Update Android CPU device detection (#45139)

AUTHORS

@@ -45,3 +45,4 @@ Sarbagya Dhaubanjar <mail@sarbagyastha.com.np>
 Rody Davis Jr <rody.davis.jr@gmail.com>
 Robin Jespersen <info@unitedpartners.de>
 Jefferson Quesado <jeff.quesado@gmail.com>
+Mark Diener <rpzrpzrpz@gmail.com>

packages/flutter_tools/lib/src/android/android_device.dart

@@ -192,7 +192,16 @@ class AndroidDevice extends Device {
       // http://developer.android.com/ndk/guides/abis.html (x86, armeabi-v7a, ...)
       switch (await _getProperty('ro.product.cpu.abi')) {
         case 'arm64-v8a':
+          // Perform additional verification for 64 bit ABI. Some devices,
+          // like the Kindle Fire 8, misreport the abilist. We might not
+          // be able to retrieve this property, in which case we fall back
+          // to assuming 64 bit.
+          final String abilist = await _getProperty('ro.product.cpu.abilist');
+          if (abilist == null || abilist.contains('arm64-v8a')) {
             _platform = TargetPlatform.android_arm64;
+          } else {
+            _platform = TargetPlatform.android_arm;
+          }
           break;
         case 'x86_64':
           _platform = TargetPlatform.android_x64;

packages/flutter_tools/test/general.shard/android/android_device_test.dart

@@ -318,6 +318,77 @@ Use the 'android' tool to install them:
     });
   });
 
+  group('ABI detection', () {
+    ProcessManager mockProcessManager;
+    String cpu;
+    String abilist;
+
+    setUp(() {
+      mockProcessManager = MockProcessManager();
+      cpu = 'unknown';
+      abilist = 'unknown';
+      when(mockProcessManager.run(
+        argThat(contains('getprop')),
+        stderrEncoding: anyNamed('stderrEncoding'),
+        stdoutEncoding: anyNamed('stdoutEncoding'),
+      )).thenAnswer((_) {
+        final StringBuffer buf = StringBuffer()
+          ..writeln('[ro.product.cpu.abi]: [$cpu]')
+          ..writeln('[ro.product.cpu.abilist]: [$abilist]');
+        final ProcessResult result = ProcessResult(1, 0, buf.toString(), '');
+        return Future<ProcessResult>.value(result);
+      });
+    });
+
+    testUsingContext('detects x64', () async {
+      cpu = 'x86_64';
+      final AndroidDevice device = AndroidDevice('test');
+
+      expect(await device.targetPlatform, TargetPlatform.android_x64);
+    }, overrides: <Type, Generator>{
+      ProcessManager: () => mockProcessManager
+    });
+
+    testUsingContext('detects x86', () async {
+      cpu = 'x86';
+      final AndroidDevice device = AndroidDevice('test');
+
+      expect(await device.targetPlatform, TargetPlatform.android_x86);
+    }, overrides: <Type, Generator>{
+      ProcessManager: () => mockProcessManager
+    });
+
+    testUsingContext('unknown device defaults to 32bit arm', () async {
+      cpu = '???';
+      final AndroidDevice device = AndroidDevice('test');
+
+      expect(await device.targetPlatform, TargetPlatform.android_arm);
+    }, overrides: <Type, Generator>{
+      ProcessManager: () => mockProcessManager
+    });
+
+    testUsingContext('detects 64 bit arm', () async {
+      cpu = 'arm64-v8a';
+      abilist = 'arm64-v8a,';
+      final AndroidDevice device = AndroidDevice('test');
+
+      // If both abi properties agree, we are 64 bit.
+      expect(await device.targetPlatform, TargetPlatform.android_arm64);
+    }, overrides: <Type, Generator>{
+      ProcessManager: () => mockProcessManager
+    });
+
+    testUsingContext('detects kind fire ABI', () async {
+      cpu = 'arm64-v8a';
+      abilist = 'arm';
+      final AndroidDevice device = AndroidDevice('test');
+
+      // If one does not contain arm64, assume 32 bit.
+      expect(await device.targetPlatform, TargetPlatform.android_arm);
+    }, overrides: <Type, Generator>{
+      ProcessManager: () => mockProcessManager
+    });
+  });
 
   group('isLocalEmulator', () {
     final ProcessManager mockProcessManager = MockProcessManager();