runtime-internal.cc

// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/v8.h"

#include "src/arguments.h"
#include "src/bootstrapper.h"
#include "src/debug.h"
#include "src/runtime/runtime-utils.h"

namespace v8 {
namespace internal {

RUNTIME_FUNCTION(Runtime_CheckIsBootstrapping) {
  SealHandleScope shs(isolate);
  DCHECK(args.length() == 0);
  RUNTIME_ASSERT(isolate->bootstrapper()->IsActive());
  return isolate->heap()->undefined_value();
}


RUNTIME_FUNCTION(Runtime_Throw) {
  HandleScope scope(isolate);
  DCHECK(args.length() == 1);

  return isolate->Throw(args[0]);
}


RUNTIME_FUNCTION(Runtime_ReThrow) {
  HandleScope scope(isolate);
  DCHECK(args.length() == 1);

  return isolate->ReThrow(args[0]);
}


RUNTIME_FUNCTION(Runtime_PromoteScheduledException) {
  SealHandleScope shs(isolate);
  DCHECK(args.length() == 0);
  return isolate->PromoteScheduledException();
}


RUNTIME_FUNCTION(Runtime_ThrowReferenceError) {
  HandleScope scope(isolate);
  DCHECK(args.length() == 1);
  CONVERT_ARG_HANDLE_CHECKED(Object, name, 0);
  THROW_NEW_ERROR_RETURN_FAILURE(
      isolate, NewReferenceError("not_defined", HandleVector(&name, 1)));
}


RUNTIME_FUNCTION(Runtime_PromiseRejectEvent) {
  DCHECK(args.length() == 3);
  HandleScope scope(isolate);
  CONVERT_ARG_HANDLE_CHECKED(JSObject, promise, 0);
  CONVERT_ARG_HANDLE_CHECKED(Object, value, 1);
  CONVERT_BOOLEAN_ARG_CHECKED(debug_event, 2);
  if (debug_event) isolate->debug()->OnPromiseReject(promise, value);
  Handle<Symbol> key = isolate->factory()->promise_has_handler_symbol();
  // Do not report if we actually have a handler.
  if (JSObject::GetDataProperty(promise, key)->IsUndefined()) {
    isolate->ReportPromiseReject(promise, value,
                                 v8::kPromiseRejectWithNoHandler);
  }
  return isolate->heap()->undefined_value();
}


RUNTIME_FUNCTION(Runtime_PromiseRevokeReject) {
  DCHECK(args.length() == 1);
  HandleScope scope(isolate);
  CONVERT_ARG_HANDLE_CHECKED(JSObject, promise, 0);
  Handle<Symbol> key = isolate->factory()->promise_has_handler_symbol();
  // At this point, no revocation has been issued before
  RUNTIME_ASSERT(JSObject::GetDataProperty(promise, key)->IsUndefined());
  isolate->ReportPromiseReject(promise, Handle<Object>(),
                               v8::kPromiseHandlerAddedAfterReject);
  return isolate->heap()->undefined_value();
}


RUNTIME_FUNCTION(Runtime_PromiseHasHandlerSymbol) {
  DCHECK(args.length() == 0);
  return isolate->heap()->promise_has_handler_symbol();
}


RUNTIME_FUNCTION(Runtime_StackGuard) {
  SealHandleScope shs(isolate);
  DCHECK(args.length() == 0);

  // First check if this is a real stack overflow.
  StackLimitCheck check(isolate);
  if (check.JsHasOverflowed()) {
    return isolate->StackOverflow();
  }

  return isolate->stack_guard()->HandleInterrupts();
}


RUNTIME_FUNCTION(Runtime_Interrupt) {
  SealHandleScope shs(isolate);
  DCHECK(args.length() == 0);
  return isolate->stack_guard()->HandleInterrupts();
}


RUNTIME_FUNCTION(Runtime_AllocateInNewSpace) {
  HandleScope scope(isolate);
  DCHECK(args.length() == 1);
  CONVERT_SMI_ARG_CHECKED(size, 0);
  RUNTIME_ASSERT(IsAligned(size, kPointerSize));
  RUNTIME_ASSERT(size > 0);
  RUNTIME_ASSERT(size <= Page::kMaxRegularHeapObjectSize);
  return *isolate->factory()->NewFillerObject(size, false, NEW_SPACE);
}


RUNTIME_FUNCTION(Runtime_AllocateInTargetSpace) {
  HandleScope scope(isolate);
  DCHECK(args.length() == 2);
  CONVERT_SMI_ARG_CHECKED(size, 0);
  CONVERT_SMI_ARG_CHECKED(flags, 1);
  RUNTIME_ASSERT(IsAligned(size, kPointerSize));
  RUNTIME_ASSERT(size > 0);
  RUNTIME_ASSERT(size <= Page::kMaxRegularHeapObjectSize);
  bool double_align = AllocateDoubleAlignFlag::decode(flags);
  AllocationSpace space = AllocateTargetSpace::decode(flags);
  return *isolate->factory()->NewFillerObject(size, double_align, space);
}


// Collect the raw data for a stack trace.  Returns an array of 4
// element segments each containing a receiver, function, code and
// native code offset.
RUNTIME_FUNCTION(Runtime_CollectStackTrace) {
  HandleScope scope(isolate);
  DCHECK(args.length() == 2);
  CONVERT_ARG_HANDLE_CHECKED(JSObject, error_object, 0);
  CONVERT_ARG_HANDLE_CHECKED(Object, caller, 1);

  if (!isolate->bootstrapper()->IsActive()) {
    // Optionally capture a more detailed stack trace for the message.
    isolate->CaptureAndSetDetailedStackTrace(error_object);
    // Capture a simple stack trace for the stack property.
    isolate->CaptureAndSetSimpleStackTrace(error_object, caller);
  }
  return isolate->heap()->undefined_value();
}


RUNTIME_FUNCTION(Runtime_GetFromCache) {
  SealHandleScope shs(isolate);
  // This is only called from codegen, so checks might be more lax.
  CONVERT_ARG_CHECKED(JSFunctionResultCache, cache, 0);
  CONVERT_ARG_CHECKED(Object, key, 1);

  {
    DisallowHeapAllocation no_alloc;

    int finger_index = cache->finger_index();
    Object* o = cache->get(finger_index);
    if (o == key) {
      // The fastest case: hit the same place again.
      return cache->get(finger_index + 1);
    }

    for (int i = finger_index - 2; i >= JSFunctionResultCache::kEntriesIndex;
         i -= 2) {
      o = cache->get(i);
      if (o == key) {
        cache->set_finger_index(i);
        return cache->get(i + 1);
      }
    }

    int size = cache->size();
    DCHECK(size <= cache->length());

    for (int i = size - 2; i > finger_index; i -= 2) {
      o = cache->get(i);
      if (o == key) {
        cache->set_finger_index(i);
        return cache->get(i + 1);
      }
    }
  }

  // There is no value in the cache.  Invoke the function and cache result.
  HandleScope scope(isolate);

  Handle<JSFunctionResultCache> cache_handle(cache);
  Handle<Object> key_handle(key, isolate);
  Handle<Object> value;
  {
    Handle<JSFunction> factory(JSFunction::cast(
        cache_handle->get(JSFunctionResultCache::kFactoryIndex)));
    // TODO(antonm): consider passing a receiver when constructing a cache.
    Handle<JSObject> receiver(isolate->global_proxy());
    // This handle is nor shared, nor used later, so it's safe.
    Handle<Object> argv[] = {key_handle};
    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
        isolate, value,
        Execution::Call(isolate, factory, receiver, arraysize(argv), argv));
  }

#ifdef VERIFY_HEAP
  if (FLAG_verify_heap) {
    cache_handle->JSFunctionResultCacheVerify();
  }
#endif

  // Function invocation may have cleared the cache.  Reread all the data.
  int finger_index = cache_handle->finger_index();
  int size = cache_handle->size();

  // If we have spare room, put new data into it, otherwise evict post finger
  // entry which is likely to be the least recently used.
  int index = -1;
  if (size < cache_handle->length()) {
    cache_handle->set_size(size + JSFunctionResultCache::kEntrySize);
    index = size;
  } else {
    index = finger_index + JSFunctionResultCache::kEntrySize;
    if (index == cache_handle->length()) {
      index = JSFunctionResultCache::kEntriesIndex;
    }
  }

  DCHECK(index % 2 == 0);
  DCHECK(index >= JSFunctionResultCache::kEntriesIndex);
  DCHECK(index < cache_handle->length());

  cache_handle->set(index, *key_handle);
  cache_handle->set(index + 1, *value);
  cache_handle->set_finger_index(index);

#ifdef VERIFY_HEAP
  if (FLAG_verify_heap) {
    cache_handle->JSFunctionResultCacheVerify();
  }
#endif

  return *value;
}


RUNTIME_FUNCTION(Runtime_MessageGetStartPosition) {
  SealHandleScope shs(isolate);
  DCHECK(args.length() == 1);
  CONVERT_ARG_CHECKED(JSMessageObject, message, 0);
  return Smi::FromInt(message->start_position());
}


RUNTIME_FUNCTION(Runtime_MessageGetScript) {
  SealHandleScope shs(isolate);
  DCHECK(args.length() == 1);
  CONVERT_ARG_CHECKED(JSMessageObject, message, 0);
  return message->script();
}


RUNTIME_FUNCTION(Runtime_IS_VAR) {
  UNREACHABLE();  // implemented as macro in the parser
  return NULL;
}


RUNTIME_FUNCTION(RuntimeReference_GetFromCache) {
  HandleScope scope(isolate);
  DCHECK(args.length() == 2);
  CONVERT_SMI_ARG_CHECKED(id, 0);
  args[0] = isolate->native_context()->jsfunction_result_caches()->get(id);
  return __RT_impl_Runtime_GetFromCache(args, isolate);
}
}
}  // namespace v8::internal