Merge pull request swiftlang#35454 from CodaFi/checkride

Author: CodaFi

lib/AST/AccessRequests.cpp

@@ -221,13 +221,21 @@ DefaultAndMaxAccessLevelRequest::evaluate(Evaluator &evaluator,
 
     Optional<AccessScope> maxScope = AccessScope::getPublic();
 
+    // Try to scope the extension's access to the least public type mentioned
+    // in its where clause.
     for (auto *typeDecl : typeDecls) {
       if (isa<TypeAliasDecl>(typeDecl) || isa<NominalTypeDecl>(typeDecl)) {
         auto scope = typeDecl->getFormalAccessScope(ED->getDeclContext());
         maxScope = maxScope->intersectWith(scope);
       }
     }
 
+    // Now include the scope of the extended nominal type.
+    if (NominalTypeDecl *nominal = ED->getExtendedNominal()) {
+      auto scope = nominal->getFormalAccessScope(ED->getDeclContext());
+      maxScope = maxScope->intersectWith(scope);
+    }
+
     if (!maxScope.hasValue()) {
       // This is an error case and will be diagnosed elsewhere.
       maxAccess = AccessLevel::Public;
@@ -244,12 +252,6 @@ DefaultAndMaxAccessLevelRequest::evaluate(Evaluator &evaluator,
     }
   }
 
-  if (NominalTypeDecl *nominal = ED->getExtendedNominal()) {
-    maxAccess = std::min(maxAccess,
-                         std::max(nominal->getFormalAccess(),
-                                  AccessLevel::FilePrivate));
-  }
-
   AccessLevel defaultAccess;
   if (auto *AA = ED->getAttrs().getAttribute<AccessControlAttr>())
     defaultAccess = std::max(AA->getAccess(), AccessLevel::FilePrivate);

test/multifile/Inputs/conditional-conformance-catch22.swift

@@ -0,0 +1,3 @@
+struct Catch22<Value>: Equatable where Value: Equatable {
+  var value: Value
+}

test/multifile/conditional-conformance.swift

@@ -0,0 +1,9 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-module-path %t/catch22.swiftmodule %S/Inputs/conditional-conformance-catch22.swift -module-name catch22 -enable-testing
+// RUN: %target-swift-frontend -typecheck %s -I %t
+
+@testable import catch22
+
+extension Catch22: Comparable where Value: Comparable {
+  public static func <(lhs: Catch22, rhs: Catch22) -> Bool { true }
+}