Issue #2305 Part 3a: Pass ResultTemplateKind through CreateRegExpMatchResult

This sets up the MatchResult with the proper structure to contain indices
when necessary.

js/src/builtin/RegExp.cpp

@@ -32,7 +32,7 @@ using mozilla::Maybe;
 using CapturesVector = GCVector<Value, 4>;
 
 /*
- * ES 2021 draft 21.2.5.2.2: Steps 16-28
+ * Implements RegExpBuiltinExec: Steps 18-35
  * https://tc39.es/ecma262/#sec-regexpbuiltinexec
  */
 bool
@@ -51,10 +51,16 @@ js::CreateRegExpMatchResult(JSContext* cx, RegExpShared& re,
      *  input:          input string
      *  index:          start index for the match
      *  groups:         named capture groups for the match
+     *  indices:        capture indices for the match, if required
      */
 
+    bool hasIndices = re.hasIndices();
+    
     /* Get the templateObject that defines the shape and type of the output object */
-    JSObject* templateObject = cx->compartment()->regExps.getOrCreateMatchResultTemplateObject(cx);
+    RegExpCompartment::ResultTemplateKind kind =
+      hasIndices ? RegExpCompartment::ResultTemplateKind::WithIndices
+                 : RegExpCompartment::ResultTemplateKind::Normal;
+    JSObject* templateObject = cx->compartment()->regExps.getOrCreateMatchResultTemplateObject(cx, kind);
     if (!templateObject)
         return false;
 
@@ -818,15 +824,42 @@ js::regexp_unicode(JSContext* cx, unsigned argc, JS::Value* vp)
     return CallNonGenericMethod<IsRegExpInstanceOrPrototype, regexp_unicode_impl>(cx, args);
 }
 
+// ES 2022 22.2.5.6.
+MOZ_ALWAYS_INLINE bool
+regexp_hasIndices_impl(JSContext* cx, const CallArgs& args)
+{
+    MOZ_ASSERT(IsRegExpInstanceOrPrototype(args.thisv()));
+
+    // Step 2.a.
+    if (!IsRegExpObject(args.thisv())) {
+        args.rval().setUndefined();
+        return true;
+    }
+
+    // Steps 3-5.
+    Rooted<RegExpObject*> reObj(cx, &args.thisv().toObject().as<RegExpObject>());
+    args.rval().setBoolean(reObj->hasIndices());
+    return true;
+}
+
+bool
+js::regexp_hasIndices(JSContext* cx, unsigned argc, JS::Value* vp)
+{
+    // Steps 1-3.
+    CallArgs args = CallArgsFromVp(argc, vp);
+    return CallNonGenericMethod<IsRegExpInstanceOrPrototype, regexp_hasIndices_impl>(cx, args);
+}
+
 const JSPropertySpec js::regexp_properties[] = {
     JS_SELF_HOSTED_GET("flags", "RegExpFlagsGetter", 0),
+    JS_PSG("hasIndices", regexp_hasIndices, 0),
     JS_PSG("global", regexp_global, 0),
     JS_PSG("ignoreCase", regexp_ignoreCase, 0),
     JS_PSG("multiline", regexp_multiline, 0),
+    JS_PSG("dotAll", regexp_dotAll, 0),
     JS_PSG("source", regexp_source, 0),
     JS_PSG("sticky", regexp_sticky, 0),
     JS_PSG("unicode", regexp_unicode, 0),
-    JS_PSG("dotAll", regexp_dotAll, 0),
     JS_PS_END
 };
 
@@ -1802,6 +1835,13 @@ js::RegExpPrototypeOptimizableRaw(JSContext* cx, JSObject* proto)
     if (!IsSelfHostedFunctionWithName(flagsGetter, cx->names().RegExpFlagsGetter))
         return false;
 
+    JSNative hasIndicesGetter;
+    if (!GetOwnNativeGetterPure(cx, proto, NameToId(cx->names().hasIndices), &hasIndicesGetter))
+        return false;
+
+    if (hasIndicesGetter != regexp_hasIndices)
+        return false;
+
     JSNative globalGetter;
     if (!GetOwnNativeGetterPure(cx, proto, NameToId(cx->names().global), &globalGetter))
         return false;

js/src/builtin/RegExp.h

@@ -124,17 +124,19 @@ extern const JSFunctionSpec regexp_methods[];
 
 // Used in RegExpObject::isOriginalFlagGetter.
 [[nodiscard]] extern bool
+regexp_hasIndices(JSContext* cx, unsigned argc, JS::Value* vp);
+[[nodiscard]] extern bool
 regexp_global(JSContext* cx, unsigned argc, JS::Value* vp);
 [[nodiscard]] extern bool
 regexp_ignoreCase(JSContext* cx, unsigned argc, JS::Value* vp);
 [[nodiscard]] extern bool
 regexp_multiline(JSContext* cx, unsigned argc, JS::Value* vp);
 [[nodiscard]] extern bool
+regexp_dotAll(JSContext* cx, unsigned argc, JS::Value* vp);
+[[nodiscard]] extern bool
 regexp_sticky(JSContext* cx, unsigned argc, JS::Value* vp);
 [[nodiscard]] extern bool
 regexp_unicode(JSContext* cx, unsigned argc, JS::Value* vp);
-[[nodiscard]] extern bool
-regexp_dotAll(JSContext* cx, unsigned argc, JS::Value* vp);
 
 } /* namespace js */
 

js/src/builtin/RegExp.js

@@ -2,8 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-// ES6 draft rev34 (2015/02/20) 21.2.5.3 get RegExp.prototype.flags
-// Updated for ES2018 /s (dotAll)
+// ES2022 22.2.5.4 get RegExp.prototype.flags
 function RegExpFlagsGetter() {
     // Steps 1-2.
     var R = this;
@@ -13,31 +12,36 @@ function RegExpFlagsGetter() {
     // Step 3.
     var result = "";
 
-    // Steps 4-6.
+    // Steps 4-5.
+    if (R.hasIndices)
+        result += "d";
+    
+    // Steps 6-7.
     if (R.global)
         result += "g";
 
-    // Steps 7-9.
+    // Steps 8-9.
     if (R.ignoreCase)
         result += "i";
 
-    // Steps 10-12.
+    // Steps 10-11.
     if (R.multiline)
         result += "m";
 
-    // Steps 13-15.
-    if (R.unicode)
-         result += "u";
-
-    // Steps 16-18.
-    if (R.sticky)
-        result += "y";
-        
-    // ES2018
+    // Steps 12-13.
     if (R.dotAll)
         result += "s";
 
-    // Step 19.
+    // Steps 14-15.
+    if (R.unicode)
+         result += "u";
+
+    // Steps 16-17.
+    if (R.sticky)
+        result += "y";
+        
+
+    // Step 18.
     return result;
 }
 _SetCanonicalName(RegExpFlagsGetter, "get flags");
@@ -227,9 +231,11 @@ function RegExpGlobalMatchOpt(rx, S, fullUnicode) {
 // Checks if following properties and getters are not modified, and accessing
 // them not observed by content script:
 //   * flags
+//   * hasIndices
 //   * global
 //   * ignoreCase
 //   * multiline
+//   * dotAll
 //   * sticky
 //   * unicode
 //   * exec

js/src/builtin/SelfHostingDefines.h

@@ -85,6 +85,7 @@
 #define REGEXP_STICKY_FLAG      0x08
 #define REGEXP_UNICODE_FLAG     0x10
 #define REGEXP_DOTALL_FLAG      0x20
+#define REGEXP_HASINDICES_FLAG  0x40
 
 #define REGEXP_STRING_ITERATOR_REGEXP_SLOT 0
 #define REGEXP_STRING_ITERATOR_STRING_SLOT 1

js/src/frontend/TokenStream.cpp

@@ -2083,7 +2083,9 @@ TokenStream::getTokenInternal(TokenKind* ttp, Modifier modifier)
             while (true) {
                 if (!peekChar(&c))
                     goto error;
-                if (c == 'g' && !(reflags & GlobalFlag))
+                if (c == 'd' && !(reflags & HasIndicesFlag))
+                    reflags = RegExpFlag(reflags | HasIndicesFlag);
+                else if (c == 'g' && !(reflags & GlobalFlag))
                     reflags = RegExpFlag(reflags | GlobalFlag);
                 else if (c == 'i' && !(reflags & IgnoreCaseFlag))
                     reflags = RegExpFlag(reflags | IgnoreCaseFlag);

js/src/jsapi.h

@@ -5831,12 +5831,13 @@ JS_ObjectIsDate(JSContext* cx, JS::HandleObject obj, bool* isDate);
 /*
  * Regular Expressions.
  */
-#define JSREG_FOLD      0x01u   /* fold uppercase to lowercase */
-#define JSREG_GLOB      0x02u   /* global exec, creates array of matches */
-#define JSREG_MULTILINE 0x04u   /* treat ^ and $ as begin and end of line */
-#define JSREG_STICKY    0x08u   /* only match starting at lastIndex */
-#define JSREG_UNICODE   0x10u   /* unicode */
-#define JSREG_DOTALL    0x20u   /* match . to everything including newlines */
+#define JSREG_FOLD       0x01u   /* fold uppercase to lowercase */
+#define JSREG_GLOB       0x02u   /* global exec, creates array of matches */
+#define JSREG_MULTILINE  0x04u   /* treat ^ and $ as begin and end of line */
+#define JSREG_STICKY     0x08u   /* only match starting at lastIndex */
+#define JSREG_UNICODE    0x10u   /* unicode */
+#define JSREG_DOTALL     0x20u   /* match . to everything including newlines */
+#define JSREG_HASINDICES 0x40u   /* add .indices property to the match result */
 
 extern JS_PUBLIC_API(JSObject*)
 JS_NewRegExpObject(JSContext* cx, const char* bytes, size_t length, unsigned flags);

js/src/vm/CommonPropertyNames.h

@@ -183,6 +183,7 @@
     macro(groups, groups, "groups") \
     macro(Handle, Handle, "Handle") \
     macro(has, has, "has") \
+    macro(hasIndices, hasIndices, "hasIndices") \
     macro(hasOwn, hasOwn, "hasOwn") \
     macro(hasOwnProperty, hasOwnProperty, "hasOwnProperty") \
     macro(highWaterMark, highWaterMark, "highWaterMark") \
@@ -197,6 +198,7 @@
     macro(includes, includes, "includes") \
     macro(incumbentGlobal, incumbentGlobal, "incumbentGlobal") \
     macro(index, index, "index") \
+    macro(indices, indices, "indices") \
     macro(infinity, infinity, "infinity") \
     macro(Infinity, Infinity, "Infinity") \
     macro(InitializeCollator, InitializeCollator, "InitializeCollator") \

js/src/vm/RegExpObject.cpp

@@ -51,6 +51,7 @@ JS_STATIC_ASSERT(MultilineFlag == JSREG_MULTILINE);
 JS_STATIC_ASSERT(StickyFlag == JSREG_STICKY);
 JS_STATIC_ASSERT(UnicodeFlag == JSREG_UNICODE);
 JS_STATIC_ASSERT(DotAllFlag == JSREG_DOTALL);
+JS_STATIC_ASSERT(HasIndicesFlag == JSREG_HASINDICES);
 
 RegExpObject*
 js::RegExpAlloc(ExclusiveContext* cx, HandleObject proto /* = nullptr */)
@@ -136,6 +137,10 @@ RegExpObject::getShared(JSContext* cx, Handle<RegExpObject*> regexp,
 /* static */ bool
 RegExpObject::isOriginalFlagGetter(JSNative native, RegExpFlag* mask)
 {
+  if (native == regexp_hasIndices) {
+      *mask = HasIndicesFlag;
+      return true;
+  }
   if (native == regexp_global) {
       *mask = GlobalFlag;
       return true;
@@ -148,6 +153,10 @@ RegExpObject::isOriginalFlagGetter(JSNative native, RegExpFlag* mask)
       *mask = MultilineFlag;
       return true;
   }
+  if (native == regexp_dotAll) {
+      *mask = DotAllFlag;
+      return true;
+  }
   if (native == regexp_sticky) {
       *mask = StickyFlag;
       return true;
@@ -156,10 +165,6 @@ RegExpObject::isOriginalFlagGetter(JSNative native, RegExpFlag* mask)
       *mask = UnicodeFlag;
       return true;
   }
-  if (native == regexp_dotAll) {
-      *mask = DotAllFlag;
-      return true;
-  }
 
   return false;
 }
@@ -488,12 +493,16 @@ RegExpObject::toString(JSContext* cx) const
     sb.infallibleAppend('/');
 
     // Steps 5-7.
+    if (hasIndices() && !sb.append('d'))
+        return nullptr;
     if (global() && !sb.append('g'))
         return nullptr;
     if (ignoreCase() && !sb.append('i'))
         return nullptr;
     if (multiline() && !sb.append('m'))
         return nullptr;
+    if (dotAll() && !sb.append('s'))
+        return nullptr;
     if (unicode() && !sb.append('u'))
         return nullptr;
     if (sticky() && !sb.append('y'))
@@ -1288,10 +1297,13 @@ RegExpShared::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
 
 RegExpCompartment::RegExpCompartment(Zone* zone)
   : set_(zone, Set(zone->runtimeFromMainThread())),
-    matchResultTemplateObject_(nullptr),
     optimizableRegExpPrototypeShape_(nullptr),
     optimizableRegExpInstanceShape_(nullptr)
-{}
+{
+  for (auto& templateObj : matchResultTemplateObjects_) {
+    templateObj = nullptr;
+  }
+}
 
 RegExpCompartment::~RegExpCompartment()
 {
@@ -1299,29 +1311,41 @@ RegExpCompartment::~RegExpCompartment()
 }
 
 ArrayObject*
-RegExpCompartment::createMatchResultTemplateObject(JSContext* cx)
+RegExpCompartment::createMatchResultTemplateObject(JSContext* cx, ResultTemplateKind kind)
 {
-    MOZ_ASSERT(!matchResultTemplateObject_);
+    MOZ_ASSERT(!matchResultTemplateObjects_[kind]);
 
     /* Create template array object */
     RootedArrayObject templateObject(cx, NewDenseUnallocatedArray(cx, RegExpObject::MaxPairCount,
                                                                   nullptr, TenuredObject));
-    if (!templateObject)
-        return matchResultTemplateObject_; // = nullptr
+    if (!templateObject) {
+        return nullptr;
+    }
 
     // Create a new group for the template.
     Rooted<TaggedProto> proto(cx, templateObject->taggedProto());
     ObjectGroup* group = ObjectGroupCompartment::makeGroup(cx, templateObject->getClass(), proto);
     if (!group)
-        return matchResultTemplateObject_; // = nullptr
+        return nullptr;
     templateObject->setGroup(group);
 
+    if (kind == ResultTemplateKind::Indices) {
+      /* The |indices| array only has a |groups| property. */
+      RootedValue groupsVal(cx, UndefinedValue());
+      if (!NativeDefineProperty(cx, templateObject, cx->names().groups,
+                                    groupsVal, nullptr, nullptr, JSPROP_ENUMERATE)) {
+        return nullptr;
+      }
+      matchResultTemplateObjects_[kind].set(templateObject);
+      return matchResultTemplateObjects_[kind];
+    }
+
     /* Set dummy index property */
     RootedValue index(cx, Int32Value(0));
     if (!NativeDefineProperty(cx, templateObject, cx->names().index, index, nullptr, nullptr,
                               JSPROP_ENUMERATE))
     {
-        return matchResultTemplateObject_; // = nullptr
+        return nullptr;
     }
 
     /* Set dummy input property */
@@ -1329,7 +1353,7 @@ RegExpCompartment::createMatchResultTemplateObject(JSContext* cx)
     if (!NativeDefineProperty(cx, templateObject, cx->names().input, inputVal, nullptr, nullptr,
                               JSPROP_ENUMERATE))
     {
-        return matchResultTemplateObject_; // = nullptr
+        return nullptr;
     }
 
     /* Set dummy groups property */
@@ -1339,14 +1363,14 @@ RegExpCompartment::createMatchResultTemplateObject(JSContext* cx)
         return nullptr;
     }
 
-    // Make sure that the properties are in the right slots.
-    DebugOnly<Shape*> shape = templateObject->lastProperty();
-    MOZ_ASSERT(shape->slot() == 2 &&
-               shape->propidRef() == NameToId(cx->names().groups));
-    MOZ_ASSERT(shape->previous()->slot() == 1 &&
-               shape->previous()->propidRef() == NameToId(cx->names().input));
-    MOZ_ASSERT(shape->previous()->previous()->slot() == 0 &&
-               shape->previous()->previous()->propidRef() == NameToId(cx->names().index));
+    if (kind == ResultTemplateKind::WithIndices) {
+      /* Set dummy indices property */
+      RootedValue indicesVal(cx, UndefinedValue());
+      if (!NativeDefineProperty(cx, templateObject, cx->names().indices,
+                                    indicesVal, nullptr, nullptr, JSPROP_ENUMERATE)) {
+        return nullptr;
+      }
+    }
 
     // Make sure type information reflects the indexed properties which might
     // be added.
@@ -1354,9 +1378,9 @@ RegExpCompartment::createMatchResultTemplateObject(JSContext* cx)
     AddTypePropertyId(cx, templateObject, JSID_VOID, TypeSet::UndefinedType());
     AddTypePropertyId(cx, templateObject, NameToId(cx->names().groups), TypeSet::AnyObjectType());
 
-    matchResultTemplateObject_.set(templateObject);
+    matchResultTemplateObjects_[kind].set(templateObject);
 
-    return matchResultTemplateObject_;
+    return matchResultTemplateObjects_[kind];
 }
 
 bool
@@ -1374,10 +1398,10 @@ RegExpCompartment::init(JSContext* cx)
 void
 RegExpCompartment::sweep(JSRuntime* rt)
 {
-    if (matchResultTemplateObject_ &&
-        IsAboutToBeFinalized(&matchResultTemplateObject_))
-    {
-        matchResultTemplateObject_.set(nullptr);
+    for (auto& templateObject : matchResultTemplateObjects_) {
+      if (templateObject && IsAboutToBeFinalized(&templateObject)) {
+        templateObject.set(nullptr);
+      }
     }
 
     if (optimizableRegExpPrototypeShape_ &&
@@ -1483,14 +1507,18 @@ ParseRegExpFlags(const CharT* chars, size_t length, RegExpFlag* flagsOut, char16
     for (size_t i = 0; i < length; i++) {
         *lastParsedOut = chars[i];
         switch (chars[i]) {
-          case 'i':
-            if (!HandleRegExpFlag(IgnoreCaseFlag, flagsOut))
+          case 'd':
+            if (!HandleRegExpFlag(HasIndicesFlag, flagsOut))
                 return false;
             break;
           case 'g':
             if (!HandleRegExpFlag(GlobalFlag, flagsOut))
                 return false;
             break;
+          case 'i':
+            if (!HandleRegExpFlag(IgnoreCaseFlag, flagsOut))
+                return false;
+            break;
           case 'm':
             if (!HandleRegExpFlag(MultilineFlag, flagsOut))
                 return false;

js/src/vm/RegExpObject.h

@@ -56,6 +56,7 @@ enum RegExpFlag : uint8_t
     StickyFlag      = 0x08,
     UnicodeFlag     = 0x10,
     DotAllFlag      = 0x20,
+    HasIndicesFlag  = 0x40,
 
     NoFlags         = 0x00,
     AllFlags        = 0x3f
@@ -66,7 +67,8 @@ static_assert(IgnoreCaseFlag == REGEXP_IGNORECASE_FLAG &&
               MultilineFlag == REGEXP_MULTILINE_FLAG &&
               StickyFlag == REGEXP_STICKY_FLAG &&
               UnicodeFlag == REGEXP_UNICODE_FLAG &&
-              DotAllFlag == REGEXP_DOTALL_FLAG,
+              DotAllFlag == REGEXP_DOTALL_FLAG &&
+              HasIndicesFlag == REGEXP_HASINDICES_FLAG,
               "Flag values should be in sync with self-hosted JS");
 
 enum RegExpRunStatus
@@ -206,12 +208,13 @@ class RegExpShared : public gc::TenuredCell
 
     JSAtom* getSource() const           { return source; }
     RegExpFlag getFlags() const         { return flags; }
-    bool ignoreCase() const             { return flags & IgnoreCaseFlag; }
+    bool hasIndices() const             { return flags & HasIndicesFlag; }
     bool global() const                 { return flags & GlobalFlag; }
+    bool ignoreCase() const             { return flags & IgnoreCaseFlag; }
     bool multiline() const              { return flags & MultilineFlag; }
-    bool sticky() const                 { return flags & StickyFlag; }
-    bool unicode() const                { return flags & UnicodeFlag; }
     bool dotAll() const                 { return flags & DotAllFlag; }
+    bool unicode() const                { return flags & UnicodeFlag; }
+    bool sticky() const                 { return flags & StickyFlag; }
 
     bool isCompiled(CompilationMode mode, bool latin1,
                     ForceByteCodeEnum force = DontForceByteCode) const {
@@ -295,12 +298,27 @@ class RegExpCompartment
     using Set = GCHashSet<ReadBarriered<RegExpShared*>, Key, RuntimeAllocPolicy>;
     JS::WeakCache<Set> set_;
 
+public:
+    enum ResultTemplateKind { Normal, WithIndices, Indices, NumKinds };
+
+private:
     /*
-     * This is the template object where the result of re.exec() is based on,
-     * if there is a result. This is used in CreateRegExpMatchResult to set
-     * the input/index properties faster.
+     * The template objects that the result of re.exec() is based on, if
+     * there is a result. These are used in CreateRegExpMatchResult.
+     * There are three template objects, each of which is an ArrayObject
+     * with some additional properties. We decide which to use based on
+     * the |hasIndices| (/d) flag.
+     *
+     *  Normal: Has |index|, |input|, and |groups| properties.
+     *          Used for the result object if |hasIndices| is not set.
+     *
+     *  WithIndices: Has |index|, |input|, |groups|, and |indices| properties.
+     *               Used for the result object if |hasIndices| is set.
+     *
+     *  Indices: Has a |groups| property. If |hasIndices| is set, used
+     *           for the |.indices| property of the result object.
      */
-    ReadBarriered<ArrayObject*> matchResultTemplateObject_;
+    ReadBarriered<ArrayObject*> matchResultTemplateObjects_[ResultTemplateKind::NumKinds];
 
     /*
      * The shape of RegExp.prototype object that satisfies following:
@@ -323,7 +341,7 @@ class RegExpCompartment
      */
     ReadBarriered<Shape*> optimizableRegExpInstanceShape_;
 
-    ArrayObject* createMatchResultTemplateObject(JSContext* cx);
+    ArrayObject* createMatchResultTemplateObject(JSContext* cx, ResultTemplateKind kind);
 
   public:
     explicit RegExpCompartment(Zone* zone);
@@ -341,10 +359,10 @@ class RegExpCompartment
              MutableHandleRegExpShared shared);
 
     /* Get or create template object used to base the result of .exec() on. */
-    ArrayObject* getOrCreateMatchResultTemplateObject(JSContext* cx) {
-        if (matchResultTemplateObject_)
-            return matchResultTemplateObject_;
-        return createMatchResultTemplateObject(cx);
+    ArrayObject* getOrCreateMatchResultTemplateObject(JSContext* cx, ResultTemplateKind kind = ResultTemplateKind::Normal) {
+        if (matchResultTemplateObjects_[kind])
+            return matchResultTemplateObjects_[kind];
+        return createMatchResultTemplateObject(cx, kind);
     }
 
     Shape* getOptimizableRegExpPrototypeShape() {
@@ -451,12 +469,13 @@ class RegExpObject : public NativeObject
         setSlot(FLAGS_SLOT, Int32Value(flags));
     }
 
-    bool ignoreCase() const { return getFlags() & IgnoreCaseFlag; }
+    bool hasIndices() const { return getFlags() & HasIndicesFlag; }
     bool global() const     { return getFlags() & GlobalFlag; }
+    bool ignoreCase() const { return getFlags() & IgnoreCaseFlag; }
     bool multiline() const  { return getFlags() & MultilineFlag; }
-    bool sticky() const     { return getFlags() & StickyFlag; }
-    bool unicode() const    { return getFlags() & UnicodeFlag; }
     bool dotAll() const     { return getFlags() & DotAllFlag; }
+    bool unicode() const    { return getFlags() & UnicodeFlag; }
+    bool sticky() const     { return getFlags() & StickyFlag; }
 
     static bool isOriginalFlagGetter(JSNative native, RegExpFlag* mask);