Re: [downstream patch FYI] workaround stale frame_info * (PR 13866)

[Pedro Alves <palves@redhat.com>]

On 06/05/2012 08:24 PM, Pedro Alves wrote:

> This fixes the crash.

I actually posted an outdated version before...  This version adds a little
comment.  I've applied it.

2012-06-05  Pedro Alves  <palves@redhat.com>

	PR backtrace/13866

	* breakpoint.c (until_break_command): Only fetch the selected
	frame after decode_line_1.
---
 gdb/breakpoint.c |   19 +++++++++++++------
 1 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 5cc1f64..12db39b 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -10815,10 +10815,10 @@ until_break_command (char *arg, int from_tty, int anywhere)
 {
   struct symtabs_and_lines sals;
   struct symtab_and_line sal;
-  struct frame_info *frame = get_selected_frame (NULL);
-  struct gdbarch *frame_gdbarch = get_frame_arch (frame);
-  struct frame_id stack_frame_id = get_stack_frame_id (frame);
-  struct frame_id caller_frame_id = frame_unwind_caller_id (frame);
+  struct frame_info *frame;
+  struct gdbarch *frame_gdbarch;
+  struct frame_id stack_frame_id;
+  struct frame_id caller_frame_id;
   struct breakpoint *breakpoint;
   struct breakpoint *breakpoint2 = NULL;
   struct cleanup *old_chain;
@@ -10854,8 +10854,15 @@ until_break_command (char *arg, int from_tty, int anywhere)
 
   old_chain = make_cleanup (null_cleanup, NULL);
 
-  /* Installing a breakpoint invalidates the frame chain (as it may
-     need to switch threads), so do any frame handling first.  */
+  /* Note linespec handling above invalidates the frame chain.
+     Installing a breakpoint also invalidates the frame chain (as it
+     may need to switch threads), so do any frame handling before
+     that.  */
+
+  frame = get_selected_frame (NULL);
+  frame_gdbarch = get_frame_arch (frame);
+  stack_frame_id = get_stack_frame_id (frame);
+  caller_frame_id = frame_unwind_caller_id (frame);
 
   /* Keep within the current frame, or in frames called by the current
      one.  */