/**
* Transforms the init method to create the newly added join point member field.
*
* @param cp the ConstantPoolGen
* @param cg the ClassGen
* @param init the constructor for the class
* @param method the current method
* @param factory the objectfactory
* @param methodSequence the methods sequence number
* @return the modified constructor
*/
private MethodGen createJoinPointField(
final ConstantPoolGen cp,
final ClassGen cg,
final Method init,
final Method method,
final InstructionFactory factory,
final int methodSequence) {
final MethodGen mg = new MethodGen(init, cg.getClassName(), cp);
final InstructionList il = mg.getInstructionList();
final InstructionHandle[] ihs = il.getInstructionHandles();
// grab the handle to the the return instruction of the constructor
InstructionHandle ih = ihs[0];
for (int i = 0; i < ihs.length; i++) {
Instruction instruction = ihs[i].getInstruction();
if (instruction instanceof ReturnInstruction) {
ih = ihs[i]; // set the instruction handle to the return instruction
break;
}
}
final String joinPoint = getJoinPointName(method, methodSequence);
final InstructionHandle ihPost;
ihPost = il.insert(ih, factory.createLoad(Type.OBJECT, 0));
il.insert(ih, factory.createNew(TransformationUtil.THREAD_LOCAL_CLASS));
il.insert(ih, InstructionConstants.DUP);
il.insert(
ih,
factory.createInvoke(
TransformationUtil.THREAD_LOCAL_CLASS,
"<init>",
Type.VOID,
new Type[] {},
Constants.INVOKESPECIAL));
il.insert(
ih,
factory.createFieldAccess(
cg.getClassName(),
joinPoint,
new ObjectType(TransformationUtil.THREAD_LOCAL_CLASS),
Constants.PUTFIELD));
il.redirectBranches(ih, ihPost);
mg.setMaxStack();
mg.setMaxLocals();
return mg;
}
/** Compiles a method that overloads NodeSortRecord.extractValueFromDOM() */
private static MethodGenerator compileExtract(
Vector sortObjects,
NodeSortRecordGenerator sortRecord,
ConstantPoolGen cpg,
String className) {
final InstructionList il = new InstructionList();
// String NodeSortRecord.extractValueFromDOM(dom,node,level);
final CompareGenerator extractMethod =
new CompareGenerator(
ACC_PUBLIC | ACC_FINAL,
org.apache.bcel.generic.Type.STRING,
new org.apache.bcel.generic.Type[] {
Util.getJCRefType(DOM_INTF_SIG),
org.apache.bcel.generic.Type.INT,
org.apache.bcel.generic.Type.INT,
Util.getJCRefType(TRANSLET_SIG),
org.apache.bcel.generic.Type.INT
},
new String[] {"dom", "current", "level", "translet", "last"},
"extractValueFromDOM",
className,
il,
cpg);
// Values needed for the switch statement
final int levels = sortObjects.size();
final int match[] = new int[levels];
final InstructionHandle target[] = new InstructionHandle[levels];
InstructionHandle tblswitch = null;
// Compile switch statement only if the key has multiple levels
if (levels > 1) {
// Put the parameter to the swtich statement on the stack
il.append(new ILOAD(extractMethod.getLocalIndex("level")));
// Append the switch statement here later on
tblswitch = il.append(new NOP());
}
// Append all the cases for the switch statment
for (int level = 0; level < levels; level++) {
match[level] = level;
final Sort sort = (Sort) sortObjects.elementAt(level);
target[level] = il.append(NOP);
sort.translateSelect(sortRecord, extractMethod);
il.append(ARETURN);
}
// Compile def. target for switch statement if key has multiple levels
if (levels > 1) {
// Append the default target - it will _NEVER_ be reached
InstructionHandle defaultTarget = il.append(new PUSH(cpg, EMPTYSTRING));
il.insert(tblswitch, new TABLESWITCH(match, target, defaultTarget));
il.append(ARETURN);
}
return extractMethod;
}
/**
* Replace instruction ih in list il with the instructions in new_il. If new_il is null, do
* nothing
*/
protected static void replace_instructions(
InstructionList il, InstructionHandle ih, InstructionList new_il) {
if ((new_il == null) || new_il.isEmpty()) return;
// If there is only one new instruction, just replace it in the handle
if (new_il.getLength() == 1) {
ih.setInstruction(new_il.getEnd().getInstruction());
return;
}
// Get the start and end instruction of the new instructions
InstructionHandle new_end = new_il.getEnd();
InstructionHandle new_start = il.insert(ih, new_il);
// Move all of the branches from the old instruction to the new start
il.redirectBranches(ih, new_start);
// Move other targets to the new instuctions.
if (ih.hasTargeters()) {
for (InstructionTargeter it : ih.getTargeters()) {
if (it instanceof LineNumberGen) {
it.updateTarget(ih, new_start);
} else if (it instanceof LocalVariableGen) {
it.updateTarget(ih, new_end);
} else if (it instanceof CodeExceptionGen) {
CodeExceptionGen exc = (CodeExceptionGen) it;
if (exc.getStartPC() == ih) exc.updateTarget(ih, new_start);
else if (exc.getEndPC() == ih) exc.updateTarget(ih, new_end);
else if (exc.getHandlerPC() == ih) exc.setHandlerPC(new_start);
else System.out.printf("Malformed CodeException: %s%n", exc);
} else {
System.out.printf("unexpected target %s%n", it);
}
}
}
// Remove the old handle. There should be no targeters left to it.
try {
il.delete(ih);
} catch (Exception e) {
throw new Error("Can't delete instruction", e);
}
}
/** Adds code in nl to start of method mg * */
public static void add_to_start(MethodGen mg, InstructionList nl) {
// Add the code before the first instruction
InstructionList il = mg.getInstructionList();
InstructionHandle old_start = il.getStart();
InstructionHandle new_start = il.insert(nl);
// Move any LineNumbers and local variable that currently point to
// the first instruction to include the new instructions. Other
// targeters (branches, exceptions) should not include the new
// code
if (old_start.hasTargeters()) {
for (InstructionTargeter it : old_start.getTargeters()) {
if ((it instanceof LineNumberGen) || (it instanceof LocalVariableGen))
it.updateTarget(old_start, new_start);
}
}
mg.setMaxStack();
mg.setMaxLocals();
}
