Need Help Linking Files

[deltagods]

Note: I'm constricted to what i describe my problem as. Meaning alternate ways of doing it is not possible.

I'm trying to seperate some functions into different files.

Header File A has some typedef
Header File B has function prototypes
Commong File has some commonly used functions and defines etc.

Source File A is the main program
Source File B-Z are the functions. (1 Function = 1 File)

Some of the functions require the common file and some require the typedefs.
But i also need the function file to be able to be compilied seperately without errors.

I've tried a lot of things but i always seem to get some type of error: multiple decleration, undeclared etc. Whats the best way of doing this?

Very much appreciated.

[laserlight]

Header File B has function prototypes
Commong File has some commonly used functions and defines etc.

As in the common header file contains the declarations (not definitions) of commonly used functions and macros, while the declarations of all the other functions are contained in header file B?

Some of the functions require the common file and some require the typedefs.
But i also need the function file to be able to be compilied seperately without errors.

Presumably you would include the common header file in all the source files, and include the other two headers where necessary.

[deltagods]

As in the common header file contains the declarations (not definitions) of commonly used functions and macros, while the declarations of all the other functions are contained in header file B?


Presumably you would include the common header file in all the source files, and include the other two headers where necessary.

Common header file has a boolean type declaration. And yes header file b has the function prototypes.

I tried including the common where its needed and the other 2 header files but i get multiple declaration errors.

[tabstop]

Can you give some specifics about what you are getting multiple declaration errors with. A function? A variable?

[deltagods]

Common.h -> Boolean Declaration

Header FileA

#define   A        20 
#define   B        60  

typedef enum state { DEAD, ALIVE } State;
typedef State Grid[A+2][B+2];

Header FileB -> Includes Common & Header FileA. Has Function Declarations

Main -> Includes Header FileB. Includes All the Function Files

Function FileA -> Include Common & Header FileA
Function FileB-Z -> Include Header FileA


With that setup i have an error for multiple definition of a function in common and the functions in each of the function files.

[laserlight]

Main -> Includes Header FileB. Includes All the Function Files

That sounds wrong. The main source file should not be including other source files. They should be compiled separately and then linked. Either that, or the main source file does include the other source files, but then you only compile the main source file. (The latter is quite a rare approach, though in some cases a library author may combine source files in this way to produce a single source file for distribution.)

[deltagods]

Yes most of the errors are gone. Makes a lot more sense now.

But i'm still stuck with the error on the function in common.

[laserlight]

But i'm still stuck with the error on the function in common.

Post the updated source of your common header file.

[deltagods]

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

typedef enum boolean { FALSE, TRUE } Boolean;

void Error(char *);

void Warning(char *);
 /* Error: report program error.


Pre:    s points to the message to be printed.
Post:  The function prints the message and terminates the program.
 */
void Error(char *s)
{
    fprintf(stderr, "%s\n", s);
    exit(1);
}

Error is
multiple definition of `Error'

Only thing is common is used for is the boolean. Which is used as a return value for one of the functions.

[laserlight]

You defined the Error function in the common header. Don't do that. Move that function definition to a source file.

Also, your header files should have header inclusion guards.