wwstage cgen resolved struct LAYOUT by bare-leaf name (structlookup /
structparamsize) at three caller-side sites — the by-value arg push
(cgenutil), the let-receive copy width (cgenstmt), and the field-read
offset (cgenexpr). Under a cross-module same-leaf collision (two modules
each exporting a `pair`, 16B vs 24B) the name lookup first-matches the
WRONG type, so the push dropped the 2nd eightbyte, the receive over-copied,
and the field read the wrong offset. cstage type-keys off the stamped
tinfo and is correct; this aligns wwstage UP to it (ww-only change).
Route all three sites through the stamped node.type_ via a new
structabisizetn(*tinfo) accessor (push + receive) and tichase(type_).fields
(field-read, structlookupchain removed). One commit (rule-11 carve-out):
the collision drives all three at once and no per-site fixture isolates, so
it cannot bisect-split. A scoped slice of the #209/#211 name-keyed-cgen
cluster retirement; the cgdot *struct-ptr/global and let-copy siblings stay
name-keyed and are filed (#31).
New table-driven test 793_xmod_struct_argpush_collide_run (4 scenarios:
push/recv/field over 16B and 12B tails) reddens under a revert of the three
cgen files. Full make test green (336 passed); make sizelint clean.
Hojun-Cho
5ae6e3419e