Shifted Pointers

Shifted pointers

offsetof
__builtin_offsetof
CONTAINING_RECORD

typedef struct vec3f {
    float x;
    float y;
    float z;
} vec3f_t;

typedef struct player {
    char name[16];
    int health;
    int armor;
    int ammo;
    vec3f_t position;
} player_t;

const char *get_player_name_from_shifted_pos_pointer(const vec3f_t *__shifted(player_t, 0x1C) pos) {
    return ADJ(pos)->name;
}

const vec3f_t *__shifted(player_t, __builtin_offsetof(player_t, position)) pos

CONTAINING_RECORD(pos, player_t, position)

#define ADJ(value) ((__parentof(value) *)((char *)(value) - __deltaof(value)))