| // P1272R4 |
| // { dg-do compile { target c++14 } } |
| |
| struct S { unsigned char a : 8, b : 5, c : 3, d, e; unsigned int f : 8, g : 24; }; |
| struct T1 { unsigned char a : 1, : 7, b : 5, c : 3, d, e; unsigned int f : 8, g : 24; }; |
| struct T2 { unsigned char a : 8, b : 1, : 4, c : 3, d, e; unsigned int f : 8, g : 24; }; |
| struct T3 { unsigned char a : 8, b : 5, c : 1, : 2, d, e; unsigned int f : 8, g : 24; }; |
| struct T4 { unsigned char a : 8, b : 5, c : 3, d, e; unsigned int f : 1, : 7, g : 24; }; |
| |
| constexpr bool |
| f1 () |
| { |
| T1 t = { 0, 0, 0, 0, 0, 0, 0 }; |
| S s = __builtin_bit_cast (S, t); |
| return true; |
| } |
| |
| constexpr bool |
| f2 () |
| { |
| T2 t = { 0, 0, 0, 0, 0, 0, 0 }; |
| S s = __builtin_bit_cast (S, t); |
| return true; |
| } |
| |
| constexpr bool |
| f3 () |
| { |
| T3 t = { 0, 0, 0, 0, 0, 0, 0 }; |
| S s = __builtin_bit_cast (S, t); |
| return true; |
| } |
| |
| constexpr bool |
| f4 () |
| { |
| T4 t = { 0, 0, 0, 0, 0, 0, 0 }; |
| S s = __builtin_bit_cast (S, t); // { dg-error "accessing uninitialized byte" } |
| return true; |
| } |
| |
| constexpr bool |
| f5 () |
| { |
| T1 t = { 0, 0, 0, 0, 0, 0, 0 }; |
| S s = __builtin_bit_cast (S, t); |
| unsigned char a = s.a; |
| return true; |
| } |
| |
| constexpr bool |
| f6 () |
| { |
| T2 t = { 0, 0, 0, 0, 0, 0, 0 }; |
| S s = __builtin_bit_cast (S, t); |
| unsigned char b = s.b; |
| return true; |
| } |
| |
| constexpr bool |
| f7 () |
| { |
| T3 t = { 0, 0, 0, 0, 0, 0, 0 }; |
| S s = __builtin_bit_cast (S, t); |
| unsigned char c = s.c; |
| return true; |
| } |
| |
| constexpr bool a = f1 (); |
| constexpr bool b = f2 (); |
| constexpr bool c = f3 (); |
| constexpr bool d = f4 (); |
| constexpr bool e = f5 (); // { dg-error "accessing uninitialized member" } |
| constexpr bool f = f6 (); // { dg-error "accessing uninitialized member" } |
| constexpr bool g = f7 (); // { dg-error "accessing uninitialized member" } |