AST: Introduce AvailabilityDomain::isActivePlatform().

Author: tshortli

include/swift/AST/AvailabilityDomain.h

@@ -217,6 +217,10 @@ class AvailabilityDomain final {
   /// compilation context.
   bool isActive(const ASTContext &ctx) const;
 
+  /// Returns true if this domain is a platform domain and is considered active
+  /// in the current compilation context.
+  bool isActivePlatform(const ASTContext &ctx) const;
+
   /// Returns the domain's minimum available range for type checking. For
   /// example, for the domain of the platform that compilation is targeting,
   /// this version is specified with the `-target` option. For the Swift

lib/AST/AvailabilityContext.cpp

@@ -237,7 +237,7 @@ AvailabilityContext::getAvailabilityRange(AvailabilityDomain domain,
                                           const ASTContext &ctx) const {
   DEBUG_ASSERT(domain.supportsContextRefinement());
 
-  if (domain.isActive(ctx) && domain.isPlatform())
+  if (domain.isActivePlatform(ctx))
     return storage->platformRange;
 
   for (auto domainInfo : storage->getDomainInfos()) {
@@ -315,7 +315,7 @@ void AvailabilityContext::constrainWithAvailabilityRange(
     const ASTContext &ctx) {
   DEBUG_ASSERT(domain.supportsContextRefinement());
 
-  if (domain.isActive(ctx) && domain.isPlatform()) {
+  if (domain.isActivePlatform(ctx)) {
     constrainWithPlatformRange(range, ctx);
     return;
   }
@@ -371,7 +371,7 @@ void AvailabilityContext::constrainWithDeclAndPlatformRange(
       break;
     case AvailabilityConstraint::Reason::PotentiallyUnavailable:
       if (auto introducedRange = attr.getIntroducedRange(ctx)) {
-        if (domain.isActive(ctx) && domain.isPlatform()) {
+        if (domain.isActivePlatform(ctx)) {
           isConstrained |= constrainRange(platformRange, *introducedRange);
         } else {
           declDomainInfos.push_back({domain, *introducedRange});

lib/AST/AvailabilityDomain.cpp

@@ -100,6 +100,13 @@ bool AvailabilityDomain::isActive(const ASTContext &ctx) const {
   }
 }
 
+bool AvailabilityDomain::isActivePlatform(const ASTContext &ctx) const {
+  if (!isPlatform())
+    return false;
+
+  return isActive(ctx);
+}
+
 static std::optional<llvm::VersionTuple>
 getDeploymentVersion(const AvailabilityDomain &domain, const ASTContext &ctx) {
   switch (domain.getKind()) {