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/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.ui4j.bytebuddy.jar.asm.commons;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import com.ui4j.bytebuddy.jar.asm.ClassVisitor;
import com.ui4j.bytebuddy.jar.asm.Handle;
import com.ui4j.bytebuddy.jar.asm.Label;
import com.ui4j.bytebuddy.jar.asm.MethodVisitor;
import com.ui4j.bytebuddy.jar.asm.Opcodes;
import com.ui4j.bytebuddy.jar.asm.Type;

/**
 * A {@link com.ui4j.bytebuddy.jar.asm.MethodVisitor} with convenient methods to generate
 * code. For example, using this adapter, the class below
 * 
 * 
 * public class Example {
 *     public static void main(String[] args) {
 *         System.out.println("Hello world!");
 *     }
 * }
 * 
* * can be generated as follows: * *
 * ClassWriter cw = new ClassWriter(true);
 * cw.visit(V1_1, ACC_PUBLIC, "Example", null, "java/lang/Object", null);
 * 
 * Method m = Method.getMethod("void <init> ()");
 * GeneratorAdapter mg = new GeneratorAdapter(ACC_PUBLIC, m, null, null, cw);
 * mg.loadThis();
 * mg.invokeConstructor(Type.getType(Object.class), m);
 * mg.returnValue();
 * mg.endMethod();
 * 
 * m = Method.getMethod("void main (String[])");
 * mg = new GeneratorAdapter(ACC_PUBLIC + ACC_STATIC, m, null, null, cw);
 * mg.getStatic(Type.getType(System.class), "out", Type.getType(PrintStream.class));
 * mg.push("Hello world!");
 * mg.invokeVirtual(Type.getType(PrintStream.class),
 *         Method.getMethod("void println (String)"));
 * mg.returnValue();
 * mg.endMethod();
 * 
 * cw.visitEnd();
 * 
* * @author Juozas Baliuka * @author Chris Nokleberg * @author Eric Bruneton * @author Prashant Deva */ public class GeneratorAdapter extends LocalVariablesSorter { private static final String CLDESC = "Ljava/lang/Class;"; private static final Type BYTE_TYPE = Type.getObjectType("java/lang/Byte"); private static final Type BOOLEAN_TYPE = Type .getObjectType("java/lang/Boolean"); private static final Type SHORT_TYPE = Type .getObjectType("java/lang/Short"); private static final Type CHARACTER_TYPE = Type .getObjectType("java/lang/Character"); private static final Type INTEGER_TYPE = Type .getObjectType("java/lang/Integer"); private static final Type FLOAT_TYPE = Type .getObjectType("java/lang/Float"); private static final Type LONG_TYPE = Type.getObjectType("java/lang/Long"); private static final Type DOUBLE_TYPE = Type .getObjectType("java/lang/Double"); private static final Type NUMBER_TYPE = Type .getObjectType("java/lang/Number"); private static final Type OBJECT_TYPE = Type .getObjectType("java/lang/Object"); private static final Method BOOLEAN_VALUE = Method .getMethod("boolean booleanValue()"); private static final Method CHAR_VALUE = Method .getMethod("char charValue()"); private static final Method INT_VALUE = Method.getMethod("int intValue()"); private static final Method FLOAT_VALUE = Method .getMethod("float floatValue()"); private static final Method LONG_VALUE = Method .getMethod("long longValue()"); private static final Method DOUBLE_VALUE = Method .getMethod("double doubleValue()"); /** * Constant for the {@link #math math} method. */ public static final int ADD = Opcodes.IADD; /** * Constant for the {@link #math math} method. */ public static final int SUB = Opcodes.ISUB; /** * Constant for the {@link #math math} method. */ public static final int MUL = Opcodes.IMUL; /** * Constant for the {@link #math math} method. */ public static final int DIV = Opcodes.IDIV; /** * Constant for the {@link #math math} method. */ public static final int REM = Opcodes.IREM; /** * Constant for the {@link #math math} method. */ public static final int NEG = Opcodes.INEG; /** * Constant for the {@link #math math} method. */ public static final int SHL = Opcodes.ISHL; /** * Constant for the {@link #math math} method. */ public static final int SHR = Opcodes.ISHR; /** * Constant for the {@link #math math} method. */ public static final int USHR = Opcodes.IUSHR; /** * Constant for the {@link #math math} method. */ public static final int AND = Opcodes.IAND; /** * Constant for the {@link #math math} method. */ public static final int OR = Opcodes.IOR; /** * Constant for the {@link #math math} method. */ public static final int XOR = Opcodes.IXOR; /** * Constant for the {@link #ifCmp ifCmp} method. */ public static final int EQ = Opcodes.IFEQ; /** * Constant for the {@link #ifCmp ifCmp} method. */ public static final int NE = Opcodes.IFNE; /** * Constant for the {@link #ifCmp ifCmp} method. */ public static final int LT = Opcodes.IFLT; /** * Constant for the {@link #ifCmp ifCmp} method. */ public static final int GE = Opcodes.IFGE; /** * Constant for the {@link #ifCmp ifCmp} method. */ public static final int GT = Opcodes.IFGT; /** * Constant for the {@link #ifCmp ifCmp} method. */ public static final int LE = Opcodes.IFLE; /** * Access flags of the method visited by this adapter. */ private final int access; /** * Return type of the method visited by this adapter. */ private final Type returnType; /** * Argument types of the method visited by this adapter. */ private final Type[] argumentTypes; /** * Types of the local variables of the method visited by this adapter. */ private final List localTypes = new ArrayList(); /** * Creates a new {@link GeneratorAdapter}. Subclasses must not use this * constructor. Instead, they must use the * {@link #GeneratorAdapter(int, MethodVisitor, int, String, String)} * version. * * @param mv * the method visitor to which this adapter delegates calls. * @param access * the method's access flags (see {@link Opcodes}). * @param name * the method's name. * @param desc * the method's descriptor (see {@link Type Type}). * @throws IllegalStateException * If a subclass calls this constructor. */ public GeneratorAdapter(final MethodVisitor mv, final int access, final String name, final String desc) { this(Opcodes.ASM5, mv, access, name, desc); if (getClass() != GeneratorAdapter.class) { throw new IllegalStateException(); } } /** * Creates a new {@link GeneratorAdapter}. * * @param api * the ASM API version implemented by this visitor. Must be one * of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}. * @param mv * the method visitor to which this adapter delegates calls. * @param access * the method's access flags (see {@link Opcodes}). * @param name * the method's name. * @param desc * the method's descriptor (see {@link Type Type}). */ protected GeneratorAdapter(final int api, final MethodVisitor mv, final int access, final String name, final String desc) { super(api, access, desc, mv); this.access = access; this.returnType = Type.getReturnType(desc); this.argumentTypes = Type.getArgumentTypes(desc); } /** * Creates a new {@link GeneratorAdapter}. Subclasses must not use this * constructor. Instead, they must use the * {@link #GeneratorAdapter(int, MethodVisitor, int, String, String)} * version. * * @param access * access flags of the adapted method. * @param method * the adapted method. * @param mv * the method visitor to which this adapter delegates calls. */ public GeneratorAdapter(final int access, final Method method, final MethodVisitor mv) { this(mv, access, null, method.getDescriptor()); } /** * Creates a new {@link GeneratorAdapter}. Subclasses must not use this * constructor. Instead, they must use the * {@link #GeneratorAdapter(int, MethodVisitor, int, String, String)} * version. * * @param access * access flags of the adapted method. * @param method * the adapted method. * @param signature * the signature of the adapted method (may be null). * @param exceptions * the exceptions thrown by the adapted method (may be * null). * @param cv * the class visitor to which this adapter delegates calls. */ public GeneratorAdapter(final int access, final Method method, final String signature, final Type[] exceptions, final ClassVisitor cv) { this(access, method, cv .visitMethod(access, method.getName(), method.getDescriptor(), signature, getInternalNames(exceptions))); } /** * Returns the internal names of the given types. * * @param types * a set of types. * @return the internal names of the given types. */ private static String[] getInternalNames(final Type[] types) { if (types == null) { return null; } String[] names = new String[types.length]; for (int i = 0; i < names.length; ++i) { names[i] = types[i].getInternalName(); } return names; } // ------------------------------------------------------------------------ // Instructions to push constants on the stack // ------------------------------------------------------------------------ /** * Generates the instruction to push the given value on the stack. * * @param value * the value to be pushed on the stack. */ public void push(final boolean value) { push(value ? 1 : 0); } /** * Generates the instruction to push the given value on the stack. * * @param value * the value to be pushed on the stack. */ public void push(final int value) { if (value >= -1 && value <= 5) { mv.visitInsn(Opcodes.ICONST_0 + value); } else if (value >= Byte.MIN_VALUE && value <= Byte.MAX_VALUE) { mv.visitIntInsn(Opcodes.BIPUSH, value); } else if (value >= Short.MIN_VALUE && value <= Short.MAX_VALUE) { mv.visitIntInsn(Opcodes.SIPUSH, value); } else { mv.visitLdcInsn(new Integer(value)); } } /** * Generates the instruction to push the given value on the stack. * * @param value * the value to be pushed on the stack. */ public void push(final long value) { if (value == 0L || value == 1L) { mv.visitInsn(Opcodes.LCONST_0 + (int) value); } else { mv.visitLdcInsn(new Long(value)); } } /** * Generates the instruction to push the given value on the stack. * * @param value * the value to be pushed on the stack. */ public void push(final float value) { int bits = Float.floatToIntBits(value); if (bits == 0L || bits == 0x3f800000 || bits == 0x40000000) { // 0..2 mv.visitInsn(Opcodes.FCONST_0 + (int) value); } else { mv.visitLdcInsn(new Float(value)); } } /** * Generates the instruction to push the given value on the stack. * * @param value * the value to be pushed on the stack. */ public void push(final double value) { long bits = Double.doubleToLongBits(value); if (bits == 0L || bits == 0x3ff0000000000000L) { // +0.0d and 1.0d mv.visitInsn(Opcodes.DCONST_0 + (int) value); } else { mv.visitLdcInsn(new Double(value)); } } /** * Generates the instruction to push the given value on the stack. * * @param value * the value to be pushed on the stack. May be null. */ public void push(final String value) { if (value == null) { mv.visitInsn(Opcodes.ACONST_NULL); } else { mv.visitLdcInsn(value); } } /** * Generates the instruction to push the given value on the stack. * * @param value * the value to be pushed on the stack. */ public void push(final Type value) { if (value == null) { mv.visitInsn(Opcodes.ACONST_NULL); } else { switch (value.getSort()) { case Type.BOOLEAN: mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Boolean", "TYPE", CLDESC); break; case Type.CHAR: mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Character", "TYPE", CLDESC); break; case Type.BYTE: mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Byte", "TYPE", CLDESC); break; case Type.SHORT: mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Short", "TYPE", CLDESC); break; case Type.INT: mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Integer", "TYPE", CLDESC); break; case Type.FLOAT: mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Float", "TYPE", CLDESC); break; case Type.LONG: mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Long", "TYPE", CLDESC); break; case Type.DOUBLE: mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Double", "TYPE", CLDESC); break; default: mv.visitLdcInsn(value); } } } /** * Generates the instruction to push a handle on the stack. * * @param handle * the handle to be pushed on the stack. */ public void push(final Handle handle) { mv.visitLdcInsn(handle); } // ------------------------------------------------------------------------ // Instructions to load and store method arguments // ------------------------------------------------------------------------ /** * Returns the index of the given method argument in the frame's local * variables array. * * @param arg * the index of a method argument. * @return the index of the given method argument in the frame's local * variables array. */ private int getArgIndex(final int arg) { int index = (access & Opcodes.ACC_STATIC) == 0 ? 1 : 0; for (int i = 0; i < arg; i++) { index += argumentTypes[i].getSize(); } return index; } /** * Generates the instruction to push a local variable on the stack. * * @param type * the type of the local variable to be loaded. * @param index * an index in the frame's local variables array. */ private void loadInsn(final Type type, final int index) { mv.visitVarInsn(type.getOpcode(Opcodes.ILOAD), index); } /** * Generates the instruction to store the top stack value in a local * variable. * * @param type * the type of the local variable to be stored. * @param index * an index in the frame's local variables array. */ private void storeInsn(final Type type, final int index) { mv.visitVarInsn(type.getOpcode(Opcodes.ISTORE), index); } /** * Generates the instruction to load 'this' on the stack. */ public void loadThis() { if ((access & Opcodes.ACC_STATIC) != 0) { throw new IllegalStateException( "no 'this' pointer within static method"); } mv.visitVarInsn(Opcodes.ALOAD, 0); } /** * Generates the instruction to load the given method argument on the stack. * * @param arg * the index of a method argument. */ public void loadArg(final int arg) { loadInsn(argumentTypes[arg], getArgIndex(arg)); } /** * Generates the instructions to load the given method arguments on the * stack. * * @param arg * the index of the first method argument to be loaded. * @param count * the number of method arguments to be loaded. */ public void loadArgs(final int arg, final int count) { int index = getArgIndex(arg); for (int i = 0; i < count; ++i) { Type t = argumentTypes[arg + i]; loadInsn(t, index); index += t.getSize(); } } /** * Generates the instructions to load all the method arguments on the stack. */ public void loadArgs() { loadArgs(0, argumentTypes.length); } /** * Generates the instructions to load all the method arguments on the stack, * as a single object array. */ public void loadArgArray() { push(argumentTypes.length); newArray(OBJECT_TYPE); for (int i = 0; i < argumentTypes.length; i++) { dup(); push(i); loadArg(i); box(argumentTypes[i]); arrayStore(OBJECT_TYPE); } } /** * Generates the instruction to store the top stack value in the given * method argument. * * @param arg * the index of a method argument. */ public void storeArg(final int arg) { storeInsn(argumentTypes[arg], getArgIndex(arg)); } // ------------------------------------------------------------------------ // Instructions to load and store local variables // ------------------------------------------------------------------------ /** * Returns the type of the given local variable. * * @param local * a local variable identifier, as returned by * {@link LocalVariablesSorter#newLocal(Type) newLocal()}. * @return the type of the given local variable. */ public Type getLocalType(final int local) { return localTypes.get(local - firstLocal); } @Override protected void setLocalType(final int local, final Type type) { int index = local - firstLocal; while (localTypes.size() < index + 1) { localTypes.add(null); } localTypes.set(index, type); } /** * Generates the instruction to load the given local variable on the stack. * * @param local * a local variable identifier, as returned by * {@link LocalVariablesSorter#newLocal(Type) newLocal()}. */ public void loadLocal(final int local) { loadInsn(getLocalType(local), local); } /** * Generates the instruction to load the given local variable on the stack. * * @param local * a local variable identifier, as returned by * {@link LocalVariablesSorter#newLocal(Type) newLocal()}. * @param type * the type of this local variable. */ public void loadLocal(final int local, final Type type) { setLocalType(local, type); loadInsn(type, local); } /** * Generates the instruction to store the top stack value in the given local * variable. * * @param local * a local variable identifier, as returned by * {@link LocalVariablesSorter#newLocal(Type) newLocal()}. */ public void storeLocal(final int local) { storeInsn(getLocalType(local), local); } /** * Generates the instruction to store the top stack value in the given local * variable. * * @param local * a local variable identifier, as returned by * {@link LocalVariablesSorter#newLocal(Type) newLocal()}. * @param type * the type of this local variable. */ public void storeLocal(final int local, final Type type) { setLocalType(local, type); storeInsn(type, local); } /** * Generates the instruction to load an element from an array. * * @param type * the type of the array element to be loaded. */ public void arrayLoad(final Type type) { mv.visitInsn(type.getOpcode(Opcodes.IALOAD)); } /** * Generates the instruction to store an element in an array. * * @param type * the type of the array element to be stored. */ public void arrayStore(final Type type) { mv.visitInsn(type.getOpcode(Opcodes.IASTORE)); } // ------------------------------------------------------------------------ // Instructions to manage the stack // ------------------------------------------------------------------------ /** * Generates a POP instruction. */ public void pop() { mv.visitInsn(Opcodes.POP); } /** * Generates a POP2 instruction. */ public void pop2() { mv.visitInsn(Opcodes.POP2); } /** * Generates a DUP instruction. */ public void dup() { mv.visitInsn(Opcodes.DUP); } /** * Generates a DUP2 instruction. */ public void dup2() { mv.visitInsn(Opcodes.DUP2); } /** * Generates a DUP_X1 instruction. */ public void dupX1() { mv.visitInsn(Opcodes.DUP_X1); } /** * Generates a DUP_X2 instruction. */ public void dupX2() { mv.visitInsn(Opcodes.DUP_X2); } /** * Generates a DUP2_X1 instruction. */ public void dup2X1() { mv.visitInsn(Opcodes.DUP2_X1); } /** * Generates a DUP2_X2 instruction. */ public void dup2X2() { mv.visitInsn(Opcodes.DUP2_X2); } /** * Generates a SWAP instruction. */ public void swap() { mv.visitInsn(Opcodes.SWAP); } /** * Generates the instructions to swap the top two stack values. * * @param prev * type of the top - 1 stack value. * @param type * type of the top stack value. */ public void swap(final Type prev, final Type type) { if (type.getSize() == 1) { if (prev.getSize() == 1) { swap(); // same as dupX1(), pop(); } else { dupX2(); pop(); } } else { if (prev.getSize() == 1) { dup2X1(); pop2(); } else { dup2X2(); pop2(); } } } // ------------------------------------------------------------------------ // Instructions to do mathematical and logical operations // ------------------------------------------------------------------------ /** * Generates the instruction to do the specified mathematical or logical * operation. * * @param op * a mathematical or logical operation. Must be one of ADD, SUB, * MUL, DIV, REM, NEG, SHL, SHR, USHR, AND, OR, XOR. * @param type * the type of the operand(s) for this operation. */ public void math(final int op, final Type type) { mv.visitInsn(type.getOpcode(op)); } /** * Generates the instructions to compute the bitwise negation of the top * stack value. */ public void not() { mv.visitInsn(Opcodes.ICONST_1); mv.visitInsn(Opcodes.IXOR); } /** * Generates the instruction to increment the given local variable. * * @param local * the local variable to be incremented. * @param amount * the amount by which the local variable must be incremented. */ public void iinc(final int local, final int amount) { mv.visitIincInsn(local, amount); } /** * Generates the instructions to cast a numerical value from one type to * another. * * @param from * the type of the top stack value * @param to * the type into which this value must be cast. */ public void cast(final Type from, final Type to) { if (from != to) { if (from == Type.DOUBLE_TYPE) { if (to == Type.FLOAT_TYPE) { mv.visitInsn(Opcodes.D2F); } else if (to == Type.LONG_TYPE) { mv.visitInsn(Opcodes.D2L); } else { mv.visitInsn(Opcodes.D2I); cast(Type.INT_TYPE, to); } } else if (from == Type.FLOAT_TYPE) { if (to == Type.DOUBLE_TYPE) { mv.visitInsn(Opcodes.F2D); } else if (to == Type.LONG_TYPE) { mv.visitInsn(Opcodes.F2L); } else { mv.visitInsn(Opcodes.F2I); cast(Type.INT_TYPE, to); } } else if (from == Type.LONG_TYPE) { if (to == Type.DOUBLE_TYPE) { mv.visitInsn(Opcodes.L2D); } else if (to == Type.FLOAT_TYPE) { mv.visitInsn(Opcodes.L2F); } else { mv.visitInsn(Opcodes.L2I); cast(Type.INT_TYPE, to); } } else { if (to == Type.BYTE_TYPE) { mv.visitInsn(Opcodes.I2B); } else if (to == Type.CHAR_TYPE) { mv.visitInsn(Opcodes.I2C); } else if (to == Type.DOUBLE_TYPE) { mv.visitInsn(Opcodes.I2D); } else if (to == Type.FLOAT_TYPE) { mv.visitInsn(Opcodes.I2F); } else if (to == Type.LONG_TYPE) { mv.visitInsn(Opcodes.I2L); } else if (to == Type.SHORT_TYPE) { mv.visitInsn(Opcodes.I2S); } } } } // ------------------------------------------------------------------------ // Instructions to do boxing and unboxing operations // ------------------------------------------------------------------------ private static Type getBoxedType(final Type type) { switch (type.getSort()) { case Type.BYTE: return BYTE_TYPE; case Type.BOOLEAN: return BOOLEAN_TYPE; case Type.SHORT: return SHORT_TYPE; case Type.CHAR: return CHARACTER_TYPE; case Type.INT: return INTEGER_TYPE; case Type.FLOAT: return FLOAT_TYPE; case Type.LONG: return LONG_TYPE; case Type.DOUBLE: return DOUBLE_TYPE; } return type; } /** * Generates the instructions to box the top stack value. This value is * replaced by its boxed equivalent on top of the stack. * * @param type * the type of the top stack value. */ public void box(final Type type) { if (type.getSort() == Type.OBJECT || type.getSort() == Type.ARRAY) { return; } if (type == Type.VOID_TYPE) { push((String) null); } else { Type boxed = getBoxedType(type); newInstance(boxed); if (type.getSize() == 2) { // Pp -> Ppo -> oPpo -> ooPpo -> ooPp -> o dupX2(); dupX2(); pop(); } else { // p -> po -> opo -> oop -> o dupX1(); swap(); } invokeConstructor(boxed, new Method("", Type.VOID_TYPE, new Type[] { type })); } } /** * Generates the instructions to box the top stack value using Java 5's * valueOf() method. This value is replaced by its boxed equivalent on top * of the stack. * * @param type * the type of the top stack value. */ public void valueOf(final Type type) { if (type.getSort() == Type.OBJECT || type.getSort() == Type.ARRAY) { return; } if (type == Type.VOID_TYPE) { push((String) null); } else { Type boxed = getBoxedType(type); invokeStatic(boxed, new Method("valueOf", boxed, new Type[] { type })); } } /** * Generates the instructions to unbox the top stack value. This value is * replaced by its unboxed equivalent on top of the stack. * * @param type * the type of the top stack value. */ public void unbox(final Type type) { Type t = NUMBER_TYPE; Method sig = null; switch (type.getSort()) { case Type.VOID: return; case Type.CHAR: t = CHARACTER_TYPE; sig = CHAR_VALUE; break; case Type.BOOLEAN: t = BOOLEAN_TYPE; sig = BOOLEAN_VALUE; break; case Type.DOUBLE: sig = DOUBLE_VALUE; break; case Type.FLOAT: sig = FLOAT_VALUE; break; case Type.LONG: sig = LONG_VALUE; break; case Type.INT: case Type.SHORT: case Type.BYTE: sig = INT_VALUE; } if (sig == null) { checkCast(type); } else { checkCast(t); invokeVirtual(t, sig); } } // ------------------------------------------------------------------------ // Instructions to jump to other instructions // ------------------------------------------------------------------------ /** * Creates a new {@link Label}. * * @return a new {@link Label}. */ public Label newLabel() { return new Label(); } /** * Marks the current code position with the given label. * * @param label * a label. */ public void mark(final Label label) { mv.visitLabel(label); } /** * Marks the current code position with a new label. * * @return the label that was created to mark the current code position. */ public Label mark() { Label label = new Label(); mv.visitLabel(label); return label; } /** * Generates the instructions to jump to a label based on the comparison of * the top two stack values. * * @param type * the type of the top two stack values. * @param mode * how these values must be compared. One of EQ, NE, LT, GE, GT, * LE. * @param label * where to jump if the comparison result is true. */ public void ifCmp(final Type type, final int mode, final Label label) { switch (type.getSort()) { case Type.LONG: mv.visitInsn(Opcodes.LCMP); break; case Type.DOUBLE: mv.visitInsn(mode == GE || mode == GT ? Opcodes.DCMPL : Opcodes.DCMPG); break; case Type.FLOAT: mv.visitInsn(mode == GE || mode == GT ? Opcodes.FCMPL : Opcodes.FCMPG); break; case Type.ARRAY: case Type.OBJECT: switch (mode) { case EQ: mv.visitJumpInsn(Opcodes.IF_ACMPEQ, label); return; case NE: mv.visitJumpInsn(Opcodes.IF_ACMPNE, label); return; } throw new IllegalArgumentException("Bad comparison for type " + type); default: int intOp = -1; switch (mode) { case EQ: intOp = Opcodes.IF_ICMPEQ; break; case NE: intOp = Opcodes.IF_ICMPNE; break; case GE: intOp = Opcodes.IF_ICMPGE; break; case LT: intOp = Opcodes.IF_ICMPLT; break; case LE: intOp = Opcodes.IF_ICMPLE; break; case GT: intOp = Opcodes.IF_ICMPGT; break; } mv.visitJumpInsn(intOp, label); return; } mv.visitJumpInsn(mode, label); } /** * Generates the instructions to jump to a label based on the comparison of * the top two integer stack values. * * @param mode * how these values must be compared. One of EQ, NE, LT, GE, GT, * LE. * @param label * where to jump if the comparison result is true. */ public void ifICmp(final int mode, final Label label) { ifCmp(Type.INT_TYPE, mode, label); } /** * Generates the instructions to jump to a label based on the comparison of * the top integer stack value with zero. * * @param mode * how these values must be compared. One of EQ, NE, LT, GE, GT, * LE. * @param label * where to jump if the comparison result is true. */ public void ifZCmp(final int mode, final Label label) { mv.visitJumpInsn(mode, label); } /** * Generates the instruction to jump to the given label if the top stack * value is null. * * @param label * where to jump if the condition is true. */ public void ifNull(final Label label) { mv.visitJumpInsn(Opcodes.IFNULL, label); } /** * Generates the instruction to jump to the given label if the top stack * value is not null. * * @param label * where to jump if the condition is true. */ public void ifNonNull(final Label label) { mv.visitJumpInsn(Opcodes.IFNONNULL, label); } /** * Generates the instruction to jump to the given label. * * @param label * where to jump if the condition is true. */ public void goTo(final Label label) { mv.visitJumpInsn(Opcodes.GOTO, label); } /** * Generates a RET instruction. * * @param local * a local variable identifier, as returned by * {@link LocalVariablesSorter#newLocal(Type) newLocal()}. */ public void ret(final int local) { mv.visitVarInsn(Opcodes.RET, local); } /** * Generates the instructions for a switch statement. * * @param keys * the switch case keys. * @param generator * a generator to generate the code for the switch cases. */ public void tableSwitch(final int[] keys, final TableSwitchGenerator generator) { float density; if (keys.length == 0) { density = 0; } else { density = (float) keys.length / (keys[keys.length - 1] - keys[0] + 1); } tableSwitch(keys, generator, density >= 0.5f); } /** * Generates the instructions for a switch statement. * * @param keys * the switch case keys. * @param generator * a generator to generate the code for the switch cases. * @param useTable * true to use a TABLESWITCH instruction, or * false to use a LOOKUPSWITCH instruction. */ public void tableSwitch(final int[] keys, final TableSwitchGenerator generator, final boolean useTable) { for (int i = 1; i < keys.length; ++i) { if (keys[i] < keys[i - 1]) { throw new IllegalArgumentException( "keys must be sorted ascending"); } } Label def = newLabel(); Label end = newLabel(); if (keys.length > 0) { int len = keys.length; int min = keys[0]; int max = keys[len - 1]; int range = max - min + 1; if (useTable) { Label[] labels = new Label[range]; Arrays.fill(labels, def); for (int i = 0; i < len; ++i) { labels[keys[i] - min] = newLabel(); } mv.visitTableSwitchInsn(min, max, def, labels); for (int i = 0; i < range; ++i) { Label label = labels[i]; if (label != def) { mark(label); generator.generateCase(i + min, end); } } } else { Label[] labels = new Label[len]; for (int i = 0; i < len; ++i) { labels[i] = newLabel(); } mv.visitLookupSwitchInsn(def, keys, labels); for (int i = 0; i < len; ++i) { mark(labels[i]); generator.generateCase(keys[i], end); } } } mark(def); generator.generateDefault(); mark(end); } /** * Generates the instruction to return the top stack value to the caller. */ public void returnValue() { mv.visitInsn(returnType.getOpcode(Opcodes.IRETURN)); } // ------------------------------------------------------------------------ // Instructions to load and store fields // ------------------------------------------------------------------------ /** * Generates a get field or set field instruction. * * @param opcode * the instruction's opcode. * @param ownerType * the class in which the field is defined. * @param name * the name of the field. * @param fieldType * the type of the field. */ private void fieldInsn(final int opcode, final Type ownerType, final String name, final Type fieldType) { mv.visitFieldInsn(opcode, ownerType.getInternalName(), name, fieldType.getDescriptor()); } /** * Generates the instruction to push the value of a static field on the * stack. * * @param owner * the class in which the field is defined. * @param name * the name of the field. * @param type * the type of the field. */ public void getStatic(final Type owner, final String name, final Type type) { fieldInsn(Opcodes.GETSTATIC, owner, name, type); } /** * Generates the instruction to store the top stack value in a static field. * * @param owner * the class in which the field is defined. * @param name * the name of the field. * @param type * the type of the field. */ public void putStatic(final Type owner, final String name, final Type type) { fieldInsn(Opcodes.PUTSTATIC, owner, name, type); } /** * Generates the instruction to push the value of a non static field on the * stack. * * @param owner * the class in which the field is defined. * @param name * the name of the field. * @param type * the type of the field. */ public void getField(final Type owner, final String name, final Type type) { fieldInsn(Opcodes.GETFIELD, owner, name, type); } /** * Generates the instruction to store the top stack value in a non static * field. * * @param owner * the class in which the field is defined. * @param name * the name of the field. * @param type * the type of the field. */ public void putField(final Type owner, final String name, final Type type) { fieldInsn(Opcodes.PUTFIELD, owner, name, type); } // ------------------------------------------------------------------------ // Instructions to invoke methods // ------------------------------------------------------------------------ /** * Generates an invoke method instruction. * * @param opcode * the instruction's opcode. * @param type * the class in which the method is defined. * @param method * the method to be invoked. */ private void invokeInsn(final int opcode, final Type type, final Method method, final boolean itf) { String owner = type.getSort() == Type.ARRAY ? type.getDescriptor() : type.getInternalName(); mv.visitMethodInsn(opcode, owner, method.getName(), method.getDescriptor(), itf); } /** * Generates the instruction to invoke a normal method. * * @param owner * the class in which the method is defined. * @param method * the method to be invoked. */ public void invokeVirtual(final Type owner, final Method method) { invokeInsn(Opcodes.INVOKEVIRTUAL, owner, method, false); } /** * Generates the instruction to invoke a constructor. * * @param type * the class in which the constructor is defined. * @param method * the constructor to be invoked. */ public void invokeConstructor(final Type type, final Method method) { invokeInsn(Opcodes.INVOKESPECIAL, type, method, false); } /** * Generates the instruction to invoke a static method. * * @param owner * the class in which the method is defined. * @param method * the method to be invoked. */ public void invokeStatic(final Type owner, final Method method) { invokeInsn(Opcodes.INVOKESTATIC, owner, method, false); } /** * Generates the instruction to invoke an interface method. * * @param owner * the class in which the method is defined. * @param method * the method to be invoked. */ public void invokeInterface(final Type owner, final Method method) { invokeInsn(Opcodes.INVOKEINTERFACE, owner, method, true); } /** * Generates an invokedynamic instruction. * * @param name * the method's name. * @param desc * the method's descriptor (see {@link Type Type}). * @param bsm * the bootstrap method. * @param bsmArgs * the bootstrap method constant arguments. Each argument must be * an {@link Integer}, {@link Float}, {@link Long}, * {@link Double}, {@link String}, {@link Type} or {@link Handle} * value. This method is allowed to modify the content of the * array so a caller should expect that this array may change. */ public void invokeDynamic(String name, String desc, Handle bsm, Object... bsmArgs) { mv.visitInvokeDynamicInsn(name, desc, bsm, bsmArgs); } // ------------------------------------------------------------------------ // Instructions to create objects and arrays // ------------------------------------------------------------------------ /** * Generates a type dependent instruction. * * @param opcode * the instruction's opcode. * @param type * the instruction's operand. */ private void typeInsn(final int opcode, final Type type) { mv.visitTypeInsn(opcode, type.getInternalName()); } /** * Generates the instruction to create a new object. * * @param type * the class of the object to be created. */ public void newInstance(final Type type) { typeInsn(Opcodes.NEW, type); } /** * Generates the instruction to create a new array. * * @param type * the type of the array elements. */ public void newArray(final Type type) { int typ; switch (type.getSort()) { case Type.BOOLEAN: typ = Opcodes.T_BOOLEAN; break; case Type.CHAR: typ = Opcodes.T_CHAR; break; case Type.BYTE: typ = Opcodes.T_BYTE; break; case Type.SHORT: typ = Opcodes.T_SHORT; break; case Type.INT: typ = Opcodes.T_INT; break; case Type.FLOAT: typ = Opcodes.T_FLOAT; break; case Type.LONG: typ = Opcodes.T_LONG; break; case Type.DOUBLE: typ = Opcodes.T_DOUBLE; break; default: typeInsn(Opcodes.ANEWARRAY, type); return; } mv.visitIntInsn(Opcodes.NEWARRAY, typ); } // ------------------------------------------------------------------------ // Miscelaneous instructions // ------------------------------------------------------------------------ /** * Generates the instruction to compute the length of an array. */ public void arrayLength() { mv.visitInsn(Opcodes.ARRAYLENGTH); } /** * Generates the instruction to throw an exception. */ public void throwException() { mv.visitInsn(Opcodes.ATHROW); } /** * Generates the instructions to create and throw an exception. The * exception class must have a constructor with a single String argument. * * @param type * the class of the exception to be thrown. * @param msg * the detailed message of the exception. */ public void throwException(final Type type, final String msg) { newInstance(type); dup(); push(msg); invokeConstructor(type, Method.getMethod("void (String)")); throwException(); } /** * Generates the instruction to check that the top stack value is of the * given type. * * @param type * a class or interface type. */ public void checkCast(final Type type) { if (!type.equals(OBJECT_TYPE)) { typeInsn(Opcodes.CHECKCAST, type); } } /** * Generates the instruction to test if the top stack value is of the given * type. * * @param type * a class or interface type. */ public void instanceOf(final Type type) { typeInsn(Opcodes.INSTANCEOF, type); } /** * Generates the instruction to get the monitor of the top stack value. */ public void monitorEnter() { mv.visitInsn(Opcodes.MONITORENTER); } /** * Generates the instruction to release the monitor of the top stack value. */ public void monitorExit() { mv.visitInsn(Opcodes.MONITOREXIT); } // ------------------------------------------------------------------------ // Non instructions // ------------------------------------------------------------------------ /** * Marks the end of the visited method. */ public void endMethod() { if ((access & Opcodes.ACC_ABSTRACT) == 0) { mv.visitMaxs(0, 0); } mv.visitEnd(); } /** * Marks the start of an exception handler. * * @param start * beginning of the exception handler's scope (inclusive). * @param end * end of the exception handler's scope (exclusive). * @param exception * internal name of the type of exceptions handled by the * handler. */ public void catchException(final Label start, final Label end, final Type exception) { if (exception == null) { mv.visitTryCatchBlock(start, end, mark(), null); } else { mv.visitTryCatchBlock(start, end, mark(), exception.getInternalName()); } } }




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