Auto generate rust bindings using rust bindgen (#4723)

* squash bingen work

* check generated code in ci

.github/workflows/cargo.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest, macos-latest-xlarge]
-        features: ["", "--features static", "--features schannel", "--features schannel,static"]
+        features: ["", "--features static", "--features schannel", "--features schannel,static", "--features overwrite"]
         exclude:
           - os: ubuntu-latest
             features: "--features schannel"
@@ -60,6 +60,8 @@ jobs:
       run: cargo clippy --all-targets -- -D warnings
     - name: Cargo build
       run: cargo build --all ${{ matrix.features }}
+    - name: Check all generated files with git
+      run: git diff --exit-code
     - name: Cargo test
       run: cargo test --all ${{ matrix.features }}
     - name: Cargo Publish (dry run)

Cargo.toml

@@ -34,7 +34,7 @@ include = [
     "/submodules/openssl/VMS",
     "/submodules/xdp-for-windows/published/external",
     "/scripts/build.rs",
-    "/src/*.rs",
+    "/src/**/*.rs",
     "/src/bin",
     "/src/core",
     "/src/inc",
@@ -49,9 +49,12 @@ default = []
 schannel = []
 static = []
 preview-api = []
+# Overwrite generated binding by reruning the bindgen
+overwrite = [ "dep:bindgen" ]
 
 [build-dependencies]
 cmake = "0.1"
+bindgen = { version = "0.71", optional = true }
 
 [dependencies]
 bitfield = "0.17.0"

scripts/build.rs

@@ -63,4 +63,47 @@ fn main() {
         }
         println!("cargo:rustc-link-lib=static=msquic");
     }
+
+    #[cfg(all(feature = "overwrite", not(target_os = "macos")))]
+    overwrite_bindgen();
+}
+
+/// Read the c header and generate rust bindings.
+/// TODO: macos currently uses linux bindings.
+#[cfg(all(feature = "overwrite", not(target_os = "macos")))]
+fn overwrite_bindgen() {
+    let manifest_dir = std::path::PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
+    let root_dir = manifest_dir;
+    // include msquic headers
+    let inc_dir = root_dir.join("src").join("inc");
+
+    // The bindgen::Builder is the main entry point
+    // to bindgen, and lets you build up options for
+    // the resulting bindings.
+    let bindings = bindgen::Builder::default()
+        // The input header we would like to generate
+        // bindings for.
+        .header(root_dir.join("src/ffi/wrapper.hpp").to_str().unwrap())
+        .clang_arg(format!("-I{}", inc_dir.to_string_lossy()))
+        .allowlist_recursively(false)
+        .allowlist_item("QUIC.*|BOOLEAN|BYTE|HQUIC|HRESULT")
+        .blocklist_type("QUIC_ADDR")
+        // Tell cargo to invalidate the built crate whenever any of the
+        // included header files changed.
+        .parse_callbacks(Box::new(bindgen::CargoCallbacks::new()))
+        // Finish the builder and generate the bindings.
+        .generate()
+        // Unwrap the Result and panic on failure.
+        .expect("Unable to generate bindings");
+
+    // Write bindings to the sys mod.
+    let out_path = root_dir.join("src/ffi");
+    #[cfg(target_os = "windows")]
+    let binding_file = "win_bindings.rs";
+    #[cfg(target_os = "linux")]
+    let binding_file = "linux_bindings.rs";
+    // TODO: support macos.
+    bindings
+        .write_to_file(out_path.join(binding_file))
+        .expect("Couldn't write bindings!");
 }