FFI Code Review

Review Workflow

1. Check Cargo.toml -- Note Rust edition (2024 has breaking changes to extern blocks and unsafe attributes), build-dependencies (bindgen, cc, pkg-config), crate-type (cdylib, staticlib), and links key
2. Check build.rs -- Verify link directives (cargo:rustc-link-lib, cargo:rustc-link-search), bindgen configuration, and C source compilation
3. Check extern blocks -- Verify calling conventions, symbol declarations, and safety annotations
4. Check type layout -- Every type crossing FFI must be #[repr(C)] or a primitive FFI type
5. Check string and pointer handling -- CStr/CString usage, null checks, ownership transfers
6. Check callbacks -- extern "C" fn pointers, panic safety across FFI boundary
7. Gates -- Complete Gates below before reporting; do not skip ahead on “internal verification”

Gates

Complete in order. Do not emit findings until Gate 4 passes for each issue.

Gate 1 — Crate context (on disk)
PASS when: You opened the reviewed crate’s Cargo.toml (workspace member path if applicable) and recorded edition =, plus any of links, crate-type, or build-dependencies that matter for this FFI.
Blocks rationalization: Edition-specific findings (unsafe extern "C" {}, #[unsafe(no_mangle)], etc.) require this — if edition is not 2024, do not flag 2024-only requirements.