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v8/src/debug.cc
jochen@chromium.org be69c78e6d Fix data race on Debug::thread_local_.current_debug_scope_ 
BUG=v8:3614
R=yangguo@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/631223004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24441 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2014-10-07 16:11:31 +00:00

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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.
#include "src/v8.h"
#include "src/api.h"
#include "src/arguments.h"
#include "src/bootstrapper.h"
#include "src/code-stubs.h"
#include "src/codegen.h"
#include "src/compilation-cache.h"
#include "src/compiler.h"
#include "src/debug.h"
#include "src/deoptimizer.h"
#include "src/execution.h"
#include "src/full-codegen.h"
#include "src/global-handles.h"
#include "src/isolate-inl.h"
#include "src/list.h"
#include "src/log.h"
#include "src/messages.h"
#include "src/natives.h"
#include "include/v8-debug.h"
namespace v8 {
namespace internal {
Debug::Debug(Isolate* isolate)
: debug_context_(Handle<Context>()),
event_listener_(Handle<Object>()),
event_listener_data_(Handle<Object>()),
message_handler_(NULL),
command_received_(0),
command_queue_(isolate->logger(), kQueueInitialSize),
event_command_queue_(isolate->logger(), kQueueInitialSize),
is_active_(false),
is_suppressed_(false),
live_edit_enabled_(true), // TODO(yangguo): set to false by default.
has_break_points_(false),
break_disabled_(false),
break_on_exception_(false),
break_on_uncaught_exception_(false),
script_cache_(NULL),
debug_info_list_(NULL),
isolate_(isolate) {
ThreadInit();
}
static v8::Handle<v8::Context> GetDebugEventContext(Isolate* isolate) {
Handle<Context> context = isolate->debug()->debugger_entry()->GetContext();
// Isolate::context() may have been NULL when "script collected" event
// occured.
if (context.is_null()) return v8::Local<v8::Context>();
Handle<Context> native_context(context->native_context());
return v8::Utils::ToLocal(native_context);
}
BreakLocationIterator::BreakLocationIterator(Handle<DebugInfo> debug_info,
BreakLocatorType type) {
debug_info_ = debug_info;
type_ = type;
reloc_iterator_ = NULL;
reloc_iterator_original_ = NULL;
Reset(); // Initialize the rest of the member variables.
}
BreakLocationIterator::~BreakLocationIterator() {
DCHECK(reloc_iterator_ != NULL);
DCHECK(reloc_iterator_original_ != NULL);
delete reloc_iterator_;
delete reloc_iterator_original_;
}
// Check whether a code stub with the specified major key is a possible break
// point location when looking for source break locations.
static bool IsSourceBreakStub(Code* code) {
CodeStub::Major major_key = CodeStub::GetMajorKey(code);
return major_key == CodeStub::CallFunction;
}
// Check whether a code stub with the specified major key is a possible break
// location.
static bool IsBreakStub(Code* code) {
CodeStub::Major major_key = CodeStub::GetMajorKey(code);
return major_key == CodeStub::CallFunction;
}
void BreakLocationIterator::Next() {
DisallowHeapAllocation no_gc;
DCHECK(!RinfoDone());
// Iterate through reloc info for code and original code stopping at each
// breakable code target.
bool first = break_point_ == -1;
while (!RinfoDone()) {
if (!first) RinfoNext();
first = false;
if (RinfoDone()) return;
// Whenever a statement position or (plain) position is passed update the
// current value of these.
if (RelocInfo::IsPosition(rmode())) {
if (RelocInfo::IsStatementPosition(rmode())) {
statement_position_ = static_cast<int>(
rinfo()->data() - debug_info_->shared()->start_position());
}
// Always update the position as we don't want that to be before the
// statement position.
position_ = static_cast<int>(
rinfo()->data() - debug_info_->shared()->start_position());
DCHECK(position_ >= 0);
DCHECK(statement_position_ >= 0);
}
if (IsDebugBreakSlot()) {
// There is always a possible break point at a debug break slot.
break_point_++;
return;
} else if (RelocInfo::IsCodeTarget(rmode())) {
// Check for breakable code target. Look in the original code as setting
// break points can cause the code targets in the running (debugged) code
// to be of a different kind than in the original code.
Address target = original_rinfo()->target_address();
Code* code = Code::GetCodeFromTargetAddress(target);
if ((code->is_inline_cache_stub() &&
!code->is_binary_op_stub() &&
!code->is_compare_ic_stub() &&
!code->is_to_boolean_ic_stub()) ||
RelocInfo::IsConstructCall(rmode())) {
break_point_++;
return;
}
if (code->kind() == Code::STUB) {
if (IsDebuggerStatement()) {
break_point_++;
return;
} else if (type_ == ALL_BREAK_LOCATIONS) {
if (IsBreakStub(code)) {
break_point_++;
return;
}
} else {
DCHECK(type_ == SOURCE_BREAK_LOCATIONS);
if (IsSourceBreakStub(code)) {
break_point_++;
return;
}
}
}
}
// Check for break at return.
if (RelocInfo::IsJSReturn(rmode())) {
// Set the positions to the end of the function.
if (debug_info_->shared()->HasSourceCode()) {
position_ = debug_info_->shared()->end_position() -
debug_info_->shared()->start_position() - 1;
} else {
position_ = 0;
}
statement_position_ = position_;
break_point_++;
return;
}
}
}
void BreakLocationIterator::Next(int count) {
while (count > 0) {
Next();
count--;
}
}
// Find the break point at the supplied address, or the closest one before
// the address.
void BreakLocationIterator::FindBreakLocationFromAddress(Address pc) {
// Run through all break points to locate the one closest to the address.
int closest_break_point = 0;
int distance = kMaxInt;
while (!Done()) {
// Check if this break point is closer that what was previously found.
if (this->pc() <= pc && pc - this->pc() < distance) {
closest_break_point = break_point();
distance = static_cast<int>(pc - this->pc());
// Check whether we can't get any closer.
if (distance == 0) break;
}
Next();
}
// Move to the break point found.
Reset();
Next(closest_break_point);
}
// Find the break point closest to the supplied source position.
void BreakLocationIterator::FindBreakLocationFromPosition(int position,
BreakPositionAlignment alignment) {
// Run through all break points to locate the one closest to the source
// position.
int closest_break_point = 0;
int distance = kMaxInt;
while (!Done()) {
int next_position;
switch (alignment) {
case STATEMENT_ALIGNED:
next_position = this->statement_position();
break;
case BREAK_POSITION_ALIGNED:
next_position = this->position();
break;
default:
UNREACHABLE();
next_position = this->statement_position();
}
// Check if this break point is closer that what was previously found.
if (position <= next_position && next_position - position < distance) {
closest_break_point = break_point();
distance = next_position - position;
// Check whether we can't get any closer.
if (distance == 0) break;
}
Next();
}
// Move to the break point found.
Reset();
Next(closest_break_point);
}
void BreakLocationIterator::Reset() {
// Create relocation iterators for the two code objects.
if (reloc_iterator_ != NULL) delete reloc_iterator_;
if (reloc_iterator_original_ != NULL) delete reloc_iterator_original_;
reloc_iterator_ = new RelocIterator(
debug_info_->code(),
~RelocInfo::ModeMask(RelocInfo::CODE_AGE_SEQUENCE));
reloc_iterator_original_ = new RelocIterator(
debug_info_->original_code(),
~RelocInfo::ModeMask(RelocInfo::CODE_AGE_SEQUENCE));
// Position at the first break point.
break_point_ = -1;
position_ = 1;
statement_position_ = 1;
Next();
}
bool BreakLocationIterator::Done() const {
return RinfoDone();
}
void BreakLocationIterator::SetBreakPoint(Handle<Object> break_point_object) {
// If there is not already a real break point here patch code with debug
// break.
if (!HasBreakPoint()) SetDebugBreak();
DCHECK(IsDebugBreak() || IsDebuggerStatement());
// Set the break point information.
DebugInfo::SetBreakPoint(debug_info_, code_position(),
position(), statement_position(),
break_point_object);
}
void BreakLocationIterator::ClearBreakPoint(Handle<Object> break_point_object) {
// Clear the break point information.
DebugInfo::ClearBreakPoint(debug_info_, code_position(), break_point_object);
// If there are no more break points here remove the debug break.
if (!HasBreakPoint()) {
ClearDebugBreak();
DCHECK(!IsDebugBreak());
}
}
void BreakLocationIterator::SetOneShot() {
// Debugger statement always calls debugger. No need to modify it.
if (IsDebuggerStatement()) return;
// If there is a real break point here no more to do.
if (HasBreakPoint()) {
DCHECK(IsDebugBreak());
return;
}
// Patch code with debug break.
SetDebugBreak();
}
void BreakLocationIterator::ClearOneShot() {
// Debugger statement always calls debugger. No need to modify it.
if (IsDebuggerStatement()) return;
// If there is a real break point here no more to do.
if (HasBreakPoint()) {
DCHECK(IsDebugBreak());
return;
}
// Patch code removing debug break.
ClearDebugBreak();
DCHECK(!IsDebugBreak());
}
void BreakLocationIterator::SetDebugBreak() {
// Debugger statement always calls debugger. No need to modify it.
if (IsDebuggerStatement()) return;
// If there is already a break point here just return. This might happen if
// the same code is flooded with break points twice. Flooding the same
// function twice might happen when stepping in a function with an exception
// handler as the handler and the function is the same.
if (IsDebugBreak()) return;
if (RelocInfo::IsJSReturn(rmode())) {
// Patch the frame exit code with a break point.
SetDebugBreakAtReturn();
} else if (IsDebugBreakSlot()) {
// Patch the code in the break slot.
SetDebugBreakAtSlot();
} else {
// Patch the IC call.
SetDebugBreakAtIC();
}
DCHECK(IsDebugBreak());
}
void BreakLocationIterator::ClearDebugBreak() {
// Debugger statement always calls debugger. No need to modify it.
if (IsDebuggerStatement()) return;
if (RelocInfo::IsJSReturn(rmode())) {
// Restore the frame exit code.
ClearDebugBreakAtReturn();
} else if (IsDebugBreakSlot()) {
// Restore the code in the break slot.
ClearDebugBreakAtSlot();
} else {
// Patch the IC call.
ClearDebugBreakAtIC();
}
DCHECK(!IsDebugBreak());
}
bool BreakLocationIterator::IsStepInLocation(Isolate* isolate) {
if (RelocInfo::IsConstructCall(original_rmode())) {
return true;
} else if (RelocInfo::IsCodeTarget(rmode())) {
HandleScope scope(debug_info_->GetIsolate());
Address target = original_rinfo()->target_address();
Handle<Code> target_code(Code::GetCodeFromTargetAddress(target));
if (target_code->kind() == Code::STUB) {
return CodeStub::GetMajorKey(*target_code) == CodeStub::CallFunction;
}
return target_code->is_call_stub();
}
return false;
}
void BreakLocationIterator::PrepareStepIn(Isolate* isolate) {
#ifdef DEBUG
HandleScope scope(isolate);
// Step in can only be prepared if currently positioned on an IC call,
// construct call or CallFunction stub call.
Address target = rinfo()->target_address();
Handle<Code> target_code(Code::GetCodeFromTargetAddress(target));
// All the following stuff is needed only for assertion checks so the code
// is wrapped in ifdef.
Handle<Code> maybe_call_function_stub = target_code;
if (IsDebugBreak()) {
Address original_target = original_rinfo()->target_address();
maybe_call_function_stub =
Handle<Code>(Code::GetCodeFromTargetAddress(original_target));
}
bool is_call_function_stub =
(maybe_call_function_stub->kind() == Code::STUB &&
CodeStub::GetMajorKey(*maybe_call_function_stub) ==
CodeStub::CallFunction);
// Step in through construct call requires no changes to the running code.
// Step in through getters/setters should already be prepared as well
// because caller of this function (Debug::PrepareStep) is expected to
// flood the top frame's function with one shot breakpoints.
// Step in through CallFunction stub should also be prepared by caller of
// this function (Debug::PrepareStep) which should flood target function
// with breakpoints.
DCHECK(RelocInfo::IsConstructCall(rmode()) ||
target_code->is_inline_cache_stub() ||
is_call_function_stub);
#endif
}
// Check whether the break point is at a position which will exit the function.
bool BreakLocationIterator::IsExit() const {
return (RelocInfo::IsJSReturn(rmode()));
}
bool BreakLocationIterator::HasBreakPoint() {
return debug_info_->HasBreakPoint(code_position());
}
// Check whether there is a debug break at the current position.
bool BreakLocationIterator::IsDebugBreak() {
if (RelocInfo::IsJSReturn(rmode())) {
return IsDebugBreakAtReturn();
} else if (IsDebugBreakSlot()) {
return IsDebugBreakAtSlot();
} else {
return Debug::IsDebugBreak(rinfo()->target_address());
}
}
// Find the builtin to use for invoking the debug break
static Handle<Code> DebugBreakForIC(Handle<Code> code, RelocInfo::Mode mode) {
Isolate* isolate = code->GetIsolate();
// Find the builtin debug break function matching the calling convention
// used by the call site.
if (code->is_inline_cache_stub()) {
switch (code->kind()) {
case Code::CALL_IC:
return isolate->builtins()->CallICStub_DebugBreak();
case Code::LOAD_IC:
return isolate->builtins()->LoadIC_DebugBreak();
case Code::STORE_IC:
return isolate->builtins()->StoreIC_DebugBreak();
case Code::KEYED_LOAD_IC:
return isolate->builtins()->KeyedLoadIC_DebugBreak();
case Code::KEYED_STORE_IC:
return isolate->builtins()->KeyedStoreIC_DebugBreak();
case Code::COMPARE_NIL_IC:
return isolate->builtins()->CompareNilIC_DebugBreak();
default:
UNREACHABLE();
}
}
if (RelocInfo::IsConstructCall(mode)) {
if (code->has_function_cache()) {
return isolate->builtins()->CallConstructStub_Recording_DebugBreak();
} else {
return isolate->builtins()->CallConstructStub_DebugBreak();
}
}
if (code->kind() == Code::STUB) {
DCHECK(CodeStub::GetMajorKey(*code) == CodeStub::CallFunction);
return isolate->builtins()->CallFunctionStub_DebugBreak();
}
UNREACHABLE();
return Handle<Code>::null();
}
void BreakLocationIterator::SetDebugBreakAtIC() {
// Patch the original code with the current address as the current address
// might have changed by the inline caching since the code was copied.
original_rinfo()->set_target_address(rinfo()->target_address());
RelocInfo::Mode mode = rmode();
if (RelocInfo::IsCodeTarget(mode)) {
Address target = rinfo()->target_address();
Handle<Code> target_code(Code::GetCodeFromTargetAddress(target));
// Patch the code to invoke the builtin debug break function matching the
// calling convention used by the call site.
Handle<Code> dbgbrk_code = DebugBreakForIC(target_code, mode);
rinfo()->set_target_address(dbgbrk_code->entry());
}
}
void BreakLocationIterator::ClearDebugBreakAtIC() {
// Patch the code to the original invoke.
rinfo()->set_target_address(original_rinfo()->target_address());
}
bool BreakLocationIterator::IsDebuggerStatement() {
return RelocInfo::DEBUG_BREAK == rmode();
}
bool BreakLocationIterator::IsDebugBreakSlot() {
return RelocInfo::DEBUG_BREAK_SLOT == rmode();
}
Object* BreakLocationIterator::BreakPointObjects() {
return debug_info_->GetBreakPointObjects(code_position());
}
// Clear out all the debug break code. This is ONLY supposed to be used when
// shutting down the debugger as it will leave the break point information in
// DebugInfo even though the code is patched back to the non break point state.
void BreakLocationIterator::ClearAllDebugBreak() {
while (!Done()) {
ClearDebugBreak();
Next();
}
}
bool BreakLocationIterator::RinfoDone() const {
DCHECK(reloc_iterator_->done() == reloc_iterator_original_->done());
return reloc_iterator_->done();
}
void BreakLocationIterator::RinfoNext() {
reloc_iterator_->next();
reloc_iterator_original_->next();
#ifdef DEBUG
DCHECK(reloc_iterator_->done() == reloc_iterator_original_->done());
if (!reloc_iterator_->done()) {
DCHECK(rmode() == original_rmode());
}
#endif
}
// Threading support.
void Debug::ThreadInit() {
thread_local_.break_count_ = 0;
thread_local_.break_id_ = 0;
thread_local_.break_frame_id_ = StackFrame::NO_ID;
thread_local_.last_step_action_ = StepNone;
thread_local_.last_statement_position_ = RelocInfo::kNoPosition;
thread_local_.step_count_ = 0;
thread_local_.last_fp_ = 0;
thread_local_.queued_step_count_ = 0;
thread_local_.step_into_fp_ = 0;
thread_local_.step_out_fp_ = 0;
// TODO(isolates): frames_are_dropped_?
base::NoBarrier_Store(&thread_local_.current_debug_scope_,
static_cast<base::AtomicWord>(NULL));
thread_local_.restarter_frame_function_pointer_ = NULL;
}
char* Debug::ArchiveDebug(char* storage) {
char* to = storage;
MemCopy(to, reinterpret_cast<char*>(&thread_local_), sizeof(ThreadLocal));
ThreadInit();
return storage + ArchiveSpacePerThread();
}
char* Debug::RestoreDebug(char* storage) {
char* from = storage;
MemCopy(reinterpret_cast<char*>(&thread_local_), from, sizeof(ThreadLocal));
return storage + ArchiveSpacePerThread();
}
int Debug::ArchiveSpacePerThread() {
return sizeof(ThreadLocal);
}
ScriptCache::ScriptCache(Isolate* isolate) : HashMap(HashMap::PointersMatch),
isolate_(isolate) {
Heap* heap = isolate_->heap();
HandleScope scope(isolate_);
// Perform two GCs to get rid of all unreferenced scripts. The first GC gets
// rid of all the cached script wrappers and the second gets rid of the
// scripts which are no longer referenced.
heap->CollectAllGarbage(Heap::kMakeHeapIterableMask, "ScriptCache");
heap->CollectAllGarbage(Heap::kMakeHeapIterableMask, "ScriptCache");
// Scan heap for Script objects.
HeapIterator iterator(heap);
DisallowHeapAllocation no_allocation;
for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
if (obj->IsScript() && Script::cast(obj)->HasValidSource()) {
Add(Handle<Script>(Script::cast(obj)));
}
}
}
void ScriptCache::Add(Handle<Script> script) {
GlobalHandles* global_handles = isolate_->global_handles();
// Create an entry in the hash map for the script.
int id = script->id()->value();
HashMap::Entry* entry =
HashMap::Lookup(reinterpret_cast<void*>(id), Hash(id), true);
if (entry->value != NULL) {
#ifdef DEBUG
// The code deserializer may introduce duplicate Script objects.
// Assert that the Script objects with the same id have the same name.
Handle<Script> found(reinterpret_cast<Script**>(entry->value));
DCHECK(script->id() == found->id());
DCHECK(!script->name()->IsString() ||
String::cast(script->name())->Equals(String::cast(found->name())));
#endif
return;
}
// Globalize the script object, make it weak and use the location of the
// global handle as the value in the hash map.
Handle<Script> script_ =
Handle<Script>::cast(global_handles->Create(*script));
GlobalHandles::MakeWeak(reinterpret_cast<Object**>(script_.location()),
this,
ScriptCache::HandleWeakScript);
entry->value = script_.location();
}
Handle<FixedArray> ScriptCache::GetScripts() {
Factory* factory = isolate_->factory();
Handle<FixedArray> instances = factory->NewFixedArray(occupancy());
int count = 0;
for (HashMap::Entry* entry = Start(); entry != NULL; entry = Next(entry)) {
DCHECK(entry->value != NULL);
if (entry->value != NULL) {
instances->set(count, *reinterpret_cast<Script**>(entry->value));
count++;
}
}
return instances;
}
void ScriptCache::Clear() {
// Iterate the script cache to get rid of all the weak handles.
for (HashMap::Entry* entry = Start(); entry != NULL; entry = Next(entry)) {
DCHECK(entry != NULL);
Object** location = reinterpret_cast<Object**>(entry->value);
DCHECK((*location)->IsScript());
GlobalHandles::ClearWeakness(location);
GlobalHandles::Destroy(location);
}
// Clear the content of the hash map.
HashMap::Clear();
}
void ScriptCache::HandleWeakScript(
const v8::WeakCallbackData<v8::Value, void>& data) {
// Retrieve the script identifier.
Handle<Object> object = Utils::OpenHandle(*data.GetValue());
int id = Handle<Script>::cast(object)->id()->value();
void* key = reinterpret_cast<void*>(id);
uint32_t hash = Hash(id);
// Remove the corresponding entry from the cache.
ScriptCache* script_cache =
reinterpret_cast<ScriptCache*>(data.GetParameter());
HashMap::Entry* entry = script_cache->Lookup(key, hash, false);
Object** location = reinterpret_cast<Object**>(entry->value);
script_cache->Remove(key, hash);
// Clear the weak handle.
GlobalHandles::Destroy(location);
}
void Debug::HandleWeakDebugInfo(
const v8::WeakCallbackData<v8::Value, void>& data) {
Debug* debug = reinterpret_cast<Isolate*>(data.GetIsolate())->debug();
DebugInfoListNode* node =
reinterpret_cast<DebugInfoListNode*>(data.GetParameter());
// We need to clear all breakpoints associated with the function to restore
// original code and avoid patching the code twice later because
// the function will live in the heap until next gc, and can be found by
// Debug::FindSharedFunctionInfoInScript.
BreakLocationIterator it(node->debug_info(), ALL_BREAK_LOCATIONS);
it.ClearAllDebugBreak();
debug->RemoveDebugInfo(node->debug_info());
#ifdef DEBUG
for (DebugInfoListNode* n = debug->debug_info_list_;
n != NULL;
n = n->next()) {
DCHECK(n != node);
}
#endif
}
DebugInfoListNode::DebugInfoListNode(DebugInfo* debug_info): next_(NULL) {
// Globalize the request debug info object and make it weak.
GlobalHandles* global_handles = debug_info->GetIsolate()->global_handles();
debug_info_ = Handle<DebugInfo>::cast(global_handles->Create(debug_info));
GlobalHandles::MakeWeak(reinterpret_cast<Object**>(debug_info_.location()),
this,
Debug::HandleWeakDebugInfo);
}
DebugInfoListNode::~DebugInfoListNode() {
GlobalHandles::Destroy(reinterpret_cast<Object**>(debug_info_.location()));
}
bool Debug::CompileDebuggerScript(Isolate* isolate, int index) {
Factory* factory = isolate->factory();
HandleScope scope(isolate);
// Bail out if the index is invalid.
if (index == -1) return false;
// Find source and name for the requested script.
Handle<String> source_code =
isolate->bootstrapper()->NativesSourceLookup(index);
Vector<const char> name = Natives::GetScriptName(index);
Handle<String> script_name =
factory->NewStringFromAscii(name).ToHandleChecked();
Handle<Context> context = isolate->native_context();
// Compile the script.
Handle<SharedFunctionInfo> function_info;
function_info = Compiler::CompileScript(
source_code, script_name, 0, 0, false, context, NULL, NULL,
ScriptCompiler::kNoCompileOptions, NATIVES_CODE);
// Silently ignore stack overflows during compilation.
if (function_info.is_null()) {
DCHECK(isolate->has_pending_exception());
isolate->clear_pending_exception();
return false;
}
// Execute the shared function in the debugger context.
Handle<JSFunction> function =
factory->NewFunctionFromSharedFunctionInfo(function_info, context);
MaybeHandle<Object> maybe_exception;
MaybeHandle<Object> result = Execution::TryCall(
function, handle(context->global_proxy()), 0, NULL, &maybe_exception);
// Check for caught exceptions.
if (result.is_null()) {
DCHECK(!isolate->has_pending_exception());
MessageLocation computed_location;
isolate->ComputeLocation(&computed_location);
Handle<Object> message = MessageHandler::MakeMessageObject(
isolate, "error_loading_debugger", &computed_location,
Vector<Handle<Object> >::empty(), Handle<JSArray>());
DCHECK(!isolate->has_pending_exception());
Handle<Object> exception;
if (maybe_exception.ToHandle(&exception)) {
isolate->set_pending_exception(*exception);
MessageHandler::ReportMessage(isolate, NULL, message);
isolate->clear_pending_exception();
}
return false;
}
// Mark this script as native and return successfully.
Handle<Script> script(Script::cast(function->shared()->script()));
script->set_type(Smi::FromInt(Script::TYPE_NATIVE));
return true;
}
bool Debug::Load() {
// Return if debugger is already loaded.
if (is_loaded()) return true;
// Bail out if we're already in the process of compiling the native
// JavaScript source code for the debugger.
if (is_suppressed_) return false;
SuppressDebug while_loading(this);
// Disable breakpoints and interrupts while compiling and running the
// debugger scripts including the context creation code.
DisableBreak disable(this, true);
PostponeInterruptsScope postpone(isolate_);
// Create the debugger context.
HandleScope scope(isolate_);
ExtensionConfiguration no_extensions;
Handle<Context> context =
isolate_->bootstrapper()->CreateEnvironment(
MaybeHandle<JSGlobalProxy>(),
v8::Handle<ObjectTemplate>(),
&no_extensions);
// Fail if no context could be created.
if (context.is_null()) return false;
// Use the debugger context.
SaveContext save(isolate_);
isolate_->set_context(*context);
// Expose the builtins object in the debugger context.
Handle<String> key = isolate_->factory()->InternalizeOneByteString(
STATIC_CHAR_VECTOR("builtins"));
Handle<GlobalObject> global =
Handle<GlobalObject>(context->global_object(), isolate_);
Handle<JSBuiltinsObject> builtin =
Handle<JSBuiltinsObject>(global->builtins(), isolate_);
RETURN_ON_EXCEPTION_VALUE(
isolate_, Object::SetProperty(global, key, builtin, SLOPPY), false);
// Compile the JavaScript for the debugger in the debugger context.
bool caught_exception =
!CompileDebuggerScript(isolate_, Natives::GetIndex("mirror")) ||
!CompileDebuggerScript(isolate_, Natives::GetIndex("debug"));
if (FLAG_enable_liveedit) {
caught_exception = caught_exception ||
!CompileDebuggerScript(isolate_, Natives::GetIndex("liveedit"));
}
// Check for caught exceptions.
if (caught_exception) return false;
debug_context_ = Handle<Context>::cast(
isolate_->global_handles()->Create(*context));
return true;
}
void Debug::Unload() {
ClearAllBreakPoints();
ClearStepping();
// Return debugger is not loaded.
if (!is_loaded()) return;
// Clear the script cache.
if (script_cache_ != NULL) {
delete script_cache_;
script_cache_ = NULL;
}
// Clear debugger context global handle.
GlobalHandles::Destroy(Handle<Object>::cast(debug_context_).location());
debug_context_ = Handle<Context>();
}
void Debug::Break(Arguments args, JavaScriptFrame* frame) {
Heap* heap = isolate_->heap();
HandleScope scope(isolate_);
DCHECK(args.length() == 0);
// Initialize LiveEdit.
LiveEdit::InitializeThreadLocal(this);
// Just continue if breaks are disabled or debugger cannot be loaded.
if (break_disabled_) return;
// Enter the debugger.
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Postpone interrupt during breakpoint processing.
PostponeInterruptsScope postpone(isolate_);
// Get the debug info (create it if it does not exist).
Handle<SharedFunctionInfo> shared =
Handle<SharedFunctionInfo>(frame->function()->shared());
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
// Find the break point where execution has stopped.
BreakLocationIterator break_location_iterator(debug_info,
ALL_BREAK_LOCATIONS);
// pc points to the instruction after the current one, possibly a break
// location as well. So the "- 1" to exclude it from the search.
break_location_iterator.FindBreakLocationFromAddress(frame->pc() - 1);
// Check whether step next reached a new statement.
if (!StepNextContinue(&break_location_iterator, frame)) {
// Decrease steps left if performing multiple steps.
if (thread_local_.step_count_ > 0) {
thread_local_.step_count_--;
}
}
// If there is one or more real break points check whether any of these are
// triggered.
Handle<Object> break_points_hit(heap->undefined_value(), isolate_);
if (break_location_iterator.HasBreakPoint()) {
Handle<Object> break_point_objects =
Handle<Object>(break_location_iterator.BreakPointObjects(), isolate_);
break_points_hit = CheckBreakPoints(break_point_objects);
}
// If step out is active skip everything until the frame where we need to step
// out to is reached, unless real breakpoint is hit.
if (StepOutActive() &&
frame->fp() != thread_local_.step_out_fp_ &&
break_points_hit->IsUndefined() ) {
// Step count should always be 0 for StepOut.
DCHECK(thread_local_.step_count_ == 0);
} else if (!break_points_hit->IsUndefined() ||
(thread_local_.last_step_action_ != StepNone &&
thread_local_.step_count_ == 0)) {
// Notify debugger if a real break point is triggered or if performing
// single stepping with no more steps to perform. Otherwise do another step.
// Clear all current stepping setup.
ClearStepping();
if (thread_local_.queued_step_count_ > 0) {
// Perform queued steps
int step_count = thread_local_.queued_step_count_;
// Clear queue
thread_local_.queued_step_count_ = 0;
PrepareStep(StepNext, step_count, StackFrame::NO_ID);
} else {
// Notify the debug event listeners.
OnDebugBreak(break_points_hit, false);
}
} else if (thread_local_.last_step_action_ != StepNone) {
// Hold on to last step action as it is cleared by the call to
// ClearStepping.
StepAction step_action = thread_local_.last_step_action_;
int step_count = thread_local_.step_count_;
// If StepNext goes deeper in code, StepOut until original frame
// and keep step count queued up in the meantime.
if (step_action == StepNext && frame->fp() < thread_local_.last_fp_) {
// Count frames until target frame
int count = 0;
JavaScriptFrameIterator it(isolate_);
while (!it.done() && it.frame()->fp() < thread_local_.last_fp_) {
count++;
it.Advance();
}
// Check that we indeed found the frame we are looking for.
CHECK(!it.done() && (it.frame()->fp() == thread_local_.last_fp_));
if (step_count > 1) {
// Save old count and action to continue stepping after StepOut.
thread_local_.queued_step_count_ = step_count - 1;
}
// Set up for StepOut to reach target frame.
step_action = StepOut;
step_count = count;
}
// Clear all current stepping setup.
ClearStepping();
// Set up for the remaining steps.
PrepareStep(step_action, step_count, StackFrame::NO_ID);
}
}
RUNTIME_FUNCTION(Debug_Break) {
// Get the top-most JavaScript frame.
JavaScriptFrameIterator it(isolate);
isolate->debug()->Break(args, it.frame());
isolate->debug()->SetAfterBreakTarget(it.frame());
return isolate->heap()->undefined_value();
}
// Check the break point objects for whether one or more are actually
// triggered. This function returns a JSArray with the break point objects
// which is triggered.
Handle<Object> Debug::CheckBreakPoints(Handle<Object> break_point_objects) {
Factory* factory = isolate_->factory();
// Count the number of break points hit. If there are multiple break points
// they are in a FixedArray.
Handle<FixedArray> break_points_hit;
int break_points_hit_count = 0;
DCHECK(!break_point_objects->IsUndefined());
if (break_point_objects->IsFixedArray()) {
Handle<FixedArray> array(FixedArray::cast(*break_point_objects));
break_points_hit = factory->NewFixedArray(array->length());
for (int i = 0; i < array->length(); i++) {
Handle<Object> o(array->get(i), isolate_);
if (CheckBreakPoint(o)) {
break_points_hit->set(break_points_hit_count++, *o);
}
}
} else {
break_points_hit = factory->NewFixedArray(1);
if (CheckBreakPoint(break_point_objects)) {
break_points_hit->set(break_points_hit_count++, *break_point_objects);
}
}
// Return undefined if no break points were triggered.
if (break_points_hit_count == 0) {
return factory->undefined_value();
}
// Return break points hit as a JSArray.
Handle<JSArray> result = factory->NewJSArrayWithElements(break_points_hit);
result->set_length(Smi::FromInt(break_points_hit_count));
return result;
}
// Check whether a single break point object is triggered.
bool Debug::CheckBreakPoint(Handle<Object> break_point_object) {
Factory* factory = isolate_->factory();
HandleScope scope(isolate_);
// Ignore check if break point object is not a JSObject.
if (!break_point_object->IsJSObject()) return true;
// Get the function IsBreakPointTriggered (defined in debug-debugger.js).
Handle<String> is_break_point_triggered_string =
factory->InternalizeOneByteString(
STATIC_CHAR_VECTOR("IsBreakPointTriggered"));
Handle<GlobalObject> debug_global(debug_context()->global_object());
Handle<JSFunction> check_break_point =
Handle<JSFunction>::cast(Object::GetProperty(
debug_global, is_break_point_triggered_string).ToHandleChecked());
// Get the break id as an object.
Handle<Object> break_id = factory->NewNumberFromInt(Debug::break_id());
// Call HandleBreakPointx.
Handle<Object> argv[] = { break_id, break_point_object };
Handle<Object> result;
if (!Execution::TryCall(check_break_point,
isolate_->js_builtins_object(),
arraysize(argv),
argv).ToHandle(&result)) {
return false;
}
// Return whether the break point is triggered.
return result->IsTrue();
}
// Check whether the function has debug information.
bool Debug::HasDebugInfo(Handle<SharedFunctionInfo> shared) {
return !shared->debug_info()->IsUndefined();
}
// Return the debug info for this function. EnsureDebugInfo must be called
// prior to ensure the debug info has been generated for shared.
Handle<DebugInfo> Debug::GetDebugInfo(Handle<SharedFunctionInfo> shared) {
DCHECK(HasDebugInfo(shared));
return Handle<DebugInfo>(DebugInfo::cast(shared->debug_info()));
}
bool Debug::SetBreakPoint(Handle<JSFunction> function,
Handle<Object> break_point_object,
int* source_position) {
HandleScope scope(isolate_);
PrepareForBreakPoints();
// Make sure the function is compiled and has set up the debug info.
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureDebugInfo(shared, function)) {
// Return if retrieving debug info failed.
return true;
}
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
// Source positions starts with zero.
DCHECK(*source_position >= 0);
// Find the break point and change it.
BreakLocationIterator it(debug_info, SOURCE_BREAK_LOCATIONS);
it.FindBreakLocationFromPosition(*source_position, STATEMENT_ALIGNED);
it.SetBreakPoint(break_point_object);
*source_position = it.position();
// At least one active break point now.
return debug_info->GetBreakPointCount() > 0;
}
bool Debug::SetBreakPointForScript(Handle<Script> script,
Handle<Object> break_point_object,
int* source_position,
BreakPositionAlignment alignment) {
HandleScope scope(isolate_);
PrepareForBreakPoints();
// Obtain shared function info for the function.
Object* result = FindSharedFunctionInfoInScript(script, *source_position);
if (result->IsUndefined()) return false;
// Make sure the function has set up the debug info.
Handle<SharedFunctionInfo> shared(SharedFunctionInfo::cast(result));
if (!EnsureDebugInfo(shared, Handle<JSFunction>::null())) {
// Return if retrieving debug info failed.
return false;
}
// Find position within function. The script position might be before the
// source position of the first function.
int position;
if (shared->start_position() > *source_position) {
position = 0;
} else {
position = *source_position - shared->start_position();
}
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
// Source positions starts with zero.
DCHECK(position >= 0);
// Find the break point and change it.
BreakLocationIterator it(debug_info, SOURCE_BREAK_LOCATIONS);
it.FindBreakLocationFromPosition(position, alignment);
it.SetBreakPoint(break_point_object);
*source_position = it.position() + shared->start_position();
// At least one active break point now.
DCHECK(debug_info->GetBreakPointCount() > 0);
return true;
}
void Debug::ClearBreakPoint(Handle<Object> break_point_object) {
HandleScope scope(isolate_);
DebugInfoListNode* node = debug_info_list_;
while (node != NULL) {
Object* result = DebugInfo::FindBreakPointInfo(node->debug_info(),
break_point_object);
if (!result->IsUndefined()) {
// Get information in the break point.
BreakPointInfo* break_point_info = BreakPointInfo::cast(result);
Handle<DebugInfo> debug_info = node->debug_info();
// Find the break point and clear it.
BreakLocationIterator it(debug_info, SOURCE_BREAK_LOCATIONS);
it.FindBreakLocationFromAddress(debug_info->code()->entry() +
break_point_info->code_position()->value());
it.ClearBreakPoint(break_point_object);
// If there are no more break points left remove the debug info for this
// function.
if (debug_info->GetBreakPointCount() == 0) {
RemoveDebugInfo(debug_info);
}
return;
}
node = node->next();
}
}
void Debug::ClearAllBreakPoints() {
DebugInfoListNode* node = debug_info_list_;
while (node != NULL) {
// Remove all debug break code.
BreakLocationIterator it(node->debug_info(), ALL_BREAK_LOCATIONS);
it.ClearAllDebugBreak();
node = node->next();
}
// Remove all debug info.
while (debug_info_list_ != NULL) {
RemoveDebugInfo(debug_info_list_->debug_info());
}
}
void Debug::FloodWithOneShot(Handle<JSFunction> function) {
PrepareForBreakPoints();
// Make sure the function is compiled and has set up the debug info.
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureDebugInfo(shared, function)) {
// Return if we failed to retrieve the debug info.
return;
}
// Flood the function with break points.
BreakLocationIterator it(GetDebugInfo(shared), ALL_BREAK_LOCATIONS);
while (!it.Done()) {
it.SetOneShot();
it.Next();
}
}
void Debug::FloodBoundFunctionWithOneShot(Handle<JSFunction> function) {
Handle<FixedArray> new_bindings(function->function_bindings());
Handle<Object> bindee(new_bindings->get(JSFunction::kBoundFunctionIndex),
isolate_);
if (!bindee.is_null() && bindee->IsJSFunction() &&
!JSFunction::cast(*bindee)->IsFromNativeScript()) {
Handle<JSFunction> bindee_function(JSFunction::cast(*bindee));
Debug::FloodWithOneShot(bindee_function);
}
}
void Debug::FloodHandlerWithOneShot() {
// Iterate through the JavaScript stack looking for handlers.
StackFrame::Id id = break_frame_id();
if (id == StackFrame::NO_ID) {
// If there is no JavaScript stack don't do anything.
return;
}
for (JavaScriptFrameIterator it(isolate_, id); !it.done(); it.Advance()) {
JavaScriptFrame* frame = it.frame();
if (frame->HasHandler()) {
// Flood the function with the catch block with break points
FloodWithOneShot(Handle<JSFunction>(frame->function()));
return;
}
}
}
void Debug::ChangeBreakOnException(ExceptionBreakType type, bool enable) {
if (type == BreakUncaughtException) {
break_on_uncaught_exception_ = enable;
} else {
break_on_exception_ = enable;
}
}
bool Debug::IsBreakOnException(ExceptionBreakType type) {
if (type == BreakUncaughtException) {
return break_on_uncaught_exception_;
} else {
return break_on_exception_;
}
}
void Debug::PrepareStep(StepAction step_action,
int step_count,
StackFrame::Id frame_id) {
HandleScope scope(isolate_);
PrepareForBreakPoints();
DCHECK(in_debug_scope());
// Remember this step action and count.
thread_local_.last_step_action_ = step_action;
if (step_action == StepOut) {
// For step out target frame will be found on the stack so there is no need
// to set step counter for it. It's expected to always be 0 for StepOut.
thread_local_.step_count_ = 0;
} else {
thread_local_.step_count_ = step_count;
}
// Get the frame where the execution has stopped and skip the debug frame if
// any. The debug frame will only be present if execution was stopped due to
// hitting a break point. In other situations (e.g. unhandled exception) the
// debug frame is not present.
StackFrame::Id id = break_frame_id();
if (id == StackFrame::NO_ID) {
// If there is no JavaScript stack don't do anything.
return;
}
if (frame_id != StackFrame::NO_ID) {
id = frame_id;
}
JavaScriptFrameIterator frames_it(isolate_, id);
JavaScriptFrame* frame = frames_it.frame();
// First of all ensure there is one-shot break points in the top handler
// if any.
FloodHandlerWithOneShot();
// If the function on the top frame is unresolved perform step out. This will
// be the case when calling unknown functions and having the debugger stopped
// in an unhandled exception.
if (!frame->function()->IsJSFunction()) {
// Step out: Find the calling JavaScript frame and flood it with
// breakpoints.
frames_it.Advance();
// Fill the function to return to with one-shot break points.
JSFunction* function = frames_it.frame()->function();
FloodWithOneShot(Handle<JSFunction>(function));
return;
}
// Get the debug info (create it if it does not exist).
Handle<JSFunction> function(frame->function());
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureDebugInfo(shared, function)) {
// Return if ensuring debug info failed.
return;
}
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
// Find the break location where execution has stopped.
BreakLocationIterator it(debug_info, ALL_BREAK_LOCATIONS);
// pc points to the instruction after the current one, possibly a break
// location as well. So the "- 1" to exclude it from the search.
it.FindBreakLocationFromAddress(frame->pc() - 1);
// Compute whether or not the target is a call target.
bool is_load_or_store = false;
bool is_inline_cache_stub = false;
bool is_at_restarted_function = false;
Handle<Code> call_function_stub;
if (thread_local_.restarter_frame_function_pointer_ == NULL) {
if (RelocInfo::IsCodeTarget(it.rinfo()->rmode())) {
bool is_call_target = false;
Address target = it.rinfo()->target_address();
Code* code = Code::GetCodeFromTargetAddress(target);
if (code->is_call_stub()) {
is_call_target = true;
}
if (code->is_inline_cache_stub()) {
is_inline_cache_stub = true;
is_load_or_store = !is_call_target;
}
// Check if target code is CallFunction stub.
Code* maybe_call_function_stub = code;
// If there is a breakpoint at this line look at the original code to
// check if it is a CallFunction stub.
if (it.IsDebugBreak()) {
Address original_target = it.original_rinfo()->target_address();
maybe_call_function_stub =
Code::GetCodeFromTargetAddress(original_target);
}
if ((maybe_call_function_stub->kind() == Code::STUB &&
CodeStub::GetMajorKey(maybe_call_function_stub) ==
CodeStub::CallFunction) ||
maybe_call_function_stub->kind() == Code::CALL_IC) {
// Save reference to the code as we may need it to find out arguments
// count for 'step in' later.
call_function_stub = Handle<Code>(maybe_call_function_stub);
}
}
} else {
is_at_restarted_function = true;
}
// If this is the last break code target step out is the only possibility.
if (it.IsExit() || step_action == StepOut) {
if (step_action == StepOut) {
// Skip step_count frames starting with the current one.
while (step_count-- > 0 && !frames_it.done()) {
frames_it.Advance();
}
} else {
DCHECK(it.IsExit());
frames_it.Advance();
}
// Skip builtin functions on the stack.
while (!frames_it.done() &&
frames_it.frame()->function()->IsFromNativeScript()) {
frames_it.Advance();
}
// Step out: If there is a JavaScript caller frame, we need to
// flood it with breakpoints.
if (!frames_it.done()) {
// Fill the function to return to with one-shot break points.
JSFunction* function = frames_it.frame()->function();
FloodWithOneShot(Handle<JSFunction>(function));
// Set target frame pointer.
ActivateStepOut(frames_it.frame());
}
} else if (!(is_inline_cache_stub || RelocInfo::IsConstructCall(it.rmode()) ||
!call_function_stub.is_null() || is_at_restarted_function)
|| step_action == StepNext || step_action == StepMin) {
// Step next or step min.
// Fill the current function with one-shot break points.
FloodWithOneShot(function);
// Remember source position and frame to handle step next.
thread_local_.last_statement_position_ =
debug_info->code()->SourceStatementPosition(frame->pc());
thread_local_.last_fp_ = frame->UnpaddedFP();
} else {
// If there's restarter frame on top of the stack, just get the pointer
// to function which is going to be restarted.
if (is_at_restarted_function) {
Handle<JSFunction> restarted_function(
JSFunction::cast(*thread_local_.restarter_frame_function_pointer_));
FloodWithOneShot(restarted_function);
} else if (!call_function_stub.is_null()) {
// If it's CallFunction stub ensure target function is compiled and flood
// it with one shot breakpoints.
bool is_call_ic = call_function_stub->kind() == Code::CALL_IC;
// Find out number of arguments from the stub minor key.
uint32_t key = call_function_stub->stub_key();
// Argc in the stub is the number of arguments passed - not the
// expected arguments of the called function.
int call_function_arg_count = is_call_ic
? CallICStub::ExtractArgcFromMinorKey(CodeStub::MinorKeyFromKey(key))
: CallFunctionStub::ExtractArgcFromMinorKey(
CodeStub::MinorKeyFromKey(key));
DCHECK(is_call_ic ||
CodeStub::GetMajorKey(*call_function_stub) ==
CodeStub::MajorKeyFromKey(key));
// Find target function on the expression stack.
// Expression stack looks like this (top to bottom):
// argN
// ...
// arg0
// Receiver
// Function to call
int expressions_count = frame->ComputeExpressionsCount();
DCHECK(expressions_count - 2 - call_function_arg_count >= 0);
Object* fun = frame->GetExpression(
expressions_count - 2 - call_function_arg_count);
// Flood the actual target of call/apply.
if (fun->IsJSFunction()) {
Isolate* isolate = JSFunction::cast(fun)->GetIsolate();
Code* apply = isolate->builtins()->builtin(Builtins::kFunctionApply);
Code* call = isolate->builtins()->builtin(Builtins::kFunctionCall);
while (fun->IsJSFunction()) {
Code* code = JSFunction::cast(fun)->shared()->code();
if (code != apply && code != call) break;
fun = frame->GetExpression(
expressions_count - 1 - call_function_arg_count);
}
}
if (fun->IsJSFunction()) {
Handle<JSFunction> js_function(JSFunction::cast(fun));
if (js_function->shared()->bound()) {
Debug::FloodBoundFunctionWithOneShot(js_function);
} else if (!js_function->IsFromNativeScript()) {
// Don't step into builtins.
// It will also compile target function if it's not compiled yet.
FloodWithOneShot(js_function);
}
}
}
// Fill the current function with one-shot break points even for step in on
// a call target as the function called might be a native function for
// which step in will not stop. It also prepares for stepping in
// getters/setters.
FloodWithOneShot(function);
if (is_load_or_store) {
// Remember source position and frame to handle step in getter/setter. If
// there is a custom getter/setter it will be handled in
// Object::Get/SetPropertyWithAccessor, otherwise the step action will be
// propagated on the next Debug::Break.
thread_local_.last_statement_position_ =
debug_info->code()->SourceStatementPosition(frame->pc());
thread_local_.last_fp_ = frame->UnpaddedFP();
}
// Step in or Step in min
it.PrepareStepIn(isolate_);
ActivateStepIn(frame);
}
}
// Check whether the current debug break should be reported to the debugger. It
// is used to have step next and step in only report break back to the debugger
// if on a different frame or in a different statement. In some situations
// there will be several break points in the same statement when the code is
// flooded with one-shot break points. This function helps to perform several
// steps before reporting break back to the debugger.
bool Debug::StepNextContinue(BreakLocationIterator* break_location_iterator,
JavaScriptFrame* frame) {
// StepNext and StepOut shouldn't bring us deeper in code, so last frame
// shouldn't be a parent of current frame.
if (thread_local_.last_step_action_ == StepNext ||
thread_local_.last_step_action_ == StepOut) {
if (frame->fp() < thread_local_.last_fp_) return true;
}
// If the step last action was step next or step in make sure that a new
// statement is hit.
if (thread_local_.last_step_action_ == StepNext ||
thread_local_.last_step_action_ == StepIn) {
// Never continue if returning from function.
if (break_location_iterator->IsExit()) return false;
// Continue if we are still on the same frame and in the same statement.
int current_statement_position =
break_location_iterator->code()->SourceStatementPosition(frame->pc());
return thread_local_.last_fp_ == frame->UnpaddedFP() &&
thread_local_.last_statement_position_ == current_statement_position;
}
// No step next action - don't continue.
return false;
}
// Check whether the code object at the specified address is a debug break code
// object.
bool Debug::IsDebugBreak(Address addr) {
Code* code = Code::GetCodeFromTargetAddress(addr);
return code->is_debug_stub() && code->extra_ic_state() == DEBUG_BREAK;
}
// Simple function for returning the source positions for active break points.
Handle<Object> Debug::GetSourceBreakLocations(
Handle<SharedFunctionInfo> shared,
BreakPositionAlignment position_alignment) {
Isolate* isolate = shared->GetIsolate();
Heap* heap = isolate->heap();
if (!HasDebugInfo(shared)) {
return Handle<Object>(heap->undefined_value(), isolate);
}
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
if (debug_info->GetBreakPointCount() == 0) {
return Handle<Object>(heap->undefined_value(), isolate);
}
Handle<FixedArray> locations =
isolate->factory()->NewFixedArray(debug_info->GetBreakPointCount());
int count = 0;
for (int i = 0; i < debug_info->break_points()->length(); i++) {
if (!debug_info->break_points()->get(i)->IsUndefined()) {
BreakPointInfo* break_point_info =
BreakPointInfo::cast(debug_info->break_points()->get(i));
if (break_point_info->GetBreakPointCount() > 0) {
Smi* position;
switch (position_alignment) {
case STATEMENT_ALIGNED:
position = break_point_info->statement_position();
break;
case BREAK_POSITION_ALIGNED:
position = break_point_info->source_position();
break;
default:
UNREACHABLE();
position = break_point_info->statement_position();
}
locations->set(count++, position);
}
}
}
return locations;
}
// Handle stepping into a function.
void Debug::HandleStepIn(Handle<JSFunction> function,
Handle<Object> holder,
Address fp,
bool is_constructor) {
Isolate* isolate = function->GetIsolate();
// If the frame pointer is not supplied by the caller find it.
if (fp == 0) {
StackFrameIterator it(isolate);
it.Advance();
// For constructor functions skip another frame.
if (is_constructor) {
DCHECK(it.frame()->is_construct());
it.Advance();
}
fp = it.frame()->fp();
}
// Flood the function with one-shot break points if it is called from where
// step into was requested.
if (fp == thread_local_.step_into_fp_) {
if (function->shared()->bound()) {
// Handle Function.prototype.bind
Debug::FloodBoundFunctionWithOneShot(function);
} else if (!function->IsFromNativeScript()) {
// Don't allow step into functions in the native context.
if (function->shared()->code() ==
isolate->builtins()->builtin(Builtins::kFunctionApply) ||
function->shared()->code() ==
isolate->builtins()->builtin(Builtins::kFunctionCall)) {
// Handle function.apply and function.call separately to flood the
// function to be called and not the code for Builtins::FunctionApply or
// Builtins::FunctionCall. The receiver of call/apply is the target
// function.
if (!holder.is_null() && holder->IsJSFunction()) {
Handle<JSFunction> js_function = Handle<JSFunction>::cast(holder);
if (!js_function->IsFromNativeScript()) {
Debug::FloodWithOneShot(js_function);
} else if (js_function->shared()->bound()) {
// Handle Function.prototype.bind
Debug::FloodBoundFunctionWithOneShot(js_function);
}
}
} else {
Debug::FloodWithOneShot(function);
}
}
}
}
void Debug::ClearStepping() {
// Clear the various stepping setup.
ClearOneShot();
ClearStepIn();
ClearStepOut();
ClearStepNext();
// Clear multiple step counter.
thread_local_.step_count_ = 0;
}
// Clears all the one-shot break points that are currently set. Normally this
// function is called each time a break point is hit as one shot break points
// are used to support stepping.
void Debug::ClearOneShot() {
// The current implementation just runs through all the breakpoints. When the
// last break point for a function is removed that function is automatically
// removed from the list.
DebugInfoListNode* node = debug_info_list_;
while (node != NULL) {
BreakLocationIterator it(node->debug_info(), ALL_BREAK_LOCATIONS);
while (!it.Done()) {
it.ClearOneShot();
it.Next();
}
node = node->next();
}
}
void Debug::ActivateStepIn(StackFrame* frame) {
DCHECK(!StepOutActive());
thread_local_.step_into_fp_ = frame->UnpaddedFP();
}
void Debug::ClearStepIn() {
thread_local_.step_into_fp_ = 0;
}
void Debug::ActivateStepOut(StackFrame* frame) {
DCHECK(!StepInActive());
thread_local_.step_out_fp_ = frame->UnpaddedFP();
}
void Debug::ClearStepOut() {
thread_local_.step_out_fp_ = 0;
}
void Debug::ClearStepNext() {
thread_local_.last_step_action_ = StepNone;
thread_local_.last_statement_position_ = RelocInfo::kNoPosition;
thread_local_.last_fp_ = 0;
}
static void CollectActiveFunctionsFromThread(
Isolate* isolate,
ThreadLocalTop* top,
List<Handle<JSFunction> >* active_functions,
Object* active_code_marker) {
// Find all non-optimized code functions with activation frames
// on the stack. This includes functions which have optimized
// activations (including inlined functions) on the stack as the
// non-optimized code is needed for the lazy deoptimization.
for (JavaScriptFrameIterator it(isolate, top); !it.done(); it.Advance()) {
JavaScriptFrame* frame = it.frame();
if (frame->is_optimized()) {
List<JSFunction*> functions(FLAG_max_inlining_levels + 1);
frame->GetFunctions(&functions);
for (int i = 0; i < functions.length(); i++) {
JSFunction* function = functions[i];
active_functions->Add(Handle<JSFunction>(function));
function->shared()->code()->set_gc_metadata(active_code_marker);
}
} else if (frame->function()->IsJSFunction()) {
JSFunction* function = frame->function();
DCHECK(frame->LookupCode()->kind() == Code::FUNCTION);
active_functions->Add(Handle<JSFunction>(function));
function->shared()->code()->set_gc_metadata(active_code_marker);
}
}
}
// Figure out how many bytes of "pc_offset" correspond to actual code by
// subtracting off the bytes that correspond to constant/veneer pools. See
// Assembler::CheckConstPool() and Assembler::CheckVeneerPool(). Note that this
// is only useful for architectures using constant pools or veneer pools.
static int ComputeCodeOffsetFromPcOffset(Code *code, int pc_offset) {
DCHECK_EQ(code->kind(), Code::FUNCTION);
DCHECK(!code->has_debug_break_slots());
DCHECK_LE(0, pc_offset);
DCHECK_LT(pc_offset, code->instruction_end() - code->instruction_start());
int mask = RelocInfo::ModeMask(RelocInfo::CONST_POOL) |
RelocInfo::ModeMask(RelocInfo::VENEER_POOL);
byte *pc = code->instruction_start() + pc_offset;
int code_offset = pc_offset;
for (RelocIterator it(code, mask); !it.done(); it.next()) {
RelocInfo* info = it.rinfo();
if (info->pc() >= pc) break;
DCHECK(RelocInfo::IsConstPool(info->rmode()));
code_offset -= static_cast<int>(info->data());
DCHECK_LE(0, code_offset);
}
return code_offset;
}
// The inverse of ComputeCodeOffsetFromPcOffset.
static int ComputePcOffsetFromCodeOffset(Code *code, int code_offset) {
DCHECK_EQ(code->kind(), Code::FUNCTION);
int mask = RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT) |
RelocInfo::ModeMask(RelocInfo::CONST_POOL) |
RelocInfo::ModeMask(RelocInfo::VENEER_POOL);
int reloc = 0;
for (RelocIterator it(code, mask); !it.done(); it.next()) {
RelocInfo* info = it.rinfo();
if (info->pc() - code->instruction_start() - reloc >= code_offset) break;
if (RelocInfo::IsDebugBreakSlot(info->rmode())) {
reloc += Assembler::kDebugBreakSlotLength;
} else {
DCHECK(RelocInfo::IsConstPool(info->rmode()));
reloc += static_cast<int>(info->data());
}
}
int pc_offset = code_offset + reloc;
DCHECK_LT(code->instruction_start() + pc_offset, code->instruction_end());
return pc_offset;
}
static void RedirectActivationsToRecompiledCodeOnThread(
Isolate* isolate,
ThreadLocalTop* top) {
for (JavaScriptFrameIterator it(isolate, top); !it.done(); it.Advance()) {
JavaScriptFrame* frame = it.frame();
if (frame->is_optimized() || !frame->function()->IsJSFunction()) continue;
JSFunction* function = frame->function();
DCHECK(frame->LookupCode()->kind() == Code::FUNCTION);
Handle<Code> frame_code(frame->LookupCode());
if (frame_code->has_debug_break_slots()) continue;
Handle<Code> new_code(function->shared()->code());
if (new_code->kind() != Code::FUNCTION ||
!new_code->has_debug_break_slots()) {
continue;
}
int old_pc_offset =
static_cast<int>(frame->pc() - frame_code->instruction_start());
int code_offset = ComputeCodeOffsetFromPcOffset(*frame_code, old_pc_offset);
int new_pc_offset = ComputePcOffsetFromCodeOffset(*new_code, code_offset);
// Compute the equivalent pc in the new code.
byte* new_pc = new_code->instruction_start() + new_pc_offset;
if (FLAG_trace_deopt) {
PrintF("Replacing code %08" V8PRIxPTR " - %08" V8PRIxPTR " (%d) "
"with %08" V8PRIxPTR " - %08" V8PRIxPTR " (%d) "
"for debugging, "
"changing pc from %08" V8PRIxPTR " to %08" V8PRIxPTR "\n",
reinterpret_cast<intptr_t>(
frame_code->instruction_start()),
reinterpret_cast<intptr_t>(
frame_code->instruction_start()) +
frame_code->instruction_size(),
frame_code->instruction_size(),
reinterpret_cast<intptr_t>(new_code->instruction_start()),
reinterpret_cast<intptr_t>(new_code->instruction_start()) +
new_code->instruction_size(),
new_code->instruction_size(),
reinterpret_cast<intptr_t>(frame->pc()),
reinterpret_cast<intptr_t>(new_pc));
}
if (FLAG_enable_ool_constant_pool) {
// Update constant pool pointer for new code.
frame->set_constant_pool(new_code->constant_pool());
}
// Patch the return address to return into the code with
// debug break slots.
frame->set_pc(new_pc);
}
}
class ActiveFunctionsCollector : public ThreadVisitor {
public:
explicit ActiveFunctionsCollector(List<Handle<JSFunction> >* active_functions,
Object* active_code_marker)
: active_functions_(active_functions),
active_code_marker_(active_code_marker) { }
void VisitThread(Isolate* isolate, ThreadLocalTop* top) {
CollectActiveFunctionsFromThread(isolate,
top,
active_functions_,
active_code_marker_);
}
private:
List<Handle<JSFunction> >* active_functions_;
Object* active_code_marker_;
};
class ActiveFunctionsRedirector : public ThreadVisitor {
public:
void VisitThread(Isolate* isolate, ThreadLocalTop* top) {
RedirectActivationsToRecompiledCodeOnThread(isolate, top);
}
};
static void EnsureFunctionHasDebugBreakSlots(Handle<JSFunction> function) {
if (function->code()->kind() == Code::FUNCTION &&
function->code()->has_debug_break_slots()) {
// Nothing to do. Function code already had debug break slots.
return;
}
// Make sure that the shared full code is compiled with debug
// break slots.
if (!function->shared()->code()->has_debug_break_slots()) {
MaybeHandle<Code> code = Compiler::GetDebugCode(function);
// Recompilation can fail. In that case leave the code as it was.
if (!code.is_null()) function->ReplaceCode(*code.ToHandleChecked());
} else {
// Simply use shared code if it has debug break slots.
function->ReplaceCode(function->shared()->code());
}
}
static void RecompileAndRelocateSuspendedGenerators(
const List<Handle<JSGeneratorObject> > &generators) {
for (int i = 0; i < generators.length(); i++) {
Handle<JSFunction> fun(generators[i]->function());
EnsureFunctionHasDebugBreakSlots(fun);
int code_offset = generators[i]->continuation();
int pc_offset = ComputePcOffsetFromCodeOffset(fun->code(), code_offset);
generators[i]->set_continuation(pc_offset);
}
}
void Debug::PrepareForBreakPoints() {
// If preparing for the first break point make sure to deoptimize all
// functions as debugging does not work with optimized code.
if (!has_break_points_) {
if (isolate_->concurrent_recompilation_enabled()) {
isolate_->optimizing_compiler_thread()->Flush();
}
Deoptimizer::DeoptimizeAll(isolate_);
Handle<Code> lazy_compile = isolate_->builtins()->CompileLazy();
// There will be at least one break point when we are done.
has_break_points_ = true;
// Keep the list of activated functions in a handlified list as it
// is used both in GC and non-GC code.
List<Handle<JSFunction> > active_functions(100);
// A list of all suspended generators.
List<Handle<JSGeneratorObject> > suspended_generators;
// A list of all generator functions. We need to recompile all functions,
// but we don't know until after visiting the whole heap which generator
// functions have suspended activations and which do not. As in the case of
// functions with activations on the stack, we need to be careful with
// generator functions with suspended activations because although they
// should be recompiled, recompilation can fail, and we need to avoid
// leaving the heap in an inconsistent state.
//
// We could perhaps avoid this list and instead re-use the GC metadata
// links.
List<Handle<JSFunction> > generator_functions;
{
// We are going to iterate heap to find all functions without
// debug break slots.
Heap* heap = isolate_->heap();
heap->CollectAllGarbage(Heap::kMakeHeapIterableMask,
"preparing for breakpoints");
HeapIterator iterator(heap);
// Ensure no GC in this scope as we are going to use gc_metadata
// field in the Code object to mark active functions.
DisallowHeapAllocation no_allocation;
Object* active_code_marker = heap->the_hole_value();
CollectActiveFunctionsFromThread(isolate_,
isolate_->thread_local_top(),
&active_functions,
active_code_marker);
ActiveFunctionsCollector active_functions_collector(&active_functions,
active_code_marker);
isolate_->thread_manager()->IterateArchivedThreads(
&active_functions_collector);
// Scan the heap for all non-optimized functions which have no
// debug break slots and are not active or inlined into an active
// function and mark them for lazy compilation.
HeapObject* obj = NULL;
while (((obj = iterator.next()) != NULL)) {
if (obj->IsJSFunction()) {
JSFunction* function = JSFunction::cast(obj);
SharedFunctionInfo* shared = function->shared();
if (!shared->allows_lazy_compilation()) continue;
if (!shared->script()->IsScript()) continue;
if (function->IsFromNativeScript()) continue;
if (shared->code()->gc_metadata() == active_code_marker) continue;
if (shared->is_generator()) {
generator_functions.Add(Handle<JSFunction>(function, isolate_));
continue;
}
Code::Kind kind = function->code()->kind();
if (kind == Code::FUNCTION &&
!function->code()->has_debug_break_slots()) {
function->ReplaceCode(*lazy_compile);
function->shared()->ReplaceCode(*lazy_compile);
} else if (kind == Code::BUILTIN &&
(function->IsInOptimizationQueue() ||
function->IsMarkedForOptimization() ||
function->IsMarkedForConcurrentOptimization())) {
// Abort in-flight compilation.
Code* shared_code = function->shared()->code();
if (shared_code->kind() == Code::FUNCTION &&
shared_code->has_debug_break_slots()) {
function->ReplaceCode(shared_code);
} else {
function->ReplaceCode(*lazy_compile);
function->shared()->ReplaceCode(*lazy_compile);
}
}
} else if (obj->IsJSGeneratorObject()) {
JSGeneratorObject* gen = JSGeneratorObject::cast(obj);
if (!gen->is_suspended()) continue;
JSFunction* fun = gen->function();
DCHECK_EQ(fun->code()->kind(), Code::FUNCTION);
if (fun->code()->has_debug_break_slots()) continue;
int pc_offset = gen->continuation();
DCHECK_LT(0, pc_offset);
int code_offset =
ComputeCodeOffsetFromPcOffset(fun->code(), pc_offset);
// This will be fixed after we recompile the functions.
gen->set_continuation(code_offset);
suspended_generators.Add(Handle<JSGeneratorObject>(gen, isolate_));
}
}
// Clear gc_metadata field.
for (int i = 0; i < active_functions.length(); i++) {
Handle<JSFunction> function = active_functions[i];
function->shared()->code()->set_gc_metadata(Smi::FromInt(0));
}
}
// Recompile generator functions that have suspended activations, and
// relocate those activations.
RecompileAndRelocateSuspendedGenerators(suspended_generators);
// Mark generator functions that didn't have suspended activations for lazy
// recompilation. Note that this set does not include any active functions.
for (int i = 0; i < generator_functions.length(); i++) {
Handle<JSFunction> &function = generator_functions[i];
if (function->code()->kind() != Code::FUNCTION) continue;
if (function->code()->has_debug_break_slots()) continue;
function->ReplaceCode(*lazy_compile);
function->shared()->ReplaceCode(*lazy_compile);
}
// Now recompile all functions with activation frames and and
// patch the return address to run in the new compiled code. It could be
// that some active functions were recompiled already by the suspended
// generator recompilation pass above; a generator with suspended
// activations could also have active activations. That's fine.
for (int i = 0; i < active_functions.length(); i++) {
Handle<JSFunction> function = active_functions[i];
Handle<SharedFunctionInfo> shared(function->shared());
// If recompilation is not possible just skip it.
if (shared->is_toplevel()) continue;
if (!shared->allows_lazy_compilation()) continue;
if (shared->code()->kind() == Code::BUILTIN) continue;
EnsureFunctionHasDebugBreakSlots(function);
}
RedirectActivationsToRecompiledCodeOnThread(isolate_,
isolate_->thread_local_top());
ActiveFunctionsRedirector active_functions_redirector;
isolate_->thread_manager()->IterateArchivedThreads(
&active_functions_redirector);
}
}
Object* Debug::FindSharedFunctionInfoInScript(Handle<Script> script,
int position) {
// Iterate the heap looking for SharedFunctionInfo generated from the
// script. The inner most SharedFunctionInfo containing the source position
// for the requested break point is found.
// NOTE: This might require several heap iterations. If the SharedFunctionInfo
// which is found is not compiled it is compiled and the heap is iterated
// again as the compilation might create inner functions from the newly
// compiled function and the actual requested break point might be in one of
// these functions.
// NOTE: The below fix-point iteration depends on all functions that cannot be
// compiled lazily without a context to not be compiled at all. Compilation
// will be triggered at points where we do not need a context.
bool done = false;
// The current candidate for the source position:
int target_start_position = RelocInfo::kNoPosition;
Handle<JSFunction> target_function;
Handle<SharedFunctionInfo> target;
Heap* heap = isolate_->heap();
while (!done) {
{ // Extra scope for iterator.
HeapIterator iterator(heap);
for (HeapObject* obj = iterator.next();
obj != NULL; obj = iterator.next()) {
bool found_next_candidate = false;
Handle<JSFunction> function;
Handle<SharedFunctionInfo> shared;
if (obj->IsJSFunction()) {
function = Handle<JSFunction>(JSFunction::cast(obj));
shared = Handle<SharedFunctionInfo>(function->shared());
DCHECK(shared->allows_lazy_compilation() || shared->is_compiled());
found_next_candidate = true;
} else if (obj->IsSharedFunctionInfo()) {
shared = Handle<SharedFunctionInfo>(SharedFunctionInfo::cast(obj));
// Skip functions that we cannot compile lazily without a context,
// which is not available here, because there is no closure.
found_next_candidate = shared->is_compiled() ||
shared->allows_lazy_compilation_without_context();
}
if (!found_next_candidate) continue;
if (shared->script() == *script) {
// If the SharedFunctionInfo found has the requested script data and
// contains the source position it is a candidate.
int start_position = shared->function_token_position();
if (start_position == RelocInfo::kNoPosition) {
start_position = shared->start_position();
}
if (start_position <= position &&
position <= shared->end_position()) {
// If there is no candidate or this function is within the current
// candidate this is the new candidate.
if (target.is_null()) {
target_start_position = start_position;
target_function = function;
target = shared;
} else {
if (target_start_position == start_position &&
shared->end_position() == target->end_position()) {
// If a top-level function contains only one function
// declaration the source for the top-level and the function
// is the same. In that case prefer the non top-level function.
if (!shared->is_toplevel()) {
target_start_position = start_position;
target_function = function;
target = shared;
}
} else if (target_start_position <= start_position &&
shared->end_position() <= target->end_position()) {
// This containment check includes equality as a function
// inside a top-level function can share either start or end
// position with the top-level function.
target_start_position = start_position;
target_function = function;
target = shared;
}
}
}
}
} // End for loop.
} // End no-allocation scope.
if (target.is_null()) return heap->undefined_value();
// There will be at least one break point when we are done.
has_break_points_ = true;
// If the candidate found is compiled we are done.
done = target->is_compiled();
if (!done) {
// If the candidate is not compiled, compile it to reveal any inner
// functions which might contain the requested source position. This
// will compile all inner functions that cannot be compiled without a
// context, because Compiler::BuildFunctionInfo checks whether the
// debugger is active.
MaybeHandle<Code> maybe_result = target_function.is_null()
? Compiler::GetUnoptimizedCode(target)
: Compiler::GetUnoptimizedCode(target_function);
if (maybe_result.is_null()) return isolate_->heap()->undefined_value();
}
} // End while loop.
return *target;
}
// Ensures the debug information is present for shared.
bool Debug::EnsureDebugInfo(Handle<SharedFunctionInfo> shared,
Handle<JSFunction> function) {
Isolate* isolate = shared->GetIsolate();
// Return if we already have the debug info for shared.
if (HasDebugInfo(shared)) {
DCHECK(shared->is_compiled());
return true;
}
// There will be at least one break point when we are done.
has_break_points_ = true;
// Ensure function is compiled. Return false if this failed.
if (!function.is_null() &&
!Compiler::EnsureCompiled(function, CLEAR_EXCEPTION)) {
return false;
}
// Create the debug info object.
Handle<DebugInfo> debug_info = isolate->factory()->NewDebugInfo(shared);
// Add debug info to the list.
DebugInfoListNode* node = new DebugInfoListNode(*debug_info);
node->set_next(debug_info_list_);
debug_info_list_ = node;
return true;
}
void Debug::RemoveDebugInfo(Handle<DebugInfo> debug_info) {
DCHECK(debug_info_list_ != NULL);
// Run through the debug info objects to find this one and remove it.
DebugInfoListNode* prev = NULL;
DebugInfoListNode* current = debug_info_list_;
while (current != NULL) {
if (*current->debug_info() == *debug_info) {
// Unlink from list. If prev is NULL we are looking at the first element.
if (prev == NULL) {
debug_info_list_ = current->next();
} else {
prev->set_next(current->next());
}
current->debug_info()->shared()->set_debug_info(
isolate_->heap()->undefined_value());
delete current;
// If there are no more debug info objects there are not more break
// points.
has_break_points_ = debug_info_list_ != NULL;
return;
}
// Move to next in list.
prev = current;
current = current->next();
}
UNREACHABLE();
}
void Debug::SetAfterBreakTarget(JavaScriptFrame* frame) {
after_break_target_ = NULL;
if (LiveEdit::SetAfterBreakTarget(this)) return; // LiveEdit did the job.
HandleScope scope(isolate_);
PrepareForBreakPoints();
// Get the executing function in which the debug break occurred.
Handle<JSFunction> function(JSFunction::cast(frame->function()));
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureDebugInfo(shared, function)) {
// Return if we failed to retrieve the debug info.
return;
}
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
Handle<Code> code(debug_info->code());
Handle<Code> original_code(debug_info->original_code());
#ifdef DEBUG
// Get the code which is actually executing.
Handle<Code> frame_code(frame->LookupCode());
DCHECK(frame_code.is_identical_to(code));
#endif
// Find the call address in the running code. This address holds the call to
// either a DebugBreakXXX or to the debug break return entry code if the
// break point is still active after processing the break point.
Address addr = Assembler::break_address_from_return_address(frame->pc());
// Check if the location is at JS exit or debug break slot.
bool at_js_return = false;
bool break_at_js_return_active = false;
bool at_debug_break_slot = false;
RelocIterator it(debug_info->code());
while (!it.done() && !at_js_return && !at_debug_break_slot) {
if (RelocInfo::IsJSReturn(it.rinfo()->rmode())) {
at_js_return = (it.rinfo()->pc() ==
addr - Assembler::kPatchReturnSequenceAddressOffset);
break_at_js_return_active = it.rinfo()->IsPatchedReturnSequence();
}
if (RelocInfo::IsDebugBreakSlot(it.rinfo()->rmode())) {
at_debug_break_slot = (it.rinfo()->pc() ==
addr - Assembler::kPatchDebugBreakSlotAddressOffset);
}
it.next();
}
// Handle the jump to continue execution after break point depending on the
// break location.
if (at_js_return) {
// If the break point as return is still active jump to the corresponding
// place in the original code. If not the break point was removed during
// break point processing.
if (break_at_js_return_active) {
addr += original_code->instruction_start() - code->instruction_start();
}
// Move back to where the call instruction sequence started.
after_break_target_ = addr - Assembler::kPatchReturnSequenceAddressOffset;
} else if (at_debug_break_slot) {
// Address of where the debug break slot starts.
addr = addr - Assembler::kPatchDebugBreakSlotAddressOffset;
// Continue just after the slot.
after_break_target_ = addr + Assembler::kDebugBreakSlotLength;
} else {
addr = Assembler::target_address_from_return_address(frame->pc());
if (IsDebugBreak(Assembler::target_address_at(addr, *code))) {
// We now know that there is still a debug break call at the target
// address, so the break point is still there and the original code will
// hold the address to jump to in order to complete the call which is
// replaced by a call to DebugBreakXXX.
// Find the corresponding address in the original code.
addr += original_code->instruction_start() - code->instruction_start();
// Install jump to the call address in the original code. This will be the
// call which was overwritten by the call to DebugBreakXXX.
after_break_target_ = Assembler::target_address_at(addr, *original_code);
} else {
// There is no longer a break point present. Don't try to look in the
// original code as the running code will have the right address. This
// takes care of the case where the last break point is removed from the
// function and therefore no "original code" is available.
after_break_target_ = Assembler::target_address_at(addr, *code);
}
}
}
bool Debug::IsBreakAtReturn(JavaScriptFrame* frame) {
HandleScope scope(isolate_);
// If there are no break points this cannot be break at return, as
// the debugger statement and stack guard bebug break cannot be at
// return.
if (!has_break_points_) {
return false;
}
PrepareForBreakPoints();
// Get the executing function in which the debug break occurred.
Handle<JSFunction> function(JSFunction::cast(frame->function()));
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureDebugInfo(shared, function)) {
// Return if we failed to retrieve the debug info.
return false;
}
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
Handle<Code> code(debug_info->code());
#ifdef DEBUG
// Get the code which is actually executing.
Handle<Code> frame_code(frame->LookupCode());
DCHECK(frame_code.is_identical_to(code));
#endif
// Find the call address in the running code.
Address addr = Assembler::break_address_from_return_address(frame->pc());
// Check if the location is at JS return.
RelocIterator it(debug_info->code());
while (!it.done()) {
if (RelocInfo::IsJSReturn(it.rinfo()->rmode())) {
return (it.rinfo()->pc() ==
addr - Assembler::kPatchReturnSequenceAddressOffset);
}
it.next();
}
return false;
}
void Debug::FramesHaveBeenDropped(StackFrame::Id new_break_frame_id,
LiveEdit::FrameDropMode mode,
Object** restarter_frame_function_pointer) {
if (mode != LiveEdit::CURRENTLY_SET_MODE) {
thread_local_.frame_drop_mode_ = mode;
}
thread_local_.break_frame_id_ = new_break_frame_id;
thread_local_.restarter_frame_function_pointer_ =
restarter_frame_function_pointer;
}
bool Debug::IsDebugGlobal(GlobalObject* global) {
return is_loaded() && global == debug_context()->global_object();
}
void Debug::ClearMirrorCache() {
PostponeInterruptsScope postpone(isolate_);
HandleScope scope(isolate_);
AssertDebugContext();
Factory* factory = isolate_->factory();
Handle<GlobalObject> global(isolate_->global_object());
JSObject::SetProperty(global,
factory->NewStringFromAsciiChecked("next_handle_"),
handle(Smi::FromInt(0), isolate_), SLOPPY).Check();
JSObject::SetProperty(global,
factory->NewStringFromAsciiChecked("mirror_cache_"),
factory->NewJSArray(0, FAST_ELEMENTS), SLOPPY).Check();
}
Handle<FixedArray> Debug::GetLoadedScripts() {
// Create and fill the script cache when the loaded scripts is requested for
// the first time.
if (script_cache_ == NULL) script_cache_ = new ScriptCache(isolate_);
// Perform GC to get unreferenced scripts evicted from the cache before
// returning the content.
isolate_->heap()->CollectAllGarbage(Heap::kNoGCFlags,
"Debug::GetLoadedScripts");
// Get the scripts from the cache.
return script_cache_->GetScripts();
}
void Debug::RecordEvalCaller(Handle<Script> script) {
script->set_compilation_type(Script::COMPILATION_TYPE_EVAL);
// For eval scripts add information on the function from which eval was
// called.
StackTraceFrameIterator it(script->GetIsolate());
if (!it.done()) {
script->set_eval_from_shared(it.frame()->function()->shared());
Code* code = it.frame()->LookupCode();
int offset = static_cast<int>(
it.frame()->pc() - code->instruction_start());
script->set_eval_from_instructions_offset(Smi::FromInt(offset));
}
}
MaybeHandle<Object> Debug::MakeJSObject(const char* constructor_name,
int argc,
Handle<Object> argv[]) {
AssertDebugContext();
// Create the execution state object.
Handle<GlobalObject> global(isolate_->global_object());
Handle<Object> constructor = Object::GetProperty(
isolate_, global, constructor_name).ToHandleChecked();
DCHECK(constructor->IsJSFunction());
if (!constructor->IsJSFunction()) return MaybeHandle<Object>();
// We do not handle interrupts here. In particular, termination interrupts.
PostponeInterruptsScope no_interrupts(isolate_);
return Execution::TryCall(Handle<JSFunction>::cast(constructor),
handle(debug_context()->global_proxy()),
argc,
argv);
}
MaybeHandle<Object> Debug::MakeExecutionState() {
// Create the execution state object.
Handle<Object> argv[] = { isolate_->factory()->NewNumberFromInt(break_id()) };
return MakeJSObject("MakeExecutionState", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakeBreakEvent(Handle<Object> break_points_hit) {
// Create the new break event object.
Handle<Object> argv[] = { isolate_->factory()->NewNumberFromInt(break_id()),
break_points_hit };
return MakeJSObject("MakeBreakEvent", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakeExceptionEvent(Handle<Object> exception,
bool uncaught,
Handle<Object> promise) {
// Create the new exception event object.
Handle<Object> argv[] = { isolate_->factory()->NewNumberFromInt(break_id()),
exception,
isolate_->factory()->ToBoolean(uncaught),
promise };
return MakeJSObject("MakeExceptionEvent", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakeCompileEvent(Handle<Script> script,
v8::DebugEvent type) {
// Create the compile event object.
Handle<Object> script_wrapper = Script::GetWrapper(script);
Handle<Object> argv[] = { script_wrapper,
isolate_->factory()->NewNumberFromInt(type) };
return MakeJSObject("MakeCompileEvent", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakePromiseEvent(Handle<JSObject> event_data) {
// Create the promise event object.
Handle<Object> argv[] = { event_data };
return MakeJSObject("MakePromiseEvent", arraysize(argv), argv);
}
MaybeHandle<Object> Debug::MakeAsyncTaskEvent(Handle<JSObject> task_event) {
// Create the async task event object.
Handle<Object> argv[] = { task_event };
return MakeJSObject("MakeAsyncTaskEvent", arraysize(argv), argv);
}
void Debug::OnThrow(Handle<Object> exception, bool uncaught) {
if (in_debug_scope() || ignore_events()) return;
// Temporarily clear any scheduled_exception to allow evaluating
// JavaScript from the debug event handler.
HandleScope scope(isolate_);
Handle<Object> scheduled_exception;
if (isolate_->has_scheduled_exception()) {
scheduled_exception = handle(isolate_->scheduled_exception(), isolate_);
isolate_->clear_scheduled_exception();
}
OnException(exception, uncaught, isolate_->GetPromiseOnStackOnThrow());
if (!scheduled_exception.is_null()) {
isolate_->thread_local_top()->scheduled_exception_ = *scheduled_exception;
}
}
void Debug::OnPromiseReject(Handle<JSObject> promise, Handle<Object> value) {
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
// Check whether the promise has been marked as having triggered a message.
Handle<Symbol> key = isolate_->factory()->promise_debug_marker_symbol();
if (JSObject::GetDataProperty(promise, key)->IsUndefined()) {
OnException(value, false, promise);
}
}
MaybeHandle<Object> Debug::PromiseHasUserDefinedRejectHandler(
Handle<JSObject> promise) {
Handle<JSFunction> fun = Handle<JSFunction>::cast(
JSObject::GetDataProperty(isolate_->js_builtins_object(),
isolate_->factory()->NewStringFromStaticChars(
"PromiseHasUserDefinedRejectHandler")));
return Execution::Call(isolate_, fun, promise, 0, NULL);
}
void Debug::OnException(Handle<Object> exception, bool uncaught,
Handle<Object> promise) {
if (!uncaught && promise->IsJSObject()) {
Handle<JSObject> jspromise = Handle<JSObject>::cast(promise);
// Mark the promise as already having triggered a message.
Handle<Symbol> key = isolate_->factory()->promise_debug_marker_symbol();
JSObject::SetProperty(jspromise, key, key, STRICT).Assert();
// Check whether the promise reject is considered an uncaught exception.
Handle<Object> has_reject_handler;
ASSIGN_RETURN_ON_EXCEPTION_VALUE(
isolate_, has_reject_handler,
PromiseHasUserDefinedRejectHandler(jspromise), /* void */);
uncaught = has_reject_handler->IsFalse();
}
// Bail out if exception breaks are not active
if (uncaught) {
// Uncaught exceptions are reported by either flags.
if (!(break_on_uncaught_exception_ || break_on_exception_)) return;
} else {
// Caught exceptions are reported is activated.
if (!break_on_exception_) return;
}
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Clear all current stepping setup.
ClearStepping();
// Create the event data object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeExceptionEvent(
exception, uncaught, promise).ToHandle(&event_data)) {
return;
}
// Process debug event.
ProcessDebugEvent(v8::Exception, Handle<JSObject>::cast(event_data), false);
// Return to continue execution from where the exception was thrown.
}
void Debug::OnCompileError(Handle<Script> script) {
// No more to do if not debugging.
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Create the compile state object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeCompileEvent(script, v8::CompileError).ToHandle(&event_data)) return;
// Process debug event.
ProcessDebugEvent(v8::CompileError, Handle<JSObject>::cast(event_data), true);
}
void Debug::OnDebugBreak(Handle<Object> break_points_hit,
bool auto_continue) {
// The caller provided for DebugScope.
AssertDebugContext();
// Bail out if there is no listener for this event
if (ignore_events()) return;
HandleScope scope(isolate_);
// Create the event data object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeBreakEvent(break_points_hit).ToHandle(&event_data)) return;
// Process debug event.
ProcessDebugEvent(v8::Break,
Handle<JSObject>::cast(event_data),
auto_continue);
}
void Debug::OnBeforeCompile(Handle<Script> script) {
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Create the event data object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeCompileEvent(script, v8::BeforeCompile).ToHandle(&event_data))
return;
// Process debug event.
ProcessDebugEvent(v8::BeforeCompile,
Handle<JSObject>::cast(event_data),
true);
}
// Handle debugger actions when a new script is compiled.
void Debug::OnAfterCompile(Handle<Script> script) {
// Add the newly compiled script to the script cache.
if (script_cache_ != NULL) script_cache_->Add(script);
// No more to do if not debugging.
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// If debugging there might be script break points registered for this
// script. Make sure that these break points are set.
// Get the function UpdateScriptBreakPoints (defined in debug-debugger.js).
Handle<String> update_script_break_points_string =
isolate_->factory()->InternalizeOneByteString(
STATIC_CHAR_VECTOR("UpdateScriptBreakPoints"));
Handle<GlobalObject> debug_global(debug_context()->global_object());
Handle<Object> update_script_break_points =
Object::GetProperty(
debug_global, update_script_break_points_string).ToHandleChecked();
if (!update_script_break_points->IsJSFunction()) {
return;
}
DCHECK(update_script_break_points->IsJSFunction());
// Wrap the script object in a proper JS object before passing it
// to JavaScript.
Handle<Object> wrapper = Script::GetWrapper(script);
// Call UpdateScriptBreakPoints expect no exceptions.
Handle<Object> argv[] = { wrapper };
if (Execution::TryCall(Handle<JSFunction>::cast(update_script_break_points),
isolate_->js_builtins_object(),
arraysize(argv),
argv).is_null()) {
return;
}
// Create the compile state object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeCompileEvent(script, v8::AfterCompile).ToHandle(&event_data)) return;
// Process debug event.
ProcessDebugEvent(v8::AfterCompile, Handle<JSObject>::cast(event_data), true);
}
void Debug::OnPromiseEvent(Handle<JSObject> data) {
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Create the script collected state object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakePromiseEvent(data).ToHandle(&event_data)) return;
// Process debug event.
ProcessDebugEvent(v8::PromiseEvent,
Handle<JSObject>::cast(event_data),
true);
}
void Debug::OnAsyncTaskEvent(Handle<JSObject> data) {
if (in_debug_scope() || ignore_events()) return;
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Create the script collected state object.
Handle<Object> event_data;
// Bail out and don't call debugger if exception.
if (!MakeAsyncTaskEvent(data).ToHandle(&event_data)) return;
// Process debug event.
ProcessDebugEvent(v8::AsyncTaskEvent,
Handle<JSObject>::cast(event_data),
true);
}
void Debug::ProcessDebugEvent(v8::DebugEvent event,
Handle<JSObject> event_data,
bool auto_continue) {
HandleScope scope(isolate_);
// Create the execution state.
Handle<Object> exec_state;
// Bail out and don't call debugger if exception.
if (!MakeExecutionState().ToHandle(&exec_state)) return;
// First notify the message handler if any.
if (message_handler_ != NULL) {
NotifyMessageHandler(event,
Handle<JSObject>::cast(exec_state),
event_data,
auto_continue);
}
// Notify registered debug event listener. This can be either a C or
// a JavaScript function. Don't call event listener for v8::Break
// here, if it's only a debug command -- they will be processed later.
if ((event != v8::Break || !auto_continue) && !event_listener_.is_null()) {
CallEventCallback(event, exec_state, event_data, NULL);
}
// Process pending debug commands.
if (event == v8::Break) {
while (!event_command_queue_.IsEmpty()) {
CommandMessage command = event_command_queue_.Get();
if (!event_listener_.is_null()) {
CallEventCallback(v8::BreakForCommand,
exec_state,
event_data,
command.client_data());
}
command.Dispose();
}
}
}
void Debug::CallEventCallback(v8::DebugEvent event,
Handle<Object> exec_state,
Handle<Object> event_data,
v8::Debug::ClientData* client_data) {
if (event_listener_->IsForeign()) {
// Invoke the C debug event listener.
v8::Debug::EventCallback callback =
FUNCTION_CAST<v8::Debug::EventCallback>(
Handle<Foreign>::cast(event_listener_)->foreign_address());
EventDetailsImpl event_details(event,
Handle<JSObject>::cast(exec_state),
Handle<JSObject>::cast(event_data),
event_listener_data_,
client_data);
callback(event_details);
DCHECK(!isolate_->has_scheduled_exception());
} else {
// Invoke the JavaScript debug event listener.
DCHECK(event_listener_->IsJSFunction());
Handle<Object> argv[] = { Handle<Object>(Smi::FromInt(event), isolate_),
exec_state,
event_data,
event_listener_data_ };
Handle<JSReceiver> global(isolate_->global_proxy());
Execution::TryCall(Handle<JSFunction>::cast(event_listener_),
global, arraysize(argv), argv);
}
}
Handle<Context> Debug::GetDebugContext() {
DebugScope debug_scope(this);
// The global handle may be destroyed soon after. Return it reboxed.
return handle(*debug_context(), isolate_);
}
void Debug::NotifyMessageHandler(v8::DebugEvent event,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
bool auto_continue) {
// Prevent other interrupts from triggering, for example API callbacks,
// while dispatching message handler callbacks.
PostponeInterruptsScope no_interrupts(isolate_);
DCHECK(is_active_);
HandleScope scope(isolate_);
// Process the individual events.
bool sendEventMessage = false;
switch (event) {
case v8::Break:
case v8::BreakForCommand:
sendEventMessage = !auto_continue;
break;
case v8::Exception:
sendEventMessage = true;
break;
case v8::BeforeCompile:
break;
case v8::AfterCompile:
sendEventMessage = true;
break;
case v8::NewFunction:
break;
default:
UNREACHABLE();
}
// The debug command interrupt flag might have been set when the command was
// added. It should be enough to clear the flag only once while we are in the
// debugger.
DCHECK(in_debug_scope());
isolate_->stack_guard()->ClearDebugCommand();
// Notify the debugger that a debug event has occurred unless auto continue is
// active in which case no event is send.
if (sendEventMessage) {
MessageImpl message = MessageImpl::NewEvent(
event,
auto_continue,
Handle<JSObject>::cast(exec_state),
Handle<JSObject>::cast(event_data));
InvokeMessageHandler(message);
}
// If auto continue don't make the event cause a break, but process messages
// in the queue if any. For script collected events don't even process
// messages in the queue as the execution state might not be what is expected
// by the client.
if (auto_continue && !has_commands()) return;
// DebugCommandProcessor goes here.
bool running = auto_continue;
Handle<Object> cmd_processor_ctor = Object::GetProperty(
isolate_, exec_state, "debugCommandProcessor").ToHandleChecked();
Handle<Object> ctor_args[] = { isolate_->factory()->ToBoolean(running) };
Handle<Object> cmd_processor = Execution::Call(
isolate_, cmd_processor_ctor, exec_state, 1, ctor_args).ToHandleChecked();
Handle<JSFunction> process_debug_request = Handle<JSFunction>::cast(
Object::GetProperty(
isolate_, cmd_processor, "processDebugRequest").ToHandleChecked());
Handle<Object> is_running = Object::GetProperty(
isolate_, cmd_processor, "isRunning").ToHandleChecked();
// Process requests from the debugger.
do {
// Wait for new command in the queue.
command_received_.Wait();
// Get the command from the queue.
CommandMessage command = command_queue_.Get();
isolate_->logger()->DebugTag(
"Got request from command queue, in interactive loop.");
if (!is_active()) {
// Delete command text and user data.
command.Dispose();
return;
}
Vector<const uc16> command_text(
const_cast<const uc16*>(command.text().start()),
command.text().length());
Handle<String> request_text = isolate_->factory()->NewStringFromTwoByte(
command_text).ToHandleChecked();
Handle<Object> request_args[] = { request_text };
Handle<Object> answer_value;
Handle<String> answer;
MaybeHandle<Object> maybe_exception;
MaybeHandle<Object> maybe_result =
Execution::TryCall(process_debug_request, cmd_processor, 1,
request_args, &maybe_exception);
if (maybe_result.ToHandle(&answer_value)) {
if (answer_value->IsUndefined()) {
answer = isolate_->factory()->empty_string();
} else {
answer = Handle<String>::cast(answer_value);
}
// Log the JSON request/response.
if (FLAG_trace_debug_json) {
PrintF("%s\n", request_text->ToCString().get());
PrintF("%s\n", answer->ToCString().get());
}
Handle<Object> is_running_args[] = { answer };
maybe_result = Execution::Call(
isolate_, is_running, cmd_processor, 1, is_running_args);
Handle<Object> result;
if (!maybe_result.ToHandle(&result)) break;
running = result->IsTrue();
} else {
Handle<Object> exception;
if (!maybe_exception.ToHandle(&exception)) break;
Handle<Object> result;
if (!Execution::ToString(isolate_, exception).ToHandle(&result)) break;
answer = Handle<String>::cast(result);
}
// Return the result.
MessageImpl message = MessageImpl::NewResponse(
event, running, exec_state, event_data, answer, command.client_data());
InvokeMessageHandler(message);
command.Dispose();
// Return from debug event processing if either the VM is put into the
// running state (through a continue command) or auto continue is active
// and there are no more commands queued.
} while (!running || has_commands());
command_queue_.Clear();
}
void Debug::SetEventListener(Handle<Object> callback,
Handle<Object> data) {
GlobalHandles* global_handles = isolate_->global_handles();
// Remove existing entry.
GlobalHandles::Destroy(event_listener_.location());
event_listener_ = Handle<Object>();
GlobalHandles::Destroy(event_listener_data_.location());
event_listener_data_ = Handle<Object>();
// Set new entry.
if (!callback->IsUndefined() && !callback->IsNull()) {
event_listener_ = global_handles->Create(*callback);
if (data.is_null()) data = isolate_->factory()->undefined_value();
event_listener_data_ = global_handles->Create(*data);
}
UpdateState();
}
void Debug::SetMessageHandler(v8::Debug::MessageHandler handler) {
message_handler_ = handler;
UpdateState();
if (handler == NULL && in_debug_scope()) {
// Send an empty command to the debugger if in a break to make JavaScript
// run again if the debugger is closed.
EnqueueCommandMessage(Vector<const uint16_t>::empty());
}
}
void Debug::UpdateState() {
is_active_ = message_handler_ != NULL || !event_listener_.is_null();
if (is_active_ || in_debug_scope()) {
// Note that the debug context could have already been loaded to
// bootstrap test cases.
isolate_->compilation_cache()->Disable();
is_active_ = Load();
} else if (is_loaded()) {
isolate_->compilation_cache()->Enable();
Unload();
}
}
// Calls the registered debug message handler. This callback is part of the
// public API.
void Debug::InvokeMessageHandler(MessageImpl message) {
if (message_handler_ != NULL) message_handler_(message);
}
// Puts a command coming from the public API on the queue. Creates
// a copy of the command string managed by the debugger. Up to this
// point, the command data was managed by the API client. Called
// by the API client thread.
void Debug::EnqueueCommandMessage(Vector<const uint16_t> command,
v8::Debug::ClientData* client_data) {
// Need to cast away const.
CommandMessage message = CommandMessage::New(
Vector<uint16_t>(const_cast<uint16_t*>(command.start()),
command.length()),
client_data);
isolate_->logger()->DebugTag("Put command on command_queue.");
command_queue_.Put(message);
command_received_.Signal();
// Set the debug command break flag to have the command processed.
if (!in_debug_scope()) isolate_->stack_guard()->RequestDebugCommand();
}
void Debug::EnqueueDebugCommand(v8::Debug::ClientData* client_data) {
CommandMessage message = CommandMessage::New(Vector<uint16_t>(), client_data);
event_command_queue_.Put(message);
// Set the debug command break flag to have the command processed.
if (!in_debug_scope()) isolate_->stack_guard()->RequestDebugCommand();
}
MaybeHandle<Object> Debug::Call(Handle<JSFunction> fun, Handle<Object> data) {
DebugScope debug_scope(this);
if (debug_scope.failed()) return isolate_->factory()->undefined_value();
// Create the execution state.
Handle<Object> exec_state;
if (!MakeExecutionState().ToHandle(&exec_state)) {
return isolate_->factory()->undefined_value();
}
Handle<Object> argv[] = { exec_state, data };
return Execution::Call(
isolate_,
fun,
Handle<Object>(debug_context()->global_proxy(), isolate_),
arraysize(argv),
argv);
}
void Debug::HandleDebugBreak() {
// Ignore debug break during bootstrapping.
if (isolate_->bootstrapper()->IsActive()) return;
// Just continue if breaks are disabled.
if (break_disabled_) return;
// Ignore debug break if debugger is not active.
if (!is_active()) return;
StackLimitCheck check(isolate_);
if (check.HasOverflowed()) return;
{ JavaScriptFrameIterator it(isolate_);
DCHECK(!it.done());
Object* fun = it.frame()->function();
if (fun && fun->IsJSFunction()) {
// Don't stop in builtin functions.
if (JSFunction::cast(fun)->IsBuiltin()) return;
GlobalObject* global = JSFunction::cast(fun)->context()->global_object();
// Don't stop in debugger functions.
if (IsDebugGlobal(global)) return;
}
}
// Collect the break state before clearing the flags.
bool debug_command_only = isolate_->stack_guard()->CheckDebugCommand() &&
!isolate_->stack_guard()->CheckDebugBreak();
isolate_->stack_guard()->ClearDebugBreak();
ProcessDebugMessages(debug_command_only);
}
void Debug::ProcessDebugMessages(bool debug_command_only) {
isolate_->stack_guard()->ClearDebugCommand();
StackLimitCheck check(isolate_);
if (check.HasOverflowed()) return;
HandleScope scope(isolate_);
DebugScope debug_scope(this);
if (debug_scope.failed()) return;
// Notify the debug event listeners. Indicate auto continue if the break was
// a debug command break.
OnDebugBreak(isolate_->factory()->undefined_value(), debug_command_only);
}
DebugScope::DebugScope(Debug* debug)
: debug_(debug),
prev_(debug->debugger_entry()),
save_(debug_->isolate_),
no_termination_exceptons_(debug_->isolate_,
StackGuard::TERMINATE_EXECUTION) {
// Link recursive debugger entry.
base::NoBarrier_Store(&debug_->thread_local_.current_debug_scope_,
reinterpret_cast<base::AtomicWord>(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.
JavaScriptFrameIterator it(isolate());
bool has_js_frames = !it.done();
debug_->thread_local_.break_frame_id_ = has_js_frames ? it.frame()->id()
: StackFrame::NO_ID;
debug_->SetNextBreakId();
debug_->UpdateState();
// Make sure that debugger is loaded and enter the debugger context.
// The previous context is kept in save_.
failed_ = !debug_->is_loaded();
if (!failed_) isolate()->set_context(*debug->debug_context());
}
DebugScope::~DebugScope() {
if (!failed_ && 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 (!isolate()->has_pending_exception()) debug_->ClearMirrorCache();
// If there are commands in the queue when leaving the debugger request
// that these commands are processed.
if (debug_->has_commands()) isolate()->stack_guard()->RequestDebugCommand();
}
// Leaving this debugger entry.
base::NoBarrier_Store(&debug_->thread_local_.current_debug_scope_,
reinterpret_cast<base::AtomicWord>(prev_));
// Restore to the previous break state.
debug_->thread_local_.break_frame_id_ = break_frame_id_;
debug_->thread_local_.break_id_ = break_id_;
debug_->UpdateState();
}
MessageImpl MessageImpl::NewEvent(DebugEvent event,
bool running,
Handle<JSObject> exec_state,
Handle<JSObject> event_data) {
MessageImpl message(true, event, running,
exec_state, event_data, Handle<String>(), NULL);
return message;
}
MessageImpl MessageImpl::NewResponse(DebugEvent event,
bool running,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
Handle<String> response_json,
v8::Debug::ClientData* client_data) {
MessageImpl message(false, event, running,
exec_state, event_data, response_json, client_data);
return message;
}
MessageImpl::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)
: is_event_(is_event),
event_(event),
running_(running),
exec_state_(exec_state),
event_data_(event_data),
response_json_(response_json),
client_data_(client_data) {}
bool MessageImpl::IsEvent() const {
return is_event_;
}
bool MessageImpl::IsResponse() const {
return !is_event_;
}
DebugEvent MessageImpl::GetEvent() const {
return event_;
}
bool MessageImpl::WillStartRunning() const {
return running_;
}
v8::Handle<v8::Object> MessageImpl::GetExecutionState() const {
return v8::Utils::ToLocal(exec_state_);
}
v8::Isolate* MessageImpl::GetIsolate() const {
return reinterpret_cast<v8::Isolate*>(exec_state_->GetIsolate());
}
v8::Handle<v8::Object> MessageImpl::GetEventData() const {
return v8::Utils::ToLocal(event_data_);
}
v8::Handle<v8::String> MessageImpl::GetJSON() const {
Isolate* isolate = event_data_->GetIsolate();
v8::EscapableHandleScope scope(reinterpret_cast<v8::Isolate*>(isolate));
if (IsEvent()) {
// Call toJSONProtocol on the debug event object.
Handle<Object> fun = Object::GetProperty(
isolate, event_data_, "toJSONProtocol").ToHandleChecked();
if (!fun->IsJSFunction()) {
return v8::Handle<v8::String>();
}
MaybeHandle<Object> maybe_json =
Execution::TryCall(Handle<JSFunction>::cast(fun), event_data_, 0, NULL);
Handle<Object> json;
if (!maybe_json.ToHandle(&json) || !json->IsString()) {
return v8::Handle<v8::String>();
}
return scope.Escape(v8::Utils::ToLocal(Handle<String>::cast(json)));
} else {
return v8::Utils::ToLocal(response_json_);
}
}
v8::Handle<v8::Context> MessageImpl::GetEventContext() const {
Isolate* isolate = event_data_->GetIsolate();
v8::Handle<v8::Context> context = GetDebugEventContext(isolate);
// Isolate::context() may be NULL when "script collected" event occures.
DCHECK(!context.IsEmpty());
return context;
}
v8::Debug::ClientData* MessageImpl::GetClientData() const {
return client_data_;
}
EventDetailsImpl::EventDetailsImpl(DebugEvent event,
Handle<JSObject> exec_state,
Handle<JSObject> event_data,
Handle<Object> callback_data,
v8::Debug::ClientData* client_data)
: event_(event),
exec_state_(exec_state),
event_data_(event_data),
callback_data_(callback_data),
client_data_(client_data) {}
DebugEvent EventDetailsImpl::GetEvent() const {
return event_;
}
v8::Handle<v8::Object> EventDetailsImpl::GetExecutionState() const {
return v8::Utils::ToLocal(exec_state_);
}
v8::Handle<v8::Object> EventDetailsImpl::GetEventData() const {
return v8::Utils::ToLocal(event_data_);
}
v8::Handle<v8::Context> EventDetailsImpl::GetEventContext() const {
return GetDebugEventContext(exec_state_->GetIsolate());
}
v8::Handle<v8::Value> EventDetailsImpl::GetCallbackData() const {
return v8::Utils::ToLocal(callback_data_);
}
v8::Debug::ClientData* EventDetailsImpl::GetClientData() const {
return client_data_;
}
CommandMessage::CommandMessage() : text_(Vector<uint16_t>::empty()),
client_data_(NULL) {
}
CommandMessage::CommandMessage(const Vector<uint16_t>& text,
v8::Debug::ClientData* data)
: text_(text),
client_data_(data) {
}
void CommandMessage::Dispose() {
text_.Dispose();
delete client_data_;
client_data_ = NULL;
}
CommandMessage CommandMessage::New(const Vector<uint16_t>& command,
v8::Debug::ClientData* data) {
return CommandMessage(command.Clone(), data);
}
CommandMessageQueue::CommandMessageQueue(int size) : start_(0), end_(0),
size_(size) {
messages_ = NewArray<CommandMessage>(size);
}
CommandMessageQueue::~CommandMessageQueue() {
while (!IsEmpty()) Get().Dispose();
DeleteArray(messages_);
}
CommandMessage CommandMessageQueue::Get() {
DCHECK(!IsEmpty());
int result = start_;
start_ = (start_ + 1) % size_;
return messages_[result];
}
void CommandMessageQueue::Put(const CommandMessage& message) {
if ((end_ + 1) % size_ == start_) {
Expand();
}
messages_[end_] = message;
end_ = (end_ + 1) % size_;
}
void CommandMessageQueue::Expand() {
CommandMessageQueue new_queue(size_ * 2);
while (!IsEmpty()) {
new_queue.Put(Get());
}
CommandMessage* array_to_free = messages_;
*this = new_queue;
new_queue.messages_ = array_to_free;
// Make the new_queue empty so that it doesn't call Dispose on any messages.
new_queue.start_ = new_queue.end_;
// Automatic destructor called on new_queue, freeing array_to_free.
}
LockingCommandMessageQueue::LockingCommandMessageQueue(Logger* logger, int size)
: logger_(logger), queue_(size) {}
bool LockingCommandMessageQueue::IsEmpty() const {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
return queue_.IsEmpty();
}
CommandMessage LockingCommandMessageQueue::Get() {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
CommandMessage result = queue_.Get();
logger_->DebugEvent("Get", result.text());
return result;
}
void LockingCommandMessageQueue::Put(const CommandMessage& message) {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
queue_.Put(message);
logger_->DebugEvent("Put", message.text());
}
void LockingCommandMessageQueue::Clear() {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
queue_.Clear();
}
} } // namespace v8::internal
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