Generate DW_AT_ranges for non-contiguous code

[Nick Clifton]

Hi Sterling,

> This enclosed (fixed) patch adds support for DW_AT_ranges when assembly 
> code is noncontiguous. See: 
> http://sourceware.org/ml/gdb/2006-05/msg00015.html for a discussion of 
> the problem this is addressing.

Does it really ?  I tried using a patched set of sources and I found 
that GDB was still unable to report the file or line number of either 
'main' or 'foo' when they were in different sections.

> I believe Tensilica's copyright assignment is already on file.

It is.

> One issue here is that this particular usage of DW_AT_ranges is dwarf 3,
> and gas emits 2 for the dwarf version number. Don't know the right thing
> to do there. Bumping the version number for this seems extreme.

Hmm, have you tried bumping the version number and seeing how it affects 
GDB ?  I am thinking that maybe it is the right thing to do, although it 
may be necessary to add another GAS command line switch to disable the 
generation of DWARF3 specific debug info for environments with debuggers 
that cannot handle it.

Cheers
   Nick