private boolean matchesNodeShape(Node template, Node ast) {
if (isTemplateParameterNode(template)) {
// Match the entire expression but only if it is an expression.
return !NodeUtil.isStatement(ast);
} else if (isTemplateLocalNameNode(template)) {
// Match any name. Maybe match locals here.
if (!ast.isName()) {
return false;
}
} else if (template.isCall()) {
// Loosely match CALL nodes. isEquivalentToShallow checks free calls against non-free calls,
// but the template should ignore that distinction.
if (ast == null || !ast.isCall() || ast.getChildCount() != template.getChildCount()) {
return false;
}
// But check any children.
} else if (!template.isEquivalentToShallow(ast)) {
return false;
}
// isEquivalentToShallow guarantees the child counts match
Node templateChild = template.getFirstChild();
Node astChild = ast.getFirstChild();
while (templateChild != null) {
if (!matchesNodeShape(templateChild, astChild)) {
return false;
}
templateChild = templateChild.getNext();
astChild = astChild.getNext();
}
return true;
}
private void validateMaximumChildCount(Node n, int i) {
boolean valid = false;
if (i == 1) {
valid = !n.hasMoreThanOneChild();
} else if (i == -1) {
valid = true; // Varying number of children.
} else {
valid = n.getChildCount() <= i;
}
if (!valid) {
violation("Expected no more than " + i + " children, but was " + n.getChildCount(), n);
}
}
private void validateMinimumChildCount(Node n, int i) {
boolean valid = false;
if (i == 1) {
valid = n.hasChildren();
} else if (i == 2) {
valid = n.hasMoreThanOneChild();
} else {
valid = n.getChildCount() >= i;
}
if (!valid) {
violation("Expected at least " + i + " children, but was " + n.getChildCount(), n);
}
}
private void handleFor(Node forNode) {
if (forNode.getChildCount() == 4) {
// We have for (init; cond; iter) { body }
Node init = forNode.getFirstChild();
Node cond = init.getNext();
Node iter = cond.getNext();
Node body = iter.getNext();
// After initialization, we transfer to the FOR which is in charge of
// checking the condition (for the first time).
createEdge(init, Branch.UNCOND, forNode);
// The edge that transfer control to the beginning of the loop body.
createEdge(forNode, Branch.ON_TRUE, computeFallThrough(body));
// The edge to end of the loop.
createEdge(forNode, Branch.ON_FALSE, computeFollowNode(forNode));
// The end of the body will have a unconditional branch to our iter
// (handled by calling computeFollowNode of the last instruction of the
// body. Our iter will jump to the forNode again to another condition
// check.
createEdge(iter, Branch.UNCOND, forNode);
connectToPossibleExceptionHandler(init, init);
connectToPossibleExceptionHandler(forNode, cond);
connectToPossibleExceptionHandler(iter, iter);
} else {
// We have for (item in collection) { body }
Node item = forNode.getFirstChild();
Node collection = item.getNext();
Node body = collection.getNext();
// The edge that transfer control to the beginning of the loop body.
createEdge(forNode, Branch.ON_TRUE, computeFallThrough(body));
// The edge to end of the loop.
createEdge(forNode, Branch.ON_FALSE, computeFollowNode(forNode));
connectToPossibleExceptionHandler(forNode, collection);
}
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isString() && !parent.isGetProp() && !parent.isRegExp()) {
String s = n.getString();
for (blacklist.reset(s); blacklist.find(); ) {
if (parent.isTemplateLit()) {
if (parent.getChildCount() > 1) {
// Ignore template string with substitutions
continue;
} else {
n = parent;
}
}
if (insideGetCssNameCall(n)) {
continue;
}
if (insideGetUniqueIdCall(n)) {
continue;
}
if (insideAssignmentToIdConstant(n)) {
continue;
}
compiler.report(t.makeError(n, level, MISSING_GETCSSNAME, blacklist.group()));
}
}
}
private void handleContinue(Node node) {
String label = null;
if (node.hasChildren()) {
label = node.getFirstChild().getString();
}
Node cur;
Node lastJump;
// Similar to handBreak's logic with a few minor variation.
Node parent = node.getParent();
for (cur = node, lastJump = node;
!isContinueTarget(cur, parent, label);
cur = parent, parent = parent.getParent()) {
if (cur.getType() == Token.TRY && NodeUtil.hasFinally(cur)) {
if (lastJump == node) {
createEdge(lastJump, Branch.UNCOND, cur.getLastChild());
} else {
finallyMap.put(lastJump, computeFallThrough(cur.getLastChild()));
}
lastJump = cur;
}
Preconditions.checkState(parent != null, "Cannot find continue target.");
}
Node iter = cur;
if (cur.getChildCount() == 4) {
iter = cur.getFirstChild().getNext().getNext();
}
if (lastJump == node) {
createEdge(node, Branch.UNCOND, iter);
} else {
finallyMap.put(lastJump, iter);
}
}
private Node createAnonymWithParamCall(
Set<String> closures, String anonymName, Node clonedorigParamNode, boolean thisChanged) {
Node newAnonymNode = new Node(Token.FUNCTION);
Node blockNode = new Node(Token.BLOCK);
newAnonymNode.addChildrenToBack(Node.newString(Token.NAME, ""));
newAnonymNode.addChildrenToBack(clonedorigParamNode);
newAnonymNode.addChildrenToBack(blockNode);
// to block add call with params as closure varibles
Node returnNode = new Node(Token.RETURN);
Node callNode = new Node(Token.CALL);
callNode.addChildrenToBack(Node.newString(Token.NAME, anonymName));
// first add all original params to this call
for (int i = 0; i < clonedorigParamNode.getChildCount(); i++) {
Node temp = clonedorigParamNode.getChildAtIndex(i).cloneTree();
callNode.addChildrenToBack(temp);
}
addParamsToMethod(closures, callNode, thisChanged, "this");
returnNode.addChildrenToBack(callNode);
blockNode.addChildrenToBack(returnNode);
return newAnonymNode;
}
/** Traverses a function. */
private void traverseFunction(Node n, Node parent) {
Preconditions.checkState(n.getChildCount() == 3);
Preconditions.checkState(n.isFunction());
final Node fnName = n.getFirstChild();
boolean isFunctionExpression = (parent != null) && NodeUtil.isFunctionExpression(n);
if (!isFunctionExpression) {
// Functions declarations are in the scope containing the declaration.
traverseBranch(fnName, n);
}
curNode = n;
pushScope(n);
if (isFunctionExpression) {
// Function expression names are only accessible within the function
// scope.
traverseBranch(fnName, n);
}
final Node args = fnName.getNext();
final Node body = args.getNext();
// Args
traverseBranch(args, n);
// Body
// ES6 "arrow" function may not have a block as a body.
traverseBranch(body, n);
popScope();
}
private void handleFunction(Node node) {
// A block transfer control to its first child if it is not empty.
Preconditions.checkState(node.getChildCount() >= 3);
createEdge(node, Branch.UNCOND, computeFallThrough(node.getFirstChild().getNext().getNext()));
Preconditions.checkState(exceptionHandler.peek() == node);
exceptionHandler.pop();
}
/** Try to fold array-length. e.g [1, 2, 3].length ==> 3, [x, y].length ==> 2 */
private Node tryFoldGetProp(Node n, Node left, Node right) {
Preconditions.checkArgument(n.isGetProp());
if (left.isObjectLit()) {
return tryFoldObjectPropAccess(n, left, right);
}
if (right.isString() && right.getString().equals("length")) {
int knownLength = -1;
switch (left.getType()) {
case ARRAYLIT:
if (mayHaveSideEffects(left)) {
// Nope, can't fold this, without handling the side-effects.
return n;
}
knownLength = left.getChildCount();
break;
case STRING:
knownLength = left.getString().length();
break;
default:
// Not a foldable case, forget it.
return n;
}
Preconditions.checkState(knownLength != -1);
Node lengthNode = IR.number(knownLength);
n.getParent().replaceChild(n, lengthNode);
reportCodeChange();
return lengthNode;
}
return n;
}
private void validateTry(Node n) {
validateNodeType(Token.TRY, n);
validateChildCountIn(n, 2, 3);
validateBlock(n.getFirstChild());
boolean seenCatchOrFinally = false;
// Validate catch
Node catches = n.getChildAtIndex(1);
validateNodeType(Token.BLOCK, catches);
validateMaximumChildCount(catches, 1);
if (catches.hasChildren()) {
validateCatch(catches.getFirstChild());
seenCatchOrFinally = true;
}
// Validate finally
if (n.getChildCount() == 3) {
validateBlock(n.getLastChild());
seenCatchOrFinally = true;
}
if (!seenCatchOrFinally) {
violation("Missing catch or finally for try statement.", n);
}
}
/** @return whether the blockNode contains only a single "throw" child node. */
private static boolean hasSingleThrow(Node blockNode) {
if (blockNode.getChildCount() == 1 && blockNode.getFirstChild().getType() == Token.THROW) {
// Functions consisting of a single "throw FOO" can be actually abstract,
// so do not check their return type nullability.
return true;
}
return false;
}
private void validateIf(Node n) {
validateNodeType(Token.IF, n);
validateChildCountIn(n, 2, 3);
validateExpression(n.getFirstChild());
validateBlock(n.getChildAtIndex(1));
if (n.getChildCount() == 3) {
validateBlock(n.getLastChild());
}
}
/** 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;
}
}
}
/**
* Finds set of all defs in function given (defSites). Adds parameters of function to this set:
* defSites. Finds all variables that are referenced in the function given (alf.names).
* windowProps are all global properties available. Closures = alf.names - defSites - windowProps
*
* @param n root node of the function who's closures are to be found
* @return set of closure names
*/
private Set<String> findClosures(Node n) {
Set<String> closureVars = null;
SimpleDefinitionFinder defFinder = new SimpleDefinitionFinder(compiler);
defFinder.process(externs, n.getLastChild());
Collection<DefinitionSite> defSites = defFinder.getDefinitionSites();
Set<String> localDefs = new HashSet<String>();
for (DefinitionSite site : defSites) {
if (site.node.getType() == Token.GETPROP) continue;
String def = site.node.getString();
if (def.length() > 0) {
localDefs.add(def);
}
}
// adding params to function as defs
Node origParamNode = n.getChildAtIndex(1);
for (int i = 0; i < origParamNode.getChildCount(); i++) {
String temp = origParamNode.getChildAtIndex(i).getString();
localDefs.add(temp);
}
// System.out.println("\nPrinting LOCAL def sites:" + defs);
/*SimpleDefinitionFinder defFinder1 = new SimpleDefinitionFinder(compiler);
defFinder1.process(externs, root);
Collection<DefinitionSite> defSites1 = defFinder1.getDefinitionSites();
Set<String> defs1 = new HashSet<String>();
for(DefinitionSite site1: defSites1){
if (site1.node.getType() == Token.GETPROP) continue;
String def = site1.node.getString();
if (def.length() > 0){
defs1.add(def);
}
}
System.out.println("\nPrinting Global def sites:" + defs1);*/
AllNamesFinder alf = new AllNamesFinder(compiler);
NodeTraversal.traverse(compiler, n.getLastChild(), alf);
// System.out.println("all names: " + alf.names);
closureVars = alf.names;
closureVars.removeAll(localDefs);
closureVars.removeAll(Props.windowProps);
closureVars.remove(
"this"); // since 'this' is later modified to $$_self we don't need to consider this as
// closure
return closureVars;
}
/**
* Gets the maximum number of arguments that this function requires, or Integer.MAX_VALUE if this
* is a variable argument function.
*/
public int getMaxArguments() {
Node params = getParametersNode();
if (params != null) {
Node lastParam = params.getLastChild();
if (lastParam == null || !lastParam.isVarArgs()) {
return params.getChildCount();
}
}
return Integer.MAX_VALUE;
}
/** Processes trailing default and rest parameters. */
private void visitParamList(Node paramList, Node function) {
Node insertSpot = null;
Node block = function.getLastChild();
for (int i = 0; i < paramList.getChildCount(); i++) {
Node param = paramList.getChildAtIndex(i);
if (param.isDefaultValue()) {
Node nameOrPattern = param.removeFirstChild();
Node defaultValue = param.removeFirstChild();
Node newParam =
nameOrPattern.isName()
? nameOrPattern
: IR.name(DESTRUCTURING_TEMP_VAR + (destructuringVarCounter++));
Node lhs = nameOrPattern.cloneTree();
Node rhs = defaultValueHook(newParam.cloneTree(), defaultValue);
Node newStatement =
nameOrPattern.isName() ? IR.exprResult(IR.assign(lhs, rhs)) : IR.var(lhs, rhs);
newStatement.useSourceInfoIfMissingFromForTree(param);
block.addChildAfter(newStatement, insertSpot);
insertSpot = newStatement;
paramList.replaceChild(param, newParam);
newParam.setOptionalArg(true);
compiler.reportCodeChange();
} else if (param.isRest()) { // rest parameter
param.setType(Token.NAME);
param.setVarArgs(true);
// Transpile to: param = [].slice.call(arguments, i);
Node newArr =
IR.exprResult(
IR.assign(
IR.name(param.getString()),
IR.call(
IR.getprop(
IR.getprop(IR.arraylit(), IR.string("slice")), IR.string("call")),
IR.name("arguments"),
IR.number(i))));
block.addChildAfter(newArr.useSourceInfoIfMissingFromForTree(param), insertSpot);
compiler.reportCodeChange();
} else if (param.isDestructuringPattern()) {
String tempVarName = DESTRUCTURING_TEMP_VAR + (destructuringVarCounter++);
paramList.replaceChild(param, IR.name(tempVarName));
Node newDecl = IR.var(param, IR.name(tempVarName));
block.addChildAfter(newDecl, insertSpot);
insertSpot = newDecl;
}
}
// For now, we are running transpilation before type-checking, so we'll
// need to make sure changes don't invalidate the JSDoc annotations.
// Therefore we keep the parameter list the same length and only initialize
// the values if they are set to undefined.
}
/**
* Traverses a function, which creates a new scope in javascript.
*
* <p>Note that CATCH blocks also create a new scope, but only for the catch variable.
* Declarations within the block actually belong to the enclosing scope. Because we don't remove
* catch variables, there's no need to treat CATCH blocks differently like we do functions.
*/
private void traverseFunction(Node n, Scope parentScope) {
Preconditions.checkState(n.getChildCount() == 3);
Preconditions.checkState(n.getType() == Token.FUNCTION);
final Node body = n.getLastChild();
Preconditions.checkState(body.getNext() == null && body.getType() == Token.BLOCK);
Scope fnScope = new SyntacticScopeCreator(compiler).createScope(n, parentScope);
traverseNode(body, n, fnScope);
collectMaybeUnreferencedVars(fnScope);
allFunctionScopes.add(fnScope);
}
private void validateTemplateLit(Node n) {
validateEs6Feature("template literal", n);
validateNodeType(Token.TEMPLATELIT, n);
if (!n.hasChildren()) {
return;
}
for (int i = 0; i < n.getChildCount(); i++) {
Node child = n.getChildAtIndex(i);
// If the first child is not a STRING, this is a tagged template.
if (i == 0 && !child.isString()) {
validateExpression(child);
} else if (child.isString()) {
validateString(child);
} else {
validateTemplateLitSub(child);
}
}
}
/**
* Gets an estimate of the cost in characters of making the function call: the sum of the
* identifiers and the separators.
*
* @param referencesThis
*/
private static int estimateCallCost(Node fnNode, boolean referencesThis) {
Node argsNode = NodeUtil.getFnParameters(fnNode);
int numArgs = argsNode.getChildCount();
int callCost = NAME_COST_ESTIMATE + PAREN_COST;
if (numArgs > 0) {
callCost += (numArgs * NAME_COST_ESTIMATE) + ((numArgs - 1) * COMMA_COST);
}
if (referencesThis) {
// TODO(johnlenz): Update this if we start supporting inlining
// other functions that reference this.
// The only functions that reference this that are currently inlined
// are those that are called via ".call" with an explicit "this".
callCost += 5 + 5; // ".call" + "this,"
}
return callCost;
}
@Override
public FlowScope getPreciserScopeKnowingConditionOutcome(
Node condition, FlowScope blindScope, boolean outcome) {
if (condition.isCall() && condition.getChildCount() == 2) {
Node callee = condition.getFirstChild();
Node param = condition.getLastChild();
if (callee.isGetProp() && param.isQualifiedName()) {
JSType paramType = getTypeIfRefinable(param, blindScope);
Node left = callee.getFirstChild();
Node right = callee.getLastChild();
if (left.isName() && "goog".equals(left.getString()) && right.isString()) {
Function<TypeRestriction, JSType> restricter = restricters.get(right.getString());
if (restricter != null) {
return restrictParameter(param, paramType, blindScope, restricter, outcome);
}
}
}
}
return nextPreciserScopeKnowingConditionOutcome(condition, blindScope, outcome);
}
private void validateExport(Node n) {
validateNodeType(Token.EXPORT, n);
if (n.getBooleanProp(Node.EXPORT_ALL_FROM)) { // export * from "mod"
validateChildCount(n, 2);
validateNodeType(Token.EMPTY, n.getFirstChild());
validateString(n.getChildAtIndex(1));
} else if (n.getBooleanProp(Node.EXPORT_DEFAULT)) { // export default foo = 2
validateChildCount(n, 1);
validateExpression(n.getFirstChild());
} else {
validateChildCountIn(n, 1, 2);
if (n.getFirstChild().getType() == Token.EXPORT_SPECS) {
validateExportSpecifiers(n.getFirstChild());
} else {
validateStatement(n.getFirstChild());
}
if (n.getChildCount() == 2) {
validateString(n.getChildAtIndex(1));
}
}
}
/** Processes trailing default and rest parameters. */
private void visitParamList(Node paramList, Node function) {
Node insertSpot = null;
Node block = function.getLastChild();
for (int i = 0; i < paramList.getChildCount(); i++) {
Node param = paramList.getChildAtIndex(i);
if (param.hasChildren()) { // default parameter
param.setOptionalArg(true);
Node defaultValue = param.removeFirstChild();
// Transpile to: param === undefined && (param = defaultValue);
Node name = IR.name(param.getString());
Node undefined = IR.name("undefined");
Node stm =
IR.exprResult(
IR.and(IR.sheq(name, undefined), IR.assign(name.cloneNode(), defaultValue)));
block.addChildAfter(stm.useSourceInfoIfMissingFromForTree(param), insertSpot);
insertSpot = stm;
compiler.reportCodeChange();
} else if (param.isRest()) { // rest parameter
param.setType(Token.NAME);
param.setVarArgs(true);
// Transpile to: param = [].slice.call(arguments, i);
Node newArr =
IR.exprResult(
IR.assign(
IR.name(param.getString()),
IR.call(
IR.getprop(
IR.getprop(IR.arraylit(), IR.string("slice")), IR.string("call")),
IR.name("arguments"),
IR.number(i))));
block.addChildAfter(newArr.useSourceInfoIfMissingFromForTree(param), insertSpot);
compiler.reportCodeChange();
}
}
// For now, we are running transpilation before type-checking, so we'll
// need to make sure changes don't invalidate the JSDoc annotations.
// Therefore we keep the parameter list the same length and only initialize
// the values if they are set to undefined.
}
private void checkRequireCall(NodeTraversal t, Node callNode, Node parent) {
Preconditions.checkState(callNode.isCall());
switch (parent.getType()) {
case Token.EXPR_RESULT:
return;
case Token.GETPROP:
if (parent.getParent().isName()) {
checkRequireCall(t, callNode, parent.getParent());
return;
}
break;
case Token.NAME:
case Token.OBJECT_PATTERN:
{
Node declaration = parent.getParent();
if (declaration.getChildCount() != 1) {
t.report(declaration, ONE_REQUIRE_PER_DECLARATION);
}
return;
}
}
t.report(callNode, REQUIRE_NOT_AT_TOP_LEVEL);
}
/**
* Expressions such as [foo() * 10 * 20] generate parse trees where no node has two const children
* ((foo() * 10) * 20), so performArithmeticOp() won't fold it -- tryFoldLeftChildOp() will.
* Specifically, it folds associative expressions where: - The left child is also an associative
* expression of the same time. - The right child is a constant NUMBER constant. - The left
* child's right child is a NUMBER constant.
*/
private Node tryFoldLeftChildOp(Node n, Node left, Node right) {
Token opType = n.getType();
Preconditions.checkState(
(NodeUtil.isAssociative(opType) && NodeUtil.isCommutative(opType)) || n.isAdd());
Preconditions.checkState(!n.isAdd() || !NodeUtil.mayBeString(n, shouldUseTypes));
// Use getNumberValue to handle constants like "NaN" and "Infinity"
// other values are converted to numbers elsewhere.
Double rightValObj = NodeUtil.getNumberValue(right, shouldUseTypes);
if (rightValObj != null && left.getType() == opType) {
Preconditions.checkState(left.getChildCount() == 2);
Node ll = left.getFirstChild();
Node lr = ll.getNext();
Node valueToCombine = ll;
Node replacement = performArithmeticOp(opType, valueToCombine, right);
if (replacement == null) {
valueToCombine = lr;
replacement = performArithmeticOp(opType, valueToCombine, right);
}
if (replacement != null) {
// Remove the child that has been combined
left.removeChild(valueToCombine);
// Replace the left op with the remaining child.
n.replaceChild(left, left.removeFirstChild());
// New "-Infinity" node need location info explicitly
// added.
replacement.useSourceInfoIfMissingFromForTree(right);
n.replaceChild(right, replacement);
reportCodeChange();
}
}
return n;
}
@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);
}
}
}
/**
* 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;
}
/**
* Tries to optimize all the arguments array access in this scope by assigning a name to each
* element.
*
* @param scope scope of the function
* @return true if any modification has been done to the AST
*/
private boolean tryReplaceArguments(Scope scope) {
Node parametersList = scope.getRootNode().getSecondChild();
Preconditions.checkState(parametersList.isParamList());
// Keep track of rather this function modified the AST and needs to be
// reported back to the compiler later.
boolean changed = false;
// Number of parameter that can be accessed without using the arguments
// array.
int numNamedParameter = parametersList.getChildCount();
// We want to guess what the highest index that has been access from the
// arguments array. We will guess that it does not use anything index higher
// than the named parameter list first until we see other wise.
int highestIndex = numNamedParameter - 1;
// Iterate through all the references to arguments array in the function to
// determine the real highestIndex.
for (Node ref : currentArgumentsAccess) {
Node getElem = ref.getParent();
// Bail on anything but argument[c] access where c is a constant.
// TODO(user): We might not need to bail out all the time, there might
// be more cases that we can cover.
if (!getElem.isGetElem() || ref != getElem.getFirstChild()) {
return false;
}
Node index = ref.getNext();
// We have something like arguments[x] where x is not a constant. That
// means at least one of the access is not known.
if (!index.isNumber() || index.getDouble() < 0) {
// TODO(user): Its possible not to give up just yet. The type
// inference did a 'semi value propagation'. If we know that string
// is never a subclass of the type of the index. We'd know that
// it is never 'callee'.
return false; // Give up.
}
Node getElemParent = getElem.getParent();
// When we have argument[0](), replacing it with a() is semantically
// different if argument[0] is a function call that refers to 'this'
if (getElemParent.isCall() && getElemParent.getFirstChild() == getElem) {
// TODO(user): We can consider using .call() if aliasing that
// argument allows shorter alias for other arguments.
return false;
}
// Replace the highest index if we see an access that has a higher index
// than all the one we saw before.
int value = (int) index.getDouble();
if (value > highestIndex) {
highestIndex = value;
}
}
// Number of extra arguments we need.
// For example: function() { arguments[3] } access index 3 so
// it will need 4 extra named arguments to changed into:
// function(a,b,c,d) { d }.
int numExtraArgs = highestIndex - numNamedParameter + 1;
// Temporary holds the new names as string for quick access later.
String[] argNames = new String[numExtraArgs];
// Insert the formal parameter to the method's signature.
// Example: function() --> function(r0, r1, r2)
for (int i = 0; i < numExtraArgs; i++) {
String name = getNewName();
argNames[i] = name;
parametersList.addChildToBack(IR.name(name).useSourceInfoIfMissingFrom(parametersList));
changed = true;
}
// This loop performs the replacement of arguments[x] -> a if x is known.
for (Node ref : currentArgumentsAccess) {
Node index = ref.getNext();
// Skip if it is unknown.
if (!index.isNumber()) {
continue;
}
int value = (int) index.getDouble();
// Unnamed parameter.
if (value >= numNamedParameter) {
ref.getGrandparent()
.replaceChild(ref.getParent(), IR.name(argNames[value - numNamedParameter]));
} else {
// Here, for no apparent reason, the user is accessing a named parameter
// with arguments[idx]. We can replace it with the actual name for them.
Node name = parametersList.getFirstChild();
// This is a linear search for the actual name from the signature.
// It is not necessary to make this fast because chances are the user
// will not deliberately write code like this.
for (int i = 0; i < value; i++) {
name = name.getNext();
}
ref.getGrandparent().replaceChild(ref.getParent(), IR.name(name.getString()));
}
changed = true;
}
return changed;
}
/**
* Validates the class definition and if valid, destructively extracts the class definition from
* the AST.
*/
private ClassDefinition extractClassDefinition(Node targetName, Node callNode) {
JSDocInfo classInfo = NodeUtil.getBestJSDocInfo(targetName);
// name = goog.defineClass(superClass, {...}, [modifier, ...])
Node superClass = NodeUtil.getArgumentForCallOrNew(callNode, 0);
if (superClass == null || (!superClass.isNull() && !superClass.isQualifiedName())) {
compiler.report(JSError.make(callNode, GOOG_CLASS_SUPER_CLASS_NOT_VALID));
return null;
}
if (NodeUtil.isNullOrUndefined(superClass) || superClass.matchesQualifiedName("Object")) {
superClass = null;
}
Node description = NodeUtil.getArgumentForCallOrNew(callNode, 1);
if (description == null || !description.isObjectLit() || !validateObjLit(description)) {
// report bad class definition
compiler.report(JSError.make(callNode, GOOG_CLASS_DESCRIPTOR_NOT_VALID));
return null;
}
int paramCount = callNode.getChildCount() - 1;
if (paramCount > 2) {
compiler.report(JSError.make(callNode, GOOG_CLASS_UNEXPECTED_PARAMS));
return null;
}
Node constructor = extractProperty(description, "constructor");
if (classInfo != null && classInfo.isInterface()) {
if (constructor != null) {
compiler.report(JSError.make(description, GOOG_CLASS_CONSTRUCTOR_ON_INTERFACE));
return null;
}
} else if (constructor == null) {
// report missing constructor
compiler.report(JSError.make(description, GOOG_CLASS_CONSTRUCTOR_MISSING));
return null;
}
if (constructor == null) {
constructor =
IR.function(
IR.name("").srcref(callNode),
IR.paramList().srcref(callNode),
IR.block().srcref(callNode));
constructor.srcref(callNode);
}
JSDocInfo info = NodeUtil.getBestJSDocInfo(constructor);
Node classModifier = null;
Node statics = null;
Node staticsProp = extractProperty(description, "statics");
if (staticsProp != null) {
if (staticsProp.isObjectLit() && validateObjLit(staticsProp)) {
statics = staticsProp;
} else if (staticsProp.isFunction()) {
classModifier = staticsProp;
} else {
compiler.report(JSError.make(staticsProp, GOOG_CLASS_STATICS_NOT_VALID));
return null;
}
}
if (statics == null) {
statics = IR.objectlit();
}
// Ok, now rip apart the definition into its component pieces.
// Remove the "special" property key nodes.
maybeDetach(constructor.getParent());
maybeDetach(statics.getParent());
if (classModifier != null) {
maybeDetach(classModifier.getParent());
}
ClassDefinition def =
new ClassDefinition(
targetName,
classInfo,
maybeDetach(superClass),
new MemberDefinition(info, null, maybeDetach(constructor)),
objectLitToList(maybeDetach(statics)),
objectLitToList(description),
maybeDetach(classModifier));
return def;
}
private static boolean isAlwaysInlinable(Node fn) {
Preconditions.checkArgument(fn.isFunction());
Node body = NodeUtil.getFunctionBody(fn);
int numOfStmsInBody = body.getChildCount();
return numOfStmsInBody == 0 || numOfStmsInBody == 1 && body.getFirstChild().isReturn();
}