1f4a2713aSLionel Sambuc<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" 2f4a2713aSLionel Sambuc "http://www.w3.org/TR/html4/strict.dtd"> 3f4a2713aSLionel Sambuc<html> 4f4a2713aSLionel Sambuc<head> 5f4a2713aSLionel Sambuc <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> 6f4a2713aSLionel Sambuc <title>Clang - Get Involved</title> 7f4a2713aSLionel Sambuc <link type="text/css" rel="stylesheet" href="menu.css"> 8f4a2713aSLionel Sambuc <link type="text/css" rel="stylesheet" href="content.css"> 9f4a2713aSLionel Sambuc</head> 10f4a2713aSLionel Sambuc<body> 11f4a2713aSLionel Sambuc 12f4a2713aSLionel Sambuc<!--#include virtual="menu.html.incl"--> 13f4a2713aSLionel Sambuc 14f4a2713aSLionel Sambuc<div id="content"> 15f4a2713aSLionel Sambuc 16f4a2713aSLionel Sambuc<h1>Getting Involved with the Clang Project</h1> 17f4a2713aSLionel Sambuc 18f4a2713aSLionel Sambuc<p>Once you have <a href="get_started.html">checked out and built</a> clang and 19f4a2713aSLionel Sambucplayed around with it, you might be wondering what you can do to make it better 20f4a2713aSLionel Sambucand contribute to its development. Alternatively, maybe you just want to follow 21f4a2713aSLionel Sambucthe development of the project to see it progress. 22f4a2713aSLionel Sambuc</p> 23f4a2713aSLionel Sambuc 24*0a6a1f1dSLionel Sambuc<h2>Contribute</h2> 25*0a6a1f1dSLionel Sambuc 26*0a6a1f1dSLionel SambucSee the <a href="hacking.html">hacking</a> document for information on how 27*0a6a1f1dSLionel Sambucto author patches. 28*0a6a1f1dSLionel Sambuc 29f4a2713aSLionel Sambuc<h2>Follow what's going on</h2> 30f4a2713aSLionel Sambuc 31f4a2713aSLionel Sambuc<p>Clang is a subproject of the <a href="http://llvm.org">LLVM Project</a>, but 32f4a2713aSLionel Sambuchas its own mailing lists because the communities have people with different 33f4a2713aSLionel Sambucinterests. The two clang lists are:</p> 34f4a2713aSLionel Sambuc 35f4a2713aSLionel Sambuc<ul> 36f4a2713aSLionel Sambuc<li><a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits">cfe-commits 37f4a2713aSLionel Sambuc</a> - This list is for patch submission/discussion.</li> 38f4a2713aSLionel Sambuc 39f4a2713aSLionel Sambuc<li><a href="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">cfe-dev</a> - 40f4a2713aSLionel SambucThis list is for everything else Clang related (questions and answers, design 41f4a2713aSLionel Sambucdiscussions, etc).</li> 42f4a2713aSLionel Sambuc 43f4a2713aSLionel Sambuc</ul> 44f4a2713aSLionel Sambuc 45f4a2713aSLionel Sambuc<p>If you are interested in clang only, these two lists should be all 46f4a2713aSLionel Sambucyou need. If you are interested in the LLVM optimizer and code generator, 47f4a2713aSLionel Sambucplease consider signing up for <a 48f4a2713aSLionel Sambuchref="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev">llvmdev</a> and <a 49f4a2713aSLionel Sambuchref="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits">llvm-commits</a> 50f4a2713aSLionel Sambucas well.</p> 51f4a2713aSLionel Sambuc 52f4a2713aSLionel Sambuc 53f4a2713aSLionel Sambuc<p>The best way to talk with other developers on the project is through the <a 54f4a2713aSLionel Sambuchref="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev">cfe-dev mailing 55f4a2713aSLionel Sambuclist</a>. The clang mailing list is a very friendly place and we welcome 56f4a2713aSLionel Sambucnewcomers. In addition to the cfe-dev list, a significant amount of design 57f4a2713aSLionel Sambucdiscussion takes place on the <a 58f4a2713aSLionel Sambuchref="http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits">cfe-commits mailing 59f4a2713aSLionel Sambuclist</a>. All of these lists have archives, so you can browse through previous 60f4a2713aSLionel Sambucdiscussions or follow the list development on the web if you prefer.</p> 61f4a2713aSLionel Sambuc 62*0a6a1f1dSLionel Sambuc<p>You can also follow the <a href="http://planet.clang.org/">Planet Clang</a> 63*0a6a1f1dSLionel Sambuccommunity news feed which offers a window into the world, work and lives of 64*0a6a1f1dSLionel SambucClang developers, contributors and the standards they implement.</p> 65*0a6a1f1dSLionel Sambuc 66*0a6a1f1dSLionel Sambuc<p>If you're looking for something to work on, check out our <a 67*0a6a1f1dSLionel Sambuchref="OpenProjects.html">Open Projects</a> page or look through the <a 68*0a6a1f1dSLionel Sambuchref="http://llvm.org/bugs/">Bugzilla bug database</a>.</p> 69f4a2713aSLionel Sambuc 70f4a2713aSLionel Sambuc<h2 id="criteria">Contributing Extensions to Clang</h2> 71f4a2713aSLionel Sambuc 72f4a2713aSLionel Sambuc<p>Clang has always been designed as a platform for experimentation, 73f4a2713aSLionel Sambucallowing programmers to easily extend the compiler to support great 74f4a2713aSLionel Sambucnew language features and tools. At some point, the authors of these 75f4a2713aSLionel Sambucextensions may propose that the extensions become a part of Clang 76f4a2713aSLionel Sambucitself, to benefit the whole Clang community. But not every idea--not 77f4a2713aSLionel Sambuceven every great idea--should become part of Clang. Extensions 78f4a2713aSLionel Sambuc(particularly language extensions) pose a long-term maintenance burden 79f4a2713aSLionel Sambucon Clang, and therefore the benefits of the extension must outweight 80f4a2713aSLionel Sambucthose costs. Hence, these are the seven criteria used to evaluate the 81f4a2713aSLionel Sambucmerits of a proposed extension:</p> 82f4a2713aSLionel Sambuc 83f4a2713aSLionel Sambuc<ol> 84f4a2713aSLionel Sambuc <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> 85f4a2713aSLionel Sambuc 86f4a2713aSLionel Sambuc <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> 87f4a2713aSLionel Sambuc 88f4a2713aSLionel Sambuc <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> 89f4a2713aSLionel Sambuc 90f4a2713aSLionel Sambuc <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> 91f4a2713aSLionel Sambuc 92f4a2713aSLionel Sambuc <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> 93f4a2713aSLionel Sambuc 94f4a2713aSLionel Sambuc <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> 95f4a2713aSLionel Sambuc 96f4a2713aSLionel Sambuc <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> 97f4a2713aSLionel Sambuc</ol> 98f4a2713aSLionel Sambuc 99f4a2713aSLionel Sambuc</div> 100f4a2713aSLionel Sambuc</body> 101f4a2713aSLionel Sambuc</html> 102