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expand.h revision 1.2.6.1 
      1 /*	$NetBSD: expand.h,v 1.2.6.1 1999/12/27 18:27:02 wrstuden Exp $	*/
      2 
      3 /*
      4  * Expanding strings
      5  */
      6 /* $Id: expand.h,v 1.2.6.1 1999/12/27 18:27:02 wrstuden Exp $ */
      7 
      8 #define X_EXTRA		8	/* this many extra bytes in X string */
      9 
     10 #if 0				/* Usage */
     11 	XString xs;
     12 	char *xp;
     13 
     14 	Xinit(xs, xp, 128, ATEMP); /* allocate initial string */
     15 	while ((c = generate()) {
     16 		Xcheck(xs, xp);	/* expand string if neccessary */
     17 		Xput(xs, xp, c); /* add character */
     18 	}
     19 	return Xclose(xs, xp);	/* resize string */
     20 /*
     21  * NOTE:
     22  *     The Xcheck and Xinit macros have a magic + X_EXTRA in the lengths.
     23  *     This is so that you can put up to X_EXTRA characters in a XString
     24  *     before calling Xcheck. (See yylex in lex.c)
     25  */
     26 #endif /* 0 */
     27 
     28 typedef struct XString {
     29 	char   *end, *beg;	/* end, begin of string */
     30 	size_t	len;		/* length */
     31 	Area	*areap;		/* area to allocate/free from */
     32 } XString;
     33 
     34 typedef char * XStringP;
     35 
     36 /* initialize expandable string */
     37 #define	Xinit(xs, xp, length, area) do { \
     38 			(xs).len = length; \
     39 			(xs).areap = (area); \
     40 			(xs).beg = alloc((xs).len + X_EXTRA, (xs).areap); \
     41 			(xs).end = (xs).beg + (xs).len; \
     42 			xp = (xs).beg; \
     43 		} while (0)
     44 
     45 /* stuff char into string */
     46 #define	Xput(xs, xp, c)	(*xp++ = (c))
     47 
     48 /* check if there are at least n bytes left */
     49 #define	XcheckN(xs, xp, n) do { \
     50 		    int more = ((xp) + (n)) - (xs).end; \
     51 		    if (more > 0) \
     52 			xp = Xcheck_grow_(&xs, xp, more); \
     53 		} while (0)
     54 
     55 /* check for overflow, expand string */
     56 #define Xcheck(xs, xp)	XcheckN(xs, xp, 1)
     57 
     58 /* free string */
     59 #define	Xfree(xs, xp)	afree((void*) (xs).beg, (xs).areap)
     60 
     61 /* close, return string */
     62 #define	Xclose(xs, xp)	(char*) aresize((void*)(xs).beg, \
     63 					(size_t)((xp) - (xs).beg), (xs).areap)
     64 /* begin of string */
     65 #define	Xstring(xs, xp)	((xs).beg)
     66 
     67 #define Xnleft(xs, xp) ((xs).end - (xp))	/* may be less than 0 */
     68 #define	Xlength(xs, xp) ((xp) - (xs).beg)
     69 #define Xsize(xs, xp) ((xs).end - (xs).beg)
     70 #define	Xsavepos(xs, xp) ((xp) - (xs).beg)
     71 #define	Xrestpos(xs, xp, n) ((xs).beg + (n))
     72 
     73 char *	Xcheck_grow_	ARGS((XString *xsp, char *xp, int more));
     74 
     75 /*
     76  * expandable vector of generic pointers
     77  */
     78 
     79 typedef struct XPtrV {
     80 	void  **cur;		/* next avail pointer */
     81 	void  **beg, **end;	/* begin, end of vector */
     82 } XPtrV;
     83 
     84 #define	XPinit(x, n) do { \
     85 			register void **vp__; \
     86 			vp__ = (void**) alloc(sizeofN(void*, n), ATEMP); \
     87 			(x).cur = (x).beg = vp__; \
     88 			(x).end = vp__ + n; \
     89 		    } while (0)
     90 
     91 #define	XPput(x, p) do { \
     92 			if ((x).cur >= (x).end) { \
     93 				int n = XPsize(x); \
     94 				(x).beg = (void**) aresize((void*) (x).beg, \
     95 						   sizeofN(void*, n*2), ATEMP); \
     96 				(x).cur = (x).beg + n; \
     97 				(x).end = (x).cur + n; \
     98 			} \
     99 			*(x).cur++ = (p); \
    100 		} while (0)
    101 
    102 #define	XPptrv(x)	((x).beg)
    103 #define	XPsize(x)	((x).cur - (x).beg)
    104 
    105 #define	XPclose(x)	(void**) aresize((void*)(x).beg, \
    106 					 sizeofN(void*, XPsize(x)), ATEMP)
    107 
    108 #define	XPfree(x)	afree((void*) (x).beg, ATEMP)
    109