Package: org.codehaus.groovy.classgen.asm

## [Java] Class BytecodeHelper

- org.codehaus.groovy.classgen.asm.BytecodeHelper

-     public class BytecodeHelper
      extends Object

  A helper class for bytecode generation with AsmClassGenerator.

- - ### Methods Summary

    Methods
    Type Params | Return Type | Name and description
    --- | --- | ---
    `` | `public static boolean` | `box(org.objectweb.asm.MethodVisitor mv, ClassNode type)` Generates the bytecode to autobox the current value on the stack.
    `` | `public static boolean` | `box(org.objectweb.asm.MethodVisitor mv, Class type)` Generates the bytecode to autobox the current value on the stack.
    `` | `public static void` | `convertPrimitiveToBoolean(org.objectweb.asm.MethodVisitor mv, ClassNode type)` Converts a primitive type to boolean.
    `` | `public static void` | `doCast(org.objectweb.asm.MethodVisitor mv, Class<?> type)` Generates bytecode for casting a value to the specified type.
    `` | `public static void` | `doCast(org.objectweb.asm.MethodVisitor mv, ClassNode type)` Generates bytecode for casting a value to the specified type.
    `` | `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.
    `` | `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
    `` | `public static void` | `doReturn(org.objectweb.asm.MethodVisitor mv, ClassNode type)` Emits the appropriate return instruction for the supplied type.
    `` | `public static String` | `formatNameForClassLoading(String name)` returns a name that Class.forName() can take.
    `` | `public static String` | `getClassInternalName(ClassNode t)` Returns: the ASM internal name of the type
    `` | `public static String` | `getClassInternalName(Class t)` Returns: the ASM internal name of the type
    `` | `public static String` | `getClassInternalName(String name)` Returns: the ASM internal name of the type
    `` | `public static String[]` | `getClassInternalNames(ClassNode[] names)` Returns: an array of ASM internal names of the type
    `` | `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 '/'.
    `` | `public static String` | `getGenericsBounds(ClassNode type)` Builds the generic bounds signature for a placeholder or parameterized type.
    `` | `public static String` | `getGenericsMethodSignature(MethodNode node)` Builds the generic signature for a method when one is required.
    `` | `public static String` | `getGenericsSignature(ClassNode node)` Builds the generic signature for a class declaration.
    `` | `public static String` | `getMethodDescriptor(MethodNode methodNode)` Returns a method descriptor for the given MethodNode.
    `` | `public static String` | `getMethodDescriptor(ClassNode returnType, Parameter[] parameters)` Returns: the ASM method type descriptor
    `` | `public static String` | `getMethodDescriptor(ClassNode returnType, ClassNode[] parameterTypes)` Returns: the ASM method type descriptor
    `` | `public static String` | `getMethodDescriptor(Class returnType, Class[] paramTypes)` Returns: the ASM method type descriptor
    `` | `public static String` | `getTypeDescription(Class c)` Returns the JVM descriptor for the supplied runtime class.
    `` | `public static String` | `getTypeDescription(ClassNode c)` array types are special: eg.: String[]: classname: [Ljava/lang/String; int[]: [I
    `` | `public static String` | `getTypeGenericsSignature(ClassNode node)` Builds the generic signature for a parameterized type reference.
    `` | `public static int` | `hashCode(String str)` Computes a hash code for a string.
    `` | `public static boolean` | `isClassLiteralPossible(ClassNode classNode)` Tells if a class node is candidate for class literal bytecode optimization.
    `` | `public static boolean` | `isSameCompilationUnit(ClassNode a, ClassNode b)` Returns true if the two classes share the same compilation unit.
    `` | `public static void` | `load(org.objectweb.asm.MethodVisitor mv, ClassNode type, int idx)` Emits the appropriate load instruction for the supplied local variable.
    `` | `public static void` | `negateBoolean(org.objectweb.asm.MethodVisitor mv)` Negates a boolean on stack.
    `` | `public static void` | `pushConstant(org.objectweb.asm.MethodVisitor mv, int value)` Pushes an integer constant onto the operand stack.
    `` | `public static void` | `store(org.objectweb.asm.MethodVisitor mv, ClassNode type, int idx)` Emits the appropriate store instruction for the supplied local variable.
    `` | `public static void` | `unbox(org.objectweb.asm.MethodVisitor mv, ClassNode type)` Generates the bytecode to unbox the current value on the stack.
    `` | `public static void` | `unbox(org.objectweb.asm.MethodVisitor mv, Class type)` Generates the bytecode to unbox the current value on the stack.
    `` | `public static void` | `visitClassLiteral(org.objectweb.asm.MethodVisitor mv, ClassNode classNode)` Visits a class literal.

  - ### Inherited Methods Summary

    Inherited Methods
    Methods inherited from class | Name
    --- | ---
    `class Object` | `equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Method Detail

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

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

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

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

    - #### public static void convertPrimitiveToBoolean(org.objectweb.asm.MethodVisitor mv, ClassNode type)

      Converts a primitive type to boolean.

      Parameters:
        `mv` - method visitor
        `type` - primitive type to convert

    - #### public static void doCast(org.objectweb.asm.MethodVisitor mv, Class<?> type)

      Generates bytecode for casting a value to the specified type.

      Parameters:
        `mv` - the MethodVisitor used to generate bytecode instructions
        `type` - the target Class type for the cast operation (must not be null)
      See Also:
        doCast(MethodVisitor, ClassNode)
        unbox(MethodVisitor, Class)
      Since:
        6.0.0

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

      Generates bytecode for casting a value to the specified type.

      Parameters:
        `mv` - the MethodVisitor used to generate bytecode instructions
        `type` - the target ClassNode type for the cast operation (must not be null)
      See Also:
        doCast(MethodVisitor, Class)
        unbox(MethodVisitor, ClassNode)

    - #### 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

    - #### 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

    - #### public static void doReturn(org.objectweb.asm.MethodVisitor mv, ClassNode type)

      Emits the appropriate return instruction for the supplied type.

      Parameters:
        `mv` - the current method visitor
        `type` - the value type being returned

    - #### 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

    - #### public static String getClassInternalName(ClassNode t)

      Returns:
        the ASM internal name of the type

    - #### public static String getClassInternalName(Class t)

      Returns:
        the ASM internal name of the type

    - #### public static String getClassInternalName(String name)

      Returns:
        the ASM internal name of the type

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

      Returns:
        an array of ASM internal names of the type

    - #### 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

    - #### public static String getGenericsBounds(ClassNode type)

      Builds the generic bounds signature for a placeholder or parameterized type.

      Parameters:
        `type` - the type node
      Returns:
        the bounds signature, or `null` if none is needed

    - #### public static String getGenericsMethodSignature(MethodNode node)

      Builds the generic signature for a method when one is required.

      Parameters:
        `node` - the method node
      Returns:
        the generic signature, or `null` if none is needed

    - #### public static String getGenericsSignature(ClassNode node)

      Builds the generic signature for a class declaration.

      Parameters:
        `node` - the class node
      Returns:
        the generic class signature, or `null` if none is needed

    - #### 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

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

      Returns:
        the ASM method type descriptor

    - #### public static String getMethodDescriptor(ClassNode returnType, ClassNode[] parameterTypes)

      Returns:
        the ASM method type descriptor

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

      Returns:
        the ASM method type descriptor

    - #### public static String getTypeDescription(Class c)

      Returns the JVM descriptor for the supplied runtime class.

      Parameters:
        `c` - the runtime class
      Returns:
        the ASM type descriptor

    - #### public static String getTypeDescription(ClassNode c)

      array types are special: eg.: String[]: classname: [Ljava/lang/String; int[]: [I

      Returns:
        the ASM type description

    - #### public static String getTypeGenericsSignature(ClassNode node)

      Builds the generic signature for a parameterized type reference.

      Parameters:
        `node` - the type node
      Returns:
        the generic type signature, or `null` if none is needed

    - #### 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

    - #### 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

    - #### 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

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

      Emits the appropriate load instruction for the supplied local variable.

      Parameters:
        `mv` - the current method visitor
        `type` - the local variable type
        `idx` - the local variable index

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

      Negates a boolean on stack.

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

      Pushes an integer constant onto the operand stack.

      Parameters:
        `mv` - the current method visitor
        `value` - the constant value

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

      Emits the appropriate store instruction for the supplied local variable.

      Parameters:
        `mv` - the current method visitor
        `type` - the local variable type
        `idx` - the local variable index

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

      Generates the bytecode to unbox the current value on the stack.

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

      Generates the bytecode to unbox the current value on the stack.

    - #### 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.