1*67e74705SXin Li<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" 2*67e74705SXin Li "http://www.w3.org/TR/html4/strict.dtd"> 3*67e74705SXin Li<html> 4*67e74705SXin Li<head> 5*67e74705SXin Li <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> 6*67e74705SXin Li <title>Clang - Get Involved</title> 7*67e74705SXin Li <link type="text/css" rel="stylesheet" href="menu.css"> 8*67e74705SXin Li <link type="text/css" rel="stylesheet" href="content.css"> 9*67e74705SXin Li</head> 10*67e74705SXin Li<body> 11*67e74705SXin Li 12*67e74705SXin Li<!--#include virtual="menu.html.incl"--> 13*67e74705SXin Li 14*67e74705SXin Li<div id="content"> 15*67e74705SXin Li 16*67e74705SXin Li<h1>Getting Involved with the Clang Project</h1> 17*67e74705SXin Li 18*67e74705SXin Li<p>Once you have <a href="get_started.html">checked out and built</a> clang and 19*67e74705SXin Liplayed around with it, you might be wondering what you can do to make it better 20*67e74705SXin Liand contribute to its development. Alternatively, maybe you just want to follow 21*67e74705SXin Lithe development of the project to see it progress. 22*67e74705SXin Li</p> 23*67e74705SXin Li 24*67e74705SXin Li<h2>Contribute</h2> 25*67e74705SXin Li 26*67e74705SXin LiSee the <a href="hacking.html">hacking</a> document for information on how 27*67e74705SXin Lito author patches. 28*67e74705SXin Li 29*67e74705SXin Li<h2>Follow what's going on</h2> 30*67e74705SXin Li 31*67e74705SXin Li<p>Clang is a subproject of the <a href="http://llvm.org">LLVM Project</a>, but 32*67e74705SXin Lihas its own mailing lists because the communities have people with different 33*67e74705SXin Liinterests. The two clang lists are:</p> 34*67e74705SXin Li 35*67e74705SXin Li<ul> 36*67e74705SXin Li<li><a href="http://lists.llvm.org/mailman/listinfo/cfe-commits">cfe-commits 37*67e74705SXin Li</a> - This list is for patch submission/discussion.</li> 38*67e74705SXin Li 39*67e74705SXin Li<li><a href="http://lists.llvm.org/mailman/listinfo/cfe-dev">cfe-dev</a> - 40*67e74705SXin LiThis list is for everything else Clang related (questions and answers, design 41*67e74705SXin Lidiscussions, etc).</li> 42*67e74705SXin Li 43*67e74705SXin Li</ul> 44*67e74705SXin Li 45*67e74705SXin Li<p>If you are interested in clang only, these two lists should be all 46*67e74705SXin Liyou need. If you are interested in the LLVM optimizer and code generator, 47*67e74705SXin Liplease consider signing up for <a 48*67e74705SXin Lihref="http://lists.llvm.org/mailman/listinfo/llvm-dev">llvm-dev</a> and <a 49*67e74705SXin Lihref="http://lists.llvm.org/mailman/listinfo/llvm-commits">llvm-commits</a> 50*67e74705SXin Lias well.</p> 51*67e74705SXin Li 52*67e74705SXin Li 53*67e74705SXin Li<p>The best way to talk with other developers on the project is through the <a 54*67e74705SXin Lihref="http://lists.llvm.org/mailman/listinfo/cfe-dev">cfe-dev mailing 55*67e74705SXin Lilist</a>. The clang mailing list is a very friendly place and we welcome 56*67e74705SXin Linewcomers. In addition to the cfe-dev list, a significant amount of design 57*67e74705SXin Lidiscussion takes place on the <a 58*67e74705SXin Lihref="http://lists.llvm.org/mailman/listinfo/cfe-commits">cfe-commits mailing 59*67e74705SXin Lilist</a>. All of these lists have archives, so you can browse through previous 60*67e74705SXin Lidiscussions or follow the list development on the web if you prefer.</p> 61*67e74705SXin Li 62*67e74705SXin Li<p>You can also follow the <a href="http://planet.clang.org/">Planet Clang</a> 63*67e74705SXin Licommunity news feed which offers a window into the world, work and lives of 64*67e74705SXin LiClang developers, contributors and the standards they implement.</p> 65*67e74705SXin Li 66*67e74705SXin Li<p>If you're looking for something to work on, check out our <a 67*67e74705SXin Lihref="OpenProjects.html">Open Projects</a> page or look through the <a 68*67e74705SXin Lihref="http://llvm.org/bugs/">Bugzilla bug database</a>.</p> 69*67e74705SXin Li 70*67e74705SXin Li<h2 id="criteria">Contributing Extensions to Clang</h2> 71*67e74705SXin Li 72*67e74705SXin Li<p>Clang has always been designed as a platform for experimentation, 73*67e74705SXin Liallowing programmers to easily extend the compiler to support great 74*67e74705SXin Linew language features and tools. At some point, the authors of these 75*67e74705SXin Liextensions may propose that the extensions become a part of Clang 76*67e74705SXin Liitself, to benefit the whole Clang community. But not every idea--not 77*67e74705SXin Lieven every great idea--should become part of Clang. Extensions 78*67e74705SXin Li(particularly language extensions) pose a long-term maintenance burden 79*67e74705SXin Lion Clang, and therefore the benefits of the extension must outweight 80*67e74705SXin Lithose costs. Hence, these are the seven criteria used to evaluate the 81*67e74705SXin Limerits of a proposed extension:</p> 82*67e74705SXin Li 83*67e74705SXin Li<ol> 84*67e74705SXin Li <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> 85*67e74705SXin Li 86*67e74705SXin 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> 87*67e74705SXin Li 88*67e74705SXin 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> 89*67e74705SXin Li 90*67e74705SXin 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> 91*67e74705SXin Li 92*67e74705SXin 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> 93*67e74705SXin Li 94*67e74705SXin 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> 95*67e74705SXin Li 96*67e74705SXin 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> 97*67e74705SXin Li</ol> 98*67e74705SXin Li 99*67e74705SXin Li</div> 100*67e74705SXin Li</body> 101*67e74705SXin Li</html> 102