LithosAnanke/.claude/memory/code-review.md

Code review notes (session 1, 2026-11-11, on StarForth-v4.0.0 @ 06f1d41a)

Per Captain Bob's Law these are FINDINGS TO REPORT, not fixes. Severity is my judgement: H can give wrong results or lose data in a path that runs today; M latent (not reached by the products yet, or needs unusual input); L comments, naming, hygiene.

v4 engine (v4/src) — read: exec.c, node.c, stack.[ch], fabric.c, wire.c, manage.c, heat.c

Overall: careful C99. All arithmetic in v4_ucell (no signed-overflow UB), D-14/D-16 guards before every opcode, the engine is libc-free so the kernel links it unchanged. Comments state the rulings they implement.

• M — manage.c pops and pushes without checking stack depth. v4_manage_serve() takes 1–4 arguments with v4_dstack_pop() and never checks n->ds.depth (contrast v4/system/blocks.c:99, which refuses a block request with too few values — added after the MESH step-6 review found the same hole there). v4_dstack_pop on an empty stack does not fault; it returns whatever is in the ring. So NODE-KILL, NODE-WIRE, NODE-SLEEP etc. typed with too few values act on stale numbers, and the result pushes can saturate a full stack silently. Latent today: only tests call it (products are one node, MESH steps 8–9 not built).
• M — 1u << (V4_PORTS + k) in fabric.c:293 (look_about) is undefined once V4_PORTS > 16; nothing checks it at compile time. This is exactly issue #20, confirmed in code. node.h defaults V4_PORTS to 8.
• L — stale comments, already known: stack.h lines 20–30 ("no overflow detection, and there never will be") (DATASHEET §13 item 4) and stack.c lines 27–30 say the same and hardcode "mod 8" though the ring size is a build parameter (host node 30/31).
• L — heat.c call_index() comment reads as an unfinished thought ("hash-mod or just take low bits? Or simply if in range use it", "ignore for now? Or clamp?"). The code is the documented D-6 stand-in, and ENGINE step-4 Part A (A1) plans to delete call[], the freeze mask and v4_heat_on_call — Part A not started. Under the "no TODO-shaped comments" standing rule this comment is exactly the kind that should not stand.
• L — node.c store/fetch compare against attach registers that are -1 when detached ("no valid address equals"). Safe for opcode paths (addresses are checked first) but a direct C caller passing -1 would hit the console/stack-register branch. Only reachable from C.
• OK, checked: branch target page-relative (iword), unext restart without refetch, resume after blocking, fault cancels resume, store refused by the node does not advance A/P (the 11-02 review fix fd208825), wire put/take/move all-or-nothing, queue pool free list, wire cut gives queues back at both ends.

manage.c finding — confirmed latent (2026-11-11)

v4_manage_serve has no caller outside v4/tests/test_manage.c (grep of kernel/src, v4/system, v4/tools). boot.c:266 serves only blocks and the kernel's word table. test_manage.c tests refusals and depth after, never a request made with too few values. So: real hole, not reachable from a product today; becomes reachable at MESH steps 8–9. A test written first (Bob's rule) would show it.

v4 system (v4/system) — read: boot.c run_line request loop, post.c judge loop, blocks.c guards

• L/M — boot.c run_line, DONE path: after the text ends, for (i < 4096u && !doing && !stopped && !asking) boot_exec(b) — if the node has not settled in 4096 steps the line is reported done anyway, with no sign. Bounded, but a silent cut-off (the method's dominant failure mode). Worth a named check or a comment of why 4096 is enough.
• OK: unknown kernel request → error 12 (D-18), not ignored; port with no one → V4_ERROR_NO_ONE; step limit → STOPPED; POST reads the stack before judging, resets it, reports a stopped node and ends POST.

kernel v4 path (kernel/src/v4) — read: sk_v4.c, sk_v4_mint.c, sk_v4_marker.c, sk_v4_grow.c, identity.c 160–320

• M — MINT-ZUSE says "failed -- nothing changed" when something has changed. failed() is called after gpt_write_one() has rewritten the stick's GPT and after the first 32 Forth blocks are zeroed, so a mint that fails at capsule_zuse_boot_genesis_mint/read-back/marker write has already erased the stick. The message is false on those paths (only the size and YES refusals are truly "nothing written").
• L — secrets left in stack memory on failure paths. sk_v4_mint_zuse wipes seed/rseed only on success; every return failed() after the mint leaves them. sk_v4_genesis (identity.c ~237) never wipes seed/rseed at all, while sk_v4_real_zuse_arrived wipes seed. Inconsistent; the seed is also kept in g_zuse_seed by design, so this is hygiene, not a leak path I can show.
• L — fatal paths spin. sk_v4_run ends in for (;;) { } on "not started", "did not let go of POST's blocks" and "stopped on a fault": a 100% core spin, the thing #151 fixed at the prompt with arch_halt().
• L — sk_v4_grow.c dev_rw4k: (uint32_t)devblock * 4u truncates for volumes past 4 TiB of 1 KiB blocks. Unreachable with the 256 GiB Artemis cap (STICK_ARTEMIS_CAP_GIB), so latent only.
• L — sk_v4_serve ignores request numbers other than 1 and 2 silently; safe because boot.c only calls it for 1..word_count (2), but the guard lives in the caller.
• OK: marker v1/v2 read with CRC and has_real > 1 refused; marker written only after mint read-back (STICK.md 6 order); line editor's over-long line refused whole (not truncated and run); logout ends a waiting line (Bob 2026-10-26); size message buffer sized right (28 bytes incl. NUL).

Not yet reviewed (honest)

identity.c 320–657 (hot-plug, offered stick, beat), gpt.c, usb/xhci.c, usb_kbd.c, hal, boot loader, the rest of kernel/src (kernel_main.c 1986 lines, repl.c — v3 path), v4/system/post_cases.c, text.c, image.c, v4/tools, capsules/v4, tools/mkcapsule.c, scripts/nightly.sh + qemu_session.py, .gitea/workflows, Makefiles, v3.