MIRAI

MIRAI is an abstract interpreter for the Rust compiler's mid-level intermediate representation (MIR). It is intended to become a widely used static analysis tool for Rust.

Using MIRAI

You'll need to install MIRAI as described here for MacOx and Windows and here for Linux.

To run mirai, use cargo with RUSTC_WRAPPER set to mirai. Use rustup override set nightly-YYYY-MM-DD to make Cargo use the same version of Rust as MIRAI. See the above installation instruction to determine which version to use. If you forget to do that or use the wrong version, you'll see an error message complaining about a dynamic load library not being found.

The easiest way to get started is to first build your project in the normal way (with one exception: set RUSTFLAGS="-Z always_encode_mir" to force the rust compiler to include MIR into its compiled output). Refer this link for details on compiling a cargo project. When there are no compile errors, no lint errors and no test failures, you can proceed to the next step and run MIRAI. For example:

touch src/lib.rs
RUSTC_WRAPPER=mirai cargo build

The touch command (which needs to reference a real file in your project) forces Cargo to re-run rustc and to not assume that it's cached error messages are still correct.

This will likely produce a lot of warnings, which you can then fix by adding annotations declared in this crate. Keep re-touching and running cargo build as above until there are no more warnings.

At this stage your code will be better documented and more readable. Perhaps you'll also have found and fixed a few bugs.

Set the verbosity level of output from MIRAI by setting the environment variable MIRAI_LOG to one of info, warn, debug, or trace.

You can also use the environment variable MIRAI_FLAGS to provide options to MIRAI. The value is a string which can contain any of the following flags:

• --test_only: instructs MIRAI to analyze only test methods in your crate. You must also provide the --tests option to the cargo build command to include those tests actually into your build.
• --diag=relaxed|strict|paranoid: configures level of diagnostics. With relaxed (the default) MIRAI will not report errors which are potential 'false positives'. With strict it will report such errors. With paranoid it will flag any direct or indirect call as a potential error.
• --single_func <name>: the name of a specific function you want to analyze.
• --: any arguments after this marker are passed on to rustc.

A more comprehensive command line interface for MIRAI is planned, but currently not implemented.

Using MIRAI together with the contracts crate

Preliminary support for MIRAI is available in the contracts crate. There is currently no official release containing this support on crates.io, so you must directly refer to the gitlab repo using a dependency like below in your Cargo.toml:

contracts = { git = "https://gitlab.com/karroffel/contracts.git", branch = "master", features = [ "mirai_assertions" ]}

See the shopping cart example for usage.

Developing MIRAI

See the developer guide for instructions on how to build, run and debug MIRAI.

Full documentation

• Overview of project.
• Architecture.
• Design discussions.
• Further reading.

Road map

• Stabilize MIRAI and get rid of crashing bugs and OOMs
• Model (ghost) variables
• Quantifiers
• Explicit loop invariants
• Structure invariants
• More standard library contracts
• Upgrade log message that affect soundness into compiler warnings
• Publish MIRAI to crates.io
• Support linting interfaces
• Tutorials and worked examples
• Loop discovery
• Loop invariant inference

Join the MIRAI community

See the CONTRIBUTING file for how to help out.

License

MIRAI is MIT licensed, as found in the LICENSE file.