stdio-common/printf_size.c

   1 /* Print size value using units for orders of magnitude.
   2    Copyright (C) 1997-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <ctype.h>
  20 #include <ieee754.h>
  21 #include <math.h>
  22 #include <printf.h>
  23 #include <libioP.h>
  24
  25 #define PUT(f, s, n) _IO_sputn (f, s, n)
  26 #define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : _IO_padn (f, c, n))
  27 #undef putc
  28 #define putc(c, f) (wide \
  29                     ? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f))
  30
  31 \f
  32 /* Macros for doing the actual output.  */
  33
  34 #define outchar(ch)                                                           \
  35   do                                                                          \
  36     {                                                                         \
  37       const int outc = (ch);                                                  \
  38       if (putc (outc, fp) == EOF)                                             \
  39         return -1;                                                            \
  40       ++done;                                                                 \
  41     } while (0)
  42
  43 #define PRINT(ptr, wptr, len)                                                 \
  44   do                                                                          \
  45     {                                                                         \
  46       size_t outlen = (len);                                                  \
  47       if (len > 20)                                                           \
  48         {                                                                     \
  49           if (PUT (fp, wide ? (const char *) wptr : ptr, outlen) != outlen)   \
  50             return -1;                                                        \
  51           ptr += outlen;                                                      \
  52           done += outlen;                                                     \
  53         }                                                                     \
  54       else                                                                    \
  55         {                                                                     \
  56           if (wide)                                                           \
  57             while (outlen-- > 0)                                              \
  58               outchar (*wptr++);                                              \
  59           else                                                                \
  60             while (outlen-- > 0)                                              \
  61               outchar (*ptr++);                                               \
  62         }                                                                     \
  63     } while (0)
  64
  65 #define PADN(ch, len)                                                         \
  66   do                                                                          \
  67     {                                                                         \
  68       if (PAD (fp, ch, len) != len)                                           \
  69         return -1;                                                            \
  70       done += len;                                                            \
  71     }                                                                         \
  72   while (0)
  73 \f
  74 /* Prototype for helper functions.  */
  75 extern int __printf_fp (FILE *fp, const struct printf_info *info,
  76                         const void *const *args);
  77
  78 \f
  79 int
  80 __printf_size (FILE *fp, const struct printf_info *info,
  81                const void *const *args)
  82 {
  83   /* Units for the both formats.  */
  84 #define BINARY_UNITS    " kmgtpezy"
  85 #define DECIMAL_UNITS   " KMGTPEZY"
  86   static const char units[2][sizeof (BINARY_UNITS)] =
  87   {
  88     BINARY_UNITS,       /* For binary format.  */
  89     DECIMAL_UNITS       /* For decimal format.  */
  90   };
  91   const char *tag = units[isupper (info->spec) != 0];
  92   int divisor = isupper (info->spec) ? 1000 : 1024;
  93
  94   /* The floating-point value to output.  */
  95   union
  96     {
  97       union ieee754_double dbl;
  98       long double ldbl;
  99 #if __HAVE_DISTINCT_FLOAT128
 100       _Float128 f128;
 101 #endif
 102     }
 103   fpnum;
 104   const void *ptr = &fpnum;
 105
 106   int is_neg = 0;
 107
 108   /* "NaN" or "Inf" for the special cases.  */
 109   const char *special = NULL;
 110   const wchar_t *wspecial = NULL;
 111
 112   struct printf_info fp_info;
 113   int done = 0;
 114   int wide = info->wide;
 115
 116 #define PRINTF_SIZE_FETCH(FLOAT, VAR)                                   \
 117   {                                                                     \
 118     (VAR) = *(const FLOAT *) args[0];                                   \
 119                                                                         \
 120     /* Check for special values: not a number or infinity.  */          \
 121     if (isnan (VAR))                                                    \
 122       {                                                                 \
 123         special = "nan";                                                \
 124         wspecial = L"nan";                                              \
 125         /* is_neg = 0; Already zero */                                  \
 126       }                                                                 \
 127     else if (isinf (VAR))                                               \
 128       {                                                                 \
 129         is_neg = signbit (VAR);                                         \
 130         special = "inf";                                                \
 131         wspecial = L"inf";                                              \
 132       }                                                                 \
 133     else                                                                \
 134       while ((VAR) >= divisor && tag[1] != '\0')                        \
 135         {                                                               \
 136           (VAR) /= divisor;                                             \
 137           ++tag;                                                        \
 138         }                                                               \
 139   }
 140
 141   /* Fetch the argument value.  */
 142 #if __HAVE_DISTINCT_FLOAT128
 143   if (info->is_binary128)
 144     PRINTF_SIZE_FETCH (_Float128, fpnum.f128)
 145   else
 146 #endif
 147 #ifndef __NO_LONG_DOUBLE_MATH
 148   if (info->is_long_double && sizeof (long double) > sizeof (double))
 149     PRINTF_SIZE_FETCH (long double, fpnum.ldbl)
 150   else
 151 #endif
 152     PRINTF_SIZE_FETCH (double, fpnum.dbl.d)
 153
 154 #undef PRINTF_SIZE_FETCH
 155
 156   if (special)
 157     {
 158       int width = info->prec > info->width ? info->prec : info->width;
 159
 160       if (is_neg || info->showsign || info->space)
 161         --width;
 162       width -= 3;
 163
 164       if (!info->left && width > 0)
 165         PADN (' ', width);
 166
 167       if (is_neg)
 168         outchar ('-');
 169       else if (info->showsign)
 170         outchar ('+');
 171       else if (info->space)
 172         outchar (' ');
 173
 174       PRINT (special, wspecial, 3);
 175
 176       if (info->left && width > 0)
 177         PADN (' ', width);
 178
 179       return done;
 180     }
 181
 182   /* Prepare to print the number.  We want to use `__printf_fp' so we
 183      have to prepare a `printf_info' structure.  */
 184   fp_info = *info;
 185   fp_info.spec = 'f';
 186   fp_info.prec = info->prec < 0 ? 3 : info->prec;
 187   fp_info.wide = wide;
 188
 189   if (fp_info.left && fp_info.pad == L' ')
 190     {
 191       /* We must do the padding ourself since the unit character must
 192          be placed before the padding spaces.  */
 193       fp_info.width = 0;
 194
 195       done = __printf_fp (fp, &fp_info, &ptr);
 196       if (done > 0)
 197         {
 198           outchar (*tag);
 199           if (info->width > done)
 200             PADN (' ', info->width - done);
 201         }
 202     }
 203   else
 204     {
 205       /* We can let __printf_fp do all the printing and just add our
 206          unit character afterwards.  */
 207       fp_info.width = info->width - 1;
 208
 209       done = __printf_fp (fp, &fp_info, &ptr);
 210       if (done > 0)
 211         outchar (*tag);
 212     }
 213
 214   return done;
 215 }
 216 ldbl_strong_alias (__printf_size, printf_size);
 217 \f
 218 /* This is the function used by `vfprintf' to determine number and
 219    type of the arguments.  */
 220 int
 221 printf_size_info (const struct printf_info *info, size_t n, int *argtypes)
 222 {
 223   /* We need only one double or long double argument.  */
 224   if (n >= 1)
 225     argtypes[0] = PA_DOUBLE | (info->is_long_double ? PA_FLAG_LONG_DOUBLE : 0);
 226
 227   return 1;
 228 }