Java LocalVariableGen类代码示例

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
/**
 * Remove the mapping from the name of the specified
 * {@link LocalVariableGen} to itself.
 * See also {@link #registerByName(LocalVariableGen)} and
 * {@link #lookUpByName(String)}
 * @param lvg a <code>LocalVariableGen</code>
 */
protected void removeByNameTracking(LocalVariableGen lvg) {
    Object duplicateNameEntry = _nameToLVGMap.get(lvg.getName());

    if (duplicateNameEntry instanceof ArrayList) {
        ArrayList sameNameList = (ArrayList) duplicateNameEntry;
        for (int i = 0; i < sameNameList.size(); i++) {
            if (sameNameList.get(i) == lvg) {
                sameNameList.remove(i);
                break;
            }
        }
    } else {
        _nameToLVGMap.remove(lvg);
    }
}
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
public void setMaxLocals() {

        // Get the current number of local variable slots
        int maxLocals = super.getMaxLocals();
        int prevLocals = maxLocals;

        // Get numer of actual variables
        final LocalVariableGen[] localVars = super.getLocalVariables();
        if (localVars != null) {
            if (localVars.length > maxLocals)
                maxLocals = localVars.length;
        }

        // We want at least 5 local variable slots (for parameters)
        if (maxLocals < 5) maxLocals = 5;

        super.setMaxLocals(maxLocals);
    }
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
public void releaseSlot(LocalVariableGen lvg) {
    final int size = lvg.getType().getSize();
    final int slot = lvg.getIndex();
    final int limit = _free;

    for (int i = 0; i < limit; i++) {
        if (_slotsTaken[i] == slot) {
            int j = i + size;
            while (j < limit) {
                _slotsTaken[i++] = _slotsTaken[j++];
            }
            _free -= size;
            return;
        }
    }
    String state = "Variable slot allocation error"+
                   "(size="+size+", slot="+slot+", limit="+limit+")";
    ErrorMsg err = new ErrorMsg(ErrorMsg.INTERNAL_ERR, state);
    throw new Error(err.toString());
}
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
public CompareGenerator(int access_flags, Type return_type,
                        Type[] arg_types, String[] arg_names,
                        String method_name, String class_name,
                        InstructionList il, ConstantPoolGen cp) {
    super(access_flags, return_type, arg_types, arg_names, method_name,
          class_name, il, cp);

    _iloadCurrent = new ILOAD(CURRENT_INDEX);
    _istoreCurrent = new ISTORE(CURRENT_INDEX);
    _aloadDom = new ALOAD(DOM_INDEX);
    _iloadLast = new ILOAD(LAST_INDEX);

    LocalVariableGen iterator =
        addLocalVariable("iterator",
                         Util.getJCRefType(Constants.NODE_ITERATOR_SIG),
                         null, null);
    ITERATOR_INDEX = iterator.getIndex();
    _aloadIterator = new ALOAD(ITERATOR_INDEX);
    _astoreIterator = new ASTORE(ITERATOR_INDEX);
    il.append(new ACONST_NULL());
    il.append(storeIterator());
}
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
/**
 * <p>Set up a mapping of the name of the specified
 * {@link LocalVariableGen} object to the <code>LocalVariableGen</code>
 * itself.</p>
 * <p>This is a bit of a hack.  XSLTC is relying on the fact that the
 * name that is being looked up won't be duplicated, which isn't
 * guaranteed.  It replaces code which used to call
 * {@link MethodGen#getLocalVariables()} and looped through the
 * <code>LocalVariableGen</code> objects it contained to find the one
 * with the specified name.  However, <code>getLocalVariables()</code>
 * has the side effect of setting the start and end for any
 * <code>LocalVariableGen</code> which did not already have them
 * set, which causes problems for outlining..</p>
 * <p>See also {@link #lookUpByName(String)} and
 * {@link #removeByNameTracking(LocalVariableGen)}</P
 * @param lvg a <code>LocalVariableGen</code>
 */
protected void registerByName(LocalVariableGen lvg) {
    Object duplicateNameEntry = _nameToLVGMap.get(lvg.getName());

    if (duplicateNameEntry == null) {
        _nameToLVGMap.put(lvg.getName(), lvg);
    } else {
        ArrayList sameNameList;

        if (duplicateNameEntry instanceof ArrayList) {
            sameNameList = (ArrayList) duplicateNameEntry;
            sameNameList.add(lvg);
        } else {
            sameNameList = new ArrayList();
            sameNameList.add(duplicateNameEntry);
            sameNameList.add(lvg);
        }

        _nameToLVGMap.put(lvg.getName(), sameNameList);
    }
}
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
/**
 * Translates a real into a non-synthesized boolean. It does not push a
 * 0 or a 1 but instead returns branchhandle list to be appended to the
 * false list. A NaN must be converted to "false".
 *
 * @see     com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateToDesynthesized
 */
public FlowList translateToDesynthesized(ClassGenerator classGen,
                                         MethodGenerator methodGen,
                                         BooleanType type) {
    LocalVariableGen local;
    final FlowList flowlist = new FlowList();
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    // Store real into a local variable
    il.append(DUP2);
    local = methodGen.addLocalVariable("real_to_boolean_tmp",
                                       com.sun.org.apache.bcel.internal.generic.Type.DOUBLE,
                                       null, null);
    local.setStart(il.append(new DSTORE(local.getIndex())));

    // Compare it to 0.0
    il.append(DCONST_0);
    il.append(DCMPG);
    flowlist.add(il.append(new IFEQ(null)));

    //!!! call isNaN
    // Compare it to itself to see if NaN
    il.append(new DLOAD(local.getIndex()));
    local.setEnd(il.append(new DLOAD(local.getIndex())));
    il.append(DCMPG);
    flowlist.add(il.append(new IFNE(null)));        // NaN != NaN
    return flowlist;
}
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
/**
 * Allocates a local variable. If the slot allocator has already been
 * initialized, then call addLocalVariable2() so that the new variable
 * is known to the allocator. Failing to do this may cause the allocator
 * to return a slot that is already in use.
 */
public LocalVariableGen addLocalVariable(String name, Type type,
                                         InstructionHandle start,
                                         InstructionHandle end)
{
    LocalVariableGen lvg;

    if (_allocatorInit) {
        lvg = addLocalVariable2(name, type, start);
    } else {
        lvg = super.addLocalVariable(name, type, start, end);
        getLocalVariableRegistry().registerLocalVariable(lvg);
    }
    return lvg;
}
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
public LocalVariableGen addLocalVariable2(String name, Type type,
                                          InstructionHandle start)
{
    LocalVariableGen lvg = super.addLocalVariable(name, type,
                                          _slotAllocator.allocateSlot(type),
                                          start, null);
    getLocalVariableRegistry().registerLocalVariable(lvg);
    return lvg;
}
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
/**
 * Registers a {@link org.apache.bcel.generic.LocalVariableGen}
 * for this method.
 * <p><b>Preconditions:</b>
 * <ul>
 * <li>The range of instructions for <code>lvg</code> does not
 * overlap with the range of instructions for any
 * <code>LocalVariableGen</code> with the same slot index previously
 * registered for this method.  <b><em>(Unchecked.)</em></b></li>
 * </ul></p>
 * @param lvg The variable to be registered
 */
protected void registerLocalVariable(LocalVariableGen lvg) {
    int slot = lvg.getIndex();

    int registrySize = _variables.size();

    // If the LocalVariableGen uses a slot index beyond any previously
    // encountered, expand the _variables, padding with intervening null
    // entries as required.
    if (slot >= registrySize) {
        for (int i = registrySize; i < slot; i++) {
            _variables.add(null);
        }
        _variables.add(lvg);
    } else {
        // If the LocalVariableGen reuses a slot, make sure the entry
        // in _variables contains an ArrayList and add the newly
        // registered LocalVariableGen to the list.  If the entry in
        // _variables just contains null padding, store the
        // LocalVariableGen directly.
        Object localsInSlot = _variables.get(slot);
        if (localsInSlot != null) {
            if (localsInSlot instanceof LocalVariableGen) {
                ArrayList listOfLocalsInSlot = new ArrayList();
                listOfLocalsInSlot.add(localsInSlot);
                listOfLocalsInSlot.add(lvg);
                _variables.set(slot, listOfLocalsInSlot);
            } else {
                ((ArrayList) localsInSlot).add(lvg);
            }
        } else {
            _variables.set(slot, lvg);
        }
    }

    registerByName(lvg);
}
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
/**
 * Determines whether a particular variable is in use at a particular offset
 * in the byte code for this method.
 * <p><b>Preconditions:</b>
 * <ul>
 * <li>The {@link InstructionList#setPositions()} has been called for the
 * {@link InstructionList} associated with this {@link MethodGenerator}.
 * </li></ul></p>
 * @param lvg the {@link LocalVariableGen} for the variable
 * @param offset the position in the byte code
 * @return <code>true</code> if and only if the specified variable is in
 * use at the particular byte code offset.
 */
boolean offsetInLocalVariableGenRange(LocalVariableGen lvg, int offset) {
    InstructionHandle lvgStart = lvg.getStart();
    InstructionHandle lvgEnd = lvg.getEnd();

    // If no start handle is recorded for the LocalVariableGen, it is
    // assumed to be in use from the beginning of the method.
    if (lvgStart == null) {
        lvgStart = getInstructionList().getStart();
    }

    // If no end handle is recorded for the LocalVariableGen, it is assumed
    // to be in use to the end of the method.
    if (lvgEnd == null) {
        lvgEnd = getInstructionList().getEnd();
    }

    // Does the range of the instruction include the specified offset?
    // Note that the InstructionHandle.getPosition method returns the
    // offset of the beginning of an instruction.  A LocalVariableGen's
    // range includes the end instruction itself, so that instruction's
    // length must be taken into consideration in computing whether the
    // varible is in range at a particular offset.
    return ((lvgStart.getPosition() <= offset)
                && (lvgEnd.getPosition()
                        + lvgEnd.getInstruction().getLength() >= offset));
}
 

import com.sun.org.apache.bcel.internal.generic.LocalVariableGen; //导入依赖的package包/类
public void initialize(LocalVariableGen[] vars) {
    final int length = vars.length;
    int slot = 0, size, index;

    for (int i = 0; i < length; i++) {
        size  = vars[i].getType().getSize();
        index = vars[i].getIndex();
        slot  = Math.max(slot, index + size);
    }
    _firstAvailableSlot = slot;
}