update rust_builder

rust_builder/cargokit/build_tool/lib/src/android_environment.dart

@@ -0,0 +1,195 @@
+/// This is copied from Cargokit (which is the official way to use it currently)
+/// Details: https://fzyzcjy.github.io/flutter_rust_bridge/manual/integrate/builtin
+
+import 'dart:io';
+import 'dart:isolate';
+import 'dart:math' as math;
+
+import 'package:collection/collection.dart';
+import 'package:path/path.dart' as path;
+import 'package:version/version.dart';
+
+import 'target.dart';
+import 'util.dart';
+
+class AndroidEnvironment {
+  AndroidEnvironment({
+    required this.sdkPath,
+    required this.ndkVersion,
+    required this.minSdkVersion,
+    required this.targetTempDir,
+    required this.target,
+  });
+
+  static void clangLinkerWrapper(List<String> args) {
+    final clang = Platform.environment['_CARGOKIT_NDK_LINK_CLANG'];
+    if (clang == null) {
+      throw Exception(
+          "cargo-ndk rustc linker: didn't find _CARGOKIT_NDK_LINK_CLANG env var");
+    }
+    final target = Platform.environment['_CARGOKIT_NDK_LINK_TARGET'];
+    if (target == null) {
+      throw Exception(
+          "cargo-ndk rustc linker: didn't find _CARGOKIT_NDK_LINK_TARGET env var");
+    }
+
+    runCommand(clang, [
+      target,
+      ...args,
+    ]);
+  }
+
+  /// Full path to Android SDK.
+  final String sdkPath;
+
+  /// Full version of Android NDK.
+  final String ndkVersion;
+
+  /// Minimum supported SDK version.
+  final int minSdkVersion;
+
+  /// Target directory for build artifacts.
+  final String targetTempDir;
+
+  /// Target being built.
+  final Target target;
+
+  bool ndkIsInstalled() {
+    final ndkPath = path.join(sdkPath, 'ndk', ndkVersion);
+    final ndkPackageXml = File(path.join(ndkPath, 'package.xml'));
+    return ndkPackageXml.existsSync();
+  }
+
+  void installNdk({
+    required String javaHome,
+  }) {
+    final sdkManagerExtension = Platform.isWindows ? '.bat' : '';
+    final sdkManager = path.join(
+      sdkPath,
+      'cmdline-tools',
+      'latest',
+      'bin',
+      'sdkmanager$sdkManagerExtension',
+    );
+
+    log.info('Installing NDK $ndkVersion');
+    runCommand(sdkManager, [
+      '--install',
+      'ndk;$ndkVersion',
+    ], environment: {
+      'JAVA_HOME': javaHome,
+    });
+  }
+
+  Future<Map<String, String>> buildEnvironment() async {
+    final hostArch = Platform.isMacOS
+        ? "darwin-x86_64"
+        : (Platform.isLinux ? "linux-x86_64" : "windows-x86_64");
+
+    final ndkPath = path.join(sdkPath, 'ndk', ndkVersion);
+    final toolchainPath = path.join(
+      ndkPath,
+      'toolchains',
+      'llvm',
+      'prebuilt',
+      hostArch,
+      'bin',
+    );
+
+    final minSdkVersion =
+        math.max(target.androidMinSdkVersion!, this.minSdkVersion);
+
+    final exe = Platform.isWindows ? '.exe' : '';
+
+    final arKey = 'AR_${target.rust}';
+    final arValue = ['${target.rust}-ar', 'llvm-ar', 'llvm-ar.exe']
+        .map((e) => path.join(toolchainPath, e))
+        .firstWhereOrNull((element) => File(element).existsSync());
+    if (arValue == null) {
+      throw Exception('Failed to find ar for $target in $toolchainPath');
+    }
+
+    final targetArg = '--target=${target.rust}$minSdkVersion';
+
+    final ccKey = 'CC_${target.rust}';
+    final ccValue = path.join(toolchainPath, 'clang$exe');
+    final cfFlagsKey = 'CFLAGS_${target.rust}';
+    final cFlagsValue = targetArg;
+
+    final cxxKey = 'CXX_${target.rust}';
+    final cxxValue = path.join(toolchainPath, 'clang++$exe');
+    final cxxfFlagsKey = 'CXXFLAGS_${target.rust}';
+    final cxxFlagsValue = targetArg;
+
+    final linkerKey =
+        'cargo_target_${target.rust.replaceAll('-', '_')}_linker'.toUpperCase();
+
+    final ranlibKey = 'RANLIB_${target.rust}';
+    final ranlibValue = path.join(toolchainPath, 'llvm-ranlib$exe');
+
+    final ndkVersionParsed = Version.parse(ndkVersion);
+    final rustFlagsKey = 'CARGO_ENCODED_RUSTFLAGS';
+    final rustFlagsValue = _libGccWorkaround(targetTempDir, ndkVersionParsed);
+
+    final runRustTool =
+        Platform.isWindows ? 'run_build_tool.cmd' : 'run_build_tool.sh';
+
+    final packagePath = (await Isolate.resolvePackageUri(
+            Uri.parse('package:build_tool/buildtool.dart')))!
+        .toFilePath();
+    final selfPath = path.canonicalize(path.join(
+      packagePath,
+      '..',
+      '..',
+      '..',
+      runRustTool,
+    ));
+
+    // Make sure that run_build_tool is working properly even initially launched directly
+    // through dart run.
+    final toolTempDir =
+        Platform.environment['CARGOKIT_TOOL_TEMP_DIR'] ?? targetTempDir;
+
+    return {
+      arKey: arValue,
+      ccKey: ccValue,
+      cfFlagsKey: cFlagsValue,
+      cxxKey: cxxValue,
+      cxxfFlagsKey: cxxFlagsValue,
+      ranlibKey: ranlibValue,
+      rustFlagsKey: rustFlagsValue,
+      linkerKey: selfPath,
+      // Recognized by main() so we know when we're acting as a wrapper
+      '_CARGOKIT_NDK_LINK_TARGET': targetArg,
+      '_CARGOKIT_NDK_LINK_CLANG': ccValue,
+      'CARGOKIT_TOOL_TEMP_DIR': toolTempDir,
+    };
+  }
+
+  // Workaround for libgcc missing in NDK23, inspired by cargo-ndk
+  String _libGccWorkaround(String buildDir, Version ndkVersion) {
+    final workaroundDir = path.join(
+      buildDir,
+      'cargokit',
+      'libgcc_workaround',
+      '${ndkVersion.major}',
+    );
+    Directory(workaroundDir).createSync(recursive: true);
+    if (ndkVersion.major >= 23) {
+      File(path.join(workaroundDir, 'libgcc.a'))
+          .writeAsStringSync('INPUT(-lunwind)');
+    } else {
+      // Other way around, untested, forward libgcc.a from libunwind once Rust
+      // gets updated for NDK23+.
+      File(path.join(workaroundDir, 'libunwind.a'))
+          .writeAsStringSync('INPUT(-lgcc)');
+    }
+
+    var rustFlags = Platform.environment['CARGO_ENCODED_RUSTFLAGS'] ?? '';
+    if (rustFlags.isNotEmpty) {
+      rustFlags = '$rustFlags\x1f';
+    }
+    rustFlags = '$rustFlags-L\x1f$workaroundDir';
+    return rustFlags;
+  }
+}