Implement the Objective-C 'instancetype' type, which is an alias of
'id' that can be used (only!) via a contextual keyword as the result
type of an Objective-C message send. 'instancetype' then gives the
method a related result type, which we have already been inferring for
a variety of methods (new, alloc, init, self, retain). Addresses
<rdar://problem/9267640>.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139275 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 3e657c7..8dfdeb4 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -148,8 +148,13 @@
<< ResultTypeRange;
}
- Diag(Overridden->getLocation(), diag::note_related_result_type_overridden)
- << Overridden->getMethodFamily();
+ if (ObjCMethodFamily Family = Overridden->getMethodFamily())
+ Diag(Overridden->getLocation(),
+ diag::note_related_result_type_overridden_family)
+ << Family;
+ else
+ Diag(Overridden->getLocation(),
+ diag::note_related_result_type_overridden);
}
return false;
@@ -2261,16 +2266,22 @@
return false;
}
+namespace {
+ /// \brief Describes the compatibility of a result type with its method.
+ enum ResultTypeCompatibilityKind {
+ RTC_Compatible,
+ RTC_Incompatible,
+ RTC_Unknown
+ };
+}
+
/// \brief Check whether the declared result type of the given Objective-C
/// method declaration is compatible with the method's class.
///
-static bool
+static ResultTypeCompatibilityKind
CheckRelatedResultTypeCompatibility(Sema &S, ObjCMethodDecl *Method,
ObjCInterfaceDecl *CurrentClass) {
QualType ResultType = Method->getResultType();
- SourceRange ResultTypeRange;
- if (const TypeSourceInfo *ResultTypeInfo = Method->getResultTypeSourceInfo())
- ResultTypeRange = ResultTypeInfo->getTypeLoc().getSourceRange();
// If an Objective-C method inherits its related result type, then its
// declared result type must be compatible with its own class type. The
@@ -2280,23 +2291,27 @@
// - it is id or qualified id, or
if (ResultObjectType->isObjCIdType() ||
ResultObjectType->isObjCQualifiedIdType())
- return false;
+ return RTC_Compatible;
if (CurrentClass) {
if (ObjCInterfaceDecl *ResultClass
= ResultObjectType->getInterfaceDecl()) {
// - it is the same as the method's class type, or
if (CurrentClass == ResultClass)
- return false;
+ return RTC_Compatible;
// - it is a superclass of the method's class type
if (ResultClass->isSuperClassOf(CurrentClass))
- return false;
+ return RTC_Compatible;
}
+ } else {
+ // Any Objective-C pointer type might be acceptable for a protocol
+ // method; we just don't know.
+ return RTC_Unknown;
}
}
- return true;
+ return RTC_Incompatible;
}
namespace {
@@ -2457,6 +2472,7 @@
Decl *ClassDecl = cast<Decl>(OCD);
QualType resultDeclType;
+ bool HasRelatedResultType = false;
TypeSourceInfo *ResultTInfo = 0;
if (ReturnType) {
resultDeclType = GetTypeFromParser(ReturnType, &ResultTInfo);
@@ -2468,6 +2484,8 @@
<< 0 << resultDeclType;
return 0;
}
+
+ HasRelatedResultType = (resultDeclType == Context.getObjCInstanceType());
} else { // get the type for "id".
resultDeclType = Context.getObjCIdType();
Diag(MethodLoc, diag::warn_missing_method_return_type)
@@ -2484,7 +2502,7 @@
MethodDeclKind == tok::objc_optional
? ObjCMethodDecl::Optional
: ObjCMethodDecl::Required,
- false);
+ HasRelatedResultType);
SmallVector<ParmVarDecl*, 16> Params;
@@ -2604,9 +2622,8 @@
CurrentClass = CatImpl->getClassInterface();
}
- bool isRelatedResultTypeCompatible =
- (getLangOptions().ObjCInferRelatedResultType &&
- !CheckRelatedResultTypeCompatibility(*this, ObjCMethod, CurrentClass));
+ ResultTypeCompatibilityKind RTC
+ = CheckRelatedResultTypeCompatibility(*this, ObjCMethod, CurrentClass);
// Search for overridden methods and merge information down from them.
OverrideSearch overrides(*this, ObjCMethod);
@@ -2615,7 +2632,7 @@
ObjCMethodDecl *overridden = *i;
// Propagate down the 'related result type' bit from overridden methods.
- if (isRelatedResultTypeCompatible && overridden->hasRelatedResultType())
+ if (RTC != RTC_Incompatible && overridden->hasRelatedResultType())
ObjCMethod->SetRelatedResultType();
// Then merge the declarations.
@@ -2633,8 +2650,10 @@
if (getLangOptions().ObjCAutoRefCount)
ARCError = CheckARCMethodDecl(*this, ObjCMethod);
- if (!ARCError && isRelatedResultTypeCompatible &&
- !ObjCMethod->hasRelatedResultType()) {
+ // Infer the related result type when possible.
+ if (!ARCError && RTC == RTC_Compatible &&
+ !ObjCMethod->hasRelatedResultType() &&
+ LangOpts.ObjCInferRelatedResultType) {
bool InferRelatedResultType = false;
switch (ObjCMethod->getMethodFamily()) {
case OMF_None: