tutorial.md

Tutorial

This document explains how to use tablegen-lsp with VS Code.

Install the VS Code Extension

Open VS Code and search for tablegen-lsp in the Extensions tab to install it.

Open the LLVM Project

Clone LLVM locally and open it in VS Code.

git clone https://github.com/llvm/llvm-project.git
code llvm-project

Now, open the llvm-project/llvm/lib/Target/RISCV/RISCV.td file. You should see include errors displayed as follows:

Configure Include Path

Open VS Code's settings and add path/to/llvm-project/llvm/include to Tablegen-lsp: Include Path.

Alternatively, add the following to your VS Code settings file settings.json:

{
  "tablegen-lsp.includePaths": [
    "path/to/llvm-project/llvm/include",
  ]
}

You will then see a message prompting you to restart the language server.

After restarting, the include errors should be resolved as follows:

Configure Root Source

When you open a file that is included in llvm-project/llvm/lib/Target/RISCV/RISCV.td (e.g., RISCVFeatures.td), you should see errors displayed as follows:

This is because the dependency on llvm/Target/Target.td, which is included from RISCV.td, is not being properly parsed. By configuring the Root Source, you can ensure parsing always starts from RISCV.td, resolving the errors.

There are two methods to configure the Source Root:

1. Open the Command Palette and execute "tablegen-lsp: Set Source Root".

2. Right-click the file and select "Set Source Root".

After setting the Source Root, the filename should appear in the status bar.

For testing, set RISCV.td as the Source Root and reopen RISCVFeatures.td - the errors should be resolved.

To clear the Source Root configuration, open the Command Palette and execute "tablegen-lsp: Clear Source Root".

Using Features

Once configuration is complete, the following features become available:

• Go to Definition
  • Right-click > "Go to Definition"
• Find References
  • Right-click > "Go to References"
• Document Links
  • Ctrl(Cmd) + Click on a file that is included
• Inlay Hints
  • Displays type information for template arguments, fields, etc.
• Code Completion
  • Suggestions for class names, field names, etc.

For more features, please refer to Features.