fix(sight): sync FFI header + drift guard + example#667
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cbindgen 0.27 does not recognize Rust 2024's `#[unsafe(no_mangle)]` and silently skips every exported function, so cbindgen.toml's `after_includes` block hand-maintains the C declarations. That block had drifted from src/ffi.rs: declared the deleted `agentsight_config_add_domain_rule` and was missing `agentsight_config_add_https` / `agentsight_config_add_http`. Re-sync the declarations to match the actual 16 FFI exports and rewrite the NOTE to (a) separate the two independent workarounds in play (`item_types=["structs"]` is required for a clean public header, even once cbindgen learns the new attribute), and (b) flag that any drift guard built on top will catch NAME divergence only — signature drift (return type, parameter types/order) still has to be kept in lockstep by hand. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The hand-maintained C declarations in cbindgen.toml have no automatic check against src/ffi.rs, which is how the header silently fell out of sync in the first place. Add a build-time guard that extracts every `pub [unsafe] extern "C" fn agentsight_*` from ffi.rs, every `<type> agentsight_*(` line from the generated header, and panics with the symmetric difference (missing-in-header / stale-in-header) when the two name sets disagree. Runs in build.rs so no .github/workflows change is needed. Reverse-tested three drift modes that the guard must catch — deleted declaration (count delta), renamed function (count preserved), and duplicate-with-drop (count preserved): all panic with precise lists. The previous count-only guard would have silently passed the latter two. The guard panic message and the cbindgen.toml note both explicitly say NAMES only — signature drift (return type / parameter types / order) is not detected and must still be maintained by hand. Also adds a crate-local .gitignore for the generated include/ so a `git add .` from the repo root cannot accidentally stage it. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
`agentsight_config_add_domain_rule` was removed from the FFI surface (split into `add_https` for SSL probe attachment and `add_http` for plain-HTTP capture); the example was still calling the deleted symbol and would not link. Switch to `add_https` (the same semantics as the old domain rule) and add the missing `-I./include` to the docstring gcc command so copy-paste compiles. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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FFI header sync fix (161 lines). Ensures cbindgen output stays consistent with Rust API changes. |
chengshuyi
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Jun 8, 2026
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What
The hand-maintained C declarations in
cbindgen.toml'safter_includesblock had drifted from the actual FFI surface insrc/ffi.rs:agentsight_config_add_domain_ruleagentsight_config_add_https/agentsight_config_add_httpexamples/agentsight_example.cstill called the deleted symbol (would not link)Root cause: cbindgen 0.27 does not recognize Rust 2024's
#[unsafe(no_mangle)]attribute and silently skips every exported function, so the toml hasitem_types = ["structs"]and the function list is pasted manually — with no mechanical check.Changes (3 commits)
chore(sight): sync FFI header with current ffi.rs— re-syncs the tomlafter_includesblock to match the actual 16 FFI exports; rewrites the NOTE to separate the two independent workarounds (item_types=["structs"]is required even after a cbindgen upgrade, to keep unrelatedpub consts out of the public header).feat(sight): add drift guard for FFI header—build.rsextracts everypub [unsafe] extern "C" fn agentsight_*fromsrc/ffi.rsand every<type> agentsight_*(declaration from the generated header, then panics with the symmetric difference (missing-in-header / stale-in-header) when the two NAME sets disagree. No.github/workflowschange needed. Also adds a crate-local.gitignorefor the generatedinclude/.fix(sight): update FFI example for current API— replaces the deletedagentsight_config_add_domain_rulecall withagentsight_config_add_httpsand adds-I./includeto the docstringgcccommand.What is intentionally NOT changed
src/ffi.rs— actual exports unchanged; this PR only realigns the header.cbindgen.tomlenumerating the cleanup steps for when it lands.include/agentsight.h— still generated, not tracked..github/workflows/— drift detection runs inbuild.rs, not CI YAML.Testing
cargo buildclean.missing / stalelist for (a) deleted declaration, (b) renamed function (count preserved — the count-only iteration would have silently passed), (c) duplicate-with-drop (count preserved). All three reverse cases tried in-tree before commit; restored after.cargo build --releaseclean;gcc -I./include -L./target/release -lagentsightlinks the example;nmshows all 13 example-used FFI symbols resolved againstlibagentsight.so(including the newagentsight_config_add_https).Known limits (called out in code + commit)
The drift guard checks NAMES only — signature drift (return type, parameter types/order/count) is not detected automatically. Both the panic message and the cbindgen.toml note say this verbatim, so a green guard cannot be misread as a full ABI assertion.
Independent of #661–#666.