Re: static functions

["Sepherosa Ziehau" <sepherosa@xxxxxxxxxxxx>]

On Thu, 31 Mar 2005 17:44:34 +0200, Joerg Sonnenberger  
<joerg@xxxxxxxxxxxxxxxxx> wrote:

> On Thu, Mar 31, 2005 at 05:36:11PM +0200, Miguel Mendez wrote:
> > On Thu, 31 Mar 2005 16:11:17 +0100
> > Jonathon McKitrick <jcm@xxxxxxxxxxxxxxxxx> wrote:
> >
> >
> > > Sorry this is such a lame question, but I never quite figured out what
> > > 'static' does to a function declaration.  Obviously for a variable, it
> > > allocates memory for the lifetime of the process rather than on the  
> > stack just
> > > for one function call.
>
> Only for function scope variables.
>
> > >  But what about 'static' for all the kernel functions
> > > that have no return value?
> >
> > static foo(blah blah) restricts the scope of the function to that
> > module, i.e. it's not visible outside that .c file. You usually do that
> > to keep private functions from being called from somewhere else. That
> > way other parts of the program will only talk to the published API.
>
> That's right. It's also what happens with file scope variables.
>
> Beside keeping the namespace cleans, it allows the compiler to choose
> a different ABI for internal functions. It also allows the compiler to
> warn about unused local functions and variables.
Then `static __inline' also makes big macro less attractive ;-)
> Joerg