1 /* The "lrecord" structure (header of a compound lisp object).
2 Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc.
3 Copyright (C) 1996 Ben Wing.
5 This file is part of XEmacs.
7 XEmacs is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
12 XEmacs is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with XEmacs; see the file COPYING. If not, write to
19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 /* Synched up with: Not in FSF. */
24 #ifndef INCLUDED_lrecord_h_
25 #define INCLUDED_lrecord_h_
27 /* The "lrecord" type of Lisp object is used for all object types
28 other than a few simple ones. This allows many types to be
29 implemented but only a few bits required in a Lisp object for type
30 information. (The tradeoff is that each object has its type marked
31 in it, thereby increasing its size.) All lrecords begin with a
32 `struct lrecord_header', which identifies the lisp object type, by
33 providing an index into a table of `struct lrecord_implementation',
34 which describes the behavior of the lisp object. It also contains
37 Lrecords are of two types: straight lrecords, and lcrecords.
38 Straight lrecords are used for those types of objects that have
39 their own allocation routines (typically allocated out of 2K chunks
40 of memory called `frob blocks'). These objects have a `struct
41 lrecord_header' at the top, containing only the bits needed to find
42 the lrecord_implementation for the object. There are special
43 routines in alloc.c to deal with each such object type.
45 Lcrecords are used for less common sorts of objects that don't do
46 their own allocation. Each such object is malloc()ed individually,
47 and the objects are chained together through a `next' pointer.
48 Lcrecords have a `struct lcrecord_header' at the top, which
49 contains a `struct lrecord_header' and a `next' pointer, and are
50 allocated using alloc_lcrecord().
52 Creating a new lcrecord type is fairly easy; just follow the
53 lead of some existing type (e.g. hash tables). Note that you
54 do not need to supply all the methods (see below); reasonable
55 defaults are provided for many of them. Alternatively, if you're
56 just looking for a way of encapsulating data (which possibly
57 could contain Lisp_Objects in it), you may well be able to use
62 /* index into lrecord_implementations_table[] */
65 /* If `mark' is 0 after the GC mark phase, the object will be freed
66 during the GC sweep phase. There are 2 ways that `mark' can be 1:
67 - by being referenced from other objects during the GC mark phase
68 - because it is permanently on, for c_readonly objects */
71 /* 1 if the object resides in logically read-only space, and does not
72 reference other non-c_readonly objects.
73 Invariant: if (c_readonly == 1), then (mark == 1 && lisp_readonly == 1) */
74 unsigned int c_readonly :1;
76 /* 1 if the object is readonly from lisp */
77 unsigned int lisp_readonly :1;
80 struct lrecord_implementation;
81 int lrecord_type_index (const struct lrecord_implementation *implementation);
83 #define set_lheader_implementation(header,imp) do { \
84 struct lrecord_header* SLI_header = (header); \
85 SLI_header->type = (imp)->lrecord_type_index; \
86 SLI_header->mark = 0; \
87 SLI_header->c_readonly = 0; \
88 SLI_header->lisp_readonly = 0; \
91 struct lcrecord_header
93 struct lrecord_header lheader;
95 /* The `next' field is normally used to chain all lcrecords together
96 so that the GC can find (and free) all of them.
97 `alloc_lcrecord' threads lcrecords together.
99 The `next' field may be used for other purposes as long as some
100 other mechanism is provided for letting the GC do its work.
102 For example, the event and marker object types allocate members
103 out of memory chunks, and are able to find all unmarked members
104 by sweeping through the elements of the list of chunks. */
105 struct lcrecord_header *next;
107 /* The `uid' field is just for debugging/printing convenience.
108 Having this slot doesn't hurt us much spacewise, since an
109 lcrecord already has the above slots plus malloc overhead. */
110 unsigned int uid :31;
112 /* The `free' field is a flag that indicates whether this lcrecord
113 is on a "free list". Free lists are used to minimize the number
114 of calls to malloc() when we're repeatedly allocating and freeing
115 a number of the same sort of lcrecord. Lcrecords on a free list
116 always get marked in a different fashion, so we can use this flag
117 as a sanity check to make sure that free lists only have freed
118 lcrecords and there are no freed lcrecords elsewhere. */
119 unsigned int free :1;
122 /* Used for lcrecords in an lcrecord-list. */
123 struct free_lcrecord_header
125 struct lcrecord_header lcheader;
131 /* Symbol value magic types come first to make SYMBOL_VALUE_MAGIC_P fast.
132 #### This should be replaced by a symbol_value_magic_p flag
133 in the Lisp_Symbol lrecord_header. */
134 lrecord_type_symbol_value_forward,
135 lrecord_type_symbol_value_varalias,
136 lrecord_type_symbol_value_lisp_magic,
137 lrecord_type_symbol_value_buffer_local,
138 lrecord_type_max_symbol_value_magic = lrecord_type_symbol_value_buffer_local,
145 lrecord_type_lcrecord_list,
146 lrecord_type_compiled_function,
147 lrecord_type_weak_list,
148 lrecord_type_bit_vector,
150 lrecord_type_hash_table,
151 lrecord_type_lstream,
152 lrecord_type_process,
153 lrecord_type_charset,
154 lrecord_type_coding_system,
155 lrecord_type_char_table,
156 lrecord_type_char_table_entry,
157 lrecord_type_char_code_table,
158 lrecord_type_byte_table,
159 lrecord_type_range_table,
161 lrecord_type_opaque_ptr,
164 lrecord_type_extent_info,
165 lrecord_type_extent_auxiliary,
169 lrecord_type_command_builder,
170 lrecord_type_timeout,
171 lrecord_type_specifier,
172 lrecord_type_console,
176 lrecord_type_window_configuration,
177 lrecord_type_gui_item,
178 lrecord_type_popup_data,
179 lrecord_type_toolbar_button,
180 lrecord_type_color_instance,
181 lrecord_type_font_instance,
182 lrecord_type_image_instance,
185 lrecord_type_database,
186 lrecord_type_tooltalk_message,
187 lrecord_type_tooltalk_pattern,
190 lrecord_type_pgresult,
191 lrecord_type_count /* must be last */
194 struct lrecord_implementation
198 /* `marker' is called at GC time, to make sure that all Lisp_Objects
199 pointed to by this object get properly marked. It should call
200 the mark_object function on all Lisp_Objects in the object. If
201 the return value is non-nil, it should be a Lisp_Object to be
202 marked (don't call the mark_object function explicitly on it,
203 because the GC routines will do this). Doing it this way reduces
204 recursion, so the object returned should preferably be the one
205 with the deepest level of Lisp_Object pointers. This function
206 can be NULL, meaning no GC marking is necessary. */
207 Lisp_Object (*marker) (Lisp_Object);
209 /* `printer' converts the object to a printed representation.
210 This can be NULL; in this case default_object_printer() will be
212 void (*printer) (Lisp_Object, Lisp_Object printcharfun, int escapeflag);
214 /* `finalizer' is called at GC time when the object is about to
215 be freed, and at dump time (FOR_DISKSAVE will be non-zero in this
216 case). It should perform any necessary cleanup (e.g. freeing
217 malloc()ed memory). This can be NULL, meaning no special
218 finalization is necessary.
220 WARNING: remember that `finalizer' is called at dump time even
221 though the object is not being freed. */
222 void (*finalizer) (void *header, int for_disksave);
224 /* This can be NULL, meaning compare objects with EQ(). */
225 int (*equal) (Lisp_Object obj1, Lisp_Object obj2, int depth);
227 /* `hash' generates hash values for use with hash tables that have
228 `equal' as their test function. This can be NULL, meaning use
229 the Lisp_Object itself as the hash. But, you must still satisfy
230 the constraint that if two objects are `equal', then they *must*
231 hash to the same value in order for hash tables to work properly.
232 This means that `hash' can be NULL only if the `equal' method is
234 unsigned long (*hash) (Lisp_Object, int);
236 /* External data layout description */
237 const struct lrecord_description *description;
239 /* These functions allow any object type to have builtin property
240 lists that can be manipulated from the lisp level with
241 `get', `put', `remprop', and `object-plist'. */
242 Lisp_Object (*getprop) (Lisp_Object obj, Lisp_Object prop);
243 int (*putprop) (Lisp_Object obj, Lisp_Object prop, Lisp_Object val);
244 int (*remprop) (Lisp_Object obj, Lisp_Object prop);
245 Lisp_Object (*plist) (Lisp_Object obj);
247 /* Only one of `static_size' and `size_in_bytes_method' is non-0.
248 If both are 0, this type is not instantiable by alloc_lcrecord(). */
250 size_t (*size_in_bytes_method) (const void *header);
252 /* The (constant) index into lrecord_implementations_table */
253 enum lrecord_type lrecord_type_index;
255 /* A "basic" lrecord is any lrecord that's not an lcrecord, i.e.
256 one that does not have an lcrecord_header at the front and which
257 is (usually) allocated in frob blocks. We only use this flag for
258 some consistency checking, and that only when error-checking is
260 unsigned int basic_p :1;
263 extern const struct lrecord_implementation *lrecord_implementations_table[];
265 #define XRECORD_LHEADER_IMPLEMENTATION(obj) \
266 LHEADER_IMPLEMENTATION (XRECORD_LHEADER (obj))
267 #define LHEADER_IMPLEMENTATION(lh) lrecord_implementations_table[(lh)->type]
269 extern int gc_in_progress;
271 #define MARKED_RECORD_P(obj) (XRECORD_LHEADER (obj)->mark)
272 #define MARKED_RECORD_HEADER_P(lheader) ((lheader)->mark)
273 #define MARK_RECORD_HEADER(lheader) ((void) ((lheader)->mark = 1))
274 #define UNMARK_RECORD_HEADER(lheader) ((void) ((lheader)->mark = 0))
276 #define C_READONLY_RECORD_HEADER_P(lheader) ((lheader)->c_readonly)
277 #define LISP_READONLY_RECORD_HEADER_P(lheader) ((lheader)->lisp_readonly)
278 #define SET_C_READONLY_RECORD_HEADER(lheader) do { \
279 struct lrecord_header *SCRRH_lheader = (lheader); \
280 SCRRH_lheader->c_readonly = 1; \
281 SCRRH_lheader->lisp_readonly = 1; \
282 SCRRH_lheader->mark = 1; \
284 #define SET_LISP_READONLY_RECORD_HEADER(lheader) \
285 ((void) ((lheader)->lisp_readonly = 1))
286 #define RECORD_MARKER(lheader) lrecord_markers[(lheader)->type]
288 /* External description stuff
290 A lrecord external description is an array of values. The first
291 value of each line is a type, the second the offset in the lrecord
292 structure. Following values are parameters, their presence, type
293 and number is type-dependant.
295 The description ends with a "XD_END" or "XD_SPECIFIER_END" record.
297 Some example descriptions :
299 static const struct lrecord_description cons_description[] = {
300 { XD_LISP_OBJECT, offsetof (Lisp_Cons, car) },
301 { XD_LISP_OBJECT, offsetof (Lisp_Cons, cdr) },
305 Which means "two lisp objects starting at the 'car' and 'cdr' elements"
307 static const struct lrecord_description string_description[] = {
308 { XD_BYTECOUNT, offsetof (Lisp_String, size) },
309 { XD_OPAQUE_DATA_PTR, offsetof (Lisp_String, data), XD_INDIRECT(0, 1) },
310 { XD_LISP_OBJECT, offsetof (Lisp_String, plist) },
313 "A pointer to string data at 'data', the size of the pointed array being the value
314 of the size variable plus 1, and one lisp object at 'plist'"
318 A Lisp object. This is also the type to use for pointers to other lrecords.
321 An array of Lisp objects or pointers to lrecords.
322 The third element is the count.
325 Lisp objects which will be reset to Qnil when dumping. Useful for cleaning
329 Link in a linked list of objects of the same type.
332 Pointer to undumpable data. Must be NULL when dumping.
335 Pointer to described struct. Parameters are number of structures and
339 Pointer to dumpable opaque data. Parameter is the size of the data.
340 Pointed data must be relocatable without changes.
343 Pointer to a C string.
346 Pointer to a doc string (C string if positive, opaque value if negative)
349 An integer which will be reset to a given value in the dump file.
353 size_t value. Used for counts.
356 int value. Used for counts.
359 long value. Used for counts.
362 bytecount value. Used for counts.
365 Special type indicating the end of the array.
368 Special type indicating the end of the array for a specifier. Extra
369 description is going to be fetched from the specifier methods.
373 XD_INDIRECT(line, delta)
374 Usable where a "count" or "size" is requested. Gives the value of
375 the element which is at line number 'line' in the description (count
376 starts at zero) and adds delta to it.
379 enum lrecord_description_type {
380 XD_LISP_OBJECT_ARRAY,
398 struct lrecord_description {
399 enum lrecord_description_type type;
402 const struct struct_description *data2;
405 struct struct_description {
407 const struct lrecord_description *description;
410 #define XD_INDIRECT(val, delta) (-1-((val)|(delta<<8)))
412 #define XD_IS_INDIRECT(code) (code<0)
413 #define XD_INDIRECT_VAL(code) ((-1-code) & 255)
414 #define XD_INDIRECT_DELTA(code) (((-1-code)>>8) & 255)
416 #define XD_DYNARR_DESC(base_type, sub_desc) \
417 { XD_STRUCT_PTR, offsetof (base_type, base), XD_INDIRECT(1, 0), sub_desc }, \
418 { XD_INT, offsetof (base_type, cur) }, \
419 { XD_INT_RESET, offsetof (base_type, max), XD_INDIRECT(1, 0) }
421 /* DEFINE_LRECORD_IMPLEMENTATION is for objects with constant size.
422 DEFINE_LRECORD_SEQUENCE_IMPLEMENTATION is for objects whose size varies.
425 #if defined (ERROR_CHECK_TYPECHECK)
426 # define DECLARE_ERROR_CHECK_TYPECHECK(c_name, structtype)
428 # define DECLARE_ERROR_CHECK_TYPECHECK(c_name, structtype)
431 #define DEFINE_BASIC_LRECORD_IMPLEMENTATION(name,c_name,marker,printer,nuker,equal,hash,desc,structtype) \
432 DEFINE_BASIC_LRECORD_IMPLEMENTATION_WITH_PROPS(name,c_name,marker,printer,nuker,equal,hash,desc,0,0,0,0,structtype)
434 #define DEFINE_BASIC_LRECORD_IMPLEMENTATION_WITH_PROPS(name,c_name,marker,printer,nuker,equal,hash,desc,getprop,putprop,remprop,plist,structtype) \
435 MAKE_LRECORD_IMPLEMENTATION(name,c_name,marker,printer,nuker,equal,hash,desc,getprop,putprop,remprop,plist,sizeof(structtype),0,1,structtype)
437 #define DEFINE_LRECORD_IMPLEMENTATION(name,c_name,marker,printer,nuker,equal,hash,desc,structtype) \
438 DEFINE_LRECORD_IMPLEMENTATION_WITH_PROPS(name,c_name,marker,printer,nuker,equal,hash,desc,0,0,0,0,structtype)
440 #define DEFINE_LRECORD_IMPLEMENTATION_WITH_PROPS(name,c_name,marker,printer,nuker,equal,hash,desc,getprop,putprop,remprop,plist,structtype) \
441 MAKE_LRECORD_IMPLEMENTATION(name,c_name,marker,printer,nuker,equal,hash,desc,getprop,putprop,remprop,plist,sizeof (structtype),0,0,structtype)
443 #define DEFINE_LRECORD_SEQUENCE_IMPLEMENTATION(name,c_name,marker,printer,nuker,equal,hash,desc,sizer,structtype) \
444 DEFINE_LRECORD_SEQUENCE_IMPLEMENTATION_WITH_PROPS(name,c_name,marker,printer,nuker,equal,hash,desc,0,0,0,0,sizer,structtype)
446 #define DEFINE_BASIC_LRECORD_SEQUENCE_IMPLEMENTATION(name,c_name,marker,printer,nuker,equal,hash,desc,sizer,structtype) \
447 MAKE_LRECORD_IMPLEMENTATION(name,c_name,marker,printer,nuker,equal,hash,desc,0,0,0,0,0,sizer,1,structtype)
449 #define DEFINE_LRECORD_SEQUENCE_IMPLEMENTATION_WITH_PROPS(name,c_name,marker,printer,nuker,equal,hash,desc,getprop,putprop,remprop,plist,sizer,structtype) \
450 MAKE_LRECORD_IMPLEMENTATION(name,c_name,marker,printer,nuker,equal,hash,desc,getprop,putprop,remprop,plist,0,sizer,0,structtype) \
452 #define MAKE_LRECORD_IMPLEMENTATION(name,c_name,marker,printer,nuker,equal,hash,desc,getprop,putprop,remprop,plist,size,sizer,basic_p,structtype) \
453 DECLARE_ERROR_CHECK_TYPECHECK(c_name, structtype) \
454 const struct lrecord_implementation lrecord_##c_name = \
455 { name, marker, printer, nuker, equal, hash, desc, \
456 getprop, putprop, remprop, plist, size, sizer, \
457 lrecord_type_##c_name, basic_p }
459 extern Lisp_Object (*lrecord_markers[]) (Lisp_Object);
461 #define INIT_LRECORD_IMPLEMENTATION(type) do { \
462 lrecord_implementations_table[lrecord_type_##type] = &lrecord_##type; \
463 lrecord_markers[lrecord_type_##type] = \
464 lrecord_implementations_table[lrecord_type_##type]->marker; \
467 #define LRECORDP(a) (XTYPE (a) == Lisp_Type_Record)
468 #define XRECORD_LHEADER(a) ((struct lrecord_header *) XPNTR (a))
470 #define RECORD_TYPEP(x, ty) \
471 (LRECORDP (x) && XRECORD_LHEADER (x)->type == (ty))
473 /* NOTE: the DECLARE_LRECORD() must come before the associated
474 DEFINE_LRECORD_*() or you will get compile errors.
476 Furthermore, you always need to put the DECLARE_LRECORD() in a header
477 file, and make sure the header file is included in inline.c, even
478 if the type is private to a particular file. Otherwise, you will
479 get undefined references for the error_check_foo() inline function
482 #ifdef ERROR_CHECK_TYPECHECK
484 # define DECLARE_LRECORD(c_name, structtype) \
485 extern const struct lrecord_implementation lrecord_##c_name; \
486 INLINE_HEADER structtype * \
487 error_check_##c_name (Lisp_Object obj); \
488 INLINE_HEADER structtype * \
489 error_check_##c_name (Lisp_Object obj) \
491 assert (RECORD_TYPEP (obj, lrecord_type_##c_name)); \
492 return (structtype *) XPNTR (obj); \
494 extern Lisp_Object Q##c_name##p
496 # define DECLARE_NONRECORD(c_name, type_enum, structtype) \
497 INLINE_HEADER structtype * \
498 error_check_##c_name (Lisp_Object obj); \
499 INLINE_HEADER structtype * \
500 error_check_##c_name (Lisp_Object obj) \
502 assert (XTYPE (obj) == type_enum); \
503 return (structtype *) XPNTR (obj); \
505 extern Lisp_Object Q##c_name##p
507 # define XRECORD(x, c_name, structtype) error_check_##c_name (x)
508 # define XNONRECORD(x, c_name, type_enum, structtype) error_check_##c_name (x)
510 # define XSETRECORD(var, p, c_name) do \
512 XSETOBJ (var, Lisp_Type_Record, p); \
513 assert (RECORD_TYPEP (var, lrecord_type_##c_name)); \
516 #else /* not ERROR_CHECK_TYPECHECK */
518 # define DECLARE_LRECORD(c_name, structtype) \
519 extern Lisp_Object Q##c_name##p; \
520 extern const struct lrecord_implementation lrecord_##c_name
521 # define DECLARE_NONRECORD(c_name, type_enum, structtype) \
522 extern Lisp_Object Q##c_name##p
523 # define XRECORD(x, c_name, structtype) ((structtype *) XPNTR (x))
524 # define XNONRECORD(x, c_name, type_enum, structtype) \
525 ((structtype *) XPNTR (x))
526 # define XSETRECORD(var, p, c_name) XSETOBJ (var, Lisp_Type_Record, p)
528 #endif /* not ERROR_CHECK_TYPECHECK */
530 #define RECORDP(x, c_name) RECORD_TYPEP (x, lrecord_type_##c_name)
532 /* Note: we now have two different kinds of type-checking macros.
533 The "old" kind has now been renamed CONCHECK_foo. The reason for
534 this is that the CONCHECK_foo macros signal a continuable error,
535 allowing the user (through debug-on-error) to substitute a different
536 value and return from the signal, which causes the lvalue argument
537 to get changed. Quite a lot of code would crash if that happened,
538 because it did things like
543 and later on did XSTRING (XCAR (list)), assuming that the type
544 is correct (when it might be wrong, if the user substituted a
545 correct value in the debugger).
547 To get around this, I made all the CHECK_foo macros signal a
548 non-continuable error. Places where a continuable error is OK
549 (generally only when called directly on the argument of a Lisp
550 primitive) should be changed to use CONCHECK().
552 FSF Emacs does not have this problem because RMS took the cheesy
553 way out and disabled returning from a signal entirely. */
555 #define CONCHECK_RECORD(x, c_name) do { \
556 if (!RECORD_TYPEP (x, lrecord_type_##c_name)) \
557 x = wrong_type_argument (Q##c_name##p, x); \
559 #define CONCHECK_NONRECORD(x, lisp_enum, predicate) do {\
560 if (XTYPE (x) != lisp_enum) \
561 x = wrong_type_argument (predicate, x); \
563 #define CHECK_RECORD(x, c_name) do { \
564 if (!RECORD_TYPEP (x, lrecord_type_##c_name)) \
565 dead_wrong_type_argument (Q##c_name##p, x); \
567 #define CHECK_NONRECORD(x, lisp_enum, predicate) do { \
568 if (XTYPE (x) != lisp_enum) \
569 dead_wrong_type_argument (predicate, x); \
572 void *alloc_lcrecord (size_t size, const struct lrecord_implementation *);
574 #define alloc_lcrecord_type(type, lrecord_implementation) \
575 ((type *) alloc_lcrecord (sizeof (type), lrecord_implementation))
577 /* Copy the data from one lcrecord structure into another, but don't
578 overwrite the header information. */
580 #define copy_lcrecord(dst, src) \
581 memcpy ((char *) (dst) + sizeof (struct lcrecord_header), \
582 (char *) (src) + sizeof (struct lcrecord_header), \
583 sizeof (*(dst)) - sizeof (struct lcrecord_header))
585 #define zero_lcrecord(lcr) \
586 memset ((char *) (lcr) + sizeof (struct lcrecord_header), 0, \
587 sizeof (*(lcr)) - sizeof (struct lcrecord_header))
589 #endif /* INCLUDED_lrecord_h_ */