CODEWITHSUNDEEP
javajava-bytecode-asmbytecode-manipulation
shijie xu
shijie xu

Reputation: 2097

ClassFormatError: Field "_callee__a1" in class <Unknown> has illegal signature "_callee"

Some exception occurs when I try to inline two classes: 

public class CI_Caller1 {
    private int _data;
    private CI_Callee_2 _callee;

    public CI_Caller1(int data, CI_Callee_2 callee){
        _data = data;
        _callee = callee;
    }
}

public class CI_Callee_2 {

    private Integer _a1;
    private String _t;

    public CI_Callee_2(Integer a1, String t){
        _a1 = a1;
        _t = t;
    }
}

The inling operation is to inline two fields, _a and _t in CI_Callee_2, as a member of CI_Caller1. The new member would be: 

private int _data;
private Integer _callee__a1;
private String _callee__t;

Everything seems correct, but when i try to load the generated byte[], exception is thrown as: 

java.lang.ClassFormatError: Field "_callee__a1" in class <Unknown> has illegal signature "_callee"
    at sun.misc.Unsafe.defineAnonymousClass(Native Method)
    at code.jit.asm.services.ACLoader.loadClass(ACLoader.java:27)

The way to vistiField is like: 

    _fieldNode = reference2CI_Callee_2FieldNode();
    //cw is class visitor to the CI_Caller1
    cw.visitField(_fieldNode.access, calculateName(fieldHoster, _fieldNode.name), 
            _fieldNode.desc, _fieldNode.signature, _fieldNode.value);

The _fieldNode here references to a CI_Callee_2's field, and its original members (and its values): 

desc: Ljava/lang/Integer;
name: _a1     //calculateName will map _a1 to _callee_a1
signature: null
value: null

I did not make any change on the _fieldNode once it is initilized with ClassNode of CI_Callee_2. (The signature value of _fieldNode keeps NULL all the time)

Is there anyone seen this exception? Thanks.

Upvotes: 0

Views: 685

Answers (1)

Erwin Bolwidt
Erwin Bolwidt

Reputation: 31269

The field you created with the name "_callee__a1" has the signature _callee. The character _ is not a valid start of a field signature. You say you want the type to be Integer, so the field signature should be Ljava/lang/Integer;. (The L indicates that this is a reference type)

Upvotes: 0

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