Please help with __attribute__ weak

[H. J. Lu]

On Tue, Jul 26, 2005 at 10:16:48AM -0400, Dimitry Golubovsky wrote:
> Dimitry Golubovsky wrote:
> 
> > I need to declare a symbol which is weaker in the executable than in any
> > external static or dynamic library.
> 
> > In other words, the executable provides some fallback function
> > implementation (in my example, for "write"). But if the linker or
> > dynamic linker resolves it, the symbol definition from an external
> > library must be used.
> 
> 
> H. J. Lu wrote:
> 
> The weak symbol is different from the normal one only during creating
> executable or shared library if it is in a relocatable file. You
> can't use weak symbol for your purpose. But you can mark your symbol in
> shared library protected.
> 
> =================
> 
> Well, libraries are not created by me, so I cannot rely on any
> possibility to mark symbols in it. Besides, this is for an automated
> tool which may deal with tens of functions at once (this is for a
> Haskell FFI generator known as `hsffig' that I am developing).
> 
> If there is no way to declare overridable symbols in executables, then
> perhaps placing all those fallback stub functions in a separate static
> library (.a) and telling the linker to use it last (after all default
> and user-specified libraries) could do the job, couldn't it?
> 

Yes.



H.J.