Revert of [regexp] Port RegExpExec

src/js/regexp.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.
 
 (function(global, utils) {
 
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------
 // Imports
 
 var ExpandReplacement;
 var GlobalArray = global.Array;
 var GlobalObject = global.Object;
 var GlobalRegExp = global.RegExp;
 var InternalArray = utils.InternalArray;
 var InternalPackedArray = utils.InternalPackedArray;
 var MaxSimple;
 var MinSimple;
 var lastMatchInfoSymbol = utils.ImportNow("regexp_last_match_info_symbol");
 var matchSymbol = utils.ImportNow("match_symbol");
 var replaceSymbol = utils.ImportNow("replace_symbol");
 var searchSymbol = utils.ImportNow("search_symbol");
 var speciesSymbol = utils.ImportNow("species_symbol");
 var splitSymbol = utils.ImportNow("split_symbol");
 var SpeciesConstructor;
-var RegExpSubclassExecJS;
 
 utils.Import(function(from) {
   ExpandReplacement = from.ExpandReplacement;
   MaxSimple = from.MaxSimple;
   MinSimple = from.MinSimple;
   SpeciesConstructor = from.SpeciesConstructor;
 });
 
 // -------------------------------------------------------------------
 
@@ skipping 71 matching lines @@
   if (matchInfo !== null) {
     // ES6 21.2.5.2.2 step 18.
     if (REGEXP_STICKY(regexp)) regexp.lastIndex = matchInfo[CAPTURE1];
     RETURN_NEW_RESULT_FROM_MATCH_INFO(matchInfo, string);
   }
   regexp.lastIndex = 0;
   return null;
 }
 
 
+// ES#sec-regexp.prototype.exec
+// RegExp.prototype.exec ( string )
+function RegExpSubclassExecJS(string) {
+  if (!IS_REGEXP(this)) {
+    throw %make_type_error(kIncompatibleMethodReceiver,
+                        'RegExp.prototype.exec', this);
+  }
+
+  string = TO_STRING(string);
+  var lastIndex = this.lastIndex;
+
+  // Conversion is required by the ES2015 specification (RegExpBuiltinExec
+  // algorithm, step 4) even if the value is discarded for non-global RegExps.
+  var i = TO_LENGTH(lastIndex);
+
+  var global = TO_BOOLEAN(REGEXP_GLOBAL(this));
+  var sticky = TO_BOOLEAN(REGEXP_STICKY(this));
+  var updateLastIndex = global || sticky;
+  if (updateLastIndex) {
+    if (i > string.length) {
+      this.lastIndex = 0;
+      return null;
+    }
+  } else {
+    i = 0;
+  }
+
+  // matchIndices is either null or the RegExpLastMatchInfo array.
+  // TODO(littledan): Whether a RegExp is sticky is compiled into the RegExp
+  // itself, but ES2015 allows monkey-patching this property to differ from
+  // the internal flags. If it differs, recompile a different RegExp?
+  var matchIndices = %_RegExpExec(this, string, i, RegExpLastMatchInfo);
+
+  if (IS_NULL(matchIndices)) {
+    this.lastIndex = 0;
+    return null;
+  }
+
+  // Successful match.
+  if (updateLastIndex) {
+    this.lastIndex = RegExpLastMatchInfo[CAPTURE1];
+  }
+  RETURN_NEW_RESULT_FROM_MATCH_INFO(matchIndices, string);
+}
+%FunctionRemovePrototype(RegExpSubclassExecJS);
+
+
 // ES#sec-regexpexec Runtime Semantics: RegExpExec ( R, S )
 // Also takes an optional exec method in case our caller
 // has already fetched exec.
 function RegExpSubclassExec(regexp, string, exec) {
   if (IS_UNDEFINED(exec)) {
     exec = regexp.exec;
   }
   if (IS_CALLABLE(exec)) {
     var result = %_Call(exec, regexp, string);
     if (!IS_RECEIVER(result) && !IS_NULL(result)) {
@@ skipping 592 matching lines @@
   this.lastIndex = previousLastIndex;
   if (IS_NULL(result)) return -1;
   return result.index;
 }
 %FunctionRemovePrototype(RegExpSubclassSearch);
 
 
 // -------------------------------------------------------------------
 
 utils.InstallFunctions(GlobalRegExp.prototype, DONT_ENUM, [
+  "exec", RegExpSubclassExecJS,
   "test", RegExpSubclassTest,
   matchSymbol, RegExpSubclassMatch,
   replaceSymbol, RegExpSubclassReplace,
   searchSymbol, RegExpSubclassSearch,
   splitSymbol, RegExpSubclassSplit,
 ]);
 
 // Temporary until all RegExpLastMatchInfo accesses are ported to C++.
 SET_PRIVATE(GlobalRegExp, lastMatchInfoSymbol, RegExpLastMatchInfo);
 
-var RegExpSubclassExecJS = GlobalRegExp.prototype.exec;
-
 // -------------------------------------------------------------------
 // Internal
 
 var InternalRegExpMatchInfo = {
   REGEXP_NUMBER_OF_CAPTURES: 2,
   REGEXP_LAST_SUBJECT:       "",
   REGEXP_LAST_INPUT:         UNDEFINED,
   CAPTURE0:                  0,
   CAPTURE1:                  0
 };
@@ skipping 15 matching lines @@
 // Exports
 
 utils.Export(function(to) {
   to.InternalRegExpMatch = InternalRegExpMatch;
   to.InternalRegExpReplace = InternalRegExpReplace;
   to.IsRegExp = IsRegExp;
   to.RegExpInitialize = RegExpInitialize;
 });
 
 })