Dexファイルフォーマットのバージョン038で、invoke-polymorphicとinvoke-customが追加されました。
Note: Support for version 038 of the format was added in the Android 8.0 release. Version 038 added new bytecodes (invoke-polymorphic and invoke-custom) and data for method handles.
これらがDexファイルに現れることを確認します。
以下に、コンパイル対象のコードを示します。
app/src/main/java/com/example/myapplication/Main.java
package com.example.myapplication;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.util.function.BiFunction;
public class Main {
public static void main(String[] args) throws Throwable {
System.out.println(MethodHandles.lookup()
.findStatic(Main.class,
"add",
MethodType.methodType(int.class, int.class, int.class))
.invoke(2, 3));
}
static int add(int a, int b) {
BiFunction<Integer, Integer, Integer> f = (i0, i1) -> i0 + i1;
return f.apply(a, b);
}
}
Dexファイルがどうなるかを確認するためだけのコードです。
Android上で動作させることは考えていません。
build.gradleはそれぞれ以下のとおりです。
build.gradle
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:2.4.0-alpha3'
}
}
allprojects {
repositories {
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
app/build.gradle
apply plugin: 'com.android.application'
android {
compileSdkVersion 'android-O'
buildToolsVersion '26.0.0-rc1'
defaultConfig {
jackOptions {
enabled = true
}
applicationId "com.example.myapplication"
minSdkVersion 'O'
versionCode 1
versionName '1.0'
}
compileOptions {
targetCompatibility JavaVersion.VERSION_1_8
sourceCompatibility JavaVersion.VERSION_1_8
}
}
compileSdkVersionをandroid-Oに、minSdkVersionをOにしています。
また、ラムダ式を使用しているので、Jackを有効にしています。
ビルドします。
$ ./gradlew clean assembleDebug
:clean
:app:clean
:app:preBuild UP-TO-DATE
:app:resolveDebugDependencies
:app:preDebugBuild
:app:compileDebugNdk NO-SOURCE
:app:checkDebugManifest
:app:prepareDebugDependencies
:app:compileDebugAidl
:app:compileDebugRenderscript
:app:generateDebugBuildConfig
:app:generateDebugResValues
:app:handleDebugMicroApk
:app:generateDebugResources
:app:mergeDebugResources
:app:processDebugManifest
:app:processDebugResources
:app:generateDebugSources
:app:transformClassesWithPreJackPackagedLibrariesForDebug
:app:transformClassesWithPreJackRuntimeLibrariesForDebug
:app:processDebugJavaRes NO-SOURCE
:app:transformResourcesWithMergeJavaResForDebug
:app:transformJackAndJavaSourcesWithJackCompileForDebug
/home/tmura/AndroidStudioProjects/MyApplication2/app/src/main/java/com/example/myapplication/Main.java:10:28-14:48: Call to a method with a polymorphic signature requires at least an android provisional level o-b1
:app:transformJackAndJavaSourcesWithJackCompileForDebug FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:transformJackAndJavaSourcesWithJackCompileForDebug'.
> com.android.build.api.transform.TransformException: com.android.builder.core.JackToolchain$ToolchainException: Jack compilation exception
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED
Total time: 3.683 secs
Call to a method with a polymorphic signature requires at least an android provisional level o-b1とのことで、レベルを設定する必要がありそうです。
jack.jarのオプションを確認します。
$ java -jar $ANDROID_HOME/build-tools/26.0.0-rc1/jack.jar --help-properties
...
jack.android.min-api-level:
Minimum Android API level compatibility (default is '1')
a released API level as an integer belonging to [1 .. 9223372036854775807] or a provisional API level as {o-b1,o-b2} (case insensitive)
o-b1: Dex file 0x37 with invoke-poly
o-b2: Dex file 0x38 with invoke-{poly,custom}
...
jack.android.min-api-levelというプロパティにo-b1またはo-b2を指定すれば良さそうです。
app/build.gradleにて、上記オプションを設定します。
app/build.gradle
android {
defaultConfig {
jackOptions {
enabled = true
additionalParameters 'jack.android.min-api-level': 'o-b1'
}
}
}
まずは、o-b1を試します。
ビルドします。
$ ./gradlew clean assembleDebug
:clean
:app:clean
:app:preBuild UP-TO-DATE
:app:resolveDebugDependencies
:app:preDebugBuild
:app:compileDebugNdk NO-SOURCE
:app:checkDebugManifest
:app:prepareDebugDependencies
:app:compileDebugAidl
:app:compileDebugRenderscript
:app:generateDebugBuildConfig
:app:generateDebugResValues
:app:handleDebugMicroApk
:app:generateDebugResources
:app:mergeDebugResources
:app:processDebugManifest
:app:processDebugResources
:app:generateDebugSources
:app:transformClassesWithPreJackPackagedLibrariesForDebug
:app:transformClassesWithPreJackRuntimeLibrariesForDebug
:app:processDebugJavaRes NO-SOURCE
:app:transformResourcesWithMergeJavaResForDebug
:app:transformJackAndJavaSourcesWithJackCompileForDebug
:app:compileDebugSources
:app:mergeDebugShaders
:app:compileDebugShaders
:app:generateDebugAssets
:app:mergeDebugAssets
:app:transformJackWithJackDexerForDebug
:app:mergeDebugJniLibFolders
:app:transformNativeLibsWithMergeJniLibsForDebug
:app:validateSigningDebug
:app:packageDebug
:app:assembleDebug
BUILD SUCCESSFUL
Total time: 4.636 secs
dexdumpします。
$ $ANDROID_HOME/build-tools/26.0.0-rc1/dexdump -d -h app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex
Processing 'app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex'...
Opened 'app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex', DEX version '037'
...
000634: |[000634] com.example.myapplication.Main.main:([Ljava/lang/String;)V
000644: 6200 0a00 |0000: sget-object v0, Ljava/lang/System;.out:Ljava/io/PrintStream; // field@000a
000648: 7100 1400 0000 |0002: invoke-static {}, Ljava/lang/invoke/MethodHandles;.lookup:()Ljava/lang/invoke/MethodHandles$Lookup; // method@0014
00064e: 0c01 |0005: move-result-object v1
000650: 1c02 0300 |0006: const-class v2, Lcom/example/myapplication/Main; // type@0003
000654: 1b03 3900 0000 |0008: const-string/jumbo v3, "add" // string@00000039
00065a: 6204 0900 |000b: sget-object v4, Ljava/lang/Integer;.TYPE:Ljava/lang/Class; // field@0009
00065e: 6205 0900 |000d: sget-object v5, Ljava/lang/Integer;.TYPE:Ljava/lang/Class; // field@0009
000662: 1216 |000f: const/4 v6, #int 1 // #1
000664: 2366 1b00 |0010: new-array v6, v6, [Ljava/lang/Class; // type@001b
000668: 6207 0900 |0012: sget-object v7, Ljava/lang/Integer;.TYPE:Ljava/lang/Class; // field@0009
00066c: 1208 |0014: const/4 v8, #int 0 // #0
00066e: 4d07 0608 |0015: aput-object v7, v6, v8
000672: 7130 1500 5406 |0017: invoke-static {v4, v5, v6}, Ljava/lang/invoke/MethodType;.methodType:(Ljava/lang/Class;Ljava/lang/Class;[Ljava/lang/Class;)Ljava/lang/invoke/MethodType; // method@0015
000678: 0c04 |001a: move-result-object v4
00067a: 6e40 1300 2143 |001b: invoke-virtual {v1, v2, v3, v4}, Ljava/lang/invoke/MethodHandles$Lookup;.findStatic:(Ljava/lang/Class;Ljava/lang/String;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/MethodHandle; // method@0013
000680: 0c01 |001e: move-result-object v1
000682: 1222 |001f: const/4 v2, #int 2 // #2
000684: 1233 |0020: const/4 v3, #int 3 // #3
000686: fa30 1200 2103 0400 |0021: invoke-polymorphic {v1, v2, v3}, Ljava/lang/invoke/MethodHandle;.invoke:([Ljava/lang/Object;)Ljava/lang/Object;, (II)Ljava/lang/Object; // method@0012, proto@0004
00068e: 0c01 |0025: move-result-object v1
000690: 6e20 0d00 1000 |0026: invoke-virtual {v0, v1}, Ljava/io/PrintStream;.println:(Ljava/lang/Object;)V // method@000d
000696: 0e00 |0029: return-void
...
Dexファイルのバージョンは037です。
MethodHandler#invoke()の箇所(下から4行目)でinvoke-polymorphicが出現しています。
上記で確認したオプションの説明通りです。
次に、o-b2を試します。
app/build.gradle
android {
defaultConfig {
jackOptions {
enabled = true
additionalParameters 'jack.android.min-api-level': 'o-b2'
}
}
}
ビルドして、確認してみます。
$ ./gradlew clean assembleDebug --quiet
$ $ANDROID_HOME/build-tools/26.0.0-rc1/dexdump -d -h app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex
Processing 'app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex'...
Opened 'app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex', DEX version '038'
...
000634: |[000634] com.example.myapplication.Main.main:([Ljava/lang/String;)V
000644: 6200 0a00 |0000: sget-object v0, Ljava/lang/System;.out:Ljava/io/PrintStream; // field@000a
000648: 7100 1400 0000 |0002: invoke-static {}, Ljava/lang/invoke/MethodHandles;.lookup:()Ljava/lang/invoke/MethodHandles$Lookup; // method@0014
00064e: 0c01 |0005: move-result-object v1
000650: 1c02 0300 |0006: const-class v2, Lcom/example/myapplication/Main; // type@0003
000654: 1b03 3900 0000 |0008: const-string/jumbo v3, "add" // string@00000039
00065a: 6204 0900 |000b: sget-object v4, Ljava/lang/Integer;.TYPE:Ljava/lang/Class; // field@0009
00065e: 6205 0900 |000d: sget-object v5, Ljava/lang/Integer;.TYPE:Ljava/lang/Class; // field@0009
000662: 1216 |000f: const/4 v6, #int 1 // #1
000664: 2366 1b00 |0010: new-array v6, v6, [Ljava/lang/Class; // type@001b
000668: 6207 0900 |0012: sget-object v7, Ljava/lang/Integer;.TYPE:Ljava/lang/Class; // field@0009
00066c: 1208 |0014: const/4 v8, #int 0 // #0
00066e: 4d07 0608 |0015: aput-object v7, v6, v8
000672: 7130 1500 5406 |0017: invoke-static {v4, v5, v6}, Ljava/lang/invoke/MethodType;.methodType:(Ljava/lang/Class;Ljava/lang/Class;[Ljava/lang/Class;)Ljava/lang/invoke/MethodType; // method@0015
000678: 0c04 |001a: move-result-object v4
00067a: 6e40 1300 2143 |001b: invoke-virtual {v1, v2, v3, v4}, Ljava/lang/invoke/MethodHandles$Lookup;.findStatic:(Ljava/lang/Class;Ljava/lang/String;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/MethodHandle; // method@0013
000680: 0c01 |001e: move-result-object v1
000682: 1222 |001f: const/4 v2, #int 2 // #2
000684: 1233 |0020: const/4 v3, #int 3 // #3
000686: fa30 1200 2103 0400 |0021: invoke-polymorphic {v1, v2, v3}, Ljava/lang/invoke/MethodHandle;.invoke:([Ljava/lang/Object;)Ljava/lang/Object;, (II)Ljava/lang/Object; // method@0012, proto@0004
00068e: 0c01 |0025: move-result-object v1
000690: 6e20 0d00 1000 |0026: invoke-virtual {v0, v1}, Ljava/io/PrintStream;.println:(Ljava/lang/Object;)V // method@000d
000696: 0e00 |0029: return-void
...
Dexファイルのバージョンは038です。
下から4行目にinvoke-polymorphicが出現しているのはオプションの説明通りですが、一方、invoke-customは見つかりませんでした。
$ $ANDROID_HOME/build-tools/26.0.0-rc1/dexdump -d -h app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex \
> | grep -i invoke-custom | wc -l
0
JavaのクラスファイルではCallSiteが現れているので、invoke-customが出現するかと思いましたが、そうはなっていませんでした。
$ ./gradlew clean compileDebugJavaWithJavac --quiet
$ javap -v -private app/build/intermediates/classes/debug/com/example/myapplication/Main.class
...
static int add(int, int);
descriptor: (II)I
flags: ACC_STATIC
Code:
stack=3, locals=3, args_size=2
0: invokedynamic #12, 0 // InvokeDynamic #0:apply:()Ljava/util/function/BiFunction;
5: astore_2
6: aload_2
7: iload_0
8: invokestatic #13 // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
11: iload_1
12: invokestatic #13 // Method java/lang/Integer.valueOf:(I)Ljava/lang/Integer;
15: invokeinterface #14, 3 // InterfaceMethod java/util/function/BiFunction.apply:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
20: checkcast #15 // class java/lang/Integer
23: invokevirtual #16 // Method java/lang/Integer.intValue:()I
26: ireturn
LineNumberTable:
line 18: 0
line 19: 6
LocalVariableTable:
Start Length Slot Name Signature
0 27 0 a I
0 27 1 b I
6 21 2 f Ljava/util/function/BiFunction;
LocalVariableTypeTable:
Start Length Slot Name Signature
6 21 2 f Ljava/util/function/BiFunction<Ljava/lang/Integer;Ljava/lang/Integer;Ljava/lang/Integer;>;
...
SourceFile: "Main.java"
InnerClasses:
public static final #81= #57 of #50; //Lookup=class java/lang/invoke/MethodHandles$Lookup of class java/lang/invoke/MethodHandles
BootstrapMethods:
0: #64 invokestatic java/lang/invoke/LambdaMetafactory.metafactory:(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodType;Ljava/lang/invoke/MethodHandle;Ljava/lang/invoke/MethodType;)Ljava/lang/invoke/CallSite;
Method arguments:
#65 (Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
#66 invokestatic com/example/myapplication/Main.lambda$add$0:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
#67 (Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
JackのRopBuilderVisitor.javaを見ると、メソッド呼び出しがinvoke-customかどうかをInvokeCustomHelper#isInvokeCustom(JAbstractMethodCall)で判断しています。
InvokeCustomHelper.javaを見ると、メソッドにCalledByInvokeCustomアノテーションが付与されていれば、invoke-customと判断しているようです。
jack/src/com/android/jack/backend/dex/invokecustom/InvokeCustomHelper.java
public static boolean isInvokeCustom(@Nonnull JAbstractMethodCall call) {
Collection<JMethod> methods = call.getMethodIdWide().getMethods();
Iterator<JMethod> methodsIt = methods.iterator();
boolean isInvokeCustom = false;
while (methodsIt.hasNext()) {
JMethod method = methodsIt.next();
if (getInvokeCustomCallsite(method) != null) {
isInvokeCustom = true;
break;
}
}
assert !isInvokeCustom || methods.size() == 1;
return isInvokeCustom;
}
@CheckForNull
public static JAnnotation getInvokeCustomCallsite(@Nonnull JMethod method) {
for (JAnnotation annotation : method.getAnnotations()) {
if (annotation.getType().getName().equals("CalledByInvokeCustom")) {
return annotation;
}
}
return null;
}
CalledByInvokeCustomはjack-testsディレクトリ配下にあるので、これを使ってみます。
$ git clone https://android.googlesource.com/toolchain/jack
$ (cd jack; git checkout -b ub-jack origin/ub-jack)
$ (cd jack/jack-tests/src; cp -p --parent com/android/jack/annotations/*.java ../../../app/src/main/java/)
さらに、Main.javaを以下のように書きかえます。
app/src/main/java/com/example/myapplication/Main.java
package com.example.myapplication;
import com.android.jack.annotations.CalledByInvokeCustom;
import com.android.jack.annotations.LinkerMethodHandle;
import com.android.jack.annotations.MethodHandleKind;
import java.lang.invoke.CallSite;
import java.lang.invoke.ConstantCallSite;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.util.function.BiFunction;
public class Main {
public static void main(String[] args) throws Throwable {
System.out.println(MethodHandles.lookup()
.findStatic(Main.class,
"add",
MethodType.methodType(int.class, int.class, int.class))
.invoke(2, 3));
}
static int add(int a, int b) {
BiFunction<Integer, Integer, Integer> f = new BiFunction<Integer, Integer, Integer>() {
@Override
public Integer apply(Integer integer, Integer integer2) {
return add0(a, b);
}
};
return f.apply(a, b);
}
@CalledByInvokeCustom(
invokeMethodHandle = @LinkerMethodHandle(kind = MethodHandleKind.INVOKE_STATIC,
enclosingType = Main.class,
name = "linkerMethod",
argumentTypes = {MethodHandles.Lookup.class, String.class, MethodType.class}),
name = "add0",
returnType = Integer.class,
argumentTypes = {Integer.class, Integer.class})
static Integer add0(Integer a, Integer b) {
return a + b;
}
private static CallSite linkerMethod(MethodHandles.Lookup caller, String name, MethodType methodType)
throws NoSuchMethodException, IllegalAccessException {
return new ConstantCallSite(caller.findStatic(caller.lookupClass(), name, methodType));
}
}
ビルドして、確認してみます。
$ ./gradlew clean assembleDebug --quiet
$ $ANDROID_HOME/build-tools/26.0.0-rc1/dexdump -d -h app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex
Processing 'app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex'...
Opened 'app/build/intermediates/transforms/jackDexer/debug/folders/1000/1f/main/classes.dex', DEX version '038'
...
000c18: |[000c18] com.example.myapplication.Main.1.apply:(Ljava/lang/Integer;Ljava/lang/Integer;)Ljava/lang/Integer;
000c28: 5220 0e00 |0000: iget v0, v2, Lcom/example/myapplication/Main$1;.val$a:I // field@000e
000c2c: 7110 3000 0000 |0002: invoke-static {v0}, Ljava/lang/Integer;.valueOf:(I)Ljava/lang/Integer; // method@0030
000c32: 0c00 |0005: move-result-object v0
000c34: 5221 0f00 |0006: iget v1, v2, Lcom/example/myapplication/Main$1;.val$b:I // field@000f
000c38: 7110 3000 0100 |0008: invoke-static {v1}, Ljava/lang/Integer;.valueOf:(I)Ljava/lang/Integer; // method@0030
000c3e: 0c01 |000b: move-result-object v1
000c40: fc20 0000 1000 |000c: invoke-custom {v0, v1}, call_site@0000
000c46: 0c00 |000f: move-result-object v0
000c48: 1100 |0010: return-object v0
...
invoke-customが現れました(下から3行目)。
将来的にはラムダ式の呼び出しはinvoke-customになるのでしょうか？
Jackは非推奨になるらしいので、dx側でinvokedynamicをinvoke-customに変換するようになるのかもしれません。
ちなみに、jack.jarにはjack.lambda.anonymousというプロパティがあるので
jack.lambda.anonymous:
Enable lambda support with an anonymous class (default is 'true')
{true,yes,on,1,false,no,off,0} (case insensitive)
これをfalseにしてみたのですが、残念ながらエラーになってしまいました。
app/build.gradle
android {
defaultConfig {
jackOptions {
enabled = true
additionalParameters 'jack.android.min-api-level': 'o-b2'
additionalParameters 'jack.lambda.anonymous': 'false'
}
}
}
$ ./gradlew clean assembleDebug --stacktrace
...
:app:transformJackAndJavaSourcesWithJackCompileForDebug FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:transformJackAndJavaSourcesWithJackCompileForDebug'.
> com.android.sched.scheduler.RunnerProcessException: Error during 'CodeItemBuilder' runner on 'static int com.example.myapplication.Main.add(int a, int b) (/home/tmura/AndroidStudioProjects/MyApplication2/app/src/main/java/com/example/myapplication/Main.java:17.5-20.5)': Unexpected error during visit: com.android.jack.ir.ast.JLambda at "/home/tmura/AndroidStudioProjects/MyApplication2/app/src/main/java/com/example/myapplication/Main.java:18.51-18.69"
* Try:
Run with --info or --debug option to get more log output.
* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:transformJackAndJavaSourcesWithJackCompileForDebug'.
...
Caused by: java.lang.AssertionError
at com.android.jack.backend.dex.rop.RopBuilderVisitor$AssignBuilderVisitor.visit(RopBuilderVisitor.java:224)
at com.android.jack.ir.ast.JLambda.traverse(JLambda.java:108)
at com.android.jack.ir.ast.JVisitor.accept(JVisitor.java:51)
... 10 more
エラー元を見ると、無条件でthrow new AssertionError()しているので、現状このオプションをfalseにすることはできないようです。
以上です。
参考
Dalvik bytecode
https://source.android.com/devices/tech/dalvik/dalvik-bytecode.html