[PATCH v2 1/5] Introduce target_ops method thread_info_to_thread_handle

[Kevin Buettner <kevinb@redhat.com>]

This patch adds a thread_info_to_thread_handle method to the target_ops
struct.  It also implements this functionality for remote targets and
linux native threads.

gdb/ChangeLog:

	* gdbthread.h (thread_to_thread_handle): Declare.
	* thread.c (gdbtypes.h): Include.
	(thread_to_thread_handle): New function.

	* target.h (struct target_ops): Add thread_info_to_thread_handle.
	(target_thread_info_to_thread_handle): Declare.
	* target.c (target_thread_info_to_thread_handle): New function.
	* target-debug.h, target-delegates.c: Regenerate.

	* linux-thread-db.c (class thread_db_target): Add method
	thread_info_to_thread_handle.
	(thread_db_target::thread_info_to_thread_handle): Define.
	* remote.c (class remote_target): Add new method
	thread_info_to_thread_handle.
	(remote_target::thread_info_to_thread_handle): Define.
---
 gdb/linux-thread-db.c  | 19 +++++++++++++++++++
 gdb/remote.c           | 10 ++++++++++
 gdb/target-debug.h     |  2 ++
 gdb/target-delegates.c | 28 ++++++++++++++++++++++++++++
 gdb/target.c           |  6 ++++++
 gdb/target.h           |  6 ++++++
 6 files changed, 71 insertions(+)

diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c
index fd67dcb17b..fe9f44046a 100644
--- a/gdb/linux-thread-db.c
+++ b/gdb/linux-thread-db.c
@@ -105,6 +105,7 @@ public:
   thread_info *thread_handle_to_thread_info (const gdb_byte *thread_handle,
 					     int handle_len,
 					     inferior *inf) override;
+  gdb::byte_vector thread_info_to_thread_handle (struct thread_info *) override;
 };
 
 static char *libthread_db_search_path;
@@ -1698,6 +1699,24 @@ thread_db_target::thread_handle_to_thread_info (const gdb_byte *thread_handle,
   return NULL;
 }
 
+/* Return the thread handle associated the thread_info pointer TP.  */
+
+gdb::byte_vector
+thread_db_target::thread_info_to_thread_handle (struct thread_info *tp)
+{
+  thread_db_thread_info *priv = get_thread_db_thread_info (tp);
+
+  if (priv == NULL)
+    return gdb::byte_vector ();
+
+  int handle_size = sizeof (priv->tid);
+  gdb::byte_vector rv (handle_size);
+
+  memcpy (rv.data (), &priv->tid, handle_size);
+
+  return rv;
+}
+
 /* Get the address of the thread local variable in load module LM which
    is stored at OFFSET within the thread local storage for thread PTID.  */
 
diff --git a/gdb/remote.c b/gdb/remote.c
index 36136e3e3e..546b0f36f7 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -495,6 +495,9 @@ public:
 					     int handle_len,
 					     inferior *inf) override;
 
+  gdb::byte_vector thread_info_to_thread_handle (struct thread_info *tp)
+						 override;
+
   void stop (ptid_t) override;
 
   void interrupt () override;
@@ -14047,6 +14050,13 @@ remote_target::thread_handle_to_thread_info (const gdb_byte *thread_handle,
   return NULL;
 }
 
+gdb::byte_vector
+remote_target::thread_info_to_thread_handle (struct thread_info *tp)
+{
+  remote_thread_info *priv = get_remote_thread_info (tp);
+  return priv->thread_handle;
+}
+
 bool
 remote_target::can_async_p ()
 {
diff --git a/gdb/target-debug.h b/gdb/target-debug.h
index d9f7d46dd9..23a8d25420 100644
--- a/gdb/target-debug.h
+++ b/gdb/target-debug.h
@@ -184,6 +184,8 @@
   target_debug_do_print (host_address_to_string (X))
 #define target_debug_print_thread_info_pp(X)		\
   target_debug_do_print (host_address_to_string (X))
+#define target_debug_print_gdb_byte_vector(X)	\
+  target_debug_do_print (host_address_to_string (X.data ()))
 
 static void
 target_debug_print_struct_target_waitstatus_p (struct target_waitstatus *status)
diff --git a/gdb/target-delegates.c b/gdb/target-delegates.c
index a25851e9cf..ffa90d966f 100644
--- a/gdb/target-delegates.c
+++ b/gdb/target-delegates.c
@@ -70,6 +70,7 @@ struct dummy_target : public target_ops
   const char *extra_thread_info (thread_info *arg0) override;
   const char *thread_name (thread_info *arg0) override;
   thread_info *thread_handle_to_thread_info (const gdb_byte *arg0, int arg1, inferior *arg2) override;
+  gdb::byte_vector thread_info_to_thread_handle (struct thread_info *arg0) override;
   void stop (ptid_t arg0) override;
   void interrupt () override;
   void pass_ctrlc () override;
@@ -237,6 +238,7 @@ struct debug_target : public target_ops
   const char *extra_thread_info (thread_info *arg0) override;
   const char *thread_name (thread_info *arg0) override;
   thread_info *thread_handle_to_thread_info (const gdb_byte *arg0, int arg1, inferior *arg2) override;
+  gdb::byte_vector thread_info_to_thread_handle (struct thread_info *arg0) override;
   void stop (ptid_t arg0) override;
   void interrupt () override;
   void pass_ctrlc () override;
@@ -1854,6 +1856,32 @@ debug_target::thread_handle_to_thread_info (const gdb_byte *arg0, int arg1, infe
   return result;
 }
 
+gdb::byte_vector
+target_ops::thread_info_to_thread_handle (struct thread_info *arg0)
+{
+  return this->beneath ()->thread_info_to_thread_handle (arg0);
+}
+
+gdb::byte_vector
+dummy_target::thread_info_to_thread_handle (struct thread_info *arg0)
+{
+  return gdb::byte_vector ();
+}
+
+gdb::byte_vector
+debug_target::thread_info_to_thread_handle (struct thread_info *arg0)
+{
+  gdb::byte_vector result;
+  fprintf_unfiltered (gdb_stdlog, "-> %s->thread_info_to_thread_handle (...)\n", this->beneath ()->shortname ());
+  result = this->beneath ()->thread_info_to_thread_handle (arg0);
+  fprintf_unfiltered (gdb_stdlog, "<- %s->thread_info_to_thread_handle (", this->beneath ()->shortname ());
+  target_debug_print_struct_thread_info_p (arg0);
+  fputs_unfiltered (") = ", gdb_stdlog);
+  target_debug_print_gdb_byte_vector (result);
+  fputs_unfiltered ("\n", gdb_stdlog);
+  return result;
+}
+
 void
 target_ops::stop (ptid_t arg0)
 {
diff --git a/gdb/target.c b/gdb/target.c
index 116510e8cb..8bfedb3619 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -2082,6 +2082,12 @@ target_thread_handle_to_thread_info (const gdb_byte *thread_handle,
 						     handle_len, inf);
 }
 
+gdb::byte_vector
+target_thread_info_to_thread_handle (struct thread_info *tip)
+{
+  return current_top_target ()->thread_info_to_thread_handle (tip);
+}
+
 void
 target_resume (ptid_t ptid, int step, enum gdb_signal signal)
 {
diff --git a/gdb/target.h b/gdb/target.h
index c95151a404..4920f00eeb 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -659,6 +659,8 @@ struct target_ops
 						       int,
 						       inferior *inf)
       TARGET_DEFAULT_RETURN (NULL);
+    virtual gdb::byte_vector thread_info_to_thread_handle (struct thread_info *)
+      TARGET_DEFAULT_RETURN (gdb::byte_vector ());
     virtual void stop (ptid_t)
       TARGET_DEFAULT_IGNORE ();
     virtual void interrupt ()
@@ -1851,6 +1853,10 @@ extern const char *target_thread_name (struct thread_info *);
 extern struct thread_info *target_thread_handle_to_thread_info
   (const gdb_byte *thread_handle, int handle_len, struct inferior *inf);
 
+/* Given a thread, return the thread handle.  */
+extern gdb::byte_vector target_thread_info_to_thread_handle
+  (struct thread_info *);
+
 /* Attempts to find the pathname of the executable file
    that was run to create a specified process.