RFC: Generating per-function DWARF line number sections

[nick clifton]

Hi Alan,
> Is it worth supporting the old style of grouping by name?

Umm, I am not quite sure what you mean here.  Can you provide an example ?

>  Why not just support ELF section groups?

This is the long term solution.  It is a more invasive change however - 
requiring the cooperation of gcc as well as gas and ld.  But, free time 
willing, this is the way that I intend to go.


>  Using names leads to eg. your
> _bfd_elf_gc_mark_extra_sections change which is quadratic in number of
> sections..

Right - the current patch is not ideal, and I did consider constructing 
lists instead of the quadratic scan.  But that is more complex, and I 
wanted to keep things simple for this first iteration of the patch,  If 
it turns out that this scan is significant slow down for the linker then 
I can always come back and recode the loop later.


> Also, why do this in gas?  It seems to me that this sort of change
> belongs in gcc.

Because the .debug_line section for most ELF-based targets is now 
constructed by gas not gcc.  Gcc emits .loc directives and gas converts 
them into .debug_line entries.

Cheers
   Nick