Version 2.5.4

src/regexp.js

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 53 matching lines @@
       case 'm':
         multiline = true;
         break;
       default:
         // Ignore flags that have no meaning to be consistent with
         // JSC.
         break;
     }
   }
 
-  if (!isConstructorCall) {
-    regExpCache.type = 'none';
-  }
   %RegExpInitializeObject(object, pattern, global, ignoreCase, multiline);
 
   // Call internal function to compile the pattern.
   %RegExpCompile(object, pattern, flags);
 }
 
 
 function RegExpConstructor(pattern, flags) {
   if (%_IsConstructCall()) {
     DoConstructRegExp(this, pattern, flags, true);
@@ skipping 27 matching lines @@
 }
 
 
 function DoRegExpExec(regexp, string, index) {
   var result = %_RegExpExec(regexp, string, index, lastMatchInfo);
   if (result !== null) lastMatchInfoOverride = null;
   return result;
 }
 
 
-function RegExpCache() {
-  this.type = 'none';
-  this.regExp = 0;
-  this.subject = 0;
-  this.replaceString = 0;
-  this.answer = 0;
-  // answerSaved marks whether the contents of answer is valid for a cache
-  // hit in RegExpExec, StringMatch and StringSplit.
-  this.answerSaved = false;
-  this.splitLimit = 0;  // Used only when type is "split".
-}
-
-
-var regExpCache = new RegExpCache();
-
-
 function BuildResultFromMatchInfo(lastMatchInfo, s) {
   var numResults = NUMBER_OF_CAPTURES(lastMatchInfo) >> 1;
   var result = %_RegExpConstructResult(numResults, lastMatchInfo[CAPTURE0], s);
   if (numResults === 1) {
     var matchStart = lastMatchInfo[CAPTURE(0)];
     var matchEnd = lastMatchInfo[CAPTURE(1)];
     result[0] = SubString(s, matchStart, matchEnd);
   } else {
     for (var i = 0; i < numResults; i++) {
       var matchStart = lastMatchInfo[CAPTURE(i << 1)];
@@ skipping 21 matching lines @@
   return result;
 }
 
 
 function RegExpExec(string) {
   if (!IS_REGEXP(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['RegExp.prototype.exec', this]);
   }
 
-  var cache = regExpCache;
-  var saveAnswer = false;
-
-  var lastIndex = this.lastIndex;
-
-  // Since cache.subject is always a string, a matching input can not
-  // cause visible side-effects when converted to a string, so we can omit
-  // the conversion required by the specification.
-  // Likewise, the regexp.lastIndex and regexp.global properties are value
-  // properties that are not configurable, so reading them can also not cause
-  // any side effects (converting lastIndex to a number can, though).
-  if (%_ObjectEquals(cache.type, 'exec') &&
-      %_ObjectEquals(0, lastIndex) &&
-      %_IsRegExpEquivalent(cache.regExp, this) &&
-      %_ObjectEquals(cache.subject, string)) {
-    if (cache.answerSaved) {
-      // The regexp.lastIndex value must be 0 for non-global RegExps, and for
-      // global RegExps we only cache negative results, which gives a lastIndex
-      // of zero as well.
-      this.lastIndex = 0;
-      return %_RegExpCloneResult(cache.answer);
-    } else {
-      saveAnswer = true;
-    }
-  }
-
   if (%_ArgumentsLength() === 0) {
     var regExpInput = LAST_INPUT(lastMatchInfo);
     if (IS_UNDEFINED(regExpInput)) {
       throw MakeError('no_input_to_regexp', [this]);
     }
     string = regExpInput;
   }
   var s;
   if (IS_STRING(string)) {
     s = string;
   } else {
     s = ToString(string);
   }
-  var global = this.global;
+  var lastIndex = this.lastIndex;
 
   // Conversion is required by the ES5 specification (RegExp.prototype.exec
   // algorithm, step 5) even if the value is discarded for non-global RegExps.
   var i = TO_INTEGER(lastIndex);
+
+  var global = this.global;
   if (global) {
     if (i < 0 || i > s.length) {
       this.lastIndex = 0;
       return null;
     }
   } else {
     i = 0;
   }
 
   %_Log('regexp', 'regexp-exec,%0r,%1S,%2i', [this, s, lastIndex]);
   // matchIndices is either null or the lastMatchInfo array.
   var matchIndices = %_RegExpExec(this, s, i, lastMatchInfo);
 
   if (matchIndices === null) {
     if (global) {
-      // Cache negative result only if initial lastIndex was zero.
       this.lastIndex = 0;
-      if (lastIndex !== 0) return matchIndices;
     }
-    cache.regExp = this;
-    cache.subject = s;            // Always a string.
-    cache.answer = null;
-    cache.answerSaved = true;     // Safe since no cloning is needed.
-    cache.type = 'exec';
-    return matchIndices;        // No match.
+    return null;
   }
 
   // Successful match.
   lastMatchInfoOverride = null;
   var result = BuildResultFromMatchInfo(matchIndices, s);
 
   if (global) {
-    // Don't cache positive results for global regexps.
     this.lastIndex = lastMatchInfo[CAPTURE1];
-  } else {
-    cache.regExp = this;
-    cache.subject = s;
-    if (saveAnswer) cache.answer = %_RegExpCloneResult(result);
-    cache.answerSaved = saveAnswer;
-    cache.type = 'exec';
   }
   return result;
-
 }
 
 
 // One-element cache for the simplified test regexp.
 var regexp_key;
 var regexp_val;
 
 // Section 15.10.6.3 doesn't actually make sense, but the intention seems to be
 // that test is defined in terms of String.prototype.exec. However, it probably
 // means the original value of String.prototype.exec, which is what everybody
 // else implements.
 function RegExpTest(string) {
   if (!IS_REGEXP(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['RegExp.prototype.test', this]);
   }
   if (%_ArgumentsLength() == 0) {
     var regExpInput = LAST_INPUT(lastMatchInfo);
     if (IS_UNDEFINED(regExpInput)) {
       throw MakeError('no_input_to_regexp', [this]);
     }
     string = regExpInput;
   }
 
-  var lastIndex = this.lastIndex;
-
-  var cache = regExpCache;
-  if (%_ObjectEquals(cache.type, 'test') &&
-      %_IsRegExpEquivalent(cache.regExp, this) &&
-      %_ObjectEquals(cache.subject, string) &&
-      %_ObjectEquals(0, lastIndex)) {
-    // The regexp.lastIndex value must be 0 for non-global RegExps, and for
-    // global RegExps we only cache negative results, which gives a resulting
-    // lastIndex of zero as well.
-    if (global) this.lastIndex = 0;
-    return cache.answer;
-  }
-
   var s;
   if (IS_STRING(string)) {
     s = string;
   } else {
     s = ToString(string);
   }
   var length = s.length;
 
+  var lastIndex = this.lastIndex;
+
   // Conversion is required by the ES5 specification (RegExp.prototype.exec
   // algorithm, step 5) even if the value is discarded for non-global RegExps.
   var i = TO_INTEGER(lastIndex);
+  
+  var global = this.global;
   if (global) {
     if (i < 0 || i > length) {
       this.lastIndex = 0;
       return false;
     }
   } else {
     i = 0;
   }
 
-  var global = this.global;
-
   // Remove irrelevant preceeding '.*' in a test regexp. The expression
   // checks whether this.source starts with '.*' and that the third
   // char is not a '?'
   if (%_StringCharCodeAt(this.source, 0) == 46 &&  // '.'
       %_StringCharCodeAt(this.source, 1) == 42 &&  // '*'
       %_StringCharCodeAt(this.source, 2) != 63) {  // '?'
     if (!%_ObjectEquals(regexp_key, this)) {
       regexp_key = this;
       regexp_val = new $RegExp(this.source.substring(2, this.source.length),
-                               (this.global ? 'g' : '')
+                               (global ? 'g' : '')
                                + (this.ignoreCase ? 'i' : '')
                                + (this.multiline ? 'm' : ''));
     }
     if (!regexp_val.test(s)) return false;
   }
 
+  var length = s.length;
+
+  if (i < 0 || i > length) {
+    this.lastIndex = 0;
+    return false;
+  }
+
   %_Log('regexp', 'regexp-exec,%0r,%1S,%2i', [this, s, lastIndex]);
   // matchIndices is either null or the lastMatchInfo array.
   var matchIndices = %_RegExpExec(this, s, i, lastMatchInfo);
 
-  var result = (matchIndices !== null);
-  if (result) {
-    lastMatchInfoOverride = null;
+  if (matchIndices === null) {
+    if (global) this.lastIndex = 0;
+    return false;
   }
-  if (global) {
-    if (result) {
-      this.lastIndex = lastMatchInfo[CAPTURE1];
-      return true;
-    } else {
-      this.lastIndex = 0;
-      if (lastIndex !== 0) return false;
-    }
-  }
-  cache.type = 'test';
-  cache.regExp = this;
-  cache.subject = s;
-  cache.answer = result;
-  return result;
+  lastMatchInfoOverride = null;
+  if (global) this.lastIndex = lastMatchInfo[CAPTURE1];
+  return true;
 }
 
 
 function RegExpToString() {
   // If this.source is an empty string, output /(?:)/.
   // http://bugzilla.mozilla.org/show_bug.cgi?id=225550
   // ecma_2/RegExp/properties-001.js.
   var src = this.source ? this.source : '(?:)';
   var result = '/' + src + '/';
   if (this.global) result += 'g';
@@ skipping 127 matching lines @@
   %FunctionSetLength($RegExp.prototype.compile, 1);
 
   // The properties input, $input, and $_ are aliases for each other.  When this
   // value is set the value it is set to is coerced to a string.
   // Getter and setter for the input.
   function RegExpGetInput() {
     var regExpInput = LAST_INPUT(lastMatchInfo);
     return IS_UNDEFINED(regExpInput) ? "" : regExpInput;
   }
   function RegExpSetInput(string) {
-    regExpCache.type = 'none';
     LAST_INPUT(lastMatchInfo) = ToString(string);
   };
 
   %DefineAccessor($RegExp, 'input', GETTER, RegExpGetInput, DONT_DELETE);
   %DefineAccessor($RegExp, 'input', SETTER, RegExpSetInput, DONT_DELETE);
   %DefineAccessor($RegExp, '$_', GETTER, RegExpGetInput, DONT_ENUM | DONT_DELETE);
   %DefineAccessor($RegExp, '$_', SETTER, RegExpSetInput, DONT_ENUM | DONT_DELETE);
   %DefineAccessor($RegExp, '$input', GETTER, RegExpGetInput, DONT_ENUM | DONT_DELETE);
   %DefineAccessor($RegExp, '$input', SETTER, RegExpSetInput, DONT_ENUM | DONT_DELETE);
 
@@ skipping 37 matching lines @@
   %DefineAccessor($RegExp, "$'", SETTER, NoOpSetter, DONT_ENUM | DONT_DELETE);
 
   for (var i = 1; i < 10; ++i) {
     %DefineAccessor($RegExp, '$' + i, GETTER, RegExpMakeCaptureGetter(i), DONT_DELETE);
     %DefineAccessor($RegExp, '$' + i, SETTER, NoOpSetter, DONT_DELETE);
   }
 }
 
 
 SetupRegExp();