Hojun-Cho 3d79735964 check: reject a deref-less multi-level **fn call, not silently miscompile (#14) ...

wwstage exprtype's N_CALL fn-value arm peeled ALL pointer levels before the
TY_FN gate, so a deref-less `pf(21)` where pf:**fn type-checked and lowered --
then segfaulted at runtime (a silent miscompile). cstage peels exactly one
level and loud-rejects (the C6a discipline, check.c:1947).

Align wwstage DOWN: peel one level (loop -> if); a remaining non-TY_FN callee
hits a loud "calling non-function" reject mirroring cstage's message. Both
stages now reject the exotic deref-less `**fn`/`***fn` shape; the legitimate
`(*pf)(21)` and one-level deref-less `f(21)` (f:*fn) still compile + run.
Multi-level autoderef is a separate deferred FEATURE, not a miscompile to lower
(rule 7/10 -- align the richer stage down to the leaner, no value ships).

ww-only change (cstage is the correct oracle); a reject emits no asm, so the
byte-id baselines and LANGBYTEID floor are unchanged.

Pins: cfail test/wcc/data/fnptr_pp_derefless_reject (both stages reject,
reddens-on-revert -- the silent miscompile resurfaces if the fix is reverted) +
test/lang/fnptr_derefless_call_test (positive guard (*pf)(21)==42 and one-level
f(21), value-asserted + byte-id, so the fix does not over-reject the legitimate
one-level autoderef).

2026-06-29 15:49:01 +09:00

308 KiB

Raw Blame History

View Raw