From: Olivier Hainque <[email protected]>
A null "pc" return address in the Unwind_Backtrace callback
normally means that unwinding has reached the top of the call
chain. Or something else, abnormal. Recognize this early as a
stop condition, which makes sure we don't accidentally add an
entry for it after applying possible offsets.
gcc/ada/ChangeLog:
* tracebak.c (trace_callback): Return early for pc == 0;
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/tracebak.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/gcc/ada/tracebak.c b/gcc/ada/tracebak.c
index 2c80b2a1610..709322ad13d 100644
--- a/gcc/ada/tracebak.c
+++ b/gcc/ada/tracebak.c
@@ -655,6 +655,10 @@ trace_callback (struct _Unwind_Context * uw_context,
uw_data_t * uw_data)
pc = (char *) _Unwind_GetIP (uw_context);
#endif
+ /* Common case of top-of-call-chain reached. */
+ if (pc == (char *)0)
+ return _URC_NORMAL_STOP;
+
if (uw_data->n_frames_skipped < uw_data->n_frames_to_skip)
{
uw_data->n_frames_skipped ++;
--
2.53.0
