Re: [RFA] cp-valprint.c::cp_print_class_method(): Use actual type in call to unpack_pointer

[Daniel Jacobowitz <drow at mvista dot com>]

On Fri, Apr 11, 2003 at 12:12:07PM +0200, Corinna Vinschen wrote:
> Hi,
> 
> according to the discussion on the gdb ML beginning with
> http://sources.redhat.com/ml/gdb/2003-03/msg00369.html
> I'm now proposing to change cp-valprint.c::cp_print_class_method() to
> call unpack_pointer() with the actual type given to cp_print_class_method().  
> 
> Rational: 
> 
> To unpack a pointer type it's often necessary to call target dependent
> address translation routines.  These routines sometimes have to know the
> actual type of the datatype to do their job right.  In case of XStormy16,
> addresses to functions and methods *could* be pointers to entries in a
> jump table.  Since this is only valid for functions and methods, the
> appropriate XStormy16 function checks the incoming datatype for being
> TYPE_CODE_FUNC or TYPE_CODE_METHOD.
> 
> The current implementation of cp_print_class_method() calls unpack_pointer()
> always with a type `pointer to void'.  This eliminates the necessary
> type info of the incoming type.  This obviously euchres target functions
> trying to find the correct address by the pointer type.
> 
> The below patch should work fine under all circumstances since 
> cp_print_class_method() is called from c_val_print only and only if type is
> TYPE_CODE_METHOD.
> 
> The patch eliminates a potential FAIL in gdb.c++/printmethod.exp:
> 
>   print theA->virt^M
>   $1 = invalid pointer to member function^M
>   FAIL: gdb.c++/printmethod.exp: print virtual method.

This is OK.  If we find somewhere that the incoming type is not a
pointer then we can deal with it later.

> 2003-04-11  Corinna Vinschen  <vinschen at redhat dot com>
> 
> 	* cp-valprint.c (cp_print_class_method): Call unpack_pointer() with
> 	actually incoming type.
> 
> Index: cp-valprint.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/cp-valprint.c,v
> retrieving revision 1.19
> diff -u -p -r1.19 cp-valprint.c
> --- cp-valprint.c	25 Feb 2003 21:36:17 -0000	1.19
> +++ cp-valprint.c	11 Apr 2003 09:53:09 -0000
> @@ -87,7 +87,7 @@ cp_print_class_method (char *valaddr,
>        fprintf_filtered (stream, "<unknown>");
>        return;
>      }
> -  addr = unpack_pointer (lookup_pointer_type (builtin_type_void), valaddr);
> +  addr = unpack_pointer (type, valaddr);
>    if (METHOD_PTR_IS_VIRTUAL (addr))
>      {
>        offset = METHOD_PTR_TO_VOFFSET (addr);
> 
> -- 
> Corinna Vinschen
> Cygwin Developer
> Red Hat, Inc.
> mailto:vinschen at redhat dot com
> 

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer