This repo is based off the official LLVM git mirror: http://llvm.org/git/llvm.git. We have added passes which randomize the implementation details of the code to combat code-reuse attacks.

Follow the LLVM instructions from http://llvm.org/docs/GettingStarted.html#git-mirror but substitute this repo for the llvm.git repo and https://github.com/securesystemslab/multicompiler-clang for the clang.git repo.

-fdiversify - Enable diversity. This is a shortcut for -Xclang -nop-insertion and -mllvm -sched-randomize.

-frandom-seed=S - Set the random seed to some 64-bit unsigned int S. Set this whenever using diversity options.

-Xclang -nop-insertion - Enable the NOP insertion pass.

-mllvm -nop-insertion-percentage=X - Insert NOPs before X% of instructions (default 50%).

-mllvm -max-nops-per-instruction=X - Insert at most X NOPs each time (default 1).

-mllvm -sched-randomize - Enable schedule randomization.

-mllvm -sched-randomize-percentage=X - Randomize X% of the instruction schedule (default 50%).

-Xclang -shuffle-functions - Enable function shuffling.

Currently, functions are shuffled on a per-translation unit basis. Global function shuffling requires building the target program with LTO (link-time optimization).