@Override
public void visit(SwitchStatement statement) {
statement.getValue().acceptVisitor(this);
statement.setValue(resultExpr);
for (SwitchClause clause : statement.getClauses()) {
List<Statement> newBody = processSequence(clause.getBody());
clause.getBody().clear();
clause.getBody().addAll(newBody);
}
List<Statement> newDefault = processSequence(statement.getDefaultClause());
statement.getDefaultClause().clear();
statement.getDefaultClause().addAll(newDefault);
resultStmt = statement;
}
@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);
}
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);
}
}
}
