gdb/

* breakpoint.c (watch_command_1): Get a pointer of the lazy
	version of the expression's value, even if reading the value from
	memory fails.  When creating a -location watchpoint, get the
	value's address from the lazy value pointer.

	gdb/testsuite/
	* gdb.base/watchpoint.exp: Test "watch -location" with an
	innacessible location.

gdb/ChangeLog

@@ -1,3 +1,10 @@
+2010-11-09  Pedro Alves  <pedro@codesourcery.com>
+
+	* breakpoint.c (watch_command_1): Get a pointer of the lazy
+	version of the expression's value, even if reading the value from
+	memory fails.  When creating a -location watchpoint, get the
+	value's address from the lazy value pointer.
+
 2010-11-07  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	* infrun.c (restore_inferior_thread_state): Use

gdb/breakpoint.c

@@ -8022,7 +8022,7 @@ watch_command_1 (char *arg, int accessflag, int from_tty, int just_location)
   struct breakpoint *b, *scope_breakpoint = NULL;
   struct expression *exp;
   struct block *exp_valid_block = NULL, *cond_exp_valid_block = NULL;
-  struct value *val, *mark;
+  struct value *val, *mark, *result;
   struct frame_info *frame;
   char *exp_start = NULL;
   char *exp_end = NULL;
@@ -8121,12 +8121,12 @@ watch_command_1 (char *arg, int accessflag, int from_tty, int just_location)
 
   exp_valid_block = innermost_block;
   mark = value_mark ();
-  fetch_subexp_value (exp, &pc, &val, NULL, NULL);
+  fetch_subexp_value (exp, &pc, &val, &result, NULL);
 
   if (just_location)
     {
       exp_valid_block = NULL;
-      val = value_addr (val);
+      val = value_addr (result);
       release_value (val);
       value_free_to_mark (mark);
     }

gdb/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2010-11-09  Pedro Alves  <pedro@codesourcery.com>
+
+	* gdb.base/watchpoint.exp: Test "watch -location" with an
+	innacessible location.
+
 2010-11-09  Edjunior Machado  <emachado@br.ibm.com>
 	    Luis Machado  <luisgpm@br.ibm.com>
 

gdb/testsuite/gdb.base/watchpoint.exp

@@ -683,6 +683,11 @@ proc test_inaccessible_watchpoint {} {
 	    "$watchpoint_msg \[0-9\]+: \\*\\(int \\*\\) 0"
 	delete_breakpoints
 
+	# The same, but using -location through an indirection.
+	gdb_test "watch -location *global_ptr" \
+	    "$watchpoint_msg \[0-9\]+: \-location: \\*global_ptr"
+	delete_breakpoints
+
 	# This step requires two HW watchpoints.  Since PPC Server only has
 	# a single one, it will use a SW watchpoint in this case.
 	if [istarget powerpc64-*] {