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>Open Clang Projects</h1> 17 18<p>Here are a few tasks that are available for newcomers to work on, depending 19on what your interests are. This list is provided to generate ideas, it is not 20intended to be comprehensive. Please ask on cfe-dev for more specifics or to 21verify that one of these isn't already completed. :)</p> 22 23<ul> 24<li><b>Compile your favorite C/ObjC project with Clang</b>: 25Clang's type-checking and code generation is very close to complete (but not bug free!) for C and Objective-C. We appreciate all reports of code that is 26rejected or miscompiled by the front-end. If you notice invalid code that is not rejected, or poor diagnostics when code is rejected, that is also very important to us. For make-based projects, 27the <a href="get_started.html#driver"><code>clang</code></a> driver works as a drop-in replacement for GCC.</li> 28 29<li><b>Undefined behavior checking</b>: CodeGen could 30insert runtime checks for all sorts of different undefined behaviors, from 31reading uninitialized variables, buffer overflows, and many other things. This 32checking would be expensive, but the optimizers could eliminate many of the 33checks in some cases, and it would be very interesting to test code in this mode 34for certain crowds of people. Because the inserted code is coming from clang, 35the "abort" message could be very detailed about exactly what went wrong.</li> 36 37<li><b>Improve target support</b>: The current target interfaces are heavily 38stubbed out and need to be implemented fully. See the FIXME's in TargetInfo. 39Additionally, the actual target implementations (instances of TargetInfoImpl) 40also need to be completed.</li> 41 42<li><b>Implement an tool to generate code documentation</b>: Clang's 43library-based design allows it to be used by a variety of tools that reason 44about source code. One great application of Clang would be to build an 45auto-documentation system like doxygen that generates code documentation from 46source code. The advantage of using Clang for such a tool is that the tool would 47use the same preprocessor/parser/ASTs as the compiler itself, giving it a very 48rich understanding of the code.</li> 49 50<li><b>Use clang libraries to implement better versions of existing tools</b>: 51Clang is built as a set of libraries, which means that it is possible to 52implement capabilities similar to other source language tools, improving them 53in various ways. Two examples are <a href="http://distcc.samba.org/">distcc</a> 54and the <a href="http://delta.tigris.org/">delta testcase reduction tool</a>. 55The former can be improved to scale better and be more efficient. The latter 56could also be faster and more efficient at reducing C-family programs if built 57on the clang preprocessor.</li> 58 59<li><b>Use clang libraries to extend Ragel with a JIT</b>: <a 60href="http://research.cs.queensu.ca/~thurston/ragel/">Ragel</a> is a state 61machine compiler that lets you embed C code into state machines and generate 62C code. It would be relatively easy to turn this into a JIT compiler using 63LLVM.</li> 64 65<li><b>Self-testing using clang</b>: There are several neat ways to 66improve the quality of clang by self-testing. Some examples: 67<ul> 68 <li>Improve the reliability of AST printing and serialization by 69 ensuring that the AST produced by clang on an input doesn't change 70 when it is reparsed or unserialized. 71 72 <li>Improve parser reliability and error generation by automatically 73 or randomly changing the input checking that clang doesn't crash and 74 that it doesn't generate excessive errors for small input 75 changes. Manipulating the input at both the text and token levels is 76 likely to produce interesting test cases. 77</ul> 78</li> 79 80<li><b>Continue work on C++ support</b>: Implementing all of C++ is a very big 81job, but there are lots of little pieces that can be picked off and implemented. Here are some small- to mid-sized C++ implementation projects: 82<ul> 83 <li>Fix bugs: there are a number of XFAIL'd test cases in Clang's repository (particularly in the CXX subdirectory). Pick a test case and fix Clang to make it work!</li> 84 <li>Write tests: the CXX test subdirectory in Clang's repository has placeholders for tests of every paragraph in the C++ standard. Pick a paragraph, write a few tests, and see if they work! Even if they don't we'd still like the new tests (with XFAIL'd) so that we know what to fix.</li> 85 <li>Explicit calls to destructors and pseudo-destructor expressions (<code>x.~X()</code>).</li> 86 <li>AST representation for implicit C++ conversions: implicit conversions that involve non-trivial operations (e.g., invoking a user-defined conversion function, performing a base-to-derived or derived-to-base conversion) need explicit representation in Clang's AST.</li> 87 <li>Default arguments for function templates: these are currently ignored.</li> 88 <li>Parsing and semantic analysis for using declarations in classes</li> 89</ul> 90 91Also, see the <a href="cxx_status.html">C++ status report page</a> to 92find out what is missing and what is already at least partially 93supported.</li> 94</ul> 95 96<p>If you hit a bug with clang, it is very useful for us if you reduce the code 97that demonstrates the problem down to something small. There are many ways to 98do this; ask on cfe-dev for advice.</p> 99 100</div> 101</body> 102</html> 103