In Objective-C, pull arbitrary attributes from overridden

methods, including indirectly overridden methods like those
declared in protocols and categories.  There are mismatches
that we would like to diagnose but aren't yet, but this   
is fine for now.

I looked at approaches that avoided doing this lookup 
unless we needed it, but the infer-related-result-type
checks were doing it anyway, so I left it with the same
fast-path check for no previous declartions of that 
selector.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135743 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 3 deletions

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 9d91a48bdc..22a9f37bf1 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1456,7 +1456,7 @@ DeclHasAttr(const Decl *D, const Attr *A) {
 
 /// mergeDeclAttributes - Copy attributes from the Old decl to the New one.
 static void mergeDeclAttributes(Decl *newDecl, const Decl *oldDecl,
-                                ASTContext &C) {
+                                ASTContext &C, bool mergeDeprecation = true) {
   if (!oldDecl->hasAttrs())
     return;
 
@@ -1469,6 +1469,11 @@ static void mergeDeclAttributes(Decl *newDecl, const Decl *oldDecl,
   for (specific_attr_iterator<InheritableAttr>
        i = oldDecl->specific_attr_begin<InheritableAttr>(),
        e = oldDecl->specific_attr_end<InheritableAttr>(); i != e; ++i) {
+    // Ignore deprecated and unavailable attributes if requested.
+    if (!mergeDeprecation &&
+        (isa<DeprecatedAttr>(*i) || isa<UnavailableAttr>(*i)))
+      continue;
+
     if (!DeclHasAttr(newDecl, *i)) {
       InheritableAttr *newAttr = cast<InheritableAttr>((*i)->clone(C));
       newAttr->setInherited(true);
@@ -1949,15 +1954,19 @@ bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old) {
 
 void Sema::mergeObjCMethodDecls(ObjCMethodDecl *newMethod,
                                 const ObjCMethodDecl *oldMethod) {
+  // We don't want to merge unavailable and deprecated attributes
+  // except from interface to implementation.
+  bool mergeDeprecation = isa<ObjCImplDecl>(newMethod->getDeclContext());
+
   // Merge the attributes.
-  mergeDeclAttributes(newMethod, oldMethod, Context);
+  mergeDeclAttributes(newMethod, oldMethod, Context, mergeDeprecation);
 
   // Merge attributes from the parameters.
   for (ObjCMethodDecl::param_iterator oi = oldMethod->param_begin(),
          ni = newMethod->param_begin(), ne = newMethod->param_end();
        ni != ne; ++ni, ++oi)
     mergeParamDeclAttributes(*ni, *oi, Context);
-  
+
   CheckObjCMethodOverride(newMethod, oldMethod, true);
 }