Incorrect DWARF-2 register numbers on PPC64?

Andrew Cagney cagney@gnu.org
Wed Jan 7 23:36:00 GMT 2004


> On Wed, Jan 07, 2004 at 06:43:10PM +0100, Mark Kettenis wrote:
> 
>> If I read your patch correctly, this fixes normal DWARF 2 debugging
>> info to use the official System V register numbers, but lets GCC
>> continue to use its own numbering for the Call Frame Info (CFI) in
>> both the .eh_frame and .debug_frame sections. 
> 
> 
> That's correct.  hppa, hppa64, iq2000 and ns32k all do the same.

Outch!

> mips and cris also define DWARF_FRAME_REGNUM, but squinting at the code
> leads me to believe they will actually use the same register numbers.

(same as which? gcc or dwarf 2?)

> 
>> This won't work for GDB
>> since it assumes that CFI uses the same register number encoding as
>> all the other DWARF 2 debug information.
> 
> 
> Hmm, I can see that a debugger might reasonably expect .debug_frame
> to have the same numbers.  When I wrote the patch, I was concentrating
> on .eh_frame rather than .debug_frame, but .debug_frame uses the
> .eh_frame numbering.  It's a little perplexing that dwarf2out.c does
> this, as it means defining DWARF_FRAME_REGNUM to something other
> than DBX_REGISTER_NUMBER is useless.  DWARF_FRAME_REGNUM ought to
> just effect .eh_frame.  I'm not keen on trying to untangle dwarf2out.c
> though..

Is it going to be possible to get this untangled before 3.4 is 
branched/released?

Andrew




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