Sema: Treat 'strict' availability flag like unavailable

This is a follow-up to r261512, which made the 'strict' availability
attribute flag behave like 'unavailable'.  However, that fix was
insufficient.  The following case would (erroneously) error when the
deployment target was older than 10.9:

    struct __attribute__((availability(macosx,strict,introduced=10.9))) A;
    __attribute__((availability(macosx,strict,introduced=10.9))) void f(A*);

The use of A* in the argument list for f is valid here, since f and A
have the same availability.

The fix is to return AR_Unavailable from DeclBase::getAvailability
instead of AR_NotYetIntroduced.  This also reverts the special handling
added in r261163, instead relying on the well-tested logic for
AR_Unavailable.

rdar://problem/23791325

llvm-svn: 262915

2 files changed, 2 insertions, 10 deletions

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 27ccb7d5d76..5ec05a6604b 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -432,7 +432,7 @@ static AvailabilityResult CheckAvailability(ASTContext &Context,
           << VTI << HintMessage;
     }
 
-    return AR_NotYetIntroduced;
+    return A->getStrict() ? AR_Unavailable : AR_NotYetIntroduced;
   }
 
   // Make sure that this declaration hasn't been obsoleted.
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 4071acd9063..4b8817529e3 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -159,19 +159,11 @@ DiagnoseAvailabilityOfDecl(Sema &S, NamedDecl *D, SourceLocation Loc,
       break;
 
     case AR_NotYetIntroduced: {
-      // With strict, the compiler will emit unavailable error.
-      AvailabilityAttr *AA = D->getAttr<AvailabilityAttr>();
-      if (AA && AA->getStrict() &&
-          S.getCurContextAvailability() != AR_NotYetIntroduced)
-        S.EmitAvailabilityWarning(Sema::AD_Unavailable,
-                                  D, Message, Loc, UnknownObjCClass, ObjCPDecl,
-                                  ObjCPropertyAccess);
-
       // Don't do this for enums, they can't be redeclared.
       if (isa<EnumConstantDecl>(D) || isa<EnumDecl>(D))
         break;
  
-      bool Warn = !AA->isInherited();
+      bool Warn = !D->getAttr<AvailabilityAttr>()->isInherited();
       // Objective-C method declarations in categories are not modelled as
       // redeclarations, so manually look for a redeclaration in a category
       // if necessary.