[SILGen] In a memberwise initializer, apply the property wrapper backing

initializer for property wrappers that are not memberwise initialized but
have an explicit original wrapped value.

Author: hborla

lib/SILGen/SILGenConstructor.cpp

@@ -220,6 +220,21 @@ static void emitImplicitValueConstructor(SILGenFunction &SGF,
 
         // Cleanup after this initialization.
         FullExpr scope(SGF.Cleanups, field->getParentPatternBinding());
+
+        // If this is a property wrapper backing storage var that isn't
+        // memberwise initialized and has an original wrapped value, apply
+        // the property wrapper backing initializer.
+        if (auto *wrappedVar = field->getOriginalWrappedProperty()) {
+          auto wrappedInfo = wrappedVar->getPropertyWrapperBackingPropertyInfo();
+          if (wrappedInfo.originalInitialValue) {
+            auto arg = SGF.emitRValue(wrappedInfo.originalInitialValue);
+            maybeEmitPropertyWrapperInitFromValue(SGF, Loc, field, subs,
+                                                  std::move(arg))
+              .forwardInto(SGF, Loc, init.get());
+            continue;
+          }
+        }
+
         SGF.emitExprInto(field->getParentInitializer(), init.get());
       }
     }
@@ -235,27 +250,38 @@ static void emitImplicitValueConstructor(SILGenFunction &SGF,
   for (VarDecl *field : decl->getStoredProperties()) {
     auto fieldTy =
         selfTy.getFieldType(field, SGF.SGM.M, SGF.getTypeExpansionContext());
-    SILValue v;
+    RValue value;
 
     // If it's memberwise initialized, do so now.
     if (field->isMemberwiseInitialized(/*preferDeclaredProperties=*/false)) {
       FullExpr scope(SGF.Cleanups, field->getParentPatternBinding());
       assert(elti != eltEnd && "number of args does not match number of fields");
       (void)eltEnd;
-      v = maybeEmitPropertyWrapperInitFromValue(
-          SGF, Loc, field, subs, std::move(*elti))
-        .forwardAsSingleStorageValue(SGF, fieldTy, Loc);
+      value = std::move(*elti);
       ++elti;
     } else {
       // Otherwise, use its initializer.
       assert(field->isParentInitialized());
+      Expr *init = field->getParentInitializer();
+
+      // If this is a property wrapper backing storage var that isn't
+      // memberwise initialized, use the original wrapped value if it exists.
+      if (auto *wrappedVar = field->getOriginalWrappedProperty()) {
+        auto wrappedInfo = wrappedVar->getPropertyWrapperBackingPropertyInfo();
+        if (wrappedInfo.originalInitialValue) {
+          init = wrappedInfo.originalInitialValue;
+        }
+      }
 
-      // Cleanup after this initialization.
-      FullExpr scope(SGF.Cleanups, field->getParentPatternBinding());
-      v = SGF.emitRValue(field->getParentInitializer())
-             .forwardAsSingleStorageValue(SGF, fieldTy, Loc);
+      value = SGF.emitRValue(init);
     }
 
+    // Cleanup after this initialization.
+    FullExpr scope(SGF.Cleanups, field->getParentPatternBinding());
+    SILValue v = maybeEmitPropertyWrapperInitFromValue(SGF, Loc, field, subs,
+                                                       std::move(value))
+        .forwardAsSingleStorageValue(SGF, fieldTy, Loc);
+
     eltValues.push_back(v);
   }
 

test/SILGen/property_wrappers.swift

@@ -32,6 +32,9 @@ struct HasMemberwiseInit<T: DefaultInit> {
 
   @WrapperWithInitialValue(wrappedValue: 17)
   var z: Int
+
+  @WrapperWithInitialValue
+  private var p: Bool = true
 }
 
 func forceHasMemberwiseInit() {
@@ -76,6 +79,11 @@ func forceHasMemberwiseInit() {
 // CHECK-NOT: return
 // CHECK: function_ref @$s17property_wrappers23WrapperWithInitialValueV07wrappedF0ACyxGx_tcfC : $@convention(method) <τ_0_0> (@in τ_0_0, @thin WrapperWithInitialValue<τ_0_0>.Type) -> @out WrapperWithInitialValue<τ_0_0>
 
+// variable initialization expression of HasMemberwiseInit._p
+// CHECK-LABEL: sil hidden [transparent] [ossa] @$s17property_wrappers17HasMemberwiseInitV2_p33_{{.*}}23WrapperWithInitialValueVySbGvpfi : $@convention(thin) <T where T : DefaultInit> () -> Bool {
+// CHECK: function_ref @$sSb22_builtinBooleanLiteralSbBi1__tcfC : $@convention(method) (Builtin.Int1, @thin Bool.Type) -> Bool
+// CHECK: return {{%.*}} : $Bool
+
 // default argument 0 of HasMemberwiseInit.init(x:y:z:)
 // CHECK: sil hidden [ossa] @$s17property_wrappers17HasMemberwiseInitV1x1y1zACyxGAA7WrapperVySbG_xAA0F16WithInitialValueVySiGtcfcfA_ : $@convention(thin) <T where T : DefaultInit> () -> Wrapper<Bool> 
 
@@ -103,8 +111,33 @@ func forceHasMemberwiseInit() {
 // CHECK-NOT: return
 // CHECK: function_ref @$s17property_wrappers17HasMemberwiseInitV2_z33_{{.*}}23WrapperWithInitialValueVySiGvpfi : $@convention(thin) <τ_0_0 where τ_0_0 : DefaultInit> () -> WrapperWithInitialValue<Int>
 
+// Initialization of p
+// CHECK-NOT: return
+// CHECK: function_ref @$s17property_wrappers17HasMemberwiseInitV2_p33_{{.*}}23WrapperWithInitialValueVySbGvpfi : $@convention(thin) <τ_0_0 where τ_0_0 : DefaultInit> () -> Bool
+// CHECK-NOT: return
+// CHECK: function_ref @$s17property_wrappers17HasMemberwiseInitV1p33_{{.*}} : $@convention(thin) <τ_0_0 where τ_0_0 : DefaultInit> (Bool) -> WrapperWithInitialValue<Bool>
+
 // CHECK: return
 
+// Non-generic struct with private property wrapper
+struct HasMemberwiseInitWithPrivateWrapper {
+  @WrapperWithInitialValue
+  var z: Int = 17
+
+  @WrapperWithInitialValue
+  private var p: Bool = true
+
+  // CHECK-LABEL: sil hidden [ossa] @$s17property_wrappers35HasMemberwiseInitWithPrivateWrapperV1zACSi_tcfC : $@convention(method) (Int, @thin HasMemberwiseInitWithPrivateWrapper.Type) -> HasMemberwiseInitWithPrivateWrapper {
+  // CHECK: function_ref @$s17property_wrappers35HasMemberwiseInitWithPrivateWrapperV1zSivpfP : $@convention(thin) (Int) -> WrapperWithInitialValue<Int>
+  // CHECK: function_ref @$s17property_wrappers35HasMemberwiseInitWithPrivateWrapperV1p33_{{.*}} : $@convention(thin) (Bool) -> WrapperWithInitialValue<Bool>
+  // CHECK: return {{%.*}} : $HasMemberwiseInitWithPrivateWrapper
+}
+
+func forceHasMemberwiseInitWithPrivateWrapper() {
+  _ = HasMemberwiseInitWithPrivateWrapper(z: 42)
+}
+
+
 // CHECK-LABEL: sil hidden [transparent] [ossa] @$s17property_wrappers9HasNestedV2_y33_{{.*}}14PrivateWrapperAELLVyx_SayxGGvpfi : $@convention(thin) <T> () -> @owned Array<T> {
 // CHECK: bb0:
 // CHECK: function_ref @$ss27_allocateUninitializedArrayySayxG_BptBwlF