Re: Removing duplicate DWARF2 info

[Daniel Berlin <dberlin at redhat dot com>]

> 
> I suspect it is more that people who usually work on the linker are busy, and
> it hasn't filtered up yet as important.

Somehow i suspect this isn't right. It's particularly annoying to rewrite
dwarf2 info once it's been written, because of how it works.

It's easier to either
A. not write it in the first place
or
B. ignore duplicates when reading it in

In fact, i've yet to see a LINKER that removes duplicate dwarf2 info.
It's always done as a prelinking step.

> 
> Consider several different build trees.  You also can't assume that all objects
> in a build tree are going to be linked into the same executable.  The classic
> case is GCC itself, which uses logically distinct build and host compilers.
> 
> In addition, libraries may be built by other people that may include debug
> information, that may or may not be the same as the information you see.

Then you can do it using a similar scheme to the way template repositories
are done, not emitting the actual debug info until right before you link,
during the recompile.

--Dan