Class Pass3aVerifier


  • public final class Pass3aVerifier
    extends PassVerifier
    This PassVerifier verifies a class file according to pass 3, static part 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:
    do_verify()
    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      private class  Pass3aVerifier.InstOperandConstraintVisitor
      This visitor class does the actual checking for the instruction operand's constraints.
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private Code code
      The one and only Code object used by an instance of this class.
      private InstructionList instructionList
      The one and only InstructionList object used by an instance of this class.
      private int methodNo
      The method number to verify.
      private Verifier verifier
      The Verifier that created this.
    • Constructor Summary

      Constructors 
      Constructor Description
      Pass3aVerifier​(Verifier verifier, int methodNo)
      Should only be instantiated by a Verifier.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private static boolean contains​(int[] ints, int i)
      A small utility method returning if a given int i is in the given int[] ints.
      private void delayedPass2Checks()
      These are the checks that could be done in pass 2 but are delayed to pass 3 for performance reasons.
      VerificationResult do_verify()
      Pass 3a is the verification of static constraints of JVM code (such as legal targets of branch instructions).
      int getMethodNo()
      Returns the method number as supplied when instantiating.
      private void pass3StaticInstructionChecks()
      These are the checks if constraints are satisfied which are described in the Java Virtual Machine Specification, Second Edition as Static Constraints on the instructions of Java Virtual Machine Code (chapter 4.8.1).
      private void pass3StaticInstructionOperandsChecks()
      These are the checks for the satisfaction of constraints which are described in the Java Virtual Machine Specification, Second Edition as Static Constraints on the operands of instructions of Java Virtual Machine Code (chapter 4.8.1).
      protected java.lang.String tostring​(java.lang.Object obj)
      This method is a slightly modified version of verifier.statics.StringRepresentation.toString(final Node obj) that accepts any Object, not just a Node.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • verifier

        private final Verifier verifier
        The Verifier that created this.
      • methodNo

        private final int methodNo
        The method number to verify. This is the index in the array returned by JavaClass.getMethods().
      • instructionList

        private InstructionList instructionList
        The one and only InstructionList object used by an instance of this class. It's here for performance reasons by do_verify() and its callees.
      • code

        private Code code
        The one and only Code object used by an instance of this class. It's here for performance reasons by do_verify() and its callees.
    • Constructor Detail

      • Pass3aVerifier

        public Pass3aVerifier​(Verifier verifier,
                              int methodNo)
        Should only be instantiated by a Verifier.
    • Method Detail

      • contains

        private static boolean contains​(int[] ints,
                                        int i)
        A small utility method returning if a given int i is in the given int[] ints.
      • delayedPass2Checks

        private void delayedPass2Checks()
        These are the checks that could be done in pass 2 but are delayed to pass 3 for performance reasons. Also, these checks need access to the code array of the Code attribute of a Method so it's okay to perform them here. Also see the description of the do_verify() method.
        Throws:
        ClassConstraintException - if the verification fails.
        See Also:
        do_verify()
      • do_verify

        public VerificationResult do_verify()
        Pass 3a is the verification of static constraints of JVM code (such as legal targets of branch instructions). This is the part of pass 3 where you do not need data flow analysis. JustIce also delays the checks for a correct exception table of a Code attribute and correct line number entries in a LineNumberTable attribute of a Code attribute (which conceptually belong to pass 2) to this pass. Also, most of the check for valid local variable entries in a LocalVariableTable attribute of a Code attribute is delayed until this pass. All these checks need access to the code array of the Code attribute.
        Specified by:
        do_verify in class PassVerifier
        Returns:
        The VerificationResult
        Throws:
        InvalidMethodException - if the method to verify does not exist.
      • getMethodNo

        public int getMethodNo()
        Returns the method number as supplied when instantiating.
      • pass3StaticInstructionChecks

        private void pass3StaticInstructionChecks()
        These are the checks if constraints are satisfied which are described in the Java Virtual Machine Specification, Second Edition as Static Constraints on the instructions of Java Virtual Machine Code (chapter 4.8.1).
        Throws:
        StaticCodeConstraintException - if the verification fails.
      • pass3StaticInstructionOperandsChecks

        private void pass3StaticInstructionOperandsChecks()
        These are the checks for the satisfaction of constraints which are described in the Java Virtual Machine Specification, Second Edition as Static Constraints on the operands of instructions of Java Virtual Machine Code (chapter 4.8.1). BCEL parses the code array to create an InstructionList and therefore has to check some of these constraints. Additional checks are also implemented here.
        Throws:
        StaticCodeConstraintException - if the verification fails.
      • tostring

        protected java.lang.String tostring​(java.lang.Object obj)
        This method is a slightly modified version of verifier.statics.StringRepresentation.toString(final Node obj) that accepts any Object, not just a Node. Returns the String representation of the Object obj; this is obj.toString() if it does not throw any RuntimeException, or else it is a string derived only from obj's class name.