[Java] Class BytecodeHelper

public class BytecodeHelper
extends Object

Method Detail

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

box top level operand

@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 doCast(org.objectweb.asm.MethodVisitor mv, ClassNode type)

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

public static String formatNameForClassLoading(String name)

load a message on the stack and remove it right away. Good for put a mark in the generated bytecode for debugging purpose.

Parameters:

msg

public static String getClassInternalName(ClassNode t)

public static String getClassInternalName(Class t)

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)

public static String getGenericsMethodSignature(MethodNode node)

public static String getGenericsSignature(ClassNode node)

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

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(Class returnType, Class[] paramTypes)

Returns:

the ASM method type descriptor

public static String getTypeDescription(Class c)

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 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)

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

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

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

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

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.