Dagger

Dagger is a binary translator to LLVM IR, with the goal of being as native as possible to the LLVM infrastructure.

Building

As an LLVM fork, Dagger is built the same way; assuming you have a reasonably recent toolchain and CMake, just do:

  $ cd dagger
  $ mkdir build
  $ cd build
  $ cmake ..
  $ make

More information on the llvm.org Getting Started and CMake pages.

Usage

While Dagger is intended to be usable as a library, it does come with tools:

Static Binary Translation to IR: llvm-dec

llvm-dec takes in an object file and produces IR.

  $ ./bin/llvm-dec ./a.out

Dynamic Binary Translation: DYN (OS X-only)

DYN is an OS X-only dylib that is intended to be preloaded so that it can hijack program execution:

  $ echo "int main() { return 42; }" | clang -x c -
  $ DYLD_INSERT_LIBRARIES=./lib/libDYN.dylib ./a.out
  $ echo $?
 42

This will "execute" a.out by translating all of its code to LLVM IR, JITting that, and finally executing it.

The DCDYN_OPTIONS environment variable can be used to pass command-line options. For instance, if you're really brave, you can try:

 $ DCDYN_OPTIONS="-print-after-all" DYLD_INSERT_LIBRARIES=build/lib/libDYN.dylib ./a.out

which will print tons of LLVM debug output.

Features

X86 is the main currently supported target. There is ongoing work on adding AArch64 support.

The Mach-O object file format is the best supported. Basic ELF is also supported. However, except for DYN, there is always a generic fallback, so YMMV with other formats.