libio/bits/stdio.h

   1 /* Optimizing macros and inline functions for stdio functions.
   2    Copyright (C) 1998-2018 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _STDIO_H
  20 # error "Never include <bits/stdio.h> directly; use <stdio.h> instead."
  21 #endif
  22
  23 #ifndef __extern_inline
  24 # define __STDIO_INLINE inline
  25 #else
  26 # define __STDIO_INLINE __extern_inline
  27 #endif
  28
  29
  30 #ifdef __USE_EXTERN_INLINES
  31 /* For -D_FORTIFY_SOURCE{,=2} bits/stdio2.h will define a different
  32    inline.  */
  33 # if !(__USE_FORTIFY_LEVEL > 0 && defined __fortify_function)
  34 /* Write formatted output to stdout from argument list ARG.  */
  35 __STDIO_INLINE int
  36 vprintf (const char *__restrict __fmt, _G_va_list __arg)
  37 {
  38   return vfprintf (stdout, __fmt, __arg);
  39 }
  40 # endif
  41
  42 /* Read a character from stdin.  */
  43 __STDIO_INLINE int
  44 getchar (void)
  45 {
  46   return _IO_getc (stdin);
  47 }
  48
  49
  50 # ifdef __USE_MISC
  51 /* Faster version when locking is not necessary.  */
  52 __STDIO_INLINE int
  53 fgetc_unlocked (FILE *__fp)
  54 {
  55   return _IO_getc_unlocked (__fp);
  56 }
  57 # endif /* misc */
  58
  59
  60 # ifdef __USE_POSIX
  61 /* This is defined in POSIX.1:1996.  */
  62 __STDIO_INLINE int
  63 getc_unlocked (FILE *__fp)
  64 {
  65   return _IO_getc_unlocked (__fp);
  66 }
  67
  68 /* This is defined in POSIX.1:1996.  */
  69 __STDIO_INLINE int
  70 getchar_unlocked (void)
  71 {
  72   return _IO_getc_unlocked (stdin);
  73 }
  74 # endif /* POSIX */
  75
  76
  77 /* Write a character to stdout.  */
  78 __STDIO_INLINE int
  79 putchar (int __c)
  80 {
  81   return _IO_putc (__c, stdout);
  82 }
  83
  84
  85 # ifdef __USE_MISC
  86 /* Faster version when locking is not necessary.  */
  87 __STDIO_INLINE int
  88 fputc_unlocked (int __c, FILE *__stream)
  89 {
  90   return _IO_putc_unlocked (__c, __stream);
  91 }
  92 # endif /* misc */
  93
  94
  95 # ifdef __USE_POSIX
  96 /* This is defined in POSIX.1:1996.  */
  97 __STDIO_INLINE int
  98 putc_unlocked (int __c, FILE *__stream)
  99 {
 100   return _IO_putc_unlocked (__c, __stream);
 101 }
 102
 103 /* This is defined in POSIX.1:1996.  */
 104 __STDIO_INLINE int
 105 putchar_unlocked (int __c)
 106 {
 107   return _IO_putc_unlocked (__c, stdout);
 108 }
 109 # endif /* POSIX */
 110
 111
 112 # ifdef __USE_GNU
 113 /* Like `getdelim', but reads up to a newline.  */
 114 __STDIO_INLINE _IO_ssize_t
 115 getline (char **__lineptr, size_t *__n, FILE *__stream)
 116 {
 117   return __getdelim (__lineptr, __n, '\n', __stream);
 118 }
 119 # endif /* GNU */
 120
 121
 122 # ifdef __USE_MISC
 123 /* Faster versions when locking is not required.  */
 124 __STDIO_INLINE int
 125 __NTH (feof_unlocked (FILE *__stream))
 126 {
 127   return _IO_feof_unlocked (__stream);
 128 }
 129
 130 /* Faster versions when locking is not required.  */
 131 __STDIO_INLINE int
 132 __NTH (ferror_unlocked (FILE *__stream))
 133 {
 134   return _IO_ferror_unlocked (__stream);
 135 }
 136 # endif /* misc */
 137
 138 #endif /* Use extern inlines.  */
 139
 140
 141 #if defined __USE_MISC && defined __GNUC__ && defined __OPTIMIZE__ \
 142     && !defined __cplusplus
 143 /* Perform some simple optimizations.  */
 144 # define fread_unlocked(ptr, size, n, stream) \
 145   (__extension__ ((__builtin_constant_p (size) && __builtin_constant_p (n)    \
 146                    && (size_t) (size) * (size_t) (n) <= 8                     \
 147                    && (size_t) (size) != 0)                                   \
 148                   ? ({ char *__ptr = (char *) (ptr);                          \
 149                        FILE *__stream = (stream);                             \
 150                        size_t __cnt;                                          \
 151                        for (__cnt = (size_t) (size) * (size_t) (n);           \
 152                             __cnt > 0; --__cnt)                               \
 153                          {                                                    \
 154                            int __c = _IO_getc_unlocked (__stream);            \
 155                            if (__c == EOF)                                    \
 156                              break;                                           \
 157                            *__ptr++ = __c;                                    \
 158                          }                                                    \
 159                        ((size_t) (size) * (size_t) (n) - __cnt)               \
 160                         / (size_t) (size); })                                 \
 161                   : (((__builtin_constant_p (size) && (size_t) (size) == 0)   \
 162                       || (__builtin_constant_p (n) && (size_t) (n) == 0))     \
 163                         /* Evaluate all parameters once.  */                  \
 164                      ? ((void) (ptr), (void) (stream), (void) (size),         \
 165                         (void) (n), (size_t) 0)                               \
 166                      : fread_unlocked (ptr, size, n, stream))))
 167
 168 # define fwrite_unlocked(ptr, size, n, stream) \
 169   (__extension__ ((__builtin_constant_p (size) && __builtin_constant_p (n)    \
 170                    && (size_t) (size) * (size_t) (n) <= 8                     \
 171                    && (size_t) (size) != 0)                                   \
 172                   ? ({ const char *__ptr = (const char *) (ptr);              \
 173                        FILE *__stream = (stream);                             \
 174                        size_t __cnt;                                          \
 175                        for (__cnt = (size_t) (size) * (size_t) (n);           \
 176                             __cnt > 0; --__cnt)                               \
 177                          if (_IO_putc_unlocked (*__ptr++, __stream) == EOF)   \
 178                            break;                                             \
 179                        ((size_t) (size) * (size_t) (n) - __cnt)               \
 180                         / (size_t) (size); })                                 \
 181                   : (((__builtin_constant_p (size) && (size_t) (size) == 0)   \
 182                       || (__builtin_constant_p (n) && (size_t) (n) == 0))     \
 183                         /* Evaluate all parameters once.  */                  \
 184                      ? ((void) (ptr), (void) (stream), (void) (size),         \
 185                         (void) (n), (size_t) 0)                               \
 186                      : fwrite_unlocked (ptr, size, n, stream))))
 187 #endif
 188
 189 /* Define helper macro.  */
 190 #undef __STDIO_INLINE