stdlib/tst-limits.c

   1 /* It is important that this comes first to not hide effects introduced
   2    by other headers.  */
   3 #include <limits.h>
   4
   5 #include <inttypes.h>
   6 #include <stdio.h>
   7
   8
   9 static long long int
  10 bitval (int bits)
  11 {
  12   long long int val = 0;
  13   while (bits-- > 0)
  14     val |= 1ll << bits;
  15   return val;
  16 }
  17
  18
  19 int
  20 main (void)
  21 {
  22   int result = 0;
  23
  24 #define TEST(name, format, expected) \
  25   printf ("%-12s expected = %-20" format "  actual = %" format "\n",          \
  26           #name ":", expected, name);                                         \
  27   result |= name != expected
  28
  29   /* The limits from ISO C99.  */
  30
  31   /* We cannot support anything but 8-bit chars.  */
  32   TEST (CHAR_BIT, "d", 8);
  33   TEST (SCHAR_MIN, "d", -128);
  34   TEST (SCHAR_MAX, "d", 127);
  35   TEST (UCHAR_MAX, "d", 255);
  36
  37   TEST (SHRT_MIN, "d", -(1 << (sizeof (short int) * CHAR_BIT - 1)));
  38   TEST (SHRT_MAX, "d", (1 << (sizeof (short int) * CHAR_BIT - 1)) - 1);
  39   TEST (USHRT_MAX, "d", (1 << sizeof (short int) * CHAR_BIT) - 1);
  40
  41   TEST (INT_MIN, "d", (int) -bitval (sizeof (int) * CHAR_BIT - 1) - 1);
  42   TEST (INT_MAX, "d", (int) bitval (sizeof (int) * CHAR_BIT - 1));
  43   TEST (UINT_MAX, "u",
  44         (unsigned int) bitval (sizeof (unsigned int) * CHAR_BIT));
  45
  46   TEST (LONG_MIN, "ld",
  47         (long int) -bitval (sizeof (long int) * CHAR_BIT - 1) - 1);
  48   TEST (LONG_MAX, "ld", (long int) bitval (sizeof (long int) * CHAR_BIT - 1));
  49   TEST (ULONG_MAX, "lu",
  50         (unsigned long int) bitval (sizeof (unsigned long int) * CHAR_BIT));
  51
  52   TEST (LLONG_MIN, "lld", -bitval (sizeof (long long int) * CHAR_BIT - 1) - 1);
  53   TEST (LLONG_MAX, "lld", bitval (sizeof (long long int) * CHAR_BIT - 1));
  54   TEST (ULLONG_MAX, "llu",
  55         (unsigned long long int) bitval (sizeof (unsigned long long int)
  56                                          * CHAR_BIT));
  57
  58   /* Values from POSIX and Unix.  */
  59 #ifdef PAGESIZE
  60   TEST (PAGESIZE, "d", getpagesize ());
  61 #elif PAGE_SIZE
  62   TEST (PAGE_SIZE, "d", getpagesize ());
  63 #endif
  64
  65   TEST (WORD_BIT, "d", (int) sizeof (int) * CHAR_BIT);
  66   TEST (LONG_BIT, "d", (int) sizeof (long int) * CHAR_BIT);
  67
  68   return result;
  69 }