How can I call functions in a different C source file from a Perl XS module?

Question

I am building an XS extension with Perl. I have two files:

1. A C header file (.h)
2. A C source file (.c)

Currently what i did is to put all the C file code before the Model= on the XS file and wrap the functions I want after the Model=.

The compliation works with no problem and i am able to call the specific functions from perl.

But I want to separate the .xs file from the C file.

I want the .xs file to contain only the wrap functions, and those functions will call the functions on the .c file, but when I do that and run the dmake command i get error code 129 undefined reference to 'parse.c' file.

I tried to include the .c file using C and OBJECT properties for WriteMakerFile and still get an error any idea how to split the xs file to 2 one c file and the other xs which wrap the c function which are part of the .c file using ExtUtils::MakeMaker.

Examples would be appreciated.

Answer 1

This is actually rather straightforward:

hello.h

#ifndef H_HELLO
const char *hello(void);
#define H_HELLO
#endif

hello.c

const char *
hello(void) {
    return "Hello";
}

Example.xs

#define PERL_NO_GET_CONTEXT
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include "ppport.h"

#include "hello.h"

MODULE = My::Example        PACKAGE = My::Example       PREFIX = MY_

PROTOTYPES: DISABLE

const char *
MY_hello()
    CODE:
        RETVAL = hello();
    OUTPUT:
        RETVAL

t/My-Example.t

use strict;
use warnings;

use Test::More;
BEGIN { use_ok('My::Example') };

is(My::Example::hello(), 'Hello', 'hello returns "Hello"');

done_testing;

[~/tmp/My-Example]$ prove -vb t/My-Example.t
t/My-Example.t ..
ok 1 - use My::Example;
ok 2 - hello returns "Hello"
1..2
ok
All tests successful.
Files=1, Tests=2,  0 wallclock secs 
( 0.04 usr  0.01 sys +  0.03 cusr  0.00 csys =  0.08 CPU)
Result: PASS

The Makefile.PL was generated by h2xs. The only thing I changed was to uncomment the following line:

# Un-comment this if you add C files to link with later:
 OBJECT => '$(O_FILES)', # link all the C files too