A Language Server Protocol (LSP) server for VHDL based on GHDL, and a client for Visual Studio Code (VSC). The LSP server can be integrated in other text editors or IDES, such as, Vim, Emacs, Atom or Theia. Contributions are welcome!

Requirements

• Build and install GHDL. Build of the shared library libghdl is enabled by default.
• Install ghdl-ls from GHDL. For example:

pip3 install .

HINT:

• To install for development: pip install -e .
• Add --user to install in your home directory.

Usage

The executable is named ghdl-ls. It uses stdin/stdout to communicate with its client.

The language server will require a project file named hdl-prj.json which will provide all required options to run GHDL analysis :

• All options to pass to ghdl -a (the analysis step)
• Your project fileset

An example of hdl-prj.json file could be :

{
    "options": {
        "ghdl_analysis": [
            "--workdir=work",
            "--ieee=synopsys",
            "-fexplicit"
        ]
    },
    "files": [
        { "file": "rtl/core.vhd",           "language": "vhdl" },
        { "file": "assembly/core_fpga.vhd", "language": "vhdl" },
        { "file": "sim/tb_core.vhd",        "library" : "sim", "language": "vhdl" }
    ]
}

A library can be specified for a file and the default is work. The only language supported is vhdl (which is the default), a file with a unknown language is simply ignored.

The json file must be ASCII or UTF-8 encoded.

You will find all valid options in the GHDL documentation in the options to invoke GHDL.

Visual Studio Code (VSC) Extension

Subdir vscode-client contains the sources of a VSC Extension; a LSP client that allows to have ghdl-ls integrated in VSC.

Build

HINT: On debian, installing npm from repositories (sudo apt install npm) will probably install an outdated version of npm with regard to Node.js version. This will make any npm install operation fail.

Therefore, you will need to upgrade npm using sudo npm install -g npm@latest and restart your terminal before going further

• Install npm or yarn.
• Install vsce through npm install -g vsce or yarn global add vsce.
• Get the sources of the vscode-client. For example: curl -fsSL https://codeload.github.com/ghdl/ghdl-language-server/tar.gz/master | tar xzf - --strip-components=1 ghdl-language-server-master/vscode-client
• The first time, execute npm install or yarn to install package dependencies.
• Execute vsce package or vsce package --yarn.
• The output is a file named vhdl-lsp-*.vsix.

Install

• Through the command-line: code --install-extension vhdl-lsp-*.vsix.
• Graphically through Install from VSIX....

HINT:

If you are using VS Code Remote Development you also need to install the extension on the VS Code server. As indicated in VS Code Remote extension, you need to use the Install from VSIX... command available in the Extenion view More actions (...) menu (click on ...).

HINT:

VSIX files are actually ZIP files. Hence, it is possible to install an extension by extracting the content to a suitable location. This is useful in the context of the VS Code Remote Development feature; which is a NOT Open Source component that is "installed and updated automatically by VS Code when it connects to an endpoint" and which cannot be used with any other client (see Can VS Code Server be installed or used on its own?).

In order to pre-install a VSIX extension in a remote host or a docker image/container where VSC is not available, just extract it to $HOME/.vscode-server/extensions. For example:

cd $(dirname $0)
vsix_file="$(ls vhdl-lsp-*.vsix)"
vsc_exts="$HOME/.vscode-server/extensions"
mkdir -p $vsc_exts
unzip "$vsix_file"
rm [Content_Types].xml
mv extension.vsixmanifest extension/.vsixmanifest
mv extension "$vsc_exts/tgingold.${vsix_file%.*}"

Issues and bug reports

In case of crash of ghdl-ls, you should set the vhdl.debugLSP setting to true.

This makes ghdl-ls write logs (vhdl-ls.log, vhdl-ls.trace.in and vhdl-ls.trace.out) which should be attached to the issue.

Ready-to-use Docker images

In the Continuous Integration (CI) pipeline of ghdl/docker, some images are generated which include ghdl-ls and vsce-client. These are uploaded to ghdl/ext:* at hub.docker.com/u/ghdl.

• ghdl/ext:ls-debian: based on Debian Buster, it contains Python 3, GHDL, libghdl-py, ghdl-ls and vscode-client.
  • ghdl/ext:latest: based on ls-debian, it contains VUnit and GtkWave too.
• ghdl/ext:ls-ubuntu: based on Ubuntu Bionic, it contains the same tools as ls-debian.

All of these can be used with VSC's 'Remote - Containers' Extension as follows:

• Start a container: docker run --name ghdl-ls --rm -d ghdl/ext:latest bash -c "/opt/ghdl/install_vsix.sh && tail -f /dev/null"
• In VSC, go to Remote-Containers: Attach to Running Container... and select the container named ghdl-ls.
  • Alternatively, if you have the 'Docker' extension installed, just go to the list of running containers and right-click on it.
• Wait until the new window is loaded and have fun!

HINT:

• There are some example VHDL files in /tmp/files.
• All the terminals you open in VSC will be inside the container.
• In order to use gtkwave, the container must have access to some X server. x11docker and/or runx can be helpful in this context.

Emacs extension

Subdir emacs-client contains instructions and an example configuration init file for use with emacs, including a LSP client that allows to have ghdl-ls integrated in Emacs.

It can be also set up automatically by installing the package vhdl-ext and adding the following snippet to your config:

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