[PATCH 6/8] Add push_target overload

[Tom Tromey <tom at tromey dot com>]

From: Tom Tromey <tromey@adacore.com>

This adds a push_target overload that takes a "target_ops_up &&".
This removes some calls to release a target_ops_up, and makes the
intent here clearer.

gdb/ChangeLog
2019-02-07  Tom Tromey  <tromey@adacore.com>

	* target.h (push_target): Declare new overload.
	* target.c (push_target): New overload, taking an rvalue reference.
	* remote.c (remote_target::open_1): Use push_target overload.
	* corelow.c (core_target_open): Use push_target overload.
---
 gdb/ChangeLog | 7 +++++++
 gdb/corelow.c | 3 +--
 gdb/remote.c  | 4 +---
 gdb/target.c  | 9 +++++++++
 gdb/target.h  | 3 +++
 5 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/gdb/corelow.c b/gdb/corelow.c
index 52d6d95b3c0..6a29d6a2328 100644
--- a/gdb/corelow.c
+++ b/gdb/corelow.c
@@ -417,8 +417,7 @@ core_target_open (const char *arg, int from_tty)
   if (!exec_bfd)
     set_gdbarch_from_file (core_bfd);
 
-  push_target (target);
-  target_holder.release ();
+  push_target (std::move (target_holder));
 
   inferior_ptid = null_ptid;
 
diff --git a/gdb/remote.c b/gdb/remote.c
index 18e678d07af..95201eeab5c 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -5547,9 +5547,7 @@ remote_target::open_1 (const char *name, int from_tty, int extended_p)
     }
 
   /* Switch to using the remote target now.  */
-  push_target (remote);
-  /* The target stack owns the target now.  */
-  target_holder.release ();
+  push_target (std::move (target_holder));
 
   /* Register extra event sources in the event loop.  */
   rs->remote_async_inferior_event_token
diff --git a/gdb/target.c b/gdb/target.c
index c1ab07f7608..116510e8cb8 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -585,6 +585,15 @@ push_target (struct target_ops *t)
   g_target_stack.push (t);
 }
 
+/* See target.h  */
+
+void
+push_target (target_ops_up &&t)
+{
+  g_target_stack.push (t.get ());
+  t.release ();
+}
+
 /* See target.h.  */
 
 int
diff --git a/gdb/target.h b/gdb/target.h
index 96413aa6c3a..c95151a4044 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -2333,6 +2333,9 @@ extern void add_deprecated_target_alias (const target_info &info,
 
 extern void push_target (struct target_ops *);
 
+/* An overload that deletes the target on failure.  */
+extern void push_target (target_ops_up &&);
+
 extern int unpush_target (struct target_ops *);
 
 extern void target_pre_inferior (int);
-- 
2.17.2