The system software includes two sub-modules mod_a and mod_b, which lead to circular dependencies due to the following reasons
- mod_a and mod_b need to use the public definition of sys, so they need to include sys_com.h
- sys_com.h provides a memory management interface. You need to know the memory node size (sizeof) of each module, so it contains mod_a.h and mod_b.h.
My personal idea is to create a new com.h, move the definitions of MOD_A_TYPE_1 and MOD_B_TYPE_1 to this file, and sys_com.h, mod_a.h and mod_b.h all include header files.
We often encounter similar problems during the project development process. What are your principles for dealing with them?Thanks in advance.
// mod_a.h
#include "sys_com.h"
typedef struct
{
int len;
} MOD_A_TYPE_1;
// mod_b.h
#include "sys_com.h"
typedef struct
{
int size;
} MOD_B_TYPE_1;
//sys_com.h
#include "mod_a.h"
#include "mod_b.h"
#define SYS_MOD_A_TYPE_1_SIZE sizeof(MOD_A_TYPE_1)
#define SYS_MOD_B_TYPE_1_SIZE sizeof(MOD_B_TYPE_1)
// pool_type
#define SYS_MEM_POOL_MOD_A_TYPE_1 1
#define SYS_MEM_POOL_MOD_B_TYPE_1 2
// @pool_type: SYS_MEM_POOL_MOD_A_TYPE_1/SYS_MEM_POOL_MOD_B_TYPE_1
void* sys_alloc_pool_mem(int pool_type)
4
sys_com.h provides a memory management interface. You need to know the memory node size (sizeof) of each module, so it contains mod_a.h and mod_b.h.
Do you? Why? It seems to me that your API has a flag to choose the struct type but it does not need to use the size directly. The way I would do this is to put the #define for the sizes directly in the C file. In fact, I question the need for the #defines at all. What advantage do they give you over directly using sizeof(type)? I think sys_com.h should look like this:
// pool_type
#define SYS_MEM_POOL_MOD_A_TYPE_1 1
#define SYS_MEM_POOL_MOD_B_TYPE_1 2
// @pool_type: SYS_MEM_POOL_MOD_A_TYPE_1/SYS_MEM_POOL_MOD_B_TYPE_1
void* sys_alloc_pool_mem(int pool_type)
and sys_com.c should do the following
#include sys_com.h
#include "mod_a.h"
#include "mod_b.h"
// If you really must have the #defines
#define SYS_MOD_A_TYPE_1_SIZE sizeof(MOD_A_TYPE_1)
#define SYS_MOD_B_TYPE_1_SIZE sizeof(MOD_B_TYPE_1)
void* sys_alloc_pool_mem(int pool_type)
{
// Implementation using the #defines or better sizeof(type)
}
Also consider putting include guards1 on all the headers to prevent circular includes e.g. in mod_a.h
#if !defined(_MOD_A_H)
#define _MOD_A_H
typedef struct
{
int len;
} MOD_A_TYPE_1;
#endif
1 Many C compilers have #pragma once to do the same thing but it is not standard.
2
May be your can use an other file to declare your types.
So:
- sys_com.h includes mod_types.h, not mod_a.h or mod_b.h
- mod_a.h and mod_b.h includes sys_com.h
Does it fit to your case ?