Module native_abi 

Native C ABI linking and invocation for extern C foreign functions.

ADR-006 §2.7.4 / §2.7.5 SURFACE: this module is a forbidden-pattern carrier — every input / output path consumed the deleted ValueWord / tag_bits / as_heap_ref / vmarray_from_vec / as_native_* / value_to_* surfaces. The C ABI extension contract (libffi-driven call) stays raw bits per §2.7.5 cross-crate ABI policy, but the marshalling between the VM stack (kinded) and the FFI argument buffer (raw) is the consumer-side migration target. Per the B11-control-flow-heap dispatch the body is stubbed pending phase-2c rebuild.

The pre-rebuild surface (now deleted):

• link_native_function(spec, layouts, cache) — parsed the textual C signature, validated layout references, opened the dynamic library, resolved the symbol, built a libffi Cif. The signature parsing + layout resolution path is independent of ValueWord and could be preserved verbatim — but NativeLinkedFunction itself is the public type used by executor/mod.rs:222 for the ForeignFunctionHandle::Native(Arc<NativeLinkedFunction>) variant; its fields stay unchanged.

• invoke_linked_function(linked, args: &[ValueWord], raw_invoker, vm_stack: &mut [ValueWord]) — encoded VM args into FFI buffers per CType arm, called libffi, then decoded the return value back into ValueWord via from_native_* / from_string / from_array(vmarray_from_vec(...)). The mutable-slice writeback path also wrote back via vmarray_from_vec. All of the above are deleted ValueWord-shape constructors; rebuild needs &[KindedSlot] in / KindedSlot out, with &mut [u64] + parallel &mut [NativeKind] for the writeback path on the §2.7.7 stack ABI.

Rebuild plan: keep the CType parser, CSignature, NativeTypeLayout resolution, libffi Cif construction, and all the type-classification helpers (none of those touch ValueWord). Migrate invoke_linked_function to the kinded API; the RawCallableInvoker extension contract on the §2.7.5 FFI side stays (*mut c_void, &u64, &[u64]) -> Result<u64, String> per module_exports.rs:21.

Structs

NativeLinkedFunction

Phase-2c rebuild placeholder. The pre-rebuild type carried libffi Cif + CodePtr + parsed CSignature + a layout map + an Arc<Library> keep-alive — that internal layout is reconstructed in phase-2c on top of the kinded marshalling path. The placeholder keeps the public type name + Arc-wrap visible to executor/mod.rs:222’s ForeignFunctionHandle::Native(Arc<...>) variant.

Functions

invoke_linked_function

Phase-2c surface stub. Pre-rebuild body marshalled &[ValueWord] args into libffi argument buffers per CType arm, called libffi via Cif::call::<T>, and decoded the return value into a ValueWord via the deleted from_native_* / from_string / from_array(vmarray_from_vec(...)) constructors. Rebuild target signature: &[KindedSlot] -> Result<KindedSlot, String> with per-NativeKind arg dispatch at the body site (§2.7.6) and a kinded result whose NativeKind is sourced from the FFI return CType (post-proof per §2.7.5.1). The vm_stack writeback path for cmut_slice<T> argument writebacks rebuilds against the §2.7.7 parallel (stack: &mut [u64], kinds: &mut [NativeKind]) pair.

link_native_function

Phase-2c surface stub. The pre-rebuild body parsed the textual C signature (fn(<params>) -> <ret>), validated cview<...> / cmut<...> / cslice<...> layout references against the program-supplied NativeStructLayoutEntry table, opened the dynamic library via libloading, resolved the symbol, and built a libffi Cif. The signature parser and layout resolver themselves do not touch ValueWord — they’re preserved as a starting point for the phase-2c rebuild. The library opening / symbol resolution path is also kind-independent.