[cfe] Add support for Fields to round-trip text serialization

The flags on the fields are serialized as lists of flag names,
allowing for any combination of the flags in any order.  Similar
technique is used in this CL to serialize the flags on Procedures and
VariableDeclarations.  This is in the contrast with the previous
approach for those nodes, when the flags were the part of the
serialized name of the node (such as "static-method" for static
Procedures or "final" for final VariableDeclarations).

Change-Id: I02eb5ac92f6273542f08f269aee8e6519d3085e9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/153766
Commit-Queue: Dmitry Stefantsov <dmitryas@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>

Author: Dmitry Stefantsov

pkg/kernel/lib/text/text_serialization_verifier.dart

@@ -333,7 +333,6 @@ class VerificationState {
       node is Component ||
       node is Constructor ||
       node is Extension ||
-      node is Field ||
       node is FieldInitializer ||
       node is InvalidInitializer ||
       node is Library ||
@@ -474,8 +473,8 @@ class TextSerializationVerifier extends RecursiveVisitor<void> {
       makeRoundTrip<Arguments>(node, argumentsSerializer);
     } else if (node is FunctionNode) {
       makeRoundTrip<FunctionNode>(node, functionNodeSerializer);
-    } else if (node is Procedure) {
-      makeRoundTrip<Procedure>(node, procedureSerializer);
+    } else if (node is Member) {
+      makeRoundTrip<Member>(node, memberSerializer);
     } else if (node is TypeParameter) {
       makeRoundTrip<TypeParameter>(node, typeParameterSerializer);
     } else if (node is NamedType) {

pkg/kernel/lib/text/text_serializer.dart

@@ -799,76 +799,53 @@ Arguments wrapArguments(
   return new Arguments(tuple.second, types: tuple.first, named: tuple.third);
 }
 
-class VariableDeclarationTagger implements Tagger<VariableDeclaration> {
-  const VariableDeclarationTagger();
-
-  String tag(VariableDeclaration decl) {
-    String prefix = "";
-    if (decl.isCovariant) {
-      prefix = "${prefix}covariant-";
-      if (decl.isFieldFormal) {
-        // Field formals can only be used in constructors,
-        // and "covariant" keyword doesn't make sense for them.
-        throw StateError("Encountered covariant field formal.");
-      }
-    }
-    if (decl.isFieldFormal) {
-      prefix = "${prefix}fieldformal-";
-    }
-
-    if (decl.isConst) {
-      // It's not clear what invariants we assume about const/final.  For now
-      // throw if we have both.
-      if (decl.isFinal) {
-        throw UnimplementedError(
-            "Encountered a variable that is both const and final.");
-      }
-      return "${prefix}const";
-    }
-    if (decl.isFinal) {
-      return "${prefix}final";
-    }
-    return "${prefix}var";
+const Map<int, String> variableDeclarationFlagToName = const {
+  VariableDeclaration.FlagFinal: "final",
+  VariableDeclaration.FlagConst: "const",
+  VariableDeclaration.FlagFieldFormal: "field-formal",
+  VariableDeclaration.FlagCovariant: "covariant",
+  VariableDeclaration.FlagInScope: "in-scope",
+  VariableDeclaration.FlagGenericCovariantImpl: "generic-covariant-impl",
+  VariableDeclaration.FlagLate: "late",
+  VariableDeclaration.FlagRequired: "required",
+};
+
+class VariableDeclarationFlagTagger implements Tagger<IntLiteral> {
+  String tag(IntLiteral wrappedFlag) {
+    int flag = wrappedFlag.value;
+    return variableDeclarationFlagToName[flag] ??
+        (throw StateError("Unknown VariableDeclaration flag value: ${flag}."));
   }
 }
 
-TextSerializer<VariableDeclaration> makeVariableDeclarationSerializer(
-        {bool isFinal = false,
-        bool isConst = false,
-        bool isCovariant = false,
-        bool isFieldFormal = false}) =>
-    new Wrapped(
-        (w) => Tuple3(w.type, w.initializer, w.annotations),
-        (u) => u.third.fold(
-            VariableDeclaration(null,
-                type: u.first,
-                initializer: u.second,
-                isFinal: isFinal,
-                isConst: isConst,
-                isCovariant: isCovariant,
-                isFieldFormal: isFieldFormal),
-            (v, a) => v..addAnnotation(a)),
-        Tuple3Serializer(dartTypeSerializer, new Optional(expressionSerializer),
-            new ListSerializer(expressionSerializer)));
+TextSerializer<int> variableDeclarationFlagsSerializer = Wrapped(
+    (w) => List.generate(30, (i) => IntLiteral(w & (1 << i)))
+        .where((f) => f.value != 0)
+        .toList(),
+    (u) => u.fold(0, (fs, f) => fs |= f.value),
+    ListSerializer(Case(
+        VariableDeclarationFlagTagger(),
+        Map.fromIterable(variableDeclarationFlagToName.entries,
+            key: (e) => e.value,
+            value: (e) =>
+                Wrapped((_) => null, (_) => IntLiteral(e.key), Nothing())))));
 
 TextSerializer<VariableDeclaration> variableDeclarationSerializer = Wrapped(
     (v) => Tuple2(v.name, v),
     (t) => t.second..name = t.first,
-    Binder(Case(VariableDeclarationTagger(), {
-      "var": makeVariableDeclarationSerializer(),
-      "final": makeVariableDeclarationSerializer(isFinal: true),
-      "const": makeVariableDeclarationSerializer(isConst: true),
-      "covariant-var": makeVariableDeclarationSerializer(isCovariant: true),
-      "covariant-final":
-          makeVariableDeclarationSerializer(isCovariant: true, isFinal: true),
-      "covariant-const":
-          makeVariableDeclarationSerializer(isCovariant: true, isConst: true),
-      "fieldformal-var": makeVariableDeclarationSerializer(isFieldFormal: true),
-      "fieldformal-final":
-          makeVariableDeclarationSerializer(isFieldFormal: true, isFinal: true),
-      "fieldformal-const":
-          makeVariableDeclarationSerializer(isFieldFormal: true, isConst: true),
-    })));
+    Binder<VariableDeclaration>(
+      new Wrapped(
+          (w) => Tuple4(w.flags, w.type, w.initializer, w.annotations),
+          (u) => u.fourth.fold(
+              VariableDeclaration(null,
+                  flags: u.first, type: u.second, initializer: u.third),
+              (v, a) => v..addAnnotation(a)),
+          Tuple4Serializer(
+              variableDeclarationFlagsSerializer,
+              dartTypeSerializer,
+              new Optional(expressionSerializer),
+              new ListSerializer(expressionSerializer))),
+    ));
 
 TextSerializer<TypeParameter> typeParameterSerializer = Wrapped(
     (p) => Tuple2(p.name, p),
@@ -1593,36 +1570,112 @@ FunctionNode wrapSyncYieldingFunctionNode(
 Case<FunctionNode> functionNodeSerializer =
     new Case.uninitialized(const FunctionNodeTagger());
 
-class ProcedureTagger implements Tagger<Procedure> {
-  const ProcedureTagger();
-
-  String tag(Procedure node) {
-    String prefix = node.isStatic ? "static-" : "";
-    switch (node.kind) {
-      case ProcedureKind.Method:
-        return "${prefix}method";
-      default:
-        throw new UnsupportedError("${node.kind}");
-    }
+const Map<int, String> procedureFlagToName = const {
+  Procedure.FlagStatic: "static",
+  Procedure.FlagAbstract: "abstract",
+  Procedure.FlagExternal: "external",
+  Procedure.FlagConst: "const",
+  Procedure.FlagForwardingStub: "forwarding-stub",
+  Procedure.FlagForwardingSemiStub: "forwarding-semi-stub",
+  Procedure.FlagRedirectingFactoryConstructor:
+      "redirecting-factory-constructor",
+  Procedure.FlagNoSuchMethodForwarder: "no-such-method-forwarder",
+  Procedure.FlagExtensionMember: "extension-member",
+  Procedure.FlagMemberSignature: "member-signature",
+  Procedure.FlagNonNullableByDefault: "non-nullable-by-default",
+};
+
+class ProcedureFlagTagger implements Tagger<IntLiteral> {
+  const ProcedureFlagTagger();
+
+  String tag(IntLiteral wrappedFlag) {
+    int flag = wrappedFlag.value;
+    return procedureFlagToName[flag] ??
+        (throw StateError("Unknown Procedure flag value: ${flag}."));
   }
 }
 
-TextSerializer<Procedure> staticMethodSerializer = new Wrapped(
-    unwrapStaticMethod,
-    wrapStaticMethod,
-    new Tuple2Serializer(nameSerializer, functionNodeSerializer));
-
-Tuple2<Name, FunctionNode> unwrapStaticMethod(Procedure procedure) {
-  return new Tuple2(procedure.name, procedure.function);
+TextSerializer<int> procedureFlagsSerializer = Wrapped(
+    (w) => List.generate(30, (i) => IntLiteral(w & (1 << i)))
+        .where((f) => f.value != 0)
+        .toList(),
+    (u) => u.fold(0, (fs, f) => fs |= f.value),
+    ListSerializer(Case(
+        ProcedureFlagTagger(),
+        Map.fromIterable(procedureFlagToName.entries,
+            key: (e) => e.value,
+            value: (e) =>
+                Wrapped((_) => null, (_) => IntLiteral(e.key), Nothing())))));
+
+const Map<int, String> fieldFlagToName = const {
+  Field.FlagFinal: "final",
+  Field.FlagConst: "const",
+  Field.FlagStatic: "static",
+  Field.FlagHasImplicitGetter: "has-implicit-getter",
+  Field.FlagHasImplicitSetter: "has-implicit-setter",
+  Field.FlagCovariant: "covariant",
+  Field.FlagGenericCovariantImpl: "generic-covariant-impl",
+  Field.FlagLate: "late",
+  Field.FlagExtensionMember: "extension-member",
+  Field.FlagNonNullableByDefault: "non-nullable-by-default",
+  Field.FlagInternalImplementation: "internal-implementation",
+};
+
+class FieldFlagTagger implements Tagger<IntLiteral> {
+  const FieldFlagTagger();
+
+  String tag(IntLiteral wrappedFlag) {
+    int flag = wrappedFlag.value;
+    return fieldFlagToName[flag] ??
+        (throw StateError("Unknown Field flag value: ${flag}."));
+  }
 }
 
-Procedure wrapStaticMethod(Tuple2<Name, FunctionNode> tuple) {
-  return new Procedure(tuple.first, ProcedureKind.Method, tuple.second,
-      isStatic: true);
+TextSerializer<int> fieldFlagsSerializer = Wrapped(
+    (w) => List.generate(30, (i) => IntLiteral(w & (1 << i)))
+        .where((f) => f.value != 0)
+        .toList(),
+    (u) => u.fold(0, (fs, f) => fs |= f.value),
+    ListSerializer(Case(
+        FieldFlagTagger(),
+        Map.fromIterable(fieldFlagToName.entries,
+            key: (e) => e.value,
+            value: (e) =>
+                Wrapped((_) => null, (_) => IntLiteral(e.key), Nothing())))));
+
+class MemberTagger implements Tagger<Member> {
+  const MemberTagger();
+
+  String tag(Member node) {
+    if (node is Field) {
+      return "field";
+    } else if (node is Procedure) {
+      switch (node.kind) {
+        case ProcedureKind.Method:
+          return "method";
+        default:
+          throw new UnsupportedError("${node.kind}");
+      }
+    } else {
+      throw UnimplementedError("MemberTagger.tag(${node.runtimeType})");
+    }
+  }
 }
 
-Case<Procedure> procedureSerializer =
-    new Case.uninitialized(const ProcedureTagger());
+TextSerializer<Field> fieldSerializer = Wrapped(
+    (w) => Tuple4(w.name, w.flags, w.type, w.initializer),
+    (u) =>
+        Field(u.first, type: u.third, initializer: u.fourth)..flags = u.second,
+    Tuple4Serializer(nameSerializer, fieldFlagsSerializer, dartTypeSerializer,
+        Optional(expressionSerializer)));
+
+TextSerializer<Procedure> methodSerializer = Wrapped(
+    (w) => Tuple3(w.name, w.flags, w.function),
+    (u) => Procedure(u.first, ProcedureKind.Method, u.third)..flags = u.second,
+    Tuple3Serializer(
+        nameSerializer, procedureFlagsSerializer, functionNodeSerializer));
+
+Case<Member> memberSerializer = new Case.uninitialized(const MemberTagger());
 
 class LibraryTagger implements Tagger<Library> {
   const LibraryTagger();
@@ -1633,20 +1686,14 @@ class LibraryTagger implements Tagger<Library> {
 }
 
 TextSerializer<Library> libraryContentsSerializer = new Wrapped(
-  unwrapLibraryNode,
-  wrapLibraryNode,
-  new Tuple2Serializer(
-      const UriSerializer(), new ListSerializer(procedureSerializer)),
+  (w) => Tuple2(w.importUri, [...w.fields, ...w.procedures]),
+  (u) => Library(u.first,
+      fields: u.second.where((m) => m is Field).cast<Field>().toList(),
+      procedures:
+          u.second.where((m) => m is Procedure).cast<Procedure>().toList()),
+  new Tuple2Serializer(const UriSerializer(), ListSerializer(memberSerializer)),
 );
 
-Tuple2<Uri, List<Procedure>> unwrapLibraryNode(Library library) {
-  return new Tuple2(library.importUri, library.procedures);
-}
-
-Library wrapLibraryNode(Tuple2<Uri, List<Procedure>> tuple) {
-  return new Library(tuple.first, procedures: tuple.second);
-}
-
 Case<Library> librarySerializer = new Case.uninitialized(const LibraryTagger());
 
 class ShowHideTagger implements Tagger<Combinator> {
@@ -1881,7 +1928,8 @@ void initializeSerializers() {
     "async-star": asyncStarFunctionNodeSerializer,
     "sync-yielding": syncYieldingStarFunctionNodeSerializer,
   });
-  procedureSerializer.registerTags({"static-method": staticMethodSerializer});
+  memberSerializer
+      .registerTags({"field": fieldSerializer, "method": methodSerializer});
   librarySerializer.registerTags({
     "legacy": libraryContentsSerializer,
     "null-safe": libraryContentsSerializer,