Re: [patch/cygwin] Remove dependency on __COPY_CONTEXT_SIZE

[Pedro Alves <palves@redhat.com>]

On 03/30/2015 11:04 AM, Corinna Vinschen wrote:

> @@ -820,7 +819,7 @@ handle_output_debug_string (struct target_waitstatus *ourstatus)
>  #endif
>  	warning (("%s"), s);
>      }
> -#ifdef __COPY_CONTEXT_SIZE
> +#ifdef __CYGWIN__
>    else
>      {
>        /* Got a cygwin signal marker.  A cygwin signal is followed by
> @@ -847,8 +846,8 @@ handle_output_debug_string (struct target_waitstatus *ourstatus)
>  	  else if ((x = (LPCVOID) (uintptr_t) strtoull (p, NULL, 0))
>  		   && ReadProcessMemory (current_process_handle, x,
>  					 &saved_context,
> -					 __COPY_CONTEXT_SIZE, &n)
> -		   && n == __COPY_CONTEXT_SIZE)
> +					 sizeof (CONTEXT), &n)

Is that really wise?  AFAIK, the size of the CONTEXT structure can
grow as MSFT adds more registers to support newer machines.

It seems to me that the gdb and cygwin.dll builds can disagree
on the size of that structure.  Seems to me that this mechanism should
have a way to let GDB know the size of the context structure.  Or maybe
read just saved_context.ContextFlags first, and infer the size from
that, reading in the most we understand?


> +		   && n == sizeof (CONTEXT))
>  	    have_saved_context = 1;
>  	  current_event.dwThreadId = retval;
>  	}
> 

Thanks,
Pedro Alves