Merge pull request #3467 from CodaFi/inherited-wealth-and-ancillary-diagnostic-relief-claims

[SE-2007][Sema] Don't subject protocol 'Self' to availability checks in lookup

Author: CodaFi

lib/Sema/TypeCheckDecl.cpp

@@ -271,13 +271,18 @@ void TypeChecker::checkInheritanceClause(Decl *decl,
   } else if (auto ext = dyn_cast<ExtensionDecl>(decl)) {
     DC = ext;
     options |= TR_GenericSignature | TR_InheritanceClause;
-  } else if (isa<GenericTypeParamDecl>(decl)) {
+  } else if (auto GP = dyn_cast<GenericTypeParamDecl>(decl)) {
     // For generic parameters, we want name lookup to look at just the
     // signature of the enclosing entity.
     DC = decl->getDeclContext();
     if (auto nominal = dyn_cast<NominalTypeDecl>(DC)) {
       DC = nominal;
       options |= TR_GenericSignature;
+      // When looking up protocol 'Self' accessibility checks are disabled to
+      // head off spurious unavailable diagnostics.
+      if (isa<ProtocolDecl>(DC) && GP->isProtocolSelf()) {
+        options |= TR_AllowUnavailable;
+      }
     } else if (auto ext = dyn_cast<ExtensionDecl>(DC)) {
       DC = ext;
       options |= TR_GenericSignature;

test/attr/attr_availability.swift

@@ -31,6 +31,13 @@ typealias int = Int // expected-note {{'int' has been explicitly marked unavaila
 @available(*, unavailable, renamed: "Float")
 typealias float = Float // expected-note {{'float' has been explicitly marked unavailable here}}
 
+protocol MyNewerProtocol {}
+
+@available(*, unavailable, renamed: "MyNewerProtocol")
+protocol MyOlderProtocol {} // expected-note {{'MyOlderProtocol' has been explicitly marked unavailable here}}
+
+extension Int: MyOlderProtocol {} // expected-error {{'MyOlderProtocol' has been renamed to 'MyNewerProtocol'}} 
+
 struct MyCollection<Element> {
   @available(*, unavailable, renamed: "Element")
   typealias T = Element // expected-note 2{{'T' has been explicitly marked unavailable here}}