private void handleDo(Node node) {
// The first edge can be the initial iteration as well as the iterations
// after.
createEdge(node, Branch.ON_TRUE, computeFallThrough(node.getFirstChild()));
// The edge that leaves the do loop if the condition fails.
createEdge(node, Branch.ON_FALSE, computeFollowNode(node));
connectToPossibleExceptionHandler(node, NodeUtil.getConditionExpression(node));
}
private void handleWhile(Node node) {
// Control goes to the first statement if the condition evaluates to true.
createEdge(node, Branch.ON_TRUE, computeFallThrough(node.getFirstChild().getNext()));
// Control goes to the follow() if the condition evaluates to false.
createEdge(node, Branch.ON_FALSE, computeFollowNode(node));
connectToPossibleExceptionHandler(node, NodeUtil.getConditionExpression(node));
}
private void handleIf(Node node) {
Node thenBlock = node.getFirstChild().getNext();
Node elseBlock = thenBlock.getNext();
createEdge(node, Branch.ON_TRUE, computeFallThrough(thenBlock));
if (elseBlock == null) {
createEdge(node, Branch.ON_FALSE, computeFollowNode(node)); // not taken branch
} else {
createEdge(node, Branch.ON_FALSE, computeFallThrough(elseBlock));
}
connectToPossibleExceptionHandler(node, NodeUtil.getConditionExpression(node));
}
/**
* @param n The node in question.
* @param cfgNode The node to add
* @param conditional true if the definition is not always executed.
*/
private void computeMustDef(Node n, Node cfgNode, MustDef output, boolean conditional) {
switch (n.getType()) {
case Token.BLOCK:
case Token.FUNCTION:
return;
case Token.WHILE:
case Token.DO:
case Token.IF:
computeMustDef(NodeUtil.getConditionExpression(n), cfgNode, output, conditional);
return;
case Token.FOR:
if (!NodeUtil.isForIn(n)) {
computeMustDef(NodeUtil.getConditionExpression(n), cfgNode, output, conditional);
} else {
// for(x in y) {...}
Node lhs = n.getFirstChild();
Node rhs = lhs.getNext();
if (NodeUtil.isVar(lhs)) {
lhs = lhs.getLastChild(); // for(var x in y) {...}
}
if (NodeUtil.isName(lhs)) {
addToDefIfLocal(lhs.getString(), cfgNode, rhs, output);
}
}
return;
case Token.AND:
case Token.OR:
computeMustDef(n.getFirstChild(), cfgNode, output, conditional);
computeMustDef(n.getLastChild(), cfgNode, output, true);
return;
case Token.HOOK:
computeMustDef(n.getFirstChild(), cfgNode, output, conditional);
computeMustDef(n.getFirstChild().getNext(), cfgNode, output, true);
computeMustDef(n.getLastChild(), cfgNode, output, true);
return;
case Token.VAR:
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
if (c.hasChildren()) {
computeMustDef(c.getFirstChild(), cfgNode, output, conditional);
addToDefIfLocal(c.getString(), conditional ? null : cfgNode, c.getFirstChild(), output);
}
}
return;
default:
if (NodeUtil.isAssignmentOp(n)) {
if (NodeUtil.isName(n.getFirstChild())) {
Node name = n.getFirstChild();
computeMustDef(name.getNext(), cfgNode, output, conditional);
addToDefIfLocal(
name.getString(), conditional ? null : cfgNode, n.getLastChild(), output);
return;
} else if (NodeUtil.isGet(n.getFirstChild())) {
// Treat all assignments to arguments as redefining the
// parameters itself.
Node obj = n.getFirstChild().getFirstChild();
if (NodeUtil.isName(obj) && "arguments".equals(obj.getString())) {
// TODO(user): More accuracy can be introduced
// ie: We know exactly what arguments[x] is if x is a constant
// number.
escapeParameters(output);
}
}
}
if (NodeUtil.isName(n) && "arguments".equals(n.getString())) {
escapeParameters(output);
}
// DEC and INC actually defines the variable.
if (n.getType() == Token.DEC || n.getType() == Token.INC) {
Node target = n.getFirstChild();
if (NodeUtil.isName(target)) {
addToDefIfLocal(target.getString(), conditional ? null : cfgNode, null, output);
return;
}
}
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
computeMustDef(c, cfgNode, output, conditional);
}
}
}
