README.md

THIS PROJECT HAS BEEN SUPERSEDED BY CIRC

Note: This project has been superseded by CirC, which is a Rust re-implementation of the compiler infrastructure.

It is archived here for reference purposes.

Compiler to circuit representations

Currently we have frontends for:

• C
• circom

We have backends for:

• R1CS (proofs via libsnark)
• SMT

Install

Install dependencies

• z3
• The Haskell tool Stack

Build project

Once the dependencies are installed, you should be able to build the compiler:

stack build

Test

stack test

To run an individual test (e.g., C value test), use:

stack test --ta '-p C value test'

Format

We use brittany. You can format all files (slow) with make fmt.

You can format all files changed since a git-ref REF in a directory using

./scripts/format.bash REF DIR

You can format all files in a directory using

./scripts/format.bash all DIR

The formatting script will not format files which have unstaged changes.

Run

For usage information:

stack exec compiler-exe -- -h

For example, to run function foo in file bar, use:

stack exec compiler-exe c foo bar.c -- --solve

Configuration

There is a configuration system in src/Util/Cfg.hs. You can add new configuration options there. Configuration options can be set by environmental variables, like so:

C_cfg_with_underscores_instead_of_dashes=value stack run -- ...

One particularly useful configuration options is C_streams, which enables logging streams. You can log to named streams using logIf in src/Util/Log.hs, and the output will only appear if the specified stream is enabled.

Directory structure

├── app               -- Compiler executable
├── src
│   ├── AST           -- Circom AST and C AST helpers 
│   ├── Codegen       -- Machinery for generating circuits 
│   │   ├── Circify   -- Language-indended machinery (branches, fns, scopes)
│   │   │   └── Memory-- Stack allocations and accesses
│   │   ├── Circom    -- Circom
│   │   └── C         -- C
│   ├── IR            -- The typed SMT intermediate representation
│   │   ├── SMT       -- Logging
│   │   │   ├── TySmt -- Sort-typed SMT terms
│   │   │   ├── Assert-- Monad for accumulating SMT assertions
│   │   │   ├── Opt   -- Optimizations over SMT
│   │   │   └── ToPf  -- Converting SMT to R1cs
│   │   └── R1cs      -- R1cs
│   │       └── Opt   -- Optimizations over R1cs
│   ├── Parser        -- Machinery for parsing source files 
│   ├── Targets       -- TBD: Alex after code changes
│   └── Util          -- Utilities (e.g., logging)
│       ├── Log       -- Logging
│       └── Cfg       -- Configuration
└── test              -- Tests