Revert "[Associated type inference] Infer escaping function types, not noescape ones."

This reverts commit 60e8de7.

Author: gottesmm

lib/Sema/TypeCheckProtocolInference.cpp

@@ -607,33 +607,6 @@ AssociatedTypeInference::inferTypeWitnessesViaAssociatedType(
   return result;
 }
 
-/// Perform any necessary adjustments to the inferred associated type to
-/// make it suitable for later use.
-static Type adjustInferredAssociatedType(Type type) {
-  // If we have an optional type, adjust its wrapped type.
-  if (auto optionalObjectType = type->getOptionalObjectType()) {
-    auto newOptionalObjectType =
-      adjustInferredAssociatedType(optionalObjectType);
-    if (newOptionalObjectType.getPointer() == optionalObjectType.getPointer())
-      return type;
-
-    return OptionalType::get(newOptionalObjectType);
-  }
-
-  // If we have a noescape function type, make it escaping.
-  if (auto funcType = type->getAs<FunctionType>()) {
-    if (funcType->isNoEscape()) {
-      return FunctionType::get(funcType->getParams(), funcType->getResult(),
-                               funcType->getExtInfo().withNoEscape(false));
-    }
-  }
-
-  // We can only infer materializable types.
-  if (!type->isMaterializable()) return nullptr;
-
-  return type;
-}
-
 /// Attempt to resolve a type witness via a specific value witness.
 InferredAssociatedTypesByWitness
 AssociatedTypeInference::inferTypeWitnessesViaValueWitness(ValueDecl *req,
@@ -689,14 +662,10 @@ AssociatedTypeInference::inferTypeWitnessesViaValueWitness(ValueDecl *req,
       if (secondType->hasError())
         return true;
 
-      Type inferredType = adjustInferredAssociatedType(secondType);
-      if (!inferredType)
-        return true;
-
       auto proto = Conformance->getProtocol();
       if (auto assocType = getReferencedAssocTypeOfProtocol(firstDepMember,
                                                             proto)) {
-        Inferred.Inferred.push_back({assocType, inferredType});
+        Inferred.Inferred.push_back({assocType, secondType});
       }
 
       // Always allow mismatches here.

test/decl/protocol/conforms/associated_type.swift

@@ -32,32 +32,3 @@ class Foo: FooType {
     func foo(action: (Bar) -> Void) {
     }
 }
-
-// rdar://problem/35297911: noescape function types
-protocol P1 {
-  associatedtype A
-
-  func f(_: A)
-  // expected-note@-1 {{protocol requires function 'f' with type '(X1c.A) -> ()' (aka '((Int) -> Int) -> ()'); do you want to add a stub?}}
-  // expected-note@-2 {{protocol requires function 'f' with type '((Int) -> Int) -> ()'; do you want to add a stub?}}
-}
-
-struct X1a : P1 {
-  func f(_: @escaping (Int) -> Int) { }
-}
-
-struct X1b : P1 {
-  typealias A = (Int) -> Int
-
-  func f(_: @escaping (Int) -> Int) { }
-}
-
-struct X1c : P1 { // expected-error{{type 'X1c' does not conform to protocol 'P1'}}
-  typealias A = (Int) -> Int
-
-  func f(_: (Int) -> Int) { } // expected-note{{candidate has non-matching type '((Int) -> Int) -> ()'}}
-}
-
-struct X1d : P1 { // expected-error{{type 'X1d' does not conform to protocol 'P1'}}
-  func f(_: (Int) -> Int) { } // expected-note{{candidate has non-matching type '((Int) -> Int) -> ()' [with A = (Int) -> Int]}}
-}