From: Duncan P. N. Exon Smith <dexonsmith@apple.com>
Date: Tue, 8 Mar 2016 06:12:54 +0000 (+0000)
Subject: Sema: Treat 'strict' availability flag like unavailable
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a1d201fccaf0e072dc2c70c2ecbc6c129087e3bd;p=clang

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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@262915 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index 27ccb7d5d7..5ec05a6604 100644
--- a/lib/AST/DeclBase.cpp
+++ b/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/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 4071acd906..4b8817529e 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/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.
diff --git a/test/Sema/attr-availability-macosx.c b/test/Sema/attr-availability-macosx.c
index 7efe750692..21a79ff17a 100644
--- a/test/Sema/attr-availability-macosx.c
+++ b/test/Sema/attr-availability-macosx.c
@@ -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 {