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 19 on what your interests are. This list is provided to generate ideas, it is not 20 intended to be comprehensive. Please ask on cfe-dev for more specifics or to 21 verify that one of these isn't already completed. :)</p> 22 23 <ul> 24 <li><b>Undefined behavior checking</b>: 25 Improve and extend the runtime checks for undefined behavior which CodeGen 26 inserts for the various <tt>-fsanitize=</tt> modes. A lot of issues can already 27 be caught, but there is more to do here.</li> 28 29 <li><b>Improve target support</b>: The current target interfaces are heavily 30 stubbed out and need to be implemented fully. See the FIXME's in TargetInfo. 31 Additionally, the actual target implementations (instances of TargetInfoImpl) 32 also need to be completed.</li> 33 34 <li><b>Implement an tool to generate code documentation</b>: Clang's 35 library-based design allows it to be used by a variety of tools that reason 36 about source code. One great application of Clang would be to build an 37 auto-documentation system like doxygen that generates code documentation from 38 source code. The advantage of using Clang for such a tool is that the tool would 39 use the same preprocessor/parser/ASTs as the compiler itself, giving it a very 40 rich understanding of the code. Clang is already able to read and understand 41 doxygen markup, but cannot yet generate documentation from it.</li> 42 43 <li><b>Use clang libraries to implement better versions of existing tools</b>: 44 Clang is built as a set of libraries, which means that it is possible to 45 implement capabilities similar to other source language tools, improving them 46 in various ways. Three examples are <a 47 href="http://distcc.samba.org/">distcc</a>, the <a 48 href="http://delta.tigris.org/">delta testcase reduction tool</a>, and the 49 "indent" source reformatting tool. 50 distcc can be improved to scale better and be more efficient. Delta could be 51 faster and more efficient at reducing C-family programs if built on the clang 52 preprocessor. The clang-based indent replacement, 53 <a href="http://clang.llvm.org/docs/ClangFormat.html">clang-format</a>, 54 could be taught to handle simple structural rules like those in <a 55 href="http://llvm.org/docs/CodingStandards.html#hl_earlyexit">the LLVM coding 56 standards</a>.</li> 57 58 <li><b>Use clang libraries to extend Ragel with a JIT</b>: <a 59 href="http://research.cs.queensu.ca/~thurston/ragel/">Ragel</a> is a state 60 machine compiler that lets you embed C code into state machines and generate 61 C code. It would be relatively easy to turn this into a JIT compiler using 62 LLVM.</li> 63 64 <li><b>Self-testing using clang</b>: There are several neat ways to 65 improve the quality of clang by self-testing. Some examples: 66 <ul> 67 <li>Improve the reliability of AST printing and serialization by 68 ensuring that the AST produced by clang on an input doesn't change 69 when it is reparsed or unserialized. 70 71 <li>Improve parser reliability and error generation by automatically 72 or randomly changing the input checking that clang doesn't crash and 73 that it doesn't generate excessive errors for small input 74 changes. Manipulating the input at both the text and token levels is 75 likely to produce interesting test cases. 76 </ul> 77 </li> 78 79 <li><b>Continue work on C++1y support</b>: 80 C++98 and C++11 are feature-complete, but there are still several C++1y features to 81 implement. Please see the <a href="cxx_status.html">C++ status report 82 page</a> to find out what is missing.</li> 83 84 <li><b>StringRef'ize APIs</b>: A thankless but incredibly useful project is 85 StringRef'izing (converting to use <tt>llvm::StringRef</tt> instead of <tt>const 86 char *</tt> or <tt>std::string</tt>) various clang interfaces. This generally 87 simplifies the code and makes it more efficient.</li> 88 89 <li><b>Universal Driver</b>: Clang is inherently a cross compiler. We would like 90 to define a new model for cross compilation which provides a great user 91 experience -- it should be easy to cross compile applications, install support 92 for new architectures, access different compilers and tools, and be consistent 93 across different platforms. See the <a href="UniversalDriver.html">Universal 94 Driver</a> web page for more information.</li> 95 96 <li><b>XML Representation of ASTs</b>: Clang maintains a rich Abstract Syntax Tree that describes the program. Clang could emit an XML document that describes the program, which others tools could consume rather than being tied directly to the Clang binary.The XML representation needs to meet several requirements: 97 <ul> 98 <li><i>General</i>, so that it's able to represent C/C++/Objective-C abstractly, and isn't tied to the specific internal ASTs that Clang uses.</li> 99 <li><i>Documented</i>, with appropriate Schema against which the output of Clang's XML formatter can be verified.</li> 100 <li><i>Stable</i> across Clang versions.</li> 101 </ul></li> 102 103 <li><b>Configuration Manager</b>: Clang/LLVM works on a large number of 104 architectures and operating systems and can cross-compile to a similarly large 105 number of configurations, but the pitfalls of chosing the command-line 106 options, making sure the right sub-architecture is chosen and that the correct 107 optional elements of your particular system can be a pain. 108 109 <p>A tool that would investigate hosts and targets, and store the configuration 110 in files that can later be used by Clang itself to avoid command-line options, 111 especially the ones regarding which target options to use, would greatle alleviate 112 this problem. A simple tool, with little or no dependency on LLVM itself, that 113 will investigate a target architecture by probing hardware, software, libraries 114 and compiling and executing code to identify all properties that would be relevant 115 to command-line options (VFP, SSE, NEON, ARM vs. Thumb etc), triple settings etc.</p> 116 117 <p>The first stage is to build a CFLAGS for Clang that would produce code on the 118 current Host to the identified Target.</p> 119 120 <p>The second stage would be to produce a configuration file (that can be used 121 independently of the Host) so that Clang can read it and not need a gazillion 122 of command-line options. Such file should be simple JSON / INI or anything that 123 a text editor could change.</p> 124 </ul> 125 126 <p>If you hit a bug with clang, it is very useful for us if you reduce the code 127 that demonstrates the problem down to something small. There are many ways to 128 do this; ask on cfe-dev for advice.</p> 129 130 </div> 131 </body> 132 </html> 133
