[llvm] r227252 - Add a Fuzzer library

[Pasi Parviainen]

On 28.1.2015 0:08, Kostya Serebryany wrote:
> Author: kcc
> Date: Tue Jan 27 16:08:41 2015
> New Revision: 227252
>
> URL: http://llvm.org/viewvc/llvm-project?rev=227252&view=rev
> Log:
> Add a Fuzzer library
>
> Summary:
> A simple genetic in-process coverage-guided fuzz testing library.
>
> I've used this fuzzer to test clang-format
> (it found 12+ bugs, thanks djasper@ for the fixes!)
> and it may also help us test other parts of LLVM.
> So why not keep it in the LLVM repository?
>
> I plan to add the cmake build rules later (in a separate patch, if that's ok)
> and also add a clang-format-fuzzer target.
>
> See README.txt for details.
>
> Test Plan: Tests will follow separately.
>
> Reviewers: djasper, chandlerc, rnk
>
> Reviewed By: rnk
>
> Subscribers: majnemer, ygribov, dblaikie, llvm-commits
>
> Differential Revision: http://reviews.llvm.org/D7184
>
> Added:
>      llvm/trunk/lib/Fuzzer/
>      llvm/trunk/lib/Fuzzer/CMakeLists.txt
>      llvm/trunk/lib/Fuzzer/FuzzerCrossOver.cpp
>      llvm/trunk/lib/Fuzzer/FuzzerFlags.def
>      llvm/trunk/lib/Fuzzer/FuzzerIO.cpp
>      llvm/trunk/lib/Fuzzer/FuzzerInternal.h
>      llvm/trunk/lib/Fuzzer/FuzzerLoop.cpp
>      llvm/trunk/lib/Fuzzer/FuzzerMain.cpp
>      llvm/trunk/lib/Fuzzer/FuzzerMutate.cpp
>      llvm/trunk/lib/Fuzzer/FuzzerUtil.cpp
>      llvm/trunk/lib/Fuzzer/README.txt
>      llvm/trunk/lib/Fuzzer/test/
>      llvm/trunk/lib/Fuzzer/test/ExactTest.cpp
>      llvm/trunk/lib/Fuzzer/test/InfiniteTest.cpp
>      llvm/trunk/lib/Fuzzer/test/NullDerefTest.cpp
>      llvm/trunk/lib/Fuzzer/test/SimpleTest.cpp
>      llvm/trunk/lib/Fuzzer/test/TestFuzzerCrossOver.cpp
>      llvm/trunk/lib/Fuzzer/test/TimeoutTest.cpp
> Modified:
>      llvm/trunk/lib/CMakeLists.txt

Putting this library directly under lib/ tree feels a little bit out of 
place. Perhaps utils/ or even tools/ trees would be more appropriate 
locations for this library, since most of its value is in testing (on 
limited environments, see below).

> Modified: llvm/trunk/lib/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CMakeLists.txt?rev=227252&r1=227251&r2=227252&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CMakeLists.txt (original)
> +++ llvm/trunk/lib/CMakeLists.txt Tue Jan 27 16:08:41 2015
> @@ -17,3 +17,4 @@ add_subdirectory(Target)
>   add_subdirectory(AsmParser)
>   add_subdirectory(LineEditor)
>   add_subdirectory(ProfileData)
> +add_subdirectory(Fuzzer)
>
> Added: llvm/trunk/lib/Fuzzer/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Fuzzer/CMakeLists.txt?rev=227252&view=auto
> ==============================================================================
> --- llvm/trunk/lib/Fuzzer/CMakeLists.txt (added)
> +++ llvm/trunk/lib/Fuzzer/CMakeLists.txt Tue Jan 27 16:08:41 2015
> @@ -0,0 +1,9 @@
> +add_library(LLVMFuzzer STATIC
> +  EXCLUDE_FROM_ALL  # Do not build if you are not building fuzzers.
> +  FuzzerCrossOver.cpp
> +  FuzzerIO.cpp
> +  FuzzerLoop.cpp
> +  FuzzerMain.cpp
> +  FuzzerMutate.cpp
> +  FuzzerUtil.cpp
> +  )
>

This target should only be added when build environment can satisfy its 
requirements (sufficient posix interfaces + asan support), otherwise 
there will be a build target which is known to fail. Fuzzers depending 
on this library can then simply enable themselves by existence of this 
target.

Pasi.