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.types.expressions;
018    
019    import com.intellij.openapi.project.Project;
020    import com.intellij.psi.PsiElement;
021    import com.intellij.psi.tree.IElementType;
022    import com.intellij.psi.util.PsiTreeUtil;
023    import org.jetbrains.annotations.NotNull;
024    import org.jetbrains.annotations.Nullable;
025    import org.jetbrains.kotlin.descriptors.*;
026    import org.jetbrains.kotlin.diagnostics.Diagnostic;
027    import org.jetbrains.kotlin.diagnostics.DiagnosticFactory;
028    import org.jetbrains.kotlin.diagnostics.Errors;
029    import org.jetbrains.kotlin.lexer.JetTokens;
030    import org.jetbrains.kotlin.psi.*;
031    import org.jetbrains.kotlin.resolve.*;
032    import org.jetbrains.kotlin.resolve.scopes.LexicalWritableScope;
033    import org.jetbrains.kotlin.resolve.scopes.WritableScope;
034    import org.jetbrains.kotlin.resolve.scopes.receivers.ClassReceiver;
035    import org.jetbrains.kotlin.resolve.scopes.receivers.ExpressionReceiver;
036    import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValue;
037    import org.jetbrains.kotlin.types.JetType;
038    import org.jetbrains.kotlin.types.expressions.typeInfoFactory.TypeInfoFactoryPackage;
039    
040    import java.util.ArrayList;
041    import java.util.List;
042    
043    import static org.jetbrains.kotlin.diagnostics.Errors.*;
044    import static org.jetbrains.kotlin.psi.PsiPackage.JetPsiFactory;
045    import static org.jetbrains.kotlin.resolve.BindingContext.PROCESSED;
046    
047    public class ExpressionTypingUtils {
048    
049        @NotNull
050        public static ReceiverValue normalizeReceiverValueForVisibility(@NotNull ReceiverValue receiverValue, @NotNull BindingContext trace) {
051            if (receiverValue instanceof ExpressionReceiver) {
052                JetExpression expression = ((ExpressionReceiver) receiverValue).getExpression();
053                JetReferenceExpression referenceExpression = null;
054                if (expression instanceof JetThisExpression) {
055                    referenceExpression = ((JetThisExpression) expression).getInstanceReference();
056                }
057                else if (expression instanceof JetConstructorDelegationReferenceExpression) {
058                    referenceExpression = (JetReferenceExpression) expression;
059                }
060    
061                if (referenceExpression != null) {
062                    DeclarationDescriptor descriptor = trace.get(BindingContext.REFERENCE_TARGET, referenceExpression);
063                    if (descriptor instanceof ClassDescriptor) {
064                        return new ClassReceiver((ClassDescriptor) descriptor.getOriginal());
065                    }
066                }
067            }
068            return receiverValue;
069        }
070    
071        @Nullable
072        public static ExpressionReceiver getExpressionReceiver(@NotNull JetExpression expression, @Nullable JetType type) {
073            if (type == null) return null;
074            return new ExpressionReceiver(expression, type);
075        }
076    
077        @Nullable
078        public static ExpressionReceiver getExpressionReceiver(
079                @NotNull ExpressionTypingFacade facade,
080                @NotNull JetExpression expression,
081                ExpressionTypingContext context
082        ) {
083            return getExpressionReceiver(expression, facade.getTypeInfo(expression, context).getType());
084        }
085    
086        @NotNull
087        public static ExpressionReceiver safeGetExpressionReceiver(
088                @NotNull ExpressionTypingFacade facade,
089                @NotNull JetExpression expression,
090                ExpressionTypingContext context
091        ) {
092            JetType type = safeGetType(facade.safeGetTypeInfo(expression, context));
093            return new ExpressionReceiver(expression, type);
094        }
095    
096        @NotNull
097        public static JetType safeGetType(@NotNull JetTypeInfo typeInfo) {
098            JetType type = typeInfo.getType();
099            assert type != null : "safeGetType should be invoked on safe JetTypeInfo; safeGetTypeInfo should return @NotNull type";
100            return type;
101        }
102    
103        @NotNull
104        public static LexicalWritableScope newWritableScopeImpl(ExpressionTypingContext context, @NotNull String scopeDebugName) {
105            LexicalWritableScope scope = new LexicalWritableScope(
106                    context.scope, context.scope.getOwnerDescriptor(), false, null, new TraceBasedRedeclarationHandler(context.trace), scopeDebugName);
107            scope.changeLockLevel(WritableScope.LockLevel.BOTH);
108            return scope;
109        }
110    
111        public static JetExpression createFakeExpressionOfType(
112                @NotNull Project project,
113                @NotNull BindingTrace trace,
114                @NotNull String argumentName,
115                @NotNull JetType argumentType
116        ) {
117            JetExpression fakeExpression = JetPsiFactory(project).createExpression(argumentName);
118            trace.recordType(fakeExpression, argumentType);
119            trace.record(PROCESSED, fakeExpression);
120            return fakeExpression;
121        }
122    
123        public static void checkVariableShadowing(
124                @NotNull ExpressionTypingContext context,
125                @NotNull VariableDescriptor variableDescriptor,
126                @Nullable VariableDescriptor oldDescriptor
127        ) {
128            if (oldDescriptor != null && isLocal(variableDescriptor.getContainingDeclaration(), oldDescriptor)) {
129                PsiElement declaration = DescriptorToSourceUtils.descriptorToDeclaration(variableDescriptor);
130                if (declaration != null) {
131                    context.trace.report(Errors.NAME_SHADOWING.on(declaration, variableDescriptor.getName().asString()));
132                }
133            }
134        }
135    
136        public static ObservableBindingTrace makeTraceInterceptingTypeMismatch(
137                @NotNull BindingTrace trace,
138                @NotNull final JetElement expressionToWatch,
139                @NotNull final boolean[] mismatchFound
140        ) {
141            return new ObservableBindingTrace(trace) {
142    
143                @Override
144                public void report(@NotNull Diagnostic diagnostic) {
145                    DiagnosticFactory<?> factory = diagnostic.getFactory();
146                    if ((factory == TYPE_MISMATCH || factory == CONSTANT_EXPECTED_TYPE_MISMATCH || factory == NULL_FOR_NONNULL_TYPE)
147                        && diagnostic.getPsiElement() == expressionToWatch) {
148                        mismatchFound[0] = true;
149                    }
150                    if (TYPE_INFERENCE_ERRORS.contains(factory) &&
151                        PsiTreeUtil.isAncestor(expressionToWatch, diagnostic.getPsiElement(), false)) {
152                        mismatchFound[0] = true;
153                    }
154                    super.report(diagnostic);
155                }
156            };
157        }
158    
159        @NotNull
160        public static JetTypeInfo getTypeInfoOrNullType(
161                @Nullable JetExpression expression,
162                @NotNull ExpressionTypingContext context,
163                @NotNull ExpressionTypingInternals facade
164        ) {
165            return expression != null
166                   ? facade.getTypeInfo(expression, context)
167                   : TypeInfoFactoryPackage.noTypeInfo(context);
168        }
169    
170        @SuppressWarnings("SuspiciousMethodCalls")
171        public static boolean isBinaryExpressionDependentOnExpectedType(@NotNull JetBinaryExpression expression) {
172            IElementType operationType = expression.getOperationReference().getReferencedNameElementType();
173            return (operationType == JetTokens.IDENTIFIER || OperatorConventions.BINARY_OPERATION_NAMES.containsKey(operationType)
174                    || operationType == JetTokens.ELVIS);
175        }
176    
177        public static boolean isUnaryExpressionDependentOnExpectedType(@NotNull JetUnaryExpression expression) {
178            return expression.getOperationReference().getReferencedNameElementType() == JetTokens.EXCLEXCL;
179        }
180    
181        public static boolean isExclExclExpression(@Nullable JetExpression expression) {
182            return expression instanceof JetUnaryExpression
183                   && ((JetUnaryExpression) expression).getOperationReference().getReferencedNameElementType() == JetTokens.EXCLEXCL;
184        }
185    
186        @NotNull
187        public static List<JetType> getValueParametersTypes(@NotNull List<ValueParameterDescriptor> valueParameters) {
188            List<JetType> parameterTypes = new ArrayList<JetType>(valueParameters.size());
189            for (ValueParameterDescriptor parameter : valueParameters) {
190                parameterTypes.add(parameter.getType());
191            }
192            return parameterTypes;
193        }
194    
195        /**
196         * The primary case for local extensions is the following:
197         *
198         * I had a locally declared extension function or a local variable of function type called foo
199         * And I called it on my x
200         * Now, someone added function foo() to the class of x
201         * My code should not change
202         *
203         * thus
204         *
205         * local extension prevail over members (and members prevail over all non-local extensions)
206         */
207        public static boolean isLocal(DeclarationDescriptor containerOfTheCurrentLocality, DeclarationDescriptor candidate) {
208            if (candidate instanceof ValueParameterDescriptor) {
209                return true;
210            }
211            DeclarationDescriptor parent = candidate.getContainingDeclaration();
212            if (!(parent instanceof FunctionDescriptor)) {
213                return false;
214            }
215            FunctionDescriptor functionDescriptor = (FunctionDescriptor) parent;
216            DeclarationDescriptor current = containerOfTheCurrentLocality;
217            while (current != null) {
218                if (current == functionDescriptor) {
219                    return true;
220                }
221                current = current.getContainingDeclaration();
222            }
223            return false;
224        }
225    
226        public static boolean dependsOnExpectedType(@Nullable JetExpression expression) {
227            JetExpression expr = JetPsiUtil.deparenthesize(expression, false);
228            if (expr == null) return false;
229    
230            if (expr instanceof JetBinaryExpressionWithTypeRHS) {
231                return false;
232            }
233            if (expr instanceof JetBinaryExpression) {
234                return isBinaryExpressionDependentOnExpectedType((JetBinaryExpression) expr);
235            }
236            if (expr instanceof JetUnaryExpression) {
237                return isUnaryExpressionDependentOnExpectedType((JetUnaryExpression) expr);
238            }
239            return true;
240        }
241    
242        private ExpressionTypingUtils() {
243        }
244    
245    }