Files
sx/examples/1229-ffi-extern-cvariadic.c
agra 9a2c78d6b9 test(ffi-linkage): Phase 5.0 prereq — xfail extern C-variadic tail loses its ...
A trailing `..args: []T` on an `extern` fn must map to the C `...` tail
like its `#foreign` twin (example 1218). Today the variadic handling in
both declareFunction (is_variadic drop) and packVariadicCallArgs
(call-site early-out) is gated on `#foreign` only, so a variadic
`extern` keeps the trailing slice param and slice-packs the extras —
garbage at the C ABI (probe: sum_ints(3,10,20,30) → 53316585, not 60).

Example 1229 pins the DESIRED correct output; the next commit extends
both gates to cover extern and greens it. Prerequisite for migrating the
fn-decl `#foreign` path onto `extern`.

645 corpus (1229 xfail), 444 unit.
2026-06-14 21:03:13 +03:00

448 B