void ObjCNonNilReturnValueChecker::checkPostObjCMessage(const ObjCMethodCall &M,
CheckerContext &C)
const {
ProgramStateRef State = C.getState();
if (!Initialized) {
ASTContext &Ctx = C.getASTContext();
ObjectAtIndex = GetUnarySelector("objectAtIndex", Ctx);
ObjectAtIndexedSubscript = GetUnarySelector("objectAtIndexedSubscript", Ctx);
NullSelector = GetNullarySelector("null", Ctx);
}
// Check the receiver type.
if (const ObjCInterfaceDecl *Interface = M.getReceiverInterface()) {
// Assume that object returned from '[self init]' or '[super init]' is not
// 'nil' if we are processing an inlined function/method.
//
// A defensive callee will (and should) check if the object returned by
// '[super init]' is 'nil' before doing it's own initialization. However,
// since 'nil' is rarely returned in practice, we should not warn when the
// caller to the defensive constructor uses the object in contexts where
// 'nil' is not accepted.
if (!C.inTopFrame() && M.getDecl() &&
M.getDecl()->getMethodFamily() == OMF_init &&
M.isReceiverSelfOrSuper()) {
State = assumeExprIsNonNull(M.getOriginExpr(), State, C);
}
FoundationClass Cl = findKnownClass(Interface);
// Objects returned from
// [NSArray|NSOrderedSet]::[ObjectAtIndex|ObjectAtIndexedSubscript]
// are never 'nil'.
if (Cl == FC_NSArray || Cl == FC_NSOrderedSet) {
Selector Sel = M.getSelector();
if (Sel == ObjectAtIndex || Sel == ObjectAtIndexedSubscript) {
// Go ahead and assume the value is non-nil.
State = assumeExprIsNonNull(M.getOriginExpr(), State, C);
}
}
// Objects returned from [NSNull null] are not nil.
if (Cl == FC_NSNull) {
if (M.getSelector() == NullSelector) {
// Go ahead and assume the value is non-nil.
State = assumeExprIsNonNull(M.getOriginExpr(), State, C);
}
}
}
C.addTransition(State);
}
