sail-lsp

A language server for Sail, the ISA specification language. Works with any LSP-capable editor (VS Code, Neovim, Emacs, Helix, Zed, etc.).

Built in Rust, modeled after rust-analyzer. Self-contained — does not call the upstream OCaml sail binary.

Install

git clone https://github.com/TinyuengKwan/sail-lsp.git
cd sail-lsp
cargo build --release
# Binary: target/release/sail-lsp

Setup

Standard library

The Sail standard library is embedded in the binary — no extra setup needed.

To use a different version of the stdlib (e.g. a local checkout of the sail compiler), set SAIL_DIR:

export SAIL_DIR=/path/to/sail   # points to the sail compiler repo root

When set, $SAIL_DIR/lib/ is used instead of the embedded copy.

Neovim

local lspconfig = require("lspconfig")
local configs = require("lspconfig.configs")

if not configs.sail_lsp then
  configs.sail_lsp = {
    default_config = {
      cmd = { "sail-lsp" },
      filetypes = { "sail" },
      root_dir = lspconfig.util.root_pattern("sail.proj", ".git"),
    },
  }
end

lspconfig.sail_lsp.setup({})

Helix

# ~/.config/helix/languages.toml
[language-server.sail-lsp]
command = "sail-lsp"

[[language]]
name = "sail"
scope = "source.sail"
file-types = ["sail"]
roots = ["sail.proj"]
language-servers = ["sail-lsp"]

VS Code

A dedicated extension is available at editors/code/. Install from a .vsix:

cd editors/code
npm install && npm run package
code --install-extension sail-lsp.vsix

This provides Sail syntax highlighting (TextMate grammar), language configuration, and automatic sail-lsp server management. See editors/code/README.md for configuration options.

Zed

Extension: TinyuengKwan/sail-zed

Features

• Navigation: goto definition/declaration/implementation, find references, call hierarchy
• Completion: 11 providers (keywords, expressions, fields, patterns, pragmas, snippets, ...)
• Hover: type signatures, doc comments, effect annotations, bitfield layouts
• Diagnostics: 40 handlers (parse, semantic, type, effect) with quick fixes
• Refactoring: 51 code actions (extract, inline, generate, rename, organize imports, ...)
• Formatting: document + range + on-type + bitfield alignment
• Highlights: semantic tokens, document highlights, matching brace
• Outline: document symbols, folding ranges, selection range
• SSR: structural search-replace with $name placeholders

Corpus quality

Validated against sail-riscv (158 files, 30,018 lines): 0 errors, 0 false positives, 0 crashes.

cargo run --example corpus_check -- /path/to/sail-riscv

Development

cargo test --workspace                  # run all tests
cargo test -p hir-ty                    # single crate
RUN_SLOW_BENCHES=1 cargo test -p sail-lsp --lib -- benchmarks  # benchmarks

See CONTRIBUTING.md for code style and architecture details.

License

MIT