MethodGen.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.bcel.generic;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Hashtable;
import java.util.List;
import java.util.Objects;
import java.util.Stack;
import java.util.stream.Collectors;
import org.apache.bcel.Const;
import org.apache.bcel.classfile.AnnotationEntry;
import org.apache.bcel.classfile.Annotations;
import org.apache.bcel.classfile.Attribute;
import org.apache.bcel.classfile.Code;
import org.apache.bcel.classfile.CodeException;
import org.apache.bcel.classfile.ExceptionTable;
import org.apache.bcel.classfile.LineNumber;
import org.apache.bcel.classfile.LineNumberTable;
import org.apache.bcel.classfile.LocalVariable;
import org.apache.bcel.classfile.LocalVariableTable;
import org.apache.bcel.classfile.LocalVariableTypeTable;
import org.apache.bcel.classfile.Method;
import org.apache.bcel.classfile.ParameterAnnotationEntry;
import org.apache.bcel.classfile.ParameterAnnotations;
import org.apache.bcel.classfile.RuntimeVisibleParameterAnnotations;
import org.apache.bcel.classfile.Utility;
import org.apache.bcel.util.BCELComparator;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.stream.Streams;
/**
* Template class for building up a method. This is done by defining exception handlers, adding thrown exceptions, local
* variables and attributes, whereas the 'LocalVariableTable' and 'LineNumberTable' attributes will be set automatically
* for the code. Use stripAttributes() if you don't like this.
*
* While generating code it may be necessary to insert NOP operations. You can use the 'removeNOPs' method to get rid
* off them. The resulting method object can be obtained via the 'getMethod()' method.
*
* @see InstructionList
* @see Method
*/
public class MethodGen extends FieldGenOrMethodGen {
static final class BranchStack {
private final Stack<BranchTarget> branchTargets = new Stack<>();
private final Hashtable<InstructionHandle, BranchTarget> visitedTargets = new Hashtable<>();
public BranchTarget pop() {
if (!branchTargets.empty()) {
return branchTargets.pop();
}
return null;
}
public void push(final InstructionHandle target, final int stackDepth) {
if (visited(target)) {
return;
}
branchTargets.push(visit(target, stackDepth));
}
private BranchTarget visit(final InstructionHandle target, final int stackDepth) {
final BranchTarget bt = new BranchTarget(target, stackDepth);
visitedTargets.put(target, bt);
return bt;
}
private boolean visited(final InstructionHandle target) {
return visitedTargets.get(target) != null;
}
}
static final class BranchTarget {
final InstructionHandle target;
final int stackDepth;
BranchTarget(final InstructionHandle target, final int stackDepth) {
this.target = target;
this.stackDepth = stackDepth;
}
}
private static BCELComparator<FieldGenOrMethodGen> bcelComparator = new BCELComparator<FieldGenOrMethodGen>() {
@Override
public boolean equals(final FieldGenOrMethodGen a, final FieldGenOrMethodGen b) {
return a == b || a != null && b != null && Objects.equals(a.getName(), b.getName()) && Objects.equals(a.getSignature(), b.getSignature());
}
@Override
public int hashCode(final FieldGenOrMethodGen o) {
return o != null ? Objects.hash(o.getSignature(), o.getName()) : 0;
}
};
private static byte[] getByteCodes(final Method method) {
final Code code = method.getCode();
if (code == null) {
throw new IllegalStateException(String.format("The method '%s' has no code.", method));
}
return code.getCode();
}
/**
* @return Comparison strategy object.
*/
public static BCELComparator<FieldGenOrMethodGen> getComparator() {
return bcelComparator;
}
/**
* Computes stack usage of an instruction list by performing control flow analysis.
*
* @return maximum stack depth used by method
*/
public static int getMaxStack(final ConstantPoolGen cp, final InstructionList il, final CodeExceptionGen[] et) {
final BranchStack branchTargets = new BranchStack();
/*
* Initially, populate the branch stack with the exception handlers, because these aren't (necessarily) branched to
* explicitly. in each case, the stack will have depth 1, containing the exception object.
*/
for (final CodeExceptionGen element : et) {
final InstructionHandle handlerPc = element.getHandlerPC();
if (handlerPc != null) {
branchTargets.push(handlerPc, 1);
}
}
int stackDepth = 0;
int maxStackDepth = 0;
InstructionHandle ih = il.getStart();
while (ih != null) {
final Instruction instruction = ih.getInstruction();
final short opcode = instruction.getOpcode();
final int delta = instruction.produceStack(cp) - instruction.consumeStack(cp);
stackDepth += delta;
if (stackDepth > maxStackDepth) {
maxStackDepth = stackDepth;
}
// choose the next instruction based on whether current is a branch.
if (instruction instanceof BranchInstruction) {
final BranchInstruction branch = (BranchInstruction) instruction;
if (instruction instanceof Select) {
// explore all of the select's targets. the default target is handled below.
final Select select = (Select) branch;
final InstructionHandle[] targets = select.getTargets();
for (final InstructionHandle target : targets) {
branchTargets.push(target, stackDepth);
}
// nothing to fall through to.
ih = null;
} else if (!(branch instanceof IfInstruction)) {
// if an instruction that comes back to following PC,
// push next instruction, with stack depth reduced by 1.
if (opcode == Const.JSR || opcode == Const.JSR_W) {
branchTargets.push(ih.getNext(), stackDepth - 1);
}
ih = null;
}
// for all branches, the target of the branch is pushed on the branch stack.
// conditional branches have a fall through case, selects don't, and
// jsr/jsr_w return to the next instruction.
branchTargets.push(branch.getTarget(), stackDepth);
} else // check for instructions that terminate the method.
if (opcode == Const.ATHROW || opcode == Const.RET || opcode >= Const.IRETURN && opcode <= Const.RETURN) {
ih = null;
}
// normal case, go to the next instruction.
if (ih != null) {
ih = ih.getNext();
}
// if we have no more instructions, see if there are any deferred branches to explore.
if (ih == null) {
final BranchTarget bt = branchTargets.pop();
if (bt != null) {
ih = bt.target;
stackDepth = bt.stackDepth;
}
}
}
return maxStackDepth;
}
/**
* @param comparator Comparison strategy object.
*/
public static void setComparator(final BCELComparator<FieldGenOrMethodGen> comparator) {
bcelComparator = comparator;
}
private String className;
private Type[] argTypes;
private String[] argNames;
private int maxLocals;
private int maxStack;
private InstructionList il;
private boolean stripAttributes;
private LocalVariableTypeTable localVariableTypeTable;
private final List<LocalVariableGen> variableList = new ArrayList<>();
private final List<LineNumberGen> lineNumberList = new ArrayList<>();
private final List<CodeExceptionGen> exceptionList = new ArrayList<>();
private final List<String> throwsList = new ArrayList<>();
private final List<Attribute> codeAttrsList = new ArrayList<>();
private List<AnnotationEntryGen>[] paramAnnotations; // Array of lists containing AnnotationGen objects
private boolean hasParameterAnnotations;
private boolean haveUnpackedParameterAnnotations;
private List<MethodObserver> observers;
/**
* Declare method. If the method is non-static the constructor automatically declares a local variable '$this' in slot
* 0. The actual code is contained in the 'il' parameter, which may further manipulated by the user. But they must take
* care not to remove any instruction (handles) that are still referenced from this object.
*
* For example one may not add a local variable and later remove the instructions it refers to without causing havoc. It
* is safe however if you remove that local variable, too.
*
* @param accessFlags access qualifiers
* @param returnType method type
* @param argTypes argument types
* @param argNames argument names (if this is null, default names will be provided for them)
* @param methodName name of method
* @param className class name containing this method (may be null, if you don't care)
* @param il instruction list associated with this method, may be null only for abstract or native methods
* @param cp constant pool
*/
public MethodGen(final int accessFlags, final Type returnType, final Type[] argTypes, String[] argNames, final String methodName, final String className,
final InstructionList il, final ConstantPoolGen cp) {
super(accessFlags);
setType(returnType);
setArgumentTypes(argTypes);
setArgumentNames(argNames);
setName(methodName);
setClassName(className);
setInstructionList(il);
setConstantPool(cp);
final boolean abstract_ = isAbstract() || isNative();
InstructionHandle start = null;
final InstructionHandle end = null;
if (!abstract_) {
start = il.getStart();
// end == null => live to end of method
/*
* Add local variables, namely the implicit 'this' and the arguments
*/
if (!isStatic() && className != null) { // Instance method -> 'this' is local var 0
addLocalVariable("this", ObjectType.getInstance(className), start, end);
}
}
if (argTypes != null) {
final int size = argTypes.length;
for (final Type argType : argTypes) {
if (Type.VOID == argType) {
throw new ClassGenException("'void' is an illegal argument type for a method");
}
}
if (argNames != null) { // Names for variables provided?
if (size != argNames.length) {
throw new ClassGenException("Mismatch in argument array lengths: " + size + " vs. " + argNames.length);
}
} else { // Give them dummy names
argNames = new String[size];
for (int i = 0; i < size; i++) {
argNames[i] = "arg" + i;
}
setArgumentNames(argNames);
}
if (!abstract_) {
for (int i = 0; i < size; i++) {
addLocalVariable(argNames[i], argTypes[i], start, end);
}
}
}
}
/**
* Instantiate from existing method.
*
* @param method method
* @param className class name containing this method
* @param cp constant pool
*/
public MethodGen(final Method method, final String className, final ConstantPoolGen cp) {
this(method.getAccessFlags(), Type.getReturnType(method.getSignature()), Type.getArgumentTypes(method.getSignature()),
null /* may be overridden anyway */
, method.getName(), className,
(method.getAccessFlags() & (Const.ACC_ABSTRACT | Const.ACC_NATIVE)) == 0 ? new InstructionList(getByteCodes(method)) : null, cp);
final Attribute[] attributes = method.getAttributes();
for (final Attribute attribute : attributes) {
Attribute a = attribute;
if (a instanceof Code) {
final Code c = (Code) a;
setMaxStack(c.getMaxStack());
setMaxLocals(c.getMaxLocals());
final CodeException[] ces = c.getExceptionTable();
if (ces != null) {
for (final CodeException ce : ces) {
final int type = ce.getCatchType();
ObjectType cType = null;
if (type > 0) {
final String cen = method.getConstantPool().getConstantString(type, Const.CONSTANT_Class);
cType = ObjectType.getInstance(cen);
}
final int endPc = ce.getEndPC();
final int length = getByteCodes(method).length;
InstructionHandle end;
if (length == endPc) { // May happen, because end_pc is exclusive
end = il.getEnd();
} else {
end = il.findHandle(endPc);
end = end.getPrev(); // Make it inclusive
}
addExceptionHandler(il.findHandle(ce.getStartPC()), end, il.findHandle(ce.getHandlerPC()), cType);
}
}
final Attribute[] cAttributes = c.getAttributes();
for (final Attribute cAttribute : cAttributes) {
a = cAttribute;
if (a instanceof LineNumberTable) {
((LineNumberTable) a).forEach(l -> {
final InstructionHandle ih = il.findHandle(l.getStartPC());
if (ih != null) {
addLineNumber(ih, l.getLineNumber());
}
});
} else if (a instanceof LocalVariableTable) {
updateLocalVariableTable((LocalVariableTable) a);
} else if (a instanceof LocalVariableTypeTable) {
this.localVariableTypeTable = (LocalVariableTypeTable) a.copy(cp.getConstantPool());
} else {
addCodeAttribute(a);
}
}
} else if (a instanceof ExceptionTable) {
Collections.addAll(throwsList, ((ExceptionTable) a).getExceptionNames());
} else if (a instanceof Annotations) {
final Annotations runtimeAnnotations = (Annotations) a;
runtimeAnnotations.forEach(element -> addAnnotationEntry(new AnnotationEntryGen(element, cp, false)));
} else {
addAttribute(a);
}
}
}
/**
* @since 6.0
*/
public void addAnnotationsAsAttribute(final ConstantPoolGen cp) {
addAll(AnnotationEntryGen.getAnnotationAttributes(cp, super.getAnnotationEntries()));
}
/**
* Add an attribute to the code. Currently, the JVM knows about the LineNumberTable, LocalVariableTable and StackMap
* attributes, where the former two will be generated automatically and the latter is used for the MIDP only. Other
* attributes will be ignored by the JVM but do no harm.
*
* @param a attribute to be added
*/
public void addCodeAttribute(final Attribute a) {
codeAttrsList.add(a);
}
/**
* Add an exception possibly thrown by this method.
*
* @param className (fully qualified) name of exception
*/
public void addException(final String className) {
throwsList.add(className);
}
/**
* Add an exception handler, i.e., specify region where a handler is active and an instruction where the actual handling
* is done.
*
* @param startPc Start of region (inclusive)
* @param endPc End of region (inclusive)
* @param handlerPc Where handling is done
* @param catchType class type of handled exception or null if any exception is handled
* @return new exception handler object
*/
public CodeExceptionGen addExceptionHandler(final InstructionHandle startPc, final InstructionHandle endPc, final InstructionHandle handlerPc,
final ObjectType catchType) {
if (startPc == null || endPc == null || handlerPc == null) {
throw new ClassGenException("Exception handler target is null instruction");
}
final CodeExceptionGen c = new CodeExceptionGen(startPc, endPc, handlerPc, catchType);
exceptionList.add(c);
return c;
}
/**
* Give an instruction a line number corresponding to the source code line.
*
* @param ih instruction to tag
* @return new line number object
* @see LineNumber
*/
public LineNumberGen addLineNumber(final InstructionHandle ih, final int srcLine) {
final LineNumberGen l = new LineNumberGen(ih, srcLine);
lineNumberList.add(l);
return l;
}
/**
* Adds a local variable to this method and assigns an index automatically.
*
* @param name variable name
* @param type variable type
* @param start from where the variable is valid, if this is null, it is valid from the start
* @param end until where the variable is valid, if this is null, it is valid to the end
* @return new local variable object
* @see LocalVariable
*/
public LocalVariableGen addLocalVariable(final String name, final Type type, final InstructionHandle start, final InstructionHandle end) {
return addLocalVariable(name, type, maxLocals, start, end);
}
/**
* Adds a local variable to this method.
*
* @param name variable name
* @param type variable type
* @param slot the index of the local variable, if type is long or double, the next available index is slot+2
* @param start from where the variable is valid
* @param end until where the variable is valid
* @return new local variable object
* @see LocalVariable
*/
public LocalVariableGen addLocalVariable(final String name, final Type type, final int slot, final InstructionHandle start, final InstructionHandle end) {
return addLocalVariable(name, type, slot, start, end, slot);
}
/**
* Adds a local variable to this method.
*
* @param name variable name
* @param type variable type
* @param slot the index of the local variable, if type is long or double, the next available index is slot+2
* @param start from where the variable is valid
* @param end until where the variable is valid
* @param origIndex the index of the local variable prior to any modifications
* @return new local variable object
* @see LocalVariable
*/
public LocalVariableGen addLocalVariable(final String name, final Type type, final int slot, final InstructionHandle start, final InstructionHandle end,
final int origIndex) {
final byte t = type.getType();
if (t != Const.T_ADDRESS) {
final int add = type.getSize();
if (slot + add > maxLocals) {
maxLocals = slot + add;
}
final LocalVariableGen l = new LocalVariableGen(slot, name, type, start, end, origIndex);
int i;
if ((i = variableList.indexOf(l)) >= 0) {
variableList.set(i, l);
} else {
variableList.add(l);
}
return l;
}
throw new IllegalArgumentException("Can not use " + type + " as type for local variable");
}
/**
* Add observer for this object.
*/
public void addObserver(final MethodObserver o) {
if (observers == null) {
observers = new ArrayList<>();
}
observers.add(o);
}
public void addParameterAnnotation(final int parameterIndex, final AnnotationEntryGen annotation) {
ensureExistingParameterAnnotationsUnpacked();
if (!hasParameterAnnotations) {
@SuppressWarnings("unchecked") // OK
final List<AnnotationEntryGen>[] parmList = new List[argTypes.length];
paramAnnotations = parmList;
hasParameterAnnotations = true;
}
final List<AnnotationEntryGen> existingAnnotations = paramAnnotations[parameterIndex];
if (existingAnnotations != null) {
existingAnnotations.add(annotation);
} else {
final List<AnnotationEntryGen> l = new ArrayList<>();
l.add(annotation);
paramAnnotations[parameterIndex] = l;
}
}
/**
* @since 6.0
*/
public void addParameterAnnotationsAsAttribute(final ConstantPoolGen cp) {
if (!hasParameterAnnotations) {
return;
}
final Attribute[] attrs = AnnotationEntryGen.getParameterAnnotationAttributes(cp, paramAnnotations);
if (attrs != null) {
addAll(attrs);
}
}
private Attribute[] addRuntimeAnnotationsAsAttribute(final ConstantPoolGen cp) {
final Attribute[] attrs = AnnotationEntryGen.getAnnotationAttributes(cp, super.getAnnotationEntries());
addAll(attrs);
return attrs;
}
private Attribute[] addRuntimeParameterAnnotationsAsAttribute(final ConstantPoolGen cp) {
if (!hasParameterAnnotations) {
return Attribute.EMPTY_ARRAY;
}
final Attribute[] attrs = AnnotationEntryGen.getParameterAnnotationAttributes(cp, paramAnnotations);
addAll(attrs);
return attrs;
}
private void adjustLocalVariableTypeTable(final LocalVariableTable lvt) {
final LocalVariable[] lv = lvt.getLocalVariableTable();
for (final LocalVariable element : localVariableTypeTable.getLocalVariableTypeTable()) {
for (final LocalVariable l : lv) {
if (element.getName().equals(l.getName()) && element.getIndex() == l.getOrigIndex()) {
element.setLength(l.getLength());
element.setStartPC(l.getStartPC());
element.setIndex(l.getIndex());
break;
}
}
}
}
/**
* @return deep copy of this method
*/
public MethodGen copy(final String className, final ConstantPoolGen cp) {
final Method m = ((MethodGen) clone()).getMethod();
final MethodGen mg = new MethodGen(m, className, super.getConstantPool());
if (super.getConstantPool() != cp) {
mg.setConstantPool(cp);
mg.getInstructionList().replaceConstantPool(super.getConstantPool(), cp);
}
return mg;
}
/**
* Goes through the attributes on the method and identifies any that are RuntimeParameterAnnotations, extracting their
* contents and storing them as parameter annotations. There are two kinds of parameter annotation - visible and
* invisible. Once they have been unpacked, these attributes are deleted. (The annotations will be rebuilt as attributes
* when someone builds a Method object out of this MethodGen object).
*/
private void ensureExistingParameterAnnotationsUnpacked() {
if (haveUnpackedParameterAnnotations) {
return;
}
// Find attributes that contain parameter annotation data
final Attribute[] attrs = getAttributes();
ParameterAnnotations paramAnnVisAttr = null;
ParameterAnnotations paramAnnInvisAttr = null;
for (final Attribute attribute : attrs) {
if (attribute instanceof ParameterAnnotations) {
// Initialize paramAnnotations
if (!hasParameterAnnotations) {
@SuppressWarnings("unchecked") // OK
final List<AnnotationEntryGen>[] parmList = new List[argTypes.length];
paramAnnotations = parmList;
Arrays.setAll(paramAnnotations, i -> new ArrayList<>());
}
hasParameterAnnotations = true;
final ParameterAnnotations rpa = (ParameterAnnotations) attribute;
if (rpa instanceof RuntimeVisibleParameterAnnotations) {
paramAnnVisAttr = rpa;
} else {
paramAnnInvisAttr = rpa;
}
final ParameterAnnotationEntry[] parameterAnnotationEntries = rpa.getParameterAnnotationEntries();
for (int j = 0; j < parameterAnnotationEntries.length; j++) {
// This returns Annotation[] ...
final ParameterAnnotationEntry immutableArray = rpa.getParameterAnnotationEntries()[j];
// ... which needs transforming into an AnnotationGen[] ...
final List<AnnotationEntryGen> mutable = makeMutableVersion(immutableArray.getAnnotationEntries());
// ... then add these to any we already know about
paramAnnotations[j].addAll(mutable);
}
}
}
if (paramAnnVisAttr != null) {
removeAttribute(paramAnnVisAttr);
}
if (paramAnnInvisAttr != null) {
removeAttribute(paramAnnInvisAttr);
}
haveUnpackedParameterAnnotations = true;
}
/**
* Return value as defined by given BCELComparator strategy. By default two MethodGen objects are said to be equal when
* their names and signatures are equal.
*
* @see Object#equals(Object)
*/
@Override
public boolean equals(final Object obj) {
return obj instanceof FieldGenOrMethodGen && bcelComparator.equals(this, (FieldGenOrMethodGen) obj);
}
// J5TODO: Should paramAnnotations be an array of arrays? Rather than an array of lists, this
// is more likely to suggest to the caller it is readonly (which a List does not).
/**
* Return a list of AnnotationGen objects representing parameter annotations
*
* @since 6.0
*/
public List<AnnotationEntryGen> getAnnotationsOnParameter(final int i) {
ensureExistingParameterAnnotationsUnpacked();
if (!hasParameterAnnotations || i > argTypes.length) {
return null;
}
return paramAnnotations[i];
}
public String getArgumentName(final int i) {
return argNames[i];
}
public String[] getArgumentNames() {
return argNames.clone();
}
public Type getArgumentType(final int i) {
return argTypes[i];
}
public Type[] getArgumentTypes() {
return argTypes.clone();
}
/**
* @return class that contains this method
*/
public String getClassName() {
return className;
}
/**
* @return all attributes of this method.
*/
public Attribute[] getCodeAttributes() {
return codeAttrsList.toArray(Attribute.EMPTY_ARRAY);
}
/**
* @return code exceptions for 'Code' attribute
*/
private CodeException[] getCodeExceptions() {
final int size = exceptionList.size();
final CodeException[] cExc = new CodeException[size];
Arrays.setAll(cExc, i -> exceptionList.get(i).getCodeException(super.getConstantPool()));
return cExc;
}
/*
* @return array of declared exception handlers
*/
public CodeExceptionGen[] getExceptionHandlers() {
return exceptionList.toArray(CodeExceptionGen.EMPTY_ARRAY);
}
/*
* @return array of thrown exceptions
*/
public String[] getExceptions() {
return throwsList.toArray(ArrayUtils.EMPTY_STRING_ARRAY);
}
/**
* @return 'Exceptions' attribute of all the exceptions thrown by this method.
*/
private ExceptionTable getExceptionTable(final ConstantPoolGen cp) {
final int size = throwsList.size();
final int[] ex = new int[size];
Arrays.setAll(ex, i -> cp.addClass(throwsList.get(i)));
return new ExceptionTable(cp.addUtf8("Exceptions"), 2 + 2 * size, ex, cp.getConstantPool());
}
public InstructionList getInstructionList() {
return il;
}
/*
* @return array of line numbers
*/
public LineNumberGen[] getLineNumbers() {
return lineNumberList.toArray(LineNumberGen.EMPTY_ARRAY);
}
/**
* @return 'LineNumberTable' attribute of all the local variables of this method.
*/
public LineNumberTable getLineNumberTable(final ConstantPoolGen cp) {
final int size = lineNumberList.size();
final LineNumber[] ln = new LineNumber[size];
Arrays.setAll(ln, i -> lineNumberList.get(i).getLineNumber());
return new LineNumberTable(cp.addUtf8("LineNumberTable"), 2 + ln.length * 4, ln, cp.getConstantPool());
}
/*
* If the range of the variable has not been set yet, it will be set to be valid from the start to the end of the
* instruction list.
*
* @return array of declared local variables sorted by index
*/
public LocalVariableGen[] getLocalVariables() {
final int size = variableList.size();
final LocalVariableGen[] lg = new LocalVariableGen[size];
variableList.toArray(lg);
for (int i = 0; i < size; i++) {
if (lg[i].getStart() == null && il != null) {
lg[i].setStart(il.getStart());
}
if (lg[i].getEnd() == null && il != null) {
lg[i].setEnd(il.getEnd());
}
}
if (size > 1) {
Arrays.sort(lg, Comparator.comparingInt(LocalVariableGen::getIndex));
}
return lg;
}
/**
* @return 'LocalVariableTable' attribute of all the local variables of this method.
*/
public LocalVariableTable getLocalVariableTable(final ConstantPoolGen cp) {
final LocalVariableGen[] lg = getLocalVariables();
final int size = lg.length;
final LocalVariable[] lv = new LocalVariable[size];
Arrays.setAll(lv, i -> lg[i].getLocalVariable(cp));
return new LocalVariableTable(cp.addUtf8("LocalVariableTable"), 2 + lv.length * 10, lv, cp.getConstantPool());
}
/**
* @return 'LocalVariableTypeTable' attribute of this method.
*/
public LocalVariableTypeTable getLocalVariableTypeTable() {
return localVariableTypeTable;
}
public int getMaxLocals() {
return maxLocals;
}
public int getMaxStack() {
return maxStack;
}
/**
* Gets method object. Never forget to call setMaxStack() or setMaxStack(max), respectively, before calling this method
* (the same applies for max locals).
*
* @return method object
*/
public Method getMethod() {
final String signature = getSignature();
final ConstantPoolGen cp = super.getConstantPool();
final int nameIndex = cp.addUtf8(super.getName());
final int signatureIndex = cp.addUtf8(signature);
/*
* Also updates positions of instructions, i.e., their indices
*/
final byte[] byteCode = il != null ? il.getByteCode() : null;
LineNumberTable lnt = null;
LocalVariableTable lvt = null;
/*
* Create LocalVariableTable and LineNumberTable attributes (for debuggers, e.g.)
*/
if (!variableList.isEmpty() && !stripAttributes) {
updateLocalVariableTable(getLocalVariableTable(cp));
addCodeAttribute(lvt = getLocalVariableTable(cp));
}
if (localVariableTypeTable != null) {
// LocalVariable length in LocalVariableTypeTable is not updated automatically. It's a difference with
// LocalVariableTable.
if (lvt != null) {
adjustLocalVariableTypeTable(lvt);
}
addCodeAttribute(localVariableTypeTable);
}
if (!lineNumberList.isEmpty() && !stripAttributes) {
addCodeAttribute(lnt = getLineNumberTable(cp));
}
final Attribute[] codeAttrs = getCodeAttributes();
/*
* Each attribute causes 6 additional header bytes
*/
int attrsLen = 0;
for (final Attribute codeAttr : codeAttrs) {
attrsLen += codeAttr.getLength() + 6;
}
final CodeException[] cExc = getCodeExceptions();
final int excLen = cExc.length * 8; // Every entry takes 8 bytes
Code code = null;
if (byteCode != null && !isAbstract() && !isNative()) {
// Remove any stale code attribute
final Attribute[] attributes = getAttributes();
for (final Attribute a : attributes) {
if (a instanceof Code) {
removeAttribute(a);
}
}
code = new Code(cp.addUtf8("Code"), 8 + byteCode.length + // prologue byte code
2 + excLen + // exceptions
2 + attrsLen, // attributes
maxStack, maxLocals, byteCode, cExc, codeAttrs, cp.getConstantPool());
addAttribute(code);
}
final Attribute[] annotations = addRuntimeAnnotationsAsAttribute(cp);
final Attribute[] parameterAnnotations = addRuntimeParameterAnnotationsAsAttribute(cp);
ExceptionTable et = null;
if (!throwsList.isEmpty()) {
addAttribute(et = getExceptionTable(cp));
// Add 'Exceptions' if there are "throws" clauses
}
final Method m = new Method(super.getAccessFlags(), nameIndex, signatureIndex, getAttributes(), cp.getConstantPool());
// Undo effects of adding attributes
if (lvt != null) {
removeCodeAttribute(lvt);
}
if (localVariableTypeTable != null) {
removeCodeAttribute(localVariableTypeTable);
}
if (lnt != null) {
removeCodeAttribute(lnt);
}
if (code != null) {
removeAttribute(code);
}
if (et != null) {
removeAttribute(et);
}
removeRuntimeAttributes(annotations);
removeRuntimeAttributes(parameterAnnotations);
return m;
}
public Type getReturnType() {
return getType();
}
@Override
public String getSignature() {
return Type.getMethodSignature(super.getType(), argTypes);
}
/**
* Return value as defined by given BCELComparator strategy. By default return the hash code of the method's name XOR
* signature.
*
* @see Object#hashCode()
*/
@Override
public int hashCode() {
return bcelComparator.hashCode(this);
}
private List<AnnotationEntryGen> makeMutableVersion(final AnnotationEntry[] mutableArray) {
return Streams.of(mutableArray).map(ae -> new AnnotationEntryGen(ae, getConstantPool(), false)).collect(Collectors.toList());
}
/**
* Remove a code attribute.
*/
public void removeCodeAttribute(final Attribute a) {
codeAttrsList.remove(a);
}
/**
* Remove all code attributes.
*/
public void removeCodeAttributes() {
localVariableTypeTable = null;
codeAttrsList.clear();
}
/**
* Remove an exception.
*/
public void removeException(final String c) {
throwsList.remove(c);
}
/**
* Remove an exception handler.
*/
public void removeExceptionHandler(final CodeExceptionGen c) {
exceptionList.remove(c);
}
/**
* Remove all line numbers.
*/
public void removeExceptionHandlers() {
exceptionList.clear();
}
/**
* Remove all exceptions.
*/
public void removeExceptions() {
throwsList.clear();
}
/**
* Remove a line number.
*/
public void removeLineNumber(final LineNumberGen l) {
lineNumberList.remove(l);
}
/**
* Remove all line numbers.
*/
public void removeLineNumbers() {
lineNumberList.clear();
}
/**
* Remove a local variable, its slot will not be reused, if you do not use addLocalVariable with an explicit index
* argument.
*/
public void removeLocalVariable(final LocalVariableGen l) {
l.dispose();
variableList.remove(l);
}
/**
* Remove all local variables.
*/
public void removeLocalVariables() {
variableList.forEach(LocalVariableGen::dispose);
variableList.clear();
}
/**
* Remove the LocalVariableTypeTable
*/
public void removeLocalVariableTypeTable() {
localVariableTypeTable = null;
}
/**
* Remove all NOPs from the instruction list (if possible) and update every object referring to them, i.e., branch
* instructions, local variables and exception handlers.
*/
public void removeNOPs() {
if (il != null) {
InstructionHandle next;
/*
* Check branch instructions.
*/
for (InstructionHandle ih = il.getStart(); ih != null; ih = next) {
next = ih.getNext();
if (next != null && ih.getInstruction() instanceof NOP) {
try {
il.delete(ih);
} catch (final TargetLostException e) {
for (final InstructionHandle target : e.getTargets()) {
for (final InstructionTargeter targeter : target.getTargeters()) {
targeter.updateTarget(target, next);
}
}
}
}
}
}
}
/**
* Remove observer for this object.
*/
public void removeObserver(final MethodObserver o) {
if (observers != null) {
observers.remove(o);
}
}
/**
* Would prefer to make this private, but need a way to test if client is using BCEL version 6.5.0 or later that
* contains fix for BCEL-329.
*
* @since 6.5.0
*/
public void removeRuntimeAttributes(final Attribute[] attributes) {
Streams.of(attributes).forEach(this::removeAttribute);
}
public void setArgumentName(final int i, final String name) {
argNames[i] = name;
}
public void setArgumentNames(final String[] argNames) {
this.argNames = ArrayUtils.nullToEmpty(argNames);
}
public void setArgumentType(final int i, final Type type) {
argTypes[i] = type;
}
public void setArgumentTypes(final Type[] argTypes) {
this.argTypes = argTypes != null ? argTypes : Type.NO_ARGS;
}
public void setClassName(final String className) { // TODO could be package-protected?
this.className = className;
}
public void setInstructionList(final InstructionList il) { // TODO could be package-protected?
this.il = il;
}
/**
* Compute maximum number of local variables.
*/
public void setMaxLocals() { // TODO could be package-protected? (some tests would need repackaging)
if (il != null) {
int max = isStatic() ? 0 : 1;
for (final Type argType : argTypes) {
max += argType.getSize();
}
for (InstructionHandle ih = il.getStart(); ih != null; ih = ih.getNext()) {
final Instruction ins = ih.getInstruction();
if (ins instanceof LocalVariableInstruction || ins instanceof RET || ins instanceof IINC) {
final int index = ((IndexedInstruction) ins).getIndex() + ((TypedInstruction) ins).getType(super.getConstantPool()).getSize();
if (index > max) {
max = index;
}
}
}
maxLocals = max;
} else {
maxLocals = 0;
}
}
/**
* Sets maximum number of local variables.
*/
public void setMaxLocals(final int m) {
maxLocals = m;
}
/**
* Computes max. stack size by performing control flow analysis.
*/
public void setMaxStack() { // TODO could be package-protected? (some tests would need repackaging)
if (il != null) {
maxStack = getMaxStack(super.getConstantPool(), il, getExceptionHandlers());
} else {
maxStack = 0;
}
}
/**
* Sets maximum stack size for this method.
*/
public void setMaxStack(final int m) { // TODO could be package-protected?
maxStack = m;
}
public void setReturnType(final Type returnType) {
setType(returnType);
}
/**
* Do not/Do produce attributes code attributesLineNumberTable and LocalVariableTable, like javac -O
*/
public void stripAttributes(final boolean flag) {
stripAttributes = flag;
}
/**
* Return string representation close to declaration format, 'public static void main(String[]) throws IOException',
* e.g.
*
* @return String representation of the method.
*/
@Override
public final String toString() {
final String access = Utility.accessToString(super.getAccessFlags());
String signature = Type.getMethodSignature(super.getType(), argTypes);
signature = Utility.methodSignatureToString(signature, super.getName(), access, true, getLocalVariableTable(super.getConstantPool()));
final StringBuilder buf = new StringBuilder(signature);
for (final Attribute a : getAttributes()) {
if (!(a instanceof Code || a instanceof ExceptionTable)) {
buf.append(" [").append(a).append("]");
}
}
if (!throwsList.isEmpty()) {
for (final String throwsDescriptor : throwsList) {
buf.append("\n\t\tthrows ").append(throwsDescriptor);
}
}
return buf.toString();
}
/**
* Call notify() method on all observers. This method is not called automatically whenever the state has changed, but
* has to be called by the user after they have finished editing the object.
*/
public void update() {
if (observers != null) {
for (final MethodObserver observer : observers) {
observer.notify(this);
}
}
}
private void updateLocalVariableTable(final LocalVariableTable a) {
removeLocalVariables();
for (final LocalVariable l : a.getLocalVariableTable()) {
InstructionHandle start = il.findHandle(l.getStartPC());
final InstructionHandle end = il.findHandle(l.getStartPC() + l.getLength());
// Repair malformed handles
if (null == start) {
start = il.getStart();
}
// end == null => live to end of method
// Since we are recreating the LocalVaraible, we must
// propagate the orig_index to new copy.
addLocalVariable(l.getName(), Type.getType(l.getSignature()), l.getIndex(), start, end, l.getOrigIndex());
}
}
}