/** Traverses a branch. */
private void traverseBranch(Node n, Node parent) {
int type = n.getType();
if (type == Token.SCRIPT) {
inputId = n.getInputId();
sourceName = getSourceName(n);
}
curNode = n;
if (!callback.shouldTraverse(this, n, parent)) {
return;
}
if (type == Token.FUNCTION) {
traverseFunction(n, parent);
} else if (useBlockScope && NodeUtil.createsBlockScope(n)) {
traverseBlockScope(n);
} else {
for (Node child = n.getFirstChild(); child != null; ) {
// child could be replaced, in which case our child node
// would no longer point to the true next
Node next = child.getNext();
traverseBranch(child, n);
child = next;
}
}
curNode = n;
callback.visit(this, n, parent);
}
@Override
public Node getAstRoot(AbstractCompiler compiler) {
Node root = ast.getAstRoot(compiler);
// The root maybe null if the AST can not be created.
if (root != null) {
Preconditions.checkState(root.isScript());
Preconditions.checkNotNull(root.getInputId());
}
return root;
}
/** Scans and gather variables declarations under a Node */
private void scanVars(Node n) {
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();
declareVar(child);
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(n.getFirstChild());
return; // should not examine function's children
case Token.CATCH:
Preconditions.checkState(n.getChildCount() == 2);
Preconditions.checkState(n.getFirstChild().isName());
// the first child is the catch var and the second child
// is the code block
final Node var = n.getFirstChild();
final Node block = var.getNext();
declareVar(var);
scanVars(block);
return; // only one child to scan
case Token.SCRIPT:
inputId = n.getInputId();
Preconditions.checkNotNull(inputId);
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);
child = next;
}
}
}
private void addInstaller(Node sourceNode, String function) {
// Find the module
InputId inputId = sourceNode.getInputId();
CompilerInput input = inputId != null ? compiler.getInput(inputId) : null;
JSModule module = input != null ? input.getModule() : null;
InjectedInstaller injected = new InjectedInstaller(module, function);
if (installers.add(injected)) {
changed = true;
Node installer = compiler.parseSyntheticCode(function).removeChildren();
installer.useSourceInfoIfMissingFromForTree(sourceNode);
Node enclosingScript = NodeUtil.getEnclosingScript(sourceNode);
enclosingScript.addChildrenToFront(installer);
}
}
/**
* Updates the internal reference map based on the provided parameters. If {@code scriptRoot} is
* not SCRIPT, it basically replaces the internal map with the new one, otherwise it replaces all
* the information associated to the given script.
*
* @param refMapPatch The reference map result of a {@link ReferenceCollectingCallback} pass which
* might be collected from the whole AST or just a sub-tree associated to a SCRIPT node.
* @param root AST sub-tree root on which reference collection was done.
*/
void updateGlobalVarReferences(Map<Var, ReferenceCollection> refMapPatch, Node root) {
if (refMap == null || !root.isScript()) {
resetGlobalVarReferences(refMapPatch);
return;
}
InputId inputId = root.getInputId();
Preconditions.checkNotNull(inputId);
// Note there are two assumptions here (i) the order of compiler inputs
// has not changed and (ii) all references are in the order they appear
// in AST (this is enforced in ReferenceCollectionCallback).
removeScriptReferences(inputId);
for (Entry<Var, ReferenceCollection> entry : refMapPatch.entrySet()) {
Var var = entry.getKey();
if (var.isGlobal()) {
replaceReferences(var.getName(), inputId, entry.getValue());
}
}
}
private void addThisVar(NodeTraversal t) {
Scope scope = t.getScope();
if (scope.isDeclared(THIS_VAR, false)) {
return;
}
Node parent = t.getScopeRoot();
if (parent.isFunction()) {
// Add the new node at the beginning of the function body.
parent = parent.getLastChild();
}
if (parent.isSyntheticBlock()) {
// Add the new node inside the SCRIPT node instead of the
// synthetic block that contains it.
parent = parent.getFirstChild();
}
Node name = IR.name(THIS_VAR).srcref(parent);
Node thisVar = IR.var(name, IR.thisNode().srcref(parent));
thisVar.srcref(parent);
parent.addChildToFront(thisVar);
scope.declare(THIS_VAR, name, null, compiler.getInput(parent.getInputId()));
}
private void addVarDecls(NodeTraversal t, boolean addThis, boolean addArguments) {
Scope scope = t.getScope();
if (scope.isDeclared(THIS_VAR, false)) {
addThis = false;
}
if (scope.isDeclared(ARGUMENTS_VAR, false)) {
addArguments = false;
}
Node parent = t.getScopeRoot();
if (parent.isFunction()) {
// Add the new node at the beginning of the function body.
parent = parent.getLastChild();
}
if (parent.isSyntheticBlock() && parent.getFirstChild().isScript()) {
// Add the new node inside the SCRIPT node instead of the
// synthetic block that contains it.
parent = parent.getFirstChild();
}
CompilerInput input = compiler.getInput(parent.getInputId());
if (addArguments) {
Node name = IR.name(ARGUMENTS_VAR).srcref(parent);
Node argumentsVar = IR.var(name, IR.name("arguments").srcref(parent));
argumentsVar.srcref(parent);
parent.addChildToFront(argumentsVar);
scope.declare(ARGUMENTS_VAR, name, null, input);
}
if (addThis) {
Node name = IR.name(THIS_VAR).srcref(parent);
Node thisVar = IR.var(name, IR.thisNode().srcref(parent));
thisVar.srcref(parent);
parent.addChildToFront(thisVar);
scope.declare(THIS_VAR, name, null, input);
}
}
private void validateHasInputId(Node n) {
InputId inputId = n.getInputId();
if (inputId == null) {
violation("Missing 'input id' annotation.", n);
}
}