Revert of [regexp] Named capture support for string replacements (pat…

…chset crosswalk-project#5 id:80001 of https://codereview.chromium.org/2775303002/ )

Reason for revert:
Invalid DCHECKs for non-matched groups.

Original issue's description:
> [regexp] Named capture support for string replacements
>
> This implements support for named captures in
> RegExp.prototype[@@replace] for when the replaceValue is not callable.
>
> Named captures can be referenced from replacement strings by using the
> "$<name>" syntax. A couple of examples:
>
> let re = /(?<fst>.)(?<snd>.)/u;
> "abcd".replace(re, "$<snd>$<fst>")  // "bacd"
> "abcd".replace(re, "$2$1")     // "bacd" (numbered refs work as always)
> "abcd".replace(re, "$<snd")    // SyntaxError (unterminated named ref)
> "abcd".replace(re, "$<42$1>")  // "cd" (invalid name)
> "abcd".replace(re, "$<thd>")   // "cd" (non-existent name)
> "abcd".replace(/(?<fst>.)|(?<snd>.)/u, "$<snd>")  // "cd" (non-matched capture)
>
> Support is currently behind the --harmony-regexp-named-captures flag.
>
> BUG=v8:5437
>
> Review-Url: https://codereview.chromium.org/2775303002
> Cr-Commit-Position: refs/heads/master@{#44171}
> Committed: https://chromium.googlesource.com/v8/v8/+/17f13863b64b25eccf565e0aa9c4c441f0562b84

TBR=yangguo@chromium.org,littledan@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:5437

Review-Url: https://codereview.chromium.org/2776293003
Cr-Commit-Position: refs/heads/master@{#44180}

src/messages.h

@@ -456,7 +456,6 @@ class ErrorUtils : public AllStatic {
   T(ReduceNoInitial, "Reduce of empty array with no initial value")            \
   T(RegExpFlags,                                                               \
     "Cannot supply flags when constructing one RegExp from another")           \
-  T(RegExpInvalidReplaceString, "Invalid replacement string: '%'")             \
   T(RegExpNonObject, "% getter called on non-object %")                        \
   T(RegExpNonRegExp, "% getter called on non-RegExp object")                   \
   T(ReinitializeIntl, "Trying to re-initialize % object.")                     \

src/objects.cc

@@ -11403,8 +11403,6 @@ int String::IndexOf(Isolate* isolate, Handle<String> receiver,
 
 MaybeHandle<String> String::GetSubstitution(Isolate* isolate, Match* match,
                                             Handle<String> replacement) {
-  DCHECK_IMPLIES(match->HasNamedCaptures(), FLAG_harmony_regexp_named_captures);
-
   Factory* factory = isolate->factory();
 
   const int replacement_length = replacement->length();
@@ -11491,37 +11489,6 @@ MaybeHandle<String> String::GetSubstitution(Isolate* isolate, Match* match,
         continue_from_ix = peek_ix + advance;
         break;
       }
-      case '<': {  // $<name> - named capture
-        if (!match->HasNamedCaptures()) {
-          builder.AppendCharacter('$');
-          continue_from_ix = peek_ix;
-          break;
-        }
-
-        Handle<String> bracket_string =
-            factory->LookupSingleCharacterStringFromCode('>');
-        const int closing_bracket_ix =
-            String::IndexOf(isolate, replacement, bracket_string, peek_ix + 1);
-
-        if (closing_bracket_ix == -1) {
-          THROW_NEW_ERROR(
-              isolate,
-              NewSyntaxError(MessageTemplate::kRegExpInvalidReplaceString,
-                             replacement),
-              String);
-        }
-
-        Handle<String> capture_name =
-            factory->NewSubString(replacement, peek_ix + 1, closing_bracket_ix);
-        bool capture_exists;
-        Handle<String> capture;
-        ASSIGN_RETURN_ON_EXCEPTION(
-            isolate, capture,
-            match->GetNamedCapture(capture_name, &capture_exists), String);
-        if (capture_exists) builder.AppendString(capture);
-        continue_from_ix = closing_bracket_ix + 1;
-        break;
-      }
       default:
         builder.AppendCharacter('$');
         continue_from_ix = peek_ix;
@@ -11692,15 +11659,6 @@ bool String::IsUtf8EqualTo(Vector<const char> str, bool allow_prefix_match) {
   return (allow_prefix_match || i == slen) && remaining_in_str == 0;
 }
 
-template <>
-bool String::IsEqualTo(Vector<const uint8_t> str) {
-  return IsOneByteEqualTo(str);
-}
-
-template <>
-bool String::IsEqualTo(Vector<const uc16> str) {
-  return IsTwoByteEqualTo(str);
-}
 
 bool String::IsOneByteEqualTo(Vector<const uint8_t> str) {
   int slen = length();

src/objects.h

@@ -8269,7 +8269,6 @@ class JSRegExp: public JSObject {
                                           Handle<String> flags_string);
 
   inline Type TypeTag();
-  // Number of captures (without the match itself).
   inline int CaptureCount();
   inline Flags GetFlags();
   inline String* Pattern();
@@ -8342,7 +8341,7 @@ class JSRegExp: public JSObject {
   // Number of captures in the compiled regexp.
   static const int kIrregexpCaptureCountIndex = kDataIndex + 5;
   // Maps names of named capture groups (at indices 2i) to their corresponding
-  // (1-based) capture group indices (at indices 2i + 1).
+  // capture group indices (at indices 2i + 1).
   static const int kIrregexpCaptureNameMapIndex = kDataIndex + 6;
 
   static const int kIrregexpDataSize = kIrregexpCaptureNameMapIndex + 1;
@@ -9197,15 +9196,10 @@ class String: public Name {
   class Match {
    public:
     virtual Handle<String> GetMatch() = 0;
+    virtual MaybeHandle<String> GetCapture(int i, bool* capture_exists) = 0;
     virtual Handle<String> GetPrefix() = 0;
     virtual Handle<String> GetSuffix() = 0;
-
     virtual int CaptureCount() = 0;
-    virtual bool HasNamedCaptures() = 0;
-    virtual MaybeHandle<String> GetCapture(int i, bool* capture_exists) = 0;
-    virtual MaybeHandle<String> GetNamedCapture(Handle<String> name,
-                                                bool* capture_exists) = 0;
-
     virtual ~Match() {}
   };
 
@@ -9220,11 +9214,6 @@ class String: public Name {
   inline bool Equals(String* other);
   inline static bool Equals(Handle<String> one, Handle<String> two);
   bool IsUtf8EqualTo(Vector<const char> str, bool allow_prefix_match = false);
-
-  // Dispatches to Is{One,Two}ByteEqualTo.
-  template <typename Char>
-  bool IsEqualTo(Vector<const Char> str);
-
   bool IsOneByteEqualTo(Vector<const uint8_t> str);
   bool IsTwoByteEqualTo(Vector<const uc16> str);