[RFC] Add watchpoint hit address function to procfs.c

["Pierre Muller" <pierre dot muller at ics-cnrs dot unistra dot fr>]

  The following patch adds support for
to_stopped_data_address field of target_ops,
using
prstatus.pr_lwp.pr_info.__data.__fault.__addr field.
(or prstatus.pr_info.__data.__fault.__addr if NEW_PROC_API
is not defined) I found that in the OpenSolaris sources.

  It works for my OpenSolaris 2.11.

  The main problem is that I have no ideas if this works for other
targets using procfs.c source.

  How should this be modified to avoid problem if other targets
do not have/set these fields?

  Comments welcome.

Pierre Muller
Pascal language support maintainer for GDB

2010-04-26  Pierre Muller  <muller@ics.u-strasbg.fr>

	* procfs.c (proc_watchpoint_address): New function.
	(procfs_stopped_data_address): New function.
	(procfs_use_watchpoints): Register new watchpoint related
	function.
	
Index: procfs.c
===================================================================
RCS file: /cvs/src/src/gdb/procfs.c,v
retrieving revision 1.131
diff -u -p -r1.131 procfs.c
--- procfs.c	20 Apr 2010 22:36:35 -0000	1.131
+++ procfs.c	26 Apr 2010 14:05:29 -0000
@@ -1312,6 +1312,30 @@ proc_what (procinfo *pi)
   return pi->prstatus.pr_what;
 #endif
 }
+/*
+ * Function: proc_watchpoint_address
+ *
+ * returns the prstatus.pr_lwp.pr_info.__data.__fault.__addr field.
+ */
+
+CORE_ADDR
+proc_watchpoint_address (procinfo *pi)
+{
+  if (!pi->status_valid)
+    if (!proc_get_status (pi))
+      return 0;	/* FIXME: not a good failure value (but what is?) */
+
+#ifdef NEW_PROC_API
+  return unsigned_pointer_to_address (target_gdbarch,
+	   builtin_type (target_gdbarch)->builtin_data_ptr,
+	   (gdb_byte *) &pi->prstatus.pr_lwp.pr_info.__data.__fault.__addr);
+#else
+  return unsigned_pointer_to_address (target_gdbarch,
+	   builtin_type (target_gdbarch)->builtin_data_ptr,
+	   (gdb_byte *) &pi->prstatus.pr_info.__data.__fault.__addr);
+#endif
+}
+
 
 #ifndef PIOCSSPCACT	/* The following is not supported on OSF.  */
 /*
@@ -5560,6 +5584,45 @@ procfs_stopped_by_watchpoint (void)
     }
   return 0;
 }
+/*
+ * Function procfs_stopped_data_address
+ * Returns non-zero if we can find the position
+ * of the triggring watchpoint.
+ */
+
+static int
+procfs_stopped_data_address (struct target_ops *targ, CORE_ADDR *addr)
+{
+  CORE_ADDR waddr;
+  procinfo *pi;
+  int watchpoint_hit = 0;
+
+  pi = find_procinfo_or_die (PIDGET (inferior_ptid), 0);
+
+  if (!pi)	/* If no process, then not stopped by watchpoint!  */
+    return 0;
+
+  if (proc_flags (pi) & (PR_STOPPED | PR_ISTOP))
+    {
+      if (proc_why (pi) == PR_FAULTED)
+	{
+#ifdef FLTWATCH
+	  if (proc_what (pi) == FLTWATCH)
+	    watchpoint_hit = 1;
+#endif
+#ifdef FLTKWATCH
+	  if (proc_what (pi) == FLTKWATCH)
+	    watchpoint_hit = 1;
+#endif
+	}
+    }
+  if (!watchpoint_hit)
+    return 0;
+  waddr = proc_watchpoint_address (pi);
+  if (addr)
+    *addr = waddr;
+  return (waddr != 0);
+}
 
 static int
 procfs_insert_watchpoint (CORE_ADDR addr, int len, int type)
@@ -5607,6 +5670,7 @@ procfs_use_watchpoints (struct target_op
   t->to_remove_watchpoint = procfs_remove_watchpoint;
   t->to_region_ok_for_hw_watchpoint = procfs_region_ok_for_hw_watchpoint;
   t->to_can_use_hw_breakpoint = procfs_can_use_hw_breakpoint;
+  t->to_stopped_data_address = procfs_stopped_data_address;
 }
 
 /*