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[bpt/emacs.git] / src / lisp.h

/* Fundamental definitions for GNU Emacs Lisp interpreter.
   Copyright (C) 1985, 1986, 1987, 1992 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs 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.

GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */


/* Define the fundamental Lisp data structures */

/* This is the set of Lisp data types */

enum Lisp_Type
  {
    /* Integer.  XINT(obj) is the integer value. */
    Lisp_Int,

    /* Symbol.  XSYMBOL (object) points to a struct Lisp_Symbol. */
    Lisp_Symbol,

    /* Marker (buffer ptr).  XMARKER(object) points to a struct Lisp_Marker. */
    Lisp_Marker,

    /* String.  XSTRING (object) points to a struct Lisp_String.
       The length of the string, and its contents, are stored therein. */
    Lisp_String,

    /* Vector of Lisp objects.  XVECTOR(object) points to a struct Lisp_Vector.
       The length of the vector, and its contents, are stored therein. */
    Lisp_Vector,

    /* Cons.  XCONS (object) points to a struct Lisp_Cons. */
    Lisp_Cons,

    /* Byte-compiled function.  A vector of 4 to 6 elements which are the
       arglist, bytecode-string, constant vector, stack size,
       (optional) doc string, and (optional) interactive spec.  */
    Lisp_Compiled,

    /* Editor buffer.  XBUFFER(obj) points to a struct buffer.  */
    Lisp_Buffer,

    /* Built-in function.  XSUBR(obj) points to a struct Lisp_Subr
       which describes how to call the function, and its documentation,
       as well as pointing to the code. */
    Lisp_Subr,

    /* Internal value return by subroutines of read.
       The user never sees this data type.
       Its value is just a number. */
    Lisp_Internal,

    /* Forwarding pointer to an int variable.
       This is allowed only in the value cell of a symbol,
       and it means that the symbol's value really lives in the
       specified int variable.
       XINTPTR(obj) points to the int variable. */
    Lisp_Intfwd,

    /* Boolean forwarding pointer to an int variable.
       This is like Lisp_Intfwd except that the ostensible
       "value" of the symbol is t if the int variable is nonzero,
       nil if it is zero.  XINTPTR(obj) points to the int variable. */
    Lisp_Boolfwd,

    /* Object describing a connection to a subprocess.
       It points to storage of type  struct Lisp_Process  */
    Lisp_Process,

    /* Forwarding pointer to a Lisp_Object variable.
       This is allowed only in the value cell of a symbol,
       and it means that the symbol's value really lives in the
       specified variable.
       XOBJFWD(obj) points to the Lisp_Object variable. */
    Lisp_Objfwd,

    /* Pointer to a vector-like object describing a display screen
       on which Emacs can display a window hierarchy.  */
    Lisp_Screen,

    /* Used when a FILE * value needs to be passed
       in an argument of type Lisp_Object.
       You must do *(FILE **) XPNTR(obj) to get the value.
       The user will never see this data type. */
    Lisp_Internal_Stream,

    /* Used in a symbol value cell when the symbol's value is per-buffer.
        The actual contents are a cons cell which starts a list like this:
        (REALVALUE BUFFER CURRENT-ALIST-ELEMENT . DEFAULT-VALUE)).

	BUFFER is the last buffer for which this symbol's value was
	made up to date.

        CURRENT-ALIST-ELEMENT is a pointer to an element of BUFFER's
	b_local_var_alist, that being the element whose car is this variable.
        Or it can be a pointer to the (CURRENT-ALIST-ELEMENT . DEFAULT-VALUE), if BUFFER
	does not have an element in its alist for this variable
	(that is, if BUFFER sees the default value of this variable).

	If we want to examine or set the value and BUFFER is current,
	we just examine or set REALVALUE.
	If BUFFER is not current, we store the current REALVALUE value into
	CURRENT-ALIST-ELEMENT, then find the appropriate alist element for
	the buffer now current and set up CURRENT-ALIST-ELEMENT.
	Then we set REALVALUE out of that element, and store into 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 REALVALUE can be a forwarding pointer.
	Each time it is examined or set, forwarding must be done.  */
    Lisp_Buffer_Local_Value,

    /* Like Lisp_Buffer_Local_Value with one difference:
	merely setting the variable while some buffer is current
	does not cause that buffer to have its own local value of this variable.
	Only make-local-variable does that.  */
    Lisp_Some_Buffer_Local_Value,


    /* Like Lisp_Objfwd except that value lives in a slot
       in the current buffer.  Value is byte index of slot within buffer */
    Lisp_Buffer_Objfwd,

    /* In symbol value cell, means var is unbound.
       In symbol function cell, means function name is undefined. */
    Lisp_Void,

    /* Window used for Emacs display.
       Data inside looks like a Lisp_Vector.  */
    Lisp_Window,

    /* Used by save,set,restore-window-configuration */
    Lisp_Window_Configuration

#ifdef LISP_FLOAT_TYPE
      ,
    Lisp_Float
#endif /* LISP_FLOAT_TYPE */
  };

#ifndef NO_UNION_TYPE

#ifndef BIG_ENDIAN

/* Definition of Lisp_Object for little-endian machines.  */

typedef
union Lisp_Object
  {
    /* Used for comparing two Lisp_Objects;
       also, positive integers can be accessed fast this way. */
    int i;

    struct
      {
	int val: 24;
	char type;
      } s;
    struct
      {
	unsigned int val: 24;
	char type;
      } u;
    struct
      {
	unsigned int val: 24;
	enum Lisp_Type type: 7;
	/* The markbit is not really part of the value of a Lisp_Object,
	   and is always zero except during garbage collection.  */
	unsigned int markbit: 1;
      } gu;
  }
Lisp_Object;

#else /* If BIG_ENDIAN */

typedef
union Lisp_Object
  {
    /* Used for comparing two Lisp_Objects;
       also, positive integers can be accessed fast this way. */
    int i;

    struct
      {
	char type;
	int val: 24;
      } s;
    struct
      {
	char type;
	unsigned int val: 24;
      } u;
    struct
      {
	/* The markbit is not really part of the value of a Lisp_Object,
	   and is always zero except during garbage collection.  */
	unsigned int markbit: 1;
	enum Lisp_Type type: 7;
	unsigned int val: 24;
      } gu;
  }
Lisp_Object;

#endif /* BIG_ENDIAN */

#endif /* NO_UNION_TYPE */


/* If union type is not wanted, define Lisp_Object as just a number
   and define the macros below to extract fields by shifting */

#ifdef NO_UNION_TYPE

#define Lisp_Object int

/* These values are overridden by the m- file on some machines.  */
#ifndef VALBITS
#define VALBITS 24
#endif

#ifndef GCTYPEBITS
#define GCTYPEBITS 7
#endif

#ifndef VALMASK
#define VALMASK ((1<<VALBITS) - 1)
#endif
#define GCTYPEMASK ((1<<GCTYPEBITS) - 1)
#define MARKBIT (1 << (VALBITS + GCTYPEBITS))

#endif /* NO_UNION_TYPE */
\f
/* These macros extract various sorts of values from a Lisp_Object.
 For example, if tem is a Lisp_Object whose type is Lisp_Cons,
 XCONS (tem) is the struct Lisp_Cons * pointing to the memory for that cons. */

#ifdef NO_UNION_TYPE

/* One need to override this if there must be high bits set in data space
   (doing the result of the below & ((1 << (GCTYPE + 1)) - 1) would work
    on all machines, but would penalise machines which don't need it)
 */
#ifndef XTYPE
#define XTYPE(a) ((enum Lisp_Type) ((a) >> VALBITS))
#endif

#ifndef XSETTYPE
#define XSETTYPE(a, b) ((a)  =  XUINT (a) | ((int)(b) << VALBITS))
#endif

/* Use XFASTINT for fast retrieval and storage of integers known
  to be positive.  This takes advantage of the fact that Lisp_Int is 0.  */
#define XFASTINT(a) (a)

/* Extract the value of a Lisp_Object as a signed integer.  */

#ifndef XINT   /* Some machines need to do this differently.  */
#define XINT(a) (((a) << (INTBITS-VALBITS)) >> (INTBITS-VALBITS))
#endif

/* Extract the value as an unsigned integer.  This is a basis
   for extracting it as a pointer to a structure in storage.  */

#ifndef XUINT
#define XUINT(a) ((a) & VALMASK)
#endif

#ifndef XPNTR
#ifdef HAVE_SHM
/* In this representation, data is found in two widely separated segments.  */
extern int pure_size;
#define XPNTR(a) \
  (XUINT (a) | (XUINT (a) > pure_size ? DATA_SEG_BITS : PURE_SEG_BITS))
#else /* not HAVE_SHM */
#ifdef DATA_SEG_BITS
/* This case is used for the rt-pc.
   In the diffs I was given, it checked for ptr = 0
   and did not adjust it in that case.
   But I don't think that zero should ever be found
   in a Lisp object whose data type says it points to something.  */
#define XPNTR(a) (XUINT (a) | DATA_SEG_BITS)
#else
#define XPNTR(a) XUINT (a)
#endif
#endif /* not HAVE_SHM */
#endif /* no XPNTR */

#ifndef XSETINT
#define XSETINT(a, b)  ((a) = ((a) & ~VALMASK) |  ((b) & VALMASK))
#endif

#ifndef XSETUINT
#define XSETUINT(a, b) XSETINT (a, b)
#endif

#ifndef XSETPNTR
#define XSETPNTR(a, b) XSETINT (a, b)
#endif

#ifndef XSET
#define XSET(var, type, ptr) \
   ((var) = ((int)(type) << VALBITS) + ((int) (ptr) & VALMASK))
#endif

/* During garbage collection, XGCTYPE must be used for extracting types
 so that the mark bit is ignored.  XMARKBIT accesses the markbit.
 Markbits are used only in particular slots of particular structure types.
 Other markbits are always zero.
 Outside of garbage collection, all mark bits are always zero.  */

#ifndef XGCTYPE
#define XGCTYPE(a) ((enum Lisp_Type) (((a) >> VALBITS) & GCTYPEMASK))
#endif

#if VALBITS + GCTYPEBITS == INTBITS - 1
/* Make XMARKBIT faster if mark bit is sign bit.  */
#ifndef XMARKBIT
#define XMARKBIT(a) ((a) < 0)
#endif
#endif /* markbit is sign bit */

#ifndef XMARKBIT
#define XMARKBIT(a) ((a) & MARKBIT)
#endif

#ifndef XSETMARKBIT
#define XSETMARKBIT(a,b) ((a) = ((a) & ~MARKBIT) | ((b) ? MARKBIT : 0))
#endif

#ifndef XMARK
#define XMARK(a) ((a) |= MARKBIT)
#endif

#ifndef XUNMARK
#define XUNMARK(a) ((a) &= ~MARKBIT)
#endif

#endif /* NO_UNION_TYPE */

#ifndef NO_UNION_TYPE

#define XTYPE(a) ((enum Lisp_Type) (a).u.type)
#define XSETTYPE(a, b) ((a).u.type = (char) (b))

/* Use XFASTINT for fast retrieval and storage of integers known
  to be positive.  This takes advantage of the fact that Lisp_Int is 0.  */
#define XFASTINT(a) ((a).i)

#ifdef EXPLICIT_SIGN_EXTEND
/* Make sure we sign-extend; compilers have been known to fail to do so.  */
#define XINT(a) (((a).i << 8) >> 8)
#else
#define XINT(a) ((a).s.val)
#endif /* EXPLICIT_SIGN_EXTEND */

#define XUINT(a) ((a).u.val)
#define XPNTR(a) ((a).u.val)
#define XSETINT(a, b) ((a).s.val = (int) (b))
#define XSETUINT(a, b) ((a).s.val = (int) (b))
#define XSETPNTR(a, b) ((a).s.val = (int) (b))

#define XSET(var, vartype, ptr) \
   (((var).s.type = ((char) (vartype))), ((var).s.val = ((int) (ptr))))

/* During garbage collection, XGCTYPE must be used for extracting types
 so that the mark bit is ignored.  XMARKBIT access the markbit.
 Markbits are used only in particular slots of particular structure types.
 Other markbits are always zero.
 Outside of garbage collection, all mark bits are always zero.  */

#define XGCTYPE(a) ((a).gu.type)
#define XMARKBIT(a) ((a).gu.markbit)
#define XSETMARKBIT(a,b) (XMARKBIT(a) = (b))
#define XMARK(a) (XMARKBIT(a) = 1)
#define XUNMARK(a) (XMARKBIT(a) = 0)

#endif /* NO_UNION_TYPE */


#define XCONS(a) ((struct Lisp_Cons *) XPNTR(a))
#define XBUFFER(a) ((struct buffer *) XPNTR(a))
#define XVECTOR(a) ((struct Lisp_Vector *) XPNTR(a))
#define XSUBR(a) ((struct Lisp_Subr *) XPNTR(a))
#define XSTRING(a) ((struct Lisp_String *) XPNTR(a))
#define XSYMBOL(a) ((struct Lisp_Symbol *) XPNTR(a))
#define XFUNCTION(a) ((Lisp_Object (*)()) XPNTR(a))
#define XMARKER(a) ((struct Lisp_Marker *) XPNTR(a))
#define XOBJFWD(a) ((Lisp_Object *) XPNTR(a))
#define XINTPTR(a) ((int *) XPNTR(a))
#define XWINDOW(a) ((struct window *) XPNTR(a))
#define XPROCESS(a) ((struct Lisp_Process *) XPNTR(a))
#define XFLOAT(a) ((struct Lisp_Float *) XPNTR(a))

#define XSETCONS(a, b) XSETPNTR(a, (int) (b))
#define XSETBUFFER(a, b) XSETPNTR(a, (int) (b))
#define XSETVECTOR(a, b) XSETPNTR(a, (int) (b))
#define XSETSUBR(a, b) XSETPNTR(a, (int) (b))
#define XSETSTRING(a, b) XSETPNTR(a, (int) (b))
#define XSETSYMBOL(a, b) XSETPNTR(a, (int) (b))
#define XSETFUNCTION(a, b) XSETPNTR(a, (int) (b))
#define XSETMARKER(a, b) XSETPNTR(a, (int) (b))
#define XSETOBJFWD(a, b) XSETPNTR(a, (int) (b))
#define XSETINTPTR(a, b) XSETPNTR(a, (int) (b))
#define XSETWINDOW(a, b) XSETPNTR(a, (int) (b))
#define XSETPROCESS(a, b) XSETPNTR(a, (int) (b))
#define XSETFLOAT(a, b) XSETPNTR(a, (int) (b))
\f
/* In a cons, the markbit of the car is the gc mark bit */

struct Lisp_Cons
  {
    Lisp_Object car, cdr;
  };

/* Like a cons, but records info on where the text lives that it was read from */
/* This is not really in use now */

struct Lisp_Buffer_Cons
  {
    Lisp_Object car, cdr;
    struct buffer *buffer;
    int bufpos;
  };

/* In a string or vector, the sign bit of the `size' is the gc mark bit */

struct Lisp_String
  {
    int size;
    unsigned char data[1];
  };

struct Lisp_Vector
  {
    int size;
    struct Lisp_Vector *next;
    Lisp_Object contents[1];
  };

/* In a symbol, the markbit of the plist is used as the gc mark bit */

struct Lisp_Symbol
  {
    struct Lisp_String *name;
    Lisp_Object value;
    Lisp_Object function;
    Lisp_Object plist;
    struct Lisp_Symbol *next;	/* -> next symbol in this obarray bucket */
  };

struct Lisp_Subr
  {
    Lisp_Object (*function) ();
    short min_args, max_args;
    char *symbol_name;
    char *prompt;
    char *doc;
  };

/* In a marker, the markbit of the chain field is used as the gc mark bit */

struct Lisp_Marker
  {
    struct buffer *buffer;
    Lisp_Object chain;
    int bufpos;
    int modified;
  };

#ifdef LISP_FLOAT_TYPE
/* Optional Lisp floating point type */
struct Lisp_Float
  {
    Lisp_Object type;		/* essentially used for mark-bit 
				   and chaining when on free-list */
    double data;  
  };
#endif /* LISP_FLOAT_TYPE */

/* A character, declared with the following typedef, is a member
   of some character set associated with the current buffer. */
typedef unsigned char UCHAR;

/* Meanings of slots in a Lisp_Compiled:  */

#define COMPILED_ARGLIST 0
#define COMPILED_BYTECODE 1
#define COMPILED_CONSTANTS 2
#define COMPILED_STACK_DEPTH 3
#define COMPILED_DOC_STRING 4
#define COMPILED_INTERACTIVE 5
\f
/* Data type checking */

#define NILP(x)  (XFASTINT (x) == XFASTINT (Qnil))

#ifdef LISP_FLOAT_TYPE
#define NUMBERP(x) (XTYPE (x) == Lisp_Int || XTYPE (x) == Lisp_Float)
#else
#define NUMBERP(x) (XTYPE (x) == Lisp_Int)
#endif

/* #define LISTP(x) (XTYPE ((x)) == Lisp_Cons)*/
#define CONSP(x) (XTYPE ((x)) == Lisp_Cons)
#define EQ(x, y) (XFASTINT (x) == XFASTINT (y))


#define CHECK_LIST(x, i) \
  { if ((XTYPE ((x)) != Lisp_Cons) && !NILP (x)) x = wrong_type_argument (Qlistp, (x)); }

#define CHECK_STRING(x, i) \
  { if (XTYPE ((x)) != Lisp_String) x = wrong_type_argument (Qstringp, (x)); }

#define CHECK_CONS(x, i) \
  { if (XTYPE ((x)) != Lisp_Cons) x = wrong_type_argument (Qconsp, (x)); }

#define CHECK_SYMBOL(x, i) \
  { if (XTYPE ((x)) != Lisp_Symbol) x = wrong_type_argument (Qsymbolp, (x)); }

#define CHECK_VECTOR(x, i) \
  { if (XTYPE ((x)) != Lisp_Vector) x = wrong_type_argument (Qvectorp, (x)); }

#define CHECK_BUFFER(x, i) \
  { if (XTYPE ((x)) != Lisp_Buffer) x = wrong_type_argument (Qbufferp, (x)); }

#define CHECK_WINDOW(x, i) \
  { if (XTYPE ((x)) != Lisp_Window) x = wrong_type_argument (Qwindowp, (x)); }

#define CHECK_PROCESS(x, i) \
  { if (XTYPE ((x)) != Lisp_Process) x = wrong_type_argument (Qprocessp, (x)); }

#define CHECK_NUMBER(x, i) \
  { if (XTYPE ((x)) != Lisp_Int) x = wrong_type_argument (Qintegerp, (x)); }

#define CHECK_NATNUM(x, i) \
  { if (XTYPE ((x)) != Lisp_Int || XINT ((x)) < 0)	\
      x = wrong_type_argument (Qnatnump, (x)); }

#define CHECK_MARKER(x, i) \
  { if (XTYPE ((x)) != Lisp_Marker) x = wrong_type_argument (Qmarkerp, (x)); }

#define CHECK_NUMBER_COERCE_MARKER(x, i) \
  { if (XTYPE ((x)) == Lisp_Marker) XFASTINT (x) = marker_position (x); \
    else if (XTYPE ((x)) != Lisp_Int) x = wrong_type_argument (Qinteger_or_marker_p, (x)); }

#ifdef LISP_FLOAT_TYPE

#ifndef DBL_DIG
#define DBL_DIG 20
#endif

#define XFLOATINT(n) extract_float((n))

#define CHECK_FLOAT(x, i)		\
{ if (XTYPE (x) != Lisp_Float)	\
    x = wrong_type_argument (Qfloatp, (x)); }

#define CHECK_NUMBER_OR_FLOAT(x, i)	\
{ if (XTYPE (x) != Lisp_Float && XTYPE (x) != Lisp_Int)	\
    x = wrong_type_argument (Qnumberp, (x)); }

#define CHECK_NUMBER_OR_FLOAT_COERCE_MARKER(x, i) \
{ if (XTYPE (x) == Lisp_Marker) XFASTINT (x) = marker_position (x);	\
  else if (XTYPE (x) != Lisp_Int && XTYPE (x) != Lisp_Float)		\
    x = wrong_type_argument (Qnumber_or_marker_p, (x)); }

#else  /* Not LISP_FLOAT_TYPE */

#define CHECK_NUMBER_OR_FLOAT CHECK_NUMBER

#define CHECK_NUMBER_OR_FLOAT_COERCE_MARKER CHECK_NUMBER_COERCE_MARKER

#define XFLOATINT(n) XINT((n))
#endif /* LISP_FLOAT_TYPE */

/* Cast pointers to this type to compare them.  Some machines want int.  */
#ifndef PNTR_COMPARISON_TYPE
#define PNTR_COMPARISON_TYPE unsigned int
#endif
\f
/* Define a built-in function for calling from Lisp.
 `lname' should be the name to give the function in Lisp,
    as a null-terminated C string.
 `fnname' should be the name of the function in C.
    By convention, it starts with F.
 `sname' should be the name for the C constant structure
    that records information on this function for internal use.
    By convention, it should be the same as `fnname' but with S instead of F.
    It's too bad that C macros can't compute this from `fnname'.
 `minargs' should be a number, the minimum number of arguments allowed.
 `maxargs' should be a number, the maximum number of arguments allowed,
    or else MANY or UNEVALLED.
    MANY means pass a vector of evaluated arguments,
	 in the form of an integer number-of-arguments
	 followed by the address of a vector of Lisp_Objects
	 which contains the argument values.
    UNEVALLED means pass the list of unevaluated arguments
 `prompt' says how to read arguments for an interactive call.
    This can be zero or a C string.
    Zero means that interactive calls are not allowed.
    A string is interpreted in a hairy way:
     it should contain one line for each argument to be read, terminated by \n.
     The first character of the line controls the type of parsing:
       s  --  read a string.
       S  --  read a symbol.
       k  --  read a key sequence and return it as a string.
       a  --  read a function name (symbol) with completion.
       C  --  read a command name (symbol) with completion.
       v  --  read a variable name (symbol) with completion.
       b  --  read a buffer name (a string) with completion.
       B  --  buffer name, may be existing buffer or may not be.
       f  --  read a file name, file must exist.
       F  --  read a file name, file need not exist.
       n  --  read a number.
       c  --  read a character and return it as a number.
       p  --  use the numeric value of the prefix argument.
       P  --  use raw value of prefix - can be nil, -, (NUMBER) or NUMBER.
       x  --  read a Lisp object from the minibuffer.
       X  --  read a Lisp form from the minibuffer and use its value.
    A null string means call interactively with no arguments.
 `doc' is documentation for the user.
*/

#define DEFUN(lname, fnname, sname, minargs, maxargs, prompt, doc) \
  Lisp_Object fnname (); \
  struct Lisp_Subr sname = {fnname, minargs, maxargs, lname, prompt, 0}; \
  Lisp_Object fnname

/* defsubr (Sname);
 is how we define the symbol for function `name' at start-up time. */
extern void defsubr ();

#define MANY -2
#define UNEVALLED -1

extern void defvar_lisp ();
extern void defvar_bool ();
extern void defvar_int ();

/* Macros we use to define forwarded Lisp variables.
   These are used in the syms_of_FILENAME functions.  */

#define DEFVARLISP(lname, vname, doc) defvar_lisp (lname, vname)
#define DEFVARBOOL(lname, vname, doc) defvar_bool (lname, vname)
#define DEFVARINT(lname, vname, doc) defvar_int (lname, vname)
#define DEFVARPERBUFFER(lname, vname, doc)  \
 defvar_per_buffer (lname, vname)

#define DEFVAR_LISP(lname, vname, doc) defvar_lisp (lname, vname)
#define DEFVAR_LISP_NOPRO(lname, vname, doc) defvar_lisp_nopro (lname, vname)
#define DEFVAR_BOOL(lname, vname, doc) defvar_bool (lname, vname)
#define DEFVAR_INT(lname, vname, doc) defvar_int (lname, vname)
#define DEFVAR_PER_BUFFER(lname, vname, doc)  \
 defvar_per_buffer (lname, vname)
\f
/* Structure for recording Lisp call stack for backtrace purposes */

struct specbinding
  {
    Lisp_Object symbol, old_value;
    Lisp_Object (*func) ();
    Lisp_Object unused;		/* Dividing by 16 is faster than by 12 */
  };

extern struct specbinding *specpdl;
extern struct specbinding *specpdl_ptr;
extern int specpdl_size;

struct handler
  {
    Lisp_Object handler;
    Lisp_Object var;
    int poll_suppress_count;	/* No error should exit a piece of code
				   in which polling is suppressed.  */
    struct catchtag *tag;
    struct handler *next;
  };

extern struct handler *handlerlist;

extern struct catchtag *catchlist;
extern struct backtrace *backtrace_list;

/* An address near the bottom of the stack.
   Tells GC how to save a copy of the stack.  */
extern char *stack_bottom;

/* Check quit-flag and quit if it is non-nil. */

#define QUIT \
  if (!NILP (Vquit_flag) && NILP (Vinhibit_quit)) \
    { Vquit_flag = Qnil; Fsignal (Qquit, Qnil); }

/* Nonzero if ought to quit now.  */

#define QUITP (!NILP (Vquit_flag) && NILP (Vinhibit_quit))
\f
/* 1 if CH is upper case.  */

#define UPPERCASEP(CH) \
  (XSTRING (current_buffer->downcase_table)->data[CH] != (CH))

/* 1 if CH is lower case.  */

#define LOWERCASEP(CH) \
  (!UPPERCASEP (CH) \
   && XSTRING (current_buffer->upcase_table)->data[CH] != (CH))

/* 1 if CH is neither upper nor lower case.  */

#define NOCASEP(CH) (XSTRING (current_buffer->upcase_table)->data[CH] == (CH))

/* Upcase a character, or make no change if that cannot be done.  */

#define UPCASE(CH) \
  (XSTRING (current_buffer->downcase_table)->data[CH] == (CH) \
   ? UPCASE1 (CH) : (CH))

/* Upcase a character known to be not upper case.  */

#define UPCASE1(CH) (XSTRING (current_buffer->upcase_table)->data[CH])

/* Downcase a character, or make no change if that cannot be done. */

#define DOWNCASE(CH) (XSTRING (current_buffer->downcase_table)->data[CH])

/* Current buffer's map from characters to lower-case characters.  */

#define DOWNCASE_TABLE XSTRING (current_buffer->downcase_table)->data

/* Table mapping each char to the next char with the same lowercase version.
   This mapping is a no-op only for characters that don't have case.  */
#define UPCASE_TABLE XSTRING (current_buffer->upcase_table)->data

extern Lisp_Object Vascii_downcase_table, Vascii_upcase_table;
\f
/* number of bytes of structure consed since last GC */

extern int consing_since_gc;

/* threshold for doing another gc */

extern int gc_cons_threshold;

/* Structure for recording stack slots that need marking */

/* This is a chain of structures, each of which points at a Lisp_Object variable
 whose value should be marked in garbage collection.
 Normally every link of the chain is an automatic variable of a function,
 and its `val' points to some argument or local variable of the function.
 On exit to the function, the chain is set back to the value it had on entry.
 This way, no link remains in the chain when the stack frame containing the link disappears.

 Every function that can call Feval must protect in this fashion all
 Lisp_Object variables whose contents will be used again. */

extern struct gcpro *gcprolist;

struct gcpro
  {
    struct gcpro *next;
    Lisp_Object *var;		/* Address of first protected variable */
    int nvars;			/* Number of consecutive protected variables */
  };

#define GCPRO1(varname) \
 {gcpro1.next = gcprolist; gcpro1.var = &varname; gcpro1.nvars = 1; \
  gcprolist = &gcpro1; }

#define GCPRO2(varname1, varname2) \
 {gcpro1.next = gcprolist; gcpro1.var = &varname1; gcpro1.nvars = 1; \
  gcpro2.next = &gcpro1; gcpro2.var = &varname2; gcpro2.nvars = 1; \
  gcprolist = &gcpro2; }

#define GCPRO3(varname1, varname2, varname3) \
 {gcpro1.next = gcprolist; gcpro1.var = &varname1; gcpro1.nvars = 1; \
  gcpro2.next = &gcpro1; gcpro2.var = &varname2; gcpro2.nvars = 1; \
  gcpro3.next = &gcpro2; gcpro3.var = &varname3; gcpro3.nvars = 1; \
  gcprolist = &gcpro3; }

#define GCPRO4(varname1, varname2, varname3, varname4) \
 {gcpro1.next = gcprolist; gcpro1.var = &varname1; gcpro1.nvars = 1; \
  gcpro2.next = &gcpro1; gcpro2.var = &varname2; gcpro2.nvars = 1; \
  gcpro3.next = &gcpro2; gcpro3.var = &varname3; gcpro3.nvars = 1; \
  gcpro4.next = &gcpro3; gcpro4.var = &varname4; gcpro4.nvars = 1; \
  gcprolist = &gcpro4; }

/* Call staticpro (&var) to protect static variable `var'. */

void staticpro();
  
#define UNGCPRO (gcprolist = gcpro1.next)

/* Evaluate expr, UNGCPRO, and then return the value of expr.  */
#define RETURN_UNGCPRO(expr)		\
  do					\
    {					\
      Lisp_Object ret_ungc_val;		\
      ret_ungc_val = (expr);		\
      UNGCPRO;				\
      return ret_ungc_val;		\
    }					\
  while (0)
\f
/* Defined in data.c */
extern Lisp_Object Qnil, Qt, Qquote, Qlambda, Qsubr, Qunbound;
extern Lisp_Object Qerror_conditions, Qerror_message, Qtop_level;
extern Lisp_Object Qerror, Qquit, Qwrong_type_argument, Qargs_out_of_range;
extern Lisp_Object Qvoid_variable, Qvoid_function;
extern Lisp_Object Qsetting_constant, Qinvalid_read_syntax;
extern Lisp_Object Qinvalid_function, Qwrong_number_of_arguments, Qno_catch;
extern Lisp_Object Qend_of_file, Qarith_error;
extern Lisp_Object Qbeginning_of_buffer, Qend_of_buffer, Qbuffer_read_only;

extern Lisp_Object Qintegerp, Qnatnump, Qsymbolp, Qlistp, Qconsp;
extern Lisp_Object Qstringp, Qarrayp, Qsequencep, Qbufferp;
extern Lisp_Object Qchar_or_string_p, Qmarkerp, Qvectorp;
extern Lisp_Object Qinteger_or_marker_p, Qboundp, Qfboundp;
extern Lisp_Object Qcdr;

#ifdef LISP_FLOAT_TYPE
extern Lisp_Object Qfloatp, Qinteger_or_floatp, Qinteger_or_float_or_marker_p;
#endif /* LISP_FLOAT_TYPE */

extern Lisp_Object Qscreenp;

extern Lisp_Object Feq (), Fnull (), Flistp (), Fconsp (), Fatom (), Fnlistp ();
extern Lisp_Object Fintegerp (), Fnatnump (), Fsymbolp ();
extern Lisp_Object Fvectorp (), Fstringp (), Farrayp (), Fsequencep ();
extern Lisp_Object Fbufferp (), Fmarkerp (), Fsubrp (), Fchar_or_string_p ();
extern Lisp_Object Finteger_or_marker_p ();
#ifdef LISP_FLOAT_TYPE
extern Lisp_Object Ffloatp(), Finteger_or_floatp();
extern Lisp_Object Finteger_or_float_or_marker_p(), Ftruncate();
#endif /* LISP_FLOAT_TYPE */

extern Lisp_Object Fcar (), Fcar_safe(), Fcdr (), Fcdr_safe();
extern Lisp_Object Fsetcar (), Fsetcdr ();
extern Lisp_Object Fboundp (), Ffboundp (), Fmakunbound (), Ffmakunbound ();
extern Lisp_Object Fsymbol_function (), Fsymbol_plist (), Fsymbol_name ();
extern Lisp_Object indirect_function (), Findirect_function ();
extern Lisp_Object Ffset (), Fsetplist ();
extern Lisp_Object Fsymbol_value (), find_symbol_value (), Fset ();
extern Lisp_Object Fdefault_value (), Fset_default ();

extern Lisp_Object Faref (), Faset (), Farray_length ();

extern Lisp_Object Fstring_to_int (), Fint_to_string ();
extern Lisp_Object Feqlsign (), Fgtr (), Flss (), Fgeq (), Fleq (), Fneq (), Fzerop ();
extern Lisp_Object Fplus (), Fminus (), Ftimes (), Fquo (), Frem (), Fmax (), Fmin ();
extern Lisp_Object Flogand (), Flogior (), Flogxor (), Flognot (), Flsh (), Fash ();
extern Lisp_Object Fadd1 (), Fsub1 ();

extern Lisp_Object make_number ();
extern void args_out_of_range ();
extern void args_out_of_range_3 ();
extern Lisp_Object wrong_type_argument ();
#ifdef LISP_FLOAT_TYPE
extern Lisp_Object Ffloat_to_int(), Fint_to_float();
extern double extract_float();
#endif /* LISP_FLOAT_TYPE */

/* Defined in fns.c */
extern Lisp_Object Qstring_lessp;
extern Lisp_Object Vfeatures;
extern Lisp_Object Fidentity (), Frandom ();
extern Lisp_Object Flength ();
extern Lisp_Object Fappend (), Fconcat (), Fvconcat (), Fcopy_sequence ();
extern Lisp_Object Fsubstring ();
extern Lisp_Object Fnthcdr (), Fmemq (), Fassq (), Fassoc ();
extern Lisp_Object Frassq (), Fdelq (), Fsort ();
extern Lisp_Object Freverse (), Fnreverse (), Fget (), Fput (), Fequal ();
extern Lisp_Object Ffillarray (), Fnconc (), Fmapcar (), Fmapconcat ();
extern Lisp_Object Fy_or_n_p (), do_yes_or_no_p ();
extern Lisp_Object Ffeaturep (), Frequire () , Fprovide ();
extern Lisp_Object concat2 (), nconc2 ();
extern Lisp_Object assq_no_quit ();

/* Defined in alloc.c */
extern Lisp_Object Vpurify_flag;
extern Lisp_Object Fcons (), Flist(), Fmake_list ();
extern Lisp_Object Fmake_vector (), Fvector (), Fmake_symbol (), Fmake_marker ();
extern Lisp_Object Fmake_string (), build_string (), make_string ();
extern Lisp_Object make_array (), make_uninit_string ();
extern Lisp_Object Fpurecopy (), make_pure_string ();
extern Lisp_Object pure_cons (), make_pure_vector ();
extern Lisp_Object Fgarbage_collect ();

/* Defined in print.c */
extern Lisp_Object Vprin1_to_string_buffer;
extern Lisp_Object Fprin1 (), Fprin1_to_string (), Fprinc ();
extern Lisp_Object Fterpri (), Fprint ();
extern Lisp_Object Vstandard_output, Qstandard_output;
extern Lisp_Object Qexternal_debugging_output;
extern void temp_output_buffer_setup (), temp_output_buffer_show ();
extern int print_level, print_escape_newlines;
extern Lisp_Object Qprint_escape_newlines;

/* Defined in lread.c */
extern Lisp_Object Qvariable_documentation, Qstandard_input;
extern Lisp_Object Vobarray, Vstandard_input;
extern Lisp_Object Fread (), Fread_from_string ();
extern Lisp_Object Fintern (), Fintern_soft (), Fload ();
extern Lisp_Object Fget_file_char (), Fread_char ();
extern Lisp_Object Feval_current_buffer (), Feval_region ();
extern Lisp_Object intern (), oblookup ();

/* Defined in eval.c */
extern Lisp_Object Qautoload, Qexit, Qinteractive, Qcommandp, Qdefun, Qmacro;
extern Lisp_Object Vinhibit_quit, Qinhibit_quit, Vquit_flag;
extern Lisp_Object Vmocklisp_arguments, Qmocklisp, Qmocklisp_arguments;
extern Lisp_Object Vautoload_queue;
extern Lisp_Object Vrun_hooks;
extern Lisp_Object Fand (), For (), Fif (), Fprogn (), Fprog1 (), Fprog2 ();
extern Lisp_Object Fsetq (), Fquote ();
extern Lisp_Object Fuser_variable_p (), Finteractive_p ();
extern Lisp_Object Fdefun (), Flet (), FletX (), Fwhile ();
extern Lisp_Object Fcatch (), Fthrow (), Funwind_protect ();
extern Lisp_Object Fcondition_case (), Fsignal ();
extern Lisp_Object Ffunction_type (), Fautoload (), Fcommandp ();
extern Lisp_Object Feval (), Fapply (), Ffuncall ();
extern Lisp_Object Fglobal_set (), Fglobal_value (), Fbacktrace ();
extern Lisp_Object apply1 (), call0 (), call1 (), call2 (), call3 ();
extern Lisp_Object apply_lambda ();
extern Lisp_Object internal_catch ();
extern Lisp_Object internal_condition_case ();
extern Lisp_Object unbind_to ();
extern void error ();
extern Lisp_Object un_autoload ();

/* Defined in editfns.c */
extern Lisp_Object Vprefix_arg, Qminus, Vcurrent_prefix_arg;
extern Lisp_Object Fgoto_char ();
extern Lisp_Object Fpoint_min_marker (), Fpoint_max_marker ();
extern Lisp_Object Fpoint_min (), Fpoint_max ();
extern Lisp_Object Fpoint (), Fpoint_marker (), Fmark_marker ();
extern Lisp_Object Ffollowing_char (), Fprevious_char (), Fchar_after ();
extern Lisp_Object Finsert ();
extern Lisp_Object Feolp (), Feobp (), Fbolp (), Fbobp ();
extern Lisp_Object Fformat (), format1 ();
extern Lisp_Object make_buffer_string (), Fbuffer_substring ();
extern Lisp_Object Fbuffer_string ();
extern Lisp_Object Fstring_equal (), Fstring_lessp (), Fbuffer_substring_lessp ();
extern Lisp_Object save_excursion_save (), save_restriction_save ();
extern Lisp_Object save_excursion_restore (), save_restriction_restore ();
extern Lisp_Object Fchar_to_string ();

/* defined in buffer.c */
extern Lisp_Object Vbuffer_alist;
extern Lisp_Object Fget_buffer (), Fget_buffer_create (), Fset_buffer ();
extern Lisp_Object Fbarf_if_buffer_read_only ();
extern Lisp_Object Fcurrent_buffer (), Fswitch_to_buffer (), Fpop_to_buffer ();
extern Lisp_Object Fother_buffer ();
extern struct buffer *all_buffers;

/* defined in marker.c */

extern Lisp_Object Fmarker_position (), Fmarker_buffer ();
extern Lisp_Object Fcopy_marker ();

/* Defined in fileio.c */

extern Lisp_Object Qfile_error;
extern Lisp_Object Ffile_name_as_directory ();
extern Lisp_Object Fexpand_file_name (), Ffile_name_nondirectory ();
extern Lisp_Object Fsubstitute_in_file_name ();
extern Lisp_Object Ffile_symlink_p ();

/* Defined in abbrev.c */

extern Lisp_Object Vfundamental_mode_abbrev_table;

/* defined in search.c */
extern Lisp_Object Fstring_match ();
extern Lisp_Object Fscan_buffer ();

/* defined in minibuf.c */

extern Lisp_Object last_minibuf_string;
extern Lisp_Object read_minibuf (), Fcompleting_read ();
extern Lisp_Object Fread_from_minibuffer ();
extern Lisp_Object Fread_variable (), Fread_buffer (), Fread_key_sequence ();
extern Lisp_Object Fread_minibuffer (), Feval_minibuffer ();
extern Lisp_Object Fread_string (), Fread_file_name ();
extern Lisp_Object Fread_no_blanks_input ();

/* Defined in callint.c */

extern Lisp_Object Vcommand_history;
extern Lisp_Object Qcall_interactively;
extern Lisp_Object Fcall_interactively ();
extern Lisp_Object Fprefix_numeric_value ();

/* defined in casefiddle.c */

extern Lisp_Object Fdowncase (), Fupcase (), Fcapitalize ();

/* defined in keyboard.c */

extern Lisp_Object Qdisabled;
extern Lisp_Object Vhelp_form, Vtop_level;
extern Lisp_Object Fdiscard_input (), Frecursive_edit ();
extern Lisp_Object Fcommand_execute (), Finput_pending_p ();

/* defined in keymap.c */

extern Lisp_Object Qkeymap;
extern Lisp_Object current_global_map;
extern Lisp_Object Fkey_description (), Fsingle_key_description ();
extern Lisp_Object Fwhere_is_internal ();
extern Lisp_Object access_keymap (), store_in_keymap ();
extern Lisp_Object get_keyelt (), get_keymap();

/* defined in indent.c */
extern Lisp_Object Fvertical_motion (), Findent_to (), Fcurrent_column ();

/* defined in window.c */
extern Lisp_Object Qwindowp;
extern Lisp_Object Fget_buffer_window ();
extern Lisp_Object Fsave_window_excursion ();
extern Lisp_Object Fset_window_configuration (), Fcurrent_window_configuration ();
extern Lisp_Object Fcoordinates_in_window_p ();
extern Lisp_Object Fwindow_at ();

/* defined in screen.c */
extern Lisp_Object Fscreenp ();
extern Lisp_Object Fselect_screen ();
extern Lisp_Object Ffocus_screen ();
extern Lisp_Object Funfocus_screen ();
extern Lisp_Object Fselected_screen ();
extern Lisp_Object Fwindow_screen ();
extern Lisp_Object Fscreen_root_window ();
extern Lisp_Object Fscreen_selected_window ();
extern Lisp_Object Fscreen_list ();
extern Lisp_Object Fnext_screen ();
extern Lisp_Object Fdelete_screen ();
extern Lisp_Object Fread_mouse_position ();
extern Lisp_Object Fset_mouse_position ();
extern Lisp_Object Fmake_screen_visible ();
extern Lisp_Object Fmake_screen_invisible ();
extern Lisp_Object Ficonify_screen ();
extern Lisp_Object Fdeiconify_screen ();
extern Lisp_Object Fscreen_visible_p ();
extern Lisp_Object Fvisible_screen_list ();
extern Lisp_Object Fscreen_parameters ();
extern Lisp_Object Fmodify_screen_parameters ();
extern Lisp_Object Fscreen_pixel_size ();
extern Lisp_Object Fscreen_height ();
extern Lisp_Object Fscreen_width ();
extern Lisp_Object Fset_screen_height ();
extern Lisp_Object Fset_screen_width ();
extern Lisp_Object Fset_screen_size ();
extern Lisp_Object Fset_screen_position ();
#ifndef HAVE_X11
extern Lisp_Object Frubber_band_rectangle ();
#endif	/* HAVE_X11 */

/* defined in emacs.c */
extern Lisp_Object decode_env_path ();
/* Nonzero means don't do interactive redisplay and don't change tty modes */
extern int noninteractive;
/* Nonzero means don't do use window-system-specific display code */
extern int inhibit_window_system;

/* defined in process.c */
extern Lisp_Object Fget_process (), Fget_buffer_process (), Fprocessp ();
extern Lisp_Object Fprocess_status (), Fkill_process ();

/* defined in callproc.c */
extern Lisp_Object Vexec_path, Vexec_directory, Vdata_directory;

/* defined in doc.c */
extern Lisp_Object Vdoc_file_name;
extern Lisp_Object Fsubstitute_command_keys ();
extern Lisp_Object Fdocumentation (), Fdocumentation_property ();

/* defined in bytecode.c */
extern Lisp_Object Qbytecode;

/* defined in macros.c */
extern Lisp_Object Qexecute_kbd_macro;
extern Lisp_Object Fexecute_kbd_macro ();

/* Nonzero means Emacs has already been initialized.
   Used during startup to detect startup of dumped Emacs.  */
extern int initialized;

extern int immediate_quit;	    /* Nonzero means ^G can quit instantly */

extern void debugger ();

extern char *malloc (), *realloc (), *getenv (), *ctime (), *getwd ();
extern long *xmalloc (), *xrealloc ();

extern char *egetenv ();