1 /* $OpenBSD: expand.h,v 1.15 2018/01/06 16:28:58 millert Exp $ */ 2 3 /* 4 * Expanding strings 5 */ 6 7 #define X_EXTRA 8 /* this many extra bytes in X string */ 8 9 #if 0 /* Usage */ 10 XString xs; 11 char *xp; 12 13 Xinit(xs, xp, 128, ATEMP); /* allocate initial string */ 14 while ((c = generate()) { 15 Xcheck(xs, xp); /* expand string if necessary */ 16 Xput(xs, xp, c); /* add character */ 17 } 18 return Xclose(xs, xp); /* resize string */ 19 /* 20 * NOTE: 21 * The Xcheck and Xinit macros have a magic + X_EXTRA in the lengths. 22 * This is so that you can put up to X_EXTRA characters in a XString 23 * before calling Xcheck. (See yylex in lex.c) 24 */ 25 #endif /* 0 */ 26 27 typedef struct XString { 28 char *end, *beg; /* end, begin of string */ 29 size_t len; /* length */ 30 Area *areap; /* area to allocate/free from */ 31 } XString; 32 33 typedef char * XStringP; 34 35 /* initialize expandable string */ 36 #define Xinit(xs, xp, length, area) do { \ 37 (xs).len = length; \ 38 (xs).areap = (area); \ 39 (xs).beg = alloc((xs).len + X_EXTRA, (xs).areap); \ 40 (xs).end = (xs).beg + (xs).len; \ 41 xp = (xs).beg; \ 42 } while (0) 43 44 /* stuff char into string */ 45 #define Xput(xs, xp, c) (*xp++ = (c)) 46 47 /* check if there are at least n bytes left */ 48 #define XcheckN(xs, xp, n) do { \ 49 ptrdiff_t more = ((xp) + (n)) - (xs).end; \ 50 if (more > 0) \ 51 xp = Xcheck_grow_(&xs, xp, more); \ 52 } while (0) 53 54 /* check for overflow, expand string */ 55 #define Xcheck(xs, xp) XcheckN(xs, xp, 1) 56 57 /* free string */ 58 #define Xfree(xs, xp) afree((xs).beg, (xs).areap) 59 60 /* close, return string */ 61 #define Xclose(xs, xp) aresize((xs).beg, ((xp) - (xs).beg), (xs).areap) 62 /* begin of string */ 63 #define Xstring(xs, xp) ((xs).beg) 64 65 #define Xnleft(xs, xp) ((xs).end - (xp)) /* may be less than 0 */ 66 #define Xlength(xs, xp) ((xp) - (xs).beg) 67 #define Xsize(xs, xp) ((xs).end - (xs).beg) 68 #define Xsavepos(xs, xp) ((xp) - (xs).beg) 69 #define Xrestpos(xs, xp, n) ((xs).beg + (n)) 70 71 char * Xcheck_grow_(XString *xsp, char *xp, size_t more); 72 73 /* 74 * expandable vector of generic pointers 75 */ 76 77 typedef struct XPtrV { 78 void **cur; /* next avail pointer */ 79 void **beg, **end; /* begin, end of vector */ 80 } XPtrV; 81 82 #define XPinit(x, n) do { \ 83 void **vp__; \ 84 vp__ = areallocarray(NULL, n, sizeof(void *), ATEMP); \ 85 (x).cur = (x).beg = vp__; \ 86 (x).end = vp__ + n; \ 87 } while (0) 88 89 #define XPput(x, p) do { \ 90 if ((x).cur >= (x).end) { \ 91 int n = XPsize(x); \ 92 (x).beg = areallocarray((x).beg, n, \ 93 2 * sizeof(void *), ATEMP); \ 94 (x).cur = (x).beg + n; \ 95 (x).end = (x).cur + n; \ 96 } \ 97 *(x).cur++ = (p); \ 98 } while (0) 99 100 #define XPptrv(x) ((x).beg) 101 #define XPsize(x) ((x).cur - (x).beg) 102 103 #define XPclose(x) areallocarray((x).beg, XPsize(x), \ 104 sizeof(void *), ATEMP) 105 106 #define XPfree(x) afree((x).beg, ATEMP) 107