@Nullable
static HighlightInfo checkVariableMustBeFinal(
PsiVariable variable,
PsiJavaCodeReferenceElement context,
@NotNull LanguageLevel languageLevel) {
if (variable.hasModifierProperty(PsiModifier.FINAL)) return null;
final PsiClass innerClass = getInnerClassVariableReferencedFrom(variable, context);
if (innerClass != null) {
if (variable instanceof PsiParameter) {
final PsiElement parent = variable.getParent();
if (parent instanceof PsiParameterList
&& parent.getParent() instanceof PsiLambdaExpression
&& notAccessedForWriting(
variable, new LocalSearchScope(((PsiParameter) variable).getDeclarationScope()))) {
return null;
}
}
if (languageLevel.isAtLeast(LanguageLevel.JDK_1_8)
&& isEffectivelyFinal(variable, innerClass, context)) {
return null;
}
final String description =
JavaErrorMessages.message("variable.must.be.final", context.getText());
final HighlightInfo highlightInfo =
HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR)
.range(context)
.descriptionAndTooltip(description)
.create();
QuickFixAction.registerQuickFixAction(
highlightInfo,
QUICK_FIX_FACTORY.createVariableAccessFromInnerClassFix(variable, innerClass));
return highlightInfo;
}
final PsiLambdaExpression lambdaExpression =
PsiTreeUtil.getParentOfType(context, PsiLambdaExpression.class);
if (lambdaExpression != null && !PsiTreeUtil.isAncestor(lambdaExpression, variable, true)) {
final PsiElement parent = variable.getParent();
if (parent instanceof PsiParameterList && parent.getParent() == lambdaExpression) {
return null;
}
if (!isEffectivelyFinal(variable, lambdaExpression, context)) {
return HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR)
.range(context)
.descriptionAndTooltip("Variable used in lambda expression should be effectively final")
.create();
}
}
return null;
}
private static boolean canWriteToFinal(
@NotNull PsiVariable variable,
@NotNull PsiExpression expression,
@NotNull PsiReferenceExpression reference,
@NotNull PsiFile containingFile) {
if (variable.hasInitializer()) return false;
if (variable instanceof PsiParameter) return false;
PsiElement innerClass = getInnerClassVariableReferencedFrom(variable, expression);
if (variable instanceof PsiField) {
// if inside some field initializer
if (HighlightUtil.findEnclosingFieldInitializer(expression) != null) return true;
// assignment from within inner class is illegal always
PsiField field = (PsiField) variable;
if (innerClass != null
&& !containingFile
.getManager()
.areElementsEquivalent(innerClass, field.getContainingClass())) return false;
final PsiMember enclosingCtrOrInitializer =
PsiUtil.findEnclosingConstructorOrInitializer(expression);
return enclosingCtrOrInitializer != null
&& isSameField(enclosingCtrOrInitializer, field, reference, containingFile);
}
if (variable instanceof PsiLocalVariable) {
boolean isAccessedFromOtherClass = innerClass != null;
if (isAccessedFromOtherClass) {
return false;
}
}
return true;
}
@Nullable
public static PsiElement getInnerClassVariableReferencedFrom(
@NotNull PsiVariable variable, @NotNull PsiElement context) {
final PsiElement[] scope;
if (variable instanceof PsiResourceVariable) {
scope = ((PsiResourceVariable) variable).getDeclarationScope();
} else if (variable instanceof PsiLocalVariable) {
final PsiElement parent = variable.getParent();
scope =
new PsiElement[] {
parent != null ? parent.getParent() : null
}; // code block or for statement
} else if (variable instanceof PsiParameter) {
scope = new PsiElement[] {((PsiParameter) variable).getDeclarationScope()};
} else {
scope = new PsiElement[] {variable.getParent()};
}
if (scope.length < 1
|| scope[0] == null
|| scope[0].getContainingFile() != context.getContainingFile()) return null;
PsiElement parent = context.getParent();
PsiElement prevParent = context;
outer:
while (parent != null) {
for (PsiElement scopeElement : scope) {
if (parent.equals(scopeElement)) break outer;
}
if (parent instanceof PsiClass
&& !(prevParent instanceof PsiExpressionList && parent instanceof PsiAnonymousClass)) {
return parent;
}
if (parent instanceof PsiLambdaExpression) {
return parent;
}
prevParent = parent;
parent = parent.getParent();
}
return null;
}
@Nullable
static HighlightInfo checkVariableMustBeFinal(
@NotNull PsiVariable variable,
@NotNull PsiJavaCodeReferenceElement context,
@NotNull LanguageLevel languageLevel) {
if (variable.hasModifierProperty(PsiModifier.FINAL)) return null;
final PsiElement innerClass = getInnerClassVariableReferencedFrom(variable, context);
if (innerClass instanceof PsiClass) {
if (variable instanceof PsiParameter) {
final PsiElement parent = variable.getParent();
if (parent instanceof PsiParameterList
&& parent.getParent() instanceof PsiLambdaExpression
&& notAccessedForWriting(
variable, new LocalSearchScope(((PsiParameter) variable).getDeclarationScope()))) {
return null;
}
}
final boolean isToBeEffectivelyFinal = languageLevel.isAtLeast(LanguageLevel.JDK_1_8);
if (isToBeEffectivelyFinal && isEffectivelyFinal(variable, innerClass, context)) {
return null;
}
final String description =
JavaErrorMessages.message(
isToBeEffectivelyFinal
? "variable.must.be.final.or.effectively.final"
: "variable.must.be.final",
context.getText());
final HighlightInfo highlightInfo =
HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR)
.range(context)
.descriptionAndTooltip(description)
.create();
QuickFixAction.registerQuickFixAction(
highlightInfo,
QUICK_FIX_FACTORY.createVariableAccessFromInnerClassFix(variable, innerClass));
return highlightInfo;
}
return checkWriteToFinalInsideLambda(variable, context);
}
public static boolean isReassigned(
PsiVariable variable,
Map<PsiElement, Collection<ControlFlowUtil.VariableInfo>> finalVarProblems) {
if (variable instanceof PsiLocalVariable) {
final PsiElement parent = variable.getParent();
if (parent == null) return false;
final PsiElement declarationScope = parent.getParent();
Collection<ControlFlowUtil.VariableInfo> codeBlockProblems =
getFinalVariableProblemsInBlock(finalVarProblems, declarationScope);
return codeBlockProblems.contains(new ControlFlowUtil.VariableInfo(variable, null));
} else if (variable instanceof PsiParameter) {
final PsiParameter parameter = (PsiParameter) variable;
return isAssigned(parameter);
} else {
return false;
}
}
private static HighlightInfo checkWriteToFinalInsideLambda(
@NotNull PsiVariable variable, @NotNull PsiJavaCodeReferenceElement context) {
final PsiLambdaExpression lambdaExpression =
PsiTreeUtil.getParentOfType(context, PsiLambdaExpression.class);
if (lambdaExpression != null && !PsiTreeUtil.isAncestor(lambdaExpression, variable, true)) {
final PsiElement parent = variable.getParent();
if (parent instanceof PsiParameterList && parent.getParent() == lambdaExpression) {
return null;
}
if (!isEffectivelyFinal(variable, lambdaExpression, context)) {
String text = JavaErrorMessages.message("lambda.variable.must.be.final");
HighlightInfo highlightInfo =
HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR)
.range(context)
.descriptionAndTooltip(text)
.create();
QuickFixAction.registerQuickFixAction(
highlightInfo,
QUICK_FIX_FACTORY.createVariableAccessFromInnerClassFix(variable, lambdaExpression));
return highlightInfo;
}
}
return null;
}
@Nullable
static HighlightInfo checkCannotWriteToFinal(
@NotNull PsiExpression expression, @NotNull PsiFile containingFile) {
PsiReferenceExpression reference = null;
boolean readBeforeWrite = false;
if (expression instanceof PsiAssignmentExpression) {
final PsiAssignmentExpression assignmentExpression = (PsiAssignmentExpression) expression;
final PsiExpression left =
PsiUtil.skipParenthesizedExprDown(assignmentExpression.getLExpression());
if (left instanceof PsiReferenceExpression) {
reference = (PsiReferenceExpression) left;
}
readBeforeWrite = assignmentExpression.getOperationTokenType() != JavaTokenType.EQ;
} else if (expression instanceof PsiPostfixExpression) {
final PsiExpression operand =
PsiUtil.skipParenthesizedExprDown(((PsiPostfixExpression) expression).getOperand());
final IElementType sign = ((PsiPostfixExpression) expression).getOperationTokenType();
if (operand instanceof PsiReferenceExpression
&& (sign == JavaTokenType.PLUSPLUS || sign == JavaTokenType.MINUSMINUS)) {
reference = (PsiReferenceExpression) operand;
}
readBeforeWrite = true;
} else if (expression instanceof PsiPrefixExpression) {
final PsiExpression operand =
PsiUtil.skipParenthesizedExprDown(((PsiPrefixExpression) expression).getOperand());
final IElementType sign = ((PsiPrefixExpression) expression).getOperationTokenType();
if (operand instanceof PsiReferenceExpression
&& (sign == JavaTokenType.PLUSPLUS || sign == JavaTokenType.MINUSMINUS)) {
reference = (PsiReferenceExpression) operand;
}
readBeforeWrite = true;
}
final PsiElement resolved = reference == null ? null : reference.resolve();
PsiVariable variable = resolved instanceof PsiVariable ? (PsiVariable) resolved : null;
if (variable == null || !variable.hasModifierProperty(PsiModifier.FINAL)) return null;
final boolean canWrite =
canWriteToFinal(variable, expression, reference, containingFile)
&& checkWriteToFinalInsideLambda(variable, reference) == null;
if (readBeforeWrite || !canWrite) {
final String name = variable.getName();
String description =
canWrite
? JavaErrorMessages.message("variable.not.initialized", name)
: JavaErrorMessages.message("assignment.to.final.variable", name);
final HighlightInfo highlightInfo =
HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR)
.range(reference.getTextRange())
.descriptionAndTooltip(description)
.create();
final PsiElement innerClass = getInnerClassVariableReferencedFrom(variable, expression);
if (innerClass == null || variable instanceof PsiField) {
QuickFixAction.registerQuickFixAction(
highlightInfo,
QUICK_FIX_FACTORY.createModifierListFix(variable, PsiModifier.FINAL, false, false));
} else {
QuickFixAction.registerQuickFixAction(
highlightInfo,
QUICK_FIX_FACTORY.createVariableAccessFromInnerClassFix(variable, innerClass));
}
return highlightInfo;
}
return null;
}
@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;
}