com.google.javascript.jscomp.ClosureOptimizePrimitives Maven / Gradle / Ivy
Show all versions of closure-compiler Show documentation
/*
* Copyright 2011 The Closure Compiler Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.javascript.jscomp;
import static com.google.javascript.rhino.dtoa.DToA.numberToString;
import com.google.javascript.jscomp.NodeTraversal.AbstractPostOrderCallback;
import com.google.javascript.jscomp.parsing.parser.FeatureSet.Feature;
import com.google.javascript.rhino.IR;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.QualifiedName;
import com.google.javascript.rhino.Token;
import java.util.HashSet;
import java.util.Set;
/**
* Compiler pass that converts primitive calls:
*
* Converts goog.object.create(key1, val1, key2, val2, ...) where all of the keys are literals
* into object literals.
*
*
Converts goog.object.createSet(key1, key2, ...) into an object literal with the given keys,
* where all the values are {@code true}.
*
*
Converts goog.reflect.objectProperty(propName, object) to JSCompiler_renameProperty
*/
final class ClosureOptimizePrimitives implements CompilerPass {
static final DiagnosticType DUPLICATE_SET_MEMBER =
DiagnosticType.warning("JSC_DUPLICATE_SET_MEMBER", "Found duplicate value ''{0}'' in set");
private static final QualifiedName GOOG_OBJECT_CREATE = QualifiedName.of("goog.object.create");
private static final QualifiedName GOOG_OBJECT_CREATESET =
QualifiedName.of("goog.object.createSet");
/** Reference to the JS compiler */
private final AbstractCompiler compiler;
/** Whether property renaming is enabled */
private final boolean propertyRenamingEnabled;
/** Whether we can use Es6 syntax */
private final boolean canUseEs6Syntax;
/** Identifies all calls to closure primitive functions */
private class FindPrimitives extends AbstractPostOrderCallback {
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
if (n.isCall()) {
Node fn = n.getFirstChild();
// TODO(user): Once goog.object becomes a goog.module, remove "goog$object$create" and
// related checks.
if (compiler.getCodingConvention().isPropertyRenameFunction(fn)) {
processRenamePropertyCall(n);
} else if (fn.matchesName("goog$object$create")
|| fn.matchesName("module$contents$goog$object_create")
|| GOOG_OBJECT_CREATE.matches(fn)) {
processObjectCreateCall(n);
} else if (fn.matchesName("goog$object$createSet")
|| fn.matchesName("module$contents$goog$object_createSet")
|| GOOG_OBJECT_CREATESET.matches(fn)) {
processObjectCreateSetCall(n);
}
}
}
}
/** @param compiler The AbstractCompiler */
ClosureOptimizePrimitives(
AbstractCompiler compiler, boolean propertyRenamingEnabled, boolean canUseEs6Syntax) {
this.compiler = compiler;
this.propertyRenamingEnabled = propertyRenamingEnabled;
this.canUseEs6Syntax = canUseEs6Syntax;
}
@Override
public void process(Node externs, Node root) {
FindPrimitives pass = new FindPrimitives();
NodeTraversal.traverse(compiler, root, pass);
}
/**
* Converts all of the given call nodes to object literals that are safe to
* do so.
*/
private void processObjectCreateCall(Node callNode) {
Node curParam = callNode.getSecondChild();
if (canOptimizeObjectCreate(curParam)) {
Node objNode = IR.objectlit().srcref(callNode);
while (curParam != null) {
Node keyNode = curParam;
Node valueNode = curParam.getNext();
curParam = valueNode.getNext();
keyNode.detach();
valueNode.detach();
addKeyValueToObjLit(objNode, keyNode, valueNode, NodeUtil.getEnclosingScript(callNode));
}
callNode.replaceWith(objNode);
compiler.reportChangeToEnclosingScope(objNode);
}
}
/**
* Converts all of the given call nodes to object literals that are safe to
* do so.
*/
private void processRenamePropertyCall(Node callNode) {
// Property reflection calls are only needed if
// property renaming is enabled. Replace the call with the
// first argument in all other cases.
if (!propertyRenamingEnabled) {
Node propName = NodeUtil.getArgumentForCallOrNew(callNode, 0);
if (propName != null) {
callNode.replaceWith(propName.detach());
compiler.reportChangeToEnclosingScope(propName);
return;
}
}
Node nameNode = callNode.getFirstChild();
if (nameNode.matchesQualifiedName(NodeUtil.JSC_PROPERTY_NAME_FN)) {
return;
}
Node newTarget = IR.name(NodeUtil.JSC_PROPERTY_NAME_FN).srcref(nameNode);
newTarget.setOriginalName(nameNode.getOriginalQualifiedName());
nameNode.replaceWith(newTarget);
callNode.putBooleanProp(Node.FREE_CALL, true);
compiler.reportChangeToEnclosingScope(callNode);
}
/**
* Returns whether the given call to goog.object.create can be converted to an
* object literal.
*/
private boolean canOptimizeObjectCreate(Node firstParam) {
Node curParam = firstParam;
while (curParam != null) {
if (!isOptimizableKey(curParam)) {
return false;
}
curParam = curParam.getNext();
// Check for an odd number of parameters.
if (curParam == null) {
return false;
}
curParam = curParam.getNext();
}
return true;
}
/**
* Converts all of the given call nodes to object literals that are safe to
* do so.
*/
private void processObjectCreateSetCall(Node callNode) {
Node curParam = callNode.getSecondChild();
if (canOptimizeObjectCreateSet(curParam)) {
Node objNode = IR.objectlit().srcref(callNode);
while (curParam != null) {
Node keyNode = curParam;
Node valueNode = IR.trueNode().srcref(keyNode);
curParam = curParam.getNext();
keyNode.detach();
addKeyValueToObjLit(objNode, keyNode, valueNode, NodeUtil.getEnclosingScript(callNode));
}
callNode.replaceWith(objNode);
compiler.reportChangeToEnclosingScope(objNode);
}
}
/**
* Returns whether the given call to goog.object.createSet can be converted to an object literal.
*/
private boolean canOptimizeObjectCreateSet(Node firstParam) {
if (firstParam != null
&& firstParam.getNext() == null
&& !(firstParam.isNumber() || firstParam.isStringLit())) {
// if there is only one argument, and it's an array, then the method uses the array elements
// as keys. Don't optimize it to {[arr]: true}. We only special-case number and string
// arguments in order to not regress ES5-out behavior
return false;
}
Node curParam = firstParam;
Set keys = new HashSet<>();
while (curParam != null) {
// All keys must be strings or numbers, otherwise we can't optimize the call.
if (!isOptimizableKey(curParam)) {
return false;
}
if (curParam.isStringLit() || curParam.isNumber()) {
String key =
curParam.isStringLit() ? curParam.getString() : numberToString(curParam.getDouble());
if (!keys.add(key)) {
compiler.report(JSError.make(firstParam.getPrevious(), DUPLICATE_SET_MEMBER, key));
return false;
}
}
curParam = curParam.getNext();
}
return true;
}
private void addKeyValueToObjLit(Node objNode, Node keyNode, Node valueNode,
Node scriptNode) {
if (keyNode.isNumber() || keyNode.isStringLit()) {
if (keyNode.isNumber()) {
keyNode = IR.string(numberToString(keyNode.getDouble()))
.srcref(keyNode);
}
// It isn't valid for a `STRING_KEY` to be marked as parenthesized.
keyNode.setIsParenthesized(false);
keyNode.setToken(Token.STRING_KEY);
keyNode.setQuotedStringKey();
objNode.addChildToBack(IR.propdef(keyNode, valueNode));
} else {
objNode.addChildToBack(IR.computedProp(keyNode, valueNode).srcref(keyNode));
NodeUtil.addFeatureToScript(scriptNode, Feature.COMPUTED_PROPERTIES, compiler);
}
}
private boolean isOptimizableKey(Node curParam) {
if (this.canUseEs6Syntax) {
return !NodeUtil.isStatement(curParam);
} else {
// Not ES6, all keys must be strings or numbers.
return curParam.isStringLit() || curParam.isNumber();
}
}
}