[PATCH v2 03/12] x86-nat: Add x86_lookup_debug_reg_state.

[John Baldwin <jhb@FreeBSD.org>]

This function returns nullptr if debug register state does not
yet exist for a given process rather than creating new state.
---
 gdb/x86-nat.c | 12 ++++++++++++
 gdb/x86-nat.h |  5 +++++
 2 files changed, 17 insertions(+)

diff --git a/gdb/x86-nat.c b/gdb/x86-nat.c
index c1e892bf564..36513dd8cfb 100644
--- a/gdb/x86-nat.c
+++ b/gdb/x86-nat.c
@@ -46,6 +46,18 @@ struct x86_dr_low_type x86_dr_low;
 static std::unordered_map<pid_t,
 			  struct x86_debug_reg_state> x86_debug_process_state;
 
+/* See x86-nat.h.  */
+
+struct x86_debug_reg_state *
+x86_lookup_debug_reg_state (pid_t pid)
+{
+  auto it = x86_debug_process_state.find (pid);
+  if (it != x86_debug_process_state.end ())
+    return &it->second;
+
+  return nullptr;
+}
+
 /* Get debug registers state for process PID.  */
 
 struct x86_debug_reg_state *
diff --git a/gdb/x86-nat.h b/gdb/x86-nat.h
index 913291a2305..d9c2a3f6e14 100644
--- a/gdb/x86-nat.h
+++ b/gdb/x86-nat.h
@@ -40,6 +40,11 @@ extern void x86_set_debug_register_length (int len);
 
 extern void x86_cleanup_dregs (void);
 
+/* Return the debug register state for process PID.  If no existing
+   state is found for this process, return nullptr.  */
+
+struct x86_debug_reg_state *x86_lookup_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.  */
 
-- 
2.34.1