C++ InterpreterFrame类代码示例

int MethodHandles::method_handle_entry_linkToInterface(Method* method, intptr_t UNUSED, TRAPS) {
  JavaThread *thread = (JavaThread *) THREAD;
  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
  interpreterState istate = frame->interpreter_state();

  // Pop appendix argument from stack. This is a MemberName which we resolve to the
  // target method.
  oop vmentry = popFromStack(THREAD);
  intptr_t* topOfStack = istate->stack();

  // Resolve target method by looking up in the receiver object's itable.
  Klass* clazz = java_lang_Class::as_Klass(java_lang_invoke_MemberName::clazz(vmentry));
  intptr_t vmindex = java_lang_invoke_MemberName::vmindex(vmentry);
  Method* target = (Method*) java_lang_invoke_MemberName::vmtarget(vmentry);

  int numArgs = target->size_of_parameters();
  oop recv = STACK_OBJECT(-numArgs);

  InstanceKlass* klass_part = InstanceKlass::cast(recv->klass());
  itableOffsetEntry* ki = (itableOffsetEntry*) klass_part->start_of_itable();
  int i;
  for ( i = 0 ; i < klass_part->itable_length() ; i++, ki++ ) {
    if (ki->interface_klass() == clazz) break;
  }

  itableMethodEntry* im = ki->first_method_entry(recv->klass());
  Method* vmtarget = im[vmindex].method();

  invoke_target(vmtarget, THREAD);

  return 0;
}

int MethodHandles::method_handle_entry_linkToVirtual(Method* method, intptr_t UNUSED, TRAPS) {
  JavaThread *thread = (JavaThread *) THREAD;

  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
  interpreterState istate = frame->interpreter_state();

  // Pop appendix argument from stack. This is a MemberName which we resolve to the
  // target method.
  oop vmentry = popFromStack(THREAD);
  intptr_t* topOfStack = istate->stack();

  // Resolve target method by looking up in the receiver object's vtable.
  intptr_t vmindex = java_lang_invoke_MemberName::vmindex(vmentry);
  Method* target = (Method*) java_lang_invoke_MemberName::vmtarget(vmentry);
  int numArgs = target->size_of_parameters();
  oop recv = STACK_OBJECT(-numArgs);
  Klass* clazz = recv->klass();
  Klass* klass_part = InstanceKlass::cast(clazz);
  klassVtable* vtable = klass_part->vtable();
  Method* vmtarget = vtable->method_at(vmindex);

  invoke_target(vmtarget, THREAD);

  return 0;
}

static void
MarkInterpreterActivation(JSTracer *trc, InterpreterActivation *act)
{
    for (InterpreterFrameIterator frames(act); !frames.done(); ++frames) {
        InterpreterFrame *fp = frames.frame();
        fp->markValues(trc, frames.sp(), frames.pc());
        fp->mark(trc);
    }
}

bool
TraceLoggerThread::enable(JSContext* cx)
{
    if (!enable())
        return fail(cx, "internal error");

    if (enabled_ == 1) {
        // Get the top Activation to log the top script/pc (No inlined frames).
        ActivationIterator iter(cx->runtime());
        Activation* act = iter.activation();

        if (!act)
            return fail(cx, "internal error");

        JSScript* script = nullptr;
        int32_t engine = 0;

        if (act->isJit()) {
            JitFrameIterator it(iter);

            while (!it.isScripted() && !it.done())
                ++it;

            MOZ_ASSERT(!it.done());
            MOZ_ASSERT(it.isIonJS() || it.isBaselineJS());

            script = it.script();
            engine = it.isIonJS() ? TraceLogger_IonMonkey : TraceLogger_Baseline;
        } else if (act->isWasm()) {
            JS_ReportErrorNumber(cx, GetErrorMessage, nullptr, JSMSG_TRACELOGGER_ENABLE_FAIL,
                                 "not yet supported in wasm code");
            return false;
        } else {
            MOZ_ASSERT(act->isInterpreter());
            InterpreterFrame* fp = act->asInterpreter()->current();
            MOZ_ASSERT(!fp->runningInJit());

            script = fp->script();
            engine = TraceLogger_Interpreter;
            if (script->compartment() != cx->compartment())
                return fail(cx, "compartment mismatch");
        }

        TraceLoggerEvent event(this, TraceLogger_Scripts, script);
        startEvent(event);
        startEvent(engine);
    }

    return true;
}

oop MethodHandles::popFromStack(TRAPS) {

  JavaThread *thread = (JavaThread *) THREAD;
  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
  interpreterState istate = frame->interpreter_state();
  intptr_t* topOfStack = istate->stack();

  oop top = STACK_OBJECT(-1);
  MORE_STACK(-1);
  istate->set_stack(topOfStack);

  return top;

}

void MethodHandles::invoke_target(Method* method, TRAPS) {

  JavaThread *thread = (JavaThread *) THREAD;
  ZeroStack *stack = thread->zero_stack();
  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
  interpreterState istate = frame->interpreter_state();

  // Trim back the stack to put the parameters at the top
  stack->set_sp(istate->stack() + 1);

  Interpreter::invoke_method(method, method->from_interpreted_entry(), THREAD);

  // Convert the result
  istate->set_stack(stack->sp() - 1);

}

InterpreterFrame *
InterpreterStack::pushInvokeFrame(JSContext *cx, const CallArgs &args, InitialFrameFlags initial)
{
    LifoAlloc::Mark mark = allocator_.mark();

    RootedFunction fun(cx, &args.callee().as<JSFunction>());
    RootedScript script(cx, fun->nonLazyScript());

    InterpreterFrame::Flags flags = ToFrameFlags(initial);
    Value *argv;
    InterpreterFrame *fp = getCallFrame(cx, args, script, &flags, &argv);
    if (!fp)
        return nullptr;

    fp->mark_ = mark;
    fp->initCallFrame(cx, nullptr, nullptr, nullptr, *fun, script, argv, args.length(), flags);
    return fp;
}

int MethodHandles::method_handle_entry_invokeBasic(Method* method, intptr_t UNUSED, TRAPS) {

  JavaThread *thread = (JavaThread *) THREAD;
  InterpreterFrame *frame = thread->top_zero_frame()->as_interpreter_frame();
  interpreterState istate = frame->interpreter_state();
  intptr_t* topOfStack = istate->stack();

  // 'this' is a MethodHandle. We resolve the target method by accessing this.form.vmentry.vmtarget.
  int numArgs = method->size_of_parameters();
  oop lform1 = java_lang_invoke_MethodHandle::form(STACK_OBJECT(-numArgs)); // this.form
  oop vmEntry1 = java_lang_invoke_LambdaForm::vmentry(lform1);
  Method* vmtarget = (Method*) java_lang_invoke_MemberName::vmtarget(vmEntry1);

  invoke_target(vmtarget, THREAD);

  // No deoptimized frames on the stack
  return 0;
}

InterpreterFrame *
InterpreterStack::pushExecuteFrame(JSContext *cx, HandleScript script, const Value &thisv,
                                   HandleObject scopeChain, ExecuteType type,
                                   AbstractFramePtr evalInFrame)
{
    LifoAlloc::Mark mark = allocator_.mark();

    unsigned nvars = 2 /* callee, this */ + script->nslots();
    uint8_t *buffer = allocateFrame(cx, sizeof(InterpreterFrame) + nvars * sizeof(Value));
    if (!buffer)
        return nullptr;

    InterpreterFrame *fp = reinterpret_cast<InterpreterFrame *>(buffer + 2 * sizeof(Value));
    fp->mark_ = mark;
    fp->initExecuteFrame(cx, script, evalInFrame, thisv, *scopeChain, type);
    fp->initVarsToUndefined();

    return fp;
}