Failure after instrumentation of code which has stackmap frames and array of more than 7 dimensions

[quiquinSP]

I am in the process of migrating a SW from Java 8 to Java 11. We are using JaCoCo for code coverage and I have found a problem when running the unit tests with JaCoCo tool (using ant).

JaCoCo fails when it instantiates a class that contains a primitive array with more than 8 dimensions. Please do not ask about the motivation of having an 8 dimensional array .... legacy code I have to maintain.

I have reduced the code to the min that reproduces the problem.

• The execution goes fine when I do not use JaCoCo/EclEmma or I use Java 8
• I have tested with two different JaCoCo versions , 0.8.2 and 0.8.3

Steps to reproduce

JaCoCo version: tested with 0.8.2 and 0.8.3
Operating system: MacOS HighSierra 10.13.6 and CentOS Linux release 7.5.1804
Tool integration: Ant 1.10.5 and Eclipse EclEmma 3.1.1.201809121651
Java Versions: OpenJDK 11.0.1 and OpenJDK 11.0.2

Use the following piece of code

import org.junit.Test;
public class PrimitiveArrayJacocoTest {

	/**
	 * Test with a boolean array
	 */
	@Test
	public void testBooleanArray() {
		// Just instantiate the class
		new BooleanArrayJacoco();		
	}
	
	/**
	 * Test with an integer array
	 */
	@Test
	public void testIntegerArray() {	
		// Just instantiate the class
		new IntegerArrayJacoco();	
	}
	
	public class BooleanArrayJacoco {
		
		public BooleanArrayJacoco() {
		    
			// Declare a 8 dimension boolean array , if the amount of dimensions is reduced test does not fail. 
		    boolean[][][][][][][][] array = new boolean[12][][][][][][][];
		    int idxDepth0 = 0; 
		    if(array[idxDepth0] == null) {
		    	array[0] = new boolean[4][][][][][][]; // Create new node with 4 array pointers
		    }
		}
		
	}
	
	public class IntegerArrayJacoco {
		
		public IntegerArrayJacoco() {
		    
			// Declare a 8 dimension integer array , if the amount of dimensions is reduced test does not fail. 
		    int[][][][][][][][] array = new int[12][][][][][][][];
		    int idxDepth0 = 0; 
		    if(array[idxDepth0] == null) {
		    	array[0] = new int[4][][][][][][]; // Create new node with 4 array pointers
		    }
		}
		
	}

}

Expected behaviour

JaCoCo is able to run the tests with no failure.

Actual behaviour

Tests fail with the following stack trace

java.lang.NoClassDefFoundError: I
 at gaia.cu1.tools.util.lookuptree.PrimitiveArrayJacocoTest.testIntegerArray(PrimitiveArrayJacocoTest.java:44)
 at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.base/java.lang.reflect.Method.invoke(Method.java:566)
 at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
 at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
 at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
 at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
 at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
 at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
 at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
 at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
 at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
 at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
 at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
 at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
 at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
 at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
 at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)
Caused by: java.lang.ClassNotFoundException: I
 at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
 at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
 at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
 ... 24 more

and running the testBooleanArray .... the same but with different ClassNotFoundException:

java.lang.NoClassDefFoundError: Z
 at gaia.cu1.tools.util.lookuptree.PrimitiveArrayJacocoTest.testBooleanArray(PrimitiveArrayJacocoTest.java:33)
 at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.base/java.lang.reflect.Method.invoke(Method.java:566)
 at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
 at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
 at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
 at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
 at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
 at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
 at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
 at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
 at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
 at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
 at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
 at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
 at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
 at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
 at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
 at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)
Caused by: java.lang.ClassNotFoundException: Z
 at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
 at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
 at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
 ... 24 more

[Godin]

Hi @quiquinSP, first of all thank you for the reproducer! 👍 ❤️

However I doubt about correctness of your statement

The execution goes fine when I use Java 8

because following reduced Example.java

public class Example {
    public static void main(String[] args) {
        boolean[][][][][][][][] a = new boolean[12][][][][][][][];
        int i = 0;
        if (a[i] == null) {
            a[0] = new boolean[4][][][][][][];
        }
        System.out.println("OK");
    }
}

demonstrates exactly the same problem even with Java 8:

$ java -version
java version "1.8.0_172"
Java(TM) SE Runtime Environment (build 1.8.0_172-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.172-b11, mixed mode)

$ javac -version
javac 1.8.0_172

$ javac -source 8 -target 8 Example.java

$  java -javaagent:jacoco-0.8.3/lib/jacocoagent.jar Example
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: Z
	at java.lang.Class.getDeclaredMethods0(Native Method)
	at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
	at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
	at java.lang.Class.getMethod0(Class.java:3018)
	at java.lang.Class.getMethod(Class.java:1784)
	at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
	at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: Z
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 7 more

but the problem goes away when class has no stackmap frames, i.e. when compiled into Java 5 bytecode:

$ javap -v -p Example | grep "StackMapTable:" | wc -l
1

$ javap -v -p Example | grep "major"
  major version: 52

$ javac -source 5 -target 5 Example.java
warning: [options] bootstrap class path not set in conjunction with -source 1.5
warning: [options] source value 1.5 is obsolete and will be removed in a future release
warning: [options] target value 1.5 is obsolete and will be removed in a future release
warning: [options] To suppress warnings about obsolete options, use -Xlint:-options.
4 warnings

$ javap -v -p Example | grep "StackMapTable:" | wc -l
0

$ javap -v -p Example | grep "major"
  major version: 49

$ java -javaagent:jacoco-0.8.3/lib/jacocoagent.jar Example
OK

and seems to be related to the bug in ASM library - https://gitlab.ow2.org/asm/asm/issues/317866

As a temporary workaround you can exclude such classes from JaCoCo instrumentation.

---

P.S. and please excuse me for pedantism, however

JaCoCo fails when it instantiates a class

JaCoCo does not perform instantiation - it performs instrumentation; instantiation, initialization and etc are performed by JVM as usual.

[quiquinSP]

Hi @Godin,

thank you very much for your prompt reaction.

However I doubt about correctness of your statement

The execution goes fine when I use Java 8

Yes, you are right the problem was not related with Java version, with Java 8 I was using a different version of JaCoCo 0.7.9 that uses a different asm version (5.2).

As a temporary workaround you can exclude such classes from JaCoCo instrumentation.

Yes, I am going to exclude this particular test from the analysis.

[Godin]

For the record - the same problem with arrays of non-primitive with more than 7 dimensions:

public class Example {
    public static void main(String[] args) {
        Object[][][][][][][][] a = new Object[1][][][][][][][];
        if (a[0] == null) {
            a = null;
        }
        System.out.println("OK");
    }
}

however exception looks differently

$ javac -source 8 -target 8 Example.java

$ java -javaagent:jacoco-0.8.3/lib/jacocoagent.jar Example
Exception in thread "main" java.lang.VerifyError: Inconsistent stackmap frames at branch target 22
Exception Details:
  Location:
    Example.main([Ljava/lang/String;)V @22: aconst_null
  Reason:
    Type '[[[[[[[[Ljava/lang/Object;' (current frame, locals[2]) is not assignable to 'Ljava/lang/Object;' (stack map, locals[2])
  Current Frame:
    bci: @12
    flags: { }
    locals: { '[Ljava/lang/String;', '[Z', '[[[[[[[[Ljava/lang/Object;' }
    stack: { '[[[[[[[Ljava/lang/Object;' }
  Stackmap Frame:
    bci: @22
    flags: { }
    locals: { '[Ljava/lang/String;', '[Z', 'Ljava/lang/Object;' }
    stack: { }
  Bytecode:
    0x0000000: b800 254c 04bd 0002 4d2c 0332 c600 0a2b
    0x0000010: 0404 54a7 000c 01c0 0003 4d2b 0504 54b2
    0x0000020: 0004 1205 b600 062b 0604 54b1
  Stackmap Table:
    append_frame(@22,Object[#39],Object[#41])
    same_frame(@31)