An example showing how to use cmock's ReturnThrePtr mock type

cmock_return_thru_ptr.c

/* bar.c */
#include foo.h

int bar (void)
{
    int a = 5, b = 0;
    e = foo(a, &b); /* Note b is local, thus test won't know its address. */
    /* ... use b ... */
    return e;
}

//~~~~~~~~~~~~~~

/* test_bar.c */
#include "unity.h"
#include "mock_foo.h"
#include "bar.h"

void test_bar (void)
{
    int qux = 4, baz = 5;

    foo_ExpectAndReturn(qux, &baz);
    foo_IgnoreArg_b();
    foo_ReturnThruPtr_b(&baz);

    bar();
}

This allows a mock of foo() to be used when testing bar and to inject data back into bar() via the second argument to foo().