Add m-esr52 at 52.6.0

1 files changed, 1555 insertions, 0 deletions

diff --git a/js/src/vm/RegExpObject.cpp b/js/src/vm/RegExpObject.cpp
new file mode 100644
index 000000000..97f1163aa
--- /dev/null
+++ b/js/src/vm/RegExpObject.cpp
@@ -0,0 +1,1555 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * 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/. */
+
+#include "vm/RegExpObject.h"
+
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/PodOperations.h"
+
+#include "jsstr.h"
+#ifdef DEBUG
+#include "jsutil.h"
+#endif
+
+#include "builtin/RegExp.h"
+#include "frontend/TokenStream.h"
+#ifdef DEBUG
+#include "irregexp/RegExpBytecode.h"
+#endif
+#include "irregexp/RegExpParser.h"
+#include "vm/MatchPairs.h"
+#include "vm/RegExpStatics.h"
+#include "vm/StringBuffer.h"
+#include "vm/TraceLogging.h"
+#ifdef DEBUG
+#include "vm/Unicode.h"
+#endif
+#include "vm/Xdr.h"
+
+#include "jsobjinlines.h"
+
+#include "vm/NativeObject-inl.h"
+#include "vm/Shape-inl.h"
+
+using namespace js;
+
+using mozilla::ArrayLength;
+using mozilla::DebugOnly;
+using mozilla::Maybe;
+using mozilla::PodCopy;
+using js::frontend::TokenStream;
+
+using JS::AutoCheckCannotGC;
+
+JS_STATIC_ASSERT(IgnoreCaseFlag == JSREG_FOLD);
+JS_STATIC_ASSERT(GlobalFlag == JSREG_GLOB);
+JS_STATIC_ASSERT(MultilineFlag == JSREG_MULTILINE);
+JS_STATIC_ASSERT(StickyFlag == JSREG_STICKY);
+JS_STATIC_ASSERT(UnicodeFlag == JSREG_UNICODE);
+
+RegExpObject*
+js::RegExpAlloc(ExclusiveContext* cx, HandleObject proto /* = nullptr */)
+{
+    // Note: RegExp objects are always allocated in the tenured heap. This is
+    // not strictly required, but simplifies embedding them in jitcode.
+    Rooted<RegExpObject*> regexp(cx);
+
+    regexp = NewObjectWithClassProto<RegExpObject>(cx, proto, TenuredObject);
+    if (!regexp)
+        return nullptr;
+
+    regexp->initPrivate(nullptr);
+
+    if (!EmptyShape::ensureInitialCustomShape<RegExpObject>(cx, regexp))
+        return nullptr;
+
+    MOZ_ASSERT(regexp->lookupPure(cx->names().lastIndex)->slot() ==
+               RegExpObject::lastIndexSlot());
+
+    return regexp;
+}
+
+/* MatchPairs */
+
+bool
+MatchPairs::initArrayFrom(MatchPairs& copyFrom)
+{
+    MOZ_ASSERT(copyFrom.pairCount() > 0);
+
+    if (!allocOrExpandArray(copyFrom.pairCount()))
+        return false;
+
+    PodCopy(pairs_, copyFrom.pairs_, pairCount_);
+
+    return true;
+}
+
+bool
+ScopedMatchPairs::allocOrExpandArray(size_t pairCount)
+{
+    /* Array expansion is forbidden, but array reuse is acceptable. */
+    if (pairCount_) {
+        MOZ_ASSERT(pairs_);
+        MOZ_ASSERT(pairCount_ == pairCount);
+        return true;
+    }
+
+    MOZ_ASSERT(!pairs_);
+    pairs_ = (MatchPair*)lifoScope_.alloc().alloc(sizeof(MatchPair) * pairCount);
+    if (!pairs_)
+        return false;
+
+    pairCount_ = pairCount;
+    return true;
+}
+
+bool
+VectorMatchPairs::allocOrExpandArray(size_t pairCount)
+{
+    if (!vec_.resizeUninitialized(sizeof(MatchPair) * pairCount))
+        return false;
+
+    pairs_ = &vec_[0];
+    pairCount_ = pairCount;
+    return true;
+}
+
+/* RegExpObject */
+
+static inline void
+RegExpSharedReadBarrier(JSContext* cx, RegExpShared* shared)
+{
+    Zone* zone = cx->zone();
+    if (zone->needsIncrementalBarrier())
+        shared->trace(zone->barrierTracer());
+    if (shared->isMarkedGray())
+        shared->unmarkGray();
+}
+
+bool
+RegExpObject::getShared(JSContext* cx, RegExpGuard* g)
+{
+    if (RegExpShared* shared = maybeShared()) {
+        // Fetching a RegExpShared from an object requires a read
+        // barrier, as the shared pointer might be weak.
+        RegExpSharedReadBarrier(cx, shared);
+
+        g->init(*shared);
+        return true;
+    }
+
+    return createShared(cx, g);
+}
+
+/* static */ bool
+RegExpObject::isOriginalFlagGetter(JSNative native, RegExpFlag* mask)
+{
+  if (native == regexp_global) {
+      *mask = GlobalFlag;
+      return true;
+  }
+  if (native == regexp_ignoreCase) {
+      *mask = IgnoreCaseFlag;
+      return true;
+  }
+  if (native == regexp_multiline) {
+      *mask = MultilineFlag;
+      return true;
+  }
+  if (native == regexp_sticky) {
+      *mask = StickyFlag;
+      return true;
+  }
+  if (native == regexp_unicode) {
+      *mask = UnicodeFlag;
+      return true;
+  }
+
+  return false;
+}
+
+/* static */ void
+RegExpObject::trace(JSTracer* trc, JSObject* obj)
+{
+    RegExpShared* shared = obj->as<RegExpObject>().maybeShared();
+    if (!shared)
+        return;
+
+    // When tracing through the object normally, we have the option of
+    // unlinking the object from its RegExpShared so that the RegExpShared may
+    // be collected. To detect this we need to test all the following
+    // conditions, since:
+    //   1. During TraceRuntime, isHeapBusy() is true, but the tracer might not
+    //      be a marking tracer.
+    //   2. When a write barrier executes, IsMarkingTracer is true, but
+    //      isHeapBusy() will be false.
+    if (trc->runtime()->isHeapCollecting() &&
+        trc->isMarkingTracer() &&
+        !obj->asTenured().zone()->isPreservingCode())
+    {
+        obj->as<RegExpObject>().NativeObject::setPrivate(nullptr);
+    } else {
+        shared->trace(trc);
+    }
+}
+
+static const ClassOps RegExpObjectClassOps = {
+    nullptr, /* addProperty */
+    nullptr, /* delProperty */
+    nullptr, /* getProperty */
+    nullptr, /* setProperty */
+    nullptr, /* enumerate */
+    nullptr, /* resolve */
+    nullptr, /* mayResolve */
+    nullptr, /* finalize */
+    nullptr, /* call */
+    nullptr, /* hasInstance */
+    nullptr, /* construct */
+    RegExpObject::trace,
+};
+
+static const ClassSpec RegExpObjectClassSpec = {
+    GenericCreateConstructor<js::regexp_construct, 2, gc::AllocKind::FUNCTION>,
+    CreateRegExpPrototype,
+    nullptr,
+    js::regexp_static_props,
+    js::regexp_methods,
+    js::regexp_properties
+};
+
+const Class RegExpObject::class_ = {
+    js_RegExp_str,
+    JSCLASS_HAS_PRIVATE |
+    JSCLASS_HAS_RESERVED_SLOTS(RegExpObject::RESERVED_SLOTS) |
+    JSCLASS_HAS_CACHED_PROTO(JSProto_RegExp),
+    &RegExpObjectClassOps,
+    &RegExpObjectClassSpec
+};
+
+RegExpObject*
+RegExpObject::create(ExclusiveContext* cx, const char16_t* chars, size_t length, RegExpFlag flags,
+                     TokenStream* tokenStream, LifoAlloc& alloc)
+{
+    RootedAtom source(cx, AtomizeChars(cx, chars, length));
+    if (!source)
+        return nullptr;
+
+    return create(cx, source, flags, tokenStream, alloc);
+}
+
+RegExpObject*
+RegExpObject::create(ExclusiveContext* cx, HandleAtom source, RegExpFlag flags,
+                     TokenStream* tokenStream, LifoAlloc& alloc)
+{
+    Maybe<CompileOptions> dummyOptions;
+    Maybe<TokenStream> dummyTokenStream;
+    if (!tokenStream) {
+        dummyOptions.emplace(cx->asJSContext());
+        dummyTokenStream.emplace(cx, *dummyOptions,
+                                   (const char16_t*) nullptr, 0,
+                                   (frontend::StrictModeGetter*) nullptr);
+        tokenStream = dummyTokenStream.ptr();
+    }
+
+    if (!irregexp::ParsePatternSyntax(*tokenStream, alloc, source, flags & UnicodeFlag))
+        return nullptr;
+
+    Rooted<RegExpObject*> regexp(cx, RegExpAlloc(cx));
+    if (!regexp)
+        return nullptr;
+
+    regexp->initAndZeroLastIndex(source, flags, cx);
+
+    return regexp;
+}
+
+bool
+RegExpObject::createShared(JSContext* cx, RegExpGuard* g)
+{
+    Rooted<RegExpObject*> self(cx, this);
+
+    MOZ_ASSERT(!maybeShared());
+    if (!cx->compartment()->regExps.get(cx, getSource(), getFlags(), g))
+        return false;
+
+    self->setShared(**g);
+    return true;
+}
+
+Shape*
+RegExpObject::assignInitialShape(ExclusiveContext* cx, Handle<RegExpObject*> self)
+{
+    MOZ_ASSERT(self->empty());
+
+    JS_STATIC_ASSERT(LAST_INDEX_SLOT == 0);
+
+    /* The lastIndex property alone is writable but non-configurable. */
+    return self->addDataProperty(cx, cx->names().lastIndex, LAST_INDEX_SLOT, JSPROP_PERMANENT);
+}
+
+void
+RegExpObject::initIgnoringLastIndex(HandleAtom source, RegExpFlag flags)
+{
+    // If this is a re-initialization with an existing RegExpShared, 'flags'
+    // may not match getShared()->flags, so forget the RegExpShared.
+    NativeObject::setPrivate(nullptr);
+
+    setSource(source);
+    setFlags(flags);
+}
+
+void
+RegExpObject::initAndZeroLastIndex(HandleAtom source, RegExpFlag flags, ExclusiveContext* cx)
+{
+    initIgnoringLastIndex(source, flags);
+    zeroLastIndex(cx);
+}
+
+static MOZ_ALWAYS_INLINE bool
+IsLineTerminator(const JS::Latin1Char c)
+{
+    return c == '\n' || c == '\r';
+}
+
+static MOZ_ALWAYS_INLINE bool
+IsLineTerminator(const char16_t c)
+{
+    return c == '\n' || c == '\r' || c == 0x2028 || c == 0x2029;
+}
+
+static MOZ_ALWAYS_INLINE bool
+AppendEscapedLineTerminator(StringBuffer& sb, const JS::Latin1Char c)
+{
+    switch (c) {
+      case '\n':
+        if (!sb.append('n'))
+            return false;
+        break;
+      case '\r':
+        if (!sb.append('r'))
+            return false;
+        break;
+      default:
+        MOZ_CRASH("Bad LineTerminator");
+    }
+    return true;
+}
+
+static MOZ_ALWAYS_INLINE bool
+AppendEscapedLineTerminator(StringBuffer& sb, const char16_t c)
+{
+    switch (c) {
+      case '\n':
+        if (!sb.append('n'))
+            return false;
+        break;
+      case '\r':
+        if (!sb.append('r'))
+            return false;
+        break;
+      case 0x2028:
+        if (!sb.append("u2028"))
+            return false;
+        break;
+      case 0x2029:
+        if (!sb.append("u2029"))
+            return false;
+        break;
+      default:
+        MOZ_CRASH("Bad LineTerminator");
+    }
+    return true;
+}
+
+template <typename CharT>
+static MOZ_ALWAYS_INLINE bool
+SetupBuffer(StringBuffer& sb, const CharT* oldChars, size_t oldLen, const CharT* it)
+{
+    if (mozilla::IsSame<CharT, char16_t>::value && !sb.ensureTwoByteChars())
+        return false;
+
+    if (!sb.reserve(oldLen + 1))
+        return false;
+
+    sb.infallibleAppend(oldChars, size_t(it - oldChars));
+    return true;
+}
+
+// Note: leaves the string buffer empty if no escaping need be performed.
+template <typename CharT>
+static bool
+EscapeRegExpPattern(StringBuffer& sb, const CharT* oldChars, size_t oldLen)
+{
+    bool inBrackets = false;
+    bool previousCharacterWasBackslash = false;
+
+    for (const CharT* it = oldChars; it < oldChars + oldLen; ++it) {
+        CharT ch = *it;
+        if (!previousCharacterWasBackslash) {
+            if (inBrackets) {
+                if (ch == ']')
+                    inBrackets = false;
+            } else if (ch == '/') {
+                // There's a forward slash that needs escaping.
+                if (sb.empty()) {
+                    // This is the first char we've seen that needs escaping,
+                    // copy everything up to this point.
+                    if (!SetupBuffer(sb, oldChars, oldLen, it))
+                        return false;
+                }
+                if (!sb.append('\\'))
+                    return false;
+            } else if (ch == '[') {
+                inBrackets = true;
+            }
+        }
+
+        if (IsLineTerminator(ch)) {
+            // There's LineTerminator that needs escaping.
+            if (sb.empty()) {
+                // This is the first char we've seen that needs escaping,
+                // copy everything up to this point.
+                if (!SetupBuffer(sb, oldChars, oldLen, it))
+                    return false;
+            }
+            if (!previousCharacterWasBackslash) {
+                if (!sb.append('\\'))
+                    return false;
+            }
+            if (!AppendEscapedLineTerminator(sb, ch))
+                return false;
+        } else if (!sb.empty()) {
+            if (!sb.append(ch))
+                return false;
+        }
+
+        if (previousCharacterWasBackslash)
+            previousCharacterWasBackslash = false;
+        else if (ch == '\\')
+            previousCharacterWasBackslash = true;
+    }
+
+    return true;
+}
+
+// ES6 draft rev32 21.2.3.2.4.
+JSAtom*
+js::EscapeRegExpPattern(JSContext* cx, HandleAtom src)
+{
+    // Step 2.
+    if (src->length() == 0)
+        return cx->names().emptyRegExp;
+
+    // We may never need to use |sb|. Start using it lazily.
+    StringBuffer sb(cx);
+
+    if (src->hasLatin1Chars()) {
+        JS::AutoCheckCannotGC nogc;
+        if (!::EscapeRegExpPattern(sb, src->latin1Chars(nogc), src->length()))
+            return nullptr;
+    } else {
+        JS::AutoCheckCannotGC nogc;
+        if (!::EscapeRegExpPattern(sb, src->twoByteChars(nogc), src->length()))
+            return nullptr;
+    }
+
+    // Step 3.
+    return sb.empty() ? src : sb.finishAtom();
+}
+
+// ES6 draft rev32 21.2.5.14. Optimized for RegExpObject.
+JSFlatString*
+RegExpObject::toString(JSContext* cx) const
+{
+    // Steps 3-4.
+    RootedAtom src(cx, getSource());
+    if (!src)
+        return nullptr;
+    RootedAtom escapedSrc(cx, EscapeRegExpPattern(cx, src));
+
+    // Step 7.
+    StringBuffer sb(cx);
+    size_t len = escapedSrc->length();
+    if (!sb.reserve(len + 2))
+        return nullptr;
+    sb.infallibleAppend('/');
+    if (!sb.append(escapedSrc))
+        return nullptr;
+    sb.infallibleAppend('/');
+
+    // Steps 5-7.
+    if (global() && !sb.append('g'))
+        return nullptr;
+    if (ignoreCase() && !sb.append('i'))
+        return nullptr;
+    if (multiline() && !sb.append('m'))
+        return nullptr;
+    if (unicode() && !sb.append('u'))
+        return nullptr;
+    if (sticky() && !sb.append('y'))
+        return nullptr;
+
+    return sb.finishString();
+}
+
+#ifdef DEBUG
+bool
+RegExpShared::dumpBytecode(JSContext* cx, bool match_only, HandleLinearString input)
+{
+    CompilationMode mode = match_only ? MatchOnly : Normal;
+    if (!compileIfNecessary(cx, input, mode, ForceByteCode))
+        return false;
+
+    const uint8_t* byteCode = compilation(mode, input->hasLatin1Chars()).byteCode;
+    const uint8_t* pc = byteCode;
+
+    auto Load32Aligned = [](const uint8_t* pc) -> int32_t {
+        MOZ_ASSERT((reinterpret_cast<uintptr_t>(pc) & 3) == 0);
+        return *reinterpret_cast<const int32_t*>(pc);
+    };
+
+    auto Load16Aligned = [](const uint8_t* pc) -> int32_t {
+        MOZ_ASSERT((reinterpret_cast<uintptr_t>(pc) & 1) == 0);
+        return *reinterpret_cast<const uint16_t*>(pc);
+    };
+
+    int32_t numRegisters = Load32Aligned(pc);
+    fprintf(stderr, "numRegisters: %d\n", numRegisters);
+    pc += 4;
+
+    fprintf(stderr, "loc     op\n");
+    fprintf(stderr, "-----   --\n");
+
+    auto DumpLower = [](const char* text) {
+        while (*text) {
+            fprintf(stderr, "%c", unicode::ToLowerCase(*text));
+            text++;
+        }
+    };
+
+#define BYTECODE(NAME) \
+    case irregexp::BC_##NAME: \
+      DumpLower(#NAME);
+#define ADVANCE(NAME) \
+    fprintf(stderr, "\n"); \
+    pc += irregexp::BC_##NAME##_LENGTH; \
+    maxPc = js::Max(maxPc, pc); \
+    break;
+#define STOP(NAME) \
+    fprintf(stderr, "\n"); \
+    pc += irregexp::BC_##NAME##_LENGTH; \
+    break;
+#define JUMP(NAME, OFFSET) \
+    fprintf(stderr, "\n"); \
+    maxPc = js::Max(maxPc, byteCode + OFFSET); \
+    pc += irregexp::BC_##NAME##_LENGTH; \
+    break;
+#define BRANCH(NAME, OFFSET) \
+    fprintf(stderr, "\n"); \
+    pc += irregexp::BC_##NAME##_LENGTH; \
+    maxPc = js::Max(maxPc, js::Max(pc, byteCode + OFFSET)); \
+    break;
+
+    // Bytecode has no end marker, we need to calculate the bytecode length by
+    // tracing jumps and branches.
+    const uint8_t* maxPc = pc;
+    while (pc <= maxPc) {
+        fprintf(stderr, "%05d:  ", int32_t(pc - byteCode));
+        int32_t insn = Load32Aligned(pc);
+        switch (insn & irregexp::BYTECODE_MASK) {
+          BYTECODE(BREAK) {
+            STOP(BREAK);
+          }
+          BYTECODE(PUSH_CP) {
+            ADVANCE(PUSH_CP);
+          }
+          BYTECODE(PUSH_BT) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d",
+                    offset);
+            // Pushed value is used by POP_BT for jumping.
+            // Resolve maxPc here.
+            BRANCH(PUSH_BT, offset);
+          }
+          BYTECODE(PUSH_REGISTER) {
+            fprintf(stderr, " reg[%d]",
+                    insn >> irregexp::BYTECODE_SHIFT);
+            ADVANCE(PUSH_REGISTER);
+          }
+          BYTECODE(SET_REGISTER) {
+            fprintf(stderr, " reg[%d], %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    Load32Aligned(pc + 4));
+            ADVANCE(SET_REGISTER);
+          }
+          BYTECODE(ADVANCE_REGISTER) {
+            fprintf(stderr, " reg[%d], %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    Load32Aligned(pc + 4));
+            ADVANCE(ADVANCE_REGISTER);
+          }
+          BYTECODE(SET_REGISTER_TO_CP) {
+            fprintf(stderr, " reg[%d], %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    Load32Aligned(pc + 4));
+            ADVANCE(SET_REGISTER_TO_CP);
+          }
+          BYTECODE(SET_CP_TO_REGISTER) {
+            fprintf(stderr, " reg[%d]",
+                    insn >> irregexp::BYTECODE_SHIFT);
+            ADVANCE(SET_CP_TO_REGISTER);
+          }
+          BYTECODE(SET_REGISTER_TO_SP) {
+            fprintf(stderr, " reg[%d]",
+                    insn >> irregexp::BYTECODE_SHIFT);
+            ADVANCE(SET_REGISTER_TO_SP);
+          }
+          BYTECODE(SET_SP_TO_REGISTER) {
+            fprintf(stderr, " reg[%d]",
+                    insn >> irregexp::BYTECODE_SHIFT);
+            ADVANCE(SET_SP_TO_REGISTER);
+          }
+          BYTECODE(POP_CP) {
+            ADVANCE(POP_CP);
+          }
+          BYTECODE(POP_BT) {
+            // Jump is already resolved in PUSH_BT.
+            STOP(POP_BT);
+          }
+          BYTECODE(POP_REGISTER) {
+            fprintf(stderr, " reg[%d]",
+                    insn >> irregexp::BYTECODE_SHIFT);
+            ADVANCE(POP_REGISTER);
+          }
+          BYTECODE(FAIL) {
+            ADVANCE(FAIL);
+          }
+          BYTECODE(SUCCEED) {
+            ADVANCE(SUCCEED);
+          }
+          BYTECODE(ADVANCE_CP) {
+            fprintf(stderr, " %d",
+                    insn >> irregexp::BYTECODE_SHIFT);
+            ADVANCE(ADVANCE_CP);
+          }
+          BYTECODE(GOTO) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d",
+                    offset);
+            JUMP(GOTO, offset);
+          }
+          BYTECODE(ADVANCE_CP_AND_GOTO) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            JUMP(ADVANCE_CP_AND_GOTO, offset);
+          }
+          BYTECODE(CHECK_GREEDY) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d",
+                    offset);
+            BRANCH(CHECK_GREEDY, offset);
+          }
+          BYTECODE(LOAD_CURRENT_CHAR) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(LOAD_CURRENT_CHAR, offset);
+          }
+          BYTECODE(LOAD_CURRENT_CHAR_UNCHECKED) {
+            fprintf(stderr, " %d",
+                    insn >> irregexp::BYTECODE_SHIFT);
+            ADVANCE(LOAD_CURRENT_CHAR_UNCHECKED);
+          }
+          BYTECODE(LOAD_2_CURRENT_CHARS) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(LOAD_2_CURRENT_CHARS, offset);
+          }
+          BYTECODE(LOAD_2_CURRENT_CHARS_UNCHECKED) {
+            fprintf(stderr, " %d",
+                    insn >> irregexp::BYTECODE_SHIFT);
+            ADVANCE(LOAD_2_CURRENT_CHARS_UNCHECKED);
+          }
+          BYTECODE(LOAD_4_CURRENT_CHARS) {
+            ADVANCE(LOAD_4_CURRENT_CHARS);
+          }
+          BYTECODE(LOAD_4_CURRENT_CHARS_UNCHECKED) {
+            ADVANCE(LOAD_4_CURRENT_CHARS_UNCHECKED);
+          }
+          BYTECODE(CHECK_4_CHARS) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " %d, %d",
+                    Load32Aligned(pc + 4),
+                    offset);
+            BRANCH(CHECK_4_CHARS, offset);
+          }
+          BYTECODE(CHECK_CHAR) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(CHECK_CHAR, offset);
+          }
+          BYTECODE(CHECK_NOT_4_CHARS) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " %d, %d",
+                    Load32Aligned(pc + 4),
+                    offset);
+            BRANCH(CHECK_NOT_4_CHARS, offset);
+          }
+          BYTECODE(CHECK_NOT_CHAR) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(CHECK_NOT_CHAR, offset);
+          }
+          BYTECODE(AND_CHECK_4_CHARS) {
+            int32_t offset = Load32Aligned(pc + 12);
+            fprintf(stderr, " %d, %d, %d",
+                    Load32Aligned(pc + 4),
+                    Load32Aligned(pc + 8),
+                    offset);
+            BRANCH(AND_CHECK_4_CHARS, offset);
+          }
+          BYTECODE(AND_CHECK_CHAR) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " %d, %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    Load32Aligned(pc + 4),
+                    offset);
+            BRANCH(AND_CHECK_CHAR, offset);
+          }
+          BYTECODE(AND_CHECK_NOT_4_CHARS) {
+            int32_t offset = Load32Aligned(pc + 12);
+            fprintf(stderr, " %d, %d, %d",
+                    Load32Aligned(pc + 4),
+                    Load32Aligned(pc + 8),
+                    offset);
+            BRANCH(AND_CHECK_NOT_4_CHARS, offset);
+          }
+          BYTECODE(AND_CHECK_NOT_CHAR) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " %d, %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    Load32Aligned(pc + 4),
+                    offset);
+            BRANCH(AND_CHECK_NOT_CHAR, offset);
+          }
+          BYTECODE(MINUS_AND_CHECK_NOT_CHAR) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " %d, %d, %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    Load16Aligned(pc + 4),
+                    Load16Aligned(pc + 6),
+                    offset);
+            BRANCH(MINUS_AND_CHECK_NOT_CHAR, offset);
+          }
+          BYTECODE(CHECK_CHAR_IN_RANGE) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " %d, %d, %d",
+                    Load16Aligned(pc + 4),
+                    Load16Aligned(pc + 6),
+                    offset);
+            BRANCH(CHECK_CHAR_IN_RANGE, offset);
+          }
+          BYTECODE(CHECK_CHAR_NOT_IN_RANGE) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " %d, %d, %d",
+                    Load16Aligned(pc + 4),
+                    Load16Aligned(pc + 6),
+                    offset);
+            BRANCH(CHECK_CHAR_NOT_IN_RANGE, offset);
+          }
+          BYTECODE(CHECK_BIT_IN_TABLE) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d, "
+                    "%02x %02x %02x %02x %02x %02x %02x %02x "
+                    "%02x %02x %02x %02x %02x %02x %02x %02x",
+                    offset,
+                    pc[8], pc[9], pc[10], pc[11],
+                    pc[12], pc[13], pc[14], pc[15],
+                    pc[16], pc[17], pc[18], pc[19],
+                    pc[20], pc[21], pc[22], pc[23]);
+            BRANCH(CHECK_BIT_IN_TABLE, offset);
+          }
+          BYTECODE(CHECK_LT) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(CHECK_LT, offset);
+          }
+          BYTECODE(CHECK_GT) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(CHECK_GT, offset);
+          }
+          BYTECODE(CHECK_REGISTER_LT) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " reg[%d], %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    Load32Aligned(pc + 4),
+                    offset);
+            BRANCH(CHECK_REGISTER_LT, offset);
+          }
+          BYTECODE(CHECK_REGISTER_GE) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " reg[%d], %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    Load32Aligned(pc + 4),
+                    offset);
+            BRANCH(CHECK_REGISTER_GE, offset);
+          }
+          BYTECODE(CHECK_REGISTER_EQ_POS) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " reg[%d], %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(CHECK_REGISTER_EQ_POS, offset);
+          }
+          BYTECODE(CHECK_NOT_REGS_EQUAL) {
+            int32_t offset = Load32Aligned(pc + 8);
+            fprintf(stderr, " reg[%d], %d, %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    Load32Aligned(pc + 4),
+                    offset);
+            BRANCH(CHECK_NOT_REGS_EQUAL, offset);
+          }
+          BYTECODE(CHECK_NOT_BACK_REF) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " reg[%d], %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(CHECK_NOT_BACK_REF, offset);
+          }
+          BYTECODE(CHECK_NOT_BACK_REF_NO_CASE) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " reg[%d], %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(CHECK_NOT_BACK_REF_NO_CASE, offset);
+          }
+          BYTECODE(CHECK_NOT_BACK_REF_NO_CASE_UNICODE) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " reg[%d], %d",
+                    insn >> irregexp::BYTECODE_SHIFT,
+                    offset);
+            BRANCH(CHECK_NOT_BACK_REF_NO_CASE_UNICODE, offset);
+          }
+          BYTECODE(CHECK_AT_START) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d",
+                    offset);
+            BRANCH(CHECK_AT_START, offset);
+          }
+          BYTECODE(CHECK_NOT_AT_START) {
+            int32_t offset = Load32Aligned(pc + 4);
+            fprintf(stderr, " %d",
+                    offset);
+            BRANCH(CHECK_NOT_AT_START, offset);
+          }
+          BYTECODE(SET_CURRENT_POSITION_FROM_END) {
+            fprintf(stderr, " %u",
+                    static_cast<uint32_t>(insn) >> irregexp::BYTECODE_SHIFT);
+            ADVANCE(SET_CURRENT_POSITION_FROM_END);
+          }
+          default:
+            MOZ_CRASH("Bad bytecode");
+        }
+    }
+
+#undef BYTECODE
+#undef ADVANCE
+#undef STOP
+#undef JUMP
+#undef BRANCH
+
+    return true;
+}
+
+bool
+RegExpObject::dumpBytecode(JSContext* cx, bool match_only, HandleLinearString input)
+{
+    RegExpGuard g(cx);
+    if (!getShared(cx, &g))
+        return false;
+
+    return g.re()->dumpBytecode(cx, match_only, input);
+}
+#endif
+
+template <typename CharT>
+static MOZ_ALWAYS_INLINE bool
+IsRegExpMetaChar(CharT ch)
+{
+    switch (ch) {
+      /* ES 2016 draft Mar 25, 2016 21.2.1 SyntaxCharacter. */
+      case '^': case '$': case '\\': case '.': case '*': case '+':
+      case '?': case '(': case ')': case '[': case ']': case '{':
+      case '}': case '|':
+        return true;
+      default:
+        return false;
+    }
+}
+
+template <typename CharT>
+bool
+js::HasRegExpMetaChars(const CharT* chars, size_t length)
+{
+    for (size_t i = 0; i < length; ++i) {
+        if (IsRegExpMetaChar<CharT>(chars[i]))
+            return true;
+    }
+    return false;
+}
+
+template bool
+js::HasRegExpMetaChars<Latin1Char>(const Latin1Char* chars, size_t length);
+
+template bool
+js::HasRegExpMetaChars<char16_t>(const char16_t* chars, size_t length);
+
+bool
+js::StringHasRegExpMetaChars(JSLinearString* str)
+{
+    AutoCheckCannotGC nogc;
+    if (str->hasLatin1Chars())
+        return HasRegExpMetaChars(str->latin1Chars(nogc), str->length());
+
+    return HasRegExpMetaChars(str->twoByteChars(nogc), str->length());
+}
+
+/* RegExpShared */
+
+RegExpShared::RegExpShared(JSAtom* source, RegExpFlag flags)
+  : source(source), flags(flags), parenCount(0), canStringMatch(false), marked_(false)
+{}
+
+RegExpShared::~RegExpShared()
+{
+    for (size_t i = 0; i < tables.length(); i++)
+        js_delete(tables[i]);
+}
+
+void
+RegExpShared::trace(JSTracer* trc)
+{
+    if (trc->isMarkingTracer())
+        marked_ = true;
+
+    TraceNullableEdge(trc, &source, "RegExpShared source");
+    for (auto& comp : compilationArray)
+        TraceNullableEdge(trc, &comp.jitCode, "RegExpShared code");
+}
+
+bool
+RegExpShared::isMarkedGray() const
+{
+    if (source && source->isMarked(gc::GRAY))
+        return true;
+    for (const auto& comp : compilationArray) {
+        if (comp.jitCode && comp.jitCode->isMarked(gc::GRAY))
+            return true;
+    }
+    return false;
+}
+
+void
+RegExpShared::unmarkGray()
+{
+    if (source)
+        JS::UnmarkGrayGCThingRecursively(JS::GCCellPtr(source));
+    for (const auto& comp : compilationArray) {
+        if (comp.jitCode)
+            JS::UnmarkGrayGCThingRecursively(JS::GCCellPtr(comp.jitCode.get()));
+    }
+}
+
+bool
+RegExpShared::compile(JSContext* cx, HandleLinearString input,
+                      CompilationMode mode, ForceByteCodeEnum force)
+{
+    TraceLoggerThread* logger = TraceLoggerForMainThread(cx->runtime());
+    AutoTraceLog logCompile(logger, TraceLogger_IrregexpCompile);
+
+    RootedAtom pattern(cx, source);
+    return compile(cx, pattern, input, mode, force);
+}
+
+bool
+RegExpShared::compile(JSContext* cx, HandleAtom pattern, HandleLinearString input,
+                      CompilationMode mode, ForceByteCodeEnum force)
+{
+    if (!ignoreCase() && !StringHasRegExpMetaChars(pattern))
+        canStringMatch = true;
+
+    CompileOptions options(cx);
+    TokenStream dummyTokenStream(cx, options, nullptr, 0, nullptr);
+
+    LifoAllocScope scope(&cx->tempLifoAlloc());
+
+    /* Parse the pattern. */
+    irregexp::RegExpCompileData data;
+    if (!irregexp::ParsePattern(dummyTokenStream, cx->tempLifoAlloc(), pattern,
+                                multiline(), mode == MatchOnly, unicode(), ignoreCase(),
+                                global(), sticky(), &data))
+    {
+        return false;
+    }
+
+    this->parenCount = data.capture_count;
+
+    irregexp::RegExpCode code = irregexp::CompilePattern(cx, this, &data, input,
+                                                         false /* global() */,
+                                                         ignoreCase(),
+                                                         input->hasLatin1Chars(),
+                                                         mode == MatchOnly,
+                                                         force == ForceByteCode,
+                                                         sticky(), unicode());
+    if (code.empty())
+        return false;
+
+    MOZ_ASSERT(!code.jitCode || !code.byteCode);
+    MOZ_ASSERT_IF(force == ForceByteCode, code.byteCode);
+
+    RegExpCompilation& compilation = this->compilation(mode, input->hasLatin1Chars());
+    if (code.jitCode)
+        compilation.jitCode = code.jitCode;
+    else if (code.byteCode)
+        compilation.byteCode = code.byteCode;
+
+    return true;
+}
+
+bool
+RegExpShared::compileIfNecessary(JSContext* cx, HandleLinearString input,
+                                 CompilationMode mode, ForceByteCodeEnum force)
+{
+    if (isCompiled(mode, input->hasLatin1Chars(), force))
+        return true;
+    return compile(cx, input, mode, force);
+}
+
+RegExpRunStatus
+RegExpShared::execute(JSContext* cx, HandleLinearString input, size_t start,
+                      MatchPairs* matches, size_t* endIndex)
+{
+    MOZ_ASSERT_IF(matches, !endIndex);
+    MOZ_ASSERT_IF(!matches, endIndex);
+    TraceLoggerThread* logger = TraceLoggerForMainThread(cx->runtime());
+
+    CompilationMode mode = matches ? Normal : MatchOnly;
+
+    /* Compile the code at point-of-use. */
+    if (!compileIfNecessary(cx, input, mode, DontForceByteCode))
+        return RegExpRunStatus_Error;
+
+    /*
+     * Ensure sufficient memory for output vector.
+     * No need to initialize it. The RegExp engine fills them in on a match.
+     */
+    if (matches && !matches->allocOrExpandArray(pairCount())) {
+        ReportOutOfMemory(cx);
+        return RegExpRunStatus_Error;
+    }
+
+    size_t length = input->length();
+
+    // Reset the Irregexp backtrack stack if it grows during execution.
+    irregexp::RegExpStackScope stackScope(cx->runtime());
+
+    if (canStringMatch) {
+        MOZ_ASSERT(pairCount() == 1);
+        size_t sourceLength = source->length();
+        if (sticky()) {
+            // First part checks size_t overflow.
+            if (sourceLength + start < sourceLength || sourceLength + start > length)
+                return RegExpRunStatus_Success_NotFound;
+            if (!HasSubstringAt(input, source, start))
+                return RegExpRunStatus_Success_NotFound;
+
+            if (matches) {
+                (*matches)[0].start = start;
+                (*matches)[0].limit = start + sourceLength;
+
+                matches->checkAgainst(length);
+            } else if (endIndex) {
+                *endIndex = start + sourceLength;
+            }
+            return RegExpRunStatus_Success;
+        }
+
+        int res = StringFindPattern(input, source, start);
+        if (res == -1)
+            return RegExpRunStatus_Success_NotFound;
+
+        if (matches) {
+            (*matches)[0].start = res;
+            (*matches)[0].limit = res + sourceLength;
+
+            matches->checkAgainst(length);
+        } else if (endIndex) {
+            *endIndex = res + sourceLength;
+        }
+        return RegExpRunStatus_Success;
+    }
+
+    do {
+        jit::JitCode* code = compilation(mode, input->hasLatin1Chars()).jitCode;
+        if (!code)
+            break;
+
+        RegExpRunStatus result;
+        {
+            AutoTraceLog logJIT(logger, TraceLogger_IrregexpExecute);
+            AutoCheckCannotGC nogc;
+            if (input->hasLatin1Chars()) {
+                const Latin1Char* chars = input->latin1Chars(nogc);
+                result = irregexp::ExecuteCode(cx, code, chars, start, length, matches, endIndex);
+            } else {
+                const char16_t* chars = input->twoByteChars(nogc);
+                result = irregexp::ExecuteCode(cx, code, chars, start, length, matches, endIndex);
+            }
+        }
+
+        if (result == RegExpRunStatus_Error) {
+            // An 'Error' result is returned if a stack overflow guard or
+            // interrupt guard failed. If CheckOverRecursed doesn't throw, break
+            // out and retry the regexp in the bytecode interpreter, which can
+            // execute while tolerating future interrupts. Otherwise, if we keep
+            // getting interrupted we will never finish executing the regexp.
+            if (!jit::CheckOverRecursed(cx))
+                return RegExpRunStatus_Error;
+            break;
+        }
+
+        if (result == RegExpRunStatus_Success_NotFound)
+            return RegExpRunStatus_Success_NotFound;
+
+        MOZ_ASSERT(result == RegExpRunStatus_Success);
+
+        if (matches)
+            matches->checkAgainst(length);
+        return RegExpRunStatus_Success;
+    } while (false);
+
+    // Compile bytecode for the RegExp if necessary.
+    if (!compileIfNecessary(cx, input, mode, ForceByteCode))
+        return RegExpRunStatus_Error;
+
+    uint8_t* byteCode = compilation(mode, input->hasLatin1Chars()).byteCode;
+    AutoTraceLog logInterpreter(logger, TraceLogger_IrregexpExecute);
+
+    AutoStableStringChars inputChars(cx);
+    if (!inputChars.init(cx, input))
+        return RegExpRunStatus_Error;
+
+    RegExpRunStatus result;
+    if (inputChars.isLatin1()) {
+        const Latin1Char* chars = inputChars.latin1Range().begin().get();
+        result = irregexp::InterpretCode(cx, byteCode, chars, start, length, matches, endIndex);
+    } else {
+        const char16_t* chars = inputChars.twoByteRange().begin().get();
+        result = irregexp::InterpretCode(cx, byteCode, chars, start, length, matches, endIndex);
+    }
+
+    if (result == RegExpRunStatus_Success && matches)
+        matches->checkAgainst(length);
+    return result;
+}
+
+size_t
+RegExpShared::sizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+    size_t n = mallocSizeOf(this);
+
+    for (size_t i = 0; i < ArrayLength(compilationArray); i++) {
+        const RegExpCompilation& compilation = compilationArray[i];
+        if (compilation.byteCode)
+            n += mallocSizeOf(compilation.byteCode);
+    }
+
+    n += tables.sizeOfExcludingThis(mallocSizeOf);
+    for (size_t i = 0; i < tables.length(); i++)
+        n += mallocSizeOf(tables[i]);
+
+    return n;
+}
+
+/* RegExpCompartment */
+
+RegExpCompartment::RegExpCompartment(JSRuntime* rt)
+  : set_(rt),
+    matchResultTemplateObject_(nullptr),
+    optimizableRegExpPrototypeShape_(nullptr),
+    optimizableRegExpInstanceShape_(nullptr)
+{}
+
+RegExpCompartment::~RegExpCompartment()
+{
+    // Because of stray mark bits being set (see RegExpCompartment::sweep)
+    // there might still be RegExpShared instances which haven't been deleted.
+    if (set_.initialized()) {
+        for (Set::Enum e(set_); !e.empty(); e.popFront()) {
+            RegExpShared* shared = e.front();
+            js_delete(shared);
+        }
+    }
+}
+
+ArrayObject*
+RegExpCompartment::createMatchResultTemplateObject(JSContext* cx)
+{
+    MOZ_ASSERT(!matchResultTemplateObject_);
+
+    /* Create template array object */
+    RootedArrayObject templateObject(cx, NewDenseUnallocatedArray(cx, RegExpObject::MaxPairCount,
+                                     nullptr, TenuredObject));
+    if (!templateObject)
+        return matchResultTemplateObject_; // = 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
+    templateObject->setGroup(group);
+
+    /* Set dummy index property */
+    RootedValue index(cx, Int32Value(0));
+    if (!NativeDefineProperty(cx, templateObject, cx->names().index, index, nullptr, nullptr,
+                              JSPROP_ENUMERATE))
+    {
+        return matchResultTemplateObject_; // = nullptr
+    }
+
+    /* Set dummy input property */
+    RootedValue inputVal(cx, StringValue(cx->runtime()->emptyString));
+    if (!NativeDefineProperty(cx, templateObject, cx->names().input, inputVal, nullptr, nullptr,
+                              JSPROP_ENUMERATE))
+    {
+        return matchResultTemplateObject_; // = nullptr
+    }
+
+    // Make sure that the properties are in the right slots.
+    DebugOnly<Shape*> shape = templateObject->lastProperty();
+    MOZ_ASSERT(shape->previous()->slot() == 0 &&
+               shape->previous()->propidRef() == NameToId(cx->names().index));
+    MOZ_ASSERT(shape->slot() == 1 &&
+               shape->propidRef() == NameToId(cx->names().input));
+
+    // Make sure type information reflects the indexed properties which might
+    // be added.
+    AddTypePropertyId(cx, templateObject, JSID_VOID, TypeSet::StringType());
+    AddTypePropertyId(cx, templateObject, JSID_VOID, TypeSet::UndefinedType());
+
+    matchResultTemplateObject_.set(templateObject);
+
+    return matchResultTemplateObject_;
+}
+
+bool
+RegExpCompartment::init(JSContext* cx)
+{
+    if (!set_.init(0)) {
+        if (cx)
+            ReportOutOfMemory(cx);
+        return false;
+    }
+
+    return true;
+}
+
+bool
+RegExpShared::needsSweep(JSRuntime* rt)
+{
+    // Sometimes RegExpShared instances are marked without the compartment
+    // being subsequently cleared. This can happen if a GC is restarted while
+    // in progress (i.e. performing a full GC in the middle of an incremental
+    // GC) or if a RegExpShared referenced via the stack is traced but is not
+    // in a zone being collected.
+    //
+    // Because of this we only treat the marked_ bit as a hint, and destroy the
+    // RegExpShared if it was accidentally marked earlier but wasn't marked by
+    // the current trace.
+    bool keep = marked() && IsMarked(rt, &source);
+    for (size_t i = 0; i < ArrayLength(compilationArray); i++) {
+        RegExpShared::RegExpCompilation& compilation = compilationArray[i];
+        if (compilation.jitCode && gc::IsAboutToBeFinalized(&compilation.jitCode))
+            keep = false;
+    }
+
+    MOZ_ASSERT(rt->isHeapMajorCollecting());
+    if (keep || rt->gc.isHeapCompacting()) {
+        clearMarked();
+        return false;
+    }
+
+    return true;
+}
+
+void
+RegExpShared::discardJitCode()
+{
+    for (size_t i = 0; i < ArrayLength(compilationArray); i++)
+        compilationArray[i].jitCode = nullptr;
+}
+
+void
+RegExpCompartment::sweep(JSRuntime* rt)
+{
+    if (!set_.initialized())
+        return;
+
+    for (Set::Enum e(set_); !e.empty(); e.popFront()) {
+        RegExpShared* shared = e.front();
+        if (shared->needsSweep(rt)) {
+            js_delete(shared);
+            e.removeFront();
+        } else {
+            // Discard code to avoid holding onto ExecutablePools.
+            if (rt->gc.isHeapCompacting())
+                shared->discardJitCode();
+        }
+    }
+
+    if (matchResultTemplateObject_ &&
+        IsAboutToBeFinalized(&matchResultTemplateObject_))
+    {
+        matchResultTemplateObject_.set(nullptr);
+    }
+
+    if (optimizableRegExpPrototypeShape_ &&
+        IsAboutToBeFinalized(&optimizableRegExpPrototypeShape_))
+    {
+        optimizableRegExpPrototypeShape_.set(nullptr);
+    }
+
+    if (optimizableRegExpInstanceShape_ &&
+        IsAboutToBeFinalized(&optimizableRegExpInstanceShape_))
+    {
+        optimizableRegExpInstanceShape_.set(nullptr);
+    }
+}
+
+bool
+RegExpCompartment::get(JSContext* cx, JSAtom* source, RegExpFlag flags, RegExpGuard* g)
+{
+    Key key(source, flags);
+    Set::AddPtr p = set_.lookupForAdd(key);
+    if (p) {
+        // Trigger a read barrier on existing RegExpShared instances fetched
+        // from the table (which only holds weak references).
+        RegExpSharedReadBarrier(cx, *p);
+
+        g->init(**p);
+        return true;
+    }
+
+    ScopedJSDeletePtr<RegExpShared> shared(cx->new_<RegExpShared>(source, flags));
+    if (!shared)
+        return false;
+
+    if (!set_.add(p, shared)) {
+        ReportOutOfMemory(cx);
+        return false;
+    }
+
+    // Trace RegExpShared instances created during an incremental GC.
+    RegExpSharedReadBarrier(cx, shared);
+
+    g->init(*shared.forget());
+    return true;
+}
+
+bool
+RegExpCompartment::get(JSContext* cx, HandleAtom atom, JSString* opt, RegExpGuard* g)
+{
+    RegExpFlag flags = RegExpFlag(0);
+    if (opt && !ParseRegExpFlags(cx, opt, &flags))
+        return false;
+
+    return get(cx, atom, flags, g);
+}
+
+size_t
+RegExpCompartment::sizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf)
+{
+    size_t n = 0;
+    n += set_.sizeOfExcludingThis(mallocSizeOf);
+    for (Set::Enum e(set_); !e.empty(); e.popFront()) {
+        RegExpShared* shared = e.front();
+        n += shared->sizeOfIncludingThis(mallocSizeOf);
+    }
+    return n;
+}
+
+/* Functions */
+
+JSObject*
+js::CloneRegExpObject(JSContext* cx, JSObject* obj_)
+{
+    Rooted<RegExpObject*> regex(cx, &obj_->as<RegExpObject>());
+
+    // Unlike RegExpAlloc, all clones must use |regex|'s group.  Allocate
+    // in the tenured heap to simplify embedding them in JIT code.
+    RootedObjectGroup group(cx, regex->group());
+    Rooted<RegExpObject*> clone(cx, NewObjectWithGroup<RegExpObject>(cx, group, TenuredObject));
+    if (!clone)
+        return nullptr;
+    clone->initPrivate(nullptr);
+
+    if (!EmptyShape::ensureInitialCustomShape<RegExpObject>(cx, clone))
+        return nullptr;
+
+    Rooted<JSAtom*> source(cx, regex->getSource());
+
+    RegExpGuard g(cx);
+    if (!regex->getShared(cx, &g))
+        return nullptr;
+
+    clone->initAndZeroLastIndex(source, g->getFlags(), cx);
+    clone->setShared(*g.re());
+
+    return clone;
+}
+
+static bool
+HandleRegExpFlag(RegExpFlag flag, RegExpFlag* flags)
+{
+    if (*flags & flag)
+        return false;
+    *flags = RegExpFlag(*flags | flag);
+    return true;
+}
+
+template <typename CharT>
+static size_t
+ParseRegExpFlags(const CharT* chars, size_t length, RegExpFlag* flagsOut, char16_t* lastParsedOut)
+{
+    *flagsOut = RegExpFlag(0);
+
+    for (size_t i = 0; i < length; i++) {
+        *lastParsedOut = chars[i];
+        switch (chars[i]) {
+          case 'i':
+            if (!HandleRegExpFlag(IgnoreCaseFlag, flagsOut))
+                return false;
+            break;
+          case 'g':
+            if (!HandleRegExpFlag(GlobalFlag, flagsOut))
+                return false;
+            break;
+          case 'm':
+            if (!HandleRegExpFlag(MultilineFlag, flagsOut))
+                return false;
+            break;
+          case 'y':
+            if (!HandleRegExpFlag(StickyFlag, flagsOut))
+                return false;
+            break;
+          case 'u':
+            if (!HandleRegExpFlag(UnicodeFlag, flagsOut))
+                return false;
+            break;
+          default:
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool
+js::ParseRegExpFlags(JSContext* cx, JSString* flagStr, RegExpFlag* flagsOut)
+{
+    JSLinearString* linear = flagStr->ensureLinear(cx);
+    if (!linear)
+        return false;
+
+    size_t len = linear->length();
+
+    bool ok;
+    char16_t lastParsed;
+    if (linear->hasLatin1Chars()) {
+        AutoCheckCannotGC nogc;
+        ok = ::ParseRegExpFlags(linear->latin1Chars(nogc), len, flagsOut, &lastParsed);
+    } else {
+        AutoCheckCannotGC nogc;
+        ok = ::ParseRegExpFlags(linear->twoByteChars(nogc), len, flagsOut, &lastParsed);
+    }
+
+    if (!ok) {
+        TwoByteChars range(&lastParsed, 1);
+        UniqueChars utf8(JS::CharsToNewUTF8CharsZ(nullptr, range).c_str());
+        if (!utf8)
+            return false;
+        JS_ReportErrorFlagsAndNumberUTF8(cx, JSREPORT_ERROR, GetErrorMessage, nullptr,
+                                         JSMSG_BAD_REGEXP_FLAG, utf8.get());
+        return false;
+    }
+
+    return true;
+}
+
+template<XDRMode mode>
+bool
+js::XDRScriptRegExpObject(XDRState<mode>* xdr, MutableHandle<RegExpObject*> objp)
+{
+    /* NB: Keep this in sync with CloneScriptRegExpObject. */
+
+    RootedAtom source(xdr->cx());
+    uint32_t flagsword = 0;
+
+    if (mode == XDR_ENCODE) {
+        MOZ_ASSERT(objp);
+        RegExpObject& reobj = *objp;
+        source = reobj.getSource();
+        flagsword = reobj.getFlags();
+    }
+    if (!XDRAtom(xdr, &source) || !xdr->codeUint32(&flagsword))
+        return false;
+    if (mode == XDR_DECODE) {
+        RegExpFlag flags = RegExpFlag(flagsword);
+        RegExpObject* reobj = RegExpObject::create(xdr->cx(), source, flags, nullptr,
+                                                   xdr->cx()->tempLifoAlloc());
+        if (!reobj)
+            return false;
+
+        objp.set(reobj);
+    }
+    return true;
+}
+
+template bool
+js::XDRScriptRegExpObject(XDRState<XDR_ENCODE>* xdr, MutableHandle<RegExpObject*> objp);
+
+template bool
+js::XDRScriptRegExpObject(XDRState<XDR_DECODE>* xdr, MutableHandle<RegExpObject*> objp);
+
+JSObject*
+js::CloneScriptRegExpObject(JSContext* cx, RegExpObject& reobj)
+{
+    /* NB: Keep this in sync with XDRScriptRegExpObject. */
+
+    RootedAtom source(cx, reobj.getSource());
+    return RegExpObject::create(cx, source, reobj.getFlags(), nullptr, cx->tempLifoAlloc());
+}
+
+JS_FRIEND_API(bool)
+js::RegExpToSharedNonInline(JSContext* cx, HandleObject obj, js::RegExpGuard* g)
+{
+    return RegExpToShared(cx, obj, g);
+}