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Chris Tate
81b70b0ee6
* feat: add host-callback channels to library mode - the profile's `callbacks` array declares named channels and `abi.callback_register_symbol` names the one registration entry point: `int32_t <sym>(const char *name, void (*fn)(void), void *ctx)` — 0 on success, -1 for an unknown or NULL name, latest registration wins, a NULL fn clears, registrations persist across init/reset. The stored pointer's typed shape is the channel's with the opaque context first, the panic sink's layout - channel signatures ride the existing marshalling classes: params are f64/bool/string/bytes plus the u8/u32/i32 plumbing classes (outbound plumbing keeps JS's ToUint32/ToInt32, the executable FFI rule); returns are scalar only (f64/bool/u8/u32/i32/void — a buffer return needs an ownership contract the mode does not define). string/bytes parameters arrive as (ptr, len) pairs borrowed for the call's duration - compiled code reaches a channel as a signature-only ambient function declaration whose direct calls deliver synchronously on the calling thread; the recognition rides the FFI import machinery under a library flavor: SC4024 refuses a call the channels cannot serve (undeclared name or off-class signature), unused channels are legal capacity, and callback-free profiles keep the ambient ReferenceError semantics - calling an unregistered channel is the SC4025 runtime trap: a detected trap through the library funnel, so the structured sink message names the channel in its text and the entry the host called in its symbol field, and profile teachings/remediations overlay it like the rest of the runtime family - registration slots are per copy of the runtime state, the sink's story: per-archive under abi.localize_runtime (the register symbol joins the localization keep-list), per-thread instance under abi.instance_per_thread. The host callback must not reenter any library entry or unwind across library frames - both emissions produce identical behavior by construction: the slot store/fetch lives in scr_library.c (scr_library_cb_set/_require/_ctx), the generated TU emits the registration dispatch and typed indirect calls, and the trap text is assembled once at export resolution - callback-free profiles emit byte-identical program TUs and serialized IR, and executable builds are byte-identical end to end - conformance: the CB suite (tests/harness/library-callbacks.test.ts) covers the acceptance stream, unregistered and pre-registration traps, symbol exactness, teaching overlays, SC4024 refusals, capacity and callback-free postures, the localized+thread-instanced composition probe, and ASan reruns; profile-shape refusals join library-profile.test.ts * fix: preserve callback binding identity * fix: harden library callback contracts * fix: recognize project callback declarations * fix: enforce host callback declarations