Research project on randomization for WebAssembly/WASM.

• Python version 3.7

• Download our changed version of Souper. The main reason behind is that we include some extra options to be able of working together with the SLUMPs core. After downloading all the submodules in SLUMPs, build every one of them following the respective instructions in the original repos.

  Inside the souper folder:

  ./build_deps.sh
  mkdir build
  cd build
  cmake  ../
  make

• Build wabt toolkit to provide the WASM to WAT conversion for debugging reasons.

  Follow this instructions inside the wabt folder:

  git submodule update --init
  mkdir build
  cd build
  cmake ..
  cmake --build .

• Install the python requirements: pip3 install -r crow/requirements.txt

• CROW shows a fail in the CLANG step: Install emscripten and run it as follows emcc -v <file>.c. Then copy all the include files in the include configuration for CROW.
• CROW shows a fail connecting to REDIS: Install Redis in your local pc and ensure that its running, or change the usage of external cache in the Souper config.
• CROW doesn't find the souper folder: Check the path in the settings file

• Optimization subset strategy: generator-method = subset | onexone | all

• Output only different binaries: prune-equal, we calculate the sha256 value for evey WASM program, then we keep only the programs with different sha values.

Change the remaining values to get different results, for instance, add extra arguments to the CLANG step.

In the project root, run bash run.sh <number_of_concurrent_generators> <file.(c|bc)>, collect the output in the folder crow_out

To run CROW in an easy way, we provide a Docker image which contains the plumping to work with Souper (our modest changed version), binaryen and wabt. To build it, run: docker build -t slumps/backend:latest -m 8g -f Dockerfile inside the docker_images folder.

If the LLVM build takes to long or fails due to memory lack in the image building: > Increase memory and/or CPU ressources in the docker engine configuration

Bothg images are avaiable in the docker Hub

The application can be ported to a docker container too. To execute SLUMPs, enter in the src file and build the docker image. Run the following command to start the application docker run -it -v $(pwd):/inputs -v $(pwd)/<logs>:/slumps/src/logs -v $(pwd)/<out folder>:/slumps/src/out slumps/crow:latest <program> <config-options> . Slumps will process the fetched code from the arguments, exporting the results to the out folder volumen. You can specify the config parameters, specify the values of <config-options> as %<namespace>.key <value>. For example, to change the timeout per program use <docker_run> %DEFAULT.timeout 3600 <program_url>, this example changes the timeout to 3600 seconds. The other available options and possible values are listed below.

Slides

We added some features/options to Souper:

• souper-subset: Based on the candidate indexes, specify the candidates to be applied, for example -souper-subset=1,2,3,4 or -souper-subset=0,3
• souper-valid-count: Search for successful optimizations without replacing
• souper-redis-host: Host for redis
• souper-redis-pass: Password for redis connection
• souper-crow-workers: Number of concurrent threads looking for replacements
• souper-crow-port: To which socket port send the found replacement information

• LLVM frontend for WASM: This will provide the WASM -> WASM behavior in CROW