Add contextual information about identifiers to the parser listener API.

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

Index: pkg/front_end/lib/src/fasta/analyzer/ast_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/analyzer/ast_builder.dart b/pkg/front_end/lib/src/fasta/analyzer/ast_builder.dart
index 558e49fcbb586950c26ae186594cd59c6d439fa3..76f75fc96f7bc05ee0abbe5daddfac89a785fdb5 100644
--- a/pkg/front_end/lib/src/fasta/analyzer/ast_builder.dart
+++ b/pkg/front_end/lib/src/fasta/analyzer/ast_builder.dart
@@ -29,6 +29,8 @@ import '../kernel/kernel_builder.dart'
 
 import '../parser/parser.dart' show optional;
 
+import '../parser/identifier_context.dart' show IdentifierContext;
+
 import '../quote.dart';
 
 import '../source/outline_builder.dart' show asyncMarkerFromTokens;
@@ -53,16 +55,9 @@ class AstBuilder extends ScopeListener {
 
   final ElementStore elementStore;
 
-  bool isFirstIdentifier = false;
-
   @override
   final Uri uri;
 
-  /// If `true`, the first call to [handleIdentifier] should push a
-  /// List<SimpleIdentifier> on the stack, and [handleQualified] should append
-  /// to the list.
-  var accumulateIdentifierComponents = false;
-
   AstBuilder(this.library, this.member, this.elementStore, Scope scope,
       [Uri uri])
       : uri = uri ?? library.fileUri,
@@ -132,22 +127,18 @@ class AstBuilder extends ScopeListener {
     push(ast.methodInvocation(null, null, null, null, arguments));
   }
 
-  void beginExpression(Token token) {
-    isFirstIdentifier = true;
-  }
-
-  void handleIdentifier(Token token) {
+  void handleIdentifier(Token token, IdentifierContext context) {
     debugEvent("handleIdentifier");
     String name = token.value;
     SimpleIdentifier identifier = ast.simpleIdentifier(toAnalyzerToken(token));
-    if (accumulateIdentifierComponents) {
-      if (isFirstIdentifier) {
+    if (context.inLibraryOrPartOfDeclaration) {
+      if (!context.isContinuation) {
         push([identifier]);
       } else {
         push(identifier);
       }
     } else {
-      if (isFirstIdentifier) {
+      if (context.isScopeReference) {
         Builder builder = scope.lookup(name, token.charOffset, uri);
         if (builder != null) {
           Element element = elementStore[builder];
@@ -157,7 +148,6 @@ class AstBuilder extends ScopeListener {
       }
       push(identifier);
     }
-    isFirstIdentifier = false;
   }
 
   void endSend(Token token) {
@@ -407,10 +397,6 @@ class AstBuilder extends ScopeListener {
     push(ast.awaitExpression(toAnalyzerToken(beginToken), pop()));
   }
 
-  void beginLiteralSymbol(Token token) {
-    isFirstIdentifier = false;
-  }
-
   void handleLiteralBool(Token token) {
     debugEvent("LiteralBool");
     bool value = identical(token.stringValue, "true");
@@ -461,20 +447,7 @@ class AstBuilder extends ScopeListener {
     // TODO(paulberry,ahe): what if the type doesn't resolve to a class
     // element?
     KernelClassElement cls = name.staticElement;
-    if (cls == null) {
-      // TODO(paulberry): This is a kludge.  Ideally we should already have
-      // set the static element at the time that handleIdentifier was called.
-      Builder builder = scope.lookup(name.name, beginToken.charOffset, uri);
-      if (builder == null) {
-        internalError("Undefined name: $name");
-      }
-      cls = elementStore[builder];
-      assert(cls != null);
-      if (name is SimpleIdentifier) {
-        name.staticElement = cls;
-      }
-    }
-    push(ast.typeName(name, arguments)..type = cls.rawType);
+    push(ast.typeName(name, arguments)..type = cls?.rawType);
   }
 
   void handleAsOperator(Token operator, Token endToken) {
@@ -877,8 +850,8 @@ class AstBuilder extends ScopeListener {
   }
 
   @override
-  void endNamedMixinApplication(
-      Token beginToken, Token equalsToken, Token implementsKeyword, Token endToken) {
+  void endNamedMixinApplication(Token beginToken, Token equalsToken,
+      Token implementsKeyword, Token endToken) {
     debugEvent("NamedMixinApplication");
     ImplementsClause implementsClause;
     if (implementsKeyword != null) {
@@ -923,12 +896,6 @@ class AstBuilder extends ScopeListener {
   }
 
   @override
-  void beginLibraryName(Token token) {
-    accumulateIdentifierComponents = true;
-    isFirstIdentifier = true;
-  }
-
-  @override
   void endLibraryName(Token libraryKeyword, Token semicolon) {
     debugEvent("LibraryName");
     List<SimpleIdentifier> libraryName = pop();
@@ -938,25 +905,22 @@ class AstBuilder extends ScopeListener {
     Comment comment = null;
     push(ast.libraryDirective(comment, metadata,
         toAnalyzerToken(libraryKeyword), name, toAnalyzerToken(semicolon)));
-    accumulateIdentifierComponents = false;
   }
 
   @override
   void handleQualified(Token period) {
     SimpleIdentifier identifier = pop();
-    if (accumulateIdentifierComponents) {
-      List<SimpleIdentifier> list = pop();
-      list.add(identifier);
-      push(list);
+    var prefix = pop();
+    if (prefix is List) {
+      // We're just accumulating components into a list.
+      prefix.add(identifier);
+      push(prefix);
+    } else if (prefix is SimpleIdentifier) {
+      // TODO(paulberry): resolve [identifier].
+      push(ast.prefixedIdentifier(prefix, toAnalyzerToken(period), identifier));
     } else {
-      var prefix = pop();
-      if (prefix is SimpleIdentifier) {
-        // TODO(paulberry): resolve [identifier].
-        push(ast.prefixedIdentifier(prefix, toAnalyzerToken(period), identifier));
-      } else {
-        // TODO(paulberry): implement.
-        logEvent('Qualified with >1 dot');
-      }
+      // TODO(paulberry): implement.
+      logEvent('Qualified with >1 dot');
     }
   }
 
@@ -972,12 +936,6 @@ class AstBuilder extends ScopeListener {
   }
 
   @override
-  void beginPartOf(Token token) {
-    accumulateIdentifierComponents = true;
-    isFirstIdentifier = true;
-  }
-
-  @override
   void endPartOf(Token partKeyword, Token semicolon) {
     debugEvent("PartOf");
     List<SimpleIdentifier> libraryName = pop();
@@ -991,7 +949,6 @@ class AstBuilder extends ScopeListener {
     Comment comment = null;
     push(ast.partOfDirective(comment, metadata, toAnalyzerToken(partKeyword),
         toAnalyzerToken(ofKeyword), uri, name, toAnalyzerToken(semicolon)));
-    accumulateIdentifierComponents = false;
   }
 
   void endUnnamedFunction(Token token) {
@@ -1119,7 +1076,7 @@ class AstBuilder extends ScopeListener {
     debugEvent("VoidKeyword");
     // TODO(paulberry): is this sufficient, or do we need to hook the "void"
     // keyword up to an element?
-    handleIdentifier(token);
+    handleIdentifier(token, IdentifierContext.typeReference);
     handleNoTypeArguments(token);
     endType(token, token);
   }