passing argument 2 of ‘send_to_host’ from incompatible pointer type [-Wincompatible-pointer-types]

Question

Getting these warnings when I used the below code snippet. Can any one help me to resolve?

new_str.c: In function ‘main’:
new_str.c:39:25: warning: passing argument 2 of ‘send_to_host’ from incompatible pointer type [-Wincompatible-pointer-types]
   39 |   send_to_host(MACRO,ram->s1);
      |                      ~~~^~~~
      |                         |
      |                         stats_t * {aka struct stats_s *}
new_str.c:28:34: note: expected ‘int *’ but argument is of type ‘stats_t *’ {aka ‘struct stats_s *’}
   28 | void send_to_host(int macro,int *data)
      |                             ~~~~~^~~~
new_str.c:42:25: warning: passing argument 2 of ‘send_to_host’ from incompatible pointer type [-Wincompatible-pointer-types]
   42 |   send_to_host(MACRO,ram->a1);
      |                      ~~~^~~~
      |                         |
      |                         abc_t * {aka struct abc_s *}
new_str.c:28:34: note: expected ‘int *’ but argument is of type ‘abc_t *’ {aka ‘struct abc_s *’}
   28 | void send_to_host(int macro,int *data)***

#include <stdio.h>
#include <stdlib.h>

#define MACRO 12

typedef struct stats_s{
  int tx;
  int rx;
  int err;
}stats_t;

typedef struct abc_s{
  int a;
  int b;
  int c;
}abc_t;

typedef struct ram_s{
  int dummy;
  int dam;
  stats_t *s1;
  abc_t *a1;
}ram_t;


ram_t ram1;

void send_to_host(int macro,int *data)  // 28
{
  printf("function called\n");
}

void main(){

  ram_t *ram;
  ram = &ram1;

  send_to_host(MACRO,ram->s1);          // 39


  send_to_host(MACRO,ram->a1);          // 42
}

Answer 1

You need to send pointer to int (reference to int type struct member) not dereference pointer to struct (this pointer is not related to the type of the parameter).

  send_to_host(MACRO,&ram -> s1 -> tx);          // 39
  send_to_host(MACRO,&ram -> a1 -> a);          // 42

Below code is not needed at all.

 ram_t *ram;
 ram = &ram1;

simply:

  send_to_host(MACRO,&ram1.s1 -> tx);          // 39
  send_to_host(MACRO,&ram1.a1 -> a);          // 42

The main function signature has to be:

int main(void){
/* ... */