Function rustc_target::abi::call::wasm::compute_wasm_abi_info

pub fn compute_wasm_abi_info<Ty>(fn_abi: &mut FnAbi<'_, Ty>)

The purpose of this ABI is for matching the WebAssembly standard. This intentionally diverges from the C ABI and is specifically crafted to take advantage of LLVM’s support of multiple returns in WebAssembly.

This ABI is bad! It uses PassMode::Direct for abi::Aggregate types, which leaks LLVM implementation details into the ABI. It’s just hard to fix because ABIs are hard to change. Also see https://github.com/rust-lang/rust/issues/115666.