78 lines · c
1#include <stdint.h>2 3struct Bits {4 uint32_t : 1;5 uint32_t b1 : 1;6 uint32_t b2 : 2;7 uint32_t : 2;8 uint32_t b3 : 3;9 // Unnamed bitfield (this will get removed).10 uint32_t : 2;11 uint32_t b4 __attribute__ ((aligned(16)));12 uint32_t b5 : 5;13 uint32_t b6 : 6;14 uint32_t b7 : 7;15 uint32_t four : 4;16};17 18struct MoreBits {19 uint32_t a : 3;20 uint8_t : 1;21 uint8_t b : 1;22 uint8_t c : 1;23 uint8_t d : 1;24};25struct MoreBits more_bits;26 27struct ManySingleBits {28 uint16_t b1 : 1, b2 : 1, b3 : 1, b4 : 1, b5 : 1, b6 : 1, b7 : 1, b8 : 1,29 b9 : 1, b10 : 1, b11 : 1, b12 : 1, b13 : 1, b14 : 1, b15 : 1, b16 : 1,30 b17 : 1;31};32struct ManySingleBits many_single_bits;33 34struct LargePackedBits {35 uint64_t a : 36;36 uint64_t b : 36;37} __attribute__((packed));38 39#pragma pack(1)40struct PackedBits {41 char a;42 uint32_t b : 5, c : 27;43};44#pragma pack()45 46int main(int argc, char const *argv[]) {47 struct Bits bits;48 bits.b1 = 1;49 bits.b2 = 3;50 bits.b3 = 7;51 bits.b4 = 15;52 bits.b5 = 31;53 bits.b6 = 63;54 bits.b7 = 127;55 bits.four = 15;56 57 more_bits.a = 3;58 more_bits.b = 0;59 more_bits.c = 1;60 more_bits.d = 0;61 62 many_single_bits.b1 = 1;63 many_single_bits.b5 = 1;64 many_single_bits.b7 = 1;65 many_single_bits.b13 = 1;66 67 struct PackedBits packed;68 packed.a = 'a';69 packed.b = 10;70 packed.c = 0x7112233;71 72 struct LargePackedBits large_packed =73 (struct LargePackedBits){0xcbbbbaaaa, 0xdffffeeee};74 struct LargePackedBits *large_packed_ptr = &large_packed;75 76 return 0; // break here77}78