/**
* Finds the constant definition that contains aAST.
*
* @param ast the AST
* @return the constant def or null if ast is not contained in a constant definition
*/
private DetailAST findContainingConstantDef(DetailAST ast) {
DetailAST varDefAST = ast;
while (varDefAST != null
&& varDefAST.getType() != TokenTypes.VARIABLE_DEF
&& varDefAST.getType() != TokenTypes.ENUM_CONSTANT_DEF) {
varDefAST = varDefAST.getParent();
}
// no containing variable definition?
if (varDefAST == null) {
return null;
}
// implicit constant?
if (ScopeUtils.inInterfaceOrAnnotationBlock(varDefAST)
|| varDefAST.getType() == TokenTypes.ENUM_CONSTANT_DEF) {
return varDefAST;
}
// explicit constant
final DetailAST modifiersAST = varDefAST.findFirstToken(TokenTypes.MODIFIERS);
if (modifiersAST.branchContains(TokenTypes.FINAL)) {
return varDefAST;
}
return null;
}
@Override
public void visitToken(DetailAST ast) {
// do not check local variables and
// fields declared in interface/annotations
if (ScopeUtils.isLocalVariableDef(ast) || ScopeUtils.inInterfaceOrAnnotationBlock(ast)) {
return;
}
final DetailAST assign = ast.findFirstToken(TokenTypes.ASSIGN);
if (assign == null) {
// no assign - no check
return;
}
final DetailAST modifiers = ast.findFirstToken(TokenTypes.MODIFIERS);
if (modifiers != null && modifiers.branchContains(TokenTypes.FINAL)) {
// do not check final variables
return;
}
final DetailAST type = ast.findFirstToken(TokenTypes.TYPE);
final DetailAST ident = ast.findFirstToken(TokenTypes.IDENT);
final DetailAST exprStart = assign.getFirstChild().getFirstChild();
if (isObjectType(type) && exprStart.getType() == TokenTypes.LITERAL_NULL) {
log(ident, MSG_KEY, ident.getText(), "null");
}
final int primitiveType = type.getFirstChild().getType();
if (primitiveType == TokenTypes.LITERAL_BOOLEAN
&& exprStart.getType() == TokenTypes.LITERAL_FALSE) {
log(ident, MSG_KEY, ident.getText(), "false");
}
if (isNumericType(primitiveType) && isZero(exprStart)) {
log(ident, MSG_KEY, ident.getText(), "0");
}
if (primitiveType == TokenTypes.LITERAL_CHAR
&& (isZero(exprStart)
|| exprStart.getType() == TokenTypes.CHAR_LITERAL
&& "'\\0'".equals(exprStart.getText()))) {
log(ident, MSG_KEY, ident.getText(), "\\0");
}
}
