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<h1>clang: a C language family frontend for LLVM</h1>
<p>The goal of the Clang project is to create a new C, C++, Objective C and
Objective C++ front-end for the <a href="http://www.llvm.org/">LLVM</a>
compiler.</p>
<h2>Why?</h2>
<p>The development of a new front-end was started out of a need -- a need
for a compiler that allows better diagnostics, better integration with
IDEs, a license that is compatible with commercial products, and a
compiler that is easier to develop and maintain. All of these were
motivations for starting work on a new front-end that could
meet these needs.</p>
<p>An good (but quite dated) introduction to Clang can be found in the
following video lectures:</p>
<ul>
<li><a href="clang_video-05-25-2007.html">Clang Introduction</a>
(May 2007)</li>
<li><a href="clang_video-07-25-2007.html">Features and Performance of
Clang</a> (July 2007)</li>
</ul>
<h2>Features/Goals</h2>
<p>Some of the goals for the project include the following:</p>
<ul>
<li>Real-world, production quality compiler.</li>
<li>A single unified parser for C, Objective C, C++, and Objective
C++.</li>
<li>Language conformance with these languages and their variants, like
C90, C99, etc.</li>
<li>GCC compatibility: support GCC extensions, but allow them to be
disabled.</li>
<li>Library based architecture with finely crafted APIs.</li>
<li>Support many clients, such as refactoring, static analysis, as well as
code generation.</li>
<li>High performance.</li>
<li>Design for integration with IDEs as well as code generation with the
<a href="http://llvm.org">LLVM Optimizer and Code Generator</a>.</li>
<li><a href="features.html#expressivediags">Expressive diagnostics</a>:
warnings and errors that are actually helpful and make sense.</li>
<li>Use the LLVM <a
href="http://llvm.org/svn/llvm-project/cfe/trunk/LICENSE.TXT">'BSD'
License</a>.</li>
</ul>
<p>Of course this is only a rough outline of the goals and features of
Clang. To get a true sense of what the new LLVM front-end is all about,
as well as why you might want to considering using it, see the <a
href="features.html">Features</a> section.</p>
<h2>Current Status</h2>
<p>Clang is still in early development stages. If you are looking for
source analysis or source-to-source transformation tools, clang is probably
a great solution for you. If you want to use it as a drop in C compiler, it
is not yet ready.</p>
<p>Clang currently has pretty good parsing and semantic analysis support for
C and Objective-C right now, and bugs are usually quickly fixed once
reported. C++ support is still very early, and we don't expect to have
respectable C++ support for another 2 years or so.</p>
<h2>Get Involved</h2>
<p>The developers of Clang include contributers from Apple and numerous
other volunteers. If you are interested in joining the community or
learning more, please consider joining the <a
href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">cfe-dev</a>
mailing list, or start by browsing its archives.</p>
<p>If you are interested in trying out Clang, please see the build
instructions on the <ahref="get_involved.html#build">Get Involved</a>
page.</p>
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