[TBDGen] Emit property wrapper backing initializer symbol

Author: DougGregor

lib/TBDGen/TBDGen.cpp

@@ -21,6 +21,7 @@
 #include "swift/AST/ASTVisitor.h"
 #include "swift/AST/Module.h"
 #include "swift/AST/ParameterList.h"
+#include "swift/AST/PropertyWrappers.h"
 #include "swift/Basic/LLVM.h"
 #include "swift/IRGen/Linking.h"
 #include "swift/SIL/FormalLinkage.h"
@@ -309,8 +310,17 @@ void TBDGenVisitor::visitVarDecl(VarDecl *VD) {
       if (VD->isLazilyInitializedGlobal())
         addSymbol(SILDeclRef(VD, SILDeclRef::Kind::GlobalAccessor));
     }
+
   }
 
+  // Wrapped non-static member properties may have a backing initializer.
+  if (auto wrapperInfo = VD->getPropertyWrapperBackingPropertyInfo()) {
+    if (wrapperInfo.initializeFromOriginal && !VD->isStatic()) {
+      addSymbol(
+          SILDeclRef(VD, SILDeclRef::Kind::PropertyWrapperBackingInitializer));
+    }
+  };
+
   visitAbstractStorageDecl(VD);
 }
 

test/TBD/property_wrapper.swift

@@ -0,0 +1,15 @@
+// RUN: %target-swift-frontend -emit-ir -o/dev/null -parse-as-library -module-name test -validate-tbd-against-ir=all %s
+
+@propertyWrapper
+public struct Wrapper<Value> {
+  public var wrappedValue: Value
+
+  public init(wrappedValue: Value) {
+    self.wrappedValue = wrappedValue
+  }
+}
+
+public struct UseWrapper {
+  @Wrapper public var string = "hello"
+}
+