com.google.javascript.jscomp.TranspilationPasses Maven / Gradle / Ivy
/*
* 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 com.google.javascript.jscomp.Es6RewriteDestructuring.ObjectDestructuringRewriteMode;
import com.google.javascript.jscomp.parsing.parser.FeatureSet;
import com.google.javascript.jscomp.parsing.parser.FeatureSet.Feature;
import com.google.javascript.rhino.Node;
/** Provides a single place to manage transpilation passes. */
public class TranspilationPasses {
private TranspilationPasses() {}
public static void addEs6ModulePass(
PassListBuilder passes,
final PreprocessorSymbolTable.CachedInstanceFactory preprocessorTableFactory) {
passes.maybeAdd(
PassFactory.builder()
.setName("es6RewriteModule")
.setInternalFactory(
(compiler) -> {
preprocessorTableFactory.maybeInitialize(compiler);
return new Es6RewriteModules(
compiler,
compiler.getModuleMetadataMap(),
compiler.getModuleMap(),
preprocessorTableFactory.getInstanceOrNull(),
compiler.getTopScope(),
compiler.getOptions().getChunkOutputType());
})
.build());
}
public static void addTranspilationRuntimeLibraries(PassListBuilder passes) {
// Inject runtime libraries needed for the transpilation we will have to do. Should run before
// typechecking.
passes.maybeAdd(injectTranspilationRuntimeLibraries);
}
public static void addEs6ModuleToCjsPass(PassListBuilder passes) {
passes.maybeAdd(es6RewriteModuleToCjs);
}
public static void addEs6RewriteImportPathPass(PassListBuilder passes) {
passes.maybeAdd(es6RelativizeImportPaths);
}
/** Adds transpilation passes that should run at the beginning of the optimization phase */
public static void addEarlyOptimizationTranspilationPasses(
PassListBuilder passes, CompilerOptions options) {
// Note that we detect feature by feature rather than by yearly languages
// in order to handle FeatureSet.BROWSER_2020, which is ES2019 without the new RegExp features.
// However, RegExp features are not transpiled, and this does not imply that we allow arbitrary
// selection of features to transpile. They still must be done in chronological order based on.
// This greatly simplifies testing and the requirements for the transpilation passes.
if (options.needsTranspilationOf(Feature.REGEXP_FLAG_D)) {
passes.maybeAdd(
createFeatureRemovalPass(
"markEs2022FeaturesNotRequiringTranspilationAsRemoved", Feature.REGEXP_FLAG_D));
}
if (options.needsTranspilationOf(Feature.PUBLIC_CLASS_FIELDS)
|| options.needsTranspilationOf(Feature.CLASS_STATIC_BLOCK)) {
passes.maybeAdd(rewriteClassMembers);
}
if (options.needsTranspilationOf(Feature.NUMERIC_SEPARATOR)) {
// Numeric separators are flagged as present by the parser,
// but never actually represented in the AST.
// The only thing we need to do is mark them as not present in the AST.
passes.maybeAdd(
createFeatureRemovalPass("markNumericSeparatorsRemoved", Feature.NUMERIC_SEPARATOR));
}
if (options.needsTranspilationOf(Feature.LOGICAL_ASSIGNMENT)) {
passes.maybeAdd(rewriteLogicalAssignmentOperatorsPass);
}
if (options.needsTranspilationOf(Feature.OPTIONAL_CHAINING)) {
passes.maybeAdd(rewriteOptionalChainingOperator);
}
if (options.needsTranspilationOf(Feature.BIGINT)) {
passes.maybeAdd(reportBigIntLiteralTranspilationUnsupported);
}
if (options.needsTranspilationOf(Feature.NULL_COALESCE_OP)) {
passes.maybeAdd(rewriteNullishCoalesceOperator);
}
if (options.needsTranspilationOf(Feature.OPTIONAL_CATCH_BINDING)) {
passes.maybeAdd(rewriteCatchWithNoBinding);
}
if (options.needsTranspilationOf(Feature.FOR_AWAIT_OF)
|| options.needsTranspilationOf(Feature.ASYNC_GENERATORS)) {
passes.maybeAdd(rewriteAsyncIteration);
}
if (options.needsTranspilationOf(Feature.OBJECT_LITERALS_WITH_SPREAD)
|| options.needsTranspilationOf(Feature.OBJECT_PATTERN_REST)) {
passes.maybeAdd(rewriteObjectSpread);
if (!options.needsTranspilationOf(Feature.OBJECT_DESTRUCTURING)
&& options.needsTranspilationOf(Feature.OBJECT_PATTERN_REST)) {
// We only need to transpile away object destructuring that uses `...`, rather than
// all destructuring.
// For this to work correctly for object destructuring in parameter lists and variable
// declarations, we need to normalize them a bit first.
passes.maybeAdd(es6RenameVariablesInParamLists);
passes.maybeAdd(es6SplitVariableDeclarations);
passes.maybeAdd(
getEs6RewriteDestructuring(ObjectDestructuringRewriteMode.REWRITE_OBJECT_REST));
}
}
if (options.needsTranspilationOf(Feature.TRAILING_COMMA_IN_PARAM_LIST)) {
passes.maybeAdd(removeTrailingCommaFromParamList);
}
if (options.needsTranspilationOf(Feature.ASYNC_FUNCTIONS)) {
passes.maybeAdd(rewriteAsyncFunctions);
}
if (options.needsTranspilationOf(Feature.EXPONENT_OP)) {
passes.maybeAdd(rewriteExponentialOperator);
}
if (options.needsTranspilationFrom(
FeatureSet.BARE_MINIMUM.with(
Feature.BINARY_LITERALS,
Feature.OCTAL_LITERALS,
Feature.REGEXP_FLAG_U,
Feature.REGEXP_FLAG_Y))) {
// Binary and octal literals are effectively transpiled by the parser.
// There's no transpilation we can do for the new regexp flags.
passes.maybeAdd(
createFeatureRemovalPass(
"markEs6FeaturesNotRequiringTranspilationAsRemoved",
Feature.BINARY_LITERALS,
Feature.OCTAL_LITERALS,
Feature.REGEXP_FLAG_U,
Feature.REGEXP_FLAG_Y));
}
if (options.needsTranspilationOf(Feature.EXTENDED_OBJECT_LITERALS)) {
passes.maybeAdd(es6NormalizeShorthandProperties);
}
if (options.needsTranspilationOf(Feature.CLASSES)) {
passes.maybeAdd(es6RewriteClassExtends);
passes.maybeAdd(es6ConvertSuper);
}
if (options.needsTranspilationFrom(
FeatureSet.BARE_MINIMUM.with(Feature.ARRAY_DESTRUCTURING, Feature.OBJECT_DESTRUCTURING))) {
passes.maybeAdd(es6RenameVariablesInParamLists);
passes.maybeAdd(es6SplitVariableDeclarations);
passes.maybeAdd(
getEs6RewriteDestructuring(ObjectDestructuringRewriteMode.REWRITE_ALL_OBJECT_PATTERNS));
}
if (options.needsTranspilationOf(Feature.NEW_TARGET)) {
passes.maybeAdd(rewriteNewDotTarget);
}
if (options.needsTranspilationOf(Feature.ARROW_FUNCTIONS)) {
passes.maybeAdd(es6RewriteArrowFunction);
}
if (options.needsTranspilationOf(Feature.CLASSES)) {
passes.maybeAdd(es6ExtractClasses);
passes.maybeAdd(es6RewriteClass);
}
if (options.needsTranspilationFrom(
FeatureSet.BARE_MINIMUM.with(Feature.REST_PARAMETERS, Feature.SPREAD_EXPRESSIONS))) {
passes.maybeAdd(es6RewriteRestAndSpread);
}
if (options.needsTranspilationFrom(
FeatureSet.BARE_MINIMUM.with(
Feature.COMPUTED_PROPERTIES, Feature.MEMBER_DECLARATIONS, Feature.TEMPLATE_LITERALS))) {
passes.maybeAdd(lateConvertEs6ToEs3);
}
if (options.needsTranspilationOf(Feature.FOR_OF)) {
passes.maybeAdd(es6ForOf);
}
if (options.needsTranspilationOf(Feature.BLOCK_SCOPED_FUNCTION_DECLARATION)) {
passes.maybeAdd(rewriteBlockScopedFunctionDeclaration);
}
if (options.needsTranspilationFrom(
FeatureSet.BARE_MINIMUM.with(Feature.LET_DECLARATIONS, Feature.CONST_DECLARATIONS))) {
passes.maybeAdd(rewriteBlockScopedDeclaration);
}
if (options.needsTranspilationOf(Feature.GENERATORS)) {
passes.maybeAdd(rewriteGenerators);
}
}
/** Adds the pass to inject ES2015 polyfills, which goes after the late ES2015 passes. */
public static void addRewritePolyfillPass(PassListBuilder passes) {
passes.maybeAdd(rewritePolyfills);
}
/** Rewrites ES6 modules */
private static final PassFactory es6RewriteModuleToCjs =
PassFactory.builder()
.setName("es6RewriteModuleToCjs")
.setInternalFactory(Es6RewriteModulesToCommonJsModules::new)
.build();
/** Rewrites ES6 modules import paths to be browser compliant */
private static final PassFactory es6RelativizeImportPaths =
PassFactory.builder()
.setName("es6RelativizeImportPaths")
.setInternalFactory(Es6RelativizeImportPaths::new)
.build();
private static final PassFactory rewriteAsyncFunctions =
PassFactory.builder()
.setName("rewriteAsyncFunctions")
.setInternalFactory(RewriteAsyncFunctions::create)
.build();
private static final PassFactory rewriteAsyncIteration =
PassFactory.builder()
.setName("rewriteAsyncIteration")
.setInternalFactory(RewriteAsyncIteration::create)
.build();
private static final PassFactory rewriteObjectSpread =
PassFactory.builder()
.setName("rewriteObjectSpread")
.setInternalFactory(RewriteObjectSpread::new)
.build();
private static final PassFactory rewriteCatchWithNoBinding =
PassFactory.builder()
.setName("rewriteCatchWithNoBinding")
.setInternalFactory(RewriteCatchWithNoBinding::new)
.build();
private static final PassFactory rewriteNewDotTarget =
PassFactory.builder()
.setName("rewriteNewDotTarget")
.setInternalFactory(RewriteNewDotTarget::new)
.build();
private static final PassFactory removeTrailingCommaFromParamList =
PassFactory.builder()
.setName("removeTrailingCommaFromParamList")
.setInternalFactory(RemoveTrailingCommaFromParamList::new)
.build();
private static final PassFactory reportBigIntLiteralTranspilationUnsupported =
PassFactory.builder()
.setName("reportBigIntTranspilationUnsupported")
.setInternalFactory(ReportBigIntLiteralTranspilationUnsupported::new)
.build();
private static final PassFactory rewriteExponentialOperator =
PassFactory.builder()
.setName("rewriteExponentialOperator")
.setInternalFactory(Es7RewriteExponentialOperator::new)
.build();
private static final PassFactory es6NormalizeShorthandProperties =
PassFactory.builder()
.setName("es6NormalizeShorthandProperties")
.setInternalFactory(Es6NormalizeShorthandProperties::new)
.build();
static final PassFactory es6RewriteClassExtends =
PassFactory.builder()
.setName(PassNames.ES6_REWRITE_CLASS_EXTENDS)
.setInternalFactory(Es6RewriteClassExtendsExpressions::new)
.build();
static final PassFactory es6ExtractClasses =
PassFactory.builder()
.setName(PassNames.ES6_EXTRACT_CLASSES)
.setInternalFactory(Es6ExtractClasses::new)
.build();
static final PassFactory rewriteClassMembers =
PassFactory.builder()
.setName("RewriteClassMembers")
.setInternalFactory(RewriteClassMembers::new)
.build();
static final PassFactory es6RewriteClass =
PassFactory.builder()
.setName("Es6RewriteClass")
.setInternalFactory(Es6RewriteClass::new)
.build();
static final PassFactory getEs6RewriteDestructuring(ObjectDestructuringRewriteMode rewriteMode) {
return PassFactory.builder()
.setName("Es6RewriteDestructuring")
.setInternalFactory(
(compiler) ->
new Es6RewriteDestructuring.Builder(compiler)
.setDestructuringRewriteMode(rewriteMode)
.build())
.build();
}
static final PassFactory es6RenameVariablesInParamLists =
PassFactory.builder()
.setName("Es6RenameVariablesInParamLists")
.setInternalFactory(Es6RenameVariablesInParamLists::new)
.build();
static final PassFactory es6RewriteArrowFunction =
PassFactory.builder()
.setName("Es6RewriteArrowFunction")
.setInternalFactory(Es6RewriteArrowFunction::new)
.build();
static final PassFactory rewritePolyfills =
PassFactory.builder()
.setName("RewritePolyfills")
.setInternalFactory(
(compiler) ->
new RewritePolyfills(
compiler,
compiler.getOptions().getRewritePolyfills(),
compiler.getOptions().getIsolatePolyfills()))
.build();
static final PassFactory es6SplitVariableDeclarations =
PassFactory.builder()
.setName("Es6SplitVariableDeclarations")
.setInternalFactory(Es6SplitVariableDeclarations::new)
.build();
static final PassFactory es6ConvertSuper =
PassFactory.builder()
.setName("es6ConvertSuper")
.setInternalFactory(Es6ConvertSuper::new)
.build();
/** Injects runtime library code needed for transpiled ES2015+ code. */
static final PassFactory injectTranspilationRuntimeLibraries =
PassFactory.builder()
.setName("es6InjectRuntimeLibraries")
.setInternalFactory(InjectTranspilationRuntimeLibraries::new)
.build();
/** Transpiles REST parameters and SPREAD in both array literals and function calls. */
static final PassFactory es6RewriteRestAndSpread =
PassFactory.builder()
.setName("es6RewriteRestAndSpread")
.setInternalFactory(Es6RewriteRestAndSpread::new)
.build();
/**
* Does the main ES2015 to ES3 conversion. There are a few other passes which run before this one,
* to convert constructs which are not converted by this pass.
*/
static final PassFactory lateConvertEs6ToEs3 =
PassFactory.builder()
.setName("lateConvertEs6")
.setInternalFactory(LateEs6ToEs3Converter::new)
.build();
static final PassFactory es6ForOf =
PassFactory.builder().setName("es6ForOf").setInternalFactory(Es6ForOfConverter::new).build();
static final PassFactory rewriteBlockScopedFunctionDeclaration =
PassFactory.builder()
.setName("Es6RewriteBlockScopedFunctionDeclaration")
.setInternalFactory(Es6RewriteBlockScopedFunctionDeclaration::new)
.build();
static final PassFactory rewriteBlockScopedDeclaration =
PassFactory.builder()
.setName("Es6RewriteBlockScopedDeclaration")
.setInternalFactory(Es6RewriteBlockScopedDeclaration::new)
.build();
static final PassFactory rewriteGenerators =
PassFactory.builder()
.setName("rewriteGenerators")
.setInternalFactory(Es6RewriteGenerators::new)
.build();
static final PassFactory rewriteLogicalAssignmentOperatorsPass =
PassFactory.builder()
.setName("rewriteLogicalAssignmentOperatorsPass")
.setInternalFactory(RewriteLogicalAssignmentOperatorsPass::new)
.build();
static final PassFactory rewriteOptionalChainingOperator =
PassFactory.builder()
.setName("rewriteOptionalChainingOperator")
.setInternalFactory(RewriteOptionalChainingOperator::new)
.build();
static final PassFactory rewriteNullishCoalesceOperator =
PassFactory.builder()
.setName("rewriteNullishCoalesceOperator")
.setInternalFactory(RewriteNullishCoalesceOperator::new)
.build();
/**
* @param script The SCRIPT node representing a JS file
* @return If the file has any features not in {@code supportedFeatures}
*/
static boolean doesScriptHaveUnsupportedFeatures(Node script, FeatureSet supportedFeatures) {
FeatureSet features = NodeUtil.getFeatureSetOfScript(script);
return features != null && !supportedFeatures.contains(features);
}
/**
* Process transpilations if the input language needs transpilation from certain features, on any
* JS file that has features not present in the compiler's output language mode.
*
* @param compiler An AbstractCompiler
* @param combinedRoot The combined root for all JS files.
* @param featureSet Ignored
* @param callbacks The callbacks that should be invoked if a file has ES2015 features.
* @deprecated Please use a regular NodeTraversal object directly, using `shouldTraverse` to skip
* SCRIPT node if desired.
*/
@Deprecated
static void processTranspile(
AbstractCompiler compiler,
Node combinedRoot,
FeatureSet featureSet,
NodeTraversal.Callback... callbacks) {
FeatureSet languageOutFeatures = compiler.getOptions().getOutputFeatureSet();
for (Node singleRoot = combinedRoot.getFirstChild();
singleRoot != null;
singleRoot = singleRoot.getNext()) {
// Only run the transpilation if this file has features not in the compiler's target output
// language. For example, if this file is purely ES6 and the output language is ES6, don't
// run any transpilation passes on it.
// TODO(lharker): We could save time by being more selective about what files we transpile.
// e.g. if a file has async functions but not `**`, don't run `**` transpilation on it.
// Right now we know what features were in a file at parse time, but not what features were
// added to that file by other transpilation passes.
if (doesScriptHaveUnsupportedFeatures(singleRoot, languageOutFeatures)) {
for (NodeTraversal.Callback callback : callbacks) {
singleRoot.putBooleanProp(Node.TRANSPILED, true);
NodeTraversal.traverse(compiler, singleRoot, callback);
}
}
}
}
static void maybeMarkFeaturesAsTranspiledAway(
AbstractCompiler compiler, FeatureSet transpiledFeatures) {
// We don't bother to do this if the compiler has halting errors, which avoids unnecessary
// warnings from AstValidator warning that the features are still there.
if (!compiler.hasHaltingErrors()) {
compiler.setFeatureSet(compiler.getFeatureSet().without(transpiledFeatures));
}
}
static void maybeMarkFeaturesAsTranspiledAway(
AbstractCompiler compiler, Feature transpiledFeature, Feature... moreTranspiledFeatures) {
if (!compiler.hasHaltingErrors()) {
compiler.setFeatureSet(
compiler.getFeatureSet().without(transpiledFeature, moreTranspiledFeatures));
}
}
/**
* Returns a pass that just removes features from the AST FeatureSet.
*
* Doing this indicates that the AST no longer contains uses of the features, or that they are
* no longer of concern for some other reason.
*/
private static PassFactory createFeatureRemovalPass(
String passName, final Feature featureToRemove, final Feature... moreFeaturesToRemove) {
return PassFactory.builder()
.setName(passName)
.setInternalFactory(
(compiler) ->
((Node externs, Node root) ->
maybeMarkFeaturesAsTranspiledAway(
compiler, featureToRemove, moreFeaturesToRemove)))
.build();
}
}