tests/test-limits-h.c

   1 /* Test of <limits.h> substitute.
   2    Copyright 2016-2024 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Paul Eggert.  */
  18
  19 #include <config.h>
  20
  21 #include <limits.h>
  22
  23 #if 4 < __GNUC__ + (3 <= __GNUC_MINOR__)
  24 # pragma GCC diagnostic ignored "-Woverlength-strings"
  25 #endif
  26
  27 #define verify_width(width, min, max) \
  28   static_assert ((max) >> ((width) - 1 - ((min) < 0)) == 1)
  29
  30 /* Macros borrowed from intprops.h.  */
  31 #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
  32 #define TYPE_WIDTH(t) (sizeof (t) * CHAR_BIT)
  33 #define TYPE_MINIMUM(t) ((t) ~ TYPE_MAXIMUM (t))
  34 #define TYPE_MAXIMUM(t)                                                 \
  35   ((t) (! TYPE_SIGNED (t)                                               \
  36         ? (t) -1                                                        \
  37         : ((((t) 1 << (TYPE_WIDTH (t) - 2)) - 1) * 2 + 1)))
  38
  39 /* Type width macros.  */
  40
  41 int type_bits[] =
  42   {
  43     CHAR_BIT,
  44     WORD_BIT,
  45     LONG_BIT
  46   };
  47 verify_width (CHAR_BIT, CHAR_MIN, CHAR_MAX);
  48 verify_width (WORD_BIT, INT_MIN, INT_MAX);
  49 verify_width (LONG_BIT, LONG_MIN, LONG_MAX);
  50
  51 /* Numerical limit macros.  */
  52
  53 char               limits1[]  = { CHAR_MIN, CHAR_MAX };
  54 static_assert (TYPE_MINIMUM (char) == CHAR_MIN);
  55 static_assert (TYPE_MAXIMUM (char) == CHAR_MAX);
  56
  57 signed char        limits2[]  = { SCHAR_MIN, SCHAR_MAX };
  58 static_assert (TYPE_MINIMUM (signed char) == SCHAR_MIN);
  59 static_assert (TYPE_MAXIMUM (signed char) == SCHAR_MAX);
  60
  61 unsigned char      limits3[]  = { UCHAR_MAX };
  62 static_assert (TYPE_MINIMUM (unsigned char) == 0);
  63 static_assert (TYPE_MAXIMUM (unsigned char) == UCHAR_MAX);
  64
  65 short              limits4[]  = { SHRT_MIN, SHRT_MAX };
  66 static_assert (TYPE_MINIMUM (short int) == SHRT_MIN);
  67 static_assert (TYPE_MAXIMUM (short int) == SHRT_MAX);
  68
  69 unsigned short     limits5[]  = { USHRT_MAX };
  70 static_assert (TYPE_MINIMUM (unsigned short int) == 0);
  71 static_assert (TYPE_MAXIMUM (unsigned short int) == USHRT_MAX);
  72
  73 int                limits6[]  = { INT_MIN, INT_MAX };
  74 static_assert (TYPE_MINIMUM (int) == INT_MIN);
  75 static_assert (TYPE_MAXIMUM (int) == INT_MAX);
  76
  77 unsigned int       limits7[]  = { UINT_MAX };
  78 static_assert (TYPE_MINIMUM (unsigned int) == 0);
  79 static_assert (TYPE_MAXIMUM (unsigned int) == UINT_MAX);
  80
  81 long               limits8[]  = { LONG_MIN, LONG_MAX };
  82 static_assert (TYPE_MINIMUM (long int) == LONG_MIN);
  83 static_assert (TYPE_MAXIMUM (long int) == LONG_MAX);
  84
  85 unsigned long      limits9[]  = { ULONG_MAX };
  86 static_assert (TYPE_MINIMUM (unsigned long int) == 0);
  87 static_assert (TYPE_MAXIMUM (unsigned long int) == ULONG_MAX);
  88
  89 long long          limits10[] = { LLONG_MIN, LLONG_MAX };
  90 static_assert (TYPE_MINIMUM (long long int) == LLONG_MIN);
  91 static_assert (TYPE_MAXIMUM (long long int) == LLONG_MAX);
  92
  93 unsigned long long limits11[] = { ULLONG_MAX };
  94 static_assert (TYPE_MINIMUM (unsigned long long int) == 0);
  95 static_assert (TYPE_MAXIMUM (unsigned long long int) == ULLONG_MAX);
  96
  97 /* Specified by POSIX, not by ISO C.  */
  98
  99 long long limits12[] = { SSIZE_MAX };
 100
 101 /* Macros specified by C23 and by ISO/IEC TS 18661-1:2014.  */
 102
 103 verify_width (CHAR_WIDTH, CHAR_MIN, CHAR_MAX);
 104 verify_width (SCHAR_WIDTH, SCHAR_MIN, SCHAR_MAX);
 105 verify_width (UCHAR_WIDTH, 0, UCHAR_MAX);
 106 verify_width (SHRT_WIDTH, SHRT_MIN, SHRT_MAX);
 107 verify_width (USHRT_WIDTH, 0, USHRT_MAX);
 108 verify_width (INT_WIDTH, INT_MIN, INT_MAX);
 109 verify_width (UINT_WIDTH, 0, UINT_MAX);
 110 verify_width (LONG_WIDTH, LONG_MIN, LONG_MAX);
 111 verify_width (ULONG_WIDTH, 0, ULONG_MAX);
 112 verify_width (LLONG_WIDTH, LLONG_MIN, LLONG_MAX);
 113 verify_width (ULLONG_WIDTH, 0, ULLONG_MAX);
 114
 115 /* Macros specified by C23.  */
 116
 117 int bool_attrs[] = { BOOL_MAX, BOOL_WIDTH };
 118 static_assert (BOOL_MAX == 1);
 119
 120 static_assert (0 < MB_LEN_MAX);
 121
 122 /* Get ssize_t, size_t.  */
 123 #include <sys/types.h>
 124
 125 static_assert (TYPE_MAXIMUM (ssize_t) == SSIZE_MAX);
 126 /* Verify that ssize_t has the same width as size_t.  */
 127 static_assert (TYPE_MAXIMUM (size_t) / 2 == SSIZE_MAX);
 128
 129 int
 130 main (void)
 131 {
 132   return 0;
 133 }