Wires up reference-counting allocator end-to-end without any
inc/dec emission. Programs run under --alloc=rc and produce
correct stdout (validated against --alloc=gc); they leak every
allocation, exactly like the pre-Boehm era. The point of 18b is
to establish the runtime contract before 18c adds the
inc/dec-emission codegen pass.
runtime/rc.c — new file. 8-byte uint64 refcount header
prepended to every payload; ailang_rc_alloc(size) returns a
ptr to the payload (header at ptr-8). ailang_rc_inc / dec are
declared but never called by codegen yet; they exist so 18c
can wire codegen against a stable runtime ABI. dec frees on
zero refcount but does NOT recursively dec child references —
that's 18c's job once it has per-ctor type info.
crates/ailang-codegen/src/lib.rs — AllocStrategy::Rc variant
added; fn_name() returns "ailang_rc_alloc". Single-line
extension because Iter 18a's bump path had already centralised
the allocator-symbol decision on fn_name() for all four
allocation sites.
crates/ail/src/main.rs — --alloc=rc accepted by Build/Run;
parse_alloc_strategy extended; locate_rc_runtime() helper
mirrors locate_bump_runtime; new Rc arm in build_to compiles
runtime/rc.c with clang -O2 -c and links the resulting .o
into the final binary (no -lgc).
E2E coverage: alloc_rc_produces_same_stdout_as_gc on
list.ail.json (42), alloc_rc_matches_gc_on_std_list_demo for
broader allocation-site coverage. Total e2e bundle: 51 tests
(was 49).
Hand-verified on:
sum.ail.json --alloc=rc → 55
list.ail.json --alloc=rc → 42
borrow_own_demo.ail.json --alloc=rc → 3 then 6
std_list_demo.ail.json --alloc=rc → matches --alloc=gc
cargo build/test --workspace green; git diff examples/ empty.
