Make the objfile destructor private

The idea behind this is that, in the long run, some code will need to
be able to hold onto an objfile after it is unlinked from the program
space.  In particular, this is needed for some functionality to be
moved to worker threads -- otherwise the objfile can be deleted while
still in use.

So, this makes ~objfile private, replacing it with an "unlink" method,
making it more obvious which operation is intended at the calling
points.

gdb/ChangeLog
2019-12-12  Tom Tromey  <tom@tromey.com>

	* symfile.c (syms_from_objfile_1): Use objfile_up.
	(syms_from_objfile_1, remove_symbol_file_command): Call unlink
	method.
	(reread_symbols): Use objfile_up.
	* solib.c (update_solib_list, reload_shared_libraries_1): Call
	unlink method.
	* objfiles.h (struct objfile) <~objfile>: Now private.
	<unlink>: New method.
	(struct objfile_deleter): New.
	(objfile_up): New typedef.
	* objfiles.c (objfile::unlink): New method.
	(free_objfile_separate_debug, free_all_objfiles)
	(objfile_purge_solibs): Use it.
	* jit.c (jit_unregister_code): Remove.
	(jit_inferior_exit_hook, jit_event_handler): Call unlink on
	objfile.
	* compile/compile-object-run.c (do_module_cleanup): Call unlink on
	objfile.
	* compile/compile-object-load.c (compile_object_load): Use
	objfile_up.

Change-Id: I934bee70b26b8b24e1735828fb1e60fe8a05714f

1 files changed, 20 insertions, 1 deletions

diff --git a/gdb/objfiles.h b/gdb/objfiles.h
index 663e639..49b4627 100644
--- a/gdb/objfiles.h
+++ b/gdb/objfiles.h
@@ -399,13 +399,18 @@ private:
   /* The only way to create an objfile is to call objfile::make.  */
   objfile (bfd *, const char *, objfile_flags);
 
+  /* The only way to free an objfile is via 'unlink'.  */
+  ~objfile ();
+
 public:
 
   /* Create an objfile.  */
   static objfile *make (bfd *bfd_, const char *name_, objfile_flags flags_,
 			objfile *parent = nullptr);
 
-  ~objfile ();
+  /* Remove an objfile from the current program space, and free
+     it.  */
+  void unlink ();
 
   DISABLE_COPY_AND_ASSIGN (objfile);
 
@@ -637,6 +642,20 @@ public:
   htab_up static_links;
 };
 
+/* A deleter for objfile.  */
+
+struct objfile_deleter
+{
+  void operator() (objfile *ptr) const
+  {
+    ptr->unlink ();
+  }
+};
+
+/* A unique pointer that holds an objfile.  */
+
+typedef std::unique_ptr<objfile, objfile_deleter> objfile_up;
+
 /* Declarations for functions defined in objfiles.c */
 
 extern struct gdbarch *get_objfile_arch (const struct objfile *);