--- /dev/null
+/* Definitions of symbol-value forwarding for XEmacs Lisp interpreter.
+ 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: Not in FSF. */
+
+/* Fsymbol_value checks whether XSYMBOL (sym)->value is one of these,
+ * and does weird magic stuff if so */
+
+#ifndef _XEMACS_SYMEVAL_H_
+#define _XEMACS_SYMEVAL_H_
+
+enum symbol_value_type
+{
+ /* The following tags use the 'symbol_value_forward' structure
+ and are strictly for variables DEFVARed on the C level. */
+ SYMVAL_FIXNUM_FORWARD, /* Forward C "int" */
+ SYMVAL_CONST_FIXNUM_FORWARD, /* Same, but can't be set */
+ SYMVAL_BOOLEAN_FORWARD, /* Forward C boolean ("int") */
+ SYMVAL_CONST_BOOLEAN_FORWARD, /* Same, but can't be set */
+ SYMVAL_OBJECT_FORWARD, /* Forward C Lisp_Object */
+ SYMVAL_CONST_OBJECT_FORWARD, /* Same, but can't be set */
+ SYMVAL_CONST_SPECIFIER_FORWARD, /* Same, can't be set, but gives a
+ different message when attempting to
+ set that says "use set-specifier" */
+ SYMVAL_DEFAULT_BUFFER_FORWARD, /* Forward Lisp_Object into Vbuffer_defaults */
+ SYMVAL_CURRENT_BUFFER_FORWARD, /* Forward Lisp_Object into current_buffer */
+ SYMVAL_CONST_CURRENT_BUFFER_FORWARD, /* Forward Lisp_Object into
+ current_buffer, can't be set */
+ SYMVAL_DEFAULT_CONSOLE_FORWARD, /* Forward Lisp_Object into
+ Vconsole_defaults */
+ SYMVAL_SELECTED_CONSOLE_FORWARD, /* Forward Lisp_Object into
+ Vselected_console */
+ SYMVAL_CONST_SELECTED_CONSOLE_FORWARD, /* Forward Lisp_Object into
+ Vselected_console,
+ can't be set */
+ SYMVAL_UNBOUND_MARKER, /* Only Qunbound actually has this tag */
+
+ /* The following tags use the 'symbol_value_buffer_local' structure */
+ SYMVAL_BUFFER_LOCAL, /* make-variable-buffer-local */
+ SYMVAL_SOME_BUFFER_LOCAL, /* make-local-variable */
+
+ /* The following tag uses the 'symbol_value_lisp_magic' structure */
+ SYMVAL_LISP_MAGIC, /* Forward to lisp callbacks */
+
+ /* The following tag uses the 'symbol_value_varalias' structure */
+ SYMVAL_VARALIAS /* defvaralias */
+
+#if 0
+ /* NYI */
+ SYMVAL_CONSTANT_SYMBOL, /* Self-evaluating symbol */
+ /* NYI */
+#endif
+};
+
+struct symbol_value_magic
+{
+ struct lcrecord_header lcheader;
+ enum symbol_value_type type;
+};
+#define SYMBOL_VALUE_MAGIC_P(x) \
+ (LRECORDP (x) \
+ && (XRECORD_LHEADER_IMPLEMENTATION (x)->printer \
+ == print_symbol_value_magic))
+#define XSYMBOL_VALUE_MAGIC_TYPE(v) \
+ (((struct symbol_value_magic *) XPNTR (v))->type)
+#define XSETSYMBOL_VALUE_MAGIC(s, p) XSETOBJ (s, Lisp_Type_Record, p)
+void print_symbol_value_magic (Lisp_Object, Lisp_Object, int);
+
+/********** The various different symbol-value-magic types ***********/
+
+/* 1. symbol-value-forward */
+
+/* This type of symbol-value-magic is used for variables declared
+ DEFVAR_LISP, DEFVAR_INT, DEFVAR_BOOL, DEFVAR_BUFFER_LOCAL,
+ DEFVAR_BUFFER_DEFAULTS, DEFVAR_SPECIFIER, and for Qunbound.
+
+ Note that some of these types of variables can be made buffer-local.
+ Then, the symbol's value field contains a symbol-value-buffer-local,
+ whose CURRENT-VALUE field then contains a symbol-value-forward.
+ */
+
+struct symbol_value_forward
+{
+ struct symbol_value_magic magic;
+ /* void *forward; -- use magic.lcheader.next instead */
+ /* Function controlling magic behavior of this forward variable.
+
+ SYM is the symbol being operated on (read, set, etc.);
+
+ VAL is either the value to set or the value to be returned.
+
+ IN_OBJECT is the buffer or console that the value is read in
+ or set in. A value of Qnil means that the current buffer
+ and possibly other buffers are being set. (This value will
+ never be passed for built-in buffer-local or console-local
+ variables such as `truncate-lines'.) (Currently, a value of
+ Qnil is always passed for DEFVAR_INT, DEFVAR_LISP, and
+ DEFVAR_BOOL variables; the code isn't smart enough to figure
+ out what buffers besides the current buffer are being
+ affected. Because the magic function is called
+ before the value is changed, it's not that easy
+ to determine which buffers are getting changed.
+ #### If this information is important, let me know
+ and I will look into providing it.) (Remember also
+ that the only console-local variables currently existing
+ are built-in ones, because others can't be created.)
+
+ FLAGS gives more information about the operation being
+ performed.
+
+ The return value indicates what the magic function actually
+ did.
+
+ Currently FLAGS and the return value are not used. This
+ function is only called when the value of a forward variable
+ is about to be changed. Note that this can occur explicitly
+ through a call to `set', `setq', `set-default', or `setq-default',
+ or implicitly by the current buffer being changed.
+
+ */
+
+ int (*magicfun) (Lisp_Object sym, Lisp_Object *val, Lisp_Object in_object,
+ int flags);
+};
+DECLARE_LRECORD (symbol_value_forward, struct symbol_value_forward);
+#define XSYMBOL_VALUE_FORWARD(x) \
+ XRECORD (x, symbol_value_forward, struct symbol_value_forward)
+#define symbol_value_forward_forward(m) ((void *)((m)->magic.lcheader.next))
+#define symbol_value_forward_magicfun(m) ((m)->magicfun)
+
+/* 2. symbol-value-buffer-local */
+
+struct symbol_value_buffer_local
+{
+ struct symbol_value_magic magic;
+ /* Used in a symbol value cell when the symbol's value is per-buffer.
+
+ The type of the symbol-value-magic will be either
+ SYMVAL_BUFFER_LOCAL (i.e. `make-variable-buffer-local' was called)
+ or SYMVAL_SOME_BUFFER_LOCAL (i.e. `make-local-variable' was called).
+ The only difference between the two is that when setting the
+ former kind of variable, an implicit `make-local-variable' is
+ called.
+
+ A buffer-local variable logically has
+
+ -- a default value
+ -- local values in some buffers
+
+ The primary place where the local values are stored is in each
+ buffer's local_var_alist slot.
+
+ In the simplest implementation, all that this structure needs to
+ keep track of is the default value; to retrieve the value in
+ a buffer, look in that buffer's local_var_alist, and use the
+ default value if there is no local value. To implement
+ `make-local-variable' in a buffer, look in the buffer's
+ local_var_alist, and if no element exists for this symbol,
+ add one, copying the value from the default value. When setting
+ the value in a buffer, look in the buffer's local_var_alist, and set
+ the value in that list if an element exists for this symbol;
+ otherwise, set the default. (Remember that SYMVAL_BUFFER_LOCAL
+ variables implicitly call `make-local-variable' first, so when
+ setting a value, there will always be an entry in the buffer's
+ local_var_alist to set.)
+
+ However, this operation is potentially slow. To speed it up,
+ we cache the value in one buffer in this structure.
+
+ NOTE: This is *not* a write-through cache. I.e. when setting
+ the value in the buffer that is cached, we *only* change the
+ cache and don't write the value through to either the buffer's
+ local_var_alist or the default value. Therefore, when retrieving
+ a value in a buffer, you must *always* look in the cache to see if
+ it refers to that buffer.
+
+ The cache consists of
+
+ -- a buffer, or nil if the cache has not been set up
+ -- the value in that buffer
+ -- the element (a cons) from the buffer's local_var_alist, or
+ nil if there is no local value in the buffer
+
+ These slots are called CURRENT-BUFFER, CURRENT-VALUE, and
+ CURRENT-ALIST-ELEMENT, respectively.
+
+ If we want to examine or set the value in BUFFER and CURRENT-BUFFER
+ equals BUFFER, we just examine or set CURRENT-VALUE. Otherwise,
+ we store CURRENT-VALUE value into CURRENT-ALIST-ELEMENT (or maybe
+ into DEFAULT-VALUE), then find the appropriate alist element for
+ BUFFER and set up CURRENT-ALIST-ELEMENT. Then we set CURRENT-VALUE
+ out of that element (or maybe out of DEFAULT-VALUE), and store
+ BUFFER into CURRENT-BUFFER.
+
+ If we are setting the variable and the current buffer does not have
+ an alist entry for this variable, an alist entry is created.
+
+ Note that CURRENT-BUFFER's local_var_alist value for this variable
+ might be out-of-date (the correct value is stored in CURRENT-VALUE).
+ Similarly, if CURRENT-BUFFER sees the default value, then
+ DEFAULT-VALUE might be out-of-date.
+
+ Note that CURRENT-VALUE (but not DEFAULT-VALUE) can be a
+ forwarding pointer. Each time it is examined or set,
+ forwarding must be done.
+ */
+ Lisp_Object default_value;
+ Lisp_Object current_value;
+ Lisp_Object current_buffer;
+ Lisp_Object current_alist_element;
+};
+DECLARE_LRECORD (symbol_value_buffer_local, struct symbol_value_buffer_local);
+#define XSYMBOL_VALUE_BUFFER_LOCAL(x) \
+ XRECORD (x, symbol_value_buffer_local, struct symbol_value_buffer_local)
+#define SYMBOL_VALUE_BUFFER_LOCAL_P(x) RECORDP (x, symbol_value_buffer_local)
+
+/* 3. symbol-value-lisp-magic */
+
+enum lisp_magic_handler
+{
+ MAGIC_HANDLER_GET_VALUE,
+ MAGIC_HANDLER_SET_VALUE,
+ MAGIC_HANDLER_BOUND_PREDICATE,
+ MAGIC_HANDLER_MAKE_UNBOUND,
+ MAGIC_HANDLER_LOCAL_PREDICATE,
+ MAGIC_HANDLER_MAKE_LOCAL,
+ MAGIC_HANDLER_MAX
+};
+
+struct symbol_value_lisp_magic
+{
+ struct symbol_value_magic magic;
+ Lisp_Object handler[MAGIC_HANDLER_MAX];
+ Lisp_Object harg[MAGIC_HANDLER_MAX];
+ Lisp_Object shadowed;
+};
+DECLARE_LRECORD (symbol_value_lisp_magic, struct symbol_value_lisp_magic);
+#define XSYMBOL_VALUE_LISP_MAGIC(x) \
+ XRECORD (x, symbol_value_lisp_magic, struct symbol_value_lisp_magic)
+#define SYMBOL_VALUE_LISP_MAGIC_P(x) RECORDP (x, symbol_value_lisp_magic)
+
+/* 4. symbol-value-varalias */
+
+struct symbol_value_varalias
+{
+ struct symbol_value_magic magic;
+ Lisp_Object aliasee;
+ Lisp_Object shadowed;
+};
+DECLARE_LRECORD (symbol_value_varalias, struct symbol_value_varalias);
+#define XSYMBOL_VALUE_VARALIAS(x) \
+ XRECORD (x, symbol_value_varalias, struct symbol_value_varalias)
+#define SYMBOL_VALUE_VARALIAS_P(x) RECORDP (x, symbol_value_varalias)
+#define symbol_value_varalias_aliasee(m) ((m)->aliasee)
+#define symbol_value_varalias_shadowed(m) ((m)->shadowed)
+
+/* DEFSUBR (Fname);
+ is how we define the symbol for function `Fname' at start-up time. */
+#define DEFSUBR(Fname) defsubr (&S##Fname)
+void defsubr (struct Lisp_Subr *);
+
+void defsymbol (Lisp_Object *location, CONST char *name);
+
+void defkeyword (Lisp_Object *location, CONST char *name);
+
+void deferror (Lisp_Object *symbol, CONST char *name,
+ CONST char *message, Lisp_Object inherits_from);
+
+/* Macros we use to define forwarded Lisp variables.
+ These are used in the syms_of_FILENAME functions. */
+
+void defvar_mumble (CONST char *names, CONST void *magic, size_t sizeof_magic);
+
+#ifdef USE_INDEXED_LRECORD_IMPLEMENTATION
+# define symbol_value_forward_lheader_initializer { 1, 0, 0 }
+#else
+# define symbol_value_forward_lheader_initializer \
+ { lrecord_symbol_value_forward }
+#endif
+
+#define DEFVAR_HEADER(lname, c_location, forward_type) \
+ DEFVAR_MAGIC_HEADER (lname, c_location, forward_type, 0)
+
+#define DEFVAR_MAGIC_HEADER(lname, c_location, forward_type, magicfun) do { \
+ static CONST struct symbol_value_forward I_hate_C \
+ = { { { symbol_value_forward_lheader_initializer, \
+ (struct lcrecord_header *) (c_location), 69 }, \
+ forward_type }, magicfun }; \
+ defvar_mumble ((lname), &I_hate_C, sizeof (I_hate_C)); \
+} while (0)
+
+#define DEFVAR_HEADER_GCPRO(lname, c_location, symbol_value_type) do { \
+ DEFVAR_HEADER (lname, c_location, symbol_value_type); \
+ staticpro (c_location); \
+} while (0)
+
+#define DEFVAR_LISP(lname, c_location) \
+ DEFVAR_HEADER_GCPRO (lname, c_location, SYMVAL_OBJECT_FORWARD)
+#define DEFVAR_CONST_LISP(lname, c_location) \
+ DEFVAR_HEADER_GCPRO (lname, c_location, SYMVAL_CONST_OBJECT_FORWARD)
+#define DEFVAR_SPECIFIER(lname, c_location) \
+ DEFVAR_HEADER_GCPRO (lname, c_location, SYMVAL_CONST_SPECIFIER_FORWARD)
+#define DEFVAR_INT(lname, c_location) \
+ DEFVAR_HEADER (lname, c_location, SYMVAL_FIXNUM_FORWARD)
+#define DEFVAR_CONST_INT(lname, c_location) \
+ DEFVAR_HEADER (lname, c_location, SYMVAL_CONST_FIXNUM_FORWARD)
+#define DEFVAR_BOOL(lname, c_location) \
+ DEFVAR_HEADER (lname, c_location, SYMVAL_BOOLEAN_FORWARD)
+#define DEFVAR_CONST_BOOL(lname, c_location) \
+ DEFVAR_HEADER (lname, c_location, SYMVAL_CONST_BOOLEAN_FORWARD)
+
+#define DEFVAR_LISP_MAGIC(lname, c_location, magicfun) do { \
+ DEFVAR_MAGIC_HEADER (lname, c_location, SYMVAL_OBJECT_FORWARD, magicfun); \
+ staticpro (c_location); \
+} while (0)
+#define DEFVAR_INT_MAGIC(lname, c_location, magicfun) \
+ DEFVAR_MAGIC_HEADER (lname, c_location, SYMVAL_FIXNUM_FORWARD, magicfun);
+#define DEFVAR_BOOL_MAGIC(lname, c_location, magicfun) \
+ DEFVAR_MAGIC_HEADER (lname, c_location, SYMVAL_BOOLEAN_FORWARD, magicfun);
+
+#endif /* _XEMACS_SYMEVAL_H_ */
projects / chise / xemacs-chise.git.1 / blobdiff