[FixCode] Add a diagnosis/fixit to help users convert void pointers.

include/swift/AST/DiagnosticsSema.def

@@ -2201,6 +2201,9 @@ NOTE(generic_type_declared_here,none,
 ERROR(cannot_partially_specialize_generic_function,none,
      "cannot partially specialize a generic function", ())
 
+WARNING(use_of_void_pointer,none,
+"Unsafe%0Pointer<Void> has been replaced by Unsafe%0RawPointer", (StringRef))
+
 // Ambiguities
 ERROR(ambiguous_decl_ref,none,
       "ambiguous use of %0", (DeclName))

lib/Sema/TypeCheckType.cpp

@@ -408,6 +408,24 @@ Type TypeChecker::resolveTypeInContext(
   return ErrorType::get(Context);
 }
 
+/// This function checks if a bound generic type is UnsafePointer<Void> or
+/// UnsafeMutablePointer<Void>. For these two type representations, we should
+/// warn users that they are deprecated and replace them with more handy
+/// UnsafeRawPointer and UnsafeMutableRawPointer, respectively.
+static bool isPointerToVoid(ASTContext &Ctx, Type Ty, bool &IsMutable) {
+  if (Ty.isNull())
+    return false;
+  auto *BGT = Ty->getAs<BoundGenericType>();
+  if (!BGT)
+    return false;
+  if (BGT->getDecl() != Ctx.getUnsafePointerDecl() &&
+      BGT->getDecl() != Ctx.getUnsafeMutablePointerDecl())
+    return false;
+  IsMutable = BGT->getDecl() == Ctx.getUnsafeMutablePointerDecl();
+  assert(BGT->getGenericArgs().size() == 1);
+  return BGT->getGenericArgs().front()->isVoid();
+}
+
 Type TypeChecker::applyGenericArguments(Type type, TypeDecl *decl,
                                         SourceLoc loc, DeclContext *dc,
                                         GenericIdentTypeRepr *generic,
@@ -473,8 +491,18 @@ Type TypeChecker::applyGenericArguments(Type type, TypeDecl *decl,
   for (auto tyR : genericArgs)
     args.push_back(tyR);
 
-  return applyUnboundGenericArguments(type, genericDecl, loc, dc, args,
-                                      isGenericSignature, resolver);
+  auto result = applyUnboundGenericArguments(type, genericDecl, loc, dc, args,
+                                             isGenericSignature, resolver);
+  bool isMutablePointer;
+  if (isPointerToVoid(dc->getASTContext(), result, isMutablePointer)) {
+    if (isMutablePointer)
+      diagnose(loc, diag::use_of_void_pointer, "Mutable").
+        fixItReplace(generic->getSourceRange(), "UnsafeMutableRawPointer");
+    else
+      diagnose(loc, diag::use_of_void_pointer, "").
+        fixItReplace(generic->getSourceRange(), "UnsafeRawPointer");
+  }
+  return result;
 }
 
 /// Apply generic arguments to the given type.

test/1_stdlib/UnsafePointerDiagnostics.swift

@@ -5,8 +5,8 @@
 func unsafePointerConversionAvailability(
   mrp: UnsafeMutableRawPointer,
   rp: UnsafeRawPointer,
-  umpv: UnsafeMutablePointer<Void>, // FIXME: This should yield a warning to rename UnsafeMutablePointer<Void> to UnsafeMutableRawPointer
-  upv: UnsafePointer<Void>,         // FIXME: This should yield a warning to rename UnsafePointer<Void> to UnsafeRawPointer
+  umpv: UnsafeMutablePointer<Void>, // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
+  upv: UnsafePointer<Void>, // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}
   umpi: UnsafeMutablePointer<Int>,
   upi: UnsafePointer<Int>,
   umps: UnsafeMutablePointer<String>,
@@ -31,27 +31,25 @@ func unsafePointerConversionAvailability(
   _ = UnsafeRawPointer(umps)
   _ = UnsafeRawPointer(ups)
 
-  // FIXME: All of these should yield a warning to rename
-  // UnsafeMutablePointer<Void> to UnsafeMutableRawPointer.
-  _ = UnsafeMutablePointer<Void>(rp) // expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Void>' with an argument list of type '(UnsafeRawPointer)'}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}} expected-note {{}}
-  _ = UnsafeMutablePointer<Void>(mrp) // expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Void>' with an argument list of type '(UnsafeMutableRawPointer)'}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}} expected-note {{}}
-  _ = UnsafeMutablePointer<Void>(umpv)
-  _ = UnsafeMutablePointer<Void>(upv)  // expected-error {{'init' has been renamed to 'init(mutating:)'}}
-  _ = UnsafeMutablePointer<Void>(umpi)
-  _ = UnsafeMutablePointer<Void>(upi)  // expected-error {{'init' has been renamed to 'init(mutating:)'}}
-  _ = UnsafeMutablePointer<Void>(umps)
-  _ = UnsafeMutablePointer<Void>(ups)  // expected-error {{'init' has been renamed to 'init(mutating:)'}}
+  // UnsafeMutablePointer<Void> to UnsafeMutableRawPointer(umpv)
+  _ = UnsafeMutablePointer<Void>(rp) // expected-warning 3 {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}} expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Void>' with an argument list of type '(UnsafeRawPointer)'}} expected-note {{overloads for 'UnsafeMutablePointer<Void>' exist with these partially matching parameter lists: (RawPointer), (OpaquePointer), (OpaquePointer?), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}} expected-note{{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type}}
+  _ = UnsafeMutablePointer<Void>(mrp) // expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Void>' with an argument list of type '(UnsafeMutableRawPointer)'}} expected-note {{}} expected-warning 3 {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}} expected-note{{overloads for 'UnsafeMutablePointer<Void>' exist with these partially matching parameter lists: (RawPointer), (OpaquePointer), (OpaquePointer?), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}}
+  _ = UnsafeMutablePointer<Void>(umpv) // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
+  _ = UnsafeMutablePointer<Void>(upv)  // expected-error {{'init' has been renamed to 'init(mutating:)'}} expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
+  _ = UnsafeMutablePointer<Void>(umpi) // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
+  _ = UnsafeMutablePointer<Void>(upi)  // expected-error {{'init' has been renamed to 'init(mutating:)'}} expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
+  _ = UnsafeMutablePointer<Void>(umps) // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
+  _ = UnsafeMutablePointer<Void>(ups)  // expected-error {{'init' has been renamed to 'init(mutating:)'}} expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
 
-  // FIXME: All of these should yield a warning to rename
-  // UnsafePointer<Void> to UnsafeRawPointer.
-  _ = UnsafePointer<Void>(rp)  // expected-error {{cannot invoke initializer for type 'UnsafePointer<Void>' with an argument list of type '(UnsafeRawPointer)'}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}} expected-note {{}}
-  _ = UnsafePointer<Void>(mrp) // expected-error {{cannot invoke initializer for type 'UnsafePointer<Void>' with an argument list of type '(UnsafeMutableRawPointer)'}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}} expected-note {{}}
-  _ = UnsafePointer<Void>(umpv)
-  _ = UnsafePointer<Void>(upv)
-  _ = UnsafePointer<Void>(umpi)
-  _ = UnsafePointer<Void>(upi)
-  _ = UnsafePointer<Void>(umps)
-  _ = UnsafePointer<Void>(ups)
+  // UnsafePointer<Void> to UnsafeRawPointer(umpv)
+  _ = UnsafePointer<Void>(rp)  // expected-error {{cannot invoke initializer for type 'UnsafePointer<Void>' with an argument list of type '(UnsafeRawPointer)'}} expected-note {{}} expected-warning 3 {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}} expected-note{{overloads for 'UnsafePointer<Void>' exist with these partially matching parameter lists: (RawPointer), (OpaquePointer), (OpaquePointer?), (UnsafePointer<Pointee>), (UnsafePointer<Pointee>?), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}}
+  _ = UnsafePointer<Void>(mrp) // expected-error {{cannot invoke initializer for type 'UnsafePointer<Void>' with an argument list of type '(UnsafeMutableRawPointer)'}} expected-note {{}} expected-warning 3 {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}} expected-note{{overloads for 'UnsafePointer<Void>' exist with these partially matching parameter lists: (RawPointer), (OpaquePointer), (OpaquePointer?), (UnsafePointer<Pointee>), (UnsafePointer<Pointee>?), (UnsafeMutablePointer<Pointee>), (UnsafeMutablePointer<Pointee>?)}}
+  _ = UnsafePointer<Void>(umpv) // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}
+  _ = UnsafePointer<Void>(upv) // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}
+  _ = UnsafePointer<Void>(umpi) // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}
+  _ = UnsafePointer<Void>(upi) // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}
+  _ = UnsafePointer<Void>(umps) // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}
+  _ = UnsafePointer<Void>(ups) // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}
 
   _ = UnsafeMutablePointer<Int>(rp) // expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Int>' with an argument list of type '(UnsafeRawPointer)'}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}} expected-note {{}}
   _ = UnsafeMutablePointer<Int>(mrp) // expected-error {{cannot invoke initializer for type 'UnsafeMutablePointer<Int>' with an argument list of type '(UnsafeMutableRawPointer)'}} expected-note {{Pointer conversion restricted: use '.assumingMemoryBound(to:)' or '.bindMemory(to:capacity:)' to view memory as a type.}} expected-note {{}}

test/SILGen/optional_chain_addressor.swift

@@ -1,6 +1,6 @@
 // RUN: %target-swift-frontend -emit-silgen -verify -parse-as-library %s
 
-func foo(x: UnsafeMutablePointer<UnsafeMutablePointer<()>?>) {
+func foo(x: UnsafeMutablePointer<UnsafeMutablePointer<()>?>) { // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}
   _ = x.pointee?.pointee
   _ = x.pointee.map { type(of: $0) }
 }

test/type/types.swift

@@ -159,5 +159,13 @@ class r21949448 {
 // SE-0066 - Standardize function type argument syntax to require parentheses
 let _ : Int -> Float // expected-error {{single argument function types require parentheses}} {{9-9=(}} {{12-12=)}}
 
-
-
+func foo1(a : UnsafePointer<Void>) {} // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}{{15-34=UnsafeRawPointer}}
+func foo2(a : UnsafeMutablePointer<()>) {} // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}{{15-39=UnsafeMutableRawPointer}}
+class C {
+  func foo1(a : UnsafePointer<Void>) {} // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}{{17-36=UnsafeRawPointer}}
+  func foo2(a : UnsafeMutablePointer<()>) {} // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}{{17-41=UnsafeMutableRawPointer}}
+  func foo3() {
+    let _ : UnsafePointer<Void> // expected-warning {{UnsafePointer<Void> has been replaced by UnsafeRawPointer}}{{13-32=UnsafeRawPointer}}
+    let _ : UnsafeMutablePointer<Void> // expected-warning {{UnsafeMutablePointer<Void> has been replaced by UnsafeMutableRawPointer}}{{13-39=UnsafeMutableRawPointer}}
+  }
+}