v8/src/debug.h

856 lines
30 KiB
C++

// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_DEBUG_H_
#define V8_DEBUG_H_
#include "assembler.h"
#include "code-stubs.h"
#include "debug-agent.h"
#include "execution.h"
#include "factory.h"
#include "hashmap.h"
#include "platform.h"
#include "string-stream.h"
#include "v8threads.h"
#ifdef ENABLE_DEBUGGER_SUPPORT
#include "../include/v8-debug.h"
namespace v8 {
namespace internal {
// Forward declarations.
class EnterDebugger;
// Step actions. NOTE: These values are in macros.py as well.
enum StepAction {
StepNone = -1, // Stepping not prepared.
StepOut = 0, // Step out of the current function.
StepNext = 1, // Step to the next statement in the current function.
StepIn = 2, // Step into new functions invoked or the next statement
// in the current function.
StepMin = 3, // Perform a minimum step in the current function.
StepInMin = 4 // Step into new functions invoked or perform a minimum step
// in the current function.
};
// Type of exception break. NOTE: These values are in macros.py as well.
enum ExceptionBreakType {
BreakException = 0,
BreakUncaughtException = 1
};
// Type of exception break. NOTE: These values are in macros.py as well.
enum BreakLocatorType {
ALL_BREAK_LOCATIONS = 0,
SOURCE_BREAK_LOCATIONS = 1
};
// Class for iterating through the break points in a function and changing
// them.
class BreakLocationIterator {
public:
explicit BreakLocationIterator(Handle<DebugInfo> debug_info,
BreakLocatorType type);
virtual ~BreakLocationIterator();
void Next();
void Next(int count);
void FindBreakLocationFromAddress(Address pc);
void FindBreakLocationFromPosition(int position);
void Reset();
bool Done() const;
void SetBreakPoint(Handle<Object> break_point_object);
void ClearBreakPoint(Handle<Object> break_point_object);
void SetOneShot();
void ClearOneShot();
void PrepareStepIn();
bool IsExit() const;
bool HasBreakPoint();
bool IsDebugBreak();
Object* BreakPointObjects();
void ClearAllDebugBreak();
inline int code_position() { return pc() - debug_info_->code()->entry(); }
inline int break_point() { return break_point_; }
inline int position() { return position_; }
inline int statement_position() { return statement_position_; }
inline Address pc() { return reloc_iterator_->rinfo()->pc(); }
inline Code* code() { return debug_info_->code(); }
inline RelocInfo* rinfo() { return reloc_iterator_->rinfo(); }
inline RelocInfo::Mode rmode() const {
return reloc_iterator_->rinfo()->rmode();
}
inline RelocInfo* original_rinfo() {
return reloc_iterator_original_->rinfo();
}
inline RelocInfo::Mode original_rmode() const {
return reloc_iterator_original_->rinfo()->rmode();
}
protected:
bool RinfoDone() const;
void RinfoNext();
BreakLocatorType type_;
int break_point_;
int position_;
int statement_position_;
Handle<DebugInfo> debug_info_;
RelocIterator* reloc_iterator_;
RelocIterator* reloc_iterator_original_;
private:
void SetDebugBreak();
void ClearDebugBreak();
void SetDebugBreakAtIC();
void ClearDebugBreakAtIC();
bool IsDebugBreakAtReturn();
void SetDebugBreakAtReturn();
void ClearDebugBreakAtReturn();
DISALLOW_COPY_AND_ASSIGN(BreakLocationIterator);
};
// Cache of all script objects in the heap. When a script is added a weak handle
// to it is created and that weak handle is stored in the cache. The weak handle
// callback takes care of removing the script from the cache. The key used in
// the cache is the script id.
class ScriptCache : private HashMap {
public:
ScriptCache() : HashMap(ScriptMatch), collected_scripts_(10) {}
virtual ~ScriptCache() { Clear(); }
// Add script to the cache.
void Add(Handle<Script> script);
// Return the scripts in the cache.
Handle<FixedArray> GetScripts();
// Generate debugger events for collected scripts.
void ProcessCollectedScripts();
private:
// Calculate the hash value from the key (script id).
static uint32_t Hash(int key) { return ComputeIntegerHash(key); }
// Scripts match if their keys (script id) match.
static bool ScriptMatch(void* key1, void* key2) { return key1 == key2; }
// Clear the cache releasing all the weak handles.
void Clear();
// Weak handle callback for scripts in the cache.
static void HandleWeakScript(v8::Persistent<v8::Value> obj, void* data);
// List used during GC to temporarily store id's of collected scripts.
List<int> collected_scripts_;
};
// Linked list holding debug info objects. The debug info objects are kept as
// weak handles to avoid a debug info object to keep a function alive.
class DebugInfoListNode {
public:
explicit DebugInfoListNode(DebugInfo* debug_info);
virtual ~DebugInfoListNode();
DebugInfoListNode* next() { return next_; }
void set_next(DebugInfoListNode* next) { next_ = next; }
Handle<DebugInfo> debug_info() { return debug_info_; }
private:
// Global (weak) handle to the debug info object.
Handle<DebugInfo> debug_info_;
// Next pointer for linked list.
DebugInfoListNode* next_;
};
// This class contains the debugger support. The main purpose is to handle
// setting break points in the code.
//
// This class controls the debug info for all functions which currently have
// active breakpoints in them. This debug info is held in the heap root object
// debug_info which is a FixedArray. Each entry in this list is of class
// DebugInfo.
class Debug {
public:
static void Setup(bool create_heap_objects);
static bool Load();
static void Unload();
static bool IsLoaded() { return !debug_context_.is_null(); }
static bool InDebugger() { return thread_local_.debugger_entry_ != NULL; }
static void PreemptionWhileInDebugger();
static void Iterate(ObjectVisitor* v);
static Object* Break(Arguments args);
static void SetBreakPoint(Handle<SharedFunctionInfo> shared,
int source_position,
Handle<Object> break_point_object);
static void ClearBreakPoint(Handle<Object> break_point_object);
static void ClearAllBreakPoints();
static void FloodWithOneShot(Handle<SharedFunctionInfo> shared);
static void FloodHandlerWithOneShot();
static void ChangeBreakOnException(ExceptionBreakType type, bool enable);
static void PrepareStep(StepAction step_action, int step_count);
static void ClearStepping();
static bool StepNextContinue(BreakLocationIterator* break_location_iterator,
JavaScriptFrame* frame);
static Handle<DebugInfo> GetDebugInfo(Handle<SharedFunctionInfo> shared);
static bool HasDebugInfo(Handle<SharedFunctionInfo> shared);
// Returns whether the operation succeeded.
static bool EnsureDebugInfo(Handle<SharedFunctionInfo> shared);
static bool IsDebugBreak(Address addr);
static bool IsDebugBreakAtReturn(RelocInfo* rinfo);
// Check whether a code stub with the specified major key is a possible break
// point location.
static bool IsSourceBreakStub(Code* code);
static bool IsBreakStub(Code* code);
// Find the builtin to use for invoking the debug break
static Handle<Code> FindDebugBreak(Handle<Code> code, RelocInfo::Mode mode);
static Handle<Object> GetSourceBreakLocations(
Handle<SharedFunctionInfo> shared);
// Getter for the debug_context.
inline static Handle<Context> debug_context() { return debug_context_; }
// Check whether a global object is the debug global object.
static bool IsDebugGlobal(GlobalObject* global);
// Fast check to see if any break points are active.
inline static bool has_break_points() { return has_break_points_; }
static void NewBreak(StackFrame::Id break_frame_id);
static void SetBreak(StackFrame::Id break_frame_id, int break_id);
static StackFrame::Id break_frame_id() {
return thread_local_.break_frame_id_;
}
static int break_id() { return thread_local_.break_id_; }
static bool StepInActive() { return thread_local_.step_into_fp_ != 0; }
static void HandleStepIn(Handle<JSFunction> function,
Handle<Object> holder,
Address fp,
bool is_constructor);
static Address step_in_fp() { return thread_local_.step_into_fp_; }
static Address* step_in_fp_addr() { return &thread_local_.step_into_fp_; }
static EnterDebugger* debugger_entry() {
return thread_local_.debugger_entry_;
}
static void set_debugger_entry(EnterDebugger* entry) {
thread_local_.debugger_entry_ = entry;
}
// Check whether any of the specified interrupts are pending.
static bool is_interrupt_pending(InterruptFlag what) {
return (thread_local_.pending_interrupts_ & what) != 0;
}
// Set specified interrupts as pending.
static void set_interrupts_pending(InterruptFlag what) {
thread_local_.pending_interrupts_ |= what;
}
// Clear specified interrupts from pending.
static void clear_interrupt_pending(InterruptFlag what) {
thread_local_.pending_interrupts_ &= ~static_cast<int>(what);
}
// Getter and setter for the disable break state.
static bool disable_break() { return disable_break_; }
static void set_disable_break(bool disable_break) {
disable_break_ = disable_break;
}
// Getters for the current exception break state.
static bool break_on_exception() { return break_on_exception_; }
static bool break_on_uncaught_exception() {
return break_on_uncaught_exception_;
}
enum AddressId {
k_after_break_target_address,
k_debug_break_return_address,
k_register_address
};
// Support for setting the address to jump to when returning from break point.
static Address* after_break_target_address() {
return reinterpret_cast<Address*>(&thread_local_.after_break_target_);
}
// Support for saving/restoring registers when handling debug break calls.
static Object** register_address(int r) {
return &registers_[r];
}
// Address of the debug break return entry code.
static Code* debug_break_return_entry() { return debug_break_return_entry_; }
// Support for getting the address of the debug break on return code.
static Code** debug_break_return_address() {
return &debug_break_return_;
}
static const int kEstimatedNofDebugInfoEntries = 16;
static const int kEstimatedNofBreakPointsInFunction = 16;
static void HandleWeakDebugInfo(v8::Persistent<v8::Value> obj, void* data);
friend class Debugger;
friend Handle<FixedArray> GetDebuggedFunctions(); // In test-debug.cc
friend void CheckDebuggerUnloaded(bool check_functions); // In test-debug.cc
// Threading support.
static char* ArchiveDebug(char* to);
static char* RestoreDebug(char* from);
static int ArchiveSpacePerThread();
// Mirror cache handling.
static void ClearMirrorCache();
// Script cache handling.
static void CreateScriptCache();
static void DestroyScriptCache();
static void AddScriptToScriptCache(Handle<Script> script);
static Handle<FixedArray> GetLoadedScripts();
// Garbage collection notifications.
static void AfterGarbageCollection();
// Code generation assumptions.
static const int kIa32CallInstructionLength = 5;
static const int kIa32JSReturnSequenceLength = 6;
// The x64 JS return sequence is padded with int3 to make it large
// enough to hold a call instruction when the debugger patches it.
static const int kX64JSReturnSequenceLength = 13;
// Code generator routines.
static void GenerateLoadICDebugBreak(MacroAssembler* masm);
static void GenerateStoreICDebugBreak(MacroAssembler* masm);
static void GenerateKeyedLoadICDebugBreak(MacroAssembler* masm);
static void GenerateKeyedStoreICDebugBreak(MacroAssembler* masm);
static void GenerateConstructCallDebugBreak(MacroAssembler* masm);
static void GenerateReturnDebugBreak(MacroAssembler* masm);
static void GenerateReturnDebugBreakEntry(MacroAssembler* masm);
static void GenerateStubNoRegistersDebugBreak(MacroAssembler* masm);
// Called from stub-cache.cc.
static void GenerateCallICDebugBreak(MacroAssembler* masm);
private:
static bool CompileDebuggerScript(int index);
static void ClearOneShot();
static void ActivateStepIn(StackFrame* frame);
static void ClearStepIn();
static void ClearStepNext();
// Returns whether the compile succeeded.
static bool EnsureCompiled(Handle<SharedFunctionInfo> shared);
static void RemoveDebugInfo(Handle<DebugInfo> debug_info);
static void SetAfterBreakTarget(JavaScriptFrame* frame);
static Handle<Object> CheckBreakPoints(Handle<Object> break_point);
static bool CheckBreakPoint(Handle<Object> break_point_object);
// Global handle to debug context where all the debugger JavaScript code is
// loaded.
static Handle<Context> debug_context_;
// Boolean state indicating whether any break points are set.
static bool has_break_points_;
// Cache of all scripts in the heap.
static ScriptCache* script_cache_;
// List of active debug info objects.
static DebugInfoListNode* debug_info_list_;
static bool disable_break_;
static bool break_on_exception_;
static bool break_on_uncaught_exception_;
// Per-thread data.
class ThreadLocal {
public:
// Counter for generating next break id.
int break_count_;
// Current break id.
int break_id_;
// Frame id for the frame of the current break.
StackFrame::Id break_frame_id_;
// Step action for last step performed.
StepAction last_step_action_;
// Source statement position from last step next action.
int last_statement_position_;
// Number of steps left to perform before debug event.
int step_count_;
// Frame pointer from last step next action.
Address last_fp_;
// Frame pointer for frame from which step in was performed.
Address step_into_fp_;
// Storage location for jump when exiting debug break calls.
Address after_break_target_;
// Top debugger entry.
EnterDebugger* debugger_entry_;
// Pending interrupts scheduled while debugging.
int pending_interrupts_;
};
// Storage location for registers when handling debug break calls
static JSCallerSavedBuffer registers_;
static ThreadLocal thread_local_;
static void ThreadInit();
// Code object for debug break return entry code.
static Code* debug_break_return_entry_;
// Code to call for handling debug break on return.
static Code* debug_break_return_;
DISALLOW_COPY_AND_ASSIGN(Debug);
};
// Message delivered to the message handler callback. This is either a debugger
// event or the response to a command.
class MessageImpl: public v8::Debug::Message {
public:
// Create a message object for a debug event.
static MessageImpl NewEvent(DebugEvent event,
bool running,
Handle<JSObject> exec_state,
Handle<JSObject> event_data);
// Create a message object for the response to a debug command.
static MessageImpl NewResponse(DebugEvent event,
bool running,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
Handle<String> response_json,
v8::Debug::ClientData* client_data);
// Implementation of interface v8::Debug::Message.
virtual bool IsEvent() const;
virtual bool IsResponse() const;
virtual DebugEvent GetEvent() const;
virtual bool WillStartRunning() const;
virtual v8::Handle<v8::Object> GetExecutionState() const;
virtual v8::Handle<v8::Object> GetEventData() const;
virtual v8::Handle<v8::String> GetJSON() const;
virtual v8::Handle<v8::Context> GetEventContext() const;
virtual v8::Debug::ClientData* GetClientData() const;
private:
MessageImpl(bool is_event,
DebugEvent event,
bool running,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
Handle<String> response_json,
v8::Debug::ClientData* client_data);
bool is_event_; // Does this message represent a debug event?
DebugEvent event_; // Debug event causing the break.
bool running_; // Will the VM start running after this event?
Handle<JSObject> exec_state_; // Current execution state.
Handle<JSObject> event_data_; // Data associated with the event.
Handle<String> response_json_; // Response JSON if message holds a response.
v8::Debug::ClientData* client_data_; // Client data passed with the request.
};
// Message send by user to v8 debugger or debugger output message.
// In addition to command text it may contain a pointer to some user data
// which are expected to be passed along with the command reponse to message
// handler.
class CommandMessage {
public:
static CommandMessage New(const Vector<uint16_t>& command,
v8::Debug::ClientData* data);
CommandMessage();
~CommandMessage();
// Deletes user data and disposes of the text.
void Dispose();
Vector<uint16_t> text() const { return text_; }
v8::Debug::ClientData* client_data() const { return client_data_; }
private:
CommandMessage(const Vector<uint16_t>& text,
v8::Debug::ClientData* data);
Vector<uint16_t> text_;
v8::Debug::ClientData* client_data_;
};
// A Queue of CommandMessage objects. A thread-safe version is
// LockingCommandMessageQueue, based on this class.
class CommandMessageQueue BASE_EMBEDDED {
public:
explicit CommandMessageQueue(int size);
~CommandMessageQueue();
bool IsEmpty() const { return start_ == end_; }
CommandMessage Get();
void Put(const CommandMessage& message);
void Clear() { start_ = end_ = 0; } // Queue is empty after Clear().
private:
// Doubles the size of the message queue, and copies the messages.
void Expand();
CommandMessage* messages_;
int start_;
int end_;
int size_; // The size of the queue buffer. Queue can hold size-1 messages.
};
// LockingCommandMessageQueue is a thread-safe circular buffer of CommandMessage
// messages. The message data is not managed by LockingCommandMessageQueue.
// Pointers to the data are passed in and out. Implemented by adding a
// Mutex to CommandMessageQueue. Includes logging of all puts and gets.
class LockingCommandMessageQueue BASE_EMBEDDED {
public:
explicit LockingCommandMessageQueue(int size);
~LockingCommandMessageQueue();
bool IsEmpty() const;
CommandMessage Get();
void Put(const CommandMessage& message);
void Clear();
private:
CommandMessageQueue queue_;
Mutex* lock_;
DISALLOW_COPY_AND_ASSIGN(LockingCommandMessageQueue);
};
class Debugger {
public:
static void DebugRequest(const uint16_t* json_request, int length);
static Handle<Object> MakeJSObject(Vector<const char> constructor_name,
int argc, Object*** argv,
bool* caught_exception);
static Handle<Object> MakeExecutionState(bool* caught_exception);
static Handle<Object> MakeBreakEvent(Handle<Object> exec_state,
Handle<Object> break_points_hit,
bool* caught_exception);
static Handle<Object> MakeExceptionEvent(Handle<Object> exec_state,
Handle<Object> exception,
bool uncaught,
bool* caught_exception);
static Handle<Object> MakeNewFunctionEvent(Handle<Object> func,
bool* caught_exception);
static Handle<Object> MakeCompileEvent(Handle<Script> script,
bool before,
bool* caught_exception);
static Handle<Object> MakeScriptCollectedEvent(int id,
bool* caught_exception);
static void OnDebugBreak(Handle<Object> break_points_hit, bool auto_continue);
static void OnException(Handle<Object> exception, bool uncaught);
static void OnBeforeCompile(Handle<Script> script);
static void OnAfterCompile(Handle<Script> script,
Handle<JSFunction> fun);
static void OnNewFunction(Handle<JSFunction> fun);
static void OnScriptCollected(int id);
static void ProcessDebugEvent(v8::DebugEvent event,
Handle<JSObject> event_data,
bool auto_continue);
static void NotifyMessageHandler(v8::DebugEvent event,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
bool auto_continue);
static void SetEventListener(Handle<Object> callback, Handle<Object> data);
static void SetMessageHandler(v8::Debug::MessageHandler2 handler);
static void SetHostDispatchHandler(v8::Debug::HostDispatchHandler handler,
int period);
// Invoke the message handler function.
static void InvokeMessageHandler(MessageImpl message);
// Add a debugger command to the command queue.
static void ProcessCommand(Vector<const uint16_t> command,
v8::Debug::ClientData* client_data = NULL);
// Check whether there are commands in the command queue.
static bool HasCommands();
static Handle<Object> Call(Handle<JSFunction> fun,
Handle<Object> data,
bool* pending_exception);
// Start the debugger agent listening on the provided port.
static bool StartAgent(const char* name, int port);
// Stop the debugger agent.
static void StopAgent();
// Unload the debugger if possible. Only called when no debugger is currently
// active.
static void UnloadDebugger();
inline static bool EventActive(v8::DebugEvent event) {
ScopedLock with(debugger_access_);
// Check whether the message handler was been cleared.
if (debugger_unload_pending_) {
UnloadDebugger();
}
// Currently argument event is not used.
return !compiling_natives_ && Debugger::IsDebuggerActive();
}
static void set_compiling_natives(bool compiling_natives) {
Debugger::compiling_natives_ = compiling_natives;
}
static bool compiling_natives() { return Debugger::compiling_natives_; }
static void set_loading_debugger(bool v) { is_loading_debugger_ = v; }
static bool is_loading_debugger() { return Debugger::is_loading_debugger_; }
private:
static bool IsDebuggerActive();
static void ListenersChanged();
static Mutex* debugger_access_; // Mutex guarding debugger variables.
static Handle<Object> event_listener_; // Global handle to listener.
static Handle<Object> event_listener_data_;
static bool compiling_natives_; // Are we compiling natives?
static bool is_loading_debugger_; // Are we loading the debugger?
static bool never_unload_debugger_; // Can we unload the debugger?
static v8::Debug::MessageHandler2 message_handler_;
static bool debugger_unload_pending_; // Was message handler cleared?
static v8::Debug::HostDispatchHandler host_dispatch_handler_;
static int host_dispatch_micros_;
static DebuggerAgent* agent_;
static const int kQueueInitialSize = 4;
static LockingCommandMessageQueue command_queue_;
static Semaphore* command_received_; // Signaled for each command received.
friend class EnterDebugger;
};
// This class is used for entering the debugger. Create an instance in the stack
// to enter the debugger. This will set the current break state, make sure the
// debugger is loaded and switch to the debugger context. If the debugger for
// some reason could not be entered FailedToEnter will return true.
class EnterDebugger BASE_EMBEDDED {
public:
EnterDebugger()
: prev_(Debug::debugger_entry()),
has_js_frames_(!it_.done()) {
ASSERT(prev_ != NULL || !Debug::is_interrupt_pending(PREEMPT));
ASSERT(prev_ != NULL || !Debug::is_interrupt_pending(DEBUGBREAK));
// Link recursive debugger entry.
Debug::set_debugger_entry(this);
// Store the previous break id and frame id.
break_id_ = Debug::break_id();
break_frame_id_ = Debug::break_frame_id();
// Create the new break info. If there is no JavaScript frames there is no
// break frame id.
if (has_js_frames_) {
Debug::NewBreak(it_.frame()->id());
} else {
Debug::NewBreak(StackFrame::NO_ID);
}
// Make sure that debugger is loaded and enter the debugger context.
load_failed_ = !Debug::Load();
if (!load_failed_) {
// NOTE the member variable save which saves the previous context before
// this change.
Top::set_context(*Debug::debug_context());
}
}
~EnterDebugger() {
// Restore to the previous break state.
Debug::SetBreak(break_frame_id_, break_id_);
// Check for leaving the debugger.
if (prev_ == NULL) {
// Clear mirror cache when leaving the debugger. Skip this if there is a
// pending exception as clearing the mirror cache calls back into
// JavaScript. This can happen if the v8::Debug::Call is used in which
// case the exception should end up in the calling code.
if (!Top::has_pending_exception()) {
// Try to avoid any pending debug break breaking in the clear mirror
// cache JavaScript code.
if (StackGuard::IsDebugBreak()) {
Debug::set_interrupts_pending(DEBUGBREAK);
StackGuard::Continue(DEBUGBREAK);
}
Debug::ClearMirrorCache();
}
// Request preemption and debug break when leaving the last debugger entry
// if any of these where recorded while debugging.
if (Debug::is_interrupt_pending(PREEMPT)) {
// This re-scheduling of preemption is to avoid starvation in some
// debugging scenarios.
Debug::clear_interrupt_pending(PREEMPT);
StackGuard::Preempt();
}
if (Debug::is_interrupt_pending(DEBUGBREAK)) {
Debug::clear_interrupt_pending(DEBUGBREAK);
StackGuard::DebugBreak();
}
// If there are commands in the queue when leaving the debugger request
// that these commands are processed.
if (Debugger::HasCommands()) {
StackGuard::DebugCommand();
}
// If leaving the debugger with the debugger no longer active unload it.
if (!Debugger::IsDebuggerActive()) {
Debugger::UnloadDebugger();
}
}
// Leaving this debugger entry.
Debug::set_debugger_entry(prev_);
}
// Check whether the debugger could be entered.
inline bool FailedToEnter() { return load_failed_; }
// Check whether there are any JavaScript frames on the stack.
inline bool HasJavaScriptFrames() { return has_js_frames_; }
// Get the active context from before entering the debugger.
inline Handle<Context> GetContext() { return save_.context(); }
private:
EnterDebugger* prev_; // Previous debugger entry if entered recursively.
JavaScriptFrameIterator it_;
const bool has_js_frames_; // Were there any JavaScript frames?
StackFrame::Id break_frame_id_; // Previous break frame id.
int break_id_; // Previous break id.
bool load_failed_; // Did the debugger fail to load?
SaveContext save_; // Saves previous context.
};
// Stack allocated class for disabling break.
class DisableBreak BASE_EMBEDDED {
public:
// Enter the debugger by storing the previous top context and setting the
// current top context to the debugger context.
explicit DisableBreak(bool disable_break) {
prev_disable_break_ = Debug::disable_break();
Debug::set_disable_break(disable_break);
}
~DisableBreak() {
Debug::set_disable_break(prev_disable_break_);
}
private:
// The previous state of the disable break used to restore the value when this
// object is destructed.
bool prev_disable_break_;
};
// Debug_Address encapsulates the Address pointers used in generating debug
// code.
class Debug_Address {
public:
Debug_Address(Debug::AddressId id, int reg = 0)
: id_(id), reg_(reg) {
ASSERT(reg == 0 || id == Debug::k_register_address);
}
static Debug_Address AfterBreakTarget() {
return Debug_Address(Debug::k_after_break_target_address);
}
static Debug_Address DebugBreakReturn() {
return Debug_Address(Debug::k_debug_break_return_address);
}
static Debug_Address Register(int reg) {
return Debug_Address(Debug::k_register_address, reg);
}
Address address() const {
switch (id_) {
case Debug::k_after_break_target_address:
return reinterpret_cast<Address>(Debug::after_break_target_address());
case Debug::k_debug_break_return_address:
return reinterpret_cast<Address>(Debug::debug_break_return_address());
case Debug::k_register_address:
return reinterpret_cast<Address>(Debug::register_address(reg_));
default:
UNREACHABLE();
return NULL;
}
}
private:
Debug::AddressId id_;
int reg_;
};
} } // namespace v8::internal
#endif // ENABLE_DEBUGGER_SUPPORT
#endif // V8_DEBUG_H_