/**
* Creates a JMultiExpression from a set of JExpressionStatements, optionally terminated by a
* JReturnStatement. If the method doesn't match this pattern, it returns <code>null</code>.
*
* <p>If a method has a non-void return statement and can be represented as a multi-expression,
* the output of the multi-expression will be the return expression of the method. If the method
* is void, the output of the multi-expression should be considered undefined.
*/
private List<JExpression> extractExpressionsFromBody(JMethodBody body) {
List<JExpression> expressions = Lists.newArrayList();
CloneCalleeExpressionVisitor cloner = new CloneCalleeExpressionVisitor();
for (JStatement stmt : body.getStatements()) {
if (stmt instanceof JDeclarationStatement) {
JDeclarationStatement declStatement = (JDeclarationStatement) stmt;
if (!(declStatement.getVariableRef() instanceof JLocalRef)) {
return null;
}
JExpression initializer = declStatement.getInitializer();
if (initializer == null) {
continue;
}
JLocal local = (JLocal) declStatement.getVariableRef().getTarget();
JExpression clone =
new JBinaryOperation(
stmt.getSourceInfo(),
local.getType(),
JBinaryOperator.ASG,
new JLocalRef(declStatement.getVariableRef().getSourceInfo(), local),
cloner.cloneExpression(initializer));
expressions.add(clone);
} else if (stmt instanceof JExpressionStatement) {
JExpressionStatement exprStmt = (JExpressionStatement) stmt;
JExpression expr = exprStmt.getExpr();
JExpression clone = cloner.cloneExpression(expr);
expressions.add(clone);
} else if (stmt instanceof JReturnStatement) {
JReturnStatement returnStatement = (JReturnStatement) stmt;
JExpression expr = returnStatement.getExpr();
if (expr != null) {
JExpression clone = cloner.cloneExpression(expr);
clone = maybeCast(clone, body.getMethod().getType());
expressions.add(clone);
}
// We hit an unconditional return; no need to evaluate anything else.
break;
} else {
// Any other kind of statement won't be inlinable.
return null;
}
}
return expressions;
}
@Override
public void endVisit(JLocalRef x, Context ctx) {
JLocal originalLocal = x.getLocal();
JLocal newLocal = newLocalsByOriginalLocal.get(originalLocal);
if (newLocal == null) {
newLocal =
JProgram.createLocal(
originalLocal.getSourceInfo(),
originalLocal.getName(),
originalLocal.getType(),
originalLocal.isFinal(),
methodBody);
newLocalsByOriginalLocal.put(originalLocal, newLocal);
}
ctx.replaceMe(new JLocalRef(x.getSourceInfo(), newLocal));
}
@Override
public void endVisit(JTryStatement x, Context ctx) {
if (x.getCatchClauses().isEmpty()) {
return;
}
SourceInfo catchInfo = x.getCatchClauses().get(0).getBlock().getSourceInfo();
JLocal exceptionVariable = newExceptionVariable(x.getSourceInfo());
JBlock newCatchBlock = new JBlock(catchInfo);
{
// $e = Exceptions.wrap($e)
JMethodCall call = new JMethodCall(catchInfo, null, wrapMethod);
call.addArg(new JLocalRef(catchInfo, exceptionVariable));
newCatchBlock.addStmt(
JProgram.createAssignmentStmt(
catchInfo, new JLocalRef(catchInfo, exceptionVariable), call));
}
/*
* Build up a series of if, else if statements to test the type of the
* exception object against the types of the user's catch block. Each catch block might have
* multiple types in Java 7.
*
* Go backwards so we can nest the else statements in the correct order!
*/
// rethrow the current exception if no one caught it.
JStatement cur = new JThrowStatement(catchInfo, new JLocalRef(catchInfo, exceptionVariable));
for (int i = x.getCatchClauses().size() - 1; i >= 0; i--) {
JTryStatement.CatchClause clause = x.getCatchClauses().get(i);
JBlock block = clause.getBlock();
JLocalRef arg = clause.getArg();
List<JType> exceptionsTypes = clause.getTypes();
catchInfo = block.getSourceInfo();
// if ($e instanceof ArgType1 or $e instanceof ArgType2 ...) {
// var userVar = $e; <user code>
// }
// Handle the first Exception type.
JExpression ifTest =
new JInstanceOf(
catchInfo,
(JReferenceType) exceptionsTypes.get(0),
new JLocalRef(catchInfo, exceptionVariable));
// Handle the rest of the Exception types if any.
for (int j = 1; j < exceptionsTypes.size(); j++) {
JExpression orExp =
new JInstanceOf(
catchInfo,
(JReferenceType) exceptionsTypes.get(j),
new JLocalRef(catchInfo, exceptionVariable));
ifTest =
new JBinaryOperation(
catchInfo, JPrimitiveType.BOOLEAN, JBinaryOperator.OR, ifTest, orExp);
}
JDeclarationStatement declaration =
new JDeclarationStatement(catchInfo, arg, new JLocalRef(catchInfo, exceptionVariable));
block.addStmt(0, declaration);
// nest the previous as an else for me
cur = new JIfStatement(catchInfo, ifTest, block, cur);
}
newCatchBlock.addStmt(cur);
// Replace with a single catch block.
x.getCatchClauses().clear();
List<JType> newCatchTypes = new ArrayList<JType>(1);
newCatchTypes.add(exceptionVariable.getType());
x.getCatchClauses()
.add(
new JTryStatement.CatchClause(
newCatchTypes,
new JLocalRef(newCatchBlock.getSourceInfo(), exceptionVariable),
newCatchBlock));
}
