Hi,
On Mon, 2018-04-23 at 14:45 +0100, Pedro Alves wrote:
> One way to hack around it would be to use for example the new
> "starti" command, which breaks at (before?) the first instruction
> of the program, issue -list-target-features, and then continue.
> There might be some better/cleaner solution, but that's what comes
> to mind right now.
IMO the clean solution is to connect to the native target
explicitly, with "-target-select native", before -exec-run,
instead of letting -exec-run automatically connect to
the native target if not connected to any other target yet.
-gdb-set mi-async on
^done
(gdb)
-target-select native
^connected
(gdb)
-list-target-features
^done,features=["async"]
(gdb)
-exec-run ...
I'd also suggest that frontends consider using
"set auto-connect-native-target off"
https://sourceware.org/gdb/onlinedocs/gdb/Starting.html
Thanks! This makes sense. The only problem I see is that it only works
reliably if one does not use CLI. In my case, I want user to be able
to use the CLI.
I don't see a way right now that you could know about that. There
would
need to be a new asynchronous event emitted when the target stack
changes.
So gave it a go and added a new event. Seems to work fine (for me):
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index 8bfb1298a5..f140a3cca2 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -22,6 +22,7 @@
#include "event-top.h"
#include "event-loop.h"
#include "inferior.h"
+#include "target.h"
#include "infrun.h"
#include "ui-out.h"
#include "top.h"
@@ -85,6 +86,7 @@ static void mi_command_param_changed (const char
*param, const char *value);
static void mi_memory_changed (struct inferior *inf, CORE_ADDR
memaddr,
ssize_t len, const bfd_byte *myaddr);
static void mi_on_sync_execution_done (void);
+static void mi_current_target_changed (struct target_ops *target);
static int report_initial_inferior (struct inferior *inf, void
*closure);
@@ -1280,6 +1282,38 @@ mi_user_selected_context_changed
(user_selected_what selection)
}
}
+static void
+mi_current_target_changed (struct target_ops *target)
+{
+ SWITCH_THRU_ALL_UIS ()
+ {
+ struct mi_interp *mi = as_mi_interp (top_level_interpreter ());
+
+ if (mi == NULL)
+ continue;
+
+ target_terminal::scoped_restore_terminal_state term_state;
+ target_terminal::ours_for_output ();
+
+ fprintf_unfiltered (mi->event_channel,
+ "target-changed,features=[");
+ if (mi_async_p ())
+ fprintf_unfiltered (mi->event_channel,
+ "\"async\"");
+ if (target_can_execute_reverse)
+ {
+ if (mi_async_p ())
+ fprintf_unfiltered (mi->event_channel,",\"reverse\"");
+ else
+ fprintf_unfiltered (mi->event_channel,"\"reverse\"");
+ }
+ fprintf_unfiltered (mi->event_channel,
+ "]");
+ gdb_flush (mi->event_channel);
+ }
+}
+
+
static int
report_initial_inferior (struct inferior *inf, void *closure)
{
@@ -1382,4 +1416,5 @@ _initialize_mi_interp (void)
gdb::observers::sync_execution_done.attach
(mi_on_sync_execution_done);
gdb::observers::user_selected_context_changed.attach
(mi_user_selected_context_changed);
+ gdb::observers::current_target_changed.attach
(mi_current_target_changed);
}
diff --git a/gdb/observable.c b/gdb/observable.c
index 5539b9837b..f99a39b909 100644
--- a/gdb/observable.c
+++ b/gdb/observable.c
@@ -74,6 +74,7 @@ DEFINE_OBSERVABLE (inferior_call_pre);
DEFINE_OBSERVABLE (inferior_call_post);
DEFINE_OBSERVABLE (register_changed);
DEFINE_OBSERVABLE (user_selected_context_changed);
+DEFINE_OBSERVABLE (current_target_changed);
} /* namespace observers */
} /* namespace gdb */
diff --git a/gdb/observable.h b/gdb/observable.h
index 34447b90bb..3f97cc5cb1 100644
--- a/gdb/observable.h
+++ b/gdb/observable.h
@@ -228,6 +228,9 @@ extern observable<struct frame_info *, int>
register_changed;
frame has changed. */
extern observable<user_selected_what> user_selected_context_changed;
+/* The current target has changed. */
+extern observable<struct target_ops *> current_target_changed;
+
} /* namespace observers */
} /* namespace gdb */
diff --git a/gdb/target.c b/gdb/target.c
index e8d4ae7ea8..5cb182c849 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -49,6 +49,7 @@
#include "byte-vector.h"
#include "terminal.h"
#include <algorithm>
+#include <observable.h>
static void generic_tls_error (void) ATTRIBUTE_NORETURN;
@@ -719,6 +720,8 @@ update_current_target (void)
if (targetdebug)
setup_target_debug ();
+
+ gdb::observers::current_target_changed.notify(¤t_target);
}
/* Push a new target type into the stack of the existing target
accessors,