cpp4.c

类PASCAL语言的编译器,LINUX环境的,我没试过是否正确.

  else {
    scanid(global, c);                         /* Get name to tokenbuf */
    (void) defendel(global, global->tokenbuf, TRUE);
  }
}

INLINE FILE_LOCAL  
ReturnCode textput(struct Global *global, char *text)
{
  /*
   * Put the string in the parm[] buffer.
   */

  int size;
  
  size = strlen(text) + 1;
  if ((global->parmp + size) >= &global->parm[NPARMWORK]) {
    cfatal(global, FATAL_MACRO_AREA_OVERFLOW);
    return(FPP_WORK_AREA_OVERFLOW);
  } else {
    strcpy(global->parmp, text);
    global->parmp += size;
  }
  return(FPP_OK);
}

FILE_LOCAL
ReturnCode charput(struct Global *global, int c)
{
  /*
   * Put the byte in the parm[] buffer.
   */
  
  if (global->parmp >= &global->parm[NPARMWORK]) {
    cfatal(global, FATAL_MACRO_AREA_OVERFLOW);
    return(FPP_WORK_AREA_OVERFLOW);
  }
  *global->parmp++ = c;
  return(FPP_OK);
}

/*
 *		M a c r o   E x p a n s i o n
 */

ReturnCode expand(struct Global *global, DEFBUF *tokenp)
{
  /*
   * Expand a macro.  Called from the cpp mainline routine (via subroutine
   * macroid()) when a token is found in the symbol table.  It calls
   * expcollect() to parse actual parameters, checking for the correct number.
   * It then creates a "file" containing a single line containing the
   * macro with actual parameters inserted appropriately.  This is
   * "pushed back" onto the input stream.  (When the get() routine runs
   * off the end of the macro line, it will dismiss the macro itself.)
   */
  int c;
  FILEINFO *file;
  ReturnCode ret=FPP_OK;
      
  /*
   * If no macro is pending, save the name of this macro
   * for an eventual error message.
   */
  if (global->recursion++ == 0)
    global->macro = tokenp;
  else if (global->recursion == RECURSION_LIMIT) {
    cerror(global, ERROR_RECURSIVE_MACRO, tokenp->name, global->macro->name);
    if (global->rec_recover) {
      do {
	c = get(global);
      } while (global->infile != NULL && global->infile->fp == NULL);
      unget(global);
      global->recursion = 0;
      return(FPP_OK);
    }
  }
  /*
   * Here's a macro to expand.
   */
  global->nargs = 0;			/* Formals counter	*/
  global->parmp = global->parm;		/* Setup parm buffer	*/
  switch (tokenp->nargs) {
  case (-2):                              /* __LINE__             */
      if(global->infile->fp)
	  /* This is a file */
	  sprintf(global->work, "%d", global->line);
      else
	  /* This is a macro! Find out the file line number! */
	  for (file = global->infile; file != NULL; file = file->parent) {
	      if (file->fp != NULL) {
		  sprintf(global->work, "%d", file->line);
		  break;
	      }
	  }
      ret=ungetstring(global, global->work);
      if(ret)
	  return(ret);
      break;
    
  case (-3):                              /* __FILE__             */
    for (file = global->infile; file != NULL; file = file->parent) {
      if (file->fp != NULL) {
	sprintf(global->work, "\"%s\"", (file->progname != NULL)
		? file->progname : file->filename);
	ret=ungetstring(global, global->work);
	if(ret)
	  return(ret);
	break;
      }
    }
    break;

  case (-4):				/* __FUNC__ */
    sprintf(global->work, "\"%s\"", global->functionname[0]?
	    global->functionname : "<unknown function>");
    ret=ungetstring(global, global->work);
    if(ret)
	return(ret);
    break;

  case (-5):                              /* __FUNC_LINE__ */
    sprintf(global->work, "%d", global->funcline);
    ret=ungetstring(global, global->work);
    if(ret)
      return(ret);
    break;

  default:
    /*
     * Nothing funny about this macro.
     */
    if (tokenp->nargs < 0) {
      cfatal(global, FATAL_ILLEGAL_MACRO, tokenp->name);
      return(FPP_ILLEGAL_MACRO);
    }
    while ((c = skipws(global)) == '\n')      /* Look for (, skipping */
      global->wrongline = TRUE;		/* spaces and newlines	*/
    if (c != '(') {
      /*
       * If the programmer writes
       *	#define foo() ...
       *	...
       *	foo [no ()]
       * just write foo to the output stream.
       */
      unget(global);
      cwarn(global, WARN_MACRO_NEEDS_ARGUMENTS, tokenp->name);

      /* fputs(tokenp->name, stdout); */
      Putstring(global, tokenp->name);
      return(FPP_OK);
    } else if (!(ret=expcollect(global))) {     /* Collect arguments    */
      if (tokenp->nargs != global->nargs) {     /* Should be an error?  */
	cwarn(global, WARN_WRONG_NUMBER_ARGUMENTS, tokenp->name);
      }
    } else {				/* Collect arguments		*/
      return(ret); /* We failed in argument colleting! */
    }
  case DEF_NOARGS:			/* No parameters just stuffs	*/
    ret=expstuff(global, tokenp->name, tokenp->repl); /* expand macro   */
  }					/* nargs switch 		*/
  return(ret);
}

INLINE FILE_LOCAL
ReturnCode expcollect(struct Global *global)
{
  /*
   * Collect the actual parameters for this macro.
   */

  int c;
  int paren;		    /* For embedded ()'s    */
  ReturnCode ret;
      
  for (;;) {
    paren = 0;			    /* Collect next arg.    */
    while ((c = skipws(global)) == '\n')/* Skip over whitespace */
      global->wrongline = TRUE;		/* and newlines.	*/
    if (c == ')') {                     /* At end of all args?  */
      /*
       * Note that there is a guard byte in parm[]
       * so we don't have to check for overflow here.
       */
      *global->parmp = EOS;	    /* Make sure terminated */
      break;			    /* Exit collection loop */
    }
    else if (global->nargs >= LASTPARM) {
      cfatal(global, FATAL_TOO_MANY_ARGUMENTS_EXPANSION);
      return(FPP_TOO_MANY_ARGUMENTS);
    }
    global->parlist[global->nargs++] = global->parmp; /* At start of new arg */
    for (;; c = cget(global)) {               /* Collect arg's bytes  */
      if (c == EOF_CHAR) {
	cerror(global, ERROR_EOF_IN_ARGUMENT);
	return(FPP_EOF_IN_MACRO); /* Sorry.               */
      }
      else if (c == '\\') {             /* Quote next character */
	charput(global, c);             /* Save the \ for later */
	charput(global, cget(global));  /* Save the next char.  */
	continue;			/* And go get another   */
      }
      else if (type[c] == QUO) {        /* Start of string?     */
	ret=scanstring(global, c, (ReturnCode (*)(struct Global *, int))charput); /* Scan it off    */
	if(ret)
	  return(ret);
	continue;			    /* Go get next char     */
      }
      else if (c == '(')                /* Worry about balance  */
	paren++;			/* To know about commas */
      else if (c == ')') {              /* Other side too       */
	if (paren == 0) {               /* At the end?          */
	  unget(global);                /* Look at it later     */
	  break;			/* Exit arg getter.     */
	}
	paren--;			/* More to come.        */
      }
      else if (c == ',' && paren == 0)  /* Comma delimits args  */
	break;
      else if (c == '\n')               /* Newline inside arg?  */
	global->wrongline = TRUE;	/* We'll need a #line   */
      charput(global, c);               /* Store this one       */
    }				        /* Collect an argument  */
    charput(global, EOS);               /* Terminate argument   */
  }				        /* Collect all args.    */
  return(FPP_OK);                       /* Normal return        */
}
  
  
#if OK_CONCAT
  
INLINE FILE_LOCAL
char *doquoting(char *to, char *from)
{
  *to++ = '"';
  while (*from) {
    if (*from == '\\' || *from == '"')
      *to++ = '\\';
    *to++ = *from++;
  }
  *to++ = '"';
      
  return to;
}
  
#endif
  
ReturnCode expstuff(struct Global *global,
		    char *MacroName,
		    char *MacroReplace)
{
  /*
   * Stuff the macro body, replacing formal parameters by actual parameters.
   */
  int c;		/* Current character	*/
  char *inp;		/* -> repl string	*/
  char *defp;		/* -> macro output buff */
  int size;		/* Actual parm. size	*/
  char *defend;		/* -> output buff end	*/
  int string_magic;	/* String formal hack	*/
  FILEINFO *file;	/* Funny #include	*/
  ReturnCode ret;
#if OK_CONCAT
  char quoting;	/* Quote macro argument */
#endif
      
  ret = getfile(global, NBUFF, MacroName, &file);
  if(ret)
    return(ret);
  inp = MacroReplace;			/* -> macro replacement */
  defp = file->buffer;			/* -> output buffer	*/
  defend = defp + (NBUFF - 1);              /* Note its end         */
  if (inp != NULL) {
    quoting = 0;
    while ((c = (*inp++ & 0xFF)) != EOS) {
#if OK_CONCAT
      if (c == QUOTE_PARM) {                /* Special token for #  */
	quoting = 1;			/* set flag, for later	*/
	continue;				/* Get next character	*/
      }
#endif
      if (c >= MAC_PARM && c <= (MAC_PARM + PAR_MAC)) {
	string_magic = (c == (MAC_PARM + PAR_MAC));
	if (string_magic)
	  c = (*inp++ & 0xFF);
	/*
	 * Replace formal parameter by actual parameter string.
	 */
	if ((c -= MAC_PARM) < global->nargs) {
	  size = strlen(global->parlist[c]);
#if OK_CONCAT
	  if (quoting) {
	    size++;
	    size *= 2;		/* worst case condition */
	  }
#endif
	  if ((defp + size) >= defend) {
	    cfatal(global, FATAL_OUT_OF_SPACE_IN_ARGUMENT, MacroName);
	    return(FPP_OUT_OF_SPACE_IN_MACRO_EXPANSION);
	  }
	  /*
	   * Erase the extra set of quotes.
	   */
	  if (string_magic && defp[-1] == global->parlist[c][0]) {
	    strcpy(defp-1, global->parlist[c]);
	    defp += (size - 2);
	  }
#if OK_CONCAT
else if (quoting)
  defp = doquoting(defp, global->parlist[c]);
#endif
else {
  strcpy(defp, global->parlist[c]);
  defp += size;
}
	}
      }
      else if (defp >= defend) {
	cfatal(global, FATAL_OUT_OF_SPACE_IN_ARGUMENT, MacroName);
	return(FPP_OUT_OF_SPACE_IN_MACRO_EXPANSION);
      } else
	*defp++ = c;
      quoting = 0;
    }
  }
  *defp = EOS;
  return(FPP_OK);
}