c - C 中结构体指针的问题

Question

我有典型的结构(ECU_t)，其中的成员被认为是指向结构的指针。现在我想做ECU_DoTask()。请帮助我

typedef enum
{
  NORMAL,
  WARNING,
}WATER_TEMP;

typedef struct
{
  WATER_TEMP water_temp;
  uint16_t speed;
  // ... other members
}Engine_t;

typedef struct
{
  Engine_t* engine;
  ABS_t*  abs;
  // ... other members
}ECU_t;

void ECU_DoTask(ECU_t* output)
{
  output->(engine->water_temp) = NORMAL; 
  // ??? it seems to be illegal command. 
  // how can i access to water_temp
}

Answer 1

engine是output的成员，water_temp是engine的成员。

所以你可以这样做:

(output->engine)->water_temp = NORMAL

或者

output->engine->water_temp = NORMAL   

as -> 是左优先运算符。