/**
* Generates the Java bytecode corresponding to this list of bytecodes. This just calls {@code
* bytecode.NonBranchingBytecode.generateJavaBytecode(JavaClassGenerator)} on each non-branching
* bytecode in the list and appends the results.
*
* @param classGen the Java class generator to be used for this generation
* @return the Java bytecode corresponding to this list of bytecodes
*/
public InstructionList generateJavaBytecode(JavaClassGenerator classGen) {
InstructionList result;
if (head instanceof NonBranchingBytecode)
// generiamo il Java bytecode dal primo bytecode, se non è una condizione di un ramo
result = ((NonBranchingBytecode) head).generateJavaBytecode(classGen);
else result = new InstructionList();
// e per quelli successivi, se esistono
if (tail != null) result.append(tail.generateJavaBytecode(classGen));
// se non sono state aggiunte istruzioni, ne aggiungiamo una fittizia cosi da ritornare sempre
// una lista non vuota
if (result.isEmpty()) result.append(new org.apache.bcel.generic.NOP());
return result;
}
/**
* 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);
}
}
