It's a bit of a problem - some of these architectures (8051 I'm looking at you) have multiple address spaces, some with 16-bit pointers, some with 8-bit ones -

It's a bit of a problem - some of these architectures (8051 I'm looking at you) have multiple address spaces, some with 16-bit pointers, some with 8-bit ones - 8051 SDCC supports 24-bit generic pointers with embedded tags saying which address space is being pointed at, you can also mark variables with explicit address space tags: packet __xdata * __data rx_packet; a pointer to (16-bit addresses) external data space stored in (8-bit addressed) local data space. Any useful compiler for an 8051 is going to need these SDCC extensions