The wcc test drivers ran `ww build <bare-/tmp src>` with no -o, so the
compiler's <stem>.sepwork scratch landed beside the source and was never
cleaned: unbounded /tmp growth (2195 stale dirs observed) that fills tmpfs
and fabricates phantom test failures + silent harness aborts, and for
in-repo fixture builds leaked .sepwork into the tracked tree.
Each leaking build now writes its source + output inside a per-invocation
tmpdir, passes -o <tmpdir>/<stem> so the .sepwork lands inside it, and
rm -rf's the tmpdir on every exit path -- including fopen-fail and the
expected-fail reject builds (scratch is mkdir'd before the build can fail).
`ww run` and explicit-`-o`/byte-id helpers are left as-is; the 990/993
byte-id comparison logic is byte-for-byte unchanged.
Two items filed separately (this commit holds the no-Makefile / no-main.c
rail):
- #13: a stale <src>.s byte-id readback (749) silently no-ops since
separate-compile emits .s to <ostem>.sepwork/__root.s; documented inline.
- #14: build-system Makefile recipes build selfhost/cmd/*/main.ww with no
-o and leak main.sepwork in-tree (bounded, gitignored; own commit).
One concern -- sepwork leak hygiene -- across 228 drivers; uniform
transform applied per-file and two-round reviewed. make test: all 402
passed, zero net-new /tmp scratch, zero test-driven in-repo .sepwork.
For an annotation-less `let p = pt{...}` checkletassign planted exprtype's
N_STRUCTLIT result — the struct decl's BODY node (N_TSTRUCT, per #66) — as
the let's type. Every cgen local-arm dispatch (cgdot read, cgassign
tagged-field store, the alias peel) is N_TNAME-keyed, so the body matched
no arm: field reads fell to the module-qualified fallback and emitted the
FIELD NAME as a global symbol (MOVQ f(SB) — link-fail, #211 name-leak
family; silent corruption if a same-named global exists), and a tagged-
field assign fell to the assign-resolver TY_TAGGED loud bound. Both PG5
wwstage symptoms, one root; plain structs leaked too. Normalizing the
inferred binding to the synthesized TNAME (mktname + tinfofornode stamp)
routes every consumer down the already-byte-id annotated path. cstage
needs no twin: check.c:1477 clet carries Sym.type (tinfo) and its
emission is annotation-invariant (probed). Test 811: 10 rows x 2 drivers
+ 10 asm-byte-id; pre-fix wwstage link-fails every unannotated row
(incl. the `...` autofill and parenthesized forms; nested s.f.g ran
but cs!=ww asm).
