AST: Introduce Decl::isUnavailableInCurrentSwiftVersion().

Author: tshortli

include/swift/AST/Attr.h

@@ -2925,11 +2925,6 @@ class DeclAttributes {
     return UnaryOperatorKind::None;
   }
 
-  /// Determine whether there is a swiftVersionSpecific attribute that's
-  /// unavailable relative to the provided language version.
-  bool
-  isUnavailableInSwiftVersion(const version::Version &effectiveVersion) const;
-
   /// Finds the most-specific platform-specific attribute that is
   /// active for the current platform.
   const AvailableAttr *

include/swift/AST/Decl.h

@@ -1402,6 +1402,10 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl>, public Swi
   /// will be deprecated in the future, or `nullptr` otherwise.
   const AvailableAttr *getSoftDeprecatedAttr() const;
 
+  /// Returns true if the decl has been marked unavailable in the Swift language
+  /// version that is currently active.
+  bool isUnavailableInCurrentSwiftVersion() const;
+
   /// Returns true if the decl is always unavailable in the current compilation
   /// context. For example, the decl could be marked explicitly unavailable on
   /// either the current platform or in the current language mode. Returns false

lib/AST/Attr.cpp

@@ -370,29 +370,6 @@ DeclAttribute *DeclAttribute::clone(ASTContext &ctx) const {
   }
 }
 
-bool
-DeclAttributes::isUnavailableInSwiftVersion(
-  const version::Version &effectiveVersion) const {
-  llvm::VersionTuple vers = effectiveVersion;
-  for (auto attr : *this) {
-    if (auto available = dyn_cast<AvailableAttr>(attr)) {
-      if (available->isInvalid())
-        continue;
-
-      if (available->isLanguageVersionSpecific()) {
-        if (available->Introduced.has_value() &&
-            available->Introduced.value() > vers)
-          return true;
-        if (available->Obsoleted.has_value() &&
-            available->Obsoleted.value() <= vers)
-          return true;
-      }
-    }
-  }
-
-  return false;
-}
-
 const AvailableAttr *
 DeclAttributes::findMostSpecificActivePlatform(const ASTContext &ctx,
                                                bool ignoreAppExtensions) const {

lib/AST/Availability.cpp

@@ -554,6 +554,21 @@ const AvailableAttr *Decl::getSoftDeprecatedAttr() const {
   return result;
 }
 
+bool Decl::isUnavailableInCurrentSwiftVersion() const {
+  llvm::VersionTuple vers = getASTContext().LangOpts.EffectiveLanguageVersion;
+  for (auto attr :
+       getAttrs().getAttributes<AvailableAttr, /*AllowInvalid=*/false>()) {
+    if (attr->isLanguageVersionSpecific()) {
+      if (attr->Introduced.has_value() && attr->Introduced.value() > vers)
+        return true;
+      if (attr->Obsoleted.has_value() && attr->Obsoleted.value() <= vers)
+        return true;
+    }
+  }
+
+  return false;
+}
+
 static const AvailableAttr *
 getDeclUnavailableAttr(const Decl *D, bool ignoreAppExtensions) {
   auto &ctx = D->getASTContext();

lib/AST/UnqualifiedLookup.cpp

@@ -453,9 +453,7 @@ void UnqualifiedLookupFactory::setAsideUnavailableResults(
   // Predicate that determines whether a lookup result should
   // be unavailable except as a last-ditch effort.
   auto unavailableLookupResult = [&](const LookupResultEntry &result) {
-    auto &effectiveVersion = Ctx.LangOpts.EffectiveLanguageVersion;
-    return result.getValueDecl()->getAttrs().isUnavailableInSwiftVersion(
-        effectiveVersion);
+    return result.getValueDecl()->isUnavailableInCurrentSwiftVersion();
   };
 
   // If all of the results we found are unavailable, keep looking.

lib/ClangImporter/ImportDecl.cpp

@@ -5079,15 +5079,12 @@ namespace {
                             bool hasKnownSwiftName, ModuleDecl *module,
                             bool allowObjCMismatchFallback,
                             bool cacheResult) {
-      const auto &languageVersion =
-          Impl.SwiftContext.LangOpts.EffectiveLanguageVersion;
-
       auto isMatch = [&](const T *singleResult, bool baseNameMatches,
                          bool allowObjCMismatch) -> bool {
         const DeclAttributes &attrs = singleResult->getAttrs();
 
         // Skip versioned variants.
-        if (attrs.isUnavailableInSwiftVersion(languageVersion))
+        if (singleResult->isUnavailableInCurrentSwiftVersion())
           return false;
 
         // If Clang decl has a custom Swift name, then we know that the name we
@@ -7692,11 +7689,9 @@ void SwiftDeclConverter::importMirroredProtocolMembers(
       if (classImplementsProtocol(superInterface, clangProto, true))
         continue;
 
-    const auto &languageVersion =
-        Impl.SwiftContext.LangOpts.EffectiveLanguageVersion;
     auto importProtocolRequirement = [&](Decl *member) {
       // Skip compatibility stubs; there's no reason to mirror them.
-      if (member->getAttrs().isUnavailableInSwiftVersion(languageVersion))
+      if (member->isUnavailableInCurrentSwiftVersion())
         return;
 
       if (auto prop = dyn_cast<VarDecl>(member)) {
@@ -8002,9 +7997,6 @@ void SwiftDeclConverter::importInheritedConstructors(
   if (curObjCClass->hasDesignatedInitializers())
     kind = CtorInitializerKind::Convenience;
 
-  const auto &languageVersion =
-      Impl.SwiftContext.LangOpts.EffectiveLanguageVersion;
-
   auto members = superclassDecl->lookupDirect(
       DeclBaseName::createConstructor());
 
@@ -8014,7 +8006,7 @@ void SwiftDeclConverter::importInheritedConstructors(
       continue;
 
     // Don't inherit compatibility stubs.
-    if (ctor->getAttrs().isUnavailableInSwiftVersion(languageVersion))
+    if (ctor->isUnavailableInCurrentSwiftVersion())
       continue;
 
     // Don't inherit (non-convenience) factory initializers.