Ada Language Server

This repository contains an implementation of the Microsoft Language Server Protocol for Ada/SPARK.

Current features:

• GNAT project files support.
• Code completion for names, keywords, aggregates, etc.
• Code navigation, such as Go to Definition/Declaration, Find All References, Call Hierarchies, etc.
• Code refactoring like insert named associations, auto-add with-clauses.
• Document/Workspace symbol search.
• Code folding and formatting.

We also provide Visual Studio Code extension at the VS Marketplace and at the Open VSX Registry.

Table of Contents

• Install
  • Dependencies
• Usage
• Supported LSP Server Requests
  • General Requests
  • Workspace Requests
  • Synchronization Requests
  • Text Document Requests
  • Protocol extensions
• How to use the VScode extension
• Integration with Coc.NVim
• Integration with vim-lsp
• Integration with LanguageClient-Neovim
• Integration with Neovim's built-in LSP client
• Integration with emacs lsp-mode
• Integration with QtCreator
• Authors & Contributors
• Contribute
• License

Install

You can build language server from sources. To build it from sources install dependencies and run

make

It will build .obj/server/ada_language_server file.

Dependencies

To build the language server you need:

• A GNAT compiler
• The Libadalang library (it should be built)
• The Libadalang-tools library
• The VSS library
• The a process spawn library

Project files of the libraries must be available via the GPR_PROJECT_PATH environment variable.

To run the language server you need gnatls (parts of GNAT installation) somewhere in the path.

Usage

The ada_language_server doesn't require any command line options, but it understands these options:

• --tracefile=<FILE> - Full path to a file containing traces configuration
• --help - Display supported command like options and exit.

You can turn some debugging and experimental features trought the traces file.

The server also gets configuration via workspace/didChangeConfiguration notification. See more details here. Each LSP client provides its-own way to set such settings.

Supported LSP Server Requests

General Requests

Request	Supported
initialize	✅
initialized	✅
shutdown	✅
exit	✅
$/cancelRequest	✅

Workspace Requests

Request	Supported
workspace/didChangeWorkspaceFolders
workspace/didChangeConfiguration	✅
workspace/didChangeWorkspaceFolders
workspace/didChangeWatchedFiles	✅
workspace/symbol	✅
workspace/executeCommand	✅

Synchronization Requests

Request	Supported
textDocument/didOpen	✅
textDocument/didChange	✅
textDocument/willSave
textDocument/willSaveWaitUntil
textDocument/didSave
textDocument/didClose	✅

Text Document Requests

Request	Supported
textDocument/completion	✅
completionItem/resolve
textDocument/hover	✅
textDocument/signatureHelp	✅
textDocument/definition	✅
textDocument/declaration	✅
textDocument/typeDefinition	✅
textDocument/implementation	✅
textDocument/references	✅
textDocument/documentHighlight	✅
textDocument/documentSymbol	✅
textDocument/codeAction	✅
textDocument/codeLens
codeLens/resolve
textDocument/documentLink
documentLink/resolve
textDocument/documentColor
textDocument/colorPresentation
textDocument/formatting	✅
textDocument/rangeFormatting
textDocument/onTypeFormatting
textDocument/rename	✅
textDocument/prepareRename	✅
textDocument/foldingRange	✅
textDocument/prepareCallHierarchy	✅
callHierarchy/incomingCalls	✅
callHierarchy/outgoingCalls	✅

Protocol extensions

The Ada Language Server supports some features that are not in the official Language Server Protocol specification. See corresponding document.

How to use the VScode extension

Getting started

Tutorial: Using Ada in VS Code.

Auto-detected tasks

The extension includes a task provider. It provides two "auto-detected" tasks (under /Terminal/Run Task... menu):

• "ada: Build current project" - launch gprbuild to build the current GPR project
• "ada: Check current file" - launch gprbuild to check errors in the current editor
• "ada: Run gnatprove on the current project" - launch gnatprove for the current GPR project
• "ada: Run gnatprove on the current file" - launch gnatprove to check errors in the current editor

You can bind keyboard shortcuts to them by adding to the keybindings.json file:

{
  "key": "alt+v",
  "command": "workbench.action.tasks.runTask",
  "args": "ada: Check current file",
  "when": "editorLangId == ada"
}

Short demo

A demo for auto-detected tasks

Go to other Ada file

The extension contributes a command and a corresponding key binding to switch between specification and implementation Ada files. The default shortcut is Alt+O.

Launch the extension to debug it

For the moment, this repository includes a vscode extension that is used as the reference extension for this implementation.

You can try it by running:

code --extensionDevelopmentPath=<path_to_this_repo>/integration/vscode/ada <workspace directory>

Configuration

You can configure the extension via the .vscode/settings.json settings file. See the setting list here.

Here is an example config file from the gnatcov project:

{
    "ada.projectFile": "gnatcov.gpr",
    "ada.scenarioVariables": {
        "BINUTILS_BUILD_DIR": "/null",
        "BINUTILS_SRC_DIR": "/null"
    },
   "ada.defaultCharset": "utf-8",
   "ada.enableDiagnostics": false,
   "ada.renameInComments": false
}

Integration with Coc.NVim

If you want to use the Ada Language Server with Vim/Neovim, you can use the Coc.NVim. You'll have to install the Ada Language Server manually somewhere on your computer. Follow installation instructions on Coc.NVim website and then configure the Ada Language Server with :CocConfig:

{
  "languageserver": {
    "ada": {
      "settings": {
        "ada": {
          "projectFile": "gnat/vss_text.gpr"
        }
      },
      "command": "<path>/ada_language_server",
      "filetypes": [
        "ads",
        "adb",
        "ada"
      ]
    }
  }
}

Integration with vim-lsp

If you want to integrate the Ada Language Server into vim, you can use the vim-lsp.

You'll have to install the Ada Language Server manually somewhere on your computer, and then you can add the following line to your .vimrc file:

if executable('ada_language_server')
    au User lsp_setup call lsp#register_server({
        \ 'name': 'ada_language_server',
        \ 'cmd': ['ada_language_server'],
        \ 'allowlist': ['ada'],
        \ 'workspace_config': {'ada': {
        \     'projectFile': "project.gpr",
        \     'scenarioVariables': {"ARCH": "x86_64-pc-linux-gnu"}}},
        \ })
endif

Integration with LanguageClient-Neovim

If you want to integrate the Ada Language Server into Neovim, you can use the LanguageClient-neovim.

You'll have to install the Ada Language Server manually somewhere on your computer, and then you can add the following line to your init.vim file:

" replace the path below with the proper path to the ada_language_server executable
let g:LanguageClient_serverCommands = {
    \ 'ada': ['path/to/ada_language_server'],
    \ }
" if you already have LanguageClient_serverCommands, just add a line for ada.

To configure the Ada Language Server for a specific workspace/project, you can use the .vim/settings.json file. It is mandatory as soon as you want to use a specific .gpr project file.

This is the way to specify a project file, eg. you cannot open a project file another way. See the setting list here.

Here is an example of a settings file:

{
    "ada.projectFile": "project.gpr",
    "ada.scenarioVariables": {
        "GLFW_Version": "3",
        "GLFW_Lib": "-lglfw",
        "Windowing_System": "x11"
    }
}

The location where the .vim folder is located will determine the relative path of the project file (so no need to prefix with ..). When vim is opened in the folder containing this .vim directory, it will use those settings for the language server even for files which might have nothing to do with that specific project, so this needs to be taken into account. Ultimately what this means is that the configuration is determined by where you open vim.

Integration with Neovim's built-in LSP client

Neovim 0.5.0 and later have a built-in LSP client which can be used with the Ada Language Server. In order to use it with minimal effort, follow these steps:

• Install the ada language server and make sure it's in your $PATH.
• Use your favorite Neovim plugin manager to add the default set of LSP configuration files to Neovim.
• Enable the Ada Language Server by adding :lua require('lspconfig').als.setup{} to your init.vim.

If you would rather not have the ada language server in your path, you can give the lsp client an absolute path to the ALS executable:

require('lspconfig').als.setup{ cmd = "/path/to/als/executable" }

Configuring the language server's settings can be achieved like this:

require('nvim_lsp').als.setup{
  settings = {
    ada = {
      projectFile = "project.gpr";
      scenarioVariables = { ... };
    }
  }
}

The Ada Language Server's settings are described here. Configuring neovim to use project-specific settings is described neovim's lspconfig wiki

Integration with emacs lsp-mode

The configuration for each project can be provided using a .dir-locals.el file defined at the root of each project.

The scenario variables should be declared in your .emacs or any loaded Emacs configuration file.

(defgroup project-build nil
  "LSP options for Project"
  :group 'ada-mode)

(defcustom project-build-type "Debug"
  "Controls the type of build of a project.
   Default is Debug, other choices are Release and Coverage."
  :type '(choice
          (const "Debug")
          (const "Coverage")
          (const "Release"))
  :group 'project-build)

Your .dir-locals.el in the project root should be similar to:

((ada-mode .
  ((eval . (lsp-register-custom-settings
      '(("ada.scenarioVariables.BINUTILS_SRC_DIR" project-binutils-dir)
        ("ada.scenarioVariables.BUILD_TYPE" project-build-type "Release"))))
   (lsp-ada-project-file . "/home/username/project/project.gpr"))
  ))

The lsp-mode provides built-in support for the ada_language_server and defines default customizable configuration values in the lsp-ada group that can be edited similarly to lsp-ada-project-file in the example above.

Integration with QtCreator

Starting with version 4.9, QtCreator supports a LSP plugin. Follow the official documentation to configure the Ada Language Server in this plugin. Make sure to set Startup behavior to Start Server per Project, otherwise QtCreator won't provide the project root to the Ada Language Server. QtCreator doesn't send any configuration request to the language server, so the only option to enable project support is to have a single .gpr file in the QtCreator project folder. For a projectless configuration, you could also place all Ada sources in the project root folder, this should work as well.

Authors & Contributors

• Maintained by AdaCore.
• Original author @MaximReznik.
• Support for the Visual Studio Code classifier and snippets contributed by @Entomy.

Contribute

Feel free to dive in! Read the developer's guide.

Don't hesitate to open an issue or submit PRs.

License

GPL-3