Author: emmettneyman Date: Thu Aug 16 13:13:40 2018 New Revision: 339933 URL: http://llvm.org/viewvc/llvm-project?rev=339933&view=rev Log: Update README and Dockerfile to include llvm-proto-fuzzer
Summary: Added commands to Dockerfile to build llvm-proto-fuzzer and the other related tools. Also added a section to the bottom of the README describing what llvm-proto-fuzzer does and how to run it. Reviewers: morehouse, kcc Reviewed By: morehouse Subscribers: cfe-commits, llvm-commits Differential Revision: https://reviews.llvm.org/D50829 Modified: cfe/trunk/tools/clang-fuzzer/Dockerfile cfe/trunk/tools/clang-fuzzer/README.txt Modified: cfe/trunk/tools/clang-fuzzer/Dockerfile URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/tools/clang-fuzzer/Dockerfile?rev=339933&r1=339932&r2=339933&view=diff ============================================================================== --- cfe/trunk/tools/clang-fuzzer/Dockerfile (original) +++ cfe/trunk/tools/clang-fuzzer/Dockerfile Thu Aug 16 13:13:40 2018 @@ -35,3 +35,7 @@ RUN mkdir build1 && cd build1 && cmake - RUN cd build1 && ninja clang-fuzzer RUN cd build1 && ninja clang-proto-fuzzer RUN cd build1 && ninja clang-proto-to-cxx +RUN cd build1 && ninja clang-loop-proto-to-cxx +RUN cd build1 && ninja clang-loop-proto-to-llvm +RUN cd build1 && ninja clang-loop-proto-fuzzer +RUN cd build1 && ninja clang-llvm-proto-fuzzer Modified: cfe/trunk/tools/clang-fuzzer/README.txt URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/tools/clang-fuzzer/README.txt?rev=339933&r1=339932&r2=339933&view=diff ============================================================================== --- cfe/trunk/tools/clang-fuzzer/README.txt (original) +++ cfe/trunk/tools/clang-fuzzer/README.txt Thu Aug 16 13:13:40 2018 @@ -80,3 +80,37 @@ custom optimization level and target tri To translate a clang-proto-fuzzer corpus output to C++: bin/clang-proto-to-cxx CORPUS_OUTPUT_FILE + +=================== + llvm-proto-fuzzer +=================== +Like, clang-proto-fuzzer, llvm-proto-fuzzer is also a protobuf-mutator based +fuzzer. It receives as input a cxx_loop_proto which it then converts into a +string of valid LLVM IR: a function with either a single loop or two nested +loops. It then creates a new string of IR by running optimization passes over +the original IR. Currently, it only runs a loop-vectorize pass but more passes +can easily be added to the fuzzer. Once there are two versions of the input +function (optimized and not), llvm-proto-fuzzer uses LLVM's JIT Engine to +compile both functions. Lastly, it runs both functions on a suite of inputs and +checks that both functions behave the same on all inputs. In this way, +llvm-proto-fuzzer can find not only compiler crashes, but also miscompiles +originating from LLVM's optimization passes. + +llvm-proto-fuzzer is built very similarly to clang-proto-fuzzer. You can run the +fuzzer with the following command: + bin/clang-llvm-proto-fuzzer CORPUS_DIR + +To translate a cxx_loop_proto file into LLVM IR do: + bin/clang-loop-proto-to-llvm CORPUS_OUTPUT_FILE +To translate a cxx_loop_proto file into C++ do: + bin/clang-loop-proto-to-cxx CORPUS_OUTPUT_FILE + +Note: To get a higher number of executions per second with llvm-proto-fuzzer it +helps to build it without ASan instrumentation and with the -O2 flag. Because +the fuzzer is not only compiling code, but also running it, as the inputs get +large, the time necessary to fuzz one input can get very high. +Example: + cmake .. -GNinja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ \ + -DCLANG_ENABLE_PROTO_FUZZER=ON -DLLVM_USE_SANITIZE_COVERAGE=YES \ + -DCMAKE_CXX_FLAGS="-O2" + ninja clang-llvm-proto-fuzzer clang-loop-proto-to-llvm _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
