Subject: bug#71874: 30.0.60; [PATCH] Fontify doxygen comments in c-ts-mode,c++-ts-mode and java-ts-mode

From: Vincenzo Pupillo <[email-masked]>
Date: Mon, 01 Jul 2024 12:48:33 +0200

Ciao,
This patch adds support for comment fontification using the doxygen parser:
https://github.com/tree-sitter-grammars/tree-sitter-doxygen

This is the same parser used by nvim treesitter and seems to be quite stable.
The attached screenshot shows the result.
This patch also works with emacs 31.

Thanks.

Vincenzo

>From 298a7676c924fdc0642dcf867f3ac0da82409968 Mon Sep 17 00:00:00 2001
From: Vincenzo Pupillo <[email-masked]>
Date: Mon, 1 Jul 2024 12:34:01 +0200
Subject: [PATCH] Fontify doxygen support to c-ts-mode, c++-ts-mode and
 java-ts-mode

Add doxygen support to 'c-ts-mode', 'c++-ts-mode' and 'java-ts-mode'
using tree-sitter-doxygen from github.com/tree-sitter-grammars.

* lisp/progmodes/c-ts-common.el
(c-ts-mode-doxygen-comment-font-lock-settings): Add font locking rules
for doxygen comment.

* lisp/progmodes/c-ts-mode.el (c-ts-mode--feature-list): Add 'document'
feature.

* lisp/progmodes/c-ts-mode.el (c-ts-mode--doxygen-comment-regex):
New regular expression for doxygen comments.

* lisp/progmodes/c-ts-mode.el (c-ts-mode): Add support for doxygen
parser.

* lisp/progmodes/c-ts-mode.el (c++-ts-mode): Add support for doxygen
parser.

* lisp/progmodes/java-ts-mode.el (java-ts-mode): Add support for doxygen
parser.
---
 lisp/progmodes/c-ts-common.el  |  22 +++++
 lisp/progmodes/c-ts-mode.el    | 126 +++++++++++++++++---------
 lisp/progmodes/java-ts-mode.el | 159 ++++++++++++++++++---------------
 3 files changed, 193 insertions(+), 114 deletions(-)

diff --git a/lisp/progmodes/c-ts-common.el b/lisp/progmodes/c-ts-common.el
index 3882a697c48..a1f257ee09a 100644
--- a/lisp/progmodes/c-ts-common.el
+++ b/lisp/progmodes/c-ts-common.el
@@ -348,6 +348,28 @@ c-ts-common-comment-indent-new-line
       (delete-region (line-beginning-position) (point))
       (insert whitespaces)))))
 
+;; Font locking using doxygen parser
+(defvar c-ts-mode-doxygen-comment-font-lock-settings
+  (treesit-font-lock-rules
+   :language 'doxygen
+   :feature 'document
+   :override t
+   '((document) @font-lock-doc-face)
+
+   :language 'doxygen
+   :override t
+   :feature 'keyword
+   '((tag_name) @font-lock-constant-face
+     (storageclass) @font-lock-constant-face)
+
+   :language 'doxygen
+   :override t
+   :feature 'definition
+   '((tag (identifier) @font-lock-variable-name-face)
+     (function (identifier) @font-lock-function-name-face)
+     (function_link) @font-lock-function-name-face))
+  "Tree-sitter font lock rules for doxygen like comment styles.")
+
 ;;; Statement indent
 
 (defvar c-ts-common-indent-offset nil
diff --git a/lisp/progmodes/c-ts-mode.el b/lisp/progmodes/c-ts-mode.el
index 2ac163d7a7e..201ff09593a 100644
--- a/lisp/progmodes/c-ts-mode.el
+++ b/lisp/progmodes/c-ts-mode.el
@@ -63,6 +63,9 @@
 ;; will set up Emacs to use the C/C++ modes defined here for other
 ;; files, provided that you have the corresponding parser grammar
 ;; libraries installed.
+;;
+;; If the tree-sitter doxygen grammar is available, then the comment
+;; blocks will be highlighted according to this grammar.
 
 ;;; Code:
 
@@ -539,7 +542,7 @@ c-ts-mode--top-level-label-matcher
 ;;; Font-lock
 
 (defvar c-ts-mode--feature-list
-  '(( comment definition)
+  '(( comment document definition)
     ( keyword preprocessor string type)
     ( assignment constant escape-sequence label literal)
     ( bracket delimiter error function operator property variable))
@@ -591,6 +594,10 @@ c-ts-mode--for-each-tail-regexp
                       "LIVE_BUFFER" "FRAME"))
   "A regexp matching all the variants of the FOR_EACH_* macro.")
 
+(defvar c-ts-mode--doxygen-comment-regex
+  (rx (| "/**" "/*!" "//!" "///"))
+  "A regexp that matches all doxygen comment styles.")
+
 (defun c-ts-mode--font-lock-settings (mode)
   "Tree-sitter font-lock settings.
 MODE is either `c' or `cpp'."
@@ -1319,30 +1326,47 @@ c-ts-mode
     (when c-ts-mode-emacs-sources-support
       (treesit-parser-create 'c nil nil 'for-each))
 
-    (treesit-parser-create 'c)
-    ;; Comments.
-    (setq-local comment-start "/* ")
-    (setq-local comment-end " */")
-    ;; Indent.
-    (setq-local treesit-simple-indent-rules
-                (c-ts-mode--get-indent-style 'c))
-    ;; Font-lock.
-    (setq-local treesit-font-lock-settings (c-ts-mode--font-lock-settings 'c))
-    ;; Navigation.
-    (setq-local treesit-defun-tactic 'top-level)
-    (treesit-major-mode-setup)
-
-    ;; Emacs source support: handle DEFUN and FOR_EACH_* gracefully.
-    (when c-ts-mode-emacs-sources-support
-      (setq-local add-log-current-defun-function
-                  #'c-ts-mode--emacs-current-defun-name)
-
-      (setq-local treesit-range-settings
-                  (treesit-range-rules 'c-ts-mode--emacs-set-ranges))
-
-      (setq-local treesit-language-at-point-function
-                  (lambda (_pos) 'c))
-      (treesit-font-lock-recompute-features '(emacs-devel)))))
+    (let ((primary-parser (treesit-parser-create 'c)))
+      ;; Comments.
+      (setq-local comment-start "/* ")
+      (setq-local comment-end " */")
+      ;; Indent.
+      (setq-local treesit-simple-indent-rules
+                  (c-ts-mode--get-indent-style 'c))
+      ;; Font-lock.
+      (setq-local treesit-font-lock-settings
+                  (c-ts-mode--font-lock-settings 'c))
+      ;; Navigation.
+      (setq-local treesit-defun-tactic 'top-level)
+      (treesit-major-mode-setup)
+
+      ;; Emacs source support: handle DEFUN and FOR_EACH_* gracefully.
+      (when c-ts-mode-emacs-sources-support
+        (setq-local add-log-current-defun-function
+                    #'c-ts-mode--emacs-current-defun-name)
+
+        (setq-local treesit-range-settings
+                    (treesit-range-rules 'c-ts-mode--emacs-set-ranges))
+
+        (setq-local treesit-language-at-point-function
+                    (lambda (_pos) 'c))
+        (treesit-font-lock-recompute-features '(emacs-devel)))
+
+      ;; Inject doxygen parser for comment.
+      (when (treesit-ready-p 'doxygen)
+        (setq-local treesit-primary-parser primary-parser)
+        (setq-local treesit-font-lock-settings
+                    (append
+                     treesit-font-lock-settings
+                     c-ts-mode-doxygen-comment-font-lock-settings))
+        (setq-local treesit-range-settings
+                    (treesit-range-rules
+                     :embed 'doxygen
+                     :host 'c
+                     :local t
+                     `(((comment) @cap
+                        (:match
+                         ,c-ts-mode--doxygen-comment-regex @cap)))))))))
 
 (derived-mode-add-parents 'c-ts-mode '(c-mode))
 
@@ -1370,24 +1394,40 @@ c++-ts-mode
   :after-hook (c-ts-mode-set-modeline)
 
   (when (treesit-ready-p 'cpp)
-
-    (treesit-parser-create 'cpp)
-
-    ;; Syntax.
-    (setq-local syntax-propertize-function
-                #'c-ts-mode--syntax-propertize)
-
-    ;; Indent.
-    (setq-local treesit-simple-indent-rules
-                (c-ts-mode--get-indent-style 'cpp))
-
-    ;; Font-lock.
-    (setq-local treesit-font-lock-settings (c-ts-mode--font-lock-settings 'cpp))
-    (treesit-major-mode-setup)
-
-    (when c-ts-mode-emacs-sources-support
-      (setq-local add-log-current-defun-function
-                  #'c-ts-mode--emacs-current-defun-name))))
+    (let ((primary-parser (treesit-parser-create 'cpp)))
+
+      ;; Syntax.
+      (setq-local syntax-propertize-function
+                  #'c-ts-mode--syntax-propertize)
+
+      ;; Indent.
+      (setq-local treesit-simple-indent-rules
+                  (c-ts-mode--get-indent-style 'cpp))
+
+      ;; Font-lock.
+      (setq-local treesit-font-lock-settings
+                  (c-ts-mode--font-lock-settings 'cpp))
+      (treesit-major-mode-setup)
+
+      (when c-ts-mode-emacs-sources-support
+        (setq-local add-log-current-defun-function
+                    #'c-ts-mode--emacs-current-defun-name))
+
+      ;; Inject doxygen parser for comment.
+      (when (treesit-ready-p 'doxygen)
+        (setq-local treesit-primary-parser primary-parser)
+        (setq-local treesit-font-lock-settings
+                    (append
+                     treesit-font-lock-settings
+                     c-ts-mode-doxygen-comment-font-lock-settings))
+        (setq-local treesit-range-settings
+                    (treesit-range-rules
+                     :embed 'doxygen
+                     :host 'cpp
+                     :local t
+                     `(((comment) @cap
+                        (:match
+                         ,c-ts-mode--doxygen-comment-regex @cap)))))))))
 
 (derived-mode-add-parents 'c++-ts-mode '(c++-mode))
 
diff --git a/lisp/progmodes/java-ts-mode.el b/lisp/progmodes/java-ts-mode.el
index bb4a7df3340..04aaf43ac66 100644
--- a/lisp/progmodes/java-ts-mode.el
+++ b/lisp/progmodes/java-ts-mode.el
@@ -24,6 +24,8 @@
 
 ;;; Commentary:
 ;;
+;; If the tree-sitter doxygen grammar is available, then the comment
+;; blocks will be highlighted according to this grammar.
 
 ;;; Code:
 
@@ -312,7 +314,7 @@ java-ts-mode--defun-name

 (defvar java-ts-mode--feature-list
-  '(( comment definition )
+  '(( comment document definition )
     ( constant keyword string type)
     ( annotation expression literal)
     ( bracket delimiter operator)))
@@ -326,76 +328,91 @@ java-ts-mode
   (unless (treesit-ready-p 'java)
     (error "Tree-sitter for Java isn't available"))
 
-  (treesit-parser-create 'java)
-
-  ;; Comments.
-  (c-ts-common-comment-setup)
-
-  ;; Indent.
-  (setq-local c-ts-common-indent-type-regexp-alist
-              `((block . ,(rx (or "class_body"
-                                  "array_initializer"
-                                  "constructor_body"
-                                  "annotation_type_body"
-                                  "interface_body"
-                                  "lambda_expression"
-                                  "enum_body"
-                                  "switch_block"
-                                  "record_declaration_body"
-                                  "block")))
-                (close-bracket . "}")
-                (if . "if_statement")
-                (else . ("if_statement" . "alternative"))
-                (for . "for_statement")
-                (while . "while_statement")
-                (do . "do_statement")))
-  (setq-local c-ts-common-indent-offset 'java-ts-mode-indent-offset)
-  (setq-local treesit-simple-indent-rules java-ts-mode--indent-rules)
-
-  ;; Electric
-  (setq-local electric-indent-chars
-              (append "{}():;," electric-indent-chars))
-
-  ;; Navigation.
-  (setq-local treesit-defun-type-regexp
-              (regexp-opt '("method_declaration"
-                            "class_declaration"
-                            "record_declaration"
-                            "interface_declaration"
-                            "enum_declaration"
-                            "import_declaration"
-                            "package_declaration"
-                            "module_declaration"
-                            "constructor_declaration")))
-  (setq-local treesit-defun-name-function #'java-ts-mode--defun-name)
-
-  (setq-local treesit-thing-settings
-              `((java
-                (sexp ,(rx (or "annotation"
-                               "parenthesized_expression"
-                               "argument_list"
-                               "identifier"
-                               "modifiers"
-                               "block"
-                               "body"
-                               "literal"
-                               "access"
-                               "reference"
-                               "_type"
-                               "true"
-                               "false")))
-                (sentence ,(rx (or "statement"
-                                   "local_variable_declaration"
-                                   "field_declaration"
-                                   "module_declaration"
-                                   "package_declaration"
-                                   "import_declaration")))
-                (text ,(regexp-opt '("line_comment"
-                                     "block_comment"
-                                     "text_block"))))))
-
-  ;; Font-lock.
-  (setq-local treesit-font-lock-settings java-ts-mode--font-lock-settings)
+  (let ((primary-parser (treesit-parser-create 'java)))
+
+    ;; Comments.
+    (c-ts-common-comment-setup)
+
+    ;; Indent.
+    (setq-local c-ts-common-indent-type-regexp-alist
+                `((block . ,(rx (or "class_body"
+                                    "array_initializer"
+                                    "constructor_body"
+                                    "annotation_type_body"
+                                    "interface_body"
+                                    "lambda_expression"
+                                    "enum_body"
+                                    "switch_block"
+                                    "record_declaration_body"
+                                    "block")))
+                  (close-bracket . "}")
+                  (if . "if_statement")
+                  (else . ("if_statement" . "alternative"))
+                  (for . "for_statement")
+                  (while . "while_statement")
+                  (do . "do_statement")))
+    (setq-local c-ts-common-indent-offset 'java-ts-mode-indent-offset)
+    (setq-local treesit-simple-indent-rules java-ts-mode--indent-rules)
+
+    ;; Electric
+    (setq-local electric-indent-chars
+                (append "{}():;," electric-indent-chars))
+
+    ;; Navigation.
+    (setq-local treesit-defun-type-regexp
+                (regexp-opt '("method_declaration"
+                              "class_declaration"
+                              "record_declaration"
+                              "interface_declaration"
+                              "enum_declaration"
+                              "import_declaration"
+                              "package_declaration"
+                              "module_declaration"
+                              "constructor_declaration")))
+    (setq-local treesit-defun-name-function #'java-ts-mode--defun-name)
+
+    (setq-local treesit-thing-settings
+                `((java
+                   (sexp ,(rx (or "annotation"
+                                  "parenthesized_expression"
+                                  "argument_list"
+                                  "identifier"
+                                  "modifiers"
+                                  "block"
+                                  "body"
+                                  "literal"
+                                  "access"
+                                  "reference"
+                                  "_type"
+                                  "true"
+                                  "false")))
+                   (sentence ,(rx (or "statement"
+                                      "local_variable_declaration"
+                                      "field_declaration"
+                                      "module_declaration"
+                                      "package_declaration"
+                                      "import_declaration")))
+                   (text ,(regexp-opt '("line_comment"
+                                        "block_comment"
+                                        "text_block"))))))
+
+    ;; Font-lock.
+    (setq-local treesit-font-lock-settings
+                java-ts-mode--font-lock-settings)
+
+    ;; Inject doxygen parser for comment.
+    (when (treesit-ready-p 'doxygen)
+      (setq-local treesit-primary-parser primary-parser)
+      (setq-local treesit-font-lock-settings
+                  (append treesit-font-lock-settings
+                          c-ts-mode-doxygen-comment-font-lock-settings))
+      (setq-local treesit-range-settings
+                  (treesit-range-rules
+                   :embed 'doxygen
+                   :host 'java
+                   :local t
+                   `(((block_comment) @cap (:match "/\\*\\*" @cap)))))))
+
   (setq-local treesit-font-lock-feature-list java-ts-mode--feature-list)
 
   ;; Imenu.
-- 
2.45.2