1 /* 2 * The authors of this software are Rob Pike and Ken Thompson. 3 * Copyright (c) 2002 by Lucent Technologies. 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose without fee is hereby granted, provided that this entire notice 6 * is included in all copies of any software which is or includes a copy 7 * or modification of this software and in all copies of the supporting 8 * documentation for such software. 9 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED 10 * WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY 11 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY 12 * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. 13 */ 14 #include "lib9.h" 15 #include "fmtdef.h" 16 17 enum 18 { 19 Maxfmt = 64 20 }; 21 22 typedef struct Convfmt Convfmt; 23 struct Convfmt 24 { 25 int c; 26 volatile Fmts fmt; /* for spin lock in fmtfmt; avoids race due to write order */ 27 }; 28 29 struct 30 { 31 /* lock by calling _fmtlock, _fmtunlock */ 32 int nfmt; 33 Convfmt fmt[Maxfmt]; 34 } fmtalloc; 35 36 static Convfmt knownfmt[] = { 37 ' ', _flagfmt, 38 '#', _flagfmt, 39 '%', _percentfmt, 40 '+', _flagfmt, 41 ',', _flagfmt, 42 '-', _flagfmt, 43 'C', _runefmt, 44 'S', _runesfmt, 45 'X', _ifmt, 46 'b', _ifmt, 47 'c', _charfmt, 48 'd', _ifmt, 49 'h', _flagfmt, 50 'l', _flagfmt, 51 'n', _countfmt, 52 'o', _ifmt, 53 'p', _ifmt, 54 'r', errfmt, 55 's', _strfmt, 56 'u', _flagfmt, 57 'x', _ifmt, 58 0, nil, 59 }; 60 61 int (*doquote)(int); 62 63 static Fmts 64 fmtfmt(int c) 65 { 66 Convfmt *p, *ep; 67 68 ep = &fmtalloc.fmt[fmtalloc.nfmt]; 69 for(p=fmtalloc.fmt; p<ep; p++) 70 if(p->c == c) 71 return p->fmt; 72 73 /* is this a predefined format char? */ 74 for(p=knownfmt; p->c; p++) 75 if(p->c == c){ 76 /* no need to lock; fmtinstall is idempotent */ 77 fmtinstall(p->c, p->fmt); 78 while(p->fmt == nil) /* loop until value is updated */ 79 ; 80 return p->fmt; 81 } 82 83 return _badfmt; 84 } 85 86 int 87 fmtinstall(int c, Fmts f) 88 { 89 Convfmt *p, *ep; 90 91 if(c<=0 || c>=65536) 92 return -1; 93 if(!f) 94 f = _badfmt; 95 96 _fmtlock(); 97 98 ep = &fmtalloc.fmt[fmtalloc.nfmt]; 99 for(p=fmtalloc.fmt; p<ep; p++) 100 if(p->c == c) 101 break; 102 103 if(p == &fmtalloc.fmt[Maxfmt]){ 104 _fmtunlock(); 105 return -1; 106 } 107 108 p->fmt = f; 109 if(p == ep){ /* installing a new format character */ 110 fmtalloc.nfmt++; 111 p->c = c; 112 } 113 114 _fmtunlock(); 115 return 0; 116 } 117 118 void* 119 _fmtdispatch(Fmt *f, void *fmt, int isrunes) 120 { 121 Rune rune, r; 122 int i, n; 123 124 f->flags = 0; 125 f->width = f->prec = 0; 126 127 for(;;){ 128 if(isrunes){ 129 r = *(Rune*)fmt; 130 fmt = (Rune*)fmt + 1; 131 }else{ 132 fmt = (char*)fmt + chartorune(&rune, fmt); 133 r = rune; 134 } 135 f->r = r; 136 switch(r){ 137 case '\0': 138 return nil; 139 case '.': 140 f->flags |= FmtWidth|FmtPrec; 141 continue; 142 case '0': 143 if(!(f->flags & FmtWidth)){ 144 f->flags |= FmtZero; 145 continue; 146 } 147 /* fall through */ 148 case '1': case '2': case '3': case '4': 149 case '5': case '6': case '7': case '8': case '9': 150 i = 0; 151 while(r >= '0' && r <= '9'){ 152 i = i * 10 + r - '0'; 153 if(isrunes){ 154 r = *(Rune*)fmt; 155 fmt = (Rune*)fmt + 1; 156 }else{ 157 r = *(char*)fmt; 158 fmt = (char*)fmt + 1; 159 } 160 } 161 if(isrunes) 162 fmt = (Rune*)fmt - 1; 163 else 164 fmt = (char*)fmt - 1; 165 numflag: 166 if(f->flags & FmtWidth){ 167 f->flags |= FmtPrec; 168 f->prec = i; 169 }else{ 170 f->flags |= FmtWidth; 171 f->width = i; 172 } 173 continue; 174 case '*': 175 i = va_arg(f->args, int); 176 if(i < 0){ 177 i = -i; 178 f->flags |= FmtLeft; 179 } 180 goto numflag; 181 } 182 n = (*fmtfmt(r))(f); 183 if(n < 0) 184 return nil; 185 if(n == 0) 186 return fmt; 187 } 188 } 189