001 /*
002 * Copyright 2010-2016 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.cfg;
018
019 import com.google.common.collect.Lists;
020 import com.google.common.collect.Maps;
021 import com.google.common.collect.Sets;
022 import com.intellij.psi.PsiElement;
023 import com.intellij.psi.tree.IElementType;
024 import com.intellij.psi.util.PsiTreeUtil;
025 import kotlin.Unit;
026 import kotlin.jvm.functions.Function1;
027 import kotlin.jvm.functions.Function3;
028 import org.jetbrains.annotations.NotNull;
029 import org.jetbrains.annotations.Nullable;
030 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
031 import org.jetbrains.kotlin.cfg.pseudocode.PseudoValue;
032 import org.jetbrains.kotlin.cfg.pseudocode.Pseudocode;
033 import org.jetbrains.kotlin.cfg.pseudocode.PseudocodeUtil;
034 import org.jetbrains.kotlin.cfg.pseudocode.PseudocodeUtilsKt;
035 import org.jetbrains.kotlin.cfg.pseudocode.instructions.Instruction;
036 import org.jetbrains.kotlin.cfg.pseudocode.instructions.InstructionVisitor;
037 import org.jetbrains.kotlin.cfg.pseudocode.instructions.KtElementInstruction;
038 import org.jetbrains.kotlin.cfg.pseudocode.instructions.eval.*;
039 import org.jetbrains.kotlin.cfg.pseudocode.instructions.jumps.*;
040 import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.LocalFunctionDeclarationInstruction;
041 import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.MarkInstruction;
042 import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.SubroutineExitInstruction;
043 import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.VariableDeclarationInstruction;
044 import org.jetbrains.kotlin.cfg.pseudocodeTraverser.Edges;
045 import org.jetbrains.kotlin.cfg.pseudocodeTraverser.PseudocodeTraverserKt;
046 import org.jetbrains.kotlin.cfg.pseudocodeTraverser.TraversalOrder;
047 import org.jetbrains.kotlin.descriptors.*;
048 import org.jetbrains.kotlin.descriptors.impl.SyntheticFieldDescriptorKt;
049 import org.jetbrains.kotlin.diagnostics.Diagnostic;
050 import org.jetbrains.kotlin.diagnostics.DiagnosticFactory;
051 import org.jetbrains.kotlin.diagnostics.Errors;
052 import org.jetbrains.kotlin.idea.MainFunctionDetector;
053 import org.jetbrains.kotlin.lexer.KtTokens;
054 import org.jetbrains.kotlin.psi.*;
055 import org.jetbrains.kotlin.resolve.*;
056 import org.jetbrains.kotlin.resolve.bindingContextUtil.BindingContextUtilsKt;
057 import org.jetbrains.kotlin.resolve.calls.callUtil.CallUtilKt;
058 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall;
059 import org.jetbrains.kotlin.resolve.calls.resolvedCallUtil.ResolvedCallUtilKt;
060 import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValue;
061 import org.jetbrains.kotlin.types.KotlinType;
062 import org.jetbrains.kotlin.types.expressions.ExpressionTypingUtils;
063
064 import java.util.*;
065
066 import static org.jetbrains.kotlin.cfg.TailRecursionKind.*;
067 import static org.jetbrains.kotlin.cfg.VariableUseState.*;
068 import static org.jetbrains.kotlin.diagnostics.Errors.*;
069 import static org.jetbrains.kotlin.diagnostics.Errors.UNREACHABLE_CODE;
070 import static org.jetbrains.kotlin.resolve.BindingContext.*;
071 import static org.jetbrains.kotlin.types.TypeUtils.*;
072
073 public class ControlFlowInformationProvider {
074
075 private final KtElement subroutine;
076 private final Pseudocode pseudocode;
077 private final BindingTrace trace;
078 private PseudocodeVariablesData pseudocodeVariablesData;
079
080 private ControlFlowInformationProvider(
081 @NotNull KtElement declaration,
082 @NotNull BindingTrace trace,
083 @NotNull Pseudocode pseudocode
084 ) {
085 this.subroutine = declaration;
086 this.trace = trace;
087 this.pseudocode = pseudocode;
088 }
089
090 public ControlFlowInformationProvider(
091 @NotNull KtElement declaration,
092 @NotNull BindingTrace trace
093 ) {
094 this(declaration, trace, new ControlFlowProcessor(trace).generatePseudocode(declaration));
095 }
096
097 private PseudocodeVariablesData getPseudocodeVariablesData() {
098 if (pseudocodeVariablesData == null) {
099 pseudocodeVariablesData = new PseudocodeVariablesData(pseudocode, trace.getBindingContext());
100 }
101 return pseudocodeVariablesData;
102 }
103
104 public void checkForLocalClassOrObjectMode() {
105 // Local classes and objects are analyzed twice: when TopDownAnalyzer processes it and as a part of its container.
106 // Almost all checks can be done when the container is analyzed
107 // except recording initialized variables (this information is needed for DeclarationChecker).
108 recordInitializedVariables();
109 }
110
111 public void checkDeclaration() {
112
113 recordInitializedVariables();
114
115 checkLocalFunctions();
116
117 markUninitializedVariables();
118
119 markUnusedVariables();
120
121 markStatements();
122
123 markUnusedExpressions();
124
125 checkIfExpressions();
126
127 checkWhenExpressions();
128 }
129
130 public void checkFunction(@Nullable KotlinType expectedReturnType) {
131 UnreachableCode unreachableCode = collectUnreachableCode();
132 reportUnreachableCode(unreachableCode);
133
134 if (subroutine instanceof KtFunctionLiteral) return;
135
136 checkDefiniteReturn(expectedReturnType != null ? expectedReturnType : NO_EXPECTED_TYPE, unreachableCode);
137
138 markTailCalls();
139 }
140
141 private void collectReturnExpressions(@NotNull final Collection<KtElement> returnedExpressions) {
142 final Set<Instruction> instructions = Sets.newHashSet(pseudocode.getInstructions());
143 SubroutineExitInstruction exitInstruction = pseudocode.getExitInstruction();
144 for (Instruction previousInstruction : exitInstruction.getPreviousInstructions()) {
145 previousInstruction.accept(new InstructionVisitor() {
146 @Override
147 public void visitReturnValue(@NotNull ReturnValueInstruction instruction) {
148 if (instructions.contains(instruction)) { //exclude non-local return expressions
149 returnedExpressions.add(instruction.getElement());
150 }
151 }
152
153 @Override
154 public void visitReturnNoValue(@NotNull ReturnNoValueInstruction instruction) {
155 if (instructions.contains(instruction)) {
156 returnedExpressions.add(instruction.getElement());
157 }
158 }
159
160
161 @Override
162 public void visitJump(@NotNull AbstractJumpInstruction instruction) {
163 // Nothing
164 }
165
166 @Override
167 public void visitUnconditionalJump(@NotNull UnconditionalJumpInstruction instruction) {
168 redirectToPrevInstructions(instruction);
169 }
170
171 private void redirectToPrevInstructions(Instruction instruction) {
172 for (Instruction previousInstruction : instruction.getPreviousInstructions()) {
173 previousInstruction.accept(this);
174 }
175 }
176
177 @Override
178 public void visitNondeterministicJump(@NotNull NondeterministicJumpInstruction instruction) {
179 redirectToPrevInstructions(instruction);
180 }
181
182 @Override
183 public void visitMarkInstruction(@NotNull MarkInstruction instruction) {
184 redirectToPrevInstructions(instruction);
185 }
186
187 @Override
188 public void visitInstruction(@NotNull Instruction instruction) {
189 if (instruction instanceof KtElementInstruction) {
190 KtElementInstruction elementInstruction = (KtElementInstruction) instruction;
191 returnedExpressions.add(elementInstruction.getElement());
192 }
193 else {
194 throw new IllegalStateException(instruction + " precedes the exit point");
195 }
196 }
197 });
198 }
199 }
200
201 private void checkLocalFunctions() {
202 for (LocalFunctionDeclarationInstruction localDeclarationInstruction : pseudocode.getLocalDeclarations()) {
203 KtElement element = localDeclarationInstruction.getElement();
204 if (element instanceof KtDeclarationWithBody) {
205 KtDeclarationWithBody localDeclaration = (KtDeclarationWithBody) element;
206
207 CallableDescriptor functionDescriptor =
208 (CallableDescriptor) trace.getBindingContext().get(BindingContext.DECLARATION_TO_DESCRIPTOR, localDeclaration);
209 KotlinType expectedType = functionDescriptor != null ? functionDescriptor.getReturnType() : null;
210
211 ControlFlowInformationProvider providerForLocalDeclaration =
212 new ControlFlowInformationProvider(localDeclaration, trace, localDeclarationInstruction.getBody());
213
214 providerForLocalDeclaration.checkFunction(expectedType);
215 }
216 }
217 }
218
219 private void checkDefiniteReturn(final @NotNull KotlinType expectedReturnType, @NotNull final UnreachableCode unreachableCode) {
220 assert subroutine instanceof KtDeclarationWithBody;
221 KtDeclarationWithBody function = (KtDeclarationWithBody) subroutine;
222
223 if (!function.hasBody()) return;
224
225 List<KtElement> returnedExpressions = Lists.newArrayList();
226 collectReturnExpressions(returnedExpressions);
227
228 final boolean blockBody = function.hasBlockBody();
229
230 final boolean[] noReturnError = new boolean[] { false };
231 for (KtElement returnedExpression : returnedExpressions) {
232 returnedExpression.accept(new KtVisitorVoid() {
233 @Override
234 public void visitReturnExpression(@NotNull KtReturnExpression expression) {
235 if (!blockBody) {
236 trace.report(RETURN_IN_FUNCTION_WITH_EXPRESSION_BODY.on(expression));
237 }
238 }
239
240 @Override
241 public void visitKtElement(@NotNull KtElement element) {
242 if (!(element instanceof KtExpression || element instanceof KtWhenCondition)) return;
243
244 if (blockBody && !noExpectedType(expectedReturnType)
245 && !KotlinBuiltIns.isUnit(expectedReturnType)
246 && !unreachableCode.getElements().contains(element)) {
247 noReturnError[0] = true;
248 }
249 }
250 });
251 }
252 if (noReturnError[0]) {
253 trace.report(NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY.on(function));
254 }
255 }
256
257 private void reportUnreachableCode(@NotNull UnreachableCode unreachableCode) {
258 for (KtElement element : unreachableCode.getElements()) {
259 trace.report(UNREACHABLE_CODE.on(element, unreachableCode.getUnreachableTextRanges(element)));
260 trace.record(BindingContext.UNREACHABLE_CODE, element, true);
261 }
262 }
263
264 @NotNull
265 private UnreachableCode collectUnreachableCode() {
266 Set<KtElement> reachableElements = Sets.newHashSet();
267 Set<KtElement> unreachableElements = Sets.newHashSet();
268 for (Instruction instruction : pseudocode.getInstructionsIncludingDeadCode()) {
269 if (!(instruction instanceof KtElementInstruction)
270 || instruction instanceof LoadUnitValueInstruction
271 || instruction instanceof MergeInstruction
272 || (instruction instanceof MagicInstruction && ((MagicInstruction) instruction).getSynthetic())) continue;
273
274 KtElement element = ((KtElementInstruction) instruction).getElement();
275
276 if (instruction instanceof JumpInstruction) {
277 boolean isJumpElement = element instanceof KtBreakExpression
278 || element instanceof KtContinueExpression
279 || element instanceof KtReturnExpression
280 || element instanceof KtThrowExpression;
281 if (!isJumpElement) continue;
282 }
283
284 if (instruction.getDead()) {
285 unreachableElements.add(element);
286 }
287 else {
288 reachableElements.add(element);
289 }
290 }
291 return new UnreachableCodeImpl(reachableElements, unreachableElements);
292 }
293
294 ////////////////////////////////////////////////////////////////////////////////
295 // Uninitialized variables analysis
296
297 private void markUninitializedVariables() {
298 final Collection<VariableDescriptor> varWithUninitializedErrorGenerated = Sets.newHashSet();
299 final Collection<VariableDescriptor> varWithValReassignErrorGenerated = Sets.newHashSet();
300 final boolean processClassOrObject = subroutine instanceof KtClassOrObject;
301
302 PseudocodeVariablesData pseudocodeVariablesData = getPseudocodeVariablesData();
303 Map<Instruction, Edges<InitControlFlowInfo>> initializers =
304 pseudocodeVariablesData.getVariableInitializers();
305 final Set<VariableDescriptor> declaredVariables = pseudocodeVariablesData.getDeclaredVariables(pseudocode, true);
306 final BlockScopeVariableInfo blockScopeVariableInfo = pseudocodeVariablesData.getBlockScopeVariableInfo();
307
308 final Map<Instruction, DiagnosticFactory<?>> reportedDiagnosticMap = Maps.newHashMap();
309
310 PseudocodeTraverserKt.traverse(
311 pseudocode, TraversalOrder.FORWARD, initializers,
312 new InstructionDataAnalyzeStrategy<Map<VariableDescriptor, VariableControlFlowState>>() {
313 @Override
314 public void execute(
315 @NotNull Instruction instruction,
316 @Nullable Map<VariableDescriptor, VariableControlFlowState> in,
317 @Nullable Map<VariableDescriptor, VariableControlFlowState> out
318 ) {
319 assert in != null && out != null;
320 VariableInitContext ctxt =
321 new VariableInitContext(instruction, reportedDiagnosticMap, in, out, blockScopeVariableInfo);
322 if (ctxt.variableDescriptor == null) return;
323 if (instruction instanceof ReadValueInstruction) {
324 ReadValueInstruction readValueInstruction = (ReadValueInstruction) instruction;
325 KtElement element = readValueInstruction.getElement();
326 if (PseudocodeUtil.isThisOrNoDispatchReceiver(readValueInstruction, trace.getBindingContext()) &&
327 declaredVariables.contains(ctxt.variableDescriptor)) {
328 checkIsInitialized(ctxt, element, varWithUninitializedErrorGenerated);
329 }
330 return;
331 }
332 if (!(instruction instanceof WriteValueInstruction)) return;
333 WriteValueInstruction writeValueInstruction = (WriteValueInstruction) instruction;
334 KtElement element = writeValueInstruction.getLValue();
335 if (!(element instanceof KtExpression)) return;
336 boolean error = checkValReassignment(ctxt, (KtExpression) element, writeValueInstruction,
337 varWithValReassignErrorGenerated);
338 if (!error && processClassOrObject) {
339 error = checkAssignmentBeforeDeclaration(ctxt, (KtExpression) element);
340 }
341 if (!error && processClassOrObject) {
342 checkInitializationForCustomSetter(ctxt, (KtExpression) element);
343 }
344 }
345 }
346 );
347 }
348
349 private void recordInitializedVariables() {
350 PseudocodeVariablesData pseudocodeVariablesData = getPseudocodeVariablesData();
351 Pseudocode pseudocode = pseudocodeVariablesData.getPseudocode();
352 Map<Instruction, Edges<InitControlFlowInfo>> initializers = pseudocodeVariablesData.getVariableInitializers();
353 recordInitializedVariables(pseudocode, initializers);
354 for (LocalFunctionDeclarationInstruction instruction : pseudocode.getLocalDeclarations()) {
355 recordInitializedVariables(instruction.getBody(), initializers);
356 }
357 }
358
359 private boolean isDefinitelyInitialized(@NotNull PropertyDescriptor propertyDescriptor) {
360 if (propertyDescriptor.isLateInit()) return true;
361 if (trace.get(BACKING_FIELD_REQUIRED, propertyDescriptor) == Boolean.TRUE) return false;
362 PsiElement property = DescriptorToSourceUtils.descriptorToDeclaration(propertyDescriptor);
363 if (property instanceof KtProperty && ((KtProperty) property).hasDelegate()) return false;
364 return true;
365 }
366
367 private void checkIsInitialized(
368 @NotNull VariableInitContext ctxt,
369 @NotNull KtElement element,
370 @NotNull Collection<VariableDescriptor> varWithUninitializedErrorGenerated
371 ) {
372 if (!(element instanceof KtSimpleNameExpression)) return;
373
374
375 boolean isDefinitelyInitialized = ctxt.exitInitState.definitelyInitialized();
376 VariableDescriptor variableDescriptor = ctxt.variableDescriptor;
377 if (!isDefinitelyInitialized && variableDescriptor instanceof PropertyDescriptor) {
378 isDefinitelyInitialized = isDefinitelyInitialized((PropertyDescriptor) variableDescriptor);
379 }
380 if (!isDefinitelyInitialized && !varWithUninitializedErrorGenerated.contains(variableDescriptor)) {
381 if (!(variableDescriptor instanceof PropertyDescriptor)) {
382 varWithUninitializedErrorGenerated.add(variableDescriptor);
383 }
384 if (variableDescriptor instanceof ValueParameterDescriptor) {
385 report(Errors.UNINITIALIZED_PARAMETER.on((KtSimpleNameExpression) element,
386 (ValueParameterDescriptor) variableDescriptor), ctxt);
387 }
388 else {
389 report(Errors.UNINITIALIZED_VARIABLE.on((KtSimpleNameExpression) element, variableDescriptor), ctxt);
390 }
391 }
392 }
393
394 // Should return KtDeclarationWithBody or KtClassOrObject
395 @Nullable
396 public static KtDeclaration getElementParentDeclaration(@NotNull KtElement element) {
397 //noinspection unchecked
398 return PsiTreeUtil.getParentOfType(element, KtDeclarationWithBody.class, KtClassOrObject.class);
399 }
400
401 @Nullable
402 private DeclarationDescriptor getDeclarationDescriptor(@Nullable KtDeclaration declaration) {
403 DeclarationDescriptor descriptor = trace.get(BindingContext.DECLARATION_TO_DESCRIPTOR, declaration);
404 if (descriptor instanceof ClassDescriptor) {
405 // For a class primary constructor, we cannot directly get ConstructorDescriptor by KtClassInitializer,
406 // so we have to do additional conversion: KtClassInitializer -> KtClassOrObject -> ClassDescriptor -> ConstructorDescriptor
407 ClassDescriptor classDescriptor = (ClassDescriptor) descriptor;
408 return classDescriptor.getUnsubstitutedPrimaryConstructor();
409 }
410 else {
411 return descriptor;
412 }
413 }
414
415 private boolean isCapturedWrite(
416 @NotNull VariableDescriptor variableDescriptor,
417 @NotNull WriteValueInstruction writeValueInstruction
418 ) {
419 DeclarationDescriptor containingDeclarationDescriptor = variableDescriptor.getContainingDeclaration();
420 // Do not consider member / top-level properties
421 if (containingDeclarationDescriptor instanceof ClassOrPackageFragmentDescriptor) return false;
422 KtDeclaration parentDeclaration = getElementParentDeclaration(writeValueInstruction.getElement());
423 while (true) {
424 DeclarationDescriptor parentDescriptor = getDeclarationDescriptor(parentDeclaration);
425 if (containingDeclarationDescriptor.equals(parentDescriptor)) {
426 return false;
427 }
428 else if (parentDeclaration instanceof KtObjectDeclaration) {
429 // anonymous object counts here the same as its owner
430 parentDeclaration = getElementParentDeclaration(parentDeclaration);
431 }
432 else {
433 return true;
434 }
435 }
436 }
437
438 private boolean checkValReassignment(
439 @NotNull VariableInitContext ctxt,
440 @NotNull KtExpression expression,
441 @NotNull WriteValueInstruction writeValueInstruction,
442 @NotNull Collection<VariableDescriptor> varWithValReassignErrorGenerated
443 ) {
444 VariableDescriptor variableDescriptor = ctxt.variableDescriptor;
445 PropertyDescriptor propertyDescriptor = SyntheticFieldDescriptorKt.getReferencedProperty(variableDescriptor);
446 if (KtPsiUtil.isBackingFieldReference(variableDescriptor) && propertyDescriptor != null) {
447 KtPropertyAccessor accessor = PsiTreeUtil.getParentOfType(expression, KtPropertyAccessor.class);
448 if (accessor != null) {
449 DeclarationDescriptor accessorDescriptor = trace.get(BindingContext.DECLARATION_TO_DESCRIPTOR, accessor);
450 if (propertyDescriptor.getGetter() == accessorDescriptor) {
451 //val can be reassigned through backing field inside its own getter
452 return false;
453 }
454 }
455 }
456
457 boolean mayBeInitializedNotHere = ctxt.enterInitState.mayBeInitialized();
458 boolean hasBackingField = true;
459 if (variableDescriptor instanceof PropertyDescriptor) {
460 hasBackingField = trace.get(BindingContext.BACKING_FIELD_REQUIRED, (PropertyDescriptor) variableDescriptor);
461 }
462 if (variableDescriptor.isVar() && variableDescriptor instanceof PropertyDescriptor) {
463 DeclarationDescriptor descriptor = BindingContextUtils.getEnclosingDescriptor(trace.getBindingContext(), expression);
464 PropertySetterDescriptor setterDescriptor = ((PropertyDescriptor) variableDescriptor).getSetter();
465
466 ResolvedCall<? extends CallableDescriptor> resolvedCall = CallUtilKt.getResolvedCall(expression, trace.getBindingContext());
467 ReceiverValue receiverValue = null;
468 if (resolvedCall != null) {
469 receiverValue = ResolvedCallUtilKt.getDispatchReceiverWithSmartCast(resolvedCall);
470 }
471
472 if (Visibilities.isVisible(receiverValue, variableDescriptor, descriptor) && setterDescriptor != null
473 && !Visibilities.isVisible(receiverValue, setterDescriptor, descriptor)) {
474 report(Errors.INVISIBLE_SETTER.on(expression, variableDescriptor, setterDescriptor.getVisibility(),
475 setterDescriptor), ctxt);
476 return true;
477 }
478 }
479 boolean isThisOrNoDispatchReceiver =
480 PseudocodeUtil.isThisOrNoDispatchReceiver(writeValueInstruction, trace.getBindingContext());
481 boolean captured = isCapturedWrite(variableDescriptor, writeValueInstruction);
482 if ((mayBeInitializedNotHere || !hasBackingField || !isThisOrNoDispatchReceiver || captured) && !variableDescriptor.isVar()) {
483 boolean hasReassignMethodReturningUnit = false;
484 KtSimpleNameExpression operationReference = null;
485 PsiElement parent = expression.getParent();
486 if (parent instanceof KtBinaryExpression) {
487 operationReference = ((KtBinaryExpression) parent).getOperationReference();
488 }
489 else if (parent instanceof KtUnaryExpression) {
490 operationReference = ((KtUnaryExpression) parent).getOperationReference();
491 }
492 if (operationReference != null) {
493 DeclarationDescriptor descriptor = trace.get(BindingContext.REFERENCE_TARGET, operationReference);
494 if (descriptor instanceof FunctionDescriptor) {
495 if (KotlinBuiltIns.isUnit(((FunctionDescriptor) descriptor).getReturnType())) {
496 hasReassignMethodReturningUnit = true;
497 }
498 }
499 if (descriptor == null) {
500 Collection<? extends DeclarationDescriptor> descriptors =
501 trace.get(BindingContext.AMBIGUOUS_REFERENCE_TARGET, operationReference);
502 if (descriptors != null) {
503 for (DeclarationDescriptor referenceDescriptor : descriptors) {
504 if (KotlinBuiltIns.isUnit(((FunctionDescriptor) referenceDescriptor).getReturnType())) {
505 hasReassignMethodReturningUnit = true;
506 }
507 }
508 }
509 }
510 }
511 if (!hasReassignMethodReturningUnit) {
512 if (!isThisOrNoDispatchReceiver || !varWithValReassignErrorGenerated.contains(variableDescriptor)) {
513 if (captured && !mayBeInitializedNotHere && hasBackingField && isThisOrNoDispatchReceiver) {
514 report(Errors.CAPTURED_VAL_INITIALIZATION.on(expression, variableDescriptor), ctxt);
515 }
516 else {
517 report(Errors.VAL_REASSIGNMENT.on(expression, variableDescriptor), ctxt);
518 }
519 }
520 if (isThisOrNoDispatchReceiver) {
521 // try to get rid of repeating VAL_REASSIGNMENT diagnostic only for vars with no receiver
522 // or when receiver is this
523 varWithValReassignErrorGenerated.add(variableDescriptor);
524 }
525 return true;
526 }
527 }
528 return false;
529 }
530
531 private boolean checkAssignmentBeforeDeclaration(@NotNull VariableInitContext ctxt, @NotNull KtExpression expression) {
532 if (!ctxt.enterInitState.isDeclared() && !ctxt.exitInitState.isDeclared()
533 && !ctxt.enterInitState.mayBeInitialized() && ctxt.exitInitState.mayBeInitialized()) {
534 report(Errors.INITIALIZATION_BEFORE_DECLARATION.on(expression, ctxt.variableDescriptor), ctxt);
535 return true;
536 }
537 return false;
538 }
539
540 private boolean checkInitializationForCustomSetter(@NotNull VariableInitContext ctxt, @NotNull KtExpression expression) {
541 VariableDescriptor variableDescriptor = ctxt.variableDescriptor;
542 if (!(variableDescriptor instanceof PropertyDescriptor)
543 || ctxt.enterInitState.mayBeInitialized()
544 || !ctxt.exitInitState.mayBeInitialized()
545 || !variableDescriptor.isVar()
546 || !trace.get(BindingContext.BACKING_FIELD_REQUIRED, (PropertyDescriptor) variableDescriptor)
547 ) {
548 return false;
549 }
550
551 PsiElement property = DescriptorToSourceUtils.descriptorToDeclaration(variableDescriptor);
552 assert property instanceof KtProperty;
553 KtPropertyAccessor setter = ((KtProperty) property).getSetter();
554 if (((PropertyDescriptor) variableDescriptor).getModality() == Modality.FINAL && (setter == null || !setter.hasBody())) {
555 return false;
556 }
557
558 KtExpression variable = expression;
559 if (expression instanceof KtDotQualifiedExpression) {
560 if (((KtDotQualifiedExpression) expression).getReceiverExpression() instanceof KtThisExpression) {
561 variable = ((KtDotQualifiedExpression) expression).getSelectorExpression();
562 }
563 }
564 if (variable instanceof KtSimpleNameExpression) {
565 trace.record(IS_UNINITIALIZED, (PropertyDescriptor) variableDescriptor);
566 return true;
567 }
568 return false;
569 }
570
571 private void recordInitializedVariables(
572 @NotNull Pseudocode pseudocode,
573 @NotNull Map<Instruction, Edges<InitControlFlowInfo>> initializersMap
574 ) {
575 Edges<InitControlFlowInfo> initializers = initializersMap.get(pseudocode.getExitInstruction());
576 if (initializers == null) return;
577 Set<VariableDescriptor> declaredVariables = getPseudocodeVariablesData().getDeclaredVariables(pseudocode, false);
578 for (VariableDescriptor variable : declaredVariables) {
579 if (variable instanceof PropertyDescriptor) {
580 VariableControlFlowState variableControlFlowState = initializers.getIncoming().get(variable);
581 if (variableControlFlowState != null && variableControlFlowState.definitelyInitialized()) continue;
582 trace.record(BindingContext.IS_UNINITIALIZED, (PropertyDescriptor) variable);
583 }
584 }
585 }
586
587 ////////////////////////////////////////////////////////////////////////////////
588 // "Unused variable" & "unused value" analyses
589
590 private void markUnusedVariables() {
591 final PseudocodeVariablesData pseudocodeVariablesData = getPseudocodeVariablesData();
592 Map<Instruction, Edges<UseControlFlowInfo>> variableStatusData = pseudocodeVariablesData.getVariableUseStatusData();
593 final Map<Instruction, DiagnosticFactory<?>> reportedDiagnosticMap = Maps.newHashMap();
594 InstructionDataAnalyzeStrategy<Map<VariableDescriptor, VariableUseState>> variableStatusAnalyzeStrategy =
595 new InstructionDataAnalyzeStrategy<Map<VariableDescriptor, VariableUseState>>() {
596 @Override
597 public void execute(
598 @NotNull Instruction instruction,
599 @Nullable Map<VariableDescriptor, VariableUseState> in,
600 @Nullable Map<VariableDescriptor, VariableUseState> out
601 ) {
602
603 assert in != null && out != null;
604 VariableContext ctxt = new VariableUseContext(instruction, reportedDiagnosticMap, in, out);
605 Set<VariableDescriptor> declaredVariables =
606 pseudocodeVariablesData.getDeclaredVariables(instruction.getOwner(), false);
607 VariableDescriptor variableDescriptor = PseudocodeUtil.extractVariableDescriptorIfAny(
608 instruction, false, trace.getBindingContext());
609 if (variableDescriptor == null || !declaredVariables.contains(variableDescriptor)
610 || !ExpressionTypingUtils.isLocal(variableDescriptor.getContainingDeclaration(), variableDescriptor)) {
611 return;
612 }
613 VariableUseState variableUseState = in.get(variableDescriptor);
614 if (instruction instanceof WriteValueInstruction) {
615 if (trace.get(CAPTURED_IN_CLOSURE, variableDescriptor) != null) return;
616 KtElement element = ((WriteValueInstruction) instruction).getElement();
617 if (variableUseState != READ) {
618 if (element instanceof KtBinaryExpression &&
619 ((KtBinaryExpression) element).getOperationToken() == KtTokens.EQ) {
620 KtExpression right = ((KtBinaryExpression) element).getRight();
621 if (right != null) {
622 report(Errors.UNUSED_VALUE.on((KtBinaryExpression) element, right, variableDescriptor), ctxt);
623 }
624 }
625 else if (element instanceof KtPostfixExpression) {
626 IElementType operationToken =
627 ((KtPostfixExpression) element).getOperationReference().getReferencedNameElementType();
628 if (operationToken == KtTokens.PLUSPLUS || operationToken == KtTokens.MINUSMINUS) {
629 report(Errors.UNUSED_CHANGED_VALUE.on(element, element), ctxt);
630 }
631 }
632 }
633 }
634 else if (instruction instanceof VariableDeclarationInstruction) {
635 KtDeclaration element = ((VariableDeclarationInstruction) instruction).getVariableDeclarationElement();
636 if (!(element instanceof KtNamedDeclaration)) return;
637 PsiElement nameIdentifier = ((KtNamedDeclaration) element).getNameIdentifier();
638 if (nameIdentifier == null) return;
639 if (!VariableUseState.isUsed(variableUseState)) {
640 if (KtPsiUtil.isVariableNotParameterDeclaration(element)) {
641 report(Errors.UNUSED_VARIABLE.on((KtNamedDeclaration) element, variableDescriptor), ctxt);
642 }
643 else if (element instanceof KtParameter) {
644 PsiElement owner = element.getParent().getParent();
645 if (owner instanceof KtPrimaryConstructor) {
646 if (!((KtParameter) element).hasValOrVar()) {
647 KtClassOrObject containingClass = ((KtPrimaryConstructor) owner).getContainingClassOrObject();
648 DeclarationDescriptor containingClassDescriptor = trace.get(
649 BindingContext.DECLARATION_TO_DESCRIPTOR, containingClass
650 );
651 if (!DescriptorUtils.isAnnotationClass(containingClassDescriptor)) {
652 report(Errors.UNUSED_PARAMETER.on((KtParameter) element, variableDescriptor), ctxt);
653 }
654 }
655 }
656 else if (owner instanceof KtFunction) {
657 MainFunctionDetector mainFunctionDetector = new MainFunctionDetector(trace.getBindingContext());
658 boolean isMain = (owner instanceof KtNamedFunction) && mainFunctionDetector.isMain((KtNamedFunction) owner);
659 if (owner instanceof KtFunctionLiteral) return;
660 DeclarationDescriptor descriptor = trace.get(BindingContext.DECLARATION_TO_DESCRIPTOR, owner);
661 assert descriptor instanceof FunctionDescriptor : owner.getText();
662 FunctionDescriptor functionDescriptor = (FunctionDescriptor) descriptor;
663 String functionName = functionDescriptor.getName().asString();
664 KtFunction function = (KtFunction) owner;
665 if (isMain
666 || ModalityKt.isOverridableOrOverrides(functionDescriptor)
667 || function.hasModifier(KtTokens.OVERRIDE_KEYWORD)
668 || "getValue".equals(functionName) || "setValue".equals(functionName)
669 || "propertyDelegated".equals(functionName)
670 ) {
671 return;
672 }
673 report(Errors.UNUSED_PARAMETER.on((KtParameter) element, variableDescriptor), ctxt);
674 }
675 }
676 }
677 else if (variableUseState == ONLY_WRITTEN_NEVER_READ && KtPsiUtil.isVariableNotParameterDeclaration(element)) {
678 report(Errors.ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE.on((KtNamedDeclaration) element, variableDescriptor), ctxt);
679 }
680 else if (variableUseState == WRITTEN_AFTER_READ && element instanceof KtVariableDeclaration) {
681 if (element instanceof KtProperty) {
682 KtExpression initializer = ((KtProperty) element).getInitializer();
683 if (initializer != null) {
684 report(Errors.VARIABLE_WITH_REDUNDANT_INITIALIZER.on(initializer, variableDescriptor), ctxt);
685 }
686 }
687 else if (element instanceof KtDestructuringDeclarationEntry) {
688 report(VARIABLE_WITH_REDUNDANT_INITIALIZER.on(element, variableDescriptor), ctxt);
689 }
690 }
691 }
692 }
693 };
694 PseudocodeTraverserKt.traverse(pseudocode, TraversalOrder.BACKWARD, variableStatusData, variableStatusAnalyzeStrategy);
695 }
696
697 ////////////////////////////////////////////////////////////////////////////////
698 // "Unused expressions" in block
699
700 private void markUnusedExpressions() {
701 final Map<Instruction, DiagnosticFactory<?>> reportedDiagnosticMap = Maps.newHashMap();
702 PseudocodeTraverserKt.traverse(
703 pseudocode, TraversalOrder.FORWARD, new ControlFlowInformationProvider.FunctionVoid1<Instruction>() {
704 @Override
705 public void execute(@NotNull Instruction instruction) {
706 if (!(instruction instanceof KtElementInstruction)) return;
707
708 KtElement element = ((KtElementInstruction)instruction).getElement();
709 if (!(element instanceof KtExpression)) return;
710
711 if (BindingContextUtilsKt.isUsedAsStatement((KtExpression) element, trace.getBindingContext())
712 && PseudocodeUtilsKt.getSideEffectFree(instruction)) {
713 VariableContext ctxt = new VariableContext(instruction, reportedDiagnosticMap);
714 report(
715 element instanceof KtLambdaExpression
716 ? Errors.UNUSED_LAMBDA_EXPRESSION.on((KtLambdaExpression) element)
717 : Errors.UNUSED_EXPRESSION.on(element),
718 ctxt
719 );
720 }
721 }
722 }
723 );
724 }
725
726 ////////////////////////////////////////////////////////////////////////////////
727 // Statements
728
729 private void markStatements() {
730 PseudocodeTraverserKt.traverse(
731 pseudocode, TraversalOrder.FORWARD, new ControlFlowInformationProvider.FunctionVoid1<Instruction>() {
732 @Override
733 public void execute(@NotNull Instruction instruction) {
734 PseudoValue value = instruction instanceof InstructionWithValue
735 ? ((InstructionWithValue) instruction).getOutputValue()
736 : null;
737 Pseudocode pseudocode = instruction.getOwner();
738 List<Instruction> usages = pseudocode.getUsages(value);
739 boolean isUsedAsExpression = !usages.isEmpty();
740 boolean isUsedAsResultOfLambda = isUsedAsResultOfLambda(usages);
741 for (KtElement element : pseudocode.getValueElements(value)) {
742 trace.record(BindingContext.USED_AS_EXPRESSION, element, isUsedAsExpression);
743 trace.record(BindingContext.USED_AS_RESULT_OF_LAMBDA, element, isUsedAsResultOfLambda);
744 }
745 }
746 }
747 );
748 }
749
750 private static boolean isUsedAsResultOfLambda(List<Instruction> usages) {
751 for (Instruction usage : usages) {
752 if (usage instanceof ReturnValueInstruction) {
753 KtElement returnElement = ((ReturnValueInstruction) usage).getElement();
754 PsiElement parentElement = returnElement.getParent();
755 if (!(returnElement instanceof KtReturnExpression ||
756 parentElement instanceof KtDeclaration && !(parentElement instanceof KtFunctionLiteral))) {
757 return true;
758 }
759 }
760 }
761 return false;
762 }
763
764 private void checkIfExpressions() {
765 PseudocodeTraverserKt.traverse(
766 pseudocode, TraversalOrder.FORWARD, new ControlFlowInformationProvider.FunctionVoid1<Instruction>() {
767 @Override
768 public void execute(@NotNull Instruction instruction) {
769 PseudoValue value = instruction instanceof InstructionWithValue
770 ? ((InstructionWithValue) instruction).getOutputValue()
771 : null;
772 for (KtElement element : instruction.getOwner().getValueElements(value)) {
773 if (!(element instanceof KtIfExpression)) continue;
774 KtIfExpression ifExpression = (KtIfExpression) element;
775
776 if (BindingContextUtilsKt.isUsedAsExpression(ifExpression, trace.getBindingContext())) {
777 KtExpression thenExpression = ifExpression.getThen();
778 KtExpression elseExpression = ifExpression.getElse();
779
780 if (thenExpression == null || elseExpression == null) {
781 trace.report(INVALID_IF_AS_EXPRESSION.on(ifExpression));
782 }
783 else {
784 checkImplicitCastOnConditionalExpression(ifExpression);
785 }
786 }
787 }
788 }
789 }
790 );
791 }
792
793 private static List<KtExpression> collectResultingExpressionsOfConditionalExpression(KtExpression expression) {
794 List<KtExpression> leafBranches = new ArrayList<KtExpression>();
795 collectResultingExpressionsOfConditionalExpressionRec(expression, leafBranches);
796 return leafBranches;
797 }
798
799 private static void collectResultingExpressionsOfConditionalExpressionRec(
800 @Nullable KtExpression expression,
801 @NotNull List<KtExpression> resultingExpressions
802 ) {
803 if (expression instanceof KtIfExpression) {
804 KtIfExpression ifExpression = (KtIfExpression) expression;
805 collectResultingExpressionsOfConditionalExpressionRec(ifExpression.getThen(), resultingExpressions);
806 collectResultingExpressionsOfConditionalExpressionRec(ifExpression.getElse(), resultingExpressions);
807 }
808 else if (expression instanceof KtWhenExpression) {
809 KtWhenExpression whenExpression = (KtWhenExpression) expression;
810 for (KtWhenEntry whenEntry : whenExpression.getEntries()) {
811 collectResultingExpressionsOfConditionalExpressionRec(whenEntry.getExpression(), resultingExpressions);
812 }
813 }
814 else if (expression != null){
815 KtExpression resultingExpression = getResultingExpression(expression);
816 if (resultingExpression instanceof KtIfExpression || resultingExpression instanceof KtWhenExpression) {
817 collectResultingExpressionsOfConditionalExpressionRec(resultingExpression, resultingExpressions);
818 }
819 else {
820 resultingExpressions.add(resultingExpression);
821 }
822 }
823 }
824
825 private void checkImplicitCastOnConditionalExpression(@NotNull KtExpression expression) {
826 Collection<KtExpression> branchExpressions = collectResultingExpressionsOfConditionalExpression(expression);
827
828 KotlinType expectedExpressionType = trace.get(EXPECTED_EXPRESSION_TYPE, expression);
829 if (expectedExpressionType != null && expectedExpressionType != DONT_CARE) return;
830
831 KotlinType expressionType = trace.getType(expression);
832 if (expressionType == null) {
833 return;
834 }
835 if (KotlinBuiltIns.isAnyOrNullableAny(expressionType)) {
836 boolean isUsedAsResultOfLambda = BindingContextUtilsKt.isUsedAsResultOfLambda(expression, trace.getBindingContext());
837 for (KtExpression branchExpression : branchExpressions) {
838 if (branchExpression == null) continue;
839 KotlinType branchType = trace.getType(branchExpression);
840 if (branchType == null
841 || KotlinBuiltIns.isAnyOrNullableAny(branchType)
842 || (isUsedAsResultOfLambda && KotlinBuiltIns.isUnitOrNullableUnit(branchType))) {
843 return;
844 }
845 }
846 for (KtExpression branchExpression : branchExpressions) {
847 if (branchExpression == null) continue;
848 KotlinType branchType = trace.getType(branchExpression);
849 if (branchType == null) continue;
850 if (KotlinBuiltIns.isNothing(branchType)) continue;
851 trace.report(IMPLICIT_CAST_TO_ANY.on(getResultingExpression(branchExpression), branchType, expressionType));
852 }
853 }
854 }
855
856 private static @NotNull KtExpression getResultingExpression(@NotNull KtExpression expression) {
857 KtExpression finger = expression;
858 while (true) {
859 KtExpression deparenthesized = KtPsiUtil.deparenthesize(finger);
860 deparenthesized = KtPsiUtil.getExpressionOrLastStatementInBlock(deparenthesized);
861 if (deparenthesized == null || deparenthesized == finger) break;
862 finger = deparenthesized;
863 }
864 return finger;
865 }
866
867 private void checkWhenExpressions() {
868 final Map<Instruction, Edges<InitControlFlowInfo>> initializers = pseudocodeVariablesData.getVariableInitializers();
869 PseudocodeTraverserKt.traverse(
870 pseudocode, TraversalOrder.FORWARD, new ControlFlowInformationProvider.FunctionVoid1<Instruction>() {
871 @Override
872 public void execute(@NotNull Instruction instruction) {
873 if (instruction instanceof MagicInstruction) {
874 MagicInstruction magicInstruction = (MagicInstruction) instruction;
875 if (magicInstruction.getKind() == MagicKind.EXHAUSTIVE_WHEN_ELSE) {
876 Instruction next = magicInstruction.getNext();
877 if (next instanceof MergeInstruction) {
878 MergeInstruction mergeInstruction = (MergeInstruction) next;
879 if (initializers.containsKey(mergeInstruction) && initializers.containsKey(magicInstruction)) {
880 InitControlFlowInfo mergeInfo = initializers.get(mergeInstruction).getIncoming();
881 InitControlFlowInfo magicInfo = initializers.get(magicInstruction).getOutgoing();
882 if (mergeInstruction.getElement() instanceof KtWhenExpression &&
883 magicInfo.checkDefiniteInitializationInWhen(mergeInfo)) {
884 trace.record(IMPLICIT_EXHAUSTIVE_WHEN, (KtWhenExpression) mergeInstruction.getElement());
885 }
886 }
887 }
888 }
889 }
890 PseudoValue value = instruction instanceof InstructionWithValue
891 ? ((InstructionWithValue) instruction).getOutputValue()
892 : null;
893 for (KtElement element : instruction.getOwner().getValueElements(value)) {
894 if (!(element instanceof KtWhenExpression)) continue;
895 KtWhenExpression whenExpression = (KtWhenExpression) element;
896
897 if (BindingContextUtilsKt.isUsedAsExpression(whenExpression, trace.getBindingContext())) {
898 checkImplicitCastOnConditionalExpression(whenExpression);
899 }
900
901 if (whenExpression.getElseExpression() != null) continue;
902
903 BindingContext context = trace.getBindingContext();
904 List<WhenMissingCase> necessaryCases = WhenChecker.getNecessaryCases(whenExpression, context);
905 if (!necessaryCases.isEmpty()) {
906 trace.report(NO_ELSE_IN_WHEN.on(whenExpression, necessaryCases));
907 }
908 else if (whenExpression.getSubjectExpression() != null) {
909 ClassDescriptor enumClassDescriptor = WhenChecker.getClassDescriptorOfTypeIfEnum(
910 trace.getType(whenExpression.getSubjectExpression()));
911 if (enumClassDescriptor != null) {
912 List<WhenMissingCase> missingCases = WhenChecker.getEnumMissingCases(
913 whenExpression, context, enumClassDescriptor
914 );
915 if (!missingCases.isEmpty()) {
916 trace.report(NON_EXHAUSTIVE_WHEN.on(whenExpression, missingCases));
917 }
918 }
919 }
920 }
921 }
922 }
923 );
924 }
925
926 ////////////////////////////////////////////////////////////////////////////////
927 // Tail calls
928
929 private void markTailCalls() {
930 final DeclarationDescriptor subroutineDescriptor = trace.get(BindingContext.DECLARATION_TO_DESCRIPTOR, subroutine);
931 if (!(subroutineDescriptor instanceof FunctionDescriptor)) return;
932 if (!((FunctionDescriptor) subroutineDescriptor).isTailrec()) return;
933
934 // finally blocks are copied which leads to multiple diagnostics reported on one instruction
935 class KindAndCall {
936 TailRecursionKind kind;
937 private final ResolvedCall<?> call;
938
939 KindAndCall(TailRecursionKind kind, ResolvedCall<?> call) {
940 this.kind = kind;
941 this.call = call;
942 }
943 }
944 final Map<KtElement, KindAndCall> calls = new HashMap<KtElement, KindAndCall>();
945 PseudocodeTraverserKt.traverse(
946 pseudocode,
947 TraversalOrder.FORWARD,
948 new FunctionVoid1<Instruction>() {
949 @Override
950 public void execute(@NotNull Instruction instruction) {
951 if (!(instruction instanceof CallInstruction)) return;
952 CallInstruction callInstruction = (CallInstruction) instruction;
953
954 ResolvedCall<?> resolvedCall = CallUtilKt.getResolvedCall(callInstruction.getElement(), trace.getBindingContext());
955 if (resolvedCall == null) return;
956
957 // is this a recursive call?
958 CallableDescriptor functionDescriptor = resolvedCall.getResultingDescriptor();
959 if (!functionDescriptor.getOriginal().equals(subroutineDescriptor)) return;
960 // Overridden functions using default arguments at tail call are not included: KT-4285
961 if (resolvedCall.getCall().getValueArguments().size() != functionDescriptor.getValueParameters().size() &&
962 !functionDescriptor.getOverriddenDescriptors().isEmpty()) return;
963
964 KtElement element = callInstruction.getElement();
965 //noinspection unchecked
966 KtExpression parent = PsiTreeUtil.getParentOfType(
967 element,
968 KtTryExpression.class, KtFunction.class, KtAnonymousInitializer.class
969 );
970
971 if (parent instanceof KtTryExpression) {
972 // We do not support tail calls Collections.singletonMap() try-catch-finally, for simplicity of the mental model
973 // very few cases there would be real tail-calls, and it's often not so easy for the user to see why
974 calls.put(element, new KindAndCall(IN_TRY, resolvedCall));
975 return;
976 }
977
978 boolean isTail = PseudocodeTraverserKt.traverseFollowingInstructions(
979 callInstruction,
980 new HashSet<Instruction>(),
981 TraversalOrder.FORWARD,
982 new TailRecursionDetector(subroutine, callInstruction)
983 );
984
985 // A tail call is not allowed to change dispatch receiver
986 // class C {
987 // fun foo(other: C) {
988 // other.foo(this) // not a tail call
989 // }
990 // }
991 boolean sameDispatchReceiver =
992 ResolvedCallUtilKt.hasThisOrNoDispatchReceiver(resolvedCall, trace.getBindingContext());
993
994 TailRecursionKind kind = isTail && sameDispatchReceiver ? TAIL_CALL : NON_TAIL;
995
996 KindAndCall kindAndCall = calls.get(element);
997 calls.put(element,
998 new KindAndCall(
999 combineKinds(kind, kindAndCall == null ? null : kindAndCall.kind),
1000 resolvedCall
1001 )
1002 );
1003 }
1004 }
1005 );
1006 boolean hasTailCalls = false;
1007 for (Map.Entry<KtElement, KindAndCall> entry : calls.entrySet()) {
1008 KtElement element = entry.getKey();
1009 KindAndCall kindAndCall = entry.getValue();
1010 switch (kindAndCall.kind) {
1011 case TAIL_CALL:
1012 trace.record(TAIL_RECURSION_CALL, kindAndCall.call.getCall(), TailRecursionKind.TAIL_CALL);
1013 hasTailCalls = true;
1014 break;
1015 case IN_TRY:
1016 trace.report(Errors.TAIL_RECURSION_IN_TRY_IS_NOT_SUPPORTED.on(element));
1017 break;
1018 case NON_TAIL:
1019 trace.report(Errors.NON_TAIL_RECURSIVE_CALL.on(element));
1020 break;
1021 }
1022 }
1023
1024 if (!hasTailCalls) {
1025 trace.report(Errors.NO_TAIL_CALLS_FOUND.on((KtNamedFunction) subroutine));
1026 }
1027 }
1028
1029 private static TailRecursionKind combineKinds(TailRecursionKind kind, @Nullable TailRecursionKind existingKind) {
1030 TailRecursionKind resultingKind;
1031 if (existingKind == null || existingKind == kind) {
1032 resultingKind = kind;
1033 }
1034 else {
1035 if (check(kind, existingKind, IN_TRY, TAIL_CALL)) {
1036 resultingKind = IN_TRY;
1037 }
1038 else if (check(kind, existingKind, IN_TRY, NON_TAIL)) {
1039 resultingKind = IN_TRY;
1040 }
1041 else {
1042 // TAIL_CALL, NON_TAIL
1043 resultingKind = NON_TAIL;
1044 }
1045 }
1046 return resultingKind;
1047 }
1048
1049 private static boolean check(Object a, Object b, Object x, Object y) {
1050 return (a == x && b == y) || (a == y && b == x);
1051 }
1052
1053 ////////////////////////////////////////////////////////////////////////////////
1054 // Utility classes and methods
1055
1056 /**
1057 * The method provides reporting of the same diagnostic only once for copied instructions
1058 * (depends on whether it should be reported for all or only for one of the copies)
1059 */
1060 private void report(
1061 @NotNull Diagnostic diagnostic,
1062 @NotNull VariableContext ctxt
1063 ) {
1064 Instruction instruction = ctxt.instruction;
1065 if (instruction.getCopies().isEmpty()) {
1066 trace.report(diagnostic);
1067 return;
1068 }
1069 Map<Instruction, DiagnosticFactory<?>> previouslyReported = ctxt.reportedDiagnosticMap;
1070 previouslyReported.put(instruction, diagnostic.getFactory());
1071
1072 boolean alreadyReported = false;
1073 boolean sameErrorForAllCopies = true;
1074 for (Instruction copy : instruction.getCopies()) {
1075 DiagnosticFactory<?> previouslyReportedErrorFactory = previouslyReported.get(copy);
1076 if (previouslyReportedErrorFactory != null) {
1077 alreadyReported = true;
1078 }
1079
1080 if (previouslyReportedErrorFactory != diagnostic.getFactory()) {
1081 sameErrorForAllCopies = false;
1082 }
1083 }
1084
1085 if (mustBeReportedOnAllCopies(diagnostic.getFactory())) {
1086 if (sameErrorForAllCopies) {
1087 trace.report(diagnostic);
1088 }
1089 }
1090 else {
1091 //only one reporting required
1092 if (!alreadyReported) {
1093 trace.report(diagnostic);
1094 }
1095 }
1096 }
1097
1098 private static boolean mustBeReportedOnAllCopies(@NotNull DiagnosticFactory<?> diagnosticFactory) {
1099 return diagnosticFactory == UNUSED_VARIABLE
1100 || diagnosticFactory == UNUSED_PARAMETER
1101 || diagnosticFactory == UNUSED_CHANGED_VALUE;
1102 }
1103
1104
1105 private class VariableContext {
1106 final Map<Instruction, DiagnosticFactory<?>> reportedDiagnosticMap;
1107 final Instruction instruction;
1108 final VariableDescriptor variableDescriptor;
1109
1110 private VariableContext(
1111 @NotNull Instruction instruction,
1112 @NotNull Map<Instruction, DiagnosticFactory<?>> map
1113 ) {
1114 this.instruction = instruction;
1115 reportedDiagnosticMap = map;
1116 variableDescriptor = PseudocodeUtil.extractVariableDescriptorIfAny(instruction, true, trace.getBindingContext());
1117 }
1118 }
1119
1120 private class VariableInitContext extends VariableContext {
1121 final VariableControlFlowState enterInitState;
1122 final VariableControlFlowState exitInitState;
1123
1124 private VariableInitContext(
1125 @NotNull Instruction instruction,
1126 @NotNull Map<Instruction, DiagnosticFactory<?>> map,
1127 @NotNull Map<VariableDescriptor, VariableControlFlowState> in,
1128 @NotNull Map<VariableDescriptor, VariableControlFlowState> out,
1129 @NotNull BlockScopeVariableInfo blockScopeVariableInfo
1130 ) {
1131 super(instruction, map);
1132 enterInitState = initialize(variableDescriptor, blockScopeVariableInfo, in);
1133 exitInitState = initialize(variableDescriptor, blockScopeVariableInfo, out);
1134 }
1135
1136 private VariableControlFlowState initialize(
1137 VariableDescriptor variableDescriptor,
1138 BlockScopeVariableInfo blockScopeVariableInfo,
1139 Map<VariableDescriptor, VariableControlFlowState> map
1140 ) {
1141 if (variableDescriptor == null) return null;
1142 VariableControlFlowState state = map.get(variableDescriptor);
1143 if (state != null) return state;
1144 return PseudocodeVariablesData.getDefaultValueForInitializers(variableDescriptor, instruction, blockScopeVariableInfo);
1145 }
1146 }
1147
1148 private class VariableUseContext extends VariableContext {
1149 final VariableUseState enterUseState;
1150 final VariableUseState exitUseState;
1151
1152
1153 private VariableUseContext(
1154 @NotNull Instruction instruction,
1155 @NotNull Map<Instruction, DiagnosticFactory<?>> map,
1156 @NotNull Map<VariableDescriptor, VariableUseState> in,
1157 @NotNull Map<VariableDescriptor, VariableUseState> out
1158 ) {
1159 super(instruction, map);
1160 enterUseState = variableDescriptor != null ? in.get(variableDescriptor) : null;
1161 exitUseState = variableDescriptor != null ? out.get(variableDescriptor) : null;
1162 }
1163 }
1164
1165 //TODO after KT-4621 rewrite to Kotlin
1166 private abstract static class InstructionDataAnalyzeStrategy<D> implements Function3<Instruction, D, D, Unit> {
1167 @Override
1168 public Unit invoke(Instruction instruction, D enterData, D exitData) {
1169 execute(instruction, enterData, exitData);
1170 return Unit.INSTANCE;
1171 }
1172
1173 public abstract void execute(Instruction instruction, D enterData, D exitData);
1174 }
1175
1176 private abstract static class FunctionVoid1<P> implements Function1<P, Unit> {
1177 @Override
1178 public Unit invoke(P p) {
1179 execute(p);
1180 return Unit.INSTANCE;
1181 }
1182
1183 public abstract void execute(P p);
1184 }
1185 }