[PATCH] Fix watchpoints on s390

[Ulrich Weigand <weigand at i1 dot informatik dot uni-erlangen dot de>]

Hello,

this is the second attempt to fix watchpoints on s390 by using
STOPPED_BY_WATCHPOINT instead of target_stopped_data_address
in bpstat_stop_status to find out whether the target stopped
due to a hardware watchpoint.

As STOPPED_BY_WATCHPOINT requires an argument not available
in breakpoint.c, and furthermore some targets define this
macro so as to access other local variables not even passed
as arguments, calling this macro from anywhere else is not
trivial.

Thus, this patch simply remembers the return value of 
STOPPED_BY_WATCHPOINT in handle_inferior_event, and passes
*that* as argument to bpstat_stop_status.  This should
work on all targets ...

Tested on s390-ibm-linux and s390x-ibm-linux, fixes all
watchpoint related regressions.

Bye,
Ulrich


ChangeLog:

	* breakpoint.c (bpstat_stop_status): Add new argument
	STOPPED_BY_WATCHPOINT.  Use it instead of testing
	target_stopped_data_address agaist 0 to check whether
	or not we stopped due to a hardware watchpoint.
	* breakpoint.h (bpstat_stop_status): Adapt prototype.
	* infrun.c (handle_inferior_event): Call bpstat_stop_status
	with new argument.

Index: gdb/breakpoint.c
===================================================================
RCS file: /cvs/src/src/gdb/breakpoint.c,v
retrieving revision 1.170
diff -c -p -r1.170 breakpoint.c
*** gdb/breakpoint.c	2 May 2004 00:21:41 -0000	1.170
--- gdb/breakpoint.c	10 May 2004 17:13:49 -0000
*************** which its expression is valid.\n");     
*** 2590,2596 ****
  }
  
  /* Get a bpstat associated with having just stopped at address
!    BP_ADDR.  */
  
  /* Determine whether we stopped at a breakpoint, etc, or whether we
     don't understand this stop.  Result is a chain of bpstat's such that:
--- 2590,2597 ----
  }
  
  /* Get a bpstat associated with having just stopped at address
!    BP_ADDR in thread PTID.  STOPPED_BY_WATCHPOINT is true if the
!    target thinks we stopped due to a hardware watchpoint.  */
  
  /* Determine whether we stopped at a breakpoint, etc, or whether we
     don't understand this stop.  Result is a chain of bpstat's such that:
*************** which its expression is valid.\n");     
*** 2607,2613 ****
     commands, FIXME??? fields.  */
  
  bpstat
! bpstat_stop_status (CORE_ADDR bp_addr, ptid_t ptid)
  {
    struct breakpoint *b, *temp;
    /* True if we've hit a breakpoint (as opposed to a watchpoint).  */
--- 2608,2614 ----
     commands, FIXME??? fields.  */
  
  bpstat
! bpstat_stop_status (CORE_ADDR bp_addr, ptid_t ptid, int stopped_by_watchpoint)
  {
    struct breakpoint *b, *temp;
    /* True if we've hit a breakpoint (as opposed to a watchpoint).  */
*************** bpstat_stop_status (CORE_ADDR bp_addr, p
*** 2631,2637 ****
  	&& !((b->type == bp_hardware_watchpoint
  	      || b->type == bp_read_watchpoint
  	      || b->type == bp_access_watchpoint)
! 	     && target_stopped_data_address () != 0)
  	&& b->type != bp_hardware_breakpoint
  	&& b->type != bp_catch_fork
  	&& b->type != bp_catch_vfork
--- 2632,2638 ----
  	&& !((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
Index: gdb/breakpoint.h
===================================================================
RCS file: /cvs/src/src/gdb/breakpoint.h,v
retrieving revision 1.32
diff -c -p -r1.32 breakpoint.h
*** gdb/breakpoint.h	8 Apr 2004 21:18:12 -0000	1.32
--- gdb/breakpoint.h	10 May 2004 17:13:49 -0000
*************** extern void bpstat_clear (bpstat *);
*** 414,420 ****
     is part of the bpstat is copied as well.  */
  extern bpstat bpstat_copy (bpstat);
  
! extern bpstat bpstat_stop_status (CORE_ADDR pc, ptid_t ptid);
  
  /* This bpstat_what stuff tells wait_for_inferior what to do with a
     breakpoint (a challenging task).  */
--- 414,421 ----
     is part of the bpstat is copied as well.  */
  extern bpstat bpstat_copy (bpstat);
  
! extern bpstat bpstat_stop_status (CORE_ADDR pc, ptid_t ptid, 
! 				  int stopped_by_watchpoint);
  
  /* This bpstat_what stuff tells wait_for_inferior what to do with a
     breakpoint (a challenging task).  */
Index: gdb/infrun.c
===================================================================
RCS file: /cvs/src/src/gdb/infrun.c,v
retrieving revision 1.151
diff -c -p -r1.151 infrun.c
*** gdb/infrun.c	1 May 2004 14:15:19 -0000	1.151
--- gdb/infrun.c	10 May 2004 17:13:49 -0000
*************** handle_inferior_event (struct execution_
*** 1367,1372 ****
--- 1367,1373 ----
       defined in the file "config/pa/nm-hppah.h", accesses the variable
       indirectly.  Mutter something rude about the HP merge.  */
    int sw_single_step_trap_p = 0;
+   int stopped_by_watchpoint = 0;
  
    /* Cache the last pid/waitstatus. */
    target_last_wait_ptid = ecs->ptid;
*************** handle_inferior_event (struct execution_
*** 1556,1562 ****
  
        stop_pc = read_pc ();
  
!       stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid);
  
        ecs->random_signal = !bpstat_explains_signal (stop_bpstat);
  
--- 1557,1563 ----
  
        stop_pc = read_pc ();
  
!       stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid, 0);
  
        ecs->random_signal = !bpstat_explains_signal (stop_bpstat);
  
*************** handle_inferior_event (struct execution_
*** 1605,1611 ****
        ecs->saved_inferior_ptid = inferior_ptid;
        inferior_ptid = ecs->ptid;
  
!       stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid);
  
        ecs->random_signal = !bpstat_explains_signal (stop_bpstat);
        inferior_ptid = ecs->saved_inferior_ptid;
--- 1606,1612 ----
        ecs->saved_inferior_ptid = inferior_ptid;
        inferior_ptid = ecs->ptid;
  
!       stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid, 0);
  
        ecs->random_signal = !bpstat_explains_signal (stop_bpstat);
        inferior_ptid = ecs->saved_inferior_ptid;
*************** handle_inferior_event (struct execution_
*** 1921,1927 ****
  
    /* It may be possible to simply continue after a watchpoint.  */
    if (HAVE_CONTINUABLE_WATCHPOINT)
!     STOPPED_BY_WATCHPOINT (ecs->ws);
  
    ecs->stop_func_start = 0;
    ecs->stop_func_end = 0;
--- 1922,1928 ----
  
    /* It may be possible to simply continue after a watchpoint.  */
    if (HAVE_CONTINUABLE_WATCHPOINT)
!     stopped_by_watchpoint = STOPPED_BY_WATCHPOINT (ecs->ws);
  
    ecs->stop_func_start = 0;
    ecs->stop_func_end = 0;
*************** handle_inferior_event (struct execution_
*** 2007,2013 ****
        else
  	{
  	  /* See if there is a breakpoint at the current PC.  */
! 	  stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid);
  
  	  /* Following in case break condition called a
  	     function.  */
--- 2008,2015 ----
        else
  	{
  	  /* See if there is a breakpoint at the current PC.  */
! 	  stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid, 
! 					    stopped_by_watchpoint);
  
  	  /* Following in case break condition called a
  	     function.  */

-- 
  Dr. Ulrich Weigand
  weigand@informatik.uni-erlangen.de