//! Generates the WPE WebKit FFI bindings, but **only under the `wpe` feature**.
 //!
 //! Without it this is a no-op, so a default (Servo) build needs no WPE headers
 //! and behaves exactly as it did before the port started. See WPE-PORT.md.
 
 fn main() {
     println!("cargo:rerun-if-changed=build.rs");
     println!("cargo:rerun-if-changed=src/wpe/wrapper.h");
     if std::env::var("CARGO_FEATURE_WPE").is_err() {
         return;
     }
 
     // Both modules are needed: wpe-webkit-2.0 is the engine, wpe-platform-2.0
     // is the embedding layer (WPEDisplay / WPEView / WPEToplevel) the port
     // subclasses. pkg-config emits the link flags for us.
     let mut clang_args = Vec::new();
     for module in ["wpe-webkit-2.0", "wpe-platform-2.0"] {
         let lib = pkg_config::Config::new()
             .probe(module)
             .unwrap_or_else(|e| panic!("`{module}` not found — pacman -S wpewebkit ({e})"));
         for path in &lib.include_paths {
             clang_args.push(format!("-I{}", path.display()));
         }
     }
 
     let bindings = bindgen::Builder::default()
         .header("src/wpe/wrapper.h")
         .clang_args(&clang_args)
         // The engine, the embedding layer, and just enough GObject to
         // register subclasses and turn a main loop.
         .allowlist_item("(wpe|WPE|webkit|WebKit)_?.*")
         // JavaScriptCore: a script message from the page arrives as a
         // JSCValue, so reading one needs `jsc_value_*`. webkit.h already
         // pulls in jsc.h; only the allowlist kept these out.
         .allowlist_item("(jsc|JSC)_?.*")
         .allowlist_item("g_(object|type|signal|bytes|timeout|free|error)_.*")
         // `g_free` itself, with no trailing word, misses the pattern above —
         // and a JSC string comes back owned, so it is needed to hand it back.
         .allowlist_function("g_free")
         // The main loop AND the context: `pump` drains the context directly.
         .allowlist_item("g_main_(loop|context)_.*")
         .allowlist_item("G(Object|Type|Value|Bytes|Error|MainLoop|ParamSpec|Closure).*")
         // The main-context poll protocol: GPollFD is what `query` fills in.
         .allowlist_item("G(MainContext|PollFD|Source).*")
         // Serving `cce:` pages: the handler answers with an input stream.
         .allowlist_item("g_(memory_input_stream|input_stream|file)_.*")
         .allowlist_item("G(InputStream|MemoryInputStream|File|Cancellable|AsyncResult).*")
         .allowlist_item("g_(type|object)_.*")
         // GObject's generated enums are plain C enums; keep them as consts so
         // vfunc tables and property flags stay comparable without casts.
         .default_enum_style(bindgen::EnumVariation::ModuleConsts)
         .derive_default(true)
         .layout_tests(false)
         .generate()
         .expect("bindgen failed over the WPE headers");
 
     let out = std::path::PathBuf::from(std::env::var("OUT_DIR").unwrap());
     bindings
         .write_to_file(out.join("wpe_bindings.rs"))
         .expect("could not write wpe_bindings.rs");
 }