r262915 - Sema: Treat 'strict' availability flag like unavailable

[Duncan P. N. Exon Smith via cfe-commits]

Author: dexonsmith
Date: Tue Mar  8 00:12:54 2016
New Revision: 262915

URL: http://llvm.org/viewvc/llvm-project?rev=262915&view=rev
Log:
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

Modified:
    cfe/trunk/lib/AST/DeclBase.cpp
    cfe/trunk/lib/Sema/SemaExpr.cpp
    cfe/trunk/test/Sema/attr-availability-macosx.c

Modified: cfe/trunk/lib/AST/DeclBase.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/DeclBase.cpp?rev=262915&r1=262914&r2=262915&view=diff
==============================================================================
--- cfe/trunk/lib/AST/DeclBase.cpp (original)
+++ cfe/trunk/lib/AST/DeclBase.cpp Tue Mar  8 00:12:54 2016
@@ -432,7 +432,7 @@ static AvailabilityResult CheckAvailabil
           << VTI << HintMessage;
     }
 
-    return AR_NotYetIntroduced;
+    return A->getStrict() ? AR_Unavailable : AR_NotYetIntroduced;
   }
 
   // Make sure that this declaration hasn't been obsoleted.

Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=262915&r1=262914&r2=262915&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Tue Mar  8 00:12:54 2016
@@ -159,19 +159,11 @@ DiagnoseAvailabilityOfDecl(Sema &S, Name
       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.

Modified: cfe/trunk/test/Sema/attr-availability-macosx.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/attr-availability-macosx.c?rev=262915&r1=262914&r2=262915&view=diff
==============================================================================
--- cfe/trunk/test/Sema/attr-availability-macosx.c (original)
+++ cfe/trunk/test/Sema/attr-availability-macosx.c Tue Mar  8 00:12:54 2016
@@ -22,6 +22,16 @@ void test() {
   f6(0); // expected-error{{'f6' is unavailable: introduced in OS X 10.6}}
 }
 
+struct __attribute__((availability(macosx,strict,introduced=10.6)))
+  not_yet_introduced_struct; // \
+    expected-note{{'not_yet_introduced_struct' has been explicitly marked unavailable here}}
+
+void uses_not_introduced_struct(struct not_yet_introduced_struct *); // \
+    expected-error{{'not_yet_introduced_struct' is unavailable: introduced in OS X 10.6}}
+
+__attribute__((availability(macosx,strict,introduced=10.6)))
+void uses_not_introduced_struct_same_availability(struct not_yet_introduced_struct *);
+
 // rdar://10535640
 
 enum {