Don’t serialize objcImpl members

Avoids failures where an imported member implementation is mistaken for a regular member, creating new ambiguities.

Fixes rdar://134736899.

Author: beccadax

include/swift/AST/Decl.h

@@ -2535,6 +2535,10 @@ class PatternBindingDecl final : public Decl,
   /// Does this binding declare something that requires storage?
   bool hasStorage() const;
 
+  /// Does this binding have at least one VarDecl that's an ObjC member
+  /// implementation?
+  bool hasAnyObjCMemberImplementations() const;
+
   /// Determines whether this binding either has an initializer expression, or is
   /// default initialized, without performing any type checking on it.
   bool isDefaultInitializable() const {

lib/AST/Decl.cpp

@@ -4620,6 +4620,16 @@ bool ValueDecl::isObjCMemberImplementation() const {
               this, [&]() { return this->getFormalAccess(); });
 }
 
+bool PatternBindingDecl::hasAnyObjCMemberImplementations() const {
+  bool foundAny = false;
+  for (auto i : range(getNumPatternEntries())) {
+    getPattern(i)->forEachVariable([&](VarDecl *VD) {
+      foundAny |= VD->isObjCMemberImplementation();
+    });
+  }
+  return foundAny;
+}
+
 /// Checks if \p VD may be used from \p useDC, taking \@testable and \@_spi
 /// imports into account.
 ///

lib/Serialization/Serialization.cpp

@@ -2024,7 +2024,6 @@ static bool shouldSerializeMember(Decl *D) {
   case DeclKind::Protocol:
   case DeclKind::Constructor:
   case DeclKind::Destructor:
-  case DeclKind::PatternBinding:
   case DeclKind::Subscript:
   case DeclKind::TypeAlias:
   case DeclKind::GenericTypeParam:
@@ -2036,7 +2035,10 @@ static bool shouldSerializeMember(Decl *D) {
   case DeclKind::Param:
   case DeclKind::Func:
   case DeclKind::Accessor:
-    return true;
+    return !cast<ValueDecl>(D)->isObjCMemberImplementation();
+
+  case DeclKind::PatternBinding:
+    return !cast<PatternBindingDecl>(D)->hasAnyObjCMemberImplementations();
   }
 
   llvm_unreachable("Unhandled DeclKind in switch.");

test/Serialization/Inputs/module.modulemap

@@ -6,3 +6,7 @@ module CLibrary {
 module RawLayoutCXX {
   header "raw_layout_cxx.h"
 }
+
+module objc_implementation {
+  header "objc_implementation.h"
+}

test/Serialization/Inputs/objc_implementation.h

@@ -0,0 +1,20 @@
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface ObjCImpl : NSObject
+
+- (instancetype)initWithNonSerialized:(int)value NS_SWIFT_NAME(init(nonSerialized:));
+- (void)nonSerializedMethod;
+@property (assign) int nonSerializedProperty;
+
+@end
+
+@interface ObjCImpl (CategoryMembers)
+
+- (void)nonSerializedCategoryMethod;
+@property (assign) int nonSerializedCategoryProperty;
+
+@end
+
+NS_ASSUME_NONNULL_END

test/Serialization/objc_implementation.swift

@@ -0,0 +1,68 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-module -module-name main -o %t -I %S/Inputs %s
+// RUN: llvm-bcanalyzer %t/main.swiftmodule > %t/main.swiftmodule.txt
+// RUN: %target-swift-ide-test -print-module -module-to-print=main -I %t -source-filename=%s >%t/main.txt
+// RUN: %FileCheck %s --check-prefixes POSITIVE,CHECK --input-file=%t/main.txt
+// RUN: %FileCheck %s --check-prefixes NEGATIVE,CHECK --input-file=%t/main.txt
+
+// REQUIRES: objc_interop
+
+import Foundation
+import objc_implementation
+
+// CHECK-LABEL: @objc @implementation extension ObjCImpl
+@objc @implementation extension ObjCImpl {
+  // These should not appear in the serialized output.
+
+  // NEGATIVE-NOT: init(nonSerialized value
+  @objc(initWithNonSerialized:)
+  public init(nonSerialized value: Int32) {
+    super.init()
+  }
+
+  // NEGATIVE-NOT: func nonSerializedMethod
+  @objc public func nonSerializedMethod() {}
+
+  // NEGATIVE-NOT: var nonSerializedProperty
+  @objc public var nonSerializedProperty: Int32 = 0
+
+  // NEGATIVE-NOT: deinit
+  deinit {}
+
+  // These should appear in the serialized output.
+
+  // POSITIVE: func serializedMethod
+  final public func serializedMethod() {}
+  // POSITIVE: var serializedProperty
+  final public var serializedProperty: Int32 = 0
+
+  // POSITIVE: init(serialized value
+  @nonobjc public convenience init(serialized value: Int32) {
+    self.init(nonSerialized: value)
+  }
+}
+
+// CHECK-LABEL: @objc(CategoryMembers) @implementation extension ObjCImpl
+@objc(CategoryMembers) @implementation extension ObjCImpl {
+  // These should not appear in the serialized output.
+
+  // NEGATIVE-NOT: func nonSerializedCategoryMethod
+  @objc public func nonSerializedCategoryMethod() {}
+
+  // NEGATIVE-NOT: var nonSerializedCategoryProperty
+  @objc public var nonSerializedCategoryProperty: Int32 {
+    get { nonSerializedProperty }
+    set { nonSerializedProperty = newValue }
+  }
+
+  // These should appear in the serialized output.
+
+  // POSITIVE: func serializedCategoryMethod()
+  final public func serializedCategoryMethod() {}
+
+  // POSITIVE: var serializedCategoryProperty
+  final public var serializedCategoryProperty: Int32 {
+    get { serializedProperty }
+    set { serializedProperty = newValue }
+  }
+}