[xemacs-hg @ 2001-06-18 07:09:50 by ben] --------------------------------------------------------------- DOCUMENTATION FIXES: --------------------------------------------------------------- eval.c: Correct documentation. elhash.c: Doc correction. --------------------------------------------------------------- LISP OBJECT CLEANUP: --------------------------------------------------------------- bytecode.h, buffer.h, casetab.h, chartab.h, console-msw.h, console.h, database.c, device.h, eldap.h, elhash.h, events.h, extents.h, faces.h, file-coding.h, frame.h, glyphs.h, gui-x.h, gui.h, keymap.h, lisp-disunion.h, lisp-union.h, lisp.h, lrecord.h, lstream.h, mule-charset.h, objects.h, opaque.h, postgresql.h, process.h, rangetab.h, specifier.h, toolbar.h, tooltalk.h, ui-gtk.h: Add wrap_* to all objects (it was already there for a few of them) -- an expression to encapsulate a pointer into a Lisp object, rather than the inconvenient XSET*. "wrap" was chosen because "make" as in make_int(), make_char() is not appropriate. (It implies allocation. The issue does not exist for ints and chars because they are not allocated.) Full error checking has been added to these expressions. When used without error checking, non-union build, use of these expressions will incur no loss of efficiency. (In fact, XSET* is now defined in terms of wrap_* in a non-union build.) In a union build, you will also get no loss of efficiency provided that you have a decent optimizing compiler, and a compiler that either understands inlines or automatically inlines those particular functions. (And since people don't normally do their production builds on union, it doesn't matter.) Update the sample Lisp object definition in lrecord.h accordingly. dumper.c: Fix places in dumper that referenced wrap_object to reference its new name, wrap_pointer_1. buffer.c, bufslots.h, conslots.h, console.c, console.h, devslots.h, device.c, device.h, frame.c, frame.h, frameslots.h, window.c, window.h, winslots.h: -- Extract out the Lisp objects of `struct device' into devslots.h, just like for the other structures. -- Extract out the remaining (not copied into the window config) Lisp objects in `struct window' into winslots.h; use different macros (WINDOW_SLOT vs. WINDOW_SAVED_SLOT) to differentiate them. -- Eliminate the `dead' flag of `struct frame', since it duplicates information already available in `framemeths', and fix FRAME_LIVE_P accordingly. (Devices and consoles already work this way.) -- In *slots.h, switch to system where MARKED_SLOT is automatically undef'd at the end of the file. (Follows what winslots.h already does.) -- Update the comments at the beginning of *slots.h to be accurate. -- When making any of the above objects dead, zero it out entirely and reset all Lisp object slots to Qnil. (We were already doing this somewhat, but not consistently.) This (1) Eliminates the possibility of extra objects hanging around that ought to be GC'd, (2) Causes an immediate crash if anyone tries to access a structure in one of these objects, (3) Ensures consistent behavior wrt dead objects. dialog-msw.c: Use internal_object_printer, since this object should not escape. --------------------------------------------------------------- FIXING A CRASH THAT I HIT ONCE (AND A RELATED BAD BEHAVIOR): --------------------------------------------------------------- eval.c: Fix up some comments about the FSF implementation. Fix two nasty bugs: (1) condition_case_unwind frees the conses sitting in the catch->tag slot too quickly, resulting in a crash that I hit. (2) catches need to be unwound one at a time when calling unwind-protect code, rather than all at once at the end; otherwise, incorrect behavior can result. (A comment shows exactly how.) backtrace.h: Improve comment about FSF differences in the handler stack. --------------------------------------------------------------- FIXING A CRASH THAT I REPEATEDLY HIT WHEN USING THE MOUSE WHEEL UNDER MSWINDOWS: --------------------------------------------------------------- Basic idea: My crash is due either to a dead, non-marked, GC-collected frame inside of a window mirror, or a prematurely freed window mirror. We need to mark the Lisp objects inside of window mirrors. Tracking the lifespan of window mirrors and scrollbar instances is extremely hard, and there may well be lurking bugs where such objects are freed too soon. The only safe way to fix these problems (and it fixes both problems at once) is to make both of these structures Lisp objects. lrecord.h, emacs.c, inline.c, scrollbar-gtk.c, scrollbar-msw.c, scrollbar-x.c, scrollbar.c, scrollbar.h, symsinit.h: Make scrollbar instances actual Lisp objects. Mark the window mirrors in them. inline.c needs to know about scrollbar.h now. Record the new type in lrecord.h. Fix up scrollbar-*.c appropriately. Create a hash table in scrollbar-msw.c so that the scrollbar instances stored in scrollbar HWND's are properly GC-protected. Create complex_vars_of_scrollbar_mswindows() to create the hash table at startup, and call it from emacs.c. Don't store the scrollbar instance as a property of the GTK scrollbar, as it's not used and if we did this, we'd have to separately GC-protect it in a hash table, like in MS Windows. lrecord.h, frame.h, frame.c, frameslots.h, redisplay.c, window.c, window.h: Move mark_window_mirror from redisplay.c to window.c. Make window mirrors actual Lisp objects. Tell lrecord.h about them. Change the window mirror member of struct frame from a pointer to a Lisp object, and add XWINDOW_MIRROR in appropriate places. Mark the scrollbar instances in the window mirror. redisplay.c, redisplay.h, alloc.c: Delete mark_redisplay. Don't call mark_redisplay. We now mark frame-specific structures in mark_frame. NOTE: I also deleted an extremely questionable call to update_frame_window_mirrors(). It was extremely questionable before, and now totally impossible, since it will create Lisp objects during redisplay. frame.c: Mark the scrollbar instances, which are now Lisp objects. Call mark_gutter() here, not in mark_redisplay(). gutter.c: Update comments about correct marking. --------------------------------------------------------------- ISSUES BROUGHT UP BY MARTIN: --------------------------------------------------------------- buffer.h: Put back these macros the way Steve T and I think they ought to be. I already explained in a previous changelog entry why I think these macros should be the way I'd defined them. Once again: We fix these macros so they don't care about the type of their lvalues. The non-C-string equivalents of these already function in the same way, and it's correct because it should be OK to pass in a CBufbyte *, a BufByte *, a Char_Binary *, an UChar_Binary *, etc. The whole reason for these different types is to work around errors caused by signed-vs-unsigned non-matching types. Any possible error that might be caught in a DFC macro would also be caught wherever the argument is used elsewhere. So creating multiple macro versions would add no useful error-checking and just further complicate an already complicated area. As for Martin's "ANSI aliasing" bug, XEmacs is not ANSI-aliasing clean and probably never will be. Unless the board agrees to change XEmacs in this way (and we really don't want to go down that road), this is not a bug. sound.h: Undo Martin's type change. signal.c: Fix problem identified by Martin with Linux and g++ due to non-standard declaration of setitimer(). systime.h: Update the docs for "qxe_" to point out why making the encapsulation explicit is always the right way to go. (setitimer() itself serves as an example.) For 21.4: update-elc-2.el: Correct misplaced parentheses, making lisp/mule not get recompiled.

;;; help-macro.el --- Makes command line help such as help-for-help

;; Copyright (C) 1993, 1994, 1997 Free Software Foundation, Inc.

;; Author: Lynn Slater <lrs@indetech.com>
;; Maintainer: FSF
;; Created: : Mon Oct  1 11:42:39 1990
;; Adapted-By: ESR

;; This file is part of XEmacs.

;; XEmacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; XEmacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with XEmacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;;; Synched up with: FSF 20.2.

;; This file supplies the macro make-help-screen which constructs
;; single character dispatching with browsable help such as that provided
;; by help-for-help. This can be used to make many modes easier to use; for
;; example, the Gnu Emacs Empire Tool uses this for every "nested" mode map
;; called from the main mode map.

;;       The name of this package was changed from help-screen.el to
;; help-macro.el in order to fit in a 14-character limit.

;;-> ***********************  Example of use *********************************

;;->(make-help-screen help-for-empire-redistribute-map
;;->		  "c:civ m:mil p:population f:food ?"
;;->		  "You have discovered the GEET redistribution commands
;;->   From here, you can use the following options:
;;->
;;->c	Redistribute civs from overfull sectors into connected underfull ones
;;->	  The functions typically named by empire-ideal-civ-fcn control
;;->          based in part on empire-sector-civ-threshold  
;;->m	Redistribute military using levels given by empire-ideal-mil-fcn
;;->p	Redistribute excess population to highways for max pop growth
;;->	  Excess is any sector so full babies will not be born.
;;->f	Even out food on highways to highway min and leave levels
;;->	  This is good to pump max food to all warehouses/dist pts
;;->
;;->
;;->Use \\[help-for-empire-redistribute-map] for help on redistribution.
;;->Use \\[help-for-empire-extract-map] for help on data extraction.
;;->Please use \\[describe-key] to find out more about any of the other keys."
;;->		  empire-shell-redistribute-map)

;;->  (define-key c-mp "\C-h" 'help-for-empire-redistribute-map)
;;->  (define-key c-mp help-character 'help-for-empire-redistribute-map)

;;; Code:

(provide 'help-macro)

;;;###autoload
(defcustom three-step-help t
  "*Non-nil means give more info about Help command in three steps.
The three steps are simple prompt, prompt with all options,
and window listing and describing the options.
A value of nil means skip the middle step, so that
\\[help-command] \\[help-command] gives the window that lists the options."
  :type 'boolean
  :group 'help-appearance)

(defmacro make-help-screen (fname help-line help-text helped-map)
  "Construct help-menu function name FNAME.
When invoked, FNAME shows HELP-LINE and reads a command using
HELPED-MAP.  If the command is the help character, FNAME displays
HELP-TEXT and continues trying to read a command using HELPED-MAP.
When FNAME finally does get a command, it executes that command and
then returns.  As of 21.5 (or 21.4?), HELP-LINE and HELP-TEXT are
`eval'd, just like for a function call.  This allows you to place
Lisp expressions in those arguments."
  `(defun ,fname ()
     ,(eval help-text)
     (interactive)
     (flet ((help-read-key (prompt)
	      ;; This is in `flet' to avoid problems with autoloading.
	      ;; #### The function is ill-conceived -- there should be
	      ;; a way to do it without all the hassle!
	      (let (events)
		(while (not (key-press-event-p
			     (aref (setq events (read-key-sequence prompt)) 0)))
		  ;; Mouse clicks are not part of the help feature, so
		  ;; reexecute them in the standard environment.
		  (mapc 'dispatch-event events))
		(let ((key (nconc (event-modifiers (aref events 0))
				  (list (event-key (aref events 0))))))
		  ;; Make the HELP key translate to C-h.
		  (when (lookup-key function-key-map key)
		    (setq key (lookup-key function-key-map key)))
		  (if (eq (length key) 1)
		      (car key)
		    key)))))
       (let ((line-prompt
	      (substitute-command-keys ,(eval help-line))))
	 (when three-step-help
	   (message "%s" line-prompt))
	 (let* ((help-screen (documentation (quote ,fname)))
		;; We bind overriding-local-map for very small
		;; sections, *excluding* where we switch buffers and
		;; where we execute the chosen help command.
		(local-map (make-sparse-keymap))
		(minor-mode-map-alist nil)
		(prev-frame (selected-frame))
		config new-frame key)
	   (unwind-protect
	       (progn
		 (set-keymap-parents local-map (list ,helped-map))
		 (cond (three-step-help
			(let* ((overriding-local-map local-map))
			  (setq key (help-read-key nil))))
		       (t
			(setq key ??)))
		 (when (or (equal key ??)
			   (equal key (list help-char)))
		   (setq config (current-window-configuration))
		   (switch-to-buffer-other-window "*Help*")
		   (and (not (eq (window-frame (selected-window))
				 prev-frame))
			(setq new-frame (window-frame (selected-window))
			      config nil))
		   (setq buffer-read-only nil)
		   (erase-buffer)
		   (insert help-screen)
		   (help-mode)
		   (goto-char (point-min))
		   (while (member key `((,help-char) ?? (control v) space ?\177
					delete backspace (meta v)))
		     (ignore-errors
		       (cond ((member key '((control v) space))
			      (scroll-up))
			     ((member key '(?\177 delete (meta v) backspace))
			      (scroll-down))))
		     (let ((cursor-in-echo-area t)
			   (overriding-local-map local-map))
		       (setq key (help-read-key
				  (format "Type one of the options listed%s: "
					  (if (pos-visible-in-window-p
					       (point-max))
					      "" " or Space to scroll")))))))
		 ;; We don't need the prompt any more.
		 (message nil)
		 (let ((defn (lookup-key local-map key)))
		   (cond (defn
			   (when config
			     (set-window-configuration config)
			     (setq config nil))
			   (when new-frame
			     (iconify-frame new-frame)
			     (setq new-frame nil))
			   (call-interactively defn))
			 (t
			  (ding)))))
	     (and (get-buffer "*Help*")
		  (bury-buffer "*Help*"))
	     (and new-frame (iconify-frame new-frame))
	     (and config
		  (set-window-configuration config))))))))

;;; help-macro.el