Fix inference of _Nullable for weak Objective-C properties.

The inference of _Nullable for weak Objective-C properties was broken
in several ways:

* It was back-patching the type information very late in the process
  of checking the attributes for an Objective-C property, which is
  just wrong.
* It was using ad hoc checks to try to suppress the warning about
  missing nullability specifiers (-Wnullability-completeness), which
  didn't actual work in all cases (rdar://problem/22985457)
* It was inferring _Nullable even outside of assumes-nonnull regions,
  which is wrong.

Putting the inference of _Nullable for weak Objective-C properties in
the same place as all of the other inference logic fixes all of these
ills.

llvm-svn: 249896

2 files changed, 9 insertions, 11 deletions

diff --git a/clang/lib/Sema/SemaObjCProperty.cpp b/clang/lib/Sema/SemaObjCProperty.cpp
index 15843fde39d..374e5ccd918 100644
--- a/clang/lib/Sema/SemaObjCProperty.cpp
+++ b/clang/lib/Sema/SemaObjCProperty.cpp
@@ -181,7 +181,7 @@ Decl *Sema::ActOnProperty(Scope *S, SourceLocation AtLoc,
   }
 
   // Validate the attributes on the @property.
-  CheckObjCPropertyAttributes(Res, AtLoc, Attributes, 
+  CheckObjCPropertyAttributes(Res, AtLoc, Attributes,
                               (isa<ObjCInterfaceDecl>(ClassDecl) ||
                                isa<ObjCProtocolDecl>(ClassDecl)));
 
@@ -2301,13 +2301,6 @@ void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
       if (*nullability == NullabilityKind::NonNull)
         Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
           << "nonnull" << "weak";
-    } else {
-        PropertyTy =
-          Context.getAttributedType(
-            AttributedType::getNullabilityAttrKind(NullabilityKind::Nullable),
-            PropertyTy, PropertyTy);
-        TypeSourceInfo *TSInfo = PropertyDecl->getTypeSourceInfo();
-        PropertyDecl->setType(PropertyTy, TSInfo);
     }
   }
 
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 049698d3820..d1bf6cc6bb2 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -3311,9 +3311,7 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
 
   // Are we in an assume-nonnull region?
   bool inAssumeNonNullRegion = false;
-  if (S.PP.getPragmaAssumeNonNullLoc().isValid() &&
-      !state.getDeclarator().isObjCWeakProperty() &&
-      !S.deduceWeakPropertyFromType(T)) {
+  if (S.PP.getPragmaAssumeNonNullLoc().isValid()) {
     inAssumeNonNullRegion = true;
     // Determine which file we saw the assume-nonnull region in.
     FileID file = getNullabilityCompletenessCheckFileID(
@@ -3392,6 +3390,13 @@ static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
         complainAboutMissingNullability = CAMN_No;
         break;
       }
+
+      // Weak properties are inferred to be nullable.
+      if (state.getDeclarator().isObjCWeakProperty() && inAssumeNonNullRegion) {
+        inferNullability = NullabilityKind::Nullable;
+        break;
+      }
+
       // fallthrough
 
     case Declarator::FileContext: