Merge pull request swiftlang#13977 from slavapestov/remove-dead-hack

Serialization: Remove some apparently dead code

Author: slavapestov

lib/Serialization/SerializeSIL.cpp

@@ -353,19 +353,6 @@ void SILSerializer::writeSILFunction(const SILFunction &F, bool DeclOnly) {
 
   SILLinkage Linkage = F.getLinkage();
 
-  // We serialize shared_external linkage as shared since:
-  //
-  // 1. shared_external linkage is just a hack to tell the optimizer that a
-  // shared function was deserialized.
-  //
-  // 2. We cannot just serialize a declaration to a shared_external function
-  // since shared_external functions still have linkonce_odr linkage at the LLVM
-  // level. This means they must be defined not just declared.
-  //
-  // TODO: When serialization is reworked, this should be removed.
-  if (hasSharedVisibility(Linkage))
-    Linkage = SILLinkage::Shared;
-
   // Check if we need to emit a body for this function.
   bool NoBody = DeclOnly || isAvailableExternally(Linkage) ||
                 F.isExternalDeclaration();

test/SIL/Serialization/visibility.sil

@@ -34,8 +34,7 @@ import Builtin
 // CHECK-DAG: sil [serialized] @public_function_test : $@convention(thin) () -> () {
 // CHECK-DAG: sil [serialized] @public_function : $@convention(thin) () -> () {
 // CHECK-DAG: sil hidden [serialized] @hidden_function : $@convention(thin) () -> () {
-// NEG-CHECK-NOT: sil shared_external [serialized] @shared_external_function_test : $@convention(thin) () -> ()
-// CHECK-DAG: sil shared [serialized] @shared_external_function_test : $@convention(thin) () -> ()
+// CHECK-DAG: sil shared_external [serialized] @shared_external_function_test : $@convention(thin) () -> ()
 
 sil_global private [serialized] @private_global : $Builtin.Word
 sil_global [serialized] @public_global : $Builtin.Word