Improve separate debug file support for elfutils

[Daniel Jacobowitz]

On Fri, Oct 06, 2006 at 04:25:50PM -0400, Daniel Jacobowitz wrote:
> It turns out that elfutils's eu-strip differs from objcopy --only-keep-debug
> in one important respect: elfutils tends to leave .symtab in the original
> file and put a NOBITS copy in the separate debug file, but objcopy moves the
> whole symtab.  This difference shows up a problem in GDB.
> 
> We search for the section containing the PC in a bunch of places, mostly for
> overlay support (does this even still work?  no idea).  When we look up the
> section for the PC, we might find either the copy in the separate debug file
> or the original; they cover the same PC ranges.  So we need to allow the
> two sections to be treated as equal.  That's what this patch implements.
> I'm not sure how well it would work with overlays - but I don't see a way,
> even in theory, to do better.
> 
> The change to "info sym" is a cosmetic improvement, which I made while
> trying to find a way to test this portably.  The original test was on ARM
> with Thumb; we would try to look up the minsym to figure out whether to
> set a 2-byte or 4-byte breakpoint, and by failing to find the minsym,
> we set the wrong type.

I've checked this in; it's separate from the issue Jan reported for
relocatable files.

-- 
Daniel Jacobowitz
CodeSourcery