Re: breakpoints/1692: [regression] watchpoints broken on native hppa2.0w-hp-hpux11.11

[mec dot gnu at mindspring dot com (Michael Elizabeth Chastain)]

The following reply was made to PR breakpoints/1692; it has been noted by GNATS.

From: mec.gnu@mindspring.com (Michael Elizabeth Chastain)
To: gdb-gnats@sources.redhat.com
Cc:  
Subject: Re: breakpoints/1692: [regression] watchpoints broken on native hppa2.0w-hp-hpux11.11
Date: Thu, 24 Jun 2004 23:58:02 -0400 (EDT)

 I narrowed the responsible patch down to this:
 
   2004-04-26  Orjan Friberg <orjanf@axis.com>
 
 	* frame.c: Include "observer.h".
 	(frame_observer_target_changed): New function.
 	(_initialize_frame): Attach target_changed observer.
 	* regcache.c: Include "observer.h".
 	(regcache_observer_target_changed): New function.
 	(_initialize_regcache): Attach target_changed observer.
 	* valops.c: Include "observer.h".
 	(value_assign): Notify target_changed event when modifying register.
 	* Makefile.in (frame.o, regcache.o, valops.o): Add $(observer_h).
 
 Looking at the mailing lists, there's already been some fallout
 from this patch.  Ulrich Weigand did a followup patch to fix problems
 with watchpoints on s390.
 
 I breakpointed the current version of gdb in bp_stop_status here:
 
     /* Hardware watchpoints are treated as non-existent if the reason we 
        stopped wasn't a hardware watchpoint (we didn't stop on some data 
        address).  Otherwise gdb won't stop on a break instruction in the code
        (not from a breakpoint) when a hardware watchpoint has been defined.  */
     if (b->type != bp_watchpoint
 	&& !((b->type == bp_hardware_watchpoint
 	      || b->type == bp_read_watchpoint
 	      || b->type == bp_access_watchpoint)
 	     && stopped_by_watchpoint)
 	&& b->type != bp_hardware_breakpoint
 	&& b->type != bp_catch_fork
 	&& b->type != bp_catch_vfork
 	&& b->type != bp_catch_exec
 	&& b->type != bp_catch_catch
 	&& b->type != bp_catch_throw)	/* a non-watchpoint bp */
 
 and I see b->type == bp_hardware_watchpoint, stopped_by_watchpoint == 0.
 
 This bug might affect other targets as well.  It's definitely
 killing watchpoints on native hppa2.0w-hp-hpux11.11.
 
 I don't know how to fix this; we need a watchpoint expert
 like Orjan or Eli.
 
 Michael C