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Re: RFC: lazily call save_current_space_and_thread
Tom> I think I can actually make make_cleanup_restore_current_thread more
Tom> efficient. But if not, I will reimplement this with a flag.
This turned out to be pretty easy; I'm not sure why I didn't do it
before.
This patch makes make_cleanup_restore_current_thread more efficient, by
having it not compute the current frame when there is no selected frame.
This approach let me remove another hack I had in my tree.
Built and regtested on x86-64 (compile farm).
Let me know what you think.
Tom
2011-03-08 Tom Tromey <tromey@redhat.com>
* thread.c (restore_selected_frame): Handle frame_level == -1.
(make_cleanup_restore_current_thread): Use
get_selected_frame_if_set.
* frame.h (get_selected_frame_if_set): Declare.
* frame.c (get_selected_frame_if_set): New function.
diff --git a/gdb/frame.c b/gdb/frame.c
index 36fcefe..8ed20b1 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -1247,6 +1247,16 @@ get_selected_frame (const char *message)
return selected_frame;
}
+/* If there is a selected frame, return it. Otherwise, return NULL. */
+
+struct frame_info *
+get_selected_frame_if_set (void)
+{
+ if (selected_frame == NULL)
+ return NULL;
+ return get_selected_frame (NULL);
+}
+
/* This is a variant of get_selected_frame() which can be called when
the inferior does not have a frame; in that case it will return
NULL instead of calling error(). */
diff --git a/gdb/frame.h b/gdb/frame.h
index 2c5276e..252b75e 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -260,6 +260,9 @@ extern void reinit_frame_cache (void);
and then return that thread's previously selected frame. */
extern struct frame_info *get_selected_frame (const char *message);
+/* If there is a selected frame, return it. Otherwise, return NULL. */
+extern struct frame_info *get_selected_frame_if_set (void);
+
/* Select a specific frame. NULL, apparently implies re-select the
inner most frame. */
extern void select_frame (struct frame_info *);
diff --git a/gdb/thread.c b/gdb/thread.c
index 7d8f6da..f7eccfe 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -1019,6 +1019,13 @@ restore_selected_frame (struct frame_id a_frame_id, int frame_level)
struct frame_info *frame = NULL;
int count;
+ /* This means there was no selected frame. */
+ if (frame_level == -1)
+ {
+ select_frame (NULL);
+ return;
+ }
+
gdb_assert (frame_level >= 0);
/* Restore by level first, check if the frame id is the same as
@@ -1137,7 +1144,13 @@ make_cleanup_restore_current_thread (void)
&& target_has_registers
&& target_has_stack
&& target_has_memory)
- frame = get_selected_frame (NULL);
+ {
+ /* If we naively call get_selected_frame here, then we can
+ end up reading debuginfo for the current frame, even
+ though the user has not selected a frame and we don't
+ actually need the debuginfo at this point. */
+ frame = get_selected_frame_if_set ();
+ }
else
frame = NULL;