Classes with virtual methods appear to be forced to pass in memory about riscv-elf-psabi-doc HOT 5 CLOSED

It looks like the Itanium C++ ABI requires that classes with nontrivial copy constructors be passed by reference: https://mentorembedded.github.io/cxx-abi/abi.html#value-parameter

from riscv-elf-psabi-doc.

My example doesn't have a nontrivial copy construction, but it's being treated as if it did.

from riscv-elf-psabi-doc.

Ah, right, I misunderstood you. Anyway, x86-64 and AArch64 have the same idiosyncrasy as we do. Can you check their ABI specs and see if you can uncover the explanation?

from riscv-elf-psabi-doc.

The footnote on https://uclibc.org/docs/psABI-x86_64.pdf#page=20 provides a non-obvious technical definition of "nontrivial copy constructor", so we're doing the right thing.

from riscv-elf-psabi-doc.

Interesting, thanks for the detective work.

from riscv-elf-psabi-doc.