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/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);