https://github.com/rust-lang/polonius

Defines the Rust borrow checker.
https://github.com/rust-lang/polonius

Last synced: 13 days ago
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Defines the Rust borrow checker.

• Host: GitHub
• URL: https://github.com/rust-lang/polonius
• Owner: rust-lang
• License: apache-2.0
• Created: 2018-05-01T15:40:59.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2023-10-16T01:48:09.000Z (about 1 year ago)
• Last Synced: 2024-05-22T11:22:12.484Z (6 months ago)
• Language: Rust
• Size: 335 MB
• Stars: 1,259
• Watchers: 67
• Forks: 72
• Open Issues: 40
• Metadata Files:
  • Readme: README.md
  • License: LICENSE-APACHE
  • Code of conduct: CODE_OF_CONDUCT.md

Awesome Lists containing this project

README

        
This is a core library that models the borrow check. It implements the analysis

described in this [blogpost][post] and in this [talk]. Details are [in the Polonius book][book].

[post]: http://smallcultfollowing.com/babysteps/blog/2018/04/27/an-alias-based-formulation-of-the-borrow-checker/

[talk]: https://youtu.be/_agDeiWek8w

[book]: https://rust-lang.github.io/polonius/

### Why the name "Polonius"?

The name comes from the famous quote ["Neither a borrower nor a lender

be"][nblnb], which comes from the character Polonius in Shakespeare's

*Hamlet*.

[nblnb]: https://literarydevices.net/neither-a-borrower-nor-a-lender-be/

### Want to run the code?

One of the goals with this repo is to experiment and compare different

implementations of the same algorithm. You can run the analysis by using `cargo run`

and you can choose the analysis with `-a`. So for example to run against an example

extract from clap, you might do:

```bash

> cargo +nightly run --release -- -a DatafrogOpt inputs/clap-rs/app-parser-{{impl}}-add_defaults/

    Finished release [optimized] target(s) in 0.05 secs

     Running `target/release/borrow-check 'inputs/clap-rs/app-parser-{{impl}}-add_defaults/'`

--------------------------------------------------

Directory: inputs/clap-rs/app-parser-{{impl}}-add_defaults/

Time: 3.856s

```

You could also try `-a Naive` to get the naive rules (more readable,

slower) -- these are the exact rules described in [the

blogpost][post]. You can also use `-a LocationInsensitive` to use a

location insensitive analysis (faster, but may yield spurious errors).

By default, `cargo run` just prints timing. If you also want to see

the results, try `--show-tuples` (which will show errors) and maybe

`-v` (to show more intermediate computations). You can supply `--help`

to get more docs.

### How to generate your own inputs

To run the borrow checker on an input, you first need to generate the

input facts.  For that, you will need to run rustc with the

`-Znll-facts` option:

```

> rustc -Znll-facts inputs/issue-47680/issue-47680.rs

```

Or, for generating the input facts of a crate using the `#![feature(nll)]` flag:

```

> cargo rustc -- -Znll-facts

```

This will generate a `nll-facts` directory with one subdirectory per function:

```bash

> ls -F nll-facts

{{impl}}-maybe_next/  main/

```

You can then run on these directories.