Project #78 was ken-flagged: cstage folded size(struct{i32,i32,i32}) to
12 (cmd/wcc/check.c:760, `(off + maxalign - 1) & ~(maxalign - 1)`) while
wwstage walked a slot-padded fsz ladder and yielded 16. The two
checkers ran different layout formulas. d4e500f (#169) closed the
cgen ABI half by introducing structabisize and walking it via per-
field tinfo.align; 39f9267 + 66a91c8 converged the remaining cgen
sites that had picked the slot-padded number. Verified at the size(T)
fold and the .s byte-id on every layout-edge shape.
Add 762_struct_abi_size.c (6 table rows) to lock the closure. Each
row carries a (sz, aln) field table; the expected size is computed in
C via the Hare layout formula (rule 13: no hardcoded size literals —
a formula bump lands in compute_expected and every row tracks). Both
gates run per row: a runtime check that `return size(T): i32` matches
the computed expected on both stages (catches a fold drift), and a
w6c vs w6c_ww .s byte-id (catches a cgen-ABI walker drift even when
the fold still matches — the two walkers are independent SSoTs).
Rows target maxalign edges:
i32_x3_maxalign4 #78 canonical, natural==ABI==12
i32_i32_i64_lead_narrow maxalign 8, narrow lead, ABI 16
i64_i32_i32_sub8_tail #169 sub-8 tail, ABI 16 (the round-up)
i16_x3_maxalign2 maxalign 2, natural==ABI==6
i32_i32_i64_mid_align mid-record align step explicit
i64_x3_natural_24 all 8-wide, natural==ABI==24
GATE POLARITY: this file must stay GREEN. A red here means either
d4e500f reverted, or one of the two layout walkers (check.c:760 /
check.ww:958 / cgen.c struct_arg_size / cgenutil.ww structabisize)
drifted from the formula.
Hojun-Cho
098b58d15c