Package: emacs;
Reported by: Alan Mackenzie <acm <at> muc.de>
Date: Wed, 15 Nov 2023 17:03:02 UTC
Severity: normal
Done: Alan Mackenzie <acm <at> muc.de>
Bug is archived. No further changes may be made.
View this message in rfc822 format
From: Stefan Monnier <monnier <at> iro.umontreal.ca> To: Richard Stallman <rms <at> gnu.org> Cc: 67196 <at> debbugs.gnu.org, acm <at> muc.de, eliz <at> gnu.org Subject: bug#67196: M-: uses a wrong value of debug-on-error when it is nil. Date: Tue, 19 Dec 2023 00:05:02 -0500
[Message part 1 (text/plain, inline)]
> > > Side note: there's recently been several things pointing to the need to
> > > add something like Common Lisp's `handler-bind`.
>
> Could someone explain the `handler-bind' construct and show its
> documentation? It might be a good idea, but it could be that we can
> do better,
Here's my current handler-bind patch, which includes some doc.
Stefan
[handler-bind.patch (text/x-diff, inline)]
commit 7252f6b48944e22980f4030c98a6c7b05243e19e
Author: Stefan Monnier <monnier <at> iro.umontreal.ca>
Date: Tue Dec 19 00:03:25 2023 -0500
tramp.el: Use `handler-bind` instead of `signal-hook-function`
* lisp/net/tramp.el (tramp--trace-errors): Rename from
`tramp-signal-hook-function` and change calling convention for
`handler-bind`.
(tramp-unknown-id-string, tramp-unknown-id-integer):
Don't use `defconst` for vars which we let-bind (in tramp-tests.el).
(tramp-file-name-handler): Use `handler-bind` instead of let-binding
`signal-hook-function`.
(tramp-handle-lock-file, tramp-handle-load, tramp-add-hops)
(tramp-run-real-handler):
* lisp/net/tramp-sshfs.el (tramp-sshfs-handle-insert-file-contents):
* lisp/net/tramp-sh.el (tramp-sh-get-signal-strings):
(tramp-send-command-and-read):
* lisp/net/tramp-message.el (tramp-debug-message, tramp-error):
* lisp/net/tramp-adb.el (tramp-do-parse-file-attributes-with-ls): Don't
let-bind `signal-hook-function`.
diff --git a/lisp/net/tramp-adb.el b/lisp/net/tramp-adb.el
index e4d3ba8c74b..0b68e7384b2 100644
--- a/lisp/net/tramp-adb.el
+++ b/lisp/net/tramp-adb.el
@@ -297,9 +297,7 @@ tramp-do-parse-file-attributes-with-ls
(cons uid tramp-unknown-id-integer)
(cons gid tramp-unknown-id-integer)
tramp-time-dont-know ; atime
- ;; `date-to-time' checks `iso8601-parse', which might fail.
- (let (signal-hook-function)
- (date-to-time date)) ; mtime
+ (date-to-time date) ; mtime
tramp-time-dont-know ; ctime
size
mod-string
diff --git a/lisp/net/tramp-message.el b/lisp/net/tramp-message.el
index e05357f1f4f..924f4d15ad2 100644
--- a/lisp/net/tramp-message.el
+++ b/lisp/net/tramp-message.el
@@ -207,8 +207,7 @@ tramp-debug-message
ARGUMENTS to actually emit the message (if applicable)."
(declare (tramp-suppress-trace t))
(let ((inhibit-message t)
- create-lockfiles file-name-handler-alist message-log-max
- signal-hook-function)
+ create-lockfiles file-name-handler-alist message-log-max)
(with-current-buffer (tramp-get-debug-buffer vec)
(goto-char (point-max))
(let ((point (point)))
@@ -364,7 +363,7 @@ tramp-error
signal identifier to be raised, remaining arguments passed to
`tramp-message'. Finally, signal SIGNAL is raised with
FMT-STRING and ARGUMENTS."
- (let (signal-hook-function)
+ (let ()
(tramp-backtrace vec-or-proc)
(unless arguments
;; FMT-STRING could be just a file name, as in
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index a7ead1f2997..77ab5b0a399 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -3168,12 +3168,11 @@ tramp-sh-get-signal-strings
(setcdr signals (cddr signals)))
;; Sanity check. "kill -l" shall have returned just the signal
;; names. Some shells don't, like the one in "docker alpine".
- (let (signal-hook-function)
- (condition-case nil
- (dolist (sig (cdr signals))
- (unless (string-match-p (rx bol (+ (any "+-" alnum)) eol) sig)
- (error nil)))
- (error (setq signals '(0)))))
+ (condition-case nil
+ (dolist (sig (cdr signals))
+ (unless (string-match-p (rx bol (+ (any "+-" alnum)) eol) sig)
+ (error nil)))
+ (error (setq signals '(0))))
(dotimes (i 128)
(push
(cond
@@ -5536,9 +5535,7 @@ tramp-send-command-and-read
;; Read the expression.
(condition-case nil
(prog1
- (let ((signal-hook-function
- (unless noerror signal-hook-function)))
- (read (current-buffer)))
+ (read (current-buffer))
;; Error handling.
(when (search-forward-regexp (rx (not space)) (line-end-position) t)
(error nil)))
diff --git a/lisp/net/tramp-sshfs.el b/lisp/net/tramp-sshfs.el
index 102ba637f55..afc2033ee6e 100644
--- a/lisp/net/tramp-sshfs.el
+++ b/lisp/net/tramp-sshfs.el
@@ -242,7 +242,7 @@ tramp-sshfs-handle-insert-file-contents
(filename &optional visit beg end replace)
"Like `insert-file-contents' for Tramp files."
(setq filename (expand-file-name filename))
- (let (signal-hook-function result)
+ (let (result)
(unwind-protect
(setq result
(insert-file-contents
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 88cbfa2d88c..ebdc8bf97ef 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -1085,10 +1085,10 @@ tramp-postfix-host-regexp
(defconst tramp-localname-regexp (rx (* (not (any "\r\n"))) eos)
"Regexp matching localnames.")
-(defconst tramp-unknown-id-string "UNKNOWN"
+(defvar tramp-unknown-id-string "UNKNOWN"
"String used to denote an unknown user or group.")
-(defconst tramp-unknown-id-integer -1
+(defvar tramp-unknown-id-integer -1
"Integer used to denote an unknown user or group.")
;;;###tramp-autoload
@@ -1994,16 +1994,16 @@ tramp-barf-if-file-missing
;; This function provides traces in case of errors not triggered by
;; Tramp functions.
-(defun tramp-signal-hook-function (error-symbol data)
- "Function to be called via `signal-hook-function'."
+(defun tramp--trace-errors (err)
+ "Function to be called via `handler-bind'."
;; `custom-initialize-*' functions provoke `void-variable' errors.
;; We don't want to see them in the backtrace.
(declare (tramp-suppress-trace t))
- (unless (eq error-symbol 'void-variable)
+ (unless (eq (car err) 'void-variable)
(let ((inhibit-message t))
(tramp-error
- (car tramp-current-connection) error-symbol
- (mapconcat (lambda (x) (format "%s" x)) data " ")))))
+ (car tramp-current-connection) (car err)
+ (mapconcat (lambda (x) (format "%s" x)) (cdr err) " ")))))
(defmacro with-parsed-tramp-file-name (filename var &rest body)
"Parse a Tramp filename and make components available in the body.
@@ -2081,7 +2081,7 @@ with-tramp-progress-reporter
(defmacro with-tramp-timeout (list &rest body)
"Like `with-timeout', but allow SECONDS to be nil.
-(fn (SECONDS TIMEOUT-FORMS...) BODY)"
+\(fn (SECONDS TIMEOUT-FORMS...) BODY)"
(declare (indent 1) (debug ((form body) body)))
(let ((seconds (car list))
(timeout-forms (cdr list)))
@@ -2248,8 +2248,7 @@ tramp-run-real-handler
,(and (eq inhibit-file-name-operation operation)
inhibit-file-name-handlers)))
(inhibit-file-name-operation operation)
- (args (if (tramp-file-name-p (car args)) (cons nil (cdr args)) args))
- signal-hook-function)
+ (args (if (tramp-file-name-p (car args)) (cons nil (cdr args)) args)))
(apply operation args)))
;; We handle here all file primitives. Most of them have the file
@@ -2386,8 +2385,8 @@ tramp-file-name-handler
(let ((current-connection tramp-current-connection)
(foreign
(tramp-find-foreign-file-name-handler v operation))
- (signal-hook-function #'tramp-signal-hook-function)
result)
+ (handler-bind ((error #'tramp--trace-errors))
;; Set `tramp-current-connection'.
(unless
(tramp-file-name-equal-p v (car tramp-current-connection))
@@ -2453,7 +2452,7 @@ tramp-file-name-handler
(unless
(tramp-file-name-equal-p
(car current-connection) (car tramp-current-connection))
- (setq tramp-current-connection current-connection))))))
+ (setq tramp-current-connection current-connection)))))))
;; When `tramp-mode' is not enabled, or the file name is quoted,
;; we don't do anything.
@@ -4584,7 +4583,7 @@ tramp-handle-lock-file
;; Do the lock.
(let ((tramp-verbose 0)
- create-lockfiles signal-hook-function)
+ create-lockfiles)
(condition-case nil
(make-symbolic-link info lockname 'ok-if-already-exists)
(error
@@ -4632,8 +4631,7 @@ tramp-handle-load
(tramp-error v 'file-missing file))
(if (not (file-exists-p file))
nil
- (let ((signal-hook-function (unless noerror signal-hook-function))
- (inhibit-message (or inhibit-message nomessage)))
+ (let ((inhibit-message (or inhibit-message nomessage)))
(with-tramp-progress-reporter v 0 (format "Loading %s" file)
(let ((local-copy (file-local-copy file)))
(unwind-protect
@@ -4651,7 +4649,7 @@ tramp-add-hops
"Add ad-hoc proxy definitions to `tramp-default-proxies-alist'."
(when-let ((hops (tramp-file-name-hop vec))
(item vec))
- (let (signal-hook-function changed)
+ (let (changed)
(dolist
(proxy (reverse (split-string hops tramp-postfix-hop-regexp 'omit)))
(let* ((host-port (tramp-file-name-host-port item))
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1994-97 Ian Jackson.