stdio-common/printf_size.c

   1 /* Print size value using units for orders of magnitude.
   2    Copyright (C) 1997-2019 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5    Based on a proposal by Larry McVoy <lm@sgi.com>.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; if not, see
  19    <https://www.gnu.org/licenses/>.  */
  20
  21 #include <ctype.h>
  22 #include <ieee754.h>
  23 #include <math.h>
  24 #include <printf.h>
  25 #include <libioP.h>
  26
  27 #define PUT(f, s, n) _IO_sputn (f, s, n)
  28 #define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : _IO_padn (f, c, n))
  29 #undef putc
  30 #define putc(c, f) (wide \
  31                     ? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f))
  32
  33 \f
  34 /* Macros for doing the actual output.  */
  35
  36 #define outchar(ch)                                                           \
  37   do                                                                          \
  38     {                                                                         \
  39       const int outc = (ch);                                                  \
  40       if (putc (outc, fp) == EOF)                                             \
  41         return -1;                                                            \
  42       ++done;                                                                 \
  43     } while (0)
  44
  45 #define PRINT(ptr, wptr, len)                                                 \
  46   do                                                                          \
  47     {                                                                         \
  48       size_t outlen = (len);                                                  \
  49       if (len > 20)                                                           \
  50         {                                                                     \
  51           if (PUT (fp, wide ? (const char *) wptr : ptr, outlen) != outlen)   \
  52             return -1;                                                        \
  53           ptr += outlen;                                                      \
  54           done += outlen;                                                     \
  55         }                                                                     \
  56       else                                                                    \
  57         {                                                                     \
  58           if (wide)                                                           \
  59             while (outlen-- > 0)                                              \
  60               outchar (*wptr++);                                              \
  61           else                                                                \
  62             while (outlen-- > 0)                                              \
  63               outchar (*ptr++);                                               \
  64         }                                                                     \
  65     } while (0)
  66
  67 #define PADN(ch, len)                                                         \
  68   do                                                                          \
  69     {                                                                         \
  70       if (PAD (fp, ch, len) != len)                                           \
  71         return -1;                                                            \
  72       done += len;                                                            \
  73     }                                                                         \
  74   while (0)
  75 \f
  76 /* Prototype for helper functions.  */
  77 extern int __printf_fp (FILE *fp, const struct printf_info *info,
  78                         const void *const *args);
  79
  80 \f
  81 int
  82 __printf_size (FILE *fp, const struct printf_info *info,
  83                const void *const *args)
  84 {
  85   /* Units for the both formats.  */
  86 #define BINARY_UNITS    " kmgtpezy"
  87 #define DECIMAL_UNITS   " KMGTPEZY"
  88   static const char units[2][sizeof (BINARY_UNITS)] =
  89   {
  90     BINARY_UNITS,       /* For binary format.  */
  91     DECIMAL_UNITS       /* For decimal format.  */
  92   };
  93   const char *tag = units[isupper (info->spec) != 0];
  94   int divisor = isupper (info->spec) ? 1000 : 1024;
  95
  96   /* The floating-point value to output.  */
  97   union
  98     {
  99       union ieee754_double dbl;
 100       long double ldbl;
 101 #if __HAVE_DISTINCT_FLOAT128
 102       _Float128 f128;
 103 #endif
 104     }
 105   fpnum;
 106   const void *ptr = &fpnum;
 107
 108   int is_neg = 0;
 109
 110   /* "NaN" or "Inf" for the special cases.  */
 111   const char *special = NULL;
 112   const wchar_t *wspecial = NULL;
 113
 114   struct printf_info fp_info;
 115   int done = 0;
 116   int wide = info->wide;
 117
 118 #define PRINTF_SIZE_FETCH(FLOAT, VAR)                                   \
 119   {                                                                     \
 120     (VAR) = *(const FLOAT *) args[0];                                   \
 121                                                                         \
 122     /* Check for special values: not a number or infinity.  */          \
 123     if (isnan (VAR))                                                    \
 124       {                                                                 \
 125         special = "nan";                                                \
 126         wspecial = L"nan";                                              \
 127         /* is_neg = 0; Already zero */                                  \
 128       }                                                                 \
 129     else if (isinf (VAR))                                               \
 130       {                                                                 \
 131         is_neg = signbit (VAR);                                         \
 132         special = "inf";                                                \
 133         wspecial = L"inf";                                              \
 134       }                                                                 \
 135     else                                                                \
 136       while ((VAR) >= divisor && tag[1] != '\0')                        \
 137         {                                                               \
 138           (VAR) /= divisor;                                             \
 139           ++tag;                                                        \
 140         }                                                               \
 141   }
 142
 143   /* Fetch the argument value.  */
 144 #if __HAVE_DISTINCT_FLOAT128
 145   if (info->is_binary128)
 146     PRINTF_SIZE_FETCH (_Float128, fpnum.f128)
 147   else
 148 #endif
 149 #ifndef __NO_LONG_DOUBLE_MATH
 150   if (info->is_long_double && sizeof (long double) > sizeof (double))
 151     PRINTF_SIZE_FETCH (long double, fpnum.ldbl)
 152   else
 153 #endif
 154     PRINTF_SIZE_FETCH (double, fpnum.dbl.d)
 155
 156 #undef PRINTF_SIZE_FETCH
 157
 158   if (special)
 159     {
 160       int width = info->prec > info->width ? info->prec : info->width;
 161
 162       if (is_neg || info->showsign || info->space)
 163         --width;
 164       width -= 3;
 165
 166       if (!info->left && width > 0)
 167         PADN (' ', width);
 168
 169       if (is_neg)
 170         outchar ('-');
 171       else if (info->showsign)
 172         outchar ('+');
 173       else if (info->space)
 174         outchar (' ');
 175
 176       PRINT (special, wspecial, 3);
 177
 178       if (info->left && width > 0)
 179         PADN (' ', width);
 180
 181       return done;
 182     }
 183
 184   /* Prepare to print the number.  We want to use `__printf_fp' so we
 185      have to prepare a `printf_info' structure.  */
 186   fp_info = *info;
 187   fp_info.spec = 'f';
 188   fp_info.prec = info->prec < 0 ? 3 : info->prec;
 189   fp_info.wide = wide;
 190
 191   if (fp_info.left && fp_info.pad == L' ')
 192     {
 193       /* We must do the padding ourself since the unit character must
 194          be placed before the padding spaces.  */
 195       fp_info.width = 0;
 196
 197       done = __printf_fp (fp, &fp_info, &ptr);
 198       if (done > 0)
 199         {
 200           outchar (*tag);
 201           if (info->width > done)
 202             PADN (' ', info->width - done);
 203         }
 204     }
 205   else
 206     {
 207       /* We can let __printf_fp do all the printing and just add our
 208          unit character afterwards.  */
 209       fp_info.width = info->width - 1;
 210
 211       done = __printf_fp (fp, &fp_info, &ptr);
 212       if (done > 0)
 213         outchar (*tag);
 214     }
 215
 216   return done;
 217 }
 218 ldbl_strong_alias (__printf_size, printf_size);
 219 \f
 220 /* This is the function used by `vfprintf' to determine number and
 221    type of the arguments.  */
 222 int
 223 printf_size_info (const struct printf_info *info, size_t n, int *argtypes)
 224 {
 225   /* We need only one double or long double argument.  */
 226   if (n >= 1)
 227     argtypes[0] = PA_DOUBLE | (info->is_long_double ? PA_FLAG_LONG_DOUBLE : 0);
 228
 229   return 1;
 230 }