stdio/FreeBSD/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  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 4. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/lib/libc/stdio/printfcommon.h,v 1.4 2009/01/22 08:14:28 das Exp $
  33  */
  34
  35 /*
  36  * This file defines common routines used by both printf and wprintf.
  37  * You must define CHAR to either char or wchar_t prior to including this.
  38  */
  39
  40
  41 #ifndef NO_FLOATING_POINT
  42
  43 #define dtoa            __dtoa
  44 #define freedtoa        __freedtoa
  45
  46 #include <float.h>
  47 #include <math.h>
  48 #include "floatio.h"
  49 #include "gdtoa.h"
  50
  51 #define DEFPREC         6
  52
  53 static int exponent(CHAR *, int, CHAR);
  54
  55 #endif /* !NO_FLOATING_POINT */
  56
  57 static CHAR     *__ujtoa(uintmax_t, CHAR *, int, int, const char *);
  58 static CHAR     *__ultoa(u_long, CHAR *, int, int, const char *);
  59
  60 #define NIOV 8
  61 struct io_state {
  62         FILE *fp;
  63         struct __suio uio;      /* output information: summary */
  64         struct __siov iov[NIOV];/* ... and individual io vectors */
  65 };
  66
  67 static inline void
  68 io_init(struct io_state *iop, FILE *fp)
  69 {
  70
  71         iop->uio.uio_iov = iop->iov;
  72         iop->uio.uio_resid = 0;
  73         iop->uio.uio_iovcnt = 0;
  74         iop->fp = fp;
  75 }
  76
  77 /*
  78  * WARNING: The buffer passed to io_print() is not copied immediately; it must
  79  * remain valid until io_flush() is called.
  80  */
  81 static inline int
  82 io_print(struct io_state *iop, const CHAR * __restrict ptr, int len)
  83 {
  84
  85         iop->iov[iop->uio.uio_iovcnt].iov_base = (char *)ptr;
  86         iop->iov[iop->uio.uio_iovcnt].iov_len = len;
  87         iop->uio.uio_resid += len;
  88         if (++iop->uio.uio_iovcnt >= NIOV)
  89                 return (__sprint(iop->fp, &iop->uio));
  90         else
  91                 return (0);
  92 }
  93
  94 /*
  95  * Choose PADSIZE to trade efficiency vs. size.  If larger printf
  96  * fields occur frequently, increase PADSIZE and make the initialisers
  97  * below longer.
  98  */
  99 #define PADSIZE 16              /* pad chunk size */
 100 static const CHAR blanks[PADSIZE] =
 101 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
 102 static const CHAR zeroes[PADSIZE] =
 103 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
 104
 105 /*
 106  * Pad with blanks or zeroes. 'with' should point to either the blanks array
 107  * or the zeroes array.
 108  */
 109 static inline int
 110 io_pad(struct io_state *iop, int howmany, const CHAR * __restrict with)
 111 {
 112         int n;
 113
 114         while (howmany > 0) {
 115                 n = (howmany >= PADSIZE) ? PADSIZE : howmany;
 116                 if (io_print(iop, with, n))
 117                         return (-1);
 118                 howmany -= n;
 119         }
 120         return (0);
 121 }
 122
 123 /*
 124  * Print exactly len characters of the string spanning p to ep, truncating
 125  * or padding with 'with' as necessary.
 126  */
 127 static inline int
 128 io_printandpad(struct io_state *iop, const CHAR *p, const CHAR *ep,
 129                int len, const CHAR * __restrict with)
 130 {
 131         int p_len;
 132
 133         p_len = ep - p;
 134         if (p_len > len)
 135                 p_len = len;
 136         if (p_len > 0) {
 137                 if (io_print(iop, p, p_len))
 138                         return (-1);
 139         } else {
 140                 p_len = 0;
 141         }
 142         return (io_pad(iop, len - p_len, with));
 143 }
 144
 145 static inline int
 146 io_flush(struct io_state *iop)
 147 {
 148
 149         return (__sprint(iop->fp, &iop->uio));
 150 }
 151
 152 /*
 153  * Convert an unsigned long to ASCII for printf purposes, returning
 154  * a pointer to the first character of the string representation.
 155  * Octal numbers can be forced to have a leading zero; hex numbers
 156  * use the given digits.
 157  */
 158 static CHAR *
 159 __ultoa(u_long val, CHAR *endp, int base, int octzero, const char *xdigs)
 160 {
 161         CHAR *cp = endp;
 162         long sval;
 163
 164         /*
 165          * Handle the three cases separately, in the hope of getting
 166          * better/faster code.
 167          */
 168         switch (base) {
 169         case 10:
 170                 if (val < 10) { /* many numbers are 1 digit */
 171                         *--cp = to_char(val);
 172                         return (cp);
 173                 }
 174                 /*
 175                  * On many machines, unsigned arithmetic is harder than
 176                  * signed arithmetic, so we do at most one unsigned mod and
 177                  * divide; this is sufficient to reduce the range of
 178                  * the incoming value to where signed arithmetic works.
 179                  */
 180                 if (val > LONG_MAX) {
 181                         *--cp = to_char(val % 10);
 182                         sval = val / 10;
 183                 } else
 184                         sval = val;
 185                 do {
 186                         *--cp = to_char(sval % 10);
 187                         sval /= 10;
 188                 } while (sval != 0);
 189                 break;
 190
 191         case 8:
 192                 do {
 193                         *--cp = to_char(val & 7);
 194                         val >>= 3;
 195                 } while (val);
 196                 if (octzero && *cp != '0')
 197                         *--cp = '0';
 198                 break;
 199
 200         case 16:
 201                 do {
 202                         *--cp = xdigs[val & 15];
 203                         val >>= 4;
 204                 } while (val);
 205                 break;
 206
 207         default:                        /* oops */
 208                 abort();
 209         }
 210         return (cp);
 211 }
 212
 213 /* Identical to __ultoa, but for intmax_t. */
 214 static CHAR *
 215 __ujtoa(uintmax_t val, CHAR *endp, int base, int octzero, const char *xdigs)
 216 {
 217         CHAR *cp = endp;
 218         intmax_t sval;
 219
 220         /* quick test for small values; __ultoa is typically much faster */
 221         /* (perhaps instead we should run until small, then call __ultoa?) */
 222         if (val <= ULONG_MAX)
 223                 return (__ultoa((u_long)val, endp, base, octzero, xdigs));
 224         switch (base) {
 225         case 10:
 226                 if (val < 10) {
 227                         *--cp = to_char(val % 10);
 228                         return (cp);
 229                 }
 230                 if (val > INTMAX_MAX) {
 231                         *--cp = to_char(val % 10);
 232                         sval = val / 10;
 233                 } else
 234                         sval = val;
 235                 do {
 236                         *--cp = to_char(sval % 10);
 237                         sval /= 10;
 238                 } while (sval != 0);
 239                 break;
 240
 241         case 8:
 242                 do {
 243                         *--cp = to_char(val & 7);
 244                         val >>= 3;
 245                 } while (val);
 246                 if (octzero && *cp != '0')
 247                         *--cp = '0';
 248                 break;
 249
 250         case 16:
 251                 do {
 252                         *--cp = xdigs[val & 15];
 253                         val >>= 4;
 254                 } while (val);
 255                 break;
 256
 257         default:
 258                 abort();
 259         }
 260         return (cp);
 261 }
 262
 263 #ifndef NO_FLOATING_POINT
 264
 265 static int
 266 exponent(CHAR *p0, int exp, CHAR fmtch)
 267 {
 268         CHAR *p, *t;
 269         CHAR expbuf[MAXEXPDIG];
 270
 271         p = p0;
 272         *p++ = fmtch;
 273         if (exp < 0) {
 274                 exp = -exp;
 275                 *p++ = '-';
 276         }
 277         else
 278                 *p++ = '+';
 279         t = expbuf + MAXEXPDIG;
 280         if (exp > 9) {
 281                 do {
 282                         *--t = to_char(exp % 10);
 283                 } while ((exp /= 10) > 9);
 284                 *--t = to_char(exp);
 285                 for (; t < expbuf + MAXEXPDIG; *p++ = *t++);
 286         }
 287         else {
 288                 /*
 289                  * Exponents for decimal floating point conversions
 290                  * (%[eEgG]) must be at least two characters long,
 291                  * whereas exponents for hexadecimal conversions can
 292                  * be only one character long.
 293                  */
 294                 if (fmtch == 'e' || fmtch == 'E')
 295                         *p++ = '0';
 296                 *p++ = to_char(exp);
 297         }
 298         return (p - p0);
 299 }
 300
 301 #endif /* !NO_FLOATING_POINT */