From 0ac3a1f26c6c02d0a81290dba4d30d57e5bd92f1 Mon Sep 17 00:00:00 2001
From: Juri Linkov <juri@linkov.net>
Date: Thu, 14 Aug 2025 19:40:08 +0300
Subject: [PATCH] New user option 'treesit-enabled-modes' (bug#79180)

* lisp/treesit.el (treesit-enabled-modes): New user option.
* src/treesit.c (treesit-major-mode-remap-alist): New variable.

* lisp/progmodes/c-ts-mode.el:
* lisp/progmodes/csharp-mode.el:
* lisp/progmodes/java-ts-mode.el:
* lisp/progmodes/js.el:
* lisp/progmodes/json-ts-mode.el:
* lisp/progmodes/ruby-ts-mode.el:
* lisp/progmodes/sh-script.el:
* lisp/textmodes/css-mode.el:
* lisp/textmodes/mhtml-ts-mode.el:
* lisp/textmodes/toml-ts-mode.el:
Add ts-mode mapping to 'treesit-major-mode-remap-alist'
for ts-modes that already have the corresponding non-ts mode
association in 'auto-mode-alist'.

* lisp/progmodes/cmake-ts-mode.el (cmake-ts-mode-maybe):
* lisp/progmodes/dockerfile-ts-mode.el (dockerfile-ts-mode-maybe):
* lisp/progmodes/elixir-ts-mode.el (elixir-ts-mode-maybe):
* lisp/progmodes/go-ts-mode.el (go-ts-mode-maybe)
(go-mod-ts-mode-maybe, go-work-ts-mode-maybe):
* lisp/progmodes/heex-ts-mode.el (heex-ts-mode-maybe):
* lisp/progmodes/lua-ts-mode.el (lua-ts-mode-maybe):
* lisp/progmodes/php-ts-mode.el (php-ts-mode-maybe):
* lisp/progmodes/rust-ts-mode.el (rust-ts-mode-maybe):
* lisp/progmodes/typescript-ts-mode.el (typescript-ts-mode-maybe)
(tsx-ts-mode-maybe):
* lisp/textmodes/markdown-ts-mode.el (markdown-ts-mode-maybe):
* lisp/textmodes/yaml-ts-mode.el (yaml-ts-mode-maybe):
Add a wrapper function to 'auto-mode-alist'
for ts-modes that have no corresponding non-ts mode.
Also add a mapping to 'treesit-major-mode-remap-alist'
for the case when a non-ts mode is installed from an external
source to be able to customize it with 'treesit-enabled-modes'.
---
 etc/NEWS                             |  6 ++++
 lisp/progmodes/c-ts-mode.el          | 31 ++++++-----------
 lisp/progmodes/cmake-ts-mode.el      | 19 +++++++++--
 lisp/progmodes/csharp-mode.el        |  9 +++--
 lisp/progmodes/dockerfile-ts-mode.el | 23 ++++++++++---
 lisp/progmodes/elixir-ts-mode.el     | 24 +++++++++----
 lisp/progmodes/go-ts-mode.el         | 51 ++++++++++++++++++++++++----
 lisp/progmodes/heex-ts-mode.el       | 21 +++++++++---
 lisp/progmodes/java-ts-mode.el       |  6 ++--
 lisp/progmodes/js.el                 | 10 +++---
 lisp/progmodes/json-ts-mode.el       |  7 ++--
 lisp/progmodes/lua-ts-mode.el        | 19 +++++++++--
 lisp/progmodes/php-ts-mode.el        | 23 ++++++++++---
 lisp/progmodes/ruby-mode.el          |  4 ---
 lisp/progmodes/ruby-ts-mode.el       | 16 ++++-----
 lisp/progmodes/rust-ts-mode.el       | 17 ++++++++--
 lisp/progmodes/sh-script.el          |  5 +++
 lisp/progmodes/typescript-ts-mode.el | 34 ++++++++++++++++---
 lisp/textmodes/css-mode.el           |  9 +++--
 lisp/textmodes/html-ts-mode.el       |  4 +--
 lisp/textmodes/markdown-ts-mode.el   | 17 ++++++++--
 lisp/textmodes/mhtml-ts-mode.el      |  7 ++--
 lisp/textmodes/toml-ts-mode.el       |  6 ++--
 lisp/textmodes/yaml-ts-mode.el       | 17 ++++++++--
 lisp/treesit.el                      | 28 ++++++++++++++-
 src/treesit.c                        | 10 ++++++
 26 files changed, 323 insertions(+), 100 deletions(-)

diff --git a/etc/NEWS b/etc/NEWS
index f8d4b8f2f67..5b3be259196 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -722,6 +722,12 @@ the default UI you get, i.e., when 'register-use-preview' is 'traditional'.
 
 ** Tree-sitter
 
+*** New user option 'treesit-enabled-modes'.
+You can customize it either to t to enable all available ts-modes,
+or to select a list of ts-modes to enable.  Depending on customization,
+it modifies the variable 'major-mode-remap-alist' from the corresponding
+variable 'treesit-major-mode-remap-alist' prepared by ts-mode packages.
+
 *** New user option 'treesit-auto-install-grammar'.
 It controls the automatic installation of tree-sitter grammar libraries
 needed for tree-sitter based modes, if these grammar libraries are not
diff --git a/lisp/progmodes/c-ts-mode.el b/lisp/progmodes/c-ts-mode.el
index 5155193c603..55240c3869a 100644
--- a/lisp/progmodes/c-ts-mode.el
+++ b/lisp/progmodes/c-ts-mode.el
@@ -65,11 +65,9 @@
 ;;
 ;;   will turn on the c++-ts-mode for C++ source files.
 ;;
-;; - If you have both C and C++ grammars installed, add
-;;
-;;     (load "c-ts-mode")
-;;
-;;   to your init file.
+;; - If you have both C and C++ grammars installed, customize
+;;   'treesit-enabled-modes' and select 'c-ts-mode',
+;;   'c++-mode', 'c-or-c++-mode'.
 ;;
 ;; You can also turn on these modes manually in a buffer.  Doing so
 ;; will set up Emacs to use the C/C++ modes defined here for other
@@ -1675,21 +1673,14 @@ the code is C or C++, and based on that chooses whether to enable
            'c-ts-mode)))
     (funcall (major-mode-remap mode))))
 
-(when (treesit-ready-p 'cpp)
-  (setq major-mode-remap-defaults
-        (assq-delete-all 'c++-mode major-mode-remap-defaults))
-  (add-to-list 'major-mode-remap-defaults '(c++-mode . c++-ts-mode)))
-
-(when (treesit-ready-p 'c)
-  (setq major-mode-remap-defaults
-        (assq-delete-all 'c-mode major-mode-remap-defaults))
-  (add-to-list 'major-mode-remap-defaults '(c-mode . c-ts-mode)))
-
-(when (and (treesit-ready-p 'cpp)
-           (treesit-ready-p 'c))
-  (setq major-mode-remap-defaults
-        (assq-delete-all 'c-or-c++-mode major-mode-remap-defaults))
-  (add-to-list 'major-mode-remap-defaults '(c-or-c++-mode . c-or-c++-ts-mode)))
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(c-mode . c-ts-mode))
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(c++-mode . c++-ts-mode))
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(c-or-c++-mode . c-or-c++-ts-mode)))
 
 (provide 'c-ts-mode)
 (provide 'c++-ts-mode)
diff --git a/lisp/progmodes/cmake-ts-mode.el b/lisp/progmodes/cmake-ts-mode.el
index 2f2d1b6e2a0..3f879e37ba2 100644
--- a/lisp/progmodes/cmake-ts-mode.el
+++ b/lisp/progmodes/cmake-ts-mode.el
@@ -255,9 +255,22 @@ Return nil if there is no name or if NODE is not a defun node."
 
 (derived-mode-add-parents 'cmake-ts-mode '(cmake-mode))
 
-(if (treesit-ready-p 'cmake)
-    (add-to-list 'auto-mode-alist
-                 '("\\(?:CMakeLists\\.txt\\|\\.cmake\\)\\'" . cmake-ts-mode)))
+;;;###autoload
+(defun cmake-ts-mode-maybe ()
+  "Enable `cmake-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'cmake)
+          (eq treesit-enabled-modes t)
+          (memq 'cmake-ts-mode treesit-enabled-modes))
+      (cmake-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist
+               '("\\(?:CMakeLists\\.txt\\|\\.cmake\\)\\'" . cmake-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(cmake-mode . cmake-ts-mode)))
 
 (provide 'cmake-ts-mode)
 
diff --git a/lisp/progmodes/csharp-mode.el b/lisp/progmodes/csharp-mode.el
index 958ccf05672..fb05389ba91 100644
--- a/lisp/progmodes/csharp-mode.el
+++ b/lisp/progmodes/csharp-mode.el
@@ -1219,12 +1219,15 @@ Key bindings:
                           "local_function_statement")
                   eos))
 
-  (treesit-major-mode-setup)
-
-  (add-to-list 'auto-mode-alist '("\\.cs\\'" . csharp-ts-mode)))
+  (treesit-major-mode-setup))
 
 (derived-mode-add-parents 'csharp-ts-mode '(csharp-mode))
 
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(csharp-mode . csharp-ts-mode)))
+
 (provide 'csharp-mode)
 
 ;;; csharp-mode.el ends here
diff --git a/lisp/progmodes/dockerfile-ts-mode.el b/lisp/progmodes/dockerfile-ts-mode.el
index fe0c9e23acc..79a2197c078 100644
--- a/lisp/progmodes/dockerfile-ts-mode.el
+++ b/lisp/progmodes/dockerfile-ts-mode.el
@@ -202,11 +202,24 @@ Return nil if there is no name or if NODE is not a stage node."
 
 (derived-mode-add-parents 'dockerfile-ts-mode '(dockerfile-mode))
 
-(if (treesit-ready-p 'dockerfile)
-    (add-to-list 'auto-mode-alist
-                 ;; NOTE: We can't use `rx' here, as it breaks bootstrap.
-                 '("\\(?:Dockerfile\\(?:\\..*\\)?\\|\\.[Dd]ockerfile\\)\\'"
-                   . dockerfile-ts-mode)))
+;;;###autoload
+(defun dockerfile-ts-mode-maybe ()
+  "Enable `dockerfile-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'dockerfile)
+          (eq treesit-enabled-modes t)
+          (memq 'dockerfile-ts-mode treesit-enabled-modes))
+      (dockerfile-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist
+               ;; NOTE: We can't use `rx' here, as it breaks bootstrap.
+               '("\\(?:Dockerfile\\(?:\\..*\\)?\\|\\.[Dd]ockerfile\\)\\'"
+                 . dockerfile-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(dockerfile-mode . dockerfile-ts-mode)))
 
 (provide 'dockerfile-ts-mode)
 
diff --git a/lisp/progmodes/elixir-ts-mode.el b/lisp/progmodes/elixir-ts-mode.el
index 8b43c032424..05ad76d100f 100644
--- a/lisp/progmodes/elixir-ts-mode.el
+++ b/lisp/progmodes/elixir-ts-mode.el
@@ -806,12 +806,24 @@ Return nil if NODE is not a defun node or doesn't have a name."
 
 (derived-mode-add-parents 'elixir-ts-mode '(elixir-mode))
 
-(if (treesit-ready-p 'elixir)
-    (progn
-      (add-to-list 'auto-mode-alist '("\\.elixir\\'" . elixir-ts-mode))
-      (add-to-list 'auto-mode-alist '("\\.ex\\'" . elixir-ts-mode))
-      (add-to-list 'auto-mode-alist '("\\.exs\\'" . elixir-ts-mode))
-      (add-to-list 'auto-mode-alist '("mix\\.lock" . elixir-ts-mode))))
+;;;###autoload
+(defun elixir-ts-mode-maybe ()
+  "Enable `elixir-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'elixir)
+          (eq treesit-enabled-modes t)
+          (memq 'elixir-ts-mode treesit-enabled-modes))
+      (elixir-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("\\.elixir\\'" . elixir-ts-mode-maybe))
+  (add-to-list 'auto-mode-alist '("\\.ex\\'" . elixir-ts-mode-maybe))
+  (add-to-list 'auto-mode-alist '("\\.exs\\'" . elixir-ts-mode-maybe))
+  (add-to-list 'auto-mode-alist '("mix\\.lock" . elixir-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(elixir-mode . elixir-ts-mode)))
 
 (provide 'elixir-ts-mode)
 
diff --git a/lisp/progmodes/go-ts-mode.el b/lisp/progmodes/go-ts-mode.el
index e8e4c9af29d..40f3de0bc15 100644
--- a/lisp/progmodes/go-ts-mode.el
+++ b/lisp/progmodes/go-ts-mode.el
@@ -359,10 +359,21 @@
 
 (derived-mode-add-parents 'go-ts-mode '(go-mode))
 
-(if (treesit-ready-p 'go)
-    ;; FIXME: Should we instead put `go-mode' in `auto-mode-alist'
-    ;; and then use `major-mode-remap-defaults' to map it to `go-ts-mode'?
-    (add-to-list 'auto-mode-alist '("\\.go\\'" . go-ts-mode)))
+;;;###autoload
+(defun go-ts-mode-maybe ()
+  "Enable `go-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'go)
+          (eq treesit-enabled-modes t)
+          (memq 'go-ts-mode treesit-enabled-modes))
+      (go-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("\\.go\\'" . go-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(go-mode . go-ts-mode)))
 
 (defun go-ts-mode--defun-name (node &optional skip-prefix)
   "Return the defun name of NODE.
@@ -622,8 +633,21 @@ what the parent of the node would be if it were a node."
 
 (derived-mode-add-parents 'go-mod-ts-mode '(go-mod-mode))
 
-(if (treesit-ready-p 'gomod t)
-    (add-to-list 'auto-mode-alist '("/go\\.mod\\'" . go-mod-ts-mode)))
+;;;###autoload
+(defun go-mod-ts-mode-maybe ()
+  "Enable `go-mod-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'gomod)
+          (eq treesit-enabled-modes t)
+          (memq 'go-mod-ts-mode treesit-enabled-modes))
+      (go-mod-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("/go\\.mod\\'" . go-mod-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(go-mod-mode . go-mod-ts-mode)))
 
 ;;;; go.work support.
 
@@ -711,7 +735,20 @@ what the parent of the node would be if it were a node."
     (treesit-major-mode-setup)))
 
 ;;;###autoload
-(add-to-list 'auto-mode-alist '("/go\\.work\\'" . go-work-ts-mode))
+(defun go-work-ts-mode-maybe ()
+  "Enable `go-work-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'gowork)
+          (eq treesit-enabled-modes t)
+          (memq 'go-work-ts-mode treesit-enabled-modes))
+      (go-work-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("/go\\.work\\'" . go-work-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(go-work-mode . go-work-ts-mode)))
 
 (provide 'go-ts-mode)
 
diff --git a/lisp/progmodes/heex-ts-mode.el b/lisp/progmodes/heex-ts-mode.el
index c478750a73e..41634d0e6a4 100644
--- a/lisp/progmodes/heex-ts-mode.el
+++ b/lisp/progmodes/heex-ts-mode.el
@@ -265,10 +265,23 @@ Return nil if NODE is not a defun node or doesn't have a name."
 
 (derived-mode-add-parents 'heex-ts-mode '(heex-mode))
 
-(if (treesit-ready-p 'heex)
-    ;; Both .heex and the deprecated .leex files should work
-    ;; with the tree-sitter-heex grammar.
-    (add-to-list 'auto-mode-alist '("\\.[hl]?eex\\'" . heex-ts-mode)))
+;;;###autoload
+(defun heex-ts-mode-maybe ()
+  "Enable `heex-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'heex)
+          (eq treesit-enabled-modes t)
+          (memq 'heex-ts-mode treesit-enabled-modes))
+      (heex-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  ;; Both .heex and the deprecated .leex files should work
+  ;; with the tree-sitter-heex grammar.
+  (add-to-list 'auto-mode-alist '("\\.[hl]?eex\\'" . heex-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(heex-mode . heex-ts-mode)))
 
 (provide 'heex-ts-mode)
 ;;; heex-ts-mode.el ends here
diff --git a/lisp/progmodes/java-ts-mode.el b/lisp/progmodes/java-ts-mode.el
index 0fe35a4df8b..e989d1b3f5d 100644
--- a/lisp/progmodes/java-ts-mode.el
+++ b/lisp/progmodes/java-ts-mode.el
@@ -524,8 +524,10 @@ Return nil if there is no name or if NODE is not a defun node."
 
 (derived-mode-add-parents 'java-ts-mode '(java-mode))
 
-(if (treesit-ready-p 'java)
-    (add-to-list 'auto-mode-alist '("\\.java\\'" . java-ts-mode)))
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(java-mode . java-ts-mode)))
 
 (provide 'java-ts-mode)
 
diff --git a/lisp/progmodes/js.el b/lisp/progmodes/js.el
index 5254e0d7089..c44b2adf146 100644
--- a/lisp/progmodes/js.el
+++ b/lisp/progmodes/js.el
@@ -4105,13 +4105,15 @@ See `treesit-thing-settings' for more information.")
     ;; Outline minor mode
     (setq-local treesit-outline-predicate js-ts-mode--outline-predicate)
 
-    (treesit-major-mode-setup)
-
-    (add-to-list 'auto-mode-alist
-                 '("\\(\\.js[mx]?\\|\\.har\\)\\'" . js-ts-mode))))
+    (treesit-major-mode-setup)))
 
 (derived-mode-add-parents 'js-ts-mode '(js-mode))
 
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(javascript-mode . js-ts-mode)))
+
 (defvar js-ts--s-p-query
   (when (treesit-available-p)
     (treesit-query-compile 'javascript
diff --git a/lisp/progmodes/json-ts-mode.el b/lisp/progmodes/json-ts-mode.el
index a18f3c342c0..b0db0a12210 100644
--- a/lisp/progmodes/json-ts-mode.el
+++ b/lisp/progmodes/json-ts-mode.el
@@ -181,9 +181,10 @@ Return nil if there is no name or if NODE is not a defun node."
 
 (derived-mode-add-parents 'json-ts-mode '(json-mode))
 
-(if (treesit-ready-p 'json)
-    (add-to-list 'auto-mode-alist
-                 '("\\.json\\'" . json-ts-mode)))
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(js-json-mode . json-ts-mode)))
 
 (provide 'json-ts-mode)
 
diff --git a/lisp/progmodes/lua-ts-mode.el b/lisp/progmodes/lua-ts-mode.el
index 3df36e329b3..07a8f0aef55 100644
--- a/lisp/progmodes/lua-ts-mode.el
+++ b/lisp/progmodes/lua-ts-mode.el
@@ -769,9 +769,22 @@ Calls REPORT-FN directly."
 
 (derived-mode-add-parents 'lua-ts-mode '(lua-mode))
 
-(when (treesit-ready-p 'lua)
-  (add-to-list 'auto-mode-alist '("\\.lua\\'" . lua-ts-mode))
-  (add-to-list 'interpreter-mode-alist '("\\<lua\\(?:jit\\)?" . lua-ts-mode)))
+;;;###autoload
+(defun lua-ts-mode-maybe ()
+  "Enable `lua-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'lua)
+          (eq treesit-enabled-modes t)
+          (memq 'lua-ts-mode treesit-enabled-modes))
+      (lua-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("\\.lua\\'" . lua-ts-mode-maybe))
+  (add-to-list 'interpreter-mode-alist '("\\<lua\\(?:jit\\)?" . lua-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(lua-mode . lua-ts-mode)))
 
 (provide 'lua-ts-mode)
 
diff --git a/lisp/progmodes/php-ts-mode.el b/lisp/progmodes/php-ts-mode.el
index d45226ad5e9..7c2a22024f8 100644
--- a/lisp/progmodes/php-ts-mode.el
+++ b/lisp/progmodes/php-ts-mode.el
@@ -1922,16 +1922,29 @@ file to use."
   (with-current-buffer php-ts-mode-inferior-php-buffer
     (kill-buffer-and-window)))
 
-(when (treesit-ready-p 'php)
+;;;###autoload
+(defun php-ts-mode-maybe ()
+  "Enable `php-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'php)
+          (eq treesit-enabled-modes t)
+          (memq 'php-ts-mode treesit-enabled-modes))
+      (php-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
   (add-to-list
-   'auto-mode-alist '("\\.\\(?:php[s345]?\\|phtml\\)\\'" . php-ts-mode))
+   'auto-mode-alist '("\\.\\(?:php[s345]?\\|phtml\\)\\'" . php-ts-mode-maybe))
   (add-to-list
-   'auto-mode-alist '("\\.\\(?:php\\|inc\\|stub\\)\\'" . php-ts-mode))
+   'auto-mode-alist '("\\.\\(?:php\\|inc\\|stub\\)\\'" . php-ts-mode-maybe))
   (add-to-list
-   'auto-mode-alist '("/\\.php_cs\\(?:\\.dist\\)?\\'" . php-ts-mode))
+   'auto-mode-alist '("/\\.php_cs\\(?:\\.dist\\)?\\'" . php-ts-mode-maybe))
   (add-to-list
    'interpreter-mode-alist
-   (cons "php\\(?:-?[34578]\\(?:\\.[0-9]+\\)*\\)?" 'php-ts-mode)))
+   (cons "php\\(?:-?[34578]\\(?:\\.[0-9]+\\)*\\)?" 'php-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(php-mode . php-ts-mode)))
 
 (provide 'php-ts-mode)
 ;;; php-ts-mode.el ends here
diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index d9044c03aea..1079aad1a55 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -2748,10 +2748,6 @@ Currently there are `ruby-mode' and `ruby-ts-mode'."
 (dolist (name (list "ruby" "rbx" "jruby" "j?ruby\\(?:[0-9.]+\\)"))
   (add-to-list 'interpreter-mode-alist (cons name 'ruby-mode)))
 
-;; See ruby-ts-mode.el for why we do this.
-(setq major-mode-remap-defaults
-      (assq-delete-all 'ruby-mode major-mode-remap-defaults))
-
 (provide 'ruby-mode)
 
 ;;; ruby-mode.el ends here
diff --git a/lisp/progmodes/ruby-ts-mode.el b/lisp/progmodes/ruby-ts-mode.el
index 35da7e0ca02..1bb4f4fb890 100644
--- a/lisp/progmodes/ruby-ts-mode.el
+++ b/lisp/progmodes/ruby-ts-mode.el
@@ -68,11 +68,8 @@
 ;;
 ;;   will turn on the ruby-ts-mode for Ruby source files.
 ;;
-;; - If you have the Ruby grammar installed, add
-;;
-;;     (load "ruby-ts-mode")
-;;
-;;   to your init file.
+;; - If you have the Ruby grammar installed, customize
+;;   'treesit-enabled-modes' and add 'ruby-ts-mode' to it.
 ;;
 ;; You can also turn on this mode manually in a buffer.
 
@@ -1280,11 +1277,10 @@ leading double colon is not added."
 
 (derived-mode-add-parents 'ruby-ts-mode '(ruby-mode))
 
-(when (treesit-ready-p 'ruby)
-  (setq major-mode-remap-defaults
-        (assq-delete-all 'ruby-mode major-mode-remap-defaults))
-  (add-to-list 'major-mode-remap-defaults
-                 '(ruby-mode . ruby-ts-mode)))
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(ruby-mode . ruby-ts-mode)))
 
 (provide 'ruby-ts-mode)
 
diff --git a/lisp/progmodes/rust-ts-mode.el b/lisp/progmodes/rust-ts-mode.el
index f0a716d25b5..b9b39a0d341 100644
--- a/lisp/progmodes/rust-ts-mode.el
+++ b/lisp/progmodes/rust-ts-mode.el
@@ -654,8 +654,21 @@ See `prettify-symbols-compose-predicate'."
 
 (derived-mode-add-parents 'rust-ts-mode '(rust-mode))
 
-(if (treesit-ready-p 'rust)
-    (add-to-list 'auto-mode-alist '("\\.rs\\'" . rust-ts-mode)))
+;;;###autoload
+(defun rust-ts-mode-maybe ()
+  "Enable `rust-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'rust)
+          (eq treesit-enabled-modes t)
+          (memq 'rust-ts-mode treesit-enabled-modes))
+      (rust-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("\\.rs\\'" . rust-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(rust-mode . rust-ts-mode)))
 
 (provide 'rust-ts-mode)
 
diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index 1ef204683b4..f69647b435d 100644
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -1648,6 +1648,11 @@ not written in Bash or sh."
 
 (derived-mode-add-parents 'bash-ts-mode '(sh-mode))
 
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(sh-mode . bash-ts-mode)))
+
 (advice-add 'bash-ts-mode :around #'sh--redirect-bash-ts-mode
             ;; Give it lower precedence than normal advice, so other
             ;; advices take precedence over it.
diff --git a/lisp/progmodes/typescript-ts-mode.el b/lisp/progmodes/typescript-ts-mode.el
index e93fd8066ce..428ae11f653 100644
--- a/lisp/progmodes/typescript-ts-mode.el
+++ b/lisp/progmodes/typescript-ts-mode.el
@@ -722,8 +722,21 @@ This mode is intended to be inherited by concrete major modes."
 
 (derived-mode-add-parents 'typescript-ts-mode '(typescript-mode))
 
-(if (treesit-ready-p 'typescript)
-    (add-to-list 'auto-mode-alist '("\\.ts\\'" . typescript-ts-mode)))
+;;;###autoload
+(defun typescript-ts-mode-maybe ()
+  "Enable `typescript-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'typescript)
+          (eq treesit-enabled-modes t)
+          (memq 'typescript-ts-mode treesit-enabled-modes))
+      (typescript-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("\\.ts\\'" . typescript-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(typescript-mode . typescript-ts-mode)))
 
 ;;;###autoload
 (define-derived-mode tsx-ts-mode typescript-ts-base-mode "TypeScript[TSX]"
@@ -842,8 +855,21 @@ at least 3 (which is the default value)."
                               ((equal (match-string 0) ">") ")>")
                               (t ".")))))))))))
 
-(if (treesit-ready-p 'tsx)
-    (add-to-list 'auto-mode-alist '("\\.tsx\\'" . tsx-ts-mode)))
+;;;###autoload
+(defun tsx-ts-mode-maybe ()
+  "Enable `tsx-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'tsx)
+          (eq treesit-enabled-modes t)
+          (memq 'tsx-ts-mode treesit-enabled-modes))
+      (tsx-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("\\.tsx\\'" . tsx-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(tsx-mode . tsx-ts-mode)))
 
 (provide 'typescript-ts-mode)
 
diff --git a/lisp/textmodes/css-mode.el b/lisp/textmodes/css-mode.el
index 45053ac6f23..0a02aedfa4f 100644
--- a/lisp/textmodes/css-mode.el
+++ b/lisp/textmodes/css-mode.el
@@ -1911,12 +1911,15 @@ can also be used to fill comments.
     (setq-local treesit-outline-predicate css-ts-mode--outline-predicate)
     (setq-local treesit-thing-settings css--treesit-thing-settings)
 
-    (treesit-major-mode-setup)
-
-    (add-to-list 'auto-mode-alist '("\\.css\\'" . css-ts-mode))))
+    (treesit-major-mode-setup)))
 
 (derived-mode-add-parents 'css-ts-mode '(css-mode))
 
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(css-mode . css-ts-mode)))
+
 ;;;###autoload
 (define-derived-mode css-mode css-base-mode "CSS"
   "Major mode to edit Cascading Style Sheets (CSS).
diff --git a/lisp/textmodes/html-ts-mode.el b/lisp/textmodes/html-ts-mode.el
index 1bf89ee8f4e..12ab735171d 100644
--- a/lisp/textmodes/html-ts-mode.el
+++ b/lisp/textmodes/html-ts-mode.el
@@ -186,8 +186,8 @@ Return nil if there is no name or if NODE is not a defun node."
 
 (derived-mode-add-parents 'html-ts-mode '(html-mode))
 
-(if (treesit-ready-p 'html t)
-    (add-to-list 'auto-mode-alist '("\\.html\\'" . html-ts-mode)))
+;; No `auto-mode-alist' associations are defined here
+;; to give preference to `mhtml-ts-mode'.
 
 (provide 'html-ts-mode)
 
diff --git a/lisp/textmodes/markdown-ts-mode.el b/lisp/textmodes/markdown-ts-mode.el
index a94d1590fa0..4af80f80b5f 100644
--- a/lisp/textmodes/markdown-ts-mode.el
+++ b/lisp/textmodes/markdown-ts-mode.el
@@ -403,8 +403,21 @@ the same features enabled in MODE."
 
 (derived-mode-add-parents 'markdown-ts-mode '(markdown-mode))
 
-(if (treesit-ready-p 'markdown)
-    (add-to-list 'auto-mode-alist '("\\.md\\'" . markdown-ts-mode)))
+;;;###autoload
+(defun markdown-ts-mode-maybe ()
+  "Enable `markdown-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'markdown)
+          (eq treesit-enabled-modes t)
+          (memq 'markdown-ts-mode treesit-enabled-modes))
+      (markdown-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("\\.md\\'" . markdown-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(markdown-mode . markdown-ts-mode)))
 
 (provide 'markdown-ts-mode)
 ;;; markdown-ts-mode.el ends here
diff --git a/lisp/textmodes/mhtml-ts-mode.el b/lisp/textmodes/mhtml-ts-mode.el
index bf50148b84e..be3873e848a 100644
--- a/lisp/textmodes/mhtml-ts-mode.el
+++ b/lisp/textmodes/mhtml-ts-mode.el
@@ -587,9 +587,10 @@ Powered by tree-sitter."
 ;; Add some extra parents.
 (derived-mode-add-parents 'mhtml-ts-mode '(css-mode js-mode))
 
-(when (and (treesit-ready-p 'html t) (treesit-ready-p 'javascript t) (treesit-ready-p 'css t))
-  (add-to-list
-   'auto-mode-alist '("\\.[sx]?html?\\(\\.[a-zA-Z_]+\\)?\\'" . mhtml-ts-mode)))
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(mhtml-mode . mhtml-ts-mode)))
 
 (provide 'mhtml-ts-mode)
 ;;; mhtml-ts-mode.el ends here
diff --git a/lisp/textmodes/toml-ts-mode.el b/lisp/textmodes/toml-ts-mode.el
index c1c5dea2bd9..511a6b5f8ed 100644
--- a/lisp/textmodes/toml-ts-mode.el
+++ b/lisp/textmodes/toml-ts-mode.el
@@ -172,8 +172,10 @@ Return nil if there is no name or if NODE is not a defun node."
 
 (derived-mode-add-parents 'toml-ts-mode '(toml-mode))
 
-(if (treesit-ready-p 'toml)
-    (add-to-list 'auto-mode-alist '("\\.toml\\'" . toml-ts-mode)))
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(conf-toml-mode . toml-ts-mode)))
 
 (provide 'toml-ts-mode)
 
diff --git a/lisp/textmodes/yaml-ts-mode.el b/lisp/textmodes/yaml-ts-mode.el
index cadae19af1e..95c9c1abd7d 100644
--- a/lisp/textmodes/yaml-ts-mode.el
+++ b/lisp/textmodes/yaml-ts-mode.el
@@ -227,8 +227,21 @@ Return nil if there is no name or if NODE is not a defun node."
 
 (derived-mode-add-parents 'yaml-ts-mode '(yaml-mode))
 
-(if (treesit-ready-p 'yaml)
-    (add-to-list 'auto-mode-alist '("\\.ya?ml\\'" . yaml-ts-mode)))
+;;;###autoload
+(defun yaml-ts-mode-maybe ()
+  "Enable `yaml-ts-mode' when its grammar is available."
+  (if (or (treesit-language-available-p 'yaml)
+          (eq treesit-enabled-modes t)
+          (memq 'yaml-ts-mode treesit-enabled-modes))
+      (yaml-ts-mode)
+    (fundamental-mode)))
+
+;;;###autoload
+(when (treesit-available-p)
+  (add-to-list 'auto-mode-alist '("\\.ya?ml\\'" . yaml-ts-mode-maybe))
+  ;; To be able to toggle between an external package and core ts-mode:
+  (add-to-list 'treesit-major-mode-remap-alist
+               '(yaml-mode . yaml-ts-mode)))
 
 (provide 'yaml-ts-mode)
 
diff --git a/lisp/treesit.el b/lisp/treesit.el
index 0d30efb3782..ecdcf0b5551 100644
--- a/lisp/treesit.el
+++ b/lisp/treesit.el
@@ -125,7 +125,8 @@ in a Emacs not built with tree-sitter library."
 
      (declare-function treesit-available-p "treesit.c")
 
-     (defvar treesit-thing-settings)))
+     (defvar treesit-thing-settings)
+     (defvar treesit-major-mode-remap-alist)))
 
 (treesit-declare-unavailable-functions)
 
@@ -5399,6 +5400,31 @@ Tree-sitter grammar for `%s' is missing; install it?"
           ;; Check that the grammar was installed successfully
           (treesit-ready-p lang)))))
 
+;;; Treesit enabled modes
+
+;;;###autoload
+(defcustom treesit-enabled-modes nil
+  "Specify what treesit modes to enable by default.
+The value can be either a list of ts-modes to enable,
+or t to enable all ts-modes."
+  :type `(choice
+          (const :tag "Disable all automatic associations" nil)
+          (const :tag "Enable all available ts-modes" t)
+          (set :tag "List of enabled ts-modes"
+               ,@(when (treesit-available-p)
+                   (sort (mapcar (lambda (m) `(function-item ,m))
+                                 (seq-uniq (mapcar #'cdr treesit-major-mode-remap-alist)))))))
+  :initialize #'custom-initialize-default
+  :set (lambda (sym val)
+         (set-default sym val)
+         (when (treesit-available-p)
+           (dolist (m treesit-major-mode-remap-alist)
+             (setq major-mode-remap-alist
+                   (if (or (eq val t) (memq (cdr m) val))
+                       (cons m major-mode-remap-alist)
+                     (delete m major-mode-remap-alist))))))
+  :version "31.1")
+
 ;;; Shortdocs
 
 (defun treesit--generate-shortdoc-examples ()
diff --git a/src/treesit.c b/src/treesit.c
index bb720589c85..bf982de580b 100644
--- a/src/treesit.c
+++ b/src/treesit.c
@@ -5299,6 +5299,16 @@ language is in this list, Emacs enables line-column tracking for the
 buffer.  */);
   Vtreesit_languages_require_line_column_tracking = Qnil;
 
+  DEFVAR_LISP ("treesit-major-mode-remap-alist",
+	       Vtreesit_major_mode_remap_alist,
+	       doc:
+	       /* Alist mapping file-specified modes to ts-modes.
+
+The value should be an alist of (MODE . TS-MODE).
+This alist is used to modify the value of `major-mode-remap-alist'
+depending on customization of `treesit-enabled-modes'.  */);
+  Vtreesit_major_mode_remap_alist = Qnil;
+
   staticpro (&Vtreesit_str_libtree_sitter);
   Vtreesit_str_libtree_sitter = build_string ("libtree-sitter-");
   staticpro (&Vtreesit_str_tree_sitter);