libdirs, lflags and inputs were fixed 64-slot arrays written with no
bound check; the 65th -L/-l flag (or input) wrote past the allocation
-> heap corruption. Size all three by argc instead, the true upper
bound since each argv slot yields at most one entry, mirroring cstage
cmd/w6l/main.c:63-67 (calloc(argc, ...)). Drop the now-dead maxinputs
"too many inputs" cap -- cstage has none, and argc-sizing makes it
unreachable.
Regenerates the w6l combined.ww. Table-driven 632 test reaches a lib
only via the Nth -L (N in {1,64,65,100,128}, both stages); pre-fix the
nflags=65 row fails (slot one past the 64-array).
wwstage cgmatch unconditionally spilled any non-ident match scrutinee
-- including an addressable BP-relative N_DOT struct field -- into
@match_spill and dispatched off the copy (frame $48); cstage reads
such a field in place at its BP offset ($32). Both stages were already
runtime-correct (latent rule-10 leanness, not a miscompile); this
aligns wwstage down to cstage so the asm is byte-identical.
The new in-place arm mirrors cstage cgen.c:10241-10296 verbatim: an
N_DOT scrutinee with a bare N_IDENT base whose type chases to a value
TY_STRUCT and whose field is found by name reads tag/payload at
localfind(base)+field.offset. The *ptr-field and call-result cases
stay on the spill path by construction (their base does not chase to
TY_STRUCT) -- no extra guard. A global value-struct base mis-resolves
identically in both stages (localfind returns 0); left untouched as a
shared latent (#29), since a ww-only guard would break byte-id.
Regenerates the w6c and wwdump combined.ww. Table-driven 831 test:
6 rows (local-field, *ptr-field, plain-ident, call-result, payload
remap, str payload) x runtime-both-stages + cs-vs-ww byte-id.
The scanner readahead silently fell through when start==0 and the
buffer was full at maxread, producing no bytes and no error. scanbyte
then spun forever re-requesting bytes that never came (catB-144) and
scanrune nil-dereferenced s.ptr[s.start] (catB-145).
Make readahead the single overflow choke-point: at the ceiling it
returns a bufio-local `overflow` before the grow, propagated through
scanbyte/scanrune/scanbytes (scanbytes drops its now-redundant manual
pre-check). Mirrors ref/hare/bufio/scanner.ha:174-182, which returns
errors::overflow there; ww uses bufio-local overflow because io.error
is a closed enum without an overflow member. Consumers (regex, the 778
embedded source) gain the totality arm.
Table-driven @test crosses {nil-ptr, zero-len} x {scanbyte, scanrune};
neutralizing the overflow return reproduces the catB-144 hang.
The one-sided guard `v > 214748364` never fired for the last digit:
at v==214748364 a next digit of '8'/'9' made `v*10+digit` overflow
i32 and wrap negative, slipping past the signed args-index bound
check at fmt.ww:703 -> OOB arg read -> SIGSEGV on any format
directive carrying an over-i32 digit run (index, width or precision).
Complete it to the canonical two-part pre-multiply Horner guard
(MAX/10, MAX%10). Hand-rolled in signed i32, not Hare scan_sz's
unsigned post-multiply wrap-check (ref/hare/strconv/stou.ha:60),
which would be signed-overflow UB-class here; noted at the site.
Table-driven subprocess test over all three scandigits call sites,
5 rows x both stages; reverting the guard reproduces exit=139.
Compound `OP=` through an index (gs[i]/a[i]) or a bare ident (g) on a
tagged union silently misbehaved: cstage dropped the index compound and
plain-stored, and BOTH stages compiled an ident compound into an add on
the tag word -- byte-identical, so the gate stayed green while the tag
was corrupted. A compound op on a whole union is nonsense.
Gate the index plain-store arm on TK_ASSIGN so a compound falls to the
existing #133 reject (wwstage's byte-id twin); add a dedicated #21 ident
reject in both stages. This closes the compound half of the tagged-payload
write class (deref #18, dot #34 already reject).
#19 (global tagged-array static-init DATA) is a separate emitter, still open.
The wwstage compound-deref arm narrowed the store for scalar pointees and
otherwise emitted a single MOVQ, so `*p OP= v` with p:*tagged clobbered
one word (the tag) and returned -- silently miscompiling what cstage
already rejects. A compound op on a whole union is nonsense. Gate the arm
on a scalar pointee size and let a tagged pointee fall through to the
existing assign-resolver reject, the byte-id twin of the cstage fatal.
cstage is unchanged.
This closes the deref member of the compound-on-tagged class; the index
and ident members (gs[i] OP= v, g OP= v) reject in a follow-up (#20/#21).
The indexed tagged-element assign arm computed its base without the
isglobal -> LEAQ name(SB) branch the scalar element arm already has, so
`gs[i] = v` on a global tagged array stored to a junk frame base and was
lost -- cstage rc=0 where wwstage (which has the branch) rc=42. Mirror
the scalar arm's base resolution; cstage aligns up to wwstage. Local
tagged arrays and scalar globals are unchanged.
The global tagged-array static initializer still mis-packs its DATA in
both stages -- a separate emitter path, filed as #19.
The N_UN/TK_STAR plain-deref assign arm fell to a single fldstoreop for
every pointee, so `*p = v` with p:*tagged wrote the rhs into the tag word
and never the payload -- identically in both stages, leaving the byte-id
gate green while the store corrupted the tag (#263-class, gate-blind).
Gate on TY_TAGGED and route through cg_widen_tagged_store into a scratch
slot, then word-copy to the destination -- the proven runtime-index arm.
Scalar pointees keep the single-store path unchanged.
A module-level nullable `(*T | void)` GLOBAL has no storage path in
either stage: let_emit_size / letemitsize returned 0 for the nullable
TY_TAGGED, so let_collect skipped registration and emit_lets skipped
DATA. The three READ paths then miscompiled SILENTLY and identically-
wrong (a #263-class both-wrong gap, not a wwstage align-up): match read
0(BP) = saved BP via the let_islet-gated #87 arm falling to localfind;
`g is *T` / `g as *T` emitted MOVQ name(SB) for a symbol with no DATA →
w6l undefined-reference. cstage's #87 match arm was itself `!is_nullable`-
gated, so both stages were wrong.
This is the silent→loud bridge: die loud at the size/storage layer the
instant a nullable global is declared, so all three read paths hit one
diagnostic instead of a silent miscompile. A silent gap here is exactly
what "stable before CSP" forbids — CSP's process/handle/chan singletons
(`let c: *Chan | void`) are THE canonical nullable-global consumer. The
full storage + read-class arc (real DATA, nil/void/address-of init, let-
registration, the three SB-resolution read arms) is deferred to task #15
(CSP-prereq); the `&`-init sub-problem additionally couples to the #48
static address-of relocation gap (which already bites a plain `*T` global
init the same way).
Diagnostic core text is identical both stages ("nullable-global storage
unimplemented (task #15)"); cstage's fatal() adds the harness-wide "ww: "
err.c prefix err.ww does not, the same per-stage asymmetry every existing
both-stage reject carries. Byte-id-neutral: the corpus declares zero
nullable globals (grep-verified), so the loud path is unreached in self-
compile and the emitted asm is zero-move; the embedded w6c/wwdump
combined.ww amalgamations are regenerated for the cgen.ww source change.
New 989_nullableglobal_reject: 6 reject rows (match/is/as on a &gv init,
plus nil-init and void-init match, plus an inline non-aliased nullable
form) prove rc!=0 + the shared diagnostic on both stages, init- and
form-invariant; 2 controls (non-nullable tagged global, plain nil-init
*T global) prove the reject is keyed on the nullable TY_TAGGED and the
#87 storage path is untouched.
A `x.f = o` copy of a whole struct field emits a MOVQ run for the
8-byte chunks plus a tail. Both stages inlined a tail that handled only
{4,1}: a 4-byte remainder went MOVL, a 1-byte MOVB, but {2,3,5,6,7} fell
through to an 8-byte MOVQ that OVER-READS the source and OVER-WRITES the
field's natural-offset successor. With #44 packing a successor at its
natural offset, that is a live clobber: outer2{i:inner2{u8,u8}, mark:i32}
copies i with `MOVQ -8(BP),AX; MOVQ AX,-16(BP)` and wipes mark@-12; the
correct move is a single MOVW. Same defect in cstage (cgen.c) and the
four wwstage field-copy sites (cgenexpr.ww: via-ptr, direct-BP-local,
global, and the multi-hop dot-chain CX variant).
Fix: replace each inline {4,1} tail with the descending greedy 4/2/1
(MOVL/MOVW/MOVB) the canonical aggregate-copy emitters already use, so
the tail is complete on every natural size. This is path (alpha) of the
#73 brief — a corpus-neutral, no-workaround completion of the inline
tail. Routing field copies through the shared aggcopy/cg_aggcopy choke-
point (beta) is the balloon: those emitters hardcode (SI)->(BX) at offset
k with zero base displacement, but the four field-copy dsts are
heterogeneous (foff(BX), boff+foff(BP) with no base reg, totaloff(CX)),
so routing forces per-site-per-stage LEAQ src->SI + LEAQ dst->BX rewrites
with no mechanical cross-stage mirror at the CX site = a gate-blind
cs!=ww risk. The emitter extraction is filed as a later addressing-
unification arc (#12). The ragged tail is corpus-absent (every corpus
field copy is tail in {0,4}, where greedy 4/2/1 emits exactly what the
old {4,1} tail did), so this is CLASS-N: zero corpus move on both stages,
byte-id holds by construction.
The cstage <=24 N_CALL receive site (cgen.c:5234) is a different copy
family (sret result read from AX/DX/CX, not a mem-to-mem field copy) and
already handles 4/2/1; left untouched. The str/slice/tagged/tuple 4/1
sites (#76) are likewise a separate family, filed not folded.
989_structcopytail_run pins it on both driver twins: tail2 (MOVW), tail6
(MOVL+MOVW), tail7 (the full MOVL+MOVW+MOVB ladder, the MOVB-path row),
plus an 8-aligned ctl8 (tail-0 control). Pre-fix cstage clobbers mark and
exits non-zero -> cs!=ww; post-fix 4/4 ok cs==ww.
wwstage's slotsize() shared its TY_STRUCT arm with TUPLE/ARRAY and
returned ti.slotsize — the SUM of the slot-padded field widths. For a
struct LOCAL that over-reserves the frame slot whenever a field is a
sub-8 nested composite: a nested inner{x:u8,y:u8} (size 2, slotsize 8)
pads its in-struct footprint, and the local inherits that pad. cstage
has no slotsize SSoT — it reserves the local at f->type->size, the
checker's NATURAL r.size (cmd/w6c/cgen.c). So on outer{a:u8,
p:inner{x:u8,y:u8}, z:i64} wwstage emitted frame $32 / struct-base
-24(BP) while cstage emitted $16 / -16(BP): a uniform -8 BP shift on
every field access. Both stages exit 0 (each self-consistent), so it is
runtime-invisible — but it is a cs!=ww .s divergence (rule 10) and a
latent byte-id gate-landmine the day such a struct enters the corpus.
Same dual-SSoT leak as #44 (field-OFFSET) / #55, one notion over:
struct-local-slot-SIZE.
Fix: split the TY_STRUCT arm out and return round8(ti.size). The TUPLE
arm (8B/elem slot, user ruling #60) and the ARRAY arm (element stride,
#48 [N]Alias 24B) keep ti.slotsize — those are deliberate, ruled
divergences and are untouched. The struct-local slot consumers
(cgendecl.ww letslotsize via cglet, cgenstmt.ww) all flow through this
arm; si.totsize (registerstruct → structabisize / global-emit) is a
separate consumer and is not this path.
CLASS-N corpus-neutral: every corpus struct local is 8-aligned, so
round8(ti.size) == slotsize for all of them and the w6c_ww/wwdump_ww
emission does not move (994 byte-id on 18 corpus inputs + 995 5-tool
self-rebuild both green post-fix). 989_structlocal_frame is the
FRAME-ABSOLUTE proof (w6c vs w6c_ww .s byte-diff; nested3 + tail_u32 +
flat control) — the .s twin of the runtime 989_nestfield_run, which
deliberately does not gate the frame and points here for it.
wwstage carried TWO struct-layout sources. registerstruct (cgenutil.ww)
recomputed each field's `fi.foff` via fieldsize — slot-padded, round-8 —
for the WRITE (construction / field store) path, while the READ path
(cgplaceaddr / dotbaseaddr) used the checker's natural `tfield.offset`.
They diverged iff a struct had a nested sub-8 composite field
(slotsize != size) plus a successor: ww wrote the successor at the
slot-padded offset and read it at the natural offset, mis-addressing its
own field. cstage has no structinfo and reads tfield directly, self-
consistently natural (cmd/w6c/cgen.c).
Fix: make `fi.foff` a VIEW of the checker's already-built natural layout.
Lock-step walk tstruct.list (AST N_TFIELD) and ti.fields (tfield) — both
head-first declared order, both skip non-TFIELD identically — and copy
foff = tf.offset, fsz = tf.type_.size. si.totsize keeps the slot-padded
stack-slot number (ti.slotsize, already 8-rounded at check.ww:2259).
fieldsize is no longer called here (its `*p OP=` scalar-width caller is
untouched). LOUD nil-guards on tstruct.type_ / tichase / a tfield walk
desync — all unreachable post-check, never silent. fi.tnode stays the
AST node (its node-keyed readers need it); repointing the ~60 fi.foff
readers to tfield is the out-of-scope (ii-b) follow-up.
This unifies ww's second source onto the value cstage already emits, so
cs==ww is preserved, not newly created (wwstage-cgen only; no cstage
edit). The shape is corpus-absent — ww uses both sources on its own
structs, so a divergent struct would have broken the bootstrap — hence
gate-blind; 989_nestfield_run is the proof (nested inner{x:u8,y:u8} in
outer{a:u8,p:inner[,z:i64]}, every field read back == written, dual-stage
cs==ww). It also makes 681 ragged_tail_12B genuinely correct: the
predecessor #71 already shrank the whole-struct copy to the source's
natural length, so packing mark at natural offset 12 no longer clobbers.
w6a's parsenum diverged from the C twin's strtoll(s,end,0)
(cmd/w6a/lex.c:30) on three hand-written-asm edge shapes (all
gate-blind — w6c emits the canonical $5/$8/-8(BP), never these):
(a) `$ 5` — leading whitespace: strtoll skips it (->5); ww had no
skip and silently encoded imm 0.
(b) `$08` — strtoll base-0 reads a leading 0 as octal, stops at '8'
(->0); ww parsed it as decimal 8.
(c) `-(BP)` — strtoll/cstage require a digit after the sign, so a bare
`-(` is unrecognised operand; ww silently took it as 0(BP).
Add the whitespace skip + octal base-0 detection to parsenum, and the
digit-after-sign guard to the operand scanner — both assemblers now
agree byte-for-byte (a/b) and both reject (c).
Not a Hare item (w6a is ww's plan9-lineage assembler); reference is the
C strtoll twin. w6a embeds into its own combined.ww snapshot; regen'd.
530_w6a_parsenum pins the byte-identity + both-reject matrix.
dirs build() capped the composed path at the 256B pathbuf with a silent
break, so a HOME (or XDG_*) near/over ~240 bytes produced a truncated
path that lookup() then mkdir'd and returned rc=0 — a silently-wrong,
freshly-created directory. ref/hare/dirs/xdg.ha routes through
path::set/push whose too_long error the `!` aborts loudly. Precompute
the composition length in build() and rt_abort when it won't fit; drop
the now-dead silent caps. (Shape (a); routing dirs through lib/path is
the filed fidelity follow-up.)
975_dirs_toolong_run pins the abort + no-stray-dir on both driver twins.
parsefile's recovery fallback chewed an unrecognized top-level
construct to the next ';' without emitting an error or bumping p.errs,
so a typo'd keyword / stray token silently vanished from the AST and
the build succeeded rc=0 with the declared work gone — no link error
catches a dropped @test or unreferenced exported fn. The C twin
(parse.c:1395-1400) errorf+p->errs++ and rejects. Emit errmsg in the
fallback arm; wwstage now rejects in lockstep with cstage.
lib/ww embeds into the w6c/wwdump combined.ww snapshots; both regen'd.
989_unknowndecl_reject pins the reject-matrix on both driver twins.
wwstage parseint dropped the pre-multiply overflow guard the C twin
carries (cmd/wcc/lex.c:156, if (v > (u64)~0ULL / (u64)base)), so any
integer literal exceeding u64 was silently accepted mod 2^64 while
cstage loudly rejected with 'bad integer literal' — a rule-10 stage
divergence and a silent wrong constant. Port the guard before the
multiply-add; wwstage now rejects in lockstep with cstage.
lib/ww embeds into the w6c/wwdump combined.ww snapshots; both regen'd.
989_intoverflow_reject pins the reject-matrix on both driver twins.
When the dynamic section pushed the header past the first page, the
entry point kept its first-page address — every sufficiently large
dynamic binary SIGSEGV'd into the headers. Recompute e_entry as
entry - 0x1000 + text_off in both stages (ELF: the entry must point
into .text wherever it lands). Both stages move in one commit: one
ELF contract; the 989_dynentry gate pins the field and the run.
A DATAR relocation against an undefined data slot was silently
dropped — the relocation vanished from the object. Reject loudly,
matching the cstage single-pass resolution behavior.
wwdump's -c/-r modes emitted output from a garbage parse silently.
Gate on the parse-error count first (the w6c main gate, main.ww:162);
wwstage-only — the C wwdump has no -c/-r modes.
The wwstage driver silently dropped directory entries past a 256
cap; the cstage twin already grows by realloc-doubling. Grow the
same way (seed 8, double) so both stages agree on any directory size.
wwstage's unguarded loop-label push wrote out of bounds at depth 17
(compiler-heap corruption); cstage guarded but emitted a wrong break
target. Loud cap error at the limit, both stages, agreeing wording.
wwstage capped defers at 16 and SILENTLY DROPPED the 17th; cstage
capped at 32. Align the cap at 32 and make exceeding it a loud
compile error in BOTH stages — the silent 16-vs-32 split was the bug
(a defer that never runs is a leaked resource). Both stages move in
one commit: one cap contract.
The try-operand resolution used bare lookups (ident + bare-leaf call);
a cross-module same-leaf collision mistyped the operand. Prefer the
current module. The historic 995 byte-id break attributed to this swap
was contamination from the guard-bug-carrying bundle — re-probed clean
in isolation and at the full stack. The N_DOT module-keyed leaf stays
task #51. Report item [11], lookup half.
The address-of-fn synthesis used a bare lookup — import order could
bind a same-leaf fn from another module, silently LEAQ-ing the wrong
function into a fn-ptr slot. Prefer the current module (mirror
check.c:410/1305). Report item #4 (loud and silent faces pinned).
A type lookup in a bundled build resolved to the newest-installed
same-leaf symbol from ANY module; prefer the current module first
(mirror cstage sym.c:131; the prior attempt's failure was its own
u64-vs-i32 guard bug, not a deeper layer — probe-proven). Also adds
the rule-7 #58 notes at the latent varianterr/scruttype pair and
rewrites the stale deferral block to closing cites. Report item [5].
Passing buf[1:] of a [MAX]u8 as a call arg dropped the default-hi
length (the arg-push N_SLICE arms' fallback covered only named-alias
bases). Same type-table resolve at pushargsrev local+global. This
closes the def-dim dimension family by construction: every N_INTLIT-
keyed dim consumer (cgslice, cgdot, letemitsize, arg-push) now
carries the tichase().alen fallback — grep-proven, no consumer
remains. Fourth member surfaced by the family grep.
buf.len on a [MAX]u8 returned 0 — the cgdot len arms (local/global/
def) and letemitsize only read an N_INTLIT dimension. Route a
non-literal dimension through tichase().alen (the #21 fix mirrored
into the field-read consumers; .ptr arms are dim-independent).
Review-era task #56.
alloc(alias{...}) keyed the size and field-fill off the syntactic
alias name — it under-allocated and emitted zero field stores. Chase
the alias via structlookupchain to the resolved struct (depth-2
chains verified). The scalar else-branch keeps its pre-existing
benign cs!=ww divergence, surfaced here and deferred as task #57
(site note at the arm). Review item #26.
The ?/! success-is-str decision was name-keyed off the FIRST variant
and only handled call operands — an ident operand with junk registers
unwrapped garbage, and error-first unions picked the wrong variant.
Key on the stamped success variant (successvariant + typeisstr,
mirror cgen.c:10459-10466/10595-10602). Review item #16.
Slicing an array whose dimension is a def constant gave len 0 — the
default-hi and cgbasecap arms only read an N_INTLIT dimension. Route
the dimension through the type table (one root, four arms: default-hi
and cgbasecap, local and global each), byte-identical for the def-dim
SLICE shape. The def-dim array .len/.ptr FIELD-read keeps the
N_INTLIT-only limitation — filed as task #56 (cgdot sibling).
Review item #21.
The unspecified tail of a short array literal repeated the last value
instead of zeroing — wwstage only (cstage already zeroes; the review's
both-stages reading didn't survive ground truth). Zero-fill the tail
per the zero-value semantics ruling. Review item #13.
The str-size arm of the global data emit was size-keyed and matched a
24-sized array, emitting a second DATAW for the same symbol. Gate on
the array kind (!isarr8). Review item #12.
A tagged for-range destructure binding took the 8-byte default
(paramfieldsize had no tagged arm), skipping the full-extent copy —
the wwstage twin of the just-closed cstage destructure family. Read
the stamped tinfo size through the type table (twin of the slice
arm; cstage reads tp->type->size). Task #53.
The per-binding copy loop moved ONE word of a 24B str/slice binding —
.len and .cap read zero/garbage in BOTH stages (byte-identical, the
deepest both-wrong-identical of the drain: the F7-era stride fix
asserted convergence without re-measuring the absolute). Copy the full
extent for an sz>8 str/slice binding; the rewritten 989_tupfieldsize
pins all three header words with sliced caps so cap!=len has teeth.
The tagged-binding arm remains open as task #53 (wwstage
paramfieldsize). Review-era task #40, recategorized #263 fused.
Both stages move in one commit: one emission contract; splitting
would leave the byte-id gates red between the halves.
cstage dereferenced 0(BP) for the base — a SEGV on every store
through a module-global struct pointer; wwstage was already correct
(the inverse-set member). Mirror ww's global-pointer load. New
989_globptrfield_run pins cs==ww both stages. Task #47.
cstage's N_TYPEASSERT assumed cgexpr filled the registers and spilled
an uninitialized payload (cs=0 for any stored value); mirror the
landed wwstage emission (tag/payload/cap from g(SB)). Flips the
residual row to cs==ww==correct. Task #46.
cstage spilled frame garbage as the box; mirror the landed wwstage
emission (copy from gi(SB)). The F8-era divergence-only rows gain
pinned cs==ww values. Task #44.
cstage zeroed the return scratch; mirror the landed wwstage emission
(copy from the g(SB) base). Flips the F8-era residual row to
cs==ww==correct. Task #42.
cstage silently dropped the store on reassigning a module-global
tagged union; mirror the landed wwstage emission (tag+payload to
g(SB) via the widener). Closes the cs half of the F8 #263 pair; the
repro row flips to cs==ww==correct. Task #41.
Widening a runtime f64 into a tagged slot pushed a stale AX as the
payload while the value sat in X0 — both stages shared the push bug
(float literals dodged it because TK_FLOAT loads AX too); the
divergent pop sides then produced different garbage. Spill the
payload from X0 (MOVSD) with the variant tag. Review item #49.
Both stages move in one commit: one emission contract; splitting
would leave the byte-id gates red between the halves.
The arg-drain loop checked node_isfloat before popping a widened
arg's GP words, so a float arg adjacent to a widened (tagged) arg
read the wrong stack slot: the f64 took the widened payload (#30), or
the float arm ate the tag word into X0 and the payload landed in DI
as the tag (#48). One missing branch, two manifestations — mirror
cstage's widen-first pop (cgen.c:9650-9665). Review items #30+#48
(fold reviewer-verified one-mechanism against the cstage twin).
A str field reached through a chained dot (o.i.s) emitted two loads
(ptr, len) and stored a stale CX as the cap — both stages, at any
non-zero chain depth. Emit the full header at the chained-dot leaf.
Review item #29.
Both stages move in one commit: one emission contract; splitting
would leave the byte-id gates red between the halves.
Reading a slice-typed tuple element (t.0) loaded only the pointer
word; len and cap took whatever was left in BX/CX — silent garbage in
BOTH stages once anything clobbered the registers between build and
read. Load all three header words at the tuple-element arm. Review
item #28.
Both stages move in one commit: one emission contract; splitting
would leave the byte-id gates red between the halves.
Casting a global str to []u8 dropped the cap=len synth (the trailing
MOVQ BX,CX) — the synth was gated on a local-ident source shape.
Key it on the source type so local/global/field/call sources all get
the header. Review item #19.
s.f *= v silently became s.f = v (and the other non-+=/-= ops dropped
likewise) in BOTH stages across five lvalue sub-arms: via-ptr field,
direct local field, str/slice pseudo-field, and the two global-field
forms. Funnel all five through a shared combine dispatch
(cgdotfieldcombine / cg_dotfield_combine) emitting the load-OP-store
sequence at field width, hard-erroring the unhandled kinds — close-by-
construction so no arm stays on the old PLUSEQ-only path (the #133
BUS-routing lesson; #227 sites A/B are the closed siblings). The
refactor routes the corpus's existing +=/-= sites through the same
helper output-identically (byte-id held). Review item #34.
Both stages move in one commit: one emission contract; splitting the
halves would leave the byte-id gates red in between.
arr[i].field /= %= <<= >>= silently dropped the op (load-combine-store
emitted plain assignment) in BOTH stages — gate-blind, the #133 class.
Route every compound op through the combine dispatch at the indexed-
field arm and hard-error the unhandled operand kinds (float/str/slice/
tagged), per the #133 template (3986818). The runtime-correct target is
the op's own algebra (a OP= b == a = a OP b). Review item #33.
Both stages move in one commit: the fix is a single emission contract —
splitting cstage cgen.c from selfhost cgenexpr.ww would leave the
byte-id gates red between the halves.
'as' on a nullable value compared the pointer itself to a tag (the
missing arm). Mirror cgtypetest's nullable fold and the cstage twin
(cgen.c:10694). Review item #17.
Try-propagation on a nullable value fell to the tagged path and
compared the pointer to a tag — the null check came out inverted.
Mirror ww's own cgtypetest nullable fold (cgenexpr.ww:652) and the
cstage twin (cgen.c:10366/10504). Review item #15.
