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Howard Hinnant3e1b0422010-08-22 01:04:38 +0000[diff] [blame]17
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]18 <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 +0000[diff] [blame]25 <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 +0000[diff] [blame]27 <a href="http://llvm.org/bugs/">Bug Reports</a>
Howard Hinnant00171852010-05-11 20:51:20 +0000[diff] [blame]28 <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 +0000[diff] [blame]30 </div>
31</div>
32
33<div id="content">
34 <!--*********************************************************************-->
35 <h1>"libc++" C++ Standard Library</h1>
36 <!--*********************************************************************-->
Howard Hinnant3e1b0422010-08-22 01:04:38 +0000[diff] [blame]37
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]38 <p>libc++ is a new implementation of the C++ standard library, targeting
Howard Hinnantd04724c2012-07-19 15:57:51 +0000[diff] [blame]39 C++11.</p>
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]40
Chris Lattner7b2aacc2010-11-16 21:40:19 +0000[diff] [blame]41 <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 +0000[diff] [blame]44
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]45 <!--=====================================================================-->
46 <h2 id="goals">Features and Goals</h2>
47 <!--=====================================================================-->
Howard Hinnant3e1b0422010-08-22 01:04:38 +0000[diff] [blame]48
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]49 <ul>
Howard Hinnantd04724c2012-07-19 15:57:51 +0000[diff] [blame]50 <li>Correctness as defined by the C++11 standard.</li>
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]51 <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 +0000[diff] [blame]60 <h2 id="why">Why a new C++ Standard Library for C++11?</h2>
Chris Lattnere2b07272010-05-12 22:21:15 +0000[diff] [blame]61 <!--=====================================================================-->
Howard Hinnant3e1b0422010-08-22 01:04:38 +0000[diff] [blame]62
Chris Lattnere2b07272010-05-12 22:21:15 +0000[diff] [blame]63 <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 +0000[diff] [blame]67
Chris Lattnere2b07272010-05-12 22:21:15 +0000[diff] [blame]68 <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 +0000[diff] [blame]75 machines (particularly in C++11, which has rvalue references). Breaking
Chris Lattnerc67061b2010-05-12 22:30:22 +0000[diff] [blame]76 ABI compatibility with old versions of the library was
Chris Lattnere2b07272010-05-12 22:21:15 +0000[diff] [blame]77 determined to be critical to achieving the performance goals of
78 libc++.</p></li>
Howard Hinnant3e1b0422010-08-22 01:04:38 +0000[diff] [blame]79
Chris Lattnere2b07272010-05-12 22:21:15 +0000[diff] [blame]80 <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 +0000[diff] [blame]82 independently extended to support C++11, but this would be a fork of the
Chris Lattnere7bdfe62010-05-12 22:33:00 +0000[diff] [blame]83 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 +0000[diff] [blame]87 </li>
88
89 <li><p>STLport and the Apache libstdcxx library are two other popular
Marshall Clowb6a04fe2012-11-14 16:31:15 +0000[diff] [blame]90 candidates, but both lack C++11 support. Our experience (and the
Howard Hinnantd04724c2012-07-19 15:57:51 +0000[diff] [blame]91 experience of libstdc++ developers) is that adding support for C++11 (in
Chris Lattnere2b07272010-05-12 22:21:15 +0000[diff] [blame]92 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 +0000[diff] [blame]94 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 +0000[diff] [blame]96
Chris Lattnere2b07272010-05-12 22:21:15 +0000[diff] [blame]97 <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 +0000[diff] [blame]103 <h2 id="requirements">Platform Support</h2>
104 <!--=====================================================================-->
105
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]106 <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 +0000[diff] [blame]112
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]113 <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 +0000[diff] [blame]120
121 <!--=====================================================================-->
122 <h2 id="dir-structure">Current Status</h2>
123 <!--=====================================================================-->
124
Howard Hinnant09ce6822012-11-27 18:52:32 +0000[diff] [blame]125 <p>libc++ is a 100% complete C++11 implementation on Apple's OS X. </p>
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000[diff] [blame]126 <p>LLVM and Clang can self host in C++ and C++11 mode with libc++ on Linux.</p>
Dan Albert66ddf1f2015-01-30 22:33:41 +0000[diff] [blame]127 <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 +0000[diff] [blame]128 C++14 can be found <a href="cxx1y_status.html">here</a>.</p>
Marshall Clow5ac35df2014-11-10 15:43:20 +0000[diff] [blame]129 <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 +0000[diff] [blame]131 <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 +0000[diff] [blame]133 <p>
Howard Hinnante1a0abb2012-07-31 21:30:28 +0000[diff] [blame]134 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 +0000[diff] [blame]137 </p>
138
Eric Fiselierdc770102014-08-18 05:25:04 +0000[diff] [blame]139 <!--======================================================================-->
Dan Albert66ddf1f2015-01-30 22:33:41 +0000[diff] [blame]140 <h2 id="buildbots">Build Bots</h2>
Eric Fiselierdc770102014-08-18 05:25:04 +0000[diff] [blame]141 <!--======================================================================-->
Eric Fiselierf4e7fc22014-12-09 22:53:21 +0000[diff] [blame]142 <p>The latest libc++ build results can be found at the following locations.</p>
Eric Fiselierdc770102014-08-18 05:25:04 +0000[diff] [blame]143 <ul>
Eric Fiselierf4e7fc22014-12-09 22:53:21 +0000[diff] [blame]144 <li><a href="http://lab.llvm.org:8011/console">
145 Buildbot libc++ builders
Eric Fiselierdc770102014-08-18 05:25:04 +0000[diff] [blame]146 </a></li>
Eric Fiselierf4e7fc22014-12-09 22:53:21 +0000[diff] [blame]147 <li><a href="http://lab.llvm.org:8080/green/view/Libcxx/">
148 Jenkins libc++ builders
Eric Fiselier7b7ef162014-10-16 02:48:59 +0000[diff] [blame]149 </a></li>
Eric Fiselierdc770102014-08-18 05:25:04 +0000[diff] [blame]150 </ul>
151
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]152 <!--=====================================================================-->
153 <h2>Get it and get involved!</h2>
154 <!--=====================================================================-->
Howard Hinnant3e1b0422010-08-22 01:04:38 +0000[diff] [blame]155
Howard Hinnantf0721aa2011-09-30 16:58:02 +0000[diff] [blame]156 <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 +0000[diff] [blame]159 <p>
Howard Hinnant79d6bcc2012-11-06 21:31:37 +0000[diff] [blame]160 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 +0000[diff] [blame]161 Xcode 4.2 or later. However if you want to install tip-of-trunk from here
Howard Hinnant961a7352012-04-03 15:08:42 +0000[diff] [blame]162 (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 +0000[diff] [blame]165 </p>
166
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]167 <p>To check out the code, use:</p>
168
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000[diff] [blame]169 <ul>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]170 <li><code>svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx</code></li>
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000[diff] [blame]171 </ul>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]172
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000[diff] [blame]173 <p>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]174 Note that for an in-tree build, you should check out libcxx to
175 llvm/projects.
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000[diff] [blame]176 </p>
177
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000[diff] [blame]178 <p>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]179 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
Eric Fiselier828d6c42015-03-19 20:59:45 +0000[diff] [blame]204 -DLIBCXX_CXX_ABI_INCLUDE_PATHS=path/to/libcxxabi/include
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]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>
Eric Fiselier26dcc932014-12-20 03:16:55 +0000[diff] [blame]219 <li><code>export
220 LIBCXX_SITE_CONFIG=path/to/build/dir/projects/libcxx/test/lit.site.cfg
221 </code></li>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]222 <li><code>lit -sv test/re/ # or whichever subset of tests you're interested
223 in</code></li>
224 </ul>
225 <p>The above is currently quite inconvenient. Sorry! We're working on it!</p>
226
227 <p>More information on using LIT can be found
228 <a href="http://llvm.org/docs/CommandGuide/lit.html">here</a>. For more
229 general information about the LLVM testing infrastructure, see the
230 <a href="http://llvm.org/docs/TestingGuide.html">LLVM Testing Infrastructure
231 Guide</a>
232 </p>
233
234 <p>
235 Shared libraries for libc++ should now be present in llvm/build/lib. Note
236 that it is safest to use this from its current location rather than
237 replacing your system's libc++ (if it has one, if not, go right ahead).
238 </p>
239
240 <p>
241 Mac users, remember to be careful when replacing the system's libc++.
Jonathan Roelofsc52d50a2015-05-08 21:11:49 +0000[diff] [blame]242 <strong>Your system will not be able to boot without a functioning
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]243 libc++.</strong>
244 </p>
245
246 <!--=====================================================================-->
Eric Fiselier24186c72015-05-12 22:55:30 +0000[diff] [blame^]247 <h3>Notes and Known Issues</h3>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]248 <!--=====================================================================-->
249
250 <p>
Eric Fiselier24186c72015-05-12 22:55:30 +0000[diff] [blame^]251 <ul>
252 <li>
253 Building libc++ with <code>-fno-rtti</code> is not supported. However
254 linking against it with <code>-fno-rtti</code> is supported.
255 </li>
256 <li>
257 On OS X v10.8 and older the CMake option
258 <code>-DLIBCXX_LIBCPPABI_VERSION=""</code> must be used during
259 configuration.
260 </li>
261 </ul>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]262 </p>
263
264 <p>Send discussions to the
265 <a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">clang mailing list</a>.</p>
266
267 <!--=====================================================================-->
268 <h2>Using libc++ in your programs</h2>
269 <!--=====================================================================-->
270
271 <!--=====================================================================-->
272 <h3>FreeBSD and Mac OS X</h3>
273 <!--=====================================================================-->
274
275 <p>
276 To use your system-installed libc++ with clang you can:
Howard Hinnantefc7aa22011-01-27 23:18:19 +0000[diff] [blame]277 </p>
278
279 <ul>
280 <li><code>clang++ -stdlib=libc++ test.cpp</code></li>
Howard Hinnantd04724c2012-07-19 15:57:51 +0000[diff] [blame]281 <li><code>clang++ -std=c++11 -stdlib=libc++ test.cpp</code></li>
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]282 </ul>
283
Howard Hinnant79d6bcc2012-11-06 21:31:37 +0000[diff] [blame]284 <p>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]285 To use your tip-of-trunk libc++ on Mac OS with clang you can:
Howard Hinnant79d6bcc2012-11-06 21:31:37 +0000[diff] [blame]286 </p>
287
288 <ul>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]289 <li><code>export DYLD_LIBRARY_PATH=path/to/build/lib</code>
Howard Hinnant79d6bcc2012-11-06 21:31:37 +0000[diff] [blame]290 <li><code>clang++ -std=c++11 -stdlib=libc++ -nostdinc++
291 -I&lt;path-to-libcxx&gt;/include -L&lt;path-to-libcxx&gt;/lib
292 test.cpp</code></li>
293 </ul>
294
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]295 <!--=====================================================================-->
296 <h3>Linux</h3>
297 <!--=====================================================================-->
298
299 <p>
300 You will need to keep the source tree of
301 <a href="http://libcxxabi.llvm.org">libc++abi</a> available on your build
302 machine and your copy of the libc++abi shared library must be placed where
303 your linker will find it.
304 </p>
305
306 <p>
307 Unfortunately you can't simply run clang with "-stdlib=libc++" at this
308 point, as clang is set up to link for libc++ linked to libsupc++. To get
309 around this you'll have to set up your linker yourself (or patch clang).
310 For example:
311 </p>
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]312
313 <ul>
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]314 <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 +0000[diff] [blame]315 </ul>
316
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]317 <p>
318 Alternately, you could just add libc++abi to your libraries list, which in
319 most situations will give the same result:
320 </p>
Howard Hinnant24147cf2012-05-20 13:03:53 +0000[diff] [blame]321
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]322 <ul>
323 <li><code>clang++ -stdlib=libc++ helloworld.cpp -lc++abi</code></li>
324 </ul>
Howard Hinnantc5b02f22010-05-11 19:53:34 +0000[diff] [blame]325
Howard Hinnantbded6c92010-10-05 16:44:40 +0000[diff] [blame]326 <!--=====================================================================-->
Marshall Clowf7cc9a12014-04-03 03:13:12 +0000[diff] [blame]327 <h2>Bug reports and patches</h2>
328 <!--=====================================================================-->
329
Dan Albert66ddf1f2015-01-30 22:33:41 +0000[diff] [blame]330 <p>
331 If you think you've found a bug in libc++, please report it using
332 the <a href="http://llvm.org/bugs">LLVM Bugzilla</a>. If you're not sure, you
333 can post a message to the <a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">cfe-dev</a>
334 mailing list or on IRC. Please include "libc++" in your subject.
335 </p>
Marshall Clowf7cc9a12014-04-03 03:13:12 +0000[diff] [blame]336
Dan Albert66ddf1f2015-01-30 22:33:41 +0000[diff] [blame]337 <p>
338 If you want to contribute a patch to libc++, the best place for that is
339 <a href="http://llvm.org/docs/Phabricator.html">Phabricator</a>. Please
340 include [libc++] in the subject and add cfe-commits as a subscriber.
341 </p>
Marshall Clowf7cc9a12014-04-03 03:13:12 +0000[diff] [blame]342
343 <!--=====================================================================-->
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]344 <h2 id="libsupcxx">Build on Linux using CMake and libsupc++.</h2>
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000[diff] [blame]345 <!--=====================================================================-->
346
347 <p>
348 You will need libstdc++ in order to provide libsupc++.
349 </p>
Dan Albert66ddf1f2015-01-30 22:33:41 +0000[diff] [blame]350
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000[diff] [blame]351 <p>
352 Figure out where the libsupc++ headers are on your system. On Ubuntu this
353 is <code>/usr/include/c++/&lt;version&gt;</code> and
354 <code>/usr/include/c++/&lt;version&gt;/&lt;target-triple&gt;</code>
355 </p>
Dan Albert66ddf1f2015-01-30 22:33:41 +0000[diff] [blame]356
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000[diff] [blame]357 <p>
358 You can also figure this out by running
359 <pre>
360$ echo | g++ -Wp,-v -x c++ - -fsyntax-only
361ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
362ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../x86_64-linux-gnu/include"
363#include "..." search starts here:
364#include &lt;...&gt; search starts here:
365 /usr/include/c++/4.7
366 /usr/include/c++/4.7/x86_64-linux-gnu
367 /usr/include/c++/4.7/backward
368 /usr/lib/gcc/x86_64-linux-gnu/4.7/include
369 /usr/local/include
370 /usr/lib/gcc/x86_64-linux-gnu/4.7/include-fixed
371 /usr/include/x86_64-linux-gnu
372 /usr/include
373End of search list.
374 </pre>
375
376 Note the first two entries happen to be what we are looking for. This
377 may not be correct on other platforms.
378 </p>
Dan Albert66ddf1f2015-01-30 22:33:41 +0000[diff] [blame]379
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000[diff] [blame]380 <p>
381 We can now run CMake:
382 <ul>
383 <li><code>CC=clang CXX=clang++ cmake -G "Unix Makefiles"
Peter Collingbourne22dc63b2013-10-06 22:13:19 +0000[diff] [blame]384 -DLIBCXX_CXX_ABI=libstdc++
Eric Fiselier828d6c42015-03-19 20:59:45 +0000[diff] [blame]385 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="/usr/include/c++/4.7/;/usr/include/c++/4.7/x86_64-linux-gnu/"
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000[diff] [blame]386 -DCMAKE_BUILD_TYPE=Release
387 -DCMAKE_INSTALL_PREFIX=/usr
388 &lt;libc++-source-dir&gt;</code></li>
Peter Collingbourne22dc63b2013-10-06 22:13:19 +0000[diff] [blame]389 <li>You can also substitute <code>-DLIBCXX_CXX_ABI=libsupc++</code>
390 above, which will cause the library to be linked to libsupc++ instead
391 of libstdc++, but this is only recommended if you know that you will
392 never need to link against libstdc++ in the same executable as libc++.
393 GCC ships libsupc++ separately but only as a static library. If a
394 program also needs to link against libstdc++, it will provide its
395 own copy of libsupc++ and this can lead to subtle problems.
Michael J. Spencera86f97e2012-12-31 19:34:21 +0000[diff] [blame]396 <li><code>make</code></li>
397 <li><code>sudo make install</code></li>
398 </ul>
399 <p>
400 You can now run clang with -stdlib=libc++.
401 </p>
402 </p>
403
404 <!--=====================================================================-->
Dan Albertce369362014-08-11 15:12:46 +0000[diff] [blame]405 <h2 id="libcxxrt">Build on Linux using CMake and libcxxrt.</h2>
Howard Hinnant8d3824d2013-02-08 19:10:36 +0000[diff] [blame]406 <!--=====================================================================-->
407
408 <p>
409 You will need to keep the source tree of
410 <a href="https://github.com/pathscale/libcxxrt/">libcxxrt</a> available
411 on your build machine and your copy of the libcxxrt shared library must
412 be placed where your linker will find it.
413 </p>
Dan Albert66ddf1f2015-01-30 22:33:41 +0000[diff] [blame]414
Howard Hinnant8d3824d2013-02-08 19:10:36 +0000[diff] [blame]415 <p>
416 We can now run CMake:
417 <ul>
418 <li><code>CC=clang CXX=clang++ cmake -G "Unix Makefiles"
419 -DLIBCXX_CXX_ABI=libcxxrt
Eric Fiselier828d6c42015-03-19 20:59:45 +0000[diff] [blame]420 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="&lt;libcxxrt-source-dir&gt;/src"
Howard Hinnant8d3824d2013-02-08 19:10:36 +0000[diff] [blame]421 -DCMAKE_BUILD_TYPE=Release
422 -DCMAKE_INSTALL_PREFIX=/usr
423 &lt;libc++-source-dir&gt;</code></li>
424 <li><code>make</code></li>
425 <li><code>sudo make install</code></li>
426 </ul>
427 <p>
428 Unfortunately you can't simply run clang with "-stdlib=libc++" at this point, as
429 clang is set up to link for libc++ linked to libsupc++. To get around this
430 you'll have to set up your linker yourself (or patch clang). For example,
431 <ul>
432 <li><code>clang++ -stdlib=libc++ helloworld.cpp -nodefaultlibs -lc++ -lcxxrt -lm -lc -lgcc_s -lgcc</code></li>
433 </ul>
434 Alternately, you could just add libcxxrt to your libraries list, which in most
435 situations will give the same result:
436 <ul>
437 <li><code>clang++ -stdlib=libc++ helloworld.cpp -lcxxrt</code></li>
438 </ul>
439 </p>
440 </p>
441
442 <!--=====================================================================-->
Eric Fiselierf2348552014-10-18 01:15:17 +0000[diff] [blame]443 <h2 id="local-abi">Using a local ABI library</h2>
444 <!--=====================================================================-->
445 <p>
446 <strong>Note: This is not recommended in almost all cases.</strong><br>
447 Generally these instructions should only be used when you can't install
448 your ABI library.
449 </p>
450 <p>
451 Normally you must link libc++ against a ABI shared library that the
452 linker can find. If you want to build and test libc++ against an ABI
453 library not in the linker's path you need to set
Eric Fiseliere1b33602014-10-19 00:42:41 +0000[diff] [blame]454 <code>-DLIBCXX_CXX_ABI_LIBRARY_PATH=/path/to/abi/lib</code> when
455 configuring CMake.
Eric Fiselierf2348552014-10-18 01:15:17 +0000[diff] [blame]456 </p>
457 <p>
458 An example build using libc++abi would look like:
459 <ul>
460 <li><code>CC=clang CXX=clang++ cmake
461 -DLIBCXX_CXX_ABI=libc++abi
Eric Fiselier828d6c42015-03-19 20:59:45 +0000[diff] [blame]462 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="/path/to/libcxxabi/include"
Eric Fiseliere1b33602014-10-19 00:42:41 +0000[diff] [blame]463 -DLIBCXX_CXX_ABI_LIBRARY_PATH="/path/to/libcxxabi-build/lib"
Eric Fiselierf2348552014-10-18 01:15:17 +0000[diff] [blame]464 path/to/libcxx</code></li>
465 <li><code>make</code></li>
466 </ul>
467 </p>
468 <p>
469 When testing libc++ LIT will automatically link against the proper ABI
470 library.
471 </p>
472
473 <!--=====================================================================-->
Howard Hinnantbded6c92010-10-05 16:44:40 +0000[diff] [blame]474 <h2>Design Documents</h2>
475 <!--=====================================================================-->
476
477<ul>
478<li><a href="atomic_design.html"><tt>&lt;atomic&gt;</tt></a></li>
Howard Hinnante20b8de2010-11-19 01:38:58 +0000[diff] [blame]479<li><a href="type_traits_design.html"><tt>&lt;type_traits&gt;</tt></a></li>
Marshall Clow68aa6b42013-03-14 19:00:34 +0000[diff] [blame]480<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 +0000[diff] [blame]481<li><a href="debug_mode.html">Status of debug mode</a></li>
Eric Fiselierab2e73d2014-12-22 20:49:45 +0000[diff] [blame]482<li><a href="lit_usage.html">LIT usage guide</a></li>
Howard Hinnantbded6c92010-10-05 16:44:40 +0000[diff] [blame]483</ul>
484
Howard Hinnantc51e1022010-05-11 19:42:16 +0000[diff] [blame]485</div>
486</body>
Chris Lattnere66f1e32010-05-11 20:37:52 +0000[diff] [blame]487</html>