#5293 - 23.1; unload-feature on buffer-local hooks

GNU bug report logs - #5293
23.1; unload-feature on buffer-local hooks

Package: emacs;

Reported by: Kevin Ryde <user42 <at> zip.com.au>

Date: Sat, 2 Jan 2010 21:07:02 UTC

Severity: minor

Merged with 34686

Found in version 26.1

Done: Štěpán Němec <stepnem <at> gmail.com>

Bug is archived. No further changes may be made.

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From: Štěpán Němec <stepnem <at> gmail.com> To: Kevin Ryde <user42 <at> zip.com.au> Cc: Juanma Barranquero <lekktu <at> gmail.com>, Stefan Monnier <monnier <at> iro.umontreal.ca>, 5293 <at> debbugs.gnu.org Subject: bug#5293: 23.1; unload-feature on buffer-local hooks Date: Mon, 06 Apr 2020 19:24:40 +0200

[Message part 1 (text/plain, inline)]

On Sat, 06 Aug 2011 11:20:41 +1000 Kevin Ryde wrote: > reopen 5293 > thanks > > Stefan Monnier <monnier <at> iro.umontreal.ca> writes: >> >>> No, just the hooks. If it makes sense to remove unloaded funcs from >>> hook global values then surely the same rationale applies to remove them >>> from the buffer-local values too. >> >> Agreed. Someone would have to try it out to see if it can be >> done efficiently. ^^^^^^^^^^^ :-D > Reopened for that, or failing that then for clarifying the docstring. > > I imagine there's not normally many hooks or many buffers, or many > buffer-local variables, whichever one of those was the efficient way to > scan ... and unload-feature isn't used very much anyway. Coming back to this after 10 years, it appears that we (I, certainly) underestimated the computation involved. While the attached patch(es) work for emacs -Q toy examples like Kevin's or more recently the one from bug#34686, when I tried M-x load-library allout RET M-x unload-feature allout RET in my normal Emacs session with ~300 buffers and ~1000 features, it took my venerable laptop 8 minutes to complete. Based on that experience, unless someone has better ideas, I suggest we close this and clarify the (henceforth intentional) lack of attention to buffer-local hook values in the documentation instead. Actually, I wonder if ignoring even the global hooks (as opined by Juanma) and enforcing more widespread usage of FEATURE-unload-function wouldn't be better; or/also, couldn't stray undefined functions on hooks be handled similarly to how it's done for errors e.g. in `post-command-hook', i.e. auto-removed when encountered? I guess wrapping all hooks like that would be overkill? (That said, I think [1/3] and [3/3] could/should be applied nonetheless.)

From 394f2bf6821196a4171fd79fc9a10dc626619a58 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C5=A0t=C4=9Bp=C3=A1n=20N=C4=9Bmec?= <stepnem <at> gmail.com> Date: Mon, 6 Apr 2020 13:25:41 +0200 Subject: [PATCH 1/3] unload-feature: Improve logic (don't repeat computation) * lisp/loadhist.el (unload-feature): Don't do the same computation twice. --- lisp/loadhist.el | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/lisp/loadhist.el b/lisp/loadhist.el index a1ff2f6270..60da00cceb 100644 --- a/lisp/loadhist.el +++ b/lisp/loadhist.el @@ -287,22 +287,23 @@ unload-feature ;; functions which the package might just have installed, and ;; there might be other important state, but this tactic ;; normally works. - (mapatoms - (lambda (x) - (when (and (boundp x) - (or (and (consp (symbol-value x)) ; Random hooks. - (string-match "-hooks?\\'" (symbol-name x))) - (memq x unload-feature-special-hooks))) ; Known abnormal hooks etc. - (dolist (y unload-function-defs-list) - (when (and (eq (car-safe y) 'defun) - (not (get (cdr y) 'autoload))) - (remove-hook x (cdr y))))))) - ;; Remove any feature-symbols from auto-mode-alist as well. - (dolist (y unload-function-defs-list) - (when (and (eq (car-safe y) 'defun) - (not (get (cdr y) 'autoload))) - (setq auto-mode-alist - (rassq-delete-all (cdr y) auto-mode-alist))))) + (let ((removables (cl-loop for def in unload-function-defs-list + when (and (eq (car-safe def) 'defun) + (not (get (cdr def) 'autoload))) + collect (cdr def)))) + (mapatoms + (lambda (x) + (when (and (boundp x) + (or (and (consp (symbol-value x)) ; Random hooks. + (string-match "-hooks?\\'" (symbol-name x))) + ;; Known abnormal hooks etc. + (memq x unload-feature-special-hooks))) + (dolist (func removables) + (remove-hook x func))))) + ;; Remove any feature-symbols from auto-mode-alist as well. + (dolist (func removables) + (setq auto-mode-alist + (rassq-delete-all func auto-mode-alist))))) ;; Change major mode in all buffers using one defined in the feature being unloaded. (unload--set-major-mode) -- 2.26.0

From d2372157c031b79cad4e3bf331aa6e167ff48199 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C5=A0t=C4=9Bp=C3=A1n=20N=C4=9Bmec?= <stepnem <at> gmail.com> Date: Mon, 6 Apr 2020 13:30:11 +0200 Subject: [PATCH 2/3] unload-feature: Handle local hooks Buffer-local hooks were introduced in 1994-09-30T20:47:13+00:00!rms <at> gnu.org 0e4d378b32 (add-hook): Initialize default value and local value. but `unload-feature' has not been updated to handle them. * lisp/loadhist.el (unload-feature): Handle local hooks. --- etc/NEWS | 3 +++ lisp/loadhist.el | 6 +++++- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/etc/NEWS b/etc/NEWS index 765a923bf7..fa90edc4d1 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -297,6 +297,9 @@ optional argument specifying whether to follow symbolic links. ** 'parse-time-string' can now parse ISO 8601 format strings, such as "2020-01-15T16:12:21-08:00". +--- +** 'unload-feature' now also tries to undo additions to buffer-local hooks. + * Changes in Emacs 28.1 on Non-Free Operating Systems diff --git a/lisp/loadhist.el b/lisp/loadhist.el index 60da00cceb..2fd2d3f6be 100644 --- a/lisp/loadhist.el +++ b/lisp/loadhist.el @@ -299,7 +299,11 @@ unload-feature ;; Known abnormal hooks etc. (memq x unload-feature-special-hooks))) (dolist (func removables) - (remove-hook x func))))) + (remove-hook x func) + (save-current-buffer + (dolist (buffer (buffer-list)) + (set-buffer buffer) + (remove-hook x func t))))))) ;; Remove any feature-symbols from auto-mode-alist as well. (dolist (func removables) (setq auto-mode-alist -- 2.26.0

From a418282b70e514065159a217a4106226395aa98e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C5=A0t=C4=9Bp=C3=A1n=20N=C4=9Bmec?= <stepnem <at> gmail.com> Date: Mon, 6 Apr 2020 17:05:33 +0200 Subject: [PATCH 3/3] unload-feature: Correct doc string to match info manual and reality 'unload-feature' doesn't try to "undo any additions the library has made" to hooks, it tries to remove functions defined by the library from hooks, no matter how they got there. * lisp/loadhist.el (unload-feature): Correct the doc string. * doc/lispref/loading.texi (Unloading): Clarify, fix typo. --- doc/lispref/loading.texi | 4 ++-- lisp/loadhist.el | 9 ++++----- 2 files changed, 6 insertions(+), 7 deletions(-) diff --git a/doc/lispref/loading.texi b/doc/lispref/loading.texi index 2894282079..f1ee638357 100644 --- a/doc/lispref/loading.texi +++ b/doc/lispref/loading.texi @@ -1063,7 +1063,7 @@ Unloading (Loading saves these in the @code{autoload} property of the symbol.) Before restoring the previous definitions, @code{unload-feature} runs -@code{remove-hook} to remove functions in the library from certain +@code{remove-hook} to remove functions defined by the library from certain hooks. These hooks include variables whose names end in @samp{-hook} (or the deprecated suffix @samp{-hooks}), plus those listed in @code{unload-feature-special-hooks}, as well as @@ -1071,7 +1071,7 @@ Unloading function because important hooks refer to functions that are no longer defined. -Standard unloading activities also undoes ELP profiling of functions +Standard unloading activities also undo ELP profiling of functions in that library, unprovides any features provided by the library, and cancels timers held in variables defined by the library. diff --git a/lisp/loadhist.el b/lisp/loadhist.el index 2fd2d3f6be..9718a4840d 100644 --- a/lisp/loadhist.el +++ b/lisp/loadhist.el @@ -234,11 +234,10 @@ unload-feature is nil, raise an error. Standard unloading activities include restoring old autoloads for -functions defined by the library, undoing any additions that the -library has made to hook variables or to `auto-mode-alist', undoing -ELP profiling of functions in that library, unproviding any features -provided by the library, and canceling timers held in variables -defined by the library. +functions defined by the library, removing such functions from +hooks and `auto-mode-alist', undoing their ELP profiling, +unproviding any features provided by the library, and canceling +timers held in variables defined by the library. If a function `FEATURE-unload-function' is defined, this function calls it with no arguments, before doing anything else. That function -- 2.26.0

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GNU bug report logs - #5293 23.1; unload-feature on buffer-local hooks

GNU bug report logs - #5293
23.1; unload-feature on buffer-local hooks