objective-C: introduce __attribute((objc_requires_super)) on method

in classes. Use it to flag those method implementations which don't
contain call to 'super' if they have 'super' class and it has the method
with this attribute set. This is wip. // rdar://6386358

llvm-svn: 163434

1 files changed, 30 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 8ffffab8b59..119ce7dfff7 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3974,6 +3974,33 @@ static void handleObjCReturnsInnerPointerAttr(Sema &S, Decl *D,
     ::new (S.Context) ObjCReturnsInnerPointerAttr(attr.getRange(), S.Context));
 }
 
+static void handleObjCRequiresSuperAttr(Sema &S, Decl *D,
+                                        const AttributeList &attr) {
+  SourceLocation loc = attr.getLoc();
+  ObjCMethodDecl *method = dyn_cast<ObjCMethodDecl>(D);
+  
+  if (!method) {
+   S.Diag(D->getLocStart(), diag::err_attribute_wrong_decl_type)
+   << SourceRange(loc, loc) << attr.getName() << ExpectedMethod;
+    return;
+  }
+  DeclContext *DC = method->getDeclContext();
+  if (const ObjCProtocolDecl *PDecl = dyn_cast_or_null<ObjCProtocolDecl>(DC)) {
+    S.Diag(D->getLocStart(), diag::warn_objc_requires_super_protocol)
+    << attr.getName() << 0;
+    S.Diag(PDecl->getLocation(), diag::note_protocol_decl);
+    return;
+  }
+  if (method->getMethodFamily() == OMF_dealloc) {
+    S.Diag(D->getLocStart(), diag::warn_objc_requires_super_protocol)
+    << attr.getName() << 1;
+    return;
+  }
+  
+  method->addAttr(
+    ::new (S.Context) ObjCRequiresSuperAttr(attr.getRange(), S.Context));
+}
+
 /// Handle cf_audited_transfer and cf_unknown_transfer.
 static void handleCFTransferAttr(Sema &S, Decl *D, const AttributeList &A) {
   if (!isa<FunctionDecl>(D)) {
@@ -4281,6 +4308,9 @@ static void ProcessInheritableDeclAttr(Sema &S, Scope *scope, Decl *D,
   case AttributeList::AT_ObjCReturnsInnerPointer:
     handleObjCReturnsInnerPointerAttr(S, D, Attr); break;
 
+  case AttributeList::AT_ObjCRequiresSuper:
+      handleObjCRequiresSuperAttr(S, D, Attr); break;
+      
   case AttributeList::AT_NSBridged:
     handleNSBridgedAttr(S, scope, D, Attr); break;