[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.

/* Fundamental definitions for XEmacs Lisp interpreter -- non-union objects.
   Copyright (C) 1985, 1986, 1987, 1992, 1993 Free Software Foundation, Inc.

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.  */

/* Synched up with: FSF 19.30.  Split out from lisp.h. */
/* This file has diverged greatly from FSF Emacs.  Syncing is no
   longer desirable or possible */

/*
 Format of a non-union-type Lisp Object

             3         2         1         0
       bit  10987654321098765432109876543210
            --------------------------------
            VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVTT

   Integers are treated specially, and look like this:

             3         2         1         0
       bit  10987654321098765432109876543210
            --------------------------------
            VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVT

 For integral Lisp types, i.e. integers and characters, the value
 bits are the Lisp object.  Some people call such Lisp_Objects "immediate".

 The object is obtained by masking off the type bits.
     Bit 1 is used as a value bit by splitting the Lisp integer type
 into two subtypes, Lisp_Type_Int_Even and Lisp_Type_Int_Odd.
 By this trickery we get 31 bits for integers instead of 30.

 For non-integral types, the value bits of a Lisp_Object contain
 a pointer to a structure containing the object.  The pointer is
 obtained by masking off the type and mark bits.

     All pointer-based types are coalesced under a single type called
 Lisp_Type_Record.  The type bits for this type are required by the
 implementation to be 00, just like the least significant bits of
 word-aligned struct pointers on 32-bit hardware.  This requires that
 all structs implementing Lisp_Objects have an alignment of at least 4
 bytes.  Because of this, Lisp_Object pointers don't have to be masked
 and are full-sized.

 There are no mark bits in the Lisp_Object itself (there used to be).

 Integers and characters don't need to be marked.  All other types are
 lrecord-based, which means they get marked by setting the mark bit in
 the struct lrecord_header.

 Here is a brief description of the following macros:

 XTYPE     The type bits of a Lisp_Object
 XPNTRVAL  The value bits of a Lisp_Object storing a pointer
 XCHARVAL  The value bits of a Lisp_Object storing a Emchar
 XREALINT  The value bits of a Lisp_Object storing an integer, signed
 XUINT     The value bits of a Lisp_Object storing an integer, unsigned
 INTP      Non-zero if this Lisp_Object is an integer
 Qzero     Lisp Integer 0
 EQ        Non-zero if two Lisp_Objects are identical, not merely equal. */


typedef EMACS_INT Lisp_Object;

#define Lisp_Type_Int_Bit (Lisp_Type_Int_Even & Lisp_Type_Int_Odd)
#define wrap_pointer_1(ptr) ((Lisp_Object) (ptr))
#define make_int(x) ((Lisp_Object) (((x) << INT_GCBITS) | Lisp_Type_Int_Bit))
#define make_char(x) ((Lisp_Object) (((x) << GCBITS) | Lisp_Type_Char))
#define VALMASK (((1UL << VALBITS) - 1UL) << GCTYPEBITS)
#define XTYPE(x) ((enum Lisp_Type) (((EMACS_UINT)(x)) & ~VALMASK))
#define XPNTRVAL(x) (x) /* This depends on Lisp_Type_Record == 0 */
#define XCHARVAL(x) ((x) >> GCBITS)
#define XREALINT(x) ((x) >> INT_GCBITS)
#define XUINT(x) ((EMACS_UINT)(x) >> INT_GCBITS)
#define INTP(x) ((EMACS_UINT)(x) & Lisp_Type_Int_Bit)
#define INT_PLUS(x,y)  ((x)+(y)-Lisp_Type_Int_Bit)
#define INT_MINUS(x,y) ((x)-(y)+Lisp_Type_Int_Bit)
#define INT_PLUS1(x)   INT_PLUS  (x, make_int (1))
#define INT_MINUS1(x)  INT_MINUS (x, make_int (1))

#define Qzero make_int (0)
#define Qnull_pointer ((Lisp_Object) 0)
#define EQ(x,y) ((x) == (y))
#define XSETINT(var, value) ((void) ((var) = make_int (value)))
#define XSETCHAR(var, value) ((void) ((var) = make_char (value)))
#define XSETOBJ(var, value) ((void) ((var) = wrap_pointer_1 (value)))

/* Convert between a (void *) and a Lisp_Object, as when the
   Lisp_Object is passed to a toolkit callback function */
#define VOID_TO_LISP(larg,varg) ((void) ((larg) = ((Lisp_Object) (varg))))
#define CVOID_TO_LISP VOID_TO_LISP
#define LISP_TO_VOID(larg) ((void *) (larg))
#define LISP_TO_CVOID(larg) ((const void *) (larg))

/* Convert a Lisp_Object into something that can't be used as an
   lvalue.  Useful for type-checking. */
#define NON_LVALUE(larg) ((larg) + 0)