Add dockerfile-ts-mode (Bug#59894)

* admin/notes/tree-sitter/build-module/batch.sh: Add dockerfile support.
* admin/notes/tree-sitter/build-module/build.sh: Support different
namespaces and add dockerfile support.
* etc/NEWS: Mention it.
* lisp/progmodes/dockerfile-ts-mode.el: New major mode with
tree-sitter support.
* lisp/progmodes/eglot.el (eglot-server-programs): Add it.

5 files changed, 188 insertions, 2 deletions

diff --git a/admin/notes/tree-sitter/build-module/batch.sh b/admin/notes/tree-sitter/build-module/batch.sh
index d45f37f4b64..6dce000caa6 100755
--- a/admin/notes/tree-sitter/build-module/batch.sh
+++ b/admin/notes/tree-sitter/build-module/batch.sh
@@ -5,6 +5,7 @@ languages=(
     'cpp'
     'css'
     'c-sharp'
+    'dockerfile'
     'go'
     'html'
     'javascript'
diff --git a/admin/notes/tree-sitter/build-module/build.sh b/admin/notes/tree-sitter/build-module/build.sh
index d562f1a7846..cc31e3f6f02 100755
--- a/admin/notes/tree-sitter/build-module/build.sh
+++ b/admin/notes/tree-sitter/build-module/build.sh
@@ -14,11 +14,15 @@ echo "Building ${lang}"
 
 ### Retrieve sources
 
+namespace="tree-sitter"
 repo="tree-sitter-${lang}"
 sourcedir="tree-sitter-${lang}/src"
 grammardir="tree-sitter-${lang}"
 
 case "${lang}" in
+    "dockerfile")
+        namespace="camdencheek"
+        ;;
     "typescript")
         sourcedir="tree-sitter-typescript/typescript/src"
         grammardir="tree-sitter-typescript/typescript"
@@ -30,7 +34,7 @@ case "${lang}" in
         ;;
 esac
 
-git clone "https://github.com/tree-sitter/${repo}.git" \
+git clone "https://github.com/${namespace}/${repo}.git" \
     --depth 1 --quiet
 cp "${grammardir}"/grammar.js "${sourcedir}"
 # We have to go into the source directory to compile, because some
diff --git a/etc/NEWS b/etc/NEWS
index e4a19e29869..233ef3f5729 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -3068,6 +3068,11 @@ A major mode based on the tree-sitter library for editing Bash shell
 scripts.  It includes support for font-locking, indentation, Imenu,
 which-func, and navigation.
 
+** New major mode 'dockerfile-ts-mode'.
+A major mode based on the tree-sitter library for editing
+Dockerfiles.  It includes support for font-locking, indentation, Imenu,
+and which-func.
+
 
 * Incompatible Lisp Changes in Emacs 29.1
 
diff --git a/lisp/progmodes/dockerfile-ts-mode.el b/lisp/progmodes/dockerfile-ts-mode.el
new file mode 100644
index 00000000000..e08387ad969
--- /dev/null
+++ b/lisp/progmodes/dockerfile-ts-mode.el
@@ -0,0 +1,176 @@
+;;; dockerfile-ts-mode.el --- tree-sitter support for Dockerfiles  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2022 Free Software Foundation, Inc.
+
+;; Author     : Randy Taylor <dev@rjt.dev>
+;; Maintainer : Randy Taylor <dev@rjt.dev>
+;; Created    : December 2022
+;; Keywords   : dockerfile 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")
+
+(defvar dockerfile-ts-mode--syntax-table
+  (let ((table (make-syntax-table)))
+    (modify-syntax-entry ?#  "<" table)
+    (modify-syntax-entry ?\n ">" table)
+    table)
+  "Syntax table for `dockerfile-ts-mode'.")
+
+(defvar dockerfile-ts-mode--indent-rules
+  `((dockerfile
+     ((parent-is "copy_instruction") (nth-sibling 1) 0)
+     ((parent-is "env_instruction") (nth-sibling 1) 0)
+     ((parent-is "expose_instruction") (nth-sibling 1) 0)
+     ((parent-is "label_instruction") (nth-sibling 1) 0)
+     ((parent-is "shell_command") first-sibling 0)
+     ((parent-is "string_array") first-sibling 1)))
+  "Tree-sitter indent rules.")
+
+(defvar dockerfile-ts-mode--keywords
+  '("ADD" "ARG" "AS" "CMD" "COPY" "CROSS_BUILD" "ENTRYPOINT" "ENV"
+    "EXPOSE" "FROM" "HEALTHCHECK" "LABEL" "MAINTAINER" "ONBUILD" "RUN"
+    "SHELL" "STOPSIGNAL" "USER" "VOLUME" "WORKDIR")
+  "Dockerfile keywords for tree-sitter font-locking.")
+
+(defvar dockerfile-ts-mode--font-lock-settings
+  (treesit-font-lock-rules
+   :language 'dockerfile
+   :feature 'bracket
+   '((["[" "]"]) @font-lock-bracket-face)
+
+   :language 'dockerfile
+   :feature 'comment
+   '((comment) @font-lock-comment-face)
+
+   :language 'dockerfile
+   :feature 'delimiter
+   '(([","]) @font-lock-delimiter-face)
+
+   :language 'dockerfile
+   :feature 'image-spec
+   '((image_spec) @font-lock-constant-face)
+
+   :language 'dockerfile
+   :feature 'keyword
+   `([,@dockerfile-ts-mode--keywords] @font-lock-keyword-face)
+
+   :language 'dockerfile
+   :feature 'number
+   '((expose_port) @font-lock-number-face)
+
+   :language 'dockerfile
+   :feature 'operator
+   '((["="]) @font-lock-operator-face)
+
+   :language 'dockerfile
+   :feature 'string
+   '((double_quoted_string) @font-lock-string-face)
+
+   :language 'dockerfile
+   :feature 'error
+   :override t
+   '((ERROR) @font-lock-warning-face))
+  "Tree-sitter font-lock settings.")
+
+(defun dockerfile-ts-mode--imenu ()
+  "Return Imenu alist for the current buffer."
+  (let* ((node (treesit-buffer-root-node))
+         (stage-tree (treesit-induce-sparse-tree
+                      node "from_instruction"
+                      nil 1000)))
+    `(("Stage" . ,(dockerfile-ts-mode--imenu-1 stage-tree)))))
+
+(defun dockerfile-ts-mode--imenu-1 (node)
+  "Helper for `dockerfile-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 #'dockerfile-ts-mode--imenu-1
+                           children))
+         (name (when ts-node
+                 (pcase (treesit-node-type ts-node)
+                   ("from_instruction" (treesit-node-text
+                                        (treesit-node-child ts-node 1) 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
+(add-to-list 'auto-mode-alist
+             `(,(rx (|
+                     (: "Dockerfile" (? "." (* nonl)))
+                     (: "." (any "dD") "ockerfile"))
+                    eol)
+               . dockerfile-ts-mode))
+
+;;;###autoload
+(define-derived-mode dockerfile-ts-mode prog-mode "Dockerfile"
+  "Major mode for editing Dockerfiles, powered by tree-sitter."
+  :group 'dockerfile
+  :syntax-table dockerfile-ts-mode--syntax-table
+
+  (when (treesit-ready-p 'dockerfile)
+    (treesit-parser-create 'dockerfile)
+
+    ;; Comments.
+    (setq-local comment-start "# ")
+    (setq-local comment-end "")
+    (setq-local comment-start-skip (rx "#" (* (syntax whitespace))))
+
+    ;; Imenu.
+    (setq-local imenu-create-index-function
+                #'dockerfile-ts-mode--imenu)
+    (setq-local which-func-functions nil)
+
+    ;; Indent.
+    (setq-local treesit-simple-indent-rules
+                dockerfile-ts-mode--indent-rules)
+
+    ;; Font-lock.
+    (setq-local treesit-font-lock-settings
+                dockerfile-ts-mode--font-lock-settings)
+    (setq-local treesit-font-lock-feature-list
+                '((comment)
+                  (keyword string)
+                  (image-spec number)
+                  (bracket delimiter error operator)))
+
+    (treesit-major-mode-setup)))
+
+(provide 'dockerfile-ts-mode)
+
+;;; dockerfile-ts-mode.el ends here
diff --git a/lisp/progmodes/eglot.el b/lisp/progmodes/eglot.el
index a53f62fc565..2ef022992e7 100644
--- a/lisp/progmodes/eglot.el
+++ b/lisp/progmodes/eglot.el
@@ -236,7 +236,7 @@ chosen (interactively or automatically)."
                                  . ,(eglot-alternatives '(("vscode-css-language-server" "--stdio")
                                                           ("css-languageserver" "--stdio"))))
                                 (html-mode . ,(eglot-alternatives '(("vscode-html-language-server" "--stdio") ("html-languageserver" "--stdio"))))
-                                (dockerfile-mode . ("docker-langserver" "--stdio"))
+                                ((dockerfile-mode dockerfile-ts-mode) . ("docker-langserver" "--stdio"))
                                 ((clojure-mode clojurescript-mode clojurec-mode)
                                  . ("clojure-lsp"))
                                 ((csharp-mode csharp-ts-mode)