Changeset 133668 in webkit for trunk/Source/JavaScriptCore/parser/Lexer.cpp

Timestamp:

Nov 6, 2012, 2:01:51 PM (13 years ago)

Author:

[email protected]

Message:

Lexer::scanRegExp, create 8 bit pattern and flag Identifiers from 16 bit source when possible
​https://bugs.webkit.org/show_bug.cgi?id=101013

Reviewed by Darin Adler.

Changed scanRegExp so that it will create 8 bit identifiers from 8 bit sources and from 16 bit sources
whan all the characters are 8 bit. Using two templated helpers, the "is all 8 bit" check is only performed
on 16 bit sources. The first helper is orCharacter() that will accumulate the or value of all characters
only for 16 bit sources. Replaced the helper Lexer::makeIdentifierSameType() with Lexer::makeRightSizedIdentifier().

• parser/Lexer.cpp:

(JSC::orCharacter<LChar>): Explicit template that serves as a placeholder.
(JSC::orCharacter<UChar>): Explicit template that actually or accumulates characters.
(JSC::Lexer::scanRegExp):

• parser/Lexer.h:

(Lexer):
(JSC::Lexer::makeRightSizedIdentifier<LChar>): New template that always creates an 8 bit Identifier.
(JSC::Lexer::makeRightSizedIdentifier<UChar>): New template that creates an 8 bit Identifier for 8 bit
data in a 16 bit source.

File:

• trunk/Source/JavaScriptCore/parser/Lexer.cpp (modified) (4 diffs)

trunk/Source/JavaScriptCore/parser/Lexer.cpp

@@ -1687 +1687 @@
 
 template <typename T>
+static inline void orCharacter(UChar&, UChar);
+
+template <>
+inline void orCharacter<LChar>(UChar&, UChar) { }
+
+template <>
+inline void orCharacter<UChar>(UChar& orAccumulator, UChar character)
+{
+    orAccumulator |= character;
+}
+
+template <typename T>
 bool Lexer<T>::scanRegExp(const Identifier*& pattern, const Identifier*& flags, UChar patternPrefix)
 {
@@ -1693 +1705 @@
     bool lastWasEscape = false;
     bool inBrackets = false;
+    UChar charactersOredTogether = 0;
 
     if (patternPrefix) {
@@ -1715 +1728 @@
 
         record16(prev);
+        orCharacter<T>(charactersOredTogether, prev);
 
         if (lastWasEscape) {
@@ -1734 +1748 @@
     }
 
-    pattern = makeIdentifierSameType(m_buffer16.data(), m_buffer16.size());
+    pattern = makeRightSizedIdentifier(m_buffer16.data(), m_buffer16.size(), charactersOredTogether);
+
     m_buffer16.resize(0);
+    charactersOredTogether = 0;
 
     while (isIdentPart(m_current)) {
         record16(m_current);
-        shift();
-    }
-
-    flags = makeIdentifierSameType(m_buffer16.data(), m_buffer16.size());
+        orCharacter<T>(charactersOredTogether, m_current);
+        shift();
+    }
+
+    flags = makeRightSizedIdentifier(m_buffer16.data(), m_buffer16.size(), charactersOredTogether);
     m_buffer16.resize(0);