1 /* Definitions of symbol-value forwarding for XEmacs Lisp interpreter.
2 Copyright (C) 1985, 1986, 1987, 1992, 1993 Free Software Foundation, Inc.
3 Copyright (C) 2000 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 /* Fsymbol_value checks whether XSYMBOL (sym)->value is one of these,
25 * and does weird magic stuff if so */
27 #ifndef INCLUDED_symeval_h_
28 #define INCLUDED_symeval_h_
30 enum symbol_value_type
32 /* The following tags use the 'symbol_value_forward' structure
33 and are strictly for variables DEFVARed on the C level. */
34 SYMVAL_FIXNUM_FORWARD, /* Forward C "Fixnum", really "EMACS_INT" */
35 SYMVAL_CONST_FIXNUM_FORWARD, /* Same, but can't be set */
36 SYMVAL_BOOLEAN_FORWARD, /* Forward C boolean ("int") */
37 SYMVAL_CONST_BOOLEAN_FORWARD, /* Same, but can't be set */
38 SYMVAL_OBJECT_FORWARD, /* Forward C Lisp_Object */
39 SYMVAL_CONST_OBJECT_FORWARD, /* Same, but can't be set */
40 SYMVAL_CONST_SPECIFIER_FORWARD, /* Same, can't be set, but gives a
41 different message when attempting to
42 set that says "use set-specifier" */
43 SYMVAL_DEFAULT_BUFFER_FORWARD, /* Forward Lisp_Object into Vbuffer_defaults */
44 SYMVAL_CURRENT_BUFFER_FORWARD, /* Forward Lisp_Object into current_buffer */
45 SYMVAL_CONST_CURRENT_BUFFER_FORWARD, /* Forward Lisp_Object into
46 current_buffer, can't be set */
47 SYMVAL_DEFAULT_CONSOLE_FORWARD, /* Forward Lisp_Object into
49 SYMVAL_SELECTED_CONSOLE_FORWARD, /* Forward Lisp_Object into
51 SYMVAL_CONST_SELECTED_CONSOLE_FORWARD, /* Forward Lisp_Object into
54 SYMVAL_UNBOUND_MARKER, /* Only Qunbound actually has this tag */
56 /* The following tags use the 'symbol_value_buffer_local' structure */
57 SYMVAL_BUFFER_LOCAL, /* make-variable-buffer-local */
58 SYMVAL_SOME_BUFFER_LOCAL, /* make-local-variable */
60 /* The following tag uses the 'symbol_value_lisp_magic' structure */
61 SYMVAL_LISP_MAGIC, /* Forward to lisp callbacks */
63 /* The following tag uses the 'symbol_value_varalias' structure */
64 SYMVAL_VARALIAS /* defvaralias */
68 SYMVAL_CONSTANT_SYMBOL, /* Self-evaluating symbol */
73 /* Underlying C type used to implement DEFVAR_INT */
74 typedef EMACS_INT Fixnum;
76 struct symbol_value_magic
78 struct lcrecord_header lcheader;
80 enum symbol_value_type type;
82 #define SYMBOL_VALUE_MAGIC_P(x) \
84 XRECORD_LHEADER (x)->type <= lrecord_type_max_symbol_value_magic)
85 #define XSYMBOL_VALUE_MAGIC_TYPE(v) \
86 (((struct symbol_value_magic *) XPNTR (v))->type)
87 #define XSETSYMBOL_VALUE_MAGIC(s, p) XSETOBJ (s, p)
88 void print_symbol_value_magic (Lisp_Object, Lisp_Object, int);
90 /********** The various different symbol-value-magic types ***********/
92 /* 1. symbol-value-forward */
94 /* This type of symbol-value-magic is used for variables declared
95 DEFVAR_LISP, DEFVAR_INT, DEFVAR_BOOL, DEFVAR_BUFFER_LOCAL,
96 DEFVAR_BUFFER_DEFAULTS, DEFVAR_SPECIFIER, and for Qunbound.
98 Note that some of these types of variables can be made buffer-local.
99 Then, the symbol's value field contains a symbol-value-buffer-local,
100 whose CURRENT-VALUE field then contains a symbol-value-forward.
103 struct symbol_value_forward
105 struct symbol_value_magic magic;
107 /* `magicfun' is a function controlling the magic behavior of this
110 SYM is the symbol being operated on (read, set, etc.);
112 VAL is either the value to set or the value to be returned.
114 IN_OBJECT is the buffer or console that the value is read in
115 or set in. A value of Qnil means that the current buffer
116 and possibly other buffers are being set. (This value will
117 never be passed for built-in buffer-local or console-local
118 variables such as `truncate-lines'.) (Currently, a value of
119 Qnil is always passed for DEFVAR_INT, DEFVAR_LISP, and
120 DEFVAR_BOOL variables; the code isn't smart enough to figure
121 out what buffers besides the current buffer are being
122 affected. Because the magic function is called
123 before the value is changed, it's not that easy
124 to determine which buffers are getting changed.
125 #### If this information is important, let me know
126 and I will look into providing it.) (Remember also
127 that the only console-local variables currently existing
128 are built-in ones, because others can't be created.)
130 FLAGS gives more information about the operation being performed.
132 The return value indicates what the magic function actually did.
134 Currently FLAGS and the return value are not used. This
135 function is only called when the value of a forward variable
136 is about to be changed. Note that this can occur explicitly
137 through a call to `set', `setq', `set-default', or `setq-default',
138 or implicitly by the current buffer being changed. */
139 int (*magicfun) (Lisp_Object sym, Lisp_Object *val, Lisp_Object in_object,
142 DECLARE_LRECORD (symbol_value_forward, struct symbol_value_forward);
143 #define XSYMBOL_VALUE_FORWARD(x) \
144 XRECORD (x, symbol_value_forward, struct symbol_value_forward)
145 #define symbol_value_forward_forward(m) ((void *)((m)->magic.value))
146 #define symbol_value_forward_magicfun(m) ((m)->magicfun)
148 /* 2. symbol-value-buffer-local */
150 struct symbol_value_buffer_local
152 struct symbol_value_magic magic;
153 /* Used in a symbol value cell when the symbol's value is per-buffer.
155 The type of the symbol-value-magic will be either
156 SYMVAL_BUFFER_LOCAL (i.e. `make-variable-buffer-local' was called)
157 or SYMVAL_SOME_BUFFER_LOCAL (i.e. `make-local-variable' was called).
158 The only difference between the two is that when setting the
159 former kind of variable, an implicit `make-local-variable' is
162 A buffer-local variable logically has
165 -- local values in some buffers
167 The primary place where the local values are stored is in each
168 buffer's local_var_alist slot.
170 In the simplest implementation, all that this structure needs to
171 keep track of is the default value; to retrieve the value in
172 a buffer, look in that buffer's local_var_alist, and use the
173 default value if there is no local value. To implement
174 `make-local-variable' in a buffer, look in the buffer's
175 local_var_alist, and if no element exists for this symbol,
176 add one, copying the value from the default value. When setting
177 the value in a buffer, look in the buffer's local_var_alist, and set
178 the value in that list if an element exists for this symbol;
179 otherwise, set the default. (Remember that SYMVAL_BUFFER_LOCAL
180 variables implicitly call `make-local-variable' first, so when
181 setting a value, there will always be an entry in the buffer's
182 local_var_alist to set.)
184 However, this operation is potentially slow. To speed it up,
185 we cache the value in one buffer in this structure.
187 NOTE: This is *not* a write-through cache. I.e. when setting
188 the value in the buffer that is cached, we *only* change the
189 cache and don't write the value through to either the buffer's
190 local_var_alist or the default value. Therefore, when retrieving
191 a value in a buffer, you must *always* look in the cache to see if
192 it refers to that buffer.
194 The cache consists of
196 -- a buffer, or nil if the cache has not been set up
197 -- the value in that buffer
198 -- the element (a cons) from the buffer's local_var_alist, or
199 nil if there is no local value in the buffer
201 These slots are called CURRENT-BUFFER, CURRENT-VALUE, and
202 CURRENT-ALIST-ELEMENT, respectively.
204 If we want to examine or set the value in BUFFER and CURRENT-BUFFER
205 equals BUFFER, we just examine or set CURRENT-VALUE. Otherwise,
206 we store CURRENT-VALUE value into CURRENT-ALIST-ELEMENT (or maybe
207 into DEFAULT-VALUE), then find the appropriate alist element for
208 BUFFER and set up CURRENT-ALIST-ELEMENT. Then we set CURRENT-VALUE
209 out of that element (or maybe out of DEFAULT-VALUE), and store
210 BUFFER into CURRENT-BUFFER.
212 If we are setting the variable and the current buffer does not have
213 an alist entry for this variable, an alist entry is created.
215 Note that CURRENT-BUFFER's local_var_alist value for this variable
216 might be out-of-date (the correct value is stored in CURRENT-VALUE).
217 Similarly, if CURRENT-BUFFER sees the default value, then
218 DEFAULT-VALUE might be out-of-date.
220 Note that CURRENT-VALUE (but not DEFAULT-VALUE) can be a
221 forwarding pointer. Each time it is examined or set,
222 forwarding must be done.
224 Lisp_Object default_value;
225 Lisp_Object current_value;
226 Lisp_Object current_buffer;
227 Lisp_Object current_alist_element;
229 DECLARE_LRECORD (symbol_value_buffer_local, struct symbol_value_buffer_local);
230 #define XSYMBOL_VALUE_BUFFER_LOCAL(x) \
231 XRECORD (x, symbol_value_buffer_local, struct symbol_value_buffer_local)
232 #define SYMBOL_VALUE_BUFFER_LOCAL_P(x) RECORDP (x, symbol_value_buffer_local)
234 /* 3. symbol-value-lisp-magic */
236 enum lisp_magic_handler
238 MAGIC_HANDLER_GET_VALUE,
239 MAGIC_HANDLER_SET_VALUE,
240 MAGIC_HANDLER_BOUND_PREDICATE,
241 MAGIC_HANDLER_MAKE_UNBOUND,
242 MAGIC_HANDLER_LOCAL_PREDICATE,
243 MAGIC_HANDLER_MAKE_LOCAL,
247 struct symbol_value_lisp_magic
249 struct symbol_value_magic magic;
250 Lisp_Object handler[MAGIC_HANDLER_MAX];
251 Lisp_Object harg[MAGIC_HANDLER_MAX];
252 Lisp_Object shadowed;
254 DECLARE_LRECORD (symbol_value_lisp_magic, struct symbol_value_lisp_magic);
255 #define XSYMBOL_VALUE_LISP_MAGIC(x) \
256 XRECORD (x, symbol_value_lisp_magic, struct symbol_value_lisp_magic)
257 #define SYMBOL_VALUE_LISP_MAGIC_P(x) RECORDP (x, symbol_value_lisp_magic)
259 /* 4. symbol-value-varalias */
261 struct symbol_value_varalias
263 struct symbol_value_magic magic;
265 Lisp_Object shadowed;
267 DECLARE_LRECORD (symbol_value_varalias, struct symbol_value_varalias);
268 #define XSYMBOL_VALUE_VARALIAS(x) \
269 XRECORD (x, symbol_value_varalias, struct symbol_value_varalias)
270 #define SYMBOL_VALUE_VARALIAS_P(x) RECORDP (x, symbol_value_varalias)
271 #define symbol_value_varalias_aliasee(m) ((m)->aliasee)
272 #define symbol_value_varalias_shadowed(m) ((m)->shadowed)
274 /* To define a Lisp primitive function using a C function `Fname', do this:
275 DEFUN ("name, Fname, ...); // at top level in foo.c
276 DEFSUBR (Fname); // in syms_of_foo();
278 void defsubr (Lisp_Subr *);
279 #define DEFSUBR(Fname) defsubr (&S##Fname)
281 /* To define a Lisp primitive macro using a C function `Fname', do this:
282 DEFUN ("name, Fname, ...); // at top level in foo.c
283 DEFSUBR_MACRO (Fname); // in syms_of_foo();
285 void defsubr_macro (Lisp_Subr *);
286 #define DEFSUBR_MACRO(Fname) defsubr_macro (&S##Fname)
288 void defsymbol_massage_name (Lisp_Object *location, const char *name);
289 void defsymbol_massage_name_nodump (Lisp_Object *location, const char *name);
290 void defsymbol_massage_multiword_predicate (Lisp_Object *location,
292 void defsymbol_massage_multiword_predicate_nodump (Lisp_Object *location,
294 void defsymbol (Lisp_Object *location, const char *name);
295 void defsymbol_nodump (Lisp_Object *location, const char *name);
297 #define DEFSYMBOL(name) defsymbol_massage_name (&name, #name)
298 #define DEFSYMBOL_NO_DUMP(name) defsymbol_massage_name_nodump (&name, #name)
299 #define DEFSYMBOL_MULTIWORD_PREDICATE(name) \
300 defsymbol_massage_multiword_predicate (&name, #name)
301 #define DEFSYMBOL_MULTIWORD_PREDICATE_NO_DUMP(name) \
302 defsymbol_massage_multiword_predicate_nodump (&name, #name)
304 void defkeyword (Lisp_Object *location, const char *name);
305 void defkeyword_massage_name (Lisp_Object *location, const char *name);
306 #define DEFKEYWORD(name) defkeyword_massage_name (&name, #name)
308 void deferror (Lisp_Object *symbol, const char *name,
309 const char *message, Lisp_Object inherits_from);
310 void deferror_massage_name (Lisp_Object *symbol, const char *name,
311 const char *message, Lisp_Object inherits_from);
312 void deferror_massage_name_and_message (Lisp_Object *symbol, const char *name,
313 Lisp_Object inherits_from);
314 #define DEFERROR(name, message, inherits_from) \
315 deferror_massage_name (&name, #name, message, inherits_from)
316 /* In this case, the error message is the same as the name, modulo some
318 #define DEFERROR_STANDARD(name, inherits_from) \
319 deferror_massage_name_and_message (&name, #name, inherits_from)
321 /* Macros we use to define forwarded Lisp variables.
322 These are used in the syms_of_FILENAME functions. */
324 void defvar_magic (const char *symbol_name, const struct symbol_value_forward *magic);
326 #define DEFVAR_SYMVAL_FWD(lname, c_location, forward_type, magicfun) do { \
327 static const struct symbol_value_forward I_hate_C = \
328 { /* struct symbol_value_forward */ \
329 { /* struct symbol_value_magic */ \
330 { /* struct lcrecord_header */ \
331 { /* struct lrecord_header */ \
332 lrecord_type_symbol_value_forward, /* lrecord_type_index */ \
334 1, /* c_readonly bit */ \
335 1 /* lisp_readonly bit */ \
346 defvar_magic ((lname), &I_hate_C); \
349 #define DEFVAR_SYMVAL_FWD_INT(lname, c_location, forward_type, magicfun) do{ \
350 DEFVAR_SYMVAL_FWD (lname, c_location, forward_type, magicfun); \
351 dump_add_opaque_int (c_location); \
354 #define DEFVAR_SYMVAL_FWD_FIXNUM(lname, c_location, forward_type, magicfun) do{ \
355 DEFVAR_SYMVAL_FWD (lname, c_location, forward_type, magicfun); \
356 dump_add_opaque_fixnum (c_location); \
359 #define DEFVAR_SYMVAL_FWD_OBJECT(lname, c_location, forward_type, magicfun) do{ \
360 DEFVAR_SYMVAL_FWD (lname, c_location, forward_type, magicfun); \
362 Lisp_Object *DSF_location = c_location; /* Type check */ \
363 staticpro (DSF_location); \
364 if (EQ (*DSF_location, Qnull_pointer)) *DSF_location = Qnil; \
368 #define DEFVAR_LISP(lname, c_location) \
369 DEFVAR_SYMVAL_FWD_OBJECT (lname, c_location, SYMVAL_OBJECT_FORWARD, 0)
370 #define DEFVAR_CONST_LISP(lname, c_location) \
371 DEFVAR_SYMVAL_FWD_OBJECT (lname, c_location, SYMVAL_CONST_OBJECT_FORWARD, 0)
372 #define DEFVAR_SPECIFIER(lname, c_location) \
373 DEFVAR_SYMVAL_FWD_OBJECT (lname, c_location, SYMVAL_CONST_SPECIFIER_FORWARD, 0)
374 #define DEFVAR_INT(lname, c_location) \
375 DEFVAR_SYMVAL_FWD_FIXNUM (lname, c_location, SYMVAL_FIXNUM_FORWARD, 0)
376 #define DEFVAR_CONST_INT(lname, c_location) \
377 DEFVAR_SYMVAL_FWD_FIXNUM (lname, c_location, SYMVAL_CONST_FIXNUM_FORWARD, 0)
378 #define DEFVAR_BOOL(lname, c_location) \
379 DEFVAR_SYMVAL_FWD_INT (lname, c_location, SYMVAL_BOOLEAN_FORWARD, 0)
380 #define DEFVAR_CONST_BOOL(lname, c_location) \
381 DEFVAR_SYMVAL_FWD_INT (lname, c_location, SYMVAL_CONST_BOOLEAN_FORWARD, 0)
382 #define DEFVAR_LISP_MAGIC(lname, c_location, magicfun) \
383 DEFVAR_SYMVAL_FWD_OBJECT (lname, c_location, SYMVAL_OBJECT_FORWARD, magicfun)
384 #define DEFVAR_INT_MAGIC(lname, c_location, magicfun) \
385 DEFVAR_SYMVAL_FWD_FIXNUM (lname, c_location, SYMVAL_FIXNUM_FORWARD, magicfun)
386 #define DEFVAR_BOOL_MAGIC(lname, c_location, magicfun) \
387 DEFVAR_SYMVAL_FWD_INT (lname, c_location, SYMVAL_BOOLEAN_FORWARD, magicfun)
389 void flush_all_buffer_local_cache (void);
391 #endif /* INCLUDED_symeval_h_ */