/**
* @param sideEffects if null, delete usages, otherwise collect side effects
* @return true if there are at least one unrecoverable side effect found, false if no side
* effects, null if read usage found (may happen if interval between fix creation in invoke()
* call was long enough)
* @throws com.intellij.util.IncorrectOperationException
*/
static Boolean processUsage(
PsiElement element, PsiVariable variable, List<PsiElement> sideEffects, int deleteMode)
throws IncorrectOperationException {
if (!element.isValid()) return null;
PsiElementFactory factory =
JavaPsiFacade.getInstance(variable.getProject()).getElementFactory();
while (element != null) {
if (element instanceof PsiAssignmentExpression) {
PsiAssignmentExpression expression = (PsiAssignmentExpression) element;
PsiExpression lExpression = expression.getLExpression();
// there should not be read access to the variable, otherwise it is not unused
if (!(lExpression instanceof PsiReferenceExpression)
|| variable != ((PsiReferenceExpression) lExpression).resolve()) {
return null;
}
PsiExpression rExpression = expression.getRExpression();
rExpression = PsiUtil.deparenthesizeExpression(rExpression);
if (rExpression == null) return true;
// replace assignment with expression and resimplify
boolean sideEffectFound = checkSideEffects(rExpression, variable, sideEffects);
if (!(element.getParent() instanceof PsiExpressionStatement)
|| PsiUtil.isStatement(rExpression)) {
if (deleteMode == MAKE_STATEMENT
|| deleteMode == DELETE_ALL
&& !(element.getParent() instanceof PsiExpressionStatement)) {
element = replaceElementWithExpression(rExpression, factory, element);
while (element.getParent() instanceof PsiParenthesizedExpression) {
element = element.getParent().replace(element);
}
List<PsiElement> references = new ArrayList<PsiElement>();
collectReferences(element, variable, references);
deleteReferences(variable, references, deleteMode);
} else if (deleteMode == DELETE_ALL) {
deleteWholeStatement(element, factory);
}
return true;
} else {
if (deleteMode != CANCEL) {
deleteWholeStatement(element, factory);
}
return !sideEffectFound;
}
} else if (element instanceof PsiExpressionStatement && deleteMode != CANCEL) {
final PsiElement parent = element.getParent();
if (parent instanceof PsiIfStatement
|| parent instanceof PsiLoopStatement
&& ((PsiLoopStatement) parent).getBody() == element) {
element.replace(
JavaPsiFacade.getElementFactory(element.getProject())
.createStatementFromText(";", element));
} else {
element.delete();
}
break;
} else if (element instanceof PsiVariable && element == variable) {
PsiExpression expression = variable.getInitializer();
if (expression != null) {
expression = PsiUtil.deparenthesizeExpression(expression);
}
boolean sideEffectsFound = checkSideEffects(expression, variable, sideEffects);
if (expression != null
&& PsiUtil.isStatement(expression)
&& variable instanceof PsiLocalVariable
&& !(variable.getParent() instanceof PsiDeclarationStatement
&& ((PsiDeclarationStatement) variable.getParent()).getDeclaredElements().length
> 1)) {
if (deleteMode == MAKE_STATEMENT) {
element = element.replace(createStatementIfNeeded(expression, factory, element));
List<PsiElement> references = new ArrayList<PsiElement>();
collectReferences(element, variable, references);
deleteReferences(variable, references, deleteMode);
} else if (deleteMode == DELETE_ALL) {
element.delete();
}
return true;
} else {
if (deleteMode != CANCEL) {
if (element instanceof PsiField) {
((PsiField) element).normalizeDeclaration();
}
element.delete();
}
return !sideEffectsFound;
}
}
element = element.getParent();
}
return true;
}
