Re: [PATCH] Replace deprecated_target_wait_hook by observers

[Simon Marchi <simon.marchi@polymtl.ca>]

> diff --git a/gdb/target.c b/gdb/target.c
> index ae2d659583e..22e58484a18 100644
> --- a/gdb/target.c
> +++ b/gdb/target.c
> @@ -26,6 +26,7 @@
>  #include "symtab.h"
>  #include "inferior.h"
>  #include "infrun.h"
> +#include "observable.h"
>  #include "bfd.h"
>  #include "symfile.h"
>  #include "objfiles.h"
> @@ -2591,12 +2592,45 @@ target_disconnect (const char *args, int from_tty)
>    current_inferior ()->top_target ()->disconnect (args, from_tty);
>  }
>  
> +/* RAII class to handle target_wait observers.
> +   These observers allow the Insight GUI to monitor user interaction while
> +   waiting on the target. */
> +
> +class scoped_target_wait
> +{
> +public:
> +  explicit scoped_target_wait (ptid_t ptid)
> +  {
> +    m_event_ptid = null_ptid;
> +    gdb::observers::target_pre_wait.notify (ptid);
> +  }
> +
> +  ~scoped_target_wait ()
> +  {
> +    gdb::observers::target_post_wait.notify (m_event_ptid);

The only dangerous things about this is if an observer throws an
exception, an exception will exit the destructor, and that aborts the
process.

Maybe something safer in that regard would be:

try
  {
    gdb::observers::target_pre_wait.notify (ptid);
    ptid_t event_ptid = target_wait (...);
    gdb::observers::target_post_wait.notify (event_ptid);
    return event_ptid;
  }
catch
  {
    gdb::observers::target_post_wait.notify (null_ptid);
    throw;
  }

Simon