[BCEL-285] "ClassFormatException: Invalid signature" thrown on generics

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 6.0
• Component/s: Parser

Environment

java 8, macOS 10.12.2

• Severity: major
• Assignee: Unassigned
• Reporter: Tom Brus
• Created: 17/Jan/17 21:05
• Updated: 25/Jul/19 21:48

Description

The following stripped down example throws an Exception in BCEL:

Bar.java

import java.io.IOException;
import java.util.stream.Stream;
import org.apache.bcel.classfile.ClassParser;

public class Main {
  public static void main(String[] args) throws IOException {
    ClassParser parser = new ClassParser(Main.class.getResourceAsStream("Main.class"), "Main.class");
    parser.parse().getMethods()[2].getCode().toString(); /* <- EXCEPTION thrown */
		
    ((Stream<? extends Object>)null).peek(x -> {}); /* <- problem spot */
  }
}

The exception is:

Exception in thread "main" org.apache.bcel.classfile.ClassFormatException: Invalid signature: `!+Ljava/lang/Object;'
	at org.apache.bcel.classfile.Utility.signatureToString(Utility.java:930)
	at org.apache.bcel.classfile.LocalVariable.toStringShared(LocalVariable.java:187)
	at org.apache.bcel.classfile.LocalVariableTypeTable.toString(LocalVariableTypeTable.java:121)
	at java.lang.String.valueOf(String.java:2994)
	at java.lang.StringBuilder.append(StringBuilder.java:131)
	at org.apache.bcel.classfile.Code.toString(Code.java:316)
	at org.apache.bcel.classfile.Code.toString(Code.java:328)
	at Main.main(Main.java:9)

This problem only occurs in eclipse (I am using NEON.2) and does not occur in Intellij (I am using 2016.3.2). This probably indicates that ecj and javac differ in their class code generator.

Since our project uses sonar:findbugs which uses BCEL this is a major problem for us.