From 3c1c4ffb2962d74d0fc62c425424eb59f23374e2 Mon Sep 17 00:00:00 2001
From: "lrn@chromium.org"
 <lrn@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Thu, 4 Nov 2010 07:19:06 +0000
Subject: [PATCH] Simplify preparsing of "new"-expressions.

Review URL: http://codereview.chromium.org/4331003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5764 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/preparser.h             | 39 ++++++++++++---------------------------
 test/cctest/test-parsing.cc |  1 +
 2 files changed, 13 insertions(+), 27 deletions(-)

diff --git a/src/preparser.h b/src/preparser.h
index 697ef6e..4b236c9 100644
--- a/src/preparser.h
+++ b/src/preparser.h
@@ -186,8 +186,7 @@ class PreParser {
   Expression ParseLeftHandSideExpression(bool* ok);
   Expression ParseNewExpression(bool* ok);
   Expression ParseMemberExpression(bool* ok);
-  Expression ParseNewPrefix(int* new_count, bool* ok);
-  Expression ParseMemberWithNewPrefixesExpression(int* new_count, bool* ok);
+  Expression ParseMemberWithNewPrefixesExpression(unsigned new_count, bool* ok);
   Expression ParsePrimaryExpression(bool* ok);
   Expression ParseArrayLiteral(bool* ok);
   Expression ParseObjectLiteral(bool* ok);
@@ -965,9 +964,8 @@ Expression PreParser<Scanner, Log>::ParseLeftHandSideExpression(bool* ok) {
 }
 
 
-
 template <typename Scanner, typename Log>
-Expression PreParser<Scanner, Log>::ParseNewPrefix(int* new_count, bool* ok) {
+Expression PreParser<Scanner, Log>::ParseNewExpression(bool* ok) {
   // NewExpression ::
   //   ('new')+ MemberExpression
 
@@ -979,38 +977,25 @@ Expression PreParser<Scanner, Log>::ParseNewPrefix(int* new_count, bool* ok) {
   // many we have parsed. This information is then passed on to the
   // member expression parser, which is only allowed to match argument
   // lists as long as it has 'new' prefixes left
-  Expect(Token::NEW, CHECK_OK);
-  *new_count++;
-
-  if (peek() == Token::NEW) {
-    ParseNewPrefix(new_count, CHECK_OK);
-  } else {
-    ParseMemberWithNewPrefixesExpression(new_count, CHECK_OK);
-  }
-
-  if (*new_count > 0) {
-    *new_count--;
-  }
-  return kUnknownExpression;
-}
-
+  unsigned new_count = 0;
+  do {
+    Consume(Token::NEW);
+    new_count++;
+  } while (peek() == Token::NEW);
 
-template <typename Scanner, typename Log>
-Expression PreParser<Scanner, Log>::ParseNewExpression(bool* ok) {
-  int new_count = 0;
-  return ParseNewPrefix(&new_count, ok);
+  return ParseMemberWithNewPrefixesExpression(new_count, ok);
 }
 
 
 template <typename Scanner, typename Log>
 Expression PreParser<Scanner, Log>::ParseMemberExpression(bool* ok) {
-  return ParseMemberWithNewPrefixesExpression(NULL, ok);
+  return ParseMemberWithNewPrefixesExpression(0, ok);
 }
 
 
 template <typename Scanner, typename Log>
 Expression PreParser<Scanner, Log>::ParseMemberWithNewPrefixesExpression(
-    int* new_count, bool* ok) {
+    unsigned new_count, bool* ok) {
   // MemberExpression ::
   //   (PrimaryExpression | FunctionLiteral)
   //     ('[' Expression ']' | '.' Identifier | Arguments)*
@@ -1051,10 +1036,10 @@ Expression PreParser<Scanner, Log>::ParseMemberWithNewPrefixesExpression(
         break;
       }
       case Token::LPAREN: {
-        if ((new_count == NULL) || *new_count == 0) return result;
+        if (new_count == 0) return result;
         // Consume one of the new prefixes (already parsed).
         ParseArguments(CHECK_OK);
-        *new_count--;
+        new_count--;
         result = kUnknownExpression;
         break;
       }
diff --git a/test/cctest/test-parsing.cc b/test/cctest/test-parsing.cc
index 3134b12..cdf1c7b 100755
--- a/test/cctest/test-parsing.cc
+++ b/test/cctest/test-parsing.cc
@@ -253,6 +253,7 @@ TEST(StandAlonePreParser) {
       "var x = 42;",
       "function foo(x, y) { return x + y; }",
       "native function foo(); return %ArgleBargle(glop);",
+      "var x = new new Function('this.x = 42');",
       NULL
   };
 
-- 
2.7.4