New tests and improvements for generics in comments parsing.

pkg/front_end/lib/src/fasta/parser/parser.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.parser.parser;
 
 import '../fasta_codes.dart'
     show
         FastaCode,
         FastaMessage,
@@ skipping 499 matching lines @@
     } else {
       token = parseLiteralStringOrRecoverExpression(token);
     }
     Token semicolon = token;
     token = expect(';', token);
     listener.endPartOf(partKeyword, semicolon, hasName);
     return token;
   }
 
   Token parseMetadataStar(Token token, {bool forParameter: false}) {
+    token = listener.injectGenericCommentTypeAssign(token);
     listener.beginMetadataStar(token);
     int count = 0;
     while (optional('@', token)) {
       token = parseMetadata(token);
       count++;
     }
     listener.endMetadataStar(count, forParameter);
     return token;
   }
 
@@ skipping 605 matching lines @@
             token, IdentifierContext.typeReferenceContinuation);
       } else {
         token =
             reportUnrecoverableErrorCodeWithToken(token, codeExpectedType).next;
         listener.handleInvalidTypeReference(token);
       }
       token = parseTypeArgumentsOpt(token);
       listener.handleType(begin, token);
     }
 
+    {
+      Token newBegin =
+          listener.replaceTokenWithGenericCommentTypeAssign(begin, token);
+      if (!identical(newBegin, begin)) {
+        listener.discardTypeReplacedWithCommentTypeAssign();
+        return parseType(newBegin);
+      }
+    }
+
     // While we see a `Function(` treat the pushed type as return type.
     // For example: `int Function() Function(int) Function(String x)`.
     while (isGeneralizedFunctionType(token)) {
       token = parseFunctionType(token);
     }
     return token;
   }
 
   /// Parses a generalized function type.
   ///
@@ skipping 383 matching lines @@
         return listener.handleMemberName(identifiers);
       } else if (optional("=", token) ||
           optional(";", token) ||
           optional(",", token)) {
         // A field or abstract getter.
         identifiers = identifiers.prepend(token);
         return listener.handleMemberName(identifiers);
       } else if (isGetter) {
         hasName = true;
       }
+      token = listener.injectGenericCommentTypeAssign(token);
       identifiers = identifiers.prepend(token);
 
       if (!isGeneralizedFunctionType(token)) {
         // Read a potential return type.
         if (isValidTypeReference(token)) {
+          Token type = token;
           // type ...
           if (optional('.', token.next)) {
             // type '.' ...
             if (token.next.next.isIdentifier) {
               // type '.' identifier
               token = token.next.next;
             }
           }
           if (optional('<', token.next)) {
             if (token.next is BeginGroupToken) {
               BeginGroupToken beginGroup = token.next;
               if (beginGroup.endGroup == null) {
                 token = reportUnmatchedToken(beginGroup).next;
               } else {
                 token = beginGroup.endGroup;
               }
             }
           }
+          // If the next token after a type has a type substitution comment
+          // /*=T*/, then the previous type tokens and the reference to them
+          // from the link should be replaced.
+          {
+            Token newType = listener.replaceTokenWithGenericCommentTypeAssign(
+                type, token.next);
+            if (!identical(newType, type)) {
+              identifiers = identifiers.tail;
+              token = newType;
+              continue;
+            }
+          }
         }
         token = token.next;
       }
       while (isGeneralizedFunctionType(token)) {
         token = token.next;
         if (optional('<', token)) {
           if (token is BeginGroupToken) {
             BeginGroupToken beginGroup = token;
             if (beginGroup.endGroup == null) {
               token = reportUnmatchedToken(beginGroup).next;
@@ skipping 2312 matching lines @@
     return reportUnrecoverableError(
         token, () => code.format(uri, token.charOffset, string));
   }
 }
 
 typedef FastaMessage NoArgument(Uri uri, int charOffset);
 
 typedef FastaMessage TokenArgument(Uri uri, int charOffset, Token token);
 
 typedef FastaMessage StringArgument(Uri uri, int charOffset, String string);