[ClangImporter] Support Swift 5 API notes

include/swift/Basic/STLExtras.h

@@ -786,6 +786,24 @@ inline OutputIterator transform(const Container &C, OutputIterator result,
   return std::transform(C.begin(), C.end(), result, op);
 }
 
+/// Provides default implementations of !=, <=, >, and >= based on == and <.
+template <typename T>
+class RelationalOperationsBase {
+public:
+  friend bool operator>(const T &left, const T &right) {
+    return right < left;
+  }
+  friend bool operator>=(const T &left, const T &right) {
+    return !(left < right);
+  }
+  friend bool operator<=(const T &left, const T &right) {
+    return !(right < left);
+  }
+  friend bool operator!=(const T &left, const T &right) {
+    return !(left == right);
+  }
+};
+
 } // end namespace swift
 
 #endif // SWIFT_BASIC_INTERLEAVE_H

lib/ClangImporter/ClangAdapter.cpp

@@ -437,7 +437,7 @@ clang::SwiftNewtypeAttr *
 importer::getSwiftNewtypeAttr(const clang::TypedefNameDecl *decl,
                               ImportNameVersion version) {
   // Newtype was introduced in Swift 3
-  if (version < ImportNameVersion::Swift3 )
+  if (version <= ImportNameVersion::swift2())
     return nullptr;
   return retrieveNewTypeAttr(decl);
 }
@@ -448,7 +448,7 @@ clang::TypedefNameDecl *importer::findSwiftNewtype(const clang::NamedDecl *decl,
                                                    clang::Sema &clangSema,
                                                    ImportNameVersion version) {
   // Newtype was introduced in Swift 3
-  if (version < ImportNameVersion::Swift3 )
+  if (version <= ImportNameVersion::swift2())
     return nullptr;
 
   auto varDecl = dyn_cast<clang::VarDecl>(decl);

lib/ClangImporter/ClangImporter.cpp

@@ -1650,7 +1650,7 @@ ClangImporter::Implementation::Implementation(ASTContext &ctx,
       BridgingHeaderExplicitlyRequested(!opts.BridgingHeader.empty()),
       DisableAdapterModules(opts.DisableAdapterModules),
       IsReadingBridgingPCH(false),
-      CurrentVersion(nameVersionFromOptions(ctx.LangOpts)),
+      CurrentVersion(ImportNameVersion::fromOptions(ctx.LangOpts)),
       BridgingHeaderLookupTable(new SwiftLookupTable(nullptr)),
       platformAvailability(ctx.LangOpts),
       nameImporter() {}
@@ -2508,32 +2508,34 @@ ClangModuleUnit::lookupNestedType(Identifier name,
 
     bool anyMatching = false;
     TypeDecl *originalDecl = nullptr;
-    owner.forEachDistinctName(clangTypeDecl, [&](ImportedName newName,
-                                                 ImportNameVersion nameVersion){
+    owner.forEachDistinctName(clangTypeDecl,
+                              [&](ImportedName newName,
+                                  ImportNameVersion nameVersion) -> bool {
       if (anyMatching)
-        return;
+        return true;
       if (!newName.getDeclName().isSimpleName(name))
-        return;
+        return true;
 
       auto decl = dyn_cast_or_null<TypeDecl>(
           owner.importDeclReal(clangTypeDecl, nameVersion));
       if (!decl)
-        return;
+        return false;
 
       if (!originalDecl)
         originalDecl = decl;
       else if (originalDecl == decl)
-        return;
+        return true;
 
       auto *importedContext = decl->getDeclContext()->
           getAsNominalTypeOrNominalTypeExtensionContext();
       if (importedContext != baseType)
-        return;
+        return true;
 
       assert(decl->getFullName().matchesRef(name) &&
              "importFullName behaved differently from importDecl");
       results.push_back(decl);
       anyMatching = true;
+      return true;
     });
   }
 
@@ -3150,10 +3152,8 @@ void ClangImporter::Implementation::lookupValue(
         const clang::NamedDecl *recentClangDecl =
             clangDecl->getMostRecentDecl();
 
-        forEachImportNameVersionFromCurrent(CurrentVersion,
-                                            [&](ImportNameVersion nameVersion) {
-          if (nameVersion == CurrentVersion)
-            return;
+        CurrentVersion.forEachOtherImportNameVersion(
+            [&](ImportNameVersion nameVersion) {
           if (anyMatching)
             return;
 
@@ -3211,12 +3211,12 @@ void ClangImporter::Implementation::lookupObjCMembers(
 
     forEachDistinctName(clangDecl,
                         [&](ImportedName importedName,
-                            ImportNameVersion nameVersion) {
+                            ImportNameVersion nameVersion) -> bool {
       // Import the declaration.
       auto decl =
           cast_or_null<ValueDecl>(importDeclReal(clangDecl, nameVersion));
       if (!decl)
-        return;
+        return false;
 
       // If the name we found matches, report the declaration.
       // FIXME: If we didn't need to check alternate decls here, we could avoid
@@ -3232,6 +3232,7 @@ void ClangImporter::Implementation::lookupObjCMembers(
           consumer.foundDecl(alternate, DeclVisibilityKind::DynamicLookup);
         }
       }
+      return true;
     });
   }
 }