private static boolean isLhsOfEnhancedForExpression(Node n) {
Node parent = n.getParent();
if (NodeUtil.isNameDeclaration(parent)) {
return isLhsOfEnhancedForExpression(parent);
}
return NodeUtil.isEnhancedFor(parent) && parent.getFirstChild() == n;
}
private void validateVarOrOptionalExpression(Node n) {
if (NodeUtil.isNameDeclaration(n)) {
validateNameDeclarationHelper(n.getType(), n);
} else {
validateOptionalExpression(n);
}
}
private void validateVarOrAssignmentTarget(Node n) {
if (NodeUtil.isNameDeclaration(n)) {
// Only one NAME can be declared for FOR-IN expressions.
validateChildCount(n, 1);
validateNameDeclarationHelper(n.getType(), n);
} else {
validateAssignmentTarget(n);
}
}
private void rewriteClassDefinition(Node n, Node parent, NodeTraversal t) {
if (parent.getParent().isConst() || parent.getParent().isLet()) {
compiler.report(JSError.make(n, POLYMER_INVALID_DECLARATION));
return;
}
ClassDefinition def = extractClassDefinition(n);
if (def != null) {
if (NodeUtil.isNameDeclaration(parent.getParent()) || parent.isAssign()) {
rewritePolymerClass(parent.getParent(), def, t);
} else {
rewritePolymerClass(parent, def, t);
}
}
}
private void visitForOf(Node node, Node parent) {
Node variable = node.removeFirstChild();
Node iterable = node.removeFirstChild();
Node body = node.removeFirstChild();
Node iterName = IR.name(ITER_BASE + compiler.getUniqueNameIdSupplier().get());
Node getNext = IR.call(IR.getprop(iterName.cloneTree(), IR.string("next")));
String variableName;
int declType;
if (variable.isName()) {
declType = Token.NAME;
variableName = variable.getQualifiedName();
} else {
Preconditions.checkState(
NodeUtil.isNameDeclaration(variable), "Expected var, let, or const. Got %s", variable);
declType = variable.getType();
variableName = variable.getFirstChild().getQualifiedName();
}
Node iterResult = IR.name(ITER_RESULT + variableName);
Node makeIter = IR.call(NodeUtil.newQName(compiler, MAKE_ITER), iterable);
compiler.needsEs6Runtime = true;
Node init = IR.var(iterName.cloneTree(), makeIter);
Node initIterResult = iterResult.cloneTree();
initIterResult.addChildToFront(getNext.cloneTree());
init.addChildToBack(initIterResult);
Node cond = IR.not(IR.getprop(iterResult.cloneTree(), IR.string("done")));
Node incr = IR.assign(iterResult.cloneTree(), getNext.cloneTree());
Node declarationOrAssign;
if (declType == Token.NAME) {
declarationOrAssign =
IR.exprResult(
IR.assign(
IR.name(variableName), IR.getprop(iterResult.cloneTree(), IR.string("value"))));
} else {
declarationOrAssign = new Node(declType, IR.name(variableName));
declarationOrAssign
.getFirstChild()
.addChildToBack(IR.getprop(iterResult.cloneTree(), IR.string("value")));
}
body.addChildToFront(declarationOrAssign);
Node newFor = IR.forNode(init, cond, incr, body);
newFor.useSourceInfoIfMissingFromForTree(node);
parent.replaceChild(node, newFor);
compiler.reportCodeChange();
}
private void validateObjectPattern(int type, Node n) {
validateNodeType(Token.OBJECT_PATTERN, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
// When the object pattern is a direct child of a var/let/const node,
// the last element is the RHS of the assignment.
if (c == n.getLastChild() && NodeUtil.isNameDeclaration(n.getParent())) {
validateExpression(c);
} else if (c.isStringKey()) {
validateObjectPatternStringKey(type, c);
} else {
// Nested destructuring pattern.
validateNameDeclarationChild(type, c);
}
}
}
/**
* Returns whether the node is the right hand side of an assignment or initialization of a
* variable named *_ID of *_ID_.
*/
private boolean insideAssignmentToIdConstant(Node n) {
Node parent = n.getParent();
if (parent.isAssign()) {
String qname = parent.getFirstChild().getQualifiedName();
return qname != null && isIdName(qname);
} else if (parent.isName()) {
Node grandParent = parent.getParent();
if (grandParent != null && NodeUtil.isNameDeclaration(grandParent)) {
String name = parent.getString();
return isIdName(name);
} else {
return false;
}
} else {
return false;
}
}
/**
* If this returns true, check for @extends and @implements annotations on this node. Otherwise,
* it's probably an alias for an existing class, so skip those annotations.
*
* @return Whether the given node declares a function. True for the following forms:
* <li>
* <pre>function foo() {}</pre>
* <li>
* <pre>var foo = function() {};</pre>
* <li>
* <pre>foo.bar = function() {};</pre>
*/
private boolean declaresFunction(Node n) {
if (n.isFunction()) {
return true;
}
if (n.isAssign() && n.getLastChild().isFunction()) {
return true;
}
if (NodeUtil.isNameDeclaration(n)
&& n.getFirstChild().hasChildren()
&& n.getFirstFirstChild().isFunction()) {
return true;
}
return false;
}
private void validateArrayPattern(int type, Node n) {
validateNodeType(Token.ARRAY_PATTERN, n);
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
// When the array pattern is a direct child of a var/let/const node,
// the last element is the RHS of the assignment.
if (c == n.getLastChild() && NodeUtil.isNameDeclaration(n.getParent())) {
validateExpression(c);
} else if (c.isRest()) {
validateRest(c);
} else if (c.isEmpty()) {
validateChildless(c);
} else {
// The members of the array pattern can be simple names,
// or nested array/object patterns, e.g. "var [a,[b,c]]=[1,[2,3]];"
validateNameDeclarationChild(type, c);
}
}
}
private static boolean isDeclarationHelper(Node node) {
Node parent = node.getParent();
// Special case for class B extends A, A is not a declaration.
if (parent.isClass() && node != parent.getFirstChild()) {
return false;
}
// This condition can be true during InlineVariables.
if (parent.getParent() == null) {
return false;
}
if (NodeUtil.isNameDeclaration(parent.getParent()) && node == parent.getLastChild()) {
// Unless it is something like "for (var/let/const a of x){}",
// this is the RHS of a var/let/const and thus not a declaration.
if (parent.getParent().getParent() == null || !parent.getParent().getParent().isForOf()) {
return false;
}
}
// Special cases for destructuring patterns.
if (parent.isDestructuringPattern()
|| (parent.isStringKey() && parent.getParent().isObjectPattern())
|| (parent.isComputedProp()
&& parent.getParent().isObjectPattern()
&& node == parent.getLastChild())
|| (parent.isDefaultValue() && node == parent.getFirstChild())) {
return isDeclarationHelper(parent);
}
// Special case for arrow function
if (parent.isArrowFunction()) {
return node == parent.getFirstChild();
}
return DECLARATION_PARENTS.contains(parent.getType());
}
/**
* Validates the class definition and if valid, destructively extracts the class definition from
* the AST.
*/
private ClassDefinition extractClassDefinition(Node callNode) {
Node descriptor = NodeUtil.getArgumentForCallOrNew(callNode, 0);
if (descriptor == null || !descriptor.isObjectLit()) {
// report bad class definition
compiler.report(JSError.make(callNode, POLYMER_DESCRIPTOR_NOT_VALID));
return null;
}
int paramCount = callNode.getChildCount() - 1;
if (paramCount != 1) {
compiler.report(JSError.make(callNode, POLYMER_UNEXPECTED_PARAMS));
return null;
}
Node elName = NodeUtil.getFirstPropMatchingKey(descriptor, "is");
if (elName == null) {
compiler.report(JSError.make(callNode, POLYMER_MISSING_IS));
return null;
}
String elNameString = CaseFormat.LOWER_HYPHEN.to(CaseFormat.UPPER_CAMEL, elName.getString());
elNameString += "Element";
Node target;
if (NodeUtil.isNameDeclaration(callNode.getParent().getParent())) {
target = IR.name(callNode.getParent().getString());
} else if (callNode.getParent().isAssign()) {
target = callNode.getParent().getFirstChild().cloneTree();
} else {
target = IR.name(elNameString);
}
target.useSourceInfoIfMissingFrom(callNode);
JSDocInfo classInfo = NodeUtil.getBestJSDocInfo(target);
JSDocInfo ctorInfo = null;
Node constructor = NodeUtil.getFirstPropMatchingKey(descriptor, "factoryImpl");
if (constructor == null) {
constructor = IR.function(IR.name(""), IR.paramList(), IR.block());
constructor.useSourceInfoFromForTree(callNode);
} else {
ctorInfo = NodeUtil.getBestJSDocInfo(constructor);
}
Node baseClass = NodeUtil.getFirstPropMatchingKey(descriptor, "extends");
String nativeBaseElement = baseClass == null ? null : baseClass.getString();
Node behaviorArray = NodeUtil.getFirstPropMatchingKey(descriptor, "behaviors");
List<BehaviorDefinition> behaviors = extractBehaviors(behaviorArray);
List<MemberDefinition> allProperties = new LinkedList<>();
for (BehaviorDefinition behavior : behaviors) {
overwriteMembersIfPresent(allProperties, behavior.props);
}
overwriteMembersIfPresent(allProperties, extractProperties(descriptor));
ClassDefinition def =
new ClassDefinition(
target,
descriptor,
classInfo,
new MemberDefinition(ctorInfo, null, constructor),
nativeBaseElement,
allProperties,
behaviors);
return def;
}
private void transformLoopClosure() {
if (loopObjectMap.isEmpty()) {
return;
}
for (Node loopNode : loopObjectMap.keySet()) {
// Introduce objects to reflect the captured scope variables.
// Fields are initially left as undefined to avoid cases like:
// var $jscomp$loop$0 = {i: 0, j: $jscomp$loop$0.i}
// They are initialized lazily by changing declarations into assignments
// later.
LoopObject object = loopObjectMap.get(loopNode);
Node objectLit = IR.objectlit();
Node objectLitNextIteration = IR.objectlit();
for (Var var : object.vars) {
objectLit.addChildToBack(IR.stringKey(var.name, IR.name("undefined")));
objectLitNextIteration.addChildToBack(
IR.stringKey(var.name, IR.getprop(IR.name(object.name), IR.string(var.name))));
}
Node updateLoopObject = IR.assign(IR.name(object.name), objectLitNextIteration);
loopNode
.getParent()
.addChildBefore(
IR.var(IR.name(object.name), objectLit).useSourceInfoIfMissingFromForTree(loopNode),
loopNode);
if (NodeUtil.isVanillaFor(loopNode)) { // For
// The initializer is pulled out and placed prior to the loop.
Node initializer = loopNode.getFirstChild();
loopNode.replaceChild(initializer, IR.empty());
if (!initializer.isEmpty()) {
loopNode.getParent().addChildBefore(initializer, loopNode);
}
Node increment = loopNode.getChildAtIndex(2);
if (increment.isEmpty()) {
loopNode.replaceChild(
increment, updateLoopObject.useSourceInfoIfMissingFromForTree(loopNode));
} else {
Node placeHolder = IR.empty();
loopNode.replaceChild(increment, placeHolder);
loopNode.replaceChild(
placeHolder,
IR.comma(updateLoopObject, increment).useSourceInfoIfMissingFromForTree(loopNode));
}
} else if (loopNode.isDo()) { // do-while, put at the end of the block
loopNode
.getFirstChild()
.addChildToBack(
IR.exprResult(updateLoopObject).useSourceInfoIfMissingFromForTree(loopNode));
} else { // For-in, for-of or while, put at the end of the block
loopNode
.getLastChild()
.addChildToBack(
IR.exprResult(updateLoopObject).useSourceInfoIfMissingFromForTree(loopNode));
}
// For captured variables, change declarations to assignments on the
// corresponding field of the introduced object. Rename all references
// accordingly.
for (Var var : object.vars) {
for (Node reference : referenceMap.get(var)) {
// For-of and for-in declarations are not altered, since they are
// used as temporary variables for assignment.
if (NodeUtil.isEnhancedFor(loopNode)
&& loopNode.getFirstChild() == reference.getParent()) {
loopNode
.getLastChild()
.addChildToFront(
IR.exprResult(
IR.assign(
IR.getprop(IR.name(object.name), IR.string(var.name)),
IR.name(var.name)))
.useSourceInfoIfMissingFromForTree(reference));
} else {
if (NodeUtil.isNameDeclaration(reference.getParent())) {
Node declaration = reference.getParent();
Node grandParent = declaration.getParent();
// Normalize: "let i = 0, j = 0;" becomes "let i = 0; let j = 0;"
while (declaration.getChildCount() > 1) {
Node name = declaration.getLastChild();
grandParent.addChildAfter(
IR.declaration(name.detachFromParent(), declaration.getType())
.useSourceInfoIfMissingFromForTree(declaration),
declaration);
}
// Change declaration to assignment, or just drop it if there's
// no initial value.
if (reference.hasChildren()) {
declaration = reference.getParent(); // Might have changed now
Node newReference = IR.name(var.name);
Node replacement =
IR.exprResult(IR.assign(newReference, reference.removeFirstChild()))
.useSourceInfoIfMissingFromForTree(declaration);
grandParent.replaceChild(declaration, replacement);
reference = newReference;
} else {
grandParent.removeChild(declaration);
}
}
// Change reference to GETPROP.
reference
.getParent()
.replaceChild(
reference,
IR.getprop(IR.name(object.name), IR.string(var.name))
.useSourceInfoIfMissingFromForTree(reference));
}
}
}
}
// Create wrapper functions and call them.
for (Node function : functionLoopObjectsMap.keySet()) {
Node returnNode = IR.returnNode();
Collection<LoopObject> objects = functionLoopObjectsMap.get(function);
Node[] objectNames = new Node[objects.size()];
Node[] objectNamesForCall = new Node[objects.size()];
int i = 0;
for (LoopObject object : objects) {
objectNames[i] = IR.name(object.name);
objectNamesForCall[i] = IR.name(object.name);
i++;
}
Node iife = IR.function(IR.name(""), IR.paramList(objectNames), IR.block(returnNode));
Node call = IR.call(iife, objectNamesForCall);
call.putBooleanProp(Node.FREE_CALL, true);
function
.getParent()
.replaceChild(function, call.useSourceInfoIfMissingFromForTree(function));
returnNode.addChildToFront(function);
}
}
private void visitArrayPattern(NodeTraversal t, Node arrayPattern, Node parent) {
Node rhs, nodeToDetach;
if (NodeUtil.isNameDeclaration(parent) && !NodeUtil.isEnhancedFor(parent.getParent())) {
// The array pattern is the only child, because Es6SplitVariableDeclarations
// has already run.
Preconditions.checkState(arrayPattern.getNext() == null);
rhs = arrayPattern.getLastChild();
nodeToDetach = parent;
} else if (parent.isAssign()) {
rhs = arrayPattern.getNext();
nodeToDetach = parent.getParent();
Preconditions.checkState(nodeToDetach.isExprResult());
} else if (parent.isArrayPattern() || parent.isDefaultValue() || parent.isStringKey()) {
// This is a nested array pattern. Don't do anything now; we'll visit it
// after visiting the parent.
return;
} else if (NodeUtil.isEnhancedFor(parent) || NodeUtil.isEnhancedFor(parent.getParent())) {
visitDestructuringPatternInEnhancedFor(arrayPattern);
return;
} else {
Preconditions.checkState(parent.isCatch() || parent.isForOf());
cannotConvertYet(
arrayPattern, "ARRAY_PATTERN that is a child of a " + Token.name(parent.getType()));
return;
}
// Convert 'var [x, y] = rhs' to:
// var temp = rhs;
// var x = temp[0];
// var y = temp[1];
String tempVarName = DESTRUCTURING_TEMP_VAR + (destructuringVarCounter++);
Node tempDecl =
IR.var(IR.name(tempVarName), rhs.detachFromParent())
.useSourceInfoIfMissingFromForTree(arrayPattern);
nodeToDetach.getParent().addChildBefore(tempDecl, nodeToDetach);
int i = 0;
for (Node child = arrayPattern.getFirstChild(), next; child != null; child = next, i++) {
next = child.getNext();
if (child.isEmpty()) {
continue;
}
Node newLHS, newRHS;
if (child.isDefaultValue()) {
Node getElem = IR.getelem(IR.name(tempVarName), IR.number(i));
// [x = defaultValue] = rhs;
// becomes
// var temp = rhs;
// x = (temp[0] === undefined) ? defaultValue : temp[0];
newLHS = child.getFirstChild().detachFromParent();
newRHS = defaultValueHook(getElem, child.getLastChild().detachFromParent());
} else if (child.isRest()) {
newLHS = child.detachFromParent();
newLHS.setType(Token.NAME);
// [].slice.call(temp, i)
newRHS =
IR.call(
IR.getprop(IR.getprop(IR.arraylit(), IR.string("slice")), IR.string("call")),
IR.name(tempVarName),
IR.number(i));
} else {
newLHS = child.detachFromParent();
newRHS = IR.getelem(IR.name(tempVarName), IR.number(i));
}
Node newNode;
if (parent.isAssign()) {
Node assignment = IR.assign(newLHS, newRHS);
newNode = IR.exprResult(assignment);
} else {
newNode = IR.declaration(newLHS, newRHS, parent.getType());
}
newNode.useSourceInfoIfMissingFromForTree(arrayPattern);
nodeToDetach.getParent().addChildBefore(newNode, nodeToDetach);
// Explicitly visit the LHS of the new node since it may be a nested
// destructuring pattern.
visit(t, newLHS, newLHS.getParent());
}
nodeToDetach.detachFromParent();
compiler.reportCodeChange();
}
private void visitObjectPattern(NodeTraversal t, Node objectPattern, Node parent) {
Node rhs, nodeToDetach;
if (NodeUtil.isNameDeclaration(parent) && !NodeUtil.isEnhancedFor(parent.getParent())) {
rhs = objectPattern.getLastChild();
nodeToDetach = parent;
} else if (parent.isAssign() && parent.getParent().isExprResult()) {
rhs = parent.getLastChild();
nodeToDetach = parent.getParent();
} else if (parent.isStringKey() || parent.isArrayPattern() || parent.isDefaultValue()) {
// Nested object pattern; do nothing. We will visit it after rewriting the parent.
return;
} else if (NodeUtil.isEnhancedFor(parent) || NodeUtil.isEnhancedFor(parent.getParent())) {
visitDestructuringPatternInEnhancedFor(objectPattern);
return;
} else {
Preconditions.checkState(parent.isCatch(), parent);
cannotConvertYet(
objectPattern, "OBJECT_PATTERN that is a child of a " + Token.name(parent.getType()));
return;
}
// Convert 'var {a: b, c: d} = rhs' to:
// var temp = rhs;
// var b = temp.a;
// var d = temp.c;
String tempVarName = DESTRUCTURING_TEMP_VAR + (destructuringVarCounter++);
Node tempDecl =
IR.var(IR.name(tempVarName), rhs.detachFromParent())
.useSourceInfoIfMissingFromForTree(objectPattern);
nodeToDetach.getParent().addChildBefore(tempDecl, nodeToDetach);
for (Node child = objectPattern.getFirstChild(), next; child != null; child = next) {
next = child.getNext();
Node newLHS, newRHS;
if (child.isStringKey()) {
Preconditions.checkState(child.hasChildren());
Node getprop =
new Node(
child.isQuotedString() ? Token.GETELEM : Token.GETPROP,
IR.name(tempVarName),
IR.string(child.getString()));
Node value = child.removeFirstChild();
if (!value.isDefaultValue()) {
newLHS = value;
newRHS = getprop;
} else {
newLHS = value.removeFirstChild();
Node defaultValue = value.removeFirstChild();
newRHS = defaultValueHook(getprop, defaultValue);
}
} else if (child.isComputedProp()) {
if (child.getLastChild().isDefaultValue()) {
newLHS = child.getLastChild().removeFirstChild();
Node getelem = IR.getelem(IR.name(tempVarName), child.removeFirstChild());
String intermediateTempVarName = DESTRUCTURING_TEMP_VAR + (destructuringVarCounter++);
Node intermediateDecl = IR.var(IR.name(intermediateTempVarName), getelem);
intermediateDecl.useSourceInfoIfMissingFromForTree(child);
nodeToDetach.getParent().addChildBefore(intermediateDecl, nodeToDetach);
newRHS =
defaultValueHook(
IR.name(intermediateTempVarName), child.getLastChild().removeFirstChild());
} else {
newRHS = IR.getelem(IR.name(tempVarName), child.removeFirstChild());
newLHS = child.removeFirstChild();
}
} else if (child.isDefaultValue()) {
newLHS = child.removeFirstChild();
Node defaultValue = child.removeFirstChild();
Node getprop = IR.getprop(IR.name(tempVarName), IR.string(newLHS.getString()));
newRHS = defaultValueHook(getprop, defaultValue);
} else {
throw new IllegalStateException("Unexpected OBJECT_PATTERN child: " + child);
}
Node newNode;
if (NodeUtil.isNameDeclaration(parent)) {
newNode = IR.declaration(newLHS, newRHS, parent.getType());
} else if (parent.isAssign()) {
newNode = IR.exprResult(IR.assign(newLHS, newRHS));
} else {
throw new IllegalStateException("not reached");
}
newNode.useSourceInfoIfMissingFromForTree(child);
nodeToDetach.getParent().addChildBefore(newNode, nodeToDetach);
// Explicitly visit the LHS of the new node since it may be a nested
// destructuring pattern.
visit(t, newLHS, newLHS.getParent());
}
nodeToDetach.detachFromParent();
compiler.reportCodeChange();
}