Introduce htab_up and use gdbpy_enter in py-framefilter.c

This introduces a new "htab_up" typedef, which is a std::unique_ptr
that can call htab_delete.  Then it changes some code in
py-framefilter.c to use both gdbpy_enter and the new htab_up.

2017-01-10  Tom Tromey  <tom@tromey.com>

	* utils.h (htab_deleter): New struct.
	(htab_up): New typedef.
	* python/py-framefilter.c (gdbpy_apply_frame_filter): Use
	gdbpy_enter, gdbpy_ref, htab_up.

1 files changed, 12 insertions, 0 deletions

diff --git a/gdb/utils.h b/gdb/utils.h
index 351814ea81..d7ae9cc81b 100644
--- a/gdb/utils.h
+++ b/gdb/utils.h
@@ -100,6 +100,18 @@ extern struct cleanup *make_cleanup_free_so (struct so_list *so);
 
 extern struct cleanup *make_cleanup_restore_current_language (void);
 
+/* A deleter for a hash table.  */
+struct htab_deleter
+{
+  void operator() (htab *ptr) const
+  {
+    htab_delete (ptr);
+  }
+};
+
+/* A unique_ptr wrapper for htab_t.  */
+typedef std::unique_ptr<htab, htab_deleter> htab_up;
+
 extern struct cleanup *make_cleanup_htab_delete (htab_t htab);
 
 struct parser_state;