ModuleInterface: Only print API-level property wrappers in swiftinterfaces.

When a function parameter has attached property wrappers (SE-0293) those
property wrappers are either considered "implementation" or "API" level.
Property wrappers that are implementation-level don't affect how the function
is called and therefore shouldn't be included in swiftinterfaces unless the
function's body is also printed.

Resolves rdar://156711817.

lib/AST/ASTPrinter.cpp

@@ -1417,7 +1417,20 @@ void PrintAST::printAttributes(const Decl *D) {
     scope.Options.ExcludeAttrList.push_back(DeclAttrKind::Consuming);
     scope.Options.ExcludeAttrList.push_back(DeclAttrKind::Borrowing);
   }
-  
+
+  // If we're printing a swiftinterface and the attached property wrappers don't
+  // have an external effect, skip them.
+  if (Options.IsForSwiftInterface) {
+    if (auto *PD = dyn_cast<ParamDecl>(D)) {
+      if (!PD->hasExternalPropertyWrapper() &&
+          PD->getDeclContext()->getResilienceExpansion() !=
+              ResilienceExpansion::Minimal) {
+        for (auto *attr : PD->getAttachedPropertyWrappers())
+          scope.Options.ExcludeCustomAttrList.push_back(attr);
+      }
+    }
+  }
+
   attrs.print(Printer, Options, D);
 }
 

test/ModuleInterface/property_wrappers.swift

@@ -9,34 +9,46 @@
 
 @propertyWrapper
 public struct Wrapper<T> {
-  public var value: T
+  public var wrappedValue: T
 
-  public var wrappedValue: T {
+  public init(wrappedValue: T) {
-    get { value }
+    self.wrappedValue = wrappedValue
-    set { value = newValue }
   }
 }
 
 @propertyWrapper
 public struct WrapperWithInitialValue<T> {
-  private var value: T
+  public var wrappedValue: T
-  
-  public var wrappedValue: T {
-    get { value }
-    set { value = newValue }
-  }
 
   public init(initialValue: T) {
-    self.value = initialValue
+    self.wrappedValue = initialValue
   }
 
   public init(alternate value: T) {
-    self.value = value
+    self.wrappedValue = value
   }
 
   public var projectedValue: Wrapper<T> {
-    get { Wrapper(value: value) }
+    get { Wrapper(wrappedValue: wrappedValue) }
-    set { value = newValue.value }
+    set { wrappedValue = newValue.wrappedValue }
+  }
+}
+
+@propertyWrapper
+public struct ProjectedValueWrapper<T> {
+  public var wrappedValue: T
+
+  public init(wrappedValue: T) {
+    self.wrappedValue = wrappedValue
+  }
+
+  public init(projectedValue: Wrapper<T>) {
+    self.wrappedValue = projectedValue.wrappedValue
+  }
+
+  public var projectedValue: Wrapper<T> {
+    get { Wrapper(wrappedValue: wrappedValue) }
+    set { wrappedValue = newValue.wrappedValue }
   }
 }
 
@@ -64,4 +76,22 @@ public struct HasWrappers {
   // CHECK-NEXT: _modify
   // CHECK-NEXT: }  
   @WrapperWithInitialValue(alternate: false) public var z
+
+  // CHECK: public func hasParameterWithImplementationWrapper(x: Swift.Int)
+  public func hasParameterWithImplementationWrapper(@Wrapper x: Int) { }
+
+  // CHECK: public func hasParameterWithImplementationWrapperComposed(x: Swift.Int)
+  public func hasParameterWithImplementationWrapperComposed(@Wrapper @ProjectedValueWrapper x: Int) { }
+
+  // CHECK: @inlinable public func hasParameterWithImplementationWrapperInlinable(@TestResilient.Wrapper x: Swift.Int)
+  @inlinable public func hasParameterWithImplementationWrapperInlinable(@Wrapper x: Int) { }
+
+  // CHECK: @_alwaysEmitIntoClient public func hasParameterWithImplementationWrapperAEIC(@TestResilient.Wrapper x: Swift.Int)
+  @_alwaysEmitIntoClient public func hasParameterWithImplementationWrapperAEIC(@Wrapper x: Int) { }
+
+  // CHECK: public func hasParameterWithAPIWrapper(@TestResilient.ProjectedValueWrapper x: Swift.Int)
+  public func hasParameterWithAPIWrapper(@ProjectedValueWrapper x: Int) { }
+
+  // CHECK: public func hasParameterWithAPIWrapperComposed(@TestResilient.ProjectedValueWrapper @TestResilient.Wrapper x: Swift.Int)
+  public func hasParameterWithAPIWrapperComposed(@ProjectedValueWrapper @Wrapper x: Int) { }
 }