Class BasicInterpreter

java.lang.Object
org.objectweb.asm.tree.analysis.Interpreter<BasicValue>
org.objectweb.asm.tree.analysis.BasicInterpreter
All Implemented Interfaces:
Opcodes
Direct Known Subclasses:
BasicVerifier

public class BasicInterpreter extends Interpreter<BasicValue> implements Opcodes
An Interpreter for BasicValue values.
  • Field Details

    • NULL_TYPE

      public static final Type NULL_TYPE
      Special type used for the null literal. This is an object reference type with descriptor 'Lnull;'.
  • Constructor Details

    • BasicInterpreter

      public BasicInterpreter()
      Constructs a new BasicInterpreter for the latest ASM API version. Subclasses must not use this constructor. Instead, they must use the BasicInterpreter(int) version.
    • BasicInterpreter

      protected BasicInterpreter(int api)
      Constructs a new BasicInterpreter.
      Parameters:
      api - the ASM API version supported by this interpreter. Must be one of the ASMx values in Opcodes.
  • Method Details

    • newValue

      public BasicValue newValue(Type type)
      Description copied from class: Interpreter
      Creates a new value that represents the given type.

      Called for method parameters (including this), exception handler variable and with null type for variables reserved by long and double types.

      An interpreter may choose to implement one or more of Interpreter.newReturnTypeValue(Type), Interpreter.newParameterValue(boolean, int, Type), Interpreter.newEmptyValue(int), Interpreter.newExceptionValue(TryCatchBlockNode, Frame, Type) to distinguish different types of new value.

      Specified by:
      newValue in class Interpreter<BasicValue>
      Parameters:
      type - a primitive or reference type, or null to represent an uninitialized value.
      Returns:
      a value that represents the given type. The size of the returned value must be equal to the size of the given type.
    • newOperation

      public BasicValue newOperation(AbstractInsnNode insn) throws AnalyzerException
      Description copied from class: Interpreter
      Interprets a bytecode instruction without arguments. This method is called for the following opcodes:

      ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0, FCONST_1, FCONST_2, DCONST_0, DCONST_1, BIPUSH, SIPUSH, LDC, JSR, GETSTATIC, NEW

      Specified by:
      newOperation in class Interpreter<BasicValue>
      Parameters:
      insn - the bytecode instruction to be interpreted.
      Returns:
      the result of the interpretation of the given instruction.
      Throws:
      AnalyzerException - if an error occurred during the interpretation.
    • copyOperation

      public BasicValue copyOperation(AbstractInsnNode insn, BasicValue value) throws AnalyzerException
      Description copied from class: Interpreter
      Interprets a bytecode instruction that moves a value on the stack or to or from local variables. This method is called for the following opcodes:

      ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE, ASTORE, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP

      Specified by:
      copyOperation in class Interpreter<BasicValue>
      Parameters:
      insn - the bytecode instruction to be interpreted.
      value - the value that must be moved by the instruction.
      Returns:
      the result of the interpretation of the given instruction. The returned value must be equal to the given value.
      Throws:
      AnalyzerException - if an error occurred during the interpretation.
    • unaryOperation

      public BasicValue unaryOperation(AbstractInsnNode insn, BasicValue value) throws AnalyzerException
      Description copied from class: Interpreter
      Interprets a bytecode instruction with a single argument. This method is called for the following opcodes:

      INEG, LNEG, FNEG, DNEG, IINC, I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, I2C, I2S, IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, TABLESWITCH, LOOKUPSWITCH, IRETURN, LRETURN, FRETURN, DRETURN, ARETURN, PUTSTATIC, GETFIELD, NEWARRAY, ANEWARRAY, ARRAYLENGTH, ATHROW, CHECKCAST, INSTANCEOF, MONITORENTER, MONITOREXIT, IFNULL, IFNONNULL

      Specified by:
      unaryOperation in class Interpreter<BasicValue>
      Parameters:
      insn - the bytecode instruction to be interpreted.
      value - the argument of the instruction to be interpreted.
      Returns:
      the result of the interpretation of the given instruction.
      Throws:
      AnalyzerException - if an error occurred during the interpretation.
    • binaryOperation

      public BasicValue binaryOperation(AbstractInsnNode insn, BasicValue value1, BasicValue value2) throws AnalyzerException
      Description copied from class: Interpreter
      Interprets a bytecode instruction with two arguments. This method is called for the following opcodes:

      IALOAD, LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IADD, LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, FDIV, DDIV, IREM, LREM, FREM, DREM, ISHL, LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ, IF_ACMPNE, PUTFIELD

      Specified by:
      binaryOperation in class Interpreter<BasicValue>
      Parameters:
      insn - the bytecode instruction to be interpreted.
      value1 - the first argument of the instruction to be interpreted.
      value2 - the second argument of the instruction to be interpreted.
      Returns:
      the result of the interpretation of the given instruction.
      Throws:
      AnalyzerException - if an error occurred during the interpretation.
    • ternaryOperation

      public BasicValue ternaryOperation(AbstractInsnNode insn, BasicValue value1, BasicValue value2, BasicValue value3) throws AnalyzerException
      Description copied from class: Interpreter
      Interprets a bytecode instruction with three arguments. This method is called for the following opcodes:

      IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE

      Specified by:
      ternaryOperation in class Interpreter<BasicValue>
      Parameters:
      insn - the bytecode instruction to be interpreted.
      value1 - the first argument of the instruction to be interpreted.
      value2 - the second argument of the instruction to be interpreted.
      value3 - the third argument of the instruction to be interpreted.
      Returns:
      the result of the interpretation of the given instruction.
      Throws:
      AnalyzerException - if an error occurred during the interpretation.
    • naryOperation

      public BasicValue naryOperation(AbstractInsnNode insn, List<? extends BasicValue> values) throws AnalyzerException
      Description copied from class: Interpreter
      Interprets a bytecode instruction with a variable number of arguments. This method is called for the following opcodes:

      INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC, INVOKEINTERFACE, MULTIANEWARRAY and INVOKEDYNAMIC

      Specified by:
      naryOperation in class Interpreter<BasicValue>
      Parameters:
      insn - the bytecode instruction to be interpreted.
      values - the arguments of the instruction to be interpreted.
      Returns:
      the result of the interpretation of the given instruction.
      Throws:
      AnalyzerException - if an error occurred during the interpretation.
    • returnOperation

      public void returnOperation(AbstractInsnNode insn, BasicValue value, BasicValue expected) throws AnalyzerException
      Description copied from class: Interpreter
      Interprets a bytecode return instruction. This method is called for the following opcodes:

      IRETURN, LRETURN, FRETURN, DRETURN, ARETURN

      Specified by:
      returnOperation in class Interpreter<BasicValue>
      Parameters:
      insn - the bytecode instruction to be interpreted.
      value - the argument of the instruction to be interpreted.
      expected - the expected return type of the analyzed method.
      Throws:
      AnalyzerException - if an error occurred during the interpretation.
    • merge

      public BasicValue merge(BasicValue value1, BasicValue value2)
      Description copied from class: Interpreter
      Merges two values. The merge operation must return a value that represents both values (for instance, if the two values are two types, the merged value must be a common super type of the two types. If the two values are integer intervals, the merged value must be an interval that contains the previous ones. Likewise for other types of values).
      Specified by:
      merge in class Interpreter<BasicValue>
      Parameters:
      value1 - a value.
      value2 - another value.
      Returns:
      the merged value. If the merged value is equal to value1, this method must return value1.