Merge pull request swiftlang#31858 from aschwaighofer/opaque_result_type_dyn_repl_fix_5.3

[5.3] IRGen: Only replace opaque result types of function result types when performing a dynamic replacement

Author: tkremenek

lib/IRGen/GenDecl.cpp

@@ -1527,17 +1527,23 @@ void IRGenerator::emitDynamicReplacements() {
   llvm::SmallSet<OpaqueTypeArchetypeType *, 8> newUniqueOpaqueTypes;
   llvm::SmallSet<OpaqueTypeArchetypeType *, 8> origUniqueOpaqueTypes;
   for (auto *newFunc : DynamicReplacements) {
-    if (!newFunc->getLoweredFunctionType()->hasOpaqueArchetype())
+    auto newResultTy = newFunc->getLoweredFunctionType()
+             ->getAllResultsInterfaceType()
+             .getASTType();
+    if (!newResultTy->hasOpaqueArchetype())
       continue;
-    CanType(newFunc->getLoweredFunctionType()).visit([&](CanType ty) {
+    newResultTy.visit([&](CanType ty) {
       if (auto opaque = ty->getAs<OpaqueTypeArchetypeType>())
         if (newUniqueOpaqueTypes.insert(opaque).second)
           newFuncTypes.push_back(opaque);
     });
     auto *origFunc = newFunc->getDynamicallyReplacedFunction();
     assert(origFunc);
-    assert(origFunc->getLoweredFunctionType()->hasOpaqueArchetype());
-    CanType(origFunc->getLoweredFunctionType()).visit([&](CanType ty) {
+    auto origResultTy = origFunc->getLoweredFunctionType()
+                            ->getAllResultsInterfaceType()
+                            .getASTType();
+    assert(origResultTy->hasOpaqueArchetype());
+    origResultTy.visit([&](CanType ty) {
       if (auto opaque = ty->getAs<OpaqueTypeArchetypeType>())
         if (origUniqueOpaqueTypes.insert(opaque).second)
           origFuncTypes.push_back(opaque);

test/IRGen/Inputs/opaque_return_type_parameter.swift

@@ -0,0 +1,15 @@
+class Base {}
+class Sub: Base {}
+
+protocol Proto {
+  associatedtype Assoc
+  func make() -> Assoc
+}
+
+private struct Container : Proto {
+  func make() -> some Base {
+    return Sub()
+  }
+
+  func update(arg: Assoc) {}
+}

test/IRGen/dynamic_replaceable_opaque_return_type_parameter.swift

@@ -0,0 +1,13 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -disable-availability-checking -enable-implicit-dynamic -enable-private-imports %S/Inputs/opaque_return_type_parameter.swift -module-name Repo -emit-module -emit-module-path %t/Repo.swiftmodule
+// RUN: %target-swift-frontend -disable-availability-checking -I %t -module-name A -swift-version 5 -primary-file %s -emit-ir | %FileCheck %s
+// RUN: %target-swift-frontend -disable-availability-checking -I %t -module-name A -swift-version 5 -primary-file %s -c -o %t/tmp.o
+@_private(sourceFile: "opaque_return_type_parameter.swift") import Repo
+
+// Make sure we are not emitting a replacement for the opaque result type used as parameter (Assoc).
+
+// CHECK-NOT: @"\01l_unnamed_dynamic_replacements"{{.*}}(%swift.type_descriptor* ()*
+
+extension Container {
+  @_dynamicReplacement(for: update(arg:)) private func __update(arg: Assoc) {}
+}