CodeWriter (Proxool Developer's API})

Overview

Package

Class

Tree

Deprecated

Index

Help

PREV CLASS NEXT CLASS

FRAMES NO FRAMES

SUMMARY: NESTED | FIELD | CONSTR | METHOD

DETAIL: FIELD | CONSTR | METHOD

org.logicalcobwebs.asm
Class CodeWriter

java.lang.Object
  org.logicalcobwebs.asm.CodeWriter

All Implemented Interfaces:: CodeVisitor

public class CodeWriter
extends java.lang.Object
implements CodeVisitor
extends java.lang.Object
implements CodeVisitor

A CodeVisitor that generates Java bytecode instructions. Each visit method of this class appends the bytecode corresponding to the visited instruction to a byte vector, in the order these methods are called.

Field Summary
`private int`	`access` Access flags of this method.
`private Attribute`	`attrs` The non standard attributes of the method.
`private Label`	`blockStack` The basic block stack used by the control flow analysis algorithm.
`private int`	`catchCount` Number of entries in the catch table of this method.
`private ByteVector`	`catchTable` The catch table of this method.
`private Attribute`	`cattrs` The non standard attributes of the method's code.
`(package private) static boolean`	`CHECK` `true` if preconditions must be checked at runtime or not.
`private ByteVector`	`code` The bytecode of this method.
`private boolean`	`computeMaxs` `true` if the maximum stack size and number of local variables must be automatically computed.
`private Label`	`currentBlock` The current basic block.
`private ClassWriter`	`cw` The class writer to which this method must be added.
`private int`	`desc` The index of the constant pool item that contains the descriptor of this method.
`private int`	`exceptionCount` Number of exceptions that can be thrown by this method.
`private int[]`	`exceptions` The exceptions that can be thrown by this method.
`private Edge`	`head` The head of the list of `Edge` objects used by this `CodeWriter`.
`private ByteVector`	`lineNumber` The LineNumberTable attribute.
`private int`	`lineNumberCount` Number of entries in the LineNumberTable attribute.
`private ByteVector`	`localVar` The LocalVariableTable attribute.
`private int`	`localVarCount` Number of entries in the LocalVariableTable attribute.
`private int`	`maxLocals` Maximum number of local variables for this method.
`private int`	`maxStack` Maximum stack size of this method.
`private int`	`maxStackSize` The (relative) maximum stack size after the last visited instruction.
`private int`	`name` The index of the constant pool item that contains the name of this method.
`(package private) CodeWriter`	`next` Next code writer (see `firstMethod`).
`private static Edge`	`pool` The shared pool of `Edge` objects.
`private boolean`	`resize` Indicates if some jump instructions are too small and need to be resized.
`private static int[]`	`SIZE` The stack size variation corresponding to each JVM instruction.
`private int`	`stackSize` The (relative) stack size after the last visited instruction.
`private Edge`	`tail` The tail of the list of `Edge` objects used by this `CodeWriter`.

Constructor Summary
`protected`	`CodeWriter(ClassWriter cw, boolean computeMaxs)` Constructs a CodeWriter.

Method Summary
`private void`	`addSuccessor(int stackSize, Label successor)` Adds a successor to the `currentBlock` block.
`private static int`	`getArgumentsAndReturnSizes(java.lang.String desc)` Computes the size of the arguments and of the return value of a method.
`protected byte[]`	`getCode()` Returns the current bytecode of this method.
`protected int`	`getCodeSize()` Returns the current size of the bytecode of this method.
`(package private) static int`	`getNewOffset(int[] indexes, int[] sizes, int begin, int end)` Computes the future value of a bytecode offset.
`(package private) int`	`getSize()` Returns the size of the bytecode of this method.
`protected void`	`init(int access, java.lang.String name, java.lang.String desc, java.lang.String[] exceptions, Attribute attrs)` Initializes this CodeWriter to define the bytecode of the specified method.
`(package private) void`	`put(ByteVector out)` Puts the bytecode of this method in the given byte vector.
`(package private) static int`	`readInt(byte[] b, int index)` Reads a signed int value in the given byte array.
`(package private) static short`	`readShort(byte[] b, int index)` Reads a signed short value in the given byte array.
`(package private) static int`	`readUnsignedShort(byte[] b, int index)` Reads an unsigned short value in the given byte array.
`protected int[]`	`resizeInstructions(int[] indexes, int[] sizes, int len)` Resizes the designated instructions, while keeping jump offsets and instruction addresses consistent.
`void`	`visitAttribute(Attribute attr)` Visits a non standard attribute of the code.
`void`	`visitFieldInsn(int opcode, java.lang.String owner, java.lang.String name, java.lang.String desc)` Visits a field instruction.
`void`	`visitIincInsn(int var, int increment)` Visits an IINC instruction.
`void`	`visitInsn(int opcode)` Visits a zero operand instruction.
`void`	`visitIntInsn(int opcode, int operand)` Visits an instruction with a single int operand.
`void`	`visitJumpInsn(int opcode, Label label)` Visits a jump instruction.
`void`	`visitLabel(Label label)` Visits a label.
`void`	`visitLdcInsn(java.lang.Object cst)` Visits a LDC instruction.
`void`	`visitLineNumber(int line, Label start)` Visits a line number declaration.
`void`	`visitLocalVariable(java.lang.String name, java.lang.String desc, Label start, Label end, int index)` Visits a local variable declaration.
`void`	`visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels)` Visits a LOOKUPSWITCH instruction.
`void`	`visitMaxs(int maxStack, int maxLocals)` Visits the maximum stack size and the maximum number of local variables of the method.
`void`	`visitMethodInsn(int opcode, java.lang.String owner, java.lang.String name, java.lang.String desc)` Visits a method instruction.
`void`	`visitMultiANewArrayInsn(java.lang.String desc, int dims)` Visits a MULTIANEWARRAY instruction.
`void`	`visitTableSwitchInsn(int min, int max, Label dflt, Label[] labels)` Visits a TABLESWITCH instruction.
`void`	`visitTryCatchBlock(Label start, Label end, Label handler, java.lang.String type)` Visits a try catch block.
`void`	`visitTypeInsn(int opcode, java.lang.String desc)` Visits a type instruction.
`void`	`visitVarInsn(int opcode, int var)` Visits a local variable instruction.
`(package private) static void`	`writeShort(byte[] b, int index, int s)` Writes a short value in the given byte array.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

CHECK

static final boolean CHECK

true if preconditions must be checked at runtime or not.

See Also:: Constant Field Values

CodeWriter next

Next code writer (see firstMethod).

cw

private ClassWriter cw

The class writer to which this method must be added.

name

private int name

The index of the constant pool item that contains the name of this method.

desc

private int desc

The index of the constant pool item that contains the descriptor of this method.

access

private int access

Access flags of this method.

maxStack

private int maxStack

Maximum stack size of this method.

maxLocals

private int maxLocals

Maximum number of local variables for this method.

code

private ByteVector code

The bytecode of this method.

catchCount

private int catchCount

Number of entries in the catch table of this method.

catchTable

private ByteVector catchTable

The catch table of this method.

exceptionCount

private int exceptionCount

Number of exceptions that can be thrown by this method.

exceptions

private int[] exceptions

The exceptions that can be thrown by this method. More precisely, this array contains the indexes of the constant pool items that contain the internal names of these exception classes.

attrs

private Attribute attrs

The non standard attributes of the method.

localVarCount

private int localVarCount

Number of entries in the LocalVariableTable attribute.

localVar

private ByteVector localVar

The LocalVariableTable attribute.

lineNumberCount

private int lineNumberCount

Number of entries in the LineNumberTable attribute.

lineNumber

private ByteVector lineNumber

The LineNumberTable attribute.

cattrs

private Attribute cattrs

The non standard attributes of the method's code.

resize

private boolean resize

Indicates if some jump instructions are too small and need to be resized.

computeMaxs

private final boolean computeMaxs

true if the maximum stack size and number of local variables must be automatically computed.

stackSize

private int stackSize

The (relative) stack size after the last visited instruction. This size is relative to the beginning of the current basic block, i.e., the true stack size after the last visited instruction is equal to the beginStackSize of the current basic block plus stackSize.

maxStackSize

private int maxStackSize

The (relative) maximum stack size after the last visited instruction. This size is relative to the beginning of the current basic block, i.e., the true maximum stack size after the last visited instruction is equal to the beginStackSize of the current basic block plus stackSize.

currentBlock

private Label currentBlock

The current basic block. This block is the basic block to which the next instruction to be visited must be added.

blockStack

private Label blockStack

The basic block stack used by the control flow analysis algorithm. This stack is represented by a linked list of Label objects, linked to each other by their Label.next field. This stack must not be confused with the JVM stack used to execute the JVM instructions!

SIZE

private static final int[] SIZE

The stack size variation corresponding to each JVM instruction. This stack variation is equal to the size of the values produced by an instruction, minus the size of the values consumed by this instruction.

head

private Edge head

The head of the list of Edge objects used by this CodeWriter. These objects, linked to each other by their Edge.poolNext field, are added back to the shared pool at the end of the control flow analysis algorithm.

tail

private Edge tail

The tail of the list of Edge objects used by this CodeWriter. These objects, linked to each other by their Edge.poolNext field, are added back to the shared pool at the end of the control flow analysis algorithm.

pool

private static Edge pool

The shared pool of Edge objects. This pool is a linked list of Edge objects, linked to each other by their Edge.poolNext field.

Constructor Detail

CodeWriter

protected CodeWriter(ClassWriter cw,
                     boolean computeMaxs)

Constructs a CodeWriter.

Parameters:: cw - the class writer in which the method must be added.; computeMaxs - true if the maximum stack size and number of local variables must be automatically computed.

Method Detail

init

protected void init(int access,
                    java.lang.String name,
                    java.lang.String desc,
                    java.lang.String[] exceptions,
                    Attribute attrs)

Initializes this CodeWriter to define the bytecode of the specified method.

Parameters:: access - the method's access flags (see Constants).; name - the method's name.; desc - the method's descriptor (see Type).; exceptions - the internal names of the method's exceptions. May be null.; attrs - the non standard attributes of the method.