[analyzer] Add osx.cocoa.NonNilReturnValue checker.
The checker adds assumptions that the return values from the known APIs
are non-nil. Teach the checker about NSArray/NSMutableArray/NSOrderedSet
objectAtIndex, objectAtIndexedSubscript.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162398 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp b/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp
index 955e79a..3dda6d0 100644
--- a/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp
+++ b/lib/StaticAnalyzer/Checkers/BasicObjCFoundationChecks.cpp
@@ -716,6 +716,47 @@
C.addTransition(State);
}
+namespace {
+/// \class ObjCNonNilReturnValueChecker
+/// \brief The checker restricts the return values of APIs known to never
+/// return nil.
+class ObjCNonNilReturnValueChecker
+ : public Checker<check::PostObjCMessage> {
+ mutable bool Initialized;
+ mutable Selector ObjectAtIndex;
+ mutable Selector ObjectAtIndexedSubscript;
+public:
+ void checkPostObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const;
+};
+}
+
+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);
+ }
+
+ // Check the receiver type.
+ if (const ObjCInterfaceDecl *Interface = M.getReceiverInterface()) {
+ FoundationClass Cl = findKnownClass(Interface);
+ 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.
+ SVal Val = State->getSVal(M.getOriginExpr(), C.getLocationContext());
+ if (!isa<DefinedOrUnknownSVal>(Val))
+ return;
+ State = State->assume(cast<DefinedOrUnknownSVal>(Val), true);
+ C.addTransition(State);
+ }
+ }
+ }
+}
//===----------------------------------------------------------------------===//
// Check registration.
@@ -744,3 +785,7 @@
void ento::registerObjCLoopChecker(CheckerManager &mgr) {
mgr.registerChecker<ObjCLoopChecker>();
}
+
+void ento::registerObjCNonNilReturnValueChecker(CheckerManager &mgr) {
+ mgr.registerChecker<ObjCNonNilReturnValueChecker>();
+}