Re: [Bug-ddrescue] [PATCH 3/5] io: Add missing prototype

[Antonio Diaz Diaz]

Rosen Penev wrote:
> > > +extern "C" void sighandler( int signum );
> > >    extern "C" void sighandler( int signum )
> > >      { if( signum_ == 0&&   signum>   0 ) signum_ = signum; }
> >
> > There is nothing missing here. A function definition is a function
> > declaration in which the body of the function is presented. Therefore
> > there is no need to declare the function twice.
>
> My understanding here is that this function needs to be static or
> declared separately. static cannot be used with extern so I went for
> the other option.

Why does it need to be static or declared separately? I can see nothing 
in the C++ standard requiring that. AFAICT, all that is required is that 
the function is declared before being used, and a definition is also a 
declaration.