Exemplo n.º 1
0
IonBailoutIterator::IonBailoutIterator(const JitActivationIterator &activations,
                                       BailoutStack *bailout)
  : IonFrameIterator(activations),
    machine_(bailout->machine())
{
    uint8_t *sp = bailout->parentStackPointer();
    uint8_t *fp = sp + bailout->frameSize();

    current_ = fp;
    type_ = IonFrame_OptimizedJS;
    topFrameSize_ = current_ - sp;
    topIonScript_ = script()->ionScript();

    if (bailout->frameClass() == FrameSizeClass::None()) {
        snapshotOffset_ = bailout->snapshotOffset();
        return;
    }

    // Compute the snapshot offset from the bailout ID.
    JitActivation *activation = activations.activation()->asJit();
    JSRuntime *rt = activation->compartment()->runtimeFromMainThread();
    IonCode *code = rt->ionRuntime()->getBailoutTable(bailout->frameClass());
    uintptr_t tableOffset = bailout->tableOffset();
    uintptr_t tableStart = reinterpret_cast<uintptr_t>(code->raw());

    JS_ASSERT(tableOffset >= tableStart &&
              tableOffset < tableStart + code->instructionsSize());
    JS_ASSERT((tableOffset - tableStart) % BAILOUT_TABLE_ENTRY_SIZE == 0);

    uint32_t bailoutId = ((tableOffset - tableStart) / BAILOUT_TABLE_ENTRY_SIZE) - 1;
    JS_ASSERT(bailoutId < BAILOUT_TABLE_SIZE);

    snapshotOffset_ = topIonScript_->bailoutToSnapshot(bailoutId);
}
BailoutEnvironment::BailoutEnvironment(IonCompartment *ion, void **sp)
  : sp_(sp)
{
    bailout_ = reinterpret_cast<ExtendedBailoutStack *>(sp);

    if (bailout_->frameClass() != FrameSizeClass::None()) {
        frameSize_ = bailout_->frameSize();
        frame_ = &sp_[sizeof(BailoutStack) / STACK_SLOT_SIZE];

        // Compute the bailout ID.
        IonCode *code = ion->getBailoutTable(bailout_->frameClass());
        uintptr_t tableOffset = bailout_->tableOffset();
        uintptr_t tableStart = reinterpret_cast<uintptr_t>(code->raw());

        JS_ASSERT(tableOffset >= tableStart &&
                  tableOffset < tableStart + code->instructionsSize());
        JS_ASSERT((tableOffset - tableStart) % BAILOUT_TABLE_ENTRY_SIZE == 0);

        bailoutId_ = ((tableOffset - tableStart) / BAILOUT_TABLE_ENTRY_SIZE) - 1;
        JS_ASSERT(bailoutId_ < BAILOUT_TABLE_SIZE);
    } else {
        frameSize_ = bailout_->frameSize();
        frame_ = &sp_[sizeof(ExtendedBailoutStack) / STACK_SLOT_SIZE];
    }
}