/** Inline a function into the call site. */
private void inlineFunction(NodeTraversal t, Reference ref, FunctionState fs) {
Function fn = fs.getFn();
String fnName = fn.getName();
Node fnNode = fs.getSafeFnNode();
Node newExpr = injector.inline(ref, fnName, fnNode);
if (!newExpr.isEquivalentTo(ref.callNode)) {
t.getCompiler().reportChangeToEnclosingScope(newExpr);
}
t.getCompiler().addToDebugLog("Inlined function: " + fn.getName());
}
@Override
public void exitScope(NodeTraversal traversal) {
Preconditions.checkNotNull(traversal);
// This is the case when we are exiting the global scope where we had never
// collected argument access list. Since we do not perform this optimization
// for the global scope, we will skip this exit point.
if (currentArgumentsAccess == null) {
return;
}
Node function = traversal.getScopeRoot();
if (!function.isFunction()) {
return;
}
// Attempt to replace the argument access and if the AST has been change,
// report back to the compiler.
if (tryReplaceArguments(traversal.getScope())) {
traversal.getCompiler().reportCodeChange();
}
// After the attempt to replace the arguments. The currentArgumentsAccess
// is stale and as we exit the Scope, no longer holds all the access to the
// current scope anymore. We'll pop the access list from the outer scope
// and set it as currentArgumentsAccess if the outer scope is not the global
// scope.
if (!argumentsAccessStack.isEmpty()) {
currentArgumentsAccess = argumentsAccessStack.pop();
} else {
currentArgumentsAccess = null;
}
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (!NodeUtil.isReferenceName(n)) {
return;
}
Scope referencedIn = t.getScope();
String oldName = n.getString();
Scope current = referencedIn;
boolean doRename = false;
String newName = null;
while (current != null) {
Map<String, String> renamesAtCurrentLevel = renameMap.get(current.getRootNode());
if (current.isDeclared(oldName, false)) {
return;
} else if (renamesAtCurrentLevel != null && renamesAtCurrentLevel.containsKey(oldName)) {
doRename = true;
newName = renamesAtCurrentLevel.get(oldName);
break;
} else {
current = current.getParent();
}
}
if (doRename) {
n.setString(newName);
t.getCompiler().reportCodeChange();
}
}
private static void reportIfWasEmpty(NodeTraversal t, Node block) {
Preconditions.checkState(block.isBlock());
// A semicolon is distinguished from a block without children by
// annotating it with EMPTY_BLOCK. Blocks without children are
// usually intentional, especially with loops.
if (!block.hasChildren() && block.isAddedBlock()) {
t.getCompiler().report(t.makeError(block, SUSPICIOUS_SEMICOLON));
}
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
// TODO(moz): Add support for renaming classes.
if (!n.isLet() && !n.isConst() && !NodeUtil.isBlockScopedFunctionDeclaration(n)) {
return;
}
Scope scope = t.getScope();
Node nameNode = n.getFirstChild();
if (!n.isFunction()
&& !nameNode.hasChildren()
&& (parent == null || !NodeUtil.isEnhancedFor(parent))) {
nameNode.addChildToFront(IR.name("undefined").useSourceInfoIfMissingFrom(nameNode));
}
String oldName = nameNode.getString();
if (n.isLet() || n.isConst()) {
blockScopedDeclarations.add(n);
}
Scope hoistScope = scope.getClosestHoistScope();
boolean doRename = false;
if (scope != hoistScope) {
doRename = hoistScope.isDeclared(oldName, true) || undeclaredNames.contains(oldName);
String newName =
doRename ? oldName + "$" + compiler.getUniqueNameIdSupplier().get() : oldName;
Var oldVar = scope.getVar(oldName);
scope.undeclare(oldVar);
hoistScope.declare(newName, nameNode, oldVar.input);
if (doRename) {
nameNode.setString(newName);
Node scopeRoot = scope.getRootNode();
if (!renameMap.containsKey(scopeRoot)) {
renameMap.put(scopeRoot, new HashMap<String, String>());
}
renameMap.get(scopeRoot).put(oldName, newName);
}
}
if (doRename) {
t.getCompiler().reportCodeChange();
}
}
private static void reportIfNaN(NodeTraversal t, Node n) {
if (NodeUtil.isNaN(n)) {
t.getCompiler().report(t.makeError(n.getParent(), SUSPICIOUS_COMPARISON_WITH_NAN));
}
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
// VOID nodes appear when there are extra semicolons at the BLOCK level.
// I've been unable to think of any cases where this indicates a bug,
// and apparently some people like keeping these semicolons around,
// so we'll allow it.
if (n.isEmpty() || n.isComma()) {
return;
}
if (parent == null) {
return;
}
int pt = parent.getType();
if (pt == Token.COMMA) {
Node gramps = parent.getParent();
if (gramps.isCall() && parent == gramps.getFirstChild()) {
// Semantically, a direct call to eval is different from an indirect
// call to an eval. See Ecma-262 S15.1.2.1. So it's ok for the first
// expression to a comma to be a no-op if it's used to indirect
// an eval.
if (n == parent.getFirstChild()
&& parent.getChildCount() == 2
&& n.getNext().isName()
&& "eval".equals(n.getNext().getString())) {
return;
}
}
if (n == parent.getLastChild()) {
for (Node an : parent.getAncestors()) {
int ancestorType = an.getType();
if (ancestorType == Token.COMMA) continue;
if (ancestorType != Token.EXPR_RESULT && ancestorType != Token.BLOCK) return;
else break;
}
}
} else if (pt != Token.EXPR_RESULT && pt != Token.BLOCK) {
if (pt == Token.FOR
&& parent.getChildCount() == 4
&& (n == parent.getFirstChild() || n == parent.getFirstChild().getNext().getNext())) {
// Fall through and look for warnings for the 1st and 3rd child
// of a for.
} else {
return; // it might be ok to not have a side-effect
}
}
boolean isSimpleOp = NodeUtil.isSimpleOperatorType(n.getType());
if (isSimpleOp || !NodeUtil.mayHaveSideEffects(n, t.getCompiler())) {
if (n.isQualifiedName() && n.getJSDocInfo() != null) {
// This no-op statement was there so that JSDoc information could
// be attached to the name. This check should not complain about it.
return;
} else if (n.isExprResult()) {
// we already reported the problem when we visited the child.
return;
}
String msg = "This code lacks side-effects. Is there a bug?";
if (n.isString()) {
msg = "Is there a missing '+' on the previous line?";
} else if (isSimpleOp) {
msg =
"The result of the '"
+ Token.name(n.getType()).toLowerCase()
+ "' operator is not being used.";
}
t.getCompiler().report(t.makeError(n, level, USELESS_CODE_ERROR, msg));
// TODO(johnlenz): determine if it is necessary to
// try to protect side-effect free statements as well.
if (!NodeUtil.isStatement(n)) {
problemNodes.add(n);
}
}
}