001 /*
002 * Copyright 2010-2013 JetBrains s.r.o.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017 package org.jetbrains.k2js.translate.expression;
018
019
020 import com.google.dart.compiler.backend.js.ast.JsFunction;
021 import com.google.dart.compiler.backend.js.ast.JsName;
022 import com.google.dart.compiler.backend.js.ast.JsParameter;
023 import com.google.dart.compiler.backend.js.ast.JsPropertyInitializer;
024 import com.google.dart.compiler.backend.js.ast.metadata.MetadataPackage;
025 import com.intellij.util.SmartList;
026 import org.jetbrains.annotations.NotNull;
027 import org.jetbrains.annotations.Nullable;
028 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
029 import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
030 import org.jetbrains.jet.lang.descriptors.Modality;
031 import org.jetbrains.jet.lang.descriptors.ValueParameterDescriptor;
032 import org.jetbrains.jet.lang.psi.JetDeclarationWithBody;
033 import org.jetbrains.jet.lang.psi.JetFunctionLiteralExpression;
034 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
035 import org.jetbrains.k2js.translate.context.AliasingContext;
036 import org.jetbrains.k2js.translate.context.Namer;
037 import org.jetbrains.k2js.translate.context.TranslationContext;
038 import org.jetbrains.k2js.translate.general.AbstractTranslator;
039 import org.jetbrains.k2js.translate.utils.TranslationUtils;
040
041 import java.util.Collections;
042 import java.util.List;
043
044 import static org.jetbrains.k2js.translate.utils.BindingUtils.getFunctionDescriptor;
045 import static org.jetbrains.k2js.translate.utils.ErrorReportingUtils.message;
046 import static org.jetbrains.k2js.translate.utils.FunctionBodyTranslator.translateFunctionBody;
047 import static org.jetbrains.k2js.translate.utils.JsAstUtils.setParameters;
048
049 public final class FunctionTranslator extends AbstractTranslator {
050 @NotNull
051 public static FunctionTranslator newInstance(@NotNull JetDeclarationWithBody function,
052 @NotNull TranslationContext context) {
053 return new FunctionTranslator(function, context);
054 }
055
056 @NotNull
057 private final TranslationContext functionBodyContext;
058 @NotNull
059 private final JetDeclarationWithBody functionDeclaration;
060 @Nullable
061 private JsName extensionFunctionReceiverName;
062 @NotNull
063 private final JsFunction functionObject;
064 @NotNull
065 private final FunctionDescriptor descriptor;
066
067 private FunctionTranslator(@NotNull JetDeclarationWithBody functionDeclaration, @NotNull TranslationContext context) {
068 super(context);
069 this.descriptor = getFunctionDescriptor(context.bindingContext(), functionDeclaration);
070 this.functionDeclaration = functionDeclaration;
071 this.functionObject = context().getFunctionObject(descriptor);
072 assert this.functionObject.getParameters().isEmpty()
073 : message(descriptor, "Function " + functionDeclaration.getText() + " processed for the second time.");
074 //NOTE: it's important we compute the context before we start the computation
075 this.functionBodyContext = getFunctionBodyContext();
076 }
077
078 @NotNull
079 private TranslationContext getFunctionBodyContext() {
080 AliasingContext aliasingContext;
081 if (isExtensionFunction()) {
082 DeclarationDescriptor expectedReceiverDescriptor = descriptor.getExtensionReceiverParameter();
083 assert expectedReceiverDescriptor != null;
084 extensionFunctionReceiverName = functionObject.getScope().declareName(Namer.getReceiverParameterName());
085 //noinspection ConstantConditions
086 aliasingContext = context().aliasingContext().inner(expectedReceiverDescriptor, extensionFunctionReceiverName.makeRef());
087 }
088 else {
089 aliasingContext = null;
090 }
091 return context().newFunctionBody(functionObject, aliasingContext);
092 }
093
094 @NotNull
095 public JsPropertyInitializer translateAsEcma5PropertyDescriptor() {
096 generateFunctionObject();
097 return TranslationUtils.translateFunctionAsEcma5PropertyDescriptor(functionObject, descriptor, context());
098 }
099
100 @NotNull
101 public JsPropertyInitializer translateAsMethod() {
102 JsName functionName = context().getNameForDescriptor(descriptor);
103 generateFunctionObject();
104 return new JsPropertyInitializer(functionName.makeRef(), functionObject);
105 }
106
107 private void generateFunctionObject() {
108 setParameters(functionObject, translateParameters());
109 translateBody();
110 }
111
112 private void translateBody() {
113 if (!functionDeclaration.hasBody()) {
114 assert descriptor.getModality().equals(Modality.ABSTRACT);
115 return;
116 }
117 functionObject.getBody().getStatements().addAll(translateFunctionBody(descriptor, functionDeclaration, functionBodyContext).getStatements());
118 }
119
120 @NotNull
121 private List<JsParameter> translateParameters() {
122 if (extensionFunctionReceiverName == null && descriptor.getValueParameters().isEmpty()) {
123 return Collections.emptyList();
124 }
125
126 List<JsParameter> jsParameters = new SmartList<JsParameter>();
127 mayBeAddThisParameterForExtensionFunction(jsParameters);
128 addParameters(jsParameters, descriptor, context());
129 return jsParameters;
130 }
131
132 public static void addParameters(List<JsParameter> list, FunctionDescriptor descriptor, TranslationContext context) {
133 for (ValueParameterDescriptor valueParameter : descriptor.getValueParameters()) {
134 JsParameter jsParameter = new JsParameter(context.getNameForDescriptor(valueParameter));
135 MetadataPackage.setHasDefaultValue(jsParameter, valueParameter.hasDefaultValue());
136 list.add(jsParameter);
137 }
138 }
139
140 private void mayBeAddThisParameterForExtensionFunction(@NotNull List<JsParameter> jsParameters) {
141 if (isExtensionFunction()) {
142 assert extensionFunctionReceiverName != null;
143 jsParameters.add(new JsParameter(extensionFunctionReceiverName));
144 }
145 }
146
147 private boolean isExtensionFunction() {
148 return DescriptorUtils.isExtension(descriptor) && !(functionDeclaration instanceof JetFunctionLiteralExpression);
149 }
150 }