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 19played around with it, you might be wondering what you can do to make it better 20and contribute to its development. Alternatively, maybe you just want to follow 21the development of the project to see it progress. 22</p> 23 24<h2>Contribute</h2> 25 26See the <a href="hacking.html">hacking</a> document for information on how 27to author patches. 28 29<h2>Follow what's going on</h2> 30 31<p>Clang is a subproject of the <a href="https://llvm.org">LLVM Project</a>, but 32has its own mailing lists because the communities have people with different 33interests. The two clang lists are:</p> 34 35<ul> 36<li><a href="https://lists.llvm.org/mailman/listinfo/cfe-commits">cfe-commits 37</a> - This list is for patch submission/discussion.</li> 38 39<li><a href="https://lists.llvm.org/mailman/listinfo/cfe-dev">cfe-dev</a> - 40This list is for everything else Clang related (questions and answers, design 41discussions, etc).</li> 42 43</ul> 44 45<p>If you are interested in clang only, these two lists should be all 46you need. If you are interested in the LLVM optimizer and code generator, 47please consider signing up for <a 48href="https://lists.llvm.org/mailman/listinfo/llvm-dev">llvm-dev</a> and <a 49href="https://lists.llvm.org/mailman/listinfo/llvm-commits">llvm-commits</a> 50as well.</p> 51 52 53<p>The most common way to talk with other developers on the project is through 54the <a href="https://lists.llvm.org/mailman/listinfo/cfe-dev">cfe-dev mailing 55list</a>. The clang mailing list is a very friendly place and we welcome 56newcomers. In addition to the cfe-dev list, a significant amount of design 57discussion takes place on the <a 58href="https://lists.llvm.org/mailman/listinfo/cfe-commits">cfe-commits mailing 59list</a>. All of these lists have archives, so you can browse through previous 60discussions or follow the list development on the web if you prefer.</p> 61 62<p>You can also follow the <a href="http://planet.clang.org/">Planet Clang</a> 63community news feed which offers a window into the world, work and lives of 64Clang developers, contributors and the standards they implement.</p> 65 66<p>If you're looking for something to work on, check out our <a 67href="OpenProjects.html">Open Projects</a> page or look through the <a 68href="https://bugs.llvm.org/">Bugzilla bug database</a>.</p> 69 70<h2 id="criteria">Contributing Extensions to Clang</h2> 71 72<p>Clang is designed to support experimentation, 73allowing programmers to easily extend the compiler to support great 74new language features and tools. At some point, the authors of these 75extensions may propose that the extensions become a part of Clang 76itself, to benefit the whole Clang community. However, extensions 77(particularly language extensions) have long-term maintenance costs 78for Clang. The benefits of the extension need to be evaluated against 79these costs. The Clang project uses the following criteria for this 80evaluation:</p> 81 82<ol> 83 <li>Evidence of a significant user community: This is based on a number of 84 factors, including an existing user community, the perceived likelihood that 85 users would adopt such a feature if it were available, and any secondary 86 effects that come from, e.g., a library adopting the feature and providing 87 benefits to its users.</li> 88 89 <li>A specific need to reside within the Clang tree: There are some extensions 90 that would be better expressed as a separate tool, and should remain as 91 separate tools even if they end up being hosted as part of the LLVM umbrella 92 project.</li> 93 94 <li>A specification: The specification must be sufficient to understand the 95 design of the feature as well as interpret the meaning of specific examples. 96 The specification should be detailed enough that another compiler vendor 97 could implement the feature.</li> 98 99 <li>Representation within the appropriate governing organization: For 100 extensions to a language governed by a standards committee (C, C++, OpenCL), 101 the extension itself must have an active proposal and proponent within that 102 committee and have a reasonable chance of acceptance. Clang should drive the 103 standard, not diverge from it. This criterion does not apply to all 104 extensions, since some extensions fall outside of the realm of the standards 105 bodies.</li> 106 107 <li>A long-term support plan: increasingly large or complex extensions to 108 Clang need matching commitments to supporting them over time, including 109 improving their implementation and specification as Clang evolves. The 110 capacity of the contributor to make that commitment is as important as the 111 commitment itself.</li> 112 113 <li>A high-quality implementation: The implementation must fit well into 114 Clang's architecture, follow LLVM's coding conventions, and meet Clang's 115 quality standards, including diagnostics and complete AST 116 representations. This is particularly important for language extensions, 117 because users will learn how those extensions work through the behavior of the 118 compiler.</li> 119 120 <li>A test suite: Extensive testing is crucial to ensure that the language 121 extension is not broken by ongoing maintenance in Clang. The test suite 122 should be complete enough that another compiler vendor could conceivably 123 validate their implementation of the feature against it.</li> 124</ol> 125 126</div> 127</body> 128</html> 129