/* Definitions of symbol-value forwarding for XEmacs Lisp interpreter. Copyright (C) 1985, 1986, 1987, 1992, 1993 Free Software Foundation, Inc. Copyright (C) 2000 Ben Wing. 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 INCLUDED_symeval_h_ #define INCLUDED_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 "Fixnum", really "EMACS_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 }; /* Underlying C type used to implement DEFVAR_INT */ typedef EMACS_INT Fixnum; struct symbol_value_magic { struct lcrecord_header lcheader; void *value; enum symbol_value_type type; }; #define SYMBOL_VALUE_MAGIC_P(x) \ (LRECORDP (x) && \ XRECORD_LHEADER (x)->type <= lrecord_type_max_symbol_value_magic) #define XSYMBOL_VALUE_MAGIC_TYPE(v) \ (((struct symbol_value_magic *) XPNTR (v))->type) #define XSETSYMBOL_VALUE_MAGIC(s, p) XSETOBJ (s, 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; /* `magicfun' is a function controlling the 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.value)) #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) /* To define a Lisp primitive function using a C function `Fname', do this: DEFUN ("name, Fname, ...); // at top level in foo.c DEFSUBR (Fname); // in syms_of_foo(); */ void defsubr (Lisp_Subr *); #define DEFSUBR(Fname) defsubr (&S##Fname) /* To define a Lisp primitive macro using a C function `Fname', do this: DEFUN ("name, Fname, ...); // at top level in foo.c DEFSUBR_MACRO (Fname); // in syms_of_foo(); */ void defsubr_macro (Lisp_Subr *); #define DEFSUBR_MACRO(Fname) defsubr_macro (&S##Fname) void defsymbol_massage_name (Lisp_Object *location, const char *name); void defsymbol_massage_name_nodump (Lisp_Object *location, const char *name); void defsymbol_massage_multiword_predicate (Lisp_Object *location, const char *name); void defsymbol_massage_multiword_predicate_nodump (Lisp_Object *location, const char *name); void defsymbol (Lisp_Object *location, const char *name); void defsymbol_nodump (Lisp_Object *location, const char *name); #define DEFSYMBOL(name) defsymbol_massage_name (&name, #name) #define DEFSYMBOL_NO_DUMP(name) defsymbol_massage_name_nodump (&name, #name) #define DEFSYMBOL_MULTIWORD_PREDICATE(name) \ defsymbol_massage_multiword_predicate (&name, #name) #define DEFSYMBOL_MULTIWORD_PREDICATE_NO_DUMP(name) \ defsymbol_massage_multiword_predicate_nodump (&name, #name) void defkeyword (Lisp_Object *location, const char *name); void defkeyword_massage_name (Lisp_Object *location, const char *name); #define DEFKEYWORD(name) defkeyword_massage_name (&name, #name) void deferror (Lisp_Object *symbol, const char *name, const char *message, Lisp_Object inherits_from); void deferror_massage_name (Lisp_Object *symbol, const char *name, const char *message, Lisp_Object inherits_from); void deferror_massage_name_and_message (Lisp_Object *symbol, const char *name, Lisp_Object inherits_from); #define DEFERROR(name, message, inherits_from) \ deferror_massage_name (&name, #name, message, inherits_from) /* In this case, the error message is the same as the name, modulo some prettifying */ #define DEFERROR_STANDARD(name, inherits_from) \ deferror_massage_name_and_message (&name, #name, inherits_from) /* Macros we use to define forwarded Lisp variables. These are used in the syms_of_FILENAME functions. */ void defvar_magic (const char *symbol_name, const struct symbol_value_forward *magic); #define DEFVAR_SYMVAL_FWD(lname, c_location, forward_type, magicfun) do { \ static const struct symbol_value_forward I_hate_C = \ { /* struct symbol_value_forward */ \ { /* struct symbol_value_magic */ \ { /* struct lcrecord_header */ \ { /* struct lrecord_header */ \ lrecord_type_symbol_value_forward, /* lrecord_type_index */ \ 1, /* mark bit */ \ 1, /* c_readonly bit */ \ 1 /* lisp_readonly bit */ \ }, \ 0, /* next */ \ 0, /* uid */ \ 0 /* free */ \ }, \ c_location, \ forward_type \ }, \ magicfun \ }; \ defvar_magic ((lname), &I_hate_C); \ } while (0) #define DEFVAR_SYMVAL_FWD_INT(lname, c_location, forward_type, magicfun) do{ \ DEFVAR_SYMVAL_FWD (lname, c_location, forward_type, magicfun); \ dump_add_opaque_int (c_location); \ } while (0) #define DEFVAR_SYMVAL_FWD_FIXNUM(lname, c_location, forward_type, magicfun) do{ \ DEFVAR_SYMVAL_FWD (lname, c_location, forward_type, magicfun); \ dump_add_opaque_fixnum (c_location); \ } while (0) #define DEFVAR_SYMVAL_FWD_OBJECT(lname, c_location, forward_type, magicfun) do{ \ DEFVAR_SYMVAL_FWD (lname, c_location, forward_type, magicfun); \ { \ Lisp_Object *DSF_location = c_location; /* Type check */ \ staticpro (DSF_location); \ if (EQ (*DSF_location, Qnull_pointer)) *DSF_location = Qnil; \ } \ } while (0) #define DEFVAR_LISP(lname, c_location) \ DEFVAR_SYMVAL_FWD_OBJECT (lname, c_location, SYMVAL_OBJECT_FORWARD, 0) #define DEFVAR_CONST_LISP(lname, c_location) \ DEFVAR_SYMVAL_FWD_OBJECT (lname, c_location, SYMVAL_CONST_OBJECT_FORWARD, 0) #define DEFVAR_SPECIFIER(lname, c_location) \ DEFVAR_SYMVAL_FWD_OBJECT (lname, c_location, SYMVAL_CONST_SPECIFIER_FORWARD, 0) #define DEFVAR_INT(lname, c_location) \ DEFVAR_SYMVAL_FWD_FIXNUM (lname, c_location, SYMVAL_FIXNUM_FORWARD, 0) #define DEFVAR_CONST_INT(lname, c_location) \ DEFVAR_SYMVAL_FWD_FIXNUM (lname, c_location, SYMVAL_CONST_FIXNUM_FORWARD, 0) #define DEFVAR_BOOL(lname, c_location) \ DEFVAR_SYMVAL_FWD_INT (lname, c_location, SYMVAL_BOOLEAN_FORWARD, 0) #define DEFVAR_CONST_BOOL(lname, c_location) \ DEFVAR_SYMVAL_FWD_INT (lname, c_location, SYMVAL_CONST_BOOLEAN_FORWARD, 0) #define DEFVAR_LISP_MAGIC(lname, c_location, magicfun) \ DEFVAR_SYMVAL_FWD_OBJECT (lname, c_location, SYMVAL_OBJECT_FORWARD, magicfun) #define DEFVAR_INT_MAGIC(lname, c_location, magicfun) \ DEFVAR_SYMVAL_FWD_FIXNUM (lname, c_location, SYMVAL_FIXNUM_FORWARD, magicfun) #define DEFVAR_BOOL_MAGIC(lname, c_location, magicfun) \ DEFVAR_SYMVAL_FWD_INT (lname, c_location, SYMVAL_BOOLEAN_FORWARD, magicfun) void flush_all_buffer_local_cache (void); #endif /* INCLUDED_symeval_h_ */