[SE-0095] [Runtime], [Demangler], & AST printer updated to new composition syntax

- All parts of the compiler now use ‘P1 & P2’ syntax
- The demangler and AST printer wrap the composition in parens if it is
in a metatype lookup
- IRGen mangles compositions differently
    - “protocol<>” is now “swift.Any”
    - “protocol<_TP1P,_TP1Q>” is now “_TP1P&_TP1Q”
- Tests cases are updated and added to test the new syntax and mangling

Author: joewillsher

include/swift/AST/Types.h

@@ -3476,7 +3476,7 @@ END_CAN_TYPE_WRAPPER(ProtocolType, NominalType)
 /// \code
 /// protocol P { /* ... */ }
 /// protocol Q { /* ... */ }
-/// var x : protocol<P, Q>
+/// var x : P & Q
 /// \endcode
 ///
 /// Here, the type of x is a composition of the protocols 'P' and 'Q'.

lib/AST/ASTPrinter.cpp

@@ -3294,6 +3294,12 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
       return !arch->isOpenedExistential();
     }
 
+    case TypeKind::ProtocolComposition: {
+      // 'Any' and single protocol compositions are simple
+      auto composition = type->getAs<ProtocolCompositionType>();
+      return composition->getProtocols().size() <= 1;
+    }
+
     default:
       return true;
     }
@@ -4043,16 +4049,18 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
   }
 
   void visitProtocolCompositionType(ProtocolCompositionType *T) {
-    Printer << tok::kw_protocol << "<";
-    bool First = true;
-    for (auto Proto : T->getProtocols()) {
-      if (First)
-        First = false;
-      else
-        Printer << ", ";
-      visit(Proto);
+    if (T->getProtocols().empty()) {
+      Printer << "Any";
+    } else {
+      bool First = true;
+      for (auto Proto : T->getProtocols()) {
+        if (First)
+          First = false;
+        else
+          Printer << " & ";
+        visit(Proto);
+      }
     }
-    Printer << ">";
   }
 
   void visitLValueType(LValueType *T) {

lib/AST/ArchetypeBuilder.cpp

@@ -826,23 +826,17 @@ void ArchetypeBuilder::PotentialArchetype::dump(llvm::raw_ostream &Out,
   if (!ConformsTo.empty()) {
     Out << " : ";
 
-    if (ConformsTo.size() != 1)
-      Out << "protocol<";
-
     bool First = true;
     for (const auto &ProtoAndSource : ConformsTo) {
       if (First)
         First = false;
       else
-        Out << ", ";
+        Out << " & ";
 
       Out << ProtoAndSource.first->getName().str() << " [";
       ProtoAndSource.second.dump(Out, SrcMgr);
       Out << "]";
     }
-
-    if (ConformsTo.size() != 1)
-      Out << ">";
   }
 
   if (Representative != this) {

lib/AST/TypeRepr.cpp

@@ -434,16 +434,18 @@ ProtocolCompositionTypeRepr::create(ASTContext &C,
 
 void ProtocolCompositionTypeRepr::printImpl(ASTPrinter &Printer,
                                             const PrintOptions &Opts) const {
-  Printer << "protocol<";
-  bool First = true;
-  for (auto Proto : Protocols) {
-    if (First)
-      First = false;
-    else
-      Printer << ", ";
-    printTypeRepr(Proto, Printer, Opts);
+  if (Protocols.empty()) {
+    Printer << "Any";
+  } else {
+    bool First = true;
+    for (auto Proto : Protocols) {
+      if (First)
+        First = false;
+      else
+        Printer << " & ";
+      printTypeRepr(Proto, Printer, Opts);
+    }
   }
-  Printer << ">";
 }
 
 void MetatypeTypeRepr::printImpl(ASTPrinter &Printer,

lib/Basic/Demangle.cpp

@@ -3465,12 +3465,10 @@ void NodePrinter::print(NodePointer pointer, bool asContext, bool suppressType)
     NodePointer type_list = pointer->getChild(0);
     if (!type_list)
       return;
-    bool needs_proto_marker = (type_list->getNumChildren() != 1);
-    if (needs_proto_marker)
-      Printer << "protocol<";
-    printChildren(type_list, ", ");
-    if (needs_proto_marker)
-      Printer << ">";
+    if (type_list->getNumChildren() == 0)
+      Printer << "Any";
+    else
+      printChildren(type_list, " & ");
     return;
   }
   case Node::Kind::Archetype: {

lib/IDE/TypeReconstruction.cpp

@@ -1890,7 +1890,7 @@ static void VisitNodeProtocolList(
     nodes.push_back(cur_node->getFirstChild());
     VisitNode(ast, nodes, protocol_types_result, generic_context);
     if (protocol_types_result._error
-            .empty() /* cannot check for empty type list as protocol<> is allowed */) {
+            .empty() /* cannot check for empty type list as Any is allowed */) {
       if (ast) {
         result._types.push_back(
             ProtocolCompositionType::get(*ast, protocol_types_result._types));

lib/IRGen/GenExistential.cpp

@@ -258,7 +258,8 @@ class ExistentialTypeInfoBase : public Base,
 
 /// A TypeInfo implementation for existential types, i.e., types like:
 ///   Printable
-///   protocol<Printable, Serializable>
+///   Printable & Serializable
+///   Any
 /// with the semantic translation:
 ///   \exists t : Printable . t
 /// t here is an ArchetypeType.

lib/IRGen/GenType.cpp

@@ -1657,16 +1657,18 @@ llvm::StructType *IRGenModule::createNominalType(CanType type) {
 llvm::StructType *
 IRGenModule::createNominalType(ProtocolCompositionType *type) {
   llvm::SmallString<32> typeName;
-
+  
   SmallVector<ProtocolDecl *, 4> protocols;
   type->getAnyExistentialTypeProtocols(protocols);
-
-  typeName.append("protocol<");
-  for (unsigned i = 0, e = protocols.size(); i != e; ++i) {
-    if (i) typeName.push_back(',');
-    LinkEntity::forNonFunction(protocols[i]).mangle(typeName);
+  
+  if (protocols.empty()) {
+    typeName.append("swift.Any");
+  } else {
+    for (unsigned i = 0, e = protocols.size(); i != e; ++i) {
+      if (i) typeName.push_back('&');
+      LinkEntity::forNonFunction(protocols[i]).mangle(typeName);
+    }
   }
-  typeName.push_back('>');
   return llvm::StructType::create(getLLVMContext(), typeName.str());
 }
 

stdlib/public/runtime/Casting.cpp

@@ -123,34 +123,33 @@ static const char *_getProtocolName(const ProtocolDescriptor *protocol) {
 }
 
 static void _buildExistentialTypeName(const ProtocolDescriptorList *protocols,
+                                      TypeSyntaxLevel level,
                                       bool qualified,
                                       std::string &result) {
   auto options = Demangle::DemangleOptions();
   options.QualifyEntities = qualified;
   options.DisplayDebuggerGeneratedModule = false;
-
+  
   // If there's only one protocol, the existential type name is the protocol
-  // name.
+  // name. If there are 0 protocols it is 'Any'
   auto descriptors = protocols->getProtocols();
+  auto numProtocols = protocols->NumProtocols;
 
-  if (protocols->NumProtocols == 1) {
-    auto name = _getProtocolName(descriptors[0]);
-    result += Demangle::demangleTypeAsString(name,
-                                             strlen(name),
-                                             options);
-    return;
-  }
-  
-  result += "protocol<";
-  for (unsigned i = 0, e = protocols->NumProtocols; i < e; ++i) {
-    if (i > 0)
-      result += ", ";
-    auto name = _getProtocolName(descriptors[i]);
-    result += Demangle::demangleTypeAsString(name,
-                                             strlen(name),
-                                             options);
+  if (numProtocols == 0) {
+    result += "Any";
+  } else {
+    // compositions of more than 1 protocol need parens in .Type contexts
+    bool needsParens = level >= TypeSyntaxLevel::TypeSimple && numProtocols != 1;
+    if (needsParens) result += "(";
+    for (unsigned i = 0, e = numProtocols; i < e; ++i) {
+      if (i) result += " & ";
+      auto name = _getProtocolName(descriptors[i]);
+      result += Demangle::demangleTypeAsString(name,
+                                               strlen(name),
+                                               options);
+    }
+    if (needsParens) result += ")";
   }
-  result += ">";
 }
 
 static void _buildFunctionTypeName(const FunctionTypeMetadata *func,
@@ -233,7 +232,7 @@ static void _buildNameForMetadata(const Metadata *type,
   }
   case MetadataKind::Existential: {
     auto exis = static_cast<const ExistentialTypeMetadata *>(type);
-    _buildExistentialTypeName(&exis->Protocols, qualified, result);
+    _buildExistentialTypeName(&exis->Protocols, level, qualified, result);
     return;
   }
   case MetadataKind::ExistentialMetatype: {

stdlib/public/runtime/Reflection.mm

@@ -47,7 +47,7 @@ - (id)debugQuickLookObject;
 
 namespace {
 
-/// The layout of protocol<>.
+/// The layout of Any.
 using Any = OpaqueExistentialContainer;
 
 // Swift assumes Any is returned in memory. 

test/1_stdlib/PrintDiagnostics.swift

@@ -2,9 +2,9 @@
 
 var stream = ""
 
-print(3, &stream) // expected-error{{'&' used with non-inout argument of type 'protocol<>'}}
-debugPrint(3, &stream) // expected-error{{'&' used with non-inout argument of type 'protocol<>'}}
+print(3, &stream) // expected-error{{'&' used with non-inout argument of type 'Any'}}
+debugPrint(3, &stream) // expected-error{{'&' used with non-inout argument of type 'Any'}}
 print(3, &stream, appendNewline: false) // expected-error {{cannot pass immutable value as inout argument: implicit conversion from 'String' to 'OutputStream' requires a temporary}}
 debugPrint(3, &stream, appendNewline: false) // expected-error {{cannot pass immutable value as inout argument: implicit conversion from 'String' to 'OutputStream' requires a temporary}} 
 print(4, quack: 5) // expected-error {{argument labels '(_:, quack:)' do not match any available overloads}}
-// expected-note@-1{{overloads for 'print' exist with these partially matching parameter lists: (protocol<>..., separator: String, terminator: String), (T, appendNewline: Bool), (T, inout OutputStream), (T, inout OutputStream, appendNewline: Bool)}}
+// expected-note@-1{{overloads for 'print' exist with these partially matching parameter lists: (Any..., separator: String, terminator: String), (T, appendNewline: Bool), (T, inout OutputStream), (T, inout OutputStream, appendNewline: Bool)}}

test/1_stdlib/Runtime.swift.gyb

@@ -311,7 +311,7 @@ Runtime.test("typeName") {
   expectEqual("a.SomeClass", _typeName(SomeClass.self))
   expectEqual("a.SomeStruct", _typeName(SomeStruct.self))
   expectEqual("a.SomeEnum", _typeName(SomeEnum.self))
-  expectEqual("protocol<>.Protocol", _typeName(Any.Protocol.self))
+  expectEqual("Any.Protocol", _typeName(Any.Protocol.self))
   expectEqual("Swift.AnyObject.Protocol", _typeName(AnyObject.Protocol.self))
   expectEqual("Swift.AnyObject.Type.Protocol", _typeName(AnyClass.Protocol.self))
   expectEqual("Swift.Optional<Swift.AnyObject>.Type", _typeName((AnyObject?).Type.self))
@@ -336,7 +336,7 @@ Runtime.test("typeName") {
     _typeName(a.dynamicType))
 
   a = Any.self
-  expectEqual("protocol<>.Protocol", _typeName(a.dynamicType))
+  expectEqual("Any.Protocol", _typeName(a.dynamicType))
 }
 
 class SomeSubclass : SomeClass {}
@@ -562,7 +562,7 @@ Reflection.test("Struct/Generic/DefaultMirror") {
     dump(value, to: &output)
 
     let expected =
-      "▿ a.GenericStructWithDefaultMirror<Swift.Int, Swift.Array<Swift.Optional<protocol<>>>>\n" +
+      "▿ a.GenericStructWithDefaultMirror<Swift.Int, Swift.Array<Swift.Optional<Any>>>\n" +
       "  - first: 123\n" +
       "  ▿ second: 3 elements\n" +
       "    ▿ Optional(\"abc\")\n" +

test/1_stdlib/RuntimeObjC.swift

@@ -767,9 +767,8 @@ Reflection.test("MetatypeMirror") {
     dump(objcProtocolConcreteMetatype, to: &output)
     expectEqual(expectedObjCProtocolConcrete, output)
 
-    typealias Composition = SomeNativeProto & SomeObjCProto
-    let compositionConcreteMetatype = Composition.self
-    let expectedComposition = "- protocol<a.SomeNativeProto, a.SomeObjCProto> #0\n"
+    let compositionConcreteMetatype = (SomeNativeProto & SomeObjCProto).self
+    let expectedComposition = "- a.SomeNativeProto & a.SomeObjCProto> #0\n"
     output = ""
     dump(compositionConcreteMetatype, to: &output)
     expectEqual(expectedComposition, output)

test/1_stdlib/TypeName.swift

@@ -50,10 +50,10 @@ TypeNameTests.test("Prints") {
 
   expectEqual("main.P", _typeName(P.self))
   typealias PP2 = P & P2
-  expectEqual("protocol<main.P, main.P2>",
+  expectEqual("main.P & main.P2",
     _typeName(PP2.self))
-  expectEqual("protocol<>", _typeName(Any.self))
-  expectEqual("protocol<main.P, main.P2>", _typeName((P & P2).self))
+  expectEqual("Any", _typeName(Any.self))
+  expectEqual("main.P & main.P2", _typeName((P & P2).self))
 
   typealias F = () -> ()
   typealias F2 = () -> () -> ()
@@ -78,8 +78,8 @@ TypeNameTests.test("Prints") {
   expectEqual("((()) -> ()).Type", _typeName(F.Type.self))
   expectEqual("main.C.Type", _typeName(C.Type.self))
   expectEqual("main.C.Type.Type", _typeName(C.Type.Type.self))
-  expectEqual("protocol<>.Type", _typeName(Any.Type.self))
-  expectEqual("protocol<>.Protocol", _typeName(Any.Protocol.self))
+  expectEqual("Any.Type", _typeName(Any.Type.self))
+  expectEqual("Any.Protocol", _typeName(Any.Protocol.self))
   expectEqual("Swift.AnyObject", _typeName(AnyObject.self))
   expectEqual("Swift.AnyObject.Type", _typeName(AnyClass.self))
   expectEqual("Swift.Optional<Swift.AnyObject>",
@@ -88,7 +88,7 @@ TypeNameTests.test("Prints") {
 
 
   typealias Tup = (Any, F, C)
-  expectEqual("(protocol<>, (()) -> (), main.C)",
+  expectEqual("(Any, (()) -> (), main.C)",
     _typeName(Tup.self))
 }
 
@@ -115,7 +115,7 @@ TypeNameTests.test("Inout") {
     _typeName(IF3c.self))
   expectEqual("(inout ((()) -> ())) -> ()",
     _typeName(IF4.self))
-  expectEqual("(inout Swift.Int, protocol<>) -> ()",
+  expectEqual("(inout Swift.Int, Any) -> ()",
     _typeName(IF5.self))
 }
 

test/ClangModules/objc_parse.swift

@@ -192,7 +192,7 @@ func testProtocols(_ b: B, bp: BProto) {
   var c1 : Cat1Proto = b
   var bcat1 = b.getAsProtoWithCat()!
   c1 = bcat1
-  bcat1 = c1 // expected-error{{value of type 'Cat1Proto' does not conform to 'protocol<BProto, Cat1Proto>' in assignment}}
+  bcat1 = c1 // expected-error{{value of type 'Cat1Proto' does not conform to 'BProto & Cat1Proto' in assignment}}
 }
 
 // Methods only defined in a protocol
@@ -505,17 +505,17 @@ func testCStyle() {
 
 func testProtocolQualified(_ obj: CopyableNSObject, cell: CopyableSomeCell,
                            plainObj: NSObject, plainCell: SomeCell) {
-  _ = obj as NSObject // expected-error {{'CopyableNSObject' (aka 'protocol<NSCopying, NSObjectProtocol>') is not convertible to 'NSObject'; did you mean to use 'as!' to force downcast?}} {{11-13=as!}}
+  _ = obj as NSObject // expected-error {{'CopyableNSObject' (aka 'NSCopying & NSObjectProtocol') is not convertible to 'NSObject'; did you mean to use 'as!' to force downcast?}} {{11-13=as!}}
   _ = obj as NSObjectProtocol
   _ = obj as NSCopying
-  _ = obj as SomeCell // expected-error {{'CopyableNSObject' (aka 'protocol<NSCopying, NSObjectProtocol>') is not convertible to 'SomeCell'; did you mean to use 'as!' to force downcast?}} {{11-13=as!}}
+  _ = obj as SomeCell // expected-error {{'CopyableNSObject' (aka 'NSCopying & NSObjectProtocol') is not convertible to 'SomeCell'; did you mean to use 'as!' to force downcast?}} {{11-13=as!}}
 
   _ = cell as NSObject
   _ = cell as NSObjectProtocol
   _ = cell as NSCopying // expected-error {{'CopyableSomeCell' (aka 'SomeCell') is not convertible to 'NSCopying'; did you mean to use 'as!' to force downcast?}} {{12-14=as!}}
   _ = cell as SomeCell
 
-  _ = plainObj as CopyableNSObject // expected-error {{'NSObject' is not convertible to 'CopyableNSObject' (aka 'protocol<NSCopying, NSObjectProtocol>'); did you mean to use 'as!' to force downcast?}} {{16-18=as!}}
+  _ = plainObj as CopyableNSObject // expected-error {{'NSObject' is not convertible to 'CopyableNSObject' (aka 'NSCopying & NSObjectProtocol'); did you mean to use 'as!' to force downcast?}} {{16-18=as!}}
   _ = plainCell as CopyableSomeCell // FIXME: This is not really typesafe.
 }
 

test/ClangModules/protocol_metatype_object_conversion.swift

@@ -14,4 +14,4 @@ func takesProtocol(_ x: Protocol) {}
 takesProtocol(ObjCProto.self)
 takesProtocol(ObjCProto2.self)
 takesProtocol(NonObjCProto.self) // expected-error{{cannot convert value of type 'NonObjCProto.Protocol' to expected argument type 'Protocol'}}
-takesProtocol(TwoObjCProtos.self) // expected-error{{cannot convert value of type 'TwoObjCProtos.Protocol' (aka 'protocol<ObjCProto, ObjCProto2>.Protocol') to expected argument type 'Protocol'}}
+takesProtocol(TwoObjCProtos.self) // expected-error{{cannot convert value of type 'TwoObjCProtos.Protocol' (aka '(ObjCProto & ObjCProto2).Protocol') to expected argument type 'Protocol'}}

test/Constraints/ErrorProtocol_bridging.swift

@@ -34,7 +34,7 @@ var ns4 = compo as NSError
 
 // NSError conversion must be explicit.
 // TODO: fixit to insert 'as NSError'
-ns4 = compo // expected-error{{cannot assign value of type 'protocol<HairyErrorProtocol, Runcible>' to type 'NSError'}}
+ns4 = compo // expected-error{{cannot assign value of type 'HairyErrorProtocol & Runcible' to type 'NSError'}}
 
 let e1 = ns1 as? FooError
 let e1fix = ns1 as FooError // expected-error{{did you mean to use 'as!'}} {{17-19=as!}}