stdio-common/printf_size.c

   1 /* Print size value using units for orders of magnitude.
   2    Copyright (C) 1997-2017 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    <http://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
  28 /* This defines make it possible to use the same code for GNU C library and
  29    the GNU I/O library.  */
  30 #define PUT(f, s, n) _IO_sputn (f, s, n)
  31 #define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : _IO_padn (f, c, n))
  32 /* We use this file GNU C library and GNU I/O library.  So make
  33    names equal.  */
  34 #undef putc
  35 #define putc(c, f) (wide \
  36                     ? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f))
  37 #define size_t  _IO_size_t
  38 #define FILE    _IO_FILE
  39 \f
  40 /* Macros for doing the actual output.  */
  41
  42 #define outchar(ch)                                                           \
  43   do                                                                          \
  44     {                                                                         \
  45       const int outc = (ch);                                                  \
  46       if (putc (outc, fp) == EOF)                                             \
  47         return -1;                                                            \
  48       ++done;                                                                 \
  49     } while (0)
  50
  51 #define PRINT(ptr, wptr, len)                                                 \
  52   do                                                                          \
  53     {                                                                         \
  54       size_t outlen = (len);                                                  \
  55       if (len > 20)                                                           \
  56         {                                                                     \
  57           if (PUT (fp, wide ? (const char *) wptr : ptr, outlen) != outlen)   \
  58             return -1;                                                        \
  59           ptr += outlen;                                                      \
  60           done += outlen;                                                     \
  61         }                                                                     \
  62       else                                                                    \
  63         {                                                                     \
  64           if (wide)                                                           \
  65             while (outlen-- > 0)                                              \
  66               outchar (*wptr++);                                              \
  67           else                                                                \
  68             while (outlen-- > 0)                                              \
  69               outchar (*ptr++);                                               \
  70         }                                                                     \
  71     } while (0)
  72
  73 #define PADN(ch, len)                                                         \
  74   do                                                                          \
  75     {                                                                         \
  76       if (PAD (fp, ch, len) != len)                                           \
  77         return -1;                                                            \
  78       done += len;                                                            \
  79     }                                                                         \
  80   while (0)
  81 \f
  82 /* Prototype for helper functions.  */
  83 extern int __printf_fp (FILE *fp, const struct printf_info *info,
  84                         const void *const *args);
  85
  86 \f
  87 int
  88 __printf_size (FILE *fp, const struct printf_info *info,
  89                const void *const *args)
  90 {
  91   /* Units for the both formats.  */
  92 #define BINARY_UNITS    " kmgtpezy"
  93 #define DECIMAL_UNITS   " KMGTPEZY"
  94   static const char units[2][sizeof (BINARY_UNITS)] =
  95   {
  96     BINARY_UNITS,       /* For binary format.  */
  97     DECIMAL_UNITS       /* For decimal format.  */
  98   };
  99   const char *tag = units[isupper (info->spec) != 0];
 100   int divisor = isupper (info->spec) ? 1000 : 1024;
 101
 102   /* The floating-point value to output.  */
 103   union
 104     {
 105       union ieee754_double dbl;
 106       long double ldbl;
 107 #if __HAVE_DISTINCT_FLOAT128
 108       _Float128 f128;
 109 #endif
 110     }
 111   fpnum;
 112   const void *ptr = &fpnum;
 113
 114   int is_neg = 0;
 115
 116   /* "NaN" or "Inf" for the special cases.  */
 117   const char *special = NULL;
 118   const wchar_t *wspecial = NULL;
 119
 120   struct printf_info fp_info;
 121   int done = 0;
 122   int wide = info->wide;
 123
 124 #define PRINTF_SIZE_FETCH(FLOAT, VAR)                                   \
 125   {                                                                     \
 126     (VAR) = *(const FLOAT *) args[0];                                   \
 127                                                                         \
 128     /* Check for special values: not a number or infinity.  */          \
 129     if (isnan (VAR))                                                    \
 130       {                                                                 \
 131         special = "nan";                                                \
 132         wspecial = L"nan";                                              \
 133         /* is_neg = 0; Already zero */                                  \
 134       }                                                                 \
 135     else if (isinf (VAR))                                               \
 136       {                                                                 \
 137         is_neg = signbit (VAR);                                         \
 138         special = "inf";                                                \
 139         wspecial = L"inf";                                              \
 140       }                                                                 \
 141     else                                                                \
 142       while ((VAR) >= divisor && tag[1] != '\0')                        \
 143         {                                                               \
 144           (VAR) /= divisor;                                             \
 145           ++tag;                                                        \
 146         }                                                               \
 147   }
 148
 149   /* Fetch the argument value.  */
 150 #if __HAVE_DISTINCT_FLOAT128
 151   if (info->is_binary128)
 152     PRINTF_SIZE_FETCH (_Float128, fpnum.f128)
 153   else
 154 #endif
 155 #ifndef __NO_LONG_DOUBLE_MATH
 156   if (info->is_long_double && sizeof (long double) > sizeof (double))
 157     PRINTF_SIZE_FETCH (long double, fpnum.ldbl)
 158   else
 159 #endif
 160     PRINTF_SIZE_FETCH (double, fpnum.dbl.d)
 161
 162 #undef PRINTF_SIZE_FETCH
 163
 164   if (special)
 165     {
 166       int width = info->prec > info->width ? info->prec : info->width;
 167
 168       if (is_neg || info->showsign || info->space)
 169         --width;
 170       width -= 3;
 171
 172       if (!info->left && width > 0)
 173         PADN (' ', width);
 174
 175       if (is_neg)
 176         outchar ('-');
 177       else if (info->showsign)
 178         outchar ('+');
 179       else if (info->space)
 180         outchar (' ');
 181
 182       PRINT (special, wspecial, 3);
 183
 184       if (info->left && width > 0)
 185         PADN (' ', width);
 186
 187       return done;
 188     }
 189
 190   /* Prepare to print the number.  We want to use `__printf_fp' so we
 191      have to prepare a `printf_info' structure.  */
 192   fp_info = *info;
 193   fp_info.spec = 'f';
 194   fp_info.prec = info->prec < 0 ? 3 : info->prec;
 195   fp_info.wide = wide;
 196
 197   if (fp_info.left && fp_info.pad == L' ')
 198     {
 199       /* We must do the padding ourself since the unit character must
 200          be placed before the padding spaces.  */
 201       fp_info.width = 0;
 202
 203       done = __printf_fp (fp, &fp_info, &ptr);
 204       if (done > 0)
 205         {
 206           outchar (*tag);
 207           if (info->width > done)
 208             PADN (' ', info->width - done);
 209         }
 210     }
 211   else
 212     {
 213       /* We can let __printf_fp do all the printing and just add our
 214          unit character afterwards.  */
 215       fp_info.width = info->width - 1;
 216
 217       done = __printf_fp (fp, &fp_info, &ptr);
 218       if (done > 0)
 219         outchar (*tag);
 220     }
 221
 222   return done;
 223 }
 224 ldbl_strong_alias (__printf_size, printf_size);
 225 \f
 226 /* This is the function used by `vfprintf' to determine number and
 227    type of the arguments.  */
 228 int
 229 printf_size_info (const struct printf_info *info, size_t n, int *argtypes)
 230 {
 231   /* We need only one double or long double argument.  */
 232   if (n >= 1)
 233     argtypes[0] = PA_DOUBLE | (info->is_long_double ? PA_FLAG_LONG_DOUBLE : 0);
 234
 235   return 1;
 236 }