Hide RegExp and String initialization in a closure.

src/string.js

 // Copyright 2012 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.
 
-// This file relies on the fact that the following declaration has been made
-// in runtime.js:
-// var $String = global.String;
+var $stringCharAt;
+var $stringIndexOf;
+var $stringSubstring;
 
-// -------------------------------------------------------------------
+(function() {
+
+%CheckIsBootstrapping();
+
+var GlobalRegExp = global.RegExp;
+var GlobalString = global.String;
+
+//-------------------------------------------------------------------
 
 function StringConstructor(x) {
   if (%_ArgumentsLength() == 0) x = '';
   if (%_IsConstructCall()) {
     %_SetValueOf(this, TO_STRING_INLINE(x));
   } else {
     return IS_SYMBOL(x) ?
         %_CallFunction(x, SymbolToString) : TO_STRING_INLINE(x);
   }
 }
@@ skipping 120 matching lines @@
 // ECMA-262 section 15.5.4.10
 function StringMatchJS(regexp) {
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.match");
 
   var subject = TO_STRING_INLINE(this);
   if (IS_REGEXP(regexp)) {
     // Emulate RegExp.prototype.exec's side effect in step 5, even though
     // value is discarded.
     var lastIndex = regexp.lastIndex;
     TO_INTEGER_FOR_SIDE_EFFECT(lastIndex);
-    if (!regexp.global) return RegExpExecNoTests(regexp, subject, 0);
-    // lastMatchInfo is defined in regexp.js.
-    var result = %StringMatch(subject, regexp, lastMatchInfo);
-    if (result !== null) lastMatchInfoOverride = null;
+    if (!regexp.global) return $regexpExecNoTests(regexp, subject, 0);
+    var result = %StringMatch(subject, regexp, $regexpLastMatchInfo);
+    if (result !== null) $regexpLastMatchInfoOverride = null;
     regexp.lastIndex = 0;
     return result;
   }
   // Non-regexp argument.
-  regexp = new $RegExp(regexp);
-  return RegExpExecNoTests(regexp, subject, 0);
+  regexp = new GlobalRegExp(regexp);
+  return $regexpExecNoTests(regexp, subject, 0);
 }
 
 
 var NORMALIZATION_FORMS = ['NFC', 'NFD', 'NFKC', 'NFKD'];
 
 
 // ECMA-262 v6, section 21.1.3.12
 //
 // For now we do nothing, as proper normalization requires big tables.
 // If Intl is enabled, then i18n.js will override it and provide the the
 // proper functionality.
 function StringNormalizeJS(form) {
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.normalize");
 
   var form = form ? TO_STRING_INLINE(form) : 'NFC';
   var normalizationForm = NORMALIZATION_FORMS.indexOf(form);
   if (normalizationForm === -1) {
     throw new $RangeError('The normalization form should be one of '
         + NORMALIZATION_FORMS.join(', ') + '.');
   }
 
   return %_ValueOf(this);
 }
 
 
-// This has the same size as the lastMatchInfo array, and can be used for
-// functions that expect that structure to be returned.  It is used when the
-// needle is a string rather than a regexp.  In this case we can't update
+// This has the same size as the $regexpLastMatchInfo array, and can be used
+// for functions that expect that structure to be returned.  It is used when
+// the needle is a string rather than a regexp.  In this case we can't update
 // lastMatchArray without erroneously affecting the properties on the global
 // RegExp object.
 var reusableMatchInfo = [2, "", "", -1, -1];
 
 
 // ECMA-262, section 15.5.4.11
 function StringReplace(search, replace) {
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.replace");
 
   var subject = TO_STRING_INLINE(this);
@@ skipping 19 matching lines @@
     // Emulate RegExp.prototype.exec's side effect in step 5, even if
     // value is discarded.
     var lastIndex = search.lastIndex;
     TO_INTEGER_FOR_SIDE_EFFECT(lastIndex);
 
     if (!IS_SPEC_FUNCTION(replace)) {
       replace = TO_STRING_INLINE(replace);
 
       if (!search.global) {
         // Non-global regexp search, string replace.
-        var match = DoRegExpExec(search, subject, 0);
+        var match = $regexpExec(search, subject, 0);
         if (match == null) {
           search.lastIndex = 0
           return subject;
         }
         if (replace.length == 0) {
           return %_SubString(subject, 0, match[CAPTURE0]) +
                  %_SubString(subject, match[CAPTURE1], subject.length)
         }
-        return ExpandReplacement(replace, subject, lastMatchInfo,
+        return ExpandReplacement(replace, subject, $regexpLastMatchInfo,
                                  %_SubString(subject, 0, match[CAPTURE0])) +
                %_SubString(subject, match[CAPTURE1], subject.length);
       }
 
       // Global regexp search, string replace.
       search.lastIndex = 0;
-      if (lastMatchInfoOverride == null) {
+      if ($regexpLastMatchInfoOverride == null) {
         return %StringReplaceGlobalRegExpWithString(
-            subject, search, replace, lastMatchInfo);
+            subject, search, replace, $regexpLastMatchInfo);
       } else {
         // We use this hack to detect whether StringReplaceRegExpWithString
         // found at least one hit. In that case we need to remove any
         // override.
-        var saved_subject = lastMatchInfo[LAST_SUBJECT_INDEX];
-        lastMatchInfo[LAST_SUBJECT_INDEX] = 0;
+        var saved_subject = $regexpLastMatchInfo[LAST_SUBJECT_INDEX];
+        $regexpLastMatchInfo[LAST_SUBJECT_INDEX] = 0;
         var answer = %StringReplaceGlobalRegExpWithString(
-            subject, search, replace, lastMatchInfo);
-        if (%_IsSmi(lastMatchInfo[LAST_SUBJECT_INDEX])) {
-          lastMatchInfo[LAST_SUBJECT_INDEX] = saved_subject;
+            subject, search, replace, $regexpLastMatchInfo);
+        if (%_IsSmi($regexpLastMatchInfo[LAST_SUBJECT_INDEX])) {
+          $regexpLastMatchInfo[LAST_SUBJECT_INDEX] = saved_subject;
         } else {
-          lastMatchInfoOverride = null;
+          $regexpLastMatchInfoOverride = null;
         }
         return answer;
       }
     }
 
     if (search.global) {
       // Global regexp search, function replace.
       return StringReplaceGlobalRegExpWithFunction(subject, search, replace);
     }
     // Non-global regexp search, function replace.
@@ skipping 143 matching lines @@
     reusableReplaceArray = null;
   } else {
     // Inside a nested replace (replace called from the replacement function
     // of another replace) or we have failed to set the reusable array
     // back due to an exception in a replacement function. Create a new
     // array to use in the future, or until the original is written back.
     resultArray = new InternalArray(16);
   }
   var res = %RegExpExecMultiple(regexp,
                                 subject,
-                                lastMatchInfo,
+                                $regexpLastMatchInfo,
                                 resultArray);
   regexp.lastIndex = 0;
   if (IS_NULL(res)) {
     // No matches at all.
     reusableReplaceArray = resultArray;
     return subject;
   }
   var len = res.length;
-  if (NUMBER_OF_CAPTURES(lastMatchInfo) == 2) {
+  if (NUMBER_OF_CAPTURES($regexpLastMatchInfo) == 2) {
     // If the number of captures is two then there are no explicit captures in
     // the regexp, just the implicit capture that captures the whole match.  In
     // this case we can simplify quite a bit and end up with something faster.
     // The builder will consist of some integers that indicate slices of the
     // input string and some replacements that were returned from the replace
     // function.
     var match_start = 0;
     var override = new InternalPackedArray(null, 0, subject);
     var receiver = %GetDefaultReceiver(replace);
     for (var i = 0; i < len; i++) {
       var elem = res[i];
       if (%_IsSmi(elem)) {
         // Integers represent slices of the original string.  Use these to
         // get the offsets we need for the override array (so things like
         // RegExp.leftContext work during the callback function.
         if (elem > 0) {
           match_start = (elem >> 11) + (elem & 0x7ff);
         } else {
           match_start = res[++i] - elem;
         }
       } else {
         override[0] = elem;
         override[1] = match_start;
-        lastMatchInfoOverride = override;
+        $regexpLastMatchInfoOverride = override;
         var func_result =
             %_CallFunction(receiver, elem, match_start, subject, replace);
         // Overwrite the i'th element in the results with the string we got
         // back from the callback function.
         res[i] = TO_STRING_INLINE(func_result);
         match_start += elem.length;
       }
     }
   } else {
     var receiver = %GetDefaultReceiver(replace);
     for (var i = 0; i < len; i++) {
       var elem = res[i];
       if (!%_IsSmi(elem)) {
         // elem must be an Array.
         // Use the apply argument as backing for global RegExp properties.
-        lastMatchInfoOverride = elem;
+        $regexpLastMatchInfoOverride = elem;
         var func_result = %Apply(replace, receiver, elem, 0, elem.length);
         // Overwrite the i'th element in the results with the string we got
         // back from the callback function.
         res[i] = TO_STRING_INLINE(func_result);
       }
     }
   }
   var result = %StringBuilderConcat(res, res.length, subject);
   resultArray.length = 0;
   reusableReplaceArray = resultArray;
   return result;
 }
 
 
 function StringReplaceNonGlobalRegExpWithFunction(subject, regexp, replace) {
-  var matchInfo = DoRegExpExec(regexp, subject, 0);
+  var matchInfo = $regexpExec(regexp, subject, 0);
   if (IS_NULL(matchInfo)) {
     regexp.lastIndex = 0;
     return subject;
   }
   var index = matchInfo[CAPTURE0];
   var result = %_SubString(subject, 0, index);
   var endOfMatch = matchInfo[CAPTURE1];
   // Compute the parameter list consisting of the match, captures, index,
   // and subject for the replace function invocation.
   // The number of captures plus one for the match.
@@ skipping 26 matching lines @@
 // ECMA-262 section 15.5.4.12
 function StringSearch(re) {
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.search");
 
   var regexp;
   if (IS_STRING(re)) {
     regexp = %_GetFromCache(STRING_TO_REGEXP_CACHE_ID, re);
   } else if (IS_REGEXP(re)) {
     regexp = re;
   } else {
-    regexp = new $RegExp(re);
+    regexp = new GlobalRegExp(re);
   }
-  var match = DoRegExpExec(regexp, TO_STRING_INLINE(this), 0);
+  var match = $regexpExec(regexp, TO_STRING_INLINE(this), 0);
   if (match) {
     return match[CAPTURE0];
   }
   return -1;
 }
 
 
 // ECMA-262 section 15.5.4.13
 function StringSlice(start, end) {
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.slice");
@@ skipping 65 matching lines @@
 
   if (limit === 0) return [];
 
   // Separator is a regular expression.
   return StringSplitOnRegExp(subject, separator, limit, length);
 }
 
 
 function StringSplitOnRegExp(subject, separator, limit, length) {
   if (length === 0) {
-    if (DoRegExpExec(separator, subject, 0, 0) != null) {
+    if ($regexpExec(separator, subject, 0, 0) != null) {
       return [];
     }
     return [subject];
   }
 
   var currentIndex = 0;
   var startIndex = 0;
   var startMatch = 0;
   var result = new InternalArray();
 
   outer_loop:
   while (true) {
 
     if (startIndex === length) {
       result[result.length] = %_SubString(subject, currentIndex, length);
       break;
     }
 
-    var matchInfo = DoRegExpExec(separator, subject, startIndex);
+    var matchInfo = $regexpExec(separator, subject, startIndex);
     if (matchInfo == null || length === (startMatch = matchInfo[CAPTURE0])) {
       result[result.length] = %_SubString(subject, currentIndex, length);
       break;
     }
     var endIndex = matchInfo[CAPTURE1];
 
     // We ignore a zero-length match at the currentIndex.
     if (startIndex === endIndex && endIndex === currentIndex) {
       startIndex++;
       continue;
@@ skipping 268 matching lines @@
 
 
 // ES6 draft, revision 26 (2014-07-18), section B.2.3.14
 function StringSup() {
   CHECK_OBJECT_COERCIBLE(this, "String.prototype.sup");
   return "<sup>" + this + "</sup>";
 }
 
 // -------------------------------------------------------------------
 
-function SetUpString() {
-  %CheckIsBootstrapping();
+// Set the String function and constructor.
+%SetCode(GlobalString, StringConstructor);
+%FunctionSetPrototype(GlobalString, new GlobalString());
 
-  // Set the String function and constructor.
-  %SetCode($String, StringConstructor);
-  %FunctionSetPrototype($String, new $String());
+// Set up the constructor property on the String prototype object.
+%AddNamedProperty(GlobalString.prototype, "constructor", GlobalString, DONT_ENUM);

[Jakob Kummerow, 2015/03/12 12:46:35]

nit: 80col

 
-  // Set up the constructor property on the String prototype object.
-  %AddNamedProperty($String.prototype, "constructor", $String, DONT_ENUM);
+// Set up the non-enumerable functions on the String object.
+InstallFunctions(GlobalString, DONT_ENUM, $Array(

[Jakob Kummerow, 2015/03/12 12:46:35]

Why "$Array"? Other files use "var GlobalArray = global.Array" for this; I
assume the "$Array = ..." definition in runtime.js is deprecated.

(again below)

+  "fromCharCode", StringFromCharCode
+));
 
-  // Set up the non-enumerable functions on the String object.
-  InstallFunctions($String, DONT_ENUM, $Array(
-    "fromCharCode", StringFromCharCode
-  ));
+// Set up the non-enumerable functions on the String prototype object.
+InstallFunctions(GlobalString.prototype, DONT_ENUM, $Array(
+  "valueOf", StringValueOf,
+  "toString", StringToString,
+  "charAt", StringCharAt,
+  "charCodeAt", StringCharCodeAt,
+  "concat", StringConcat,
+  "indexOf", StringIndexOfJS,
+  "lastIndexOf", StringLastIndexOfJS,
+  "localeCompare", StringLocaleCompareJS,
+  "match", StringMatchJS,
+  "normalize", StringNormalizeJS,
+  "replace", StringReplace,
+  "search", StringSearch,
+  "slice", StringSlice,
+  "split", StringSplitJS,
+  "substring", StringSubstring,
+  "substr", StringSubstr,
+  "toLowerCase", StringToLowerCaseJS,
+  "toLocaleLowerCase", StringToLocaleLowerCase,
+  "toUpperCase", StringToUpperCaseJS,
+  "toLocaleUpperCase", StringToLocaleUpperCase,
+  "trim", StringTrimJS,
+  "trimLeft", StringTrimLeft,
+  "trimRight", StringTrimRight,
+  "link", StringLink,
+  "anchor", StringAnchor,
+  "fontcolor", StringFontcolor,
+  "fontsize", StringFontsize,
+  "big", StringBig,
+  "blink", StringBlink,
+  "bold", StringBold,
+  "fixed", StringFixed,
+  "italics", StringItalics,
+  "small", StringSmall,
+  "strike", StringStrike,
+  "sub", StringSub,
+  "sup", StringSup
+));
 
-  // Set up the non-enumerable functions on the String prototype object.
-  InstallFunctions($String.prototype, DONT_ENUM, $Array(
-    "valueOf", StringValueOf,
-    "toString", StringToString,
-    "charAt", StringCharAt,
-    "charCodeAt", StringCharCodeAt,
-    "concat", StringConcat,
-    "indexOf", StringIndexOfJS,
-    "lastIndexOf", StringLastIndexOfJS,
-    "localeCompare", StringLocaleCompareJS,
-    "match", StringMatchJS,
-    "normalize", StringNormalizeJS,
-    "replace", StringReplace,
-    "search", StringSearch,
-    "slice", StringSlice,
-    "split", StringSplitJS,
-    "substring", StringSubstring,
-    "substr", StringSubstr,
-    "toLowerCase", StringToLowerCaseJS,
-    "toLocaleLowerCase", StringToLocaleLowerCase,
-    "toUpperCase", StringToUpperCaseJS,
-    "toLocaleUpperCase", StringToLocaleUpperCase,
-    "trim", StringTrimJS,
-    "trimLeft", StringTrimLeft,
-    "trimRight", StringTrimRight,
-    "link", StringLink,
-    "anchor", StringAnchor,
-    "fontcolor", StringFontcolor,
-    "fontsize", StringFontsize,
-    "big", StringBig,
-    "blink", StringBlink,
-    "bold", StringBold,
-    "fixed", StringFixed,
-    "italics", StringItalics,
-    "small", StringSmall,
-    "strike", StringStrike,
-    "sub", StringSub,
-    "sup", StringSup
-  ));
-}
+$stringCharAt = StringCharAt;
+$stringIndexOf = StringIndexOfJS;
+$stringSubstring = StringSubstring;
 
-SetUpString();
+})();