spacemacs/layers/+lang/rust/README.org

Rust layer

• Description
  • Features:
• Install
  • Layer
  • Choosing a backend
    • Racer
    • LSP
      • Switch to another LSP server
      • Autocompletion
      • Debugger (dap integration)
  • Cargo
    • cargo-edit
    • cargo-audit
  • Rustfmt
  • Clippy
• Key bindings
  • debugger

Description

This layer supports Rust development in Spacemacs.

Features:

• Auto-completion and navigation support through lsp-mode or Racer
• Interactive debugger using dap-mode
• support for the Rust package manager Cargo

Install

Layer

To use this configuration layer, add it to your ~/.spacemacs. You will need to add rust to the existing dotspacemacs-configuration-layers list in this file.

Choosing a backend

To choose a default backend set the layer variable rust-backend:

  (rust :variables rust-backend 'racer)

Alternatively the lsp backend will be automatically chosen if the layer lsp is used and you did not specify any value for rust-backend.

Backend can be chosen on a per project basis using directory local variables (files named .dir-locals.el at the root of a project), an example to use the lsp backend:

  ;;; Directory Local Variables
  ;;; For more information see (info "(emacs) Directory Variables")

  ((rust-mode (rust-backend . lsp)))

Note: you can easily add a directory local variable with SPC f v d.

Racer

You must install Racer to use this backend. Make sure the racer binary is available in your PATH and to set the environment variable RUST_SRC_PATH, as described in the installation instructions.

To enable auto-completion, ensure that the auto-completion layer is enabled.

LSP

You must add lsp to the existing dotspacemacs-configuration-layers in your ~/.spacemacs.

Consult the installation command for the desired language server found at lsp-mode for instructions.

The default LSP server for Rust is rls, i.e. rust language server. To choose the experimental rust-analyzer, you need to set the layer variable lsp-rust-server of lsp layer:

  (lsp :variables lsp-rust-server 'rust-analyzer)

Switch to another LSP server

If both rls and rust-analyzer server are installed, you can press SPC m s s to select another LSP server backend, and press SPC m b r to restart the LSP server to finish the switching.

Autocompletion

To enable auto-completion, ensure that the auto-completion layer is enabled.

By default, currently Racer is the only code completion backend of rls, so you also need to install it.

Debugger (dap integration)

To install the debug adapter you may run M-x dap-gdb-lldb-setup when you are on Linux or download it manually from Native Debug and adjust dap-gdb-lldb-path.

Cargo

Cargo is a project management command line tool for Rust. Installation instructions can be found on the main page of Cargo.

cargo-edit

cargo-edit allows you to add, remove, and upgrade dependencies by modifying your Cargo.toml file.

  cargo install cargo-edit

cargo-audit

cargo-audit audits Cargo.lock files for crates with security vulnerabilities.

  cargo install cargo-audit

Rustfmt

Format Rust code according to style guidelines using rustfmt.

  rustup component add rustfmt

To enable automatic buffer formatting on save, set the variable rust-format-on-save to t.

Clippy

Clippy provides a collection of lints to to catch common mistakes and improve your code.

  rustup component add clippy

Key bindings

Key binding	Description
SPC m = =	reformat the buffer
SPC m c .	repeat the last Cargo command
SPC m c a	add a new dependency with cargo-edit
SPC m c A	audit dependencies for known vulnerability with cargo-audit
SPC m c C	remove build artifacts
SPC m c c	compile project
SPC m c D	generate documentation and open it in default browser
SPC m c d	generate documentation
SPC m c E	run a project example
SPC m c e	run benchmarks
SPC m c f	format all project files with rustfmt
SPC m c i	initialise a new project with Cargo (init)
SPC m c l	run linter (cargo-clippy)
SPC m c n	create a new project with Cargo (new)
SPC m c o	run all tests in current file with Cargo
SPC m c r	remove a dependency with cargo-edit
SPC m c s	search for packages on crates.io with Cargo
SPC m c t	run the current test with Cargo
SPC m c u	update dependencies with Cargo
SPC m c U	upgrade dependencies to LATEST version with cargo-edit
SPC m c v	check (verify) a project with Cargo
SPC m c X	execute a specific binary
SPC m c x	execute the default binary
SPC m g g	jump to definition
SPC m h h	describe symbol at point
SPC m s s	switch to other LSP server backend
SPC m t	run tests with Cargo

debugger

Using the dap layer you'll get access to all the DAP key bindings, see the complete list of key bindings on the dap layer description.