lib/libc/stdio/printfcommon.h

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Chris Torek.
   7  *
   8  * Copyright (c) 2011 The FreeBSD Foundation
   9  * All rights reserved.
  10  * Portions of this software were developed by David Chisnall
  11  * under sponsorship from the FreeBSD Foundation.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 4. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  * $FreeBSD$
  38  */
  39
  40 /*
  41  * This file defines common routines used by both printf and wprintf.
  42  * You must define CHAR to either char or wchar_t prior to including this.
  43  */
  44
  45
  46 #ifndef NO_FLOATING_POINT
  47
  48 #define dtoa            __dtoa
  49 #define freedtoa        __freedtoa
  50
  51 #include <float.h>
  52 #include <math.h>
  53 #include "floatio.h"
  54 #include "gdtoa.h"
  55
  56 #define DEFPREC         6
  57
  58 static int exponent(CHAR *, int, CHAR);
  59
  60 #endif /* !NO_FLOATING_POINT */
  61
  62 static CHAR     *__ujtoa(uintmax_t, CHAR *, int, int, const char *);
  63 static CHAR     *__ultoa(u_long, CHAR *, int, int, const char *);
  64
  65 #define NIOV 8
  66 struct io_state {
  67         FILE *fp;
  68         struct __suio uio;      /* output information: summary */
  69         struct __siov iov[NIOV];/* ... and individual io vectors */
  70 };
  71
  72 static inline void
  73 io_init(struct io_state *iop, FILE *fp)
  74 {
  75
  76         iop->uio.uio_iov = iop->iov;
  77         iop->uio.uio_resid = 0;
  78         iop->uio.uio_iovcnt = 0;
  79         iop->fp = fp;
  80 }
  81
  82 /*
  83  * WARNING: The buffer passed to io_print() is not copied immediately; it must
  84  * remain valid until io_flush() is called.
  85  */
  86 static inline int
  87 io_print(struct io_state *iop, const CHAR * __restrict ptr, int len, locale_t locale)
  88 {
  89
  90         iop->iov[iop->uio.uio_iovcnt].iov_base = (char *)ptr;
  91         iop->iov[iop->uio.uio_iovcnt].iov_len = len;
  92         iop->uio.uio_resid += len;
  93         if (++iop->uio.uio_iovcnt >= NIOV)
  94                 return (__sprint(iop->fp, &iop->uio, locale));
  95         else
  96                 return (0);
  97 }
  98
  99 /*
 100  * Choose PADSIZE to trade efficiency vs. size.  If larger printf
 101  * fields occur frequently, increase PADSIZE and make the initialisers
 102  * below longer.
 103  */
 104 #define PADSIZE 16              /* pad chunk size */
 105 static const CHAR blanks[PADSIZE] =
 106 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
 107 static const CHAR zeroes[PADSIZE] =
 108 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
 109
 110 /*
 111  * Pad with blanks or zeroes. 'with' should point to either the blanks array
 112  * or the zeroes array.
 113  */
 114 static inline int
 115 io_pad(struct io_state *iop, int howmany, const CHAR * __restrict with,
 116                 locale_t locale)
 117 {
 118         int n;
 119
 120         while (howmany > 0) {
 121                 n = (howmany >= PADSIZE) ? PADSIZE : howmany;
 122                 if (io_print(iop, with, n, locale))
 123                         return (-1);
 124                 howmany -= n;
 125         }
 126         return (0);
 127 }
 128
 129 /*
 130  * Print exactly len characters of the string spanning p to ep, truncating
 131  * or padding with 'with' as necessary.
 132  */
 133 static inline int
 134 io_printandpad(struct io_state *iop, const CHAR *p, const CHAR *ep,
 135                int len, const CHAR * __restrict with, locale_t locale)
 136 {
 137         int p_len;
 138
 139         p_len = ep - p;
 140         if (p_len > len)
 141                 p_len = len;
 142         if (p_len > 0) {
 143                 if (io_print(iop, p, p_len, locale))
 144                         return (-1);
 145         } else {
 146                 p_len = 0;
 147         }
 148         return (io_pad(iop, len - p_len, with, locale));
 149 }
 150
 151 static inline int
 152 io_flush(struct io_state *iop, locale_t locale)
 153 {
 154
 155         return (__sprint(iop->fp, &iop->uio, locale));
 156 }
 157
 158 /*
 159  * Convert an unsigned long to ASCII for printf purposes, returning
 160  * a pointer to the first character of the string representation.
 161  * Octal numbers can be forced to have a leading zero; hex numbers
 162  * use the given digits.
 163  */
 164 static CHAR *
 165 __ultoa(u_long val, CHAR *endp, int base, int octzero, const char *xdigs)
 166 {
 167         CHAR *cp = endp;
 168         long sval;
 169
 170         /*
 171          * Handle the three cases separately, in the hope of getting
 172          * better/faster code.
 173          */
 174         switch (base) {
 175         case 10:
 176                 if (val < 10) { /* many numbers are 1 digit */
 177                         *--cp = to_char(val);
 178                         return (cp);
 179                 }
 180                 /*
 181                  * On many machines, unsigned arithmetic is harder than
 182                  * signed arithmetic, so we do at most one unsigned mod and
 183                  * divide; this is sufficient to reduce the range of
 184                  * the incoming value to where signed arithmetic works.
 185                  */
 186                 if (val > LONG_MAX) {
 187                         *--cp = to_char(val % 10);
 188                         sval = val / 10;
 189                 } else
 190                         sval = val;
 191                 do {
 192                         *--cp = to_char(sval % 10);
 193                         sval /= 10;
 194                 } while (sval != 0);
 195                 break;
 196
 197         case 8:
 198                 do {
 199                         *--cp = to_char(val & 7);
 200                         val >>= 3;
 201                 } while (val);
 202                 if (octzero && *cp != '0')
 203                         *--cp = '0';
 204                 break;
 205
 206         case 16:
 207                 do {
 208                         *--cp = xdigs[val & 15];
 209                         val >>= 4;
 210                 } while (val);
 211                 break;
 212
 213         default:                        /* oops */
 214                 abort();
 215         }
 216         return (cp);
 217 }
 218
 219 /* Identical to __ultoa, but for intmax_t. */
 220 static CHAR *
 221 __ujtoa(uintmax_t val, CHAR *endp, int base, int octzero, const char *xdigs)
 222 {
 223         CHAR *cp = endp;
 224         intmax_t sval;
 225
 226         /* quick test for small values; __ultoa is typically much faster */
 227         /* (perhaps instead we should run until small, then call __ultoa?) */
 228         if (val <= ULONG_MAX)
 229                 return (__ultoa((u_long)val, endp, base, octzero, xdigs));
 230         switch (base) {
 231         case 10:
 232                 if (val < 10) {
 233                         *--cp = to_char(val % 10);
 234                         return (cp);
 235                 }
 236                 if (val > INTMAX_MAX) {
 237                         *--cp = to_char(val % 10);
 238                         sval = val / 10;
 239                 } else
 240                         sval = val;
 241                 do {
 242                         *--cp = to_char(sval % 10);
 243                         sval /= 10;
 244                 } while (sval != 0);
 245                 break;
 246
 247         case 8:
 248                 do {
 249                         *--cp = to_char(val & 7);
 250                         val >>= 3;
 251                 } while (val);
 252                 if (octzero && *cp != '0')
 253                         *--cp = '0';
 254                 break;
 255
 256         case 16:
 257                 do {
 258                         *--cp = xdigs[val & 15];
 259                         val >>= 4;
 260                 } while (val);
 261                 break;
 262
 263         default:
 264                 abort();
 265         }
 266         return (cp);
 267 }
 268
 269 #ifndef NO_FLOATING_POINT
 270
 271 static int
 272 exponent(CHAR *p0, int exp, CHAR fmtch)
 273 {
 274         CHAR *p, *t;
 275         CHAR expbuf[MAXEXPDIG];
 276
 277         p = p0;
 278         *p++ = fmtch;
 279         if (exp < 0) {
 280                 exp = -exp;
 281                 *p++ = '-';
 282         }
 283         else
 284                 *p++ = '+';
 285         t = expbuf + MAXEXPDIG;
 286         if (exp > 9) {
 287                 do {
 288                         *--t = to_char(exp % 10);
 289                 } while ((exp /= 10) > 9);
 290                 *--t = to_char(exp);
 291                 for (; t < expbuf + MAXEXPDIG; *p++ = *t++);
 292         }
 293         else {
 294                 /*
 295                  * Exponents for decimal floating point conversions
 296                  * (%[eEgG]) must be at least two characters long,
 297                  * whereas exponents for hexadecimal conversions can
 298                  * be only one character long.
 299                  */
 300                 if (fmtch == 'e' || fmtch == 'E')
 301                         *p++ = '0';
 302                 *p++ = to_char(exp);
 303         }
 304         return (p - p0);
 305 }
 306
 307 #endif /* !NO_FLOATING_POINT */