A `{.ffi.}` proc that returns a registered struct now delivers it natively
instead of CBOR-encoding it. The FFI-thread handler builds the return's
`<T>Pod` mirror on the heap (`nimToPod`) and stashes it on the request; the
callback receives it as a typed `const <T>*` (msg = pointer, len = sizeof), and
handleRes deep-frees it the instant the callback returns — callback-lifetime
ownership, the caller frees nothing.
Mechanics: FFIThreadRequest gains respPod/respPodLen/respPodFree fields that
handleRes honors ahead of the byte payload; the macro emits a per-proc
cdecl freer (`freePod` + `ffiCFree`) for the response POD. String and
seq[byte] returns still travel as raw bytes; the CBOR path (`<name>_cbor`) is a
separate handler and is unchanged. The C header documents the new return shape.
Validated end-to-end from C (EchoResponse, ComplexResponse with nested
seq/option graphs) including under ASAN — no UAF or double-free.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The native (zero-serialization) path previously handed `{.ffi.}` struct
params to the FFI thread using the Nim object layout (GC'd `string` fields),
which does not match the C-POD layout the generated header declares — an ABI
mismatch that left struct-param procs uncallable from C and skipped by the Go
codegen.
Wire the generated POD machinery into both the `{.ffi.}` and `{.ffiCtor.}`
native paths: a registered `{.ffi.}` struct now travels as its `<T>Pod`
mirror — `clonePod` deep-copies it off the caller's buffers into shared
(`c_malloc`) memory on the caller thread, `podToNim` rebuilds the Nim value on
the FFI thread, and `freePod` releases it from the CArgs free proc. `string`
collapses to `cstring` (alloc/ffiCFree); scalars copy direct. New classifiers
(`nativeWireType` / `nativeArgCopyStmt` / `nativeArgUnpackStmt`) keep both
paths and the CArgs alloc/free in lockstep so ownership can't drift.
The load-bearing invariant: the `<T>Pod` `{.bycopy.}` layout is identical to
the C struct emitted by `codegen/c.emitCStructs`, so the `exportc` symbol's
ABI matches the header even though Nim's own struct name differs. Keep the two
emitters in sync.
Validated end-to-end from C (TimerConfig, EchoRequest, and a nested
ComplexRequest with seq-of-structs, seq-of-strings and two Options) and clean
under ASAN. Struct *returns* still travel as CBOR on the native path; that is
left for a follow-up.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
A single {.ffi.} definition now produces BOTH interfaces, chosen by the
caller at link time rather than by a global compile flag:
- `<name>` — native typed-arg C export. Args travel to the FFI thread in
a c_malloc'd C-POD struct passed by pointer (no CBOR), and the
result is delivered to the callback as raw bytes. This is the
preferred path for same-process callers: no serialization on
either side.
- `<name>_cbor` — the existing CBOR-buffer dispatcher, kept for generic /
cross-language callers.
Both share the user's helper proc; they register distinct handlers keyed by
"<Camel>Req" (CBOR) and "<Camel>ReqNative". FFIThreadRequest gains a `cborMode`
flag and a `payloadFree` hook so the native C-POD payload (which owns duplicated
cstring fields) is released correctly and an empty native result is delivered as
a zero-length buffer instead of the CBOR null sentinel. alloc.nim gains
ffiCMalloc/ffiCFree (prefixed to avoid Nim's style-insensitive clash with
ansi_c.c_malloc/c_free).
Verified end-to-end on a scalar-param lib: native calls return raw strings
("calc v1", "sum=42"); the _cbor variant still returns CBOR.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
0.2.0 carries each request as a single CBOR buffer over the exported ABI,
which is awkward for hand-written host bindings (every consumer would have
to encode CBOR and decode responses by hand). These two generators emit
ergonomic, ready-to-use bindings from the same {.ffi.} registry the C++/Rust
generators already consume.
- c.nim (targetLang=c): a self-contained <lib>.h with a small CBOR encoder,
ffi_decode_text(), and `static inline <lib>_<proc>(ctx, cb, ud, args...)`
wrappers that CBOR-encode and forward to the real export. The wrapper keeps
the export's source name but is given a distinct symbol via an __asm__ label
so the raw export's asm alias doesn't bind back to the wrapper (which would
recurse). Scalar/string params only; others fall back to the raw CBOR decl.
- go.nim (targetLang=go): a single <lib>.go cgo package that #includes the
generated <lib>.h and adds a condvar-backed response capture. This is the
key bit: 0.2.0 removed the synchronous fast-path, so a caller can no longer
read a result right after the call — the generated bridges block on the
callback, turning each async export into a blocking Go method. Also emits a
go.mod for importability.
Wired both into genBindings dispatch (targetLang "c"/"go") and added
genbindings_c / genbindings_go tasks. Both verified end-to-end against a
scalar-param test lib (build + run) and the real libwaku surface.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
