Source code

    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 */
    017package org.apache.bcel.generic;
    018
    019import java.util.ArrayList;
    020import java.util.Arrays;
    021import java.util.Collections;
    022import java.util.Comparator;
    023import java.util.Hashtable;
    024import java.util.List;
    025import java.util.Objects;
    026import java.util.Stack;
    027
    028import org.apache.bcel.Const;
    029import org.apache.bcel.classfile.AnnotationEntry;
    030import org.apache.bcel.classfile.Annotations;
    031import org.apache.bcel.classfile.Attribute;
    032import org.apache.bcel.classfile.Code;
    033import org.apache.bcel.classfile.CodeException;
    034import org.apache.bcel.classfile.ExceptionTable;
    035import org.apache.bcel.classfile.LineNumber;
    036import org.apache.bcel.classfile.LineNumberTable;
    037import org.apache.bcel.classfile.LocalVariable;
    038import org.apache.bcel.classfile.LocalVariableTable;
    039import org.apache.bcel.classfile.LocalVariableTypeTable;
    040import org.apache.bcel.classfile.Method;
    041import org.apache.bcel.classfile.ParameterAnnotationEntry;
    042import org.apache.bcel.classfile.ParameterAnnotations;
    043import org.apache.bcel.classfile.RuntimeVisibleParameterAnnotations;
    044import org.apache.bcel.classfile.Utility;
    045import org.apache.bcel.util.BCELComparator;
    046import org.apache.commons.lang3.ArrayUtils;
    047
    048/**
    049 * Template class for building up a method. This is done by defining exception handlers, adding thrown exceptions, local
    050 * variables and attributes, whereas the `LocalVariableTable' and `LineNumberTable' attributes will be set automatically
    051 * for the code. Use stripAttributes() if you don't like this.
    052 *
    053 * While generating code it may be necessary to insert NOP operations. You can use the `removeNOPs' method to get rid
    054 * off them. The resulting method object can be obtained via the `getMethod()' method.
    055 *
    056 * @see InstructionList
    057 * @see Method
    058 */
    059public class MethodGen extends FieldGenOrMethodGen {
    060
    061    static final class BranchStack {
    062
    063        private final Stack<BranchTarget> branchTargets = new Stack<>();
    064        private final Hashtable<InstructionHandle, BranchTarget> visitedTargets = new Hashtable<>();
    065
    066        public BranchTarget pop() {
    067            if (!branchTargets.empty()) {
    068                return branchTargets.pop();
    069            }
    070            return null;
    071        }
    072
    073        public void push(final InstructionHandle target, final int stackDepth) {
    074            if (visited(target)) {
    075                return;
    076            }
    077            branchTargets.push(visit(target, stackDepth));
    078        }
    079
    080        private BranchTarget visit(final InstructionHandle target, final int stackDepth) {
    081            final BranchTarget bt = new BranchTarget(target, stackDepth);
    082            visitedTargets.put(target, bt);
    083            return bt;
    084        }
    085
    086        private boolean visited(final InstructionHandle target) {
    087            return visitedTargets.get(target) != null;
    088        }
    089    }
    090
    091    static final class BranchTarget {
    092
    093        final InstructionHandle target;
    094        final int stackDepth;
    095
    096        BranchTarget(final InstructionHandle target, final int stackDepth) {
    097            this.target = target;
    098            this.stackDepth = stackDepth;
    099        }
    100    }
    101
    102    private static BCELComparator bcelComparator = new BCELComparator() {
    103
    104        @Override
    105        public boolean equals(final Object o1, final Object o2) {
    106            final FieldGenOrMethodGen THIS = (FieldGenOrMethodGen) o1;
    107            final FieldGenOrMethodGen THAT = (FieldGenOrMethodGen) o2;
    108            return Objects.equals(THIS.getName(), THAT.getName()) && Objects.equals(THIS.getSignature(), THAT.getSignature());
    109        }
    110
    111        @Override
    112        public int hashCode(final Object o) {
    113            final FieldGenOrMethodGen THIS = (FieldGenOrMethodGen) o;
    114            return THIS.getSignature().hashCode() ^ THIS.getName().hashCode();
    115        }
    116    };
    117
    118    private static byte[] getByteCodes(final Method method) {
    119        final Code code = method.getCode();
    120        if (code == null) {
    121            throw new IllegalStateException(String.format("The method '%s' has no code.", method));
    122        }
    123        return code.getCode();
    124    }
    125
    126    /**
    127     * @return Comparison strategy object
    128     */
    129    public static BCELComparator getComparator() {
    130        return bcelComparator;
    131    }
    132
    133    /**
    134     * Computes stack usage of an instruction list by performing control flow analysis.
    135     *
    136     * @return maximum stack depth used by method
    137     */
    138    public static int getMaxStack(final ConstantPoolGen cp, final InstructionList il, final CodeExceptionGen[] et) {
    139        final BranchStack branchTargets = new BranchStack();
    140        /*
    141         * Initially, populate the branch stack with the exception handlers, because these aren't (necessarily) branched to
    142         * explicitly. in each case, the stack will have depth 1, containing the exception object.
    143         */
    144        for (final CodeExceptionGen element : et) {
    145            final InstructionHandle handlerPc = element.getHandlerPC();
    146            if (handlerPc != null) {
    147                branchTargets.push(handlerPc, 1);
    148            }
    149        }
    150        int stackDepth = 0;
    151        int maxStackDepth = 0;
    152        InstructionHandle ih = il.getStart();
    153        while (ih != null) {
    154            final Instruction instruction = ih.getInstruction();
    155            final short opcode = instruction.getOpcode();
    156            final int delta = instruction.produceStack(cp) - instruction.consumeStack(cp);
    157            stackDepth += delta;
    158            if (stackDepth > maxStackDepth) {
    159                maxStackDepth = stackDepth;
    160            }
    161            // choose the next instruction based on whether current is a branch.
    162            if (instruction instanceof BranchInstruction) {
    163                final BranchInstruction branch = (BranchInstruction) instruction;
    164                if (instruction instanceof Select) {
    165                    // explore all of the select's targets. the default target is handled below.
    166                    final Select select = (Select) branch;
    167                    final InstructionHandle[] targets = select.getTargets();
    168                    for (final InstructionHandle target : targets) {
    169                        branchTargets.push(target, stackDepth);
    170                    }
    171                    // nothing to fall through to.
    172                    ih = null;
    173                } else if (!(branch instanceof IfInstruction)) {
    174                    // if an instruction that comes back to following PC,
    175                    // push next instruction, with stack depth reduced by 1.
    176                    if (opcode == Const.JSR || opcode == Const.JSR_W) {
    177                        branchTargets.push(ih.getNext(), stackDepth - 1);
    178                    }
    179                    ih = null;
    180                }
    181                // for all branches, the target of the branch is pushed on the branch stack.
    182                // conditional branches have a fall through case, selects don't, and
    183                // jsr/jsr_w return to the next instruction.
    184                branchTargets.push(branch.getTarget(), stackDepth);
    185            } else // check for instructions that terminate the method.
    186            if (opcode == Const.ATHROW || opcode == Const.RET || opcode >= Const.IRETURN && opcode <= Const.RETURN) {
    187                ih = null;
    188            }
    189            // normal case, go to the next instruction.
    190            if (ih != null) {
    191                ih = ih.getNext();
    192            }
    193            // if we have no more instructions, see if there are any deferred branches to explore.
    194            if (ih == null) {
    195                final BranchTarget bt = branchTargets.pop();
    196                if (bt != null) {
    197                    ih = bt.target;
    198                    stackDepth = bt.stackDepth;
    199                }
    200            }
    201        }
    202        return maxStackDepth;
    203    }
    204
    205    /**
    206     * @param comparator Comparison strategy object
    207     */
    208    public static void setComparator(final BCELComparator comparator) {
    209        bcelComparator = comparator;
    210    }
    211
    212    private String className;
    213    private Type[] argTypes;
    214    private String[] argNames;
    215    private int maxLocals;
    216    private int maxStack;
    217    private InstructionList il;
    218
    219    private boolean stripAttributes;
    220    private LocalVariableTypeTable localVariableTypeTable;
    221    private final List<LocalVariableGen> variableList = new ArrayList<>();
    222
    223    private final List<LineNumberGen> lineNumberList = new ArrayList<>();
    224
    225    private final List<CodeExceptionGen> exceptionList = new ArrayList<>();
    226
    227    private final List<String> throwsList = new ArrayList<>();
    228
    229    private final List<Attribute> codeAttrsList = new ArrayList<>();
    230
    231    private List<AnnotationEntryGen>[] paramAnnotations; // Array of lists containing AnnotationGen objects
    232
    233    private boolean hasParameterAnnotations;
    234
    235    private boolean haveUnpackedParameterAnnotations;
    236
    237    private List<MethodObserver> observers;
    238
    239    /**
    240     * Declare method. If the method is non-static the constructor automatically declares a local variable `$this' in slot
    241     * 0. The actual code is contained in the `il' parameter, which may further manipulated by the user. But they must take
    242     * care not to remove any instruction (handles) that are still referenced from this object.
    243     *
    244     * For example one may not add a local variable and later remove the instructions it refers to without causing havoc. It
    245     * is safe however if you remove that local variable, too.
    246     *
    247     * @param accessFlags access qualifiers
    248     * @param returnType method type
    249     * @param argTypes argument types
    250     * @param argNames argument names (if this is null, default names will be provided for them)
    251     * @param methodName name of method
    252     * @param className class name containing this method (may be null, if you don't care)
    253     * @param il instruction list associated with this method, may be null only for abstract or native methods
    254     * @param cp constant pool
    255     */
    256    public MethodGen(final int accessFlags, final Type returnType, final Type[] argTypes, String[] argNames, final String methodName, final String className,
    257        final InstructionList il, final ConstantPoolGen cp) {
    258        super(accessFlags);
    259        setType(returnType);
    260        setArgumentTypes(argTypes);
    261        setArgumentNames(argNames);
    262        setName(methodName);
    263        setClassName(className);
    264        setInstructionList(il);
    265        setConstantPool(cp);
    266        final boolean abstract_ = isAbstract() || isNative();
    267        InstructionHandle start = null;
    268        final InstructionHandle end = null;
    269        if (!abstract_) {
    270            start = il.getStart();
    271            // end == null => live to end of method
    272            /*
    273             * Add local variables, namely the implicit `this' and the arguments
    274             */
    275            if (!isStatic() && className != null) { // Instance method -> `this' is local var 0
    276                addLocalVariable("this", ObjectType.getInstance(className), start, end);
    277            }
    278        }
    279        if (argTypes != null) {
    280            final int size = argTypes.length;
    281            for (final Type argType : argTypes) {
    282                if (Type.VOID == argType) {
    283                    throw new ClassGenException("'void' is an illegal argument type for a method");
    284                }
    285            }
    286            if (argNames != null) { // Names for variables provided?
    287                if (size != argNames.length) {
    288                    throw new ClassGenException("Mismatch in argument array lengths: " + size + " vs. " + argNames.length);
    289                }
    290            } else { // Give them dummy names
    291                argNames = new String[size];
    292                for (int i = 0; i < size; i++) {
    293                    argNames[i] = "arg" + i;
    294                }
    295                setArgumentNames(argNames);
    296            }
    297            if (!abstract_) {
    298                for (int i = 0; i < size; i++) {
    299                    addLocalVariable(argNames[i], argTypes[i], start, end);
    300                }
    301            }
    302        }
    303    }
    304
    305    /**
    306     * Instantiate from existing method.
    307     *
    308     * @param method method
    309     * @param className class name containing this method
    310     * @param cp constant pool
    311     */
    312    public MethodGen(final Method method, final String className, final ConstantPoolGen cp) {
    313        this(method.getAccessFlags(), Type.getReturnType(method.getSignature()), Type.getArgumentTypes(method.getSignature()),
    314            null /* may be overridden anyway */
    315            , method.getName(), className,
    316            (method.getAccessFlags() & (Const.ACC_ABSTRACT | Const.ACC_NATIVE)) == 0 ? new InstructionList(getByteCodes(method)) : null, cp);
    317        final Attribute[] attributes = method.getAttributes();
    318        for (final Attribute attribute : attributes) {
    319            Attribute a = attribute;
    320            if (a instanceof Code) {
    321                final Code c = (Code) a;
    322                setMaxStack(c.getMaxStack());
    323                setMaxLocals(c.getMaxLocals());
    324                final CodeException[] ces = c.getExceptionTable();
    325                if (ces != null) {
    326                    for (final CodeException ce : ces) {
    327                        final int type = ce.getCatchType();
    328                        ObjectType cType = null;
    329                        if (type > 0) {
    330                            final String cen = method.getConstantPool().getConstantString(type, Const.CONSTANT_Class);
    331                            cType = ObjectType.getInstance(cen);
    332                        }
    333                        final int endPc = ce.getEndPC();
    334                        final int length = getByteCodes(method).length;
    335                        InstructionHandle end;
    336                        if (length == endPc) { // May happen, because end_pc is exclusive
    337                            end = il.getEnd();
    338                        } else {
    339                            end = il.findHandle(endPc);
    340                            end = end.getPrev(); // Make it inclusive
    341                        }
    342                        addExceptionHandler(il.findHandle(ce.getStartPC()), end, il.findHandle(ce.getHandlerPC()), cType);
    343                    }
    344                }
    345                final Attribute[] cAttributes = c.getAttributes();
    346                for (final Attribute cAttribute : cAttributes) {
    347                    a = cAttribute;
    348                    if (a instanceof LineNumberTable) {
    349                        ((LineNumberTable) a).forEach(l -> {
    350                            final InstructionHandle ih = il.findHandle(l.getStartPC());
    351                            if (ih != null) {
    352                                addLineNumber(ih, l.getLineNumber());
    353                            }
    354                        });
    355                    } else if (a instanceof LocalVariableTable) {
    356                        updateLocalVariableTable((LocalVariableTable) a);
    357                    } else if (a instanceof LocalVariableTypeTable) {
    358                        this.localVariableTypeTable = (LocalVariableTypeTable) a.copy(cp.getConstantPool());
    359                    } else {
    360                        addCodeAttribute(a);
    361                    }
    362                }
    363            } else if (a instanceof ExceptionTable) {
    364                Collections.addAll(throwsList, ((ExceptionTable) a).getExceptionNames());
    365            } else if (a instanceof Annotations) {
    366                final Annotations runtimeAnnotations = (Annotations) a;
    367                runtimeAnnotations.forEach(element -> addAnnotationEntry(new AnnotationEntryGen(element, cp, false)));
    368            } else {
    369                addAttribute(a);
    370            }
    371        }
    372    }
    373
    374    /**
    375     * @since 6.0
    376     */
    377    public void addAnnotationsAsAttribute(final ConstantPoolGen cp) {
    378        addAll(AnnotationEntryGen.getAnnotationAttributes(cp, super.getAnnotationEntries()));
    379    }
    380
    381    /**
    382     * Add an attribute to the code. Currently, the JVM knows about the LineNumberTable, LocalVariableTable and StackMap
    383     * attributes, where the former two will be generated automatically and the latter is used for the MIDP only. Other
    384     * attributes will be ignored by the JVM but do no harm.
    385     *
    386     * @param a attribute to be added
    387     */
    388    public void addCodeAttribute(final Attribute a) {
    389        codeAttrsList.add(a);
    390    }
    391
    392    /**
    393     * Add an exception possibly thrown by this method.
    394     *
    395     * @param className (fully qualified) name of exception
    396     */
    397    public void addException(final String className) {
    398        throwsList.add(className);
    399    }
    400
    401    /**
    402     * Add an exception handler, i.e., specify region where a handler is active and an instruction where the actual handling
    403     * is done.
    404     *
    405     * @param startPc Start of region (inclusive)
    406     * @param endPc End of region (inclusive)
    407     * @param handlerPc Where handling is done
    408     * @param catchType class type of handled exception or null if any exception is handled
    409     * @return new exception handler object
    410     */
    411    public CodeExceptionGen addExceptionHandler(final InstructionHandle startPc, final InstructionHandle endPc, final InstructionHandle handlerPc,
    412        final ObjectType catchType) {
    413        if (startPc == null || endPc == null || handlerPc == null) {
    414            throw new ClassGenException("Exception handler target is null instruction");
    415        }
    416        final CodeExceptionGen c = new CodeExceptionGen(startPc, endPc, handlerPc, catchType);
    417        exceptionList.add(c);
    418        return c;
    419    }
    420
    421    /**
    422     * Give an instruction a line number corresponding to the source code line.
    423     *
    424     * @param ih instruction to tag
    425     * @return new line number object
    426     * @see LineNumber
    427     */
    428    public LineNumberGen addLineNumber(final InstructionHandle ih, final int srcLine) {
    429        final LineNumberGen l = new LineNumberGen(ih, srcLine);
    430        lineNumberList.add(l);
    431        return l;
    432    }
    433
    434    /**
    435     * Adds a local variable to this method and assigns an index automatically.
    436     *
    437     * @param name variable name
    438     * @param type variable type
    439     * @param start from where the variable is valid, if this is null, it is valid from the start
    440     * @param end until where the variable is valid, if this is null, it is valid to the end
    441     * @return new local variable object
    442     * @see LocalVariable
    443     */
    444    public LocalVariableGen addLocalVariable(final String name, final Type type, final InstructionHandle start, final InstructionHandle end) {
    445        return addLocalVariable(name, type, maxLocals, start, end);
    446    }
    447
    448    /**
    449     * Adds a local variable to this method.
    450     *
    451     * @param name variable name
    452     * @param type variable type
    453     * @param slot the index of the local variable, if type is long or double, the next available index is slot+2
    454     * @param start from where the variable is valid
    455     * @param end until where the variable is valid
    456     * @return new local variable object
    457     * @see LocalVariable
    458     */
    459    public LocalVariableGen addLocalVariable(final String name, final Type type, final int slot, final InstructionHandle start, final InstructionHandle end) {
    460        return addLocalVariable(name, type, slot, start, end, slot);
    461    }
    462
    463    /**
    464     * Adds a local variable to this method.
    465     *
    466     * @param name variable name
    467     * @param type variable type
    468     * @param slot the index of the local variable, if type is long or double, the next available index is slot+2
    469     * @param start from where the variable is valid
    470     * @param end until where the variable is valid
    471     * @param origIndex the index of the local variable prior to any modifications
    472     * @return new local variable object
    473     * @see LocalVariable
    474     */
    475    public LocalVariableGen addLocalVariable(final String name, final Type type, final int slot, final InstructionHandle start, final InstructionHandle end,
    476        final int origIndex) {
    477        final byte t = type.getType();
    478        if (t != Const.T_ADDRESS) {
    479            final int add = type.getSize();
    480            if (slot + add > maxLocals) {
    481                maxLocals = slot + add;
    482            }
    483            final LocalVariableGen l = new LocalVariableGen(slot, name, type, start, end, origIndex);
    484            int i;
    485            if ((i = variableList.indexOf(l)) >= 0) {
    486                variableList.set(i, l);
    487            } else {
    488                variableList.add(l);
    489            }
    490            return l;
    491        }
    492        throw new IllegalArgumentException("Can not use " + type + " as type for local variable");
    493    }
    494
    495    /**
    496     * Add observer for this object.
    497     */
    498    public void addObserver(final MethodObserver o) {
    499        if (observers == null) {
    500            observers = new ArrayList<>();
    501        }
    502        observers.add(o);
    503    }
    504
    505    public void addParameterAnnotation(final int parameterIndex, final AnnotationEntryGen annotation) {
    506        ensureExistingParameterAnnotationsUnpacked();
    507        if (!hasParameterAnnotations) {
    508            @SuppressWarnings("unchecked") // OK
    509            final List<AnnotationEntryGen>[] parmList = new List[argTypes.length];
    510            paramAnnotations = parmList;
    511            hasParameterAnnotations = true;
    512        }
    513        final List<AnnotationEntryGen> existingAnnotations = paramAnnotations[parameterIndex];
    514        if (existingAnnotations != null) {
    515            existingAnnotations.add(annotation);
    516        } else {
    517            final List<AnnotationEntryGen> l = new ArrayList<>();
    518            l.add(annotation);
    519            paramAnnotations[parameterIndex] = l;
    520        }
    521    }
    522
    523    /**
    524     * @since 6.0
    525     */
    526    public void addParameterAnnotationsAsAttribute(final ConstantPoolGen cp) {
    527        if (!hasParameterAnnotations) {
    528            return;
    529        }
    530        final Attribute[] attrs = AnnotationEntryGen.getParameterAnnotationAttributes(cp, paramAnnotations);
    531        if (attrs != null) {
    532            addAll(attrs);
    533        }
    534    }
    535
    536    private Attribute[] addRuntimeAnnotationsAsAttribute(final ConstantPoolGen cp) {
    537        final Attribute[] attrs = AnnotationEntryGen.getAnnotationAttributes(cp, super.getAnnotationEntries());
    538        addAll(attrs);
    539        return attrs;
    540    }
    541
    542    private Attribute[] addRuntimeParameterAnnotationsAsAttribute(final ConstantPoolGen cp) {
    543        if (!hasParameterAnnotations) {
    544            return Attribute.EMPTY_ARRAY;
    545        }
    546        final Attribute[] attrs = AnnotationEntryGen.getParameterAnnotationAttributes(cp, paramAnnotations);
    547        addAll(attrs);
    548        return attrs;
    549    }
    550
    551    private void adjustLocalVariableTypeTable(final LocalVariableTable lvt) {
    552        final LocalVariable[] lv = lvt.getLocalVariableTable();
    553        for (final LocalVariable element : localVariableTypeTable.getLocalVariableTypeTable()) {
    554            for (final LocalVariable l : lv) {
    555                if (element.getName().equals(l.getName()) && element.getIndex() == l.getOrigIndex()) {
    556                    element.setLength(l.getLength());
    557                    element.setStartPC(l.getStartPC());
    558                    element.setIndex(l.getIndex());
    559                    break;
    560                }
    561            }
    562        }
    563    }
    564
    565    /**
    566     * @return deep copy of this method
    567     */
    568    public MethodGen copy(final String className, final ConstantPoolGen cp) {
    569        final Method m = ((MethodGen) clone()).getMethod();
    570        final MethodGen mg = new MethodGen(m, className, super.getConstantPool());
    571        if (super.getConstantPool() != cp) {
    572            mg.setConstantPool(cp);
    573            mg.getInstructionList().replaceConstantPool(super.getConstantPool(), cp);
    574        }
    575        return mg;
    576    }
    577
    578    /**
    579     * Goes through the attributes on the method and identifies any that are RuntimeParameterAnnotations, extracting their
    580     * contents and storing them as parameter annotations. There are two kinds of parameter annotation - visible and
    581     * invisible. Once they have been unpacked, these attributes are deleted. (The annotations will be rebuilt as attributes
    582     * when someone builds a Method object out of this MethodGen object).
    583     */
    584    private void ensureExistingParameterAnnotationsUnpacked() {
    585        if (haveUnpackedParameterAnnotations) {
    586            return;
    587        }
    588        // Find attributes that contain parameter annotation data
    589        final Attribute[] attrs = getAttributes();
    590        ParameterAnnotations paramAnnVisAttr = null;
    591        ParameterAnnotations paramAnnInvisAttr = null;
    592        for (final Attribute attribute : attrs) {
    593            if (attribute instanceof ParameterAnnotations) {
    594                // Initialize paramAnnotations
    595                if (!hasParameterAnnotations) {
    596                    @SuppressWarnings("unchecked") // OK
    597                    final List<AnnotationEntryGen>[] parmList = new List[argTypes.length];
    598                    paramAnnotations = parmList;
    599                    Arrays.setAll(paramAnnotations, i -> new ArrayList<>());
    600                }
    601                hasParameterAnnotations = true;
    602                final ParameterAnnotations rpa = (ParameterAnnotations) attribute;
    603                if (rpa instanceof RuntimeVisibleParameterAnnotations) {
    604                    paramAnnVisAttr = rpa;
    605                } else {
    606                    paramAnnInvisAttr = rpa;
    607                }
    608                final ParameterAnnotationEntry[] parameterAnnotationEntries = rpa.getParameterAnnotationEntries();
    609                for (int j = 0; j < parameterAnnotationEntries.length; j++) {
    610                    // This returns Annotation[] ...
    611                    final ParameterAnnotationEntry immutableArray = rpa.getParameterAnnotationEntries()[j];
    612                    // ... which needs transforming into an AnnotationGen[] ...
    613                    final List<AnnotationEntryGen> mutable = makeMutableVersion(immutableArray.getAnnotationEntries());
    614                    // ... then add these to any we already know about
    615                    paramAnnotations[j].addAll(mutable);
    616                }
    617            }
    618        }
    619        if (paramAnnVisAttr != null) {
    620            removeAttribute(paramAnnVisAttr);
    621        }
    622        if (paramAnnInvisAttr != null) {
    623            removeAttribute(paramAnnInvisAttr);
    624        }
    625        haveUnpackedParameterAnnotations = true;
    626    }
    627
    628    /**
    629     * Return value as defined by given BCELComparator strategy. By default two MethodGen objects are said to be equal when
    630     * their names and signatures are equal.
    631     *
    632     * @see Object#equals(Object)
    633     */
    634    @Override
    635    public boolean equals(final Object obj) {
    636        return bcelComparator.equals(this, obj);
    637    }
    638
    639    // J5TODO: Should paramAnnotations be an array of arrays? Rather than an array of lists, this
    640    // is more likely to suggest to the caller it is readonly (which a List does not).
    641    /**
    642     * Return a list of AnnotationGen objects representing parameter annotations
    643     *
    644     * @since 6.0
    645     */
    646    public List<AnnotationEntryGen> getAnnotationsOnParameter(final int i) {
    647        ensureExistingParameterAnnotationsUnpacked();
    648        if (!hasParameterAnnotations || i > argTypes.length) {
    649            return null;
    650        }
    651        return paramAnnotations[i];
    652    }
    653
    654    public String getArgumentName(final int i) {
    655        return argNames[i];
    656    }
    657
    658    public String[] getArgumentNames() {
    659        return argNames.clone();
    660    }
    661
    662    public Type getArgumentType(final int i) {
    663        return argTypes[i];
    664    }
    665
    666    public Type[] getArgumentTypes() {
    667        return argTypes.clone();
    668    }
    669
    670    /**
    671     * @return class that contains this method
    672     */
    673    public String getClassName() {
    674        return className;
    675    }
    676
    677    /**
    678     * @return all attributes of this method.
    679     */
    680    public Attribute[] getCodeAttributes() {
    681        return codeAttrsList.toArray(Attribute.EMPTY_ARRAY);
    682    }
    683
    684    /**
    685     * @return code exceptions for `Code' attribute
    686     */
    687    private CodeException[] getCodeExceptions() {
    688        final int size = exceptionList.size();
    689        final CodeException[] cExc = new CodeException[size];
    690        Arrays.setAll(cExc, i -> exceptionList.get(i).getCodeException(super.getConstantPool()));
    691        return cExc;
    692    }
    693
    694    /*
    695     * @return array of declared exception handlers
    696     */
    697    public CodeExceptionGen[] getExceptionHandlers() {
    698        return exceptionList.toArray(CodeExceptionGen.EMPTY_ARRAY);
    699    }
    700
    701    /*
    702     * @return array of thrown exceptions
    703     */
    704    public String[] getExceptions() {
    705        return throwsList.toArray(ArrayUtils.EMPTY_STRING_ARRAY);
    706    }
    707
    708    /**
    709     * @return `Exceptions' attribute of all the exceptions thrown by this method.
    710     */
    711    private ExceptionTable getExceptionTable(final ConstantPoolGen cp) {
    712        final int size = throwsList.size();
    713        final int[] ex = new int[size];
    714        Arrays.setAll(ex, i -> cp.addClass(throwsList.get(i)));
    715        return new ExceptionTable(cp.addUtf8("Exceptions"), 2 + 2 * size, ex, cp.getConstantPool());
    716    }
    717
    718    public InstructionList getInstructionList() {
    719        return il;
    720    }
    721
    722    /*
    723     * @return array of line numbers
    724     */
    725    public LineNumberGen[] getLineNumbers() {
    726        return lineNumberList.toArray(LineNumberGen.EMPTY_ARRAY);
    727    }
    728
    729    /**
    730     * @return `LineNumberTable' attribute of all the local variables of this method.
    731     */
    732    public LineNumberTable getLineNumberTable(final ConstantPoolGen cp) {
    733        final int size = lineNumberList.size();
    734        final LineNumber[] ln = new LineNumber[size];
    735        Arrays.setAll(ln, i -> lineNumberList.get(i).getLineNumber());
    736        return new LineNumberTable(cp.addUtf8("LineNumberTable"), 2 + ln.length * 4, ln, cp.getConstantPool());
    737    }
    738
    739    /*
    740     * 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
    741     * instruction list.
    742     *
    743     * @return array of declared local variables sorted by index
    744     */
    745    public LocalVariableGen[] getLocalVariables() {
    746        final int size = variableList.size();
    747        final LocalVariableGen[] lg = new LocalVariableGen[size];
    748        variableList.toArray(lg);
    749        for (int i = 0; i < size; i++) {
    750            if (lg[i].getStart() == null && il != null) {
    751                lg[i].setStart(il.getStart());
    752            }
    753            if (lg[i].getEnd() == null && il != null) {
    754                lg[i].setEnd(il.getEnd());
    755            }
    756        }
    757        if (size > 1) {
    758            Arrays.sort(lg, Comparator.comparingInt(LocalVariableGen::getIndex));
    759        }
    760        return lg;
    761    }
    762
    763    /**
    764     * @return `LocalVariableTable' attribute of all the local variables of this method.
    765     */
    766    public LocalVariableTable getLocalVariableTable(final ConstantPoolGen cp) {
    767        final LocalVariableGen[] lg = getLocalVariables();
    768        final int size = lg.length;
    769        final LocalVariable[] lv = new LocalVariable[size];
    770        Arrays.setAll(lv, i -> lg[i].getLocalVariable(cp));
    771        return new LocalVariableTable(cp.addUtf8("LocalVariableTable"), 2 + lv.length * 10, lv, cp.getConstantPool());
    772    }
    773
    774    /**
    775     * @return `LocalVariableTypeTable' attribute of this method.
    776     */
    777    public LocalVariableTypeTable getLocalVariableTypeTable() {
    778        return localVariableTypeTable;
    779    }
    780
    781    public int getMaxLocals() {
    782        return maxLocals;
    783    }
    784
    785    public int getMaxStack() {
    786        return maxStack;
    787    }
    788
    789    /**
    790     * Get method object. Never forget to call setMaxStack() or setMaxStack(max), respectively, before calling this method
    791     * (the same applies for max locals).
    792     *
    793     * @return method object
    794     */
    795    public Method getMethod() {
    796        final String signature = getSignature();
    797        final ConstantPoolGen cp = super.getConstantPool();
    798        final int nameIndex = cp.addUtf8(super.getName());
    799        final int signatureIndex = cp.addUtf8(signature);
    800        /*
    801         * Also updates positions of instructions, i.e., their indices
    802         */
    803        byte[] byteCode = il != null ? il.getByteCode() : null;
    804        LineNumberTable lnt = null;
    805        LocalVariableTable lvt = null;
    806        /*
    807         * Create LocalVariableTable and LineNumberTable attributes (for debuggers, e.g.)
    808         */
    809        if (!variableList.isEmpty() && !stripAttributes) {
    810            updateLocalVariableTable(getLocalVariableTable(cp));
    811            addCodeAttribute(lvt = getLocalVariableTable(cp));
    812        }
    813        if (localVariableTypeTable != null) {
    814            // LocalVariable length in LocalVariableTypeTable is not updated automatically. It's a difference with
    815            // LocalVariableTable.
    816            if (lvt != null) {
    817                adjustLocalVariableTypeTable(lvt);
    818            }
    819            addCodeAttribute(localVariableTypeTable);
    820        }
    821        if (!lineNumberList.isEmpty() && !stripAttributes) {
    822            addCodeAttribute(lnt = getLineNumberTable(cp));
    823        }
    824        final Attribute[] codeAttrs = getCodeAttributes();
    825        /*
    826         * Each attribute causes 6 additional header bytes
    827         */
    828        int attrsLen = 0;
    829        for (final Attribute codeAttr : codeAttrs) {
    830            attrsLen += codeAttr.getLength() + 6;
    831        }
    832        final CodeException[] cExc = getCodeExceptions();
    833        final int excLen = cExc.length * 8; // Every entry takes 8 bytes
    834        Code code = null;
    835        if (byteCode != null && !isAbstract() && !isNative()) {
    836            // Remove any stale code attribute
    837            final Attribute[] attributes = getAttributes();
    838            for (final Attribute a : attributes) {
    839                if (a instanceof Code) {
    840                    removeAttribute(a);
    841                }
    842            }
    843            code = new Code(cp.addUtf8("Code"), 8 + byteCode.length + // prologue byte code
    844                2 + excLen + // exceptions
    845                2 + attrsLen, // attributes
    846                maxStack, maxLocals, byteCode, cExc, codeAttrs, cp.getConstantPool());
    847            addAttribute(code);
    848        }
    849        final Attribute[] annotations = addRuntimeAnnotationsAsAttribute(cp);
    850        final Attribute[] parameterAnnotations = addRuntimeParameterAnnotationsAsAttribute(cp);
    851        ExceptionTable et = null;
    852        if (!throwsList.isEmpty()) {
    853            addAttribute(et = getExceptionTable(cp));
    854            // Add `Exceptions' if there are "throws" clauses
    855        }
    856        final Method m = new Method(super.getAccessFlags(), nameIndex, signatureIndex, getAttributes(), cp.getConstantPool());
    857        // Undo effects of adding attributes
    858        if (lvt != null) {
    859            removeCodeAttribute(lvt);
    860        }
    861        if (localVariableTypeTable != null) {
    862            removeCodeAttribute(localVariableTypeTable);
    863        }
    864        if (lnt != null) {
    865            removeCodeAttribute(lnt);
    866        }
    867        if (code != null) {
    868            removeAttribute(code);
    869        }
    870        if (et != null) {
    871            removeAttribute(et);
    872        }
    873        removeRuntimeAttributes(annotations);
    874        removeRuntimeAttributes(parameterAnnotations);
    875        return m;
    876    }
    877
    878    public Type getReturnType() {
    879        return getType();
    880    }
    881
    882    @Override
    883    public String getSignature() {
    884        return Type.getMethodSignature(super.getType(), argTypes);
    885    }
    886
    887    /**
    888     * Return value as defined by given BCELComparator strategy. By default return the hashcode of the method's name XOR
    889     * signature.
    890     *
    891     * @see Object#hashCode()
    892     */
    893    @Override
    894    public int hashCode() {
    895        return bcelComparator.hashCode(this);
    896    }
    897
    898    private List<AnnotationEntryGen> makeMutableVersion(final AnnotationEntry[] mutableArray) {
    899        final List<AnnotationEntryGen> result = new ArrayList<>();
    900        for (final AnnotationEntry element : mutableArray) {
    901            result.add(new AnnotationEntryGen(element, getConstantPool(), false));
    902        }
    903        return result;
    904    }
    905
    906    /**
    907     * Remove a code attribute.
    908     */
    909    public void removeCodeAttribute(final Attribute a) {
    910        codeAttrsList.remove(a);
    911    }
    912
    913    /**
    914     * Remove all code attributes.
    915     */
    916    public void removeCodeAttributes() {
    917        localVariableTypeTable = null;
    918        codeAttrsList.clear();
    919    }
    920
    921    /**
    922     * Remove an exception.
    923     */
    924    public void removeException(final String c) {
    925        throwsList.remove(c);
    926    }
    927
    928    /**
    929     * Remove an exception handler.
    930     */
    931    public void removeExceptionHandler(final CodeExceptionGen c) {
    932        exceptionList.remove(c);
    933    }
    934
    935    /**
    936     * Remove all line numbers.
    937     */
    938    public void removeExceptionHandlers() {
    939        exceptionList.clear();
    940    }
    941
    942    /**
    943     * Remove all exceptions.
    944     */
    945    public void removeExceptions() {
    946        throwsList.clear();
    947    }
    948
    949    /**
    950     * Remove a line number.
    951     */
    952    public void removeLineNumber(final LineNumberGen l) {
    953        lineNumberList.remove(l);
    954    }
    955
    956    /**
    957     * Remove all line numbers.
    958     */
    959    public void removeLineNumbers() {
    960        lineNumberList.clear();
    961    }
    962
    963    /**
    964     * Remove a local variable, its slot will not be reused, if you do not use addLocalVariable with an explicit index
    965     * argument.
    966     */
    967    public void removeLocalVariable(final LocalVariableGen l) {
    968        l.dispose();
    969        variableList.remove(l);
    970    }
    971
    972    /**
    973     * Remove all local variables.
    974     */
    975    public void removeLocalVariables() {
    976        variableList.forEach(LocalVariableGen::dispose);
    977        variableList.clear();
    978    }
    979
    980    /**
    981     * Remove the LocalVariableTypeTable
    982     */
    983    public void removeLocalVariableTypeTable() {
    984        localVariableTypeTable = null;
    985    }
    986
    987    /**
    988     * Remove all NOPs from the instruction list (if possible) and update every object referring to them, i.e., branch
    989     * instructions, local variables and exception handlers.
    990     */
    991    public void removeNOPs() {
    992        if (il != null) {
    993            InstructionHandle next;
    994            /*
    995             * Check branch instructions.
    996             */
    997            for (InstructionHandle ih = il.getStart(); ih != null; ih = next) {
    998                next = ih.getNext();
    999                if (next != null && ih.getInstruction() instanceof NOP) {
    1000                    try {
    1001                        il.delete(ih);
    1002                    } catch (final TargetLostException e) {
    1003                        for (final InstructionHandle target : e.getTargets()) {
    1004                            for (final InstructionTargeter targeter : target.getTargeters()) {
    1005                                targeter.updateTarget(target, next);
    1006                            }
    1007                        }
    1008                    }
    1009                }
    1010            }
    1011        }
    1012    }
    1013
    1014    /**
    1015     * Remove observer for this object.
    1016     */
    1017    public void removeObserver(final MethodObserver o) {
    1018        if (observers != null) {
    1019            observers.remove(o);
    1020        }
    1021    }
    1022
    1023    /**
    1024     * Would prefer to make this private, but need a way to test if client is using BCEL version 6.5.0 or later that
    1025     * contains fix for BCEL-329.
    1026     *
    1027     * @since 6.5.0
    1028     */
    1029    public void removeRuntimeAttributes(final Attribute[] attrs) {
    1030        for (final Attribute attr : attrs) {
    1031            removeAttribute(attr);
    1032        }
    1033    }
    1034
    1035    public void setArgumentName(final int i, final String name) {
    1036        argNames[i] = name;
    1037    }
    1038
    1039    public void setArgumentNames(final String[] argNames) {
    1040        this.argNames = argNames;
    1041    }
    1042
    1043    public void setArgumentType(final int i, final Type type) {
    1044        argTypes[i] = type;
    1045    }
    1046
    1047    public void setArgumentTypes(final Type[] argTypes) {
    1048        this.argTypes = argTypes;
    1049    }
    1050
    1051    public void setClassName(final String className) { // TODO could be package-protected?
    1052        this.className = className;
    1053    }
    1054
    1055    public void setInstructionList(final InstructionList il) { // TODO could be package-protected?
    1056        this.il = il;
    1057    }
    1058
    1059    /**
    1060     * Compute maximum number of local variables.
    1061     */
    1062    public void setMaxLocals() { // TODO could be package-protected? (some tests would need repackaging)
    1063        if (il != null) {
    1064            int max = isStatic() ? 0 : 1;
    1065            if (argTypes != null) {
    1066                for (final Type argType : argTypes) {
    1067                    max += argType.getSize();
    1068                }
    1069            }
    1070            for (InstructionHandle ih = il.getStart(); ih != null; ih = ih.getNext()) {
    1071                final Instruction ins = ih.getInstruction();
    1072                if (ins instanceof LocalVariableInstruction || ins instanceof RET || ins instanceof IINC) {
    1073                    final int index = ((IndexedInstruction) ins).getIndex() + ((TypedInstruction) ins).getType(super.getConstantPool()).getSize();
    1074                    if (index > max) {
    1075                        max = index;
    1076                    }
    1077                }
    1078            }
    1079            maxLocals = max;
    1080        } else {
    1081            maxLocals = 0;
    1082        }
    1083    }
    1084
    1085    /**
    1086     * Set maximum number of local variables.
    1087     */
    1088    public void setMaxLocals(final int m) {
    1089        maxLocals = m;
    1090    }
    1091
    1092    /**
    1093     * Computes max. stack size by performing control flow analysis.
    1094     */
    1095    public void setMaxStack() { // TODO could be package-protected? (some tests would need repackaging)
    1096        if (il != null) {
    1097            maxStack = getMaxStack(super.getConstantPool(), il, getExceptionHandlers());
    1098        } else {
    1099            maxStack = 0;
    1100        }
    1101    }
    1102
    1103    /**
    1104     * Set maximum stack size for this method.
    1105     */
    1106    public void setMaxStack(final int m) { // TODO could be package-protected?
    1107        maxStack = m;
    1108    }
    1109
    1110    public void setReturnType(final Type returnType) {
    1111        setType(returnType);
    1112    }
    1113
    1114    /**
    1115     * Do not/Do produce attributes code attributesLineNumberTable and LocalVariableTable, like javac -O
    1116     */
    1117    public void stripAttributes(final boolean flag) {
    1118        stripAttributes = flag;
    1119    }
    1120
    1121    /**
    1122     * Return string representation close to declaration format, `public static void main(String[]) throws IOException',
    1123     * e.g.
    1124     *
    1125     * @return String representation of the method.
    1126     */
    1127    @Override
    1128    public final String toString() {
    1129        final String access = Utility.accessToString(super.getAccessFlags());
    1130        String signature = Type.getMethodSignature(super.getType(), argTypes);
    1131        signature = Utility.methodSignatureToString(signature, super.getName(), access, true, getLocalVariableTable(super.getConstantPool()));
    1132        final StringBuilder buf = new StringBuilder(signature);
    1133        for (final Attribute a : getAttributes()) {
    1134            if (!(a instanceof Code || a instanceof ExceptionTable)) {
    1135                buf.append(" [").append(a).append("]");
    1136            }
    1137        }
    1138
    1139        if (!throwsList.isEmpty()) {
    1140            for (final String throwsDescriptor : throwsList) {
    1141                buf.append("\n\t\tthrows ").append(throwsDescriptor);
    1142            }
    1143        }
    1144        return buf.toString();
    1145    }
    1146
    1147    /**
    1148     * Call notify() method on all observers. This method is not called automatically whenever the state has changed, but
    1149     * has to be called by the user after they have finished editing the object.
    1150     */
    1151    public void update() {
    1152        if (observers != null) {
    1153            for (final MethodObserver observer : observers) {
    1154                observer.notify(this);
    1155            }
    1156        }
    1157    }
    1158
    1159    private void updateLocalVariableTable(final LocalVariableTable a) {
    1160        removeLocalVariables();
    1161        for (final LocalVariable l : a.getLocalVariableTable()) {
    1162            InstructionHandle start = il.findHandle(l.getStartPC());
    1163            final InstructionHandle end = il.findHandle(l.getStartPC() + l.getLength());
    1164            // Repair malformed handles
    1165            if (null == start) {
    1166                start = il.getStart();
    1167            }
    1168            // end == null => live to end of method
    1169            // Since we are recreating the LocalVaraible, we must
    1170            // propagate the orig_index to new copy.
    1171            addLocalVariable(l.getName(), Type.getType(l.getSignature()), l.getIndex(), start, end, l.getOrigIndex());
    1172        }
    1173    }
    1174}