Compilers already have ABIs, they're just compiler-specific and not documented. If they didn't have an ABI, then you couldn't link 2 C++ libraries together. In

Compilers already have ABIs, they're just compiler-specific and not documented. If they didn't have an ABI, then you couldn't link 2 C++ libraries together. In terms of having one spec that handles arbitrary architectures, maybe it could be defined relative to the C ABI? I don't actually know how what the internal ABIs used by the current crop of C++ compilers looks like, so I don't know if they could be expressed relative to the C ABI or not. Alternatively, one could come up with a set of configurable values that define what makes one architecture different from another (such as word size, long/pointer size (if different than word size), endianness, etc). You know, the stuff that the compiler already has to know about in order to compile for an architecture (and I'm pretty sure clang at the least already has a way to even define new target triples in terms of a set of configurable values for this sort of thing). I assume existing compilers don't invent entirely brand new ABIs for each new architecture but instead just adapt an internal standard C++ ABI to the new architecture using a similar process already. The same could be done for a public standard C++ ABI.