Compilation

As an alternative to being directly interpreted (the default), Formulog programs can be compiled into a mix of C++ and Souffle code, which can then in turn be compiled into an efficient executable. To enable compilation, set the --codegen (-c) flag; generated code will be placed in the directory ./codegen/ (you can change this using the --codegen-dir option). Within this directory you can use cmake to compile the generated code into a binary named flg.

For example, to compile and execute the greeting.flg program from above, you can use these steps:

java -jar formulog.jar -c examples/greeting.flg && \
  cd codegen && \
  cmake -B build -S . && \
  cmake --build build -j && \
  ./build/flg --dump-idb

This should produce output like the following:

Parsing...
Finished parsing (0.000s)
Evaluating...
Finished evaluating (0.029s)

==================== SELECTED IDB RELATIONS ====================

---------- greeting (3) ----------
greeting("Hello, Bob")
greeting("Hello, World")
greeting("Hello, Alice")

Use the command ./build/flg -h see options available when running the executable.

For more information about the Formulog compiler, see the OOPSLA’24 paper Making Formulog Fast: An Argument for Unconventional Datalog Evaluation by Aaron Bembenek, Michael Greenberg, and Stephen Chong.

Dependencies

To build the generated code, you must have:

• A C++ compiler that supports the C++17 standard (and OpenMP, if you want to produce a parallelized binary)
• cmake (v3.21+)
• boost (a version compatible with v1.81)
• oneTBB (v2021.8.0 is known to work)
• souffle (v2.3 is known to work; you have to use our custom fork if you want to combine compilation with eager evaluation.)

The Formulog Docker image already has these dependencies installed.