ls

SystemVerilog Language Server

The language server can be hooked up to your IDE or text editor to provide assistance while programming. It helps highlight syntax errors or lint violations and provides fixes for issues if they are available.

The language server is part of the Verible suite and called verible-verilog-ls.

This is work in progress

There are a few changes in the review pipeline, so here is the current progress

• Publish diagnostics for syntax errors and lint rules
  • Use lint configuration from .rules.verible_lint instead of all enabled
• Provide code actions for autofixes provided by lint rules
• Generate file symbol outline ('navigation tree')
• Provide formatting.
• Highlight all the symbols that are the same as current under cursor.
  • Take scope and type into account to only highlight same symbols.
• Provide useful information on hover (#1187)
• Find definition of a symbol even if in another file (check Configuring the Language Server for a project).
• Find references of a symbol even if in another file (check Configuring the Language Server for a project).
• Find declaration of a symbol even if in another file. (#1189)
• Provide Document Links (e.g. opening include files) (#1190)
• Rename refactor a symbol

Configuring the Language Server for a project

Adding verible.filelist for project-wide symbol discovery

verible-verilog-ls by default loads and analyses only currently edited files in the editor. To be able to utilize such features as going to definition, going to references, printing hover info project-wide, add a verible.filelist file to the project.

verible.filelist is a file containing a list of design files (listed line by line). It is used to collect data necessary to build a symbol table and other helper structures to allow Language Server to find symbols' origin and type to support afore-mentioned features.

If a list of files used in design is already present, it can just be linked in the project root under name verible.filelist. Otherwise, it can be easily created using such tools as find, e.g.:

find . -name "*.sv" -o -name "*.svh" -o -name "*.v" | sort > verible.filelist

The paths in the verible.filelist can be either relative to the location of the file or absolute. It is possible to change the default name of the filelist with the --file_list_path <new-file-name> flag.

Project Root

The Language Server looks for the verible.filelist file in the project root.

From Editor

The project root is typically determined by the editor and sent to the language server. The provided workspace directory can vary between editors, usually it is a directory:

• Where the editor was started,
• Where the editor found the root of the project (e.g. based on .git directory)
• That is provided by the user in the project's settings in the editor.

Fallback

If there is no valid project root directory provided by the editor, Verible falls back to use the current directory.

You can override the project root that is used with the environment variable VERIBLE_LS_PROJECTROOT_OVERRIDE. If that is set, it takes precedence over the editor-provided project root.

Adding project-specific linter configuration

By default, Language Server publishes all possible linting issues for a given document. It is possible to disable certain linter warnings for a given project using the .rules.verible_lint file. It is a simple file that consists of comma-separated or newline-separated settings for rules, e.g.:

-module-filename
+posix-eof
-no-tabs

Disables the check for matching module and file name, tabs instead of spaces and enables rule disallowing ending file without an empty newline. For more information on linter setup and available flags, check SystemVerilog Style Linter.

Possibly the easiest way to introduce per-project linter configuration for the Language Server would be to run it with --rules_config_search path. It will search for the .rules.verible_lint file up in the directory hierarchy with respect to the file's current path.

It is also possible to provide a direct path to the linter configuration, e.g.:

verible-verilog-ls --rules_config <path-to-config>

Or provide rules configuration directly, e.g.:

verible-verilog-ls --rules=+line-length=length:80,-no-tabs

Other customizations of the Language Server

To check other configuration options for the verible-verilog-ls, run:

verible-verilog-ls --helpfull

Hooking up to editor

After installing the verible tools, you can configure your editor to use the language server.

This will be specific to your editor. In essence, you need to tell it to start the verible-verilog-ls language server whenever it works with Verilog or SystemVerilog files.

Here are a few common editors, but there are many more that support language servers. If you have configured it for your editor, consider sending a pull request that adds a section to this README (or file an issue an mention what you had to do and we add it here).

In alphabetical order

Emacs

The lsp-mode needs to be installed from wherever you get your emacs packages.

Here is a simple setup: put this in your ~/.emacs file and make sure the binary is in your $PATH (or use full path).

(require 'lsp-mode)
(add-to-list 'lsp-language-id-configuration '(verilog-mode . "verilog"))
(lsp-register-client
 (make-lsp-client :new-connection (lsp-stdio-connection "verible-verilog-ls")
                  :major-modes '(verilog-mode)
                  :server-id 'verible-ls))

(add-hook 'verilog-mode-hook 'lsp)

It is also possible to automatically configure eglot and lsp-mode using the verilog-ext package:

(require 'verilog-ext)
(verilog-ext-mode-setup)
(verilog-ext-eglot-set-server 've-verible-ls) ;`eglot' config
(verilog-ext-lsp-set-server 've-verible-ls)   ; `lsp' config

Kakoune

First, go to kak-lsp project and follow the installation and configuration steps. Then, either find a kak-lsp.toml language server configuration file or create a new one in the ~/.config/kak-lsp directory (using a default template from the project repository).

After this, in the kak-lsp.toml file create a new entry:

[languages.verilog]
filetypes = ["v", "sv"]
roots = ["verible.filelist", ".git"]
command = "verible-verilog-ls"
offset_encoding = "utf-8"

To add additional configuration arguments to the verible-verilog-ls, add args list, e.g.:

args = ["--rules_config_search"]

Later, in the kakrc file (usually located in ~/.config/kak/kakrc), adjust a hook for enabling Language Server to start for verilog language, e.g.:

hook global WinSetOption filetype=(rust|python|go|javascript|typescript|c|cpp|verilog) %{
    lsp-enable-window
}

Kate

https://docs.kde.org/trunk5/en/kate/kate/kate-application-plugin-lspclient.html

First, enable LSP by checking Settings > Configure Kate > Plugins > LSP Client Then, there is a new {} LSP Client icon appearing on the left of the configure dialog. In the User Server Settings tab, enter the lsp server configuration to get it started up on our Verilog/SystemVerilog projects.

{
    "servers": {
        "verilog": {
            "command": ["verible-verilog-ls"],
            "root": "",
            "url": "https://github.com/chipsalliance/verible"
        },
        "systemverilog": {
            "command": ["verible-verilog-ls"],
            "root": "",
            "url": "https://github.com/chipsalliance/verible"
        }
    }
}

It is possible to provide additional flags and arguments in command entry as list, e.g. ["verible-verilog-ls", "--rules_config_search"].

Neovim

Make sure to have version 0.5.0 or newer and install the nvim-lspconfig plugin. You can install it with the popular vim-plug plugin manager by adding the following code to your ~/.config/nvim/init.vim file:

call plug#begin()
Plug 'neovim/nvim-lspconfig'
call plug#end()

Then to install it open neovim and type: :PlugInstall

After installing nvim-lspconfig, enable the verible config by appending the following script to your ~/.config/nvim/init.nvim file:

lua << EOF

-- Mappings.
-- See `:help vim.diagnostic.*` for documentation on any of the below functions
local opts = { noremap=true, silent=true }
vim.keymap.set('n', '<space>e', vim.diagnostic.open_float, opts)
vim.keymap.set('n', '[d', vim.diagnostic.goto_prev, opts)
vim.keymap.set('n', ']d', vim.diagnostic.goto_next, opts)
vim.keymap.set('n', '<space>q', vim.diagnostic.setloclist, opts)

-- Use an on_attach function to only map the following keys
-- after the language server attaches to the current buffer
local on_attach = function(client, bufnr)
  -- Enable completion triggered by <c-x><c-o>
  vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')

  -- Mappings.
  -- See `:help vim.lsp.*` for documentation on any of the below functions
  local bufopts = { noremap=true, silent=true, buffer=bufnr }
  vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, bufopts)
  vim.keymap.set('n', 'gd', vim.lsp.buf.definition, bufopts)
  vim.keymap.set('n', 'K', vim.lsp.buf.hover, bufopts)
  vim.keymap.set('n', 'gi', vim.lsp.buf.implementation, bufopts)
  vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, bufopts)
  vim.keymap.set('n', '<space>wa', vim.lsp.buf.add_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wr', vim.lsp.buf.remove_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wl', function()
    print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
  end, bufopts)
  vim.keymap.set('n', '<space>D', vim.lsp.buf.type_definition, bufopts)
  vim.keymap.set('n', '<space>rn', vim.lsp.buf.rename, bufopts)
  vim.keymap.set('n', '<space>a', vim.lsp.buf.code_action, bufopts)
  vim.keymap.set('n', 'gr', vim.lsp.buf.references, bufopts)
  vim.keymap.set('n', '<space>f', vim.lsp.buf.formatting, bufopts)
end

local lsp_flags = {
  -- This is the default in Nvim 0.7+
  debounce_text_changes = 150,
}

require'lspconfig'.verible.setup {
    on_attach = on_attach,
    flags = lsp_flags,
    root_dir = function() return vim.uv.cwd() end
}
EOF

This script initializes the verible language server in neovim and also enables shortcuts for functionalities such as auto-fix (space + a). See https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#verible for configuration options.

Sublime

Consult https://lsp.readthedocs.io/

Installation steps

1. Enable package control if not already Tools > Install Package control...
2. Install LSP base package: Preferences > Package Control search for Install Package. Confirm, then search for LSP.
3. Also, while at it, if you haven't already, install the SystemVerilog package, which gives you general syntax highlighting.
4. Go to Preferences > Package Settings > LSP > Settings. It opens a global setting file and a user setting skeleton. Put the following in your user LSP.sublime-settings; it already provides the empty outer braces, you need to add the "clients" section.

// Settings in here override those in "LSP/LSP.sublime-settings"
{
  "clients": {
    "verible-verilog-ls": {
      "command": ["verible-verilog-ls"],
      "enabled": true,
      "selector": "source.systemverilog"
    }
  }
}

There is a Tools > LSP > Troubleshoot Server Configuration which might be helpful in case of issues.

To customize the Language Server with additional flags, type the command flags in the command list, e.g. ["verible-verilog-ls", "--rules_config_search"].

Vim

To make LSP work in Vim a dedicated LSP plugin is required.

The recommended plugin is vim-lsp, which is compatible with Vim8 and later releases. Please refer to its README for installation guides and configuration recommendations.

To enable Verible with the following plugins, add the corresponding snippet to your configuration file (e.g. ~/.vimrc):

Configure with vim-lsp:

if executable('verible-verilog-ls')
    au User lsp_setup call lsp#register_server({
        \ 'name': 'verible-verilog-ls',
        \ 'cmd': {server_info->['verible-verilog-ls']},
        \ 'allowlist': ['verilog', 'systemverilog'],
        \ })
endif

Make sure verible-verilog-ls is available in your PATH and can be executed. Alternatively modify the snippet above to use an absolute path. To add configuration flags to customize the Language Server, add them to the list in the server_info.

Alternatively, Verible can be configured with lsp, which is written in vim9script and compatible with vim v9+.

Configure with lsp:

call LspAddServer([#{
    \   name: 'verible-verilog-ls',
    \   filetype: ['systemverilog', 'verilog'],
    \   path: 'verible-verilog-ls',
    \   args: []
    \ }])

Add configuration flags to args (eg. args: ['--column_limit=80']).

VSCode

Use released extension

You can install the extension directly from the VSCode marketplace.

To install the extension launch VS Code Quick Open (Ctrl+P), paste the following command, and press enter.

ext install CHIPSAlliance.verible

Build yourself

This is based on the VSCode packaging extension guide.

First install the verible tools and vscode.

For the following, you need a recent version of both nodejs and npm.

Change into the vscode/ subdirectory and run the following:

npm install
npm run vsix
code --install-extension verible.vsix

Configuring Language Server arguments

To configure the extension, in Extensions list select Verible, and select Extension Settings. In there you can find an Arguments setting, where you can add command-line arguments for verible-verilog-ls executable, e.g.:

• --rules_config_search - search recursively for linter configuration, starting from edited file's directory.
• --rules_config="<path-to-config>" - use linter configuration in a specified path
• --wrap_end_else_clauses - splits end else into separate lines.
• --indentation_spaces=4 - indent width specified for the formatter.

There should be one flag per item.

For more language server options, check:

verible-verilog-ls --helpfull