[SILGen] Serialize and give PublicNonABI linkage to property wrapper

generator functions for parameters of public functions.

Author: hborla

lib/SIL/IR/SILDeclRef.cpp

@@ -248,8 +248,15 @@ SILLinkage SILDeclRef::getLinkage(ForDefinition_t forDefinition) const {
     return forDefinition ? linkage : addExternalToLinkage(linkage);
   };
 
-  // Function-local declarations have private linkage, unless serialized.
   ValueDecl *d = getDecl();
+
+  // Property wrapper generators of public functions have PublicNonABI linkage
+  if (isPropertyWrapperBackingInitializer() && isa<ParamDecl>(d)) {
+    if (isSerialized())
+      return maybeAddExternal(SILLinkage::PublicNonABI);
+  }
+
+  // Function-local declarations have private linkage, unless serialized.
   DeclContext *moduleContext = d->getDeclContext();
   while (!moduleContext->isModuleScopeContext()) {
     if (moduleContext->isLocalContext()) {
@@ -488,9 +495,16 @@ IsSerialized_t SILDeclRef::isSerialized() const {
 
   auto *d = getDecl();
 
-  // Default argument generators are serialized if the containing
-  // declaration is public.
-  if (isDefaultArgGenerator()) {
+  // Default and property wrapper argument generators are serialized if the
+  // containing declaration is public.
+  if (isDefaultArgGenerator() || (isPropertyWrapperBackingInitializer() &&
+                                  isa<ParamDecl>(d))) {
+    if (isPropertyWrapperBackingInitializer()) {
+      if (auto *func = dyn_cast_or_null<ValueDecl>(d->getDeclContext()->getAsDecl())) {
+        d = func;
+      }
+    }
+
     // Ask the AST if we're inside an @inlinable context.
     if (d->getDeclContext()->getResilienceExpansion()
           == ResilienceExpansion::Minimal) {

test/SILGen/property_wrapper_parameter.swift

@@ -30,10 +30,10 @@ public func testSimpleWrapperParameter(@Wrapper value: Int) {
   _ = $value
 
   // property wrapper backing initializer of value #1 in testSimpleWrapperParameter(value:)
-  // CHECK: sil private [ossa] @$s26property_wrapper_parameter26testSimpleWrapperParameter5valueyAA0F0VySiG_tFACL_SivpfP : $@convention(thin) (Int) -> Wrapper<Int>
+  // CHECK: sil non_abi [serialized] [ossa] @$s26property_wrapper_parameter26testSimpleWrapperParameter5valueyAA0F0VySiG_tFACL_SivpfP : $@convention(thin) (Int) -> Wrapper<Int>
 
   // property wrapper init from projected value of value #1 in testSimpleWrapperParameter(value:)
-  // CHECK: sil private [ossa] @$s26property_wrapper_parameter26testSimpleWrapperParameter5valueyAA0F0VySiG_tFACL_SivpfW : $@convention(thin) (Projection<Int>) -> Wrapper<Int>
+  // CHECK: sil non_abi [serialized] [ossa] @$s26property_wrapper_parameter26testSimpleWrapperParameter5valueyAA0F0VySiG_tFACL_SivpfW : $@convention(thin) (Projection<Int>) -> Wrapper<Int>
 
   // getter of $value #1 in testSimpleWrapperParameter(value:)
   // CHECK: sil private [ossa] @$s26property_wrapper_parameter26testSimpleWrapperParameter5valueyAA0F0VySiG_tF6$valueL_AA10ProjectionVySiGvg : $@convention(thin) (Wrapper<Int>) -> Projection<Int>
@@ -184,3 +184,29 @@ func testImplicitPropertyWrapper(projection: ProjectionWrapper<Int>) {
   // getter of value #1 in closure #2 in implicit closure #2 in testImplicitPropertyWrapper(projection:)
   // CHECK: sil private [ossa] @$s26property_wrapper_parameter27testImplicitPropertyWrapper10projectionyAA010ProjectionG0VySiG_tFSi_AFtAFcfu0_Si_AFtAFcfU0_5valueL_Sivg : $@convention(thin) () -> Int
 }
+
+@propertyWrapper
+public struct PublicWrapper<T> {
+  public var wrappedValue: T
+
+  public init(wrappedValue: T) {
+    self.wrappedValue = wrappedValue
+  }
+
+  public var projectedValue: PublicWrapper<T> {
+    return self
+  }
+
+  public init(projectedValue: PublicWrapper<T>) {
+    self.wrappedValue = projectedValue.wrappedValue
+  }
+}
+
+// CHECK-LABEL: sil [ossa] @$s26property_wrapper_parameter10publicFunc5valueyAA13PublicWrapperVySSG_tF : $@convention(thin) (@guaranteed PublicWrapper<String>) -> ()
+public func publicFunc(@PublicWrapper value: String) {
+  // property wrapper backing initializer of value #1 in publicFunc(value:)
+  // CHECK: sil non_abi [serialized] [ossa] @$s26property_wrapper_parameter10publicFunc5valueyAA13PublicWrapperVySSG_tFACL_SSvpfP : $@convention(thin) (@owned String) -> @owned PublicWrapper<String>
+
+  // property wrapper init from projected value of value #1 in publicFunc(value:)
+  // CHECK: sil non_abi [serialized] [ossa] @$s26property_wrapper_parameter10publicFunc5valueyAA13PublicWrapperVySSG_tFACL_SSvpfW : $@convention(thin) (@owned PublicWrapper<String>) -> @owned PublicWrapper<String>
+}