hkalbasi/prusti-assistant

VS Code extension to verify Rust programs with the Prusti verifier.

Prusti Assistant

This Visual Studio Code extension provides interactive IDE features for verifying Rusti programs with the Prusti verifier.

For advanced use cases, consider switching to the command-line version of Prusti.

Requirements

In order to use this extension, please install the following components:

• Java JDK version 11 or later, 64 bit. We recommend OpenJDK 15.0.1.
• Rustup version 1.23.0 or later (on Windows this also requires the C++ build tools for Visual Studio 2013 or later).

First Usage

1. Install the requirements (listed above) and restart the IDE.
   • This will ensure that programs like rustup are in the program path used by the IDE.
2. Install the "Prusti Assistant" extension.
3. Open a Rust file to activate the extension.
   • At its first activation, this extension will automatically download Prusti and install the required Rust toolchain.
4. Click on the "Verify with Prusti" button in the status bar.
   • Alternativelly, you can run the Prusti: verify the current crate or file command.
   • If the program is in a folder with a Cargo.toml file, Prusti will verify the crate in which the file is contained.
   • If no Cargo.toml file can be found in a parent folder of the workspace, Prusti will verify the file as a standalone Rust program. No Cargo dependencies are allowed in this mode.
5. Follow the progress from the status bar.
   • You should see a "Verifying crate [folder name]" or "Verifying file [name]" message while Prusti is running.
6. The result of the verification is reported in the status bar and in the "Problems" tab.
   • You can open the "Problems" tab by clicking on Prusti's status bar.
   • Be aware that the "Problems" tab is shared by all extensions. If you are not sure which extension generated which error, try disabling other extensions. (Related VS Code issue: #51103.)

To update Prusti, run the command Prusti: update verifier in the command palette.

If something fails, check the "Troubleshooting" section below.

Features

Commands

This extension provides the following commands:

• Prusti: verify the current crate or file to verify a Rust program;
• Prusti: update verifier to update Prusti.
• Prusti: restart Prusti server to restart the Prusti server used by this extension.

Configuration

The main configuration options used by this extension are the following:

• prusti-assistant.verifyOnSave: Specifies if programs should be verified on save.
• prusti-assistant.verifyOnOpen: Specifies if programs should be verified when opened.
• prusti-assistant.buildChannel: Allows to choose between the latest Prusti release version (the default) and a slightly newer but potentially unstable Prusti development version.
• prusti-assistant.checkForUpdates: Specifies if Prusti should check for updates at startup.

Inline Code Diagnostics

This extension automatically provides inline diagnostics for Prusti errors.

Snippets

Basic code-completion snippets are provided for Prusti annotations.

Troubleshooting

If Prusti fails to run, you can inspect Prusti's log from VS Code (View -> Output -> Prusti Assistant ...) and see if one of the following solutions applies to you.

Problem	Solution
error[E0514]: found crate 'cfg_if' compiled by an incompatible version of rustc	There is a conflict between Prusti and a previous Cargo compilation. Run cargo clean or manually delete the target folder. Then, rerun Prusti.
error: the 'cargo' binary, normally provided by the 'cargo' component, is not applicable to the 'nightly-2021-09-20-x86_64-unknown-linux-gnu' toolchain or error[E0463]: can't find crate for std or error[E0463]: can't find crate for core	The Rust toolchain installed by Rustup is probably corrupted (see issue rustup/#2417). Uninstall the nightly toolchain mentioned in the error (or all installed nightly toolchains). Then, rerun Prusti.

Thanks to @Pointerbender for reporting issues and suggesting solutions!