How to Return Function Pointer's Memory Address?

[Bryan Parkoff]

I set Function Pointer variable to private so unauthorized users cannot
access it, but they are allowed to use Get_ and Set_ functions to modify
Function Pointer variable. Look at my example.

unsigned char foo(void)
{
return 0xC1;
}

unsigned char (*pfoo)(void) = foo;

unsigned char* Get_foo(void)
{
// return pfoo; // Error -- can't return function pointer
return unsigned char (*pfoo)(void); // Error -- can't return function
pointer
}

Can you please correct Get_foo() function?

Bryan Parkoff

 

[Ben]

I set Function Pointer variable to private so unauthorized users cannot
access it, but they are allowed to use Get_ and Set_ functions to modify
Function Pointer variable. Look at my example.

unsigned char foo(void)
{
return 0xC1;
}

unsigned char (*pfoo)(void) = foo;

unsigned char* Get_foo(void)
{
// return pfoo; // Error -- can't return function pointer
return unsigned char (*pfoo)(void); // Error -- can't return function
pointer
}

Can you please correct Get_foo() function?

Take a look here:

http://www.newty.de/fpt/fpt.html#r_value

Ben

 

[Gabriel]

I set Function Pointer variable to private so unauthorized users cannot
access it, but they are allowed to use Get_ and Set_ functions to modify
Function Pointer variable. Look at my example.

unsigned char foo(void)

Bad habit.
unsigned char foo()

{
return 0xC1;
}

unsigned char (*pfoo)(void) = foo;

unsigned char(*pfoo)() = foo;

unsigned char* Get_foo(void)

unsigned char(*)() Get_Foo()

{
// return pfoo; // Error -- can't return function pointer
return unsigned char (*pfoo)(void); // Error -- can't return function
pointer
}

Can you please correct Get_foo() function?

Sure.

The above works. But it is easier to write:
unsigned char foo()
{
return 0xC1;
}

typedef unsigned char (*pfoo_type)();

pfoo_type pfoo = foo;

pfoo_type Get_Foo()
{
return pfoo;
}

Gabriel