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/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 759f6c9..4bb5d72 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -151,7 +151,8 @@
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 bf4632c..e4323c3 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -10039,6 +10039,9 @@
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 b0d5453..af8380d 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -1094,6 +1094,73 @@
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<ObjCImplDecl>(MD->getDeclContext())) {
+ const ObjCContainerDecl *iface;
+ if (const ObjCCategoryImplDecl *catImpl =
+ dyn_cast<ObjCCategoryImplDecl>(impl)) {
+ iface = catImpl->getCategoryDecl();
+ } else {
+ iface = impl->getClassInterface();
+ }
+
+ const ObjCMethodDecl *ifaceMD =
+ iface->getMethod(MD->getSelector(), MD->isInstanceMethod());
+ if (ifaceMD) return findExplicitInstancetypeDeclarer(ifaceMD, instancetype);
+ }
+
+ SmallVector<const ObjCMethodDecl *, 4> 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<ObjCMethodDecl>(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<ObjCMessageExpr>(E);
diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 2ddabbd..75aa17b 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -5590,6 +5590,26 @@
//===----------------------------------------------------------------------===//
// 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 @@
<< 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 @@
<< 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 b5b35fc..0c51e44 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -2536,20 +2536,7 @@
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<Expr>();
- }
+ 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 @@
// 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<Expr>();
- 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<Expr>();
+ }
+
+ CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc);
}
if (RetValExp) {