1 files changed, 28 insertions, 10 deletions
diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index cda70c5edcd4f..5c2c9cbd01802 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -415,6 +415,19 @@ const Attr *Decl::getDefiningAttr() const {
   return nullptr;
 }
 
+StringRef getRealizedPlatform(const AvailabilityAttr *A,
+                              const ASTContext &Context) {
+  // Check if this is an App Extension "platform", and if so chop off
+  // the suffix for matching with the actual platform.
+  StringRef RealizedPlatform = A->getPlatform()->getName();
+  if (!Context.getLangOpts().AppExt)
+    return RealizedPlatform;
+  size_t suffix = RealizedPlatform.rfind("_app_extension");
+  if (suffix != StringRef::npos)
+    return RealizedPlatform.slice(0, suffix);
+  return RealizedPlatform;
+}
+
 /// \brief Determine the availability of the given declaration based on
 /// the target platform.
 ///
@@ -434,20 +447,11 @@ static AvailabilityResult CheckAvailability(ASTContext &Context,
   if (EnclosingVersion.empty())
     return AR_Available;
 
-  // Check if this is an App Extension "platform", and if so chop off
-  // the suffix for matching with the actual platform.
   StringRef ActualPlatform = A->getPlatform()->getName();
-  StringRef RealizedPlatform = ActualPlatform;
-  if (Context.getLangOpts().AppExt) {
-    size_t suffix = RealizedPlatform.rfind("_app_extension");
-    if (suffix != StringRef::npos)
-      RealizedPlatform = RealizedPlatform.slice(0, suffix);
-  }
-
   StringRef TargetPlatform = Context.getTargetInfo().getPlatformName();
 
   // Match the platform name.
-  if (RealizedPlatform != TargetPlatform)
+  if (getRealizedPlatform(A, Context) != TargetPlatform)
     return AR_Available;
 
   StringRef PrettyPlatformName
@@ -567,6 +571,20 @@ AvailabilityResult Decl::getAvailability(std::string *Message,
   return Result;
 }
 
+VersionTuple Decl::getVersionIntroduced() const {
+  const ASTContext &Context = getASTContext();
+  StringRef TargetPlatform = Context.getTargetInfo().getPlatformName();
+  for (const auto *A : attrs()) {
+    if (const auto *Availability = dyn_cast<AvailabilityAttr>(A)) {
+      if (getRealizedPlatform(Availability, Context) != TargetPlatform)
+        continue;
+      if (!Availability->getIntroduced().empty())
+        return Availability->getIntroduced();
+    }
+  }
+  return VersionTuple();
+}
+
 bool Decl::canBeWeakImported(bool &IsDefinition) const {
   IsDefinition = false;