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> 32and has a Discourse forum and mailing list:</p> 33 34<ul> 35<li><a href="https://discourse.llvm.org/c/clang/6">Clang Frontend Discourse forum</a> - 36This forum is for discussions related to Clang (questions and answers, design 37discussions, RFCs, etc).</li> 38 39<li><a href="https://discord.gg/xS7Z362">Discord chat</a> - Real-time chat for 40discussions related to Clang (primarily for questions and answers).</li> 41 42<li>Regular meetings are held on the 43<a href="https://drive.google.com/file/d/1S7V0MHP4xMs1yUQ9Gv9LHn5bwDfFVapn/view?usp=sharing"> 44first and third Wednesday</a> of each month to discuss C and C++ 45standards-related activities happening within the Clang community. These 46meetings are a way to coordinate efforts between implementers and provide 47updates on how standards activities are going. Meeting agendas and minutes are 48available 49<a href="https://docs.google.com/document/d/1x5-RbOC6-jnI_NcJ9Dp4pSmGhhNe7lUevuWUIB46TeM/edit?usp=sharing"> 50here<a>. 51</li> 52 53<li><a href="https://llvm.org/docs/GettingInvolved.html#office-hours">Clang office hours</a> - 54People within the community hold dedicated office hours at different points 55during the month, which is a great way opportunity for getting questions 56answered, having more in-depth design discussions, or learning about what's 57going on in the community in general.</li> 58 59<li><a href="https://lists.llvm.org/mailman/listinfo/cfe-commits">cfe-commits 60</a> - Historical record of commits to Clang and contains early community patch 61review commentary.</li> 62 63</ul> 64 65<p>The most common way to talk with other developers on the project is through 66the <a href="https://discourse.llvm.org/c/clang/6">Clang Frontend Discourse forum 67</a>. The clang forum is a very friendly place and we welcome newcomers. The 68forum is archived so you can browse through previous discussions or follow 69development on the web if you prefer.</p> 70 71<p>If you're looking for something to work on, check out our <a 72href="OpenProjects.html">Open Projects</a> page or look through the <a 73href="https://github.com/llvm/llvm-project/issues/">LLVM bug tracker</a>.</p> 74 75<h2 id="criteria">Contributing Extensions to Clang</h2> 76 77<p>Clang is designed to support experimentation, 78allowing programmers to easily extend the compiler to support great 79new language features and tools. At some point, the authors of these 80extensions may propose that the extensions become a part of Clang 81itself, to benefit the whole Clang community. However, extensions 82(particularly language extensions) have long-term maintenance costs 83for Clang. The benefits of the extension need to be evaluated against 84these costs. The Clang project uses the following criteria for this 85evaluation:</p> 86 87<ol> 88 <li>Evidence of a significant user community: This is based on a number of 89 factors, including an existing user community, the perceived likelihood that 90 users would adopt such a feature if it were available, and any secondary 91 effects that come from, e.g., a library adopting the feature and providing 92 benefits to its users.</li> 93 94 <li>A specific need to reside within the Clang tree: There are some extensions 95 that would be better expressed as a separate tool, and should remain as 96 separate tools even if they end up being hosted as part of the LLVM umbrella 97 project.</li> 98 99 <li>A specification: The specification must be sufficient to understand the 100 design of the feature as well as interpret the meaning of specific examples. 101 The specification should be detailed enough that another compiler vendor 102 could implement the feature.</li> 103 104 <li>Representation within the appropriate governing organization: For 105 extensions to a language governed by a standards committee (C, C++, OpenCL), 106 the extension itself must have an active proposal and proponent within that 107 committee and have a reasonable chance of acceptance. Clang should drive the 108 standard, not diverge from it. This criterion does not apply to all 109 extensions, since some extensions fall outside of the realm of the standards 110 bodies.</li> 111 112 <li>A long-term support plan: increasingly large or complex extensions to 113 Clang need matching commitments to supporting them over time, including 114 improving their implementation and specification as Clang evolves. The 115 capacity of the contributor to make that commitment is as important as the 116 commitment itself.</li> 117 118 <li>A high-quality implementation: The implementation must fit well into 119 Clang's architecture, follow LLVM's coding conventions, and meet Clang's 120 quality standards, including diagnostics and complete AST 121 representations. This is particularly important for language extensions, 122 because users will learn how those extensions work through the behavior of the 123 compiler.</li> 124 125 <li>A test suite: Extensive testing is crucial to ensure that the language 126 extension is not broken by ongoing maintenance in Clang. The test suite 127 should be complete enough that another compiler vendor could conceivably 128 validate their implementation of the feature against it.</li> 129 130 <li>A support story for other impacted projects within the monorepo: If the 131 extension can impact other parts of the project (libc++, lldb, compiler-rt, 132 etc), the proposal needs to document the impact for these projects to fully 133 support the extension and what level of support is expected. The impacted 134 project communities need to agree with that plan.</li> 135</ol> 136 137</div> 138</body> 139</html> 140