{"@attributes":{"version":"2.0"},"channel":{"title":"this, that and more","description":"mostly dev stuff, sometimes life","link":"https:\/\/duswnchl.github.io\/tags\/igalia-planet\/","pubDate":"Tue, 31 Mar 2026 03:00:45 +0000","lastBuildDate":"Tue, 31 Mar 2026 03:00:45 +0000","generator":"Jekyll v4.4.1","item":[{"title":"Smarter Chromium GN in Vim with gn-language-server","description":"

GN Language Server for Chromium development was announced on chromium-dev<\/a>.\nIt\u2019s very easy to install in VSCode, NeoVim or Emacs. But how can we configure\nit with classic Vim + YCM<\/a>?<\/p>\n\n

Setup<\/h2>\n\n

First, install the language server with Cargo.<\/p>\n

cargo install<\/span> --locked<\/span> gn-language-server\n<\/code><\/pre><\/div><\/div>\n
Then, add this to your vimrc.<\/p>\n
let <\/span>g:ycm_language_server =<\/span> [<\/span>\n      \\ <\/span>{<\/span>\n      \\ <\/span>  'name'<\/span>: 'gn'<\/span>,\n      \\ <\/span>  'cmdline'<\/span>: [<\/span> 'gn-language-server'<\/span> ]<\/span>,\n      \\ <\/span>  'filetypes'<\/span>: [<\/span> 'gn'<\/span> ]<\/span>,\n      \\ <\/span>}<\/span>\n  \\ <\/span>]<\/span>\n<\/code><\/pre><\/div><\/div>\n\n
That easy, right?<\/p>\n\n
What\u2019s Working<\/h2>\n\n
Hover Documentation<\/h3>\n
\"hover\"<\/p>\n
Go To Imports<\/h3>\n
\"jump_import\"<\/p>\n
Go To Dependencies<\/h3>\n
\"jump_deps\"<\/p>\n\n
Current Limitations<\/h2>\n
The following features are not working yet. They may need more configuration or\nfurther work:<\/p>\n\n
Code Folding<\/h3>\n
Classic Vim and YCM don\u2019t support LSP-based folding, and I\u2019m not a big fan of\nthat feature anyway. But you can configure another plugin that supports\nLSP-based folding, or simply rely on indent-based folding.<\/p>\n\n
Go To Definition<\/h3>\n
When I try to go to the definition of template<\/code>, I get an error KeyError:\n'uri'<\/code>. I\u2019m not sure whether this is caused by my local configuration, but it\nneeds further investigation.\n\"go_def_error\"<\/p>\n\n","pubDate":"Tue, 10 Mar 2026 03:06:00 +0000","link":"https:\/\/duswnchl.github.io\/posts\/smarter-chromium-gn-in-vim-with-gn-language-server\/","guid":"https:\/\/duswnchl.github.io\/posts\/smarter-chromium-gn-in-vim-with-gn-language-server\/","category":["chromium","igalia-planet","dyk"]},{"title":"Tips for using Vim when developing Chromium","description":"
There are lots of powerful IDEs which are broadly used by developers. Vim is a\ntext editor, but it can be turned into a good IDE with awesome plugins and a\nlittle bit of configuration.<\/p>\n\n
Many people already prefer using Vim to develop software because of its\nlightness and availability. I am one of them, and always use Vim to develop\nChromium. However, someone would think that it\u2019s hard to get Vim to reach the\nsame performance as other IDEs, since Chromium is a very huge project.<\/p>\n\n
For those potential users, this post introduces some tips for using Vim as an\nIDE when developing Chromium.<\/p>\n\n
\n  
The context of this document is for Linux users who are used to using Vim.<\/p>\n<\/blockquote>\n\n
Code Formatting<\/h2>\n
I strongly recommend using vim-codefmt<\/a> for code formatting. It supports\nmost file types in Chromium including GN (See GN docs<\/a>) and autoformatting.\nHowever, I don\u2019t like to use autoformatting and just bind :FormatLines<\/code> to\nctrl-I<\/code> for formating a selected visual block.<\/p>\n\n
map <C-I> :FormatLines<CR>\n<\/code><\/pre><\/div><\/div>\n\n
\"codefmt\"<\/p>\n\n
Another option is using clang-format<\/code> in depot_tools<\/code> by clang-format.vim<\/code> in\ntools\/vim<\/a>. Please check about tools\/vim<\/a> at the following section.<\/p>\n\n
tools\/vim<\/h2>\n\n
You can easily find a bunch of Vim files in tools\/vim<\/a>. I create a .vimrc<\/em>\nfile locally in a working directory and load only what I need.<\/p>\n\n
let <\/span>chtool_path<\/span>=<\/span>getcwd()<\/span>.'\/tools'<\/span>\n\nfiletype off\nlet<\/span> &rtp.=<\/span>','<\/span>.chtool_path.'\/vim\/mojom'<\/span>\nexec<\/span> 'source'<\/span> chtool_path.'\/vim\/filetypes.vim'<\/span>\nexec<\/span> 'source'<\/span> chtool_path.'\/vim\/ninja-build.vim'<\/span>\nfiletype plugin indent on\n<\/code><\/pre><\/div><\/div>\n\n
Chromium provides vimscript files for syntax highliting and file detection of\nMojom, which is the IDL for Mojo interfaces (IPC) among Chromium services. And\nninja-build.vim<\/code> allows you compile a file with ctrl-O<\/code> or build the specific\ntarget with :CrBuild<\/code> command. See each Vim files for details.<\/p>\n\n
Running Tests<\/h3>\n\n
tools\/autotest.py<\/a> is very useful when you run tests of Chromium. As the\ndescription of the script, autotest.py<\/code> finds the appropriate test suits and\nbuilds it, then runs it. !<\/code> is an option for running autotest.py<\/code> inside Vim,\nbut sometimes it\u2019s a hassle to type all parameters. What about to write simple\ncommands (or functions) with scripts under tools\/vim<\/code>?<\/p>\n\n
This is an example script for running a test for the current line. Some codes\nare copied from ninja-build.vim<\/code> and imported from ninja-output.py<\/code>.<\/p>\n\n
pythonx <<<\/span> endpython<\/span>\nimport os, vim\n\ndef path_to_build_dir():\n  # Codes from tools\/vim\/ninja-build.vim.\n  chrome_root = os.path.dirname(vim.current.buffer.name)\n  fingerprints = ['chrome', 'net', 'v8', 'build', 'skia']\n  while chrome_root  and not all(\n      [os.path.isdir(os.path.join(chrome_root , fp)) for fp in fingerprints]):\n    chrome_root = os.path.dirname(chrome_root)\n  sys.path.append(os.path.join(chrome_root, 'tools', 'vim'))\n  # Import GetNinjaOutputDirectory from tools\/vim\/ninja_output.py.\n  from ninja_output import GetNinjaOutputDirectory\n  return GetNinjaOutputDirectory(chrome_root)\n\ndef run_test_for_line(linenumb):\n  run_cmd = ' '.join(['!tools\/autotest.py', '-C', path_to_build_dir(), '%',\n                      '--line', linenumb] )\n  vim.command(run_cmd)\n<\/span>endpython\n\n<\/span>fun! RunTestForCurrentLine()<\/span>\n  let <\/span>l:current_line =<\/span> shellescape(<\/span>line(<\/span>'.'<\/span>))<\/span>\n  pythonx run_test_for_line(<\/span>vim.eval(<\/span>'l:current_line'<\/span>))<\/span>\nendfun\n\nmap <C-T> :call RunTestForCurrentLine()<\/span><CR>\n<\/code><\/pre><\/div><\/div>\n\n
Place the cursor on what we want to test and ctrl-t<\/code> \u2026 Here you go.\n\"autotest\"<\/p>\n\n
YouCompleteMe<\/h3>\n\n
tools\/vim<\/a> has an example configuration for YouCompleteMe<\/a> (a code\ncompletion engine for Vim). See tools\/vim\/chromium.ycm_extra_conf.py<\/a>.<\/p>\n\n
let <\/span>g:ycm_extra_conf_globlist =<\/span> [<\/span>'..\/.ycm_extra_conf.py'<\/span>]<\/span>\nlet <\/span>g:ycm_goto_buffer_command =<\/span> 'split-or-existing-window'<\/span>\n<\/code><\/pre><\/div><\/div>\n\n
As you already know, YouCompleteMe requires clangd. Very fortunately, Chromium\nalready supports clangd and remote index server to get daily index snapshots.<\/p>\n\n
Here are short demos for completion suggestions,\n\"ycm_auto\"<\/p>\n\n
and code jumping(:YcmCompleter GoTo<\/code>, :YcmCompleter GoToReferences<\/code>) during\nChromium development.\n\"ycm_jump\"<\/p>\n\n
Commenter<\/h2>\n\n
A good developer writes good comments, so being a good commenter makes you a\ngood developer (joke). In my humble opinion, NERD commenter<\/a> will make you a\ngood developer (joke again). You can get all details from the docs of NERD\ncommenter, and Chromium needs only an additional option for mojom.<\/p>\n\n
let <\/span>g:NERDCustomDelimiters =<\/span> {<\/span> 'mojom'<\/span>: {<\/span>'left'<\/span>: '\/\/'<\/span>}<\/span> }<\/span>\n<\/code><\/pre><\/div><\/div>\n\n
Conclusion<\/h2>\n\n
Thanks for reading and I hope this blog post can be some help to your\ndevelopment enviroment for Chromium. Any comment for sharing some other cool\ntips always be welcomed, so that we can make our Vim more productive. (Right,\nthis is the real purpose of this blog post.)<\/p>\n\n
\u2026. I will be back someday with debugging Chromium in Vim.\n\"sneak<\/p>\n\n","pubDate":"Mon, 30 Jan 2023 02:14:00 +0000","link":"https:\/\/duswnchl.github.io\/posts\/tips-for-using-vim-when-developing-chromium\/","guid":"https:\/\/duswnchl.github.io\/posts\/tips-for-using-vim-when-developing-chromium\/","category":["chromium","vim","igalia-planet","dev"]}]}}
File Navigation<\/h2>\n\n
Chromium is really huge, so we benefit from efficient file navigation tools.\nThere are lots of awesome fuzzy finder plugins for this purpose and I have been\nusing command-t<\/a> for a long time. But command-t requires a Vim executable\nwith ruby\/lua support or Neovim. If you need a simpler yet still powerful\nnavigator, fzf.vim<\/a> is an altenative great option.<\/p>\n\n
Since Chromium a git project, search commands based by git ls-files<\/code> will\nprovide results very quickly. Use the option let g:CommandTFileScanner = 'git'<\/code>\nfor command-t<\/code>, and use the command :GFiles<\/code> for fzf.vim<\/code>.<\/p>\n\n
\"filenav\"<\/p>\n\n
In case you can\u2019t depend on git ls-files<\/code> based commands, please make sure your\nplugin use rg<\/code> or fd<\/code> which are the fastest command line search tools. For\nexample, fzf.vim<\/a> has an option FZF_DEFAULT_COMMAND<\/code> and the following\nsuggestion in the manual: export FZF_DEFAULT_COMMAND='fd --type f'<\/code>.<\/p>\n\n
Do not skip documents about using Clangd to build chromium<\/a> and chromium\nremote index server<\/a>.<\/p>\n\n