/**
* Removes all CALL nodes in the given TweakInfos, replacing calls to getter functions with the
* tweak's default value.
*/
private boolean stripAllCalls(Map<String, TweakInfo> tweakInfos) {
for (TweakInfo tweakInfo : tweakInfos.values()) {
boolean isRegistered = tweakInfo.isRegistered();
for (TweakFunctionCall functionCall : tweakInfo.functionCalls) {
Node callNode = functionCall.callNode;
Node parent = callNode.getParent();
if (functionCall.tweakFunc.isGetterFunction()) {
Node newValue;
if (isRegistered) {
newValue = tweakInfo.getDefaultValueNode().cloneNode();
} else {
// When we find a getter of an unregistered tweak, there has
// already been a warning about it, so now just use a default
// value when stripping.
TweakFunction registerFunction = functionCall.tweakFunc.registerFunction;
newValue = registerFunction.createDefaultValueNode();
}
parent.replaceChild(callNode, newValue);
} else {
Node voidZeroNode = IR.voidNode(IR.number(0).srcref(callNode)).srcref(callNode);
parent.replaceChild(callNode, voidZeroNode);
}
}
}
return !tweakInfos.isEmpty();
}
/** Replace the current assign with its right hand side. */
void remove() {
Node parent = assignNode.getParent();
if (mayHaveSecondarySideEffects) {
Node replacement = assignNode.getLastChild().detachFromParent();
// Aggregate any expressions in GETELEMs.
for (Node current = assignNode.getFirstChild();
current.getType() != Token.NAME;
current = current.getFirstChild()) {
if (current.getType() == Token.GETELEM) {
replacement =
new Node(Token.COMMA, current.getLastChild().detachFromParent(), replacement);
replacement.copyInformationFrom(current);
}
}
parent.replaceChild(assignNode, replacement);
} else {
Node gramps = parent.getParent();
if (parent.getType() == Token.EXPR_RESULT) {
gramps.removeChild(parent);
} else {
parent.replaceChild(assignNode, assignNode.getLastChild().detachFromParent());
}
}
}
/** 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.
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isThis()) {
Node name = IR.name(THIS_VAR).srcref(n);
parent.replaceChild(n, name);
changedThis = true;
} else if (n.isName() && n.getString().equals("arguments")) {
Node name = IR.name(ARGUMENTS_VAR).srcref(n);
parent.replaceChild(n, name);
changedArguments = true;
}
}
/**
* Expressions such as [foo() + 'a' + 'b'] generate parse trees where no node has two const
* children ((foo() + 'a') + 'b'), so tryFoldAdd() won't fold it -- tryFoldLeftChildAdd() will
* (for Strings). Specifically, it folds Add expressions where: - The left child is also and add
* expression - The right child is a constant value - The left child's right child is a STRING
* constant.
*/
private Node tryFoldChildAddString(Node n, Node left, Node right) {
if (NodeUtil.isLiteralValue(right, false) && left.isAdd()) {
Node ll = left.getFirstChild();
Node lr = ll.getNext();
// Left's right child MUST be a string. We would not want to fold
// foo() + 2 + 'a' because we don't know what foo() will return, and
// therefore we don't know if left is a string concat, or a numeric add.
if (lr.isString()) {
String leftString = NodeUtil.getStringValue(lr);
String rightString = NodeUtil.getStringValue(right);
if (leftString != null && rightString != null) {
left.removeChild(ll);
String result = leftString + rightString;
n.replaceChild(left, ll);
n.replaceChild(right, IR.string(result));
reportCodeChange();
return n;
}
}
}
if (NodeUtil.isLiteralValue(left, false) && right.isAdd()) {
Node rl = right.getFirstChild();
Node rr = right.getLastChild();
// Left's right child MUST be a string. We would not want to fold
// foo() + 2 + 'a' because we don't know what foo() will return, and
// therefore we don't know if left is a string concat, or a numeric add.
if (rl.isString()) {
String leftString = NodeUtil.getStringValue(left);
String rightString = NodeUtil.getStringValue(rl);
if (leftString != null && rightString != null) {
right.removeChild(rr);
String result = leftString + rightString;
n.replaceChild(right, rr);
n.replaceChild(left, IR.string(result));
reportCodeChange();
return n;
}
}
}
return n;
}
/**
* Rename or remove labels.
*
* @param node The label node.
* @param parent The parent of the label node.
*/
private void visitLabel(Node node, Node parent) {
Node nameNode = node.getFirstChild();
Preconditions.checkState(nameNode != null);
String name = nameNode.getString();
LabelInfo li = getLabelInfo(name);
// This is a label...
if (li.referenced || !removeUnused) {
String newName = getNameForId(li.id);
if (!name.equals(newName)) {
// ... and it is used, give it the short name.
nameNode.setString(newName);
compiler.reportCodeChange();
}
} else {
// ... and it is not referenced, just remove it.
Node newChild = node.getLastChild();
node.removeChild(newChild);
parent.replaceChild(node, newChild);
if (newChild.isBlock()) {
NodeUtil.tryMergeBlock(newChild);
}
compiler.reportCodeChange();
}
// Remove the label from the current stack of labels.
namespaceStack.peek().renameMap.remove(name);
}
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 =
variable.isName()
? variable.getQualifiedName()
: variable.getFirstChild().getQualifiedName(); // var or let
Node iterResult = IR.name(ITER_RESULT + variableName);
Node makeIter =
IR.call(NodeUtil.newQualifiedNameNode(compiler.getCodingConvention(), MAKE_ITER), iterable);
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());
body.addChildToFront(
IR.var(IR.name(variableName), IR.getprop(iterResult.cloneTree(), IR.string("value"))));
Node newFor = IR.forNode(init, cond, incr, body);
newFor.useSourceInfoIfMissingFromForTree(node);
parent.replaceChild(node, newFor);
compiler.reportCodeChange();
}
/**
* Replaces a GETPROP a.b.c with a NAME a$b$c.
*
* @param alias A flattened prefix name (e.g. "a$b")
* @param n The GETPROP node corresponding to the original name (e.g. "a.b")
* @param parent {@code n}'s parent
* @param originalName String version of the property name.
*/
private void flattenNameRef(String alias, Node n, Node parent, String originalName) {
Preconditions.checkArgument(
n.isGetProp(), "Expected GETPROP, found %s. Node: %s", Token.name(n.getType()), n);
// BEFORE:
// getprop
// getprop
// name a
// string b
// string c
// AFTER:
// name a$b$c
Node ref = NodeUtil.newName(compiler, alias, n, originalName);
NodeUtil.copyNameAnnotations(n.getLastChild(), ref);
if (parent.isCall() && n == parent.getFirstChild()) {
// The node was a call target, we are deliberately flatten these as
// we node the "this" isn't provided by the namespace. Mark it as such:
parent.putBooleanProp(Node.FREE_CALL, true);
}
TypeI type = n.getTypeI();
if (type != null) {
ref.setTypeI(type);
}
parent.replaceChild(n, ref);
compiler.reportCodeChange();
}
/**
* 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;
}
private Node tryReduceVoid(Node n) {
Node child = n.getFirstChild();
if ((!child.isNumber() || child.getDouble() != 0.0) && !mayHaveSideEffects(n)) {
n.replaceChild(child, IR.number(0));
reportCodeChange();
}
return n;
}
void replaceNodeInPlace(Node n, Node replacement) {
Node parent = n.getParent();
if (n.hasChildren()) {
Node children = n.removeChildren();
replacement.addChildrenToFront(children);
}
parent.replaceChild(n, replacement);
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isThis()) {
Node name = IR.name(THIS_VAR).srcref(n);
parent.replaceChild(n, name);
changed = true;
}
}
/**
* Processes array literals or calls containing spreads. Eg.: [1, 2, ...x, 4, 5] => [1,
* 2].concat(x, [4, 5]); Eg.: f(...arr) => f.apply(null, arr) Eg.: new F(...args) => new
* Function.prototype.bind.apply(F, [].concat(args))
*/
private void visitArrayLitOrCallWithSpread(Node node, Node parent) {
Preconditions.checkArgument(node.isCall() || node.isArrayLit() || node.isNew());
List<Node> groups = new ArrayList<>();
Node currGroup = null;
Node callee = node.isArrayLit() ? null : node.removeFirstChild();
Node currElement = node.removeFirstChild();
while (currElement != null) {
if (currElement.isSpread()) {
if (currGroup != null) {
groups.add(currGroup);
currGroup = null;
}
groups.add(currElement.removeFirstChild());
} else {
if (currGroup == null) {
currGroup = IR.arraylit();
}
currGroup.addChildToBack(currElement);
}
currElement = node.removeFirstChild();
}
if (currGroup != null) {
groups.add(currGroup);
}
Node result = null;
Node joinedGroups =
IR.call(
IR.getprop(IR.arraylit(), IR.string("concat")),
groups.toArray(new Node[groups.size()]));
if (node.isArrayLit()) {
result = joinedGroups;
} else if (node.isCall()) {
if (NodeUtil.mayHaveSideEffects(callee) && callee.isGetProp()) {
Node statement = node;
while (!NodeUtil.isStatement(statement)) {
statement = statement.getParent();
}
Node freshVar = IR.name(FRESH_SPREAD_VAR + freshSpreadVarCounter++);
Node n = IR.var(freshVar.cloneTree());
n.useSourceInfoIfMissingFromForTree(statement);
statement.getParent().addChildBefore(n, statement);
callee.addChildToFront(IR.assign(freshVar.cloneTree(), callee.removeFirstChild()));
result = IR.call(IR.getprop(callee, IR.string("apply")), freshVar, joinedGroups);
} else {
Node context = callee.isGetProp() ? callee.getFirstChild().cloneTree() : IR.nullNode();
result = IR.call(IR.getprop(callee, IR.string("apply")), context, joinedGroups);
}
} else {
Node bindApply =
NodeUtil.newQualifiedNameNode(
compiler.getCodingConvention(), "Function.prototype.bind.apply");
result = IR.newNode(bindApply, callee, joinedGroups);
}
result.useSourceInfoIfMissingFromForTree(node);
parent.replaceChild(node, result);
compiler.reportCodeChange();
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
switch (n.getType()) {
case Token.THIS:
parent.replaceChild(n, Node.newString(Token.NAME, "$$_self"));
thisChanged = true;
compiler.reportCodeChange();
}
}
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();
}
@Override
protected void aliasNode(Node throwNode, Node parent) {
Node name =
NodeUtil.newName(
compiler.getCodingConvention(), getAliasName(), throwNode, getAliasName());
Node aliasCall = IR.call(name, throwNode.removeFirstChild());
aliasCall.putBooleanProp(Node.FREE_CALL, true);
Node exprResult = IR.exprResult(aliasCall);
parent.replaceChild(throwNode, exprResult);
}
/** Flattens a stub declaration. This is mostly a hack to support legacy users. */
private void flattenSimpleStubDeclaration(Name name, String alias) {
Ref ref = Iterables.getOnlyElement(name.getRefs());
Node nameNode = NodeUtil.newName(compiler, alias, ref.node, name.getFullName());
Node varNode = IR.var(nameNode).useSourceInfoIfMissingFrom(nameNode);
Preconditions.checkState(ref.node.getParent().isExprResult());
Node parent = ref.node.getParent();
Node grandparent = parent.getParent();
grandparent.replaceChild(parent, varNode);
compiler.reportCodeChange();
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
// System.out.println(n);
switch (n.getType()) {
case Token.FUNCTION:
Node functionNameNode = n.getFirstChild();
String currFunctionName = functionNameNode.getString();
if (!anonymizedFnNodes.contains(n)) {
if (currFunctionName.length() == 0) {
Set<String> closures = findClosures(n);
// System.out.println("closures" + closures);
n.detachFromParent(); // detach anonymous function from.
// change all references to 'this' in method to $$_self
boolean thisChanged = changeThisTo$$_self(n);
// clone the parameters of modified $$$anonym(originalParams..., closures..) so that
// we can use it for parameters of function call below
Node clonedorigParamNode = n.getChildAtIndex(1).cloneTree();
clonedorigParamNode.setType(Token.LP);
// parent
// give 'n' a name and attach to end
// e.g. function $$anonym(originalParams..., closures..)
String anonymName = "$$anonym" + anonymCount++;
Node funcNameNode = Node.newString(Token.NAME, anonymName);
n.replaceChild(n.getFirstChild(), funcNameNode);
Node parametersNode = n.getChildAtIndex(1);
addParamsToMethod(closures, parametersNode, thisChanged, "$$_self");
root.getFirstChild().addChildrenToBack(n);
// replace original anonymous call to new anonymous function that closes over
// params and then makes a call to our named function
Node newAnonymNode =
createAnonymWithParamCall(closures, anonymName, clonedorigParamNode, thisChanged);
parent.addChildrenToBack(newAnonymNode);
// add to list of anonymized nodes so that we can ignore it on second pass
anonymizedFnNodes.add(newAnonymNode);
compiler.reportCodeChange();
} else { // named function just find closures and add as parameter
// TODO
}
}
}
}
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isCall()) {
Node target = n.getFirstChild();
// TODO(johnlenz): add this to the coding convention
// so we can remove goog.reflect.sinkValue as well.
if (target.isName() && target.getString().equals(PROTECTOR_FN)) {
Node expr = n.getLastChild();
n.detachChildren();
parent.replaceChild(n, expr);
}
}
}
/**
* Attempt to inline an global alias of a global name. This requires that the name is well
* defined: assigned unconditionally, assigned exactly once. It is assumed that, the name for
* which it is an alias must already meet these same requirements.
*
* @param alias The alias to inline
* @return Whether the alias was inlined.
*/
private boolean inlineGlobalAliasIfPossible(Name name, Ref alias, GlobalNamespace namespace) {
// Ensure that the alias is assigned to global name at that the
// declaration.
Node aliasParent = alias.node.getParent();
if (aliasParent.isAssign() && NodeUtil.isExecutedExactlyOnce(aliasParent)
// We special-case for constructors here, to inline constructor aliases
// more aggressively in global scope.
// We do this because constructor properties are always collapsed,
// so we want to inline the aliases also to avoid breakages.
|| aliasParent.isName() && name.isConstructor()) {
Node lvalue = aliasParent.isName() ? aliasParent : aliasParent.getFirstChild();
if (!lvalue.isQualifiedName()) {
return false;
}
name = namespace.getSlot(lvalue.getQualifiedName());
if (name != null && name.isInlinableGlobalAlias()) {
Set<AstChange> newNodes = new LinkedHashSet<>();
List<Ref> refs = new ArrayList<>(name.getRefs());
for (Ref ref : refs) {
switch (ref.type) {
case SET_FROM_GLOBAL:
continue;
case DIRECT_GET:
case ALIASING_GET:
Node newNode = alias.node.cloneTree();
Node node = ref.node;
node.getParent().replaceChild(node, newNode);
newNodes.add(new AstChange(ref.module, ref.scope, newNode));
name.removeRef(ref);
break;
default:
throw new IllegalStateException();
}
}
rewriteAliasProps(name, alias.node, 0, newNodes);
// just set the original alias to null.
aliasParent.replaceChild(alias.node, IR.nullNode());
compiler.reportCodeChange();
// Inlining the variable may have introduced new references
// to descendants of {@code name}. So those need to be collected now.
namespace.scanNewNodes(newNodes);
return true;
}
}
return false;
}
/** 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;
}
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();
}
/**
* 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;
}
/** Collapse VARs and EXPR_RESULT node into FOR loop initializers where possible. */
private void maybeCollapseIntoForStatements(Node n, Node parent) {
// Only SCRIPT, BLOCK, and LABELs can have FORs that can be collapsed into.
// LABELs are not supported here.
if (parent == null || !NodeUtil.isStatementBlock(parent)) {
return;
}
// Is the current node something that can be in a for loop initializer?
if (!NodeUtil.isExpressionNode(n) && !NodeUtil.isVar(n)) {
return;
}
// Is the next statement a valid FOR?
Node nextSibling = n.getNext();
if (nextSibling != null
&& nextSibling.getType() == Token.FOR
&& !NodeUtil.isForIn(nextSibling)
&& nextSibling.getFirstChild().getType() == Token.EMPTY) {
// Does the current node contain an in operator? If so, embedding
// the expression in a for loop can cause some Javascript parsers (such
// as the Playstation 3's browser based on Access's NetFront
// browser) to fail to parse the code.
// See bug 1778863 for details.
if (NodeUtil.containsType(n, Token.IN)) {
return;
}
// Move the current node into the FOR loop initializer.
Node forNode = nextSibling;
Node oldInitializer = forNode.getFirstChild();
parent.removeChild(n);
Node newInitializer;
if (NodeUtil.isVar(n)) {
newInitializer = n;
} else {
// Extract the expression from EXPR_RESULT node.
Preconditions.checkState(n.hasOneChild());
newInitializer = n.getFirstChild();
n.removeChild(newInitializer);
}
forNode.replaceChild(oldInitializer, newInitializer);
compiler.reportCodeChange();
}
}
/** Add blocks to IF, WHILE, DO, etc. */
private void normalizeBlocks(Node n) {
if (NodeUtil.isControlStructure(n) && !n.isLabel() && !n.isSwitch()) {
for (Node c = n.getFirstChild(); c != null; c = c.getNext()) {
if (NodeUtil.isControlStructureCodeBlock(n, c) && !c.isBlock()) {
Node newBlock = IR.block().srcref(n);
n.replaceChild(c, newBlock);
newBlock.setIsAddedBlock(true);
if (!c.isEmpty()) {
newBlock.addChildrenToFront(c);
}
c = newBlock;
reportChange();
}
}
}
}
/** Try to fold a AND/OR node. */
private Node tryFoldAndOr(Node n, Node left, Node right) {
Node parent = n.getParent();
Node result = null;
Token type = n.getType();
TernaryValue leftVal = NodeUtil.getImpureBooleanValue(left);
if (leftVal != TernaryValue.UNKNOWN) {
boolean lval = leftVal.toBoolean(true);
// (TRUE || x) => TRUE (also, (3 || x) => 3)
// (FALSE && x) => FALSE
if (lval && type == Token.OR || !lval && type == Token.AND) {
result = left;
} else if (!mayHaveSideEffects(left)) {
// (FALSE || x) => x
// (TRUE && x) => x
result = right;
} else {
// Left side may have side effects, but we know its boolean value.
// e.g. true_with_sideeffects || foo() => true_with_sideeffects, foo()
// or: false_with_sideeffects && foo() => false_with_sideeffects, foo()
// This, combined with PeepholeRemoveDeadCode, helps reduce expressions
// like "x() || false || z()".
n.detachChildren();
result = IR.comma(left, right);
}
}
// Note: Right hand side folding is handled by
// PeepholeMinimizeConditions#tryMinimizeCondition
if (result != null) {
// Fold it!
n.detachChildren();
parent.replaceChild(n, result);
reportCodeChange();
return result;
} else {
return n;
}
}
private void maybeReplaceJqueryPrototypeAlias(Node n) {
// Check to see if this is the assignment of the original alias.
// If so, leave it intact.
if (NodeUtil.isLValue(n)) {
Node maybeAssign = n.getParent();
while (!NodeUtil.isStatement(maybeAssign) && !maybeAssign.isAssign()) {
maybeAssign = maybeAssign.getParent();
}
if (maybeAssign.isAssign()) {
maybeAssign = maybeAssign.getParent();
if (maybeAssign.isBlock() || maybeAssign.isScript() || NodeUtil.isStatement(maybeAssign)) {
return;
}
}
}
Node fn = n.getLastChild();
if (fn != null) {
n.replaceChild(fn, IR.string("prototype").srcref(fn));
compiler.reportCodeChange();
}
}
private Node tryFoldInForcedStringContext(Node n) {
// For now, we only know how to fold ctors.
Preconditions.checkArgument(n.isNew());
Node objectType = n.getFirstChild();
if (!objectType.isName()) {
return n;
}
if (objectType.getString().equals("String")) {
Node value = objectType.getNext();
String stringValue = null;
if (value == null) {
stringValue = "";
} else {
if (!NodeUtil.isImmutableValue(value)) {
return n;
}
stringValue = NodeUtil.getStringValue(value);
}
if (stringValue == null) {
return n;
}
Node parent = n.getParent();
Node newString = IR.string(stringValue);
parent.replaceChild(n, newString);
newString.useSourceInfoIfMissingFrom(parent);
reportCodeChange();
return newString;
}
return n;
}
private void replaceOriginalJqueryEachCall(Node n, Node expandedBlock) {
// Check to see if the return value of the original jQuery.expandedEach
// call is used. If so, we need to wrap each loop expansion in an anonymous
// function and return the original objectToLoopOver.
if (n.getParent().isExprResult()) {
Node parent = n.getParent();
Node grandparent = parent.getParent();
Node insertAfter = parent;
while (expandedBlock.hasChildren()) {
Node child = expandedBlock.getFirstChild().detachFromParent();
grandparent.addChildAfter(child, insertAfter);
insertAfter = child;
}
grandparent.removeChild(parent);
} else {
// Return the original object
Node callTarget = n.getFirstChild();
Node objectToLoopOver = callTarget.getNext();
objectToLoopOver.detachFromParent();
Node ret = IR.returnNode(objectToLoopOver).srcref(callTarget);
expandedBlock.addChildToBack(ret);
// Wrap all of the expanded loop calls in a new anonymous function
Node fnc =
IR.function(
IR.name("").srcref(callTarget), IR.paramList().srcref(callTarget), expandedBlock);
n.replaceChild(callTarget, fnc);
n.putBooleanProp(Node.FREE_CALL, true);
// remove any other pre-existing call arguments
while (fnc.getNext() != null) {
n.removeChildAfter(fnc);
}
}
compiler.reportCodeChange();
}
@Override
protected void aliasNode(Node n, Node parent) {
Node aliasNode =
NodeUtil.newName(compiler.getCodingConvention(), getAliasName(), n, getAliasName());
parent.replaceChild(n, aliasNode);
}