frames.h

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// Copyright 2012 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_EXECUTION_FRAMES_H_
#define V8_EXECUTION_FRAMES_H_
 
#include "include/v8-initialization.h"
#include "src/base/bounds.h"
#include "src/codegen/handler-table.h"
#include "src/codegen/safepoint-table.h"
#include "src/common/assert-scope.h"
#include "src/common/globals.h"
#include "src/objects/code.h"
#include "src/objects/deoptimization-data.h"
#include "src/objects/objects.h"
 
#if V8_ENABLE_WEBASSEMBLY
#include "src/wasm/stacks.h"
#include "src/wasm/wasm-code-manager.h"
#endif  // V8_ENABLE_WEBASSEMBLY
 
//
// Frame inheritance hierarchy (please keep in sync with frame-constants.h):
// - CommonFrame
//   - CommonFrameWithJSLinkage
//     - JavaScriptFrame (aka StandardFrame)
//       - UnoptimizedJSFrame
//         - InterpretedFrame
//         - BaselineFrame
//       - OptimizedJSFrame
//         - MaglevFrame
//         - TurbofanJSFrame
//     - TypedFrameWithJSLinkage
//       - BuiltinFrame
//       - JavaScriptBuiltinContinuationFrame
//         - JavaScriptBuiltinContinuationWithCatchFrame
//   - TurbofanStubWithContextFrame
//   - TypedFrame
//     - NativeFrame
//     - EntryFrame
//       - ConstructEntryFrame
//     - ExitFrame
//       - BuiltinExitFrame
//     - StubFrame
//       - JsToWasmFrame
//       - CWasmEntryFrame
//     - Internal
//       - ConstructFrame
//       - FastConstructFrame
//       - BuiltinContinuationFrame
//     - WasmFrame
//       - WasmExitFrame
//       - WasmToJsFrame
//       - WasmInterpreterEntryFrame (#if V8_ENABLE_DRUMBRAKE)
//     - WasmDebugBreakFrame
//     - WasmLiftoffSetupFrame
//     - IrregexpFrame
 
namespace v8 {
namespace internal {
namespace wasm {
class WasmCode;
struct JumpBuffer;
class StackMemory;
}  // namespace wasm
 
class AbstractCode;
class Debug;
class ExternalCallbackScope;
class InnerPointerToCodeCache;
class Isolate;
class ObjectVisitor;
class Register;
class RootVisitor;
class StackFrameInfo;
class StackFrameIteratorBase;
class StringStream;
class ThreadLocalTop;
class WasmInstanceObject;
class WasmModuleObject;
 
#if V8_ENABLE_DRUMBRAKE
class Tuple2;
#endif  // V8_ENABLE_DRUMBRAKE
 
class StackHandlerConstants : public AllStatic {
 public:
  static const int kNextOffset = 0 * kSystemPointerSize;
  static const int kPaddingOffset = 1 * kSystemPointerSize;
 
  static const int kSize = kPaddingOffset + kSystemPointerSize;
  static const int kSlotCount = kSize >> kSystemPointerSizeLog2;
};
 
class StackHandler {
 public:
  // Get the address of this stack handler.
  inline Address address() const;
 
  // Get the next stack handler in the chain.
  inline StackHandler* next() const;
 
  // Get the next stack handler, as an Address. This is safe to use even
  // when the next handler is null.
  inline Address next_address() const;
 
  // Conversion support.
  static inline StackHandler* FromAddress(Address address);
 
 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(StackHandler);
};
 
#define STACK_FRAME_TYPE_LIST(V)                                          \
  V(ENTRY, EntryFrame)                                                    \
  V(CONSTRUCT_ENTRY, ConstructEntryFrame)                                 \
  V(EXIT, ExitFrame)                                                      \
  IF_WASM(V, WASM, WasmFrame)                                             \
  IF_WASM(V, WASM_TO_JS, WasmToJsFrame)                                   \
  IF_WASM(V, WASM_TO_JS_FUNCTION, WasmToJsFunctionFrame)                  \
  IF_WASM(V, JS_TO_WASM, JsToWasmFrame)                                   \
  IF_WASM(V, STACK_SWITCH, StackSwitchFrame)                              \
  IF_WASM_DRUMBRAKE(V, WASM_INTERPRETER_ENTRY, WasmInterpreterEntryFrame) \
  IF_WASM(V, WASM_DEBUG_BREAK, WasmDebugBreakFrame)                       \
  IF_WASM(V, C_WASM_ENTRY, CWasmEntryFrame)                               \
  IF_WASM(V, WASM_EXIT, WasmExitFrame)                                    \
  IF_WASM(V, WASM_LIFTOFF_SETUP, WasmLiftoffSetupFrame)                   \
  IF_WASM(V, WASM_SEGMENT_START, WasmSegmentStartFrame)                   \
  V(INTERPRETED, InterpretedFrame)                                        \
  V(BASELINE, BaselineFrame)                                              \
  V(MAGLEV, MaglevFrame)                                                  \
  V(TURBOFAN_JS, TurbofanJSFrame)                                         \
  V(STUB, StubFrame)                                                      \
  V(TURBOFAN_STUB_WITH_CONTEXT, TurbofanStubWithContextFrame)             \
  V(BUILTIN_CONTINUATION, BuiltinContinuationFrame)                       \
  V(JAVASCRIPT_BUILTIN_CONTINUATION, JavaScriptBuiltinContinuationFrame)  \
  V(JAVASCRIPT_BUILTIN_CONTINUATION_WITH_CATCH,                           \
    JavaScriptBuiltinContinuationWithCatchFrame)                          \
  V(INTERNAL, InternalFrame)                                              \
  V(CONSTRUCT, ConstructFrame)                                            \
  V(FAST_CONSTRUCT, FastConstructFrame)                                   \
  V(BUILTIN, BuiltinFrame)                                                \
  V(BUILTIN_EXIT, BuiltinExitFrame)                                       \
  V(API_CALLBACK_EXIT, ApiCallbackExitFrame)                              \
  V(API_ACCESSOR_EXIT, ApiAccessorExitFrame)                              \
  V(NATIVE, NativeFrame)                                                  \
  V(IRREGEXP, IrregexpFrame)
 
// Abstract base class for all stack frames.
class StackFrame {
 public:
#define DECLARE_TYPE(type, ignore) type,
  enum Type {
    NO_FRAME_TYPE = 0,
    STACK_FRAME_TYPE_LIST(DECLARE_TYPE) NUMBER_OF_TYPES,
    // Used by FrameScope to indicate that the stack frame is constructed
    // manually and the FrameScope does not need to emit code.
    MANUAL
  };
#undef DECLARE_TYPE
 
  // Used to mark the outermost JS entry frame.
  //
  // The mark is an opaque value that should be pushed onto the stack directly,
  // carefully crafted to not be interpreted as a tagged pointer.
  enum JsFrameMarker {
    INNER_JSENTRY_FRAME = (0 << kSmiTagSize) | kSmiTag,
    OUTERMOST_JSENTRY_FRAME = (1 << kSmiTagSize) | kSmiTag
  };
  static_assert((INNER_JSENTRY_FRAME & kHeapObjectTagMask) != kHeapObjectTag);
  static_assert((OUTERMOST_JSENTRY_FRAME & kHeapObjectTagMask) !=
                kHeapObjectTag);
 
  struct State {
    Address sp = kNullAddress;
    Address fp = kNullAddress;
    Address* pc_address = nullptr;
    Address callee_fp = kNullAddress;
    Address callee_pc = kNullAddress;
    Address* constant_pool_address = nullptr;
    bool is_profiler_entry_frame = false;
    bool is_stack_exit_frame = false;
  };
 
  // Convert a stack frame type to a marker that can be stored on the stack.
  //
  // The marker is an opaque value, not intended to be interpreted in any way
  // except being checked by IsTypeMarker or converted by MarkerToType.
  // It has the same tagging as Smis, so any marker value that does not pass
  // IsTypeMarker can instead be interpreted as a tagged pointer.
  //
  // Note that the marker is not a Smi: Smis on 64-bit architectures are stored
  // in the top 32 bits of a 64-bit value, which in turn makes them expensive
  // (in terms of code/instruction size) to push as immediates onto the stack.
  static constexpr int32_t TypeToMarker(Type type) {
    DCHECK_GE(type, 0);
    return (type << kSmiTagSize) | kSmiTag;
  }
 
  // Convert a marker back to a stack frame type.
  //
  // Unlike the return value of TypeToMarker, this takes an intptr_t, as that is
  // the type of the value on the stack.
  static constexpr Type MarkerToType(intptr_t marker) {
    DCHECK(IsTypeMarker(marker));
    return static_cast<Type>(marker >> kSmiTagSize);
  }
 
  // Check if a marker is a stack frame type marker.
  //
  // Returns true if the given marker is tagged as a stack frame type marker,
  // and should be converted back to a stack frame type using MarkerToType.
  static constexpr bool IsTypeMarker(uintptr_t function_or_marker) {
    static_assert(kSmiTag == 0);
    static_assert((std::numeric_limits<uintptr_t>::max() >> kSmiTagSize) >
                  Type::NUMBER_OF_TYPES);
    return (function_or_marker & kSmiTagMask) == kSmiTag &&
           function_or_marker < (Type::NUMBER_OF_TYPES << kSmiTagSize);
  }
 
  // Copy constructor; it breaks the connection to host iterator
  // (as an iterator usually lives on stack).
  StackFrame(const StackFrame& original) V8_NOEXCEPT
      : iterator_(nullptr),
        isolate_(original.isolate_),
        state_(original.state_) {}
 
  // Type testers.
  bool is_entry() const { return type() == ENTRY; }
  bool is_construct_entry() const { return type() == CONSTRUCT_ENTRY; }
  bool is_exit() const { return type() == EXIT; }
  bool is_optimized_js() const {
    static_assert(TURBOFAN_JS == MAGLEV + 1);
    return base::IsInRange(type(), MAGLEV, TURBOFAN_JS);
  }
  bool is_unoptimized_js() const {
    static_assert(BASELINE == INTERPRETED + 1);
    return base::IsInRange(type(), INTERPRETED, BASELINE);
  }
  bool is_interpreted() const { return type() == INTERPRETED; }
  bool is_baseline() const { return type() == BASELINE; }
  bool is_maglev() const { return type() == MAGLEV; }
  bool is_turbofan_js() const { return type() == TURBOFAN_JS; }
#if V8_ENABLE_WEBASSEMBLY
  bool is_wasm() const {
    return this->type() == WASM || this->type() == WASM_SEGMENT_START
#ifdef V8_ENABLE_DRUMBRAKE
           || this->type() == WASM_INTERPRETER_ENTRY
#endif  // V8_ENABLE_DRUMBRAKE
        ;
  }
  bool is_c_wasm_entry() const { return type() == C_WASM_ENTRY; }
  bool is_wasm_liftoff_setup() const { return type() == WASM_LIFTOFF_SETUP; }
#if V8_ENABLE_DRUMBRAKE
  bool is_wasm_interpreter_entry() const {
    return type() == WASM_INTERPRETER_ENTRY;
  }
#endif  // V8_ENABLE_DRUMBRAKE
  bool is_wasm_debug_break() const { return type() == WASM_DEBUG_BREAK; }
  bool is_wasm_to_js() const {
    return type() == WASM_TO_JS || type() == WASM_TO_JS_FUNCTION;
  }
  bool is_js_to_wasm() const { return type() == JS_TO_WASM; }
#endif  // V8_ENABLE_WEBASSEMBLY
  bool is_builtin() const { return type() == BUILTIN; }
  bool is_internal() const { return type() == INTERNAL; }
  bool is_builtin_continuation() const {
    return type() == BUILTIN_CONTINUATION;
  }
  bool is_javascript_builtin_continuation() const {
    return type() == JAVASCRIPT_BUILTIN_CONTINUATION;
  }
  bool is_javascript_builtin_with_catch_continuation() const {
    return type() == JAVASCRIPT_BUILTIN_CONTINUATION_WITH_CATCH;
  }
  bool is_construct() const { return type() == CONSTRUCT; }
  bool is_fast_construct() const { return type() == FAST_CONSTRUCT; }
  bool is_builtin_exit() const { return type() == BUILTIN_EXIT; }
  bool is_api_accessor_exit() const { return type() == API_ACCESSOR_EXIT; }
  bool is_api_callback_exit() const { return type() == API_CALLBACK_EXIT; }
  bool is_irregexp() const { return type() == IRREGEXP; }
 
  static bool IsJavaScript(Type t) {
    static_assert(INTERPRETED + 1 == BASELINE);
    static_assert(BASELINE + 1 == MAGLEV);
    static_assert(MAGLEV + 1 == TURBOFAN_JS);
    return t >= INTERPRETED && t <= TURBOFAN_JS;
  }
  bool is_javascript() const { return IsJavaScript(type()); }
 
  // Accessors.
  Address sp() const {
    DCHECK(!InFastCCall());
    return state_.sp;
  }
  Address fp() const { return state_.fp; }
  Address callee_fp() const { return state_.callee_fp; }
  Address callee_pc() const { return state_.callee_pc; }
  Address caller_sp() const { return GetCallerStackPointer(); }
  inline Address pc() const;
  bool is_profiler_entry_frame() const {
    return state_.is_profiler_entry_frame;
  }
  bool is_stack_exit_frame() const { return state_.is_stack_exit_frame; }
 
  // Skip authentication of the PC, when using CFI. Used in the profiler, where
  // in certain corner-cases we do not use an address on the stack, which would
  // be signed, as the PC of the frame.
  inline Address unauthenticated_pc() const;
  static inline Address unauthenticated_pc(Address* pc_address);
 
  // Conditionally calls either pc() or unauthenticated_pc() based on whether
  // this is fast C call stack frame.
  inline Address maybe_unauthenticated_pc() const;
  static inline Address maybe_unauthenticated_pc(Address* pc_address);
 
  // If the stack pointer is missing, this is a fast C call frame. For such
  // frames we cannot compute a stack pointer because of the missing ExitFrame.
  bool InFastCCall() const { return state_.sp == kNullAddress; }
 
  Address constant_pool() const { return *constant_pool_address(); }
  void set_constant_pool(Address constant_pool) {
    *constant_pool_address() = constant_pool;
  }
 
  Address* pc_address() const { return state_.pc_address; }
 
  Address* constant_pool_address() const {
    return state_.constant_pool_address;
  }
 
  // Get the id of this stack frame.
  StackFrameId id() const { return static_cast<StackFrameId>(caller_sp()); }
 
  // Get the top handler from the current stack iterator.
  inline StackHandler* top_handler() const;
 
  // Get the type of this frame.
  virtual Type type() const = 0;
 
  // Get the code associated with this frame. The result might be a Code object
  // or an empty value.
  // This method is used by Isolate::PushStackTraceAndDie() for collecting a
  // stack trace on fatal error and thus it might be called in the middle of GC
  // and should be as safe as possible.
  virtual Tagged<HeapObject> unchecked_code() const = 0;
 
  // Search for the code associated with this frame.
  V8_EXPORT_PRIVATE Tagged<Code> LookupCode() const;
  V8_EXPORT_PRIVATE std::pair<Tagged<Code>, int> LookupCodeAndOffset() const;
  V8_EXPORT_PRIVATE Tagged<GcSafeCode> GcSafeLookupCode() const;
  V8_EXPORT_PRIVATE std::pair<Tagged<GcSafeCode>, int>
  GcSafeLookupCodeAndOffset() const;
 
  virtual void Iterate(RootVisitor* v) const = 0;
  void IteratePc(RootVisitor* v, Address* constant_pool_address,
                 Tagged<GcSafeCode> holder) const;
 
  // Sets a callback function for return-address rewriting profilers
  // to resolve the location of a return address to the location of the
  // profiler's stashed return address.
  static void SetReturnAddressLocationResolver(
      ReturnAddressLocationResolver resolver);
 
  static inline Address ReadPC(Address* pc_address);
 
  // Resolves pc_address through the resolution address function if one is set.
  static inline Address* ResolveReturnAddressLocation(Address* pc_address);
 
  // Printing support.
  enum PrintMode { OVERVIEW, DETAILS };
  virtual void Print(StringStream* accumulator, PrintMode mode,
                     int index) const;
 
  Isolate* isolate() const { return isolate_; }
 
  void operator=(const StackFrame& original) = delete;
 
 protected:
  inline explicit StackFrame(StackFrameIteratorBase* iterator);
 
  // Compute the stack pointer for the calling frame.
  virtual Address GetCallerStackPointer() const = 0;
 
  const StackFrameIteratorBase* const iterator_;
 
 private:
  Isolate* const isolate_;
  State state_;
 
  static ReturnAddressLocationResolver return_address_location_resolver_;
 
  // Fill in the state of the calling frame.
  virtual void ComputeCallerState(State* state) const = 0;
 
  // Get the type and the state of the calling frame.
  virtual Type GetCallerState(State* state) const;
 
  static const intptr_t kIsolateTag = 1;
 
  friend class StackFrameIterator;
  friend class StackFrameIteratorBase;
  friend class StackHandlerIterator;
  friend class StackFrameIteratorForProfiler;
};
 
class CommonFrame;
 
class V8_EXPORT_PRIVATE FrameSummary {
 public:
// Subclasses for the different summary kinds:
#define FRAME_SUMMARY_VARIANTS(F)                                          \
  F(JAVASCRIPT, JavaScriptFrameSummary, javascript_summary_, JavaScript)   \
  IF_WASM(F, BUILTIN, BuiltinFrameSummary, builtin_summary_, Builtin)      \
  IF_WASM(F, WASM, WasmFrameSummary, wasm_summary_, Wasm)                  \
  IF_WASM_DRUMBRAKE(F, WASM_INTERPRETED, WasmInterpretedFrameSummary,      \
                    wasm_interpreted_summary_, WasmInterpreted)            \
  IF_WASM(F, WASM_INLINED, WasmInlinedFrameSummary, wasm_inlined_summary_, \
          WasmInlined)
 
#define FRAME_SUMMARY_KIND(kind, type, field, desc) kind,
  enum Kind { FRAME_SUMMARY_VARIANTS(FRAME_SUMMARY_KIND) };
#undef FRAME_SUMMARY_KIND
 
  class FrameSummaryBase {
   public:
    FrameSummaryBase(Isolate* isolate, Kind kind)
        : isolate_(isolate), kind_(kind) {}
    Isolate* isolate() const { return isolate_; }
    Kind kind() const { return kind_; }
 
   private:
    Isolate* isolate_;
    Kind kind_;
  };
 
  class JavaScriptFrameSummary : public FrameSummaryBase {
   public:
    JavaScriptFrameSummary(Isolate* isolate, Tagged<Object> receiver,
                           Tagged<JSFunction> function,
                           Tagged<AbstractCode> abstract_code, int code_offset,
                           bool is_constructor, Tagged<FixedArray> parameters);
 
    void EnsureSourcePositionsAvailable();
    bool AreSourcePositionsAvailable() const;
 
    Handle<Object> receiver() const { return receiver_; }
    Handle<JSFunction> function() const { return function_; }
    Handle<AbstractCode> abstract_code() const { return abstract_code_; }
    int code_offset() const { return code_offset_; }
    bool is_constructor() const { return is_constructor_; }
    DirectHandle<FixedArray> parameters() const { return parameters_; }
    bool is_subject_to_debugging() const;
    int SourcePosition() const;
    int SourceStatementPosition() const;
    Handle<Object> script() const;
    DirectHandle<Context> native_context() const;
    DirectHandle<StackFrameInfo> CreateStackFrameInfo() const;
 
   private:
    Handle<Object> receiver_;
    Handle<JSFunction> function_;
    Handle<AbstractCode> abstract_code_;
    int code_offset_;
    bool is_constructor_;
    Handle<FixedArray> parameters_;
  };
 
#if V8_ENABLE_WEBASSEMBLY
  class WasmFrameSummary : public FrameSummaryBase {
   public:
    WasmFrameSummary(Isolate* isolate,
                     Handle<WasmTrustedInstanceData> instance_data,
                     wasm::WasmCode* code, int byte_offset, int function_index,
                     bool at_to_number_conversion);
 
    Handle<Object> receiver() const;
    uint32_t function_index() const;
    wasm::WasmCode* code() const { return code_; }
    // Returns the wire bytes offset relative to the function entry.
    int code_offset() const { return byte_offset_; }
    bool is_constructor() const { return false; }
    bool is_subject_to_debugging() const { return true; }
    int SourcePosition() const;
    int SourceStatementPosition() const { return SourcePosition(); }
    Handle<Script> script() const;
    DirectHandle<WasmInstanceObject> wasm_instance() const;
    DirectHandle<WasmTrustedInstanceData> wasm_trusted_instance_data() const {
      return instance_data_;
    }
    DirectHandle<Context> native_context() const;
    bool at_to_number_conversion() const { return at_to_number_conversion_; }
    DirectHandle<StackFrameInfo> CreateStackFrameInfo() const;
 
   private:
    Handle<WasmTrustedInstanceData> instance_data_;
    bool at_to_number_conversion_;
    wasm::WasmCode* code_;
    int byte_offset_;
    int function_index_;
  };
 
  // Summary of a wasm frame inlined into JavaScript. (Wasm frames inlined into
  // wasm are expressed by a WasmFrameSummary.)
  class WasmInlinedFrameSummary : public FrameSummaryBase {
   public:
    WasmInlinedFrameSummary(Isolate* isolate,
                            Handle<WasmTrustedInstanceData> instance_data,
                            int function_index, int op_wire_bytes_offset);
 
    DirectHandle<WasmInstanceObject> wasm_instance() const;
    DirectHandle<WasmTrustedInstanceData> wasm_trusted_instance_data() const {
      return instance_data_;
    }
    Handle<Object> receiver() const;
    uint32_t function_index() const;
    int code_offset() const { return op_wire_bytes_offset_; }
    bool is_constructor() const { return false; }
    bool is_subject_to_debugging() const { return true; }
    Handle<Script> script() const;
    int SourcePosition() const;
    int SourceStatementPosition() const { return SourcePosition(); }
    DirectHandle<Context> native_context() const;
    DirectHandle<StackFrameInfo> CreateStackFrameInfo() const;
 
   private:
    Handle<WasmTrustedInstanceData> instance_data_;
    int function_index_;
    int op_wire_bytes_offset_;  // relative to function offset.
  };
 
  class BuiltinFrameSummary : public FrameSummaryBase {
   public:
    BuiltinFrameSummary(Isolate*, Builtin);
 
    Builtin builtin() const { return builtin_; }
 
    Handle<Object> receiver() const;
    int code_offset() const { return 0; }
    bool is_constructor() const { return false; }
    bool is_subject_to_debugging() const { return false; }
    Handle<Object> script() const;
    int SourcePosition() const { return kNoSourcePosition; }
    int SourceStatementPosition() const { return 0; }
    DirectHandle<Context> native_context() const;
    DirectHandle<StackFrameInfo> CreateStackFrameInfo() const;
 
   private:
    Builtin builtin_;
  };
 
#if V8_ENABLE_DRUMBRAKE
  class WasmInterpretedFrameSummary : public FrameSummaryBase {
   public:
    WasmInterpretedFrameSummary(Isolate*, Handle<WasmInstanceObject>,
                                uint32_t function_index, int byte_offset);
    Handle<WasmInstanceObject> wasm_instance() const { return wasm_instance_; }
    Handle<WasmTrustedInstanceData> instance_data() const;
    uint32_t function_index() const { return function_index_; }
    int byte_offset() const { return byte_offset_; }
 
    Handle<Object> receiver() const;
    int code_offset() const { return byte_offset_; }
    bool is_constructor() const { return false; }
    bool is_subject_to_debugging() const { return true; }
    int SourcePosition() const;
    int SourceStatementPosition() const { return SourcePosition(); }
    Handle<Script> script() const;
    DirectHandle<Context> native_context() const;
    DirectHandle<StackFrameInfo> CreateStackFrameInfo() const;
 
   private:
    Handle<WasmInstanceObject> wasm_instance_;
    uint32_t function_index_;
    int byte_offset_;
  };
#endif  // V8_ENABLE_DRUMBRAKE
#endif  // V8_ENABLE_WEBASSEMBLY
 
#define FRAME_SUMMARY_CONS(kind, type, field, desc) \
  FrameSummary(type summ) : field(summ) {}  // NOLINT
  FRAME_SUMMARY_VARIANTS(FRAME_SUMMARY_CONS)
#undef FRAME_SUMMARY_CONS
 
  ~FrameSummary();
 
  static FrameSummary GetTop(const CommonFrame* frame);
  static FrameSummary GetBottom(const CommonFrame* frame);
  static FrameSummary GetSingle(const CommonFrame* frame);
  static FrameSummary Get(const CommonFrame* frame, int index);
 
  void EnsureSourcePositionsAvailable();
  bool AreSourcePositionsAvailable() const;
 
  // Dispatched accessors.
  Handle<Object> receiver() const;
  int code_offset() const;
  bool is_constructor() const;
  bool is_subject_to_debugging() const;
  Handle<Object> script() const;
  int SourcePosition() const;
  int SourceStatementPosition() const;
  DirectHandle<Context> native_context() const;
  DirectHandle<StackFrameInfo> CreateStackFrameInfo() const;
 
#define FRAME_SUMMARY_CAST(kind_, type, field, desc)      \
  bool Is##desc() const { return base_.kind() == kind_; } \
  const type& As##desc() const {                          \
    DCHECK_EQ(base_.kind(), kind_);                       \
    return field;                                         \
  }
  FRAME_SUMMARY_VARIANTS(FRAME_SUMMARY_CAST)
#undef FRAME_SUMMARY_CAST
 
 private:
#define FRAME_SUMMARY_FIELD(kind, type, field, desc) type field;
  union {
    FrameSummaryBase base_;
    FRAME_SUMMARY_VARIANTS(FRAME_SUMMARY_FIELD)
  };
#undef FRAME_SUMMARY_FIELD
};
 
// FrameSummaries represents a collection of summarized frames
// within a standard frame. In unoptimized code, there is only one frame,
// while in optimized code, multiple frames may exist due to inlining.
// The functions are ordered bottom-to-top (i.e. summaries.last() is the
// top-most activation; caller comes before callee).
struct FrameSummaries {
  std::vector<FrameSummary> frames;
  bool top_frame_is_construct_call = false;
 
  FrameSummaries() = default;
 
  explicit FrameSummaries(FrameSummary summary) : frames() {
    frames.push_back(summary);
  }
 
  int size() const { return static_cast<int>(frames.size()); }
};
 
class CommonFrame : public StackFrame {
 public:
  // Accessors.
  virtual Tagged<Object> context()
      const;  // TODO(victorgomes): CommonFrames don't have context.
  virtual int position() const;
 
  // Access the expressions in the stack frame including locals.
  inline Tagged<Object> GetExpression(int index) const;
  inline void SetExpression(int index, Tagged<Object> value);
  int ComputeExpressionsCount() const;
 
  Address GetCallerStackPointer() const override;
 
  // Build a list with summaries for this frame including all inlined frames.
  // The functions are ordered bottom-to-top (i.e. summaries.last() is the
  // top-most activation; caller comes before callee).
  virtual FrameSummaries Summarize() const;
 
  static CommonFrame* cast(StackFrame* frame) {
    // It is always safe to cast to common.
    return static_cast<CommonFrame*>(frame);
  }
 
 protected:
  inline explicit CommonFrame(StackFrameIteratorBase* iterator);
 
  bool HasTaggedOutgoingParams(Tagged<GcSafeCode> code_lookup) const;
 
  void ComputeCallerState(State* state) const override;
 
  // Accessors.
  inline Address caller_fp() const;
  inline Address caller_pc() const;
 
  // Iterate over expression stack including stack handlers, locals,
  // and parts of the fixed part including context and code fields.
  void IterateExpressions(RootVisitor* v) const;
 
  void IterateTurbofanJSOptimizedFrame(RootVisitor* v) const;
 
  // Returns the address of the n'th expression stack element.
  virtual Address GetExpressionAddress(int n) const;
};
 
// This frame is used for TF-optimized code without JS linkage, but
// contains the context instead of a type marker.
class TurbofanStubWithContextFrame : public CommonFrame {
 public:
  Type type() const override { return TURBOFAN_STUB_WITH_CONTEXT; }
 
  Tagged<HeapObject> unchecked_code() const override;
  void Iterate(RootVisitor* v) const override;
 
 protected:
  inline explicit TurbofanStubWithContextFrame(
      StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class TypedFrame : public CommonFrame {
 public:
  Tagged<HeapObject> unchecked_code() const override { return {}; }
  void Iterate(RootVisitor* v) const override;
 
  void IterateParamsOfGenericWasmToJSWrapper(RootVisitor* v) const;
  void IterateParamsOfOptimizedWasmToJSWrapper(RootVisitor* v) const;
 
 protected:
  inline explicit TypedFrame(StackFrameIteratorBase* iterator);
};
 
class CommonFrameWithJSLinkage : public CommonFrame {
 public:
  // Accessors.
  virtual Tagged<JSFunction> function() const = 0;
 
  // Access the parameters.
  virtual Tagged<Object> receiver() const;
  virtual Tagged<Object> GetParameter(int index) const;
  virtual int ComputeParametersCount() const;
  DirectHandle<FixedArray> GetParameters() const;
  virtual int GetActualArgumentCount() const;
 
  Tagged<HeapObject> unchecked_code() const override;
 
  // Lookup exception handler for current {pc}, returns -1 if none found. Also
  // returns data associated with the handler site specific to the frame type:
  //  - OptimizedJSFrame  : Data is not used and will not return a value.
  //  - UnoptimizedJSFrame: Data is the register index holding the context.
  virtual int LookupExceptionHandlerInTable(
      int* data, HandlerTable::CatchPrediction* prediction);
 
  // Check if this frame is a constructor frame invoked through 'new'.
  virtual bool IsConstructor() const;
 
  // Summarize Frame
  FrameSummaries Summarize() const override;
 
 protected:
  inline explicit CommonFrameWithJSLinkage(StackFrameIteratorBase* iterator);
 
  // Determines if the standard frame for the given frame pointer is a
  // construct frame.
  static inline bool IsConstructFrame(Address fp);
  inline Address GetParameterSlot(int index) const;
};
 
class TypedFrameWithJSLinkage : public CommonFrameWithJSLinkage {
 public:
  void Iterate(RootVisitor* v) const override;
 
 protected:
  inline explicit TypedFrameWithJSLinkage(StackFrameIteratorBase* iterator);
};
 
class JavaScriptFrame : public CommonFrameWithJSLinkage {
 public:
  Type type() const override = 0;
 
  // Accessors.
  Tagged<JSFunction> function() const override;
  Tagged<Object> unchecked_function() const;
  Tagged<Script> script() const;
  Tagged<Object> context() const override;
  int GetActualArgumentCount() const override;
 
  inline void set_receiver(Tagged<Object> value);
 
  // Debugger access.
  void SetParameterValue(int index, Tagged<Object> value) const;
 
  // Check if this frame is a constructor frame invoked through 'new'.
  bool IsConstructor() const override;
 
  // Garbage collection support.
  void Iterate(RootVisitor* v) const override;
 
  // Printing support.
  void Print(StringStream* accumulator, PrintMode mode,
             int index) const override;
 
  // Return a list with {SharedFunctionInfo} objects of this frame.
  virtual void GetFunctions(
      std::vector<Tagged<SharedFunctionInfo>>* functions) const;
 
  void GetFunctions(std::vector<Handle<SharedFunctionInfo>>* functions) const;
 
  // Returns {AbstractCode, code offset} pair for this frame's PC value.
  std::tuple<Tagged<AbstractCode>, int> GetActiveCodeAndOffset() const;
 
  // Architecture-specific register description.
  static Register fp_register();
  static Register context_register();
  static Register constant_pool_pointer_register();
 
  bool is_unoptimized() const { return is_unoptimized_js(); }
  bool is_optimized() const { return is_optimized_js(); }
  bool is_turbofan() const { return is_turbofan_js(); }
 
  static JavaScriptFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_javascript());
    return static_cast<JavaScriptFrame*>(frame);
  }
 
  static void PrintFunctionAndOffset(Isolate* isolate,
                                     Tagged<JSFunction> function,
                                     Tagged<AbstractCode> code, int code_offset,
                                     FILE* file, bool print_line_number);
 
  static void PrintTop(Isolate* isolate, FILE* file, bool print_args,
                       bool print_line_number);
 
  static void CollectFunctionAndOffsetForICStats(Isolate* isolate,
                                                 Tagged<JSFunction> function,
                                                 Tagged<AbstractCode> code,
                                                 int code_offset);
 
 protected:
  inline explicit JavaScriptFrame(StackFrameIteratorBase* iterator);
 
  Address GetCallerStackPointer() const override;
 
  virtual void PrintFrameKind(StringStream* accumulator) const {}
 
 private:
  inline Tagged<Object> function_slot_object() const;
 
  friend class StackFrameIteratorBase;
};
 
class NativeFrame : public TypedFrame {
 public:
  Type type() const override { return NATIVE; }
 
  // Garbage collection support.
  void Iterate(RootVisitor* v) const override {}
 
 protected:
  inline explicit NativeFrame(StackFrameIteratorBase* iterator);
 
 private:
  void ComputeCallerState(State* state) const override;
 
  friend class StackFrameIteratorBase;
};
 
// Entry frames are used to enter JavaScript execution from C.
class EntryFrame : public TypedFrame {
 public:
  Type type() const override { return ENTRY; }
 
  Tagged<HeapObject> unchecked_code() const override;
 
  // Garbage collection support.
  void Iterate(RootVisitor* v) const override;
 
  static EntryFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_entry());
    return static_cast<EntryFrame*>(frame);
  }
 
 protected:
  inline explicit EntryFrame(StackFrameIteratorBase* iterator);
 
  // The caller stack pointer for entry frames is always zero. The
  // real information about the caller frame is available through the
  // link to the top exit frame.
  Address GetCallerStackPointer() const override { return 0; }
 
 private:
  void ComputeCallerState(State* state) const override;
  Type GetCallerState(State* state) const override;
 
  friend class StackFrameIteratorBase;
};
 
class ConstructEntryFrame : public EntryFrame {
 public:
  Type type() const override { return CONSTRUCT_ENTRY; }
 
  Tagged<HeapObject> unchecked_code() const override;
 
  static ConstructEntryFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_construct_entry());
    return static_cast<ConstructEntryFrame*>(frame);
  }
 
 protected:
  inline explicit ConstructEntryFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
// Exit frames are used to exit JavaScript execution and go to C, or to switch
// out of the current stack for wasm stack-switching.
class ExitFrame : public TypedFrame {
 public:
  Type type() const override { return EXIT; }
 
  // Garbage collection support.
  void Iterate(RootVisitor* v) const override;
 
  static ExitFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_exit());
    return static_cast<ExitFrame*>(frame);
  }
 
  // Compute the state and type of an exit frame given a frame
  // pointer. Used when constructing the first stack frame seen by an
  // iterator and the frames following entry frames.
  static Type GetStateForFramePointer(Address fp, State* state);
  static Address ComputeStackPointer(Address fp);
  static StackFrame::Type ComputeFrameType(Address fp);
  static void FillState(Address fp, Address sp, State* state);
 
 protected:
  inline explicit ExitFrame(StackFrameIteratorBase* iterator);
 
 private:
  void ComputeCallerState(State* state) const override;
 
  friend class StackFrameIteratorBase;
};
 
// Builtin exit frames are a special case of exit frames, which are used
// whenever C++ builtins (e.g., Math.acos) are called. Their main purpose is
// to allow such builtins to appear in stack traces.
class BuiltinExitFrame : public ExitFrame {
 public:
  Type type() const override { return BUILTIN_EXIT; }
 
  Tagged<JSFunction> function() const;
 
  Tagged<Object> receiver() const;
  Tagged<Object> GetParameter(int i) const;
  int ComputeParametersCount() const;
  DirectHandle<FixedArray> GetParameters() const;
 
  // Check if this frame is a constructor frame invoked through 'new'.
  bool IsConstructor() const;
 
  void Print(StringStream* accumulator, PrintMode mode,
             int index) const override;
 
  // Summarize Frame
  FrameSummaries Summarize() const override;
 
 protected:
  inline explicit BuiltinExitFrame(StackFrameIteratorBase* iterator);
 
 private:
  inline Tagged<Object> receiver_slot_object() const;
  inline Tagged<Object> argc_slot_object() const;
  inline Tagged<Object> target_slot_object() const;
  inline Tagged<Object> new_target_slot_object() const;
 
  friend class StackFrameIteratorBase;
};
 
// Api callback exit frames are a special case of exit frames, which are used
// whenever an Api functions (such as v8::Function or v8::FunctionTemplate) are
// called. Their main purpose is to support preprocessing of exceptions thrown
// from Api functions and as a bonus it allows these functions to appear in
// stack traces (see v8_flags.experimental_stack_trace_frames).
class ApiCallbackExitFrame : public ExitFrame {
 public:
  Type type() const override { return API_CALLBACK_EXIT; }
 
  // In case function slot contains FunctionTemplateInfo, instantiate the
  // function, stores it in the function slot and returns JSFunction handle.
  DirectHandle<JSFunction> GetFunction() const;
 
  DirectHandle<FunctionTemplateInfo> GetFunctionTemplateInfo() const;
 
  inline Tagged<Object> receiver() const;
  inline Tagged<Object> GetParameter(int i) const;
  inline int ComputeParametersCount() const;
  DirectHandle<FixedArray> GetParameters() const;
 
  inline Tagged<Object> context() const override;
 
  // Check if this frame is a constructor frame invoked through 'new'.
  inline bool IsConstructor() const;
 
  void Print(StringStream* accumulator, PrintMode mode,
             int index) const override;
 
  // Summarize Frame
  FrameSummaries Summarize() const override;
 
  static ApiCallbackExitFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_api_callback_exit());
    return static_cast<ApiCallbackExitFrame*>(frame);
  }
 
 protected:
  inline explicit ApiCallbackExitFrame(StackFrameIteratorBase* iterator);
 
 private:
  // ApiCallbackExitFrame might contain either FunctionTemplateInfo or
  // JSFunction in the function slot.
  inline Tagged<HeapObject> target() const;
 
  inline void set_target(Tagged<HeapObject> function) const;
 
  inline FullObjectSlot target_slot() const;
 
  friend class StackFrameIteratorBase;
};
 
// Api accessor exit frames are a special case of exit frames, which are used
// whenever an Api property accessor callbacks (v8::AccessorGetterCallback or
// v8::AccessorSetterCallback) are called. Their main purpose is to support
// preprocessing of exceptions thrown from these callbacks.
class ApiAccessorExitFrame : public ExitFrame {
 public:
  Type type() const override { return API_ACCESSOR_EXIT; }
 
  inline Tagged<Name> property_name() const;
 
  inline Tagged<Object> receiver() const;
  inline Tagged<Object> holder() const;
 
  void Print(StringStream* accumulator, PrintMode mode,
             int index) const override;
 
  // Summarize Frame
  FrameSummaries Summarize() const override;
 
  static ApiAccessorExitFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_api_accessor_exit());
    return static_cast<ApiAccessorExitFrame*>(frame);
  }
 
 protected:
  inline explicit ApiAccessorExitFrame(StackFrameIteratorBase* iterator);
 
 private:
  inline FullObjectSlot property_name_slot() const;
  inline FullObjectSlot receiver_slot() const;
  inline FullObjectSlot holder_slot() const;
 
  friend class StackFrameIteratorBase;
};
 
class StubFrame : public TypedFrame {
 public:
  Type type() const override { return STUB; }
 
  Tagged<HeapObject> unchecked_code() const override;
 
  // Lookup exception handler for current {pc}, returns -1 if none found. Only
  // TurboFan stub frames are supported.
  int LookupExceptionHandlerInTable();
 
  FrameSummaries Summarize() const override;
 
 protected:
  inline explicit StubFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class OptimizedJSFrame : public JavaScriptFrame {
 public:
  // Return a list with {SharedFunctionInfo} objects of this frame.
  // The functions are ordered bottom-to-top (i.e. functions.last()
  // is the top-most activation)
  void GetFunctions(
      std::vector<Tagged<SharedFunctionInfo>>* functions) const override;
 
  FrameSummaries Summarize() const override;
 
  Tagged<DeoptimizationData> GetDeoptimizationData(Tagged<Code> code,
                                                   int* deopt_index) const;
 
  static int StackSlotOffsetRelativeToFp(int slot_index);
 
  // Lookup exception handler for current {pc}, returns -1 if none found.
  int LookupExceptionHandlerInTable(
      int* data, HandlerTable::CatchPrediction* prediction) override;
 
  virtual int FindReturnPCForTrampoline(Tagged<Code> code,
                                        int trampoline_pc) const = 0;
 
 protected:
  inline explicit OptimizedJSFrame(StackFrameIteratorBase* iterator);
};
 
// An unoptimized frame is a JavaScript frame that is executing bytecode. It
// may be executing it using the interpreter, or via baseline code compiled from
// the bytecode.
class UnoptimizedJSFrame : public JavaScriptFrame {
 public:
  // Accessors.
  int position() const override;
 
  // Lookup exception handler for current {pc}, returns -1 if none found.
  int LookupExceptionHandlerInTable(
      int* data, HandlerTable::CatchPrediction* prediction) override;
 
  // Returns the current offset into the bytecode stream.
  virtual int GetBytecodeOffset() const = 0;
 
  // Returns the frame's current bytecode array.
  Tagged<BytecodeArray> GetBytecodeArray() const;
 
  // Access to the interpreter register file for this frame.
  Tagged<Object> ReadInterpreterRegister(int register_index) const;
 
  inline void SetFeedbackVector(Tagged<FeedbackVector> feedback_vector);
 
  // Build a list with summaries for this frame including all inlined frames.
  FrameSummaries Summarize() const override;
 
  static UnoptimizedJSFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_unoptimized_js());
    return static_cast<UnoptimizedJSFrame*>(frame);
  }
 
 protected:
  inline explicit UnoptimizedJSFrame(StackFrameIteratorBase* iterator);
 
  Address GetExpressionAddress(int n) const override;
 
 private:
  friend class StackFrameIteratorBase;
};
 
class InterpretedFrame : public UnoptimizedJSFrame {
 public:
  Type type() const override { return INTERPRETED; }
 
  // Returns the current offset into the bytecode stream.
  int GetBytecodeOffset() const override;
 
  // Updates the current offset into the bytecode stream, mainly used for stack
  // unwinding to continue execution at a different bytecode offset.
  void PatchBytecodeOffset(int new_offset);
 
  // Updates the frame's BytecodeArray with |bytecode_array|. Used by the
  // debugger to swap execution onto a BytecodeArray patched with breakpoints.
  void PatchBytecodeArray(Tagged<BytecodeArray> bytecode_array);
 
  static InterpretedFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_interpreted());
    return static_cast<InterpretedFrame*>(frame);
  }
  static const InterpretedFrame* cast(const StackFrame* frame) {
    DCHECK(frame->is_interpreted());
    return static_cast<const InterpretedFrame*>(frame);
  }
 
 protected:
  inline explicit InterpretedFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class BaselineFrame : public UnoptimizedJSFrame {
 public:
  Type type() const override { return BASELINE; }
 
  // Returns the current offset into the bytecode stream.
  int GetBytecodeOffset() const override;
 
  intptr_t GetPCForBytecodeOffset(int lookup_offset) const;
 
  void PatchContext(Tagged<Context> value);
 
  static BaselineFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_baseline());
    return static_cast<BaselineFrame*>(frame);
  }
  static const BaselineFrame* cast(const StackFrame* frame) {
    DCHECK(frame->is_baseline());
    return static_cast<const BaselineFrame*>(frame);
  }
 
 protected:
  inline explicit BaselineFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class MaglevFrame : public OptimizedJSFrame {
 public:
  Type type() const override { return MAGLEV; }
 
  static MaglevFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_maglev());
    return static_cast<MaglevFrame*>(frame);
  }
 
  void Iterate(RootVisitor* v) const override;
 
  int FindReturnPCForTrampoline(Tagged<Code> code,
                                int trampoline_pc) const override;
 
  DirectHandle<JSFunction> GetInnermostFunction() const;
  BytecodeOffset GetBytecodeOffsetForOSR() const;
 
  static intptr_t StackGuardFrameSize(int register_input_count);
 
 protected:
  inline explicit MaglevFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class TurbofanJSFrame : public OptimizedJSFrame {
 public:
  Type type() const override { return TURBOFAN_JS; }
 
  int ComputeParametersCount() const override;
 
  void Iterate(RootVisitor* v) const override;
 
  int FindReturnPCForTrampoline(Tagged<Code> code,
                                int trampoline_pc) const override;
 
 protected:
  inline explicit TurbofanJSFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
 
  Tagged<Object> StackSlotAt(int index) const;
};
 
// Builtin frames are built for builtins with JavaScript linkage, such as
// various standard library functions (i.e. Math.asin, Math.floor, etc.).
class BuiltinFrame final : public TypedFrameWithJSLinkage {
 public:
  Type type() const final { return BUILTIN; }
 
  static BuiltinFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_builtin());
    return static_cast<BuiltinFrame*>(frame);
  }
 
  Tagged<JSFunction> function() const override;
  int ComputeParametersCount() const override;
 
 protected:
  inline explicit BuiltinFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
#if V8_ENABLE_WEBASSEMBLY
class WasmFrame : public TypedFrame {
 public:
  Type type() const override { return WASM; }
 
  // Printing support.
  void Print(StringStream* accumulator, PrintMode mode,
             int index) const override;
 
  // Lookup exception handler for current {pc}, returns -1 if none found.
  int LookupExceptionHandlerInTable();
 
  void Iterate(RootVisitor* v) const override;
 
  // Accessors.
  virtual V8_EXPORT_PRIVATE Tagged<WasmInstanceObject> wasm_instance() const;
  virtual Tagged<WasmTrustedInstanceData> trusted_instance_data() const;
  V8_EXPORT_PRIVATE wasm::NativeModule* native_module() const;
 
  virtual wasm::WasmCode* wasm_code() const;
  int function_index() const;
  Tagged<Script> script() const;
  // Byte position in the module, or asm.js source position.
  int position() const override;
  Tagged<Object> context() const override;
  bool at_to_number_conversion() const;
  // Generated code byte offset in the function.
  int generated_code_offset() const;
  bool is_inspectable() const;
 
  FrameSummaries Summarize() const override;
 
  static WasmFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_wasm()
#ifdef V8_ENABLE_DRUMBRAKE
           && !frame->is_wasm_interpreter_entry()
#endif  // V8_ENABLE_DRUMBRAKE
    );
    return static_cast<WasmFrame*>(frame);
  }
 
 protected:
  inline explicit WasmFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
  Tagged<WasmModuleObject> module_object() const;
};
 
// WasmSegmentStartFrame is a regular Wasm frame moved to the
// beginning of a new stack segment allocated for growable stack.
// It requires special handling on return. To indicate that, the WASM frame type
// is replaced by WASM_SEGMENT_START.
class WasmSegmentStartFrame : public WasmFrame {
 public:
  // type() intentionally returns WASM frame type because WasmSegmentStartFrame
  // behaves exactly like regular WasmFrame in all scenarios.
  Type type() const override { return WASM; }
 
 protected:
  inline explicit WasmSegmentStartFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
// Wasm to C-API exit frame.
class WasmExitFrame : public WasmFrame {
 public:
  Type type() const override { return WASM_EXIT; }
  static Address ComputeStackPointer(Address fp);
 
 protected:
  inline explicit WasmExitFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
#if V8_ENABLE_DRUMBRAKE
class WasmInterpreterEntryFrame final : public WasmFrame {
 public:
  Type type() const override { return WASM_INTERPRETER_ENTRY; }
 
  // GC support.
  void Iterate(RootVisitor* v) const override;
 
  // Printing support.
  void Print(StringStream* accumulator, PrintMode mode,
             int index) const override;
 
  FrameSummaries Summarize() const override;
 
  // Determine the code for the frame.
  Tagged<HeapObject> unchecked_code() const override;
 
  // Accessors.
  Tagged<Tuple2> interpreter_object() const;
  V8_EXPORT_PRIVATE Tagged<WasmInstanceObject> wasm_instance() const override;
  Tagged<WasmTrustedInstanceData> trusted_instance_data() const override;
 
  wasm::WasmCode* wasm_code() const override { UNREACHABLE(); }
  int function_index(int inlined_function_index) const;
  int position() const override;
  Tagged<Object> context() const override;
 
  static WasmInterpreterEntryFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_wasm_interpreter_entry());
    return static_cast<WasmInterpreterEntryFrame*>(frame);
  }
 
 protected:
  inline explicit WasmInterpreterEntryFrame(StackFrameIteratorBase* iterator);
 
  Address GetCallerStackPointer() const override;
 
 private:
  friend class StackFrameIteratorBase;
  Tagged<WasmModuleObject> module_object() const;
};
#endif  // V8_ENABLE_DRUMBRAKE
 
class WasmDebugBreakFrame final : public TypedFrame {
 public:
  Type type() const override { return WASM_DEBUG_BREAK; }
 
  // GC support.
  void Iterate(RootVisitor* v) const override;
 
  void Print(StringStream* accumulator, PrintMode mode,
             int index) const override;
 
  static WasmDebugBreakFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_wasm_debug_break());
    return static_cast<WasmDebugBreakFrame*>(frame);
  }
 
 protected:
  inline explicit WasmDebugBreakFrame(StackFrameIteratorBase*);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class WasmToJsFrame : public WasmFrame {
 public:
  Type type() const override { return WASM_TO_JS; }
 
#if V8_ENABLE_DRUMBRAKE
  void Iterate(RootVisitor* v) const override;
#endif  // V8_ENABLE_DRUMBRAKE
 
  int position() const override { return 0; }
  Tagged<WasmInstanceObject> wasm_instance() const override;
  Tagged<WasmTrustedInstanceData> trusted_instance_data() const override;
 
 protected:
  inline explicit WasmToJsFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class WasmToJsFunctionFrame : public TypedFrame {
 public:
  Type type() const override { return WASM_TO_JS_FUNCTION; }
 
 protected:
  inline explicit WasmToJsFunctionFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class JsToWasmFrame : public StubFrame {
 public:
  Type type() const override { return JS_TO_WASM; }
 
  void Iterate(RootVisitor* v) const override;
 
 protected:
  inline explicit JsToWasmFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class StackSwitchFrame : public ExitFrame {
 public:
  Type type() const override { return STACK_SWITCH; }
  void Iterate(RootVisitor* v) const override;
  static void GetStateForJumpBuffer(wasm::JumpBuffer* jmpbuf, State* state);
 
 protected:
  inline explicit StackSwitchFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class CWasmEntryFrame : public StubFrame {
 public:
  Type type() const override { return C_WASM_ENTRY; }
 
#if V8_ENABLE_DRUMBRAKE
  void Iterate(RootVisitor* v) const override;
#endif  // V8_ENABLE_DRUMBRAKE
 
 protected:
  inline explicit CWasmEntryFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
  Type GetCallerState(State* state) const override;
};
 
class WasmLiftoffSetupFrame : public TypedFrame {
 public:
  Type type() const override { return WASM_LIFTOFF_SETUP; }
 
  FullObjectSlot wasm_instance_data_slot() const;
 
  int GetDeclaredFunctionIndex() const;
 
  wasm::NativeModule* GetNativeModule() const;
 
  // Garbage collection support.
  void Iterate(RootVisitor* v) const override;
 
  static WasmLiftoffSetupFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_wasm_liftoff_setup());
    return static_cast<WasmLiftoffSetupFrame*>(frame);
  }
 
 protected:
  inline explicit WasmLiftoffSetupFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
#endif  // V8_ENABLE_WEBASSEMBLY
 
class InternalFrame : public TypedFrame {
 public:
  Type type() const override { return INTERNAL; }
 
  // Garbage collection support.
  void Iterate(RootVisitor* v) const override;
 
  static InternalFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_internal());
    return static_cast<InternalFrame*>(frame);
  }
 
 protected:
  inline explicit InternalFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
// Construct frames are special trampoline frames introduced to handle
// function invocations through 'new'.
class ConstructFrame : public InternalFrame {
 public:
  Type type() const override { return CONSTRUCT; }
 
  static ConstructFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_construct());
    return static_cast<ConstructFrame*>(frame);
  }
 
  void Iterate(RootVisitor* v) const override;
 
 protected:
  inline explicit ConstructFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
// Fast construct frames are special construct trampoline frames that avoid
// pushing arguments to the stack twice.
class FastConstructFrame : public InternalFrame {
 public:
  Type type() const override { return FAST_CONSTRUCT; }
 
  static FastConstructFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_fast_construct());
    return static_cast<FastConstructFrame*>(frame);
  }
 
 protected:
  inline explicit FastConstructFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class BuiltinContinuationFrame : public InternalFrame {
 public:
  Type type() const override { return BUILTIN_CONTINUATION; }
 
  static BuiltinContinuationFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_builtin_continuation());
    return static_cast<BuiltinContinuationFrame*>(frame);
  }
 
 protected:
  inline explicit BuiltinContinuationFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class JavaScriptBuiltinContinuationFrame : public TypedFrameWithJSLinkage {
 public:
  Type type() const override { return JAVASCRIPT_BUILTIN_CONTINUATION; }
 
  static JavaScriptBuiltinContinuationFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_javascript_builtin_continuation());
    return static_cast<JavaScriptBuiltinContinuationFrame*>(frame);
  }
 
  Tagged<JSFunction> function() const override;
  int ComputeParametersCount() const override;
  intptr_t GetSPToFPDelta() const;
 
  Tagged<Object> context() const override;
 
 protected:
  inline explicit JavaScriptBuiltinContinuationFrame(
      StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class JavaScriptBuiltinContinuationWithCatchFrame
    : public JavaScriptBuiltinContinuationFrame {
 public:
  Type type() const override {
    return JAVASCRIPT_BUILTIN_CONTINUATION_WITH_CATCH;
  }
 
  static JavaScriptBuiltinContinuationWithCatchFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_javascript_builtin_with_catch_continuation());
    return static_cast<JavaScriptBuiltinContinuationWithCatchFrame*>(frame);
  }
 
  // Patch in the exception object at the appropriate location into the stack
  // frame.
  void SetException(Tagged<Object> exception);
 
 protected:
  inline explicit JavaScriptBuiltinContinuationWithCatchFrame(
      StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class IrregexpFrame : public TypedFrame {
 public:
  Type type() const override { return IRREGEXP; }
 
  void Iterate(RootVisitor* v) const override {
    // Irregexp frames should not be visited by GC because they are not visible
    // to any stack iterator except StackFrameIteratorForProfiler, which is not
    // used by GC.
    UNREACHABLE();
  }
 
  static IrregexpFrame* cast(StackFrame* frame) {
    DCHECK(frame->is_irregexp());
    return static_cast<IrregexpFrame*>(frame);
  }
 
 protected:
  inline explicit IrregexpFrame(StackFrameIteratorBase* iterator);
 
 private:
  friend class StackFrameIteratorBase;
};
 
class StackFrameIteratorBase {
 public:
  StackFrameIteratorBase(const StackFrameIteratorBase&) = delete;
  StackFrameIteratorBase& operator=(const StackFrameIteratorBase&) = delete;
 
  Isolate* isolate() const { return isolate_; }
#if V8_ENABLE_WEBASSEMBLY
  wasm::StackMemory* wasm_stack() const { return wasm_stack_; }
#endif
 
  bool done() const { return frame_ == nullptr; }
 
#ifdef DEBUG
  // The StackFrameIteratorForProfiler is limited in functionality because it
  // may run at an arbitrary point in time where stack contents are not
  // guaranteed to be in a consistent state and heap accesses may be limited.
  virtual bool IsStackFrameIteratorForProfiler() const = 0;
#endif  // DEBUG
  virtual StackFrame::Type ComputeStackFrameType(
      StackFrame::State* state) const = 0;
 
 protected:
  // An iterator that iterates over a given thread's stack.
  explicit StackFrameIteratorBase(Isolate* isolate);
 
  Isolate* const isolate_;
  union {
    char uninitialized_;
#define DECLARE_SINGLETON(ignore, type) type type##_;
  STACK_FRAME_TYPE_LIST(DECLARE_SINGLETON)
#undef DECLARE_SINGLETON
  };
  StackFrame* frame_;
  StackHandler* handler_;
#if V8_ENABLE_WEBASSEMBLY
  // Stop at the end of the topmost (wasm) stack.
  bool first_stack_only_ = false;
  // // Current wasm stack being iterated.
  wasm::StackMemory* wasm_stack_ = nullptr;
#endif
 
  StackHandler* handler() const {
    DCHECK(!done());
    return handler_;
  }
 
  // Update the current frame to the given state.
  void SetNewFrame(StackFrame::Type type, StackFrame::State* state);
  // A helper function, can set the frame to nullptr.
  void SetNewFrame(StackFrame::Type type);
 
 private:
  friend class StackFrame;
};
 
class StackFrameIterator : public StackFrameIteratorBase {
 public:
  // An iterator that iterates over the isolate's current thread's stack,
  V8_EXPORT_PRIVATE explicit StackFrameIterator(Isolate* isolate);
  // An iterator that iterates over a given thread's stack.
  V8_EXPORT_PRIVATE StackFrameIterator(Isolate* isolate, ThreadLocalTop* t);
#if V8_ENABLE_WEBASSEMBLY
  // Depending on the use case, users of the StackFrameIterator should either:
  // - Use the default constructor, which iterates the active stack and its
  // ancestors, but not the suspended stacks.
  // - Or use the constructor below to iterate the topmost stack only, and
  // iterate the {Isolate::wasm_stacks()} list on the side to visit all
  // inactive stacks.
  struct FirstStackOnly {};
  V8_EXPORT_PRIVATE StackFrameIterator(Isolate* isolate, ThreadLocalTop* t,
                                       FirstStackOnly);
  // An iterator that iterates over a given wasm stack segment.
  V8_EXPORT_PRIVATE StackFrameIterator(Isolate* isolate,
                                       wasm::StackMemory* stack);
#endif
 
  StackFrameIterator(const StackFrameIterator&) = delete;
  StackFrameIterator& operator=(const StackFrameIterator&) = delete;
 
  StackFrame* frame() const {
    DCHECK(!done());
    return frame_;
  }
  V8_EXPORT_PRIVATE void Advance();
  StackFrame* Reframe();
 
#if V8_ENABLE_WEBASSEMBLY
  // Go to the first frame of this stack.
  void Reset(ThreadLocalTop* top, wasm::StackMemory* stack);
#endif
 
#ifdef DEBUG
  bool IsStackFrameIteratorForProfiler() const override { return false; }
#endif  // DEBUG
  StackFrame::Type ComputeStackFrameType(
      StackFrame::State* state) const override;
 
 private:
  // Go back to the first frame.
  void Reset(ThreadLocalTop* top);
};
 
// A wrapper around StackFrameIterator that skips over all non-JS frames.
class JavaScriptStackFrameIterator final {
 public:
  explicit JavaScriptStackFrameIterator(Isolate* isolate) : iterator_(isolate) {
    if (!done()) Advance();
  }
  JavaScriptStackFrameIterator(Isolate* isolate, ThreadLocalTop* top)
      : iterator_(isolate, top) {
    if (!done()) Advance();
  }
 
  JavaScriptFrame* frame() const {
    return JavaScriptFrame::cast(iterator_.frame());
  }
  JavaScriptFrame* Reframe() {
    return JavaScriptFrame::cast(iterator_.Reframe());
  }
  bool done() const { return iterator_.done(); }
 
  V8_EXPORT_PRIVATE void Advance();
 
 private:
  StackFrameIterator iterator_;
};
 
// A wrapper around StackFrameIterator that skips over all non-debuggable
// frames (i.e. it iterates over Wasm and debuggable JS frames).
class V8_EXPORT_PRIVATE DebuggableStackFrameIterator {
 public:
  explicit DebuggableStackFrameIterator(Isolate* isolate);
  // Skip frames until the frame with the given id is reached.
  DebuggableStackFrameIterator(Isolate* isolate, StackFrameId id);
 
  bool done() const { return iterator_.done(); }
  void Advance();
  int FrameFunctionCount() const;
 
  inline CommonFrame* frame() const;
  inline CommonFrame* Reframe();
 
  inline bool is_javascript() const;
#if V8_ENABLE_WEBASSEMBLY
  inline bool is_wasm() const;
#if V8_ENABLE_DRUMBRAKE
  inline bool is_wasm_interpreter_entry() const;
#endif  // V8_ENABLE_DRUMBRAKE
#endif  // V8_ENABLE_WEBASSEMBLY
  inline JavaScriptFrame* javascript_frame() const;
 
  // Use this instead of FrameSummary::GetTop(javascript_frame) to keep
  // filtering behavior consistent with the rest of
  // DebuggableStackFrameIterator.
  FrameSummary GetTopValidFrame() const;
 
 private:
  StackFrameIterator iterator_;
  static bool IsValidFrame(StackFrame* frame);
};
 
// Similar to StackFrameIterator, but can be created and used at any time and
// any stack state. Currently, the only user is the profiler; if this ever
// changes, find another name for this class.
// IMPORTANT: Do not mark this class as V8_EXPORT_PRIVATE. The profiler creates
// instances of this class from a signal handler. If we use V8_EXPORT_PRIVATE
// "ld" inserts a symbol stub for the constructor call that may crash with
// a stackoverflow when called from a signal handler.
class StackFrameIteratorForProfiler : public StackFrameIteratorBase {
 public:
  StackFrameIteratorForProfiler(Isolate* isolate, Address pc, Address fp,
                                Address sp, Address lr, Address js_entry_sp);
 
  inline StackFrame* frame() const;
  void Advance();
 
  StackFrame::Type top_frame_type() const { return top_frame_type_; }
 
#ifdef DEBUG
  bool IsStackFrameIteratorForProfiler() const override { return true; }
#endif  // DEBUG
  StackFrame::Type ComputeStackFrameType(
      StackFrame::State* state) const override;
 
 private:
  void AdvanceOneFrame();
 
  bool IsValidStackAddress(Address addr) const {
    return low_bound_ <= addr && addr <= high_bound_;
  }
  bool IsValidState(const StackFrame::State& frame) const;
  bool HasValidExitIfEntryFrame(const StackFrame* frame) const;
  bool IsValidExitFrame(Address fp) const;
  bool IsValidTop(ThreadLocalTop* top) const;
  static bool IsValidFrameType(StackFrame::Type type);
 
  StackFrame::Type GetCallerIfValid(StackFrame* frame,
                                    StackFrame::State* state);
 
  // Returns true if the pc points to a bytecode handler and the frame pointer
  // doesn't seem to be a bytecode handler's frame, which implies that the
  // bytecode handler has an elided frame. This is not precise and might give
  // false negatives since it relies on checks to the frame's type marker,
  // which might be uninitialized.
  bool IsNoFrameBytecodeHandlerPc(Isolate* isolate, Address pc,
                                  Address fp) const;
 
  const Address low_bound_;
  const Address high_bound_;
  StackFrame::Type top_frame_type_;
  ExternalCallbackScope* external_callback_scope_;
  Address top_link_register_;
#if V8_ENABLE_WEBASSEMBLY
  std::vector<std::unique_ptr<wasm::StackMemory>>& wasm_stacks_;
#endif
};
 
// We cannot export 'StackFrameIteratorForProfiler' for cctests since the
// linker inserted symbol stub may cause a stack overflow
// (https://crbug.com/1449195).
// We subclass it and export the subclass instead.
class V8_EXPORT_PRIVATE StackFrameIteratorForProfilerForTesting
    : public StackFrameIteratorForProfiler {
 public:
  StackFrameIteratorForProfilerForTesting(Isolate* isolate, Address pc,
                                          Address fp, Address sp, Address lr,
                                          Address js_entry_sp);
  // Redeclare methods needed by the test. Otherwise we'd have to
  // export individual methods on the base class (which we don't want to risk).
  void Advance();
};
 
// Frame layout helper classes. Used by the deoptimizer and instruction
// selector.
// -------------------------------------------------------------------------
 
// How to calculate the frame layout information. Precise, when all information
// is available during deoptimization. Conservative, when an overapproximation
// is fine.
// TODO(jgruber): Investigate whether the conservative kind can be removed. It
// seems possible: 1. is_topmost should be known through the outer_state chain
// of FrameStateDescriptor; 2. the deopt_kind may be a property of the bailout
// id; 3. for continuation_mode, we only care whether it is a mode with catch,
// and that is likewise known at compile-time.
// There is nothing specific blocking this, the investigation just requires time
// and it is not that important to get the exact frame height at compile-time.
enum class FrameInfoKind {
  kPrecise,
  kConservative,
};
 
// Used by the deoptimizer. Corresponds to frame kinds:
enum class BuiltinContinuationMode {
  STUB,                        // BuiltinContinuationFrame
  JAVASCRIPT,                  // JavaScriptBuiltinContinuationFrame
  JAVASCRIPT_WITH_CATCH,       // JavaScriptBuiltinContinuationWithCatchFrame
  JAVASCRIPT_HANDLE_EXCEPTION  // JavaScriptBuiltinContinuationWithCatchFrame
};
 
class UnoptimizedFrameInfo {
 public:
  static UnoptimizedFrameInfo Precise(int parameters_count_with_receiver,
                                      int translation_height, bool is_topmost,
                                      bool pad_arguments) {
    return {parameters_count_with_receiver, translation_height, is_topmost,
            pad_arguments, FrameInfoKind::kPrecise};
  }
 
  static UnoptimizedFrameInfo Conservative(int parameters_count_with_receiver,
                                           int locals_count) {
    return {parameters_count_with_receiver, locals_count, false, true,
            FrameInfoKind::kConservative};
  }
 
  static uint32_t GetStackSizeForAdditionalArguments(int parameters_count);
 
  uint32_t register_stack_slot_count() const {
    return register_stack_slot_count_;
  }
  uint32_t frame_size_in_bytes_without_fixed() const {
    return frame_size_in_bytes_without_fixed_;
  }
  uint32_t frame_size_in_bytes() const { return frame_size_in_bytes_; }
 
 private:
  UnoptimizedFrameInfo(int parameters_count_with_receiver,
                       int translation_height, bool is_topmost,
                       bool pad_arguments, FrameInfoKind frame_info_kind);
 
  uint32_t register_stack_slot_count_;
  uint32_t frame_size_in_bytes_without_fixed_;
  uint32_t frame_size_in_bytes_;
};
 
class ConstructStubFrameInfo {
 public:
  static ConstructStubFrameInfo Precise(int translation_height,
                                        bool is_topmost) {
    return {translation_height, is_topmost, FrameInfoKind::kPrecise};
  }
 
  static ConstructStubFrameInfo Conservative(int parameters_count) {
    return {parameters_count, false, FrameInfoKind::kConservative};
  }
 
  uint32_t frame_size_in_bytes_without_fixed() const {
    return frame_size_in_bytes_without_fixed_;
  }
  uint32_t frame_size_in_bytes() const { return frame_size_in_bytes_; }
 
 private:
  ConstructStubFrameInfo(int translation_height, bool is_topmost,
                         FrameInfoKind frame_info_kind);
 
  uint32_t frame_size_in_bytes_without_fixed_;
  uint32_t frame_size_in_bytes_;
};
 
class FastConstructStubFrameInfo {
 public:
  static FastConstructStubFrameInfo Precise(bool is_topmost) {
    return FastConstructStubFrameInfo(is_topmost);
  }
 
  static FastConstructStubFrameInfo Conservative() {
    // Assume it is the top most frame when conservative.
    return FastConstructStubFrameInfo(true);
  }
 
  uint32_t frame_size_in_bytes_without_fixed() const {
    return frame_size_in_bytes_without_fixed_;
  }
  uint32_t frame_size_in_bytes() const { return frame_size_in_bytes_; }
 
 private:
  explicit FastConstructStubFrameInfo(bool is_topmost);
 
  uint32_t frame_size_in_bytes_without_fixed_;
  uint32_t frame_size_in_bytes_;
};
 
// Used by BuiltinContinuationFrameInfo.
class CallInterfaceDescriptor;
class RegisterConfiguration;
 
class BuiltinContinuationFrameInfo {
 public:
  static BuiltinContinuationFrameInfo Precise(
      int translation_height,
      const CallInterfaceDescriptor& continuation_descriptor,
      const RegisterConfiguration* register_config, bool is_topmost,
      DeoptimizeKind deopt_kind, BuiltinContinuationMode continuation_mode) {
    return {translation_height,
            continuation_descriptor,
            register_config,
            is_topmost,
            deopt_kind,
            continuation_mode,
            FrameInfoKind::kPrecise};
  }
 
  static BuiltinContinuationFrameInfo Conservative(
      int parameters_count,
      const CallInterfaceDescriptor& continuation_descriptor,
      const RegisterConfiguration* register_config) {
    // It doesn't matter what we pass as is_topmost, deopt_kind and
    // continuation_mode; these values are ignored in conservative mode.
    return {parameters_count,
            continuation_descriptor,
            register_config,
            false,
            DeoptimizeKind::kEager,
            BuiltinContinuationMode::STUB,
            FrameInfoKind::kConservative};
  }
 
  bool frame_has_result_stack_slot() const {
    return frame_has_result_stack_slot_;
  }
  uint32_t translated_stack_parameter_count() const {
    return translated_stack_parameter_count_;
  }
  uint32_t stack_parameter_count() const { return stack_parameter_count_; }
  uint32_t frame_size_in_bytes() const { return frame_size_in_bytes_; }
  uint32_t frame_size_in_bytes_above_fp() const {
    return frame_size_in_bytes_above_fp_;
  }
 
 private:
  BuiltinContinuationFrameInfo(
      int translation_height,
      const CallInterfaceDescriptor& continuation_descriptor,
      const RegisterConfiguration* register_config, bool is_topmost,
      DeoptimizeKind deopt_kind, BuiltinContinuationMode continuation_mode,
      FrameInfoKind frame_info_kind);
 
  bool frame_has_result_stack_slot_;
  uint32_t translated_stack_parameter_count_;
  uint32_t stack_parameter_count_;
  uint32_t frame_size_in_bytes_;
  uint32_t frame_size_in_bytes_above_fp_;
};
 
}  // namespace internal
}  // namespace v8
 
#endif  // V8_EXECUTION_FRAMES_H_