 <!--=====================================================================-->
258 <h2>Using libc++ in your programs</h2>
259 <!--=====================================================================-->
260
261 <!--=====================================================================-->
262 <h3>FreeBSD and Mac OS X</h3>
263 <!--=====================================================================-->
264
265 <p>
266 To use your system-installed libc++ with clang you can:
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000267 </p>
268
269 <ul>
270 <li><code>clang++ -stdlib=libc++ test.cpp</code></li>
Howard Hinnantd04724c2012-07-19 15:57:51 +0000271 <li><code>clang++ -std=c++11 -stdlib=libc++ test.cpp</code></li>
Howard Hinnantc51e1022010-05-11 19:42:16 +0000272 </ul>
273
Howard Hinnant79d6bcc2012-11-06 21:31:37 +0000274 <p>
Dan Albertce369362014-08-11 15:12:46 +0000275 To use your tip-of-trunk libc++ on Mac OS with clang you can:
Howard Hinnant79d6bcc2012-11-06 21:31:37 +0000276 </p>
277
278 <ul>
Dan Albertce369362014-08-11 15:12:46 +0000279 <li><code>export DYLD_LIBRARY_PATH=path/to/build/lib</code>
Howard Hinnant79d6bcc2012-11-06 21:31:37 +0000280 <li><code>clang++ -std=c++11 -stdlib=libc++ -nostdinc++
281 -I&lt;path-to-libcxx&gt;/include -L&lt;path-to-libcxx&gt;/lib
282 test.cpp</code></li>
283 </ul>
284
Dan Albertce369362014-08-11 15:12:46 +0000285 <!--=====================================================================-->
286 <h3>Linux</h3>
287 <!--=====================================================================-->
288
289 <p>
290 You will need to keep the source tree of
291 <a href="http://libcxxabi.llvm.org">libc++abi</a> available on your build
292 machine and your copy of the libc++abi shared library must be placed where
293 your linker will find it.
294 </p>
295
296 <p>
297 Unfortunately you can't simply run clang with "-stdlib=libc++" at this
298 point, as clang is set up to link for libc++ linked to libsupc++. To get
299 around this you'll have to set up your linker yourself (or patch clang).
300 For example:
301 </p>
Howard Hinnantc51e1022010-05-11 19:42:16 +0000302
303 <ul>
Dan Albertce369362014-08-11 15:12:46 +0000304 <li><code>clang++ -stdlib=libc++ helloworld.cpp -nodefaultlibs -lc++ -lc++abi -lm -lc -lgcc_s -lgcc</code></li>
Howard Hinnantc51e1022010-05-11 19:42:16 +0000305 </ul>
306
Dan Albertce369362014-08-11 15:12:46 +0000307 <p>
308 Alternately, you could just add libc++abi to your libraries list, which in
309 most situations will give the same result:
310 </p>
Howard Hinnant24147cf2012-05-20 13:03:53 +0000311
Dan Albertce369362014-08-11 15:12:46 +0000312 <ul>
313 <li><code>clang++ -stdlib=libc++ helloworld.cpp -lc++abi</code></li>
314 </ul>
Howard Hinnantc5b02f22010-05-11 19:53:34 +0000315
Howard Hinnantbded6c92010-10-05 16:44:40 +0000316 <!--=====================================================================-->
Marshall Clowf7cc9a12014-04-03 03:13:12 +0000317 <h2>Bug reports and patches</h2>
318 <!--=====================================================================-->
319
320<p>
321If you think you've found a bug in libc++, please report it using
322the <a href="http://llvm.org/bugs">LLVM Bugzilla</a>. If you're not sure, you
Marshall Clowc15fec52014-04-07 07:28:33 +0000323can post a message to the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">cfe-dev</a>
Marshall Clowf7cc9a12014-04-03 03:13:12 +0000324mailing list or on IRC. Please include "libc++" in your subject.
325</p>
326
327<p>
328If you want to contribute a patch to libc++, the best place for that is the
329<a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits">cfe-commits</a>
330mailing list. Please include "libc++" and "PATCH" in your subject.
331</p>
332
333 <!--=====================================================================-->
Dan Albertce369362014-08-11 15:12:46 +0000334 <h2 id="libsupcxx">Build on Linux using CMake and libsupc++.</h2>
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000335 <!--=====================================================================-->
336
337 <p>
338 You will need libstdc++ in order to provide libsupc++.
339 </p>
340
341 <p>
342 Figure out where the libsupc++ headers are on your system. On Ubuntu this
343 is <code>/usr/include/c++/&lt;version&gt;</code> and
344 <code>/usr/include/c++/&lt;version&gt;/&lt;target-triple&gt;</code>
345 </p>
346
347 <p>
348 You can also figure this out by running
349 <pre>
350$ echo | g++ -Wp,-v -x c++ - -fsyntax-only
351ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
352ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../x86_64-linux-gnu/include"
353#include "..." search starts here:
354#include &lt;...&gt; search starts here:
355 /usr/include/c++/4.7
356 /usr/include/c++/4.7/x86_64-linux-gnu
357 /usr/include/c++/4.7/backward
358 /usr/lib/gcc/x86_64-linux-gnu/4.7/include
359 /usr/local/include
360 /usr/lib/gcc/x86_64-linux-gnu/4.7/include-fixed
361 /usr/include/x86_64-linux-gnu
362 /usr/include
363End of search list.
364 </pre>
365
366 Note the first two entries happen to be what we are looking for. This
367 may not be correct on other platforms.
368 </p>
369
370 <p>
371 We can now run CMake:
372 <ul>
373 <li><code>CC=clang CXX=clang++ cmake -G "Unix Makefiles"
Peter Collingbourne22dc63b2013-10-06 22:13:19 +0000374 -DLIBCXX_CXX_ABI=libstdc++
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000375 -DLIBCXX_LIBSUPCXX_INCLUDE_PATHS="/usr/include/c++/4.7/;/usr/include/c++/4.7/x86_64-linux-gnu/"
376 -DCMAKE_BUILD_TYPE=Release
377 -DCMAKE_INSTALL_PREFIX=/usr
378 &lt;libc++-source-dir&gt;</code></li>
Peter Collingbourne22dc63b2013-10-06 22:13:19 +0000379 <li>You can also substitute <code>-DLIBCXX_CXX_ABI=libsupc++</code>
380 above, which will cause the library to be linked to libsupc++ instead
381 of libstdc++, but this is only recommended if you know that you will
382 never need to link against libstdc++ in the same executable as libc++.
383 GCC ships libsupc++ separately but only as a static library. If a
384 program also needs to link against libstdc++, it will provide its
385 own copy of libsupc++ and this can lead to subtle problems.
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000386 <li><code>make</code></li>
387 <li><code>sudo make install</code></li>
388 </ul>
389 <p>
390 You can now run clang with -stdlib=libc++.
391 </p>
392 </p>
393
394 <!--=====================================================================-->
Dan Albertce369362014-08-11 15:12:46 +0000395 <h2 id="libcxxrt">Build on Linux using CMake and libcxxrt.</h2>
Howard Hinnant8d3824d2013-02-08 19:10:36 +0000396 <!--=====================================================================-->
397
398 <p>
399 You will need to keep the source tree of
400 <a href="https://github.com/pathscale/libcxxrt/">libcxxrt</a> available
401 on your build machine and your copy of the libcxxrt shared library must
402 be placed where your linker will find it.
403 </p>
404
405 <p>
406 We can now run CMake:
407 <ul>
408 <li><code>CC=clang CXX=clang++ cmake -G "Unix Makefiles"
409 -DLIBCXX_CXX_ABI=libcxxrt
Howard Hinnant727ff912013-02-26 16:27:55 +0000410 -DLIBCXX_LIBCXXRT_INCLUDE_PATHS="&lt;libcxxrt-source-dir&gt;/src"
Howard Hinnant8d3824d2013-02-08 19:10:36 +0000411 -DCMAKE_BUILD_TYPE=Release
412 -DCMAKE_INSTALL_PREFIX=/usr
413 &lt;libc++-source-dir&gt;</code></li>
414 <li><code>make</code></li>
415 <li><code>sudo make install</code></li>
416 </ul>
417 <p>
418 Unfortunately you can't simply run clang with "-stdlib=libc++" at this point, as
419 clang is set up to link for libc++ linked to libsupc++. To get around this
420 you'll have to set up your linker yourself (or patch clang). For example,
421 <ul>
422 <li><code>clang++ -stdlib=libc++ helloworld.cpp -nodefaultlibs -lc++ -lcxxrt -lm -lc -lgcc_s -lgcc</code></li>
423 </ul>
424 Alternately, you could just add libcxxrt to your libraries list, which in most
425 situations will give the same result:
426 <ul>
427 <li><code>clang++ -stdlib=libc++ helloworld.cpp -lcxxrt</code></li>
428 </ul>
429 </p>
430 </p>
431
432 <!--=====================================================================-->
Eric Fiselierf2348552014-10-18 01:15:17 +0000433 <h2 id="local-abi">Using a local ABI library</h2>
434 <!--=====================================================================-->
435 <p>
436 <strong>Note: This is not recommended in almost all cases.</strong><br>
437 Generally these instructions should only be used when you can't install
438 your ABI library.
439 </p>
440 <p>
441 Normally you must link libc++ against a ABI shared library that the
442 linker can find. If you want to build and test libc++ against an ABI
443 library not in the linker's path you need to set
Eric Fiseliere1b33602014-10-19 00:42:41 +0000444 <code>-DLIBCXX_CXX_ABI_LIBRARY_PATH=/path/to/abi/lib</code> when
445 configuring CMake.
Eric Fiselierf2348552014-10-18 01:15:17 +0000446 </p>
447 <p>
448 An example build using libc++abi would look like:
449 <ul>
450 <li><code>CC=clang CXX=clang++ cmake
451 -DLIBCXX_CXX_ABI=libc++abi
452 -DLIBCXX_LIBCXXABI_INCLUDE_PATHS="/path/to/libcxxabi/include"
Eric Fiseliere1b33602014-10-19 00:42:41 +0000453 -DLIBCXX_CXX_ABI_LIBRARY_PATH="/path/to/libcxxabi-build/lib"
Eric Fiselierf2348552014-10-18 01:15:17 +0000454 path/to/libcxx</code></li>
455 <li><code>make</code></li>
456 </ul>
457 </p>
458 <p>
459 When testing libc++ LIT will automatically link against the proper ABI
460 library.
461 </p>
462
463 <!--=====================================================================-->
Howard Hinnantbded6c92010-10-05 16:44:40 +0000464 <h2>Design Documents</h2>
465 <!--=====================================================================-->
466
467<ul>
468<li><a href="atomic_design.html"><tt>&lt;atomic&gt;</tt></a></li>
Howard Hinnante20b8de2010-11-19 01:38:58 +0000469<li><a href="type_traits_design.html"><tt>&lt;type_traits&gt;</tt></a></li>
Marshall Clow68aa6b42013-03-14 19:00:34 +0000470<li><a href="http://cplusplusmusings.wordpress.com/2012/07/05/clang-and-standard-libraries-on-mac-os-x/">Excellent notes by Marshall Clow</a></li>
Howard Hinnant57724c32013-03-14 18:37:48 +0000471<li><a href="debug_mode.html">Status of debug mode</a></li>
Howard Hinnantbded6c92010-10-05 16:44:40 +0000472</ul>
473
Howard Hinnantc51e1022010-05-11 19:42:16 +0000474</div>
475</body>
Chris Lattnere66f1e32010-05-11 20:37:52 +0000476</html>