Add m-esr52 at 52.6.0

1 files changed, 617 insertions, 0 deletions

diff --git a/js/src/jsatom.cpp b/js/src/jsatom.cpp
new file mode 100644
index 000000000..3f8e8d8f8
--- /dev/null
+++ b/js/src/jsatom.cpp
@@ -0,0 +1,617 @@
+/* -*- 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/. */
+
+/*
+ * JS atom table.
+ */
+
+#include "jsatominlines.h"
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/RangedPtr.h"
+
+#include <string.h>
+
+#include "jscntxt.h"
+#include "jsstr.h"
+#include "jstypes.h"
+
+#include "gc/Marking.h"
+#include "vm/Symbol.h"
+#include "vm/Xdr.h"
+
+#include "jscntxtinlines.h"
+#include "jscompartmentinlines.h"
+#include "jsobjinlines.h"
+
+#include "vm/String-inl.h"
+
+using namespace js;
+using namespace js::gc;
+
+using mozilla::ArrayEnd;
+using mozilla::ArrayLength;
+using mozilla::RangedPtr;
+
+const char*
+js::AtomToPrintableString(ExclusiveContext* cx, JSAtom* atom, JSAutoByteString* bytes)
+{
+    JSString* str = QuoteString(cx, atom, 0);
+    if (!str)
+        return nullptr;
+    return bytes->encodeLatin1(cx, str);
+}
+
+#define DEFINE_PROTO_STRING(name,code,init,clasp) const char js_##name##_str[] = #name;
+JS_FOR_EACH_PROTOTYPE(DEFINE_PROTO_STRING)
+#undef DEFINE_PROTO_STRING
+
+#define CONST_CHAR_STR(idpart, id, text) const char js_##idpart##_str[] = text;
+FOR_EACH_COMMON_PROPERTYNAME(CONST_CHAR_STR)
+#undef CONST_CHAR_STR
+
+/* Constant strings that are not atomized. */
+const char js_break_str[]           = "break";
+const char js_case_str[]            = "case";
+const char js_catch_str[]           = "catch";
+const char js_class_str[]           = "class";
+const char js_const_str[]           = "const";
+const char js_continue_str[]        = "continue";
+const char js_debugger_str[]        = "debugger";
+const char js_default_str[]         = "default";
+const char js_do_str[]              = "do";
+const char js_else_str[]            = "else";
+const char js_enum_str[]            = "enum";
+const char js_export_str[]          = "export";
+const char js_extends_str[]         = "extends";
+const char js_finally_str[]         = "finally";
+const char js_for_str[]             = "for";
+const char js_getter_str[]          = "getter";
+const char js_if_str[]              = "if";
+const char js_implements_str[]      = "implements";
+const char js_import_str[]          = "import";
+const char js_in_str[]              = "in";
+const char js_instanceof_str[]      = "instanceof";
+const char js_interface_str[]       = "interface";
+const char js_package_str[]         = "package";
+const char js_private_str[]         = "private";
+const char js_protected_str[]       = "protected";
+const char js_public_str[]          = "public";
+const char js_send_str[]            = "send";
+const char js_setter_str[]          = "setter";
+const char js_switch_str[]          = "switch";
+const char js_this_str[]            = "this";
+const char js_try_str[]             = "try";
+const char js_typeof_str[]          = "typeof";
+const char js_void_str[]            = "void";
+const char js_while_str[]           = "while";
+const char js_with_str[]            = "with";
+
+// Use a low initial capacity for atom hash tables to avoid penalizing runtimes
+// which create a small number of atoms.
+static const uint32_t JS_STRING_HASH_COUNT = 64;
+
+AtomSet::Ptr js::FrozenAtomSet::readonlyThreadsafeLookup(const AtomSet::Lookup& l) const {
+    return mSet->readonlyThreadsafeLookup(l);
+}
+
+struct CommonNameInfo
+{
+    const char* str;
+    size_t length;
+};
+
+bool
+JSRuntime::initializeAtoms(JSContext* cx)
+{
+    atoms_ = cx->new_<AtomSet>();
+    if (!atoms_ || !atoms_->init(JS_STRING_HASH_COUNT))
+        return false;
+
+    // |permanentAtoms| hasn't been created yet.
+    MOZ_ASSERT(!permanentAtoms);
+
+    if (parentRuntime) {
+        staticStrings = parentRuntime->staticStrings;
+        commonNames = parentRuntime->commonNames;
+        emptyString = parentRuntime->emptyString;
+        permanentAtoms = parentRuntime->permanentAtoms;
+        wellKnownSymbols = parentRuntime->wellKnownSymbols;
+        return true;
+    }
+
+    staticStrings = cx->new_<StaticStrings>();
+    if (!staticStrings || !staticStrings->init(cx))
+        return false;
+
+    static const CommonNameInfo cachedNames[] = {
+#define COMMON_NAME_INFO(idpart, id, text) { js_##idpart##_str, sizeof(text) - 1 },
+        FOR_EACH_COMMON_PROPERTYNAME(COMMON_NAME_INFO)
+#undef COMMON_NAME_INFO
+#define COMMON_NAME_INFO(name, code, init, clasp) { js_##name##_str, sizeof(#name) - 1 },
+        JS_FOR_EACH_PROTOTYPE(COMMON_NAME_INFO)
+#undef COMMON_NAME_INFO
+#define COMMON_NAME_INFO(name) { #name, sizeof(#name) - 1 },
+        JS_FOR_EACH_WELL_KNOWN_SYMBOL(COMMON_NAME_INFO)
+#undef COMMON_NAME_INFO
+#define COMMON_NAME_INFO(name) { "Symbol." #name, sizeof("Symbol." #name) - 1 },
+        JS_FOR_EACH_WELL_KNOWN_SYMBOL(COMMON_NAME_INFO)
+#undef COMMON_NAME_INFO
+    };
+
+    commonNames = cx->new_<JSAtomState>();
+    if (!commonNames)
+        return false;
+
+    ImmutablePropertyNamePtr* names = reinterpret_cast<ImmutablePropertyNamePtr*>(commonNames);
+    for (size_t i = 0; i < ArrayLength(cachedNames); i++, names++) {
+        JSAtom* atom = Atomize(cx, cachedNames[i].str, cachedNames[i].length, PinAtom);
+        if (!atom)
+            return false;
+        names->init(atom->asPropertyName());
+    }
+    MOZ_ASSERT(uintptr_t(names) == uintptr_t(commonNames + 1));
+
+    emptyString = commonNames->empty;
+
+    // Create the well-known symbols.
+    wellKnownSymbols = cx->new_<WellKnownSymbols>();
+    if (!wellKnownSymbols)
+        return false;
+
+    ImmutablePropertyNamePtr* descriptions = commonNames->wellKnownSymbolDescriptions();
+    ImmutableSymbolPtr* symbols = reinterpret_cast<ImmutableSymbolPtr*>(wellKnownSymbols);
+    for (size_t i = 0; i < JS::WellKnownSymbolLimit; i++) {
+        JS::Symbol* symbol = JS::Symbol::new_(cx, JS::SymbolCode(i), descriptions[i]);
+        if (!symbol) {
+            ReportOutOfMemory(cx);
+            return false;
+        }
+        symbols[i].init(symbol);
+    }
+
+    return true;
+}
+
+void
+JSRuntime::finishAtoms()
+{
+    js_delete(atoms_);
+
+    if (!parentRuntime) {
+        js_delete(staticStrings);
+        js_delete(commonNames);
+        js_delete(permanentAtoms);
+        js_delete(wellKnownSymbols);
+    }
+
+    atoms_ = nullptr;
+    staticStrings = nullptr;
+    commonNames = nullptr;
+    permanentAtoms = nullptr;
+    wellKnownSymbols = nullptr;
+    emptyString = nullptr;
+}
+
+void
+js::MarkAtoms(JSTracer* trc, AutoLockForExclusiveAccess& lock)
+{
+    JSRuntime* rt = trc->runtime();
+
+    if (rt->atomsAreFinished())
+        return;
+
+    for (AtomSet::Enum e(rt->atoms(lock)); !e.empty(); e.popFront()) {
+        const AtomStateEntry& entry = e.front();
+        if (!entry.isPinned())
+            continue;
+
+        JSAtom* atom = entry.asPtrUnbarriered();
+        TraceRoot(trc, &atom, "interned_atom");
+        MOZ_ASSERT(entry.asPtrUnbarriered() == atom);
+    }
+}
+
+void
+js::MarkPermanentAtoms(JSTracer* trc)
+{
+    JSRuntime* rt = trc->runtime();
+
+    // Permanent atoms only need to be marked in the runtime which owns them.
+    if (rt->parentRuntime)
+        return;
+
+    // Static strings are not included in the permanent atoms table.
+    if (rt->staticStrings)
+        rt->staticStrings->trace(trc);
+
+    if (rt->permanentAtoms) {
+        for (FrozenAtomSet::Range r(rt->permanentAtoms->all()); !r.empty(); r.popFront()) {
+            const AtomStateEntry& entry = r.front();
+
+            JSAtom* atom = entry.asPtrUnbarriered();
+            TraceProcessGlobalRoot(trc, atom, "permanent_table");
+        }
+    }
+}
+
+void
+js::MarkWellKnownSymbols(JSTracer* trc)
+{
+    JSRuntime* rt = trc->runtime();
+
+    if (rt->parentRuntime)
+        return;
+
+    if (WellKnownSymbols* wks = rt->wellKnownSymbols) {
+        for (size_t i = 0; i < JS::WellKnownSymbolLimit; i++)
+            TraceProcessGlobalRoot(trc, wks->get(i).get(), "well_known_symbol");
+    }
+}
+
+void
+JSRuntime::sweepAtoms()
+{
+    if (atoms_)
+        atoms_->sweep();
+}
+
+bool
+JSRuntime::transformToPermanentAtoms(JSContext* cx)
+{
+    MOZ_ASSERT(!parentRuntime);
+
+    // All static strings were created as permanent atoms, now move the contents
+    // of the atoms table into permanentAtoms and mark each as permanent.
+
+    MOZ_ASSERT(!permanentAtoms);
+    permanentAtoms = cx->new_<FrozenAtomSet>(atoms_);   // takes ownership of atoms_
+
+    atoms_ = cx->new_<AtomSet>();
+    if (!atoms_ || !atoms_->init(JS_STRING_HASH_COUNT))
+        return false;
+
+    for (FrozenAtomSet::Range r(permanentAtoms->all()); !r.empty(); r.popFront()) {
+        AtomStateEntry entry = r.front();
+        JSAtom* atom = entry.asPtr(cx);
+        atom->morphIntoPermanentAtom();
+    }
+
+    return true;
+}
+
+bool
+AtomIsPinned(JSContext* cx, JSAtom* atom)
+{
+    /* We treat static strings as interned because they're never collected. */
+    if (StaticStrings::isStatic(atom))
+        return true;
+
+    AtomHasher::Lookup lookup(atom);
+
+    /* Likewise, permanent strings are considered to be interned. */
+    MOZ_ASSERT(cx->isPermanentAtomsInitialized());
+    AtomSet::Ptr p = cx->permanentAtoms().readonlyThreadsafeLookup(lookup);
+    if (p)
+        return true;
+
+    AutoLockForExclusiveAccess lock(cx);
+
+    p = cx->runtime()->atoms(lock).lookup(lookup);
+    if (!p)
+        return false;
+
+    return p->isPinned();
+}
+
+/* |tbchars| must not point into an inline or short string. */
+template <typename CharT>
+MOZ_ALWAYS_INLINE
+static JSAtom*
+AtomizeAndCopyChars(ExclusiveContext* cx, const CharT* tbchars, size_t length, PinningBehavior pin)
+{
+    if (JSAtom* s = cx->staticStrings().lookup(tbchars, length))
+         return s;
+
+    AtomHasher::Lookup lookup(tbchars, length);
+
+    // Note: when this function is called while the permanent atoms table is
+    // being initialized (in initializeAtoms()), |permanentAtoms| is not yet
+    // initialized so this lookup is always skipped. Only once
+    // transformToPermanentAtoms() is called does |permanentAtoms| get
+    // initialized and then this lookup will go ahead.
+    if (cx->isPermanentAtomsInitialized()) {
+        AtomSet::Ptr pp = cx->permanentAtoms().readonlyThreadsafeLookup(lookup);
+        if (pp)
+            return pp->asPtr(cx);
+    }
+
+    AutoLockForExclusiveAccess lock(cx);
+
+    AtomSet& atoms = cx->atoms(lock);
+    AtomSet::AddPtr p = atoms.lookupForAdd(lookup);
+    if (p) {
+        JSAtom* atom = p->asPtr(cx);
+        p->setPinned(bool(pin));
+        return atom;
+    }
+
+    AutoCompartment ac(cx, cx->atomsCompartment(lock), &lock);
+
+    JSFlatString* flat = NewStringCopyN<NoGC>(cx, tbchars, length);
+    if (!flat) {
+        // Grudgingly forgo last-ditch GC. The alternative would be to release
+        // the lock, manually GC here, and retry from the top. If you fix this,
+        // please also fix or comment the similar case in Symbol::new_.
+        ReportOutOfMemory(cx);
+        return nullptr;
+    }
+
+    JSAtom* atom = flat->morphAtomizedStringIntoAtom(lookup.hash);
+    MOZ_ASSERT(atom->hash() == lookup.hash);
+
+    // We have held the lock since looking up p, and the operations we've done
+    // since then can't GC; therefore the atoms table has not been modified and
+    // p is still valid.
+    if (!atoms.add(p, AtomStateEntry(atom, bool(pin)))) {
+        ReportOutOfMemory(cx); /* SystemAllocPolicy does not report OOM. */
+        return nullptr;
+    }
+
+    return atom;
+}
+
+template JSAtom*
+AtomizeAndCopyChars(ExclusiveContext* cx, const char16_t* tbchars, size_t length, PinningBehavior pin);
+
+template JSAtom*
+AtomizeAndCopyChars(ExclusiveContext* cx, const Latin1Char* tbchars, size_t length, PinningBehavior pin);
+
+JSAtom*
+js::AtomizeString(ExclusiveContext* cx, JSString* str,
+                  js::PinningBehavior pin /* = js::DoNotPinAtom */)
+{
+    if (str->isAtom()) {
+        JSAtom& atom = str->asAtom();
+        /* N.B. static atoms are effectively always interned. */
+        if (pin != PinAtom || js::StaticStrings::isStatic(&atom))
+            return &atom;
+
+        AtomHasher::Lookup lookup(&atom);
+
+        /* Likewise, permanent atoms are always interned. */
+        MOZ_ASSERT(cx->isPermanentAtomsInitialized());
+        AtomSet::Ptr p = cx->permanentAtoms().readonlyThreadsafeLookup(lookup);
+        if (p)
+            return &atom;
+
+        AutoLockForExclusiveAccess lock(cx);
+
+        p = cx->atoms(lock).lookup(lookup);
+        MOZ_ASSERT(p); /* Non-static atom must exist in atom state set. */
+        MOZ_ASSERT(p->asPtrUnbarriered() == &atom);
+        MOZ_ASSERT(pin == PinAtom);
+        p->setPinned(bool(pin));
+        return &atom;
+    }
+
+    JSLinearString* linear = str->ensureLinear(cx);
+    if (!linear)
+        return nullptr;
+
+    JS::AutoCheckCannotGC nogc;
+    return linear->hasLatin1Chars()
+           ? AtomizeAndCopyChars(cx, linear->latin1Chars(nogc), linear->length(), pin)
+           : AtomizeAndCopyChars(cx, linear->twoByteChars(nogc), linear->length(), pin);
+}
+
+JSAtom*
+js::Atomize(ExclusiveContext* cx, const char* bytes, size_t length, PinningBehavior pin)
+{
+    CHECK_REQUEST(cx);
+
+    if (!JSString::validateLength(cx, length))
+        return nullptr;
+
+    const Latin1Char* chars = reinterpret_cast<const Latin1Char*>(bytes);
+    return AtomizeAndCopyChars(cx, chars, length, pin);
+}
+
+template <typename CharT>
+JSAtom*
+js::AtomizeChars(ExclusiveContext* cx, const CharT* chars, size_t length, PinningBehavior pin)
+{
+    CHECK_REQUEST(cx);
+
+    if (!JSString::validateLength(cx, length))
+        return nullptr;
+
+    return AtomizeAndCopyChars(cx, chars, length, pin);
+}
+
+template JSAtom*
+js::AtomizeChars(ExclusiveContext* cx, const Latin1Char* chars, size_t length, PinningBehavior pin);
+
+template JSAtom*
+js::AtomizeChars(ExclusiveContext* cx, const char16_t* chars, size_t length, PinningBehavior pin);
+
+JSAtom*
+js::AtomizeUTF8Chars(JSContext* cx, const char* utf8Chars, size_t utf8ByteLength)
+{
+    // This could be optimized to hand the char16_t's directly to the JSAtom
+    // instead of making a copy. UTF8CharsToNewTwoByteCharsZ should be
+    // refactored to take an ExclusiveContext so that this function could also.
+
+    UTF8Chars utf8(utf8Chars, utf8ByteLength);
+
+    size_t length;
+    UniqueTwoByteChars chars(JS::UTF8CharsToNewTwoByteCharsZ(cx, utf8, &length).get());
+    if (!chars)
+        return nullptr;
+
+    return AtomizeChars(cx, chars.get(), length);
+}
+
+bool
+js::IndexToIdSlow(ExclusiveContext* cx, uint32_t index, MutableHandleId idp)
+{
+    MOZ_ASSERT(index > JSID_INT_MAX);
+
+    char16_t buf[UINT32_CHAR_BUFFER_LENGTH];
+    RangedPtr<char16_t> end(ArrayEnd(buf), buf, ArrayEnd(buf));
+    RangedPtr<char16_t> start = BackfillIndexInCharBuffer(index, end);
+
+    JSAtom* atom = AtomizeChars(cx, start.get(), end - start);
+    if (!atom)
+        return false;
+
+    idp.set(JSID_FROM_BITS((size_t)atom));
+    return true;
+}
+
+template <AllowGC allowGC>
+static JSAtom*
+ToAtomSlow(ExclusiveContext* cx, typename MaybeRooted<Value, allowGC>::HandleType arg)
+{
+    MOZ_ASSERT(!arg.isString());
+
+    Value v = arg;
+    if (!v.isPrimitive()) {
+        if (!cx->shouldBeJSContext() || !allowGC)
+            return nullptr;
+        RootedValue v2(cx, v);
+        if (!ToPrimitive(cx->asJSContext(), JSTYPE_STRING, &v2))
+            return nullptr;
+        v = v2;
+    }
+
+    if (v.isString()) {
+        JSAtom* atom = AtomizeString(cx, v.toString());
+        if (!allowGC && !atom)
+            cx->recoverFromOutOfMemory();
+        return atom;
+    }
+    if (v.isInt32()) {
+        JSAtom* atom = Int32ToAtom(cx, v.toInt32());
+        if (!allowGC && !atom)
+            cx->recoverFromOutOfMemory();
+        return atom;
+    }
+    if (v.isDouble()) {
+        JSAtom* atom = NumberToAtom(cx, v.toDouble());
+        if (!allowGC && !atom)
+            cx->recoverFromOutOfMemory();
+        return atom;
+    }
+    if (v.isBoolean())
+        return v.toBoolean() ? cx->names().true_ : cx->names().false_;
+    if (v.isNull())
+        return cx->names().null;
+    return cx->names().undefined;
+}
+
+template <AllowGC allowGC>
+JSAtom*
+js::ToAtom(ExclusiveContext* cx, typename MaybeRooted<Value, allowGC>::HandleType v)
+{
+    if (!v.isString())
+        return ToAtomSlow<allowGC>(cx, v);
+
+    JSString* str = v.toString();
+    if (str->isAtom())
+        return &str->asAtom();
+
+    JSAtom* atom = AtomizeString(cx, str);
+    if (!atom && !allowGC) {
+        MOZ_ASSERT_IF(cx->isJSContext(), cx->asJSContext()->isThrowingOutOfMemory());
+        cx->recoverFromOutOfMemory();
+    }
+    return atom;
+}
+
+template JSAtom*
+js::ToAtom<CanGC>(ExclusiveContext* cx, HandleValue v);
+
+template JSAtom*
+js::ToAtom<NoGC>(ExclusiveContext* cx, const Value& v);
+
+template<XDRMode mode>
+bool
+js::XDRAtom(XDRState<mode>* xdr, MutableHandleAtom atomp)
+{
+    if (mode == XDR_ENCODE) {
+        static_assert(JSString::MAX_LENGTH <= INT32_MAX, "String length must fit in 31 bits");
+        uint32_t length = atomp->length();
+        uint32_t lengthAndEncoding = (length << 1) | uint32_t(atomp->hasLatin1Chars());
+        if (!xdr->codeUint32(&lengthAndEncoding))
+            return false;
+
+        JS::AutoCheckCannotGC nogc;
+        return atomp->hasLatin1Chars()
+               ? xdr->codeChars(atomp->latin1Chars(nogc), length)
+               : xdr->codeChars(const_cast<char16_t*>(atomp->twoByteChars(nogc)), length);
+    }
+
+    /* Avoid JSString allocation for already existing atoms. See bug 321985. */
+    uint32_t lengthAndEncoding;
+    if (!xdr->codeUint32(&lengthAndEncoding))
+        return false;
+
+    uint32_t length = lengthAndEncoding >> 1;
+    bool latin1 = lengthAndEncoding & 0x1;
+
+    JSContext* cx = xdr->cx();
+    JSAtom* atom;
+    if (latin1) {
+        const Latin1Char* chars = nullptr;
+        if (length)
+            chars = reinterpret_cast<const Latin1Char*>(xdr->buf.read(length));
+        atom = AtomizeChars(cx, chars, length);
+    } else {
+#if MOZ_LITTLE_ENDIAN
+        /* Directly access the little endian chars in the XDR buffer. */
+        const char16_t* chars = nullptr;
+        if (length)
+            chars = reinterpret_cast<const char16_t*>(xdr->buf.read(length * sizeof(char16_t)));
+        atom = AtomizeChars(cx, chars, length);
+#else
+        /*
+         * We must copy chars to a temporary buffer to convert between little and
+         * big endian data.
+         */
+        char16_t* chars;
+        char16_t stackChars[256];
+        if (length <= ArrayLength(stackChars)) {
+            chars = stackChars;
+        } else {
+            /*
+             * This is very uncommon. Don't use the tempLifoAlloc arena for this as
+             * most allocations here will be bigger than tempLifoAlloc's default
+             * chunk size.
+             */
+            chars = cx->runtime()->pod_malloc<char16_t>(length);
+            if (!chars)
+                return false;
+        }
+
+        JS_ALWAYS_TRUE(xdr->codeChars(chars, length));
+        atom = AtomizeChars(cx, chars, length);
+        if (chars != stackChars)
+            js_free(chars);
+#endif /* !MOZ_LITTLE_ENDIAN */
+    }
+
+    if (!atom)
+        return false;
+    atomp.set(atom);
+    return true;
+}
+
+template bool
+js::XDRAtom(XDRState<XDR_ENCODE>* xdr, MutableHandleAtom atomp);
+
+template bool
+js::XDRAtom(XDRState<XDR_DECODE>* xdr, MutableHandleAtom atomp);