Re: [RFA] enable software single step on alpha-osf

[Joel Brobecker <brobecker@gnat.com>]

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> >2002-07-18  Joel Brobecker  <brobecker@gnat.com>
> >
> >        * alpha-osf1-tdep.c (alpha_osf1_init_abi): Unfortunately,
> >        procfs appears to be broken when debugging on multi-processor
> >        machines. So enable software single stepping in order to avoid
> >        using the procfs interface to do next/step operations, using
> >        internal breakpoints instead.
> >
> >        * infrun.c (handle_inferior_event): Readjust the stop_pc by
> >        DECR_PC_AFTER_BREAK when hitting a single step breakpoint, to
> >        make this pc address equal to the value it would have if the
> >        system stepping capability was used. Also set a new flag used
> >        to ensure that we don't readjust the PC one more time later.
> >
> >        * breakpoint.c (bpstat_stop_status): Do not adjust the PC
> >        address by DECR_PC_AFTER_BREAK when software single step is
> >        in use for this architecture, as this has already been taken
> >        care of in handle_inferior_event().
> >
> 
> Yes and thanks.  Finally something in wfi that I understand!

Me too. 10 lines understood, 1500 more to go :). Thanks for the careful
review.

This patch has been checked-in. Here is a patch to update the NEWS file,
as suggested by Eli. I'm not very good at wording, so any suggestion for
improvement is more than welcome.

2002-08-17  Joel Brobecker  <brobecker@gnat.com>

        * NEWS: Add an entry regarding the improvement of the next/step
        operation on Alpha Tru64 multi-processor machines.

-- 
Joel

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Index: NEWS
===================================================================
RCS file: /cvs/src/src/gdb/NEWS,v
retrieving revision 1.86
diff -c -3 -r1.86 NEWS
*** NEWS	15 Aug 2002 22:51:40 -0000	1.86
--- NEWS	17 Aug 2002 06:22:04 -0000
***************
*** 91,96 ****
--- 91,102 ----
  to a bfd-format or binary file (dump and append), and back
  from a file into memory (restore).
  
+ * Improved "next/step" support on multi-processor Alpha Tru64.
+ 
+ On multi-processor Alpha Tru64, next/step operations sometimes used to
+ cause problems, such as the random apperance of SIGSEGV or SIGTRAP
+ signals for instance.
+ 
  *** Changes in GDB 5.2.1:
  
  * New targets.