rust: Make binder-ndk-sys crate buildable via Cargo for NDK

Test: cargo build --target=aarch64-linux-android
Bug: 368303574
Change-Id: I58e41d34bc16d28bb899dc8a58dce12627f7ab4e

Author: maurer

libs/binder/rust/Android.bp

@@ -140,6 +140,9 @@ rust_bindgen {
         "--raw-line",
         "use libc::sockaddr;",
     ],
+    cflags: [
+        "-DANDROID_PLATFORM",
+    ],
     shared_libs: [
         "libbinder_ndk",
     ],
@@ -180,6 +183,9 @@ rust_bindgen {
         // rustified
         "libbinder_ndk_bindgen_flags.txt",
     ],
+    cflags: [
+        "-DANDROID_PLATFORM",
+    ],
     shared_libs: [
         "libbinder_ndk_on_trusty_mock",
         "libc++",

libs/binder/rust/sys/BinderBindings.hpp

@@ -15,15 +15,19 @@
  */
 
 #include <android/binder_ibinder.h>
+#include <android/binder_parcel.h>
+#include <android/binder_status.h>
+
+/* Platform only */
+#if defined(ANDROID_PLATFORM) || defined(__ANDROID_VENDOR__)
 #include <android/binder_ibinder_platform.h>
 #include <android/binder_manager.h>
-#include <android/binder_parcel.h>
 #include <android/binder_parcel_platform.h>
 #include <android/binder_process.h>
 #include <android/binder_rpc.h>
 #include <android/binder_shell.h>
 #include <android/binder_stability.h>
-#include <android/binder_status.h>
+#endif
 
 namespace android {
 
@@ -81,8 +85,10 @@ enum {
 
 enum {
     FLAG_ONEWAY = FLAG_ONEWAY,
+#if defined(ANDROID_PLATFORM) || defined(__ANDROID_VENDOR__)
     FLAG_CLEAR_BUF = FLAG_CLEAR_BUF,
     FLAG_PRIVATE_LOCAL = FLAG_PRIVATE_LOCAL,
+#endif
 };
 
 } // namespace consts

libs/binder/rust/sys/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "android-binder-ndk-sys"
+version = "0.1.0"
+edition = "2021"
+description = "Bindgen bindings to android binder, restricted to the NDK"
+license = "Apache-2.0"
+
+[dependencies]
+
+[lib]
+path = "lib.rs"
+
+[build-dependencies]
+bindgen = "0.70.1"

libs/binder/rust/sys/build.rs

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use std::env;
+use std::path::PathBuf;
+
+fn main() {
+    let ndk_home = PathBuf::from(env::var("ANDROID_NDK_HOME").unwrap());
+    let toolchain = ndk_home.join("toolchains/llvm/prebuilt/linux-x86_64/");
+    let sysroot = toolchain.join("sysroot");
+    let bindings = bindgen::Builder::default()
+        .clang_arg(format!("--sysroot={}", sysroot.display()))
+        // TODO figure out what the "standard" #define is and use that instead
+        .header("BinderBindings.hpp")
+        .parse_callbacks(Box::new(bindgen::CargoCallbacks::new()))
+        // Keep in sync with libbinder_ndk_bindgen_flags.txt
+        .default_enum_style(bindgen::EnumVariation::Rust { non_exhaustive: true })
+        .constified_enum("android::c_interface::consts::.*")
+        .allowlist_type("android::c_interface::.*")
+        .allowlist_type("AStatus")
+        .allowlist_type("AIBinder_Class")
+        .allowlist_type("AIBinder")
+        .allowlist_type("AIBinder_Weak")
+        .allowlist_type("AIBinder_DeathRecipient")
+        .allowlist_type("AParcel")
+        .allowlist_type("binder_status_t")
+        .blocklist_function("vprintf")
+        .blocklist_function("strtold")
+        .blocklist_function("_vtlog")
+        .blocklist_function("vscanf")
+        .blocklist_function("vfprintf_worker")
+        .blocklist_function("vsprintf")
+        .blocklist_function("vsnprintf")
+        .blocklist_function("vsnprintf_filtered")
+        .blocklist_function("vfscanf")
+        .blocklist_function("vsscanf")
+        .blocklist_function("vdprintf")
+        .blocklist_function("vasprintf")
+        .blocklist_function("strtold_l")
+        .allowlist_function(".*")
+        .generate()
+        .expect("Couldn't generate bindings");
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+    bindings.write_to_file(out_path.join("bindings.rs")).expect("Couldn't write bindings.");
+    println!("cargo::rustc-link-lib=binder_ndk");
+}

libs/binder/rust/sys/lib.rs

@@ -20,6 +20,7 @@ use std::error::Error;
 use std::fmt;
 
 #[cfg(not(target_os = "trusty"))]
+#[allow(bad_style)]
 mod bindings {
     include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
 }