[ObjC] Supress the 'implementing unavailable method' warning when

the method declaration is unavailable for an app extension platform

Rationale:
Classes are often shared between an app extension code and
non-app extension code. There's no way to remove the implementation
using preprocessor when building the app extension, so we should not warn here.

rdar://38150617

llvm-svn: 331421

1 files changed, 10 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index 5b8a9f39176..e1eed827167 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -266,12 +266,20 @@ static void DiagnoseObjCImplementedDeprecations(Sema &S, const NamedDecl *ND,
   if (!ND)
     return;
   bool IsCategory = false;
-  AvailabilityResult Availability = ND->getAvailability();
+  StringRef RealizedPlatform;
+  AvailabilityResult Availability = ND->getAvailability(
+      /*Message=*/nullptr, /*EnclosingVersion=*/VersionTuple(),
+      &RealizedPlatform);
   if (Availability != AR_Deprecated) {
     if (isa<ObjCMethodDecl>(ND)) {
       if (Availability != AR_Unavailable)
         return;
-      // Warn about implementing unavailable methods.
+      if (RealizedPlatform.empty())
+        RealizedPlatform = S.Context.getTargetInfo().getPlatformName();
+      // Warn about implementing unavailable methods, unless the unavailable
+      // is for an app extension.
+      if (RealizedPlatform.endswith("_app_extension"))
+        return;
       S.Diag(ImplLoc, diag::warn_unavailable_def);
       S.Diag(ND->getLocation(), diag::note_method_declared_at)
           << ND->getDeclName();