Re: Linker for OOP

[Nick Clifton <nickc at redhat dot com>]

Hi Mikiya,

>    `(const:M EXP)'
>         Represents a constant that is the result of an assembly-time
>         arithmetic computation.  The operand, EXP, is an expression that
>         contains only constants (`const_int', `symbol_ref' and `label_ref'
>         expressions) combined with `plus' and `minus'.  However, not all
>         combinations are valid, since the assembler cannot do arbitrary
>         arithmetic on relocatable symbols.
>
>         M should be `Pmode'.
> ------------------------------------------------------------------------
>
> Are there any plan to implement this facility as an extension to
> object file format?

No.  Or at least not that I know about.  In order to support arbitrarily 
complex expressions of the type described in the above extract, it would 
be necessary for the linker and (for shared libraries) the loader, to be 
able to support multiple, prioritized relocations on the same address. 
Since relocations are target specific it would be necessary to extend 
the ABIs of individual architectures to add the required support.

Cheers
  Nick