etags.c

早期freebsd实现

	  continue;
	}
    }
  return (pfcnt);
}

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

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

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));
}

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

  while (isspace(*dbp))
    dbp++;
  if (*dbp == 0 || !isalpha(*dbp))
    return;
  for (cp = dbp+1; *cp && (isalpha(*cp) || isdigit(*cp)); cp++)
    continue;
  c = cp[0];
  cp[0] = 0;
  strcpy(nambuf, dbp);
  cp[0] = c;
  pfnote(nambuf, TRUE, lb.buffer, cp - lb.buffer + 1, lineno, linecharno);
  pfcnt++;
}

/*
 * lisp tag functions
 * just look for (def or (DEF
 */

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

  while (!feof (fi))
    {
      lineno++;
      linecharno = charno;
      charno += readline (&lb, fi) + 1;
      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();
	}
    }
}

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;
  strcpy(nambuf, dbp);
  cp[0] = c;
  pfnote(nambuf, TRUE, 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
 */

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

  while (!feof (fi))
    {
      lineno++;
      linecharno = charno;
      charno += readline (&lb, fi) + 1;
      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
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, 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.  */

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";

struct TEX_tabent *TEX_decode_env (); 

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

/*
 * TeX/LaTeX scanning loop.
 */

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) + 1;
      dbp = lb.buffer;
      lasthit = dbp;

      while (!feof (fi))
	{	/* Scan each line in file */
	  lineno++;
	  linecharno = charno;
	  charno += readline (&lb, fi) + 1;
	  dbp = lb.buffer;
	  lasthit = dbp;
	  while (dbp = index (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. */

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 (), *index ();

  struct TEX_tabent *tab;
  int size, i;

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

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

  /* Unpack environment string into token table. Be careful about */
  /* zero-length strings (leading ':', "::" and trailing ':') */
  for (i = 0; *env;)
    {
      p = index (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.  */

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++;
  strncpy (nambuf, name, p - name);
  nambuf[p - name] = 0;

  pfnote (nambuf, TRUE, 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' */
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 = (char *) xmalloc (200);
}

/* Read a line of text from `stream' into `linebuffer'.
 Return the length of the line.  */

long
readline (linebuffer, stream)
     struct linebuffer *linebuffer;
     register FILE *stream;
{
  char *buffer = linebuffer->buffer;
  register char *p = linebuffer->buffer;
  register char *pend;

  pend = p + linebuffer->size;

  while (1)
    {
      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;
	  break;
	}
      *p++ = c;
    }

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

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

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

/*
 * Return the ptr in sp at which the character c last
 * appears; NULL if not found
 *
 * Identical to v7 rindex, included for portability.
 */

char *
rindex(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 v7 index, included for portability.
 */

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

/* Print error message and exit.  */

fatal (s1, s2)
     char *s1, *s2;
{
  error (s1, s2);
  exit (BAD);
}

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

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

/* 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 = (char *) xmalloc (len1 + len2 + len3 + 1);

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

  return result;
}

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

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

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