Emitting an optional Builtin.RawPointer during IRGen

Development Compiler
1

Hey compiler team! I'm working on a builtin that emits a Builtin.RawPointer. However, the emitted code is failable and I need to express that. Right now I'm checking if the bit pattern of the raw pointer equals 0, but this seems like the wrong abstraction. Options I see are:

  1. Continue to check the bit pattern*,
  2. Return a Builtin.Word instead (and cast to UnsafeMutableRawPointer after checking for 0*), or
  3. Figure out how to return Builtin.RawPointer? i.e. an optional.

I'd prefer the third option, but I don't seem to be able to convince IRGenFunction to accept a pointer value as such a thing. There aren't any other builtins that currently return optional values so I can't just crib from them. Any thoughts on the right way forward?

* Presumably there's no immediate plans to deploy Swift on a CPU architecture or operating system where a NULL pointer's bit pattern is not all zeroes. :slight_smile: