Re: [RFC] Changes to *_*regset functions

[Kevin Buettner <kevinb at cygnus dot com>]

On Jul 13, 10:26am, Daniel Jacobowitz wrote:

> Given that almost every call to or definition of these functions starts by
> casting its arguments anyway, I'd like to change the prototypes to the
> somewhat vaguer:
> 
> extern void supply_gregset (char *gregs);
> extern void supply_fpregset (char *fpregs);
> extern void fill_gregset (char *gregs, int regno);
> extern void fill_fpregset (char *fpregs, int regno);
> 
> It'll add a couple of casts, and remove a couple, and end up with functions
> that can be safely defined in a cross debugger.
> 
> Any objection to this?

For this type of thing, I'd prefer to see void * rather than char *.

Of course, the problem with using void * is that we can now pass any
pointer type at all and the compiler won't bat an eye.  One of the
things that I learned while doing the ptid_t conversions was that
passing structs (and not pointers to structs) was incredibly useful
for catching type errors.  (Pointers to structs work okay too if your
code compiles cleanly with -Werror.)  Of course, your struct could be
defined something like this:

    struct gdb_gregset
      {
        void *gregset_ptr;	/* pointer to a chunk of memory with the
				   registers.  */
      };

Then one of your prototypes could be:
    
    extern void supply_gregset (struct gdb_gregset gregs);

Kevin