1// Copyright 2016 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5import 'package:meta/meta.dart'; 6 7import '../base/common.dart'; 8import '../base/context.dart'; 9import '../base/file_system.dart'; 10import '../base/io.dart' show ProcessResult; 11import '../base/os.dart'; 12import '../base/platform.dart'; 13import '../base/process.dart'; 14import '../base/process_manager.dart'; 15import '../base/version.dart'; 16import '../convert.dart'; 17import '../globals.dart'; 18import 'android_studio.dart' as android_studio; 19 20AndroidSdk get androidSdk => context.get<AndroidSdk>(); 21 22const String kAndroidHome = 'ANDROID_HOME'; 23const String kAndroidSdkRoot = 'ANDROID_SDK_ROOT'; 24 25// Android SDK layout: 26 27// $ANDROID_HOME/platform-tools/adb 28 29// $ANDROID_HOME/build-tools/19.1.0/aapt, dx, zipalign 30// $ANDROID_HOME/build-tools/22.0.1/aapt 31// $ANDROID_HOME/build-tools/23.0.2/aapt 32// $ANDROID_HOME/build-tools/24.0.0-preview/aapt 33// $ANDROID_HOME/build-tools/25.0.2/apksigner 34 35// $ANDROID_HOME/platforms/android-22/android.jar 36// $ANDROID_HOME/platforms/android-23/android.jar 37// $ANDROID_HOME/platforms/android-N/android.jar 38 39final RegExp _numberedAndroidPlatformRe = RegExp(r'^android-([0-9]+)$'); 40final RegExp _sdkVersionRe = RegExp(r'^ro.build.version.sdk=([0-9]+)$'); 41 42/// The minimum Android SDK version we support. 43const int minimumAndroidSdkVersion = 25; 44 45/// Locate ADB. Prefer to use one from an Android SDK, if we can locate that. 46/// This should be used over accessing androidSdk.adbPath directly because it 47/// will work for those users who have Android Platform Tools installed but 48/// not the full SDK. 49String getAdbPath([ AndroidSdk existingSdk ]) { 50 if (existingSdk?.adbPath != null) 51 return existingSdk.adbPath; 52 53 final AndroidSdk sdk = AndroidSdk.locateAndroidSdk(); 54 55 if (sdk?.latestVersion == null) { 56 return os.which('adb')?.path; 57 } else { 58 return sdk.adbPath; 59 } 60} 61 62/// Locate 'emulator'. Prefer to use one from an Android SDK, if we can locate that. 63/// This should be used over accessing androidSdk.emulatorPath directly because it 64/// will work for those users who have Android Tools installed but 65/// not the full SDK. 66String getEmulatorPath([ AndroidSdk existingSdk ]) { 67 return existingSdk?.emulatorPath ?? 68 AndroidSdk.locateAndroidSdk()?.emulatorPath; 69} 70 71/// Locate the path for storing AVD emulator images. Returns null if none found. 72String getAvdPath() { 73 74 final List<String> searchPaths = <String>[ 75 platform.environment['ANDROID_AVD_HOME'], 76 ]; 77 78 if (platform.environment['HOME'] != null) 79 searchPaths.add(fs.path.join(platform.environment['HOME'], '.android', 'avd')); 80 81 if (platform.isWindows) { 82 final String homeDrive = platform.environment['HOMEDRIVE']; 83 final String homePath = platform.environment['HOMEPATH']; 84 85 if (homeDrive != null && homePath != null) { 86 // Can't use path.join for HOMEDRIVE/HOMEPATH 87 // https://github.com/dart-lang/path/issues/37 88 final String home = homeDrive + homePath; 89 searchPaths.add(fs.path.join(home, '.android', 'avd')); 90 } 91 } 92 93 return searchPaths.where((String p) => p != null).firstWhere( 94 (String p) => fs.directory(p).existsSync(), 95 orElse: () => null, 96 ); 97} 98 99/// Locate 'avdmanager'. Prefer to use one from an Android SDK, if we can locate that. 100/// This should be used over accessing androidSdk.avdManagerPath directly because it 101/// will work for those users who have Android Tools installed but 102/// not the full SDK. 103String getAvdManagerPath([ AndroidSdk existingSdk ]) { 104 return existingSdk?.avdManagerPath ?? 105 AndroidSdk.locateAndroidSdk()?.avdManagerPath; 106} 107 108class AndroidNdkSearchError { 109 AndroidNdkSearchError(this.reason); 110 111 /// The message explaining why NDK was not found. 112 final String reason; 113} 114 115class AndroidNdk { 116 AndroidNdk._(this.directory, this.compiler, this.compilerArgs); 117 118 /// The path to the NDK. 119 final String directory; 120 121 /// The path to the NDK compiler. 122 final String compiler; 123 124 /// The mandatory arguments to the NDK compiler. 125 final List<String> compilerArgs; 126 127 /// Locate NDK within the given SDK or throw [AndroidNdkSearchError]. 128 static AndroidNdk locateNdk(String androidHomeDir) { 129 if (androidHomeDir == null) { 130 throw AndroidNdkSearchError('Can not locate NDK because no SDK is found'); 131 } 132 133 String findBundle(String androidHomeDir) { 134 final String ndkDirectory = fs.path.join(androidHomeDir, 'ndk-bundle'); 135 if (!fs.isDirectorySync(ndkDirectory)) { 136 throw AndroidNdkSearchError('Can not locate ndk-bundle, tried: $ndkDirectory'); 137 } 138 return ndkDirectory; 139 } 140 141 // Returns list that contains toolchain bin folder and compiler binary name. 142 List<String> findToolchainAndCompiler(String ndkDirectory) { 143 String directory; 144 if (platform.isLinux) { 145 directory = 'linux-x86_64'; 146 } else if (platform.isMacOS) { 147 directory = 'darwin-x86_64'; 148 } else { 149 throw AndroidNdkSearchError('Only Linux and macOS are supported'); 150 } 151 152 final String toolchainBin = fs.path.join(ndkDirectory, 153 'toolchains', 'arm-linux-androideabi-4.9', 'prebuilt', directory, 154 'bin'); 155 final String ndkCompiler = fs.path.join(toolchainBin, 156 'arm-linux-androideabi-gcc'); 157 if (!fs.isFileSync(ndkCompiler)) { 158 throw AndroidNdkSearchError('Can not locate GCC binary, tried $ndkCompiler'); 159 } 160 161 return <String>[toolchainBin, ndkCompiler]; 162 } 163 164 List<String> findSysroot(String ndkDirectory) { 165 // If entity represents directory with name android-<version> that 166 // contains arch-arm subdirectory then returns version, otherwise 167 // returns null. 168 int toPlatformVersion(FileSystemEntity entry) { 169 if (entry is! Directory) { 170 return null; 171 } 172 173 if (!fs.isDirectorySync(fs.path.join(entry.path, 'arch-arm'))) { 174 return null; 175 } 176 177 final String name = fs.path.basename(entry.path); 178 179 const String platformPrefix = 'android-'; 180 if (!name.startsWith(platformPrefix)) { 181 return null; 182 } 183 184 return int.tryParse(name.substring(platformPrefix.length)); 185 } 186 187 final String platformsDir = fs.path.join(ndkDirectory, 'platforms'); 188 final List<int> versions = fs 189 .directory(platformsDir) 190 .listSync() 191 .map(toPlatformVersion) 192 .where((int version) => version != null) 193 .toList(growable: false); 194 versions.sort(); 195 196 final int suitableVersion = versions 197 .firstWhere((int version) => version >= 9, orElse: () => null); 198 if (suitableVersion == null) { 199 throw AndroidNdkSearchError('Can not locate a suitable platform ARM sysroot (need android-9 or newer), tried to look in $platformsDir'); 200 } 201 202 final String armPlatform = fs.path.join(ndkDirectory, 'platforms', 203 'android-$suitableVersion', 'arch-arm'); 204 return <String>['--sysroot', armPlatform]; 205 } 206 207 int findNdkMajorVersion(String ndkDirectory) { 208 final String propertiesFile = fs.path.join(ndkDirectory, 'source.properties'); 209 if (!fs.isFileSync(propertiesFile)) { 210 throw AndroidNdkSearchError('Can not establish ndk-bundle version: $propertiesFile not found'); 211 } 212 213 // Parse source.properties: each line has Key = Value format. 214 final Iterable<String> propertiesFileLines = fs.file(propertiesFile) 215 .readAsStringSync() 216 .split('\n') 217 .map<String>((String line) => line.trim()) 218 .where((String line) => line.isNotEmpty); 219 final Map<String, String> properties = <String, String>{}; 220 for (String line in propertiesFileLines) { 221 final List<String> parts = line.split(' = '); 222 if (parts.length == 2) { 223 properties[parts[0]] = parts[1]; 224 } else { 225 printError('Malformed line in ndk source.properties: "$line".'); 226 } 227 } 228 229 if (!properties.containsKey('Pkg.Revision')) { 230 throw AndroidNdkSearchError('Can not establish ndk-bundle version: $propertiesFile does not contain Pkg.Revision'); 231 } 232 233 // Extract major version from Pkg.Revision property which looks like <ndk-version>.x.y. 234 return int.parse(properties['Pkg.Revision'].split('.').first); 235 } 236 237 final String ndkDir = findBundle(androidHomeDir); 238 final int ndkVersion = findNdkMajorVersion(ndkDir); 239 final List<String> ndkToolchainAndCompiler = findToolchainAndCompiler(ndkDir); 240 final String ndkToolchain = ndkToolchainAndCompiler[0]; 241 final String ndkCompiler = ndkToolchainAndCompiler[1]; 242 final List<String> ndkCompilerArgs = findSysroot(ndkDir); 243 if (ndkVersion >= 18) { 244 // Newer versions of NDK use clang instead of gcc, which falls back to 245 // system linker instead of using toolchain linker. Force clang to 246 // use appropriate linker by passing -fuse-ld=<path-to-ld> command line 247 // flag. 248 final String ndkLinker = fs.path.join(ndkToolchain, 'arm-linux-androideabi-ld'); 249 if (!fs.isFileSync(ndkLinker)) { 250 throw AndroidNdkSearchError('Can not locate linker binary, tried $ndkLinker'); 251 } 252 ndkCompilerArgs.add('-fuse-ld=$ndkLinker'); 253 } 254 return AndroidNdk._(ndkDir, ndkCompiler, ndkCompilerArgs); 255 } 256 257 /// Returns a descriptive message explaining why NDK can not be found within 258 /// the given SDK. 259 static String explainMissingNdk(String androidHomeDir) { 260 try { 261 locateNdk(androidHomeDir); 262 return 'Unexpected error: found NDK on the second try'; 263 } on AndroidNdkSearchError catch (e) { 264 return e.reason; 265 } 266 } 267} 268 269class AndroidSdk { 270 AndroidSdk(this.directory, [this.ndk]) { 271 reinitialize(); 272 } 273 274 static const String _javaHomeEnvironmentVariable = 'JAVA_HOME'; 275 static const String _javaExecutable = 'java'; 276 277 /// The path to the Android SDK. 278 final String directory; 279 280 /// Android NDK (can be `null`). 281 final AndroidNdk ndk; 282 283 List<AndroidSdkVersion> _sdkVersions; 284 AndroidSdkVersion _latestVersion; 285 286 /// Whether the `platform-tools` directory exists in the Android SDK. 287 /// 288 /// It is possible to have an Android SDK folder that is missing this with 289 /// the expectation that it will be downloaded later, e.g. by gradle or the 290 /// sdkmanager. The [licensesAvailable] property should be used to determine 291 /// whether the licenses are at least possibly accepted. 292 bool get platformToolsAvailable => fs.directory(fs.path.join(directory, 'platform-tools')).existsSync(); 293 294 /// Whether the `licenses` directory exists in the Android SDK. 295 /// 296 /// The existence of this folder normally indicates that the SDK licenses have 297 /// been accepted, e.g. via the sdkmanager, Android Studio, or by copying them 298 /// from another workstation such as in CI scenarios. If these files are valid 299 /// gradle or the sdkmanager will be able to download and use other parts of 300 /// the SDK on demand. 301 bool get licensesAvailable => fs.directory(fs.path.join(directory, 'licenses')).existsSync(); 302 303 static AndroidSdk locateAndroidSdk() { 304 String findAndroidHomeDir() { 305 String androidHomeDir; 306 if (config.containsKey('android-sdk')) { 307 androidHomeDir = config.getValue('android-sdk'); 308 } else if (platform.environment.containsKey(kAndroidHome)) { 309 androidHomeDir = platform.environment[kAndroidHome]; 310 } else if (platform.environment.containsKey(kAndroidSdkRoot)) { 311 androidHomeDir = platform.environment[kAndroidSdkRoot]; 312 } else if (platform.isLinux) { 313 if (homeDirPath != null) 314 androidHomeDir = fs.path.join(homeDirPath, 'Android', 'Sdk'); 315 } else if (platform.isMacOS) { 316 if (homeDirPath != null) 317 androidHomeDir = fs.path.join(homeDirPath, 'Library', 'Android', 'sdk'); 318 } else if (platform.isWindows) { 319 if (homeDirPath != null) 320 androidHomeDir = fs.path.join(homeDirPath, 'AppData', 'Local', 'Android', 'sdk'); 321 } 322 323 if (androidHomeDir != null) { 324 if (validSdkDirectory(androidHomeDir)) 325 return androidHomeDir; 326 if (validSdkDirectory(fs.path.join(androidHomeDir, 'sdk'))) 327 return fs.path.join(androidHomeDir, 'sdk'); 328 } 329 330 // in build-tools/$version/aapt 331 final List<File> aaptBins = os.whichAll('aapt'); 332 for (File aaptBin in aaptBins) { 333 // Make sure we're using the aapt from the SDK. 334 aaptBin = fs.file(aaptBin.resolveSymbolicLinksSync()); 335 final String dir = aaptBin.parent.parent.parent.path; 336 if (validSdkDirectory(dir)) 337 return dir; 338 } 339 340 // in platform-tools/adb 341 final List<File> adbBins = os.whichAll('adb'); 342 for (File adbBin in adbBins) { 343 // Make sure we're using the adb from the SDK. 344 adbBin = fs.file(adbBin.resolveSymbolicLinksSync()); 345 final String dir = adbBin.parent.parent.path; 346 if (validSdkDirectory(dir)) 347 return dir; 348 } 349 350 return null; 351 } 352 353 final String androidHomeDir = findAndroidHomeDir(); 354 if (androidHomeDir == null) { 355 // No dice. 356 printTrace('Unable to locate an Android SDK.'); 357 return null; 358 } 359 360 // Try to find the NDK compiler. If we can't find it, it's also ok. 361 AndroidNdk ndk; 362 try { 363 ndk = AndroidNdk.locateNdk(androidHomeDir); 364 } on AndroidNdkSearchError { 365 // Ignore AndroidNdkSearchError's but don't ignore any other 366 // exceptions. 367 } 368 369 return AndroidSdk(androidHomeDir, ndk); 370 } 371 372 static bool validSdkDirectory(String dir) { 373 return sdkDirectoryHasLicenses(dir) || sdkDirectoryHasPlatformTools(dir); 374 } 375 376 static bool sdkDirectoryHasPlatformTools(String dir) { 377 return fs.isDirectorySync(fs.path.join(dir, 'platform-tools')); 378 } 379 380 static bool sdkDirectoryHasLicenses(String dir) { 381 return fs.isDirectorySync(fs.path.join(dir, 'licenses')); 382 } 383 384 List<AndroidSdkVersion> get sdkVersions => _sdkVersions; 385 386 AndroidSdkVersion get latestVersion => _latestVersion; 387 388 String get adbPath => getPlatformToolsPath(platform.isWindows ? 'adb.exe' : 'adb'); 389 390 String get emulatorPath => getEmulatorPath(); 391 392 String get avdManagerPath => getAvdManagerPath(); 393 394 Directory get _platformsDir => fs.directory(fs.path.join(directory, 'platforms')); 395 396 Iterable<Directory> get _platforms { 397 Iterable<Directory> platforms = <Directory>[]; 398 if (_platformsDir.existsSync()) { 399 platforms = _platformsDir 400 .listSync() 401 .whereType<Directory>(); 402 } 403 return platforms; 404 } 405 406 /// Validate the Android SDK. This returns an empty list if there are no 407 /// issues; otherwise, it returns a list of issues found. 408 List<String> validateSdkWellFormed() { 409 if (adbPath == null || !processManager.canRun(adbPath)) 410 return <String>['Android SDK file not found: ${adbPath ?? 'adb'}.']; 411 412 if (sdkVersions.isEmpty || latestVersion == null) { 413 final StringBuffer msg = StringBuffer('No valid Android SDK platforms found in ${_platformsDir.path}.'); 414 if (_platforms.isEmpty) { 415 msg.write(' Directory was empty.'); 416 } else { 417 msg.write(' Candidates were:\n'); 418 msg.write(_platforms 419 .map((Directory dir) => ' - ${dir.basename}') 420 .join('\n')); 421 } 422 return <String>[msg.toString()]; 423 } 424 425 return latestVersion.validateSdkWellFormed(); 426 } 427 428 String getPlatformToolsPath(String binaryName) { 429 final String path = fs.path.join(directory, 'platform-tools', binaryName); 430 if (fs.file(path).existsSync()) 431 return path; 432 return null; 433 } 434 435 String getEmulatorPath() { 436 final String binaryName = platform.isWindows ? 'emulator.exe' : 'emulator'; 437 // Emulator now lives inside "emulator" but used to live inside "tools" so 438 // try both. 439 final List<String> searchFolders = <String>['emulator', 'tools']; 440 for (final String folder in searchFolders) { 441 final String path = fs.path.join(directory, folder, binaryName); 442 if (fs.file(path).existsSync()) 443 return path; 444 } 445 return null; 446 } 447 448 String getAvdManagerPath() { 449 final String binaryName = platform.isWindows ? 'avdmanager.bat' : 'avdmanager'; 450 final String path = fs.path.join(directory, 'tools', 'bin', binaryName); 451 if (fs.file(path).existsSync()) 452 return path; 453 return null; 454 } 455 456 /// Sets up various paths used internally. 457 /// 458 /// This method should be called in a case where the tooling may have updated 459 /// SDK artifacts, such as after running a gradle build. 460 void reinitialize() { 461 List<Version> buildTools = <Version>[]; // 19.1.0, 22.0.1, ... 462 463 final Directory buildToolsDir = fs.directory(fs.path.join(directory, 'build-tools')); 464 if (buildToolsDir.existsSync()) { 465 buildTools = buildToolsDir 466 .listSync() 467 .map((FileSystemEntity entity) { 468 try { 469 return Version.parse(entity.basename); 470 } catch (error) { 471 return null; 472 } 473 }) 474 .where((Version version) => version != null) 475 .toList(); 476 } 477 478 // Match up platforms with the best corresponding build-tools. 479 _sdkVersions = _platforms.map<AndroidSdkVersion>((Directory platformDir) { 480 final String platformName = platformDir.basename; 481 int platformVersion; 482 483 try { 484 final Match numberedVersion = _numberedAndroidPlatformRe.firstMatch(platformName); 485 if (numberedVersion != null) { 486 platformVersion = int.parse(numberedVersion.group(1)); 487 } else { 488 final String buildProps = platformDir.childFile('build.prop').readAsStringSync(); 489 final String versionString = const LineSplitter() 490 .convert(buildProps) 491 .map<Match>(_sdkVersionRe.firstMatch) 492 .firstWhere((Match match) => match != null) 493 .group(1); 494 platformVersion = int.parse(versionString); 495 } 496 } catch (error) { 497 return null; 498 } 499 500 Version buildToolsVersion = Version.primary(buildTools.where((Version version) { 501 return version.major == platformVersion; 502 }).toList()); 503 504 buildToolsVersion ??= Version.primary(buildTools); 505 506 if (buildToolsVersion == null) 507 return null; 508 509 return AndroidSdkVersion._( 510 this, 511 sdkLevel: platformVersion, 512 platformName: platformName, 513 buildToolsVersion: buildToolsVersion, 514 ); 515 }).where((AndroidSdkVersion version) => version != null).toList(); 516 517 _sdkVersions.sort(); 518 519 _latestVersion = _sdkVersions.isEmpty ? null : _sdkVersions.last; 520 } 521 522 /// Returns the filesystem path of the Android SDK manager tool or null if not found. 523 String get sdkManagerPath { 524 return fs.path.join(directory, 'tools', 'bin', 'sdkmanager'); 525 } 526 527 /// First try Java bundled with Android Studio, then sniff JAVA_HOME, then fallback to PATH. 528 static String findJavaBinary() { 529 530 if (android_studio.javaPath != null) 531 return fs.path.join(android_studio.javaPath, 'bin', 'java'); 532 533 final String javaHomeEnv = platform.environment[_javaHomeEnvironmentVariable]; 534 if (javaHomeEnv != null) { 535 // Trust JAVA_HOME. 536 return fs.path.join(javaHomeEnv, 'bin', 'java'); 537 } 538 539 // MacOS specific logic to avoid popping up a dialog window. 540 // See: http://stackoverflow.com/questions/14292698/how-do-i-check-if-the-java-jdk-is-installed-on-mac. 541 if (platform.isMacOS) { 542 try { 543 final String javaHomeOutput = runCheckedSync(<String>['/usr/libexec/java_home'], hideStdout: true); 544 if (javaHomeOutput != null) { 545 final List<String> javaHomeOutputSplit = javaHomeOutput.split('\n'); 546 if ((javaHomeOutputSplit != null) && (javaHomeOutputSplit.isNotEmpty)) { 547 final String javaHome = javaHomeOutputSplit[0].trim(); 548 return fs.path.join(javaHome, 'bin', 'java'); 549 } 550 } 551 } catch (_) { /* ignore */ } 552 } 553 554 // Fallback to PATH based lookup. 555 return os.which(_javaExecutable)?.path; 556 } 557 558 Map<String, String> _sdkManagerEnv; 559 /// Returns an environment with the Java folder added to PATH for use in calling 560 /// Java-based Android SDK commands such as sdkmanager and avdmanager. 561 Map<String, String> get sdkManagerEnv { 562 if (_sdkManagerEnv == null) { 563 // If we can locate Java, then add it to the path used to run the Android SDK manager. 564 _sdkManagerEnv = <String, String>{}; 565 final String javaBinary = findJavaBinary(); 566 if (javaBinary != null) { 567 _sdkManagerEnv['PATH'] = 568 fs.path.dirname(javaBinary) + os.pathVarSeparator + platform.environment['PATH']; 569 } 570 } 571 return _sdkManagerEnv; 572 } 573 574 /// Returns the version of the Android SDK manager tool or null if not found. 575 String get sdkManagerVersion { 576 if (!processManager.canRun(sdkManagerPath)) 577 throwToolExit('Android sdkmanager not found. Update to the latest Android SDK to resolve this.'); 578 final ProcessResult result = processManager.runSync(<String>[sdkManagerPath, '--version'], environment: sdkManagerEnv); 579 if (result.exitCode != 0) { 580 printTrace('sdkmanager --version failed: exitCode: ${result.exitCode} stdout: ${result.stdout} stderr: ${result.stderr}'); 581 return null; 582 } 583 return result.stdout.trim(); 584 } 585 586 @override 587 String toString() => 'AndroidSdk: $directory'; 588} 589 590class AndroidSdkVersion implements Comparable<AndroidSdkVersion> { 591 AndroidSdkVersion._( 592 this.sdk, { 593 @required this.sdkLevel, 594 @required this.platformName, 595 @required this.buildToolsVersion, 596 }) : assert(sdkLevel != null), 597 assert(platformName != null), 598 assert(buildToolsVersion != null); 599 600 final AndroidSdk sdk; 601 final int sdkLevel; 602 final String platformName; 603 final Version buildToolsVersion; 604 605 String get buildToolsVersionName => buildToolsVersion.toString(); 606 607 String get androidJarPath => getPlatformsPath('android.jar'); 608 609 String get aaptPath => getBuildToolsPath('aapt'); 610 611 List<String> validateSdkWellFormed() { 612 if (_exists(androidJarPath) != null) 613 return <String>[_exists(androidJarPath)]; 614 615 if (_canRun(aaptPath) != null) 616 return <String>[_canRun(aaptPath)]; 617 618 return <String>[]; 619 } 620 621 String getPlatformsPath(String itemName) { 622 return fs.path.join(sdk.directory, 'platforms', platformName, itemName); 623 } 624 625 String getBuildToolsPath(String binaryName) { 626 return fs.path.join(sdk.directory, 'build-tools', buildToolsVersionName, binaryName); 627 } 628 629 @override 630 int compareTo(AndroidSdkVersion other) => sdkLevel - other.sdkLevel; 631 632 @override 633 String toString() => '[${sdk.directory}, SDK version $sdkLevel, build-tools $buildToolsVersionName]'; 634 635 String _exists(String path) { 636 if (!fs.isFileSync(path)) 637 return 'Android SDK file not found: $path.'; 638 return null; 639 } 640 641 String _canRun(String path) { 642 if (!processManager.canRun(path)) 643 return 'Android SDK file not found: $path.'; 644 return null; 645 } 646} 647