gnu/dist/gdb6/gdb/testsuite/gdb.base/bitfields.c

   1 /* Test program to test bit field operations */
   2
   3 /* For non-ANSI compilers, use plain ints for the signed bit fields.  However,
   4    whether they actually end up signed or not is implementation defined, so
   5    this may cause some tests to fail.  But at least we can still compile
   6    the test program and run the tests... */
   7
   8 #if !defined(__STDC__) && !defined(__cplusplus)
   9 #define signed  /**/
  10 #endif
  11
  12 struct fields
  13 {
  14   unsigned char uc    ;
  15   signed int    s1 : 1;
  16   unsigned int  u1 : 1;
  17   signed int    s2 : 2;
  18   unsigned int  u2 : 2;
  19   signed int    s3 : 3;
  20   unsigned int  u3 : 3;
  21   signed int    s9 : 9;
  22   unsigned int  u9 : 9;
  23   signed char   sc    ;
  24 } flags;
  25
  26 void break1 ()
  27 {
  28 }
  29
  30 void break2 ()
  31 {
  32 }
  33
  34 void break3 ()
  35 {
  36 }
  37
  38 void break4 ()
  39 {
  40 }
  41
  42 void break5 ()
  43 {
  44 }
  45
  46 void break6 ()
  47 {
  48 }
  49
  50 void break7 ()
  51 {
  52 }
  53
  54 void break8 ()
  55 {
  56 }
  57
  58 void break9 ()
  59 {
  60 }
  61
  62 void break10 ()
  63 {
  64 }
  65
  66 /* This is used by bitfields.exp to determine if the target understands
  67    signed bitfields.  */
  68 int i;
  69
  70 int main ()
  71 {
  72   /* For each member, set that member to 1, allow gdb to verify that the
  73      member (and only that member) is 1, and then reset it back to 0. */
  74
  75 #ifdef usestubs
  76   set_debug_traps();
  77   breakpoint();
  78 #endif
  79   flags.uc = 1;
  80   break1 ();
  81   flags.uc = 0;
  82
  83   flags.s1 = -1;
  84   break1 ();
  85   flags.s1 = 0;
  86
  87   flags.u1 = 1;
  88   break1 ();
  89   flags.u1 = 0;
  90
  91   flags.s2  = 1;
  92   break1 ();
  93   flags.s2 = 0;
  94
  95   flags.u2 = 1;
  96   break1 ();
  97   flags.u2 = 0;
  98
  99   flags.s3  = 1;
 100   break1 ();
 101   flags.s3 = 0;
 102
 103   flags.u3 = 1;
 104   break1 ();
 105   flags.u3 = 0;
 106
 107   flags.s9 = 1;
 108   break1 ();
 109   flags.s9 = 0;
 110
 111   flags.u9 = 1;
 112   break1 ();
 113   flags.u9 = 0;
 114
 115   flags.sc = 1;
 116   break1 ();
 117   flags.sc = 0;
 118
 119   /* Fill alternating fields with all 1's and verify that none of the bits
 120      "bleed over" to the other fields. */
 121
 122   flags.uc = 0xFF;
 123   flags.u1 = 0x1;
 124   flags.u2 = 0x3;
 125   flags.u3 = 0x7;
 126   flags.u9 = 0x1FF;
 127   break2 ();
 128   flags.uc = 0;
 129   flags.u1 = 0;
 130   flags.u2 = 0;
 131   flags.u3 = 0;
 132   flags.u9 = 0;
 133
 134   flags.s1 = -1;
 135   flags.s2 = -1;
 136   flags.s3 = -1;
 137   flags.s9 = -1;
 138   flags.sc = 0xFF;
 139   break2 ();
 140   flags.s1 = 0;
 141   flags.s2 = 0;
 142   flags.s3 = 0;
 143   flags.s9 = 0;
 144   flags.sc = 0;
 145
 146   /* Fill the unsigned fields with the maximum positive value and verify
 147      that the values are printed correctly. */
 148
 149   /* Maximum positive values */
 150   flags.u1 = 0x1;
 151   flags.u2 = 0x3;
 152   flags.u3 = 0x7;
 153   flags.u9 = 0x1FF;
 154   break3 ();
 155   flags.u1 = 0;
 156   flags.u2 = 0;
 157   flags.u3 = 0;
 158   flags.u9 = 0;
 159
 160   /* Fill the signed fields with the maximum positive value, then the maximally
 161      negative value, then -1, and verify in each case that the values are
 162      printed correctly. */
 163
 164   /* Maximum positive values */
 165   flags.s1 = 0x0;
 166   flags.s2 = 0x1;
 167   flags.s3 = 0x3;
 168   flags.s9 = 0xFF;
 169   break4 ();
 170
 171   /* Maximally negative values */
 172   flags.s1 = -0x1;
 173   flags.s2 = -0x2;
 174   flags.s3 = -0x4;
 175   flags.s9 = -0x100;
 176   /* Extract bitfield value so that bitfield.exp can check if the target
 177      understands signed bitfields.  */
 178   i = flags.s9;
 179   break4 ();
 180
 181   /* -1 */
 182   flags.s1 = -1;
 183   flags.s2 = -1;
 184   flags.s3 = -1;
 185   flags.s9 = -1;
 186   break4 ();
 187
 188   flags.s1 = 0;
 189   flags.s2 = 0;
 190   flags.s3 = 0;
 191   flags.s9 = 0;
 192
 193   return 0;
 194 }