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.
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.