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Open Clang Projects

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Here are a few tasks that are available for newcomers to work on, depending +on what your interests are. This list is provided to generate ideas, it is not +intended to be comprehensive. Please ask on cfe-dev for more specifics or to +verify that one of these isn't already completed. :)

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Compile your favorite C/ObjC project with Clang: +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 ccc driver works as a drop-in replacement for GCC.
Overflow detection: 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.
Undefined behavior checking: 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.
Continue work on C++ support: 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 C++ status report page to find out what is +missing and what is already at least partially supported.
Improve target support: The current target interfaces are heavily +stubbed out and need to be implemented fully. See the FIXME's in TargetInfo. +Additionally, the actual target implementations (instances of TargetInfoImpl) +also need to be completed.
Implement an tool to generate code documentation: Clang's +library-based design allows it to be used by a variety of tools that reason +about source code. One great application of Clang would be to build an +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.
Use clang libraries to implement better versions of existing tools: +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 distcc +and the delta testcase reduction tool. +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.
Use clang libraries to extend Ragel with a JIT: Ragel is a state +machine compiler that lets you embed C code into state machines and generate +C code. It would be relatively easy to turn this into a JIT compiler using +LLVM.
Self-testing using clang: There are several neat ways to +improve the quality of clang by self-testing. Some examples: +
- Improve the reliability of AST printing and serialization by + ensuring that the AST produced by clang on an input doesn't change + when it is reparsed or unserialized. + +
- Improve parser reliability and error generation by automatically + or randomly changing the input checking that clang doesn't crash and + that it doesn't generate excessive errors for small input + changes. Manipulating the input at both the text and token levels is + likely to produce interesting test cases. +
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If you hit a bug with clang, it is very useful for us if you reduce the code +that demonstrates the problem down to something small. There are many ways to +do this; ask on cfe-dev for advice.

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Open Projects

Here are a few tasks that are available for newcomers to work on, depending -on what your interests are. This list is provided to generate ideas, it is not -intended to be comprehensive. Please ask on cfe-dev for more specifics or to -verify that one of these isn't already completed. :)

If you hit a bug with clang, it is very useful for us if you reduce the code -that demonstrates the problem down to something small. There are many ways to -do this; ask on cfe-dev for advice.