[jira] [Updated] (BCEL-137) "Invalid method signature: TT;" when using MethodGen for a method having a generic parameter

["Emmanuel Bourg (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/BCEL-137?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Emmanuel Bourg updated BCEL-137:
--------------------------------

         Priority: Blocker
      Environment:     (was: Operating System: All
Platform: All)
    Fix Version/s: 6.0
         Priority:   (was: P2)
         Severity:   (was: major)

> "Invalid method signature: TT;" when using MethodGen for a method having a generic parameter
> --------------------------------------------------------------------------------------------
>
>                 Key: BCEL-137
>                 URL: https://issues.apache.org/jira/browse/BCEL-137
>             Project: Commons BCEL
>          Issue Type: Bug
>          Components: Main
>    Affects Versions: unspecified
>            Reporter: Enrico Gueli
>            Assignee: Apache Commons Developers
>            Priority: Blocker
>             Fix For: 6.0
>
>         Attachments: patch.txt
>
>
> The following code throws a "ClassFormatException: Invalid method signature: TT;" when executed:
> ===========================================================
> import org.apache.bcel.Repository;
> import org.apache.bcel.classfile.JavaClass;
> import org.apache.bcel.classfile.Method;
> import org.apache.bcel.generic.ConstantPoolGen;
> import org.apache.bcel.generic.MethodGen;
> class MyClassLoader extends ClassLoader {
> 	@Override
> 	public Class<?> loadClass(String name) throws ClassNotFoundException {
> 		if (name.startsWith("java.lang"))
> 			return super.loadClass(name);
> 		JavaClass jcl;
> 		jcl = Repository.lookupClass(name);
> 		scanMethods(jcl);
> 		byte[] data = jcl.getBytes();
> 		return defineClass(name, data, 0, data.length);
> 	}
> 	private void scanMethods(JavaClass jcl) {
> 		ConstantPoolGen cpg = new ConstantPoolGen(jcl.getConstantPool());
> 		Method[] methods = jcl.getMethods();
> 		for (int i = 0; i < methods.length; i++) {
> 			MethodGen mg = new MethodGen(methods[i], jcl.getClassName(), cpg);
> 		}
> 	}
> }
> class Foo<T> {
> 	public void bar(T x) {
> 	}
> }
> public class MethSignTest {
> 	public MethSignTest() {
> 		Foo<Integer> foo = new Foo<Integer>();
> 	}
> 	@SuppressWarnings("unchecked")
> 	public static void main(String[] args) {
> 		try {
> 			MyClassLoader mcl = new MyClassLoader();
> 			Class<MethSignTest> c = (Class<MethSignTest>) mcl
> 					.loadClass(MethSignTest.class.getName());
> 			c.newInstance();
> 		} catch (Exception e) {
> 			e.printStackTrace();
> 		}
> 	}
> }
> ===========================================================
> Here's the full stack trace:
> org.apache.bcel.classfile.ClassFormatException: Invalid method signature: TT;
> 	at org.apache.bcel.classfile.Utility.typeOfSignature(Utility.java:986)
> 	at org.apache.bcel.generic.Type.getType(Type.java:169)
> 	at org.apache.bcel.generic.MethodGen.<init>(MethodGen.java:255)
> 	at methodsignature.MyClassLoader.scanMethods(MethSignTest.java:26)
> 	at methodsignature.MyClassLoader.loadClass(MethSignTest.java:17)
> 	at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
> 	at methodsignature.MethSignTest.<init>(MethSignTest.java:38)
> 	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
> 	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
> 	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
> 	at java.lang.reflect.Constructor.newInstance(Constructor.java:501)
> 	at java.lang.Class.newInstance0(Class.java:350)
> 	at java.lang.Class.newInstance(Class.java:303)
> 	at methodsignature.MethSignTest.main(MethSignTest.java:47)
> This misbehaviour occurs at least since revision 617860.



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