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