Thread: corrupt function parameters question

I have two large arrays of structures I could not declare as arrays (array too big error) but could allocate dynamically

n[138] and p[317]
and am trying to pass them as parameters to a function.

void create_reports (n_t n[], p_t p[]);

int main(void)
{

n_t *n;
p_t *p;

n = calloc(138,sizeof(n_t));
p = calloc(317,sizeof(p_t));
...
create_reports(n,p);

return(0);
}

The program works fine with smaller arrays but seems to pass the function garbled values with the full sized arrays. Am I running out of memory? Is it being passed by value and not address?

>arrays (array too big error) but could allocate dynamically


How do you know? I don't see any error checking to see if the calloc() call was successful. In which case you're writing all over your RAM!

...
hth

Depends what n_p and n_t types are - if they're large structures, could be a problem

n[138] and p[317]
and am trying to pass them as parameters to a function.

void create_reports (n_t n[], p_t p[]);

Code:

// this is on the stack, which is a real problem for old compilers on old OS, with very small stacks
int main(void)  { 
  n_t n[138];
  p_t p[317];
  // blah
}

// these are not on the stack, but in the normal data segment, but their scope is still within main
int main(void)  { 
  static n_t n[138];
  static p_t p[317];
  // blah
}

Your prototype for your solution is
    void create_reports (n_t *n, p_t *p);

And the call is
    create_reports(n,p);

Forgot to include the error checking, but it is in place:

if (!p)
exit(1);
if (!n)
exit(1);

Will try them as static, but I thought static variables could not be changed?

I appreciate the responses.