[TCLCORE] Proposed addition of a new Tcl_Obj internal rep field for pointer+size

[<apn...@ya...>]

Custom Tcl_Obj's often require a pointer and length internal representation.
In Tcl 8, the Tcl_Obj.internalRep.ptrAndLongRep field targeted this use
case.

 

With Tcl 9, where supported lengths on 64-bit platforms are greater than
ULONG_MAX on Windows, this no longer suffices for the purpose. Hijacking the
twoPtrValue field involves casts, not desirable imo.

 

I would therefore like to add the following additional field to the
Tcl_ObjIntenalRep union

 

struct {

   void *ptr;

   Tcl_Size size;

} ptrAndSize;

 

Note Tcl_Size was chosen, not Tcl_WideInt,  ptrdiff_t or size_t so that the
size of Tcl_Obj is not affected on any platform for both 32- and 64-bit Tcl
9 and 8.7.

 

I would like to see this for 9.0.1.

 

Anybody have objections?

 

Is this something that would need a TIP and a vote?

 

/Ashok