[AST] InitAccessors: fallback to init accessor effects if @storageRestrictions is not used

(cherry picked from commit e84cd81)

Author: xedin

lib/AST/Decl.cpp

@@ -9529,15 +9529,27 @@ void AccessorDecl::printUserFacingName(raw_ostream &out) const {
 
 ArrayRef<VarDecl *> AccessorDecl::getInitializedProperties() const {
   assert(isInitAccessor());
+
   if (auto *SR = getAttrs().getAttribute<StorageRestrictionsAttr>())
     return SR->getInitializesProperties(const_cast<AccessorDecl *>(this));
+
+  // Fallback to old effect style declaration.
+  if (auto *initAttr = getAttrs().getAttribute<InitializesAttr>())
+    return initAttr->getPropertyDecls(const_cast<AccessorDecl *>(this));
+
   return {};
 }
 
 ArrayRef<VarDecl *> AccessorDecl::getAccessedProperties() const {
   assert(isInitAccessor());
+
   if (auto *SR = getAttrs().getAttribute<StorageRestrictionsAttr>())
     return SR->getAccessesProperties(const_cast<AccessorDecl *>(this));
+
+  // Fallback to old effect style declaration.
+  if (auto *accessAttr = getAttrs().getAttribute<AccessesAttr>())
+    return accessAttr->getPropertyDecls(const_cast<AccessorDecl *>(this));
+
   return {};
 }
 

test/Interpreter/init_accessors.swift

@@ -538,3 +538,25 @@ test_init_accessors_without_setters()
 // CHECK: test-without-setter1: 42
 // CHECK-NEXT: test-without-setter2: [1, 2, 3]
 // CHECK-NEXT: test-without-setter3: ["a", "b", "c"]
+
+func test_effects_are_still_supported() {
+  struct Test {
+    var _a: Int
+    var _b: Int
+
+    var a: Int {
+      init(initialValue) initializes(_a) accesses(_b) {
+        _a = initialValue
+        _b = 0
+      }
+
+      get { _a }
+    }
+  }
+
+  let test = Test(_b: 1, a: 42)
+  print("effects-support-test: \(test)")
+}
+
+test_effects_are_still_supported()
+// CHEKC: effects-support-test: Test(_a: 42, b: 0)