@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;
}
