/**
* If we haven't found a return value yet, try to look at the "return" statements in the function.
*/
FunctionTypeBuilder inferReturnStatementsAsLastResort(@Nullable Node functionBlock) {
if (functionBlock == null || compiler.getInput(sourceName).isExtern()) {
return this;
}
Preconditions.checkArgument(functionBlock.getType() == Token.BLOCK);
if (returnType == null) {
boolean hasNonEmptyReturns = false;
List<Node> worklist = Lists.newArrayList(functionBlock);
while (!worklist.isEmpty()) {
Node current = worklist.remove(worklist.size() - 1);
int cType = current.getType();
if (cType == Token.RETURN && current.getFirstChild() != null || cType == Token.THROW) {
hasNonEmptyReturns = true;
break;
} else if (NodeUtil.isStatementBlock(current) || NodeUtil.isControlStructure(current)) {
for (Node child = current.getFirstChild(); child != null; child = child.getNext()) {
worklist.add(child);
}
}
}
if (!hasNonEmptyReturns) {
returnType = typeRegistry.getNativeType(VOID_TYPE);
returnTypeInferred = true;
}
}
return this;
}
/** Scans and gather variables declarations under a Node */
private void scanVars(Node n, Node parent) {
switch (n.getType()) {
case Token.VAR:
// Declare all variables. e.g. var x = 1, y, z;
for (Node child = n.getFirstChild(); child != null; ) {
Node next = child.getNext();
Preconditions.checkState(child.getType() == Token.NAME);
String name = child.getString();
declareVar(name, child, n, parent, null, n);
child = next;
}
return;
case Token.FUNCTION:
if (NodeUtil.isFunctionExpression(n)) {
return;
}
String fnName = n.getFirstChild().getString();
if (fnName.isEmpty()) {
// This is invalid, but allow it so the checks can catch it.
return;
}
declareVar(fnName, n.getFirstChild(), n, parent, null, n);
return; // should not examine function's children
case Token.CATCH:
Preconditions.checkState(n.getChildCount() == 2);
Preconditions.checkState(n.getFirstChild().getType() == Token.NAME);
// the first child is the catch var and the third child
// is the code block
final Node var = n.getFirstChild();
final Node block = var.getNext();
declareVar(var.getString(), var, n, parent, null, n);
scanVars(block, n);
return; // only one child to scan
case Token.SCRIPT:
sourceName = (String) n.getProp(Node.SOURCENAME_PROP);
break;
}
// Variables can only occur in statement-level nodes, so
// we only need to traverse children in a couple special cases.
if (NodeUtil.isControlStructure(n) || NodeUtil.isStatementBlock(n)) {
for (Node child = n.getFirstChild(); child != null; ) {
Node next = child.getNext();
scanVars(child, n);
child = next;
}
}
}
/** Add blocks to IF, WHILE, DO, etc. */
private void normalizeBlocks(Node n) {
if (NodeUtil.isControlStructure(n) && !n.isLabel() && !n.isSwitch()) {
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
if (NodeUtil.isControlStructureCodeBlock(n, c) && !c.isBlock()) {
Node newBlock = IR.block().srcref(n);
n.replaceChild(c, newBlock);
newBlock.setIsAddedBlock(true);
if (!c.isEmpty()) {
newBlock.addChildrenToFront(c);
}
c = newBlock;
reportChange();
}
}
}
}
@Override
public final boolean shouldTraverse(NodeTraversal nodeTraversal, Node n, Node parent) {
return parent == null
|| NodeUtil.isControlStructure(parent)
|| NodeUtil.isStatementBlock(parent);
}