2011-09-13 Pedro Alves <pedro@codesourcery.com>

	* breakpoint.c (update_watchpoint): Handle the case of the
	watchpoint to update not being in the breakpoint list yet.
	(hw_watchpoint_use_count): New, factored out from
	hw_watchpoint_used_count.
	(hw_watchpoint_used_count): Rename to ...
	(hw_watchpoint_used_count_others): ... this.  Add `except'
	parameter.  Don't count resources of `except'.  Use
	hw_watchpoint_use_count.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 824274541abf5bda5485da07c17317e938ae5a2b..7cec15e4f93784890a7be1cc4bdfc716306b0fe1 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,14 @@
+2011-09-13  Pedro Alves  <pedro@codesourcery.com>
+
+       * breakpoint.c (update_watchpoint): Handle the case of the
+       watchpoint to update not being in the breakpoint list yet.
+       (hw_watchpoint_use_count): New, factored out from
+       hw_watchpoint_used_count.
+       (hw_watchpoint_used_count): Rename to ...
+       (hw_watchpoint_used_count_others): ... this.  Add `except'
+       parameter.  Don't count resources of `except'.  Use
+       hw_watchpoint_use_count.
+
 2011-09-13  Pedro Alves  <pedro@codesourcery.com>
 
        * gdbthread.h (enum thread_state): Moved here.

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 8c5b6e5c9ca62ec2d490f77ac0e1d09aa5990f11..14c8903aecc5dfffb8ac977aea0ef21792abcb1f 100644 (file)
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -176,7 +176,11 @@ static void maintenance_info_breakpoints (char *, int);
 
 static int hw_breakpoint_used_count (void);
 
-static int hw_watchpoint_used_count (enum bptype, int *);
+static int hw_watchpoint_use_count (struct breakpoint *);
+
+static int hw_watchpoint_used_count_others (struct breakpoint *except,
+                                           enum bptype type,
+                                           int *other_type_used);
 
 static void hbreak_command (char *, int);
 
@@ -1458,6 +1462,7 @@ update_watchpoint (struct watchpoint *b, int reparse)
          if (reg_cnt)
            {
              int i, target_resources_ok, other_type_used;
+             enum bptype type;
 
              /* Use an exact watchpoint when there's only one memory region to be
                 watched, and only one debug register is needed to watch it.  */
@@ -1466,16 +1471,29 @@ update_watchpoint (struct watchpoint *b, int reparse)
              /* We need to determine how many resources are already
                 used for all other hardware watchpoints plus this one
                 to see if we still have enough resources to also fit
-                this watchpoint in as well.  To guarantee the
-                hw_watchpoint_used_count call below counts this
-                watchpoint, make sure that it is marked as a hardware
-                watchpoint.  */
-             if (b->base.type == bp_watchpoint)
-               b->base.type = bp_hardware_watchpoint;
-
-             i = hw_watchpoint_used_count (b->base.type, &other_type_used);
-             target_resources_ok = target_can_use_hardware_watchpoint
-                   (b->base.type, i, other_type_used);
+                this watchpoint in as well.  */
+
+             /* If this is a software watchpoint, we try to turn it
+                to a hardware one -- count resources as if B was of
+                hardware watchpoint type.  */
+             type = b->base.type;
+             if (type == bp_watchpoint)
+               type = bp_hardware_watchpoint;
+
+             /* This watchpoint may or may not have been placed on
+                the list yet at this point (it won't be in the list
+                if we're trying to create it for the first time,
+                through watch_command), so always account for it
+                manually.  */
+
+             /* Count resources used by all watchpoints except B.  */
+             i = hw_watchpoint_used_count_others (&b->base, type, &other_type_used);
+
+             /* Add in the resources needed for B.  */
+             i += hw_watchpoint_use_count (&b->base);
+
+             target_resources_ok
+               = target_can_use_hardware_watchpoint (type, i, other_type_used);
              if (target_resources_ok <= 0)
                {
                  int sw_mode = b->base.ops->works_in_software_mode (&b->base);
@@ -1486,8 +1504,17 @@ update_watchpoint (struct watchpoint *b, int reparse)
                  else if (target_resources_ok < 0 && !sw_mode)
                    error (_("There are not enough available hardware "
                             "resources for this watchpoint."));
-                 else
-                   b->base.type = bp_watchpoint;
+
+                 /* Downgrade to software watchpoint.  */
+                 b->base.type = bp_watchpoint;
+               }
+             else
+               {
+                 /* If this was a software watchpoint, we've just
+                    found we have enough resources to turn it to a
+                    hardware watchpoint.  Otherwise, this is a
+                    nop.  */
+                 b->base.type = type;
                }
            }
          else if (!b->base.ops->works_in_software_mode (&b->base))
@@ -6846,28 +6873,52 @@ hw_breakpoint_used_count (void)
   return i;
 }
 
+/* Returns the resources B would use if it were a hardware
+   watchpoint.  */
+
 static int
-hw_watchpoint_used_count (enum bptype type, int *other_type_used)
+hw_watchpoint_use_count (struct breakpoint *b)
 {
   int i = 0;
-  struct breakpoint *b;
   struct bp_location *bl;
 
+  if (!breakpoint_enabled (b))
+    return 0;
+
+  for (bl = b->loc; bl; bl = bl->next)
+    {
+      /* Special types of hardware watchpoints may use more than
+        one register.  */
+      i += b->ops->resources_needed (bl);
+    }
+
+  return i;
+}
+
+/* Returns the sum the used resources of all hardware watchpoints of
+   type TYPE in the breakpoints list.  Also returns in OTHER_TYPE_USED
+   the sum of the used resources of all hardware watchpoints of other
+   types _not_ TYPE.  */
+
+static int
+hw_watchpoint_used_count_others (struct breakpoint *except,
+                                enum bptype type, int *other_type_used)
+{
+  int i = 0;
+  struct breakpoint *b;
+
   *other_type_used = 0;
   ALL_BREAKPOINTS (b)
     {
+      if (b == except)
+       continue;
       if (!breakpoint_enabled (b))
        continue;
 
-       if (b->type == type)
-         for (bl = b->loc; bl; bl = bl->next)
-           {
-             /* Special types of hardware watchpoints may use more than
-                one register.  */
-             i += b->ops->resources_needed (bl);
-           }
-       else if (is_hardware_watchpoint (b))
-         *other_type_used = 1;
+      if (b->type == type)
+       i += hw_watchpoint_use_count (b);
+      else if (is_hardware_watchpoint (b))
+       *other_type_used = 1;
     }
 
   return i;