[scanner] Use more range checks and const

Bug: v8:7926
Change-Id: I62e05240fd2bb165ddf8965b77763ec11a40a609
Reviewed-on: https://chromium-review.googlesource.com/1202543
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55636}

src/char-predicates-inl.h

@@ -18,17 +18,14 @@ inline int AsciiAlphaToLower(uc32 c) {
   return c | 0x20;
 }
 
-
 inline bool IsCarriageReturn(uc32 c) {
   return c == 0x000D;
 }
 
-
 inline bool IsLineFeed(uc32 c) {
   return c == 0x000A;
 }
 
-
 inline bool IsAsciiIdentifier(uc32 c) {
   return IsAlphaNumeric(c) || c == '$' || c == '_';
 }
@@ -52,6 +49,8 @@ inline bool IsOctalDigit(uc32 c) {
   return IsInRange(c, '0', '7');
 }
 
+inline bool IsNonOctalDecimalDigit(uc32 c) { return IsInRange(c, '8', '9'); }
+
 inline bool IsBinaryDigit(uc32 c) {
   // ECMA-262, 6th, 7.8.3
   return c == '0' || c == '1';

src/parsing/scanner.cc

@@ -158,11 +158,11 @@ void Scanner::BookmarkScope::Apply() {
   bookmark_ = kBookmarkWasApplied;
 }
 
-bool Scanner::BookmarkScope::HasBeenSet() {
+bool Scanner::BookmarkScope::HasBeenSet() const {
   return bookmark_ != kNoBookmark && bookmark_ != kBookmarkWasApplied;
 }
 
-bool Scanner::BookmarkScope::HasBeenApplied() {
+bool Scanner::BookmarkScope::HasBeenApplied() const {
   return bookmark_ == kBookmarkWasApplied;
 }
 
@@ -530,7 +530,7 @@ uc32 Scanner::ScanOctalEscape(uc32 c, int length) {
   // can be reported later (in strict mode).
   // We don't report the error immediately, because the octal escape can
   // occur before the "use strict" directive.
-  if (c != '0' || i > 0 || c0_ == '8' || c0_ == '9') {
+  if (c != '0' || i > 0 || IsNonOctalDecimalDigit(c0_)) {
     octal_pos_ = Location(source_pos() - i - 1, source_pos() - 1);
     octal_message_ = capture_raw ? MessageTemplate::kTemplateOctalLiteral
                                  : MessageTemplate::kStrictOctalEscape;
@@ -806,11 +806,11 @@ bool Scanner::ScanImplicitOctalDigits(int start_pos,
 
   while (true) {
     // (possible) octal number
-    if (c0_ == '8' || c0_ == '9') {
+    if (IsNonOctalDecimalDigit(c0_)) {
       *kind = DECIMAL_WITH_LEADING_ZERO;
       return true;
     }
-    if (c0_ < '0' || '7' < c0_) {
+    if (!IsOctalDigit(c0_)) {
       // Octal literal finished.
       octal_pos_ = Location(start_pos, source_pos());
       octal_message_ = MessageTemplate::kStrictOctalLiteral;
@@ -878,7 +878,7 @@ Token::Value Scanner::ScanNumber(bool seen_period) {
         AddLiteralCharAdvance();
         kind = BINARY;
         if (!ScanBinaryDigits()) return Token::ILLEGAL;
-      } else if ('0' <= c0_ && c0_ <= '7') {
+      } else if (IsOctalDigit(c0_)) {
         kind = IMPLICIT_OCTAL;
         if (!ScanImplicitOctalDigits(start_pos, &kind)) {
           return Token::ILLEGAL;
@@ -886,7 +886,7 @@ Token::Value Scanner::ScanNumber(bool seen_period) {
         if (kind == DECIMAL_WITH_LEADING_ZERO) {
           at_start = false;
         }
-      } else if (c0_ == '8' || c0_ == '9') {
+      } else if (IsNonOctalDecimalDigit(c0_)) {
         kind = DECIMAL_WITH_LEADING_ZERO;
       } else if (allow_harmony_numeric_separator() && c0_ == '_') {
         ReportScannerError(Location(source_pos(), source_pos() + 1),

src/parsing/scanner.h

@@ -198,8 +198,8 @@ class Scanner {
 
     void Set();
     void Apply();
-    bool HasBeenSet();
-    bool HasBeenApplied();
+    bool HasBeenSet() const;
+    bool HasBeenApplied() const;
 
    private:
     static const size_t kNoBookmark;
@@ -241,10 +241,12 @@ class Scanner {
   // Returns the token following peek()
   Token::Value PeekAhead();
   // Returns the current token again.
-  Token::Value current_token() { return current().token; }
+  Token::Value current_token() const { return current().token; }
 
-  Token::Value current_contextual_token() { return current().contextual_token; }
-  Token::Value next_contextual_token() { return next().contextual_token; }
+  Token::Value current_contextual_token() const {
+    return current().contextual_token;
+  }
+  Token::Value next_contextual_token() const { return next().contextual_token; }
 
   // Returns the location information for the current token
   // (the token last returned by Next()).
@@ -317,11 +319,13 @@ class Scanner {
            current().literal_chars.Equals(
                Vector<const char>("use strict", strlen("use strict")));
   }
+
   bool IsGetOrSet(bool* is_get, bool* is_set) const {
     *is_get = CurrentMatchesContextual(Token::GET);
     *is_set = CurrentMatchesContextual(Token::SET);
     return *is_get || *is_set;
   }
+
   bool IsLet() const {
     return CurrentMatches(Token::LET) ||
            CurrentMatchesContextualEscaped(Token::LET);
@@ -333,7 +337,7 @@ class Scanner {
   bool IsDuplicateSymbol(DuplicateFinder* duplicate_finder,
                          AstValueFactory* ast_value_factory) const;
 
-  UnicodeCache* unicode_cache() { return unicode_cache_; }
+  UnicodeCache* unicode_cache() const { return unicode_cache_; }
 
   // Returns the location of the last seen octal literal.
   Location octal_position() const { return octal_pos_; }