@cindex file local variables
A file can specify local variable values to use when editing the
-file with Emacs. Visiting the file checks for local variable
-specifications; it automatically makes these variables local to the
-buffer, and sets them to the values specified in the file.
+file with Emacs. Visiting the file or setting a major mode checks for
+local variable specifications; it automatically makes these variables
+local to the buffer, and sets them to the values specified in the
+file.
@menu
* Specifying File Variables:: Specifying file local variables.
Finally, it specifies a different @file{ChangeLog} file name for any
file in the @file{src/imported} subdirectory.
+You can specify the variables @code{mode}, @code{eval}, and
+@code{unibyte} in your @file{.dir-locals.el}, and they have the same
+meanings as they would have in file local variables. @code{coding}
+cannot be specified as a directory local variable. @xref{File
+Variables}.
+
@findex add-dir-local-variable
@findex delete-dir-local-variable
@findex copy-file-locals-to-dir-locals
Each major mode should have a normal @dfn{mode hook} named
@code{@var{modename}-mode-hook}. The very last thing the major mode command
should do is to call @code{run-mode-hooks}. This runs the normal
-hook @code{change-major-mode-after-body-hook}, the mode hook,
+hook @code{change-major-mode-after-body-hook}, the mode hook, the
+function @code{hack-local-variables} (when the buffer is visiting a file),
and then the normal hook @code{after-change-major-mode-hook}.
@xref{Mode Hooks}.
It also processes local variables specified in the file text.
@deffn Command normal-mode &optional find-file
-This function establishes the proper major mode and buffer-local variable
-bindings for the current buffer. First it calls @code{set-auto-mode}
-(see below), then it runs @code{hack-local-variables} to parse, and
-bind or evaluate as appropriate, the file's local variables
-(@pxref{File Local Variables}).
+This function establishes the proper major mode and buffer-local
+variable bindings for the current buffer. It calls
+@code{set-auto-mode} (see below). As from Emacs 25.2, it no longer
+runs @code{hack-local-variables}, this now being done in
+@code{run-mode-hooks} at the initialization of major modes
+(@pxref{Mode Hooks}).
If the @var{find-file} argument to @code{normal-mode} is non-@code{nil},
@code{normal-mode} assumes that the @code{find-file} function is calling
@var{find-file} is normally @code{nil}. In this case,
@code{normal-mode} unconditionally processes any file local variables.
-The function calls @code{set-auto-mode} to choose a major mode. If this
-does not specify a mode, the buffer stays in the major mode determined
-by the default value of @code{major-mode} (see below).
+The function calls @code{set-auto-mode} to choose and set a major
+mode. If this does not specify a mode, the buffer stays in the major
+mode determined by the default value of @code{major-mode} (see below).
@cindex file mode specification error
@code{normal-mode} uses @code{condition-case} around the call to the
@defun set-auto-mode &optional keep-mode-if-same
@cindex visited file mode
- This function selects the major mode that is appropriate for the
-current buffer. It bases its decision (in order of precedence) on the
-@w{@samp{-*-}} line, on any @samp{mode:} local variable near the end of
-a file, on the @w{@samp{#!}} line (using @code{interpreter-mode-alist}),
-on the text at the beginning of the buffer (using
-@code{magic-mode-alist}), and finally on the visited file name (using
-@code{auto-mode-alist}). @xref{Choosing Modes, , How Major Modes are
-Chosen, emacs, The GNU Emacs Manual}. If @code{enable-local-variables}
-is @code{nil}, @code{set-auto-mode} does not check the @w{@samp{-*-}}
-line, or near the end of the file, for any mode tag.
+ This function selects and sets the major mode that is appropriate
+for the current buffer. It bases its decision (in order of
+precedence) on the @w{@samp{-*-}} line, on any @samp{mode:} local
+variable near the end of a file, on the @w{@samp{#!}} line (using
+@code{interpreter-mode-alist}), on the text at the beginning of the
+buffer (using @code{magic-mode-alist}), and finally on the visited
+file name (using @code{auto-mode-alist}). @xref{Choosing Modes, , How
+Major Modes are Chosen, emacs, The GNU Emacs Manual}. If
+@code{enable-local-variables} is @code{nil}, @code{set-auto-mode} does
+not check the @w{@samp{-*-}} line, or near the end of the file, for
+any mode tag.
@vindex inhibit-local-variables-regexps
There are some file types where it is not appropriate to scan the file
@defun run-mode-hooks &rest hookvars
Major modes should run their mode hook using this function. It is
similar to @code{run-hooks} (@pxref{Hooks}), but it also runs
-@code{change-major-mode-after-body-hook} and
-@code{after-change-major-mode-hook}.
+@code{change-major-mode-after-body-hook}, @code{hack-local-variables}
+(when the buffer is visiting a file) (@pxref{File Local Variables}),
+and @code{after-change-major-mode-hook}.
When this function is called during the execution of a
-@code{delay-mode-hooks} form, it does not run the hooks immediately.
-Instead, it arranges for the next call to @code{run-mode-hooks} to run
-them.
+@code{delay-mode-hooks} form, it does not run the hooks or
+@code{hack-local-variables} immediately. Instead, it arranges for the
+next call to @code{run-mode-hooks} to run them.
@end defun
@defmac delay-mode-hooks body@dots{}
to use this, @pxref{Auto Major Mode}.
@end defvar
-@defun hack-local-variables &optional mode-only
+@defun hack-local-variables &optional handle-mode
This function parses, and binds or evaluates as appropriate, any local
variables specified by the contents of the current buffer. The variable
@code{enable-local-variables} has its effect here. However, this
function ignores a @samp{mode} element if it specifies the same major
mode as the buffer already has.
-If the optional argument @var{mode-only} is non-@code{nil}, then all
-this function does is return a symbol specifying the major mode,
-if the @w{@samp{-*-}} line or the local variables list specifies one,
-and @code{nil} otherwise. It does not set the mode nor any other
-file-local variable.
+If the optional argument @var{handle-mode} is @code{t}, then all this
+function does is return a symbol specifying the major mode, if the
+@w{@samp{-*-}} line or the local variables list specifies one, and
+@code{nil} otherwise. It does not set the mode or any other
+file-local variable. If @var{handle-mode} has any value other than
+@code{nil} or @code{t}, any settings of @samp{mode} in the
+@w{@samp{-*-}} line or the local variables list are ignored, and the
+other settings are applied. If @var{handle-mode} is @code{nil}, all
+the file local variables are set.
@end defun
@defvar file-local-variables-alist
;; s-a-m and h-l-v may parse the same regions, looking for "mode:".
(with-demoted-errors "File mode specification error: %s"
(set-auto-mode))
- (with-demoted-errors "File local-variables error: %s"
- (hack-local-variables)))
+ ;; `delay-mode-hooks' being non-nil will have prevented the major
+ ;; mode's call to `run-mode-hooks' from calling
+ ;; `hack-local-variables'. In that case, call it now.
+ (when delay-mode-hooks
+ (with-demoted-errors "File local-variables error: %s"
+ (hack-local-variables 'no-mode))))
;; Turn font lock off and on, to make sure it takes account of
;; whatever file local variables are relevant to it.
(when (and font-lock-mode
;; TODO? Warn once per file rather than once per session?
(defvar hack-local-variables--warned-lexical nil)
-(defun hack-local-variables (&optional mode-only)
+(defun hack-local-variables (&optional handle-mode)
"Parse and put into effect this buffer's local variables spec.
Uses `hack-local-variables-apply' to apply the variables.
-If MODE-ONLY is non-nil, all we do is check whether a \"mode:\"
+If HANDLE-MODE is nil, we apply all the specified local
+variables. If HANDLE-MODE is neither nil nor t, we do the same,
+except that any settings of `mode' are ignored.
+
+If HANDLE-MODE is t, all we do is check whether a \"mode:\"
is specified, and return the corresponding mode symbol, or nil.
In this case, we try to ignore minor-modes, and only return a
major-mode.
(let ((enable-local-variables
(and local-enable-local-variables enable-local-variables))
result)
- (unless mode-only
+ (unless (eq handle-mode t)
(setq file-local-variables-alist nil)
(with-demoted-errors "Directory-local variables error: %s"
;; Note this is a no-op if enable-local-variables is nil.
;; This entire function is basically a no-op if enable-local-variables
;; is nil. All it does is set file-local-variables-alist to nil.
(when enable-local-variables
- ;; This part used to ignore enable-local-variables when mode-only
- ;; was non-nil. That was inappropriate, eg consider the
+ ;; This part used to ignore enable-local-variables when handle-mode
+ ;; was t. That was inappropriate, eg consider the
;; (artificial) example of:
;; (setq local-enable-local-variables nil)
;; Open a file foo.txt that contains "mode: sh".
;; It correctly opens in text-mode.
;; M-x set-visited-file name foo.c, and it incorrectly stays in text-mode.
(unless (or (inhibit-local-variables-p)
- ;; If MODE-ONLY is non-nil, and the prop line specifies a
+ ;; If HANDLE-MODE is t, and the prop line specifies a
;; mode, then we're done, and have no need to scan further.
- (and (setq result (hack-local-variables-prop-line mode-only))
- mode-only))
+ (and (setq result (hack-local-variables-prop-line
+ (eq handle-mode t)))
+ (eq handle-mode t)))
;; Look for "Local variables:" line in last page.
(save-excursion
(goto-char (point-max))
(goto-char (point-min))
(while (not (or (eobp)
- (and mode-only result)))
+ (and (eq handle-mode t) result)))
;; Find the variable name;
(unless (looking-at hack-local-variable-regexp)
(error "Malformed local variable line: %S"
(forward-char 1)
(let ((read-circle nil))
(setq val (read (current-buffer))))
- (if mode-only
+ (if (eq handle-mode t)
(and (eq var 'mode)
;; Specifying minor-modes via mode: is
;; deprecated, but try to reject them anyway.
;; to use 'thisbuf's name in the
;; warning message.
(or (buffer-file-name thisbuf) ""))))))
+ ((and (eq var 'mode) handle-mode))
(t
(ignore-errors
(push (cons (if (eq var 'eval)
val) result))))))
(forward-line 1))))))))
;; Now we've read all the local variables.
- ;; If MODE-ONLY is non-nil, return whether the mode was specified.
- (if mode-only result
+ ;; If HANDLE-MODE is t, return whether the mode was specified.
+ (if (eq handle-mode t) result
;; Otherwise, set the variables.
(hack-local-variables-filter result nil)
(hack-local-variables-apply)))))
(defun run-mode-hooks (&rest hooks)
"Run mode hooks `delayed-mode-hooks' and HOOKS, or delay HOOKS.
-If the variable `delay-mode-hooks' is non-nil, does not run any hooks,
+Call `hack-local-variables' to set up file local and directory local
+variables.
+
+If the variable `delay-mode-hooks' is non-nil, does not do anything,
just adds the HOOKS to the list `delayed-mode-hooks'.
Otherwise, runs hooks in the sequence: `change-major-mode-after-body-hook',
-`delayed-mode-hooks' (in reverse order), HOOKS, and finally
+`delayed-mode-hooks' (in reverse order), HOOKS, then runs
+`hack-local-variables' and finally runs the hook
`after-change-major-mode-hook'. Major mode functions should use
this instead of `run-hooks' when running their FOO-mode-hook."
(if delay-mode-hooks
(setq hooks (nconc (nreverse delayed-mode-hooks) hooks))
(setq delayed-mode-hooks nil)
(apply 'run-hooks (cons 'change-major-mode-after-body-hook hooks))
+ (if (buffer-file-name)
+ (with-demoted-errors "File local-variables error: %s"
+ (hack-local-variables 'no-mode)))
(run-hooks 'after-change-major-mode-hook)))
(defmacro delay-mode-hooks (&rest body)
projects / emacs.git / commitdiff