SIL: @objc thunks should not be serialized

Author: slavapestov

lib/SIL/SILDeclRef.cpp

@@ -444,6 +444,11 @@ bool SILDeclRef::isTransparent() const {
 
 /// True if the function should have its body serialized.
 IsSerialized_t SILDeclRef::isSerialized() const {
+  // Native-to-foreign thunks are only referenced from the Objective-C
+  // method table.
+  if (isForeign)
+    return IsNotSerialized;
+
   DeclContext *dc;
   if (auto closure = getAbstractClosureExpr())
     dc = closure->getLocalContext();

test/ClangImporter/static_inline.swift

@@ -6,7 +6,7 @@
 // RUN: %FileCheck < %t/static_inline.sil %s
 // RUN: %target-swift-frontend -parse-as-library -module-name=static_inline -O -emit-ir %t/static_inline.sil -enable-objc-interop -import-objc-header %S/Inputs/static_inline.h | %FileCheck --check-prefix=CHECK-IR %s
 
-// CHECK: sil shared [serializable] [clang c_inline_func] @c_inline_func : $@convention(c) (Int32) -> Int32
+// CHECK: sil shared [clang c_inline_func] @c_inline_func : $@convention(c) (Int32) -> Int32
 
 // CHECK-IR-LABEL: define{{.*}} i32 @"$s13static_inline6testit1xs5Int32VAE_tF"(i32)
 // CHECK-IR: = add {{.*}}, 27

test/SILGen/inlinable_attribute_objc.swift

@@ -10,9 +10,22 @@ import Foundation
 
 public class Horse : NSObject {
   @objc public dynamic func gallop() {}
+  @objc public func someMethod() {}
+  @objc public convenience init(saddle: ()) {
+    self.init()
+  }
+  @objc public override init() {}
 }
 
-// Make sure we can reference dynamic thunks and curry thunks
+// @objc thunks are not serialized, since they are only referenced from
+// method tables.
+
+// CHECK-LABEL: sil [thunk] [ossa] @$s24inlinable_attribute_objc5HorseC6gallopyyFTo : $@convention(objc_method) (Horse) -> ()
+// CHECK-LABEL: sil [thunk] [ossa] @$s24inlinable_attribute_objc5HorseC10someMethodyyFTo : $@convention(objc_method) (Horse) -> ()
+// CHECK-LABEL: sil [thunk] [ossa] @$s24inlinable_attribute_objc5HorseC6saddleACyt_tcfcTo : $@convention(objc_method) (@owned Horse) -> @owned Horse
+// CHECK-LABEL: sil [thunk] [ossa] @$s24inlinable_attribute_objc5HorseCACycfcTo : $@convention(objc_method) (@owned Horse) -> @owned Horse
+
+// However, make sure we can reference dynamic thunks and curry thunks
 // from inlinable scopes
 
 // CHECK-LABEL: sil [serialized] [ossa] @$s24inlinable_attribute_objc15talkAboutAHorse1hyAA5HorseC_tF : $@convention(thin) (@guaranteed Horse) -> () {