-<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"\r
- "http://www.w3.org/TR/html4/strict.dtd">\r
-<html>\r
-<head>\r
- <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />\r
- <title>Clang - Get Involved</title>\r
- <link type="text/css" rel="stylesheet" href="menu.css" />\r
- <link type="text/css" rel="stylesheet" href="content.css" />\r
-</head>\r
-<body>\r
-\r
-<!--#include virtual="menu.html.incl"-->\r
-\r
-<div id="content">\r
-\r
-<h1>Getting Involved with the Clang Project</h1>\r
-\r
-<p>Once you have <a href="get_started.html">checked out and built</a> clang and\r
-played around with it, you might be wondering what you can do to make it better\r
-and contribute to its development. Alternatively, maybe you just want to follow\r
-the development of the project to see it progress.\r
-</p>\r
-\r
-<h2>Follow what's going on</h2>\r
-\r
-<p>Clang is a subproject of the <a href="http://llvm.org">LLVM Project</a>, but\r
-has its own mailing lists because the communities have people with different\r
-interests. The two clang lists are:</p>\r
-\r
-<ul>\r
-<li><a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits">cfe-commits\r
-</a> - This list is for patch submission/discussion.</li>\r
-\r
-<li><a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">cfe-dev</a> - \r
-This list is for everything else clang related (questions and answers, bug\r
-reports, etc).</li>\r
-\r
-</ul>\r
-\r
-<p>If you are interested in clang only, these two lists should be all\r
-you need. If you are interested in the LLVM optimizer and code generator,\r
-please consider signing up for <a \r
-href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">llvmdev</a> and <a\r
-href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits">llvm-commits</a>\r
-as well.</p>\r
-\r
-\r
-<p>The best way to talk with other developers on the project is through the <a\r
-href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">cfe-dev mailing\r
-list</a>. The clang mailing list is a very friendly place and we welcome\r
-newcomers. In addition to the cfe-dev list, a significant amount of design\r
-discussion takes place on the <a \r
-href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits">cfe-commits mailing\r
-list</a>. All of these lists have archives, so you can browse through previous\r
-discussions or follow the list development on the web if you prefer.</p>\r
-\r
-\r
-<h2>Open Projects</h2>\r
-\r
-<p>Here are a few tasks that are available for newcomers to work on, depending\r
-on what your interests are. This list is provided to generate ideas, it is not\r
-intended to be comprehensive. Please ask on cfe-dev for more specifics or to\r
-verify that one of these isn't already completed. :)</p>\r
-\r
-<ul>\r
-<li><b>Compile your favorite C/ObjC project with "clang -fsyntax-only"</b>:\r
-the clang type checker and verifier is quite close to complete (but not bug\r
-free!) for C and Objective C. We appreciate all reports of code that is\r
-rejected by the front-end, and if you notice invalid code that is not rejected\r
-by clang, that is also very important to us. For make-based projects,\r
-the <a href="get_started.html#ccc"><code>ccc</code></a> script in clang's\r
-<tt>utils</tt> folder might help to get you started.</li>\r
-\r
-<li><b>Compile your favorite C project with "clang -emit-llvm"</b>:\r
-The clang to LLVM converter is getting more mature, so you may be able to\r
-compile it. If not, please let us know. Again,\r
-<a href="get_started.html#ccc"><code>ccc</code></a> might help you. Once it\r
-compiles it should run. If not, that's a bug :)</li>\r
-\r
-<li><b>Debug Info Generation</b>: -emit-llvm doesn't fully support emission\r
-of <a href="http://llvm.org/docs/SourceLevelDebugging.html">LLVM debug info</a>\r
-(which the code generator turns into DWARF). The missing pieces are pretty \r
-minor at this point.</li>\r
-\r
-<li><b>Overflow detection</b>: an interesting project would be to add a \r
-compilation mode that causes -emit-llvm to generate overflow tests for all\r
-signed integer arithmetic operators, and call abort if they overflow. Overflow\r
-is undefined in C and hard for people to reason about. LLVM IR also has\r
-intrinsics for generating arithmetic with overflow checks directly.</li>\r
-\r
-<li><b>Continue work on C++ support</b>: Implementing all of C++ is a very big\r
-job, but there are lots of little pieces that can be picked off and implemented.\r
-See the <a href="cxx_status.html">C++ status report page</a> to find out what is\r
-missing and what is already at least partially supported.</li>\r
-\r
-<li><b>Improve target support</b>: The current target interfaces are heavily\r
-stubbed out and need to be implemented fully. See the FIXME's in TargetInfo.\r
-Additionally, the actual target implementations (instances of TargetInfoImpl)\r
-also need to be completed. This includes defining builtin macros for linux\r
-targets and other stuff like that.</li>\r
-\r
-<li><b>Implement 'builtin' headers</b>: GCC provides a bunch of builtin headers,\r
-such as stdbool.h, iso646.h, float.h, limits.h, etc. It also provides a bunch\r
-of target-specific headers like altivec.h and xmmintrin.h. clang will\r
-eventually need to provide its own copies of these (and there is a <a href=\r
-"http://lists.cs.uiuc.edu/pipermail/cfe-dev/2007-December/000560.html">lot of \r
-improvement</a> that can be made to the GCC ones!) that are clean-room\r
-implemented to avoid GPL taint.</li>\r
-\r
-<li><b>Implement a clang 'libgcc'</b>: As with the headers, clang (or a another\r
-related subproject of llvm) will need to implement the features that libgcc\r
-provides. libgcc provides a bunch of routines the code generator uses for\r
-"fallback" when the chip doesn't support some operation (e.g. 64-bit divide on\r
-a 32-bit chip). It also provides software floating point support and many other\r
-things. I don't think that there is a specific licensing reason to reimplement\r
-libgcc, but there is a lot of room for improvement in it in many \r
-dimensions.</li>\r
-\r
-<li><b>Implement an tool to generate code documentation</b>: Clang's\r
-library-based design allows it to be used by a variety of tools that reason\r
-about source code. One great application of Clang would be to build an\r
-auto-documentation system like doxygen that generates code documentation from\r
-source code. The advantage of using Clang for such a tool is that the tool would\r
-use the same preprocessor/parser/ASTs as the compiler itself, giving it a very\r
-rich understanding of the code.</li> \r
-\r
-<li><b>Use clang libraries to implement better versions of existing tools</b>:\r
-Clang is built as a set of libraries, which means that it is possible to\r
-implement capabilities similar to other source language tools, improving them\r
-in various ways. Two examples are <a href="http://distcc.samba.org/">distcc</a>\r
-and the <a href="http://delta.tigris.org/">delta testcase reduction tool</a>.\r
-The former can be improved to scale better and be more efficient. The later\r
-could also be faster and more efficient at reducing C-family programs if built\r
-on the clang preprocessor.</li>\r
-\r
-<li><b>Use clang libraries to extend Ragel with a JIT</b>: <a \r
-href="http://research.cs.queensu.ca/~thurston/ragel/">Ragel</a> is a state\r
-machine compiler that lets you embed C code into state machines and generate\r
-C code. It would be relatively easy to turn this into a JIT compiler using\r
-LLVM.</li>\r
-\r
-<li><b>Self-testing using clang</b>: There are several neat ways to\r
-improve the quality of clang by self-testing. Some examples:\r
-<ul>\r
- <li>Improve the reliability of AST printing and serialization by\r
- ensuring that the AST produced by clang on an input doesn't change\r
- when it is reparsed or unserialized.\r
-\r
- <li>Improve parser reliability and error generation by automatically\r
- or randomly changing the input checking that clang doesn't crash and\r
- that it doesn't generate excessive errors for small input\r
- changes. Manipulating the input at both the text and token levels is\r
- likely to produce interesting test cases.\r
-</ul>\r
-</li>\r
-\r
-</ul>\r
-\r
-<p>If you hit a bug with clang, it is very useful for us if you reduce the code\r
-that demonstrates the problem down to something small. There are many ways to\r
-do this; ask on cfe-dev for advice.</p>\r
-\r
-</div>\r
-</body>\r
-</html>\r
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
+ "http://www.w3.org/TR/html4/strict.dtd">
+<html>
+<head>
+ <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
+ <title>Clang - Get Involved</title>
+ <link type="text/css" rel="stylesheet" href="menu.css">
+ <link type="text/css" rel="stylesheet" href="content.css">
+</head>
+<body>
+
+<!--#include virtual="menu.html.incl"-->
+
+<div id="content">
+
+<h1>Getting Involved with the Clang Project</h1>
+
+<p>Once you have <a href="get_started.html">checked out and built</a> clang and
+played around with it, you might be wondering what you can do to make it better
+and contribute to its development. Alternatively, maybe you just want to follow
+the development of the project to see it progress.
+</p>
+
+<h2>Contribute</h2>
+
+See the <a href="hacking.html">hacking</a> document for information on how
+to author patches.
+
+<h2>Follow what's going on</h2>
+
+<p>Clang is a subproject of the <a href="http://llvm.org">LLVM Project</a>, but
+has its own mailing lists because the communities have people with different
+interests. The two clang lists are:</p>
+
+<ul>
+<li><a href="http://lists.llvm.org/mailman/listinfo/cfe-commits">cfe-commits
+</a> - This list is for patch submission/discussion.</li>
+
+<li><a href="http://lists.llvm.org/mailman/listinfo/cfe-dev">cfe-dev</a> -
+This list is for everything else Clang related (questions and answers, design
+discussions, etc).</li>
+
+</ul>
+
+<p>If you are interested in clang only, these two lists should be all
+you need. If you are interested in the LLVM optimizer and code generator,
+please consider signing up for <a
+href="http://lists.llvm.org/mailman/listinfo/llvm-dev">llvm-dev</a> and <a
+href="http://lists.llvm.org/mailman/listinfo/llvm-commits">llvm-commits</a>
+as well.</p>
+
+
+<p>The best way to talk with other developers on the project is through the <a
+href="http://lists.llvm.org/mailman/listinfo/cfe-dev">cfe-dev mailing
+list</a>. The clang mailing list is a very friendly place and we welcome
+newcomers. In addition to the cfe-dev list, a significant amount of design
+discussion takes place on the <a
+href="http://lists.llvm.org/mailman/listinfo/cfe-commits">cfe-commits mailing
+list</a>. All of these lists have archives, so you can browse through previous
+discussions or follow the list development on the web if you prefer.</p>
+
+<p>You can also follow the <a href="http://planet.clang.org/">Planet Clang</a>
+community news feed which offers a window into the world, work and lives of
+Clang developers, contributors and the standards they implement.</p>
+
+<p>If you're looking for something to work on, check out our <a
+href="OpenProjects.html">Open Projects</a> page or look through the <a
+href="http://llvm.org/bugs/">Bugzilla bug database</a>.</p>
+
+<h2 id="criteria">Contributing Extensions to Clang</h2>
+
+<p>Clang has always been designed as a platform for experimentation,
+allowing programmers to easily extend the compiler to support great
+new language features and tools. At some point, the authors of these
+extensions may propose that the extensions become a part of Clang
+itself, to benefit the whole Clang community. But not every idea--not
+even every great idea--should become part of Clang. Extensions
+(particularly language extensions) pose a long-term maintenance burden
+on Clang, and therefore the benefits of the extension must outweight
+those costs. Hence, these are the seven criteria used to evaluate the
+merits of a proposed extension:</p>
+
+<ol>
+ <li>Evidence of a significant user community: This is based on a number of factors, including an actual, existing user community, the perceived likelihood that users would adopt such a feature if it were available, and any "trickle-down" effects that come from, e.g., a library adopting the feature and providing benefits to its users.</li>
+
+ <li>A specific need to reside within the Clang tree: There are some extensions that would be better expressed as a separate tool, and should remain as separate tools even if they end up being hosted as part of the LLVM umbrella project.</li>
+
+ <li>A complete specification: The specification must be sufficient to understand the design of the feature as well as interpret the meaning of specific examples. The specification should be detailed enough that another compiler vendor could conceivably implement the feature.</li>
+
+ <li>Representation within the appropriate governing organization: For extensions to a language governed by a standards committee (C, C++, OpenCL), the extension itself must have an active proposal and proponent within that committee and have a reasonable chance of acceptance. Clang should drive the standard, not diverge from it. This criterion does not apply to all extensions, since some extensions fall outside of the realm of the standards bodies.</li>
+
+ <li>A long-term support plan: Contributing a non-trivial extension to Clang implies a commitment to supporting that extension, improving the implementation and specification as Clang evolves. The capacity of the contributor to make that commitment is as important as the commitment itself.</li>
+
+ <li>A high-quality implementation: The implementation must fit well into Clang's architecture, follow LLVM's coding conventions, and meet Clang's quality standards, including high-quality diagnostics and rich AST representations. This is particularly important for language extensions, because users will learn how those extensions work through the behavior of the compiler.</li>
+
+ <li>A proper test suite: Extensive testing is crucial to ensure that the language extension is not broken by ongoing maintenance in Clang. The test suite should be complete enough that another compiler vendor could conceivably validate their implementation of the feature against it.</li>
+</ol>
+
+</div>
+</body>
+</html>
projects / clang / blobdiff