[PATCH] gdb/mi: add no-history stop reason

Bruno Larsen via Gdb-patches
2023-01-02T15:57:40Z

When executing in reverse and runs out of recorded history, GDB prints
a warning to the user, but does not add a reason in the stopped record,
for example:

*stopped,frame={addr="0x000000000040113e",func="main",args=[],file="/home/blarsen/Documents/fsf_build/gdb/testsuite/../../../binutils-gdb/gdb/testsuite/gdb.reverse/solib-reverse.c",fullname="/home/blarsen/Documents/binutils-gdb/gdb/testsuite/gdb.reverse/solib-reverse.c",line="27",arch="i386:x86-64"},thread-id="1",stopped-threads="all",core="1"

This problem was reported as record/29260.

This commit adds the reason no-history to the record, making it easier
for interfaces using the mi interpreter to report the result.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29260
---
gdb/NEWS | 5 +++++
gdb/doc/gdb.texinfo | 2 ++
gdb/infrun.c | 5 ++++-
3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/gdb/NEWS b/gdb/NEWS
index e61f06081de..3673bed8f46 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -5,6 +5,11 @@

* MI version 1 has been removed.

+* MI changes
+
+** mi now reports 'no_history' as a stop reason when hitting the end of the
+ reverse execution history.
+
*** Changes in GDB 13

* MI version 1 is deprecated, and will be removed in GDB 14.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index a72b2b9eb26..8982151a7e3 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -30851,6 +30851,8 @@ The inferior returned from a system call. This is reported when
@item exec
The inferior called @code{exec}. This is reported when @code{catch exec}
(@pxref{Set Catchpoints}) has been used.
+@item no-history
+There isn't enough history recorded to continue reverse execution.
@end table

The @var{id} field identifies the global thread ID of the thread
diff --git a/gdb/infrun.c b/gdb/infrun.c
index d5f97e33625..601d1a54701 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -8406,7 +8406,10 @@ print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
void
print_no_history_reason (struct ui_out *uiout)
{
- uiout->text ("\nNo more reverse-execution history.\n");
+ if (uiout->is_mi_like_p ())
+ uiout->field_string ("reason", "no-history");
+ else
+ uiout->text ("\nNo more reverse-execution history.\n");
}

/* Print current location without a level number, if we have changed
--
2.39.0