Re: how to link a section in specific .o inside .a via linker script?

[Nick Clifton <nickc at redhat dot com>]

Hi Mat,

> I am creating a linker script to place sections at exactly the
> addresses I want them.

> However, I want a specific section from a specific .o file that is
> inside a specific .a file. 

The problem here is that the purpose of libraries is to allow the linker 
to choose which, if any, of the object files it contains should be 
included in the final output.  If you know in advance that you are 
definitely going to need a particular object file that is normally held 
in a library then the "proper" way of doing things would be to extract 
it from the library first, and then include it on the linker command line.

 > I've been playing around with an experimental patch to fix this, where
> there is a new (admittedly ugly) MEMBER operator in the linker script
> that lets you specify a pair of a .a and .o file, that you can use in
> place of any normal (possibly wildcarded) filename, e.g in my case:
>
>     /* Only get .text section from bar.o inside foo.a */
>     .text : { MEMBER(foo.a , bar.o)(.text) }

Interesting.  Would this syntax mean that .text section from bar.o *has* 
to be included in the linker's output at this point, or that it *might* 
be included in the  output, but only if the linker decides that bar.o is 
needed ?

Cheers
  Nick