Re: RFA: [buildsym.c] Turn off unused addr bits in linetable

[Elena Zannoni <ezannoni@cygnus.com>]

Fernando, did you check this in?  Thanks for investigating.  

BTW. Sh doesn't define ADDR_BITS_REMOVE. But it uses it! I'll have to
fix that.


Elena


Andrew Cagney writes:
 > Fernando Nasser wrote:
 > > 
 > > Andrew,
 > > 
 > > I looked at all the targets that define ADDR_BITS_REMOVE() (which are
 > > arm, h8500, m88k, mips, pa, w65, z8k and sh) and all that define
 > > BREAKPOINT_FROM_PC() (which are arm, mips, mcore and mn10300, as far as
 > > I can tell).
 > > 
 > > I am convinced that this is the right thing to do.  I really wonder, in
 > > some cases, how could it have worked without it (maybe the stub or the
 > > OS cleared the bits for us).
 > 
 > I suspect that it is like the 32 bit MIPS - no one was sure how it
 > should work.  Only when the decision that the 32 bit MIPS was have all
 > addresses converted to cannonical form (i.e. sign extend them) did a
 > heap of problems get flushed.
 > 
 > I'd lace your patch with comments explaining how the table contains
 > cannonical addresses and those addresses don't contain any stray magic
 > bits.  That way the next person will know where the error is when they
 > find a comparison is doing strange things because the addresses don't
 > quite match.
 > 
 > > Anyway, there is only one way of knowing it for sure.  The only thing we
 > > know right now is that ARM is broken without it.
 > > 
 > > OK to commit?
 > 
 > I withdraw my objection.  I think the maintainer had already approved
 > it.
 > 
 > Thanks for investigating this!
 > 
 > 	Andrew
 > 
 > PS: A multi-arch footnote (Hi nick :-):  At some stage or another, an
 > additional interface into BFD is going to be needed so that GDB can ask
 > BFD what the architecture/machine tupple for a given address is. 
 > Details are for much later.  This is just a little flag :-)
 >