Parser support for generic annotations.

This CL updates the parser so that it allows annotations of the form:

    `@` <constructorDesignation> <argumentPart>

Where <argumentPart> can contain type arguments.  Previously this was
prohibited at parse time.

Generic annotations are still prohibited in the current language
version, but the error is now generated by the parser listener
(BodyBuilder in the case of CFE, AstBuilder in the case of analyzer);
this should open the door for future CLs to add support for generic
annotations when the `generic-metadata` experimental flag is supplied.

Bug: #44838
Change-Id: I90604f38bcb378fc798c5737e486fb26589d4d1e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/182668
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>

pkg/_fe_analyzer_shared/lib/src/messages/codes_generated.dart

@@ -6430,6 +6430,17 @@ const MessageCode messageMetadataTypeArguments = const MessageCode(
     index: 91,
     message: r"""An annotation (metadata) can't use type arguments.""");
 
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const Code<Null> codeMetadataTypeArgumentsUninstantiated =
+    messageMetadataTypeArgumentsUninstantiated;
+
+// DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
+const MessageCode messageMetadataTypeArgumentsUninstantiated = const MessageCode(
+    "MetadataTypeArgumentsUninstantiated",
+    index: 114,
+    message:
+        r"""An annotation (metadata) with type arguments must be followed by an argument list.""");
+
 // DO NOT EDIT. THIS FILE IS GENERATED. SEE TOP OF FILE.
 const Template<Message Function(String name)> templateMethodNotFound =
     const Template<Message Function(String name)>(

pkg/_fe_analyzer_shared/lib/src/parser/parser_impl.dart

@@ -1055,16 +1055,18 @@ class Parser {
     token = ensureIdentifier(atToken, IdentifierContext.metadataReference);
     token =
         parseQualifiedRestOpt(token, IdentifierContext.metadataContinuation);
-    if (optional("<", token.next!)) {
-      reportRecoverableError(token.next!, codes.messageMetadataTypeArguments);
-    }
+    bool hasTypeArguments = optional("<", token.next!);
     token = computeTypeParamOrArg(token).parseArguments(token, this);
     Token? period = null;
     if (optional('.', token.next!)) {
       period = token.next!;
       token = ensureIdentifier(
           period, IdentifierContext.metadataContinuationAfterTypeArguments);
     }
+    if (hasTypeArguments && !optional("(", token.next!)) {
+      reportRecoverableError(
+          token, codes.messageMetadataTypeArgumentsUninstantiated);
+    }
     token = parseArgumentsOpt(token);
     listener.endMetadata(atToken, period, token.next!);
     return token;

pkg/analyzer/lib/error/error.dart

@@ -624,6 +624,7 @@ const List<ErrorCode> errorCodeValues = [
   ParserErrorCode.ABSTRACT_TYPEDEF,
   ParserErrorCode.ANNOTATION_ON_TYPE_ARGUMENT,
   ParserErrorCode.ANNOTATION_WITH_TYPE_ARGUMENTS,
+  ParserErrorCode.ANNOTATION_WITH_TYPE_ARGUMENTS_UNINSTANTIATED,
   ParserErrorCode.ASYNC_KEYWORD_USED_AS_IDENTIFIER,
   ParserErrorCode.BINARY_OPERATOR_WRITTEN_OUT,
   ParserErrorCode.BREAK_OUTSIDE_OF_LOOP,

pkg/analyzer/lib/src/dart/error/syntactic_errors.dart

@@ -61,6 +61,9 @@ class ParserErrorCode extends ErrorCode {
   static const ParserErrorCode ANNOTATION_WITH_TYPE_ARGUMENTS =
       _ANNOTATION_WITH_TYPE_ARGUMENTS;
 
+  static const ParserErrorCode ANNOTATION_WITH_TYPE_ARGUMENTS_UNINSTANTIATED =
+      _ANNOTATION_WITH_TYPE_ARGUMENTS_UNINSTANTIATED;
+
   /**
    * 16.32 Identifier Reference: It is a compile-time error if any of the
    * identifiers async, await, or yield is used as an identifier in a function

pkg/analyzer/lib/src/dart/error/syntactic_errors.g.dart

@@ -121,6 +121,7 @@ final fastaAnalyzerErrorCodes = <ErrorCode?>[
   _ANNOTATION_ON_TYPE_ARGUMENT,
   _BINARY_OPERATOR_WRITTEN_OUT,
   _EXPECTED_IDENTIFIER_BUT_GOT_KEYWORD,
+  _ANNOTATION_WITH_TYPE_ARGUMENTS_UNINSTANTIATED,
 ];
 
 const ParserErrorCode _ABSTRACT_CLASS_MEMBER = ParserErrorCode(
@@ -150,6 +151,10 @@ const ParserErrorCode _ANNOTATION_WITH_TYPE_ARGUMENTS = ParserErrorCode(
     'ANNOTATION_WITH_TYPE_ARGUMENTS',
     r"An annotation (metadata) can't use type arguments.");
 
+const ParserErrorCode _ANNOTATION_WITH_TYPE_ARGUMENTS_UNINSTANTIATED =
+    ParserErrorCode('ANNOTATION_WITH_TYPE_ARGUMENTS_UNINSTANTIATED',
+        r"An annotation (metadata) with type arguments must be followed by an argument list.");
+
 const ParserErrorCode _BINARY_OPERATOR_WRITTEN_OUT = ParserErrorCode(
     'BINARY_OPERATOR_WRITTEN_OUT',
     r"Binary operator '#string' is written as '#string2' instead of the written out word.",

pkg/analyzer/lib/src/fasta/ast_builder.dart

@@ -22,6 +22,7 @@ import 'package:_fe_analyzer_shared/src/messages/codes.dart'
         messageInvalidInitializer,
         messageInvalidSuperInInitializer,
         messageInvalidThisInInitializer,
+        messageMetadataTypeArguments,
         messageMissingAssignableSelector,
         messageNativeClauseShouldBeAnnotation,
         messageOperatorWithTypeParameters,
@@ -1831,7 +1832,12 @@ class AstBuilder extends StackListener {
     var invocation = pop() as MethodInvocation?;
     var constructorName =
         periodBeforeName != null ? pop() as SimpleIdentifier : null;
-    pop(); // Type arguments, not allowed.
+    var typeArguments = pop() as TypeArgumentList?;
+    if (typeArguments != null &&
+        !_featureSet.isEnabled(Feature.generic_metadata)) {
+      handleRecoverableError(messageMetadataTypeArguments,
+          typeArguments.beginToken, typeArguments.beginToken);
+    }
     var name = pop() as Identifier;
     push(ast.annotation(
         atSign: atSign,

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

@@ -630,7 +630,8 @@ class BodyBuilder extends ScopeListener<JumpTarget>
     if (arguments != null) {
       push(arguments);
       _buildConstructorReferenceInvocation(
-          beginToken.next, beginToken.offset, Constness.explicitConst);
+          beginToken.next, beginToken.offset, Constness.explicitConst,
+          inMetadata: true);
       push(popForValue());
     } else {
       pop(); // Name last identifier
@@ -4360,11 +4361,13 @@ class BodyBuilder extends ScopeListener<JumpTarget>
   void endNewExpression(Token token) {
     debugEvent("NewExpression");
     _buildConstructorReferenceInvocation(
-        token.next, token.offset, Constness.explicitNew);
+        token.next, token.offset, Constness.explicitNew,
+        inMetadata: false);
   }
 
   void _buildConstructorReferenceInvocation(
-      Token nameToken, int offset, Constness constness) {
+      Token nameToken, int offset, Constness constness,
+      {bool inMetadata}) {
     assert(checkState(nameToken, [
       /*arguments*/ ValueKinds.Arguments,
       /*constructor name identifier*/ ValueKinds.IdentifierOrNull,
@@ -4381,6 +4384,10 @@ class BodyBuilder extends ScopeListener<JumpTarget>
     Token nameLastToken = nameLastIdentifier?.token ?? nameToken;
     String name = pop();
     List<UnresolvedType> typeArguments = pop();
+    if (inMetadata && typeArguments != null) {
+      handleRecoverableError(fasta.messageMetadataTypeArguments,
+          nameLastToken.next, nameLastToken.next);
+    }
 
     Object type = pop();
 
@@ -4406,7 +4413,8 @@ class BodyBuilder extends ScopeListener<JumpTarget>
   void endImplicitCreationExpression(Token token) {
     debugEvent("ImplicitCreationExpression");
     _buildConstructorReferenceInvocation(
-        token.next, token.offset, Constness.implicit);
+        token.next, token.offset, Constness.implicit,
+        inMetadata: false);
   }
 
   @override
@@ -4660,7 +4668,8 @@ class BodyBuilder extends ScopeListener<JumpTarget>
   void endConstExpression(Token token) {
     debugEvent("endConstExpression");
     _buildConstructorReferenceInvocation(
-        token.next, token.offset, Constness.explicitConst);
+        token.next, token.offset, Constness.explicitConst,
+        inMetadata: false);
   }
 
   @override

pkg/front_end/messages.yaml

@@ -1501,6 +1501,13 @@ MetadataTypeArguments:
   template: "An annotation (metadata) can't use type arguments."
   analyzerCode: ParserErrorCode.ANNOTATION_WITH_TYPE_ARGUMENTS
 
+MetadataTypeArgumentsUninstantiated:
+  index: 114
+  template: "An annotation (metadata) with type arguments must be followed by an argument list."
+  analyzerCode: ParserErrorCode.ANNOTATION_WITH_TYPE_ARGUMENTS_UNINSTANTIATED
+  script:
+    - "@deprecated<int> class C {}"
+
 ConstructorNotFound:
   template: "Couldn't find constructor '#name'."
   analyzerCode: CONSTRUCTOR_NOT_FOUND

pkg/front_end/test/spell_checking_list_code.txt

@@ -1268,6 +1268,7 @@ unification
 unifier
 unify
 uninstantiable
+uninstantiated
 unions
 uniqueness
 unittest