IssueTracker

Versions

• r8 version: R8 main (build engineering)
• art version: ART version 2.1.0 x86_64
• java version: 17.0.12

Description

We encountered an issue while running the following test case. When processing the test case with R8, the final output shows that the return value of getClass is Impl1. However, according to the actual logic of the source code, the program should return Impl2. When processed with D8 or executed directly with the JVM, the program returns Impl2 as expected. The test case is a simplified result of our efforts. Is this an abnormal behavior of R8?

Step to Reproduce

1. javac -target 17 -source 17 -cp . Test.java
2. jar cvf classes.jar ./*.class
3. java -cp r8.jar com.android.tools.r8.R8 --pg-conf proguard-rules.pro --release --output ./ ./classes.jar
4. env ANDROID_LOG_TAGS=*:f ANDROID_DATA=./ /path/to/art --64 --no-compile -cp ./classes.dex Test

D8 & JVM result

A::foo
class [[Lc133$Impl2;

R8 result

A::foo
class [[Lc133$Impl1;

Testcase Source Code

class Test {
    public static void main(String[] strArr) {
        try {
            String[] var0 = { "x0" };
            c133.main(var0);
        } catch (Exception ex) {
        }
    }
}

class c133 {
    static Impl1[][] getArrayOfImpl1() {
        return new Impl1[][] { { new c133.Impl1() } };
    }

    static Impl2[][] getArrayOfImpl2() {
        return new Impl2[][] { { new c133.Impl2() } };
    }

    static I[][] getArrayOfIWithCast(boolean b) {
        Object arrayOfI;
        if (b)
            arrayOfI = c133.getArrayOfImpl1();
        else {
            arrayOfI = c133.getArrayOfImpl2();
            new c177.B().callFoo();
        }
        return (I[][]) arrayOfI;
    }

    static void main(String[] args) {
        System.out.println(c133.getArrayOfIWithCast(args.length == 0).getClass());
    }

    interface I {
    }

    static class Impl1 implements I {
    }

    static class Impl2 implements I {
    }
}

class c177 {
    static class A {
        void foo() {
            System.out.println("A::foo");
        }

        void callFoo() {
            foo();
        }
    }

    static class B extends A {
    }
}

rules.pro

-libraryjars android-35.jar
-dontobfuscate
-keep class Test { public static void main(java.lang.String[]); }