You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
143 lines
5.7 KiB
143 lines
5.7 KiB
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" |
|
"http://www.w3.org/TR/html4/strict.dtd"> |
|
<!-- Material used from: HTML 4.01 specs: http://www.w3.org/TR/html401/ --> |
|
<html> |
|
<head> |
|
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> |
|
<title>"libc++abi" C++ Standard Library Support</title> |
|
<link type="text/css" rel="stylesheet" href="menu.css"> |
|
<link type="text/css" rel="stylesheet" href="content.css"> |
|
</head> |
|
|
|
<body> |
|
<div id="menu"> |
|
<div> |
|
<a href="http://llvm.org/">LLVM Home</a> |
|
</div> |
|
|
|
<div class="submenu"> |
|
<label>libc++abi Info</label> |
|
<a href="/index.html">About</a> |
|
</div> |
|
|
|
<div class="submenu"> |
|
<label>Quick Links</label> |
|
<a href="http://lists.llvm.org/mailman/listinfo/cfe-dev">cfe-dev</a> |
|
<a href="http://lists.llvm.org/mailman/listinfo/cfe-commits">cfe-commits</a> |
|
<a href="http://llvm.org/bugs/">Bug Reports</a> |
|
<a href="http://llvm.org/svn/llvm-project/libcxxabi/trunk/">Browse SVN</a> |
|
<a href="http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/">Browse ViewVC</a> |
|
</div> |
|
</div> |
|
|
|
<div id="content"> |
|
<!--*********************************************************************--> |
|
<h1>"libc++abi" C++ Standard Library Support</h1> |
|
<!--*********************************************************************--> |
|
|
|
<p>libc++abi is a new implementation of low level support for a standard |
|
C++ library.</p> |
|
|
|
<p>All of the code in libc++abi is <a |
|
href="http://llvm.org/docs/DeveloperPolicy.html#license">dual licensed</a> |
|
under the MIT license and the UIUC License (a BSD-like license).</p> |
|
|
|
<!--=====================================================================--> |
|
<h2 id="goals">Features and Goals</h2> |
|
<!--=====================================================================--> |
|
|
|
<ul> |
|
<li>Correctness as defined by the C++11 standard.</li> |
|
<li>Provide a portable sublayer to ease the porting of <a href="http://libcxx.llvm.org/">libc++</a></li> |
|
<li>On Mac OS X, be ABI compatible with the existing low-level support.</li> |
|
</ul> |
|
|
|
<!--=====================================================================--> |
|
<h2 id="requirements">Platform Support</h2> |
|
<!--=====================================================================--> |
|
|
|
<p>libc++abi is known to work on the following platforms, using clang.</p> |
|
|
|
<ul> |
|
<li>Darwin</li> |
|
</ul> |
|
|
|
<!--=====================================================================--> |
|
<h2 id="dir-structure">Current Status</h2> |
|
<!--=====================================================================--> |
|
|
|
<p>libc++abi is complete. <a href="spec.html">Here</a> is a |
|
list of functionality.</p> |
|
|
|
<!--=====================================================================--> |
|
<h2>Get it and get involved!</h2> |
|
<!--=====================================================================--> |
|
|
|
<p>To check out the code, use:</p> |
|
|
|
<ul> |
|
<li><code>svn co http://llvm.org/svn/llvm-project/libcxxabi/trunk libcxxabi</code></li> |
|
</ul> |
|
|
|
<p>To build:</p> |
|
<ul> |
|
<li>Check out libcxxabi into <code>llvm/projects</code></li> |
|
<li><code>cd llvm</code></li> |
|
<li><code>mkdir build && cd build</code></li> |
|
<li><code>cmake .. # on linux you may need to prefix with CC=clang CXX=clang++</code></li> |
|
<li><code>make</code></li> |
|
</ul> |
|
|
|
<p>To do a standalone build:</p> |
|
<ul> |
|
<li> |
|
Check out the <a href="http://libcxx.llvm.org">libcxx source</a> tree. |
|
</li> |
|
<li><code>cd libcxxabi</code></li> |
|
<li><code>mkdir build && cd build</code></li> |
|
<li><code>cmake -DLIBCXXABI_LIBCXX_PATH=path/to/libcxx .. # on |
|
linux you may need -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++</code></li> |
|
<li><code>make</code></li> |
|
</ul> |
|
<p> By default CMake uses <code>llvm-config</code> to locate the required |
|
LLVM sources. If CMake cannot find <code>llvm-config</code> then you must |
|
configure CMake using either of the following options. |
|
</p> |
|
<ul> |
|
<li><code>-DLLVM_CONFIG_PATH=path/to/llvm-config</code></li> |
|
<li><code>-DLLVM_PATH=path/to/llvm-source-root</code></li> |
|
</ul> |
|
|
|
</p> |
|
|
|
<p>To run the tests:</p> |
|
<ul> |
|
<li><code>make check-cxxabi</code></li> |
|
</ul> |
|
<p>Note: in a standalone build, the system's libc++ will be used for tests. If |
|
the system's libc++ was statically linked against libc++abi (or linked against |
|
a different ABI library), this may interfere with test results.</p> |
|
|
|
<p>Send discussions to the |
|
(<a href="http://lists.llvm.org/mailman/listinfo/cfe-dev">clang mailing list</a>).</p> |
|
|
|
<!--=====================================================================--> |
|
<h2>Frequently asked questions</h2> |
|
<!--=====================================================================--> |
|
|
|
<p>Q: Why are the destructors for the standard exception classes defined in libc++abi? |
|
They're just empty, can't they be defined inline?</p> |
|
<p>A: The destructors for them live in libc++abi because they are "key" functions. |
|
The Itanium ABI describes a "key" function as the first virtual declared. |
|
And wherever the key function is defined, that is where the <code>type_info</code> gets defined. |
|
And in libc++ types are the same type if and only if they have the same <code>type_info</code> |
|
(as in there must be only one type info per type in the entire application). |
|
And on OS X, libstdc++ and libc++ share these exception types. |
|
So to be able to throw in one dylib and catch in another (a <code>std::exception</code> for example), |
|
there must be only one <code>std::exception type_info</code> in the entire app. |
|
That typeinfo gets laid down beside <code>~exception()</code> in libc++abi (for both libstdc++ and libc++).</p> |
|
<p>--Howard Hinnant</p> |
|
|
|
</div> |
|
</body> |
|
</html>
|
|
|