cpp4.c

/******************************************************************************
Copyright (c) 1999 Daniel Stenberg

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
******************************************************************************/
#include <stdio.h>
#include <ctype.h>

#include "cppdef.h"
#include "cpp.h"

INLINE FILE_LOCAL ReturnCode fpp_checkparm(struct Global *, int, DEFBUF *, int);
INLINE FILE_LOCAL ReturnCode fpp_stparmscan(struct Global *, int);
INLINE FILE_LOCAL ReturnCode fpp_textput(struct Global *, char *);
FILE_LOCAL ReturnCode fpp_charput(struct Global *, int);
INLINE FILE_LOCAL ReturnCode fpp_expcollect(struct Global *);
INLINE FILE_LOCAL char *fpp_doquoting(char *, char *);


ReturnCode fpp_dodefine(struct Global *global)
{
  /*
   * Called from control when a #define is scanned.  This module
   * parses formal parameters and the replacement string.  When
   * the formal parameter name is encountered in the replacement
   * string, it is replaced by a character in the range 128 to
   * 128+NPARAM (this allows up to 32 parameters within the
   * Dec Multinational range).  If cpp is ported to an EBCDIC
   * machine, you will have to make other arrangements.
   *
   * There is some special case code to distinguish
   *	#define foo	bar
   * from #define foo()   bar
   *
   * Also, we make sure that
   *	#define foo	foo
   * expands to "foo" but doesn't put cpp into an infinite loop.
   *
   * A warning message is printed if you redefine a symbol to a
   * different text.  I.e,
   *	#define foo	123
   *	#define foo	123
   * is ok, but
   *	#define foo	123
   *	#define foo	+123
   * is not.
   *
   * The following subroutines are called from define():
   * fpp_checkparm	called when a token is scanned.  It checks through the
   *		array of formal parameters.  If a match is found, the
   *		token is replaced by a control byte which will be used
   *		to locate the parameter when the macro is expanded.
   * fpp_textput	puts a string in the macro work area (parm[]), updating
   *		parmp to point to the first free byte in parm[].
   *		fpp_textput() tests for work buffer overflow.
   * fpp_charput	puts a single character in the macro work area (parm[])
   *		in a manner analogous to fpp_textput().
   */
  int c;
  DEFBUF *dp;	/* -> new definition	*/
  int isredefine;	/* FPP_TRUE if redefined	*/
  char *old = NULL;		/* Remember redefined	*/
  ReturnCode ret;
#if OK_CONCAT
  int quoting;	/* Remember we saw a #	*/
#endif
  
  if (type[(c = fpp_skipws(global))] != LET) {
    fpp_cerror(global, ERROR_DEFINE_SYNTAX);
    global->inmacro = FPP_FALSE;		/* Stop <newline> hack	*/
    return(FPP_OK);
  }
  isredefine = FPP_FALSE;			/* Set if redefining	*/
  if ((dp = fpp_lookid(global, c)) == NULL) { /* If not known now     */
    dp = fpp_defendel(global, global->tokenbuf, FPP_FALSE); /* Save the name  */
    if(!dp)
      return(FPP_OUT_OF_MEMORY);
  } else {				/* It's known:          */
    isredefine = FPP_TRUE;			/* Remember this fact	*/
    old = dp->repl;			/* Remember replacement */
    dp->repl = NULL;			/* No replacement now	*/
  }
  global->parlist[0] = global->parmp = global->parm; /* Setup parm buffer */
  if ((c = fpp_get(global)) == '(') {       /* With arguments?      */
    global->nargs = 0;			/* Init formals counter */
    do {				/* Collect formal parms */
      if (global->nargs >= LASTPARM) {
	fpp_cfatal(global, FATAL_TOO_MANY_ARGUMENTS_MACRO);
	return(FPP_TOO_MANY_ARGUMENTS);
      } else if ((c = fpp_skipws(global)) == ')')
	break;			/* Got them all 	*/
      else if (type[c] != LET) {         /* Bad formal syntax    */
	fpp_cerror(global, ERROR_DEFINE_SYNTAX);
	global->inmacro = FPP_FALSE;		/* Stop <newline> hack	*/
	return(FPP_OK);
      }
      fpp_scanid(global, c);                        /* Get the formal param */
      global->parlist[global->nargs++] = global->parmp; /* Save its start */
      ret=fpp_textput(global, global->tokenbuf); /* Save text in parm[]  */
      if(ret)
	return(ret);
    } while ((c = fpp_skipws(global)) == ',');    /* Get another argument */
    if (c != ')') {                     /* Must end at )        */
      fpp_cerror(global, ERROR_DEFINE_SYNTAX);
      global->inmacro = FPP_FALSE;		/* Stop <newline> hack	*/
      return(FPP_OK);
    }
    c = ' ';                            /* Will skip to body    */
  }
  else {
    /*
     * DEF_NOARGS is needed to distinguish between
     * "#define foo" and "#define foo()".
     */
    global->nargs = DEF_NOARGS;         /* No () parameters     */
  }
  if (type[c] == SPA)                   /* At whitespace?       */
    c = fpp_skipws(global);                 /* Not any more.        */
  global->workp = global->work;         /* Replacement put here */
  global->inmacro = FPP_TRUE;               /* Keep \<newline> now	*/
  quoting = 0;                          /* No # seen yet.	*/
  while (c != EOF_CHAR && c != '\n') {  /* Compile macro body   */
#if OK_CONCAT
    if (c == '#') {                     /* Token concatenation? */
      if ((c = fpp_get(global)) != '#') {   /* No, not really       */
        quoting = 1;                    /* Maybe quoting op.    */
        continue;
      }
      while (global->workp > global->work && type[(unsigned)*(global->workp - 1)] == SPA)
        --global->workp;                /* Erase leading spaces */
//       if ((ret=save(global, TOK_SEP)))  /* Stuff a delimiter    */
//         return(ret);
      c = fpp_skipws(global);               /* Eat whitespace       */
      continue;
    }
#endif
    switch (type[c]) {
    case LET:
#if OK_CONCAT
      ret=fpp_checkparm(global, c, dp, quoting);      /* Might be a formal    */
#else
      ret=fpp_checkparm(c, dp);               /* Might be a formal    */
#endif
      if(ret)
	return(ret);
      break;
	
    case DIG:				/* Number in mac. body	*/
    case DOT:				/* Maybe a float number */
      ret=fpp_scannumber(global, c, fpp_save);  /* Scan it off          */
      if(ret)
	return(ret);
      break;
	
    case QUO:				/* String in mac. body	*/
      ret=fpp_stparmscan(global, c);
      if(ret)
	return(ret);
      break;
	
    case BSH:				/* Backslash		*/
      ret=fpp_save(global, '\\');
      if(ret)
	return(ret);
      if ((c = fpp_get(global)) == '\n')
	global->wrongline = FPP_TRUE;
      ret=fpp_save(global, c);
      if(ret)
	return(ret);
      break;
      
    case SPA:				/* Absorb whitespace	*/
      /*
       * Note: the "end of comment" marker is passed on
       * to allow comments to separate tokens.
       */
      if (global->workp[-1] == ' ')   /* Absorb multiple      */
	break;			/* spaces		*/
      else if (c == '\t')
	c = ' ';                      /* Normalize tabs       */
      /* Fall through to store character			*/
    default:				/* Other character	*/
      ret=fpp_save(global, c);
      if(ret)
	return(ret);
      break;
    }
    c = fpp_get(global);
    quoting = 0;			/* Only when immediately*/
    /* preceding a formal	*/
  }
  global->inmacro = FPP_FALSE;		/* Stop newline hack	*/
  fpp_unget(global);                            /* For control check    */
  if (global->workp > global->work && global->workp[-1] == ' ') /* Drop trailing blank  */
    global->workp--;
  *global->workp = EOS;		/* Terminate work	*/
  dp->repl = fpp_savestring(global, global->work); /* Save the string      */
  dp->nargs = global->nargs;			/* Save arg count	*/
  if (isredefine) {                   /* Error if redefined   */
    if ((old != NULL && dp->repl != NULL && !streq(old, dp->repl))
	|| (old == NULL && dp->repl != NULL)
	|| (old != NULL && dp->repl == NULL)) {
      fpp_cerror(global, ERROR_REDEFINE, dp->name);
    }
    if (old != NULL)                  /* We don't need the    */
      free(old);                      /* old definition now.  */
  }
  return(FPP_OK);
}

INLINE FILE_LOCAL
ReturnCode fpp_checkparm(struct Global *global,
		     int c,
		     DEFBUF *dp,
		     int quoting)	/* Preceded by a # ?	*/
{
  /*
   * Replace this param if it's defined.  Note that the macro name is a
   * possible replacement token. We stuff DEF_MAGIC in front of the token
   * which is treated as a LETTER by the token scanner and eaten by
   * the fpp_output routine. This prevents the macro expander from
   * looping if someone writes "#define foo foo".
   */
  
  int i;
  char *cp;
  ReturnCode ret=FPP_OK;
      
  fpp_scanid(global, c);                /* Get parm to tokenbuf */
  for (i = 0; i < global->nargs; i++) {     /* For each argument    */
    if (streq(global->parlist[i], global->tokenbuf)) {  /* If it's known */
#if OK_CONCAT
      if (quoting) {                    /* Special handling of  */
	ret=fpp_save(global, QUOTE_PARM);     /* #formal inside defn  */
	if(ret)
	  return(ret);
      }
#endif
      ret=fpp_save(global, i + MAC_PARM);     /* Save a magic cookie  */
      return(ret);		      /* And exit the search	*/
    }
  }
  if (streq(dp->name, global->tokenbuf))    /* Macro name in body?  */
    ret=fpp_save(global, DEF_MAGIC);            /* Save magic marker    */
  for (cp = global->tokenbuf; *cp != EOS;)  /* And fpp_save             */
    ret=fpp_save(global, *cp++);                /* The token itself     */
  return(ret);
}

INLINE FILE_LOCAL
ReturnCode fpp_stparmscan(struct Global *global, int delim)
{
  /*
   * Normal string parameter scan.
   */
  
  unsigned char	*wp;
  int i;
  ReturnCode ret;
      
  wp = (unsigned char *)global->workp;	/* Here's where it starts       */
  ret=fpp_scanstring(global, delim, fpp_save);
  if(ret)
    return(ret);		/* Exit on fpp_scanstring error	*/
  global->workp[-1] = EOS;		/* Erase trailing quote 	*/
  wp++;				/* -> first string content byte */
  for (i = 0; i < global->nargs; i++) {
    if (streq(global->parlist[i], (char *)wp)) {
      *wp++ = MAC_PARM + PAR_MAC;	/* Stuff a magic marker */
      *wp++ = (i + MAC_PARM);         /* Make a formal marker */
      *wp = wp[-3];			/* Add on closing quote */
      global->workp = (char *)wp + 1; 	/* Reset string end	*/
      return(FPP_OK);
    }
  }
  global->workp[-1] = wp[-1];	/* Nope, reset end quote.	*/
  return(FPP_OK);
}
  
void fpp_doundef(struct Global *global)
  /*
   * Remove the symbol from the defined list.
   * Called from the #control processor.
   */
{
  int c;
  if (type[(c = fpp_skipws(global))] != LET)
    fpp_cerror(global, ERROR_ILLEGAL_UNDEF);
  else {
    fpp_scanid(global, c);                         /* Get name to tokenbuf */
    (void) fpp_defendel(global, global->tokenbuf, FPP_TRUE);
  }
}

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

  size_t size;
  
  size = strlen(text) + 1;
  if ((global->parmp + size) >= &global->parm[NPARMWORK]) {
    fpp_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 fpp_charput(struct Global *global, int c)
{
  /*
   * Put the byte in the parm[] buffer.
   */
  
  if (global->parmp >= &global->parm[NPARMWORK]) {
    fpp_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 fpp_expand(struct Global *global, DEFBUF *tokenp)
{
  /*
   * Expand a macro.  Called from the cpp mainline routine (via subroutine
   * fpp_macroid()) when a token is found in the symbol table.  It calls
   * fpp_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 fpp_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) {
    fpp_cerror(global, ERROR_RECURSIVE_MACRO, tokenp->name, global->macro->name);
    if (global->rec_recover) {
      do {
	c = fpp_get(global);
      } while (global->infile != NULL && global->infile->fp == NULL);
      fpp_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=fpp_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=fpp_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=fpp_ungetstring(global, global->work);
    if(ret)
	return(ret);
    break;

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

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

      /* fputs(tokenp->name, stdout); */
      fpp_Putstring(global, tokenp->name);
      return(FPP_OK);
    } else if (!(ret=fpp_expcollect(global))) {     /* Collect arguments    */
      if (tokenp->nargs != global->nargs) {     /* Should be an error?  */
	fpp_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=fpp_expstuff(global, tokenp->name, tokenp->repl); /* expand macro   */
  }					/* nargs switch 		*/
  return(ret);
}

INLINE FILE_LOCAL
ReturnCode fpp_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 = fpp_skipws(global)) == '\n')/* Skip over whitespace */
      global->wrongline = FPP_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) {
      fpp_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 = fpp_cget(global)) {               /* Collect arg's bytes  */
      if (c == EOF_CHAR) {
	fpp_cerror(global, ERROR_EOF_IN_ARGUMENT);
	return(FPP_EOF_IN_MACRO); /* Sorry.               */
      }
      else if (c == '\\') {             /* Quote next character */
	fpp_charput(global, c);             /* Save the \ for later */
	fpp_charput(global, fpp_cget(global));  /* Save the next char.  */
	continue;			/* And go get another   */
      }
      else if (type[c] == QUO) {        /* Start of string?     */
	ret=fpp_scanstring(global, c, (ReturnCode (*)(struct Global *, int))fpp_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?          */
	  fpp_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 = FPP_TRUE;	/* We'll need a #line   */
      fpp_charput(global, c);               /* Store this one       */
    }				        /* Collect an argument  */
    fpp_charput(global, EOS);               /* Terminate argument   */
  }				        /* Collect all args.    */
  return(FPP_OK);                       /* Normal return        */
}
  
  
#if OK_CONCAT
  
INLINE FILE_LOCAL
char *fpp_doquoting(char *to, char *from)
{
  *to++ = '"';
  while (*from) {
    if (*from == '\\' || *from == '"')
      *to++ = '\\';
    *to++ = *from++;
  }
  *to++ = '"';
      
  return to;
}
  
#endif
  
ReturnCode fpp_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 */
  size_t 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 = fpp_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) {
	    fpp_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 = fpp_doquoting(defp, global->parlist[c]);
#endif
else {
  strcpy(defp, global->parlist[c]);
  defp += size;
}
	}
      }
      else if (defp >= defend) {
	fpp_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);
}