Re: [PATCH] gdbarch: Add pc_signed field and use it when adjusting BP addresses

["Ulrich Weigand" <uweigand@de.ibm.com>]

Vlad Ivanov wrote:
> 15.03.2018, 14:33, "Andreas Schwab" <schwab@suse.de>:
> > On Mär 15 2018, vlad.ivanov@lab-systems.ru wrote:
> >
> >>  diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
> >>  index 454fda7684..247ec34857 100644
> >>  --- a/gdb/breakpoint.c
> >>  +++ b/gdb/breakpoint.c
> >>  @@ -6999,7 +6999,10 @@ adjust_breakpoint_address (struct gdbarch *gdbarch,
> >>             adjusted_bpaddr = gdbarch_adjust_breakpoint_address (gdbarch, bpaddr);
> >>           }
> >>
> >>  - adjusted_bpaddr = address_significant (gdbarch, adjusted_bpaddr);
> >>  + /* Don't cut out "insignificant" address bits on targets with
> >>  + signed PC. */
> >>  + if (!gdbarch_pc_signed (gdbarch))
> >>  + adjusted_bpaddr = address_significant (gdbarch, adjusted_bpaddr);
> >
> > Shouldn't it be sign-extended instead?
> >
> > Andreas.
> >
> 
> MIPS backend already returns a sign-extended value, and address_significant 
> cuts out bits 63 to 32. This makes breakpoint address comparison in step 
> routines to misbehave.

If the address is already correct, why don't you simply set
gdbarch_significant_addr_bit
to 64 in the mips back-end instead of adding a new gdbarch routine?

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU/Linux compilers and toolchain
  Ulrich.Weigand@de.ibm.com