# CLEAN — GCC
Scanned 2026-03-30 for CWE-407 diamond recursion (O(2^D)).

## Scope

Sparse clone: `gcc/gcc/` — 524 .cc/.c files. Includes `ipa-devirt.cc`,
`dwarf2out.cc`, `tree.cc`, `vtable-verify.cc`, `tree-vect-slp.cc`.
No `cp/class.cc` or `cp/typeck.cc` (cp/ subdirectory not in clone).

## Findings

- `ipa-devirt.cc` — `record_target_from_binfo` recurses over `BINFO_BASE_ITERATE`
  with `matched_vtables->add(BINFO_VTABLE(...))` guard (line 2591). GCC
  `hash_set::add` returns true if already present (inverted from std::set).
  Guard is correctly applied. In addition, GCC's BINFO tree for non-virtual
  inheritance is a tree (not a DAG), so shared ancestors only appear once
  per path. For virtual inheritance BINFOs are shared objects — the
  `matched_vtables` guard prevents re-traversal. CLEAN.
- `tree-vect-slp.cc` — `vect_slp_analyze_node_operations` uses
  `visited_set.add(node)` (returns true if already present = early-out).
  Correctly guarded. CLEAN.
- `dwarf2out.cc` — BINFO base iteration is shallow (direct bases only,
  non-recursive for diamond purposes). CLEAN.
- No `visited.insert()` without `.second` check found in any .cc file.

**Result: No actionable O(2^D) diamond defects in available code.**