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24 <label>Quick Links</label>
Chris Lattnera535ffd2010-05-11 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 Hinnantbc8d3f92010-05-11 19:42:16 +000027 <a href="http://llvm.org/bugs/">Bug Reports</a>
Howard Hinnant76e1ffc2010-05-11 20:51:20 +000028 <a href="http://llvm.org/svn/llvm-project/libcxx/trunk/">Browse SVN</a>
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34 <!--*********************************************************************-->
35 <h1>"libc++" C++ Standard Library</h1>
36 <!--*********************************************************************-->
Howard Hinnantd2bb0322010-08-22 01:04:38 +000037
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000038 <p>libc++ is a new implementation of the C++ standard library, targeting
Howard Hinnantaf347342012-07-19 15:57:51 +000039 C++11.</p>
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000040
Chris Lattnerf38bc6e2010-11-16 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 Hinnantd2bb0322010-08-22 01:04:38 +000044
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000045 <!--=====================================================================-->
46 <h2 id="goals">Features and Goals</h2>
47 <!--=====================================================================-->
Howard Hinnantd2bb0322010-08-22 01:04:38 +000048
Howard Hinnantbc8d3f92010-05-11 19:42:16 +000049 <ul>
Howard Hinnantaf347342012-07-19 15:57:51 +000050 <li>Correctness as defined by the C++11 standard.</li>
Howard Hinnantbc8d3f92010-05-11 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 Clowfaa17162012-11-14 16:31:15 +000060 <h2 id="why">Why a new C++ Standard Library for C++11?</h2>
Chris Lattner24173b82010-05-12 22:21:15 +000061 <!--=====================================================================-->
Howard Hinnantd2bb0322010-08-22 01:04:38 +000062
Chris Lattner24173b82010-05-12 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 Hinnantd2bb0322010-08-22 01:04:38 +000067
Chris Lattner24173b82010-05-12 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 Clowfaa17162012-11-14 16:31:15 +000075 machines (particularly in C++11, which has rvalue references). Breaking
Chris Lattnera5058d92010-05-12 22:30:22 +000076 ABI compatibility with old versions of the library was
Chris Lattner24173b82010-05-12 22:21:15 +000077 determined to be critical to achieving the performance goals of
78 libc++.</p></li>
Howard Hinnantd2bb0322010-08-22 01:04:38 +000079
Chris Lattner24173b82010-05-12 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 Clowfaa17162012-11-14 16:31:15 +000082 independently extended to support C++11, but this would be a fork of the
Chris Lattnerf3382492010-05-12 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 Lattner24173b82010-05-12 22:21:15 +000087 </li>
88
89 <li><p>STLport and the Apache libstdcxx library are two other popular
Marshall Clowfaa17162012-11-14 16:31:15 +000090 candidates, but both lack C++11 support. Our experience (and the
Howard Hinnantaf347342012-07-19 15:57:51 +000091 experience of libstdc++ developers) is that adding support for C++11 (in
Chris Lattner24173b82010-05-12 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 Lattnerbfa808e2010-05-12 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 Hinnantd2bb0322010-08-22 01:04:38 +000096
Chris Lattner24173b82010-05-12 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 Hinnantbc8d3f92010-05-11 19:42:16 +0000103 <h2 id="requirements">Platform Support</h2>
104 <!--=====================================================================-->
105
Dan Albert35d775d2014-08-11 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 Hinnantbc8d3f92010-05-11 19:42:16 +0000112
Dan Albert35d775d2014-08-11 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 Hinnantbc8d3f92010-05-11 19:42:16 +0000120
121 <!--=====================================================================-->
122 <h2 id="dir-structure">Current Status</h2>
123 <!--=====================================================================-->
124
Howard Hinnantb0895ff2012-11-27 18:52:32 +0000125 <p>libc++ is a 100% complete C++11 implementation on Apple's OS X. </p>
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000126 <p>LLVM and Clang can self host in C++ and C++11 mode with libc++ on Linux.</p>
Dan Alberte3eda9d2015-01-30 22:33:41 +0000127 <p>libc++ is also a 100% complete C++14 implementation. A list of new features and changes for
Marshall Clowe4915d92014-04-03 02:35:29 +0000128 C++14 can be found <a href="cxx1y_status.html">here</a>.</p>
Marshall Clow1e895c12014-11-10 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 Clowd2f0b5c2014-06-02 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 Hinnant0cbb3a12011-09-28 15:44:39 +0000133 <p>
Howard Hinnantee7a0bf2012-07-31 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 Hinnant0cbb3a12011-09-28 15:44:39 +0000137 </p>
138
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000139 <!--======================================================================-->
Dan Alberte3eda9d2015-01-30 22:33:41 +0000140 <h2 id="buildbots">Build Bots</h2>
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000141 <!--======================================================================-->
Eric Fiselier453a5002014-12-09 22:53:21 +0000142 <p>The latest libc++ build results can be found at the following locations.</p>
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000143 <ul>
Eric Fiselier453a5002014-12-09 22:53:21 +0000144 <li><a href="http://lab.llvm.org:8011/console">
145 Buildbot libc++ builders
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000146 </a></li>
Eric Fiselier453a5002014-12-09 22:53:21 +0000147 <li><a href="http://lab.llvm.org:8080/green/view/Libcxx/">
148 Jenkins libc++ builders
Eric Fiseliera43d1142014-10-16 02:48:59 +0000149 </a></li>
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000150 </ul>
151
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000152 <!--=====================================================================-->
153 <h2>Get it and get involved!</h2>
154 <!--=====================================================================-->
Howard Hinnantd2bb0322010-08-22 01:04:38 +0000155
Howard Hinnant2481cba2011-09-30 16:58:02 +0000156 <p>First please review our
157 <a href="http://llvm.org/docs/DeveloperPolicy.html">Developer's Policy</a>.
158
Howard Hinnant704f09b2011-11-17 17:14:16 +0000159 <p>
Howard Hinnant22b781b2012-11-06 21:31:37 +0000160 On Mac OS 10.7 (Lion) and later, the easiest way to get this library is to install
Howard Hinnant704f09b2011-11-17 17:14:16 +0000161 Xcode 4.2 or later. However if you want to install tip-of-trunk from here
Howard Hinnant271a1c02012-04-03 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 Hinnant704f09b2011-11-17 17:14:16 +0000165 </p>
166
Dan Albert35d775d2014-08-11 15:12:46 +0000167 <p>To check out the code, use:</p>
168
Howard Hinnant65451f12011-01-27 23:18:19 +0000169 <ul>
Dan Albert35d775d2014-08-11 15:12:46 +0000170 <li><code>svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx</code></li>
Howard Hinnant65451f12011-01-27 23:18:19 +0000171 </ul>
Dan Albert35d775d2014-08-11 15:12:46 +0000172
Howard Hinnant65451f12011-01-27 23:18:19 +0000173 <p>
Dan Albert35d775d2014-08-11 15:12:46 +0000174 Note that for an in-tree build, you should check out libcxx to
175 llvm/projects.
Howard Hinnant65451f12011-01-27 23:18:19 +0000176 </p>
177
Howard Hinnant65451f12011-01-27 23:18:19 +0000178 <p>
Dan Albert35d775d2014-08-11 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>
Eric Fiselier5514d362015-07-29 23:46:55 +0000189 <li><code>cd llvm</code></li>
Dan Albert35d775d2014-08-11 15:12:46 +0000190 <li><code>mkdir build &amp;&amp; cd build</code></li>
Eric Fiselier5514d362015-07-29 23:46:55 +0000191 <li><code>cmake .. # Linux may require -DCMAKE_C_COMPILER=clang
Dan Albert35d775d2014-08-11 15:12:46 +0000192 -DCMAKE_CXX_COMPILER=clang++</code></li>
193 <li><code>make cxx</code></li>
194 </ul>
195
Eric Fiselier5514d362015-07-29 23:46:55 +0000196 <p>Out-of-tree build:</p>
Dan Albert35d775d2014-08-11 15:12:46 +0000197 <ul>
Eric Fiselier5514d362015-07-29 23:46:55 +0000198 <li>Check out libcxx</li>
Dan Albert35d775d2014-08-11 15:12:46 +0000199 <li>If not on a Mac, also check out
200 <a href="http://libcxxabi.llvm.org/">libcxxabi</a></li>
Eric Fiselier5514d362015-07-29 23:46:55 +0000201 <li><code>cd libcxx</code></li>
Dan Albert35d775d2014-08-11 15:12:46 +0000202 <li><code>mkdir build &amp;&amp; cd build</code></li>
Eric Fiselier5514d362015-07-29 23:46:55 +0000203 <li><code>cmake -DLIBCXX_CXX_ABI=libcxxabi
Eric Fiselier02c24c12015-03-19 20:59:45 +0000204 -DLIBCXX_CXX_ABI_INCLUDE_PATHS=path/to/libcxxabi/include
Eric Fiselier5514d362015-07-29 23:46:55 +0000205 -DLIT_EXECUTABLE=path/to/llvm/utils/lit/lit.py .. # Linux may require
206 -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++</code></li>
Dan Albert35d775d2014-08-11 15:12:46 +0000207 <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 Fiselier4778eed2014-12-20 03:16:55 +0000219 <li><code>export
220 LIBCXX_SITE_CONFIG=path/to/build/dir/projects/libcxx/test/lit.site.cfg
221 </code></li>
Dan Albert35d775d2014-08-11 15:12:46 +0000222 <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 Roelofsd20675f2015-05-08 21:11:49 +0000242 <strong>Your system will not be able to boot without a functioning
Dan Albert35d775d2014-08-11 15:12:46 +0000243 libc++.</strong>
244 </p>
245
246 <!--=====================================================================-->
Eric Fiseliera5ad9ac2015-05-12 22:55:30 +0000247 <h3>Notes and Known Issues</h3>
Dan Albert35d775d2014-08-11 15:12:46 +0000248 <!--=====================================================================-->
249
250 <p>
Eric Fiseliera5ad9ac2015-05-12 22:55:30 +0000251 <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 Albert35d775d2014-08-11 15:12:46 +0000262 </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 Hinnant65451f12011-01-27 23:18:19 +0000277 </p>
278
279 <ul>
280 <li><code>clang++ -stdlib=libc++ test.cpp</code></li>
Howard Hinnantaf347342012-07-19 15:57:51 +0000281 <li><code>clang++ -std=c++11 -stdlib=libc++ test.cpp</code></li>
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000282 </ul>
283
Howard Hinnant22b781b2012-11-06 21:31:37 +0000284 <p>
Dan Albert35d775d2014-08-11 15:12:46 +0000285 To use your tip-of-trunk libc++ on Mac OS with clang you can:
Howard Hinnant22b781b2012-11-06 21:31:37 +0000286 </p>
287
288 <ul>
Dan Albert35d775d2014-08-11 15:12:46 +0000289 <li><code>export DYLD_LIBRARY_PATH=path/to/build/lib</code>
Howard Hinnant22b781b2012-11-06 21:31:37 +0000290 <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 Albert35d775d2014-08-11 15:12:46 +0000295 <!--=====================================================================-->
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 Hinnantbc8d3f92010-05-11 19:42:16 +0000312
313 <ul>
Dan Albert35d775d2014-08-11 15:12:46 +0000314 <li><code>clang++ -stdlib=libc++ helloworld.cpp -nodefaultlibs -lc++ -lc++abi -lm -lc -lgcc_s -lgcc</code></li>
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000315 </ul>
316
Dan Albert35d775d2014-08-11 15:12:46 +0000317 <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 Hinnant51065652012-05-20 13:03:53 +0000321
Dan Albert35d775d2014-08-11 15:12:46 +0000322 <ul>
323 <li><code>clang++ -stdlib=libc++ helloworld.cpp -lc++abi</code></li>
324 </ul>
Howard Hinnant8c217372010-05-11 19:53:34 +0000325
Howard Hinnant56f0d5b2010-10-05 16:44:40 +0000326 <!--=====================================================================-->
Marshall Clow992f9d52014-04-03 03:13:12 +0000327 <h2>Bug reports and patches</h2>
328 <!--=====================================================================-->
329
Dan Alberte3eda9d2015-01-30 22:33:41 +0000330 <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 Clow992f9d52014-04-03 03:13:12 +0000336
Dan Alberte3eda9d2015-01-30 22:33:41 +0000337 <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 Clow992f9d52014-04-03 03:13:12 +0000342
343 <!--=====================================================================-->
Dan Albert35d775d2014-08-11 15:12:46 +0000344 <h2 id="libsupcxx">Build on Linux using CMake and libsupc++.</h2>
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000345 <!--=====================================================================-->
346
347 <p>
348 You will need libstdc++ in order to provide libsupc++.
349 </p>
Dan Alberte3eda9d2015-01-30 22:33:41 +0000350
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000351 <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 Alberte3eda9d2015-01-30 22:33:41 +0000356
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000357 <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 Alberte3eda9d2015-01-30 22:33:41 +0000379
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000380 <p>
381 We can now run CMake:
382 <ul>
383 <li><code>CC=clang CXX=clang++ cmake -G "Unix Makefiles"
Peter Collingbourned0d308f2013-10-06 22:13:19 +0000384 -DLIBCXX_CXX_ABI=libstdc++
Eric Fiselier02c24c12015-03-19 20:59:45 +0000385 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="/usr/include/c++/4.7/;/usr/include/c++/4.7/x86_64-linux-gnu/"
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000386 -DCMAKE_BUILD_TYPE=Release
387 -DCMAKE_INSTALL_PREFIX=/usr
388 &lt;libc++-source-dir&gt;</code></li>
Peter Collingbourned0d308f2013-10-06 22:13:19 +0000389 <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. Spencerdb8a0302012-12-31 19:34:21 +0000396 <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 Albert35d775d2014-08-11 15:12:46 +0000405 <h2 id="libcxxrt">Build on Linux using CMake and libcxxrt.</h2>
Howard Hinnantaf4d1612013-02-08 19:10:36 +0000406 <!--=====================================================================-->
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 Alberte3eda9d2015-01-30 22:33:41 +0000414
Howard Hinnantaf4d1612013-02-08 19:10:36 +0000415 <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 Fiselier02c24c12015-03-19 20:59:45 +0000420 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="&lt;libcxxrt-source-dir&gt;/src"
Howard Hinnantaf4d1612013-02-08 19:10:36 +0000421 -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 Fiselier9071bc02014-10-18 01:15:17 +0000443 <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 Fiseliercb7e32c2014-10-19 00:42:41 +0000454 <code>-DLIBCXX_CXX_ABI_LIBRARY_PATH=/path/to/abi/lib</code> when
455 configuring CMake.
Eric Fiselier9071bc02014-10-18 01:15:17 +0000456 </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 Fiselier02c24c12015-03-19 20:59:45 +0000462 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="/path/to/libcxxabi/include"
Eric Fiseliercb7e32c2014-10-19 00:42:41 +0000463 -DLIBCXX_CXX_ABI_LIBRARY_PATH="/path/to/libcxxabi-build/lib"
Eric Fiselier9071bc02014-10-18 01:15:17 +0000464 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 Hinnant56f0d5b2010-10-05 16:44:40 +0000474 <h2>Design Documents</h2>
475 <!--=====================================================================-->
476
477<ul>
478<li><a href="atomic_design.html"><tt>&lt;atomic&gt;</tt></a></li>
Howard Hinnant9835d762010-11-19 01:38:58 +0000479<li><a href="type_traits_design.html"><tt>&lt;type_traits&gt;</tt></a></li>
Marshall Clowe47bc9b2013-03-14 19:00:34 +0000480<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 Hinnantc7cbe502013-03-14 18:37:48 +0000481<li><a href="debug_mode.html">Status of debug mode</a></li>
Eric Fiselier71dc14e2014-12-22 20:49:45 +0000482<li><a href="lit_usage.html">LIT usage guide</a></li>
Howard Hinnant56f0d5b2010-10-05 16:44:40 +0000483</ul>
484
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000485</div>
486</body>
Chris Lattner4b748952010-05-11 20:37:52 +0000487</html>