[RFC] remote-sim.c: Make sim memory accessible after a "load"

[Kevin Buettner <kevinb at redhat dot com>]

The patch below depends upon:

    http://sourceware.org/ml/gdb-patches/2010-07/msg00059.html

It makes sim memory accessible immediately after a "load".  For more
discussion of this matter, see:

    http://sourceware.org/ml/gdb-patches/2010-06/msg00656.html

I've tested it (along with its dependency) against the following
simulators:  arm, frv, mips, powerpc, and v850.   No regressions
found for any of these simulators.

Comments?

Kevin

	* remote-sim.c (gdbsim_xfer_inferior_memory): Replace
	`target_has_execution' check with `to_has_memory' check.
	(gdbsim_has_all_memory, gdbsim_has_memory): New functions.
	(init_gdbsym_ops): Initialize relevant fields of `gdbsim_ops'
	with `gdbsim_has_all_memory' and `gdbsim_has_memory'.

--- ../../../sourceware-multi-1/src/gdb/remote-sim.c	2010-07-02 13:00:24.000000000 -0700
+++ remote-sim.c	2010-07-01 17:15:30.000000000 -0700
@@ -903,10 +903,10 @@ gdbsim_xfer_inferior_memory (CORE_ADDR m
   struct sim_inferior_data *sim_data
     = get_sim_inferior_data (SIM_INSTANCE_NOT_NEEDED);
 
-  /* If no program is running yet, then ignore the simulator for
-     memory.  Pass the request down to the next target, hopefully
-     an exec file.  */
-  if (!target_has_execution)
+  /* If this target doesn't have memory yet, return 0 causing the
+     request to be passed to a lower target, hopefully an exec
+     file.  */
+  if (!target->to_has_memory (target))
     return 0;
 
   if (!sim_data->program_loaded)
@@ -1047,6 +1047,32 @@ gdbsim_pid_to_str (struct target_ops *op
   return normal_pid_to_str (ptid);
 }
 
+/* Simulator memory may be accessed after the program has been loaded.  */
+
+int
+gdbsim_has_all_memory (struct target_ops *ops)
+{
+  struct sim_inferior_data *sim_data
+    = get_sim_inferior_data (SIM_INSTANCE_NOT_NEEDED);
+
+  if (!sim_data->program_loaded)
+    return 0;
+
+  return 1;
+}
+
+int
+gdbsim_has_memory (struct target_ops *ops)
+{
+  struct sim_inferior_data *sim_data
+    = get_sim_inferior_data (SIM_INSTANCE_NOT_NEEDED);
+
+  if (!sim_data->program_loaded)
+    return 0;
+
+  return 1;
+}
+
 /* Define the target subroutine names */
 
 struct target_ops gdbsim_ops;
@@ -1077,8 +1103,8 @@ init_gdbsim_ops (void)
   gdbsim_ops.to_thread_alive = gdbsim_thread_alive;
   gdbsim_ops.to_pid_to_str = gdbsim_pid_to_str;
   gdbsim_ops.to_stratum = process_stratum;
-  gdbsim_ops.to_has_all_memory = default_child_has_all_memory;
-  gdbsim_ops.to_has_memory = default_child_has_memory;
+  gdbsim_ops.to_has_all_memory = gdbsim_has_all_memory;
+  gdbsim_ops.to_has_memory = gdbsim_has_memory;
   gdbsim_ops.to_has_stack = default_child_has_stack;
   gdbsim_ops.to_has_registers = default_child_has_registers;
   gdbsim_ops.to_has_execution = default_child_has_execution;