test/Sema/bitfield-layout.c

   1 // RUN: %clang_cc1 %s -fsyntax-only -verify -triple=i686-apple-darwin9
   2
   3 #define CHECK_SIZE(kind, name, size) extern int name##1[sizeof(kind name) == size ? 1 : -1];
   4 #define CHECK_ALIGN(kind, name, size) extern int name##2[__alignof(kind name) == size ? 1 : -1];
   5
   6 // Zero-width bit-fields
   7 struct a {char x; int : 0; char y;};
   8 CHECK_SIZE(struct, a, 5)
   9 CHECK_ALIGN(struct, a, 1)
  10
  11 union b {char x; int : 0; char y;};
  12 CHECK_SIZE(union, b, 1)
  13 CHECK_ALIGN(union, b, 1)
  14
  15 // Unnamed bit-field align
  16 struct c {char x; int : 20;};
  17 CHECK_SIZE(struct, c, 4)
  18 CHECK_ALIGN(struct, c, 1)
  19
  20 union d {char x; int : 20;};
  21 CHECK_SIZE(union, d, 3)
  22 CHECK_ALIGN(union, d, 1)
  23
  24 // Bit-field packing
  25 struct __attribute__((packed)) e {int x : 4, y : 30, z : 30;};
  26 CHECK_SIZE(struct, e, 8)
  27 CHECK_ALIGN(struct, e, 1)
  28
  29 // Alignment on bit-fields
  30 struct f {__attribute((aligned(8))) int x : 30, y : 30, z : 30;};
  31 CHECK_SIZE(struct, f, 24)
  32 CHECK_ALIGN(struct, f, 8)
  33
  34 // Large structure (overflows i32, in bits).
  35 struct s0 {
  36   char a[0x32100000];
  37   int x:30, y:30;
  38 };
  39
  40 CHECK_SIZE(struct, s0, 0x32100008)
  41 CHECK_ALIGN(struct, s0, 4)
  42