gn-mode: Add matching for variables in strings.

tools/gn/misc/emacs/gn.el

-;;; gn.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.
-
-;; Put this somewhere in your load-path and
-;; (require 'gn)
-
-;; TODO(erg): There's a lot of general improvements that could be made here:
-;;
-;; - We syntax highlight builtin actions, but don't highlight instantiations of
-;;   templates. Should we?
-;; - `fill-paragraph' works for comments, but when pointed at code, breaks
-;;   spectacularly.
-;; - Might want to support `imenu' users. Even if it's just a list of toplevel
-;;   targets?
-
-(eval-when-compile (require 'cl))       ;For the `case' macro.
-(require 'smie)
-
-(defvar gn-font-lock-target-declaration-keywords
-  '("action" "action_foreach" "copy" "executable" "group"
-    "shared_library" "source_set" "static_library" "if" "else"))
-
-(defvar gn-font-lock-buildfile-fun-keywords
-  '("assert" "config" "declare_args" "defined" "exec_script" "foreach"
-    "get_label_info" "get_path_info" "get_target_outputs" "getenv" "import"
-    "print" "process_file_template" "read_file" "rebase_path"
-    "set_default_toolchain" "set_defaults" "set_sources_assignment_filter"
-    "template" "tool" "toolchain" "toolchain_args" "write_file"))
-
-(defvar gn-font-lock-predefined-var-keywords
-  '("current_cpu" "current_os" "current_toolchain" "default_toolchain"
-    "host_cpu" "host_os" "python_path" "root_build_dir" "root_gen_dir"
-    "root_out_dir" "target_cpu" "target_gen_dir" "target_os" "target_out_dir"))
-
-(defvar gn-font-lock-var-keywords
-  '("all_dependent_configs" "allow_circular_includes_from" "args" "cflags"
-    "cflags_c" "cflags_cc" "cflags_objc" "cflags_objcc" "check_includes"
-    "complete_static_lib" "configs" "data" "data_deps" "defines" "depfile"
-    "deps" "forward_dependent_configs_from" "include_dirs" "inputs"
-    "ldflags" "lib_dirs" "libs" "output_extension" "output_name" "outputs"
-    "public" "public_configs" "public_deps" "script" "sources" "testonly"
-    "visibility"))
-
-(defconst gn-font-lock-keywords
-  `((,(regexp-opt gn-font-lock-target-declaration-keywords 'words) .
-     font-lock-keyword-face)
-    (,(regexp-opt gn-font-lock-buildfile-fun-keywords 'words) .
-     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)))
-
-(defvar gn-indent-basic 2)
-
-(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)))))
-
-;;;###autoload
-(define-derived-mode gn-mode prog-mode "GN"
-  "Major mode for editing gn (Generate Ninja)."
-
-  (setq-local font-lock-defaults '(gn-font-lock-keywords))
-
-  (setq-local comment-use-syntax t)
-  (setq-local comment-start "#")
-  (setq-local comment-end "")
-
-  (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)