Merge pull request #83811 from egorzhdan/egorzhdan/ambiguous-init

[cxx-interop] Avoid ambiguous C++ overloads for functions from Swift extensions

Author: egorzhdan

lib/PrintAsClang/DeclAndTypePrinter.cpp

@@ -253,7 +253,6 @@ class DeclAndTypePrinter::Implementation
   /// Prints the members of a class, extension, or protocol.
   template <bool AllowDelayed = false, typename R>
   void printMembers(R &&members) {
-    CxxEmissionScopeRAII cxxScopeRAII(owningPrinter);
     // Using statements for nested types.
     if (outputLang == OutputLanguageMode::Cxx) {
       for (const Decl *member : members) {
@@ -373,7 +372,12 @@ class DeclAndTypePrinter::Implementation
     if (outputLang == OutputLanguageMode::Cxx) {
       // FIXME: Non objc class.
       ClangClassTypePrinter(os).printClassTypeDecl(
-          CD, [&]() { printMembers(CD->getAllMembers()); }, owningPrinter);
+          CD,
+          [&]() {
+            CxxEmissionScopeRAII cxxScopeRAII(owningPrinter);
+            printMembers(CD->getAllMembers());
+          },
+          owningPrinter);
       recordEmittedDeclInCurrentCxxLexicalScope(CD);
       return;
     }
@@ -426,6 +430,7 @@ class DeclAndTypePrinter::Implementation
     printer.printValueTypeDecl(
         SD, /*bodyPrinter=*/
         [&]() {
+          CxxEmissionScopeRAII cxxScopeRAII(owningPrinter);
           printMembers(SD->getAllMembers());
           for (const auto *ed :
                owningPrinter.interopContext.getExtensionsForNominalType(SD)) {
@@ -922,6 +927,7 @@ class DeclAndTypePrinter::Implementation
           os << "  }\n"; // operator cases()'s closing bracket
           os << "\n";
 
+          CxxEmissionScopeRAII cxxScopeRAII(owningPrinter);
           printMembers(ED->getAllMembers());
 
           for (const auto *ext :

test/Interop/SwiftToCxx/initializers/init-in-extension-in-cxx.swift

@@ -0,0 +1,22 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend %s -module-name Init -clang-header-expose-decls=all-public -typecheck -verify -emit-clang-header-path %t/inits.h
+// RUN: %FileCheck %s < %t/inits.h
+
+// RUN: %check-interop-cxx-header-in-clang(%t/inits.h -Wno-unused-function -DSWIFT_CXX_INTEROP_HIDE_STL_OVERLAY)
+
+public struct OverloadedInitInExtension {
+    let x: Int
+
+    public init(_ x: Int) {
+        self.x = x
+    }
+}
+extension OverloadedInitInExtension {
+    public init(viaExtension x: Int) {
+        self.x = x
+    }
+}
+
+// Make sure we don't emit ambiguous overloads:
+// CHECK: static SWIFT_INLINE_THUNK OverloadedInitInExtension init(swift::Int x)
+// CHECK-NOT: static SWIFT_INLINE_THUNK OverloadedInitInExtension init(swift::Int x)

test/Interop/SwiftToCxx/methods/method-in-extension-in-cxx.swift

@@ -0,0 +1,22 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend %s -module-name Method -clang-header-expose-decls=all-public -typecheck -verify -emit-clang-header-path %t/methods.h
+// RUN: %FileCheck %s < %t/methods.h
+
+// RUN: %check-interop-cxx-header-in-clang(%t/methods.h -Wno-unused-function -DSWIFT_CXX_INTEROP_HIDE_STL_OVERLAY)
+
+public struct OverloadedMethodInExtension {
+    var x: Int
+
+    public mutating func add(_ x: Int) {
+        self.x += x
+    }
+}
+extension OverloadedMethodInExtension {
+    public mutating func add(viaExtension x: Int) {
+        self.x += x
+    }
+}
+
+// Make sure we don't emit ambiguous overloads:
+// CHECK: SWIFT_INLINE_THUNK void OverloadedMethodInExtension::add(swift::Int x)
+// CHECK-NOT: SWIFT_INLINE_THUNK void OverloadedMethodInExtension::add(swift::Int x)