| // { dg-options "-Warray-bounds" } |
| // { dg-do compile } |
| |
| // Test case exercising pr c/67882 - surprising offsetof result |
| // on an invalid array member without diagnostic. |
| |
| typedef struct A1 { |
| char a1[1]; |
| char c; |
| } A1; |
| |
| typedef struct A1_x_2 { |
| char a1[1]; |
| char a[][2]; |
| } A1_x_2; |
| |
| typedef struct A1_1_x { |
| char a1_1[1][1]; |
| char a[]; |
| } A1_1_x; |
| |
| typedef struct Ax_2_3 { |
| int i; |
| char a_x_2_3[][2][3]; |
| } Ax_2_3; |
| |
| typedef struct A1_1 { |
| char a1_1[1][1]; |
| char c; |
| } A1_1; |
| |
| typedef struct B { |
| A1_1 a2_3[2][3]; |
| char a1_1[3][5]; |
| char a[]; |
| } B; |
| |
| // Structures with members that contain flexible array members are |
| // an extension accepted by GCC. |
| typedef struct C { |
| A1_1_x a5_7 [5][7]; |
| int a; |
| } C; |
| |
| // Structs with a "fake" flexible array member (a GCC extension). |
| typedef struct FA0 { |
| int i; |
| char a0 [0]; |
| } FA0; |
| |
| typedef struct FA1 { |
| int i; |
| char a1 [1]; |
| } FA1; |
| |
| typedef struct FA3 { |
| int i; |
| char a3 [3]; |
| } FA3; |
| |
| // A "fake" multidimensional flexible array member. |
| typedef struct FA5_7 { |
| int i; |
| char a5_7 [5][7]; |
| } FA5_7; |
| |
| static void test (void) |
| { |
| // Verify that offsetof references to array elements past the end of |
| // the array member are diagnosed. As an extension, permit references |
| // to the element just past-the-end of the array. |
| |
| int a[] = { |
| __builtin_offsetof (A1, a1), // valid |
| __builtin_offsetof (A1, a1 [0]), // valid |
| |
| // The following expression is valid because it forms the equivalent |
| // of an address pointing just past the last element of the array. |
| __builtin_offsetof (A1, a1 [1]), // valid |
| |
| __builtin_offsetof (A1, a1 [2]), // { dg-warning "index" } |
| |
| __builtin_offsetof (A1_x_2, a1), // valid |
| __builtin_offsetof (A1_x_2, a1 [0]), // valid |
| __builtin_offsetof (A1_x_2, a1 [1]), // valid |
| __builtin_offsetof (A1_x_2, a1 [2]), // { dg-warning "index" } |
| |
| __builtin_offsetof (A1_x_2, a), // valid |
| __builtin_offsetof (A1_x_2, a [0]), // valid |
| __builtin_offsetof (A1_x_2, a [1]), // valid |
| __builtin_offsetof (A1_x_2, a [99]), // valid |
| |
| __builtin_offsetof (A1_x_2, a), // valid |
| __builtin_offsetof (A1_x_2, a [0][0]), // valid |
| __builtin_offsetof (A1_x_2, a [0][1]), // valid |
| |
| // The following expression is valid because it forms the equivalent |
| // of an address pointing just past the last element of the first |
| // array. |
| __builtin_offsetof (A1_x_2, a [0][2]), // valid |
| |
| // Unlike the case above, this is invalid since it refers to an element |
| // past one one just-past-the-end in A[][2]. |
| __builtin_offsetof (A1_x_2, a [0][3]), // { dg-warning "index" } |
| |
| __builtin_offsetof (A1_x_2, a [1][0]), // valid |
| __builtin_offsetof (A1_x_2, a [1][1]), // valid |
| __builtin_offsetof (A1_x_2, a [1][2]), // valid |
| __builtin_offsetof (A1_x_2, a [99][0]), // valid |
| __builtin_offsetof (A1_x_2, a [99][1]), // valid |
| __builtin_offsetof (A1_x_2, a [99][2]), // valid |
| |
| __builtin_offsetof (A1_1_x, a), // valid |
| __builtin_offsetof (A1_1_x, a [0]), // valid |
| __builtin_offsetof (A1_1_x, a [1]), // valid |
| __builtin_offsetof (A1_1_x, a [99]), // valid |
| |
| __builtin_offsetof (A1_1_x, a1_1 [0][0]), // valid |
| __builtin_offsetof (A1_1_x, a1_1 [0][1]), // valid |
| __builtin_offsetof (A1_1_x, a1_1 [0][2]), // { dg-warning "index" } |
| __builtin_offsetof (A1_1_x, a1_1 [1][0]), // { dg-warning "index" } |
| __builtin_offsetof (A1_1_x, a1_1 [1][1]), // { dg-warning "index" } |
| |
| __builtin_offsetof (Ax_2_3, a_x_2_3 [0][1][3]), // valid |
| __builtin_offsetof (Ax_2_3, a_x_2_3 [0][1][4]), // { dg-warning "index" } |
| __builtin_offsetof (Ax_2_3, a_x_2_3 [0][2]), // valid |
| __builtin_offsetof (Ax_2_3, a_x_2_3 [0][2][0]), // { dg-warning "index" } |
| |
| __builtin_offsetof (B, a2_3 [0][0].c), // valid |
| __builtin_offsetof (B, a2_3 [0][0].a1_1 [0][0]), // valid |
| __builtin_offsetof (B, a2_3 [1][3]), // valid |
| __builtin_offsetof (B, a2_3 [1][4]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [0][0].a1_1 [0][1]), // valid |
| __builtin_offsetof (B, a2_3 [0][0].a1_1 [0][2]), // { dg-warning "index" } |
| |
| __builtin_offsetof (B, a2_3 [0][0].a1_1 [1][0]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [0][0].a1_1 [1][1]), // { dg-warning "index" } |
| |
| __builtin_offsetof (B, a2_3 [1][2].a1_1 [0][0]), // valid |
| |
| // Forming an offset to the just-past-end element is valid. |
| __builtin_offsetof (B, a2_3 [1][2].a1_1 [0][1]), // valid |
| __builtin_offsetof (B, a2_3 [1][2].a1_1 [1][0]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [1][2].a1_1 [1][1]), // { dg-warning "index" } |
| |
| // Forming an offset to the just-past-end element is valid. |
| __builtin_offsetof (B, a2_3 [1][3]), // valid |
| // ...but these are diagnosed because they dereference a just-past-the-end |
| // element. |
| __builtin_offsetof (B, a2_3 [1][3].a1_1 [0][0]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [1][3].a1_1 [0][0]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [1][3].a1_1 [0][1]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [1][3].a1_1 [1][0]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [1][3].a1_1 [1][1]), // { dg-warning "index" } |
| |
| // Analogous to the case above, these are both diagnosed because they |
| // dereference just-past-the-end elements of the a2_3 array. |
| __builtin_offsetof (B, a2_3 [1][3].c), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [1][3].c), // { dg-warning "index" } |
| |
| // The following are all invalid because of the reference to a2_3[2]. |
| __builtin_offsetof (B, a2_3 [2][0].a1_1 [0][0]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [2][0].a1_1 [0][1]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [2][0].a1_1 [1][0]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [2][0].a1_1 [1][1]), // { dg-warning "index" } |
| __builtin_offsetof (B, a2_3 [2][0].c), // { dg-warning "index" } |
| |
| __builtin_offsetof (C, a5_7 [4][6]), |
| __builtin_offsetof (C, a5_7 [4][6].a), |
| __builtin_offsetof (C, a5_7 [4][6].a [0]), |
| __builtin_offsetof (C, a5_7 [4][6].a [99]), |
| |
| __builtin_offsetof (C, a5_7 [4][7]), // valid |
| // Diagnose the following even though the object whose offset is |
| // computed is a flexible array member. |
| __builtin_offsetof (C, a5_7 [4][7].a), // { dg-warning "index" } |
| __builtin_offsetof (C, a5_7 [4][7].a [0]), // { dg-warning "index" } |
| __builtin_offsetof (C, a5_7 [4][7].a [99]), // { dg-warning "index" } |
| |
| // Verify that no diagnostic is issued for offsetof expressions |
| // involving structs where the array has a rank of 1 and is the last |
| // member (e.g., those are treated as flexible array members). |
| __builtin_offsetof (FA0, a0 [0]), |
| __builtin_offsetof (FA0, a0 [1]), |
| __builtin_offsetof (FA0, a0 [99]), |
| |
| __builtin_offsetof (FA1, a1 [0]), |
| __builtin_offsetof (FA1, a1 [1]), |
| __builtin_offsetof (FA1, a1 [99]), |
| |
| __builtin_offsetof (FA3, a3 [0]), |
| __builtin_offsetof (FA3, a3 [3]), |
| __builtin_offsetof (FA3, a3 [99]), |
| |
| __builtin_offsetof (FA5_7, a5_7 [0][0]), |
| |
| // Unlike one-dimensional arrays, verify that out-of-bounds references |
| // to "fake" flexible arrays with rank of 2 and greater are diagnosed. |
| |
| // The following are valid because they compute the offset of just past |
| // the end of each of the a5_7[0] and a5_7[1] arrays. |
| __builtin_offsetof (FA5_7, a5_7 [0][7]), // valid |
| __builtin_offsetof (FA5_7, a5_7 [1][7]), // valid |
| |
| // The following two are accepted as an extesion (because a5_7 is |
| // treated as a flexible array member). |
| __builtin_offsetof (FA5_7, a5_7 [5][0]), // extension |
| __builtin_offsetof (FA5_7, a5_7 [5][7]), // extension |
| |
| // The following are invalid since in both cases they denote an element |
| // that's beyond just-past-the-end of the array. |
| __builtin_offsetof (FA5_7, a5_7 [0][8]), // { dg-warning "index" } |
| __builtin_offsetof (FA5_7, a5_7 [6][8]) // { dg-warning "index" } |
| }; |
| |
| (void)&a; |
| } |
