001    /*
002     * Copyright 2010-2015 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.kotlin.js.translate.operation;
018    
019    import com.google.dart.compiler.backend.js.ast.JsBinaryOperation;
020    import com.google.dart.compiler.backend.js.ast.JsBinaryOperator;
021    import com.google.dart.compiler.backend.js.ast.JsExpression;
022    import com.google.dart.compiler.util.AstUtil;
023    import com.intellij.psi.tree.IElementType;
024    import org.jetbrains.annotations.NotNull;
025    import org.jetbrains.kotlin.descriptors.CallableDescriptor;
026    import org.jetbrains.kotlin.js.translate.context.TemporaryVariable;
027    import org.jetbrains.kotlin.js.translate.context.TranslationContext;
028    import org.jetbrains.kotlin.js.translate.general.AbstractTranslator;
029    import org.jetbrains.kotlin.js.translate.reference.AccessTranslator;
030    import org.jetbrains.kotlin.psi.KtExpression;
031    import org.jetbrains.kotlin.psi.KtUnaryExpression;
032    import org.jetbrains.kotlin.resolve.calls.tasks.DynamicCallsKt;
033    import org.jetbrains.kotlin.types.expressions.OperatorConventions;
034    
035    import static org.jetbrains.kotlin.js.translate.reference.AccessTranslationUtils.getAccessTranslator;
036    import static org.jetbrains.kotlin.js.translate.utils.BindingUtils.getCallableDescriptorForOperationExpression;
037    import static org.jetbrains.kotlin.js.translate.utils.PsiUtils.getBaseExpression;
038    import static org.jetbrains.kotlin.js.translate.utils.PsiUtils.isPrefix;
039    import static org.jetbrains.kotlin.js.translate.utils.TranslationUtils.hasCorrespondingFunctionIntrinsic;
040    
041    // TODO: provide better increment translator logic
042    public abstract class IncrementTranslator extends AbstractTranslator {
043    
044        public static boolean isIncrement(IElementType operationToken) {
045            //noinspection SuspiciousMethodCalls
046            return OperatorConventions.INCREMENT_OPERATIONS.contains(operationToken);
047        }
048    
049        @NotNull
050        public static JsExpression translate(@NotNull KtUnaryExpression expression,
051                                             @NotNull TranslationContext context) {
052            if (hasCorrespondingFunctionIntrinsic(context, expression) || isDynamic(context, expression)) {
053                return IntrinsicIncrementTranslator.doTranslate(expression, context);
054            }
055            return (new OverloadedIncrementTranslator(expression, context)).translateIncrementExpression();
056        }
057    
058        @NotNull
059        protected final KtUnaryExpression expression;
060        @NotNull
061        protected final AccessTranslator accessTranslator;
062    
063        protected IncrementTranslator(@NotNull KtUnaryExpression expression,
064                                      @NotNull TranslationContext context) {
065            super(context);
066            this.expression = expression;
067            KtExpression baseExpression = getBaseExpression(expression);
068            this.accessTranslator = getAccessTranslator(baseExpression, context()).getCached();
069        }
070    
071        @NotNull
072        protected JsExpression translateIncrementExpression() {
073            if (isPrefix(expression)) {
074                return asPrefix();
075            }
076            return asPostfix();
077        }
078    
079        //TODO: decide if this expression can be optimised in case of direct access (not property)
080        @NotNull
081        private JsExpression asPrefix() {
082            // code fragment: expr(a++)
083            // generate: expr(a = a.inc(), a)
084            JsExpression getExpression = accessTranslator.translateAsGet();
085            JsExpression reassignment = variableReassignment(getExpression);
086            JsExpression getNewValue = accessTranslator.translateAsGet();
087            return new JsBinaryOperation(JsBinaryOperator.COMMA, reassignment, getNewValue);
088        }
089    
090        //TODO: decide if this expression can be optimised in case of direct access (not property)
091        @NotNull
092        private JsExpression asPostfix() {
093            // code fragment: expr(a++)
094            // generate: expr( (t1 = a, t2 = t1, a = t1.inc(), t2) )
095            TemporaryVariable t1 = context().declareTemporary(accessTranslator.translateAsGet());
096            TemporaryVariable t2 = context().declareTemporary(t1.reference());
097            JsExpression variableReassignment = variableReassignment(t1.reference());
098            return AstUtil.newSequence(t1.assignmentExpression(), t2.assignmentExpression(),
099                                       variableReassignment, t2.reference());
100        }
101    
102        @NotNull
103        private JsExpression variableReassignment(@NotNull JsExpression toCallMethodUpon) {
104            JsExpression overloadedMethodCallOnPropertyGetter = operationExpression(toCallMethodUpon);
105            return accessTranslator.translateAsSet(overloadedMethodCallOnPropertyGetter);
106        }
107    
108        @NotNull
109        abstract JsExpression operationExpression(@NotNull JsExpression receiver);
110    
111        private static boolean isDynamic(TranslationContext context, KtUnaryExpression expression) {
112            CallableDescriptor operationDescriptor = getCallableDescriptorForOperationExpression(context.bindingContext(), expression);
113            return DynamicCallsKt.isDynamic(operationDescriptor);
114        }
115    }