[CodeCompletion] Don’t compute type relations if the contextual type is Any

Computing type relations to 'Any' is not very enlightning because everything would be convertible to it. If the contextual type is 'Any', just report all type relations as 'Unknown'.

rdar://64812321
rdar://84684686

Author: ahoppen

lib/IDE/CodeCompletionResultType.cpp

@@ -305,12 +305,34 @@ TypeRelation USRBasedTypeContext::ContextualType::typeRelation(
 
 // MARK: - CodeCompletionResultType
 
+/// Returns \c true if \p Ty is the 'Any' type or some type that is sufficiently
+/// similar to Any, like the 'Any' metatype or an optional type wrapping 'Any'.
+static bool isEssentiallyAnyType(Type Ty) {
+  while (true) {
+    if (auto MT = Ty->getAs<AnyMetatypeType>()) {
+      Ty = MT->getInstanceType();
+    } else if (auto OT = Ty->getOptionalObjectType()) {
+      Ty = OT;
+    } else {
+      break;
+    }
+  }
+  return Ty->isAny();
+}
+
 static TypeRelation calculateTypeRelation(Type Ty, Type ExpectedTy,
                                           const DeclContext &DC) {
   if (Ty.isNull() || ExpectedTy.isNull() || Ty->is<ErrorType>() ||
       ExpectedTy->is<ErrorType>())
     return TypeRelation::Unrelated;
 
+  /// Computing type relations to 'Any' is not very enlightning because
+  /// everything would be convertible to it. If the contextual type is 'Any',
+  /// just report all type relations as 'Unknown'.
+  if (isEssentiallyAnyType(ExpectedTy)) {
+    return TypeRelation::Unknown;
+  }
+
   // Equality/Conversion of GenericTypeParameterType won't account for
   // requirements – ignore them
   if (!Ty->hasTypeParameter() && !ExpectedTy->hasTypeParameter()) {

test/IDE/complete_at_top_level.swift

@@ -328,7 +328,7 @@ var stringInterp = "\(#^STRING_INTERP_3?check=STRING_INTERP^#)"
 _ = "" + "\(#^STRING_INTERP_4?check=STRING_INTERP^#)" + ""
 // STRING_INTERP: Begin completions
 // STRING_INTERP-DAG: Decl[InstanceMethod]/CurrNominal/Flair[ArgLabels]/IsSystem: ['(']{#(value): T#}[')'][#Void#];
-// STRING_INTERP-DAG: Decl[Struct]/CurrModule/TypeRelation[Convertible]: FooStruct[#FooStruct#]; name=FooStruct
+// STRING_INTERP-DAG: Decl[Struct]/CurrModule: FooStruct[#FooStruct#]; name=FooStruct
 // STRING_INTERP-DAG: Decl[FreeFunction]/CurrModule/TypeRelation[Invalid]: fooFunc1()[#Void#];
 // STRING_INTERP-DAG: Decl[FreeFunction]/CurrModule: optStr()[#String?#];
 // STRING_INTERP-DAG: Decl[GlobalVar]/Local: fooObject[#FooStruct#];

test/IDE/complete_type_any.swift

@@ -1,8 +1,5 @@
-// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=ANY_IN_FUNC_PARAM | %FileCheck %s -check-prefix=ANY_IN_FUNC_PARAM
-// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=ANY_IN_VAR_TYPE | %FileCheck %s -check-prefix=ANY_IN_VAR_TYPE
-// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=ANY_METATYPE_VARIABLE | %FileCheck %s -check-prefix=ANY_METATYPE_VARIABLE
-// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=ANY_METATYPE_MEMBER | %FileCheck %s -check-prefix=ANY_METATYPE_MEMBER
-// RUN: %target-swift-ide-test -code-completion -source-filename %s -code-completion-token=ANY_IN_TYPEALIAS | %FileCheck %s -check-prefix=ANY_IN_TYPEALIAS
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-ide-test -batch-code-completion -source-filename %s -filecheck %raw-FileCheck -completion-output-dir %t
 
 func testAnyInParamList(a: #^ANY_IN_FUNC_PARAM^#
 // ANY_IN_FUNC_PARAM: Begin completions
@@ -31,4 +28,32 @@ typealias A = #^ANY_IN_TYPEALIAS^#
 // ANY_IN_TYPEALIAS-DAG: Keyword/None: Any[#Any#]; name=Any
 // ANY_IN_TYPEALIAS: End completions
 
+func testRdar64812321() {
+  func foo<T>(x: T) {}
+  func foo(x: Any.Type) {}
 
+  struct MyStruct {}
+  let myStruct = MyStruct()
+
+  foo(x: #^ANY_RELATIONSHIP^#)
+  // The MyStruct type should not be preferred over the myStruct instance.
+
+// ANY_RELATIONSHIP: Begin completions
+// ANY_RELATIONSHIP-DAG: Decl[LocalVar]/Local:              myStruct[#MyStruct#]; name=myStruct
+// ANY_RELATIONSHIP-DAG: Decl[Struct]/Local:            MyStruct[#MyStruct#]; name=MyStruct
+// ANY_RELATIONSHIP: End completions
+}
+
+func testRdar84684686() {
+  func foo(_ x: Any?) {}
+
+  struct S {
+    static func bar(x: Int) -> Int { x }
+  }
+
+  // We should suggest a function call to `bar` here (i.e. `bar(x: <#Int#>)`), not a function reference (i.e. `bar(x:)`)
+  foo(S.#^ANY_PREFERS_FUNCTION_CALL^#)
+// ANY_PREFERS_FUNCTION_CALL: Begin completions
+// ANY_PREFERS_FUNCTION_CALL-DAG: Decl[StaticMethod]/CurrNominal:     bar({#x: Int#})[#Int#]; name=bar(x:)
+// ANY_PREFERS_FUNCTION_CALL: End completions
+}