package net.bytebuddy.implementation.bytecode.member;
import lombok.EqualsAndHashCode;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.description.method.ParameterDescription;
import net.bytebuddy.description.type.TypeDefinition;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.implementation.Implementation;
import net.bytebuddy.implementation.bytecode.StackManipulation;
import net.bytebuddy.implementation.bytecode.StackSize;
import net.bytebuddy.implementation.bytecode.assign.TypeCasting;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import java.util.ArrayList;
import java.util.List;
/**
* A stack assignment that loads a method variable from a given index of the local variable array.
*/
public enum MethodVariableAccess {
/**
* The accessor handler for a JVM-integer.
*/
INTEGER(Opcodes.ILOAD, Opcodes.ISTORE, StackSize.SINGLE),
/**
* The accessor handler for a {@code long}.
*/
LONG(Opcodes.LLOAD, Opcodes.LSTORE, StackSize.DOUBLE),
/**
* The accessor handler for a {@code float}.
*/
FLOAT(Opcodes.FLOAD, Opcodes.FSTORE, StackSize.SINGLE),
/**
* The accessor handler for a {@code double}.
*/
DOUBLE(Opcodes.DLOAD, Opcodes.DSTORE, StackSize.DOUBLE),
/**
* The accessor handler for a reference type.
*/
REFERENCE(Opcodes.ALOAD, Opcodes.ASTORE, StackSize.SINGLE);
/**
* The opcode for loading this variable type.
*/
private final int loadOpcode;
/**
* The opcode for storing a local variable type.
*/
private final int storeOpcode;
/**
* The size of the local variable on the JVM stack.
*/
private final StackSize size;
/**
* Creates a new method variable access for a given JVM type.
*
* @param loadOpcode The opcode for loading this variable type.
* @param storeOpcode The opcode for storing this variable type.
* @param stackSize The size of the JVM type.
*/
MethodVariableAccess(int loadOpcode, int storeOpcode, StackSize stackSize) {
this.loadOpcode = loadOpcode;
this.size = stackSize;
this.storeOpcode = storeOpcode;
}
/**
* Locates the correct accessor for a variable of a given type.
*
* @param typeDefinition The type of the variable to be loaded.
* @return An accessor for the given type.
*/
public static MethodVariableAccess of(TypeDefinition typeDefinition) {
if (typeDefinition.isPrimitive()) {
if (typeDefinition.represents(long.class)) {
return LONG;
} else if (typeDefinition.represents(double.class)) {
return DOUBLE;
} else if (typeDefinition.represents(float.class)) {
return FLOAT;
} else if (typeDefinition.represents(void.class)) {
throw new IllegalArgumentException("Variable type cannot be void");
} else {
return INTEGER;
}
} else {
return REFERENCE;
}
}
/**
* Loads all arguments of the provided method onto the operand stack.
*
* @param methodDescription The method for which all parameters are to be loaded onto the operand stack.
* @return A stack manipulation that loads all parameters of the provided method onto the operand stack.
*/
public static MethodLoading allArgumentsOf(MethodDescription methodDescription) {
return new MethodLoading(methodDescription, MethodLoading.TypeCastingHandler.NoOp.INSTANCE);
}
/**
* Loads a reference to the {@code this} reference what is only meaningful for a non-static method.
*
* @return A stack manipulation loading the {@code this} reference.
*/
public static StackManipulation loadThis() {
return MethodVariableAccess.REFERENCE.loadFrom(0);
}
/**
* Creates a stack assignment for a reading given offset of the local variable array.
*
* @param offset The offset of the variable where {@code double} and {@code long} types count two slots.
* @return A stack manipulation representing the variable read.
*/
public StackManipulation loadFrom(int offset) {
return new OffsetLoading(offset);
}
/**
* Creates a stack assignment for writing to a given offset of the local variable array.
*
* @param offset The offset of the variable where {@code double} and {@code long} types count two slots.
* @return A stack manipulation representing the variable write.
*/
public StackManipulation storeAt(int offset) {
return new OffsetWriting(offset);
}
/**
* Creates a stack assignment for incrementing the given offset of the local variable array.
*
* @param offset The offset of the variable where {@code double} and {@code long} types count two slots.
* @param value The incremented value.
* @return A stack manipulation representing the variable write.
*/
public StackManipulation increment(int offset, int value) {
if (this != INTEGER) {
throw new IllegalStateException("Cannot increment type: " + this);
}
return new OffsetIncrementing(offset, value);
}
/**
* Loads a parameter's value onto the operand stack.
*
* @param parameterDescription The parameter which to load onto the operand stack.
* @return A stack manipulation loading a parameter onto the operand stack.
*/
public static StackManipulation load(ParameterDescription parameterDescription) {
return of(parameterDescription.getType()).loadFrom(parameterDescription.getOffset());
}
/**
* Stores the top operand stack value at the supplied parameter.
*
* @param parameterDescription The parameter which to store a value for.
* @return A stack manipulation storing the top operand stack value at this parameter.
*/
public static StackManipulation store(ParameterDescription parameterDescription) {
return of(parameterDescription.getType()).storeAt(parameterDescription.getOffset());
}
/**
* Increments the value of the supplied parameter.
*
* @param parameterDescription The parameter which to increment.
* @param value The value to increment with.
* @return A stack manipulation incrementing the supplied parameter.
*/
public static StackManipulation increment(ParameterDescription parameterDescription, int value) {
return of(parameterDescription.getType()).increment(parameterDescription.getOffset(), value);
}
/**
* A stack manipulation that loads all parameters of a given method onto the operand stack.
*/
@EqualsAndHashCode
public static class MethodLoading implements StackManipulation {
/**
* The method for which all parameters are loaded onto the operand stack.
*/
private final MethodDescription methodDescription;
/**
* A type casting handler which is capable of transforming all method parameters.
*/
private final TypeCastingHandler typeCastingHandler;
/**
* Creates a new method loading stack manipulation.
*
* @param methodDescription The method for which all parameters are loaded onto the operand stack.
* @param typeCastingHandler A type casting handler which is capable of transforming all method parameters.
*/
protected MethodLoading(MethodDescription methodDescription, TypeCastingHandler typeCastingHandler) {
this.methodDescription = methodDescription;
this.typeCastingHandler = typeCastingHandler;
}
@Override
public boolean isValid() {
return true;
}
@Override
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
List<StackManipulation> stackManipulations = new ArrayList<StackManipulation>();
for (ParameterDescription parameterDescription : methodDescription.getParameters()) {
TypeDescription parameterType = parameterDescription.getType().asErasure();
stackManipulations.add(of(parameterType).loadFrom(parameterDescription.getOffset()));
stackManipulations.add(typeCastingHandler.ofIndex(parameterType, parameterDescription.getIndex()));
}
return new Compound(stackManipulations).apply(methodVisitor, implementationContext);
}
/**
* Prepends a reference to the {@code this} instance to the loaded parameters if the represented method is non-static.
*
* @return A stack manipulation that loads all method parameters onto the operand stack while additionally loading a reference
* to {@code this} if the represented is non-static. Any potential parameter transformation is preserved.
*/
public StackManipulation prependThisReference() {
return methodDescription.isStatic()
? this
: new Compound(MethodVariableAccess.loadThis(), this);
}
/**
* Applies a transformation to all loaded arguments of the method being loaded to be casted to the corresponding parameter of
* the provided method. This way, the parameters can be used for invoking a bridge target method.
*
* @param bridgeTarget The method that is the target of the bridge method for which the parameters are being loaded.
* @return A stack manipulation that loads all parameters casted to the types of the supplied bridge target.
*/
public MethodLoading asBridgeOf(MethodDescription bridgeTarget) {
return new MethodLoading(methodDescription, new TypeCastingHandler.ForBridgeTarget(bridgeTarget));
}
/**
* A type casting handler allows a type transformation of all arguments of a method after loading them onto the operand stack.
*/
protected interface TypeCastingHandler {
/**
* Yields a stack transformation to transform the given argument of the method for which the arguments are loaded onto the operand stack.
*
* @param parameterType The parameter type that is to be transformed.
* @param index The index of the transformed parameter.
* @return A transformation to apply after loading the parameter onto the operand stack.
*/
StackManipulation ofIndex(TypeDescription parameterType, int index);
/**
* A non-operative type casting handler.
*/
enum NoOp implements TypeCastingHandler {
/**
* The singleton instance.
*/
INSTANCE;
@Override
public StackManipulation ofIndex(TypeDescription parameterType, int index) {
return Trivial.INSTANCE;
}
}
/**
* A type casting handler that casts all parameters of a method to the parameter types of a compatible method
* with covariant parameter types. This allows a convenient implementation of bridge methods.
*/
@EqualsAndHashCode
class ForBridgeTarget implements TypeCastingHandler {
/**
* The target of the method bridge.
*/
private final MethodDescription bridgeTarget;
/**
* Creates a new type casting handler for a bridge target.
*
* @param bridgeTarget The target of the method bridge.
*/
public ForBridgeTarget(MethodDescription bridgeTarget) {
this.bridgeTarget = bridgeTarget;
}
@Override
public StackManipulation ofIndex(TypeDescription parameterType, int index) {
TypeDescription targetType = bridgeTarget.getParameters().get(index).getType().asErasure();
return parameterType.equals(targetType)
? Trivial.INSTANCE
: TypeCasting.to(targetType);
}
}
}
}
/**
* A stack manipulation for loading a variable of a method's local variable array onto the operand stack.
*/
protected class OffsetLoading implements StackManipulation {
/**
* The offset of the local variable array from which the variable should be loaded.
*/
private final int offset;
/**
* Creates a new argument loading stack manipulation.
*
* @param offset The offset of the local variable array from which the variable should be loaded.
*/
protected OffsetLoading(int offset) {
this.offset = offset;
}
@Override
public boolean isValid() {
return true;
}
@Override
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
methodVisitor.visitVarInsn(loadOpcode, offset);
return size.toIncreasingSize();
}
/**
* Returns the outer instance.
*
* @return The outer instance.
*/
private MethodVariableAccess getMethodVariableAccess() {
return MethodVariableAccess.this;
}
@Override // HE: Remove when Lombok support for getOuter is added.
public boolean equals(Object other) {
return this == other || !(other == null || getClass() != other.getClass())
&& MethodVariableAccess.this == ((OffsetLoading) other).getMethodVariableAccess()
&& offset == ((OffsetLoading) other).offset;
}
@Override // HE: Remove when Lombok support for getOuter is added.
public int hashCode() {
return MethodVariableAccess.this.hashCode() + 31 * offset;
}
}
/**
* A stack manipulation for storing a variable into a method's local variable array.
*/
protected class OffsetWriting implements StackManipulation {
/**
* The offset of the local variable array to which the value should be written.
*/
private final int offset;
/**
* Creates a new argument writing stack manipulation.
*
* @param offset The offset of the local variable array to which the value should be written.
*/
protected OffsetWriting(int offset) {
this.offset = offset;
}
@Override
public boolean isValid() {
return true;
}
@Override
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
methodVisitor.visitVarInsn(storeOpcode, offset);
return size.toDecreasingSize();
}
/**
* Returns the outer instance.
*
* @return The outer instance.
*/
private MethodVariableAccess getMethodVariableAccess() {
return MethodVariableAccess.this;
}
@Override
public boolean equals(Object other) {
return this == other || !(other == null || getClass() != other.getClass())
&& MethodVariableAccess.this == ((OffsetWriting) other).getMethodVariableAccess()
&& offset == ((OffsetWriting) other).offset;
}
@Override
public int hashCode() {
return MethodVariableAccess.this.hashCode() + 31 * offset;
}
}
/**
* A stack manipulation that increments an integer variable.
*/
@EqualsAndHashCode
protected static class OffsetIncrementing implements StackManipulation {
/**
* The index of the local variable array from which the variable should be loaded.
*/
private final int offset;
/**
* The value to increment.
*/
private final int value;
/**
* Creates a new argument loading stack manipulation.
*
* @param offset The index of the local variable array from which the variable should be loaded.
* @param value The value to increment.
*/
protected OffsetIncrementing(int offset, int value) {
this.offset = offset;
this.value = value;
}
@Override
public boolean isValid() {
return true;
}
@Override
public Size apply(MethodVisitor methodVisitor, Implementation.Context implementationContext) {
methodVisitor.visitIincInsn(offset, value);
return new Size(0, 0);
}
}
}