contexts-inl.h

// Copyright 2015 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.

#ifndef V8_CONTEXTS_INL_H_
#define V8_CONTEXTS_INL_H_

#include "src/contexts.h"

#include "src/heap/heap-write-barrier.h"
#include "src/objects-inl.h"
#include "src/objects/fixed-array-inl.h"
#include "src/objects/map-inl.h"
#include "src/objects/regexp-match-info.h"
#include "src/objects/scope-info.h"
#include "src/objects/shared-function-info.h"

// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"

namespace v8 {
namespace internal {

OBJECT_CONSTRUCTORS_IMPL(ScriptContextTable, FixedArray)
CAST_ACCESSOR2(ScriptContextTable)

int ScriptContextTable::used() const { return Smi::ToInt(get(kUsedSlotIndex)); }

void ScriptContextTable::set_used(int used) {
  set(kUsedSlotIndex, Smi::FromInt(used));
}

// static
Handle<Context> ScriptContextTable::GetContext(Isolate* isolate,
                                               Handle<ScriptContextTable> table,
                                               int i) {
  DCHECK(i < table->used());
  return Handle<Context>::cast(
      FixedArray::get(*table, i + kFirstContextSlotIndex, isolate));
}

OBJECT_CONSTRUCTORS_IMPL(Context, HeapObjectPtr)
NEVER_READ_ONLY_SPACE_IMPL(Context)
CAST_ACCESSOR2(Context)
SMI_ACCESSORS(Context, length, kLengthOffset)

CAST_ACCESSOR2(NativeContext)

Object* Context::get(int index) const {
  DCHECK_LT(static_cast<unsigned>(index),
            static_cast<unsigned>(this->length()));
  return RELAXED_READ_FIELD(this, OffsetOfElementAt(index));
}

void Context::set(int index, Object* value) {
  DCHECK_LT(static_cast<unsigned>(index),
            static_cast<unsigned>(this->length()));
  int offset = OffsetOfElementAt(index);
  RELAXED_WRITE_FIELD(this, offset, value);
  WRITE_BARRIER(this, offset, value);
}

void Context::set(int index, Object* value, WriteBarrierMode mode) {
  DCHECK_LT(static_cast<unsigned>(index),
            static_cast<unsigned>(this->length()));
  int offset = OffsetOfElementAt(index);
  RELAXED_WRITE_FIELD(this, offset, value);
  CONDITIONAL_WRITE_BARRIER(this, offset, value, mode);
}

void Context::set_scope_info(ScopeInfo scope_info) {
  set(SCOPE_INFO_INDEX, scope_info);
}

Context Context::previous() {
  Object* result = get(PREVIOUS_INDEX);
  DCHECK(IsBootstrappingOrValidParentContext(result, *this));
  return Context::unchecked_cast(result);
}
void Context::set_previous(Context context) { set(PREVIOUS_INDEX, context); }

Object* Context::next_context_link() { return get(Context::NEXT_CONTEXT_LINK); }

bool Context::has_extension() { return !extension()->IsTheHole(); }
HeapObject* Context::extension() {
  return HeapObject::cast(get(EXTENSION_INDEX));
}
void Context::set_extension(HeapObject* object) {
  set(EXTENSION_INDEX, object);
}

NativeContext Context::native_context() const {
  Object* result = get(NATIVE_CONTEXT_INDEX);
  DCHECK(IsBootstrappingOrNativeContext(this->GetIsolate(), result));
  return NativeContext::unchecked_cast(result);
}

void Context::set_native_context(NativeContext context) {
  set(NATIVE_CONTEXT_INDEX, context);
}

bool Context::IsFunctionContext() const {
  return map()->instance_type() == FUNCTION_CONTEXT_TYPE;
}

bool Context::IsCatchContext() const {
  return map()->instance_type() == CATCH_CONTEXT_TYPE;
}

bool Context::IsWithContext() const {
  return map()->instance_type() == WITH_CONTEXT_TYPE;
}

bool Context::IsDebugEvaluateContext() const {
  return map()->instance_type() == DEBUG_EVALUATE_CONTEXT_TYPE;
}

bool Context::IsAwaitContext() const {
  return map()->instance_type() == AWAIT_CONTEXT_TYPE;
}

bool Context::IsBlockContext() const {
  return map()->instance_type() == BLOCK_CONTEXT_TYPE;
}

bool Context::IsModuleContext() const {
  return map()->instance_type() == MODULE_CONTEXT_TYPE;
}

bool Context::IsEvalContext() const {
  return map()->instance_type() == EVAL_CONTEXT_TYPE;
}

bool Context::IsScriptContext() const {
  return map()->instance_type() == SCRIPT_CONTEXT_TYPE;
}

bool Context::HasSameSecurityTokenAs(Context that) const {
  return this->native_context()->security_token() ==
         that->native_context()->security_token();
}

#define NATIVE_CONTEXT_FIELD_ACCESSORS(index, type, name) \
  void Context::set_##name(type##ArgType value) {         \
    DCHECK(IsNativeContext());                            \
    set(index, value);                                    \
  }                                                       \
  bool Context::is_##name(type##ArgType value) const {    \
    DCHECK(IsNativeContext());                            \
    return type::cast(get(index)) == value;               \
  }                                                       \
  type##ArgType Context::name() const {                   \
    DCHECK(IsNativeContext());                            \
    return type::cast(get(index));                        \
  }
NATIVE_CONTEXT_FIELDS(NATIVE_CONTEXT_FIELD_ACCESSORS)
#undef NATIVE_CONTEXT_FIELD_ACCESSORS

#define CHECK_FOLLOWS2(v1, v2) STATIC_ASSERT((v1 + 1) == (v2))
#define CHECK_FOLLOWS4(v1, v2, v3, v4) \
  CHECK_FOLLOWS2(v1, v2);              \
  CHECK_FOLLOWS2(v2, v3);              \
  CHECK_FOLLOWS2(v3, v4)

int Context::FunctionMapIndex(LanguageMode language_mode, FunctionKind kind,
                              bool has_prototype_slot, bool has_shared_name,
                              bool needs_home_object) {
  if (IsClassConstructor(kind)) {
    // Like the strict function map, but with no 'name' accessor. 'name'
    // needs to be the last property and it is added during instantiation,
    // in case a static property with the same name exists"
    return CLASS_FUNCTION_MAP_INDEX;
  }

  int base = 0;
  if (IsGeneratorFunction(kind)) {
    CHECK_FOLLOWS4(GENERATOR_FUNCTION_MAP_INDEX,
                   GENERATOR_FUNCTION_WITH_NAME_MAP_INDEX,
                   GENERATOR_FUNCTION_WITH_HOME_OBJECT_MAP_INDEX,
                   GENERATOR_FUNCTION_WITH_NAME_AND_HOME_OBJECT_MAP_INDEX);
    CHECK_FOLLOWS4(
        ASYNC_GENERATOR_FUNCTION_MAP_INDEX,
        ASYNC_GENERATOR_FUNCTION_WITH_NAME_MAP_INDEX,
        ASYNC_GENERATOR_FUNCTION_WITH_HOME_OBJECT_MAP_INDEX,
        ASYNC_GENERATOR_FUNCTION_WITH_NAME_AND_HOME_OBJECT_MAP_INDEX);

    base = IsAsyncFunction(kind) ? ASYNC_GENERATOR_FUNCTION_MAP_INDEX
                                 : GENERATOR_FUNCTION_MAP_INDEX;

  } else if (IsAsyncFunction(kind)) {
    CHECK_FOLLOWS4(ASYNC_FUNCTION_MAP_INDEX, ASYNC_FUNCTION_WITH_NAME_MAP_INDEX,
                   ASYNC_FUNCTION_WITH_HOME_OBJECT_MAP_INDEX,
                   ASYNC_FUNCTION_WITH_NAME_AND_HOME_OBJECT_MAP_INDEX);

    base = ASYNC_FUNCTION_MAP_INDEX;

  } else if (IsArrowFunction(kind) || IsConciseMethod(kind) ||
             IsAccessorFunction(kind)) {
    DCHECK_IMPLIES(IsArrowFunction(kind), !needs_home_object);
    CHECK_FOLLOWS4(STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX,
                   METHOD_WITH_NAME_MAP_INDEX,
                   METHOD_WITH_HOME_OBJECT_MAP_INDEX,
                   METHOD_WITH_NAME_AND_HOME_OBJECT_MAP_INDEX);

    base = STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX;

  } else {
    DCHECK(!needs_home_object);
    CHECK_FOLLOWS2(SLOPPY_FUNCTION_MAP_INDEX,
                   SLOPPY_FUNCTION_WITH_NAME_MAP_INDEX);
    CHECK_FOLLOWS2(STRICT_FUNCTION_MAP_INDEX,
                   STRICT_FUNCTION_WITH_NAME_MAP_INDEX);

    base = is_strict(language_mode) ? STRICT_FUNCTION_MAP_INDEX
                                    : SLOPPY_FUNCTION_MAP_INDEX;
  }
  int offset = static_cast<int>(!has_shared_name) |
               (static_cast<int>(needs_home_object) << 1);
  DCHECK_EQ(0, offset & ~3);

  return base + offset;
}

#undef CHECK_FOLLOWS2
#undef CHECK_FOLLOWS4

Map Context::GetInitialJSArrayMap(ElementsKind kind) const {
  DCHECK(IsNativeContext());
  if (!IsFastElementsKind(kind)) return Map();
  DisallowHeapAllocation no_gc;
  Object* const initial_js_array_map = get(Context::ArrayMapIndex(kind));
  DCHECK(!initial_js_array_map->IsUndefined());
  return Map::cast(initial_js_array_map);
}

MicrotaskQueue* NativeContext::microtask_queue() const {
  return reinterpret_cast<MicrotaskQueue*>(
      READ_INTPTR_FIELD(this, kMicrotaskQueueOffset));
}

void NativeContext::set_microtask_queue(MicrotaskQueue* microtask_queue) {
  WRITE_INTPTR_FIELD(this, kMicrotaskQueueOffset,
                     reinterpret_cast<intptr_t>(microtask_queue));
}

OBJECT_CONSTRUCTORS_IMPL(NativeContext, Context)

}  // namespace internal
}  // namespace v8

#include "src/objects/object-macros-undef.h"

#endif  // V8_CONTEXTS_INL_H_