public static boolean isFieldInitializedAfterObjectConstruction(@NotNull PsiField field) { if (field.hasInitializer()) return true; final boolean isFieldStatic = field.hasModifierProperty(PsiModifier.STATIC); final PsiClass aClass = field.getContainingClass(); if (aClass != null) { // field might be assigned in the other field initializers if (isFieldInitializedInOtherFieldInitializer(aClass, field, isFieldStatic)) return true; } final PsiClassInitializer[] initializers; if (aClass != null) { initializers = aClass.getInitializers(); } else { return false; } for (PsiClassInitializer initializer : initializers) { if (initializer.hasModifierProperty(PsiModifier.STATIC) == isFieldStatic && variableDefinitelyAssignedIn(field, initializer.getBody())) { return true; } } if (isFieldStatic) { return false; } else { // instance field should be initialized at the end of the each constructor final PsiMethod[] constructors = aClass.getConstructors(); if (constructors.length == 0) return false; nextConstructor: for (PsiMethod constructor : constructors) { PsiCodeBlock ctrBody = constructor.getBody(); if (ctrBody == null) return false; final List<PsiMethod> redirectedConstructors = JavaHighlightUtil.getChainedConstructors(constructor); for (int j = 0; redirectedConstructors != null && j < redirectedConstructors.size(); j++) { PsiMethod redirectedConstructor = redirectedConstructors.get(j); final PsiCodeBlock body = redirectedConstructor.getBody(); if (body != null && variableDefinitelyAssignedIn(field, body)) continue nextConstructor; } if (!ctrBody.isValid() || variableDefinitelyAssignedIn(field, ctrBody)) { continue; } return false; } return true; } }
@Override public void onReferencesBuild(RefElement refElement) { if (refElement instanceof RefClass) { final PsiClass psiClass = (PsiClass) refElement.getElement(); if (psiClass != null) { if (refElement.isEntry()) { ((RefClassImpl) refElement).setFlag(false, CAN_BE_FINAL_MASK); } PsiMethod[] psiMethods = psiClass.getMethods(); PsiField[] psiFields = psiClass.getFields(); HashSet<PsiVariable> allFields = new HashSet<PsiVariable>(); ContainerUtil.addAll(allFields, psiFields); ArrayList<PsiVariable> instanceInitializerInitializedFields = new ArrayList<PsiVariable>(); boolean hasInitializers = false; for (PsiClassInitializer initializer : psiClass.getInitializers()) { PsiCodeBlock body = initializer.getBody(); hasInitializers = true; ControlFlow flow; try { flow = ControlFlowFactory.getInstance(body.getProject()) .getControlFlow( body, LocalsOrMyInstanceFieldsControlFlowPolicy.getInstance(), false); } catch (AnalysisCanceledException e) { flow = ControlFlow.EMPTY; } Collection<PsiVariable> writtenVariables = new ArrayList<PsiVariable>(); ControlFlowUtil.getWrittenVariables(flow, 0, flow.getSize(), false, writtenVariables); for (PsiVariable psiVariable : writtenVariables) { if (allFields.contains(psiVariable)) { if (instanceInitializerInitializedFields.contains(psiVariable)) { allFields.remove(psiVariable); instanceInitializerInitializedFields.remove(psiVariable); } else { instanceInitializerInitializedFields.add(psiVariable); } } } for (PsiVariable psiVariable : writtenVariables) { if (!instanceInitializerInitializedFields.contains(psiVariable)) { allFields.remove(psiVariable); } } } for (PsiMethod psiMethod : psiMethods) { if (psiMethod.isConstructor()) { PsiCodeBlock body = psiMethod.getBody(); if (body != null) { hasInitializers = true; ControlFlow flow; try { flow = ControlFlowFactory.getInstance(body.getProject()) .getControlFlow( body, LocalsOrMyInstanceFieldsControlFlowPolicy.getInstance(), false); } catch (AnalysisCanceledException e) { flow = ControlFlow.EMPTY; } Collection<PsiVariable> writtenVariables = ControlFlowUtil.getWrittenVariables(flow, 0, flow.getSize(), false); for (PsiVariable psiVariable : writtenVariables) { if (instanceInitializerInitializedFields.contains(psiVariable)) { allFields.remove(psiVariable); instanceInitializerInitializedFields.remove(psiVariable); } } List<PsiMethod> redirectedConstructors = HighlightControlFlowUtil.getChainedConstructors(psiMethod); if (redirectedConstructors == null || redirectedConstructors.isEmpty()) { List<PsiVariable> ssaVariables = ControlFlowUtil.getSSAVariables(flow); ArrayList<PsiVariable> good = new ArrayList<PsiVariable>(ssaVariables); good.addAll(instanceInitializerInitializedFields); allFields.retainAll(good); } else { allFields.removeAll(writtenVariables); } } } } for (PsiField psiField : psiFields) { if ((!hasInitializers || !allFields.contains(psiField)) && psiField.getInitializer() == null) { final RefFieldImpl refField = (RefFieldImpl) myManager.getReference(psiField); if (refField != null) { refField.setFlag(false, CAN_BE_FINAL_MASK); } } } } } else if (refElement instanceof RefMethod) { final RefMethod refMethod = (RefMethod) refElement; if (refMethod.isEntry()) { ((RefMethodImpl) refMethod).setFlag(false, CAN_BE_FINAL_MASK); } } }
@Nullable public static HighlightInfo checkFinalVariableMightAlreadyHaveBeenAssignedTo( @NotNull PsiVariable variable, @NotNull PsiReferenceExpression expression, @NotNull Map<PsiElement, Collection<ControlFlowUtil.VariableInfo>> finalVarProblems) { if (!PsiUtil.isAccessedForWriting(expression)) return null; final PsiElement scope = variable instanceof PsiField ? variable.getParent() : variable.getParent() == null ? null : variable.getParent().getParent(); PsiElement codeBlock = PsiUtil.getTopLevelEnclosingCodeBlock(expression, scope); if (codeBlock == null) return null; Collection<ControlFlowUtil.VariableInfo> codeBlockProblems = getFinalVariableProblemsInBlock(finalVarProblems, codeBlock); boolean alreadyAssigned = false; for (ControlFlowUtil.VariableInfo variableInfo : codeBlockProblems) { if (variableInfo.expression == expression) { alreadyAssigned = true; break; } } if (!alreadyAssigned) { if (!(variable instanceof PsiField)) return null; final PsiField field = (PsiField) variable; final PsiClass aClass = field.getContainingClass(); if (aClass == null) return null; // field can get assigned in other field initializers final PsiField[] fields = aClass.getFields(); boolean isFieldStatic = field.hasModifierProperty(PsiModifier.STATIC); for (PsiField psiField : fields) { PsiExpression initializer = psiField.getInitializer(); if (psiField != field && psiField.hasModifierProperty(PsiModifier.STATIC) == isFieldStatic && initializer != null && initializer != codeBlock && !variableDefinitelyNotAssignedIn(field, initializer)) { alreadyAssigned = true; break; } } if (!alreadyAssigned) { // field can get assigned in class initializers final PsiMember enclosingConstructorOrInitializer = PsiUtil.findEnclosingConstructorOrInitializer(expression); if (enclosingConstructorOrInitializer == null || !aClass .getManager() .areElementsEquivalent( enclosingConstructorOrInitializer.getContainingClass(), aClass)) { return null; } final PsiClassInitializer[] initializers = aClass.getInitializers(); for (PsiClassInitializer initializer : initializers) { if (initializer.hasModifierProperty(PsiModifier.STATIC) == field.hasModifierProperty(PsiModifier.STATIC)) { final PsiCodeBlock body = initializer.getBody(); if (body == codeBlock) return null; try { final ControlFlow controlFlow = getControlFlow(body); if (!ControlFlowUtil.isVariableDefinitelyNotAssigned(field, controlFlow)) { alreadyAssigned = true; break; } } catch (AnalysisCanceledException e) { // incomplete code return null; } } } } if (!alreadyAssigned && !field.hasModifierProperty(PsiModifier.STATIC)) { // then check if instance field already assigned in other constructor final PsiMethod ctr = codeBlock.getParent() instanceof PsiMethod ? (PsiMethod) codeBlock.getParent() : null; // assignment to final field in several constructors threatens us only if these are linked // (there is this() call in the beginning) final List<PsiMethod> redirectedConstructors = ctr != null && ctr.isConstructor() ? JavaHighlightUtil.getChainedConstructors(ctr) : null; for (int j = 0; redirectedConstructors != null && j < redirectedConstructors.size(); j++) { PsiMethod redirectedConstructor = redirectedConstructors.get(j); PsiCodeBlock body = redirectedConstructor.getBody(); if (body != null && variableDefinitelyAssignedIn(variable, body)) { alreadyAssigned = true; break; } } } } if (alreadyAssigned) { String description = JavaErrorMessages.message("variable.already.assigned", variable.getName()); final HighlightInfo highlightInfo = HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR) .range(expression) .descriptionAndTooltip(description) .create(); QuickFixAction.registerQuickFixAction( highlightInfo, QUICK_FIX_FACTORY.createModifierListFix(variable, PsiModifier.FINAL, false, false)); QuickFixAction.registerQuickFixAction( highlightInfo, QUICK_FIX_FACTORY.createDeferFinalAssignmentFix(variable, expression)); return highlightInfo; } return null; }
@Nullable public static HighlightInfo checkVariableInitializedBeforeUsage( @NotNull PsiReferenceExpression expression, @NotNull PsiVariable variable, @NotNull Map<PsiElement, Collection<PsiReferenceExpression>> uninitializedVarProblems, @NotNull PsiFile containingFile) { if (variable instanceof ImplicitVariable) return null; if (!PsiUtil.isAccessedForReading(expression)) return null; int startOffset = expression.getTextRange().getStartOffset(); final PsiElement topBlock; if (variable.hasInitializer()) { topBlock = PsiUtil.getVariableCodeBlock(variable, variable); if (topBlock == null) return null; } else { PsiElement scope = variable instanceof PsiField ? ((PsiField) variable).getContainingClass() : variable.getParent() != null ? variable.getParent().getParent() : null; if (scope instanceof PsiCodeBlock && scope.getParent() instanceof PsiSwitchStatement) { scope = PsiTreeUtil.getParentOfType(scope, PsiCodeBlock.class); } topBlock = FileTypeUtils.isInServerPageFile(scope) && scope instanceof PsiFile ? scope : PsiUtil.getTopLevelEnclosingCodeBlock(expression, scope); if (variable instanceof PsiField) { // non final field already initialized with default value if (!variable.hasModifierProperty(PsiModifier.FINAL)) return null; // final field may be initialized in ctor or class initializer only // if we're inside non-ctr method, skip it if (PsiUtil.findEnclosingConstructorOrInitializer(expression) == null && HighlightUtil.findEnclosingFieldInitializer(expression) == null) { return null; } if (topBlock == null) return null; final PsiElement parent = topBlock.getParent(); // access to final fields from inner classes always allowed if (inInnerClass(expression, ((PsiField) variable).getContainingClass(), containingFile)) return null; final PsiCodeBlock block; final PsiClass aClass; if (parent instanceof PsiMethod) { PsiMethod constructor = (PsiMethod) parent; if (!containingFile .getManager() .areElementsEquivalent( constructor.getContainingClass(), ((PsiField) variable).getContainingClass())) return null; // static variables already initialized in class initializers if (variable.hasModifierProperty(PsiModifier.STATIC)) return null; // as a last chance, field may be initialized in this() call final List<PsiMethod> redirectedConstructors = JavaHighlightUtil.getChainedConstructors(constructor); for (int j = 0; redirectedConstructors != null && j < redirectedConstructors.size(); j++) { PsiMethod redirectedConstructor = redirectedConstructors.get(j); // variable must be initialized before its usage // ??? // if (startOffset < redirectedConstructor.getTextRange().getStartOffset()) continue; PsiCodeBlock body = redirectedConstructor.getBody(); if (body != null && variableDefinitelyAssignedIn(variable, body)) { return null; } } block = constructor.getBody(); aClass = constructor.getContainingClass(); } else if (parent instanceof PsiClassInitializer) { final PsiClassInitializer classInitializer = (PsiClassInitializer) parent; if (!containingFile .getManager() .areElementsEquivalent( classInitializer.getContainingClass(), ((PsiField) variable).getContainingClass())) return null; block = classInitializer.getBody(); aClass = classInitializer.getContainingClass(); } else { // field reference outside code block // check variable initialized before its usage final PsiField field = (PsiField) variable; aClass = field.getContainingClass(); if (aClass == null || isFieldInitializedInOtherFieldInitializer( aClass, field, field.hasModifierProperty(PsiModifier.STATIC))) { return null; } final PsiField anotherField = PsiTreeUtil.getTopmostParentOfType(expression, PsiField.class); int offset = startOffset; if (anotherField != null && anotherField.getContainingClass() == aClass && !field.hasModifierProperty(PsiModifier.STATIC)) { offset = 0; } block = null; // initializers will be checked later final PsiMethod[] constructors = aClass.getConstructors(); for (PsiMethod constructor : constructors) { // variable must be initialized before its usage if (offset < constructor.getTextRange().getStartOffset()) continue; PsiCodeBlock body = constructor.getBody(); if (body != null && variableDefinitelyAssignedIn(variable, body)) { return null; } // as a last chance, field may be initialized in this() call final List<PsiMethod> redirectedConstructors = JavaHighlightUtil.getChainedConstructors(constructor); for (int j = 0; redirectedConstructors != null && j < redirectedConstructors.size(); j++) { PsiMethod redirectedConstructor = redirectedConstructors.get(j); // variable must be initialized before its usage if (offset < redirectedConstructor.getTextRange().getStartOffset()) continue; PsiCodeBlock redirectedBody = redirectedConstructor.getBody(); if (redirectedBody != null && variableDefinitelyAssignedIn(variable, redirectedBody)) { return null; } } } } if (aClass != null) { // field may be initialized in class initializer final PsiClassInitializer[] initializers = aClass.getInitializers(); for (PsiClassInitializer initializer : initializers) { PsiCodeBlock body = initializer.getBody(); if (body == block) break; // variable referenced in initializer must be initialized in initializer preceding // assignment // variable referenced in field initializer or in class initializer boolean shouldCheckInitializerOrder = block == null || block.getParent() instanceof PsiClassInitializer; if (shouldCheckInitializerOrder && startOffset < initializer.getTextRange().getStartOffset()) continue; if (initializer.hasModifierProperty(PsiModifier.STATIC) == variable.hasModifierProperty(PsiModifier.STATIC)) { if (variableDefinitelyAssignedIn(variable, body)) return null; } } } } } if (topBlock == null) return null; Collection<PsiReferenceExpression> codeBlockProblems = uninitializedVarProblems.get(topBlock); if (codeBlockProblems == null) { try { final ControlFlow controlFlow = getControlFlow(topBlock); codeBlockProblems = ControlFlowUtil.getReadBeforeWriteLocals(controlFlow); } catch (AnalysisCanceledException | IndexNotReadyException e) { codeBlockProblems = Collections.emptyList(); } uninitializedVarProblems.put(topBlock, codeBlockProblems); } if (codeBlockProblems.contains(expression)) { final String name = expression.getElement().getText(); String description = JavaErrorMessages.message("variable.not.initialized", name); HighlightInfo highlightInfo = HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR) .range(expression) .descriptionAndTooltip(description) .create(); QuickFixAction.registerQuickFixAction( highlightInfo, QUICK_FIX_FACTORY.createAddVariableInitializerFix(variable)); if (variable instanceof PsiField) { QuickFixAction.registerQuickFixAction( highlightInfo, QUICK_FIX_FACTORY.createModifierListFix(variable, PsiModifier.FINAL, false, false)); } return highlightInfo; } return null; }