Merge pull request #61242 from tshortli/diagnose-decl-more-available-than-unavailable-enclosing-scope

Sema: Diagnose declarations that are annotated to be more available than their unavailable enclosing scope

Author: swift-ci

include/swift/AST/DiagnosticsSema.def

@@ -5696,14 +5696,22 @@ ERROR(availability_decl_more_than_enclosing, none,
       "%0 cannot be more available than enclosing scope",
       (DescriptiveDeclKind))
 
+WARNING(availability_decl_more_than_unavailable_enclosing, none,
+        "%0 cannot be more available than unavailable enclosing scope",
+        (DescriptiveDeclKind))
+
 NOTE(availability_implicit_decl_here, none,
      "%0 implicitly declared here with availability of %1 %2 or newer",
      (DescriptiveDeclKind, StringRef, llvm::VersionTuple))
 
-NOTE(availability_decl_more_than_enclosing_enclosing_here, none,
+NOTE(availability_decl_more_than_enclosing_here, none,
      "enclosing scope requires availability of %0 %1 or newer",
      (StringRef, llvm::VersionTuple))
 
+NOTE(availability_decl_more_than_unavailable_enclosing_here, none,
+     "enclosing scope has been explicitly marked unavailable here",
+     ())
+
 ERROR(availability_decl_only_version_newer, none,
       "%0 is only available in %1 %2 or newer",
       (DeclName, StringRef, llvm::VersionTuple))

lib/Sema/TypeCheckAttr.cpp

@@ -1814,9 +1814,15 @@ void AttributeChecker::visitAvailableAttr(AvailableAttr *attr) {
   // is fully contained within that declaration's range. If there is no such
   // enclosing declaration, then there is nothing to check.
   Optional<AvailabilityContext> EnclosingAnnotatedRange;
+  bool EnclosingDeclIsUnavailable = false;
   Decl *EnclosingDecl = getEnclosingDeclForDecl(D);
 
   while (EnclosingDecl) {
+    if (EnclosingDecl->getAttrs().getUnavailable(Ctx)) {
+      EnclosingDeclIsUnavailable = true;
+      break;
+    }
+
     EnclosingAnnotatedRange =
         AvailabilityInference::annotatedAvailableRange(EnclosingDecl, Ctx);
 
@@ -1830,7 +1836,13 @@ void AttributeChecker::visitAvailableAttr(AvailableAttr *attr) {
       VersionRange::allGTE(attr->Introduced.getValue())};
 
   if (EnclosingDecl) {
-    if (!AttrRange.isContainedIn(EnclosingAnnotatedRange.getValue())) {
+    if (EnclosingDeclIsUnavailable) {
+      diagnose(D->isImplicit() ? EnclosingDecl->getLoc() : attr->getLocation(),
+               diag::availability_decl_more_than_unavailable_enclosing,
+               D->getDescriptiveKind());
+      diagnose(EnclosingDecl->getLoc(),
+               diag::availability_decl_more_than_unavailable_enclosing_here);
+    } else if (!AttrRange.isContainedIn(EnclosingAnnotatedRange.getValue())) {
       diagnose(D->isImplicit() ? EnclosingDecl->getLoc() : attr->getLocation(),
                diag::availability_decl_more_than_enclosing,
                D->getDescriptiveKind());
@@ -1841,7 +1853,7 @@ void AttributeChecker::visitAvailableAttr(AvailableAttr *attr) {
                  prettyPlatformString(targetPlatform(Ctx.LangOpts)),
                  AttrRange.getOSVersion().getLowerEndpoint());
       diagnose(EnclosingDecl->getLoc(),
-               diag::availability_decl_more_than_enclosing_enclosing_here,
+               diag::availability_decl_more_than_enclosing_here,
                prettyPlatformString(targetPlatform(Ctx.LangOpts)),
                EnclosingAnnotatedRange->getOSVersion().getLowerEndpoint());
     }

test/Sema/availability_versions.swift

@@ -1725,10 +1725,12 @@ struct HasUnavailableExtension {
 
 @available(OSX, unavailable)
 extension HasUnavailableExtension {
+    // expected-note@-1 {{enclosing scope has been explicitly marked unavailable here}}
+
   public func inheritsUnavailable() { }
       // expected-note@-1 {{'inheritsUnavailable()' has been explicitly marked unavailable here}}
 
-  @available(OSX 10.9, *)
+  @available(OSX 10.9, *) // expected-warning {{instance method cannot be more available than unavailable enclosing scope}}
   public func moreAvailableButStillUnavailable() { }
       // expected-note@-1 {{'moreAvailableButStillUnavailable()' has been explicitly marked unavailable here}}
 }

test/attr/attr_availability_transitive_osx.swift

@@ -105,6 +105,7 @@ extension Outer {
 }
 
 @available(OSX, unavailable)
+// expected-note@+1 {{enclosing scope has been explicitly marked unavailable here}}
 extension Outer {
   // expected-note@+1 {{'outer_osx_init_osx' has been explicitly marked unavailable here}}
   static var outer_osx_init_osx = osx() // OK
@@ -123,7 +124,7 @@ extension Outer {
   }
 
   // This @available should be ignored; inherited unavailability takes precedence
-  @available(OSX 999, *)
+  @available(OSX 999, *) // expected-warning {{instance method cannot be more available than unavailable enclosing scope}}
   // expected-note@+1 {{'osx_more_available_but_still_unavailable_call_osx()' has been explicitly marked unavailable here}}
   func osx_more_available_but_still_unavailable_call_osx() {
     osx() // OK