Re: [MiNT] sleep patch

[Alan Hourihane <alanh@fairlite.co.uk>]

On Fri, 2009-02-27 at 11:16 +0100, Vincent Rivière wrote:
> Alan Hourihane wrote:
> >>  unsigned int
> >> -sleep (unsigned int n)
> >> +__sleep (unsigned int n)
> >>  {
> >>  	long stop;
> >>  	long old_alarm_func;
> > 
> > Has this already been fixed with...
> > 
> > weak_alias (__sleep, sleep)
> 
> The previous line was not the fix, it was the bug ;-)
> The syntax is :
> weak_alias (<existing function name>, <new weak name>)
> 
> So without my patch, the weak_alias directive produces a duplicate
> definition of the symbol _sleep when assembling.
> 
> Note for people unfamiliar with weak aliases: it is a means for allowing
> a program to easily override (replace) a MiNTLib function simply by
> defining a function with the same name.
> 
> If a program defines a sleep() function, it will be used by the program
> and the MiNTLib itself. In that case, the weak alias and the __sleep()
> functions are ignored.
> 
> If a program does not define a sleep() function, it would normally
> produce an unresolved external. So the linker looks for a weak alias for
> that function. If there is one, all the references to the alias will be
> treated as references to the implementation provided by the MiNTLib.
> 
> So 2 solutions :
> - remove the weak alias, so sleep() will not be overridable
> - apply my patch, so sleep() will be overridable

Ah yes, my bad. Quite right Vincent.

Applied.

Alan.