[Sema/SILGen] Consider init exprs associated with init accessor properties for memberwise init

Author: xedin

lib/SILGen/SILGenConstructor.cpp

@@ -1474,6 +1474,13 @@ void SILGenFunction::emitMemberInitializers(DeclContext *dc,
     if (auto pbd = dyn_cast<PatternBindingDecl>(member)) {
       if (pbd->isStatic()) continue;
 
+      // Skip properties with init accessors, they could only be used
+      // explicitly and in memberwise initializers.
+      if (auto *var = pbd->getSingleVar()) {
+        if (var->hasInitAccessor())
+          continue;
+      }
+
       for (auto i : range(pbd->getNumPatternEntries())) {
         auto init = pbd->getExecutableInit(i);
         if (!init) continue;

lib/Sema/CodeSynthesis.cpp

@@ -144,12 +144,6 @@ static void maybeAddMemberwiseDefaultArg(ParamDecl *arg, VarDecl *var,
   if (!var->getParentPattern()->getSingleVar())
     return;
 
-  // FIXME: Don't attempt to synthesize default arguments for init
-  //        accessor properties because there could be multiple properties
-  //        with default values they are going to initialize.
-  if (var->getAccessor(AccessorKind::Init))
-    return;
-
   // Whether we have explicit initialization.
   bool isExplicitlyInitialized = false;
   if (auto pbd = var->getParentPatternBinding()) {

lib/Sema/TypeCheckStorage.cpp

@@ -3359,7 +3359,7 @@ static void finishStorageImplInfo(AbstractStorageDecl *storage,
   auto dc = storage->getDeclContext();
 
   if (auto var = dyn_cast<VarDecl>(storage)) {
-    if (!info.hasStorage()) {
+    if (!info.hasStorage() && !var->hasInitAccessor()) {
       if (auto *init = var->getParentExecutableInitializer()) {
         auto &Diags = var->getASTContext().Diags;
         Diags.diagnose(init->getLoc(), diag::getset_init)

test/Interpreter/init_accessors.swift

@@ -393,3 +393,72 @@ test_memberwise_ordering()
 // CHECK: test-memberwise-ordering-1: Test1(_a: 0, _b: 42)
 // CHECK-NEXT: test-memberwise-ordering-2: Test2(_a: -1, _b: -2)
 // CHECK-NEXT: test-memberwise-ordering-3: Test3(_a: 1, _b: 2, _c: 3)
+
+func test_memberwise_with_default_args() {
+  struct TestWithoutDefault {
+    var _a: Int
+    var _b: Int
+
+    var pair: (Int, Int) = (-1, 42) {
+      init(initialValue) initializes(_a, _b) {
+        _a = initialValue.0
+        _b = initialValue.1
+      }
+
+      get { (0, 42) }
+      set { }
+    }
+  }
+
+  let test1 = TestWithoutDefault()
+  print("test-memberwise_with_default-1: \(test1)")
+
+  let test2 = TestWithoutDefault(pair: (42, -1))
+  print("test-memberwise_with_default-2: \(test2)")
+
+  struct TestDefaulted {
+    var _a: Int = 0
+    var _b: Int = 0
+
+    var pair: (Int, Int) = (1, 2) {
+      init(initialValue) initializes(_a, _b) {
+        _a = initialValue.0
+        _b = initialValue.1
+      }
+
+      get { (_a, _b) }
+      set { }
+    }
+  }
+
+  let test3 = TestDefaulted()
+  print("test-defaulted-1: \(test3)")
+
+  let test4 = TestDefaulted(pair: (3, 4))
+  print("test-defaulted-2: \(test4)")
+
+  class TestClass {
+    var _q: String = "<<default>>"
+    var _a: Int = 1
+
+    var pair: (String, Int) = ("", 42) {
+      init(initialValue) initializes(_q, _a) {
+        _q = initialValue.0
+        _a = initialValue.1
+      }
+
+      get { (_q, _a) }
+      set { }
+    }
+  }
+
+  let test5 = TestClass()
+  print("test-defaulted-class: \(test5.pair)")
+}
+
+test_memberwise_with_default_args()
+// CHECK: test-memberwise_with_default-1: TestWithoutDefault(_a: -1, _b: 42)
+// CHECK-NEXT: test-memberwise_with_default-2: TestWithoutDefault(_a: 42, _b: -1)
+// CHECK-NEXT: test-defaulted-1: TestDefaulted(_a: 0, _b: 0)
+// CHECK-NEXT: test-defaulted-2: TestDefaulted(_a: 3, _b: 4)
+// CHECK-NEXT: test-defaulted-class: ("<<default>>", 1)