org.codehaus.groovy.classgen.asm

## Class BytecodeHelper

- java.lang.Object
- - org.codehaus.groovy.classgen.asm.BytecodeHelper

- All Implemented Interfaces:
    org.objectweb.asm.Opcodes

      public class BytecodeHelper
      extends Object
      implements org.objectweb.asm.Opcodes

  A helper class for bytecode generation with AsmClassGenerator.
  Version:
    $Revision$
  Author:
    James Strachan, Bing Ran, Jochen Theodorou

- - ### Field Summary

    - ### Fields inherited from interface org.objectweb.asm.Opcodes

      `AALOAD, AASTORE, ACC_ABSTRACT, ACC_ANNOTATION, ACC_BRIDGE, ACC_DEPRECATED, ACC_ENUM, ACC_FINAL, ACC_INTERFACE, ACC_MANDATED, ACC_NATIVE, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_SYNTHETIC, ACC_TRANSIENT, ACC_VARARGS, ACC_VOLATILE, ACONST_NULL, ALOAD, ANEWARRAY, ARETURN, ARRAYLENGTH, ASM4, ASM5, ASTORE, ATHROW, BALOAD, BASTORE, BIPUSH, CALOAD, CASTORE, CHECKCAST, D2F, D2I, D2L, DADD, DALOAD, DASTORE, DCMPG, DCMPL, DCONST_0, DCONST_1, DDIV, DLOAD, DMUL, DNEG, DOUBLE, DREM, DRETURN, DSTORE, DSUB, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, F_APPEND, F_CHOP, F_FULL, F_NEW, F_SAME, F_SAME1, F2D, F2I, F2L, FADD, FALOAD, FASTORE, FCMPG, FCMPL, FCONST_0, FCONST_1, FCONST_2, FDIV, FLOAD, FLOAT, FMUL, FNEG, FREM, FRETURN, FSTORE, FSUB, GETFIELD, GETSTATIC, GOTO, H_GETFIELD, H_GETSTATIC, H_INVOKEINTERFACE, H_INVOKESPECIAL, H_INVOKESTATIC, H_INVOKEVIRTUAL, H_NEWINVOKESPECIAL, H_PUTFIELD, H_PUTSTATIC, I2B, I2C, I2D, I2F, I2L, I2S, IADD, IALOAD, IAND, IASTORE, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, ICONST_M1, IDIV, IF_ACMPEQ, IF_ACMPNE, IF_ICMPEQ, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ICMPLT, IF_ICMPNE, IFEQ, IFGE, IFGT, IFLE, IFLT, IFNE, IFNONNULL, IFNULL, IINC, ILOAD, IMUL, INEG, INSTANCEOF, INTEGER, INVOKEDYNAMIC, INVOKEINTERFACE, INVOKESPECIAL, INVOKESTATIC, INVOKEVIRTUAL, IOR, IREM, IRETURN, ISHL, ISHR, ISTORE, ISUB, IUSHR, IXOR, JSR, L2D, L2F, L2I, LADD, LALOAD, LAND, LASTORE, LCMP, LCONST_0, LCONST_1, LDC, LDIV, LLOAD, LMUL, LNEG, LONG, LOOKUPSWITCH, LOR, LREM, LRETURN, LSHL, LSHR, LSTORE, LSUB, LUSHR, LXOR, MONITORENTER, MONITOREXIT, MULTIANEWARRAY, NEW, NEWARRAY, NOP, NULL, POP, POP2, PUTFIELD, PUTSTATIC, RET, RETURN, SALOAD, SASTORE, SIPUSH, SWAP, T_BOOLEAN, T_BYTE, T_CHAR, T_DOUBLE, T_FLOAT, T_INT, T_LONG, T_SHORT, TABLESWITCH, TOP, UNINITIALIZED_THIS, V1_1, V1_2, V1_3, V1_4, V1_5, V1_6, V1_7, V1_8`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `BytecodeHelper()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `static boolean` | `box(org.objectweb.asm.MethodVisitor mv, Class type)` Deprecated.
    `static boolean` | `box(org.objectweb.asm.MethodVisitor mv, ClassNode type)` Deprecated.
    `static void` | `doCast(org.objectweb.asm.MethodVisitor mv, Class type)`
    `static void` | `doCast(org.objectweb.asm.MethodVisitor mv, ClassNode type)`
    `static void` | `doCastToPrimitive(org.objectweb.asm.MethodVisitor mv, ClassNode sourceType, ClassNode targetType)` Given a wrapped number type (Byte, Integer, Short, ...), generates bytecode to convert it to a primitive number (int, long, double) using calls to wrapped.[targetType]Value()
    `static void` | `doCastToWrappedType(org.objectweb.asm.MethodVisitor mv, ClassNode sourceType, ClassNode targetType)` Given a primitive number type (byte, integer, short, ...), generates bytecode to convert it to a wrapped number (Integer, Long, Double) using calls to [WrappedType].valueOf
    `static void` | `doReturn(org.objectweb.asm.MethodVisitor mv, ClassNode returnType)`
    `static String` | `formatNameForClassLoading(String name)` returns a name that Class.forName() can take.
    `static String` | `getClassInternalName(Class t)`
    `static String` | `getClassInternalName(ClassNode t)`
    `static String` | `getClassInternalName(String name)`
    `static String[]` | `getClassInternalNames(ClassNode[] names)`
    `static String` | `getClassLoadingTypeDescription(ClassNode c)` array types are special: eg.: String[]: classname: [Ljava.lang.String; Object: classname: java.lang.Object int[] : classname: [I unlike getTypeDescription '.' is not replaced by '/'.
    `static String` | `getGenericsBounds(ClassNode type)`
    `static String` | `getGenericsMethodSignature(MethodNode node)`
    `static String` | `getGenericsSignature(ClassNode node)`
    `static String` | `getMethodDescriptor(Class returnType, Class[] paramTypes)`
    `static String` | `getMethodDescriptor(ClassNode returnType, Parameter[] parameters)`
    `static String` | `getMethodDescriptor(MethodNode methodNode)` Returns a method descriptor for the given `MethodNode`.
    `static String` | `getTypeDescription(Class c)`
    `static String` | `getTypeDescription(ClassNode c)` array types are special: eg.: String[]: classname: [Ljava/lang/String; int[]: [I
    `static int` | `hashCode(String str)` Computes a hash code for a string.
    `static boolean` | `isClassLiteralPossible(ClassNode classNode)` Tells if a class node is candidate for class literal bytecode optimization.
    `static boolean` | `isSameCompilationUnit(ClassNode a, ClassNode b)` Returns true if the two classes share the same compilation unit.
    `static void` | `load(org.objectweb.asm.MethodVisitor mv, ClassNode type, int idx)`
    `static void` | `negateBoolean(org.objectweb.asm.MethodVisitor mv)` negate a boolean on stack.
    `static void` | `pushConstant(org.objectweb.asm.MethodVisitor mv, int value)`
    `static void` | `unbox(org.objectweb.asm.MethodVisitor mv, Class type)` Generates the bytecode to unbox the current value on the stack
    `static void` | `unbox(org.objectweb.asm.MethodVisitor mv, ClassNode type)`
    `static void` | `visitClassLiteral(org.objectweb.asm.MethodVisitor mv, ClassNode classNode)` Visits a class literal.

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### BytecodeHelper

          public BytecodeHelper()

  - ### Method Detail

    - #### getClassInternalName

          public static String getClassInternalName(ClassNode t)

    - #### getClassInternalName

          public static String getClassInternalName(Class t)

    - #### getClassInternalName

          public static String getClassInternalName(String name)

      Returns:
        the ASM internal name of the type

    - #### getMethodDescriptor

          public static String getMethodDescriptor(ClassNode returnType,
                                   Parameter[] parameters)

    - #### getMethodDescriptor

          public static String getMethodDescriptor(MethodNode methodNode)

      Returns a method descriptor for the given `MethodNode`.
      Parameters:
        `methodNode` - the method node for which to create the descriptor
      Returns:
        a method descriptor as defined in section JVMS section 4.3.3

    - #### getMethodDescriptor

          public static String getMethodDescriptor(Class returnType,
                                   Class[] paramTypes)

      Returns:
        the ASM method type descriptor

    - #### getTypeDescription

          public static String getTypeDescription(Class c)

    - #### getClassLoadingTypeDescription

          public static String getClassLoadingTypeDescription(ClassNode c)

      array types are special: eg.: String[]: classname: [Ljava.lang.String; Object: classname: java.lang.Object int[] : classname: [I unlike getTypeDescription '.' is not replaced by '/'. it seems that makes problems for the class loading if '.' is replaced by '/'
      Returns:
        the ASM type description for class loading

    - #### getTypeDescription

          public static String getTypeDescription(ClassNode c)

      array types are special: eg.: String[]: classname: [Ljava/lang/String; int[]: [I
      Returns:
        the ASM type description

    - #### getClassInternalNames

          public static String[] getClassInternalNames(ClassNode[] names)

      Returns:
        an array of ASM internal names of the type

    - #### pushConstant

          public static void pushConstant(org.objectweb.asm.MethodVisitor mv,
                          int value)

    - #### negateBoolean

          public static void negateBoolean(org.objectweb.asm.MethodVisitor mv)

      negate a boolean on stack. true->false, false->true

    - #### formatNameForClassLoading

          public static String formatNameForClassLoading(String name)

      returns a name that Class.forName() can take. Notably for arrays: [I, [Ljava.lang.String; etc Regular object type: java.lang.String
      Parameters:
        `name` -

    - #### doReturn

          public static void doReturn(org.objectweb.asm.MethodVisitor mv,
                      ClassNode returnType)

    - #### getGenericsMethodSignature

          public static String getGenericsMethodSignature(MethodNode node)

    - #### getGenericsSignature

          public static String getGenericsSignature(ClassNode node)

    - #### getGenericsBounds

          public static String getGenericsBounds(ClassNode type)

    - #### load

          public static void load(org.objectweb.asm.MethodVisitor mv,
                  ClassNode type,
                  int idx)

    - #### doCast

          public static void doCast(org.objectweb.asm.MethodVisitor mv,
                    ClassNode type)

    - #### doCastToPrimitive

          public static void doCastToPrimitive(org.objectweb.asm.MethodVisitor mv,
                               ClassNode sourceType,
                               ClassNode targetType)

      Given a wrapped number type (Byte, Integer, Short, ...), generates bytecode to convert it to a primitive number (int, long, double) using calls to wrapped.[targetType]Value()
      Parameters:
        `mv` - method visitor
        `sourceType` - the wrapped number type
        `targetType` - the primitive target type

    - #### doCastToWrappedType

          public static void doCastToWrappedType(org.objectweb.asm.MethodVisitor mv,
                                 ClassNode sourceType,
                                 ClassNode targetType)

      Given a primitive number type (byte, integer, short, ...), generates bytecode to convert it to a wrapped number (Integer, Long, Double) using calls to [WrappedType].valueOf
      Parameters:
        `mv` - method visitor
        `sourceType` - the primitive number type
        `targetType` - the wrapped target type

    - #### doCast

          public static void doCast(org.objectweb.asm.MethodVisitor mv,
                    Class type)

    - #### unbox

          public static void unbox(org.objectweb.asm.MethodVisitor mv,
                   Class type)

      Generates the bytecode to unbox the current value on the stack

    - #### unbox

          public static void unbox(org.objectweb.asm.MethodVisitor mv,
                   ClassNode type)

    - #### box

          @Deprecated
          public static boolean box(org.objectweb.asm.MethodVisitor mv,
                               ClassNode type)

      Deprecated.
      box top level operand

    - #### box

          @Deprecated
          public static boolean box(org.objectweb.asm.MethodVisitor mv,
                               Class type)

      Deprecated.
      Generates the bytecode to autobox the current value on the stack

    - #### visitClassLiteral

          public static void visitClassLiteral(org.objectweb.asm.MethodVisitor mv,
                               ClassNode classNode)

      Visits a class literal. If the type of the classnode is a primitive type, the generated bytecode will be a GETSTATIC Integer.TYPE. If the classnode is not a primitive type, we will generate a LDC instruction.

    - #### isClassLiteralPossible

          public static boolean isClassLiteralPossible(ClassNode classNode)

      Tells if a class node is candidate for class literal bytecode optimization. If so, bytecode may use LDC instructions instead of static constant Class fields to retrieve class literals.
      Parameters:
        `classNode` - the classnode for which we want to know if bytecode optimization is possible
      Returns:
        true if the bytecode can be optimized

    - #### isSameCompilationUnit

          public static boolean isSameCompilationUnit(ClassNode a,
                                      ClassNode b)

      Returns true if the two classes share the same compilation unit.
      Parameters:
        `a` - class a
        `b` - class b
      Returns:
        true if both classes share the same compilation unit

    - #### hashCode

          public static int hashCode(String str)

      Computes a hash code for a string. The purpose of this hashcode is to be constant independently of the JDK being used.
      Parameters:
        `str` - the string for which to compute the hashcode
      Returns:
        hashcode of the string