Add x86_debug_reg_state to gdbserver

This commit introduces a new function, x86_debug_reg_state, that
shared x86 code can use to access the local mirror of a process's
debug registers.  This function already existed in GDB and was
in use by GDB's x86_linux_prepare_to_resume.  An equivalent was
written for gdbserver and gdbserver's x86_linux_prepare_to_resume
was modified to use it.

gdb/ChangeLog:

	* x86-nat.h (x86_debug_reg_state): Move declaration to...
	* nat/x86-dregs.h (x86_debug_reg_state): New declaration.

gdb/gdbserver/ChangeLog:

	* linux-x86-low.c (x86_debug_reg_state): New function.
	(x86_linux_prepare_to_resume): Use the above.

5 files changed, 27 insertions, 9 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 3ff9280..0be8425 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2015-03-24  Gary Benson  <gbenson@redhat.com>
 
+	* x86-nat.h (x86_debug_reg_state): Move declaration to...
+	* nat/x86-dregs.h (x86_debug_reg_state): New declaration.
+
+2015-03-24  Gary Benson  <gbenson@redhat.com>
+
 	* nat/linux-nat.h (current_lwp_ptid): New declaration.
 	* linux-nat.c (current_lwp_ptid): New function.
 	* x86-linux-nat.c: Include nat/linux-nat.h.
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 3e51d94..49477df 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,5 +1,10 @@
 2015-03-24  Gary Benson  <gbenson@redhat.com>
 
+	* linux-x86-low.c (x86_debug_reg_state): New function.
+	(x86_linux_prepare_to_resume): Use the above.
+
+2015-03-24  Gary Benson  <gbenson@redhat.com>
+
 	* linux-low.c (current_lwp_ptid): New function.
 	* linux-x86-low.c: Include nat/linux-nat.h.
 	(x86_dr_low_get_addr): Use current_lwp_ptid.
diff --git a/gdb/gdbserver/linux-x86-low.c b/gdb/gdbserver/linux-x86-low.c
index 66dfc5d..fe4fd25 100644
--- a/gdb/gdbserver/linux-x86-low.c
+++ b/gdb/gdbserver/linux-x86-low.c
@@ -776,6 +776,16 @@ x86_linux_new_thread (void)
   return info;
 }
 
+/* See nat/x86-dregs.h.  */
+
+struct x86_debug_reg_state *
+x86_debug_reg_state (pid_t pid)
+{
+  struct process_info *proc = find_process_pid (pid);
+
+  return &proc->priv->arch_private->debug_reg_state;
+}
+
 /* Called when resuming a thread.
    If the debug regs have changed, update the thread's copies.  */
 
@@ -787,11 +797,9 @@ x86_linux_prepare_to_resume (struct lwp_info *lwp)
 
   if (lwp->arch_private->debug_registers_changed)
     {
-      int i;
-      int pid = ptid_get_pid (ptid);
-      struct process_info *proc = find_process_pid (pid);
       struct x86_debug_reg_state *state
-	= &proc->priv->arch_private->debug_reg_state;
+	= x86_debug_reg_state (ptid_get_pid (ptid));
+      int i;
 
       x86_linux_dr_set (ptid, DR_CONTROL, 0);
 
diff --git a/gdb/nat/x86-dregs.h b/gdb/nat/x86-dregs.h
index a2b9926..61a97c8 100644
--- a/gdb/nat/x86-dregs.h
+++ b/gdb/nat/x86-dregs.h
@@ -92,6 +92,11 @@ struct x86_debug_reg_state
 #define ALL_DEBUG_ADDRESS_REGISTERS(i) \
   for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
 
+/* Return a pointer to the local mirror of the debug registers of
+   process PID.  This function must be provided by the client
+   if required.  */
+extern struct x86_debug_reg_state *x86_debug_reg_state (pid_t pid);
+
 /* Insert a watchpoint to watch a memory region which starts at
    address ADDR and whose length is LEN bytes.  Watch memory accesses
    of the type TYPE.  Return 0 on success, -1 on failure.  */
diff --git a/gdb/x86-nat.h b/gdb/x86-nat.h
index c8ebd74..dcfef36 100644
--- a/gdb/x86-nat.h
+++ b/gdb/x86-nat.h
@@ -44,11 +44,6 @@ extern void x86_set_debug_register_length (int len);
 
 extern void x86_cleanup_dregs (void);
 
-/* Return a pointer to the local mirror of the debug registers of
-   process PID.  */
-
-extern struct x86_debug_reg_state *x86_debug_reg_state (pid_t pid);
-
 /* Called whenever GDB is no longer debugging process PID.  It deletes
    data structures that keep track of debug register state.  */