Bugzilla – Full Text Bug Listing
| Summary: | JDWP - Error when methodID==zero | ||
|---|---|---|---|
| Product: | [Eclipse Project] JDT | Reporter: | Lars Even <larseven> |
| Component: | Debug | Assignee: | JDT-Debug-Inbox <jdt-debug-inbox> |
| Status: | CLOSED FIXED | QA Contact: | |
| Severity: | normal | ||
| Priority: | P3 | ||
| Version: | 3.1 | ||
| Target Milestone: | --- | ||
| Hardware: | PC | ||
| OS: | Windows 2000 | ||
| Whiteboard: | |||
In the JVMDI specification, method ID zero is reserved for obsolete methods. (In reply to comment #1) > In the JVMDI specification, method ID zero is reserved for obsolete methods. Thanks Jared, I think that the problem is that the KVM Debug Proxy (KDP) from Sun generates method IDs that starts with index 0. (The KDP can be found in the J2ME_CLDC package). I modified the KDP and changed the initiation of method_index_base (line 13 in kdp\ProxyListener.java) to start at 1 instead of 0. I also made some adjustments in my customized KVM. These modifications solved the problem. Perhaps there are situations where the method_index_base should start at 0? If not; I think Sun should alter their source code. I am now marking this bug as fixed. -Lars E. Closed |
I am debugging a simple application on a remote VM using Eclipse 3.1.0 M7. My VM is a modified version of Sun's KVM. My problem is the JDWP/KDWP specified "methodID" (see definition at the end of this message). Eclipse does not seem to agree that zero is a valid methodID. Consider the following example 1. class Foo{ 2. 3. public Foo(){ 4. // Do something 5. } 6. 7. public Method_1(){} 8. public Method_2(){} 9. 10. public static void main(){ 11. new Foo(); 12. } 13. } I have set Eclipse to communicate with the VM through a KDWP-proxy-server. The KDWP-proxy-server loads the Foo-class and generates the following methodsIDs: method name: Foo.<init> methodID: 0 method name: Method_1 methodID: 1 method name: Method_2 methodID: 2 method name: main methodID: 3 When I set a breakpoint at line 4, Eclipse sends an EventRequest JDWP-command containing the methodID "0". After having pressed resume, I get to the breakpoint, and the VM sends an Event JDWP-command. The methodID is also this time "0", but this causes an internal error in Eclipse. Unfortunately no details on this internal error is presented. The isObsolete() method taken from org.eclipse.jdi.internal.MethodImpl is implemented as: public boolean isObsolete() { if (virtualMachineImpl().isJdwpVersionGreaterOrEqual(1, 4)) { return fMethodID.value() == 0; } return false; } This should perhaps be changed so that zero becomes a valid methodID. -Lars Even *) JDWP-Specification MethodID: Uniquely identifies a method in some class in the target VM. The methodID must uniquely identify the method within its class/interface or any of its subclasses/subinterfaces/implementors. A methodID is not necessarily unique on its own; it is always paired with a referenceTypeID to uniquely identify one method. The referenceTypeID can identify either the declaring type of the method or a subtype. (http://codenewbie.com/documentation/j2sdk-1_5_0/guide/jpda/jdwp-spec.html)