[jboss-jira] [JBoss JIRA] Commented: (JASSIST-80) Editing MethodCall produces incorrect byte code | java.lang.VerifyError: Illegal target of jump or branch | invalid instruction

[Shigeru Chiba (JIRA)]

    [ https://jira.jboss.org/jira/browse/JASSIST-80?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12463130#action_12463130 ] 

Shigeru Chiba commented on JASSIST-80:
--------------------------------------

The attached files are only .class files before/after the instrumentation. 
Could you show us a Java program that transformed the class file (maybe by Javassist)?
It is really hard to see fix this bug without knowing how you modified the class file.
If it is difficult to show that Java program, telling us the overview of that program is also helpful.

Thank you!

> Editing MethodCall produces incorrect byte code | java.lang.VerifyError: Illegal target of jump or branch | invalid instruction
> -------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: JASSIST-80
>                 URL: https://jira.jboss.org/jira/browse/JASSIST-80
>             Project: Javassist
>          Issue Type: Bug
>    Affects Versions: 3.10.0.GA
>         Environment: $ java -version
> java version "1.6.0_07"
> Java(TM) SE Runtime Environment (build 1.6.0_07-b06-153)
> Java HotSpot(TM) 64-Bit Server VM (build 1.6.0_07-b06-57, mixed mode) 
>            Reporter: Martin Burger
>            Assignee: Shigeru Chiba
>         Attachments: TokenStream.java, TokenStream_instrumented.class, TokenStream_instrumented.dump, TokenStream_original.class
>
>
> Note: Most likely this issue is related to JASSIST-79.
> I instrument method calls in a class called org.mozilla.javascript.TokenStream.
> If I run (or, load) this class, a java.lang.VerifyError will be thrown:
> Exception in thread "main" java.lang.VerifyError: (class: org/mozilla/javascript/TokenStream, method: getToken$JINSI_4etOXffNDXVw signature: ()I) Illegal target of jump or branch
> It seems Javassist introduces a defective goto statement at position 33217 in method getToken$JINSI_4etOXffNDXVw:
> 33217	goto	465
> The corresponding Java code (excerpt):
>             case '-':
>                 if (matchChar('=')) {
>                     this.op = SUB;
>                     c = ASSIGN;
>                 } else if (matchChar('-')) {
>                     if (0 == (flags & TSF_DIRTYLINE)) {
>                         // treat HTML end-comment after possible whitespace
>                         // after line start as comment-utill-eol
>                         if (matchChar('>')) {
>                             skipLine();
>                             continue retry;
>                         }
>                     }
>                     c = DEC;
>                 } else {
>                     c = SUB;
>                 }
>                 flags |= TSF_DIRTYLINE;
>                 return c;
> I think the continue statement is related to this defect.
> JAD fails to decompile the instrumented class:
> ERROR: invalid instruction at 33217 in the method getToken$JINSI_4etOXffNDXVw. The method will be decompiled incorrectly.
> Javassist's framedump fails, too:
> Exception in thread "main" java.lang.RuntimeException: javassist.bytecode.BadBytecode: Stack is empty[pos = 465]
>         at javassist.bytecode.analysis.FramePrinter.print(FramePrinter.java:89)
>         at javassist.bytecode.analysis.FramePrinter.print(FramePrinter.java:60)
>         at javassist.bytecode.analysis.FramePrinter.print(FramePrinter.java:51)
>         at javassist.tools.framedump.main(framedump.java:45)
> Caused by: javassist.bytecode.BadBytecode: Stack is empty[pos = 465]
>         at javassist.bytecode.analysis.Analyzer.analyzeNextEntry(Analyzer.java:179)
>         at javassist.bytecode.analysis.Analyzer.analyze(Analyzer.java:143)
>         at javassist.bytecode.analysis.FramePrinter.print(FramePrinter.java:87)
>         ... 3 more
> Caused by: java.lang.IndexOutOfBoundsException: Stack is empty
>         at javassist.bytecode.analysis.Frame.pop(Frame.java:130)
>         at javassist.bytecode.analysis.Executor.simplePop(Executor.java:970)
>         at javassist.bytecode.analysis.Executor.evalStore(Executor.java:869)
>         at javassist.bytecode.analysis.Executor.execute(Executor.java:188)
>         at javassist.bytecode.analysis.Analyzer.analyzeNextEntry(Analyzer.java:177)
>         ... 5 more

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