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.jet.lang.types.expressions;
018
019 import com.intellij.openapi.util.Ref;
020 import com.intellij.psi.tree.IElementType;
021 import org.jetbrains.annotations.NotNull;
022 import org.jetbrains.annotations.Nullable;
023 import org.jetbrains.jet.lang.psi.*;
024 import org.jetbrains.jet.lang.resolve.BindingContext;
025 import org.jetbrains.jet.lang.resolve.calls.context.ResolutionContext;
026 import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowInfo;
027 import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValue;
028 import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValueFactory;
029 import org.jetbrains.jet.lang.types.ErrorUtils;
030 import org.jetbrains.jet.lang.types.JetType;
031 import org.jetbrains.jet.lang.types.JetTypeInfo;
032 import org.jetbrains.jet.lang.types.TypeUtils;
033 import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
034 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
035 import org.jetbrains.jet.lexer.JetTokens;
036
037 import static org.jetbrains.jet.lang.diagnostics.Errors.*;
038 import static org.jetbrains.jet.lang.resolve.BindingContext.AUTOCAST;
039
040 public class DataFlowUtils {
041 private DataFlowUtils() {
042 }
043
044 @NotNull
045 public static DataFlowInfo extractDataFlowInfoFromCondition(@Nullable JetExpression condition, final boolean conditionValue, final ExpressionTypingContext context) {
046 if (condition == null) return context.dataFlowInfo;
047 final Ref<DataFlowInfo> result = new Ref<DataFlowInfo>(null);
048 condition.accept(new JetVisitorVoid() {
049 @Override
050 public void visitIsExpression(JetIsExpression expression) {
051 if (conditionValue && !expression.isNegated() || !conditionValue && expression.isNegated()) {
052 result.set(context.trace.get(BindingContext.DATAFLOW_INFO_AFTER_CONDITION, expression));
053 }
054 }
055
056 @Override
057 public void visitBinaryExpression(JetBinaryExpression expression) {
058 IElementType operationToken = expression.getOperationToken();
059 if (OperatorConventions.BOOLEAN_OPERATIONS.containsKey(operationToken)) {
060 DataFlowInfo dataFlowInfo = extractDataFlowInfoFromCondition(expression.getLeft(), conditionValue, context);
061 JetExpression expressionRight = expression.getRight();
062 if (expressionRight != null) {
063 DataFlowInfo rightInfo = extractDataFlowInfoFromCondition(expressionRight, conditionValue, context);
064 boolean and = operationToken == JetTokens.ANDAND;
065 if (and == conditionValue) { // this means: and && conditionValue || !and && !conditionValue
066 dataFlowInfo = dataFlowInfo.and(rightInfo);
067 }
068 else {
069 dataFlowInfo = dataFlowInfo.or(rightInfo);
070 }
071 }
072 result.set(dataFlowInfo);
073 }
074 else {
075 JetExpression left = expression.getLeft();
076 if (left == null) return;
077 JetExpression right = expression.getRight();
078 if (right == null) return;
079
080 JetType lhsType = context.trace.getBindingContext().get(BindingContext.EXPRESSION_TYPE, left);
081 if (lhsType == null) return;
082 JetType rhsType = context.trace.getBindingContext().get(BindingContext.EXPRESSION_TYPE, right);
083 if (rhsType == null) return;
084
085 BindingContext bindingContext = context.trace.getBindingContext();
086 DataFlowValue leftValue = DataFlowValueFactory.INSTANCE.createDataFlowValue(left, lhsType, bindingContext);
087 DataFlowValue rightValue = DataFlowValueFactory.INSTANCE.createDataFlowValue(right, rhsType, bindingContext);
088
089 Boolean equals = null;
090 if (operationToken == JetTokens.EQEQ || operationToken == JetTokens.EQEQEQ) {
091 equals = true;
092 }
093 else if (operationToken == JetTokens.EXCLEQ || operationToken == JetTokens.EXCLEQEQEQ) {
094 equals = false;
095 }
096 if (equals != null) {
097 if (equals == conditionValue) { // this means: equals && conditionValue || !equals && !conditionValue
098 result.set(context.dataFlowInfo.equate(leftValue, rightValue));
099 }
100 else {
101 result.set(context.dataFlowInfo.disequate(leftValue, rightValue));
102 }
103
104 }
105 }
106 }
107
108 @Override
109 public void visitUnaryExpression(JetUnaryExpression expression) {
110 IElementType operationTokenType = expression.getOperationReference().getReferencedNameElementType();
111 if (operationTokenType == JetTokens.EXCL) {
112 JetExpression baseExpression = expression.getBaseExpression();
113 if (baseExpression != null) {
114 result.set(extractDataFlowInfoFromCondition(baseExpression, !conditionValue, context));
115 }
116 }
117 }
118
119 @Override
120 public void visitParenthesizedExpression(JetParenthesizedExpression expression) {
121 JetExpression body = expression.getExpression();
122 if (body != null) {
123 body.accept(this);
124 }
125 }
126 });
127 if (result.get() == null) {
128 return context.dataFlowInfo;
129 }
130 return context.dataFlowInfo.and(result.get());
131 }
132
133 @NotNull
134 public static JetTypeInfo checkType(@Nullable JetType expressionType, @NotNull JetExpression expression, @NotNull ResolutionContext context, @NotNull DataFlowInfo dataFlowInfo) {
135 return JetTypeInfo.create(checkType(expressionType, expression, context), dataFlowInfo);
136 }
137
138 @Nullable
139 public static JetType checkType(@Nullable JetType expressionType, @NotNull JetExpression expression, @NotNull ResolutionContext context) {
140 if (context.expectedType != TypeUtils.NO_EXPECTED_TYPE) {
141 context.trace.record(BindingContext.EXPECTED_EXPRESSION_TYPE, expression, context.expectedType);
142 }
143
144 if (expressionType == null || context.expectedType == null || context.expectedType == TypeUtils.NO_EXPECTED_TYPE ||
145 JetTypeChecker.INSTANCE.isSubtypeOf(expressionType, context.expectedType)) {
146 return expressionType;
147 }
148
149 DataFlowValue dataFlowValue = DataFlowValueFactory.INSTANCE.createDataFlowValue(expression, expressionType, context.trace.getBindingContext());
150 for (JetType possibleType : context.dataFlowInfo.getPossibleTypes(dataFlowValue)) {
151 if (JetTypeChecker.INSTANCE.isSubtypeOf(possibleType, context.expectedType)) {
152 if (dataFlowValue.isStableIdentifier()) {
153 context.trace.record(AUTOCAST, expression, possibleType);
154 }
155 else {
156 context.trace.report(AUTOCAST_IMPOSSIBLE.on(expression, possibleType, expression.getText()));
157 }
158 return possibleType;
159 }
160 }
161 context.trace.report(TYPE_MISMATCH.on(expression, context.expectedType, expressionType));
162 return expressionType;
163 }
164
165 @NotNull
166 public static JetTypeInfo checkStatementType(@NotNull JetExpression expression, @NotNull ResolutionContext context, @NotNull DataFlowInfo dataFlowInfo) {
167 return JetTypeInfo.create(checkStatementType(expression, context), dataFlowInfo);
168 }
169
170 @Nullable
171 public static JetType checkStatementType(@NotNull JetExpression expression, @NotNull ResolutionContext context) {
172 if (context.expectedType != TypeUtils.NO_EXPECTED_TYPE && !KotlinBuiltIns.getInstance().isUnit(context.expectedType) && !ErrorUtils.isErrorType(context.expectedType)) {
173 context.trace.report(EXPECTED_TYPE_MISMATCH.on(expression, context.expectedType));
174 return null;
175 }
176 return KotlinBuiltIns.getInstance().getUnitType();
177 }
178
179 @NotNull
180 public static JetTypeInfo checkImplicitCast(@Nullable JetType expressionType, @NotNull JetExpression expression, @NotNull ExpressionTypingContext context, boolean isStatement, DataFlowInfo dataFlowInfo) {
181 return JetTypeInfo.create(checkImplicitCast(expressionType, expression, context, isStatement), dataFlowInfo);
182 }
183
184 @Nullable
185 public static JetType checkImplicitCast(@Nullable JetType expressionType, @NotNull JetExpression expression, @NotNull ExpressionTypingContext context, boolean isStatement) {
186 if (expressionType != null && context.expectedType == TypeUtils.NO_EXPECTED_TYPE && !isStatement &&
187 (KotlinBuiltIns.getInstance().isUnit(expressionType) || KotlinBuiltIns.getInstance().isAny(expressionType))) {
188 context.trace.report(IMPLICIT_CAST_TO_UNIT_OR_ANY.on(expression, expressionType));
189
190 }
191 return expressionType;
192 }
193
194 @NotNull
195 public static JetTypeInfo illegalStatementType(@NotNull JetExpression expression, @NotNull ExpressionTypingContext context, @NotNull ExpressionTypingInternals facade) {
196 facade.checkStatementType(expression, context.replaceExpectedType(TypeUtils.NO_EXPECTED_TYPE));
197 context.trace.report(EXPRESSION_EXPECTED.on(expression, expression));
198 return JetTypeInfo.create(null, context.dataFlowInfo);
199 }
200 }