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Howard Hinnantd2bb0322010-08-22 01:04:38 +0000[diff] [blame]17
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]18 <div class="submenu">
19 <label>libc++ Info</label>
20 <a href="/index.html">About</a>
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22
23 <div class="submenu">
24 <label>Quick Links</label>
Tanya Lattnerd08dbfc2015-08-05 03:59:14 +0000[diff] [blame]25 <a href="http://lists.llvm.org/mailman/listinfo/cfe-dev">cfe-dev</a>
26 <a href="http://lists.llvm.org/mailman/listinfo/cfe-commits">cfe-commits</a>
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]27 <a href="http://llvm.org/bugs/">Bug Reports</a>
Howard Hinnant76e1ffc2010-05-11 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 Hinnantbc8d3f92010-05-11 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 Hinnantd2bb0322010-08-22 01:04:38 +0000[diff] [blame]37
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]38 <p>libc++ is a new implementation of the C++ standard library, targeting
Howard Hinnantaf347342012-07-19 15:57:51 +0000[diff] [blame]39 C++11.</p>
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]40
Chris Lattnerf38bc6e2010-11-16 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 Hinnantd2bb0322010-08-22 01:04:38 +0000[diff] [blame]44
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]45 <!--=====================================================================-->
46 <h2 id="goals">Features and Goals</h2>
47 <!--=====================================================================-->
Howard Hinnantd2bb0322010-08-22 01:04:38 +0000[diff] [blame]48
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]49 <ul>
Howard Hinnantaf347342012-07-19 15:57:51 +0000[diff] [blame]50 <li>Correctness as defined by the C++11 standard.</li>
Howard Hinnantbc8d3f92010-05-11 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 Clowfaa17162012-11-14 16:31:15 +0000[diff] [blame]60 <h2 id="why">Why a new C++ Standard Library for C++11?</h2>
Chris Lattner24173b82010-05-12 22:21:15 +0000[diff] [blame]61 <!--=====================================================================-->
Howard Hinnantd2bb0322010-08-22 01:04:38 +0000[diff] [blame]62
Chris Lattner24173b82010-05-12 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 Hinnantd2bb0322010-08-22 01:04:38 +0000[diff] [blame]67
Chris Lattner24173b82010-05-12 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 Clowfaa17162012-11-14 16:31:15 +0000[diff] [blame]75 machines (particularly in C++11, which has rvalue references). Breaking
Chris Lattnera5058d92010-05-12 22:30:22 +0000[diff] [blame]76 ABI compatibility with old versions of the library was
Chris Lattner24173b82010-05-12 22:21:15 +0000[diff] [blame]77 determined to be critical to achieving the performance goals of
78 libc++.</p></li>
Howard Hinnantd2bb0322010-08-22 01:04:38 +0000[diff] [blame]79
Chris Lattner24173b82010-05-12 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 Clowfaa17162012-11-14 16:31:15 +0000[diff] [blame]82 independently extended to support C++11, but this would be a fork of the
Chris Lattnerf3382492010-05-12 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 Lattner24173b82010-05-12 22:21:15 +0000[diff] [blame]87 </li>
88
89 <li><p>STLport and the Apache libstdcxx library are two other popular
Marshall Clowfaa17162012-11-14 16:31:15 +0000[diff] [blame]90 candidates, but both lack C++11 support. Our experience (and the
Howard Hinnantaf347342012-07-19 15:57:51 +0000[diff] [blame]91 experience of libstdc++ developers) is that adding support for C++11 (in
Chris Lattner24173b82010-05-12 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 Lattnerbfa808e2010-05-12 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 Hinnantd2bb0322010-08-22 01:04:38 +0000[diff] [blame]96
Chris Lattner24173b82010-05-12 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 Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]103 <h2 id="requirements">Platform Support</h2>
104 <!--=====================================================================-->
105
Dan Albert35d775d2014-08-11 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 Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]112
Dan Albert35d775d2014-08-11 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 Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]120
121 <!--=====================================================================-->
122 <h2 id="dir-structure">Current Status</h2>
123 <!--=====================================================================-->
124
Howard Hinnantb0895ff2012-11-27 18:52:32 +0000[diff] [blame]125 <p>libc++ is a 100% complete C++11 implementation on Apple's OS X. </p>
Michael J. Spencerdb8a0302012-12-31 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 Alberte3eda9d2015-01-30 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 Clowe4915d92014-04-03 02:35:29 +0000[diff] [blame]128 C++14 can be found <a href="cxx1y_status.html">here</a>.</p>
Marshall Clow1e895c12014-11-10 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 Clowd2f0b5c2014-06-02 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 Hinnant0cbb3a12011-09-28 15:44:39 +0000[diff] [blame]133 <p>
Howard Hinnantee7a0bf2012-07-31 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 Hinnant0cbb3a12011-09-28 15:44:39 +0000[diff] [blame]137 </p>
138
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000[diff] [blame]139 <!--======================================================================-->
Dan Alberte3eda9d2015-01-30 22:33:41 +0000[diff] [blame]140 <h2 id="buildbots">Build Bots</h2>
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000[diff] [blame]141 <!--======================================================================-->
Eric Fiselier453a5002014-12-09 22:53:21 +0000[diff] [blame]142 <p>The latest libc++ build results can be found at the following locations.</p>
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000[diff] [blame]143 <ul>
Eric Fiselier453a5002014-12-09 22:53:21 +0000[diff] [blame]144 <li><a href="http://lab.llvm.org:8011/console">
145 Buildbot libc++ builders
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000[diff] [blame]146 </a></li>
Eric Fiselier453a5002014-12-09 22:53:21 +0000[diff] [blame]147 <li><a href="http://lab.llvm.org:8080/green/view/Libcxx/">
148 Jenkins libc++ builders
Eric Fiseliera43d1142014-10-16 02:48:59 +0000[diff] [blame]149 </a></li>
Eric Fiseliercaf1c022014-08-18 05:25:04 +0000[diff] [blame]150 </ul>
151
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]152 <!--=====================================================================-->
153 <h2>Get it and get involved!</h2>
154 <!--=====================================================================-->
Howard Hinnantd2bb0322010-08-22 01:04:38 +0000[diff] [blame]155
Howard Hinnant2481cba2011-09-30 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 Hinnant704f09b2011-11-17 17:14:16 +0000[diff] [blame]159 <p>
Howard Hinnant22b781b2012-11-06 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 Hinnant704f09b2011-11-17 17:14:16 +0000[diff] [blame]161 Xcode 4.2 or later. However if you want to install tip-of-trunk from here
Howard Hinnant271a1c02012-04-03 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 Hinnant704f09b2011-11-17 17:14:16 +0000[diff] [blame]165 </p>
166
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]167 <p>To check out the code, use:</p>
168
Howard Hinnant65451f12011-01-27 23:18:19 +0000[diff] [blame]169 <ul>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]170 <li><code>svn co http://llvm.org/svn/llvm-project/libcxx/trunk libcxx</code></li>
Howard Hinnant65451f12011-01-27 23:18:19 +0000[diff] [blame]171 </ul>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]172
Howard Hinnant65451f12011-01-27 23:18:19 +0000[diff] [blame]173 <p>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]174 Note that for an in-tree build, you should check out libcxx to
175 llvm/projects.
Howard Hinnant65451f12011-01-27 23:18:19 +0000[diff] [blame]176 </p>
177
Howard Hinnant65451f12011-01-27 23:18:19 +0000[diff] [blame]178 <p>
Dan Albert35d775d2014-08-11 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>
Eric Fiseliereb6e2ea2015-07-30 22:30:34 +0000[diff] [blame]187 <li><code>cd where-you-want-to-live</code></li>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]188 <li>Check out libcxx and <a href="http://libcxxabi.llvm.org/">libcxxabi</a>
189 into llvm/projects</li>
Eric Fiseliereb6e2ea2015-07-30 22:30:34 +0000[diff] [blame]190 <li><code>cd where-you-want-to-build</code></li>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]191 <li><code>mkdir build &amp;&amp; cd build</code></li>
Eric Fiseliereb6e2ea2015-07-30 22:30:34 +0000[diff] [blame]192 <li><code>cmake path/to/llvm # Linux may require -DCMAKE_C_COMPILER=clang
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]193 -DCMAKE_CXX_COMPILER=clang++</code></li>
194 <li><code>make cxx</code></li>
195 </ul>
196
Eric Fiseliereb6e2ea2015-07-30 22:30:34 +0000[diff] [blame]197 <p>Out-of-tree buildc:</p>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]198 <ul>
Eric Fiseliereb6e2ea2015-07-30 22:30:34 +0000[diff] [blame]199 <li><code>cd where-you-want-to-live</code></li>
200 <li>Check out libcxx and llvm</li>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]201 <li>If not on a Mac, also check out
202 <a href="http://libcxxabi.llvm.org/">libcxxabi</a></li>
Eric Fiseliereb6e2ea2015-07-30 22:30:34 +0000[diff] [blame]203 <li><code>cd where-you-want-to-build</code></li>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]204 <li><code>mkdir build &amp;&amp; cd build</code></li>
Eric Fiseliereb6e2ea2015-07-30 22:30:34 +0000[diff] [blame]205 <li><code>cmake -DLLVM_PATH=path/to/llvm
206 -DLIBCXX_CXX_ABI=libcxxabi
Eric Fiselier02c24c12015-03-19 20:59:45 +0000[diff] [blame]207 -DLIBCXX_CXX_ABI_INCLUDE_PATHS=path/to/libcxxabi/include
Eric Fiseliereb6e2ea2015-07-30 22:30:34 +0000[diff] [blame]208 -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
209 path/to/libcxx
210 </code></li>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]211 <li><code>make</code></li>
212 </ul>
213
214 <p>To run the tests:</p>
215 <ul>
216 <li><code>make check-libcxx</code></li>
217 </ul>
218
219 <p>If you wish to run a subset of the test suite:</p>
220 <ul>
221 <li><code>cd path/to/libcxx/libcxx</code></li>
222 <li><code>alias lit='python path/to/llvm/utils/lit/lit.py'</code></li>
Eric Fiselier4778eed2014-12-20 03:16:55 +0000[diff] [blame]223 <li><code>export
224 LIBCXX_SITE_CONFIG=path/to/build/dir/projects/libcxx/test/lit.site.cfg
225 </code></li>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]226 <li><code>lit -sv test/re/ # or whichever subset of tests you're interested
227 in</code></li>
228 </ul>
229 <p>The above is currently quite inconvenient. Sorry! We're working on it!</p>
230
231 <p>More information on using LIT can be found
232 <a href="http://llvm.org/docs/CommandGuide/lit.html">here</a>. For more
233 general information about the LLVM testing infrastructure, see the
234 <a href="http://llvm.org/docs/TestingGuide.html">LLVM Testing Infrastructure
235 Guide</a>
236 </p>
237
238 <p>
239 Shared libraries for libc++ should now be present in llvm/build/lib. Note
240 that it is safest to use this from its current location rather than
241 replacing your system's libc++ (if it has one, if not, go right ahead).
242 </p>
243
244 <p>
245 Mac users, remember to be careful when replacing the system's libc++.
Jonathan Roelofsd20675f2015-05-08 21:11:49 +0000[diff] [blame]246 <strong>Your system will not be able to boot without a functioning
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]247 libc++.</strong>
248 </p>
249
250 <!--=====================================================================-->
Eric Fiseliera5ad9ac2015-05-12 22:55:30 +0000[diff] [blame]251 <h3>Notes and Known Issues</h3>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]252 <!--=====================================================================-->
253
254 <p>
Eric Fiseliera5ad9ac2015-05-12 22:55:30 +0000[diff] [blame]255 <ul>
256 <li>
257 Building libc++ with <code>-fno-rtti</code> is not supported. However
258 linking against it with <code>-fno-rtti</code> is supported.
259 </li>
260 <li>
261 On OS X v10.8 and older the CMake option
262 <code>-DLIBCXX_LIBCPPABI_VERSION=""</code> must be used during
263 configuration.
264 </li>
265 </ul>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]266 </p>
267
268 <p>Send discussions to the
Tanya Lattnerd08dbfc2015-08-05 03:59:14 +0000[diff] [blame]269 <a href="http://lists.llvm.org/mailman/listinfo/cfe-dev">clang mailing list</a>.</p>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]270
271 <!--=====================================================================-->
272 <h2>Using libc++ in your programs</h2>
273 <!--=====================================================================-->
274
275 <!--=====================================================================-->
276 <h3>FreeBSD and Mac OS X</h3>
277 <!--=====================================================================-->
278
279 <p>
280 To use your system-installed libc++ with clang you can:
Howard Hinnant65451f12011-01-27 23:18:19 +0000[diff] [blame]281 </p>
282
283 <ul>
284 <li><code>clang++ -stdlib=libc++ test.cpp</code></li>
Howard Hinnantaf347342012-07-19 15:57:51 +0000[diff] [blame]285 <li><code>clang++ -std=c++11 -stdlib=libc++ test.cpp</code></li>
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]286 </ul>
287
Howard Hinnant22b781b2012-11-06 21:31:37 +0000[diff] [blame]288 <p>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]289 To use your tip-of-trunk libc++ on Mac OS with clang you can:
Howard Hinnant22b781b2012-11-06 21:31:37 +0000[diff] [blame]290 </p>
291
292 <ul>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]293 <li><code>export DYLD_LIBRARY_PATH=path/to/build/lib</code>
Howard Hinnant22b781b2012-11-06 21:31:37 +0000[diff] [blame]294 <li><code>clang++ -std=c++11 -stdlib=libc++ -nostdinc++
295 -I&lt;path-to-libcxx&gt;/include -L&lt;path-to-libcxx&gt;/lib
296 test.cpp</code></li>
297 </ul>
298
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]299 <!--=====================================================================-->
300 <h3>Linux</h3>
301 <!--=====================================================================-->
302
303 <p>
304 You will need to keep the source tree of
305 <a href="http://libcxxabi.llvm.org">libc++abi</a> available on your build
306 machine and your copy of the libc++abi shared library must be placed where
307 your linker will find it.
308 </p>
309
310 <p>
311 Unfortunately you can't simply run clang with "-stdlib=libc++" at this
312 point, as clang is set up to link for libc++ linked to libsupc++. To get
313 around this you'll have to set up your linker yourself (or patch clang).
314 For example:
315 </p>
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]316
317 <ul>
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]318 <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 +0000[diff] [blame]319 </ul>
320
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]321 <p>
322 Alternately, you could just add libc++abi to your libraries list, which in
323 most situations will give the same result:
324 </p>
Howard Hinnant51065652012-05-20 13:03:53 +0000[diff] [blame]325
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]326 <ul>
327 <li><code>clang++ -stdlib=libc++ helloworld.cpp -lc++abi</code></li>
328 </ul>
Howard Hinnant8c217372010-05-11 19:53:34 +0000[diff] [blame]329
Howard Hinnant56f0d5b2010-10-05 16:44:40 +0000[diff] [blame]330 <!--=====================================================================-->
Marshall Clow992f9d52014-04-03 03:13:12 +0000[diff] [blame]331 <h2>Bug reports and patches</h2>
332 <!--=====================================================================-->
333
Dan Alberte3eda9d2015-01-30 22:33:41 +0000[diff] [blame]334 <p>
335 If you think you've found a bug in libc++, please report it using
336 the <a href="http://llvm.org/bugs">LLVM Bugzilla</a>. If you're not sure, you
Tanya Lattnerd08dbfc2015-08-05 03:59:14 +0000[diff] [blame]337 can post a message to the <a href="http://lists.llvm.org/mailman/listinfo/cfe-dev">cfe-dev</a>
Dan Alberte3eda9d2015-01-30 22:33:41 +0000[diff] [blame]338 mailing list or on IRC. Please include "libc++" in your subject.
339 </p>
Marshall Clow992f9d52014-04-03 03:13:12 +0000[diff] [blame]340
Dan Alberte3eda9d2015-01-30 22:33:41 +0000[diff] [blame]341 <p>
342 If you want to contribute a patch to libc++, the best place for that is
343 <a href="http://llvm.org/docs/Phabricator.html">Phabricator</a>. Please
344 include [libc++] in the subject and add cfe-commits as a subscriber.
345 </p>
Marshall Clow992f9d52014-04-03 03:13:12 +0000[diff] [blame]346
347 <!--=====================================================================-->
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]348 <h2 id="libsupcxx">Build on Linux using CMake and libsupc++.</h2>
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000[diff] [blame]349 <!--=====================================================================-->
350
351 <p>
352 You will need libstdc++ in order to provide libsupc++.
353 </p>
Dan Alberte3eda9d2015-01-30 22:33:41 +0000[diff] [blame]354
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000[diff] [blame]355 <p>
356 Figure out where the libsupc++ headers are on your system. On Ubuntu this
357 is <code>/usr/include/c++/&lt;version&gt;</code> and
358 <code>/usr/include/c++/&lt;version&gt;/&lt;target-triple&gt;</code>
359 </p>
Dan Alberte3eda9d2015-01-30 22:33:41 +0000[diff] [blame]360
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000[diff] [blame]361 <p>
362 You can also figure this out by running
363 <pre>
364$ echo | g++ -Wp,-v -x c++ - -fsyntax-only
365ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
366ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../x86_64-linux-gnu/include"
367#include "..." search starts here:
368#include &lt;...&gt; search starts here:
369 /usr/include/c++/4.7
370 /usr/include/c++/4.7/x86_64-linux-gnu
371 /usr/include/c++/4.7/backward
372 /usr/lib/gcc/x86_64-linux-gnu/4.7/include
373 /usr/local/include
374 /usr/lib/gcc/x86_64-linux-gnu/4.7/include-fixed
375 /usr/include/x86_64-linux-gnu
376 /usr/include
377End of search list.
378 </pre>
379
380 Note the first two entries happen to be what we are looking for. This
381 may not be correct on other platforms.
382 </p>
Dan Alberte3eda9d2015-01-30 22:33:41 +0000[diff] [blame]383
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000[diff] [blame]384 <p>
385 We can now run CMake:
386 <ul>
387 <li><code>CC=clang CXX=clang++ cmake -G "Unix Makefiles"
Peter Collingbourned0d308f2013-10-06 22:13:19 +0000[diff] [blame]388 -DLIBCXX_CXX_ABI=libstdc++
Eric Fiselier02c24c12015-03-19 20:59:45 +0000[diff] [blame]389 -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 +0000[diff] [blame]390 -DCMAKE_BUILD_TYPE=Release
391 -DCMAKE_INSTALL_PREFIX=/usr
392 &lt;libc++-source-dir&gt;</code></li>
Peter Collingbourned0d308f2013-10-06 22:13:19 +0000[diff] [blame]393 <li>You can also substitute <code>-DLIBCXX_CXX_ABI=libsupc++</code>
394 above, which will cause the library to be linked to libsupc++ instead
395 of libstdc++, but this is only recommended if you know that you will
396 never need to link against libstdc++ in the same executable as libc++.
397 GCC ships libsupc++ separately but only as a static library. If a
398 program also needs to link against libstdc++, it will provide its
399 own copy of libsupc++ and this can lead to subtle problems.
Michael J. Spencerdb8a0302012-12-31 19:34:21 +0000[diff] [blame]400 <li><code>make</code></li>
401 <li><code>sudo make install</code></li>
402 </ul>
403 <p>
404 You can now run clang with -stdlib=libc++.
405 </p>
406 </p>
407
408 <!--=====================================================================-->
Dan Albert35d775d2014-08-11 15:12:46 +0000[diff] [blame]409 <h2 id="libcxxrt">Build on Linux using CMake and libcxxrt.</h2>
Howard Hinnantaf4d1612013-02-08 19:10:36 +0000[diff] [blame]410 <!--=====================================================================-->
411
412 <p>
413 You will need to keep the source tree of
414 <a href="https://github.com/pathscale/libcxxrt/">libcxxrt</a> available
415 on your build machine and your copy of the libcxxrt shared library must
416 be placed where your linker will find it.
417 </p>
Dan Alberte3eda9d2015-01-30 22:33:41 +0000[diff] [blame]418
Howard Hinnantaf4d1612013-02-08 19:10:36 +0000[diff] [blame]419 <p>
420 We can now run CMake:
421 <ul>
422 <li><code>CC=clang CXX=clang++ cmake -G "Unix Makefiles"
423 -DLIBCXX_CXX_ABI=libcxxrt
Eric Fiselier02c24c12015-03-19 20:59:45 +0000[diff] [blame]424 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="&lt;libcxxrt-source-dir&gt;/src"
Howard Hinnantaf4d1612013-02-08 19:10:36 +0000[diff] [blame]425 -DCMAKE_BUILD_TYPE=Release
426 -DCMAKE_INSTALL_PREFIX=/usr
427 &lt;libc++-source-dir&gt;</code></li>
428 <li><code>make</code></li>
429 <li><code>sudo make install</code></li>
430 </ul>
431 <p>
432 Unfortunately you can't simply run clang with "-stdlib=libc++" at this point, as
433 clang is set up to link for libc++ linked to libsupc++. To get around this
434 you'll have to set up your linker yourself (or patch clang). For example,
435 <ul>
436 <li><code>clang++ -stdlib=libc++ helloworld.cpp -nodefaultlibs -lc++ -lcxxrt -lm -lc -lgcc_s -lgcc</code></li>
437 </ul>
438 Alternately, you could just add libcxxrt to your libraries list, which in most
439 situations will give the same result:
440 <ul>
441 <li><code>clang++ -stdlib=libc++ helloworld.cpp -lcxxrt</code></li>
442 </ul>
443 </p>
444 </p>
445
446 <!--=====================================================================-->
Eric Fiselier9071bc02014-10-18 01:15:17 +0000[diff] [blame]447 <h2 id="local-abi">Using a local ABI library</h2>
448 <!--=====================================================================-->
449 <p>
450 <strong>Note: This is not recommended in almost all cases.</strong><br>
451 Generally these instructions should only be used when you can't install
452 your ABI library.
453 </p>
454 <p>
455 Normally you must link libc++ against a ABI shared library that the
456 linker can find. If you want to build and test libc++ against an ABI
457 library not in the linker's path you need to set
Eric Fiseliercb7e32c2014-10-19 00:42:41 +0000[diff] [blame]458 <code>-DLIBCXX_CXX_ABI_LIBRARY_PATH=/path/to/abi/lib</code> when
459 configuring CMake.
Eric Fiselier9071bc02014-10-18 01:15:17 +0000[diff] [blame]460 </p>
461 <p>
462 An example build using libc++abi would look like:
463 <ul>
464 <li><code>CC=clang CXX=clang++ cmake
465 -DLIBCXX_CXX_ABI=libc++abi
Eric Fiselier02c24c12015-03-19 20:59:45 +0000[diff] [blame]466 -DLIBCXX_CXX_ABI_INCLUDE_PATHS="/path/to/libcxxabi/include"
Eric Fiseliercb7e32c2014-10-19 00:42:41 +0000[diff] [blame]467 -DLIBCXX_CXX_ABI_LIBRARY_PATH="/path/to/libcxxabi-build/lib"
Eric Fiselier9071bc02014-10-18 01:15:17 +0000[diff] [blame]468 path/to/libcxx</code></li>
469 <li><code>make</code></li>
470 </ul>
471 </p>
472 <p>
473 When testing libc++ LIT will automatically link against the proper ABI
474 library.
475 </p>
476
477 <!--=====================================================================-->
Howard Hinnant56f0d5b2010-10-05 16:44:40 +0000[diff] [blame]478 <h2>Design Documents</h2>
479 <!--=====================================================================-->
480
481<ul>
482<li><a href="atomic_design.html"><tt>&lt;atomic&gt;</tt></a></li>
Howard Hinnant9835d762010-11-19 01:38:58 +0000[diff] [blame]483<li><a href="type_traits_design.html"><tt>&lt;type_traits&gt;</tt></a></li>
Marshall Clowe47bc9b2013-03-14 19:00:34 +0000[diff] [blame]484<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 +0000[diff] [blame]485<li><a href="debug_mode.html">Status of debug mode</a></li>
Eric Fiselier71dc14e2014-12-22 20:49:45 +0000[diff] [blame]486<li><a href="lit_usage.html">LIT usage guide</a></li>
Howard Hinnant56f0d5b2010-10-05 16:44:40 +0000[diff] [blame]487</ul>
488
Howard Hinnantbc8d3f92010-05-11 19:42:16 +0000[diff] [blame]489</div>
490</body>
Chris Lattner4b748952010-05-11 20:37:52 +0000[diff] [blame]491</html>