private void handleReturn(Node node) {
Node lastJump = null;
for (Iterator<Node> iter = exceptionHandler.iterator(); iter.hasNext(); ) {
Node curHandler = iter.next();
if (NodeUtil.isFunction(curHandler)) {
break;
}
if (NodeUtil.hasFinally(curHandler)) {
if (lastJump == null) {
createEdge(node, Branch.UNCOND, curHandler.getLastChild());
} else {
finallyMap.put(lastJump, computeFallThrough(curHandler.getLastChild()));
}
lastJump = curHandler;
}
}
if (node.hasChildren()) {
connectToPossibleExceptionHandler(node, node.getFirstChild());
}
if (lastJump == null) {
createEdge(node, Branch.UNCOND, null);
} else {
finallyMap.put(lastJump, null);
}
}
private boolean isFusableControlStatement(Node n) {
switch (n.getToken()) {
case IF:
case THROW:
case SWITCH:
case EXPR_RESULT:
return true;
case RETURN:
// We don't want to add a new return value.
return n.hasChildren();
case FOR:
if (NodeUtil.isForIn(n)) {
// Avoid cases where we have for(var x = foo() in a) { ....
return !mayHaveSideEffects(n.getFirstChild());
} else {
// Avoid cases where we have for(var x;_;_) { ....
return !n.getFirstChild().isVar();
}
case LABEL:
return isFusableControlStatement(n.getLastChild());
case BLOCK:
return !n.isSyntheticBlock() && isFusableControlStatement(n.getFirstChild());
default:
break;
}
return false;
}
private void validateContinue(Node n) {
validateNodeType(Token.CONTINUE, n);
validateMaximumChildCount(n, 1);
if (n.hasChildren()) {
validateLabelName(n.getFirstChild());
}
}
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);
}
}
private void validateBreak(Node n) {
validateNodeType(Token.BREAK, n);
validateMaximumChildCount(n, 1);
if (n.hasChildren()) {
validateLabelName(n.getFirstChild());
}
}
private void validateReturn(Node n) {
validateNodeType(Token.RETURN, n);
validateMaximumChildCount(n, 1);
if (n.hasChildren()) {
validateExpression(n.getFirstChild());
}
}
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);
}
}
/**
* Inline a function that fulfills the requirements of canInlineReferenceDirectly into the call
* site, replacing only the CALL node.
*/
private Node inlineReturnValue(Node callNode, Node fnNode) {
Node block = fnNode.getLastChild();
Node callParentNode = callNode.getParent();
// NOTE: As the normalize pass guarantees globals aren't being
// shadowed and an expression can't introduce new names, there is
// no need to check for conflicts.
// Create an argName -> expression map, checking for side effects.
Map<String, Node> argMap =
FunctionArgumentInjector.getFunctionCallParameterMap(
fnNode, callNode, this.safeNameIdSupplier);
Node newExpression;
if (!block.hasChildren()) {
Node srcLocation = block;
newExpression = NodeUtil.newUndefinedNode(srcLocation);
} else {
Node returnNode = block.getFirstChild();
Preconditions.checkArgument(returnNode.getType() == Token.RETURN);
// Clone the return node first.
Node safeReturnNode = returnNode.cloneTree();
Node inlineResult = FunctionArgumentInjector.inject(safeReturnNode, null, argMap);
Preconditions.checkArgument(safeReturnNode == inlineResult);
newExpression = safeReturnNode.removeFirstChild();
}
callParentNode.replaceChild(callNode, newExpression);
return newExpression;
}
/** For each node, update the block stack and reference collection as appropriate. */
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isName()
|| n.isRest()
|| (n.isStringKey() && parent.isObjectPattern() && !n.hasChildren())) {
Var v;
if (n.getString().equals("arguments")) {
v = t.getScope().getArgumentsVar();
} else {
v = t.getScope().getVar(n.getString());
}
if (v != null) {
if (varFilter.apply(v)) {
addReference(v, new Reference(n, t, peek(blockStack)));
}
if (v.getParentNode() != null
&& NodeUtil.isHoistedFunctionDeclaration(v.getParentNode())
&&
// If we're only traversing a narrow scope, do not try to climb outside.
(narrowScope == null || narrowScope.getDepth() <= v.getScope().getDepth())) {
outOfBandTraversal(v);
}
}
}
if (isBlockBoundary(n, parent)) {
pop(blockStack);
}
}
/**
* Gets whether a node is a CALL node whose return value should be stripped. A call's return
* value should be stripped if the function getting called is a static method in a class that
* gets stripped. For example, if "goog.debug.Logger" is a strip name, then this function
* returns true for a call such as "goog.debug.Logger.getLogger(...)". It may also simply be a
* function that is getting stripped. For example, if "getLogger" is a strip name, but not
* "goog.debug.Logger", this will still return true.
*
* @param n A node (typically a CALL node)
* @return Whether the call's return value should be stripped
*/
boolean isCallWhoseReturnValueShouldBeStripped(@Nullable Node n) {
return n != null
&& (n.getType() == Token.CALL || n.getType() == Token.NEW)
&& n.hasChildren()
&& (qualifiedNameBeginsWithStripType(n.getFirstChild())
|| nameEndsWithFieldNameToStrip(n.getFirstChild()));
}
/**
* Expand a jQuery.expandedEach call
*
* <p>Expanded jQuery.expandedEach calls will replace the GETELEM nodes of a property assignment
* with GETPROP nodes to allow for renaming.
*/
private void maybeExpandJqueryEachCall(NodeTraversal t, Node n) {
Node objectToLoopOver = n.getChildAtIndex(1);
if (objectToLoopOver == null) {
return;
}
Node callbackFunction = objectToLoopOver.getNext();
if (callbackFunction == null || !callbackFunction.isFunction()) {
return;
}
// Run the peephole optimizations on the first argument to handle
// cases like ("a " + "b").split(" ")
peepholePasses.process(null, n.getChildAtIndex(1));
// Create a reference tree
Node nClone = n.cloneTree();
objectToLoopOver = nClone.getChildAtIndex(1);
// Check to see if the first argument is something we recognize and can
// expand.
if (!objectToLoopOver.isObjectLit()
&& !(objectToLoopOver.isArrayLit() && isArrayLitValidForExpansion(objectToLoopOver))) {
t.report(n, JQUERY_UNABLE_TO_EXPAND_INVALID_LIT_ERROR, (String) null);
return;
}
// Find all references to the callback function arguments
List<Node> keyNodeReferences = new ArrayList<>();
List<Node> valueNodeReferences = new ArrayList<>();
new NodeTraversal(
compiler,
new FindCallbackArgumentReferences(
callbackFunction,
keyNodeReferences,
valueNodeReferences,
objectToLoopOver.isArrayLit()))
.traverseInnerNode(
NodeUtil.getFunctionBody(callbackFunction), callbackFunction, t.getScope());
if (keyNodeReferences.isEmpty()) {
// We didn't do anything useful ...
t.report(n, JQUERY_USELESS_EACH_EXPANSION, (String) null);
return;
}
Node fncBlock =
tryExpandJqueryEachCall(
t, nClone, callbackFunction, keyNodeReferences, valueNodeReferences);
if (fncBlock != null && fncBlock.hasChildren()) {
replaceOriginalJqueryEachCall(n, fncBlock);
} else {
// We didn't do anything useful ...
t.report(n, JQUERY_USELESS_EACH_EXPANSION, (String) null);
}
}
public void findNamedFunctions(NodeTraversal t, Node n, Node parent) {
if (!NodeUtil.isStatement(n)) {
// There aren't any interesting functions here.
return;
}
switch (n.getType()) {
// Functions expressions in the form of:
// var fooFn = function(x) { return ... }
case Token.VAR:
Preconditions.checkState(n.hasOneChild());
Node nameNode = n.getFirstChild();
if (nameNode.isName()
&& nameNode.hasChildren()
&& nameNode.getFirstChild().isFunction()) {
maybeAddFunction(new FunctionVar(n), t.getModule());
}
break;
// Named functions
// function Foo(x) { return ... }
case Token.FUNCTION:
Preconditions.checkState(NodeUtil.isStatementBlock(parent) || parent.isLabel());
if (!NodeUtil.isFunctionExpression(n)) {
Function fn = new NamedFunction(n);
maybeAddFunction(fn, t.getModule());
}
break;
}
}
private JSType getNamedTypeHelper(
Node n, DeclaredTypeRegistry registry, ImmutableList<String> outerTypeParameters)
throws UnknownTypeException {
String typeName = n.getString();
switch (typeName) {
case "boolean":
return JSType.BOOLEAN;
case "null":
return JSType.NULL;
case "number":
return JSType.NUMBER;
case "string":
return JSType.STRING;
case "undefined":
case "void":
return JSType.UNDEFINED;
case "Function":
return maybeMakeNullable(registry.getCommonTypes().qmarkFunction());
case "Object":
// We don't generally handle parameterized Object<...>, but we want to
// at least not warn about inexistent properties on it, so we type it
// as @dict.
return maybeMakeNullable(n.hasChildren() ? JSType.TOP_DICT : JSType.TOP_OBJECT);
default:
return lookupTypeByName(typeName, n, registry, outerTypeParameters);
}
}
private void validateYield(Node n) {
validateEs6Feature("yield", n);
validateNodeType(Token.YIELD, n);
validateChildCountIn(n, 0, 1);
if (n.hasChildren()) {
validateExpression(n.getFirstChild());
}
}
/** Converts extended object literal {a} to {a:a}. */
private void visitStringKey(Node n) {
if (!n.hasChildren()) {
Node name = IR.name(n.getString());
name.copyInformationFrom(n);
n.addChildToBack(name);
compiler.reportCodeChange();
}
}
/** Converts extended object literal {a} to {a:a}. */
private void visitStringKey(Node n) {
if (!n.hasChildren()) {
Node name = IR.name(n.getString());
name.useSourceInfoIfMissingFrom(n);
n.addChildToBack(name);
compiler.reportCodeChange();
}
}
void replaceNodeInPlace(Node n, Node replacement) {
Node parent = n.getParent();
if (n.hasChildren()) {
Node children = n.removeChildren();
replacement.addChildrenToFront(children);
}
parent.replaceChild(n, replacement);
}
private JSType getNominalTypeHelper(
RawNominalType rawType,
Node n,
DeclaredTypeRegistry registry,
ImmutableList<String> outerTypeParameters)
throws UnknownTypeException {
NominalType uninstantiated = rawType.getAsNominalType();
if (!rawType.isGeneric() && !n.hasChildren()) {
return rawType.getInstanceWithNullability(NULLABLE_TYPES_BY_DEFAULT);
}
ImmutableList.Builder<JSType> typeList = ImmutableList.builder();
if (n.hasChildren()) {
// Compute instantiation of polymorphic class/interface.
Preconditions.checkState(n.getFirstChild().isBlock(), n);
for (Node child : n.getFirstChild().children()) {
typeList.add(getTypeFromCommentHelper(child, registry, outerTypeParameters));
}
}
ImmutableList<JSType> typeArguments = typeList.build();
ImmutableList<String> typeParameters = rawType.getTypeParameters();
int typeArgsSize = typeArguments.size();
int typeParamsSize = typeParameters.size();
if (typeArgsSize != typeParamsSize) {
// We used to also warn when (typeArgsSize < typeParamsSize), but it
// happens so often that we stopped. Array, Object and goog.Promise are
// common culprits, but many other types as well.
if (typeArgsSize > typeParamsSize) {
warnings.add(
JSError.make(
n,
INVALID_GENERICS_INSTANTIATION,
uninstantiated.getName(),
String.valueOf(typeParamsSize),
String.valueOf(typeArgsSize)));
}
return maybeMakeNullable(
JSType.fromObjectType(
ObjectType.fromNominalType(
uninstantiated.instantiateGenerics(
fixLengthOfTypeList(typeParameters.size(), typeArguments)))));
}
return maybeMakeNullable(
JSType.fromObjectType(
ObjectType.fromNominalType(uninstantiated.instantiateGenerics(typeArguments))));
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (NodeUtil.isVarDeclaration(n) && removable.contains(n.getString())) {
parent.removeChild(n);
if (!parent.hasChildren()) {
parent.getParent().removeChild(parent);
}
}
}
private boolean hasShorthandAssignment(Node objLit) {
Preconditions.checkState(objLit.isObjectLit());
for (Node property : objLit.children()) {
if (property.isStringKey() && !property.hasChildren()) {
return true;
}
}
return false;
}
private void visitObjectWithComputedProperty(Node obj, Node parent) {
Preconditions.checkArgument(obj.isObjectLit());
List<Node> props = new ArrayList<>();
Node currElement = obj.getFirstChild();
while (currElement != null) {
if (currElement.getBooleanProp(Node.COMPUTED_PROP_GETTER)
|| currElement.getBooleanProp(Node.COMPUTED_PROP_SETTER)) {
cannotConvertYet(currElement, "computed getter/setter");
return;
} else if (currElement.isGetterDef() || currElement.isSetterDef()) {
currElement = currElement.getNext();
} else {
Node nextNode = currElement.getNext();
obj.removeChild(currElement);
props.add(currElement);
currElement = nextNode;
}
}
String objName = FRESH_COMP_PROP_VAR + compiler.getUniqueNameIdSupplier().get();
props = Lists.reverse(props);
Node result = IR.name(objName);
for (Node propdef : props) {
if (propdef.isComputedProp()) {
Node propertyExpression = propdef.removeFirstChild();
Node value = propdef.removeFirstChild();
result =
IR.comma(IR.assign(IR.getelem(IR.name(objName), propertyExpression), value), result);
} else {
if (!propdef.hasChildren()) {
Node name = IR.name(propdef.getString()).useSourceInfoIfMissingFrom(propdef);
propdef.addChildToBack(name);
}
Node val = propdef.removeFirstChild();
propdef.setType(Token.STRING);
int type = propdef.isQuotedString() ? Token.GETELEM : Token.GETPROP;
Node access = new Node(type, IR.name(objName), propdef);
result = IR.comma(IR.assign(access, val), result);
}
}
Node statement = obj;
while (!NodeUtil.isStatement(statement)) {
statement = statement.getParent();
}
result.useSourceInfoIfMissingFromForTree(obj);
parent.replaceChild(obj, result);
Node var = IR.var(IR.name(objName), obj);
var.useSourceInfoIfMissingFromForTree(statement);
statement.getParent().addChildBefore(var, statement);
compiler.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));
}
}
/** @return The difference between the function definition cost and inline cost. */
private static int inlineCostDelta(Node fnNode, Set<String> namesToAlias, InliningMode mode) {
// The part of the function that is never inlined:
// "function xx(xx,xx){}" (15 + (param count * 3) -1;
int paramCount = NodeUtil.getFnParameters(fnNode).getChildCount();
int commaCount = (paramCount > 1) ? paramCount - 1 : 0;
int costDeltaFunctionOverhead =
15 + commaCount + (paramCount * InlineCostEstimator.ESTIMATED_IDENTIFIER_COST);
Node block = fnNode.getLastChild();
if (!block.hasChildren()) {
// Assume the inline cost is zero for empty functions.
return -costDeltaFunctionOverhead;
}
if (mode == InliningMode.DIRECT) {
// The part of the function that is inlined using direct inlining:
// "return " (7)
return -(costDeltaFunctionOverhead + 7);
} else {
int aliasCount = namesToAlias.size();
// Originally, we estimated purely base on the function code size, relying
// on later optimizations. But that did not produce good results, so here
// we try to estimate the something closer to the actual inlined coded.
// NOTE 1: Result overhead is only if there is an assignment, but
// getting that information would require some refactoring.
// NOTE 2: The aliasing overhead is currently an under-estimate,
// as some parameters are aliased because of the parameters used.
// Perhaps we should just assume all parameters will be aliased?
final int INLINE_BLOCK_OVERHEAD = 4; // "X:{}"
final int PER_RETURN_OVERHEAD = 2; // "return" --> "break X"
final int PER_RETURN_RESULT_OVERHEAD = 3; // "XX="
final int PER_ALIAS_OVERHEAD = 3; // "XX="
// TODO(johnlenz): Counting the number of returns is relatively expensive
// this information should be determined during the traversal and
// cached.
int returnCount =
NodeUtil.getNodeTypeReferenceCount(
block, Token.RETURN, new NodeUtil.MatchShallowStatement());
int resultCount = (returnCount > 0) ? returnCount - 1 : 0;
int baseOverhead = (returnCount > 0) ? INLINE_BLOCK_OVERHEAD : 0;
int overhead =
baseOverhead
+ returnCount * PER_RETURN_OVERHEAD
+ resultCount * PER_RETURN_RESULT_OVERHEAD
+ aliasCount * PER_ALIAS_OVERHEAD;
return (overhead - costDeltaFunctionOverhead);
}
}
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);
}
}
/** Remove useless calls: Object.defineProperties(o, {}) -> o */
private Node tryFoldCall(Node n) {
Preconditions.checkArgument(n.isCall());
if (NodeUtil.isObjectDefinePropertiesDefinition(n)) {
Node srcObj = n.getLastChild();
if (srcObj.isObjectLit() && !srcObj.hasChildren()) {
Node parent = n.getParent();
Node destObj = n.getSecondChild().detachFromParent();
parent.replaceChild(n, destObj);
reportCodeChange();
}
}
return n;
}
/**
* Build parameter and local information for the template and replace the references in the
* template 'fn' with placeholder nodes use to facility matching.
*/
private void prepTemplatePlaceholders(Node fn) {
final List<String> locals = templateLocals;
final List<String> params = templateParams;
final Map<String, JSType> paramTypes = new HashMap<>();
// drop the function name so it isn't include in the name maps
String fnName = fn.getFirstChild().getString();
fn.getFirstChild().setString("");
// Build a list of parameter names and types.
Node templateParametersNode = fn.getSecondChild();
JSDocInfo info = NodeUtil.getBestJSDocInfo(fn);
if (templateParametersNode.hasChildren()) {
Preconditions.checkNotNull(
info, "Missing JSDoc declaration for template function %s", fnName);
}
for (Node paramNode : templateParametersNode.children()) {
String name = paramNode.getString();
JSTypeExpression expression = info.getParameterType(name);
Preconditions.checkNotNull(
expression, "Missing JSDoc for parameter %s of template function %s", name, fnName);
JSType type = expression.evaluate(null, compiler.getTypeIRegistry());
Preconditions.checkNotNull(type);
params.add(name);
paramTypes.put(name, type);
}
// Find references to local variables and parameters and replace them.
traverse(
fn,
new Visitor() {
@Override
public void visit(Node n) {
if (n.isName()) {
Node parent = n.getParent();
String name = n.getString();
if (!name.isEmpty() && parent.isVar() && !locals.contains(name)) {
locals.add(n.getString());
}
if (params.contains(name)) {
JSType type = paramTypes.get(name);
replaceNodeInPlace(n, createTemplateParameterNode(params.indexOf(name), type));
} else if (locals.contains(name)) {
replaceNodeInPlace(n, createTemplateLocalNameNode(locals.indexOf(name)));
}
}
}
});
}
private void validateObjectLitGetKey(Node n) {
validateNodeType(Token.GETTER_DEF, n);
validateChildCount(n);
validateObjectLiteralKeyName(n);
Node function = n.getFirstChild();
validateFunctionExpression(function);
// objlit get functions must be nameless, and must have zero parameters.
if (!function.getFirstChild().getString().isEmpty()) {
violation("Expected unnamed function expression.", n);
}
Node functionParams = function.getChildAtIndex(1);
if (functionParams.hasChildren()) {
violation("get methods must not have parameters.", n);
}
}
/**
* Removes declarations of any variables whose names are strip names or whose whose rvalues are
* static method calls on strip types. Builds a set of removed variables so that all references
* to them can be removed.
*
* @param t The traversal
* @param n A VAR node
* @param parent {@code n}'s parent
*/
void removeVarDeclarationsByNameOrRvalue(NodeTraversal t, Node n, Node parent) {
for (Node nameNode = n.getFirstChild(); nameNode != null; nameNode = nameNode.getNext()) {
String name = nameNode.getString();
if (isStripName(name) || isCallWhoseReturnValueShouldBeStripped(nameNode.getFirstChild())) {
// Remove the NAME.
Scope scope = t.getScope();
varsToRemove.add(scope.getVar(name));
n.removeChild(nameNode);
compiler.reportCodeChange();
}
}
if (!n.hasChildren()) {
// Must also remove the VAR.
replaceWithEmpty(n, parent);
compiler.reportCodeChange();
}
}
/**
* Flattens a particular prefix of a single name reference.
*
* @param alias A flattened prefix name (e.g. "a$b")
* @param n The node corresponding to a subproperty name (e.g. "a.b.c.d")
* @param depth The difference in depth between the property name and the prefix name (e.g. 2)
* @param originalName String version of the property name.
*/
private void flattenNameRefAtDepth(String alias, Node n, int depth, String originalName) {
// This method has to work for both GETPROP chains and, in rare cases,
// OBJLIT keys, possibly nested. That's why we check for children before
// proceeding. In the OBJLIT case, we don't need to do anything.
int nType = n.getType();
boolean isQName = nType == Token.NAME || nType == Token.GETPROP;
boolean isObjKey = NodeUtil.isObjectLitKey(n);
Preconditions.checkState(isObjKey || isQName);
if (isQName) {
for (int i = 1; i < depth && n.hasChildren(); i++) {
n = n.getFirstChild();
}
if (n.isGetProp() && n.getFirstChild().isGetProp()) {
flattenNameRef(alias, n.getFirstChild(), n, originalName);
}
}
}
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);
}
}
}