CODEWITHSUNDEEP
c
GreySage
GreySage

Reputation: 1180

Do I need to include files that my included files depend on?

I have a C program named coderTest.c in a directory. In a sub-directory, src, I have several files, one.c, two.c, three.c, and their associated header files one.h, two.h, three.h.

I want to use functions from one.c and two.c in coderTest.c. Both one.c and two.c use functions from three.c. Do I need to include three.c in coderTest.c, or will it take care of it's dependency on it's own?

I am using #include "src/one.h" for one and two.

Upvotes: 1

Views: 179

Answers (4)

ryyker
ryyker

Reputation: 23218

You can do what you want several ways as long as visibility to necessary prototypes is provided. In addition to where best to include header files, consider using wrappers to guarantee your header is used only once:

 #ifndef _SOMEFILE_H_
 #define _SOMEFILE_H_

     the entire file

 #endif /* SOMEFILE_H__SEEN */

Also consider readability. For example given: coderTest.c, one.c/.h, two.c/.h, three.c/.h are as you described:
1) You should include three.h in both one.c and two.c.
2) For coderTest.c, #include headers of all supporting headers either in the file itself, or perhaps in a collector header: conderTest.h:

coderTest.h: 

#include "./src/one.h"
#include "./src/two.h"
#include "./src/three.h"

coderTest.c 

#include "coderTest.h"

Upvotes: 0

Grzegorz Szpetkowski
Grzegorz Szpetkowski

Reputation: 37914

Do I need to include three.c in coderTest.c, or will it take care of it's dependency on it's own?

You don't need to include "src/three.h" in coderTest.c, but this does not mean, that compiler does handle dependency automagically. This header needs to be included in one.c, two.c and three.c. The last one is to confirm that header's declarations and definitions match with each other properly.

As a result, you project might look as:

coderTest.c:

#include "src/one.h"
#include "src/two.h"
// ...

src/one.c:

#include "one.h"
#include "three.h"
// ...

src/two.c:

#include "two.h"
#include "three.h"
// ...

src/three.c:

#include "three.h"
// ...

To prevent multiple includes of same header, use header guards for each header file individually.

Upvotes: 2

Coding Orange
Coding Orange

Reputation: 542

As long as two.c and one.c properly #include "three.h" then the compiler will be able to chain the dependencies together without a problem. If you wanted to run something from three.c in coderTest.c it would want you to #include it in there as well.

Do your files have the preprocessor directives #IFNDEF, #DEFINE, and #ENDIFin place to prevent duplicate importing?

Upvotes: 0

The Brofessor
The Brofessor

Reputation: 1048

In coderTest.c, include the following: #include "src/two.h #include "src/one.h

In one.c, include: #include "src/three.h

In two.c, include: #include "src/three.h

Do I need to include three.c in coderTest.c, or will it take care of it's dependency on it's own?

No you don't need to include three.c in coderTest.c, because one.c and two.c abstract it away.

Upvotes: 0

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