From: John McCall Date: Tue, 19 Mar 2013 07:04:25 +0000 (+0000) Subject: Add a clarifying note when a return statement is rejected because X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7cca821e1acf0f1b4fe892c3111bfb2086832e4e;p=clang Add a clarifying note when a return statement is rejected because we expect a related result type. rdar://12493140 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177378 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td index e08c5fc985..93f0697a56 100644 --- a/include/clang/Basic/DiagnosticSemaKinds.td +++ b/include/clang/Basic/DiagnosticSemaKinds.td @@ -6198,15 +6198,19 @@ def warn_related_result_type_compatibility_class : Warning< def warn_related_result_type_compatibility_protocol : Warning< "protocol method is expected to return an instance of the implementing " "class, but is declared to return %0">; -def note_related_result_type_overridden_family : Note< - "overridden method is part of the '%select{|alloc|copy|init|mutableCopy|" - "new|autorelease|dealloc|finalize|release|retain|retainCount|self}0' method " - "family">; +def note_related_result_type_family : Note< + "%select{overridden|current}0 method is part of the '%select{|alloc|copy|init|" + "mutableCopy|new|autorelease|dealloc|finalize|release|retain|retainCount|" + "self}1' method family%select{| and is expected to return an instance of its " + "class type}0">; def note_related_result_type_overridden : Note< "overridden method returns an instance of its class type">; def note_related_result_type_inferred : Note< "%select{class|instance}0 method %1 is assumed to return an instance of " "its receiver type (%2)">; +def note_related_result_type_explicit : Note< + "%select{overridden|current}0 method is explicitly declared 'instancetype'" + "%select{| and is expected to return an instance of its class type}0">; } diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h index 9205e2a4a8..3f3fcb57a1 100644 --- a/include/clang/Sema/Sema.h +++ b/include/clang/Sema/Sema.h @@ -7026,6 +7026,11 @@ public: /// with a related result type, emit a note describing what happened. void EmitRelatedResultTypeNote(const Expr *E); + /// \brief Given that we had incompatible pointer types in a return + /// statement, check whether we're in a method with a related result + /// type, and if so, emit a note describing what happened. + void EmitRelatedResultTypeNoteForReturn(QualType destType); + /// CheckBooleanCondition - Diagnose problems involving the use of /// the given expression as a boolean condition (e.g. in an if /// statement). Also performs the standard function and array diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp index 759f6c9e8b..4bb5d72b28 100644 --- a/lib/Sema/SemaDeclObjC.cpp +++ b/lib/Sema/SemaDeclObjC.cpp @@ -151,7 +151,8 @@ void Sema::CheckObjCMethodOverride(ObjCMethodDecl *NewMethod, if (ObjCMethodFamily Family = Overridden->getMethodFamily()) Diag(Overridden->getLocation(), - diag::note_related_result_type_overridden_family) + diag::note_related_result_type_family) + << /*overridden method*/ 0 << Family; else Diag(Overridden->getLocation(), diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp index bf4632c7bf..e4323c35a6 100644 --- a/lib/Sema/SemaExpr.cpp +++ b/lib/Sema/SemaExpr.cpp @@ -10039,6 +10039,9 @@ bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, if (CheckInferredResultType) EmitRelatedResultTypeNote(SrcExpr); + + if (Action == AA_Returning && ConvTy == IncompatiblePointer) + EmitRelatedResultTypeNoteForReturn(DstType); if (Complained) *Complained = true; diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp index b0d5453808..af8380df18 100644 --- a/lib/Sema/SemaExprObjC.cpp +++ b/lib/Sema/SemaExprObjC.cpp @@ -1094,6 +1094,73 @@ QualType Sema::getMessageSendResultType(QualType ReceiverType, return ReceiverType; } +/// Look for an ObjC method whose result type exactly matches the given type. +static const ObjCMethodDecl * +findExplicitInstancetypeDeclarer(const ObjCMethodDecl *MD, + QualType instancetype) { + if (MD->getResultType() == instancetype) return MD; + + // For these purposes, a method in an @implementation overrides a + // declaration in the @interface. + if (const ObjCImplDecl *impl = + dyn_cast(MD->getDeclContext())) { + const ObjCContainerDecl *iface; + if (const ObjCCategoryImplDecl *catImpl = + dyn_cast(impl)) { + iface = catImpl->getCategoryDecl(); + } else { + iface = impl->getClassInterface(); + } + + const ObjCMethodDecl *ifaceMD = + iface->getMethod(MD->getSelector(), MD->isInstanceMethod()); + if (ifaceMD) return findExplicitInstancetypeDeclarer(ifaceMD, instancetype); + } + + SmallVector overrides; + MD->getOverriddenMethods(overrides); + for (unsigned i = 0, e = overrides.size(); i != e; ++i) { + if (const ObjCMethodDecl *result = + findExplicitInstancetypeDeclarer(overrides[i], instancetype)) + return result; + } + + return 0; +} + +void Sema::EmitRelatedResultTypeNoteForReturn(QualType destType) { + // Only complain if we're in an ObjC method and the required return + // type doesn't match the method's declared return type. + ObjCMethodDecl *MD = dyn_cast(CurContext); + if (!MD || !MD->hasRelatedResultType() || + Context.hasSameUnqualifiedType(destType, MD->getResultType())) + return; + + // Look for a method overridden by this method which explicitly uses + // 'instancetype'. + if (const ObjCMethodDecl *overridden = + findExplicitInstancetypeDeclarer(MD, Context.getObjCInstanceType())) { + SourceLocation loc; + SourceRange range; + if (TypeSourceInfo *TSI = overridden->getResultTypeSourceInfo()) { + range = TSI->getTypeLoc().getSourceRange(); + loc = range.getBegin(); + } + if (loc.isInvalid()) + loc = overridden->getLocation(); + Diag(loc, diag::note_related_result_type_explicit) + << /*current method*/ 1 << range; + return; + } + + // Otherwise, if we have an interesting method family, note that. + // This should always trigger if the above didn't. + if (ObjCMethodFamily family = MD->getMethodFamily()) + Diag(MD->getLocation(), diag::note_related_result_type_family) + << /*current method*/ 1 + << family; +} + void Sema::EmitRelatedResultTypeNote(const Expr *E) { E = E->IgnoreParenImpCasts(); const ObjCMessageExpr *MsgSend = dyn_cast(E); diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp index 2ddabbdb26..75aa17bf07 100644 --- a/lib/Sema/SemaInit.cpp +++ b/lib/Sema/SemaInit.cpp @@ -5590,6 +5590,26 @@ static bool DiagnoseUninitializedReference(Sema &S, SourceLocation Loc, //===----------------------------------------------------------------------===// // Diagnose initialization failures //===----------------------------------------------------------------------===// + +/// Emit notes associated with an initialization that failed due to a +/// "simple" conversion failure. +static void emitBadConversionNotes(Sema &S, const InitializedEntity &entity, + Expr *op) { + QualType destType = entity.getType(); + if (destType.getNonReferenceType()->isObjCObjectPointerType() && + op->getType()->isObjCObjectPointerType()) { + + // Emit a possible note about the conversion failing because the + // operand is a message send with a related result type. + S.EmitRelatedResultTypeNote(op); + + // Emit a possible note about a return failing because we're + // expecting a related result type. + if (entity.getKind() == InitializedEntity::EK_Result) + S.EmitRelatedResultTypeNoteForReturn(destType); + } +} + bool InitializationSequence::Diagnose(Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind, @@ -5734,9 +5754,7 @@ bool InitializationSequence::Diagnose(Sema &S, << Args[0]->isLValue() << Args[0]->getType() << Args[0]->getSourceRange(); - if (DestType.getNonReferenceType()->isObjCObjectPointerType() && - Args[0]->getType()->isObjCObjectPointerType()) - S.EmitRelatedResultTypeNote(Args[0]); + emitBadConversionNotes(S, Entity, Args[0]); break; case FK_ConversionFailed: { @@ -5749,9 +5767,7 @@ bool InitializationSequence::Diagnose(Sema &S, << Args[0]->getSourceRange(); S.HandleFunctionTypeMismatch(PDiag, FromType, DestType); S.Diag(Kind.getLocation(), PDiag); - if (DestType.getNonReferenceType()->isObjCObjectPointerType() && - Args[0]->getType()->isObjCObjectPointerType()) - S.EmitRelatedResultTypeNote(Args[0]); + emitBadConversionNotes(S, Entity, Args[0]); break; } diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp index b5b35fc48b..0c51e44371 100644 --- a/lib/Sema/SemaStmt.cpp +++ b/lib/Sema/SemaStmt.cpp @@ -2536,20 +2536,7 @@ Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { if (!FnRetType->isDependentType() && !RetValExp->isTypeDependent()) { // we have a non-void function with an expression, continue checking - if (!RelatedRetType.isNull()) { - // If we have a related result type, perform an extra conversion here. - // FIXME: The diagnostics here don't really describe what is happening. - InitializedEntity Entity = - InitializedEntity::InitializeTemporary(RelatedRetType); - - ExprResult Res = PerformCopyInitialization(Entity, SourceLocation(), - RetValExp); - if (Res.isInvalid()) { - // FIXME: Cleanup temporaries here, anyway? - return StmtError(); - } - RetValExp = Res.takeAs(); - } + QualType RetType = (RelatedRetType.isNull() ? FnRetType : RelatedRetType); // C99 6.8.6.4p3(136): The return statement is not an assignment. The // overlap restriction of subclause 6.5.16.1 does not apply to the case of @@ -2559,18 +2546,33 @@ Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { // the C version of which boils down to CheckSingleAssignmentConstraints. NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, - FnRetType, + RetType, NRVOCandidate != 0); ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, - FnRetType, RetValExp); + RetType, RetValExp); if (Res.isInvalid()) { - // FIXME: Cleanup temporaries here, anyway? + // FIXME: Clean up temporaries here anyway? return StmtError(); } - RetValExp = Res.takeAs(); - if (RetValExp) - CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); + + // If we have a related result type, we need to implicitly + // convert back to the formal result type. We can't pretend to + // initialize the result again --- we might end double-retaining + // --- so instead we initialize a notional temporary; this can + // lead to less-than-great diagnostics, but this stage is much + // less likely to fail than the previous stage. + if (!RelatedRetType.isNull()) { + Entity = InitializedEntity::InitializeTemporary(FnRetType); + Res = PerformCopyInitialization(Entity, ReturnLoc, RetValExp); + if (Res.isInvalid()) { + // FIXME: Clean up temporaries here anyway? + return StmtError(); + } + RetValExp = Res.takeAs(); + } + + CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); } if (RetValExp) { diff --git a/test/CodeGenObjC/arc.m b/test/CodeGenObjC/arc.m index 0ef3d89510..3778625aa9 100644 --- a/test/CodeGenObjC/arc.m +++ b/test/CodeGenObjC/arc.m @@ -621,7 +621,9 @@ void test21(unsigned n) { // CHECK-NEXT: store i8* {{%.*}}, i8** [[CMD]] // CHECK-NEXT: [[T0:%.*]] = load [[TEST27]]** [[SELF]] // CHECK-NEXT: [[T1:%.*]] = bitcast [[TEST27]]* [[T0]] to i8* -// CHECK-NEXT: [[RET:%.*]] = call i8* @objc_retain(i8* [[T1]]) +// CHECK-NEXT: [[T2:%.*]] = call i8* @objc_retain(i8* [[T1]]) +// CHECK-NEXT: [[T3:%.*]] = bitcast i8* [[T2]] to [[TEST27]]* +// CHECK-NEXT: [[RET:%.*]] = bitcast [[TEST27]]* [[T3]] to i8* // CHECK-NEXT: store i32 {{[0-9]+}}, i32* [[DEST]] // CHECK-NEXT: [[T0:%.*]] = load [[TEST27]]** [[SELF]] // CHECK-NEXT: [[T1:%.*]] = bitcast [[TEST27]]* [[T0]] to i8* @@ -685,7 +687,9 @@ static id _test29_allocator = 0; // Return statement. // CHECK-NEXT: [[T2:%.*]] = bitcast i8* [[CALL]] // CHECK-NEXT: [[CALL:%.*]] = bitcast -// CHECK-NEXT: [[RET:%.*]] = call i8* @objc_retain(i8* [[CALL]]) [[NUW]] +// CHECK-NEXT: [[T0:%.*]] = call i8* @objc_retain(i8* [[CALL]]) [[NUW]] +// CHECK-NEXT: [[T1:%.*]] = bitcast i8* [[T0]] to [[TEST29]]* +// CHECK-NEXT: [[RET:%.*]] = bitcast [[TEST29]]* [[T1]] to i8* // CHECK-NEXT: store i32 1, i32* [[CLEANUP]] // Cleanup. @@ -739,7 +743,9 @@ static id _test29_allocator = 0; // Return statement. // CHECK-NEXT: [[T0:%.*]] = load [[TEST29]]** [[SELF]] // CHECK-NEXT: [[T1:%.*]] = bitcast [[TEST29]]* [[T0]] to i8* -// CHECK-NEXT: [[RET:%.*]] = call i8* @objc_retain(i8* [[T1]]) [[NUW]] +// CHECK-NEXT: [[T0:%.*]] = call i8* @objc_retain(i8* [[T1]]) [[NUW]] +// CHECK-NEXT: [[T1:%.*]] = bitcast i8* [[T0]] to [[TEST29]]* +// CHECK-NEXT: [[RET:%.*]] = bitcast [[TEST29]]* [[T1]] to i8* // CHECK-NEXT: store i32 1, i32* [[CLEANUP]] // Cleanup. @@ -794,7 +800,9 @@ char *helper; // Return. // CHECK-NEXT: [[T0:%.*]] = load [[TEST30]]** [[SELF]] // CHECK-NEXT: [[T1:%.*]] = bitcast [[TEST30]]* [[T0]] to i8* -// CHECK-NEXT: [[RET:%.*]] = call i8* @objc_retain(i8* [[T1]]) +// CHECK-NEXT: [[T0:%.*]] = call i8* @objc_retain(i8* [[T1]]) +// CHECK-NEXT: [[T1:%.*]] = bitcast i8* [[T0]] to [[TEST30]]* +// CHECK-NEXT: [[RET:%.*]] = bitcast [[TEST30]]* [[T1]] to i8* // CHECK-NEXT: store i32 1 // Cleanup. diff --git a/test/SemaObjC/instancetype.m b/test/SemaObjC/instancetype.m index 40f35d93b2..8137964737 100644 --- a/test/SemaObjC/instancetype.m +++ b/test/SemaObjC/instancetype.m @@ -5,9 +5,9 @@ #endif @interface Root -+ (instancetype)alloc; ++ (instancetype)alloc; // expected-note {{explicitly declared 'instancetype'}} - (instancetype)init; // expected-note{{overridden method is part of the 'init' method family}} -- (instancetype)self; +- (instancetype)self; // expected-note {{explicitly declared 'instancetype'}} - (Class)class; @property (assign) Root *selfProp; @@ -143,7 +143,7 @@ void test_instancetype_narrow_method_search() { @implementation Subclass4 + (id)alloc { - return self; // expected-warning{{incompatible pointer types casting 'Class' to type 'Subclass4 *'}} + return self; // expected-warning{{incompatible pointer types returning 'Class' from a function with result type 'Subclass4 *'}} } - (Subclass3 *)init { return 0; } // don't complain: we lost the related return type @@ -164,14 +164,14 @@ void test_instancetype_inherited() { // Check that related return types tighten up the semantics of // Objective-C method implementations. @implementation Subclass2 -- (instancetype)initSubclass2 { +- (instancetype)initSubclass2 { // expected-note {{explicitly declared 'instancetype'}} Subclass1 *sc1 = [[Subclass1 alloc] init]; - return sc1; // expected-warning{{incompatible pointer types casting 'Subclass1 *' to type 'Subclass2 *'}} + return sc1; // expected-warning{{incompatible pointer types returning 'Subclass1 *' from a function with result type 'Subclass2 *'}} } - (void)methodOnSubclass2 {} - (id)self { Subclass1 *sc1 = [[Subclass1 alloc] init]; - return sc1; // expected-warning{{incompatible pointer types casting 'Subclass1 *' to type 'Subclass2 *'}} + return sc1; // expected-warning{{incompatible pointer types returning 'Subclass1 *' from a function with result type 'Subclass2 *'}} } @end @@ -188,3 +188,29 @@ void test_instancetype_inherited() { @end +// rdar://12493140 +@protocol P4 +- (instancetype) foo; // expected-note {{current method is explicitly declared 'instancetype' and is expected to return an instance of its class type}} +@end +@interface A4 : Root +- (instancetype) bar; // expected-note {{current method is explicitly declared 'instancetype' and is expected to return an instance of its class type}} +- (instancetype) baz; // expected-note {{overridden method returns an instance of its class type}} expected-note {{previous definition is here}} +@end +@interface B4 : Root @end + +@implementation A4 { + B4 *_b; +} +- (id) foo { + return _b; // expected-warning {{incompatible pointer types returning 'B4 *' from a function with result type 'A4 *'}} +} +- (id) bar { + return _b; // expected-warning {{incompatible pointer types returning 'B4 *' from a function with result type 'A4 *'}} +} + +// This is really just to ensure that we don't crash. +// FIXME: only one diagnostic, please +- (float) baz { // expected-warning {{method is expected to return an instance of its class type 'A4', but is declared to return 'float'}} expected-warning {{conflicting return type in implementation}} + return 0; +} +@end diff --git a/test/SemaObjC/related-result-type-inference.m b/test/SemaObjC/related-result-type-inference.m index b1d77dc172..50aaf2da4d 100644 --- a/test/SemaObjC/related-result-type-inference.m +++ b/test/SemaObjC/related-result-type-inference.m @@ -175,7 +175,7 @@ void test_inference() { @implementation Fail - (id) initWithX { - return (id)self; // expected-warning {{returning 'Fail *' from a function with incompatible result type 'id'}} + return (id)self; // expected-warning {{casting 'Fail *' to incompatible type 'id'}} } @end diff --git a/test/SemaObjCXX/instancetype.mm b/test/SemaObjCXX/instancetype.mm new file mode 100644 index 0000000000..bbf100ef04 --- /dev/null +++ b/test/SemaObjCXX/instancetype.mm @@ -0,0 +1,216 @@ +// RUN: %clang_cc1 -fsyntax-only -verify %s + +#if !__has_feature(objc_instancetype) +# error Missing 'instancetype' feature macro. +#endif + +@interface Root ++ (instancetype)alloc; +- (instancetype)init; // expected-note{{overridden method is part of the 'init' method family}} +- (instancetype)self; // expected-note {{explicitly declared 'instancetype'}} +- (Class)class; + +@property (assign) Root *selfProp; +- (instancetype)selfProp; +@end + +@protocol Proto1 +@optional +- (instancetype)methodInProto1; +@end + +@protocol Proto2 +@optional +- (instancetype)methodInProto2; // expected-note{{overridden method returns an instance of its class type}} +- (instancetype)otherMethodInProto2; // expected-note{{overridden method returns an instance of its class type}} +@end + +@interface Subclass1 : Root +- (instancetype)initSubclass1; +- (void)methodOnSubclass1; ++ (instancetype)allocSubclass1; +@end + +@interface Subclass2 : Root +- (instancetype)initSubclass2; +- (void)methodOnSubclass2; +@end + +// Sanity check: the basic initialization pattern. +void test_instancetype_alloc_init_simple() { + Root *r1 = [[Root alloc] init]; + Subclass1 *sc1 = [[Subclass1 alloc] init]; +} + +// Test that message sends to instancetype methods have the right type. +void test_instancetype_narrow_method_search() { + // instancetype on class methods + Subclass1 *sc1 = [[Subclass1 alloc] initSubclass2]; // expected-warning{{'Subclass1' may not respond to 'initSubclass2'}} + Subclass2 *sc2 = [[Subclass2 alloc] initSubclass2]; // okay + + // instancetype on instance methods + [[[Subclass1 alloc] init] methodOnSubclass2]; // expected-warning{{'Subclass1' may not respond to 'methodOnSubclass2'}} + [[[Subclass2 alloc] init] methodOnSubclass2]; + + // instancetype on class methods using protocols + typedef Subclass1 SC1Proto1; + typedef Subclass1 SC1Proto2; + [[SC1Proto1 alloc] methodInProto2]; // expected-warning{{method '-methodInProto2' not found (return type defaults to 'id')}} + [[SC1Proto2 alloc] methodInProto2]; + + // instancetype on instance methods + Subclass1 *sc1proto1 = 0; + [[sc1proto1 self] methodInProto2]; // expected-warning{{method '-methodInProto2' not found (return type defaults to 'id')}} + Subclass1 *sc1proto2 = 0; + [[sc1proto2 self] methodInProto2]; + + // Exact type checks + typeof([[Subclass1 alloc] init]) *ptr1 = (Subclass1 **)0; + typeof([[Subclass2 alloc] init]) *ptr2 = (Subclass2 **)0; + + // Message sends to Class. + Subclass1 *sc1proto1_2 = [[[sc1proto1 class] alloc] init]; + + // Property access + [sc1proto1.self methodInProto2]; // expected-warning{{method '-methodInProto2' not found (return type defaults to 'id')}} + [sc1proto2.self methodInProto2]; + [Subclass1.alloc initSubclass2]; // expected-warning{{'Subclass1' may not respond to 'initSubclass2'}} + [Subclass2.alloc initSubclass2]; + + [sc1proto1.selfProp methodInProto2]; // expected-warning{{method '-methodInProto2' not found (return type defaults to 'id')}} + [sc1proto2.selfProp methodInProto2]; +} + +// Test that message sends to super methods have the right type. +@interface Subsubclass1 : Subclass1 +- (instancetype)initSubclass1; ++ (instancetype)allocSubclass1; + +- (void)onlyInSubsubclass1; +@end + +@implementation Subsubclass1 +- (instancetype)initSubclass1 { + // Check based on method search. + [[super initSubclass1] methodOnSubclass2]; // expected-warning{{'Subsubclass1' may not respond to 'methodOnSubclass2'}} + [super.initSubclass1 methodOnSubclass2]; // expected-warning{{'Subsubclass1' may not respond to 'methodOnSubclass2'}} + + self = [super init]; // common pattern + + // Exact type check. + typeof([super initSubclass1]) *ptr1 = (Subsubclass1**)0; + + return self; +} + ++ (instancetype)allocSubclass1 { + // Check based on method search. + [[super allocSubclass1] methodOnSubclass2]; // expected-warning{{'Subsubclass1' may not respond to 'methodOnSubclass2'}} + + // The ASTs don't model super property accesses well enough to get this right + [super.allocSubclass1 methodOnSubclass2]; // expected-warning{{'Subsubclass1' may not respond to 'methodOnSubclass2'}} + + // Exact type check. + typeof([super allocSubclass1]) *ptr1 = (Subsubclass1**)0; + + return [super allocSubclass1]; +} + +- (void)onlyInSubsubclass1 {} +@end + +// Check compatibility rules for inheritance of related return types. +@class Subclass4; + +@interface Subclass3 +- (Subclass3 *)methodInProto1; +- (Subclass4 *)methodInProto2; // expected-warning{{method is expected to return an instance of its class type 'Subclass3', but is declared to return 'Subclass4 *'}} +@end + +@interface Subclass4 : Root ++ (Subclass4 *)alloc; // okay +- (Subclass3 *)init; // expected-warning{{method is expected to return an instance of its class type 'Subclass4', but is declared to return 'Subclass3 *'}} +- (id)self; // expected-note{{overridden method is part of the 'self' method family}} +- (instancetype)initOther; +@end + +@protocol Proto3 +@optional +- (id)methodInProto1; +- (Subclass1 *)methodInProto2; +- (int)otherMethodInProto2; // expected-warning{{protocol method is expected to return an instance of the implementing class, but is declared to return 'int'}} +@end + +@implementation Subclass4 ++ (id)alloc { + return self; // FIXME: we accept this in ObjC++ but not ObjC? +} + +- (Subclass3 *)init { return 0; } // don't complain: we lost the related return type + +- (Subclass3 *)self { return 0; } // expected-warning{{method is expected to return an instance of its class type 'Subclass4', but is declared to return 'Subclass3 *'}} + +- (Subclass4 *)initOther { return 0; } + +@end + +// Check that inherited related return types influence the types of +// message sends. +void test_instancetype_inherited() { + [[Subclass4 alloc] initSubclass1]; // expected-warning{{'Subclass4' may not respond to 'initSubclass1'}} + [[Subclass4 alloc] initOther]; +} + +// Check that related return types tighten up the semantics of +// Objective-C method implementations. +@implementation Subclass2 +- (instancetype)initSubclass2 { // expected-note {{explicitly declared 'instancetype'}} + Subclass1 *sc1 = [[Subclass1 alloc] init]; + return sc1; // expected-error{{cannot initialize return object of type 'Subclass2 *' with an lvalue of type 'Subclass1 *'}} +} +- (void)methodOnSubclass2 {} +- (id)self { + Subclass1 *sc1 = [[Subclass1 alloc] init]; + return sc1; // expected-error{{cannot initialize return object of type 'Subclass2 *' with an lvalue of type 'Subclass1 *'}} +} +@end + +@interface MyClass : Root ++ (int)myClassMethod; +@end + +@implementation MyClass ++ (int)myClassMethod { return 0; } + +- (void)blah { + int i = [[MyClass self] myClassMethod]; +} + +@end + +// rdar://12493140 +@protocol P4 +- (instancetype) foo; // expected-note {{current method is explicitly declared 'instancetype' and is expected to return an instance of its class type}} +@end +@interface A4 : Root +- (instancetype) bar; // expected-note {{current method is explicitly declared 'instancetype' and is expected to return an instance of its class type}} +- (instancetype) baz; // expected-note {{overridden method returns an instance of its class type}} expected-note {{previous definition is here}} +@end +@interface B4 : Root @end + +@implementation A4 { + B4 *_b; +} +- (id) foo { + return _b; // expected-error {{cannot initialize return object of type 'A4 *' with an lvalue of type 'B4 *'}} +} +- (id) bar { + return _b; // expected-error {{cannot initialize return object of type 'A4 *' with an lvalue of type 'B4 *'}} +} + +// This is really just to ensure that we don't crash. +// FIXME: only one diagnostic, please +- (float) baz { // expected-warning {{method is expected to return an instance of its class type 'A4', but is declared to return 'float'}} expected-warning {{conflicting return type in implementation}} + return 0; +} +@end