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15 <a href="http://llvm.org/">LLVM Home</a>
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Howard Hinnant2807d4a2010-08-22 01:04:38 +0000[diff] [blame]17
Howard Hinnant3e519522010-05-11 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 Lattnerf9e7e3a2010-05-11 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 Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]27 <a href="http://llvm.org/bugs/">Bug Reports</a>
Howard Hinnant38a59272010-05-11 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 Hinnant3e519522010-05-11 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 Hinnant2807d4a2010-08-22 01:04:38 +0000[diff] [blame]37
Howard Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]38 <p>libc++ is a new implementation of the C++ standard library, targeting
Howard Hinnant51eb2ad2012-07-19 15:57:51 +0000[diff] [blame]39 C++11.</p>
Howard Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]40
Chris Lattner58dffe62010-11-16 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 Hinnant2807d4a2010-08-22 01:04:38 +0000[diff] [blame]44
Howard Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]45 <!--=====================================================================-->
46 <h2 id="goals">Features and Goals</h2>
47 <!--=====================================================================-->
Howard Hinnant2807d4a2010-08-22 01:04:38 +0000[diff] [blame]48
Howard Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]49 <ul>
Howard Hinnant51eb2ad2012-07-19 15:57:51 +0000[diff] [blame]50 <li>Correctness as defined by the C++11 standard.</li>
Howard Hinnant3e519522010-05-11 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 Clow497d9d22012-11-14 16:31:15 +0000[diff] [blame]60 <h2 id="why">Why a new C++ Standard Library for C++11?</h2>
Chris Lattner27de3d62010-05-12 22:21:15 +0000[diff] [blame]61 <!--=====================================================================-->
Howard Hinnant2807d4a2010-08-22 01:04:38 +0000[diff] [blame]62
Chris Lattner27de3d62010-05-12 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 Hinnant2807d4a2010-08-22 01:04:38 +0000[diff] [blame]67
Chris Lattner27de3d62010-05-12 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 Clow497d9d22012-11-14 16:31:15 +0000[diff] [blame]75 machines (particularly in C++11, which has rvalue references). Breaking
Chris Lattnerf005e8d2010-05-12 22:30:22 +0000[diff] [blame]76 ABI compatibility with old versions of the library was
Chris Lattner27de3d62010-05-12 22:21:15 +0000[diff] [blame]77 determined to be critical to achieving the performance goals of
78 libc++.</p></li>
Howard Hinnant2807d4a2010-08-22 01:04:38 +0000[diff] [blame]79
Chris Lattner27de3d62010-05-12 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 Clow497d9d22012-11-14 16:31:15 +0000[diff] [blame]82 independently extended to support C++11, but this would be a fork of the
Chris Lattnera940b5b2010-05-12 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 Lattner27de3d62010-05-12 22:21:15 +0000[diff] [blame]87 </li>
88
89 <li><p>STLport and the Apache libstdcxx library are two other popular
Marshall Clow497d9d22012-11-14 16:31:15 +0000[diff] [blame]90 candidates, but both lack C++11 support. Our experience (and the
Howard Hinnant51eb2ad2012-07-19 15:57:51 +0000[diff] [blame]91 experience of libstdc++ developers) is that adding support for C++11 (in
Chris Lattner27de3d62010-05-12 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 Lattnerd55fd112010-05-12 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 Hinnant2807d4a2010-08-22 01:04:38 +0000[diff] [blame]96
Chris Lattner27de3d62010-05-12 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 Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]103 <h2 id="requirements">Platform Support</h2>
104 <!--=====================================================================-->
105
Dan Albertec4de782014-08-11 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 Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]112
Dan Albertec4de782014-08-11 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 Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]120
121 <!--=====================================================================-->
122 <h2 id="dir-structure">Current Status</h2>
123 <!--=====================================================================-->
124
Howard Hinnant6852b552012-11-27 18:52:32 +0000[diff] [blame]125 <p>libc++ is a 100% complete C++11 implementation on Apple's OS X. </p>
Michael J. Spencerbb8cfd02012-12-31 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 Albert2477bed2015-01-30 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 Clowca6e3662014-04-03 02:35:29 +0000[diff] [blame]128 C++14 can be found <a href="cxx1y_status.html">here</a>.</p>
Marshall Clow68640682014-11-10 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 Clowf39d9142014-06-02 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 Hinnantd7aac282011-09-28 15:44:39 +0000[diff] [blame]133 <p>
Howard Hinnant8eb04fe2012-07-31 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 Hinnantd7aac282011-09-28 15:44:39 +0000[diff] [blame]137 </p>
138
Eric Fiseliercd6ac3a2014-08-18 05:25:04 +0000[diff] [blame]139 <!--======================================================================-->
Dan Albert2477bed2015-01-30 22:33:41 +0000[diff] [blame]140 <h2 id="buildbots">Build Bots</h2>
Eric Fiseliercd6ac3a2014-08-18 05:25:04 +0000[diff] [blame]141 <!--======================================================================-->
Eric Fiselierf60e4412014-12-09 22:53:21 +0000[diff] [blame]142 <p>The latest libc++ build results can be found at the following locations.</p>
Eric Fiseliercd6ac3a2014-08-18 05:25:04 +0000[diff] [blame]143 <ul>
Eric Fiselierf60e4412014-12-09 22:53:21 +0000[diff] [blame]144 <li><a href="http://lab.llvm.org:8011/console">
145 Buildbot libc++ builders
Eric Fiseliercd6ac3a2014-08-18 05:25:04 +0000[diff] [blame]146 </a></li>
Eric Fiselierf60e4412014-12-09 22:53:21 +0000[diff] [blame]147 <li><a href="http://lab.llvm.org:8080/green/view/Libcxx/">
148 Jenkins libc++ builders
Eric Fiselier8c5bc1c2014-10-16 02:48:59 +0000[diff] [blame]149 </a></li>
Eric Fiseliercd6ac3a2014-08-18 05:25:04 +0000[diff] [blame]150 </ul>
151
Howard Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]152 <!--=====================================================================-->
153 <h2>Get it and get involved!</h2>
154 <!--=====================================================================-->
Howard Hinnant2807d4a2010-08-22 01:04:38 +0000[diff] [blame]155
Howard Hinnant4f4d3102011-09-30 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 Hinnant73191602011-11-17 17:14:16 +0000[diff] [blame]159 <p>
Howard Hinnant1c8358c2012-11-06 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 Hinnant73191602011-11-17 17:14:16 +0000[diff] [blame]161 Xcode 4.2 or later. However if you want to install tip-of-trunk from here
Howard Hinnant6e3e78a2012-04-03 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 Hinnant73191602011-11-17 17:14:16 +0000[diff] [blame]165 </p>
166
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]167 <p>To check out the code, use:</p>
168
Howard Hinnante4de2792011-01-27 23:18:19 +0000[diff] [blame]169 <ul>
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]170 <li><code>svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx</code></li>
Howard Hinnante4de2792011-01-27 23:18:19 +0000[diff] [blame]171 </ul>
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]172
Howard Hinnante4de2792011-01-27 23:18:19 +0000[diff] [blame]173 <p>
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]174 Note that for an in-tree build, you should check out libcxx to
175 llvm/projects.
Howard Hinnante4de2792011-01-27 23:18:19 +0000[diff] [blame]176 </p>
177
Howard Hinnante4de2792011-01-27 23:18:19 +0000[diff] [blame]178 <p>
Dan Albertec4de782014-08-11 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 Fiselier237b6ed2015-03-19 20:59:45 +0000[diff] [blame]204 -DLIBCXX_CXX_ABI_INCLUDE_PATHS=path/to/libcxxabi/include
Dan Albertec4de782014-08-11 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 Fiseliera78a2672014-12-20 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 Albertec4de782014-08-11 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 Roelofs19928342015-05-08 21:11:49 +0000[diff] [blame]242 <strong>Your system will not be able to boot without a functioning
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]243 libc++.</strong>
244 </p>
245
246 <!--=====================================================================-->
Eric Fiselier9243c762015-05-12 22:55:30 +0000[diff] [blame^]247 <h3>Notes and Known Issues</h3>
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]248 <!--=====================================================================-->
249
250 <p>
Eric Fiselier9243c762015-05-12 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 Albertec4de782014-08-11 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 Hinnante4de2792011-01-27 23:18:19 +0000[diff] [blame]277 </p>
278
279 <ul>
280 <li><code>clang++ -stdlib=libc++ test.cpp</code></li>
Howard Hinnant51eb2ad2012-07-19 15:57:51 +0000[diff] [blame]281 <li><code>clang++ -std=c++11 -stdlib=libc++ test.cpp</code></li>
Howard Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]282 </ul>
283
Howard Hinnant1c8358c2012-11-06 21:31:37 +0000[diff] [blame]284 <p>
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]285 To use your tip-of-trunk libc++ on Mac OS with clang you can:
Howard Hinnant1c8358c2012-11-06 21:31:37 +0000[diff] [blame]286 </p>
287
288 <ul>
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]289 <li><code>export DYLD_LIBRARY_PATH=path/to/build/lib</code>
Howard Hinnant1c8358c2012-11-06 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 Albertec4de782014-08-11 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 Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]312
313 <ul>
Dan Albertec4de782014-08-11 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 Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]315 </ul>
316
Dan Albertec4de782014-08-11 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 Hinnant49c3b202012-05-20 13:03:53 +0000[diff] [blame]321
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]322 <ul>
323 <li><code>clang++ -stdlib=libc++ helloworld.cpp -lc++abi</code></li>
324 </ul>
Howard Hinnant180e1d72010-05-11 19:53:34 +0000[diff] [blame]325
Howard Hinnant1de22662010-10-05 16:44:40 +0000[diff] [blame]326 <!--=====================================================================-->
Marshall Clow17c6aa02014-04-03 03:13:12 +0000[diff] [blame]327 <h2>Bug reports and patches</h2>
328 <!--=====================================================================-->
329
Dan Albert2477bed2015-01-30 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 Clow17c6aa02014-04-03 03:13:12 +0000[diff] [blame]336
Dan Albert2477bed2015-01-30 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 Clow17c6aa02014-04-03 03:13:12 +0000[diff] [blame]342
343 <!--=====================================================================-->
Dan Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]344 <h2 id="libsupcxx">Build on Linux using CMake and libsupc++.</h2>
Michael J. Spencerbb8cfd02012-12-31 19:34:21 +0000[diff] [blame]345 <!--=====================================================================-->
346
347 <p>
348 You will need libstdc++ in order to provide libsupc++.
349 </p>
Dan Albert2477bed2015-01-30 22:33:41 +0000[diff] [blame]350
Michael J. Spencerbb8cfd02012-12-31 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 Albert2477bed2015-01-30 22:33:41 +0000[diff] [blame]356
Michael J. Spencerbb8cfd02012-12-31 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 Albert2477bed2015-01-30 22:33:41 +0000[diff] [blame]379
Michael J. Spencerbb8cfd02012-12-31 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 Collingbourne26dd09e2013-10-06 22:13:19 +0000[diff] [blame]384 -DLIBCXX_CXX_ABI=libstdc++
Eric Fiselier237b6ed2015-03-19 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. Spencerbb8cfd02012-12-31 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 Collingbourne26dd09e2013-10-06 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. Spencerbb8cfd02012-12-31 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 Albertec4de782014-08-11 15:12:46 +0000[diff] [blame]405 <h2 id="libcxxrt">Build on Linux using CMake and libcxxrt.</h2>
Howard Hinnantaf00dc02013-02-08 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 Albert2477bed2015-01-30 22:33:41 +0000[diff] [blame]414
Howard Hinnantaf00dc02013-02-08 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 Fiselier237b6ed2015-03-19 20:59:45 +0000[diff] [blame]420 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="&lt;libcxxrt-source-dir&gt;/src"
Howard Hinnantaf00dc02013-02-08 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 Fiselier6f9da552014-10-18 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 Fiseliera63c1492014-10-19 00:42:41 +0000[diff] [blame]454 <code>-DLIBCXX_CXX_ABI_LIBRARY_PATH=/path/to/abi/lib</code> when
455 configuring CMake.
Eric Fiselier6f9da552014-10-18 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 Fiselier237b6ed2015-03-19 20:59:45 +0000[diff] [blame]462 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="/path/to/libcxxabi/include"
Eric Fiseliera63c1492014-10-19 00:42:41 +0000[diff] [blame]463 -DLIBCXX_CXX_ABI_LIBRARY_PATH="/path/to/libcxxabi-build/lib"
Eric Fiselier6f9da552014-10-18 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 Hinnant1de22662010-10-05 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 Hinnant4b889672010-11-19 01:38:58 +0000[diff] [blame]479<li><a href="type_traits_design.html"><tt>&lt;type_traits&gt;</tt></a></li>
Marshall Clow928f65a2013-03-14 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 Hinnantd70e6572013-03-14 18:37:48 +0000[diff] [blame]481<li><a href="debug_mode.html">Status of debug mode</a></li>
Eric Fiselier19c07162014-12-22 20:49:45 +0000[diff] [blame]482<li><a href="lit_usage.html">LIT usage guide</a></li>
Howard Hinnant1de22662010-10-05 16:44:40 +0000[diff] [blame]483</ul>
484
Howard Hinnant3e519522010-05-11 19:42:16 +0000[diff] [blame]485</div>
486</body>
Chris Lattner6f12a7f2010-05-11 20:37:52 +0000[diff] [blame]487</html>