;;; cmake-ts-mode.el --- tree-sitter support for CMake -*- lexical-binding: t; -*-
;; Copyright (C) 2022-2023 Free Software Foundation, Inc.
;; Author : Randy Taylor <dev@rjt.dev>
;; Maintainer : Randy Taylor <dev@rjt.dev>
;; Created : December 2022
;; Keywords : cmake languages tree-sitter
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;;
;;; Code:
(require 'treesit)
(eval-when-compile (require 'rx))
(declare-function treesit-parser-create "treesit.c")
(declare-function treesit-induce-sparse-tree "treesit.c")
(declare-function treesit-node-child "treesit.c")
(declare-function treesit-node-start "treesit.c")
(declare-function treesit-node-type "treesit.c")
(defcustom cmake-ts-mode-indent-offset 2
"Number of spaces for each indentation step in `cmake-ts-mode'."
:version "29.1"
:type 'integer
:safe 'integerp
:group 'cmake)
(defvar cmake-ts-mode--syntax-table
(let ((table (make-syntax-table)))
(modify-syntax-entry ?# "<" table)
(modify-syntax-entry ?\n ">" table)
(modify-syntax-entry ?$ "'" table)
table)
"Syntax table for `cmake-ts-mode'.")
(defvar cmake-ts-mode--indent-rules
`((cmake
((node-is ")") parent-bol 0)
((node-is "else_command") parent-bol 0)
((node-is "elseif_command") parent-bol 0)
((node-is "endforeach_command") parent-bol 0)
((node-is "endfunction_command") parent-bol 0)
((node-is "endif_command") parent-bol 0)
((parent-is "foreach_loop") parent-bol cmake-ts-mode-indent-offset)
((parent-is "function_def") parent-bol cmake-ts-mode-indent-offset)
((parent-is "if_condition") parent-bol cmake-ts-mode-indent-offset)
((parent-is "normal_command") parent-bol cmake-ts-mode-indent-offset)))
"Tree-sitter indent rules for `cmake-ts-mode'.")
(defvar cmake-ts-mode--constants
'("1" "ON" "TRUE" "YES" "Y" "0" "OFF" "FALSE" "NO" "N" "IGNORE"
"NOTFOUND")
"CMake constants for tree-sitter font-locking.")
(defvar cmake-ts-mode--keywords
'((else) (elseif) (endforeach) (endfunction) (endif) (endmacro)
(endwhile) (foreach) (function) (if) (macro) (while))
"CMake keywords for tree-sitter font-locking.")
(defvar cmake-ts-mode--foreach-options
'("IN" "ITEMS" "LISTS" "RANGE" "ZIP_LISTS")
"CMake foreach options for tree-sitter font-locking.")
(defvar cmake-ts-mode--if-conditions
'("AND" "COMMAND" "DEFINED" "EQUAL" "EXISTS" "GREATER"
"GREATER_EQUAL" "LESS" "LESS_EQUAL" "MATCHES" "NOT" "OR"
"PATH_EQUAL" "STREQUAL" "STRGREATER" "STRGREATER_EQUAL" "STRLESS"
"STRLESS_EQUAL" "VERSION_EQUAL" "VERSION_GREATER"
"VERSION_GREATER_EQUAL" "VERSION_LESS" "VERSION_LESS_EQUAL")
"CMake if conditions for tree-sitter font-locking.")
(defvar cmake-ts-mode--font-lock-settings
(treesit-font-lock-rules
:language 'cmake
:feature 'bracket
'((["(" ")"]) @font-lock-bracket-face)
:language 'cmake
:feature 'builtin
`(((foreach_command
((argument) @font-lock-constant-face
(:match ,(rx-to-string
`(seq bol
(or ,@cmake-ts-mode--foreach-options)
eol))
@font-lock-constant-face))))
((if_command
((argument) @font-lock-constant-face
(:match ,(rx-to-string
`(seq bol
(or ,@cmake-ts-mode--if-conditions)
eol))
@font-lock-constant-face)))))
:language 'cmake
:feature 'comment
'([(bracket_comment) (line_comment)] @font-lock-comment-face)
:language 'cmake
:feature 'constant
`(((argument) @font-lock-constant-face
(:match ,(rx-to-string
`(seq bol
(or ,@cmake-ts-mode--constants)
eol))
@font-lock-constant-face)))
:language 'cmake
:feature 'function
'((normal_command (identifier) @font-lock-function-name-face))
:language 'cmake
:feature 'keyword
`([,@cmake-ts-mode--keywords] @font-lock-keyword-face)
:language 'cmake
:feature 'number
'(((unquoted_argument) @font-lock-number-face
(:match "^[[:digit:]]*\\.?[[:digit:]]*\\.?[[:digit:]]+$" @font-lock-number-face)))
:language 'cmake
:feature 'string
'([(bracket_argument) (quoted_argument)] @font-lock-string-face)
:language 'cmake
:feature 'escape-sequence
:override t
'((escape_sequence) @font-lock-escape-face)
:language 'cmake
:feature 'misc-punctuation
;; Don't override strings.
:override 'nil
'((["$" "{" "}" "<" ">"]) @font-lock-misc-punctuation-face)
:language 'cmake
:feature 'variable
:override t
'((variable) @font-lock-variable-name-face)
:language 'cmake
:feature 'error
:override t
'((ERROR) @font-lock-warning-face))
"Tree-sitter font-lock settings for `cmake-ts-mode'.")
(defun cmake-ts-mode--imenu ()
"Return Imenu alist for the current buffer."
(let* ((node (treesit-buffer-root-node))
(func-tree (treesit-induce-sparse-tree
node "function_def" nil 1000))
(func-index (cmake-ts-mode--imenu-1 func-tree)))
(append
(when func-index `(("Function" . ,func-index))))))
(defun cmake-ts-mode--imenu-1 (node)
"Helper for `cmake-ts-mode--imenu'.
Find string representation for NODE and set marker, then recurse
the subtrees."
(let* ((ts-node (car node))
(children (cdr node))
(subtrees (mapcan #'cmake-ts-mode--imenu-1
children))
(name (when ts-node
(pcase (treesit-node-type ts-node)
("function_def"
(treesit-node-text
(treesit-node-child (treesit-node-child ts-node 0) 2) t)))))
(marker (when ts-node
(set-marker (make-marker)
(treesit-node-start ts-node)))))
(cond
((or (null ts-node) (null name)) subtrees)
(subtrees
`((,name ,(cons name marker) ,@subtrees)))
(t
`((,name . ,marker))))))
;;;###autoload
(define-derived-mode cmake-ts-mode prog-mode "CMake"
"Major mode for editing CMake files, powered by tree-sitter."
:group 'cmake
:syntax-table cmake-ts-mode--syntax-table
(when (treesit-ready-p 'cmake)
(treesit-parser-create 'cmake)
;; Comments.
(setq-local comment-start "# ")
(setq-local comment-end "")
(setq-local comment-start-skip (rx "#" (* (syntax whitespace))))
;; Imenu.
(setq-local imenu-create-index-function #'cmake-ts-mode--imenu)
(setq-local which-func-functions nil)
;; Indent.
(setq-local treesit-simple-indent-rules cmake-ts-mode--indent-rules)
;; Font-lock.
(setq-local treesit-font-lock-settings cmake-ts-mode--font-lock-settings)
(setq-local treesit-font-lock-feature-list
'((comment)
(keyword string)
;; 'function' and 'variable' here play slightly
;; different roles than in other ts modes, so we
;; kept them at level 3.
(builtin constant escape-sequence function number variable)
(bracket error misc-punctuation)))
(treesit-major-mode-setup)))
(if (treesit-ready-p 'cmake)
(add-to-list 'auto-mode-alist
'("\\(?:CMakeLists\\.txt\\|\\.cmake\\)\\'" . cmake-ts-mode)))
(provide 'cmake-ts-mode)
;;; cmake-ts-mode.el ends here