[Property Wrappers] Unify the initializer type checking code paths between

wrapped parameters and wrapped properties.

This fixes a bug where @autoclosure was not propagated from the wrapper's
init(wrappedValue:) to a wrapped argument.

Author: hborla

include/swift/Sema/ConstraintSystem.h

@@ -1695,6 +1695,10 @@ class SolutionApplicationTarget {
   static SolutionApplicationTarget forUninitializedWrappedVar(
       VarDecl *wrappedVar);
 
+  /// Form a target for a synthesized property wrapper initializer.
+  static SolutionApplicationTarget forPropertyWrapperInitializer(
+      VarDecl *wrappedVar, DeclContext *dc, Expr *initializer);
+
   Expr *getAsExpr() const {
     switch (kind) {
     case Kind::expression:
@@ -1802,7 +1806,7 @@ class SolutionApplicationTarget {
   bool isOptionalSomePatternInit() const {
     return kind == Kind::expression &&
         expression.contextualPurpose == CTP_Initialization &&
-        isa<OptionalSomePattern>(expression.pattern) &&
+        dyn_cast_or_null<OptionalSomePattern>(expression.pattern) &&
         !expression.pattern->isImplicit();
   }
 
@@ -1826,7 +1830,9 @@ class SolutionApplicationTarget {
 
     // Don't create property wrapper generator functions for static variables and
     // local variables with initializers.
-    if (wrappedVar->isStatic() || wrappedVar->getDeclContext()->isLocalContext())
+    bool hasInit = expression.propertyWrapper.hasInitialWrappedValue;
+    if (wrappedVar->isStatic() ||
+        (hasInit && wrappedVar->getDeclContext()->isLocalContext()))
       return false;
 
     return expression.propertyWrapper.innermostWrappedValueInit == apply;

lib/Sema/CSApply.cpp

@@ -8432,13 +8432,18 @@ static Optional<SolutionApplicationTarget> applySolutionToInitialization(
   // been subsumed by the backing property.
   if (wrappedVar) {
     ASTContext &ctx = cs.getASTContext();
-    wrappedVar->getParentPatternBinding()->setInitializerSubsumed(0);
     ctx.setSideCachedPropertyWrapperBackingPropertyType(
         wrappedVar, initType->mapTypeOutOfContext());
 
     // Record the semantic initializer on the outermost property wrapper.
     wrappedVar->getAttachedPropertyWrappers().front()
         ->setSemanticInit(initializer);
+
+    // If this is a wrapped parameter, we're done.
+    if (isa<ParamDecl>(wrappedVar))
+      return resultTarget;
+
+    wrappedVar->getParentPatternBinding()->setInitializerSubsumed(0);
   }
 
   // Coerce the pattern to the type of the initializer.

lib/Sema/ConstraintSystem.cpp

@@ -5102,7 +5102,14 @@ SolutionApplicationTarget::SolutionApplicationTarget(
 void SolutionApplicationTarget::maybeApplyPropertyWrapper() {
   assert(kind == Kind::expression);
   assert(expression.contextualPurpose == CTP_Initialization);
-  auto singleVar = expression.pattern->getSingleVar();
+
+  VarDecl *singleVar;
+  if (auto *pattern = expression.pattern) {
+    singleVar = pattern->getSingleVar();
+  } else {
+    singleVar = expression.propertyWrapper.wrappedVar;
+  }
+
   if (!singleVar)
     return;
 
@@ -5232,6 +5239,23 @@ SolutionApplicationTarget::forUninitializedWrappedVar(VarDecl *wrappedVar) {
   return SolutionApplicationTarget(wrappedVar);
 }
 
+SolutionApplicationTarget
+SolutionApplicationTarget::forPropertyWrapperInitializer(
+    VarDecl *wrappedVar, DeclContext *dc, Expr *initializer) {
+  SolutionApplicationTarget target(
+      initializer, dc, CTP_Initialization, wrappedVar->getType(),
+      /*isDiscarded=*/false);
+  target.expression.propertyWrapper.wrappedVar = wrappedVar;
+  if (auto *patternBinding = wrappedVar->getParentPatternBinding()) {
+    auto index = patternBinding->getPatternEntryIndexForVarDecl(wrappedVar);
+    target.expression.initialization.patternBinding = patternBinding;
+    target.expression.initialization.patternBindingIndex = index;
+    target.expression.pattern = patternBinding->getPattern(index);
+  }
+  target.maybeApplyPropertyWrapper();
+  return target;
+}
+
 ContextualPattern
 SolutionApplicationTarget::getContextualPattern() const {
   assert(kind == Kind::expression);

lib/Sema/TypeCheckConcurrency.cpp

@@ -2597,8 +2597,8 @@ void swift::checkEnumElementActorIsolation(
 }
 
 void swift::checkPropertyWrapperActorIsolation(
-   PatternBindingDecl *binding, Expr *expr) {
-  ActorIsolationChecker checker(binding->getDeclContext());
+    VarDecl *wrappedVar, Expr *expr) {
+  ActorIsolationChecker checker(wrappedVar->getDeclContext());
   expr->walk(checker);
 }
 

lib/Sema/TypeCheckConcurrency.h

@@ -44,6 +44,7 @@ class ProtocolConformance;
 class TopLevelCodeDecl;
 class TypeBase;
 class ValueDecl;
+class VarDecl;
 
 /// Add notes suggesting the addition of 'async' or '@asyncHandler', as
 /// appropriate, to a diagnostic for a function that isn't an async context.
@@ -54,8 +55,7 @@ void checkTopLevelActorIsolation(TopLevelCodeDecl *decl);
 void checkFunctionActorIsolation(AbstractFunctionDecl *decl);
 void checkInitializerActorIsolation(Initializer *init, Expr *expr);
 void checkEnumElementActorIsolation(EnumElementDecl *element, Expr *expr);
-void checkPropertyWrapperActorIsolation(
-    PatternBindingDecl *binding, Expr *expr);
+void checkPropertyWrapperActorIsolation(VarDecl *wrappedVar, Expr *expr);
 
 /// Determine the isolation of a particular closure.
 ///

lib/Sema/TypeCheckStorage.cpp

@@ -2571,31 +2571,24 @@ static VarDecl *synthesizePropertyWrapperProjectionVar(
 
 static void typeCheckSynthesizedWrapperInitializer(VarDecl *wrappedVar,
                                                    Expr *&initializer) {
-  // Figure out the context in which the initializer was written.
-  auto *parentPBD = wrappedVar->getParentPatternBinding();
-  auto i = parentPBD->getPatternEntryIndexForVarDecl(wrappedVar);
-  DeclContext *originalDC = parentPBD->getDeclContext();
-  if (!originalDC->isLocalContext()) {
-    auto initContext =
-        cast_or_null<PatternBindingInitializer>(parentPBD->getInitContext(i));
-    if (initContext)
-      originalDC = initContext;
-  }
+  auto *dc = wrappedVar->getInnermostDeclContext();
+  auto &ctx = wrappedVar->getASTContext();
+  auto *initContext = new (ctx) PropertyWrapperInitializer(
+      dc, wrappedVar, PropertyWrapperInitializer::Kind::WrappedValue);
 
   // Type-check the initialization.
-  auto *pattern = parentPBD->getPattern(i);
-  TypeChecker::typeCheckBinding(pattern, initializer, originalDC,
-                                wrappedVar->getType(), parentPBD, i);
+  using namespace constraints;
+  auto target = SolutionApplicationTarget::forPropertyWrapperInitializer(
+      wrappedVar, initContext, initializer);
+  auto result = TypeChecker::typeCheckExpression(target);
+  if (!result)
+    return;
 
-  if (auto initializerContext =
-          dyn_cast_or_null<Initializer>(parentPBD->getInitContext(i))) {
-    TypeChecker::contextualizeInitializer(initializerContext, initializer);
-  }
+  initializer = result->getAsExpr();
 
-  auto *backingVar = wrappedVar->getPropertyWrapperBackingProperty();
-  auto *backingPBD = backingVar->getParentPatternBinding();
-  checkPropertyWrapperActorIsolation(backingPBD, initializer);
-  TypeChecker::checkPropertyWrapperEffects(backingPBD, initializer);
+  TypeChecker::contextualizeInitializer(initContext, initializer);
+  checkPropertyWrapperActorIsolation(wrappedVar, initializer);
+  TypeChecker::checkInitializerEffects(initContext, initializer);
 }
 
 static PropertyWrapperMutability::Value
@@ -2954,21 +2947,7 @@ PropertyWrapperInitializerInfoRequest::evaluate(Evaluator &evaluator,
              !var->getName().hasDollarPrefix()) {
     wrappedValueInit = PropertyWrapperValuePlaceholderExpr::create(
         ctx, var->getSourceRange(), var->getType(), /*wrappedValue=*/nullptr);
-
-    if (auto *param = dyn_cast<ParamDecl>(var)) {
-      wrappedValueInit = buildPropertyWrapperInitCall(
-          var, storageType, wrappedValueInit, PropertyWrapperInitKind::WrappedValue);
-      TypeChecker::typeCheckExpression(wrappedValueInit, dc);
-
-      // Check initializer effects.
-      auto *initContext = new (ctx) PropertyWrapperInitializer(
-          dc, param, PropertyWrapperInitializer::Kind::WrappedValue);
-      TypeChecker::contextualizeInitializer(initContext, wrappedValueInit);
-      checkInitializerActorIsolation(initContext, wrappedValueInit);
-      TypeChecker::checkInitializerEffects(initContext, wrappedValueInit);
-    } else {
-      typeCheckSynthesizedWrapperInitializer(var, wrappedValueInit);
-    }
+    typeCheckSynthesizedWrapperInitializer(var, wrappedValueInit);
   }
 
   return PropertyWrapperInitializerInfo(wrappedValueInit, projectedValueInit);