/******************************************************************************
 * NOTE: This file has been modified for use with MSDOS and the WATCOM C/386
 * compiler.  It has also been modified to treat ".asm" files as assembly
 * language files.
 *	Darryl Okahata, March 1993.
 *****************************************************************************/

/* $Id: etags.c,v 1.25 1992/06/04 21:00:52 kendall Exp $ */
/* Tags file maker to go with GNUmacs
   Copyright (C) 1984, 1987, 1988 Free Software Foundation, Inc. and Ken Arnold

   This program 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 of the License, or
   (at your option) any later version.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   Or contact Sam Kendall, CenterLine Software Inc., 10 Fawcett Street,
   Cambridge, MA 02138  USA.  Email is kendall@CenterLine.COM or
   uunet!saber!kendall.
*/

/*
 * Authors:
 *	Ctags originally by Ken Arnold.
 *	FORTRAN added by Jim Kleckner.
 *	Bill Joy added Pascal and -x.
 *	Ed Pelegri-Llopart added C typedefs.
 *	Gnu Emacs TAGS format and modifications by RMS?
 *	Sam Kendall added C++.
 */

#include <stdio.h>
#include <ctype.h>

#ifdef __TURBOC__
extern unsigned int _stklen=40000U;
# undef MSDOS
# define MSDOS
#endif

#ifdef __STDC__

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

#else

extern char *malloc (), *realloc ();
extern char *getenv ();
extern char *strchr (), *strrchr ();
extern char *strcpy (), *strncpy ();
extern int   strcmp ();

#endif

/* Define the symbol ETAGS to make the program "etags",
 which makes emacs-style tag tables by default.
 Define CTAGS to make the program "ctags" compatible with the usual one.
 Define neither one to get behavior that depends
 on the name with which the program is invoked; this is the default. */

#if !defined(ETAGS) && !defined(CTAGS)
/* If neither is defined, program can be run as either. */
#define ETAGS
#define CTAGS
#endif

/* On VMS, CTAGS is not useful, so always do ETAGS.  */
#ifdef VMS
#ifndef ETAGS
#define ETAGS
#endif
#endif

/* Exit codes for success and failure.  */
#ifdef VMS
#define	GOOD	(1)
#define BAD	(0)
#else
#define	GOOD	(0)
#define	BAD	(1)
#endif

#ifdef MSDOS
# define DIRECTORY_SEP		'\\'
# include <fcntl.h>
#else
# define DIRECTORY_SEP		'/'
#endif

/*
 * The FILEPOS abstract type, which represents a position in a file,
 * plus the following accessor functions:
 *
 *	long GET_CHARNO (pos)
 *				returns absolute char number.
 *	long GET_COOKIE (pos)
 *				returns ftell () cookie.
 *	void SET_FILEPOS (pos, fp, charno)
 *	    FILE *fp; long charno;
 *				sets `pos' from the current file
 *				position of `fp' and from `charno',
 *				which must be the absolute character
 *				number corresponding to the current
 *				position of `fp'.
 *
 * The `pos' parameter is an lvalue expression of type FILEPOS.
 * Parameters to the accessor functions are evaluated 0 or more times,
 * and so must have no side effects.
 *
 * FILEPOS objects can also be assigned and passed to and from
 * functions in the normal C manner.
 *
 * Implementation notes: the `+ 0' is to enforce rvalue-ness.
 */
#ifdef VMS
typedef struct { long cookie; long charno; } FILEPOS;
# define GET_CHARNO(pos)	((pos).charno + 0)
# define GET_COOKIE(pos)	((pos).cookie + 0)
# define SET_FILEPOS(pos, fp, cno) \
    ((void) ((pos).cookie = ftell (fp), (pos).charno = (cno)))
#else
# ifndef DEBUG
	/* UNIX real implementation */
typedef long FILEPOS;
#  define GET_CHARNO(pos)	((pos) + 0)
#  define GET_COOKIE(pos)	GET_CHARNO (pos)
#  define SET_FILEPOS(pos, fp, cno)	((void) ((pos) = (cno)))
# else
	/* UNIX debugging implementation */
typedef struct { long charno; } FILEPOS;
#  define GET_CHARNO(pos)	((pos).charno + 0)
#  define GET_COOKIE(pos)	GET_CHARNO (pos)
#  define SET_FILEPOS(pos, fp, cno)					\
    ((void) ((pos).charno = (cno),					\
	     (cno) != ftell (fp) ? (error ("SET_FILEPOS inconsistency"), 0) \
	     			 : 0))
# endif
#endif

#define streq(s, t)	(strcmp (s, t) == 0)
#define strneq(s, t, n)	(strncmp (s, t, n) == 0)
#define	reg	register
#define	logical	char

#define	TRUE	1
#define	FALSE	0

#define	iswhite(arg)	(_wht[arg])	/* T if char is white		*/
#define	begtoken(arg)	(_btk[arg])	/* T if char can start token	*/
#define	intoken(arg)	(_itk[arg])	/* T if char can be in token	*/
#define	endtoken(arg)	(_etk[arg])	/* T if char ends tokens	*/
#define	isgood(arg)	(_gd[arg])	/* T if char can be after ')'	*/

#ifndef MSDOS
#define	max(I1,I2)	((I1) > (I2) ? (I1) : (I2))
#endif

struct	nd_st {			/* sorting structure			*/
	char	*name;			/* function or type name	*/
	char	*file;			/* file name			*/
	logical is_func;		/* use pattern or line no	*/
	logical rewritten;		/* list name separately		*/
	logical	been_warned;		/* set if noticed dup		*/
	int	lno;			/* line number tag is on	*/
	long    cno;			/* character number line starts on */
	char	*pat;			/* search pattern		*/
	struct	nd_st	*left,*right;	/* left and right sons		*/
};

long	ftell ();
typedef	struct	nd_st	NODE;

logical gotone,				/* found a func already on line	*/
					/* boolean "func" (see init)	*/
	_wht[0177],_etk[0177],_itk[0177],_btk[0177],_gd[0177];


void	init ();
void	find_entries ();
void	pfnote ();
void	free_tree ();
void	add_node ();
void	put_entries ();
int	total_size_of_entries ();
void	C_entries ();
logical	consider_token ();
void	getline ();
int	PF_funcs ();
logical	tail ();
void	takeprec ();
void	getit ();
void	L_funcs ();
void	L_getit ();
void	Scheme_funcs ();
void	TEX_funcs ();
void	initbuffer ();
long	readline ();
char	*savestr ();
char	*savenstr ();
#ifdef __STDC__
void	fatal (const char *s1, ...);
void	error (const char *s1, ...);
#else
void	fatal ();
void	error ();
#endif
char	*concat	();
void	initbuffer ();
char	*xmalloc ();
char	*xrealloc ();

/*
 * MACRO
 *	xnew -- allocate storage
 *
 * SYNOPSIS
 *	Type *xnew (int n, Type);
 */
#define xnew(n, Type)	((Type *) xmalloc ((n) * sizeof (Type)))



/*
 *	Symbol table stuff.
 *
 * Should probably be implemented with hash table; linked list for now.
 */

enum sym_type { st_none, st_C_struct, st_C_enum, st_C_define, st_C_typedef };

struct stab_entry {
	char *		sym;
	int		symlen;
	enum sym_type	type;
	struct stab_entry * next;
};

typedef struct stab_entry	Stab_entry;
typedef Stab_entry *		Stab;


#ifdef __STDC__
/* The following must come after all typedefs! */
# include "etags1.h"	/* function prototypes are in etags.h */
#endif


/*
 * NAME
 *	Stab, Stab_entry, stab_create, stab_search, stab_find -- symbol table
 *
 * SYNOPSIS
 *	Types: Stab, Stab_entry, enum sym_type
 *
 *	Stab * stab_create ()
 *
 *	Stab_entry * stab_find (stab, sym)
 *	Stab *stab;
 *	char *sym;
 *
 *	Stab_entry * stab_search (stab, sym)
 *	Stab *stab;
 *	char *sym;
 *
 * DESCRIPTION
 *	stab_create creates a Stab, a symbol table object, and returns a
 *	pointer to it.  stab_find finds a symbol in a Stab; it returns a
 *	pointer to the Stab_entry if found, otherwise NULL.  stab_search
 *	is like stab_find, except that it creates a new Stab_entry,
 *	initialized with type = st_none, if one did not exist already
 *	(it never returns NULL).
 *
 *	A Stab_entry is a structure that contains at least the following
 *	members:
 *
 *		char *name;		// must not be modified
 *		enum sym_type type;	// should be set
 *
 *	The type field is initially set to st_none; it should be set to
 *	something else by the caller of stab_search.  Other possible values
 *	of an enum sym_type can be added.
 */

Stab *
stab_create ()
{
  Stab *sp;
  sp = xnew (1, Stab);
  *sp = NULL;	/* a Stab starts out as a null Stab_entry* */
  return sp;
}

Stab_entry *
stab_find (stab, sym, symlen)
     Stab *stab;
     register char *sym;
     register int symlen;
{
  register Stab_entry *se;
  for ( se = *stab; se != NULL; se = se->next ) {
    if (se->symlen == symlen && strneq (se->sym, sym, symlen))
      return se;
  }

  return NULL;
}

Stab_entry *
stab_search (stab, sym, symlen)
     register Stab *stab;
     char *sym;
     int symlen;
{
  register Stab_entry *se;
  se = stab_find (stab, sym, symlen);

  if (se == NULL) {
    /* make a new one */
    se = xnew (1, Stab_entry);
    se->sym = savenstr (sym, symlen);
    se->symlen = symlen;
    se->type = st_none;
    se->next = *stab;
    *stab = se;
  }

  return se;
}

/*
 * NAME
 *	stab_type -- type of a symbol table entry
 *
 * SYNOPSIS
 *	enum sym_type stab_type (Stab_entry *se);
 *
 * WARNING
 *	May evaluate its argument more than once.
 */

#define stab_type(se)	((se)==NULL ? st_none : (se)->type)
    


typedef int LINENO;

typedef struct {
     char *p;
     int len;
     FILEPOS linestart;
     LINENO lineno;
     logical rewritten;
} TOKEN;


	/* typedefs are recognized using a simple finite automaton.
	 * tydef is its state variable.
	 */
typedef enum {none, begin, middle, end } TYST;

TYST tydef = none;


	/* struct tags for C++ are recognized using another simple
	 * finite automaton.  `structdef' is its state variable.
	 * This machinery is only invoked for C++; otherwise structdef
	 * should remain snone.  However, this machinery can easily be
	 * adapted to find structure tags in normal C code.
	 */
typedef enum {
     snone,		/* nothing seen yet */
     skeyseen,		/* struct-like keyword seen */
     stagseen,		/* struct-like tag seen */
     scolonseen,	/* colon seen after struct-like tag */
     sinbody		/* in a class body: recognize member func defs */
     } STRUCTST;
STRUCTST structdef = snone;
/*
 * When structdef is stagseen, scolonseen, or sinbody, structtag is the
 * struct tag, and structkey is the preceding struct-like keyword.
 */
char structtag[512];
Stab_entry *structkey;

/*
 * Yet another little state machine to deal with preprocessor lines.
 */
typedef enum {
  dnone,		/* nothing seen */
  dsharpseen,		/* '#' seen as first char on line */
  ddefineseen,		/* '#' and 'define' seen */
  dignorerest		/* ignore rest of line */
  } DEFINEST;
DEFINEST definedef;

/*
 * LEVEL_OK_FOR_FUNCDEF allows C++ function definition within class body.
 * Currently tydef and structdef stuff (typedefs and struct definitions) are
 * only noticed when level==0, but that may change.
 *
 * Note that this macro may only be evaluated inside C_entries().  It is
 * for self-documentation only.
 */
#define LEVEL_OK_FOR_FUNCDEF()					\
	(level==0 || c_ext && level==1 && structdef==sinbody)

/* C extensions.  Currently all listed extensions are C++ dialects, so
 * `c_ext' is used as an abbreviation for `c_ext&C_PLPL'.  If a non-C++
 * dialect is added, this must change.
 */
#define C_PLPL	0x1	/* C++ */
#define C_STAR	0x3	/* C* */

char	searchar = '/';			/* use /.../ searches 		*/

LINENO	lineno;			/* line number of current line */
long	charno;			/* current character number */
FILEPOS	linepos;		/* start of line (C only) */
FILEPOS	prev_linepos;		/* start of previous line (C only) */

long	linecharno;		/* charno of start of line; not used by C, but
				 * by every other language.
				 */

char    *curfile,		/* current input file name		*/
	*outfile,		/* output file				*/
	*white	= " \f\t\n",	/* white chars				*/
	*endtk	= " \t\n\"'#()[]{}=-+%*/&|^~!<>;,.:?",
				/* token ending chars			*/
	*begtk	= "ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz$",
				/* token starting chars			*/
	*intk	= "ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz$0123456789",
				/* valid in-token chars			*/
	*notgd	= ",;";		/* non-valid after-function chars	*/

int	file_num;		/* current file number			*/
int	aflag;			/* -a: append to tags */
int	eflag;			/* emacs style output (no -e option any more) */
/* The following three default to 1 for etags, but to 0 for ctags.  */
int	tflag;			/* -t: create tags for typedefs */
int	strflag;		/* -T: create tags for typedefs, level */
				/* 0 struct/enum/union decls, and C++ */
				/* member functions */
int	constantflag;		/* -d: create tags for C #define and enum */
				/* constants. Default under etags.  Enum */
				/* constants not implemented. */
				/* -D: opposite of -d.  Default under ctags. */
int	uflag;			/* -u: update tags */
int	vflag;			/* -v: create vgrind style index output */
int	wflag;			/* -w: suppress warnings */
int	xflag;			/* -x: create cxref style output */
int	Cflag = TRUE;		/* .[hc] means C++, not C (default) */
int	noindentflag;		/* -S: ignore indentation in C */
int	iflag;			/* -i: treat all spec'd files as
				   included sub-tag-tables.  */

/* Name this program was invoked with.  */
char *progname;

FILE	*inf,			/* ioptr for current input file		*/
	*outf;			/* ioptr for tags file			*/

NODE	*head;			/* the head of the binary tree of tags	*/

/* A `struct linebuffer' is a structure which holds a line of text.
 `readline' reads a line from a stream into a linebuffer
 and works regardless of the length of the line.  */

struct linebuffer
  {
    long size;
    char *buffer;
  };

struct linebuffer lb;	/* the current line */
struct linebuffer lb1;	/* sometimes, a previous line in which a token lies */
struct linebuffer filename_lb;	/* used to read in filenames */

#ifdef __STDC__
# include "etags2.h"
#endif

#if 0  /* VMS now provides the `system' function.  */
#ifdef VMS

#include descrip

system (buf)
     char *buf;
{
  struct dsc$descriptor_s command =
    {
      strlen (buf), DSC$K_DTYPE_T, DSC$K_CLASS_S, buf
    };

  LIB$SPAWN (&command);
}
#endif /* VMS */
#endif /* 0 */


main (argc,argv)
     int	argc;
     char	*argv[];
{
  char cmd[100];
  int i;
  int outfflag = 0;
  char *this_file;
#ifdef VMS
  char got_err;

  extern char *gfnames ();
  extern char *massage_name ();
#endif

  progname = argv[0];

#if defined(MSDOS)
  _fmode = O_BINARY;
#endif

#ifndef CTAGS
  eflag = 1;
#else
#ifndef ETAGS
  eflag = 0;
#else
  /* Be ctags only if we are run as "ctags" or close to it. */
  {
    char *subname = strrchr (argv[0], DIRECTORY_SEP);
    subname = subname ? subname + 1 : argv[0];
    /* allow, for example, "ctags", "ctags-new", or "nctags" */
    eflag = !(strneq (subname, "ctags", 5) || strneq (subname+1, "ctags", 5));
  }
#endif
#endif

  /*
   * If etags, always find typedefs and structure tags.  Why not?
   * Also default is to find macro constants.
   */
  if (eflag)
    tflag = strflag = constantflag = 1;

  for ( ; argc > 1 && argv[1][0] == '-' && argv[1][1] != '\0'; argc--, argv++)
    {
      for (i=1; argv[1][i]; i++)
	{
	  switch (argv[1][i])
	    {
	      /* Common options. */
	    case 'a':
	      aflag++;
	      break;
	    case 'd':
	      constantflag = 1;
	      break;
	    case 'D':
	      constantflag = 0;
	      break;
	    case 'o':
	      if (outfflag)
		{
		  fprintf (stderr,
			   "%s: -o flag may only be given once\n", progname);
		  goto usage;
		}
	      outfflag++, argc--; argv++;
	      if (argc <= 1 || argv[1][0] == '\0')
		{
		  fprintf (stderr,
			   "%s: -o flag must be followed by a filename\n",
			   progname);
		  goto usage;
		}
	      outfile = argv[1];
	      goto next_arg;
	    case 'S':
	      noindentflag++;
	      break;
	    case 't':
	      tflag++;
	      break;
	    case 'T':
	      tflag++;
	      strflag++;
	      break;

	      /* Etags options */
	    case 'i':
	      iflag++;
	      if (!eflag) goto usage;
	      break;

	      /* Ctags options. */
	    case 'B':
	      searchar='?';
	      if (eflag) goto usage;
	      break;
	    case 'F':
	      searchar='/';
	      if (eflag) goto usage;
	      break;
	    case 'u':
	      uflag++;
	      if (eflag) goto usage;
	      break;
	    case 'v':
	      vflag++;
	      /*FALLTHRU*/
	    case 'x':
	      xflag++;
	      if (eflag) goto usage;
	      break;
	    case 'w':
	      wflag++;
	      if (eflag) goto usage;
	      break;

	    default:
	      goto usage;
	    }
	}
    next_arg: ;
    }

  if (argc <= 1)
    {
    usage:
      fprintf (stderr, "Usage:\n");
#if defined(ETAGS) || (!defined(ETAGS) && !defined(CTAGS))
      if (eflag)
	  fprintf (stderr, "\tetags [-a] [-o tagsfile] file ...\n");
#endif
#if defined(CTAGS) || (!defined(ETAGS) && !defined(CTAGS))
      if (!eflag)
	  fprintf (stderr, "\tctags [-aBdFtTuwvx] [-o tagsfile] file ...\n");
#endif
      exit (BAD);
    }

  if (outfile == 0)
    {
      outfile = eflag ? "TAGS" : "tags";
    }

  init ();			/* set up boolean "functions"		*/

  initbuffer (&lb);
  initbuffer (&lb1);
  initbuffer (&filename_lb);
  /*
   * loop through files finding functions
   */
  if (eflag)
    {
      if (streq (outfile, "-"))
	outf = stdout;
      else
	outf = fopen (outfile, aflag ? "a" : "w");
      if (!outf)
	{
	  perror (outfile);
	  exit (1);
	}
    }

  file_num = 1;
#ifdef VMS
  for (argc--, argv++;
       (this_file = gfnames (&argc, &argv, &got_err)) != NULL; file_num++)
    {
      if (got_err)
	{
	  error ("Can't find file %s\n", this_file);
	  argc--, argv++;
	}
      else
	{
	  this_file = massage_name (this_file);
# if 0
    }}  /* solely to balance out the ifdef'd parens above */
# endif
#else     
  for (; file_num < argc; file_num++)
    {
      this_file = argv[file_num];
      if (1)
	{
#endif
	  /* Input file named "-" means read file names from stdin
	     and use them.  */
	  if (streq (this_file, "-"))
	    {
	      while (! feof (stdin))
		{
		    (void) readline (&filename_lb, stdin);
		    if (strlen(filename_lb.buffer) > 0)
		      process_file (filename_lb.buffer);
		}
	    }
	  else
	    process_file (this_file);
	}
    }

  if (eflag)
    {
      (void) fclose (outf);
      exit (0);
    }

  if (xflag)
    {
      put_entries (head);
      exit (GOOD);
    }
  if (uflag)	/* uflag cannot be set under VMS */
    {
      for (i=1; i<argc; i++)
	{
	  sprintf (cmd,
		   "mv %s OTAGS;fgrep -v '\t%s\t' OTAGS >%s;rm OTAGS",
		   outfile, argv[i], outfile);
	  (void) system (cmd);
	}
      aflag++;
    }
  outf = fopen (outfile, aflag ? "a" : "w");
  if (outf == NULL)
    {
      perror (outfile);
      exit (GOOD);
    }
  put_entries (head);
  (void) fclose (outf);
  if (uflag)
    {
      sprintf (cmd, "sort %s -o %s", outfile, outfile);
      (void) system (cmd);
    }
  exit (GOOD);
}


/*
 * This routine is called on each file argument.
 */
void process_file (file)
     char *file;
{
#ifdef MSDOS
  /*
   * Lowercase all MSDOS file names
   */
  strlwr(file);
#endif
  if (streq (file, outfile) && ! streq (outfile, "-"))
    {
      fprintf (stderr, "Skipping inclusion of %s in self.\n", file);
      return;
    }
  if (iflag)
    {
      fprintf (outf, "\f\n%s,include\n", file);
      return;
    }
  if (eflag)
    {
      char *cp = strrchr (file, DIRECTORY_SEP);
      if (cp)  ++cp;  else  cp = file;
      if (streq (cp, outfile)) /*file == "TAGS"*/
	{
	  fprintf (outf, "\f\n%s,include\n", file);
	  return;
	}
    }
  find_entries (file);
  if (eflag)
    {
      fprintf (outf, "\f\n%s,%d\n",
	       file, total_size_of_entries (head));
      put_entries (head);
      free_tree (head);
      head = NULL;
    }
}

/*
 * This routine sets up the boolean psuedo-functions which work
 * by seting boolean flags dependent upon the corresponding character
 * Every char which is NOT in that string is not a white char.  Therefore,
 * all of the array "_wht" is set to FALSE, and then the elements
 * subscripted by the chars in "white" are set to TRUE.  Thus "_wht"
 * of a char is TRUE if it is the string "white", else FALSE.
 */
void
init ()
{
  reg char *sp;
  reg int i;

  for (i = 0; i < 0177; i++)
    {
      _wht[i] = _etk[i] = _itk[i] = _btk[i] = FALSE;
      _gd[i] = TRUE;
    }
  for (sp = white; *sp; sp++)
    _wht[*sp] = TRUE;
  for (sp = endtk; *sp; sp++)
    _etk[*sp] = TRUE;
  for (sp = intk; *sp; sp++)
    _itk[*sp] = TRUE;
  for (sp = begtk; *sp; sp++)
    _btk[*sp] = TRUE;
  for (sp = notgd; *sp; sp++)
    _gd[*sp] = FALSE;
  _wht[0] = _wht['\n'];
  _etk[0] = _etk['\n'];
  _btk[0] = _btk['\n'];
  _itk[0] = _itk['\n'];
  _gd[0] = _gd['\n'];
}

/*
 * This routine opens the specified file and calls the function
 * which finds the function and type definitions.
 */
void
find_entries (file)
     char *file;
{
  char *cp;

  inf = fopen (file, "r");
  if (inf == NULL)
    {
      perror (file);
      return;
    }
  curfile = savestr (file);
  cp = strrchr (file, '.');
  /* .tex, .aux or .bbl implies LaTeX source code */
  if (cp && (streq (cp + 1, "tex") || streq (cp + 1, "aux")
	     || streq (cp + 1, "bbl")))
    {
      TEX_funcs (inf);
      goto close_and_return;
    }
  /* .l or .el or .lisp (or .cl or .clisp or ...) implies lisp source code */
  if (cp && (streq (cp + 1, "l") ||
	     streq (cp + 1, "el") ||
	     streq (cp + 1, "lsp") ||
	     streq (cp + 1, "lisp") ||
	     streq (cp + 1, "cl") ||
	     streq (cp + 1, "clisp")))
    {
      L_funcs (inf);
      goto close_and_return;
    }
  /* .scm or .sm or .scheme or ... implies scheme source code */
  if (cp && (streq (cp + 1, "sm") ||
	     streq (cp + 1, "scm") ||
	     streq (cp + 1, "scheme") ||
	     streq (cp + 1, "t") ||
	     streq (cp + 1, "sch") ||
	     streq (cp + 1, "SM") ||
	     streq (cp + 1, "SCM") ||
             /* The `SCM' or `scm' prefix with a version number */
             (cp[-1] == 'm' && cp[-2] == 'c' && cp[-3] == 's') ||
             (cp[-1] == 'M' && cp[-2] == 'C' && cp[-3] == 'S')))
    {
      Scheme_funcs (inf);
      fclose (inf);
      return;
    }
  /* Assume that ".s" or ".a" is assembly code. -wolfgang.  */
  /* Further assume that ".asm" is also assembly code.  -- Darryl Okahata */
  if (cp && (((cp[1] == 's' || cp[1] == 'a') && cp[2] == '\0') ||
	     streq(cp + 1, "asm")
	     ))
    {
      Asm_funcs (inf);
      fclose (inf);
      return;
    }
  /* .[HC]  .[hci]xx  .[hc]c  .[hc]pp: a C++ file */
  if (cp && (streq (cp + 1, "H") ||
	     streq (cp + 1, "C") ||
	     streq (cp + 1, "hxx") ||
	     streq (cp + 1, "cxx") ||
	     streq (cp + 1, "ixx") ||
	     streq (cp + 1, "hc") ||
	     streq (cp + 1, "cc") ||
	     streq (cp + 1, "hpp") ||
	     streq (cp + 1, "cpp")))
    {
      C_entries (C_PLPL);	/* C++ */
      goto close_and_return;
    }
  /* .cs or .hs: a C* file */
  if (cp && (cp[1] == 'c' || cp[1] == 'h') && cp[2] == 's' && cp[3] == '\0')
    {
      C_entries (C_STAR);
      goto close_and_return;
    }
  /* if not a .c or .h or .y file, try fortran */
  else if (cp && (cp[1] != 'c' && cp[1] != 'h' && cp[1] != 'y')
      && cp[2] == '\0')
    {
      if (PF_funcs (inf) != 0)
	goto close_and_return;
      rewind (inf);	/* no fortran tags found, try C */
    }
  C_entries (Cflag ? C_PLPL : 0);

  close_and_return:
  (void) fclose (inf);
}

/* Record a tag. */
/* Should take a TOKEN* instead!! */

void
pfnote (name, is_func, rewritten, linestart, linelen, lno, cno)
     char *name;	/* tag name */
     logical is_func;	/* function or type name? */
     logical rewritten; /* tag different from text of definition? */
     char *linestart;
     int linelen;
     int lno;
     long cno;
{
  register char *fp;
  register NODE *np;
  char tem[51];
  char c;

  np = (NODE *) malloc (sizeof (NODE));
  if (np == NULL)
    {
      if (!eflag)
	{
	  /* It's okay to output early in etags -- it only disrupts the
	   * character count of the tag entries, which is no longer used
	   * by tags.el anyway.
	   */
	  error ("too many entries to sort");
	}
      put_entries (head);
      free_tree (head);
      head = NULL;
      np = xnew (1, NODE);
    }
  /* If ctags mode, change name "main" to M<thisfilename>. */
  if (!eflag && !xflag && streq (name, "main"))
    {
      fp = strrchr (curfile, DIRECTORY_SEP);
      name = concat ("M", fp==0 ? curfile : fp+1, "");
      fp = strrchr (name, '.');
      if (fp && fp[1] != '\0' && fp[2] == '\0')
	*fp = 0;
      rewritten = TRUE;
    }
  np->name = savestr (name);
  np->file = curfile;
  np->is_func = is_func;
  np->rewritten = rewritten;
  np->lno = lno;
  /* UNCOMMENT THE +1 HERE: */
  np->cno = cno /* + 1 */;	/* our char numbers are 0-base; emacs's are 1-base */
  np->left = np->right = 0;
  if (eflag)
    {
      c = linestart[linelen];
      linestart[linelen] = 0;
    }
  else if (xflag == 0)
    {
      sprintf (tem, strlen (linestart) < 50 ? "%s$" : "%.50s", linestart);
      linestart = tem;
    }
  np->pat = savestr (linestart);
  if (eflag)
    {
      linestart[linelen] = c;
    }

  add_node (np, &head);
}

/*
 * free_tree ()
 *	recurse on left children, iterate on right children.
 */
void
free_tree (node)
     register NODE *node;
{
  while (node)
    {
      register NODE *node_right = node->right;
      free_tree (node->left);
      free (node->name);
      free (node->pat);
      free ((char *) node);
      node = node_right;
    }
}

/*
 * add_node ()
 *	Adds a node to the tree of nodes.  In etags mode, we don't keep
 *	it sorted; we just keep a linear list.  In ctags mode, maintain
 *	an ordered tree, with no attempt at balancing.
 *
 *	add_node is the only function allowed to add nodes, so it can
 *	maintain state.
 */
void
add_node (node, cur_node_p)
     NODE *node, **cur_node_p;
{
  register int dif;
  register NODE *cur_node = *cur_node_p;
  static NODE *last_node = NULL;	/* careful */

  if (cur_node == NULL)
    {
      *cur_node_p = node;
      last_node = node;
      return;
    }

  if (eflag)
    {
      /* Etags Mode */
      if (!last_node)
	  fatal ("internal error in add_node");
      last_node->right = node;
      last_node = node;
    }
  else
    {
      /* Ctags Mode */
      dif = strcmp (node->name, cur_node->name);

      /*
       * If this tag name matches an existing one, then
       * do not add the node, but maybe print a warning.
       */
      if (!dif)
	{
	  if (node->file == cur_node->file)
	    {
	      if (!wflag)
		{
		  fprintf (stderr,"Duplicate entry in file %s, line %d: %s\n",
			   node->file,lineno,node->name);
		  fprintf (stderr,"Second entry ignored\n");
		}
	      return;
	    }
	  if (!cur_node->been_warned && !wflag)
	    {
	      fprintf (stderr,
		       "Duplicate entry in files %s and %s: %s (Warning only)\n",
		       node->file, cur_node->file, node->name);
	    }
	  cur_node->been_warned = TRUE;
	  return;
	} 

      /* Actually add the node */
      add_node (node, dif < 0 ? &cur_node->left : &cur_node->right);
    }
}

void
put_entries (node)
     reg NODE *node;
{
  reg char *sp;

  if (node == NULL)
    return;

  /* Output subentries that precede this one */
  put_entries (node->left);

  /* Output this entry */

  if (eflag)
    {
      if (node->rewritten)
	{
#ifdef MSDOS
	  fprintf (outf, "%s\177%d,%d,\001%s\n",
		   node->pat, node->lno, node->cno - (node->lno - 1),
		   node->name);
#else
	  fprintf (outf, "%s\177%d,%d,\001%s\n",
		   node->pat, node->lno, node->cno, node->name);
#endif
	}
      else
	{
#ifdef MSDOS
	  fprintf (outf, "%s\177%d,%d\n",
		   node->pat, node->lno, node->cno - (node->lno - 1));
#else
	  fprintf (outf, "%s\177%d,%d\n",
		   node->pat, node->lno, node->cno);
#endif
	}
    }
  else if (!xflag)
    {
      fprintf (outf, "%s\t%s\t",
	       node->name, node->file);

      if (node->is_func)
	{		/* a function */
	  putc (searchar, outf);
	  putc ('^', outf);

	  for (sp = node->pat; *sp; sp++)
	    {
	      if (*sp == '\\' || *sp == searchar)
		putc ('\\', outf);
	      putc (*sp, outf);
	    }
	  putc (searchar, outf);
	}
      else
	{		/* a typedef; text pattern inadequate */
	  fprintf (outf, "%d", node->lno);
	}
      putc ('\n', outf);
    }
  else if (vflag)
    fprintf (stdout, "%s %s %d\n",
	     node->name, node->file, (node->lno+63)/64);
  else
    fprintf (stdout, "%-16s%4d %-16s %s\n",
	     node->name, node->lno, node->file, node->pat);

  /* Output subentries that follow this one */
  put_entries (node->right);
}

/* Length of a number's decimal representation. */
int
number_len (num)
     long num;
{
  int len = 0;
  if (!num)
    return 1;
  for (; num; num /= 10)
    ++len;
  return len;
}
  
/*
 * Return total number of characters that put_entries will output for
 * the nodes in the subtree of the specified node.  Works only if eflag
 * is set, but called only in that case.  This count is irrelevant with
 * the new tags.el, but is still supplied for backward compatibility.
 */
int
total_size_of_entries (node)
     reg NODE *node;
{
  reg int total;

  if (node == NULL)
    return 0;

  total = 0;
  for ( ; node; node = node->right)
    {
      /* Count left subentries. */
      total += total_size_of_entries (node->left);

      /* Count this entry */
      total += strlen (node->pat) + 1;
      total += number_len ((long) node->lno) + 1 + number_len (node->cno) + 1;
      if (node->rewritten)
	total += 2 + strlen (node->name); /* ,\001name */
    }

  return total;
}

/*
 * The C symbol tables.
 */

Stab *C_stab, *C_PLPL_stab, *C_STAR_stab;

/*
 * SYNOPSIS
 *	Stab *get_C_stab (int c_ext);
 */
#define get_C_stab(c_ext) ((c_ext&C_STAR) ? C_STAR_stab :		\
			   c_ext ? C_PLPL_stab :			\
			   C_stab)

void
add_keyword (stab, sym, type)
     Stab *stab;
     char *sym;
     enum sym_type type;
{
  stab_search (stab, sym, strlen (sym))->type = type;
}

Stab *
C_create_stab (c_ext)
     int c_ext;
{
  Stab *stab;
  
  stab = stab_create ();

  /* C, C++ and C* */
  if (c_ext&C_PLPL)
    add_keyword (stab, "class", st_C_struct);
  if (c_ext&C_STAR)
    add_keyword (stab, "domain", st_C_struct);
  add_keyword (stab, "union", st_C_struct);
  add_keyword (stab, "struct", st_C_struct);
  add_keyword (stab, "enum", st_C_enum);
  add_keyword (stab, "typedef", st_C_typedef);
  add_keyword (stab, "define", st_C_define);

  return stab;
}

void
C_create_stabs ()
{
  C_stab = C_create_stab (0);
  C_PLPL_stab = C_create_stab (C_PLPL);
  C_STAR_stab = C_create_stab (C_STAR|C_PLPL);
}

/*
 * C_entries ()
 *	This routine finds functions and typedefs in C syntax and adds them
 *	to the list.
 */

#define CNL_SAVE_DEFINEDEF						\
{									\
  prev_linepos = linepos;						\
  SET_FILEPOS (linepos, inf, charno);					\
  lineno++;								\
  charno += readline (&lb, inf);					\
  lp = lb.buffer;							\
}

#define CNL								\
{									\
  CNL_SAVE_DEFINEDEF;							\
  definedef = dnone;							\
}

void
C_entries (c_ext)
     int c_ext;		/* extension of C? */
{
  register int c;	/* latest char read; '\0' for end of line */
  register int tokoff;	/* offset in line of beginning of latest token */
  register int toklen;	/* length of latest token */
  register char *lp;	/* pointer one beyond the character `c' */
  logical incomm, inquote, inchar, midtoken;
  int level;		/* current curly brace level */
  char tokb[BUFSIZ];

  lineno = 0;
  charno = 0;
  lp = lb.buffer;
  *lp = 0;

  definedef = dnone;
  gotone = midtoken = inquote = inchar = incomm = FALSE;
  level = 0;

  C_create_stabs ();

  while (! feof (inf))
    {
      c = *lp++;
      if (c == 0)
	{
	  CNL;
	  gotone = FALSE;
	}
      if (c == '\\')
	{
	  c = *lp++;
	  if (c == 0)
	    {
	      CNL_SAVE_DEFINEDEF;
	    }
	  c = ' ';
	} 
      else if (incomm)
	{
	  if (c == '*')
	    {
	      while ((c = *lp++) == '*')
		continue;
	      if (c == 0)
		{
		  CNL;
		}
	      if (c == '/')
		incomm = FALSE;
	    }
	}
      else if (inquote)
	{
	  /*
	  * Too dumb to know about \" not being magic, but
	  * they usually occur in pairs anyway.
	  */
	  if (c == '"')
	    inquote = FALSE;
	  continue;
	}
      else if (inchar)
	{
	  if (c == '\'')
	    inchar = FALSE;
	  continue;
	}
      else switch (c)
	{
	case '"':
	  inquote = TRUE;
	  continue;
	case '\'':
	  inchar = TRUE;
	  continue;
	case '/':
	  if (*lp == '*')
	    {
	      lp++;
	      incomm = TRUE;
	    }
	  else if (c_ext && *lp == '/')
	    {
	      CNL;	/* C++ comment: skip rest of line */
	    }
	  continue;
	case '#':
	  if (lp == lb.buffer + 1 && definedef == dnone)
	    definedef = dsharpseen;
	  continue;

	/*
	 * The next two are to help the strucdef state machine.
	 * They break when they are finished, so they don't interfere
	 * with anything else that is going on.
	 */
        case ':':
	  if (structdef==stagseen)
	    structdef = scolonseen;
	  break;
	/* Not a struct definition when semicolon seen in non-sinbody context. */
	case ';':
	  if (structdef != snone && structdef != sinbody)
	    {
	      structdef = snone;
	      (void) strcpy (structtag, "<error 1>");
	    }
	  break;

	case '{':
	  if (tydef == begin)
	    {
	      tydef = middle;
	    }
	  switch (structdef)
	    {
	    case skeyseen:		/* unnamed struct */
	      structtag[0] = '\0';
	      /* FALLTHRU */
	    case stagseen:
	    case scolonseen:		/* named struct */
	      structdef = sinbody;
	      break;
	    }
	  level++;
	  continue;
	case '}':
	  if (!noindentflag && lp == lb.buffer + 1)
	    level = 0;	/* reset level if first column */
	  else if (level > 0)
	    level--;
	  if (level==0 && tydef==middle)
	    {
	      tydef=end;
	    }
	  if (level==0)
	    {
	      structdef = snone;
	      (void) strcpy (structtag, "<error 2>");
	    }
	  continue;
	}
      if (LEVEL_OK_FOR_FUNCDEF () && !inquote && !incomm && gotone == FALSE)
	{
	  if (midtoken)
	    {
	      if (endtoken (c))
		{
		  if (c_ext && c==':' && *lp==':' && intoken (*(lp+1)))
		    {
		      /*
		       * This handles :: in the middle, but not at beginning
		       * of an identifier.
		       */
		      lp += 2;
		      toklen += 3;
		    }
		  else
		    {
		      /*
		       * We've just finished lexing an identifier.
		       * Note that if `c' is '\0', `lb' is the NEXT
		       * line, `lp' points to the beginning of it, and
		       * old pointers into `lb.buffer' may no longer be
		       * valid, since `lb.buffer' may have been
		       * reallocated.  In this case (which corresponds
		       * to an identifier followed immediately by a
		       * newline), we re-read the line into lb1.
		       *
		       * This would be faster if the previous line's
		       * buffer were always saved.
		       */
		      logical is_func;
		      char *tok_linebuf;
		      TOKEN tok;
		      logical bingo, tok_at_end_of_line;
		      char *lp_tmp;	/* addressable */

		      if (c == '\0')
			{
			  getline (GET_COOKIE (prev_linepos));
			  tok_linebuf = lb1.buffer;
			  tok_at_end_of_line = TRUE;
			  tok.linestart = prev_linepos;
			  tok.lineno = lineno - 1;
			}
		      else
			{
			  tok_linebuf = lb.buffer;
			  tok_at_end_of_line = FALSE;
			  tok.linestart = linepos;
			  tok.lineno = lineno;
			}
		      tok.p = tok_linebuf + tokoff;
		      tok.len = toklen;
		      tok.rewritten = FALSE;
		      lp_tmp = lp;
		      bingo = consider_token (c, &lp_tmp, &tok,
					      &is_func, c_ext, level);
		      lp = lp_tmp;
		      if (bingo)
			{
			  if (GET_CHARNO (tok.linestart) != GET_CHARNO (linepos)
			      && !tok_at_end_of_line)
			    {
			      /*
			       * Resynchronize tok.p to point into the right
			       * linebuffer.
			       */
			      getline (GET_COOKIE (tok.linestart));
			      if (!tok.rewritten)
				tok.p = lb1.buffer + (tok.p - tok_linebuf);
			      tok_linebuf = lb1.buffer;
			    }
			  if (structdef==sinbody && definedef==dnone && is_func)
			    { 	/* function defined in C++ class body */
			      sprintf (tokb, "%s::%.*s",
				       structtag[0]=='\0' ? "_anonymous_"
				       			  : structtag,
				       tok.len, tok.p);
			      tok.rewritten = TRUE;
			    }
			  else
			    {
			      sprintf (tokb, "%.*s", tok.len, tok.p);
			    }
			  pfnote (tokb, is_func, tok.rewritten, tok_linebuf,
				  tokoff + toklen + (tok_at_end_of_line?0:1),
				  tok.lineno, GET_CHARNO (tok.linestart));
			  gotone = is_func;	/* function */
			}
		      midtoken = FALSE;
		    }
	        }
	      else if (intoken (c))
		toklen++;
	    }
	  else if (begtoken (c))
	    {
	      tokoff = lp - 1 - lb.buffer;
	      toklen = 1;
	      midtoken = TRUE;
	    }
	}
      if (c == ';'  &&  tydef==end)	/* clean with typedefs */
	tydef=none;
    }
}

/*
 * consider_token ()
 *	checks to see if the current token is at the start of a
 *	function, or corresponds to a typedef.  It updates the input
 *	line pointer *LPP so that the '(' will be in it when it returns.
 *
 *	*IS_FUNC gets TRUE iff the token is a function.
 *	C_EXT is which language we are looking at.
 *
 *	In the future we will need some way to adjust where the end of
 *	the token is; for instance, implementing the C++ keyword
 *	`operator' properly will adjust the end of the token to be after
 *	whatever follows `operator'.
 *
 * Globals
 *	structdef	IN OUT
 *	definedef	IN OUT
 *	tydef		IN OUT
 */

logical
consider_token (c, lpp, tokp, is_func, c_ext, level)
     reg char c;	/* IN: first char after the token */
     char **lpp;	/* IN OUT: *lpp points to 2nd char after the token */
     reg TOKEN *tokp;	/* IN */
     logical *is_func;	/* OUT */
     int c_ext;		/* IN */
     int level;		/* IN */
{
  reg char *lp = *lpp;
  /*
   * next_token_is_func
   *	set this to TRUE, and the next token considered is called a function.
   */
  static logical next_token_is_func;
  logical firsttok;	/* TRUE if have seen first token in ()'s */
  Stab_entry *tokse = stab_find (get_C_stab (c_ext), tokp->p, tokp->len);
  enum sym_type toktype = stab_type (tokse);
 
  *is_func = TRUE;			/* a function */

  /*
   * Advance the definedef state machine.  We set `gotone' for good measure;
   * it's redundant.
   */
  switch (definedef)
    {
    case dnone:
      /* We're not on a preprocessor line. */
      break;
    case dsharpseen:
      if (toktype == st_C_define)
	{
	  definedef = ddefineseen;
	  gotone = FALSE;
	}
      else
	{
	  definedef = dignorerest;
	  gotone = TRUE;
	}
      goto badone;
    case ddefineseen:
      /*
       * Make a tag for any macro.
       * This will flub up if there is a newline immediately following
       * the macro name.
       */
      *is_func = (c == '(');
      definedef = dignorerest;
      gotone = TRUE;
      if (!*is_func && !constantflag)
	goto badone;
      goto goodone;
    case dignorerest:
      goto badone;
    default:
      error ("internal error: definedef value");
    }

  /*
   * Skip whitespace and comments after the token.  This loop should
   * also skip C++ comments.
   */
  while (1)
    {
      /* At whitespace => skip it.  */
      if (iswhite (c))
	{
	  c = *lp++;
	}
      /* At a comment => skip to end of comment.  */
      else if (c == '/' && *lp == '*')
	{
	  /* If we find a comment, skip it.  */
	  while (!(c == '*' && *lp == '/'))
	    {
	      c = *lp++;
	      if (c == 0)
		{
		  if (feof (inf))
		    break;
		  CNL;
		}
	    }
	  if (c == '*' && *lp == '/')
	    {
	      lp++;		/* lp now points past the '/' */
	      c = *lp++;	/* c is now the --whatever-- after the '/' */
	    }
	}
      else
	break;

      /* If we arrived at eof or eol, decide which one it is.
	 If it's eol, advance to the next line.  */

      if (c == 0)
	{
	  if (feof (inf))
	    break;
	  CNL;
	}
    }

  /*
   * If you have custom token types, or when configuration files can
   * define custom token types, this switch will be larger.
   */
  switch (toktype)
    {
    case st_C_typedef:
      if (tflag)
	{
	  tydef = begin;
	  goto badone;
	}
      break;
    }
  
  /*
   * This structdef business is currently only invoked when level==0.
   * It should be recursively invoked whatever the level, and a stack of
   * states kept, to allow for definitions of structs within structs.
   *
   * This structdef business is NOT invoked when we are ctags and the
   * file is plain C.  This is because a struct tag may have the same
   * name as another tag, and this loses with ctags.
   *
   * This if statement deals with the tydef state machine as follows: if
   * tydef==begin and token is struct/union/class/enum, goto badone.
   * All the other code here is for the structdef state machine.
   */
  switch (toktype)
    {
    case st_C_struct:
    case st_C_enum:
      if (tydef==begin || (strflag && level==0 && structdef==snone))
	{
	  structdef = skeyseen;
	  structkey = tokse;
	}
      goto badone;
    }

  if (structdef==skeyseen)
    {
      /* If next char is '{' or (for C++) ':', found a structure tag. */
      if (c == '{' || c_ext && c == ':')
	{
	  /*
	   * We should do this slightly differently for straight C:
	   * instead of defining `tag', as we now do, we should define
	   * `struct tag'.  (Do this only if the find-tag defaulting is
	   * done on a sophisticated per-mode basis, so that if the user
	   * says meta-. anywhere in `struct foo', the default comes out
	   * `struct foo', not `struct' or `foo'.)  This will require
	   * remembering which keyword (struct/union/class/enum) we saw, as a
	   * Stab_entry* -- this will also make it possible to merge the
	   * skeyseen and senumseen states, if we want.
	   */
	  if (stab_type (structkey) == st_C_struct)
	    {
	      (void) strncpy (structtag, tokp->p, tokp->len);
	      structtag[tokp->len] = '\0';	/* for struct/union/class */
	      structdef = stagseen;
	    }
	  else
	    {
	      structtag[0] = '\0';		/* for enum */
	    }
	  *is_func = FALSE;	/* not a function */
	  goto goodone;
	}
      else
	{
	  /* Not a definition: reset structdef */
	  structdef = snone;
	  (void) strcpy (structtag, "<error 3>");
	}
      /* Now what?  And how does/should this stuff interact with tydef?? */
      /* Also maybe reset lp to *lpp for benefit of the function finding code. */
    }
  if (tydef==begin)
    {
      tydef=end;
      goto badone;
    }
  if (tydef==end)
    {
      *is_func = 0;
      goto goodone;
    }
  /* Detect GNUmacs's function-defining macros. */
  if (definedef == dnone && strneq (tokp->p, "DEF", 3))
    {
      next_token_is_func = TRUE;
      goto badone;
    }
  if (next_token_is_func)
    {
      next_token_is_func = FALSE;
      goto goodone;
    }
  if (c != '(')
    goto badone;
  firsttok = FALSE;
  while ((c = *lp++) != ')')
    {
      if (c == 0)
	{
	  if (feof (inf))
	    break;
	  CNL;
	}
      /*
	* This line used to confuse ctags:
	*	int	(*oldhup)();
	* This fixes it. A nonwhite char before the first
	* token, other than a / (in case of a comment in there)
	* makes this not a declaration.
	*/
      if (begtoken (c) || c=='/') firsttok++;
      else if (! iswhite (c) && !firsttok) goto badone;
    }
  while (iswhite (c = *lp++))
    {
      if (c == 0)
	{
	  if (feof (inf))
	    break;
	  CNL;
	}
    }
  if (! isgood (c))
    goto badone;

 goodone:
  *lpp = lp - 1;
  return TRUE;

 badone:
  *lpp = lp - 1;
  return FALSE;
}

void
getline (atcookie)
     long atcookie;
{
  long saveftell = ftell (inf);

  (void) fseek (inf, atcookie, 0);
  (void) readline (&lb1, inf);
  (void) fseek (inf, saveftell, 0);
}

/* Fortran parsing */

char	*dbp;
int	pfcnt;

int
PF_funcs (fi)
     FILE *fi;
{
  lineno = 0;
  charno = 0;
  pfcnt = 0;

  while (! feof (fi))
    {
      lineno++;
      linecharno = charno;
      charno += readline (&lb, fi);
      dbp = lb.buffer;
      if (*dbp == '%') dbp++ ;	/* Ratfor escape to fortran */
      while (isspace (*dbp))
	dbp++;
      if (*dbp == 0)
	continue;
      switch (*dbp |' ')
	{
	case 'i':
	  if (tail ("integer"))
	    takeprec ();
	  break;
	case 'r':
	  if (tail ("real"))
	    takeprec ();
	  break;
	case 'l':
	  if (tail ("logical"))
	    takeprec ();
	  break;
	case 'c':
	  if (tail ("complex") || tail ("character"))
	    takeprec ();
	  break;
	case 'd':
	  if (tail ("double"))
	    {
	      while (isspace (*dbp))
		dbp++;
	      if (*dbp == 0)
		continue;
	      if (tail ("precision"))
		break;
	      continue;
	    }
	  break;
	}
      while (isspace (*dbp))
	dbp++;
      if (*dbp == 0)
	continue;
      switch (*dbp|' ')
	{
	case 'f':
	  if (tail ("function"))
	    getit ();
	  continue;
	case 's':
	  if (tail ("subroutine"))
	    getit ();
	  continue;
	case 'p':
	  if (tail ("program"))
	    {
	      getit ();
	      continue;
	    }
	  if (tail ("procedure"))
	    getit ();
	  continue;
	}
    }
  return (pfcnt);
}

logical
tail (cp)
     char *cp;
{
  register int len = 0;

  while (*cp && (*cp&~' ') == ((*(dbp+len))&~' '))
    cp++, len++;
  if (*cp == 0)
    {
      dbp += len;
      return (1);
    }
  return (0);
}

void
takeprec ()
{
  while (isspace (*dbp))
    dbp++;
  if (*dbp != '*')
    return;
  dbp++;
  while (isspace (*dbp))
    dbp++;
  if (! isdigit (*dbp))
    {
      --dbp;		/* force failure */
      return;
    }
  do
    dbp++;
  while (isdigit (*dbp));
}

void
getit ()
{
  register char *cp;
  char c;
  char nambuf[BUFSIZ];

  while (isspace (*dbp))
    dbp++;
  if (*dbp == 0 || (!isalpha(*dbp)) && (*dbp != '_'))
    return;
  for (cp = dbp+1; *cp && (isalpha(*cp) || isdigit(*cp) || (*cp == '_')); cp++)
    continue;
  c = cp[0];
  cp[0] = 0;
  (void) strcpy (nambuf, dbp);
  cp[0] = c;
  pfnote (nambuf, TRUE, FALSE, lb.buffer, cp - lb.buffer + 1, lineno, linecharno);
  pfcnt++;
}

/* Handle a file of assembler code.  */

void Asm_funcs (fi)
     FILE *fi;
{
  int i;
  register char c;

  lineno = 0;
  charno = 0;
  pfcnt = 0;

  while (! feof (fi))
    {
      lineno++;
      linecharno = charno;
      charno += readline (&lb, fi);
      dbp = lb.buffer;

      for (i = 0; ((c = dbp[i]) && !isspace(c)) && (c != ':') ; i++)
	;

      if ((i > 0) && (c == ':'))
	getit();
    }
}

/*
 * lisp tag functions
 * just look for (def or (DEF
 */

void
L_funcs (fi)
     FILE *fi;
{
  lineno = 0;
  charno = 0;
  pfcnt = 0;

  while (! feof (fi))
    {
      lineno++;
      linecharno = charno;
      charno += readline (&lb, fi);
      dbp = lb.buffer;
      if (dbp[0] == '(' && 
	  (dbp[1] == 'D' || dbp[1] == 'd') &&
	    (dbp[2] == 'E' || dbp[2] == 'e') &&
	      (dbp[3] == 'F' || dbp[3] == 'f'))
	{
	  while (! isspace (*dbp)) dbp++;
	  while (isspace (*dbp)) dbp++;
	  L_getit ();
	}
    }
}

void
L_getit ()
{
  register char *cp;
  char c;
  char nambuf[BUFSIZ];

  if (*dbp == 0) return;
  for (cp = dbp+1; *cp && *cp != '(' && *cp != ' '; cp++)
    continue;
  c = cp[0];
  cp[0] = 0;
  (void) strcpy (nambuf, dbp);
  cp[0] = c;
  pfnote (nambuf, TRUE, FALSE, lb.buffer, cp - lb.buffer + 1, lineno, linecharno);
  pfcnt++;
}

/*
 * Scheme tag functions
 * look for (def... xyzzy
 * look for (def... (xyzzy
 * look for (def ... ((...(xyzzy ....
 * look for (set! xyzzy
 */

#ifndef __STDC__
/* ANSI C prototypes are declared elsewhere ... */
static void get_scheme ();
#endif

void
Scheme_funcs (fi)
     FILE *fi;
{
  lineno = 0;
  charno = 0;
  pfcnt = 0;

  while (! feof (fi))
    {
      lineno++;
      linecharno = charno;
      charno += readline (&lb, fi);
      dbp = lb.buffer;
      if (dbp[0] == '(' && 
	  (dbp[1] == 'D' || dbp[1] == 'd') &&
	    (dbp[2] == 'E' || dbp[2] == 'e') &&
	      (dbp[3] == 'F' || dbp[3] == 'f'))
	{
	  while (! isspace (*dbp)) dbp++;
          /* Skip over open parens and white space */
          while (*dbp && (isspace (*dbp) || *dbp == '(')) dbp++;
	  get_scheme ();
	}
      if (dbp[0] == '(' && 
	  (dbp[1] == 'S' || dbp[1] == 's') &&
	    (dbp[2] == 'E' || dbp[2] == 'e') &&
	      (dbp[3] == 'T' || dbp[3] == 't') &&
                (dbp[4] == '!' || dbp[4] == '!') &&
                  (isspace (dbp[5])))
	{
	  while (! isspace (*dbp)) dbp++;
          /* Skip over white space */
          while (isspace (*dbp)) dbp++;
	  get_scheme ();
	}
    }
}

static void
get_scheme ()
{
  register char *cp;
  char c;
  char nambuf[BUFSIZ];

  if (*dbp == 0) return;
  /* Go till you get to white space or a syntactic break */
  for (cp = dbp+1; *cp && *cp != '(' && *cp != ')' && ! isspace (*cp); cp++)
    continue;
  /* Null terminate the string there. */
  c = cp[0];
  cp[0] = 0;
  /* Copy the string */
  strcpy (nambuf, dbp);
  /* Unterminate the string */
  cp[0] = c;
  /* Announce the change */
  pfnote (nambuf, TRUE, FALSE, lb.buffer, cp - lb.buffer + 1, lineno, linecharno);
  pfcnt++;
}

/* Find tags in TeX and LaTeX input files.  */

/* TEX_toktab is a table of TeX control sequences that define tags.
   Each TEX_tabent records one such control sequence.
   CONVERT THIS TO USE THE Stab TYPE!! */

struct TEX_tabent
{
  char *name;
  int len;
};

struct TEX_tabent *TEX_toktab = NULL; /* Table with tag tokens */

/* Default set of control sequences to put into TEX_toktab.
   The value of environment var TEXTAGS is prepended to this.  */

static char *TEX_defenv =
  ":chapter:section:subsection:subsubsection:eqno:label:ref:cite:bibitem:typeout";

void TEX_mode ();
struct TEX_tabent *TEX_decode_env (); 
void TEX_getit ();
int TEX_Token ();

static char TEX_esc = '\\';
static char TEX_opgrp = '{';
static char TEX_clgrp = '}';

/*
 * TeX/LaTeX scanning loop.
 */

void
TEX_funcs (fi)
    FILE *fi;
{
  char *lasthit;

  lineno = 0;
  charno = 0;
  pfcnt = 0;

  /* Select either \ or ! as escape character.  */
  TEX_mode (fi);

  /* Initialize token table once from environment. */
  if (!TEX_toktab)
    TEX_toktab = TEX_decode_env ("TEXTAGS", TEX_defenv);

  while (! feof (fi))
    {
      lineno++;
      linecharno = charno;
      charno += readline (&lb, fi);
      dbp = lb.buffer;
      lasthit = dbp;

      while (! feof (fi))
	{	/* Scan each line in file */
	  lineno++;
	  linecharno = charno;
	  charno += readline (&lb, fi);
	  dbp = lb.buffer;
	  lasthit = dbp;
	  while (dbp = strchr (dbp, TEX_esc)) /* Look at each escape in line */
	    {
	      register int i;

	      if (! *(++dbp))
		break;
	      linecharno += dbp - lasthit;
	      lasthit = dbp;
	      i = TEX_Token (lasthit);
	      if (0 <= i)
		{
		  TEX_getit (lasthit, TEX_toktab[i].len);
		  break;		/* We only save a line once */
		}
	    }
	}
    }
}

#define TEX_LESC '\\'
#define TEX_SESC '!'

/* Figure out whether TeX's escapechar is '\\' or '!' and set grouping */
/* chars accordingly. */

void
TEX_mode (f)
     FILE *f;
{
  int c;

  while ((c = getc (f)) != EOF)
    if (c == TEX_LESC || c == TEX_SESC)
      break;

  if (c == TEX_LESC)
    {
      TEX_esc = TEX_LESC;
      TEX_opgrp = '{';
      TEX_clgrp = '}';
    } 
  else
    {
      TEX_esc = TEX_SESC;
      TEX_opgrp = '<';
      TEX_clgrp = '>';
    }
  rewind (f);
}

/* Read environment and prepend it to the default string. */
/* Build token table. */

struct TEX_tabent *
TEX_decode_env (evarname, defenv)
     char *evarname;
     char *defenv;
{
  register char *env, *p;
  extern char *savenstr ();
#ifndef __STDC__
  extern char *strchr ();
#endif

  struct TEX_tabent *tab;
  int size, i;

  /* Append default string to environment. */
  env = getenv (evarname);
  if (!env)
    env = defenv;
  else
    env = concat (env, defenv, "");

  /* Allocate a token table */
  for (size = 1, p=env; p;)
    if ((p = strchr (p, ':')) && *(++p))
      size++;
  tab = xnew (size, struct TEX_tabent);

  /* Unpack environment string into token table. Be careful about */
  /* zero-length strings (leading ':', "::" and trailing ':') */
  for (i = 0; *env;)
    {
      p = strchr (env, ':');
      if (!p)			/* End of environment string. */
	p = env + strlen (env);
      if (p - env > 0)
	{	/* Only non-zero strings. */
	  tab[i].name = savenstr (env, p - env);
	  tab[i].len = strlen (tab[i].name);
	  i++;
	}
      if (*p)
	env = p + 1;
      else
	{
	  tab[i].name = NULL;	/* Mark end of table. */
	  tab[i].len = 0;
	  break;
	}
    }
  return tab;
}

/* Record a tag defined by a TeX command of length LEN and starting at NAME.
   The name being defined actually starts at (NAME + LEN + 1).
   But we seem to include the TeX command in the tag name.  */

void
TEX_getit (name, len)
    char *name;
    int len;
{
  char *p = name + len;
  char nambuf[BUFSIZ];

  if (*name == 0) return;

  /* Let tag name extend to next group close (or end of line) */
  while (*p && *p != TEX_clgrp)
    p++;
  (void) strncpy (nambuf, name, p - name);
  nambuf[p - name] = 0;

  pfnote (nambuf, TRUE, FALSE, lb.buffer, strlen (lb.buffer), lineno, linecharno);
  pfcnt++;
}

/* If the text at CP matches one of the tag-defining TeX command names,
   return the index of that command in TEX_toktab.
   Otherwise return -1.  */

/* Keep the capital `T' in `Token' for dumb truncating compilers
   (this distinguishes it from `TEX_toktab' */
int
TEX_Token (cp)
    char *cp;
{
  int i;

  for (i = 0; TEX_toktab[i].len > 0; i++)
    if (strncmp (TEX_toktab[i].name, cp, TEX_toktab[i].len) == 0)
      return i;
  return -1;
}

/* Initialize a linebuffer for use */

void
initbuffer (linebuffer)
     struct linebuffer *linebuffer;
{
  linebuffer->size = 200;
  linebuffer->buffer = xnew (200, char);
}

/*
 * Read a line of text from `stream' into `linebuffer'.
 * Return the number of characters read from `stream', which is the length of the
 * line including the newline, if any.
 */
long
readline (linebuffer, stream)
     struct linebuffer *linebuffer;
     register FILE *stream;
{
  char *buffer = linebuffer->buffer;
  register char *p = linebuffer->buffer;
  register char *pend = p + linebuffer->size;
  int newline;	/* 1 if ended with newline, 0 if ended with EOF */

  while (1)
    {
      register int c = getc (stream);
      if (p == pend)
	{
	  linebuffer->size *= 2;
	  buffer = (char *) xrealloc (buffer, linebuffer->size);
	  p += buffer - linebuffer->buffer;
	  pend = buffer + linebuffer->size;
	  linebuffer->buffer = buffer;
	}
      if (c < 0 || c == '\n')
	{
	  *p = 0;
	  newline = (c == '\n' ? 1 : 0);
	  break;
	}
      *p++ = c;
    }

  return p - buffer + newline;
}

char *
savestr (cp)
     char *cp;
{
  return savenstr (cp, strlen (cp));
}

char *
savenstr (cp, len)
    char *cp;
    int len;
{
  register char *dp;

  dp = xnew (len + 1, char);
  (void) strncpy (dp, cp, len);
  dp[len] = '\0';
  return dp;
}

#if 0
/*
 * Return the ptr in sp at which the character c last
 * appears; NULL if not found
 *
 * Identical to ANSI C strrchr, included in case it's needed.
 */

char *
strrchr (sp, c)
     register char *sp, c;
{
  register char *r;

  r = NULL;
  do
    {
      if (*sp == c)
	r = sp;
    } while (*sp++);
  return (r);
}

/*
 * Return the ptr in sp at which the character c first
 * appears; NULL if not found
 *
 * Identical to ANSI C strchr, included for portability.
 */

char *
strchr (sp, c)
     register char *sp, c;
{
  do
    {
      if (*sp == c)
	return (sp);
    } while (*sp++);
  return (NULL);
}

#endif /* 0 */

/* Print error message and exit.  */

/* VARARGS1 */
#ifdef __STDC__
void
fatal (const char *s1, ...)
{
  va_list	args;

  va_start(args, s1);
  fprintf (stderr, "%s: ", progname);
  vfprintf (stderr, s1, args);
  fprintf (stderr, "\n");
  va_end(args);
  exit (1);
}
#else
void
fatal (s1, s2)
     char *s1, *s2;
{
  error (s1, s2);
  exit (1);
}
#endif

/* Print error message.  `s1' is printf control string, `s2' is arg for it. */

/* VARARGS1 */
#ifdef __STDC__

void
error (const char *s1, ...)
{
  va_list	args;

  va_start(args, s1);
  fprintf (stderr, "%s: ", progname);
  vfprintf (stderr, s1, args);
  fprintf (stderr, "\n");
  va_end(args);
}

#else

void
error (s1, s2)
     char *s1, *s2;
{
  fprintf (stderr, "%s: ", progname);
  fprintf (stderr, s1, s2);
  fprintf (stderr, "\n");
}

#endif

/* Return a newly-allocated string whose contents concatenate those of s1, s2, s3.  */

char *
concat (s1, s2, s3)
     char *s1, *s2, *s3;
{
  int len1 = strlen (s1), len2 = strlen (s2), len3 = strlen (s3);
  char *result = xnew (len1 + len2 + len3 + 1, char);

  (void) strcpy (result, s1);
  (void) strcpy (result + len1, s2);
  (void) strcpy (result + len1 + len2, s3);
  *(result + len1 + len2 + len3) = 0;

  return result;
}

/* Like malloc but get fatal error if memory is exhausted.  */

char *
xmalloc (size)
     int size;
{
  char *result = malloc (size);
  if (!result)
    fatal ("virtual memory exhausted", 0);
  return result;
}

char *
xrealloc (ptr, size)
     char *ptr;
     long size;
{
  char *result = realloc (ptr, size);
  if (!result)
    fatal ("virtual memory exhausted");
  return result;
}
