dwarf debug information emission for assembly source files

[Ramana]

Hi,

>From the discussion
http://sourceware.org/ml/binutils/2012-03/msg00286.html, I understand
that the gas is not capable of emitting dwarf debug information,
except the debug line information, for the assembly source files which
doesn't provide any debug information explicitly (no debug directives,
section definitions etc).

Are there any existing ELF ports which have this feature implemented?
If not, what it takes/involves to implement that?

Thanks,
Ram