gdb/continuations: use lambdas instead of function pointers

Use lambdas and std::list to track inferior continuations.  This is a
refactoring.

gdb/ChangeLog:
2021-04-22  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	* inferior.h (class inferior) <continuations>: Change the type
	to be an std::list of std::function's.
	Update the references and uses below.
	* continuations.c (struct continuation): Delete.
	(make_continuation): Delete.
	(do_my_continuations_1): Delete.
	(do_my_continuations): Delete.
	(discard_my_continuations_1): Delete.
	(discard_my_continuations): Delete.
	(add_inferior_continuation): Update.
	(do_all_inferior_continuations): Update.
	(discard_all_inferior_continuations): Update.
	* continuations.h (add_inferior_continuation): Update to take
	an std::function as the parameter.
	* infcmd.c (struct attach_command_continuation_args): Delete.
	(attach_command_continuation): Delete.
	(attach_command_continuation_free_args): Delete.
	(attach_command): Update.
	(notice_new_inferior): Update.

1 files changed, 2 insertions, 2 deletions

diff --git a/gdb/inferior.h b/gdb/inferior.h
index 9ca510e..9e7291a 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -22,6 +22,7 @@
 #define INFERIOR_H 1
 
 #include <exception>
+#include <list>
 
 struct target_waitstatus;
 struct frame_info;
@@ -32,7 +33,6 @@ struct regcache;
 struct ui_out;
 struct terminal_info;
 struct target_desc_info;
-struct continuation;
 struct inferior;
 struct thread_info;
 
@@ -510,7 +510,7 @@ public:
 
   /* What is left to do for an execution command after any thread of
      this inferior stops.  */
-  continuation *continuations = NULL;
+  std::list<std::function<void ()>> continuations;
 
   /* True if setup_inferior wasn't called for this inferior yet.
      Until that is done, we must not access inferior memory or