Thread: How do I wrap this?

I ported the PCRE2 open source library to the mainframe (works like a charm.) Now my task is to provide an API for old style languages that are used in that environment. One thing that I have to do is provide a 8 character max shorthand names to the available API functions. (I know that you are rolling your eyes, but that's the nature of the beast What I do is to wrap the native long name function with a shorthand name function with identical signature.
For example:
The original package has

Code:

PCRE2_SPTR pcre2_get_mark(pcre2_match_data *match_data);

I wrap it with:

Code:

extern PCRE2_SPTR GETMARK(pcre2_match_data *match_data); 
.
.
PCRE2_SPTR GETMARK(pcre2_match_data *match_data) 
{ 
return pcre2_get_mark(match_data); 
}

So now the old style languages may CALL "GETMARK" ...
This solution works fine and is the desirable solution. But here is the problem, one of the functions have a signature that I do not understand and certainly do not know how to wrap as described above:

Code:

pcre2_general_context *pcre2_general_context_create( 
void *(*private_malloc)(PCRE2_SIZE, void *), 
void (*private_free)(void *, void *), void *memory_data);

Do you have any idea how to do the wrapper:

Code:

pcre2_general_context *GENCNTCR( 
void *(*private_malloc)(PCRE2_SIZE, void *), 
void (*private_free)(void *, void *), void *memory_data) 
{ 
return .......; 
}

Thank you
ZA

It's just:

Code:

return pcre2_general_context_create(private_malloc, private_free, memory_data);

You need to brush up on function pointers.

Thank you so much
I will try that
And yes, certainly I need to brush up on function pointers

ZA

Originally Posted by algorism

It's just:

Code:

return pcre2_general_context_create(private_malloc, private_free, memory_data);

You need to brush up on function pointers.

Originally Posted by zatlas1

And yes, certainly I need to brush up on function pointers

Function pointers are a little weird looking. The basic idea is to start with a prototype:

Code:

int myfunc (const char *s);

Then put parentheses around the name and add an asterisk before it:

Code:

int (*myfunc) (const char *s);

That's a function pointer! It's name is myfunc. You can use it like this:

Code:

#include <stdio.h>
#include <string.h>

int afunc(const char *s) {
    return (int)strlen(s);
}

int main() {
    int (*myfunc) (const char *s) = afunc;
    int n = myfunc("hello");
    printf("%d\n", n);
    return 0;
}