misc/emacs/gn-mode.el - gn - Git at Google

 ;;; gn-mode.el - A major mode for editing gn files.

 ;; Copyright 2015 The Chromium Authors. All rights reserved.
 ;; Use of this source code is governed by a BSD-style license that can be
 ;; found in the LICENSE file.

 ;; Author: Elliot Glaysher <erg@chromium.org>
 ;; Created: April 03, 2015
 ;; Keywords: tools, gn, ninja, chromium

 ;; This file is not part of GNU Emacs.

 ;;; Commentary:

 ;; A major mode for editing GN files. GN stands for Generate Ninja. GN is the
 ;; meta build system used in Chromium. For more information on GN, see the GN
 ;; manual: <https://gn.googlesource.com/gn/+/refs/heads/master/README.md>

 ;;; To Do:

 ;; - We syntax highlight builtin actions, but don't highlight instantiations of
 ;;   templates. Should we?


 (require 'smie)

 (defgroup gn nil
   "Major mode for editing Generate Ninja files."
   :prefix "gn-"
   :group 'languages)

 (defcustom gn-indent-basic 2
   "The number of spaces to indent a new scope."
   :group 'gn
   :type 'integer)

 (defcustom gn-format-command "gn format --stdin"
   "The command to run to format gn files in place."
   :group 'gn
   :type 'string)

 (defgroup gn-faces nil
   "Faces used in Generate Ninja mode."
   :group 'gn
   :group 'faces)

 (defface gn-embedded-variable
   '((t :inherit font-lock-variable-name-face))
   "Font lock face used to highlight variable names in strings."
   :group 'gn-faces)

 (defface gn-embedded-variable-boundary
   '((t :bold t
        :inherit gn-embedded-variable))
   "Font lock face used to highlight the '$' that starts a
 variable name or the '{{' and '}}' which surround it."
   :group 'gn-faces)

 (defvar gn-font-lock-reserved-keywords
   '("true" "false" "if" "else"))

 (defvar gn-font-lock-target-declaration-keywords
   '("action" "action_foreach" "bundle_data" "copy" "create_bundle" "executable"
     "group" "loadable_module" "shared_library" "source_set" "static_library"
     "generated_file" "target" "rust_library" "rust_proc_macro"))

 ;; pool() is handled specially since it's also a variable name
 (defvar gn-font-lock-buildfile-fun-keywords
   '("assert" "config" "declare_args" "defined" "exec_script" "foreach"
     "forward_variables_from" "get_label_info" "get_path_info"
     "get_target_outputs" "getenv" "import" "not_needed" "print"
     "process_file_template" "read_file" "rebase_path" "set_default_toolchain"
     "set_defaults" "split_list" "string_join" "string_split" "template" "tool"
     "toolchain" "propagates_configs" "write_file"))

 (defvar gn-font-lock-predefined-var-keywords
   '("current_cpu" "current_os" "current_toolchain" "default_toolchain"
     "host_cpu" "host_os" "invoker" "python_path" "root_build_dir" "root_gen_dir"
     "root_out_dir" "target_cpu" "target_gen_dir" "target_name" "target_os"
     "target_out_dir"))

 (defvar gn-font-lock-var-keywords
   '("all_dependent_configs" "allow_circular_includes_from" "arflags" "args"
     "asmflags" "assert_no_deps" "bundle_deps_filter" "bundle_executable_dir"
     "bundle_resources_dir" "bundle_root_dir" "cflags" "cflags_c" "cflags_cc"
     "cflags_objc" "cflags_objcc" "check_includes" "code_signing_args"
     "code_signing_outputs" "code_signing_script" "code_signing_sources"
     "complete_static_lib" "configs" "data" "data_deps" "defines" "depfile"
     "deps" "framework_dir" "frameworks" "include_dirs" "inputs" "ldflags"
     "lib_dirs" "libs" "output_dir" "output_extension" "output_name"
     "output_prefix_override" "outputs" "pool" "precompiled_header"
     "precompiled_header_type" "precompiled_source" "product_type" "public"
     "public_configs" "public_deps" "response_file_contents" "script" "sources"
     "testonly" "visibility" "write_runtime_deps" "bundle_contents_dir"
     "contents" "output_conversion" "rebase" "data_keys" "walk_keys"))

 (defconst gn-font-lock-keywords
   `((,(regexp-opt gn-font-lock-reserved-keywords 'words) .
      font-lock-keyword-face)
     (,(regexp-opt gn-font-lock-target-declaration-keywords 'words) .
      font-lock-type-face)
     (,(regexp-opt gn-font-lock-buildfile-fun-keywords 'words) .
      font-lock-function-name-face)
     ;; pool() as a function
     ("\\<\\(pool\\)\\s-*("
      (1 font-lock-function-name-face))
     (,(regexp-opt gn-font-lock-predefined-var-keywords 'words) .
      font-lock-constant-face)
     (,(regexp-opt gn-font-lock-var-keywords 'words) .
      font-lock-variable-name-face)
     ;; $variables_like_this
     ("\\(\\$\\)\\([a-zA-Z0-9_]+\\)"
      (1 'gn-embedded-variable-boundary t)
      (2 'gn-embedded-variable t))
     ;; ${variables_like_this}
     ("\\(\\${\\)\\([^\n }]+\\)\\(}\\)"
      (1 'gn-embedded-variable-boundary t)
      (2 'gn-embedded-variable t)
      (3 'gn-embedded-variable-boundary t))
     ;; {{placeholders}}    (see substitute_type.h)
     ("\\({{\\)\\([^\n }]+\\)\\(}}\\)"
      (1 'gn-embedded-variable-boundary t)
      (2 'gn-embedded-variable t)
      (3 'gn-embedded-variable-boundary t))))

 (defun gn-smie-rules (kind token)
   "These are slightly modified indentation rules from the SMIE
   Indentation Example info page. This changes the :before rule
   and adds a :list-intro to handle our x = [ ] syntax."
   (pcase (cons kind token)
     (`(:elem . basic) gn-indent-basic)
     (`(,_ . ",") (smie-rule-separator kind))
     (`(:list-intro . "") gn-indent-basic)
     (`(:before . ,(or `"[" `"(" `"{"))
      (if (smie-rule-hanging-p) (smie-rule-parent)))
     (`(:before . "if")
      (and (not (smie-rule-bolp)) (smie-rule-prev-p "else")
           (smie-rule-parent)))))

 (defun gn-fill-paragraph (&optional justify)
   "We only fill inside of comments in GN mode."
   (interactive "P")
   (or (fill-comment-paragraph justify)
       ;; Never return nil; `fill-paragraph' will perform its default behavior
       ;; if we do.
       t))

 (defun gn-run-format ()
   "Run 'gn format' on the buffer in place."
   (interactive)
   ;; We can't `save-excursion' here; that will put us at the beginning of the
   ;; shell output, aka the beginning of the document.
   (let ((my-start-line (line-number-at-pos)))
     (shell-command-on-region (point-min) (point-max) gn-format-command nil t)
     (goto-line my-start-line)))

 (defvar gn-mode-map
   (let ((map (make-sparse-keymap)))
     (define-key map "\C-c\C-f" 'gn-run-format)
     map))

 ;;;###autoload
 (define-derived-mode gn-mode prog-mode "GN"
   "Major mode for editing gn (Generate Ninja)."
   :group 'gn

   (setq-local comment-use-syntax t)
   (setq-local comment-start "#")
   (setq-local comment-end "")
   (setq-local indent-tabs-mode nil)

   (setq-local fill-paragraph-function 'gn-fill-paragraph)

   (setq-local font-lock-defaults '(gn-font-lock-keywords))

   ;; For every 'rule("name") {', adds "name" to the imenu for quick navigation.
   (setq-local imenu-generic-expression
               '((nil "^\s*[a-zA-Z0-9_]+(\"\\([a-zA-Z0-9_]+\\)\")\s*{" 1)))

   (smie-setup nil #'gn-smie-rules)
   (setq-local smie-indent-basic gn-indent-basic)

   ;; python style comment: “# …”
   (modify-syntax-entry ?# "< b" gn-mode-syntax-table)
   (modify-syntax-entry ?\n "> b" gn-mode-syntax-table)
   (modify-syntax-entry ?_ "w" gn-mode-syntax-table))

 ;;;###autoload
 (add-to-list 'auto-mode-alist '("\\.gni?\\'" . gn-mode))

 (provide 'gn-mode)
	;;; gn-mode.el - A major mode for editing gn files.

	;; Copyright 2015 The Chromium Authors. All rights reserved.
	;; Use of this source code is governed by a BSD-style license that can be
	;; found in the LICENSE file.

	;; Author: Elliot Glaysher <erg@chromium.org>
	;; Created: April 03, 2015
	;; Keywords: tools, gn, ninja, chromium

	;; This file is not part of GNU Emacs.

	;;; Commentary:

	;; A major mode for editing GN files. GN stands for Generate Ninja. GN is the
	;; meta build system used in Chromium. For more information on GN, see the GN
	;; manual: <https://gn.googlesource.com/gn/+/refs/heads/master/README.md>

	;;; To Do:

	;; - We syntax highlight builtin actions, but don't highlight instantiations of
	;; templates. Should we?



	(require 'smie)

	(defgroup gn nil
	"Major mode for editing Generate Ninja files."
	:prefix "gn-"
	:group 'languages)

	(defcustom gn-indent-basic 2
	"The number of spaces to indent a new scope."
	:group 'gn
	:type 'integer)

	(defcustom gn-format-command "gn format --stdin"
	"The command to run to format gn files in place."
	:group 'gn
	:type 'string)

	(defgroup gn-faces nil
	"Faces used in Generate Ninja mode."
	:group 'gn
	:group 'faces)

	(defface gn-embedded-variable
	'((t :inherit font-lock-variable-name-face))
	"Font lock face used to highlight variable names in strings."
	:group 'gn-faces)

	(defface gn-embedded-variable-boundary
	'((t :bold t
	:inherit gn-embedded-variable))
	"Font lock face used to highlight the '$' that starts a
	variable name or the '{{' and '}}' which surround it."
	:group 'gn-faces)

	(defvar gn-font-lock-reserved-keywords
	'("true" "false" "if" "else"))

	(defvar gn-font-lock-target-declaration-keywords
	'("action" "action_foreach" "bundle_data" "copy" "create_bundle" "executable"
	"group" "loadable_module" "shared_library" "source_set" "static_library"
	"generated_file" "target" "rust_library" "rust_proc_macro"))

	;; pool() is handled specially since it's also a variable name
	(defvar gn-font-lock-buildfile-fun-keywords
	'("assert" "config" "declare_args" "defined" "exec_script" "foreach"
	"forward_variables_from" "get_label_info" "get_path_info"
	"get_target_outputs" "getenv" "import" "not_needed" "print"
	"process_file_template" "read_file" "rebase_path" "set_default_toolchain"
	"set_defaults" "split_list" "string_join" "string_split" "template" "tool"
	"toolchain" "propagates_configs" "write_file"))

	(defvar gn-font-lock-predefined-var-keywords
	'("current_cpu" "current_os" "current_toolchain" "default_toolchain"
	"host_cpu" "host_os" "invoker" "python_path" "root_build_dir" "root_gen_dir"
	"root_out_dir" "target_cpu" "target_gen_dir" "target_name" "target_os"
	"target_out_dir"))

	(defvar gn-font-lock-var-keywords
	'("all_dependent_configs" "allow_circular_includes_from" "arflags" "args"
	"asmflags" "assert_no_deps" "bundle_deps_filter" "bundle_executable_dir"
	"bundle_resources_dir" "bundle_root_dir" "cflags" "cflags_c" "cflags_cc"
	"cflags_objc" "cflags_objcc" "check_includes" "code_signing_args"
	"code_signing_outputs" "code_signing_script" "code_signing_sources"
	"complete_static_lib" "configs" "data" "data_deps" "defines" "depfile"
	"deps" "framework_dir" "frameworks" "include_dirs" "inputs" "ldflags"
	"lib_dirs" "libs" "output_dir" "output_extension" "output_name"
	"output_prefix_override" "outputs" "pool" "precompiled_header"
	"precompiled_header_type" "precompiled_source" "product_type" "public"
	"public_configs" "public_deps" "response_file_contents" "script" "sources"
	"testonly" "visibility" "write_runtime_deps" "bundle_contents_dir"
	"contents" "output_conversion" "rebase" "data_keys" "walk_keys"))

	(defconst gn-font-lock-keywords
	`((,(regexp-opt gn-font-lock-reserved-keywords 'words) .
	font-lock-keyword-face)
	(,(regexp-opt gn-font-lock-target-declaration-keywords 'words) .
	font-lock-type-face)
	(,(regexp-opt gn-font-lock-buildfile-fun-keywords 'words) .
	font-lock-function-name-face)
	;; pool() as a function
	("\\<\\(pool\\)\\s-*("
	(1 font-lock-function-name-face))
	(,(regexp-opt gn-font-lock-predefined-var-keywords 'words) .
	font-lock-constant-face)
	(,(regexp-opt gn-font-lock-var-keywords 'words) .
	font-lock-variable-name-face)
	;; $variables_like_this
	("\\(\\$\\)\\([a-zA-Z0-9_]+\\)"
	(1 'gn-embedded-variable-boundary t)
	(2 'gn-embedded-variable t))
	;; ${variables_like_this}
	("\\(\\${\\)\\([^\n }]+\\)\\(}\\)"
	(1 'gn-embedded-variable-boundary t)
	(2 'gn-embedded-variable t)
	(3 'gn-embedded-variable-boundary t))
	;; {{placeholders}} (see substitute_type.h)
	("\\({{\\)\\([^\n }]+\\)\\(}}\\)"
	(1 'gn-embedded-variable-boundary t)
	(2 'gn-embedded-variable t)
	(3 'gn-embedded-variable-boundary t))))

	(defun gn-smie-rules (kind token)
	"These are slightly modified indentation rules from the SMIE
	Indentation Example info page. This changes the :before rule
	and adds a :list-intro to handle our x = [ ] syntax."
	(pcase (cons kind token)
	(`(:elem . basic) gn-indent-basic)
	(`(,_ . ",") (smie-rule-separator kind))
	(`(:list-intro . "") gn-indent-basic)
	(`(:before . ,(or `"[" `"(" `"{"))
	(if (smie-rule-hanging-p) (smie-rule-parent)))
	(`(:before . "if")
	(and (not (smie-rule-bolp)) (smie-rule-prev-p "else")
	(smie-rule-parent)))))

	(defun gn-fill-paragraph (&optional justify)
	"We only fill inside of comments in GN mode."
	(interactive "P")
	(or (fill-comment-paragraph justify)
	;; Never return nil; `fill-paragraph' will perform its default behavior
	;; if we do.
	t))

	(defun gn-run-format ()
	"Run 'gn format' on the buffer in place."
	(interactive)
	;; We can't `save-excursion' here; that will put us at the beginning of the
	;; shell output, aka the beginning of the document.
	(let ((my-start-line (line-number-at-pos)))
	(shell-command-on-region (point-min) (point-max) gn-format-command nil t)
	(goto-line my-start-line)))

	(defvar gn-mode-map
	(let ((map (make-sparse-keymap)))
	(define-key map "\C-c\C-f" 'gn-run-format)
	map))

	;;;###autoload
	(define-derived-mode gn-mode prog-mode "GN"
	"Major mode for editing gn (Generate Ninja)."
	:group 'gn

	(setq-local comment-use-syntax t)
	(setq-local comment-start "#")
	(setq-local comment-end "")
	(setq-local indent-tabs-mode nil)

	(setq-local fill-paragraph-function 'gn-fill-paragraph)

	(setq-local font-lock-defaults '(gn-font-lock-keywords))

	;; For every 'rule("name") {', adds "name" to the imenu for quick navigation.
	(setq-local imenu-generic-expression
	'((nil "^\s[a-zA-Z0-9_]+(\"\\([a-zA-Z0-9_]+\\)\")\s{" 1)))

	(smie-setup nil #'gn-smie-rules)
	(setq-local smie-indent-basic gn-indent-basic)

	;; python style comment: “# …”
	(modify-syntax-entry ?# "< b" gn-mode-syntax-table)
	(modify-syntax-entry ?\n "> b" gn-mode-syntax-table)
	(modify-syntax-entry ?_ "w" gn-mode-syntax-table))

	;;;###autoload
	(add-to-list 'auto-mode-alist '("\\.gni?\\'" . gn-mode))

	(provide 'gn-mode)