New ObjC warning: circular containers.
This commit adds new warning to prevent user from creating 'circular containers'.
Mutable collections from NSFoundation allows user to add collection to itself, e.g.:
NSMutableArray *a = [NSMutableArray new];
[a addObject:a];
The code above leads to really weird behaviour (crashes, 'endless' recursion) and
retain cycles (collection retains itself) if ARC enabled.
Patch checks the following collections:
- NSMutableArray,
- NSMutableDictionary,
- NSMutableSet,
- NSMutableOrderedSet,
- NSCountedSet.
llvm-svn: 231265
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 884bd7d..eeed7db 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -8187,6 +8187,236 @@
return !isLowercase(str.front());
}
+Optional<int> GetNSMutableArrayArgumentIndex(Sema &S, ObjCMessageExpr *Message) {
+
+ if (S.NSMutableArrayPointer.isNull()) {
+ IdentifierInfo *NSMutableArrayId =
+ S.NSAPIObj->getNSClassId(NSAPI::ClassId_NSMutableArray);
+ NamedDecl *IF = S.LookupSingleName(S.TUScope, NSMutableArrayId,
+ Message->getLocStart(),
+ Sema::LookupOrdinaryName);
+ ObjCInterfaceDecl *InterfaceDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
+ if (!InterfaceDecl) {
+ return None;
+ }
+ QualType NSMutableArrayObject =
+ S.Context.getObjCInterfaceType(InterfaceDecl);
+ S.NSMutableArrayPointer =
+ S.Context.getObjCObjectPointerType(NSMutableArrayObject);
+ }
+
+ if (S.NSMutableArrayPointer != Message->getReceiverType()) {
+ return None;
+ }
+
+ Selector Sel = Message->getSelector();
+
+ Optional<NSAPI::NSArrayMethodKind> MKOpt =
+ S.NSAPIObj->getNSArrayMethodKind(Sel);
+ if (!MKOpt) {
+ return None;
+ }
+
+ NSAPI::NSArrayMethodKind MK = *MKOpt;
+
+ switch (MK) {
+ case NSAPI::NSMutableArr_addObject:
+ case NSAPI::NSMutableArr_insertObjectAtIndex:
+ case NSAPI::NSMutableArr_setObjectAtIndexedSubscript:
+ return 0;
+ case NSAPI::NSMutableArr_replaceObjectAtIndex:
+ return 1;
+
+ default:
+ return None;
+ }
+
+ return None;
+}
+
+static
+Optional<int> GetNSMutableDictionaryArgumentIndex(Sema &S,
+ ObjCMessageExpr *Message) {
+
+ if (S.NSMutableDictionaryPointer.isNull()) {
+ IdentifierInfo *NSMutableDictionaryId =
+ S.NSAPIObj->getNSClassId(NSAPI::ClassId_NSMutableDictionary);
+ NamedDecl *IF = S.LookupSingleName(S.TUScope, NSMutableDictionaryId,
+ Message->getLocStart(),
+ Sema::LookupOrdinaryName);
+ ObjCInterfaceDecl *InterfaceDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
+ if (!InterfaceDecl) {
+ return None;
+ }
+ QualType NSMutableDictionaryObject =
+ S.Context.getObjCInterfaceType(InterfaceDecl);
+ S.NSMutableDictionaryPointer =
+ S.Context.getObjCObjectPointerType(NSMutableDictionaryObject);
+ }
+
+ if (S.NSMutableDictionaryPointer != Message->getReceiverType()) {
+ return None;
+ }
+
+ Selector Sel = Message->getSelector();
+
+ Optional<NSAPI::NSDictionaryMethodKind> MKOpt =
+ S.NSAPIObj->getNSDictionaryMethodKind(Sel);
+ if (!MKOpt) {
+ return None;
+ }
+
+ NSAPI::NSDictionaryMethodKind MK = *MKOpt;
+
+ switch (MK) {
+ case NSAPI::NSMutableDict_setObjectForKey:
+ case NSAPI::NSMutableDict_setValueForKey:
+ case NSAPI::NSMutableDict_setObjectForKeyedSubscript:
+ return 0;
+
+ default:
+ return None;
+ }
+
+ return None;
+}
+
+static Optional<int> GetNSSetArgumentIndex(Sema &S, ObjCMessageExpr *Message) {
+
+ ObjCInterfaceDecl *InterfaceDecl;
+ if (S.NSMutableSetPointer.isNull()) {
+ IdentifierInfo *NSMutableSetId =
+ S.NSAPIObj->getNSClassId(NSAPI::ClassId_NSMutableSet);
+ NamedDecl *IF = S.LookupSingleName(S.TUScope, NSMutableSetId,
+ Message->getLocStart(),
+ Sema::LookupOrdinaryName);
+ InterfaceDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
+ if (InterfaceDecl) {
+ QualType NSMutableSetObject =
+ S.Context.getObjCInterfaceType(InterfaceDecl);
+ S.NSMutableSetPointer =
+ S.Context.getObjCObjectPointerType(NSMutableSetObject);
+ }
+ }
+
+ if (S.NSCountedSetPointer.isNull()) {
+ IdentifierInfo *NSCountedSetId =
+ S.NSAPIObj->getNSClassId(NSAPI::ClassId_NSCountedSet);
+ NamedDecl *IF = S.LookupSingleName(S.TUScope, NSCountedSetId,
+ Message->getLocStart(),
+ Sema::LookupOrdinaryName);
+ InterfaceDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
+ if (InterfaceDecl) {
+ QualType NSCountedSetObject =
+ S.Context.getObjCInterfaceType(InterfaceDecl);
+ S.NSCountedSetPointer =
+ S.Context.getObjCObjectPointerType(NSCountedSetObject);
+ }
+ }
+
+ if (S.NSMutableOrderedSetPointer.isNull()) {
+ IdentifierInfo *NSOrderedSetId =
+ S.NSAPIObj->getNSClassId(NSAPI::ClassId_NSMutableOrderedSet);
+ NamedDecl *IF = S.LookupSingleName(S.TUScope, NSOrderedSetId,
+ Message->getLocStart(),
+ Sema::LookupOrdinaryName);
+ InterfaceDecl = dyn_cast_or_null<ObjCInterfaceDecl>(IF);
+ if (InterfaceDecl) {
+ QualType NSOrderedSetObject =
+ S.Context.getObjCInterfaceType(InterfaceDecl);
+ S.NSMutableOrderedSetPointer =
+ S.Context.getObjCObjectPointerType(NSOrderedSetObject);
+ }
+ }
+
+ QualType ReceiverType = Message->getReceiverType();
+
+ bool IsMutableSet = !S.NSMutableSetPointer.isNull() &&
+ ReceiverType == S.NSMutableSetPointer;
+ bool IsMutableOrderedSet = !S.NSMutableOrderedSetPointer.isNull() &&
+ ReceiverType == S.NSMutableOrderedSetPointer;
+ bool IsCountedSet = !S.NSCountedSetPointer.isNull() &&
+ ReceiverType == S.NSCountedSetPointer;
+
+ if (!IsMutableSet && !IsMutableOrderedSet && !IsCountedSet) {
+ return None;
+ }
+
+ Selector Sel = Message->getSelector();
+
+ Optional<NSAPI::NSSetMethodKind> MKOpt = S.NSAPIObj->getNSSetMethodKind(Sel);
+ if (!MKOpt) {
+ return None;
+ }
+
+ NSAPI::NSSetMethodKind MK = *MKOpt;
+
+ switch (MK) {
+ case NSAPI::NSMutableSet_addObject:
+ case NSAPI::NSOrderedSet_setObjectAtIndex:
+ case NSAPI::NSOrderedSet_setObjectAtIndexedSubscript:
+ case NSAPI::NSOrderedSet_insertObjectAtIndex:
+ return 0;
+ case NSAPI::NSOrderedSet_replaceObjectAtIndexWithObject:
+ return 1;
+ }
+
+ return None;
+}
+
+void Sema::CheckObjCCircularContainer(ObjCMessageExpr *Message) {
+ if (!Message->isInstanceMessage()) {
+ return;
+ }
+
+ Optional<int> ArgOpt;
+
+ if (!(ArgOpt = GetNSMutableArrayArgumentIndex(*this, Message)) &&
+ !(ArgOpt = GetNSMutableDictionaryArgumentIndex(*this, Message)) &&
+ !(ArgOpt = GetNSSetArgumentIndex(*this, Message))) {
+ return;
+ }
+
+ int ArgIndex = *ArgOpt;
+
+ Expr *Receiver = Message->getInstanceReceiver()->IgnoreImpCasts();
+ if (OpaqueValueExpr *OE = dyn_cast<OpaqueValueExpr>(Receiver)) {
+ Receiver = OE->getSourceExpr()->IgnoreImpCasts();
+ }
+
+ Expr *Arg = Message->getArg(ArgIndex)->IgnoreImpCasts();
+ if (OpaqueValueExpr *OE = dyn_cast<OpaqueValueExpr>(Arg)) {
+ Arg = OE->getSourceExpr()->IgnoreImpCasts();
+ }
+
+ if (DeclRefExpr *ReceiverRE = dyn_cast<DeclRefExpr>(Receiver)) {
+ if (DeclRefExpr *ArgRE = dyn_cast<DeclRefExpr>(Arg)) {
+ if (ReceiverRE->getDecl() == ArgRE->getDecl()) {
+ ValueDecl *Decl = ReceiverRE->getDecl();
+ Diag(Message->getSourceRange().getBegin(),
+ diag::warn_objc_circular_container)
+ << Decl->getName();
+ Diag(Decl->getLocation(),
+ diag::note_objc_circular_container_declared_here)
+ << Decl->getName();
+ }
+ }
+ } else if (ObjCIvarRefExpr *IvarRE = dyn_cast<ObjCIvarRefExpr>(Receiver)) {
+ if (ObjCIvarRefExpr *IvarArgRE = dyn_cast<ObjCIvarRefExpr>(Arg)) {
+ if (IvarRE->getDecl() == IvarArgRE->getDecl()) {
+ ObjCIvarDecl *Decl = IvarRE->getDecl();
+ Diag(Message->getSourceRange().getBegin(),
+ diag::warn_objc_circular_container)
+ << Decl->getName();
+ Diag(Decl->getLocation(),
+ diag::note_objc_circular_container_declared_here)
+ << Decl->getName();
+ }
+ }
+ }
+
+}
+
/// Check a message send to see if it's likely to cause a retain cycle.
void Sema::checkRetainCycles(ObjCMessageExpr *msg) {
// Only check instance methods whose selector looks like a setter.