diamond hunt: godot-0009/0010 + meson-0002 + typeorm-0004/0005 + ts-0003; count 629→635

New diamond recursion defects (O(2^D) → O(N)):
- godot-0009: Font::_is_cyclic no visited set — CJK fallback diamond, 2648x at F=4,D=8
- godot-0010: Font::_update_rids_fb no visited set — duplicate RIDs + O(N^2) hot path
- meson-0002: get_internal_static_libraries_recurse link_whole guard missing — 132x at D=10
- typescript-0003: hasBaseType inner check() no visited set — 1024x at D=10; hot on instanceof

New O(N²) defects:
- typeorm-0004: SubjectTopologicalSorter Array.indexOf dedup — 200x at N=400
- typeorm-0005: DepGraph.createDFS result.indexOf + addDependency edge dedup — 300x at N=600

CLEAN confirmed (diamond recursion sweep): bazel, cargo, cmake, composer, dgl, diesel,
doctrine-orm, efcore, helm, mybatis, networkx-deeper, ninja, npm-arborist, peewee, pip,
rubygems, seaorm, sqlalchemy, swift

UNDF: 571→578 assigned; MOAD count: 629→635

defects/swift/patch/swift-diamond-recursion-CLEAN.md

@@ -0,0 +1,17 @@
+## Diamond Recursion Scan — CLEAN
+
+**Scan date:** 2026-03-29
+**Pattern:** Recursive cycle/dependency check without visited set (CWE-407 diamond recursion, O(2^D))
+
+### Files examined
+
+- `lib/Sema/TypeCheckCircularity.cpp` — infinite-size type check
+- `lib/Sema/TypeCheckDecl.cpp` — declaration type checking
+
+### Findings
+
+**TypeCheckCircularity.cpp:** Uses `llvm::DenseMap<CanType, TrackingInfo> TrackingMap` as a global visited set for the circularity check. The `TrackingMap.insert()` + `isBeingExpanded()` flags prevent re-entry on any previously seen type. Clean O(N) traversal.
+
+**TypeCheckDecl.cpp:** `canSkipCircularityCheck` is a fast early-exit predicate, not a recursive traversal.
+
+### Verdict: CLEAN — no diamond recursion CWE-407 found