Default argument generator functions are not dynamically replaceable for now

Author: aschwaighofer

lib/SIL/SILDeclRef.cpp

@@ -1038,7 +1038,8 @@ static bool isDesignatedConstructorForClass(ValueDecl *decl) {
 }
 
 bool SILDeclRef::canBeDynamicReplacement() const {
-  if (kind == SILDeclRef::Kind::Destroyer)
+  if (kind == SILDeclRef::Kind::Destroyer ||
+      kind == SILDeclRef::Kind::DefaultArgGenerator)
     return false;
   if (kind == SILDeclRef::Kind::Initializer)
     return isDesignatedConstructorForClass(getDecl());
@@ -1048,6 +1049,8 @@ bool SILDeclRef::canBeDynamicReplacement() const {
 }
 
 bool SILDeclRef::isDynamicallyReplaceable() const {
+  if (kind == SILDeclRef::Kind::DefaultArgGenerator)
+    return false;
   if (isStoredPropertyInitializer())
     return false;
 

lib/TBDGen/TBDGen.cpp

@@ -214,7 +214,8 @@ void TBDGenVisitor::visitAbstractFunctionDecl(AbstractFunctionDecl *AFD) {
     addSymbol(SILDeclRef(AFD).asForeign());
   }
 
-  auto publicDefaultArgGenerators = SwiftModule->isTestingEnabled();
+  auto publicDefaultArgGenerators = SwiftModule->isTestingEnabled() ||
+                                    SwiftModule->arePrivateImportsEnabled();
   if (!publicDefaultArgGenerators)
     return;
 

test/SILGen/dynamically_replaceable.swift

@@ -350,3 +350,9 @@ func getsetX(_ x: Int) -> Int {
   globalX = x
   return globalX
 }
+
+// CHECK-LABEL: sil hidden [ossa] @$s23dynamically_replaceable18funcWithDefaultArgyySSFfA_
+// CHECK-LABEL: sil hidden [dynamically_replacable] [ossa] @$s23dynamically_replaceable18funcWithDefaultArgyySSF
+dynamic func funcWithDefaultArg(_ arg : String = String("hello")) {
+  print("hello")
+}

test/TBD/private_import.swift

@@ -0,0 +1,3 @@
+// RUN: %target-swift-frontend -emit-ir -o/dev/null -parse-as-library -module-name test -validate-tbd-against-ir=missing -enable-private-imports %s
+func funcWithDefaultArg(_ arg : String = String("hello")) {
+}