TranspilationPasses.java
/*
* Copyright 2016 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.jscomp.parsing.parser.FeatureSet.ES8;
import static com.google.javascript.jscomp.parsing.parser.FeatureSet.ES8_MODULES;
import static com.google.javascript.jscomp.parsing.parser.FeatureSet.ES_NEXT;
import com.google.javascript.jscomp.NodeTraversal.Callback;
import com.google.javascript.jscomp.PassFactory.HotSwapPassFactory;
import com.google.javascript.jscomp.parsing.parser.FeatureSet;
import com.google.javascript.rhino.Node;
import java.util.List;
/**
* Provides a single place to manage transpilation passes.
*/
public class TranspilationPasses {
private TranspilationPasses() {}
public static void addEs6ModulePass(List<PassFactory> passes) {
passes.add(es6RewriteModule);
}
public static void addEs6ModuleToCjsPass(List<PassFactory> passes) {
passes.add(es6RewriteModuleToCjs);
}
public static void addEs2018Passes(List<PassFactory> passes) {
passes.add(rewriteObjRestSpread);
}
public static void addEs2017Passes(List<PassFactory> passes) {
passes.add(rewriteAsyncFunctions);
}
public static void addEs2016Passes(List<PassFactory> passes) {
passes.add(convertEs7ToEs6);
}
/**
* Adds all the early ES6 transpilation passes, which go before the Dart pass.
*
* <p>Includes ES6 features that are straightforward to transpile.
* We won't handle them natively in the rest of the compiler, so we always
* transpile them, even if the output language is also ES6.
*/
public static void addEs6EarlyPasses(List<PassFactory> passes) {
passes.add(es6NormalizeShorthandProperties);
passes.add(es6SuperCheck);
passes.add(es6ConvertSuper);
passes.add(es6RenameVariablesInParamLists);
passes.add(es6SplitVariableDeclarations);
passes.add(es6RewriteDestructuring);
passes.add(es6RewriteArrowFunction);
}
/** Adds all the late ES6 transpilation passes, which go after the Dart pass */
public static void addEs6LatePasses(List<PassFactory> passes) {
// TODO(b/64811685): Delete this method and use addEs6PassesBeforeNTI and addEs6PassesAfterNTI.
passes.add(es6ExtractClasses);
passes.add(es6RewriteClass);
passes.add(earlyConvertEs6ToEs3);
passes.add(lateConvertEs6ToEs3);
passes.add(rewriteBlockScopedFunctionDeclaration);
passes.add(rewriteBlockScopedDeclaration);
passes.add(rewriteGenerators);
}
/**
* Adds all the late ES6 transpilation passes, which go after the Dart pass
* and go before TypeChecking
*
* <p>Includes ES6 features that are best handled natively by the compiler.
* As we convert more passes to handle these features, we will be moving the
* transpilation later in the compilation, and eventually only transpiling
* when the output is lower than ES6.
*/
public static void addEs6PassesBeforeNTI(List<PassFactory> passes) {
passes.add(es6ExtractClasses);
passes.add(es6RewriteClass);
passes.add(earlyConvertEs6ToEs3);
passes.add(rewriteBlockScopedFunctionDeclaration);
passes.add(rewriteBlockScopedDeclaration);
}
/** Adds all transpilation passes that runs after NTI */
public static void addEs6PassesAfterNTI(List<PassFactory> passes) {
passes.add(lateConvertEs6ToEs3);
passes.add(rewriteGenerators);
}
/**
* Adds the pass to inject ES6 polyfills, which goes after the late ES6 passes.
*/
public static void addRewritePolyfillPass(List<PassFactory> passes) {
passes.add(rewritePolyfills);
}
/** Rewrites ES6 modules */
private static final HotSwapPassFactory es6RewriteModule =
new HotSwapPassFactory("es6RewriteModule") {
@Override
protected HotSwapCompilerPass create(AbstractCompiler compiler) {
return new Es6RewriteModules(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES_NEXT;
}
};
/** Rewrites ES6 modules */
private static final PassFactory es6RewriteModuleToCjs =
new PassFactory("es6RewriteModuleToCjs", true) {
@Override
protected CompilerPass create(AbstractCompiler compiler) {
return new Es6RewriteModulesToCommonJsModules(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8_MODULES;
}
};
private static final PassFactory rewriteAsyncFunctions =
new HotSwapPassFactory("rewriteAsyncFunctions") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new RewriteAsyncFunctions(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
private static final PassFactory rewriteObjRestSpread =
new HotSwapPassFactory("rewriteObjRestSpread") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new EsNextToEs8Converter(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES_NEXT;
}
};
private static final PassFactory convertEs7ToEs6 =
new HotSwapPassFactory("convertEs7ToEs6") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es7ToEs6Converter(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
private static final HotSwapPassFactory es6NormalizeShorthandProperties =
new HotSwapPassFactory("es6NormalizeShorthandProperties") {
@Override
protected HotSwapCompilerPass create(AbstractCompiler compiler) {
return new Es6NormalizeShorthandProperties(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
private static final PassFactory es6SuperCheck =
new PassFactory("es6SuperCheck", true) {
@Override
protected CompilerPass create(final AbstractCompiler compiler) {
return new Es6SuperCheck(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory es6ExtractClasses =
new HotSwapPassFactory(PassNames.ES6_EXTRACT_CLASSES) {
@Override
protected HotSwapCompilerPass create(AbstractCompiler compiler) {
return new Es6ExtractClasses(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory es6RewriteClass =
new HotSwapPassFactory("Es6RewriteClass") {
@Override
protected HotSwapCompilerPass create(AbstractCompiler compiler) {
return new Es6RewriteClass(compiler, !compiler.getOptions().inIncrementalCheckMode());
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory es6RewriteDestructuring =
new HotSwapPassFactory("Es6RewriteDestructuring") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es6RewriteDestructuring(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory es6RenameVariablesInParamLists =
new HotSwapPassFactory("Es6RenameVariablesInParamLists") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es6RenameVariablesInParamLists(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory es6RewriteArrowFunction =
new HotSwapPassFactory("Es6RewriteArrowFunction") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es6RewriteArrowFunction(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory rewritePolyfills =
new HotSwapPassFactory("RewritePolyfills") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new RewritePolyfills(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8_MODULES;
}
};
static final HotSwapPassFactory es6SplitVariableDeclarations =
new HotSwapPassFactory("Es6SplitVariableDeclarations") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es6SplitVariableDeclarations(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory es6ConvertSuperConstructorCalls =
new HotSwapPassFactory("es6ConvertSuperConstructorCalls") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es6ConvertSuperConstructorCalls(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory es6ConvertSuper =
new HotSwapPassFactory("es6ConvertSuper") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es6ConvertSuper(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
/**
* Does ES6 to ES3 conversion of Rest, Spread and Symbol.
* There are a few other passes which run before or after this one,
* to convert constructs which are not converted by this pass.
*/
static final HotSwapPassFactory earlyConvertEs6ToEs3 =
new HotSwapPassFactory("earlyConvertEs6") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new EarlyEs6ToEs3Converter(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
/**
* Does the main ES6 to ES3 conversion.
* There are a few other passes which run before this one,
* to convert constructs which are not converted by this pass.
* This pass can run after NTI
*/
static final HotSwapPassFactory lateConvertEs6ToEs3 =
new HotSwapPassFactory("lateConvertEs6") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new LateEs6ToEs3Converter(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory rewriteBlockScopedFunctionDeclaration =
new HotSwapPassFactory("Es6RewriteBlockScopedFunctionDeclaration") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es6RewriteBlockScopedFunctionDeclaration(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory rewriteBlockScopedDeclaration =
new HotSwapPassFactory("Es6RewriteBlockScopedDeclaration") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es6RewriteBlockScopedDeclaration(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
static final HotSwapPassFactory rewriteGenerators =
new HotSwapPassFactory("rewriteGenerators") {
@Override
protected HotSwapCompilerPass create(final AbstractCompiler compiler) {
return new Es6RewriteGenerators(compiler);
}
@Override
protected FeatureSet featureSet() {
return ES8;
}
};
/**
* @param script The SCRIPT node representing a JS file
* @return If the file has any features which are part of ES6 or higher but not part of ES5.
*/
static boolean isScriptEs6OrHigher(Node script) {
FeatureSet features = (FeatureSet) script.getProp(Node.FEATURE_SET);
return features != null && !FeatureSet.ES5.contains(features);
}
/**
* Process checks if the input language contains the provided features, on any JS file that has
* ES6 features.
*
* @param compiler An AbstractCompiler
* @param combinedRoot The combined root for all JS files.
* @param featureSet The features which this check targets.
* @param callbacks The callbacks that should be invoked if a file has ES6 features.
*/
static void processCheck(
AbstractCompiler compiler, Node combinedRoot, FeatureSet featureSet, Callback... callbacks) {
if (compiler.getOptions().getLanguageIn().toFeatureSet().contains(featureSet)) {
for (Node singleRoot : combinedRoot.children()) {
if (isScriptEs6OrHigher(singleRoot)) {
for (Callback callback : callbacks) {
NodeTraversal.traverseEs6(compiler, singleRoot, callback);
}
}
}
}
}
/**
* Hot-swap ES6+ checks if the input language contains the provided features, on any JS file that
* has ES6 features.
*
* @param compiler An AbstractCompiler
* @param scriptRoot The SCRIPT root for the JS file.
* @param featureSet The features which this check targets.
* @param callbacks The callbacks that should be invoked if the file has ES6 features.
*/
static void hotSwapCheck(
AbstractCompiler compiler, Node scriptRoot, FeatureSet featureSet, Callback... callbacks) {
if (compiler.getOptions().getLanguageIn().toFeatureSet().contains(featureSet)) {
if (isScriptEs6OrHigher(scriptRoot)) {
for (Callback callback : callbacks) {
NodeTraversal.traverseEs6(compiler, scriptRoot, callback);
}
}
}
}
/**
* Process transpilations if the input language needs transpilation from certain features, on any
* JS file that has ES6 features.
*
* @param compiler An AbstractCompiler
* @param combinedRoot The combined root for all JS files.
* @param featureSet The features which this pass helps transpile.
* @param callbacks The callbacks that should be invoked if a file has ES6 features.
*/
static void processTranspile(
AbstractCompiler compiler, Node combinedRoot, FeatureSet featureSet, Callback... callbacks) {
if (compiler.getOptions().needsTranspilationFrom(featureSet)) {
for (Node singleRoot : combinedRoot.children()) {
// TODO(lharker): Only run callbacks if the script has features from the given featureSet,
// instead of whenever the script has any ES6+ features. We can't do this until ensuring
// that all passes correctly update the script's associated FeatureSet.
// The same applies in hotSwapTranspile, hotSwapCheck, and processCheck.
if (isScriptEs6OrHigher(singleRoot)) {
for (Callback callback : callbacks) {
singleRoot.putBooleanProp(Node.TRANSPILED, true);
NodeTraversal.traverseEs6(compiler, singleRoot, callback);
}
}
}
}
}
/**
* Hot-swap ES6+ transpilations if the input language needs transpilation from certain features,
* on any JS file that has ES6 features.
*
* @param compiler An AbstractCompiler
* @param scriptRoot The SCRIPT root for the JS file.
* @param featureSet The features which this pass helps transpile.
* @param callbacks The callbacks that should be invoked if the file has ES6 features.
*/
static void hotSwapTranspile(
AbstractCompiler compiler, Node scriptRoot, FeatureSet featureSet, Callback... callbacks) {
if (compiler.getOptions().needsTranspilationFrom(featureSet)) {
if (isScriptEs6OrHigher(scriptRoot)) {
for (Callback callback : callbacks) {
scriptRoot.putBooleanProp(Node.TRANSPILED, true);
NodeTraversal.traverseEs6(compiler, scriptRoot, callback);
}
}
}
}
public static void addPostCheckPasses(List<PassFactory> passes) {
passes.add(es6ConvertSuperConstructorCalls);
}
}