"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
- <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
+ <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Clang - Get Involved</title>
- <link type="text/css" rel="stylesheet" href="menu.css" />
- <link type="text/css" rel="stylesheet" href="content.css" />
+ <link type="text/css" rel="stylesheet" href="menu.css">
+ <link type="text/css" rel="stylesheet" href="content.css">
</head>
<body>
verify that one of these isn't already completed. :)</p>
<ul>
-<li><b>Compile your favorite C/ObjC project with Clang</b>:
-Clang'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
-rejected 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,
-the <a href="get_started.html#ccc"><code>ccc</code></a> driver works as a drop-in replacement for GCC.</li>
-
-<li><b>Overflow detection</b>: an interesting project would be to add a -ftrapv
-compilation mode that causes -emit-llvm to generate overflow tests for all
-signed integer arithmetic operators, and call abort if they overflow. Overflow
-is undefined in C and hard for people to reason about. LLVM IR also has
-intrinsics for generating arithmetic with overflow checks directly.</li>
-
-<li><b>Undefined behavior checking</b>: similar to adding -ftrapv, codegen could
-insert runtime checks for all sorts of different undefined behaviors, from
-reading uninitialized variables, buffer overflows, and many other things. This
-checking would be expensive, but the optimizers could eliminate many of the
-checks in some cases, and it would be very interesting to test code in this mode
-for certain crowds of people. Because the inserted code is coming from clang,
-the "abort" message could be very detailed about exactly what went wrong.</li>
-
-<li><b>Continue work on C++ support</b>: Implementing all of C++ is a very big
-job, but there are lots of little pieces that can be picked off and implemented.
-See the <a href="cxx_status.html">C++ status report page</a> to find out what is
-missing and what is already at least partially supported.</li>
+<li><b>Undefined behavior checking</b>:
+Improve and extend the runtime checks for undefined behavior which CodeGen
+inserts for the various <tt>-fsanitize=</tt> modes. A lot of issues can already
+be caught, but there is more to do here.</li>
<li><b>Improve target support</b>: The current target interfaces are heavily
stubbed out and need to be implemented fully. See the FIXME's in TargetInfo.
auto-documentation system like doxygen that generates code documentation from
source code. The advantage of using Clang for such a tool is that the tool would
use the same preprocessor/parser/ASTs as the compiler itself, giving it a very
-rich understanding of the code.</li>
+rich understanding of the code. Clang is already able to read and understand
+doxygen markup, but cannot yet generate documentation from it.</li>
<li><b>Use clang libraries to implement better versions of existing tools</b>:
Clang is built as a set of libraries, which means that it is possible to
implement capabilities similar to other source language tools, improving them
-in various ways. Two examples are <a href="http://distcc.samba.org/">distcc</a>
-and the <a href="http://delta.tigris.org/">delta testcase reduction tool</a>.
-The former can be improved to scale better and be more efficient. The later
-could also be faster and more efficient at reducing C-family programs if built
-on the clang preprocessor.</li>
+in various ways. Three examples are <a
+href="http://distcc.samba.org/">distcc</a>, the <a
+href="http://delta.tigris.org/">delta testcase reduction tool</a>, and the
+"indent" source reformatting tool.
+distcc can be improved to scale better and be more efficient. Delta could be
+faster and more efficient at reducing C-family programs if built on the clang
+preprocessor. The clang-based indent replacement,
+<a href="http://clang.llvm.org/docs/ClangFormat.html">clang-format</a>,
+could be taught to handle simple structural rules like those in <a
+href="http://llvm.org/docs/CodingStandards.html#hl_earlyexit">the LLVM coding
+standards</a>.</li>
<li><b>Use clang libraries to extend Ragel with a JIT</b>: <a
href="http://research.cs.queensu.ca/~thurston/ragel/">Ragel</a> is a state
</ul>
</li>
+<li><b>Continue work on C++1y support</b>:
+ C++98 and C++11 are feature-complete, but there are still several C++1y features to
+ implement. Please see the <a href="cxx_status.html">C++ status report
+ page</a> to find out what is missing.</li>
+
+<li><b>StringRef'ize APIs</b>: A thankless but incredibly useful project is
+StringRef'izing (converting to use <tt>llvm::StringRef</tt> instead of <tt>const
+char *</tt> or <tt>std::string</tt>) various clang interfaces. This generally
+simplifies the code and makes it more efficient.</li>
+
+<li><b>Universal Driver</b>: Clang is inherently a cross compiler. We would like
+to define a new model for cross compilation which provides a great user
+experience -- it should be easy to cross compile applications, install support
+for new architectures, access different compilers and tools, and be consistent
+across different platforms. See the <a href="UniversalDriver.html">Universal
+Driver</a> web page for more information.</li>
+
+<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:
+ <ul>
+ <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>
+ <li><i>Documented</i>, with appropriate Schema against which the output of Clang's XML formatter can be verified.</li>
+ <li><i>Stable</i> across Clang versions.</li>
+ </ul></li>
+
+<li><b>Configuration Manager</b>: Clang/LLVM works on a large number of
+architectures and operating systems and can cross-compile to a similarly large
+number of configurations, but the pitfalls of chosing the command-line
+options, making sure the right sub-architecture is chosen and that the correct
+optional elements of your particular system can be a pain.
+
+<p>A tool that would investigate hosts and targets, and store the configuration
+in files that can later be used by Clang itself to avoid command-line options,
+especially the ones regarding which target options to use, would greatle alleviate
+this problem. A simple tool, with little or no dependency on LLVM itself, that
+will investigate a target architecture by probing hardware, software, libraries
+and compiling and executing code to identify all properties that would be relevant
+to command-line options (VFP, SSE, NEON, ARM vs. Thumb etc), triple settings etc.</p>
+
+<p>The first stage is to build a CFLAGS for Clang that would produce code on the
+current Host to the identified Target.</p>
+
+<p>The second stage would be to produce a configuration file (that can be used
+independently of the Host) so that Clang can read it and not need a gazillion
+of command-line options. Such file should be simple JSON / INI or anything that
+a text editor could change.</p>
</ul>
<p>If you hit a bug with clang, it is very useful for us if you reduce the code
projects / clang / blobdiff