Package org.plumelib.bcelutil

Class StackVer

java.lang.Object
org.plumelib.bcelutil.StackVer
public final class StackVer extends Object
This is a slightly modified version of Pass3bVerifier from BCEL. It uses NoConstaintsVisitor as InstConstraintVisitor appears to be quite out of date and incorrectly fails on many valid class files. Hence, StackVer assumes the method is valid and is only interested in the result of the symbolic execution in order to capture the state of the local variables and stack at the start of each byte code instruction.

To see the diffs, you will need a git clone of git@github.com:apache/commons-bcel.git. The particular version StackVer is based on can be retrieved with git show e6dcacb9ca1d:src/main/java/org/apache/bcel/verifier/structurals/Pass3bVerifier.java then run google-java-format on the downloaded file.

The original documentation follows.

This PassVerifier verifies a method of class file according to pass 3, so-called structural verification as described in The Java Virtual Machine Specification, 2nd edition. More detailed information is to be found at the do_verify() method's documentation.

See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    StackVer()
    This class should only be instantiated by a Verifier.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addMessage(String message)
    This method adds a (warning) message to the message pool of this PassVerifier.
    org.apache.bcel.verifier.VerificationResult
    do_stack_ver(org.apache.bcel.generic.MethodGen mg)
    Pass 3b implements the data flow analysis as described in the Java Virtual Machine Specification, Second Edition.
    StackTypes
    get_stackTypes()
    Return the types on the stack at each byte code offset.
    void
    invalidReturnTypeError(org.apache.bcel.generic.Type returnedType, org.apache.bcel.generic.MethodGen m)
    Throws an exception indicating the returned type is not compatible with the return type of the given method.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • StackVer

      public StackVer()
      This class should only be instantiated by a Verifier.
      See Also:
      • Verifier

  • Method Details

    • get_stackTypes

      public StackTypes get_stackTypes()
      Return the types on the stack at each byte code offset. Only valid after do_stack_ver() is called.
      Returns:
      the StackTypes object for the method being verified

    • invalidReturnTypeError

      public void invalidReturnTypeError(org.apache.bcel.generic.Type returnedType, org.apache.bcel.generic.MethodGen m)
      Throws an exception indicating the returned type is not compatible with the return type of the given method.
      Parameters:
      returnedType - the type of the returned expression
      m - the method we are processing
      Throws:
      org.apache.bcel.verifier.exc.StructuralCodeConstraintException - always
      Since:
      6.0

    • do_stack_ver

      public org.apache.bcel.verifier.VerificationResult do_stack_ver(org.apache.bcel.generic.MethodGen mg)
      Pass 3b implements the data flow analysis as described in the Java Virtual Machine Specification, Second Edition. Later versions will use LocalVariablesInfo objects to verify if the verifier-inferred types and the class file's debug information (LocalVariables attributes) match [TODO].
      Parameters:
      mg - MethodGen for the method to be verified
      Returns:
      the VerificationResult
      See Also:
      • LocalVariablesInfo
      • Pass2Verifier.getLocalVariablesInfo(int)

    • addMessage

      public void addMessage(String message)
      This method adds a (warning) message to the message pool of this PassVerifier.
      Parameters:
      message - the String containing the warning message