A PLAIN (non-alias) module-level tagged-union global SEGV'd on BOTH
stages: no static DATA was emitted (let_emit_size/letemitsize returned 0
for TY_TAGGED) so the global was never registered, and the match
scrutinee resolved it as a frame-local at offset 0 — reading saved BP as
the tag. Two sub-sites, one route (neither half ships alone — DATA
without SB-resolution still SEGVs; SB-resolution without DATA reads
nothing):
(a) DATA-emitter — a non-nullable TY_TAGGED arm emits the box that
byte-MIRRORS a runtime LOCAL of the same type: tag word at +0 (the
const-selected variant index via cg_tag_for_variant / taggedvariant-
index), payload at +8, zero-padded to the union box size. int and
str/slice literal variants are wired (str carries a DATAR ptr patch
at +8); any other variant payload loud-stops (rule 7). emit_tagged_
data + emittaggeddata are the per-stage twins; let_pre_intern/
letpreintern gain the matching str-variant intern. Nullable stays 0
so the (*T|void) one-word fold keeps the 8B scalar arm.
(b) match-scrutinee global resolution — the PLAIN-tagged twin of #78:
a global tagged ident scrutinee LEAQs name(SB) and copies the box
into an @match_spill slot the dispatch indexes off BP.
DATA target (mirror of the local box, verified byte-for-byte): for
(i32|str)=42 the 32B box is tag0 | 42@8 | zero-pad; for ="x" it is
tag1 | ptr0@8(DATAR _S_n) | len@16 | cap@24. cs and ww emit byte-
identical asm.
Pins (rob §3, dual-stage 910 cstage + 997 wwstage, attest_pass.ww): the
tagged global-vs-local byte-identity pin (match over the GLOBAL gives the
same arm/value as over a LOCAL — was SEGV both stages) and the str-
variant tag-1 pin, plus the #86 tuple global-vs-local lock-pin guarding
the already-correct emitter path.
929 fail_global_src graduates: a >48B tagged GLOBAL by-value arg now
resolves through the cgplaceaddr MEMORY-class arm (LEAQ g(SB) + blit)
instead of the #38b loud-stop, and runs correctly (uninit zero box ->
first variant); the row becomes a positive run pin. The struct-variant
>48B init still loud-stops via the data emitter.
The first-class-VALUE copy of a tagged ident (`let q = g`) stays a
pre-existing silent #49/#46 sibling (local and global identically),
filed separately — out of this fold's two sub-sites.
Hojun-Cho
4459a49d3a