@Override
public void visit(ConstructMultiArrayInstruction insn) {
Expr[] dimensionExprs = new Expr[insn.getDimensions().size()];
for (int i = 0; i < dimensionExprs.length; ++i) {
dimensionExprs[i] = Expr.var(insn.getDimensions().get(i).getIndex());
}
assign(Expr.createArray(insn.getItemType(), dimensionExprs), insn.getReceiver());
}
@Override
public void visit(BinaryExpr expr) {
switch (expr.getOperation()) {
case AND:
case OR:
resultExpr = expr;
return;
default:
break;
}
expr.getSecondOperand().acceptVisitor(this);
Expr b = resultExpr;
if (b instanceof ConstantExpr && expr.getOperation() == BinaryOperation.SUBTRACT) {
if (tryMakePositive((ConstantExpr) b)) {
expr.setOperation(BinaryOperation.ADD);
}
}
expr.getFirstOperand().acceptVisitor(this);
Expr a = resultExpr;
Expr p = a;
Expr q = b;
boolean invert = false;
if (isZero(p)) {
Expr tmp = p;
p = q;
q = tmp;
invert = true;
}
if (isComparison(p) && isZero(q)) {
switch (expr.getOperation()) {
case EQUALS:
case NOT_EQUALS:
case LESS:
case LESS_OR_EQUALS:
case GREATER:
case GREATER_OR_EQUALS:
{
BinaryExpr comparison = (BinaryExpr) p;
Expr result =
BinaryExpr.binary(
expr.getOperation(),
comparison.getFirstOperand(),
comparison.getSecondOperand());
result.setLocation(comparison.getLocation());
if (invert) {
result = ExprOptimizer.invert(result);
}
resultExpr = result;
return;
}
default:
break;
}
}
expr.setFirstOperand(a);
expr.setSecondOperand(b);
resultExpr = expr;
}
@Override
public void visit(AssignInstruction insn) {
AssignmentStatement stmt =
Statement.assign(
Expr.var(insn.getReceiver().getIndex()), Expr.var(insn.getAssignee().getIndex()));
stmt.getDebugNames().addAll(insn.getReceiver().getDebugNames());
stmt.setLocation(currentLocation);
statements.add(stmt);
}
@Override
public void visit(NewMultiArrayExpr expr) {
for (int i = 0; i < expr.getDimensions().size(); ++i) {
Expr dimension = expr.getDimensions().get(i);
dimension.acceptVisitor(this);
expr.getDimensions().set(i, resultExpr);
}
resultExpr = expr;
}
@Override
public void visit(CloneArrayInstruction insn) {
MethodDescriptor cloneMethodDesc =
new MethodDescriptor("clone", ValueType.object("java.lang.Object"));
MethodReference cloneMethod = new MethodReference("java.lang.Object", cloneMethodDesc);
assign(
Expr.invoke(cloneMethod, Expr.var(insn.getArray().getIndex()), new Expr[0]),
insn.getReceiver());
}
@Override
public void visit(WhileStatement statement) {
if (statement.getBody().size() == 1 && statement.getBody().get(0) instanceof WhileStatement) {
WhileStatement innerLoop = (WhileStatement) statement.getBody().get(0);
BreakToContinueReplacer replacer = new BreakToContinueReplacer(innerLoop, statement);
replacer.visitSequence(innerLoop.getBody());
statement.getBody().clear();
statement.getBody().addAll(innerLoop.getBody());
}
List<Statement> statements = processSequence(statement.getBody());
for (int i = 0; i < statements.size(); ++i) {
if (statements.get(i) instanceof ContinueStatement) {
ContinueStatement continueStmt = (ContinueStatement) statements.get(i);
if (continueStmt.getTarget() == statement) {
statements.subList(i, statements.size()).clear();
break;
}
}
}
statement.getBody().clear();
statement.getBody().addAll(statements);
if (statement.getCondition() != null) {
List<Statement> sequenceBackup = resultSequence;
resultSequence = new ArrayList<>();
statement.getCondition().acceptVisitor(this);
statement.setCondition(resultExpr);
resultSequence = sequenceBackup;
}
while (true) {
if (!statement.getBody().isEmpty()
&& statement.getBody().get(0) instanceof ConditionalStatement) {
ConditionalStatement cond = (ConditionalStatement) statement.getBody().get(0);
if (cond.getConsequent().size() == 1
&& cond.getConsequent().get(0) instanceof BreakStatement) {
BreakStatement breakStmt = (BreakStatement) cond.getConsequent().get(0);
if (breakStmt.getTarget() == statement) {
statement.getBody().remove(0);
if (statement.getCondition() != null) {
Expr newCondition =
Expr.binary(
BinaryOperation.AND,
statement.getCondition(),
ExprOptimizer.invert(cond.getCondition()));
newCondition.setLocation(statement.getCondition().getLocation());
statement.setCondition(newCondition);
} else {
statement.setCondition(ExprOptimizer.invert(cond.getCondition()));
}
continue;
}
}
}
break;
}
resultStmt = statement;
}
@Override
public void visit(PutElementInstruction insn) {
AssignmentStatement stmt =
Statement.assign(
Expr.subscript(
Expr.var(insn.getArray().getIndex()), Expr.var(insn.getIndex().getIndex())),
Expr.var(insn.getValue().getIndex()));
stmt.setLocation(currentLocation);
statements.add(stmt);
}
@Override
public void visit(PutFieldInstruction insn) {
Expr right = Expr.var(insn.getValue().getIndex());
Expr left;
if (insn.getInstance() != null) {
left = Expr.qualify(Expr.var(insn.getInstance().getIndex()), insn.getField());
} else {
left = Expr.qualify(null, insn.getField());
}
AssignmentStatement stmt = Statement.assign(left, right);
stmt.setLocation(currentLocation);
statements.add(stmt);
}
@Override
public void visit(MonitorExitInstruction insn) {
MonitorExitStatement stmt = new MonitorExitStatement();
stmt.setLocation(currentLocation);
stmt.setObjectRef(Expr.var(insn.getObjectRef().getIndex()));
statements.add(stmt);
}
@Override
public void visit(RaiseInstruction insn) {
ThrowStatement stmt = new ThrowStatement();
stmt.setLocation(currentLocation);
stmt.setException(Expr.var(insn.getException().getIndex()));
statements.add(stmt);
}
@Override
public void visit(ExitInstruction insn) {
ReturnStatement stmt =
Statement.exitFunction(
insn.getValueToReturn() != null ? Expr.var(insn.getValueToReturn().getIndex()) : null);
stmt.setLocation(currentLocation);
statements.add(stmt);
}
@Override
public void visit(GetFieldInstruction insn) {
if (insn.getInstance() != null) {
AssignmentStatement stmt =
Statement.assign(
Expr.var(insn.getReceiver().getIndex()),
Expr.qualify(Expr.var(insn.getInstance().getIndex()), insn.getField()));
stmt.setLocation(currentLocation);
statements.add(stmt);
} else {
Expr fieldExpr = Expr.qualify(null, insn.getField());
AssignmentStatement stmt =
Statement.assign(Expr.var(insn.getReceiver().getIndex()), fieldExpr);
stmt.setLocation(currentLocation);
statements.add(stmt);
}
}
@Override
public void visit(InvokeInstruction insn) {
Expr[] exprArgs = new Expr[insn.getMethod().getParameterTypes().length];
for (int i = 0; i < insn.getArguments().size(); ++i) {
exprArgs[i] = Expr.var(insn.getArguments().get(i).getIndex());
}
InvocationExpr invocationExpr;
if (insn.getInstance() != null) {
if (insn.getType() == InvocationType.VIRTUAL) {
invocationExpr =
Expr.invoke(insn.getMethod(), Expr.var(insn.getInstance().getIndex()), exprArgs);
} else {
invocationExpr =
Expr.invokeSpecial(insn.getMethod(), Expr.var(insn.getInstance().getIndex()), exprArgs);
}
} else {
invocationExpr = Expr.invokeStatic(insn.getMethod(), exprArgs);
}
AssignmentStatement stmt;
if (insn.getReceiver() != null) {
stmt = Statement.assign(Expr.var(insn.getReceiver().getIndex()), invocationExpr);
stmt.getDebugNames().addAll(insn.getReceiver().getDebugNames());
} else {
stmt = Statement.assign(null, invocationExpr);
}
stmt.setLocation(currentLocation);
stmt.setAsync(async);
async = false;
statements.add(stmt);
}
@Override
public void visit(CastIntegerInstruction insn) {
Expr value = Expr.var(insn.getValue().getIndex());
switch (insn.getDirection()) {
case FROM_INTEGER:
switch (insn.getTargetType()) {
case BYTE:
value = Expr.unary(UnaryOperation.INT_TO_BYTE, value);
break;
case SHORT:
value = Expr.unary(UnaryOperation.INT_TO_SHORT, value);
break;
case CHARACTER:
value = Expr.unary(UnaryOperation.INT_TO_CHAR, value);
break;
}
break;
case TO_INTEGER:
break;
}
assign(value, insn.getReceiver());
}
@Override
public void visit(BranchingInstruction insn) {
switch (insn.getCondition()) {
case EQUAL:
branch(
compare(BinaryOperation.EQUALS, insn.getOperand()),
insn.getConsequent(),
insn.getAlternative());
break;
case NOT_EQUAL:
branch(
compare(BinaryOperation.NOT_EQUALS, insn.getOperand()),
insn.getConsequent(),
insn.getAlternative());
break;
case GREATER:
branch(
compare(BinaryOperation.GREATER, insn.getOperand()),
insn.getConsequent(),
insn.getAlternative());
break;
case GREATER_OR_EQUAL:
branch(
compare(BinaryOperation.GREATER_OR_EQUALS, insn.getOperand()),
insn.getConsequent(),
insn.getAlternative());
break;
case LESS:
branch(
compare(BinaryOperation.LESS, insn.getOperand()),
insn.getConsequent(),
insn.getAlternative());
break;
case LESS_OR_EQUAL:
branch(
compare(BinaryOperation.LESS_OR_EQUALS, insn.getOperand()),
insn.getConsequent(),
insn.getAlternative());
break;
case NOT_NULL:
branch(
Expr.binary(
BinaryOperation.STRICT_NOT_EQUALS,
Expr.var(insn.getOperand().getIndex()),
Expr.constant(null)),
insn.getConsequent(),
insn.getAlternative());
break;
case NULL:
branch(
Expr.binary(
BinaryOperation.STRICT_EQUALS,
Expr.var(insn.getOperand().getIndex()),
Expr.constant(null)),
insn.getConsequent(),
insn.getAlternative());
break;
}
}
@Override
public void visit(CastNumberInstruction insn) {
Expr value = Expr.var(insn.getValue().getIndex());
switch (insn.getTargetType()) {
case INT:
switch (insn.getSourceType()) {
case DOUBLE:
case FLOAT:
value = castToInteger(value);
break;
case LONG:
value = castLongToInt(value);
break;
default:
break;
}
break;
case LONG:
switch (insn.getSourceType()) {
case INT:
value = castIntToLong(value);
break;
case FLOAT:
case DOUBLE:
value = castToLong(value);
break;
default:
break;
}
break;
case FLOAT:
case DOUBLE:
if (insn.getSourceType() == NumericOperandType.LONG) {
value = castFromLong(value);
}
break;
default:
break;
}
assign(value, insn.getReceiver());
}
private boolean tryApplyConstructor(InvocationExpr expr) {
if (!expr.getMethod().getName().equals("<init>")) {
return false;
}
if (resultSequence == null || resultSequence.isEmpty()) {
return false;
}
Statement last = resultSequence.get(resultSequence.size() - 1);
if (!(last instanceof AssignmentStatement)) {
return false;
}
AssignmentStatement assignment = (AssignmentStatement) last;
if (!(assignment.getLeftValue() instanceof VariableExpr)) {
return false;
}
VariableExpr var = (VariableExpr) assignment.getLeftValue();
if (!(expr.getArguments().get(0) instanceof VariableExpr)) {
return false;
}
VariableExpr target = (VariableExpr) expr.getArguments().get(0);
if (target.getIndex() != var.getIndex()) {
return false;
}
if (!(assignment.getRightValue() instanceof NewExpr)) {
return false;
}
NewExpr constructed = (NewExpr) assignment.getRightValue();
if (!constructed.getConstructedClass().equals(expr.getMethod().getClassName())) {
return false;
}
Expr[] args = expr.getArguments().toArray(new Expr[0]);
args = Arrays.copyOfRange(args, 1, args.length);
InvocationExpr constructrExpr = Expr.constructObject(expr.getMethod(), args);
constructrExpr.setLocation(expr.getLocation());
assignment.setRightValue(constructrExpr);
readFrequencies[var.getIndex()]--;
return true;
}
@Override
public void visit(SwitchInstruction insn) {
SwitchStatement stmt = new SwitchStatement();
stmt.setId("sblock" + (lastSwitchId++));
stmt.setValue(Expr.var(insn.getCondition().getIndex()));
Map<Integer, List<Integer>> switchMap = new HashMap<>();
for (int i = 0; i < insn.getEntries().size(); ++i) {
SwitchTableEntry entry = insn.getEntries().get(i);
List<Integer> conditions = switchMap.get(entry.getTarget().getIndex());
if (conditions == null) {
conditions = new ArrayList<>();
switchMap.put(entry.getTarget().getIndex(), conditions);
}
conditions.add(entry.getCondition());
}
List<Integer> targets = new ArrayList<>(switchMap.keySet());
Collections.sort(targets);
for (int target : targets) {
SwitchClause clause = new SwitchClause();
List<Integer> conditionList = switchMap.get(target);
int[] conditions = new int[conditionList.size()];
for (int i = 0; i < conditionList.size(); ++i) {
conditions[i] = conditionList.get(i);
}
clause.setConditions(conditions);
Statement jumpStmt = generateJumpStatement(stmt, target);
if (jumpStmt != null) {
clause.getBody().add(jumpStmt);
}
stmt.getClauses().add(clause);
}
Statement breakStmt = generateJumpStatement(insn.getDefaultTarget());
if (breakStmt != null) {
stmt.getDefaultClause().add(breakStmt);
}
statements.add(stmt);
}
@Override
public void visit(NegateInstruction insn) {
switch (insn.getOperandType()) {
case INT:
assign(
castToInteger(
Expr.unary(UnaryOperation.NEGATE, Expr.var(insn.getOperand().getIndex()))),
insn.getReceiver());
break;
case LONG:
assign(
Expr.unary(UnaryOperation.NEGATE_LONG, Expr.var(insn.getOperand().getIndex())),
insn.getReceiver());
break;
default:
assign(
Expr.unary(UnaryOperation.NEGATE, Expr.var(insn.getOperand().getIndex())),
insn.getReceiver());
break;
}
}
@Override
public void visit(IsInstanceInstruction insn) {
assign(
Expr.instanceOf(Expr.var(insn.getValue().getIndex()), insn.getType()), insn.getReceiver());
}
private void assign(Expr source, Variable target) {
AssignmentStatement stmt = Statement.assign(Expr.var(target.getIndex()), source);
stmt.setLocation(currentLocation);
stmt.getDebugNames().addAll(target.getDebugNames());
statements.add(stmt);
}
private Expr castToInteger(Expr value) {
return Expr.binary(BinaryOperation.BITWISE_OR, value, Expr.constant(0));
}
private void eliminateRedundantBreaks(List<Statement> statements, IdentifiedStatement exit) {
if (statements.isEmpty()) {
return;
}
Statement last = statements.get(statements.size() - 1);
if (last instanceof BreakStatement && exit != null) {
IdentifiedStatement target = ((BreakStatement) last).getTarget();
if (exit == target) {
statements.remove(statements.size() - 1);
}
}
if (statements.isEmpty()) {
return;
}
for (int i = 0; i < statements.size(); ++i) {
Statement stmt = statements.get(i);
if (stmt instanceof ConditionalStatement) {
ConditionalStatement cond = (ConditionalStatement) stmt;
check_conditional:
{
last =
cond.getConsequent().isEmpty()
? null
: cond.getConsequent().get(cond.getConsequent().size() - 1);
if (last instanceof BreakStatement) {
BreakStatement breakStmt = (BreakStatement) last;
if (exit != null && exit == breakStmt.getTarget()) {
cond.getConsequent().remove(cond.getConsequent().size() - 1);
List<Statement> remaining = statements.subList(i + 1, statements.size());
cond.getAlternative().addAll(remaining);
remaining.clear();
break check_conditional;
}
}
last =
cond.getAlternative().isEmpty()
? null
: cond.getAlternative().get(cond.getAlternative().size() - 1);
if (last instanceof BreakStatement) {
BreakStatement breakStmt = (BreakStatement) last;
if (exit != null && exit == breakStmt.getTarget()) {
cond.getAlternative().remove(cond.getAlternative().size() - 1);
List<Statement> remaining = statements.subList(i + 1, statements.size());
cond.getConsequent().addAll(remaining);
remaining.clear();
}
}
}
if (i == statements.size() - 1) {
eliminateRedundantBreaks(cond.getConsequent(), exit);
eliminateRedundantBreaks(cond.getAlternative(), exit);
}
normalizeConditional(cond);
if (cond.getConsequent().size() == 1
&& cond.getConsequent().get(0) instanceof ConditionalStatement) {
ConditionalStatement innerCond = (ConditionalStatement) cond.getConsequent().get(0);
if (innerCond.getAlternative().isEmpty()) {
if (cond.getAlternative().isEmpty()) {
cond.getConsequent().clear();
cond.getConsequent().addAll(innerCond.getConsequent());
cond.setCondition(
Expr.binary(
BinaryOperation.AND,
cond.getCondition(),
innerCond.getCondition(),
cond.getCondition().getLocation()));
--i;
} else if (cond.getAlternative().size() != 1
|| !(cond.getAlternative().get(0) instanceof ConditionalStatement)) {
cond.setCondition(ExprOptimizer.invert(cond.getCondition()));
cond.getConsequent().clear();
cond.getConsequent().addAll(cond.getAlternative());
cond.getAlternative().clear();
cond.getAlternative().add(innerCond);
--i;
}
}
}
} else if (stmt instanceof BlockStatement) {
BlockStatement nestedBlock = (BlockStatement) stmt;
eliminateRedundantBreaks(nestedBlock.getBody(), nestedBlock);
} else if (stmt instanceof WhileStatement) {
WhileStatement whileStmt = (WhileStatement) stmt;
eliminateRedundantBreaks(whileStmt.getBody(), null);
} else if (stmt instanceof SwitchStatement) {
SwitchStatement switchStmt = (SwitchStatement) stmt;
for (SwitchClause clause : switchStmt.getClauses()) {
eliminateRedundantBreaks(clause.getBody(), null);
}
eliminateRedundantBreaks(switchStmt.getDefaultClause(), null);
}
}
}
@Override
public void visit(StringConstantInstruction insn) {
assign(Expr.constant(insn.getConstant()), insn.getReceiver());
}
private Expr castLongToInt(Expr value) {
return Expr.unary(UnaryOperation.LONG_TO_INT, value);
}
private Expr castIntToLong(Expr value) {
return Expr.unary(UnaryOperation.INT_TO_LONG, value);
}
@Override
public void visit(NullCheckInstruction insn) {
assign(
Expr.unary(UnaryOperation.NULL_CHECK, Expr.var(insn.getValue().getIndex())),
insn.getReceiver());
}
private Expr compare(BinaryOperation op, Variable value) {
Expr expr = Expr.binary(op, Expr.var(value.getIndex()), Expr.constant(0));
expr.setLocation(currentLocation);
return expr;
}
private void intBinary(int first, int second, Variable result, BinaryOperation op) {
assign(castToInteger(Expr.binary(op, Expr.var(first), Expr.var(second))), result);
}
private Expr castFromLong(Expr value) {
return Expr.unary(UnaryOperation.LONG_TO_NUM, value);
}
