Add m-esr52 at 52.6.0

1 files changed, 367 insertions, 0 deletions

diff --git a/js/src/vm/GeneratorObject.cpp b/js/src/vm/GeneratorObject.cpp
new file mode 100644
index 000000000..690c0bf48
--- /dev/null
+++ b/js/src/vm/GeneratorObject.cpp
@@ -0,0 +1,367 @@
+/* -*- 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/GeneratorObject.h"
+
+#include "jsobj.h"
+
+#include "jsatominlines.h"
+#include "jsscriptinlines.h"
+
+#include "vm/NativeObject-inl.h"
+#include "vm/Stack-inl.h"
+
+using namespace js;
+
+JSObject*
+GeneratorObject::create(JSContext* cx, AbstractFramePtr frame)
+{
+    MOZ_ASSERT(frame.script()->isGenerator());
+    MOZ_ASSERT(frame.script()->nfixed() == 0);
+
+    Rooted<GlobalObject*> global(cx, cx->global());
+    RootedNativeObject obj(cx);
+    if (frame.script()->isStarGenerator()) {
+        RootedValue pval(cx);
+        RootedObject fun(cx, frame.callee());
+        // FIXME: This would be faster if we could avoid doing a lookup to get
+        // the prototype for the instance.  Bug 906600.
+        if (!GetProperty(cx, fun, fun, cx->names().prototype, &pval))
+            return nullptr;
+        RootedObject proto(cx, pval.isObject() ? &pval.toObject() : nullptr);
+        if (!proto) {
+            proto = GlobalObject::getOrCreateStarGeneratorObjectPrototype(cx, global);
+            if (!proto)
+                return nullptr;
+        }
+        obj = NewNativeObjectWithGivenProto(cx, &StarGeneratorObject::class_, proto);
+    } else {
+        MOZ_ASSERT(frame.script()->isLegacyGenerator());
+        RootedObject proto(cx, GlobalObject::getOrCreateLegacyGeneratorObjectPrototype(cx, global));
+        if (!proto)
+            return nullptr;
+        obj = NewNativeObjectWithGivenProto(cx, &LegacyGeneratorObject::class_, proto);
+    }
+    if (!obj)
+        return nullptr;
+
+    GeneratorObject* genObj = &obj->as<GeneratorObject>();
+    genObj->setCallee(*frame.callee());
+    genObj->setNewTarget(frame.newTarget());
+    genObj->setEnvironmentChain(*frame.environmentChain());
+    if (frame.script()->needsArgsObj())
+        genObj->setArgsObj(frame.argsObj());
+    genObj->clearExpressionStack();
+
+    return obj;
+}
+
+bool
+GeneratorObject::suspend(JSContext* cx, HandleObject obj, AbstractFramePtr frame, jsbytecode* pc,
+                         Value* vp, unsigned nvalues)
+{
+    MOZ_ASSERT(*pc == JSOP_INITIALYIELD || *pc == JSOP_YIELD);
+
+    Rooted<GeneratorObject*> genObj(cx, &obj->as<GeneratorObject>());
+    MOZ_ASSERT(!genObj->hasExpressionStack());
+
+    if (*pc == JSOP_YIELD && genObj->isClosing() && genObj->is<LegacyGeneratorObject>()) {
+        RootedValue val(cx, ObjectValue(*frame.callee()));
+        ReportValueError(cx, JSMSG_BAD_GENERATOR_YIELD, JSDVG_IGNORE_STACK, val, nullptr);
+        return false;
+    }
+
+    uint32_t yieldIndex = GET_UINT24(pc);
+    genObj->setYieldIndex(yieldIndex);
+    genObj->setEnvironmentChain(*frame.environmentChain());
+
+    if (nvalues) {
+        ArrayObject* stack = NewDenseCopiedArray(cx, nvalues, vp);
+        if (!stack)
+            return false;
+        genObj->setExpressionStack(*stack);
+    }
+
+    return true;
+}
+
+bool
+GeneratorObject::finalSuspend(JSContext* cx, HandleObject obj)
+{
+    Rooted<GeneratorObject*> genObj(cx, &obj->as<GeneratorObject>());
+    MOZ_ASSERT(genObj->isRunning() || genObj->isClosing());
+
+    bool closing = genObj->isClosing();
+    genObj->setClosed();
+
+    if (genObj->is<LegacyGeneratorObject>() && !closing)
+        return ThrowStopIteration(cx);
+
+    return true;
+}
+
+void
+js::SetReturnValueForClosingGenerator(JSContext* cx, AbstractFramePtr frame)
+{
+    CallObject& callObj = frame.callObj();
+
+    // Get the generator object stored on the scope chain and close it.
+    Shape* shape = callObj.lookup(cx, cx->names().dotGenerator);
+    GeneratorObject& genObj = callObj.getSlot(shape->slot()).toObject().as<GeneratorObject>();
+    genObj.setClosed();
+
+    // Return value is already set in GeneratorThrowOrClose.
+    if (genObj.is<StarGeneratorObject>())
+        return;
+
+    // Legacy generator .close() always returns |undefined|.
+    MOZ_ASSERT(genObj.is<LegacyGeneratorObject>());
+    frame.setReturnValue(UndefinedValue());
+}
+
+bool
+js::GeneratorThrowOrClose(JSContext* cx, AbstractFramePtr frame, Handle<GeneratorObject*> genObj,
+                          HandleValue arg, uint32_t resumeKind)
+{
+    if (resumeKind == GeneratorObject::THROW) {
+        cx->setPendingException(arg);
+        genObj->setRunning();
+    } else {
+        MOZ_ASSERT(resumeKind == GeneratorObject::CLOSE);
+
+        if (genObj->is<StarGeneratorObject>()) {
+            MOZ_ASSERT(arg.isObject());
+            frame.setReturnValue(arg);
+        } else {
+            MOZ_ASSERT(arg.isUndefined());
+        }
+
+        cx->setPendingException(MagicValue(JS_GENERATOR_CLOSING));
+        genObj->setClosing();
+    }
+    return false;
+}
+
+bool
+GeneratorObject::resume(JSContext* cx, InterpreterActivation& activation,
+                        HandleObject obj, HandleValue arg, GeneratorObject::ResumeKind resumeKind)
+{
+    Rooted<GeneratorObject*> genObj(cx, &obj->as<GeneratorObject>());
+    MOZ_ASSERT(genObj->isSuspended());
+
+    RootedFunction callee(cx, &genObj->callee());
+    RootedValue newTarget(cx, genObj->newTarget());
+    RootedObject envChain(cx, &genObj->environmentChain());
+    if (!activation.resumeGeneratorFrame(callee, newTarget, envChain))
+        return false;
+    activation.regs().fp()->setResumedGenerator();
+
+    if (genObj->hasArgsObj())
+        activation.regs().fp()->initArgsObj(genObj->argsObj());
+
+    if (genObj->hasExpressionStack()) {
+        uint32_t len = genObj->expressionStack().length();
+        MOZ_ASSERT(activation.regs().spForStackDepth(len));
+        const Value* src = genObj->expressionStack().getDenseElements();
+        mozilla::PodCopy(activation.regs().sp, src, len);
+        activation.regs().sp += len;
+        genObj->clearExpressionStack();
+    }
+
+    JSScript* script = callee->nonLazyScript();
+    uint32_t offset = script->yieldOffsets()[genObj->yieldIndex()];
+    activation.regs().pc = script->offsetToPC(offset);
+
+    // Always push on a value, even if we are raising an exception. In the
+    // exception case, the stack needs to have something on it so that exception
+    // handling doesn't skip the catch blocks. See TryNoteIter::settle.
+    activation.regs().sp++;
+    MOZ_ASSERT(activation.regs().spForStackDepth(activation.regs().stackDepth()));
+    activation.regs().sp[-1] = arg;
+
+    switch (resumeKind) {
+      case NEXT:
+        genObj->setRunning();
+        return true;
+
+      case THROW:
+      case CLOSE:
+        return GeneratorThrowOrClose(cx, activation.regs().fp(), genObj, arg, resumeKind);
+
+      default:
+        MOZ_CRASH("bad resumeKind");
+    }
+}
+
+bool
+LegacyGeneratorObject::close(JSContext* cx, HandleObject obj)
+{
+     Rooted<LegacyGeneratorObject*> genObj(cx, &obj->as<LegacyGeneratorObject>());
+
+    // Avoid calling back into JS unless it is necessary.
+     if (genObj->isClosed())
+        return true;
+
+    RootedValue rval(cx);
+
+    RootedValue closeValue(cx);
+    if (!GlobalObject::getIntrinsicValue(cx, cx->global(), cx->names().LegacyGeneratorCloseInternal,
+                                         &closeValue))
+    {
+        return false;
+    }
+    MOZ_ASSERT(closeValue.isObject());
+    MOZ_ASSERT(closeValue.toObject().is<JSFunction>());
+
+    FixedInvokeArgs<0> args(cx);
+
+    RootedValue v(cx, ObjectValue(*genObj));
+    return Call(cx, closeValue, v, args, &v);
+}
+
+const Class LegacyGeneratorObject::class_ = {
+    "Generator",
+    JSCLASS_HAS_RESERVED_SLOTS(GeneratorObject::RESERVED_SLOTS)
+};
+
+const Class StarGeneratorObject::class_ = {
+    "Generator",
+    JSCLASS_HAS_RESERVED_SLOTS(GeneratorObject::RESERVED_SLOTS)
+};
+
+static const JSFunctionSpec star_generator_methods[] = {
+    JS_SELF_HOSTED_FN("next", "StarGeneratorNext", 1, 0),
+    JS_SELF_HOSTED_FN("throw", "StarGeneratorThrow", 1, 0),
+    JS_SELF_HOSTED_FN("return", "StarGeneratorReturn", 1, 0),
+    JS_FS_END
+};
+
+#define JSPROP_ROPERM   (JSPROP_READONLY | JSPROP_PERMANENT)
+
+static const JSFunctionSpec legacy_generator_methods[] = {
+    JS_SELF_HOSTED_SYM_FN(iterator, "LegacyGeneratorIteratorShim", 0, 0),
+    // "send" is an alias for "next".
+    JS_SELF_HOSTED_FN("next", "LegacyGeneratorNext", 1, JSPROP_ROPERM),
+    JS_SELF_HOSTED_FN("send", "LegacyGeneratorNext", 1, JSPROP_ROPERM),
+    JS_SELF_HOSTED_FN("throw", "LegacyGeneratorThrow", 1, JSPROP_ROPERM),
+    JS_SELF_HOSTED_FN("close", "LegacyGeneratorClose", 0, JSPROP_ROPERM),
+    JS_FS_END
+};
+
+#undef JSPROP_ROPERM
+
+static JSObject*
+NewSingletonObjectWithObjectPrototype(JSContext* cx, Handle<GlobalObject*> global)
+{
+    RootedObject proto(cx, global->getOrCreateObjectPrototype(cx));
+    if (!proto)
+        return nullptr;
+    return NewObjectWithGivenProto<PlainObject>(cx, proto, SingletonObject);
+}
+
+JSObject*
+js::NewSingletonObjectWithFunctionPrototype(JSContext* cx, Handle<GlobalObject*> global)
+{
+    RootedObject proto(cx, global->getOrCreateFunctionPrototype(cx));
+    if (!proto)
+        return nullptr;
+    return NewObjectWithGivenProto<PlainObject>(cx, proto, SingletonObject);
+}
+
+/* static */ bool
+GlobalObject::initLegacyGeneratorProto(JSContext* cx, Handle<GlobalObject*> global)
+{
+    if (global->getReservedSlot(LEGACY_GENERATOR_OBJECT_PROTO).isObject())
+        return true;
+
+    RootedObject proto(cx, NewSingletonObjectWithObjectPrototype(cx, global));
+    if (!proto || !proto->setDelegate(cx))
+        return false;
+    if (!DefinePropertiesAndFunctions(cx, proto, nullptr, legacy_generator_methods))
+        return false;
+
+    global->setReservedSlot(LEGACY_GENERATOR_OBJECT_PROTO, ObjectValue(*proto));
+    return true;
+}
+
+/* static */ bool
+GlobalObject::initStarGenerators(JSContext* cx, Handle<GlobalObject*> global)
+{
+    if (global->getReservedSlot(STAR_GENERATOR_OBJECT_PROTO).isObject())
+        return true;
+
+    RootedObject iteratorProto(cx, GlobalObject::getOrCreateIteratorPrototype(cx, global));
+    if (!iteratorProto)
+        return false;
+
+    RootedObject genObjectProto(cx, global->createBlankPrototypeInheriting(cx,
+                                                                           &PlainObject::class_,
+                                                                           iteratorProto));
+    if (!genObjectProto)
+        return false;
+    if (!DefinePropertiesAndFunctions(cx, genObjectProto, nullptr, star_generator_methods) ||
+        !DefineToStringTag(cx, genObjectProto, cx->names().Generator))
+    {
+        return false;
+    }
+
+    RootedObject genFunctionProto(cx, NewSingletonObjectWithFunctionPrototype(cx, global));
+    if (!genFunctionProto || !genFunctionProto->setDelegate(cx))
+        return false;
+    if (!LinkConstructorAndPrototype(cx, genFunctionProto, genObjectProto) ||
+        !DefineToStringTag(cx, genFunctionProto, cx->names().GeneratorFunction))
+    {
+        return false;
+    }
+
+    RootedValue function(cx, global->getConstructor(JSProto_Function));
+    if (!function.toObjectOrNull())
+        return false;
+    RootedObject proto(cx, &function.toObject());
+    RootedAtom name(cx, cx->names().GeneratorFunction);
+    RootedObject genFunction(cx, NewFunctionWithProto(cx, Generator, 1,
+                                                      JSFunction::NATIVE_CTOR, nullptr, name,
+                                                      proto, gc::AllocKind::FUNCTION,
+                                                      SingletonObject));
+    if (!genFunction)
+        return false;
+    if (!LinkConstructorAndPrototype(cx, genFunction, genFunctionProto))
+        return false;
+
+    global->setReservedSlot(STAR_GENERATOR_OBJECT_PROTO, ObjectValue(*genObjectProto));
+    global->setReservedSlot(STAR_GENERATOR_FUNCTION, ObjectValue(*genFunction));
+    global->setReservedSlot(STAR_GENERATOR_FUNCTION_PROTO, ObjectValue(*genFunctionProto));
+    return true;
+}
+
+MOZ_MUST_USE bool
+js::CheckStarGeneratorResumptionValue(JSContext* cx, HandleValue v)
+{
+    // yield/return value should be an Object.
+    if (!v.isObject())
+        return false;
+
+    JSObject* obj = &v.toObject();
+
+    // It should have `done` data property with boolean value.
+    Value doneVal;
+    if (!GetPropertyPure(cx, obj, NameToId(cx->names().done), &doneVal))
+        return false;
+    if (!doneVal.isBoolean())
+        return false;
+
+    // It should have `value` data property, but the type doesn't matter
+    JSObject* ignored;
+    Shape* shape;
+    if (!LookupPropertyPure(cx, obj, NameToId(cx->names().value), &ignored, &shape))
+        return false;
+    if (!shape)
+        return false;
+    if (!shape->hasDefaultGetter())
+        return false;
+
+    return true;
+}