Revert "Warn about async-imported selector conflicts"

This reverts commit b8422a1.

Author: beccadax

lib/Sema/TypeCheckDeclObjC.cpp

@@ -2257,12 +2257,6 @@ namespace {
   /// Produce a deterministic ordering of the given declarations.
   struct OrderDeclarations {
     bool operator()(ValueDecl *lhs, ValueDecl *rhs) const {
-      // If one declaration is imported from ObjC and the other is native Swift,
-      // put the imported Clang one first.
-      if (lhs->hasClangNode() != rhs->hasClangNode()) {
-        return lhs->hasClangNode();
-      }
-
       // If the declarations come from different modules, order based on the
       // module.
       ModuleDecl *lhsModule = lhs->getDeclContext()->getParentModule();
@@ -2512,10 +2506,6 @@ bool swift::diagnoseObjCMethodConflicts(SourceFile &sf) {
       RULE(!isa<ExtensionDecl>(a->getDeclContext()),
            !isa<ExtensionDecl>(b->getDeclContext()));
 
-      // Is one of these imported from Objective-C?
-      RULE(a->hasClangNode(),
-           b->hasClangNode());
-
       // Are these from different source files? If so, fall back to the order in
       // which the declarations were type checked.
       // FIXME: This is gross and nondeterministic.
@@ -2544,28 +2534,16 @@ bool swift::diagnoseObjCMethodConflicts(SourceFile &sf) {
         if (auto accessor = dyn_cast<AccessorDecl>(originalMethod))
           originalDecl = accessor->getStorage();
 
-      // Conflicts between two imported ObjC methods are caused by the same
-      // clang decl having several Swift names.
-      if (originalDecl->hasClangNode() && conflictingDecl->hasClangNode())
-        continue;
-
-      bool breakingInSwift5 = false;
-      // Imported ObjC async methods weren't fully checked for selector
-      // conflicts until 5.7.
-      if (originalMethod->hasClangNode() && originalMethod->hasAsync())
-        breakingInSwift5 = true;
-      // Protocols weren't checked for selector conflicts in 5.0.
-      if (!isa<ClassDecl>(conflict.typeDecl))
-        breakingInSwift5 = true;
-
       bool redeclSame = (diagInfo == origDiagInfo);
       auto diag = Ctx.Diags.diagnose(conflictingDecl,
                                      redeclSame ? diag::objc_redecl_same
                                                 : diag::objc_redecl,
                                      diagInfo.first, diagInfo.second,
                                      origDiagInfo.first, origDiagInfo.second,
                                      conflict.selector);
-      diag.warnUntilSwiftVersionIf(breakingInSwift5, 6);
+
+      // Protocols weren't checked for selector conflicts in 5.0.
+      diag.warnUntilSwiftVersionIf(!isa<ClassDecl>(conflict.typeDecl), 6);
 
       auto objcAttr = getObjCAttrIfFromAccessNote(conflictingDecl);
       swift::softenIfAccessNote(conflictingDecl, objcAttr, diag);

test/Concurrency/Inputs/Delegate.h

@@ -21,10 +21,4 @@
 -(void)myAsyncMethod:(void (^ _Nullable)(NSError * _Nullable, NSString * _Nullable))completionHandler;
 @end
 
-@interface Delegate (SwiftImpls)
-
-- (void)makeRequestFromSwift:(Request * _Nonnull)request completionHandler:(void (^ _Nullable)(void))handler;
-
-@end
-
 #endif

test/Concurrency/objc_async_overload.swift

@@ -53,10 +53,3 @@ extension Delegate {
     }
   }
 }
-
-// rdar://95887113 - Implementing an ObjC category method in Swift is not strictly valid, but should be tolerated
-
-extension Delegate {
-  @objc public func makeRequest(fromSwift: Request, completionHandler: (() -> Void)?) {}
-  // expected-warning@-1 {{method 'makeRequest(fromSwift:completionHandler:)' with Objective-C selector 'makeRequestFromSwift:completionHandler:' conflicts with method 'makeRequest(fromSwift:)' with the same Objective-C selector; this is an error in Swift 6}}
-}