Patch to propagate GDB's knowledge of the executing state to frontend

[Yao Qi]

On 10/25/2012 07:09 PM, ali_anwar wrote:
> Hi,
>
> Attached patch is to let GDB propagate the target state under following
> two scenarios:
>
> 1. Attached patch will enable GDB to inform about the state of the
> target when it was not able to fetch the non-general registers, when
> target is already stopped.
>
> The reason behind this behavior was an error message which was caused
> when the GDB was not able to fetch the value of a certain register. The
> GDB should have told the front end about the current state of the
> target. The attached patch makes sure that it happens. This patch should
> be a safety measure in case some debugging stub behaves badly.
>
> 2. Attached patch will enable GDB to inform about the state of the
> target when it was not able to fetch the backtrace once the step has
> already occurred and target is in stopped state.
>

It is better to describe what will happen or what is wrong if this patch 
is not applied.

> Index: ChangeLog
> ===================================================================
> RCS file: /cvs/src/src/gdb/ChangeLog,v
> retrieving revision 1.14760
> diff -u -r1.14760 ChangeLog
> --- ChangeLog	24 Oct 2012 19:08:15 -0000	1.14760
> +++ ChangeLog	25 Oct 2012 10:52:02 -0000
> @@ -1,3 +1,13 @@
> +2012-10-25  Ali Anwar<ali_anwar@codesourcery.com>
> +
> +	* infrun.c (handle_inferior_event_stub, regcache_dup_stub):
> +	New functions.
> +	(normal_stop): Change to propagate GDB's knowledge of the
> +	executing state to frontend when not able to fetch registers.
> +	(wait_for_inferior): Chnage to propagate GDB's knowledge of
                              ^^^^^^ typo


> +	the executing state if not able to fetch backtrace once the
> +	step has already occured.
                          ^^^^^^^ typo.

In each changelog entry, we'll put 'what do we change' instead of 'why 
do we change in this way'.  So this entry can be simplified.

> Index: infrun.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/infrun.c,v
> retrieving revision 1.559
> diff -u -r1.559 infrun.c
> --- infrun.c	17 Sep 2012 07:26:55 -0000	1.559
> +++ infrun.c	25 Oct 2012 10:52:04 -0000
> @@ -73,6 +73,10 @@
>
>   static int hook_stop_stub (void *);
>
> +static int regcache_dup_stub (void *);
> +
> +static int handle_inferior_event_stub (void *);
> +
>   static int restore_selected_frame (void *);
>
>   static int follow_fork (void);
> @@ -2701,7 +2705,8 @@
>         old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
>
>         /* Now figure out what to do with the result of the result.  */
> -      handle_inferior_event (ecs);
> +      catch_errors (handle_inferior_event_stub, ecs,
> +                    "Error while handling inferior event:\n", RETURN_MASK_ALL);
>
>         /* No error, don't finish the state yet.  */
>         discard_cleanups (old_chain);
> @@ -6082,7 +6087,8 @@
>
>         /* NB: The copy goes through to the target picking up the value of
>   	 all the registers.  */
> -      stop_registers = regcache_dup (get_current_regcache ());
> +      catch_errors (regcache_dup_stub, NULL,
> +                    "Error while running regcache_dup:\n", RETURN_MASK_ALL);
>       }
>
>     if (stop_stack_dummy == STOP_STACK_DUMMY)
> @@ -6154,6 +6160,20 @@
>   }
>
>   static int
> +handle_inferior_event_stub (void *ecs)
> +{
> +  handle_inferior_event (ecs);
> +  return (0);

parentheses are not needed.

> +}
> +
> +static int
> +regcache_dup_stub (void *arg)
> +{
> +  stop_registers = regcache_dup (get_current_regcache ());
> +  return (0);

Likewise.

-- 
Yao