Make template scan related function take a template<bool> parameter

src/scanner.h

 // Copyright 2011 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.
 
 // Features shared by parsing and pre-parsing scanners.
 
 #ifndef V8_SCANNER_H_
 #define V8_SCANNER_H_
 
 #include "src/allocation.h"
@@ skipping 304 matching lines @@
 
 // ----------------------------------------------------------------------------
 // JavaScript Scanner.
 
 class Scanner {
  public:
   // Scoped helper for literal recording. Automatically drops the literal
   // if aborting the scanning before it's complete.
   class LiteralScope {
    public:
-    explicit LiteralScope(Scanner* self, bool capture_raw = false)
-        : scanner_(self), complete_(false) {
+    explicit LiteralScope(Scanner* self) : scanner_(self), complete_(false) {
       scanner_->StartLiteral();
-      if (capture_raw) scanner_->StartRawLiteral();
     }
      ~LiteralScope() {
        if (!complete_) scanner_->DropLiteral();
      }
     void Complete() {
       scanner_->TerminateLiteral();
       complete_ = true;
     }
 
    private:
@@ skipping 160 matching lines @@
   struct TokenDesc {
     Token::Value token;
     Location location;
     LiteralBuffer* literal_chars;
     LiteralBuffer* raw_literal_chars;
   };
 
   static const int kCharacterLookaheadBufferSize = 1;
 
   // Scans octal escape sequence. Also accepts "\0" decimal escape sequence.
+  template <bool capture_raw>
   uc32 ScanOctalEscape(uc32 c, int length);
 
   // Call this after setting source_ to the input.
   void Init() {
     // Set c0_ (one character ahead)
     STATIC_ASSERT(kCharacterLookaheadBufferSize == 1);
     Advance();
     // Initialize current_ to not refer to a literal.
     current_.literal_chars = NULL;
     current_.raw_literal_chars = NULL;
   }
 
   // Literal buffer support
   inline void StartLiteral() {
     LiteralBuffer* free_buffer = (current_.literal_chars == &literal_buffer1_) ?
             &literal_buffer2_ : &literal_buffer1_;
     free_buffer->Reset();
     next_.literal_chars = free_buffer;
   }
 
   inline void StartRawLiteral() {
     raw_literal_buffer_.Reset();
     next_.raw_literal_chars = &raw_literal_buffer_;
-    capturing_raw_literal_ = true;
   }
 
   INLINE(void AddLiteralChar(uc32 c)) {
     DCHECK_NOT_NULL(next_.literal_chars);
     next_.literal_chars->AddChar(c);
   }
 
   INLINE(void AddRawLiteralChar(uc32 c)) {
-    DCHECK(capturing_raw_literal_);
     DCHECK_NOT_NULL(next_.raw_literal_chars);
     next_.raw_literal_chars->AddChar(c);
   }
 
   INLINE(void ReduceRawLiteralLength(int delta)) {
-    DCHECK(capturing_raw_literal_);
     DCHECK_NOT_NULL(next_.raw_literal_chars);
     next_.raw_literal_chars->ReduceLength(delta);
   }
 
   // Complete scanning of a literal.
-  inline void TerminateLiteral() { capturing_raw_literal_ = false; }
+  inline void TerminateLiteral() {

[Dmitry Lomov (no reviews), 2014/12/04 18:04:23]

Nit: if it does nothing, why not remove it?

[arv (Not doing code reviews), 2014/12/04 18:07:09]

Old code... I guess at some point it did something...

There is a "contract" that certain functions only return valid values between
StartLiteral and TerminateLiteral. I'll see if I can make the comment clear
after removing TerminateLiteral.

+    // Does nothing in the current implementation.
+  }
 
   // Stops scanning of a literal and drop the collected characters,
   // e.g., due to an encountered error.
   inline void DropLiteral() {
     next_.literal_chars = NULL;
     next_.raw_literal_chars = NULL;
-    capturing_raw_literal_ = false;
   }
 
   inline void AddLiteralCharAdvance() {
     AddLiteralChar(c0_);
     Advance();
   }
 
   // Low-level scanning support.
+  template <bool capture_raw>
   void Advance() {
-    if (capturing_raw_literal_) {
+    if (capture_raw) {
       AddRawLiteralChar(c0_);
     }
     c0_ = source_->Advance();
     if (unibrow::Utf16::IsLeadSurrogate(c0_)) {
       uc32 c1 = source_->Advance();
       if (!unibrow::Utf16::IsTrailSurrogate(c1)) {
         source_->PushBack(c1);
       } else {
         c0_ = unibrow::Utf16::CombineSurrogatePair(c0_, c1);
       }
     }
   }
 
+  void Advance() { Advance<false>(); }
+
   void PushBack(uc32 ch) {
     if (ch > static_cast<uc32>(unibrow::Utf16::kMaxNonSurrogateCharCode)) {
       source_->PushBack(unibrow::Utf16::TrailSurrogate(c0_));
       source_->PushBack(unibrow::Utf16::LeadSurrogate(c0_));
-      if (capturing_raw_literal_) ReduceRawLiteralLength(2);
     } else {
       source_->PushBack(c0_);
-      if (capturing_raw_literal_) ReduceRawLiteralLength(1);
     }
     c0_ = ch;
   }
 
   inline Token::Value Select(Token::Value tok) {
     Advance();
     return tok;
   }
 
   inline Token::Value Select(uc32 next, Token::Value then, Token::Value else_) {
@@ skipping 49 matching lines @@
   }
   Vector<const uint16_t> raw_literal_two_byte_string() {
     DCHECK_NOT_NULL(current_.raw_literal_chars);
     return current_.raw_literal_chars->two_byte_literal();
   }
   bool is_raw_literal_one_byte() {
     DCHECK_NOT_NULL(current_.raw_literal_chars);
     return current_.raw_literal_chars->is_one_byte();
   }
 
-
+  template <bool capture_raw>
   uc32 ScanHexNumber(int expected_length);
   // Scan a number of any length but not bigger than max_value. For example, the
   // number can be 000000001, so it's very long in characters but its value is
   // small.
+  template <bool capture_raw>
   uc32 ScanUnlimitedLengthHexNumber(int max_value);
 
   // Scans a single JavaScript token.
   void Scan();
 
   bool SkipWhiteSpace();
   Token::Value SkipSingleLineComment();
   Token::Value SkipSourceURLComment();
   void TryToParseSourceURLComment();
   Token::Value SkipMultiLineComment();
   // Scans a possible HTML comment -- begins with '<!'.
   Token::Value ScanHtmlComment();
 
   void ScanDecimalDigits();
   Token::Value ScanNumber(bool seen_period);
   Token::Value ScanIdentifierOrKeyword();
   Token::Value ScanIdentifierSuffix(LiteralScope* literal);
 
   Token::Value ScanString();
 
   // Scans an escape-sequence which is part of a string and adds the
   // decoded character to the current literal. Returns true if a pattern
   // is scanned.
+  template <bool capture_raw>
   bool ScanEscape();
   // Decodes a Unicode escape-sequence which is part of an identifier.
   // If the escape sequence cannot be decoded the result is kBadChar.
   uc32 ScanIdentifierUnicodeEscape();
   // Helper for the above functions.
+  template <bool capture_raw>
   uc32 ScanUnicodeEscape();
 
   Token::Value ScanTemplateSpan();
 
   // Return the current source position.
   int source_pos() {
     return source_->pos() - kCharacterLookaheadBufferSize;
   }
 
   UnicodeCache* unicode_cache_;
 
   // Buffers collecting literal strings, numbers, etc.
   LiteralBuffer literal_buffer1_;
   LiteralBuffer literal_buffer2_;
 
   // Values parsed from magic comments.
   LiteralBuffer source_url_;
   LiteralBuffer source_mapping_url_;
 
   // Buffer to store raw string values
   LiteralBuffer raw_literal_buffer_;
 
-  // We only need to capture the raw literal when we are scanning template
-  // literal spans.
-  bool capturing_raw_literal_;
-
   TokenDesc current_;  // desc for current token (as returned by Next())
   TokenDesc next_;     // desc for next token (one token look-ahead)
 
   // Input stream. Must be initialized to an Utf16CharacterStream.
   Utf16CharacterStream* source_;
 
 
   // Start position of the octal literal last scanned.
   Location octal_pos_;
 
@@ skipping 17 matching lines @@
   bool harmony_classes_;
   // Whether we scan TEMPLATE_SPAN and TEMPLATE_TAIL
   bool harmony_templates_;
   // Whether we allow \u{xxxxx}.
   bool harmony_unicode_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_SCANNER_H_