- Language enum: Unknown, Rust, Cpp, Swift on RustExprNode
- 4 new Clang node kinds: ThrowExpr, CXXConstructExpr, LambdaExpr, StmtExpr
- Updated json_keys namespace with new constants
- 42 roundtrip test assertions pass
- All 3 frontends now share the same IR representation
First non-clang frontend for fold. Scans Rust source for the
subset of issues that meaningfully exist there: raw-pointer
dereferences in `unsafe` blocks (Heuristic confidence) and
within-Rust Type-1/2/3 clones via the existing clone detector.
Reuses the M30 frontend-agnostic IR + AnalysisBackend
abstraction unchanged.
Architecture: a separate `tools/fold-rust` cargo binary that the
C++ `RustBackend` shells out to. Two subprocess invocation
modes:
- `extract --unit <file>`: standalone .rs file, no Cargo
context (limited; external-crate imports won't resolve).
- `cargo-check --crate-dir <dir>`: invokes `cargo check` with
RUSTC_WORKSPACE_WRAPPER set to ourselves so cargo supplies
the full --extern/-L/--cfg per-TU. Mirrors the
clippy/miri/kani pattern.
RustBackend::discoverUnits walks up from each `.rs` input to
find the nearest Cargo.toml and collapses sibling files to one
crate unit; orphan files fall back to single-file extract.
scan_router auto-detects --mode=rust when all paths are `.rs`;
mixed Rust + C/C++ warns and defaults to source mode.
Includes:
- tools/fold-rust/: cargo crate pinned to nightly-2026-05-22.
HIR-driven DerefHunter (raw-pointer dereference detection
via typeck `is_raw_ptr()`) and HashWalker (FNV-1a + mix64
port of src/ir/normalize.cpp for FunctionSummary hashes).
- include/fold/ir/expr_json.{hpp,cpp}: RustExprNode +
RustNodeArena + bidirectional JSON wire format for
ir::Expr; round-trip tested across 8 Kinds.
- include/fold/frontend/rust_backend.{hpp,cpp}: AnalysisBackend
impl. posix_spawnp + NDJSON parser. Caches summaries +
findings across extractFunctions calls; polymorphic
runDetectorsOnShard dispatch routes summaries to
detectClones.
- src/cli/{main,scan_router,scan_runner}.cpp: --mode=rust
branch + autoDetectRust(). Mode validation extended to
accept rust.
- docs/rust-frontend.md: scope, wire format, rustc-private
pin + bump procedure, verification snippets.
44/44 unit + integration tests still green. Verified
end-to-end on a 3-function rename-pair fixture: 1 clone
cluster + 1 raw-deref finding through both `extract` and
`cargo-check` paths.
Out of scope (tracked separately): equiv + class-dup
detectors (need encoder frontend-agnostification),
dead-statement (needs Rust CFG), cross-language clones
(needs unified kind-tag taxonomy), Proved/ConcreteWitness
promotion (needs encoder integration), `cargo fuzz`
harnesses.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
