[es6] support template literals after MemberExpression

src/preparser.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PREPARSER_H
 #define V8_PREPARSER_H
 
 #include "src/v8.h"
 
 #include "src/bailout-reason.h"
@@ skipping 571 matching lines @@
   ExpressionT ParseUnaryExpression(bool* ok);
   ExpressionT ParsePostfixExpression(bool* ok);
   ExpressionT ParseLeftHandSideExpression(bool* ok);
   ExpressionT ParseMemberWithNewPrefixesExpression(bool* ok);
   ExpressionT ParseMemberExpression(bool* ok);
   ExpressionT ParseMemberExpressionContinuation(ExpressionT expression,
                                                 bool* ok);
   ExpressionT ParseArrowFunctionLiteral(int start_pos, ExpressionT params_ast,
                                         bool* ok);
   ExpressionT ParseTemplateLiteral(ExpressionT tag, int start, bool* ok);
+  ExpressionT ParseTemplateLiteralAsMemberExpressionContinuation(
+      ExpressionT tag, bool* ok);
   void AddTemplateExpression(ExpressionT);
   ExpressionT ParseSuperExpression(bool is_new, bool* ok);
 
   // Checks if the expression is a valid reference expression (e.g., on the
   // left-hand side of assignments). Although ruled out by ECMA as early errors,
   // we allow calls for web compatibility and rewrite them to a runtime throw.
   ExpressionT CheckAndRewriteReferenceExpression(
       ExpressionT expression,
       Scanner::Location location, const char* message, bool* ok);
 
@@ skipping 2046 matching lines @@
         // These calls are marked as potentially direct eval calls. Whether
         // they are actually direct calls to eval is determined at run time.
         this->CheckPossibleEvalCall(result, scope_);
         result = factory()->NewCall(result, args, pos);
         if (fni_ != NULL) fni_->RemoveLastFunction();
         break;
       }
 
       case Token::TEMPLATE_SPAN:
       case Token::TEMPLATE_TAIL: {
-        int pos;
-        if (scanner()->current_token() == Token::IDENTIFIER) {
-          pos = position();
-        } else {
-          pos = peek_position();
-          if (result->IsFunctionLiteral() && mode() == PARSE_EAGERLY) {
-            // If the tag function looks like an IIFE, set_parenthesized() to
-            // force eager compilation.
-            result->AsFunctionLiteral()->set_parenthesized();
-          }
-        }
-        result = ParseTemplateLiteral(result, pos, CHECK_OK);
+        result = ParseTemplateLiteralAsMemberExpressionContinuation(
+            result, CHECK_OK);
         break;
       }
 
       case Token::PERIOD: {
         Consume(Token::PERIOD);
         int pos = position();
         IdentifierT name = ParseIdentifierName(CHECK_OK);
         result = factory()->NewProperty(
             result, factory()->NewStringLiteral(name, pos), pos);
         if (fni_ != NULL) this->PushLiteralName(fni_, name);
@@ skipping 130 matching lines @@
   *ok = false;
   return this->EmptyExpression();
 }
 
 
 template <class Traits>
 typename ParserBase<Traits>::ExpressionT
 ParserBase<Traits>::ParseMemberExpressionContinuation(ExpressionT expression,
                                                       bool* ok) {
   // Parses this part of MemberExpression:
   // ('[' Expression ']' | '.' Identifier)*

[arv (Not doing code reviews), 2015/03/11 18:48:54]

update this comment?

   while (true) {
     switch (peek()) {
       case Token::LBRACK: {
         Consume(Token::LBRACK);
         int pos = position();
         ExpressionT index = this->ParseExpression(true, CHECK_OK);
         expression = factory()->NewProperty(expression, index, pos);
         if (fni_ != NULL) {
           this->PushPropertyName(fni_, index);
         }
         Expect(Token::RBRACK, CHECK_OK);
         break;
       }
       case Token::PERIOD: {
         Consume(Token::PERIOD);
         int pos = position();
         IdentifierT name = ParseIdentifierName(CHECK_OK);
         expression = factory()->NewProperty(
             expression, factory()->NewStringLiteral(name, pos), pos);
         if (fni_ != NULL) {
           this->PushLiteralName(fni_, name);
         }
         break;
       }
+      case Token::TEMPLATE_SPAN:
+      case Token::TEMPLATE_TAIL: {
+        expression = ParseTemplateLiteralAsMemberExpressionContinuation(
+            expression, CHECK_OK);
+        break;
+      }
       default:
         return expression;
     }
   }
   DCHECK(false);
   return this->EmptyExpression();
 }
 
 
 template <class Traits>
 typename ParserBase<Traits>::ExpressionT
+ParserBase<Traits>::ParseTemplateLiteralAsMemberExpressionContinuation(
+    ExpressionT expression, bool* ok) {
+  int pos;
+  if (scanner()->current_token() == Token::IDENTIFIER) {
+    pos = position();
+  } else {
+    pos = peek_position();
+    if (expression->IsFunctionLiteral() && mode() == PARSE_EAGERLY) {
+      // If the tag function looks like an IIFE, set_parenthesized() to
+      // force eager compilation.
+      expression->AsFunctionLiteral()->set_parenthesized();
+    }
+  }
+  return ParseTemplateLiteral(expression, pos, CHECK_OK);
+}
+
+
+template <class Traits>
+typename ParserBase<Traits>::ExpressionT
 ParserBase<Traits>::ParseArrowFunctionLiteral(int start_pos,
                                               ExpressionT params_ast,
                                               bool* ok) {
   if (peek() == Token::ARROW && scanner_->HasAnyLineTerminatorBeforeNext()) {
     // ASI inserts `;` after arrow parameters if a line terminator is found.
     // `=> ...` is never a valid expression, so report as syntax error.
     // If next token is not `=>`, it's a syntax error anyways.
     ReportUnexpectedTokenAt(scanner_->peek_location(), Token::ARROW);
     *ok = false;
     return this->EmptyExpression();
@@ skipping 269 matching lines @@
       *ok = false;
       return;
     }
     has_seen_constructor_ = true;
     return;
   }
 }
 } }  // v8::internal
 
 #endif  // V8_PREPARSER_H