objc++-arc: more diagnosis of converting a weak-unavailable

object to a __weak object type. // rdar://9732636


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134706 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 16 insertions, 11 deletions

diff --git a/lib/Sema/SemaCXXCast.cpp b/lib/Sema/SemaCXXCast.cpp
index 0721814c18..50e39e0d04 100644
--- a/lib/Sema/SemaCXXCast.cpp
+++ b/lib/Sema/SemaCXXCast.cpp
@@ -1774,15 +1774,8 @@ Sema::CXXCheckCStyleCast(SourceRange R, QualType CastTy, ExprValueKind &VK,
     }
   }
 
-  if (getLangOptions().ObjCAutoRefCount && tcr == TC_Success) {
+  if (getLangOptions().ObjCAutoRefCount && tcr == TC_Success)
     CheckObjCARCConversion(R, CastTy, CastExpr, CCK);
-    if (!CheckObjCARCUnavailableWeakConversion(CastTy, 
-                                               origCastExprType))
-      Diag(CastExpr->getLocStart(), 
-           diag::err_arc_cast_of_weak_unavailable)
-      << origCastExprType << CastTy 
-      << CastExpr->getSourceRange();
-  }
 
   if (tcr != TC_Success && msg != 0) {
     if (CastExpr->getType() == Context.OverloadTy) {
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index fea31aa046..09c68aef69 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -4068,7 +4068,7 @@ ExprResult Sema::CheckCastTypes(SourceLocation CastStartLoc, SourceRange TyR,
     } 
     else if (!CheckObjCARCUnavailableWeakConversion(castType, castExprType)) {
            Diag(castExpr->getLocStart(), 
-                diag::err_arc_cast_of_weak_unavailable)
+                diag::err_arc_convesion_of_weak_unavailable) << 1
                 << castExprType << castType 
                 << castExpr->getSourceRange();
           return ExprError();
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 4c096fe0ec..7ee9c1bec2 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -2340,8 +2340,20 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
       if (From->getType()->isObjCObjectPointerType() &&
           ToType->isObjCObjectPointerType())
         EmitRelatedResultTypeNote(From);
-    }
-
+    } 
+    else if (getLangOptions().ObjCAutoRefCount &&
+             !CheckObjCARCUnavailableWeakConversion(ToType, 
+                                                    From->getType())) {
+           if (Action == AA_Initializing)
+             Diag(From->getSourceRange().getBegin(), 
+                  diag::err_arc_weak_unavailable_assign);
+           else
+             Diag(From->getSourceRange().getBegin(),
+                  diag::err_arc_convesion_of_weak_unavailable) 
+                  << (Action == AA_Casting) << From->getType() << ToType 
+                  << From->getSourceRange();
+         }
+             
     CastKind Kind = CK_Invalid;
     CXXCastPath BasePath;
     if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle))