[Diagnostics] Change phrasing of the existential_requires_any warning

The previous warning "must be explicitly marked as 'any'" isn't clear if
you don't already know the feature, this new phrasing should make it
clearer by including the correct spelling of the type as an example.

Fixes rdar://90384448

Author: porglezomp

include/swift/AST/DiagnosticsSema.def

@@ -4737,8 +4737,8 @@ ERROR(any_not_existential,none,
        "'any' has no effect on %select{concrete type|type parameter}0 %1",
        (bool, Type))
 ERROR(existential_requires_any,none,
-      "%select{protocol |}1%0 as a type must be explicitly marked as 'any'",
-      (Type, bool))
+      "use of %select{protocol |}2%0 as a type must be written %1",
+      (Type, Type, bool))
 
 ERROR(nonisolated_let,none,
       "'nonisolated' is meaningless on 'let' declarations because "

lib/Sema/TypeCheckType.cpp

@@ -4254,6 +4254,7 @@ class ExistentialTypeVisitor
         Ctx.Diags.diagnose(comp->getNameLoc(),
                            diag::existential_requires_any,
                            proto->getDeclaredInterfaceType(),
+                           proto->getExistentialType(),
                            /*isAlias=*/false)
             .limitBehavior(DiagnosticBehavior::Warning)
             .fixItReplace(replaceRepr->getSourceRange(), fix);
@@ -4273,6 +4274,7 @@ class ExistentialTypeVisitor
           Ctx.Diags.diagnose(comp->getNameLoc(),
                              diag::existential_requires_any,
                              alias->getDeclaredInterfaceType(),
+                             ExistentialType::get(alias->getDeclaredInterfaceType()),
                              /*isAlias=*/true)
               .limitBehavior(DiagnosticBehavior::Warning)
               .fixItReplace(replaceRepr->getSourceRange(), fix);

test/Generics/function_defs.swift

@@ -34,7 +34,7 @@ func min<T : MethodLessComparable>(_ x: T, y: T) -> T {
 //===----------------------------------------------------------------------===//
 
 func existential<T : EqualComparable, U : EqualComparable>(_ t1: T, t2: T, u: U) {
-  var eqComp : EqualComparable = t1 // expected-warning {{protocol 'EqualComparable' as a type must be explicitly marked as 'any'}}
+  var eqComp : EqualComparable = t1 // expected-warning {{use of protocol 'EqualComparable' as a type must be written 'any EqualComparable'}}
   eqComp = u
   if t1.isEqual(eqComp) {} // expected-error{{cannot convert value of type 'any EqualComparable' to expected argument type 'T'}}
   if eqComp.isEqual(t2) {}

test/decl/nested/protocol.swift

@@ -31,7 +31,7 @@ protocol OuterProtocol {
 struct ConformsToOuterProtocol : OuterProtocol {
   typealias Hen = Int
 
-  func f() { let _ = InnerProtocol.self } // expected-warning {{protocol 'InnerProtocol' as a type must be explicitly marked as 'any'}}
+  func f() { let _ = InnerProtocol.self } // expected-warning {{use of protocol 'InnerProtocol' as a type must be written 'any InnerProtocol'}}
 }
 
 protocol Racoon {

test/decl/protocol/conforms/inherited.swift

@@ -167,13 +167,13 @@ class B : A {
 }
 
 func testB(_ b: B) {
-  var _: P1 = b // expected-warning {{protocol 'P1' as a type must be explicitly marked as 'any'}}
-  var _: P4 = b // expected-warning {{protocol 'P4' as a type must be explicitly marked as 'any'}}
+  var _: P1 = b // expected-warning {{use of protocol 'P1' as a type must be written 'any P1'}}
+  var _: P4 = b // expected-warning {{use of protocol 'P4' as a type must be written 'any P4'}}
   var _: P5 = b
   var _: P6 = b
-  var _: P7 = b // expected-warning {{protocol 'P7' as a type must be explicitly marked as 'any'}}
+  var _: P7 = b // expected-warning {{use of protocol 'P7' as a type must be written 'any P7'}}
   var _: P8 = b
-  var _: P9 = b // expected-warning {{protocol 'P9' as a type must be explicitly marked as 'any'}}
+  var _: P9 = b // expected-warning {{use of protocol 'P9' as a type must be written 'any P9'}}
 }
 
 // Class A5 conforms to P5 in an inheritable manner.

test/decl/protocol/existential_member_accesses_self_assoctype.swift

@@ -805,7 +805,7 @@ do {
     let _: any Class<Struct<Bool>.Inner> & ConcreteAssocTypes =
       arg[
         // FIXME: Sema thinks (any ConcreteAssocTypes).self is a function ref.
-        // expected-warning@+1 {{protocol 'ConcreteAssocTypes' as a type must be explicitly marked as 'any'}}
+        // expected-warning@+1 {{use of protocol 'ConcreteAssocTypes' as a type must be written 'any ConcreteAssocTypes'}}
         subscript4: Struct<Bool>(), ConcreteAssocTypes.self, { true }
       ]
   }

test/decl/protocol/existential_member_accesses_self_assoctype_fixit.swift

@@ -12,12 +12,12 @@ protocol P {
 protocol Q {}
 
 do {
-  func test(p: P) { // expected-warning {{protocol 'P' as a type must be explicitly marked as 'any'}}
+  func test(p: P) { // expected-warning {{use of protocol 'P' as a type must be written 'any P'}}
     p.method(false) // expected-error {{member 'method' cannot be used on value of type 'any P'; consider using a generic constraint instead}} {{-1:16--1:17=<#generic parameter name#>}} {{-1:12--1:12=<<#generic parameter name#>: P>}} {{none}}
   }
 }
 do {
-  func test(p: ((P))) { // expected-warning {{protocol 'P' as a type must be explicitly marked as 'any'}}
+  func test(p: ((P))) { // expected-warning {{use of protocol 'P' as a type must be written 'any P'}}
     p.method(false) // expected-error {{member 'method' cannot be used on value of type 'any P'; consider using a generic constraint instead}} {{-1:18--1:19=<#generic parameter name#>}} {{-1:12--1:12=<<#generic parameter name#>: P>}} {{none}}
   }
 }
@@ -57,12 +57,12 @@ do {
   }
 }
 do {
-  func test(p: P.Type) { // expected-warning {{protocol 'P' as a type must be explicitly marked as 'any'}}
+  func test(p: P.Type) { // expected-warning {{use of protocol 'P' as a type must be written 'any P'}}
     p.staticMethod(false) // expected-error {{member 'staticMethod' cannot be used on value of type 'any P.Type'; consider using a generic constraint instead}} {{-1:16--1:17=<#generic parameter name#>}} {{-1:12--1:12=<<#generic parameter name#>: P>}} {{none}}
   }
 }
 do {
-  func test(p: (P).Type) { // expected-warning {{protocol 'P' as a type must be explicitly marked as 'any'}}
+  func test(p: (P).Type) { // expected-warning {{use of protocol 'P' as a type must be written 'any P'}}
     p.staticMethod(false) // expected-error {{member 'staticMethod' cannot be used on value of type 'any (P).Type'; consider using a generic constraint instead}} {{-1:17--1:18=<#generic parameter name#>}} {{-1:12--1:12=<<#generic parameter name#>: P>}} {{none}}
   }
 }
@@ -78,12 +78,12 @@ do {
 }
 
 do {
-  func test(p: P & Q) { // expected-warning {{protocol 'P' as a type must be explicitly marked as 'any'}}
+  func test(p: P & Q) { // expected-warning {{use of protocol 'P' as a type must be written 'any P'}}
     p.method(false) // expected-error {{member 'method' cannot be used on value of type 'any P & Q'; consider using a generic constraint instead}} {{-1:16--1:21=<#generic parameter name#>}} {{-1:12--1:12=<<#generic parameter name#>: P & Q>}} {{none}}
   }
 }
 do {
-  func test(p: ((P & Q))) { // expected-warning {{protocol 'P' as a type must be explicitly marked as 'any'}}
+  func test(p: ((P & Q))) { // expected-warning {{use of protocol 'P' as a type must be written 'any P'}}
     p.method(false) // expected-error {{member 'method' cannot be used on value of type 'any P & Q'; consider using a generic constraint instead}} {{-1:18--1:23=<#generic parameter name#>}} {{-1:12--1:12=<<#generic parameter name#>: P & Q>}} {{none}}
   }
 }
@@ -123,12 +123,12 @@ do {
   }
 }
 do {
-  func test(p: (P & Q).Type) { // expected-warning {{protocol 'P' as a type must be explicitly marked as 'any'}}
+  func test(p: (P & Q).Type) { // expected-warning {{use of protocol 'P' as a type must be written 'any P'}}
     p.staticMethod(false) // expected-error {{member 'staticMethod' cannot be used on value of type 'any (P & Q).Type'; consider using a generic constraint instead}} {{-1:16--1:23=<#generic parameter name#>}} {{-1:12--1:12=<<#generic parameter name#>: P & Q>}} {{none}}
   }
 }
 do {
-  func test(p: ((P & Q)).Type) { // expected-warning {{protocol 'P' as a type must be explicitly marked as 'any'}}
+  func test(p: ((P & Q)).Type) { // expected-warning {{use of protocol 'P' as a type must be written 'any P'}}
     p.staticMethod(false) // expected-error {{member 'staticMethod' cannot be used on value of type 'any ((P & Q)).Type'; consider using a generic constraint instead}} {{-1:18--1:23=<#generic parameter name#>}} {{-1:12--1:12=<<#generic parameter name#>: P & Q>}} {{none}}
   }
 }

test/decl/protocol/protocols.swift

@@ -446,7 +446,7 @@ func i<T : C3>(_ x : T?) -> Bool {
   // expected-warning@-1 {{checking a value with optional type 'T?' against type 'any P1' succeeds whenever the value is non-nil; did you mean to use '!= nil'?}}
 }
 func j(_ x : C1) -> Bool {
-  return x is P1 // expected-warning {{protocol 'P1' as a type must be explicitly marked as 'any'}}
+  return x is P1 // expected-warning {{use of protocol 'P1' as a type must be written 'any P1'}}
 }
 func k(_ x : C1?) -> Bool {
   return x is any P1

test/decl/protocol/recursive_requirement.swift

@@ -91,7 +91,7 @@ protocol AsExistentialB {
 }
 
 protocol AsExistentialAssocTypeA {
-  var delegate : AsExistentialAssocTypeB? { get } // expected-warning {{protocol 'AsExistentialAssocTypeB' as a type must be explicitly marked as 'any'}}
+  var delegate : AsExistentialAssocTypeB? { get } // expected-warning {{use of protocol 'AsExistentialAssocTypeB' as a type must be written 'any AsExistentialAssocTypeB'}}
 }
 protocol AsExistentialAssocTypeB {
   func aMethod(_ object : AsExistentialAssocTypeA)
@@ -103,7 +103,7 @@ protocol AsExistentialAssocTypeAgainA {
   associatedtype Bar
 }
 protocol AsExistentialAssocTypeAgainB {
-  func aMethod(_ object : AsExistentialAssocTypeAgainA) // expected-warning {{protocol 'AsExistentialAssocTypeAgainA' as a type must be explicitly marked as 'any'}}
+  func aMethod(_ object : AsExistentialAssocTypeAgainA) // expected-warning {{use of protocol 'AsExistentialAssocTypeAgainA' as a type must be written 'any AsExistentialAssocTypeAgainA'}}
 }
 
 // SR-547

test/type/explicit_existential.swift

@@ -244,16 +244,16 @@ protocol Output {
   associatedtype A
 }
 
-// expected-warning@+2{{protocol 'Input' as a type must be explicitly marked as 'any'}}{{30-35=any Input}}
-// expected-warning@+1{{protocol 'Output' as a type must be explicitly marked as 'any'}}{{40-46=any Output}}
+// expected-warning@+2{{use of protocol 'Input' as a type must be written 'any Input'}}{{30-35=any Input}}
+// expected-warning@+1{{use of protocol 'Output' as a type must be written 'any Output'}}{{40-46=any Output}}
 typealias InvalidFunction = (Input) -> Output
 func testInvalidFunctionAlias(fn: InvalidFunction) {}
 
 typealias ExistentialFunction = (any Input) -> any Output
 func testFunctionAlias(fn: ExistentialFunction) {}
 
 typealias Constraint = Input
-func testConstraintAlias(x: Constraint) {} // expected-warning{{'Constraint' (aka 'Input') as a type must be explicitly marked as 'any'}}{{29-39=any Constraint}}
+func testConstraintAlias(x: Constraint) {} // expected-warning{{use of 'Constraint' (aka 'Input') as a type must be written 'any Constraint'}}{{29-39=any Constraint}}
 
 typealias Existential = any Input
 func testExistentialAlias(x: Existential, y: any Constraint) {}
@@ -287,25 +287,25 @@ func testAnyFixIt() {
     func method() -> any HasAssoc {}
   }
 
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{10-18=any HasAssoc}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{10-18=any HasAssoc}}
   let _: HasAssoc = ConformingType()
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{19-27=any HasAssoc}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{19-27=any HasAssoc}}
   let _: Optional<HasAssoc> = nil
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{10-23=any HasAssoc.Type}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{10-23=any HasAssoc.Type}}
   let _: HasAssoc.Type = ConformingType.self
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{10-25=any (HasAssoc).Type}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{10-25=any (HasAssoc).Type}}
   let _: (HasAssoc).Type = ConformingType.self
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{10-27=any ((HasAssoc)).Type}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{10-27=any ((HasAssoc)).Type}}
   let _: ((HasAssoc)).Type = ConformingType.self
-  // expected-warning@+2 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{10-18=(any HasAssoc)}}
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{30-38=(any HasAssoc)}}
+  // expected-warning@+2 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{10-18=(any HasAssoc)}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{30-38=(any HasAssoc)}}
   let _: HasAssoc.Protocol = HasAssoc.self
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{11-19=any HasAssoc}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{11-19=any HasAssoc}}
   let _: (HasAssoc).Protocol = (any HasAssoc).self
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{10-18=(any HasAssoc)}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{10-18=(any HasAssoc)}}
   let _: HasAssoc? = ConformingType()
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{10-23=(any HasAssoc.Type)}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{10-23=(any HasAssoc.Type)}}
   let _: HasAssoc.Type? = ConformingType.self
-  // expected-warning@+1 {{'HasAssoc' as a type must be explicitly marked as 'any'}}{{10-18=(any HasAssoc)}}
+  // expected-warning@+1 {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}{{10-18=(any HasAssoc)}}
   let _: HasAssoc.Protocol? = (any HasAssoc).self
 }

test/type/protocol_types.swift

@@ -3,7 +3,7 @@
 protocol HasSelfRequirements {
   func foo(_ x: Self)
 
-  func returnsOwnProtocol() -> HasSelfRequirements // expected-warning {{protocol 'HasSelfRequirements' as a type must be explicitly marked as 'any'}}
+  func returnsOwnProtocol() -> HasSelfRequirements // expected-warning {{use of protocol 'HasSelfRequirements' as a type must be written 'any HasSelfRequirements'}}
 }
 protocol Bar {
   // init() methods should not prevent use as an existential.
@@ -74,7 +74,7 @@ do {
 
   func checkIt(_ js: Any) throws {
     switch js {
-    case let dbl as HasAssoc: // expected-warning {{protocol 'HasAssoc' as a type must be explicitly marked as 'any'}}
+    case let dbl as HasAssoc: // expected-warning {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}
       throw MyError.bad(dbl)
 
     default:
@@ -83,7 +83,7 @@ do {
   }
 }
 
-func testHasAssoc(_ x: Any, _: HasAssoc) { // expected-warning {{protocol 'HasAssoc' as a type must be explicitly marked as 'any'}}
+func testHasAssoc(_ x: Any, _: HasAssoc) { // expected-warning {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}
   if let p = x as? any HasAssoc {
     p.foo() // don't crash here.
   }
@@ -92,12 +92,12 @@ func testHasAssoc(_ x: Any, _: HasAssoc) { // expected-warning {{protocol 'HasAs
     typealias Assoc = Int
     func foo() {}
 
-    func method() -> HasAssoc {} // expected-warning {{protocol 'HasAssoc' as a type must be explicitly marked as 'any'}}
+    func method() -> HasAssoc {} // expected-warning {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}
   }
 }
 
 // SR-38
-var b: HasAssoc // expected-warning {{protocol 'HasAssoc' as a type must be explicitly marked as 'any'}}
+var b: HasAssoc // expected-warning {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}
 
 // Further generic constraint error testing - typealias used inside statements
 protocol P {}
@@ -118,20 +118,20 @@ typealias X = Struct1<Pub & Bar>
 _ = Struct1<Pub & Bar>.self
 
 typealias AliasWhere<T> = T
-where T : HasAssoc, T.Assoc == HasAssoc // expected-warning {{protocol 'HasAssoc' as a type must be explicitly marked as 'any'}}
+where T : HasAssoc, T.Assoc == HasAssoc // expected-warning {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}
 
 struct StructWhere<T>
 where T : HasAssoc,
       T.Assoc == any HasAssoc {}
 
-protocol ProtocolWhere where T == HasAssoc { // expected-warning {{protocol 'HasAssoc' as a type must be explicitly marked as 'any'}}
+protocol ProtocolWhere where T == HasAssoc { // expected-warning {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}
   associatedtype T
 
   associatedtype U : HasAssoc
     where U.Assoc == any HasAssoc
 }
 
-extension HasAssoc where Assoc == HasAssoc {} // expected-warning {{protocol 'HasAssoc' as a type must be explicitly marked as 'any'}}
+extension HasAssoc where Assoc == HasAssoc {} // expected-warning {{use of protocol 'HasAssoc' as a type must be written 'any HasAssoc'}}
 
 func FunctionWhere<T>(_: T)
 where T : HasAssoc,