/**
* Analyzes the given method.
*
* @param owner the internal name of the class to which the method belongs.
* @param m the method to be analyzed.
* @return the symbolic state of the execution stack frame at each bytecode instruction of the
* method. The size of the returned array is equal to the number of instructions (and labels)
* of the method. A given frame is <tt>null</tt> if and only if the corresponding instruction
* cannot be reached (dead code).
* @throws AnalyzerException if a problem occurs during the analysis.
*/
public Frame[] analyze(final String owner, final MethodNode m) throws AnalyzerException {
if ((m.access & (ACC_ABSTRACT | ACC_NATIVE)) != 0) {
frames = new Frame[0];
return frames;
}
n = m.instructions.size();
insns = m.instructions;
handlers = new List[n];
frames = new Frame[n];
subroutines = new Subroutine[n];
queued = new boolean[n];
queue = new int[n];
top = 0;
// computes exception handlers for each instruction
for (int i = 0; i < m.tryCatchBlocks.size(); ++i) {
TryCatchBlockNode tcb = (TryCatchBlockNode) m.tryCatchBlocks.get(i);
int begin = insns.indexOf(tcb.start);
int end = insns.indexOf(tcb.end);
for (int j = begin; j < end; ++j) {
List insnHandlers = handlers[j];
if (insnHandlers == null) {
insnHandlers = new ArrayList();
handlers[j] = insnHandlers;
}
insnHandlers.add(tcb);
}
}
// computes the subroutine for each instruction:
Subroutine main = new Subroutine(null, m.maxLocals, null);
List subroutineCalls = new ArrayList();
Map subroutineHeads = new HashMap();
findSubroutine(0, main, subroutineCalls);
while (!subroutineCalls.isEmpty()) {
JumpInsnNode jsr = (JumpInsnNode) subroutineCalls.remove(0);
Subroutine sub = (Subroutine) subroutineHeads.get(jsr.label);
if (sub == null) {
sub = new Subroutine(jsr.label, m.maxLocals, jsr);
subroutineHeads.put(jsr.label, sub);
findSubroutine(insns.indexOf(jsr.label), sub, subroutineCalls);
} else {
sub.callers.add(jsr);
}
}
for (int i = 0; i < n; ++i) {
if (subroutines[i] != null && subroutines[i].start == null) {
subroutines[i] = null;
}
}
// initializes the data structures for the control flow analysis
Frame current = newFrame(m.maxLocals, m.maxStack);
Frame handler = newFrame(m.maxLocals, m.maxStack);
Type[] args = Type.getArgumentTypes(m.desc);
int local = 0;
if ((m.access & ACC_STATIC) == 0) {
Type ctype = Type.getObjectType(owner);
current.setLocal(local++, interpreter.newValue(ctype));
}
for (int i = 0; i < args.length; ++i) {
current.setLocal(local++, interpreter.newValue(args[i]));
if (args[i].getSize() == 2) {
current.setLocal(local++, interpreter.newValue(null));
}
}
while (local < m.maxLocals) {
current.setLocal(local++, interpreter.newValue(null));
}
merge(0, current, null);
// control flow analysis
while (top > 0) {
int insn = queue[--top];
Frame f = frames[insn];
Subroutine subroutine = subroutines[insn];
queued[insn] = false;
try {
AbstractInsnNode insnNode = m.instructions.get(insn);
int insnOpcode = insnNode.getOpcode();
int insnType = insnNode.getType();
if (insnType == AbstractInsnNode.LABEL
|| insnType == AbstractInsnNode.LINE
|| insnType == AbstractInsnNode.FRAME) {
merge(insn + 1, f, subroutine);
newControlFlowEdge(insn, insn + 1);
} else {
current.init(f).execute(insnNode, interpreter);
subroutine = subroutine == null ? null : subroutine.copy();
if (insnNode instanceof JumpInsnNode) {
JumpInsnNode j = (JumpInsnNode) insnNode;
if (insnOpcode != GOTO && insnOpcode != JSR) {
merge(insn + 1, current, subroutine);
newControlFlowEdge(insn, insn + 1);
}
int jump = insns.indexOf(j.label);
if (insnOpcode == JSR) {
merge(jump, current, new Subroutine(j.label, m.maxLocals, j));
} else {
merge(jump, current, subroutine);
}
newControlFlowEdge(insn, jump);
} else if (insnNode instanceof LookupSwitchInsnNode) {
LookupSwitchInsnNode lsi = (LookupSwitchInsnNode) insnNode;
int jump = insns.indexOf(lsi.dflt);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
for (int j = 0; j < lsi.labels.size(); ++j) {
LabelNode label = (LabelNode) lsi.labels.get(j);
jump = insns.indexOf(label);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
}
} else if (insnNode instanceof TableSwitchInsnNode) {
TableSwitchInsnNode tsi = (TableSwitchInsnNode) insnNode;
int jump = insns.indexOf(tsi.dflt);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
for (int j = 0; j < tsi.labels.size(); ++j) {
LabelNode label = (LabelNode) tsi.labels.get(j);
jump = insns.indexOf(label);
merge(jump, current, subroutine);
newControlFlowEdge(insn, jump);
}
} else if (insnOpcode == RET) {
if (subroutine == null) {
throw new AnalyzerException("RET instruction outside of a sub routine");
}
for (int i = 0; i < subroutine.callers.size(); ++i) {
Object caller = subroutine.callers.get(i);
int call = insns.indexOf((AbstractInsnNode) caller);
if (frames[call] != null) {
merge(call + 1, frames[call], current, subroutines[call], subroutine.access);
newControlFlowEdge(insn, call + 1);
}
}
} else if (insnOpcode != ATHROW && (insnOpcode < IRETURN || insnOpcode > RETURN)) {
if (subroutine != null) {
if (insnNode instanceof VarInsnNode) {
int var = ((VarInsnNode) insnNode).var;
subroutine.access[var] = true;
if (insnOpcode == LLOAD
|| insnOpcode == DLOAD
|| insnOpcode == LSTORE
|| insnOpcode == DSTORE) {
subroutine.access[var + 1] = true;
}
} else if (insnNode instanceof IincInsnNode) {
int var = ((IincInsnNode) insnNode).var;
subroutine.access[var] = true;
}
}
merge(insn + 1, current, subroutine);
newControlFlowEdge(insn, insn + 1);
}
}
List insnHandlers = handlers[insn];
if (insnHandlers != null) {
for (int i = 0; i < insnHandlers.size(); ++i) {
TryCatchBlockNode tcb = (TryCatchBlockNode) insnHandlers.get(i);
Type type;
if (tcb.type == null) {
type = Type.getObjectType("java/lang/Throwable");
} else {
type = Type.getObjectType(tcb.type);
}
int jump = insns.indexOf(tcb.handler);
if (newControlFlowExceptionEdge(insn, jump)) {
handler.init(f);
handler.clearStack();
handler.push(interpreter.newValue(type));
merge(jump, handler, subroutine);
}
}
}
} catch (AnalyzerException e) {
throw new AnalyzerException("Error at instruction " + insn + ": " + e.getMessage(), e);
} catch (Exception e) {
throw new AnalyzerException("Error at instruction " + insn + ": " + e.getMessage(), e);
}
}
return frames;
}
/**
* Analyzes the given method.
*
* @param c the class to which the method belongs.
* @param m the method to be analyzed.
* @return the symbolic state of the execution stack frame at each bytecode instruction of the
* method. The size of the returned array is equal to the number of instructions (and labels)
* of the method. A given frame is <tt>null</tt> if and only if the corresponding instruction
* cannot be reached (dead code).
* @throws AnalyzerException if a problem occurs during the analysis.
*/
public Frame[] analyze(final ClassNode c, final MethodNode m) throws AnalyzerException {
n = m.instructions.size();
indexes = new IntMap(2 * n);
handlers = new List[n];
frames = new Frame[n];
subroutines = new Subroutine[n];
queued = new boolean[n];
queue = new int[n];
top = 0;
// computes instruction indexes
for (int i = 0; i < n; ++i) {
indexes.put(m.instructions.get(i), i);
}
// computes exception handlers for each instruction
for (int i = 0; i < m.tryCatchBlocks.size(); ++i) {
TryCatchBlockNode tcb = (TryCatchBlockNode) m.tryCatchBlocks.get(i);
int begin = indexes.get(tcb.start);
int end = indexes.get(tcb.end);
for (int j = begin; j < end; ++j) {
List insnHandlers = handlers[j];
if (insnHandlers == null) {
insnHandlers = new ArrayList();
handlers[j] = insnHandlers;
}
insnHandlers.add(tcb);
}
}
// initializes the data structures for the control flow analysis algorithm
Frame current = newFrame(m.maxLocals, m.maxStack);
Frame handler = newFrame(m.maxLocals, m.maxStack);
Type[] args = Type.getArgumentTypes(m.desc);
int local = 0;
if ((m.access & ACC_STATIC) == 0) {
Type ctype = Type.getType("L" + c.name + ";");
current.setLocal(local++, interpreter.newValue(ctype));
}
for (int i = 0; i < args.length; ++i) {
current.setLocal(local++, interpreter.newValue(args[i]));
if (args[i].getSize() == 2) {
current.setLocal(local++, interpreter.newValue(null));
}
}
while (local < m.maxLocals) {
current.setLocal(local++, interpreter.newValue(null));
}
merge(0, current, null);
// control flow analysis
while (top > 0) {
int insn = queue[--top];
Frame f = frames[insn];
Subroutine subroutine = subroutines[insn];
queued[insn] = false;
try {
Object o = m.instructions.get(insn);
jsr = false;
if (o instanceof Label) {
merge(insn + 1, f, subroutine);
} else {
AbstractInsnNode insnNode = (AbstractInsnNode) o;
int insnOpcode = insnNode.getOpcode();
current.init(f).execute(insnNode, interpreter);
subroutine = subroutine == null ? null : subroutine.copy();
if (insnNode instanceof JumpInsnNode) {
JumpInsnNode j = (JumpInsnNode) insnNode;
if (insnOpcode != GOTO && insnOpcode != JSR) {
merge(insn + 1, current, subroutine);
}
if (insnOpcode == JSR) {
jsr = true;
merge(indexes.get(j.label), current, new Subroutine(j.label, m.maxLocals, j));
} else {
merge(indexes.get(j.label), current, subroutine);
}
} else if (insnNode instanceof LookupSwitchInsnNode) {
LookupSwitchInsnNode lsi = (LookupSwitchInsnNode) insnNode;
merge(indexes.get(lsi.dflt), current, subroutine);
for (int j = 0; j < lsi.labels.size(); ++j) {
Label label = (Label) lsi.labels.get(j);
merge(indexes.get(label), current, subroutine);
}
} else if (insnNode instanceof TableSwitchInsnNode) {
TableSwitchInsnNode tsi = (TableSwitchInsnNode) insnNode;
merge(indexes.get(tsi.dflt), current, subroutine);
for (int j = 0; j < tsi.labels.size(); ++j) {
Label label = (Label) tsi.labels.get(j);
merge(indexes.get(label), current, subroutine);
}
} else if (insnOpcode == RET) {
if (subroutine == null) {
throw new AnalyzerException("RET instruction outside of a sub routine");
} else {
for (int i = 0; i < subroutine.callers.size(); ++i) {
int caller = indexes.get(subroutine.callers.get(i));
merge(caller + 1, frames[caller], current, subroutines[caller], subroutine.access);
}
}
} else if (insnOpcode != ATHROW && (insnOpcode < IRETURN || insnOpcode > RETURN)) {
if (subroutine != null) {
if (insnNode instanceof VarInsnNode) {
int var = ((VarInsnNode) insnNode).var;
subroutine.access[var] = true;
if (insnOpcode == LLOAD
|| insnOpcode == DLOAD
|| insnOpcode == LSTORE
|| insnOpcode == DSTORE) {
subroutine.access[var + 1] = true;
}
} else if (insnNode instanceof IincInsnNode) {
int var = ((IincInsnNode) insnNode).var;
subroutine.access[var] = true;
}
}
merge(insn + 1, current, subroutine);
}
}
List insnHandlers = handlers[insn];
if (insnHandlers != null) {
for (int i = 0; i < insnHandlers.size(); ++i) {
TryCatchBlockNode tcb = (TryCatchBlockNode) insnHandlers.get(i);
Type type;
if (tcb.type == null) {
type = Type.getType("Ljava/lang/Throwable;");
} else {
type = Type.getType("L" + tcb.type + ";");
}
handler.init(f);
handler.clearStack();
handler.push(interpreter.newValue(type));
merge(indexes.get(tcb.handler), handler, subroutine);
}
}
} catch (Exception e) {
throw new AnalyzerException("Error at instruction " + insn + ": " + e.getMessage());
}
}
return frames;
}
public void execute(final AbstractInsnNode insn, final Interpreter interpreter)
throws AnalyzerException {
Value value1, value2, value3, value4;
List values;
int var;
switch (insn.getOpcode()) {
case Opcodes.NOP:
break;
case Opcodes.ACONST_NULL:
case Opcodes.ICONST_M1:
case Opcodes.ICONST_0:
case Opcodes.ICONST_1:
case Opcodes.ICONST_2:
case Opcodes.ICONST_3:
case Opcodes.ICONST_4:
case Opcodes.ICONST_5:
case Opcodes.LCONST_0:
case Opcodes.LCONST_1:
case Opcodes.FCONST_0:
case Opcodes.FCONST_1:
case Opcodes.FCONST_2:
case Opcodes.DCONST_0:
case Opcodes.DCONST_1:
case Opcodes.BIPUSH:
case Opcodes.SIPUSH:
case Opcodes.LDC:
push(interpreter.newOperation(insn));
break;
case Opcodes.ILOAD:
case Opcodes.LLOAD:
case Opcodes.FLOAD:
case Opcodes.DLOAD:
case Opcodes.ALOAD:
push(interpreter.copyOperation(insn, getLocal(((VarInsnNode) insn).var)));
break;
case Opcodes.IALOAD:
case Opcodes.LALOAD:
case Opcodes.FALOAD:
case Opcodes.DALOAD:
case Opcodes.AALOAD:
case Opcodes.BALOAD:
case Opcodes.CALOAD:
case Opcodes.SALOAD:
value2 = pop();
value1 = pop();
push(interpreter.binaryOperation(insn, value1, value2));
break;
case Opcodes.ISTORE:
case Opcodes.LSTORE:
case Opcodes.FSTORE:
case Opcodes.DSTORE:
case Opcodes.ASTORE:
value1 = interpreter.copyOperation(insn, pop());
var = ((VarInsnNode) insn).var;
setLocal(var, value1);
if (value1.getSize() == 2) {
setLocal(var + 1, interpreter.newValue(null));
}
if (var > 0) {
Value local = getLocal(var - 1);
if (local != null && local.getSize() == 2) {
setLocal(var - 1, interpreter.newValue(null));
}
}
break;
case Opcodes.IASTORE:
case Opcodes.LASTORE:
case Opcodes.FASTORE:
case Opcodes.DASTORE:
case Opcodes.AASTORE:
case Opcodes.BASTORE:
case Opcodes.CASTORE:
case Opcodes.SASTORE:
value3 = pop();
value2 = pop();
value1 = pop();
interpreter.ternaryOperation(insn, value1, value2, value3);
break;
case Opcodes.POP:
if (pop().getSize() == 2) {
throw new AnalyzerException(insn, "Illegal use of POP");
}
break;
case Opcodes.POP2:
if (pop().getSize() == 1) {
if (pop().getSize() != 1) {
throw new AnalyzerException(insn, "Illegal use of POP2");
}
}
break;
case Opcodes.DUP:
value1 = pop();
if (value1.getSize() != 1) {
throw new AnalyzerException(insn, "Illegal use of DUP");
}
push(value1);
push(interpreter.copyOperation(insn, value1));
break;
case Opcodes.DUP_X1:
value1 = pop();
value2 = pop();
if (value1.getSize() != 1 || value2.getSize() != 1) {
throw new AnalyzerException(insn, "Illegal use of DUP_X1");
}
push(interpreter.copyOperation(insn, value1));
push(value2);
push(value1);
break;
case Opcodes.DUP_X2:
value1 = pop();
if (value1.getSize() == 1) {
value2 = pop();
if (value2.getSize() == 1) {
value3 = pop();
if (value3.getSize() == 1) {
push(interpreter.copyOperation(insn, value1));
push(value3);
push(value2);
push(value1);
break;
}
} else {
push(interpreter.copyOperation(insn, value1));
push(value2);
push(value1);
break;
}
}
throw new AnalyzerException(insn, "Illegal use of DUP_X2");
case Opcodes.DUP2:
value1 = pop();
if (value1.getSize() == 1) {
value2 = pop();
if (value2.getSize() == 1) {
push(value2);
push(value1);
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
}
} else {
push(value1);
push(interpreter.copyOperation(insn, value1));
break;
}
throw new AnalyzerException(insn, "Illegal use of DUP2");
case Opcodes.DUP2_X1:
value1 = pop();
if (value1.getSize() == 1) {
value2 = pop();
if (value2.getSize() == 1) {
value3 = pop();
if (value3.getSize() == 1) {
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
push(value3);
push(value2);
push(value1);
break;
}
}
} else {
value2 = pop();
if (value2.getSize() == 1) {
push(interpreter.copyOperation(insn, value1));
push(value2);
push(value1);
break;
}
}
throw new AnalyzerException(insn, "Illegal use of DUP2_X1");
case Opcodes.DUP2_X2:
value1 = pop();
if (value1.getSize() == 1) {
value2 = pop();
if (value2.getSize() == 1) {
value3 = pop();
if (value3.getSize() == 1) {
value4 = pop();
if (value4.getSize() == 1) {
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
push(value4);
push(value3);
push(value2);
push(value1);
break;
}
} else {
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
push(value3);
push(value2);
push(value1);
break;
}
}
} else {
value2 = pop();
if (value2.getSize() == 1) {
value3 = pop();
if (value3.getSize() == 1) {
push(interpreter.copyOperation(insn, value1));
push(value3);
push(value2);
push(value1);
break;
}
} else {
push(interpreter.copyOperation(insn, value1));
push(value2);
push(value1);
break;
}
}
throw new AnalyzerException(insn, "Illegal use of DUP2_X2");
case Opcodes.SWAP:
value2 = pop();
value1 = pop();
if (value1.getSize() != 1 || value2.getSize() != 1) {
throw new AnalyzerException(insn, "Illegal use of SWAP");
}
push(interpreter.copyOperation(insn, value2));
push(interpreter.copyOperation(insn, value1));
break;
case Opcodes.IADD:
case Opcodes.LADD:
case Opcodes.FADD:
case Opcodes.DADD:
case Opcodes.ISUB:
case Opcodes.LSUB:
case Opcodes.FSUB:
case Opcodes.DSUB:
case Opcodes.IMUL:
case Opcodes.LMUL:
case Opcodes.FMUL:
case Opcodes.DMUL:
case Opcodes.IDIV:
case Opcodes.LDIV:
case Opcodes.FDIV:
case Opcodes.DDIV:
case Opcodes.IREM:
case Opcodes.LREM:
case Opcodes.FREM:
case Opcodes.DREM:
value2 = pop();
value1 = pop();
push(interpreter.binaryOperation(insn, value1, value2));
break;
case Opcodes.INEG:
case Opcodes.LNEG:
case Opcodes.FNEG:
case Opcodes.DNEG:
push(interpreter.unaryOperation(insn, pop()));
break;
case Opcodes.ISHL:
case Opcodes.LSHL:
case Opcodes.ISHR:
case Opcodes.LSHR:
case Opcodes.IUSHR:
case Opcodes.LUSHR:
case Opcodes.IAND:
case Opcodes.LAND:
case Opcodes.IOR:
case Opcodes.LOR:
case Opcodes.IXOR:
case Opcodes.LXOR:
value2 = pop();
value1 = pop();
push(interpreter.binaryOperation(insn, value1, value2));
break;
case Opcodes.IINC:
var = ((IincInsnNode) insn).var;
setLocal(var, interpreter.unaryOperation(insn, getLocal(var)));
break;
case Opcodes.I2L:
case Opcodes.I2F:
case Opcodes.I2D:
case Opcodes.L2I:
case Opcodes.L2F:
case Opcodes.L2D:
case Opcodes.F2I:
case Opcodes.F2L:
case Opcodes.F2D:
case Opcodes.D2I:
case Opcodes.D2L:
case Opcodes.D2F:
case Opcodes.I2B:
case Opcodes.I2C:
case Opcodes.I2S:
push(interpreter.unaryOperation(insn, pop()));
break;
case Opcodes.LCMP:
case Opcodes.FCMPL:
case Opcodes.FCMPG:
case Opcodes.DCMPL:
case Opcodes.DCMPG:
value2 = pop();
value1 = pop();
push(interpreter.binaryOperation(insn, value1, value2));
break;
case Opcodes.IFEQ:
case Opcodes.IFNE:
case Opcodes.IFLT:
case Opcodes.IFGE:
case Opcodes.IFGT:
case Opcodes.IFLE:
interpreter.unaryOperation(insn, pop());
break;
case Opcodes.IF_ICMPEQ:
case Opcodes.IF_ICMPNE:
case Opcodes.IF_ICMPLT:
case Opcodes.IF_ICMPGE:
case Opcodes.IF_ICMPGT:
case Opcodes.IF_ICMPLE:
case Opcodes.IF_ACMPEQ:
case Opcodes.IF_ACMPNE:
value2 = pop();
value1 = pop();
interpreter.binaryOperation(insn, value1, value2);
break;
case Opcodes.GOTO:
break;
case Opcodes.JSR:
push(interpreter.newOperation(insn));
break;
case Opcodes.RET:
break;
case Opcodes.TABLESWITCH:
case Opcodes.LOOKUPSWITCH:
interpreter.unaryOperation(insn, pop());
break;
case Opcodes.IRETURN:
case Opcodes.LRETURN:
case Opcodes.FRETURN:
case Opcodes.DRETURN:
case Opcodes.ARETURN:
value1 = pop();
interpreter.unaryOperation(insn, value1);
interpreter.returnOperation(insn, value1, returnValue);
break;
case Opcodes.RETURN:
if (returnValue != null) {
throw new AnalyzerException(insn, "Incompatible return type");
}
break;
case Opcodes.GETSTATIC:
push(interpreter.newOperation(insn));
break;
case Opcodes.PUTSTATIC:
interpreter.unaryOperation(insn, pop());
break;
case Opcodes.GETFIELD:
push(interpreter.unaryOperation(insn, pop()));
break;
case Opcodes.PUTFIELD:
value2 = pop();
value1 = pop();
interpreter.binaryOperation(insn, value1, value2);
break;
case Opcodes.INVOKEVIRTUAL:
case Opcodes.INVOKESPECIAL:
case Opcodes.INVOKESTATIC:
case Opcodes.INVOKEINTERFACE:
case Opcodes.INVOKEDYNAMIC:
values = new ArrayList();
String desc = ((MethodInsnNode) insn).desc;
for (int i = Type.getArgumentTypes(desc).length; i > 0; --i) {
values.add(0, pop());
}
if (insn.getOpcode() != Opcodes.INVOKESTATIC && insn.getOpcode() != Opcodes.INVOKEDYNAMIC) {
values.add(0, pop());
}
if (Type.getReturnType(desc) == Type.VOID_TYPE) {
interpreter.naryOperation(insn, values);
} else {
push(interpreter.naryOperation(insn, values));
}
break;
case Opcodes.NEW:
push(interpreter.newOperation(insn));
break;
case Opcodes.NEWARRAY:
case Opcodes.ANEWARRAY:
case Opcodes.ARRAYLENGTH:
push(interpreter.unaryOperation(insn, pop()));
break;
case Opcodes.ATHROW:
interpreter.unaryOperation(insn, pop());
break;
case Opcodes.CHECKCAST:
case Opcodes.INSTANCEOF:
push(interpreter.unaryOperation(insn, pop()));
break;
case Opcodes.MONITORENTER:
case Opcodes.MONITOREXIT:
interpreter.unaryOperation(insn, pop());
break;
case Opcodes.MULTIANEWARRAY:
values = new ArrayList();
for (int i = ((MultiANewArrayInsnNode) insn).dims; i > 0; --i) {
values.add(0, pop());
}
push(interpreter.naryOperation(insn, values));
break;
case Opcodes.IFNULL:
case Opcodes.IFNONNULL:
interpreter.unaryOperation(insn, pop());
break;
default:
throw new RuntimeException("Illegal opcode " + insn.getOpcode());
}
}
