指向堆栈的 C 指针导致警告

Question

以下代码正在生成指针警告，我不确定如何解决？

gcc -std=c11 -pg -g3 -ggdb -W -Wall -lefence  -I.  -o main.o -c main.c
main.c: In function ‘push_state’:
main.c:15:16: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
    *++s->point = s->top;
                ^
main.c: In function ‘pop_state’:
main.c:19:11: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
    s->top=*s->point--;
           ^

#include <stdio.h>
typedef struct stack{
   int **point;      // pointer to location in memory
   int *memory[24];  // stack memory
   int top;
   int i;
}Stack;

void push_state(Stack *s){
   s->top=s->i++;
   *++s->point = s->top;
};
void pop_state(Stack *s){
   s->top = *s->point--;
};
void get_top(Stack *s){
   printf("Stack top: %dn",s->top);
};
void start(){
   Stack s;
   s.point=&s.memory[0];
   s.i=0;
   push_state(&s);
   get_top(&s);
   pop_state(&s);
   get_top(&s);
}

int main( int argc, char *argv[] )  {
   start();
  return 0;
}

Answer 1

如警告中所述，t->top 是整数，但*++s->point是指针，因此无法将整数转换为指针。

Answer 2

也许你想要这个;

typedef struct stack{
   int **point;      // pointer to location in memory
   int *memory[24];  // stack memory
   int *top;
   int i;
}Stack;

void push_state(Stack *s){
   s->top=s->memory[s->i++];
   *++s->point = s->top;
};

Answer 3

我正在发布我的问题的解决方案：问题在于，s.point=&s.memory[0];不正确，也应该s.point=s.memory; **point不正确，它应该*point，*memory[24];应该动态*memory和声明。感谢乔纳森·莱夫勒（Jonathan Leffler）让我回去重新考虑一下，从**point中删除多余的*。

#include <stdio.h>
#include <stdlib.h>
#define push(s) (*++s->point = s->top)
#define pop(s)   (*s->point--)
#define look(s) (*s->point)
#define MALLOC(p,s) if(((p) = malloc(s * sizeof(p))) == NULL){ exit(EXIT_FAILURE); }
typedef struct stack{
   int *point;      // pointer to location in memory
   int *memory;  // stack memory
   int top;
   int i;
}Stack;
void push_state(Stack *s){
   ++(s->top);
   push(s);
};
void pop_state(Stack *s){
   s->top = pop(s);
};
void look_top(Stack *s){
   printf("look %d, Stack top:  %dn",look(s), s->top);
};
void start(){
   Stack s;
   s.top=0;
   MALLOC(s.memory,24);
   //s.point=&s.memory[0]; <- wrong assignment
   s.point=s.memory;
   push_state(&s); 
   push_state(&s); 
   push_state(&s); 
   look_top(&s);    
   pop_state(&s);  
   look_top(&s);   
   pop_state(&s);
   look_top(&s);   
   push_state(&s);
   look_top(&s);
}
int main( int argc, char *argv[] )  {
   start();
   return 0;
}