checkpatch.nvim

An asynchronous Neovim plugin for running checkpatch.pl (with full compatibility for QEMU 7.2+ and Linux kernel checkpatch.pl).

Populates Neovim's Quickfix list and native Diagnostics (vim.diagnostic) with errors, warnings, and style checks reported by checkpatch.pl.

---

Features

• Multiple Execution Scopes:
  • :CheckpatchFile - Run checkpatch on the current active buffer/file.
  • :CheckpatchModified - Run checkpatch on modified files in the working tree (filtered to modified lines by default).
  • :CheckpatchStaged - Run checkpatch on staged files in git (filtered to staged lines by default).
  • :CheckpatchAll - Run checkpatch on all tracked source files in the git repository.
  • :CheckpatchClear - Clear checkpatch diagnostics and quickfix list.
• Diff Hunk Line Filtering: When running staged or modified checks, checkpatch.nvim parses git diff -U0 hunks to ensure only warnings/errors on modified lines are reported, ignoring pre-existing issues on unmodified lines.
• Asynchronous Execution: Uses vim.system to prevent freezing the UI even when scanning thousands of files.
• Full QEMU 7.2+ Compatibility: Tested specifically against QEMU 7.2 scripts/checkpatch.pl, with fallback support for standard multi-line kernel checkpatch formats.
• Quickfix & Diagnostics Integration: Populates the quickfix list (:copen) and places inline diagnostic signs and highlights (vim.diagnostic).

---

Installation

Using lazy.nvim:

{
  "buxtonpaul/checkpatch.nvim",
  config = function()
    require("checkpatch").setup({
      -- Custom path to checkpatch.pl (defaults to auto-detecting ./scripts/checkpatch.pl or PATH)
      cmd = nil,
      -- Flags passed to checkpatch.pl
      extra_args = { "--no-tree", "--terse", "--no-summary" },
      -- Automatically open quickfix list if issues are found
      auto_open_quickfix = true,
      -- Populate native vim.diagnostic
      populate_diagnostics = true,
      -- Populate quickfix list
      populate_quickfix = true,
      -- Only report issues on modified/added lines during staged and modified checks
      filter_changed_lines = true,
      -- Save buffer before checking if modified
      save_before_check = true,
      -- File extensions to include for modified/staged/all checks
      file_extensions = { "c", "h", "cpp", "hpp", "cc", "hh", "cxx", "S" },
      -- Show notifications
      notify = true,
    })
  end,
}

---

Commands

Command	Description
:CheckpatchFile	Run checkpatch.pl on the current file
:CheckpatchModified	Run checkpatch.pl on modified working tree files in git (filtered to changed lines)
:CheckpatchStaged	Run checkpatch.pl on staged files in git (filtered to staged lines)
:CheckpatchAll	Run checkpatch.pl on all tracked files in git
:CheckpatchClear	Clear all checkpatch diagnostics and quickfix items

---

Lua API

You can also trigger checks programmatically from Lua or bind them to custom keymaps:

local checkpatch = require("checkpatch")

-- Keymaps example
vim.keymap.set("n", "<leader>cf", checkpatch.check_file, { desc = "Checkpatch current file" })
vim.keymap.set("n", "<leader>cm", checkpatch.check_modified, { desc = "Checkpatch modified files" })
vim.keymap.set("n", "<leader>cs", checkpatch.check_staged, { desc = "Checkpatch staged files" })
vim.keymap.set("n", "<leader>ca", checkpatch.check_all, { desc = "Checkpatch all files" })
vim.keymap.set("n", "<leader>cc", checkpatch.clear, { desc = "Checkpatch clear" })

---

Configuration Options

Option	Type	Default	Description
cmd	`string	function	nil`
extra_args	table	{ "--no-tree", "--terse", "--no-summary" }	Command line flags passed to checkpatch.pl.
auto_open_quickfix	boolean	true	Open quickfix list automatically when errors/warnings are found.
populate_diagnostics	boolean	true	Publish issues to vim.diagnostic.
populate_quickfix	boolean	true	Populate Neovim quickfix list (setqflist).
filter_changed_lines	boolean	true	When enabled, filters :CheckpatchStaged and :CheckpatchModified results to only lines that were added/modified in the git diff.
save_before_check	boolean	true	Auto-save modified buffer before checking current file.
file_extensions	table	{ "c", "h", "cpp", "hpp", "cc", "hh", "cxx", "S" }	File extensions filtered when running batch checks (Modified, Staged, All).
notify	boolean	true	Show status notifications using vim.notify.

---

Running Tests

Tests can be run headlessly using Neovim:

nvim --headless -u NONE -c "set runtimepath+=." -c "runtime plugin/checkpatch.lua" -c "luafile tests/run_tests.lua"
nvim --headless -u NONE -c "set runtimepath+=." -c "runtime plugin/checkpatch.lua" -c "luafile tests/test_git_commands.lua"
nvim --headless -u NONE -c "set runtimepath+=." -c "runtime plugin/checkpatch.lua" -c "luafile tests/test_staged_line_filter.lua"