Traitify ParserBase and move functions there.

(Second try, with fixes. First try: https://codereview.chromium.org/149913006/ )

The long-term goal is to move all recursive descent functions from Parser and
PreParser into ParserBase, but first they need to be unified.

Notes:
- The functions moved in this CL: ParseIdentifier, ParseIdentifierName,
ParseIdentifierNameOrGetOrSet, ParseIdentifierOrStrictReservedWord.
- IOW, this CL removes Parser::ParseIdentifier and PreParser::ParseIdentifier
and adds ParserBase::ParseIdentifier, etc.
- Error reporting used to require virtual funcs; now error reporting is moved to
the Traits too, and ParserBase no longer needs to be virtual.
- I had to move PreParser::Identifier out of the PreParser class, because
otherwise PreParserTraits cannot use it in a typedef.

BUG=v8:3126
LOG=N
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/158913003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19265 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/parser.h

@@ -404,10 +404,44 @@ class RegExpParser BASE_EMBEDDED {
 // ----------------------------------------------------------------------------
 // JAVASCRIPT PARSING
 
-// Forward declaration.
+class Parser;
 class SingletonLogger;
 
-class Parser : public ParserBase {
+class ParserTraits {
+ public:
+  typedef Parser* ParserType;
+  // Return types for traversing functions.
+  typedef Handle<String> IdentifierType;
+
+  explicit ParserTraits(Parser* parser) : parser_(parser) {}
+
+  // Helper functions for recursive descent.
+  bool is_classic_mode() const;
+  bool is_generator() const;
+  bool IsEvalOrArguments(Handle<String> identifier) const;
+
+  // Reporting errors.
+  void ReportMessageAt(Scanner::Location source_location,
+                       const char* message,
+                       Vector<const char*> args);
+  void ReportMessage(const char* message, Vector<Handle<String> > args);
+  void ReportMessageAt(Scanner::Location source_location,
+                       const char* message,
+                       Vector<Handle<String> > args);
+
+  // Identifiers:
+  static IdentifierType EmptyIdentifier() {
+    return Handle<String>();
+  }
+
+  IdentifierType GetSymbol();
+
+ private:
+  Parser* parser_;
+};
+
+
+class Parser : public ParserBase<ParserTraits> {
  public:
   explicit Parser(CompilationInfo* info);
   ~Parser() {
@@ -427,6 +461,8 @@ class Parser : public ParserBase {
   bool Parse();
 
  private:
+  friend class ParserTraits;
+
   static const int kMaxNumFunctionLocals = 131071;  // 2^17-1
 
   enum Mode {
@@ -521,10 +557,6 @@ class Parser : public ParserBase {
     Mode old_mode_;
   };
 
-  virtual bool is_classic_mode() {
-    return top_scope_->is_classic_mode();
-  }
-
   // Returns NULL if parsing failed.
   FunctionLiteral* ParseProgram();
 
@@ -541,17 +573,6 @@ class Parser : public ParserBase {
 
   // Report syntax error
   void ReportInvalidPreparseData(Handle<String> name, bool* ok);
-  void ReportMessage(const char* message, Vector<const char*> args);
-  void ReportMessage(const char* message, Vector<Handle<String> > args);
-  void ReportMessageAt(Scanner::Location location, const char* type) {
-    ReportMessageAt(location, type, Vector<const char*>::empty());
-  }
-  void ReportMessageAt(Scanner::Location loc,
-                       const char* message,
-                       Vector<const char*> args);
-  void ReportMessageAt(Scanner::Location loc,
-                       const char* message,
-                       Vector<Handle<String> > args);
 
   void set_pre_parse_data(ScriptDataImpl *data) {
     pre_parse_data_ = data;
@@ -571,9 +592,6 @@ class Parser : public ParserBase {
         ? top_scope_ : top_scope_->DeclarationScope();
   }
 
-  // Check if the given string is 'eval' or 'arguments'.
-  bool IsEvalOrArguments(Handle<String> string);
-
   // All ParseXXX functions take as the last argument an *ok parameter
   // which is set to false if parsing failed; it is unchanged otherwise.
   // By making the 'exception handling' explicit, we are forced to check
@@ -660,8 +678,6 @@ class Parser : public ParserBase {
   // Magical syntax support.
   Expression* ParseV8Intrinsic(bool* ok);
 
-  bool is_generator() const { return current_function_state_->is_generator(); }
-
   bool CheckInOrOf(bool accept_OF, ForEachStatement::VisitMode* visit_mode);
 
   Handle<String> LiteralString(PretenureFlag tenured) {
@@ -684,20 +700,10 @@ class Parser : public ParserBase {
     }
   }
 
-  Handle<String> GetSymbol();
-
   // Get odd-ball literals.
   Literal* GetLiteralUndefined(int position);
   Literal* GetLiteralTheHole(int position);
 
-  Handle<String> ParseIdentifier(AllowEvalOrArgumentsAsIdentifier, bool* ok);
-  Handle<String> ParseIdentifierOrStrictReservedWord(
-      bool* is_strict_reserved, bool* ok);
-  Handle<String> ParseIdentifierName(bool* ok);
-  Handle<String> ParseIdentifierNameOrGetOrSet(bool* is_get,
-                                               bool* is_set,
-                                               bool* ok);
-
   // Determine if the expression is a variable proxy and mark it as being used
   // in an assignment or with a increment/decrement operator. This is currently
   // used on for the statically checking assignments to harmony const bindings.

test/cctest/test-parsing.cc

@@ -1108,8 +1108,9 @@ enum ParserSyncTestResult {
   kError
 };
 
-
-void SetParserFlags(i::ParserBase* parser, i::EnumSet<ParserFlag> flags) {
+template <typename Traits>
+void SetParserFlags(i::ParserBase<Traits>* parser,
+                    i::EnumSet<ParserFlag> flags) {
   parser->set_allow_lazy(flags.Contains(kAllowLazy));
   parser->set_allow_natives_syntax(flags.Contains(kAllowNativesSyntax));
   parser->set_allow_harmony_scoping(flags.Contains(kAllowHarmonyScoping));