src/system.h

   1 /* System dependent declarations.
   2
   3    Copyright (C) 1988-1989, 1992-1995, 1998, 2001-2002, 2004, 2006, 2009-2013,
   4    2015-2025 Free Software Foundation, Inc.
   5
   6    This file is part of GNU DIFF.
   7
   8    This program is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include <config.h>
  22
  23 #include <verify.h>
  24
  25 #include <sys/types.h>
  26
  27 #include <sys/stat.h>
  28 #include <stat-macros.h>
  29 #include <stat-size.h>
  30 #include <stat-time.h>
  31 #include <timespec.h>
  32
  33 #include <unistd.h>
  34
  35 #include <fcntl.h>
  36 #include <time.h>
  37
  38 #include <sys/wait.h>
  39
  40 #include <dirent.h>
  41 #ifndef _D_EXACT_NAMLEN
  42 # define _D_EXACT_NAMLEN(dp) strlen ((dp)->d_name)
  43 #endif
  44
  45 #include <stdlib.h>
  46
  47 #include <inttypes.h>
  48 #include <limits.h>
  49 #include <locale.h>
  50 #include <stdbit.h>
  51 #include <stdckdint.h>
  52 #include <stddef.h>
  53 #include <string.h>
  54
  55 #include <gettext.h>
  56 #if ! ENABLE_NLS
  57 # undef textdomain
  58 # define textdomain(Domainname) /* empty */
  59 # undef bindtextdomain
  60 # define bindtextdomain(Domainname, Dirname) /* empty */
  61 #endif
  62
  63 #define _(msgid) gettext (msgid)
  64 #define N_(msgid) msgid
  65
  66 #include <errno.h>
  67
  68 #include <signal.h>
  69 #if !defined SIGCHLD && defined SIGCLD
  70 # define SIGCHLD SIGCLD
  71 #endif
  72
  73 #include <attribute.h>
  74 #include <idx.h>
  75 #include <intprops.h>
  76 #include <minmax.h>
  77 #include <propername.h>
  78 #include <same-inode.h>
  79
  80 #include "version.h"
  81
  82 /* Evaluate an assertion E that is guaranteed to be true.
  83    E should not crash, loop forever, or have side effects.  */
  84 #if defined DDEBUG && !defined NDEBUG
  85 /* Abort the program if E is false.  */
  86 # include <assert.h>
  87 # define dassert(e) assert (e)
  88 #else
  89 /* The compiler can assume E, as behavior is undefined otherwise.  */
  90 # define dassert(e) assume (e)
  91 #endif
  92
  93 #ifndef SYSTEM_INLINE
  94 # define SYSTEM_INLINE _GL_INLINE
  95 #endif
  96
  97 _GL_INLINE_HEADER_BEGIN
  98
  99 /* Type used for fast comparison of several bytes at a time.
 100    The type is a pointer to an incomplete struct,
 101    so that its values are less likely to be misused.
 102    This used to be uintmax_t, but changing it to the size of a pointer
 103    made plain 'cmp' 90% faster (GCC 4.8.1, x86).  */
 104
 105 #ifndef word
 106 typedef struct incomplete *word;
 107 #endif
 108
 109 /* The signed integer type of a line number.  Since files are read
 110    into main memory, ptrdiff_t should be wide enough.  pI is for
 111    printing line numbers.  */
 112
 113 typedef ptrdiff_t lin;
 114 #define LIN_MAX PTRDIFF_MAX
 115 #define pI "t"
 116 static_assert (LIN_MAX == IDX_MAX);
 117 \f
 118 /* This section contains POSIX-compliant defaults for macros
 119    that are meant to be overridden by hand in config.h as needed.  */
 120
 121 #ifndef file_name_cmp
 122 # define file_name_cmp strcmp
 123 #endif
 124
 125 #ifndef initialize_main
 126 # define initialize_main(argcp, argvp)
 127 #endif
 128
 129 #ifndef NULL_DEVICE
 130 # define NULL_DEVICE "/dev/null"
 131 #endif
 132
 133 #define STREQ(a, b) (strcmp (a, b) == 0)
 134
 135 /* Return the floor of the log base 2 of N.  Return -1 if N is zero.  */
 136 SYSTEM_INLINE int floor_log2 (idx_t n)
 137 {
 138   static_assert (IDX_MAX <= SIZE_MAX);
 139   size_t s = n;
 140   int w = stdc_bit_width (s);
 141   return w - 1;
 142 }
 143
 144 _GL_INLINE_HEADER_END
 145
 146 extern bool same_file (struct stat const *, struct stat const *)
 147   ATTRIBUTE_PURE;
 148 extern off_t stat_size (struct stat const *)
 149   ATTRIBUTE_PURE;