about summary refs log tree commit diff
path: root/stdio-common/printf_size.c
blob: 4bcd51c92e2b95d5c9809060c36c26407488496c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
/* Print size value using units for orders of magnitude.
   Copyright (C) 1997-2020 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   Based on a proposal by Larry McVoy <lm@sgi.com>.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <ctype.h>
#include <ieee754.h>
#include <math.h>
#include <printf.h>
#include <libioP.h>

#define PUT(f, s, n) _IO_sputn (f, s, n)
#define PAD(f, c, n) (wide ? _IO_wpadn (f, c, n) : _IO_padn (f, c, n))
#undef putc
#define putc(c, f) (wide \
		    ? (int)_IO_putwc_unlocked (c, f) : _IO_putc_unlocked (c, f))


/* Macros for doing the actual output.  */

#define outchar(ch)							      \
  do									      \
    {									      \
      const int outc = (ch);						      \
      if (putc (outc, fp) == EOF)					      \
	return -1;							      \
      ++done;								      \
    } while (0)

#define PRINT(ptr, wptr, len)						      \
  do									      \
    {									      \
      size_t outlen = (len);						      \
      if (len > 20)							      \
	{								      \
	  if (PUT (fp, wide ? (const char *) wptr : ptr, outlen) != outlen)   \
	    return -1;							      \
	  ptr += outlen;						      \
	  done += outlen;						      \
	}								      \
      else								      \
	{								      \
	  if (wide)							      \
	    while (outlen-- > 0)					      \
	      outchar (*wptr++);					      \
	  else								      \
	    while (outlen-- > 0)					      \
	      outchar (*ptr++);						      \
	}								      \
    } while (0)

#define PADN(ch, len)							      \
  do									      \
    {									      \
      if (PAD (fp, ch, len) != len)					      \
	return -1;							      \
      done += len;							      \
    }									      \
  while (0)

/* Prototype for helper functions.  */
extern int __printf_fp (FILE *fp, const struct printf_info *info,
			const void *const *args);


int
__printf_size (FILE *fp, const struct printf_info *info,
	       const void *const *args)
{
  /* Units for the both formats.  */
#define BINARY_UNITS	" kmgtpezy"
#define DECIMAL_UNITS	" KMGTPEZY"
  static const char units[2][sizeof (BINARY_UNITS)] =
  {
    BINARY_UNITS,	/* For binary format.  */
    DECIMAL_UNITS	/* For decimal format.  */
  };
  const char *tag = units[isupper (info->spec) != 0];
  int divisor = isupper (info->spec) ? 1000 : 1024;

  /* The floating-point value to output.  */
  union
    {
      union ieee754_double dbl;
      long double ldbl;
#if __HAVE_DISTINCT_FLOAT128
      _Float128 f128;
#endif
    }
  fpnum;
  const void *ptr = &fpnum;

  int is_neg = 0;

  /* "NaN" or "Inf" for the special cases.  */
  const char *special = NULL;
  const wchar_t *wspecial = NULL;

  struct printf_info fp_info;
  int done = 0;
  int wide = info->wide;

#define PRINTF_SIZE_FETCH(FLOAT, VAR)					\
  {									\
    (VAR) = *(const FLOAT *) args[0];					\
									\
    /* Check for special values: not a number or infinity.  */		\
    if (isnan (VAR))							\
      {									\
	special = "nan";						\
	wspecial = L"nan";						\
	/* is_neg = 0; Already zero */					\
      }									\
    else if (isinf (VAR))						\
      {									\
	is_neg = signbit (VAR);						\
	special = "inf";						\
	wspecial = L"inf";						\
      }									\
    else								\
      while ((VAR) >= divisor && tag[1] != '\0')			\
	{								\
	  (VAR) /= divisor;						\
	  ++tag;							\
	}								\
  }

  /* Fetch the argument value.	*/
#if __HAVE_DISTINCT_FLOAT128
  if (info->is_binary128)
    PRINTF_SIZE_FETCH (_Float128, fpnum.f128)
  else
#endif
#ifndef __NO_LONG_DOUBLE_MATH
  if (info->is_long_double && sizeof (long double) > sizeof (double))
    PRINTF_SIZE_FETCH (long double, fpnum.ldbl)
  else
#endif
    PRINTF_SIZE_FETCH (double, fpnum.dbl.d)

#undef PRINTF_SIZE_FETCH

  if (special)
    {
      int width = info->prec > info->width ? info->prec : info->width;

      if (is_neg || info->showsign || info->space)
	--width;
      width -= 3;

      if (!info->left && width > 0)
	PADN (' ', width);

      if (is_neg)
	outchar ('-');
      else if (info->showsign)
	outchar ('+');
      else if (info->space)
	outchar (' ');

      PRINT (special, wspecial, 3);

      if (info->left && width > 0)
	PADN (' ', width);

      return done;
    }

  /* Prepare to print the number.  We want to use `__printf_fp' so we
     have to prepare a `printf_info' structure.  */
  fp_info = *info;
  fp_info.spec = 'f';
  fp_info.prec = info->prec < 0 ? 3 : info->prec;
  fp_info.wide = wide;

  if (fp_info.left && fp_info.pad == L' ')
    {
      /* We must do the padding ourself since the unit character must
	 be placed before the padding spaces.  */
      fp_info.width = 0;

      done = __printf_fp (fp, &fp_info, &ptr);
      if (done > 0)
	{
	  outchar (*tag);
	  if (info->width > done)
	    PADN (' ', info->width - done);
	}
    }
  else
    {
      /* We can let __printf_fp do all the printing and just add our
	 unit character afterwards.  */
      fp_info.width = info->width - 1;

      done = __printf_fp (fp, &fp_info, &ptr);
      if (done > 0)
	outchar (*tag);
    }

  return done;
}
ldbl_strong_alias (__printf_size, printf_size);

/* This is the function used by `vfprintf' to determine number and
   type of the arguments.  */
int
printf_size_info (const struct printf_info *info, size_t n, int *argtypes)
{
  /* We need only one double or long double argument.  */
  if (n >= 1)
    argtypes[0] = PA_DOUBLE | (info->is_long_double ? PA_FLAG_LONG_DOUBLE : 0);

  return 1;
}