anvil-sys

Raw Rust bindings to the plugin API 2 of Anvil, the native plugin loader for Europa Universalis IV 1.37.5 (include/anvil/anvil_plugin.h), and to the services Anvil ships: anvil-game.game and anvil-game.world (anvil_game.h), anvil-overlay.panel (anvil_panel.h) and anvil.benchmark (anvil_benchmark.h). no_std, no dependencies.

Most plugins want the safe crate on top of it, anvil-sdk (library anvil).

• src/bindings.rs is generated by bindgen from the headers and committed. CI regenerates it and fails when it differs (sdk/rust/regen-bindings.ps1).
• A service table is #[repr(C)] with Option<unsafe extern "C" fn> fields; the ANVIL_*_HAS macros are C, so compare size with offset_of! before using a function appended after the service's first release.
• AnvilCpuContext is #[repr(C)], 408 bytes (checked at compile time).
• C enums are plain integer constants (AnvilResult, ANVIL_OK, …): a value from the host never becomes an invalid Rust enum.
• AnvilPluginLoadFn is the type of anvil_plugin_load, the one function a plugin exports. The crate declares no extern functions.

A plugin on the raw API is a cdylib that exports anvil_plugin_load and returns an AnvilResult. Catch panics at every function the game or Anvil calls: unwinding into them aborts the process. anvil gen --lang rust writes the typed symbols (symbols.gen.rs) from the plugin's symbols.toml.

The version of this crate is the version of Anvil whose headers it binds.

License: MIT.