;;; nadvice.el --- Light-weight advice primitives for Elisp functions -*- lexical-binding: t -*-
-;; Copyright (C) 2012-2013 Free Software Foundation, Inc.
+;; Copyright (C) 2012-2014 Free Software Foundation, Inc.
;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
;; Keywords: extensions, lisp, tools
;;;; Lightweight advice/hook
(defvar advice--where-alist
- '((:around "\300\301\302\003#\207" 5)
- (:before "\300\301\002\"\210\300\302\002\"\207" 4)
- (:after "\300\302\002\"\300\301\003\"\210\207" 5)
- (:after-until "\300\302\002\"\206\013\000\300\301\002\"\207" 4)
- (:after-while "\300\302\002\"\205\013\000\300\301\002\"\207" 4)
- (:before-until "\300\301\002\"\206\013\000\300\302\002\"\207" 4)
- (:before-while "\300\301\002\"\205\013\000\300\302\002\"\207" 4))
- "List of descriptions of how to add a function.
-Each element has the form (WHERE BYTECODE STACK) where:
- WHERE is a keyword indicating where the function is added.
- BYTECODE is the corresponding byte-code that will be used.
- STACK is the amount of stack space needed by the byte-code.")
-
-(defvar advice--bytecodes (mapcar #'cadr advice--where-alist))
+ '((:around . (apply function main args))
+ (:before . (progn
+ (apply function args)
+ (apply main args)))
+ (:after . (prog1 (apply main args)
+ (apply function args)))
+ (:override . (apply function args))
+ (:after-until . (or (apply main args) (apply function args)))
+ (:after-while . (and (apply main args) (apply function args)))
+ (:before-until . (or (apply function args) (apply main args)))
+ (:before-while . (and (apply function args) (apply main args)))
+ (:filter-args . (apply main (apply function args)))
+ (:filter-return . (funcall function (apply main args))))
+ "List of descriptions of how to add a function.")
+
+(setq advice--where-alist
+ (mapcar #'(lambda (tem)
+ (cons (car tem)
+ (eval `(lambda (function main)
+ (lambda (&rest args)
+ ,(cdr tem))))))
+ advice--where-alist))
(defun advice--p (object)
- (and (byte-code-function-p object)
- (eq 128 (aref object 0))
- (memq (length object) '(5 6))
- (memq (aref object 1) advice--bytecodes)
- (eq #'apply (aref (aref object 2) 0))))
-
-(defsubst advice--car (f) (aref (aref f 2) 1))
-(defsubst advice--cdr (f) (aref (aref f 2) 2))
-(defsubst advice--props (f) (aref (aref f 2) 3))
-
-(defun advice--make-docstring (_string function)
- "Build the raw doc-string of SYMBOL, presumably advised."
- (let ((flist (indirect-function function))
- (docstring nil))
+ (when (funcall (@ (guile) procedure?) object)
+ (funcall (@ (guile) procedure-property) object 'advice)))
+
+(defun advice--car (f)
+ (when (funcall (@ (guile) procedure?) f)
+ (funcall (@ (guile) procedure-property) f 'advice-car)))
+
+(defun advice--cdr (f)
+ (when (funcall (@ (guile) procedure?) f)
+ (funcall (@ (guile) procedure-property) f 'advice-cdr)))
+
+(defun advice--props (f)
+ (when (funcall (@ (guile) procedure?) f)
+ (funcall (@ (guile) procedure-property) f 'advice-props)))
+
+(defun advice--cd*r (f)
+ (while (advice--p f)
+ (setq f (advice--cdr f)))
+ f)
+
+(defun advice--make-docstring (function)
+ "Build the raw docstring for FUNCTION, presumably advised."
+ (let* ((flist (indirect-function function))
+ (docfun nil)
+ (docstring nil))
(if (eq 'macro (car-safe flist)) (setq flist (cdr flist)))
(while (advice--p flist)
(let ((bytecode (aref flist 1))
+ (doc (aref flist 4))
(where nil))
+ ;; Hack attack! For advices installed before calling
+ ;; Snarf-documentation, the integer offset into the DOC file will not
+ ;; be installed in the "core unadvised function" but in the advice
+ ;; object instead! So here we try to undo the damage.
+ (if (integerp doc) (setq docfun flist))
(dolist (elem advice--where-alist)
- (if (eq bytecode (cadr elem)) (setq where (car elem))))
+ (if (eq bytecode (cdr elem)) (setq where (car elem))))
(setq docstring
(concat
docstring
"\n")))
(setq flist (advice--cdr flist)))
(if docstring (setq docstring (concat docstring "\n")))
- (let* ((origdoc (unless (eq function flist) ;Avoid inf-loops.
- (documentation flist t)))
+ (unless docfun (setq docfun flist))
+ (let* ((origdoc (unless (eq function docfun) ;Avoid inf-loops.
+ (documentation docfun t)))
(usage (help-split-fundoc origdoc function)))
(setq usage (if (null usage)
(let ((arglist (help-function-arglist flist)))
(setq origdoc (cdr usage)) (car usage)))
(help-add-fundoc-usage (concat docstring origdoc) usage))))
-(defvar advice--docstring
- ;; Can't eval-when-compile nor use defconst because it then gets pure-copied,
- ;; which drops the text-properties.
- ;;(eval-when-compile
- (propertize "Advised function"
- 'dynamic-docstring-function #'advice--make-docstring)) ;; )
-
(defun advice-eval-interactive-spec (spec)
"Evaluate the interactive spec SPEC."
(cond
;; ((functionp spec) (funcall spec))
(t (eval spec))))
+(defun advice--interactive-form (function)
+ ;; Like `interactive-form' but tries to avoid autoloading functions.
+ (when (commandp function)
+ (if (not (and (symbolp function) (autoloadp (indirect-function function))))
+ (interactive-form function)
+ `(interactive (advice-eval-interactive-spec
+ (cadr (interactive-form ',function)))))))
+
(defun advice--make-interactive-form (function main)
;; TODO: make it so that interactive spec can be a constant which
;; dynamically checks the advice--car/cdr to do its job.
;; For that, advice-eval-interactive-spec needs to be more faithful.
- ;; FIXME: The calls to interactive-form below load autoloaded functions
- ;; too eagerly.
- (let ((fspec (cadr (interactive-form function))))
+ (let* ((iff (advice--interactive-form function))
+ (ifm (advice--interactive-form main))
+ (fspec (cadr iff)))
(when (eq 'function (car-safe fspec)) ;; Macroexpanded lambda?
(setq fspec (nth 1 fspec)))
(if (functionp fspec)
- `(funcall ',fspec
- ',(cadr (interactive-form main)))
- (cadr (or (interactive-form function)
- (interactive-form main))))))
+ `(funcall ',fspec ',(cadr ifm))
+ (cadr (or iff ifm)))))
-(defsubst advice--make-1 (byte-code stack-depth function main props)
+(defun advice--make-1 (type make-wrapper function main props)
"Build a function value that adds FUNCTION to MAIN."
(let ((adv-sig (gethash main advertised-signature-table))
(advice
- (apply #'make-byte-code 128 byte-code
- (vector #'apply function main props) stack-depth
- advice--docstring
- (when (or (commandp function) (commandp main))
- (list (advice--make-interactive-form
- function main))))))
+ (funcall make-wrapper function main)))
+ (funcall (@ (guile) set-procedure-property!)
+ advice 'advice-type type)
+ (funcall (@ (guile) set-procedure-property!)
+ advice 'advice-car function)
+ (funcall (@ (guile) set-procedure-property!)
+ advice 'advice-cdr main)
+ (funcall (@ (guile) set-procedure-property!)
+ advice 'advice-props props)
+ (when (or (commandp function) (commandp main))
+ (funcall (@ (guile) set-procedure-property!)
+ advice
+ 'interactive-form
+ (advice--make-interactive-form function main)))
(when adv-sig (puthash advice adv-sig advertised-signature-table))
advice))
(defun advice--make (where function main props)
"Build a function value that adds FUNCTION to MAIN at WHERE.
WHERE is a symbol to select an entry in `advice--where-alist'."
- (let ((desc (assq where advice--where-alist)))
- (unless desc (error "Unknown add-function location `%S'" where))
- (advice--make-1 (nth 1 desc) (nth 2 desc)
- function main props)))
-
-(defun advice--member-p (function definition)
+ (let ((fd (or (cdr (assq 'depth props)) 0))
+ (md (if (advice--p main)
+ (or (cdr (assq 'depth (advice--props main))) 0))))
+ (if (and md (> fd md))
+ ;; `function' should go deeper.
+ (let ((rest (advice--make where function (advice--cdr main) props)))
+ (advice--make-1 (aref main 1) (aref main 3)
+ (advice--car main) rest (advice--props main)))
+ (let ((desc (assq where advice--where-alist)))
+ (unless desc (error "Unknown add-function location `%S'" where))
+ (advice--make-1 (car desc) (cdr desc)
+ function main props)))))
+
+(defun advice--member-p (function use-name definition)
(let ((found nil))
(while (and (not found) (advice--p definition))
- (if (or (equal function (advice--car definition))
- (equal function (cdr (assq 'name (advice--props definition)))))
- (setq found t)
+ (if (if (eq use-name :use-both)
+ (or (equal function
+ (cdr (assq 'name (advice--props definition))))
+ (equal function (advice--car definition)))
+ (equal function (if use-name
+ (cdr (assq 'name (advice--props definition)))
+ (advice--car definition))))
+ (setq found definition)
(setq definition (advice--cdr definition))))
found))
(lambda (first rest props)
(cond ((not first) rest)
((or (equal function first)
- (equal function (cdr (assq 'name props))))
- (list rest))))))
+ (equal function (cdr (assq 'name props))))
+ (list (advice--remove-function rest function)))))))
-(defvar advice--buffer-local-function-sample nil)
+(defvar advice--buffer-local-function-sample nil
+ "keeps an example of the special \"run the default value\" functions.
+These functions play the same role as t in buffer-local hooks, and to recognize
+them, we keep a sample here against which to compare. Each instance is
+different, but `function-equal' will hopefully ignore those differences.")
(defun advice--set-buffer-local (var val)
- (if (function-equal val advice--buffer-local-function-sample)
+ (if (equal val advice--buffer-local-function-sample)
(kill-local-variable var)
(set (make-local-variable var) val)))
(declare (gv-setter advice--set-buffer-local))
(if (local-variable-p var) (symbol-value var)
(setq advice--buffer-local-function-sample
+ ;; This function acts like the t special value in buffer-local hooks.
(lambda (&rest args) (apply (default-value var) args)))))
+(eval-and-compile
+ (defun advice--normalize-place (place)
+ (cond ((eq 'local (car-safe place)) `(advice--buffer-local ,@(cdr place)))
+ ((eq 'var (car-safe place)) (nth 1 place))
+ ((symbolp place) `(default-value ',place))
+ (t place))))
+
;;;###autoload
(defmacro add-function (where place function &optional props)
;; TODO:
- ;; - obsolete with-wrapper-hook (mostly requires buffer-local support).
- ;; - provide some kind of control over ordering. E.g. debug-on-entry, ELP
- ;; and tracing want to stay first.
;; - maybe let `where' specify some kind of predicate and use it
;; to implement things like mode-local or eieio-defmethod.
;; Of course, that only makes sense if the predicates of all advices can
`:before' (lambda (&rest r) (apply FUNCTION r) (apply OLDFUN r))
`:after' (lambda (&rest r) (prog1 (apply OLDFUN r) (apply FUNCTION r)))
`:around' (lambda (&rest r) (apply FUNCTION OLDFUN r))
+`:override' (lambda (&rest r) (apply FUNCTION r))
`:before-while' (lambda (&rest r) (and (apply FUNCTION r) (apply OLDFUN r)))
`:before-until' (lambda (&rest r) (or (apply FUNCTION r) (apply OLDFUN r)))
`:after-while' (lambda (&rest r) (and (apply OLDFUN r) (apply FUNCTION r)))
`:after-until' (lambda (&rest r) (or (apply OLDFUN r) (apply FUNCTION r)))
+`:filter-args' (lambda (&rest r) (apply OLDFUN (funcall FUNCTION r)))
+`:filter-return'(lambda (&rest r) (funcall FUNCTION (apply OLDFUN r)))
If FUNCTION was already added, do nothing.
PROPS is an alist of additional properties, among which the following have
a special meaning:
- `name': a string or symbol. It can be used to refer to this piece of advice.
+- `depth': a number indicating a preference w.r.t ordering.
+ The default depth is 0. By convention, a depth of 100 means that
+ the advice should be innermost (i.e. at the end of the list),
+ whereas a depth of -100 means that the advice should be outermost.
-PLACE cannot be a simple variable. Instead it should either be
-\(default-value 'VAR) or (local 'VAR) depending on whether FUNCTION
-should be applied to VAR buffer-locally or globally.
+If PLACE is a symbol, its `default-value' will be affected.
+Use (local 'SYMBOL) if you want to apply FUNCTION to SYMBOL buffer-locally.
+Use (var VAR) if you want to apply FUNCTION to the (lexical) VAR.
If one of FUNCTION or OLDFUN is interactive, then the resulting function
is also interactive. There are 3 cases:
`advice-eval-interactive-spec') and return the list of arguments to use.
- Else, use the interactive spec of FUNCTION and ignore the one of OLDFUN."
(declare (debug t)) ;;(indent 2)
- (cond ((eq 'local (car-safe place))
- (setq place `(advice--buffer-local ,@(cdr place))))
- ((symbolp place)
- (error "Use (default-value '%S) or (local '%S)" place place)))
- `(advice--add-function ,where (gv-ref ,place) ,function ,props))
+ `(advice--add-function ,where (gv-ref ,(advice--normalize-place place))
+ ,function ,props))
;;;###autoload
(defun advice--add-function (where ref function props)
- (unless (advice--member-p function (gv-deref ref))
+ (let* ((name (cdr (assq 'name props)))
+ (a (advice--member-p (or name function) (if name t) (gv-deref ref))))
+ (when a
+ ;; The advice is already present. Remove the old one, first.
+ (setf (gv-deref ref)
+ (advice--remove-function (gv-deref ref)
+ (or name (advice--car a)))))
(setf (gv-deref ref)
(advice--make where function (gv-deref ref) props))))
+;;;###autoload
(defmacro remove-function (place function)
"Remove the FUNCTION piece of advice from PLACE.
If FUNCTION was not added to PLACE, do nothing.
Instead of FUNCTION being the actual function, it can also be the `name'
of the piece of advice."
(declare (debug t))
- (cond ((eq 'local (car-safe place))
- (setq place `(advice--buffer-local ,@(cdr place))))
- ((symbolp place)
- (error "Use (default-value '%S) or (local '%S)" place place)))
- (gv-letplace (getter setter) place
+ (gv-letplace (getter setter) (advice--normalize-place place)
(macroexp-let2 nil new `(advice--remove-function ,getter ,function)
`(unless (eq ,new ,getter) ,(funcall setter new)))))
+(defun advice-function-mapc (f function-def)
+ "Apply F to every advice function in FUNCTION-DEF.
+F is called with two arguments: the function that was added, and the
+properties alist that was specified when it was added."
+ (while (advice--p function-def)
+ (funcall f (advice--car function-def) (advice--props function-def))
+ (setq function-def (advice--cdr function-def))))
+
+(defun advice-function-member-p (advice function-def)
+ "Return non-nil if ADVICE is already in FUNCTION-DEF.
+Instead of ADVICE being the actual function, it can also be the `name'
+of the piece of advice."
+ (advice--member-p advice :use-both function-def))
+
;;;; Specific application of add-function to `symbol-function' for advice.
(defun advice--subst-main (old new)
(cond
((special-form-p def)
;; Not worth the trouble trying to handle this, I think.
- (error "advice-add failure: %S is a special form" symbol))
- ((and (symbolp def)
- (eq 'macro (car-safe (ignore-errors (indirect-function def)))))
- (let ((newval (cons 'macro (cdr (indirect-function def)))))
- (put symbol 'advice--saved-rewrite (cons def newval))
+ (error "Advice impossible: %S is a special form" symbol))
+ ((and (symbolp def) (macrop def))
+ (let ((newval `(macro . ,(lambda (&rest r) (macroexpand `(,def . ,r))))))
+ (put symbol 'advice--saved-rewrite (cons def (cdr newval)))
newval))
;; `f' might be a pure (hence read-only) cons!
((and (eq 'macro (car-safe def))
(defsubst advice--strip-macro (x)
(if (eq 'macro (car-safe x)) (cdr x) x))
+(defun advice--symbol-function (symbol)
+ ;; The value conceptually stored in `symbol-function' is split into two
+ ;; parts:
+ ;; - the normal function definition.
+ ;; - the list of advice applied to it.
+ ;; `advice--symbol-function' is intended to return the second part (i.e. the
+ ;; list of advice, which includes a hole at the end which typically holds the
+ ;; first part, but this function doesn't care much which value is found
+ ;; there).
+ ;; In the "normal" state both parts are combined into a single value stored
+ ;; in the "function slot" of the symbol. But the way they are combined is
+ ;; different depending on whether the definition is a function or a macro.
+ ;; Also if the function definition is nil (i.e. unbound) or is an autoload,
+ ;; the second part is stashed away temporarily in the `advice--pending'
+ ;; symbol property.
+ (or (get symbol 'advice--pending)
+ (advice--strip-macro (symbol-function symbol))))
+
(defun advice--defalias-fset (fsetfun symbol newdef)
+ (unless fsetfun (setq fsetfun #'fset))
(when (get symbol 'advice--saved-rewrite)
(put symbol 'advice--saved-rewrite nil))
(setq newdef (advice--normalize symbol newdef))
- (let* ((olddef (advice--strip-macro
- (if (fboundp symbol) (symbol-function symbol))))
- (oldadv
- (cond
- ((null (get symbol 'advice--pending))
- (or olddef
- (progn
- (message "Delayed advice activation failed for %s: no data"
- symbol)
- nil)))
- ((or (not olddef) (autoloadp olddef))
- (prog1 (get symbol 'advice--pending)
- (put symbol 'advice--pending nil)))
- (t (message "Dropping left-over advice--pending for %s" symbol)
- (put symbol 'advice--pending nil)
- olddef))))
- (let* ((snewdef (advice--strip-macro newdef))
- (snewadv (advice--subst-main oldadv snewdef)))
- (funcall (or fsetfun #'fset) symbol
- (if (eq snewdef newdef) snewadv (cons 'macro snewadv))))))
-
+ (let ((oldadv (advice--symbol-function symbol)))
+ (if (and newdef (not (autoloadp newdef)))
+ (let* ((snewdef (advice--strip-macro newdef))
+ (snewadv (advice--subst-main oldadv snewdef)))
+ (put symbol 'advice--pending nil)
+ (funcall fsetfun symbol
+ (if (eq snewdef newdef) snewadv (cons 'macro snewadv))))
+ (unless (eq oldadv (get symbol 'advice--pending))
+ (put symbol 'advice--pending (advice--subst-main oldadv nil)))
+ (funcall fsetfun symbol newdef))))
;;;###autoload
(defun advice-add (symbol where function &optional props)
;; TODO:
;; - record the advice location, to display in describe-function.
;; - change all defadvice in lisp/**/*.el.
- ;; - rewrite advice.el on top of this.
;; - obsolete advice.el.
- (let* ((f (and (fboundp symbol) (symbol-function symbol)))
+ (let* ((f (symbol-function symbol))
(nf (advice--normalize symbol f)))
- (unless (eq f nf) ;; Most importantly, if nf == nil!
- (fset symbol nf))
+ (unless (eq f nf) (fset symbol nf))
(add-function where (cond
((eq (car-safe nf) 'macro) (cdr nf))
;; Reasons to delay installation of the advice:
;; - If the function is not yet defined, installing
;; the advice would affect `fboundp'ness.
- ;; - If it's an autoloaded command,
- ;; advice--make-interactive-form would end up
- ;; loading the command eagerly.
+ ;; - the symbol-function slot of an autoloaded
+ ;; function is not itself a function value.
;; - `autoload' does nothing if the function is
;; not an autoload or undefined.
((or (not nf) (autoloadp nf))
(get symbol 'advice--pending))
(t (symbol-function symbol)))
function props)
+ (put symbol 'function-documentation `(advice--make-docstring ',symbol))
(add-function :around (get symbol 'defalias-fset-function)
#'advice--defalias-fset))
nil)
;;;###autoload
(defun advice-remove (symbol function)
"Like `remove-function' but for the function named SYMBOL.
-Contrary to `remove-function', this will work also when SYMBOL is a macro
-and it will not signal an error if SYMBOL is not `fboundp'.
+Contrary to `remove-function', this also works when SYMBOL is a macro
+or an autoload and it preserves `fboundp'.
Instead of the actual function to remove, FUNCTION can also be the `name'
of the piece of advice."
- (when (fboundp symbol)
- (let ((f (symbol-function symbol)))
- ;; Can't use the `if' place here, because the body is too large,
- ;; resulting in use of code that only works with lexical-scoping.
- (remove-function (if (eq (car-safe f) 'macro)
- (cdr f)
- (symbol-function symbol))
- function)
- (unless (advice--p
- (if (eq (car-safe f) 'macro) (cdr f) (symbol-function symbol)))
- ;; Not advised any more.
- (remove-function (get symbol 'defalias-fset-function)
- #'advice--defalias-fset)
- (if (eq (symbol-function symbol)
- (cdr (get symbol 'advice--saved-rewrite)))
- (fset symbol (car (get symbol 'advice--saved-rewrite))))))
- nil))
-
-;; (defun advice-mapc (fun symbol)
-;; "Apply FUN to every function added as advice to SYMBOL.
-;; FUN is called with a two arguments: the function that was added, and the
-;; properties alist that was specified when it was added."
-;; (let ((def (or (get symbol 'advice--pending)
-;; (if (fboundp symbol) (symbol-function symbol)))))
-;; (while (advice--p def)
-;; (funcall fun (advice--car def) (advice--props def))
-;; (setq def (advice--cdr def)))))
+ (let ((f (symbol-function symbol)))
+ (remove-function (cond ;This is `advice--symbol-function' but as a "place".
+ ((get symbol 'advice--pending)
+ (get symbol 'advice--pending))
+ ((eq (car-safe f) 'macro) (cdr f))
+ (t (symbol-function symbol)))
+ function)
+ (unless (advice--p (advice--symbol-function symbol))
+ (remove-function (get symbol 'defalias-fset-function)
+ #'advice--defalias-fset)
+ (let ((asr (get symbol 'advice--saved-rewrite)))
+ (and asr (eq (cdr-safe (symbol-function symbol))
+ (cdr asr))
+ (fset symbol (car (get symbol 'advice--saved-rewrite)))))))
+ nil)
+
+(defun advice-mapc (fun symbol)
+ "Apply FUN to every advice function in SYMBOL.
+FUN is called with a two arguments: the function that was added, and the
+properties alist that was specified when it was added."
+ (advice-function-mapc fun (advice--symbol-function symbol)))
;;;###autoload
-(defun advice-member-p (advice function-name)
- "Return non-nil if ADVICE has been added to FUNCTION-NAME.
+(defun advice-member-p (advice symbol)
+ "Return non-nil if ADVICE has been added to SYMBOL.
Instead of ADVICE being the actual function, it can also be the `name'
of the piece of advice."
- (advice--member-p advice
- (or (get function-name 'advice--pending)
- (advice--strip-macro
- (if (fboundp function-name)
- (symbol-function function-name))))))
+ (advice-function-member-p advice (advice--symbol-function symbol)))
;; When code is advised, called-interactively-p needs to be taught to skip
;; the advising frames.
(get-next-frame
(lambda ()
(setq frame1 frame2)
- (setq frame2 (internal--called-interactively-p--get-frame i))
+ (setq frame2 (backtrace-frame i #'called-interactively-p))
;; (message "Advice Frame %d = %S" i frame2)
(setq i (1+ i)))))
(when (and (eq (nth 1 frame2) 'apply)
HCoop / bpt / emacs.git / blobdiff