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// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#ifndef RUNTIME_VM_DEBUGGER_H_
#define RUNTIME_VM_DEBUGGER_H_
#include "include/dart_tools_api.h"
#include "vm/kernel_isolate.h"
#include "vm/object.h"
#include "vm/port.h"
#include "vm/scopes.h"
#include "vm/service_event.h"
#include "vm/simulator.h"
DECLARE_FLAG(bool, verbose_debug);
// 'Trace Debugger' TD_Print.
#if defined(_MSC_VER)
#define TD_Print(format, ...) \
if (FLAG_verbose_debug) Log::Current()->Print(format, __VA_ARGS__)
#else
#define TD_Print(format, ...) \
if (FLAG_verbose_debug) Log::Current()->Print(format, ##__VA_ARGS__)
#endif
namespace dart {
class CodeBreakpoint;
class Isolate;
class JSONArray;
class JSONStream;
class ObjectPointerVisitor;
class BreakpointLocation;
class StackFrame;
// A user-defined breakpoint, which either fires once, for a particular closure,
// or always. The API's notion of a breakpoint corresponds to this object.
class Breakpoint {
public:
Breakpoint(intptr_t id, BreakpointLocation* bpt_location)
: id_(id),
kind_(Breakpoint::kNone),
next_(NULL),
closure_(Instance::null()),
bpt_location_(bpt_location),
is_synthetic_async_(false) {}
intptr_t id() const { return id_; }
Breakpoint* next() const { return next_; }
void set_next(Breakpoint* n) { next_ = n; }
BreakpointLocation* bpt_location() const { return bpt_location_; }
void set_bpt_location(BreakpointLocation* new_bpt_location);
bool IsRepeated() const { return kind_ == kRepeated; }
bool IsSingleShot() const { return kind_ == kSingleShot; }
bool IsPerClosure() const { return kind_ == kPerClosure; }
RawInstance* closure() const { return closure_; }
void SetIsRepeated() {
ASSERT(kind_ == kNone);
kind_ = kRepeated;
}
void SetIsSingleShot() {
ASSERT(kind_ == kNone);
kind_ = kSingleShot;
}
void SetIsPerClosure(const Instance& closure) {
ASSERT(kind_ == kNone);
kind_ = kPerClosure;
closure_ = closure.raw();
}
// Mark that this breakpoint is a result of a step OverAwait request.
void set_is_synthetic_async(bool is_synthetic_async) {
is_synthetic_async_ = is_synthetic_async;
}
bool is_synthetic_async() const { return is_synthetic_async_; }
void PrintJSON(JSONStream* stream);
private:
void VisitObjectPointers(ObjectPointerVisitor* visitor);
enum ConditionKind {
kNone,
kRepeated,
kSingleShot,
kPerClosure,
};
intptr_t id_;
ConditionKind kind_;
Breakpoint* next_;
RawInstance* closure_;
BreakpointLocation* bpt_location_;
bool is_synthetic_async_;
friend class BreakpointLocation;
DISALLOW_COPY_AND_ASSIGN(Breakpoint);
};
// BreakpointLocation represents a collection of breakpoint conditions at the
// same token position in Dart source. There may be more than one CodeBreakpoint
// object per BreakpointLocation.
// An unresolved breakpoint is one where the underlying code has not
// been compiled yet. Since the code has not been compiled, we don't know
// the definitive source location yet. The requested source location may
// change when the underlying code gets compiled.
// A latent breakpoint represents a breakpoint location in Dart source
// that is not loaded in the VM when the breakpoint is requested.
// When a script with matching url is loaded, a latent breakpoint
// becomes an unresolved breakpoint.
class BreakpointLocation {
public:
// Create a new unresolved breakpoint.
BreakpointLocation(const Script& script,
TokenPosition token_pos,
TokenPosition end_token_pos,
intptr_t requested_line_number,
intptr_t requested_column_number);
// Create a new latent breakpoint.
BreakpointLocation(const String& url,
intptr_t requested_line_number,
intptr_t requested_column_number);
~BreakpointLocation();
RawFunction* function() const { return function_; }
TokenPosition token_pos() const { return token_pos_; }
TokenPosition end_token_pos() const { return end_token_pos_; }
RawScript* script() const { return script_; }
RawString* url() const { return url_; }
intptr_t requested_line_number() const { return requested_line_number_; }
intptr_t requested_column_number() const { return requested_column_number_; }
intptr_t LineNumber();
intptr_t ColumnNumber();
void GetCodeLocation(Library* lib,
Script* script,
TokenPosition* token_pos) const;
Breakpoint* AddRepeated(Debugger* dbg);
Breakpoint* AddSingleShot(Debugger* dbg);
Breakpoint* AddPerClosure(Debugger* dbg,
const Instance& closure,
bool for_over_await);
bool AnyEnabled() const;
bool IsResolved() const { return is_resolved_; }
bool IsLatent() const { return !token_pos_.IsReal(); }
private:
void VisitObjectPointers(ObjectPointerVisitor* visitor);
void SetResolved(const Function& func, TokenPosition token_pos);
BreakpointLocation* next() const { return this->next_; }
void set_next(BreakpointLocation* value) { next_ = value; }
void AddBreakpoint(Breakpoint* bpt, Debugger* dbg);
Breakpoint* breakpoints() const { return this->conditions_; }
void set_breakpoints(Breakpoint* head) { this->conditions_ = head; }
RawScript* script_;
RawString* url_;
TokenPosition token_pos_;
TokenPosition end_token_pos_;
bool is_resolved_;
BreakpointLocation* next_;
Breakpoint* conditions_;
intptr_t requested_line_number_;
intptr_t requested_column_number_;
// Valid for resolved breakpoints:
RawFunction* function_;
intptr_t line_number_;
intptr_t column_number_;
friend class Debugger;
DISALLOW_COPY_AND_ASSIGN(BreakpointLocation);
};
// CodeBreakpoint represents a location in compiled code. There may be
// more than one CodeBreakpoint for one BreakpointLocation, e.g. when a
// function gets compiled as a regular function and as a closure.
class CodeBreakpoint {
public:
CodeBreakpoint(const Code& code,
TokenPosition token_pos,
uword pc,
RawPcDescriptors::Kind kind);
~CodeBreakpoint();
RawFunction* function() const;
uword pc() const { return pc_; }
TokenPosition token_pos() const { return token_pos_; }
RawScript* SourceCode();
RawString* SourceUrl();
intptr_t LineNumber();
void Enable();
void Disable();
bool IsEnabled() const { return is_enabled_; }
RawCode* OrigStubAddress() const;
private:
void VisitObjectPointers(ObjectPointerVisitor* visitor);
BreakpointLocation* bpt_location() const { return bpt_location_; }
void set_bpt_location(BreakpointLocation* value) { bpt_location_ = value; }
void set_next(CodeBreakpoint* value) { next_ = value; }
CodeBreakpoint* next() const { return this->next_; }
void PatchCode();
void RestoreCode();
RawCode* code_;
TokenPosition token_pos_;
uword pc_;
intptr_t line_number_;
bool is_enabled_;
BreakpointLocation* bpt_location_;
CodeBreakpoint* next_;
RawPcDescriptors::Kind breakpoint_kind_;
#if !defined(TARGET_ARCH_DBC)
RawCode* saved_value_;
#else
// When running on the DBC interpreter we patch bytecode in place with
// DebugBreak. This is an instruction that was replaced. DebugBreak
// will execute it after the breakpoint.
Instr saved_value_;
Instr saved_value_fastsmi_;
#endif
friend class Debugger;
DISALLOW_COPY_AND_ASSIGN(CodeBreakpoint);
};
// ActivationFrame represents one dart function activation frame
// on the call stack.
class ActivationFrame : public ZoneAllocated {
public:
enum Kind {
kRegular,
kAsyncSuspensionMarker,
kAsyncCausal,
kAsyncActivation,
};
ActivationFrame(uword pc,
uword fp,
uword sp,
const Code& code,
const Array& deopt_frame,
intptr_t deopt_frame_offset,
Kind kind = kRegular);
ActivationFrame(uword pc, const Code& code);
explicit ActivationFrame(Kind kind);
explicit ActivationFrame(const Closure& async_activation);
uword pc() const { return pc_; }
uword fp() const { return fp_; }
uword sp() const { return sp_; }
const Function& function() const {
ASSERT(!function_.IsNull());
return function_;
}
const Code& code() const {
ASSERT(!code_.IsNull());
return code_;
}
bool is_interpreted() const { return is_interpreted_; }
RawString* QualifiedFunctionName();
RawString* SourceUrl();
RawScript* SourceScript();
RawLibrary* Library();
TokenPosition TokenPos();
intptr_t LineNumber();
intptr_t ColumnNumber();
// Returns true if this frame is for a function that is visible
// to the user and can be debugged.
bool IsDebuggable() const;
// Returns true if it is possible to rewind the debugger to this frame.
bool IsRewindable() const;
// The context level of a frame is the context level at the
// PC/token index of the frame. It determines the depth of the context
// chain that belongs to the function of this activation frame.
intptr_t ContextLevel();
const char* ToCString();
intptr_t NumLocalVariables();
void VariableAt(intptr_t i,
String* name,
TokenPosition* declaration_token_pos,
TokenPosition* visible_start_token_pos,
TokenPosition* visible_end_token_pos,
Object* value);
RawArray* GetLocalVariables();
RawObject* GetParameter(intptr_t index);
RawObject* GetClosure();
RawObject* GetReceiver();
const Context& GetSavedCurrentContext();
RawObject* GetAsyncOperation();
RawTypeArguments* BuildParameters(
const GrowableObjectArray& param_names,
const GrowableObjectArray& param_values,
const GrowableObjectArray& type_params_names);
RawObject* EvaluateCompiledExpression(const uint8_t* kernel_bytes,
intptr_t kernel_length,
const Array& arguments,
const Array& type_definitions,
const TypeArguments& type_arguments);
// Print the activation frame into |jsobj|. if |full| is false, script
// and local variable objects are only references. if |full| is true,
// the complete script, function, and, local variable objects are included.
void PrintToJSONObject(JSONObject* jsobj, bool full = false);
RawObject* GetAsyncAwaiter();
RawObject* GetCausalStack();
bool HandlesException(const Instance& exc_obj);
private:
void PrintToJSONObjectRegular(JSONObject* jsobj, bool full);
void PrintToJSONObjectAsyncCausal(JSONObject* jsobj, bool full);
void PrintToJSONObjectAsyncSuspensionMarker(JSONObject* jsobj, bool full);
void PrintToJSONObjectAsyncActivation(JSONObject* jsobj, bool full);
void PrintContextMismatchError(intptr_t ctx_slot,
intptr_t frame_ctx_level,
intptr_t var_ctx_level);
void PrintDescriptorsError(const char* message);
intptr_t TryIndex();
intptr_t DeoptId();
void GetPcDescriptors();
void GetVarDescriptors();
void GetDescIndices();
RawObject* GetAsyncContextVariable(const String& name);
RawObject* GetAsyncStreamControllerStreamAwaiter(const Object& stream);
RawObject* GetAsyncStreamControllerStream();
RawObject* GetAsyncCompleterAwaiter(const Object& completer);
RawObject* GetAsyncCompleter();
void ExtractTokenPositionFromAsyncClosure();
bool IsAsyncMachinery() const;
static const char* KindToCString(Kind kind) {
switch (kind) {
case kRegular:
return "Regular";
case kAsyncCausal:
return "AsyncCausal";
case kAsyncSuspensionMarker:
return "AsyncSuspensionMarker";
case kAsyncActivation:
return "AsyncActivation";
default:
UNREACHABLE();
return "";
}
}
RawObject* GetStackVar(VariableIndex var_index);
RawObject* GetContextVar(intptr_t ctxt_level, intptr_t slot_index);
uword pc_;
uword fp_;
uword sp_;
// The anchor of the context chain for this function.
Context& ctx_;
Code& code_;
Function& function_;
bool live_frame_; // Is this frame a live frame?
bool token_pos_initialized_;
TokenPosition token_pos_;
intptr_t try_index_;
intptr_t deopt_id_;
intptr_t line_number_;
intptr_t column_number_;
intptr_t context_level_;
// Some frames are deoptimized into a side array in order to inspect them.
const Array& deopt_frame_;
const intptr_t deopt_frame_offset_;
Kind kind_;
bool is_interpreted_; // Running under kernel bytecode interpreter.
bool vars_initialized_;
LocalVarDescriptors& var_descriptors_;
ZoneGrowableArray<intptr_t> desc_indices_;
PcDescriptors& pc_desc_;
friend class Debugger;
friend class DebuggerStackTrace;
DISALLOW_COPY_AND_ASSIGN(ActivationFrame);
};
// Array of function activations on the call stack.
class DebuggerStackTrace : public ZoneAllocated {
public:
explicit DebuggerStackTrace(int capacity) : trace_(capacity) {}
intptr_t Length() const { return trace_.length(); }
ActivationFrame* FrameAt(int i) const { return trace_[i]; }
ActivationFrame* GetHandlerFrame(const Instance& exc_obj) const;
private:
void AddActivation(ActivationFrame* frame);
void AddMarker(ActivationFrame::Kind marker);
void AddAsyncCausalFrame(uword pc, const Code& code);
ZoneGrowableArray<ActivationFrame*> trace_;
friend class Debugger;
DISALLOW_COPY_AND_ASSIGN(DebuggerStackTrace);
};
// On which exceptions to pause.
typedef enum {
kNoPauseOnExceptions = 1,
kPauseOnUnhandledExceptions,
kPauseOnAllExceptions,
kInvalidExceptionPauseInfo
} Dart_ExceptionPauseInfo;
class Debugger {
public:
enum ResumeAction {
kContinue,
kStepInto,
kStepOver,
kStepOut,
kStepRewind,
kStepOverAsyncSuspension,
};
explicit Debugger(Isolate* isolate);
~Debugger();
void NotifyIsolateCreated();
void Shutdown();
void OnIsolateRunnable();
void NotifyCompilation(const Function& func);
void NotifyDoneLoading();
RawFunction* ResolveFunction(const Library& library,
const String& class_name,
const String& function_name);
// Set breakpoint at closest location to function entry.
Breakpoint* SetBreakpointAtEntry(const Function& target_function,
bool single_shot);
Breakpoint* SetBreakpointAtActivation(const Instance& closure,
bool for_over_await);
Breakpoint* BreakpointAtActivation(const Instance& closure);
// TODO(turnidge): script_url may no longer be specific enough.
Breakpoint* SetBreakpointAtLine(const String& script_url,
intptr_t line_number);
Breakpoint* SetBreakpointAtLineCol(const String& script_url,
intptr_t line_number,
intptr_t column_number);
BreakpointLocation* BreakpointLocationAtLineCol(const String& script_url,
intptr_t line_number,
intptr_t column_number);
void RemoveBreakpoint(intptr_t bp_id);
Breakpoint* GetBreakpointById(intptr_t id);
void MaybeAsyncStepInto(const Closure& async_op);
void AsyncStepInto(const Closure& async_op);
void Continue();
bool SetResumeAction(ResumeAction action,
intptr_t frame_index = 1,
const char** error = NULL);
bool IsStepping() const { return resume_action_ != kContinue; }
bool IsSingleStepping() const { return resume_action_ == kStepInto; }
bool IsPaused() const { return pause_event_ != NULL; }
// Put the isolate into single stepping mode when Dart code next runs.
//
// This is used by the vm service to allow the user to step while
// paused at isolate start.
void EnterSingleStepMode();
// Indicates why the debugger is currently paused. If the debugger
// is not paused, this returns NULL. Note that the debugger can be
// paused for breakpoints, isolate interruption, and (sometimes)
// exceptions.
const ServiceEvent* PauseEvent() const { return pause_event_; }
void SetExceptionPauseInfo(Dart_ExceptionPauseInfo pause_info);
Dart_ExceptionPauseInfo GetExceptionPauseInfo() const;
void VisitObjectPointers(ObjectPointerVisitor* visitor);
// Returns true if there is at least one breakpoint set in func or code.
// Checks for both user-defined and internal temporary breakpoints.
// This may be called from different threads, therefore do not use the,
// debugger's zone.
bool HasBreakpoint(const Function& func, Zone* zone);
bool HasBreakpoint(const Code& code);
// Returns true if the call at address pc is patched to point to
// a debugger stub.
bool HasActiveBreakpoint(uword pc);
// Returns a stack trace with frames corresponding to invisible functions
// omitted. CurrentStackTrace always returns a new trace on the current stack.
// The trace returned by StackTrace may have been cached; it is suitable for
// use when stepping, but otherwise may be out of sync with the current stack.
DebuggerStackTrace* StackTrace();
DebuggerStackTrace* CurrentStackTrace();
DebuggerStackTrace* AsyncCausalStackTrace();
DebuggerStackTrace* CurrentAsyncCausalStackTrace();
DebuggerStackTrace* AwaiterStackTrace();
DebuggerStackTrace* CurrentAwaiterStackTrace();
// Returns a debugger stack trace corresponding to a dart.core.StackTrace.
// Frames corresponding to invisible functions are omitted. It is not valid
// to query local variables in the returned stack.
DebuggerStackTrace* StackTraceFrom(const class StackTrace& dart_stacktrace);
// Utility functions.
static const char* QualifiedFunctionName(const Function& func);
// Pause execution for a breakpoint. Called from generated code.
RawError* PauseBreakpoint();
// Pause execution due to stepping. Called from generated code.
RawError* PauseStepping();
// Pause execution due to isolate interrupt.
RawError* PauseInterrupted();
// Pause after a reload request.
RawError* PausePostRequest();
// Pause execution due to an uncaught exception.
void PauseException(const Instance& exc);
// Pause execution due to a call to the debugger() function from
// Dart.
void PauseDeveloper(const String& msg);
RawCode* GetPatchedStubAddress(uword breakpoint_address);
void PrintBreakpointsToJSONArray(JSONArray* jsarr) const;
void PrintSettingsToJSONObject(JSONObject* jsobj) const;
static bool IsDebuggable(const Function& func);
intptr_t limitBreakpointId() { return next_id_; }
// Callback to the debugger to continue frame rewind, post-deoptimization.
void RewindPostDeopt();
static DebuggerStackTrace* CollectAwaiterReturnStackTrace();
private:
RawError* PauseRequest(ServiceEvent::EventKind kind);
// Finds the breakpoint we hit at |location|.
Breakpoint* FindHitBreakpoint(BreakpointLocation* location,
ActivationFrame* top_frame);
// Will return false if we are not at an await.
bool SetupStepOverAsyncSuspension(const char** error);
bool NeedsIsolateEvents();
bool NeedsDebugEvents();
void InvokeEventHandler(ServiceEvent* event);
void SendBreakpointEvent(ServiceEvent::EventKind kind, Breakpoint* bpt);
bool IsAtAsyncJump(ActivationFrame* top_frame);
void FindCompiledFunctions(const Script& script,
TokenPosition start_pos,
TokenPosition end_pos,
GrowableObjectArray* function_list);
bool FindBestFit(const Script& script,
TokenPosition token_pos,
TokenPosition last_token_pos,
Function* best_fit);
RawFunction* FindInnermostClosure(const Function& function,
TokenPosition token_pos);
TokenPosition ResolveBreakpointPos(const Function& func,
TokenPosition requested_token_pos,
TokenPosition last_token_pos,
intptr_t requested_column);
void DeoptimizeWorld();
BreakpointLocation* SetBreakpoint(const Script& script,
TokenPosition token_pos,
TokenPosition last_token_pos,
intptr_t requested_line,
intptr_t requested_column,
const Function& function);
bool RemoveBreakpointFromTheList(intptr_t bp_id, BreakpointLocation** list);
Breakpoint* GetBreakpointByIdInTheList(intptr_t id, BreakpointLocation* list);
void RemoveUnlinkedCodeBreakpoints();
void UnlinkCodeBreakpoints(BreakpointLocation* bpt_location);
BreakpointLocation* GetLatentBreakpoint(const String& url,
intptr_t line,
intptr_t column);
void RegisterBreakpointLocation(BreakpointLocation* bpt);
void RegisterCodeBreakpoint(CodeBreakpoint* bpt);
BreakpointLocation* GetBreakpointLocation(const Script& script,
TokenPosition token_pos,
intptr_t requested_column);
void MakeCodeBreakpointAt(const Function& func, BreakpointLocation* bpt);
// Returns NULL if no breakpoint exists for the given address.
CodeBreakpoint* GetCodeBreakpoint(uword breakpoint_address);
void SyncBreakpointLocation(BreakpointLocation* loc);
void PrintBreakpointsListToJSONArray(BreakpointLocation* sbpt,
JSONArray* jsarr) const;
ActivationFrame* TopDartFrame() const;
static ActivationFrame* CollectDartFrame(
Isolate* isolate,
uword pc,
StackFrame* frame,
const Code& code,
const Array& deopt_frame,
intptr_t deopt_frame_offset,
ActivationFrame::Kind kind = ActivationFrame::kRegular);
#if !defined(DART_PRECOMPILED_RUNTIME)
static RawArray* DeoptimizeToArray(Thread* thread,
StackFrame* frame,
const Code& code);
#endif
// Appends at least one stack frame. Multiple frames will be appended
// if |code| at the frame's pc contains inlined functions.
static void AppendCodeFrames(Thread* thread,
Isolate* isolate,
Zone* zone,
DebuggerStackTrace* stack_trace,
StackFrame* frame,
Code* code,
Code* inlined_code,
Array* deopt_frame);
static DebuggerStackTrace* CollectStackTrace();
static DebuggerStackTrace* CollectAsyncCausalStackTrace();
void SignalPausedEvent(ActivationFrame* top_frame, Breakpoint* bpt);
intptr_t nextId() { return next_id_++; }
bool ShouldPauseOnException(DebuggerStackTrace* stack_trace,
const Instance& exc);
// Handles any events which pause vm execution. Breakpoints,
// interrupts, etc.
void Pause(ServiceEvent* event);
void HandleSteppingRequest(DebuggerStackTrace* stack_trace,
bool skip_next_step = false);
void CacheStackTraces(DebuggerStackTrace* stack_trace,
DebuggerStackTrace* async_causal_stack_trace,
DebuggerStackTrace* awaiter_stack_trace);
void ClearCachedStackTraces();
// Can we rewind to the indicated frame?
bool CanRewindFrame(intptr_t frame_index, const char** error) const;
void RewindToFrame(intptr_t frame_index);
void RewindToUnoptimizedFrame(StackFrame* frame, const Code& code);
void RewindToOptimizedFrame(StackFrame* frame,
const Code& code,
intptr_t post_deopt_frame_index);
void ResetSteppingFramePointers();
bool SteppedForSyntheticAsyncBreakpoint() const;
void CleanupSyntheticAsyncBreakpoint();
void RememberTopFrameAwaiter();
void SetAsyncSteppingFramePointer();
Isolate* isolate_;
// ID number generator.
intptr_t next_id_;
BreakpointLocation* latent_locations_;
BreakpointLocation* breakpoint_locations_;
CodeBreakpoint* code_breakpoints_;
// Tells debugger what to do when resuming execution after a breakpoint.
ResumeAction resume_action_;
intptr_t resume_frame_index_;
intptr_t post_deopt_frame_index_;
// Do not call back to breakpoint handler if this flag is set.
// Effectively this means ignoring breakpoints. Set when Dart code may
// be run as a side effect of getting values of fields.
bool ignore_breakpoints_;
// Indicates why the debugger is currently paused. If the debugger
// is not paused, this is NULL. Note that the debugger can be
// paused for breakpoints, isolate interruption, and (sometimes)
// exceptions.
ServiceEvent* pause_event_;
// Current stack trace. Valid only while IsPaused().
DebuggerStackTrace* stack_trace_;
DebuggerStackTrace* async_causal_stack_trace_;
DebuggerStackTrace* awaiter_stack_trace_;
// When stepping through code, only pause the program if the top
// frame corresponds to this fp value, or if the top frame is
// lower on the stack.
uword stepping_fp_;
// Used to track the current async/async* function.
uword async_stepping_fp_;
RawObject* top_frame_awaiter_;
// If we step while at a breakpoint, we would hit the same pc twice.
// We use this field to let us skip the next single-step after a
// breakpoint.
bool skip_next_step_;
bool needs_breakpoint_cleanup_;
// We keep this breakpoint alive until after the debugger does the step over
// async continuation machinery so that we can report that we've stopped
// at the breakpoint.
Breakpoint* synthetic_async_breakpoint_;
Dart_ExceptionPauseInfo exc_pause_info_;
friend class Isolate;
friend class BreakpointLocation;
DISALLOW_COPY_AND_ASSIGN(Debugger);
};
} // namespace dart
#endif // RUNTIME_VM_DEBUGGER_H_