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v8/src/debug.cc

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Initial export. git-svn-id: http://v8.googlecode.com/svn/trunk@2 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-07-03 15:10:15 +00:00
// Copyright 2006-2008 Google Inc. All Rights Reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "v8.h"
#include "api.h"
#include "arguments.h"
#include "bootstrapper.h"
#include "code-stubs.h"
#include "compiler.h"
#include "debug.h"
#include "execution.h"
#include "global-handles.h"
#include "natives.h"
#include "stub-cache.h"
namespace v8 { namespace internal {
DEFINE_bool(remote_debugging, false, "enable remote debugging");
DEFINE_int(debug_port, 5858, "port for remote debugging");
DEFINE_bool(trace_debug_json, false, "trace debugging JSON request/response");
DECLARE_bool(allow_natives_syntax);
static void PrintLn(v8::Local<v8::Value> value) {
v8::Local<v8::String> s = value->ToString();
char* data = NewArray<char>(s->Length() + 1);
if (data == NULL) {
V8::FatalProcessOutOfMemory("PrintLn");
return;
}
s->WriteAscii(data);
PrintF("%s\n", data);
DeleteArray(data);
}
PendingRequest::PendingRequest(const uint16_t* json_request, int length)
: json_request_(Vector<uint16_t>::empty()),
next_(NULL) {
// Copy the request.
json_request_ =
Vector<uint16_t>(const_cast<uint16_t *>(json_request), length).Clone();
}
PendingRequest::~PendingRequest() {
// Deallocate what was allocated.
if (!json_request_.is_empty()) {
json_request_.Dispose();
}
}
Handle<String> PendingRequest::request() {
// Create a string in the heap from the pending request.
if (!json_request_.is_empty()) {
return Factory::NewStringFromTwoByte(
Vector<const uint16_t>(
reinterpret_cast<const uint16_t*>(json_request_.start()),
json_request_.length()));
} else {
return Handle<String>();
}
}
static Handle<Code> ComputeCallDebugBreak(int argc) {
CALL_HEAP_FUNCTION(StubCache::ComputeCallDebugBreak(argc), Code);
}
static Handle<Code> ComputeCallDebugPrepareStepIn(int argc) {
CALL_HEAP_FUNCTION(StubCache::ComputeCallDebugPrepareStepIn(argc), Code);
}
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() {
ASSERT(reloc_iterator_ != NULL);
ASSERT(reloc_iterator_original_ != NULL);
delete reloc_iterator_;
delete reloc_iterator_original_;
}
void BreakLocationIterator::Next() {
AssertNoAllocation nogc;
ASSERT(!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;
// Update the current source position each time a source position is
// passed.
if (is_position(rmode())) {
position_ = rinfo()->data() - debug_info_->shared()->start_position();
if (is_statement_position(rmode())) {
statement_position_ =
rinfo()->data() - debug_info_->shared()->start_position();
}
ASSERT(position_ >= 0);
ASSERT(statement_position_ >= 0);
}
// 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.
if (is_code_target(rmode())) {
Address target = original_rinfo()->target_address();
Code* code = Debug::GetCodeTarget(target);
if (code->is_inline_cache_stub() || is_js_construct_call(rmode())) {
break_point_++;
return;
}
if (code->kind() == Code::STUB) {
if (type_ == ALL_BREAK_LOCATIONS) {
if (Debug::IsBreakStub(code)) {
break_point_++;
return;
}
} else {
ASSERT(type_ == SOURCE_BREAK_LOCATIONS);
if (Debug::IsSourceBreakStub(code)) {
break_point_++;
return;
}
}
}
}
// Check for break at return.
// Currently is_exit_js_frame is used on ARM.
if (is_js_return(rmode()) || is_exit_js_frame(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();
} else {
position_ = 0;
}
statement_position_ = position_;
break_point_++;
return;
}
}
}
void BreakLocationIterator::Next(int count) {
while (count > 0) {
Next();
count--;
}
}
// Find the break point closest to the supplied 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 = 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) {
// Run through all break points to locate the one closest to the source
// position.
int closest_break_point = 0;
int distance = kMaxInt;
while (!Done()) {
// Check if this break point is closer that what was previously found.
if (position <= statement_position() &&
statement_position() - position < distance) {
closest_break_point = break_point();
distance = statement_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());
reloc_iterator_original_ = new RelocIterator(debug_info_->original_code());
// 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();
}
ASSERT(IsDebugBreak());
// 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();
ASSERT(!IsDebugBreak());
}
}
void BreakLocationIterator::SetOneShot() {
// If there is a real break point here no more to do.
if (HasBreakPoint()) {
ASSERT(IsDebugBreak());
return;
}
// Patch code with debug break.
SetDebugBreak();
}
void BreakLocationIterator::ClearOneShot() {
// If there is a real break point here no more to do.
if (HasBreakPoint()) {
ASSERT(IsDebugBreak());
return;
}
// Patch code removing debug break.
ClearDebugBreak();
ASSERT(!IsDebugBreak());
}
void BreakLocationIterator::SetDebugBreak() {
// If there is already a break point here just return. This might happen if
// the same code is flodded with break points twice. Flodding 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 (is_js_return(rmode())) {
// This path is currently only used on IA32 as JSExitFrame on ARM uses a
// stub.
// Patch the JS frame exit code with a debug break call. See
// VisitReturnStatement and ExitJSFrame in codegen-ia32.cc for the
// precise return instructions sequence.
ASSERT(Debug::kIa32JSReturnSequenceLength >=
Debug::kIa32CallInstructionLength);
rinfo()->patch_code_with_call(Debug::debug_break_return_entry()->entry(),
Debug::kIa32JSReturnSequenceLength - Debug::kIa32CallInstructionLength);
} else {
// 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());
// Patch the code to invoke the builtin debug break function matching the
// calling convention used by the call site.
Handle<Code> dbgbrk_code(Debug::FindDebugBreak(rinfo()));
rinfo()->set_target_address(dbgbrk_code->entry());
}
ASSERT(IsDebugBreak());
}
void BreakLocationIterator::ClearDebugBreak() {
if (is_js_return(rmode())) {
// Restore the JS frame exit code.
rinfo()->patch_code(original_rinfo()->pc(),
Debug::kIa32JSReturnSequenceLength);
} else {
// Patch the code to the original invoke.
rinfo()->set_target_address(original_rinfo()->target_address());
}
ASSERT(!IsDebugBreak());
}
void BreakLocationIterator::PrepareStepIn() {
// Step in can only be prepared if currently positioned on an IC call or
// construct call.
Address target = rinfo()->target_address();
Code* code = Debug::GetCodeTarget(target);
if (code->is_call_stub()) {
// Step in through IC call is handled by the runtime system. Therefore make
// sure that the any current IC is cleared and the runtime system is
// called. If the executing code has a debug break at the location change
// the call in the original code as it is the code there that will be
// executed in place of the debug break call.
Handle<Code> stub = ComputeCallDebugPrepareStepIn(code->arguments_count());
if (IsDebugBreak()) {
original_rinfo()->set_target_address(stub->entry());
} else {
rinfo()->set_target_address(stub->entry());
}
} else {
// Step in through constructs call requires no changs to the running code.
ASSERT(is_js_construct_call(rmode()));
}
}
// Check whether the break point is at a position which will exit the function.
bool BreakLocationIterator::IsExit() const {
// Currently is_exit_js_frame is used on ARM.
return (is_js_return(rmode()) || is_exit_js_frame(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 (is_js_return(rmode())) {
// This is IA32 specific but works as long as the ARM version
// still uses a stub for JSExitFrame.
//
// TODO(1240753): Make the test architecture independent or split
// parts of the debugger into architecture dependent files.
return (*(rinfo()->pc()) == 0xE8);
} else {
return Debug::IsDebugBreak(rinfo()->target_address());
}
}
Object* BreakLocationIterator::BreakPointObjects() {
return debug_info_->GetBreakPointObjects(code_position());
}
bool BreakLocationIterator::RinfoDone() const {
ASSERT(reloc_iterator_->done() == reloc_iterator_original_->done());
return reloc_iterator_->done();
}
void BreakLocationIterator::RinfoNext() {
reloc_iterator_->next();
reloc_iterator_original_->next();
#ifdef DEBUG
ASSERT(reloc_iterator_->done() == reloc_iterator_original_->done());
if (!reloc_iterator_->done()) {
ASSERT(rmode() == original_rmode());
}
#endif
}
bool Debug::has_break_points_ = false;
DebugInfoListNode* Debug::debug_info_list_ = NULL;
// Threading support.
void Debug::ThreadInit() {
thread_local_.last_step_action_ = StepNone;
thread_local_.last_statement_position_ = kNoPosition;
thread_local_.step_count_ = 0;
thread_local_.last_fp_ = 0;
thread_local_.step_into_fp_ = 0;
thread_local_.after_break_target_ = 0;
}
JSCallerSavedBuffer Debug::registers_;
Debug::ThreadLocal Debug::thread_local_;
char* Debug::ArchiveDebug(char* storage) {
char* to = storage;
memcpy(to, reinterpret_cast<char*>(&thread_local_), sizeof(ThreadLocal));
to += sizeof(ThreadLocal);
memcpy(to, reinterpret_cast<char*>(&registers_), sizeof(registers_));
ThreadInit();
ASSERT(to <= storage + ArchiveSpacePerThread());
return storage + ArchiveSpacePerThread();
}
char* Debug::RestoreDebug(char* storage) {
char* from = storage;
memcpy(reinterpret_cast<char*>(&thread_local_), from, sizeof(ThreadLocal));
from += sizeof(ThreadLocal);
memcpy(reinterpret_cast<char*>(&registers_), from, sizeof(registers_));
ASSERT(from <= storage + ArchiveSpacePerThread());
return storage + ArchiveSpacePerThread();
}
int Debug::ArchiveSpacePerThread() {
return sizeof(ThreadLocal) + sizeof(registers_);
}
// Default call debugger on uncaught exception.
bool Debug::break_on_exception_ = false;
bool Debug::break_on_uncaught_exception_ = true;
Handle<Context> Debug::debug_context_ = Handle<Context>();
Code* Debug::debug_break_return_entry_ = NULL;
Code* Debug::debug_break_return_ = NULL;
void Debug::HandleWeakDebugInfo(v8::Persistent<v8::Object> obj, void* data) {
DebugInfoListNode* node = reinterpret_cast<DebugInfoListNode*>(data);
RemoveDebugInfo(node->debug_info());
#ifdef DEBUG
node = Debug::debug_info_list_;
while (node != NULL) {
ASSERT(node != reinterpret_cast<DebugInfoListNode*>(data));
node = node->next();
}
#endif
}
DebugInfoListNode::DebugInfoListNode(DebugInfo* debug_info): next_(NULL) {
// Globalize the request debug info object and make it weak.
debug_info_ = Handle<DebugInfo>::cast((GlobalHandles::Create(debug_info)));
GlobalHandles::MakeWeak(reinterpret_cast<Object**>(debug_info_.location()),
this, Debug::HandleWeakDebugInfo);
}
DebugInfoListNode::~DebugInfoListNode() {
GlobalHandles::Destroy(reinterpret_cast<Object**>(debug_info_.location()));
}
void Debug::Setup(bool create_heap_objects) {
ThreadInit();
if (create_heap_objects) {
// Get code to handle entry to debug break on return.
debug_break_return_entry_ =
Builtins::builtin(Builtins::Return_DebugBreakEntry);
ASSERT(debug_break_return_entry_->IsCode());
// Get code to handle debug break on return.
debug_break_return_ =
Builtins::builtin(Builtins::Return_DebugBreak);
ASSERT(debug_break_return_->IsCode());
}
}
bool Debug::CompileDebuggerScript(int index) {
HandleScope scope;
// Find source and name for the requested script.
if (index == -1) {
return false;
}
Handle<String> source_code = Bootstrapper::NativesSourceLookup(index);
Vector<const char> name = Natives::GetScriptName(index);
Handle<String> script_name = Factory::NewStringFromAscii(name);
// Compile the script.
bool allow_natives_syntax = FLAG_allow_natives_syntax;
FLAG_allow_natives_syntax = true;
Handle<JSFunction> boilerplate;
boilerplate = Compiler::Compile(source_code, script_name, 0, 0, NULL, NULL);
FLAG_allow_natives_syntax = allow_natives_syntax;
// Silently ignore stack overflows during compilation.
if (boilerplate.is_null()) {
ASSERT(Top::has_pending_exception());
Top::clear_pending_exception();
return false;
}
// Execute the boilerplate function in the global object for the supplied
// context.
bool caught_exception = false;
Handle<Context> context = Top::global_context();
Handle<JSFunction> debug_fun(Factory::NewFunctionFromBoilerplate(boilerplate,
context));
Handle<GlobalObject> debug_global(context->global());
Handle<Object> result = Execution::TryCall(debug_fun, debug_global,
0, NULL, &caught_exception);
if (caught_exception) {
MessageHandler::ReportMessage("error_loading_debugger",
NULL,
HandleVector<Object>(&result, 1));
return false;
}
// Mark this script as native.
Handle<Script> script(Script::cast(debug_fun->shared()->script()));
script->set_type(Smi::FromInt(SCRIPT_TYPE_NATIVE));
return true;
}
bool Debug::Load() {
// Return if debugger is already loaded.
if (IsLoaded()) {
return true;
}
// Create the debugger context.
HandleScope scope;
Handle<Object> empty_global_object;
Handle<Context> debug_context;
v8::Handle<v8::ObjectTemplate> global_template =
v8::Handle<v8::ObjectTemplate>();
debug_context = Bootstrapper::CreateEnvironment(empty_global_object,
global_template,
NULL);
// Enter the debugger context.
SaveContext save;
Top::set_context(*debug_context);
Top::set_security_context(*debug_context);
// Compile the JavaScript for the debugger in the debugger context.
Debugger::set_compiling_natives(true);
if (!CompileDebuggerScript(Natives::GetIndex("mirror"))) {
return false;
};
if (!CompileDebuggerScript(Natives::GetIndex("debug"))) {
return false;
};
Debugger::set_compiling_natives(false);
// Expose the builtins object in the debugger context.
Handle<String> builtins_string = Factory::LookupAsciiSymbol("builtins");
Handle<JSGlobalObject> global(JSGlobalObject::cast(debug_context->global()));
SetProperty(global, builtins_string,
Handle<JSObject>(global->builtins()), NONE);
// Debugger loaded.
debug_context_ = Handle<Context>::cast(GlobalHandles::Create(*debug_context));
return true;
}
void Debug::Unload() {
// Return debugger is not loaded.
if (!IsLoaded()) {
return;
}
// Clear debugger context global handle.
GlobalHandles::Destroy(reinterpret_cast<Object**>(debug_context_.location()));
debug_context_ = Handle<Context>();
}
void Debug::Iterate(ObjectVisitor* v) {
#define VISIT(field) v->VisitPointer(reinterpret_cast<Object**>(&(field)));
VISIT(debug_break_return_entry_);
VISIT(debug_break_return_);
#undef VISIT
}
Object* Debug::Break(Arguments args) {
HandleScope scope;
ASSERT(args.length() == 1);
if (!Load()) {
return Heap::undefined_value();
}
SaveBreakFrame save;
EnterDebuggerContext enter;
// Get the top-most JavaScript frame.
JavaScriptFrameIterator it;
JavaScriptFrame* frame = it.frame();
// Deactivate interrupt during breakpoint processing.
StackGuard::DisableInterrupts();
// Get the debug info (create it if it does not exist).
Handle<SharedFunctionInfo> shared =
Handle<SharedFunctionInfo>(JSFunction::cast(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);
break_location_iterator.FindBreakLocationFromAddress(frame->pc());
// 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());
if (break_location_iterator.HasBreakPoint()) {
Handle<Object> break_point_objects =
Handle<Object>(break_location_iterator.BreakPointObjects());
break_points_hit = CheckBreakPoints(break_point_objects);
}
// Notify debugger if a real break point is triggered or if performing single
// stepping with no more steps to perform. Otherwise do another step.
if (!break_points_hit->IsUndefined() ||
(thread_local_.last_step_action_ != StepNone &&
thread_local_.step_count_ == 0)) {
// Clear all current stepping setup.
ClearStepping();
// Notify the debug event listeners.
Debugger::OnDebugBreak(break_points_hit);
} 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_;
// Clear all current stepping setup.
ClearStepping();
// Set up for the remaining steps.
PrepareStep(step_action, step_count);
}
// Reactivate interrupt.
StackGuard::EnableInterrupts();
// Install jump to the call address which was overwritten.
SetAfterBreakTarget(frame);
// Return whatever - return value is ignored.
return 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) {
int break_points_hit_count = 0;
Handle<JSArray> break_points_hit = Factory::NewJSArray(1);
// If there are multiple break points they are in a Fixedrray.
ASSERT(!break_point_objects->IsUndefined());
if (break_point_objects->IsFixedArray()) {
Handle<FixedArray> array(FixedArray::cast(*break_point_objects));
for (int i = 0; i < array->length(); i++) {
Handle<Object> o(array->get(i));
if (CheckBreakPoint(o)) {
break_points_hit->SetElement(break_points_hit_count++, *o);
}
}
} else {
if (CheckBreakPoint(break_point_objects)) {
break_points_hit->SetElement(break_points_hit_count++,
*break_point_objects);
}
}
// Return undefined if no break points where triggered.
if (break_points_hit_count == 0) {
return Factory::undefined_value();
}
return break_points_hit;
}
// Check whether a single break point object is triggered.
bool Debug::CheckBreakPoint(Handle<Object> break_point_object) {
// Ignore check if break point object is not a JSObject.
if (!break_point_object->IsJSObject()) return true;
// Get the function CheckBreakPoint (defined in debug.js).
Handle<JSFunction> check_break_point =
Handle<JSFunction>(JSFunction::cast(
debug_context()->global()->GetProperty(
*Factory::LookupAsciiSymbol("IsBreakPointTriggered"))));
// Get the break id as an object.
Handle<Object> break_id = Factory::NewNumberFromInt(Top::break_id());
// Call HandleBreakPointx.
bool caught_exception = false;
const int argc = 2;
Object** argv[argc] = {
break_id.location(),
reinterpret_cast<Object**>(break_point_object.location())
};
Handle<Object> result = Execution::TryCall(check_break_point,
Top::builtins(), argc, argv,
&caught_exception);
// If exception or non boolean result handle as not triggered
if (caught_exception || !result->IsBoolean()) {
return false;
}
// Return whether the break point is triggered.
return *result == Heap::true_value();
}
// 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. If the function currently has no
// debug info it will be created. The reason for having this function is that
// the debug info member is of type Object and not DebugInfo, as it can contain
// undefined to indicate that currently no debug info exists for the function.
Handle<DebugInfo> Debug::GetDebugInfo(Handle<SharedFunctionInfo> shared) {
// If the debug info does not exist create it.
if (!HasDebugInfo(shared)) {
AddDebugInfo(shared);
}
// Return the debug info.
return Handle<DebugInfo>(DebugInfo::cast(shared->debug_info()));
}
void Debug::SetBreakPoint(Handle<SharedFunctionInfo> shared,
int source_position,
Handle<Object> break_point_object) {
// Make sure the function is compiled before accessing code object.
EnsureCompiled(shared);
// Get the debug info (create it if it does not exist).
Handle<DebugInfo> debug_info;
if (shared->debug_info()->IsUndefined()) {
debug_info = AddDebugInfo(shared);
} else {
debug_info = Handle<DebugInfo>(DebugInfo::cast(shared->debug_info()));
}
// Source positions starts with zero.
ASSERT(source_position >= 0);
// Find the break point and change it.
BreakLocationIterator it(debug_info, SOURCE_BREAK_LOCATIONS);
it.FindBreakLocationFromPosition(source_position);
it.SetBreakPoint(break_point_object);
// At least one active break point now.
ASSERT(debug_info->GetBreakPointCount() > 0);
}
void Debug::ClearBreakPoint(Handle<Object> break_point_object) {
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();
Handle<SharedFunctionInfo> shared(debug_info->shared());
int source_position = break_point_info->statement_position()->value();
// Source positions starts with zero.
ASSERT(source_position >= 0);
// Find the break point and clear it.
BreakLocationIterator it(debug_info, SOURCE_BREAK_LOCATIONS);
it.FindBreakLocationFromPosition(source_position);
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::FloodWithOneShot(Handle<SharedFunctionInfo> shared) {
// Make sure the function is compiled before accessing code object.
EnsureCompiled(shared);
// Get the debug info.
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
// Flood the function with break points.
BreakLocationIterator it(debug_info, ALL_BREAK_LOCATIONS);
while (!it.Done()) {
it.SetOneShot();
it.Next();
}
}
void Debug::FloodHandlerWithOneShot() {
StackFrame::Id id = Top::break_frame_id();
for (JavaScriptFrameIterator it(id); !it.done(); it.Advance()) {
JavaScriptFrame* frame = it.frame();
if (frame->HasHandler()) {
Handle<SharedFunctionInfo> shared =
Handle<SharedFunctionInfo>(
JSFunction::cast(frame->function())->shared());
// Flood the function with the catch block with break points
FloodWithOneShot(shared);
return;
}
}
}
void Debug::ChangeBreakOnException(ExceptionBreakType type, bool enable) {
if (type == BreakUncaughtException) {
break_on_uncaught_exception_ = enable;
} else {
break_on_exception_ = enable;
}
}
void Debug::PrepareStep(StepAction step_action, int step_count) {
HandleScope scope;
ASSERT(Debug::InDebugger());
// Remember this step action and count.
thread_local_.last_step_action_ = step_action;
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 = Top::break_frame_id();
JavaScriptFrameIterator frames_it(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 = JSFunction::cast(frames_it.frame()->function());
FloodWithOneShot(Handle<SharedFunctionInfo>(function->shared()));
return;
}
// Get the debug info (create it if it does not exist).
Handle<SharedFunctionInfo> shared =
Handle<SharedFunctionInfo>(JSFunction::cast(frame->function())->shared());
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
// Find the break location where execution has stopped.
BreakLocationIterator it(debug_info, ALL_BREAK_LOCATIONS);
it.FindBreakLocationFromAddress(frame->pc());
// Compute whether or not the target is a call target.
bool is_call_target = false;
if (is_code_target(it.rinfo()->rmode())) {
Address target = it.rinfo()->target_address();
Code* code = Debug::GetCodeTarget(target);
if (code->is_call_stub()) is_call_target = true;
}
// If this is the last break code target step out is the only posibility.
if (it.IsExit() || step_action == StepOut) {
// Step out: If there is a JavaScript caller frame, we need to
// flood it with breakpoints.
frames_it.Advance();
if (!frames_it.done()) {
// Fill the function to return to with one-shot break points.
JSFunction* function = JSFunction::cast(frames_it.frame()->function());
FloodWithOneShot(Handle<SharedFunctionInfo>(function->shared()));
}
} else if (!(is_call_target || is_js_construct_call(it.rmode())) ||
step_action == StepNext || step_action == StepMin) {
// Step next or step min.
// Fill the current function with one-shot break points.
FloodWithOneShot(shared);
// 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->fp();
} else {
// 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.
FloodWithOneShot(shared);
// Step in or Step in min
it.PrepareStepIn();
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
// flodded 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) {
// 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->fp() &&
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 = GetCodeTarget(addr);
return code->state() == DEBUG_BREAK;
}
// Check whether a code stub with the specified major key is a possible break
// point location when looking for source break locations.
bool Debug::IsSourceBreakStub(Code* code) {
CodeStub::Major major_key = code->major_key();
return major_key == CodeStub::CallFunction;
}
// Check whether a code stub with the specified major key is a possible break
// location.
bool Debug::IsBreakStub(Code* code) {
CodeStub::Major major_key = code->major_key();
return major_key == CodeStub::CallFunction ||
major_key == CodeStub::StackCheck;
}
// Find the builtin to use for invoking the debug break
Handle<Code> Debug::FindDebugBreak(RelocInfo* rinfo) {
// Find the builtin debug break function matching the calling convention
// used by the call site.
RelocMode mode = rinfo->rmode();
if (is_code_target(mode)) {
Address target = rinfo->target_address();
Code* code = Debug::GetCodeTarget(target);
if (code->is_inline_cache_stub()) {
if (code->is_call_stub()) {
return ComputeCallDebugBreak(code->arguments_count());
}
if (code->is_load_stub()) {
return Handle<Code>(Builtins::builtin(Builtins::LoadIC_DebugBreak));
}
if (code->is_store_stub()) {
return Handle<Code>(Builtins::builtin(Builtins::StoreIC_DebugBreak));
}
if (code->is_keyed_load_stub()) {
Handle<Code> result =
Handle<Code>(Builtins::builtin(Builtins::KeyedLoadIC_DebugBreak));
return result;
}
if (code->is_keyed_store_stub()) {
Handle<Code> result =
Handle<Code>(Builtins::builtin(Builtins::KeyedStoreIC_DebugBreak));
return result;
}
}
if (is_js_construct_call(mode)) {
Handle<Code> result =
Handle<Code>(Builtins::builtin(Builtins::ConstructCall_DebugBreak));
return result;
}
// Currently is_exit_js_frame is used on ARM.
if (is_exit_js_frame(mode)) {
return Handle<Code>(Builtins::builtin(Builtins::Return_DebugBreak));
}
if (code->kind() == Code::STUB) {
ASSERT(code->major_key() == CodeStub::CallFunction ||
code->major_key() == CodeStub::StackCheck);
Handle<Code> result =
Handle<Code>(Builtins::builtin(Builtins::StubNoRegisters_DebugBreak));
return result;
}
}
UNREACHABLE();
return Handle<Code>::null();
}
// Simple function for returning the source positions for active break points.
Handle<Object> Debug::GetSourceBreakLocations(
Handle<SharedFunctionInfo> shared) {
if (!HasDebugInfo(shared)) return Handle<Object>(Heap::undefined_value());
Handle<DebugInfo> debug_info = GetDebugInfo(shared);
if (debug_info->GetBreakPointCount() == 0) {
return Handle<Object>(Heap::undefined_value());
}
Handle<FixedArray> locations =
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) {
locations->set(count++, break_point_info->statement_position());
}
}
}
return locations;
}
void Debug::ClearStepping() {
// Clear the various stepping setup.
ClearOneShot();
ClearStepIn();
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 automaticaly
// 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) {
thread_local_.step_into_fp_ = frame->fp();
}
void Debug::ClearStepIn() {
thread_local_.step_into_fp_ = 0;
}
void Debug::ClearStepNext() {
thread_local_.last_step_action_ = StepNone;
thread_local_.last_statement_position_ = kNoPosition;
thread_local_.last_fp_ = 0;
}
void Debug::EnsureCompiled(Handle<SharedFunctionInfo> shared) {
if (!shared->is_compiled()) {
// TODO(1240742): We need to handle stack-overflow exceptions
// here. It might make sense to add a boolean return value to
// EnsureCompiled to indicate whether or not the compilation
// succeeded.
CompileLazyShared(shared, KEEP_EXCEPTION);
}
ASSERT(shared->is_compiled());
}
Handle<DebugInfo> Debug::AddDebugInfo(Handle<SharedFunctionInfo> shared) {
ASSERT(!HasDebugInfo(shared));
// Make sure that the function is compiled.
EnsureCompiled(shared);
// Create the debug info object.
Handle<DebugInfo> debug_info =
Handle<DebugInfo>::cast(Factory::NewStruct(DEBUG_INFO_TYPE));
// Get the function original code.
Handle<Code> code(shared->code());
// Debug info contains function, a copy of the original code and the executing
// code.
debug_info->set_shared(*shared);
debug_info->set_original_code(*Factory::CopyCode(code));
debug_info->set_code(*code);
// Link debug info to function.
shared->set_debug_info(*debug_info);
// Initially no active break points.
debug_info->set_break_points(
*Factory::NewFixedArray(Debug::kEstimatedNofBreakPointsInFunction));
// Add debug info to the list.
DebugInfoListNode* node = new DebugInfoListNode(*debug_info);
node->set_next(debug_info_list_);
debug_info_list_ = node;
// Now there is at least one break point.
has_break_points_ = true;
return debug_info;
}
void Debug::RemoveDebugInfo(Handle<DebugInfo> debug_info) {
ASSERT(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(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) {
// Get the executing function in which the debug break occurred.
Handle<SharedFunctionInfo> shared =
Handle<SharedFunctionInfo>(JSFunction::cast(frame->function())->shared());
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->FindCode());
ASSERT(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 = frame->pc() - Assembler::kTargetAddrToReturnAddrDist;
// Check if the location is at JS exit.
bool at_js_exit = false;
RelocIterator it(debug_info->code());
while (!it.done()) {
if (is_js_return(it.rinfo()->rmode())) {
at_js_exit = it.rinfo()->pc() == addr - 1;
}
it.next();
}
// Handle the jump to continue execution after break point depending on the
// break location.
if (at_js_exit) {
// First check if the call in the code is still the debug break return
// entry code. If it is the break point is still active. If not the break
// point was removed during break point processing.
if (Assembler::target_address_at(addr) ==
debug_break_return_entry()->entry()) {
// Break point still active. Jump to the corresponding place in the
// original code.
addr += original_code->instruction_start() - code->instruction_start();
}
// Move one byte back to where the call instruction was placed.
thread_local_.after_break_target_ = addr - 1;
} else {
// Check if there still is a debug break call at the target address. If the
// break point has been removed it will have disappeared. If it have
// disappeared 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. If the debug break call is still there find the address in
// the original code.
if (IsDebugBreak(Assembler::target_address_at(addr))) {
// If the break point is still there find the call address which was
// overwritten in the original code by the 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.
thread_local_.after_break_target_ = Assembler::target_address_at(addr);
}
}
Code* Debug::GetCodeTarget(Address target) {
// Maybe this can be refactored with the stuff in ic-inl.h?
Code* result =
Code::cast(HeapObject::FromAddress(target - Code::kHeaderSize));
return result;
}
bool Debug::IsDebugGlobal(GlobalObject* global) {
return IsLoaded() && global == Debug::debug_context()->global();
}
bool Debugger::debugger_active_ = false;
bool Debugger::compiling_natives_ = false;
DebugMessageThread* Debugger::message_thread_ = NULL;
v8::DebugMessageHandler Debugger::debug_message_handler_ = NULL;
void* Debugger::debug_message_handler_data_ = NULL;
Mutex* Debugger::pending_requests_access_ = OS::CreateMutex();
PendingRequest* Debugger::pending_requests_head_ = NULL;
PendingRequest* Debugger::pending_requests_tail_ = NULL;
void Debugger::DebugRequest(const uint16_t* json_request, int length) {
// Create a pending request.
PendingRequest* pending_request = new PendingRequest(json_request, length);
// Add the pending request to list.
Guard with(pending_requests_access_);
if (pending_requests_head_ == NULL) {
ASSERT(pending_requests_tail_ == NULL);
pending_requests_head_ = pending_request;
pending_requests_tail_ = pending_request;
} else {
ASSERT(pending_requests_tail_ != NULL);
pending_requests_tail_->set_next(pending_request);
pending_requests_tail_ = pending_request;
}
// Use the stack guard to signal the debug request.
StackGuard::DebugBreak();
}
bool Debugger::ProcessPendingRequests() {
HandleScope scope;
// Lock access to pending requests list while processing them. Typically
// there will be either zero or one pending request.
Guard with(pending_requests_access_);
EnterDebuggerContext enter;
// Get the current execution state.
bool caught_exception;
Handle<Object> exec_state = MakeExecutionState(&caught_exception);
if (caught_exception) {
return false;
}
// Process the list of pending requests.
bool plain_break = false;
PendingRequest* pending_request = pending_requests_head_;
if (pending_request == NULL) {
// If no pending commands plain break issued some other way (e.g. debugger
// statement).
plain_break = true;
}
while (pending_request != NULL) {
Handle<String> response = ProcessRequest(exec_state,
pending_request->request(),
false);
OnPendingRequestProcessed(response);
// Check whether one of the commands is a plain break request.
if (!plain_break) {
plain_break = IsPlainBreakRequest(pending_request->request());
}
// Move to the next item in the list.
PendingRequest* next = pending_request->next();
delete pending_request;
pending_request = next;
}
// List processed.
pending_requests_head_ = NULL;
pending_requests_tail_ = NULL;
return plain_break;
}
Handle<Object> Debugger::MakeJSObject(Vector<const char> constructor_name,
int argc, Object*** argv,
bool* caught_exception) {
ASSERT(Top::context() == *Debug::debug_context());
// Create the execution state object.
Handle<String> constructor_str = Factory::LookupSymbol(constructor_name);
Handle<Object> constructor(Top::global()->GetProperty(*constructor_str));
ASSERT(constructor->IsJSFunction());
if (!constructor->IsJSFunction()) {
*caught_exception = true;
return Factory::undefined_value();
}
Handle<Object> js_object = Execution::TryCall(
Handle<JSFunction>::cast(constructor),
Handle<JSObject>(Debug::debug_context()->global()), argc, argv,
caught_exception);
return js_object;
}
Handle<Object> Debugger::MakeExecutionState(bool* caught_exception) {
// Create the execution state object.
Handle<Object> break_id = Factory::NewNumberFromInt(Top::break_id());
const int argc = 1;
Object** argv[argc] = { break_id.location() };
return MakeJSObject(CStrVector("MakeExecutionState"),
argc, argv, caught_exception);
}
Handle<Object> Debugger::MakeBreakEvent(Handle<Object> exec_state,
Handle<Object> break_points_hit,
bool* caught_exception) {
// Create the new break event object.
const int argc = 2;
Object** argv[argc] = { exec_state.location(),
break_points_hit.location() };
return MakeJSObject(CStrVector("MakeBreakEvent"),
argc,
argv,
caught_exception);
}
Handle<Object> Debugger::MakeExceptionEvent(Handle<Object> exec_state,
Handle<Object> exception,
bool uncaught,
bool* caught_exception) {
// Create the new exception event object.
const int argc = 3;
Object** argv[argc] = { exec_state.location(),
exception.location(),
uncaught ? Factory::true_value().location() :
Factory::false_value().location()};
return MakeJSObject(CStrVector("MakeExceptionEvent"),
argc, argv, caught_exception);
}
Handle<Object> Debugger::MakeNewFunctionEvent(Handle<Object> function,
bool* caught_exception) {
// Create the new function event object.
const int argc = 1;
Object** argv[argc] = { function.location() };
return MakeJSObject(CStrVector("MakeNewFunctionEvent"),
argc, argv, caught_exception);
}
Handle<Object> Debugger::MakeCompileEvent(Handle<Script> script,
Handle<Object> script_function,
bool* caught_exception) {
// Create the compile event object.
Handle<Object> exec_state = MakeExecutionState(caught_exception);
Handle<Object> script_source(script->source());
Handle<Object> script_name(script->name());
const int argc = 3;
Object** argv[argc] = { script_source.location(),
script_name.location(),
script_function.location() };
return MakeJSObject(CStrVector("MakeCompileEvent"),
argc,
argv,
caught_exception);
}
Handle<String> Debugger::ProcessRequest(Handle<Object> exec_state,
Handle<Object> request,
bool stopped) {
// Get the function ProcessDebugRequest (declared in debug.js).
Handle<JSFunction> process_denbug_request =
Handle<JSFunction>(JSFunction::cast(
Debug::debug_context()->global()->GetProperty(
*Factory::LookupAsciiSymbol("ProcessDebugRequest"))));
// Call ProcessDebugRequest expect String result. The ProcessDebugRequest
// will never throw an exception (see debug.js).
bool has_pending_exception = false;
const int argc = 3;
Object** argv[argc] = { exec_state.location(),
request.location(),
stopped ? Factory::true_value().location() :
Factory::false_value().location()};
Handle<Object> result = Execution::Call(process_denbug_request,
Factory::undefined_value(),
argc, argv,
&has_pending_exception);
ASSERT(!has_pending_exception);
return Handle<String>::cast(result);
}
bool Debugger::IsPlainBreakRequest(Handle<Object> request) {
// Get the function IsPlainBreakRequest (defined in debug.js).
Handle<JSFunction> process_denbug_request =
Handle<JSFunction>(JSFunction::cast(
Debug::debug_context()->global()->GetProperty(
*Factory::LookupAsciiSymbol("IsPlainBreakRequest"))));
// Call ProcessDebugRequest expect String result.
bool has_pending_exception = false;
const int argc = 1;
Object** argv[argc] = { request.location() };
Handle<Object> result = Execution::Call(process_denbug_request,
Factory::undefined_value(),
argc, argv,
&has_pending_exception);
ASSERT(!has_pending_exception);
return *result == Heap::true_value();
}
void Debugger::OnException(Handle<Object> exception, bool uncaught) {
HandleScope scope;
// Bail out based on state or if there is no listener for this event
if (Debug::InDebugger()) return;
if (!Debugger::EventActive(v8::Exception)) return;
// Bail out if exception breaks are not active
if (uncaught) {
// Uncaught exceptions are reported by either flags.
if (!(Debug::break_on_uncaught_exception() ||
Debug::break_on_exception())) return;
} else {
// Caught exceptions are reported is activated.
if (!Debug::break_on_exception()) return;
}
// Enter the debugger.
SaveBreakFrame save;
EnterDebuggerContext enter;
// Clear all current stepping setup.
Debug::ClearStepping();
// Create the event data object.
bool caught_exception = false;
Handle<Object> exec_state = MakeExecutionState(&caught_exception);
Handle<Object> event_data;
if (!caught_exception) {
event_data = MakeExceptionEvent(exec_state, exception, uncaught,
&caught_exception);
}
// Bail out and don't call debugger if exception.
if (caught_exception) {
return;
}
// Process debug event
ProcessDebugEvent(v8::Exception, event_data);
// Return to continue execution from where the exception was thrown.
}
void Debugger::OnDebugBreak(Handle<Object> break_points_hit) {
HandleScope scope;
// Bail out if there is no listener for this event
if (!Debugger::EventActive(v8::Break)) return;
// Debugger must be entered in advance.
ASSERT(Top::context() == *Debug::debug_context());
// Create the event data object.
bool caught_exception = false;
Handle<Object> exec_state = MakeExecutionState(&caught_exception);
Handle<Object> event_data;
if (!caught_exception) {
event_data = MakeBreakEvent(exec_state, break_points_hit,
&caught_exception);
}
// Bail out and don't call debugger if exception.
if (caught_exception) {
return;
}
// Process debug event
ProcessDebugEvent(v8::Break, event_data);
}
void Debugger::OnBeforeCompile(Handle<Script> script) {
HandleScope scope;
// Bail out based on state or if there is no listener for this event
if (Debug::InDebugger()) return;
if (compiling_natives()) return;
if (!EventActive(v8::BeforeCompile)) return;
// Enter the debugger.
Debug::Load();
SaveBreakFrame save;
EnterDebuggerContext enter;
// Create the event data object.
bool caught_exception = false;
Handle<Object> event_data = MakeCompileEvent(script,
Factory::undefined_value(),
&caught_exception);
// Bail out and don't call debugger if exception.
if (caught_exception) {
return;
}
// Process debug event
ProcessDebugEvent(v8::BeforeCompile, event_data);
}
// Handle debugger actions when a new script is compiled.
void Debugger::OnAfterCompile(Handle<Script> script, Handle<JSFunction> fun) {
// No compile events while compiling natives.
if (compiling_natives()) return;
// No more to do if not debugging.
if (!debugger_active()) return;
HandleScope scope;
EnterDebuggerContext enter;
bool caught_exception = false;
// 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-delay.js).
Handle<Object> update_script_break_points =
Handle<Object>(Debug::debug_context()->global()->GetProperty(
*Factory::LookupAsciiSymbol("UpdateScriptBreakPoints")));
if (!update_script_break_points->IsJSFunction()) {
return;
}
ASSERT(update_script_break_points->IsJSFunction());
// Wrap the script object in a proper JS object before passing it
// to JavaScript.
Handle<JSValue> wrapper = GetScriptWrapper(script);
// Call UpdateScriptBreakPoints expect no exceptions.
const int argc = 1;
Object** argv[argc] = { reinterpret_cast<Object**>(wrapper.location()) };
Handle<Object> result = Execution::TryCall(
Handle<JSFunction>::cast(update_script_break_points),
Top::builtins(), argc, argv,
&caught_exception);
if (caught_exception) {
return;
}
// Bail out based on state or if there is no listener for this event
if (Debug::InDebugger()) return;
if (!Debugger::EventActive(v8::AfterCompile)) return;
// Create the compile state object.
Handle<Object> event_data = MakeCompileEvent(script,
Factory::undefined_value(),
&caught_exception);
// Bail out and don't call debugger if exception.
if (caught_exception) {
return;
}
// Process debug event
ProcessDebugEvent(v8::AfterCompile, event_data);
}
void Debugger::OnNewFunction(Handle<JSFunction> function) {
return;
HandleScope scope;
// Bail out based on state or if there is no listener for this event
if (Debug::InDebugger()) return;
if (compiling_natives()) return;
if (!Debugger::EventActive(v8::NewFunction)) return;
// Enter the debugger.
SaveBreakFrame save;
EnterDebuggerContext enter;
// Create the event object.
bool caught_exception = false;
Handle<Object> event_data = MakeNewFunctionEvent(function, &caught_exception);
// Bail out and don't call debugger if exception.
if (caught_exception) {
return;
}
// Process debug event.
ProcessDebugEvent(v8::NewFunction, event_data);
}
void Debugger::OnPendingRequestProcessed(Handle<Object> event_data) {
// Process debug event.
ProcessDebugEvent(v8::PendingRequestProcessed, event_data);
}
void Debugger::ProcessDebugEvent(v8::DebugEvent event,
Handle<Object> event_data) {
// Create the execution state.
bool caught_exception = false;
Handle<Object> exec_state = MakeExecutionState(&caught_exception);
if (caught_exception) {
return;
}
// First notify the builtin debugger.
if (message_thread_ != NULL) {
message_thread_->DebugEvent(event, exec_state, event_data);
}
// Notify registered debug event listeners. The list can contain both C and
// JavaScript functions.
v8::NeanderArray listeners(Factory::debug_event_listeners());
int length = listeners.length();
for (int i = 0; i < length; i++) {
if (listeners.get(i)->IsUndefined()) continue; // Skip deleted ones.
v8::NeanderObject listener(JSObject::cast(listeners.get(i)));
Handle<Object> callback_data(listener.get(1));
if (listener.get(0)->IsProxy()) {
// C debug event listener.
Handle<Proxy> callback_obj(Proxy::cast(listener.get(0)));
v8::DebugEventCallback callback =
FUNCTION_CAST<v8::DebugEventCallback>(callback_obj->proxy());
callback(event,
v8::Utils::ToLocal(Handle<JSObject>::cast(exec_state)),
v8::Utils::ToLocal(Handle<JSObject>::cast(event_data)),
v8::Utils::ToLocal(callback_data));
} else {
// JavaScript debug event listener.
ASSERT(listener.get(0)->IsJSFunction());
Handle<JSFunction> fun(JSFunction::cast(listener.get(0)));
// Invoke the JavaScript debug event listener.
const int argc = 4;
Object** argv[argc] = { Handle<Object>(Smi::FromInt(event)).location(),
exec_state.location(),
event_data.location(),
callback_data.location() };
Handle<Object> result = Execution::TryCall(fun, Top::global(),
argc, argv, &caught_exception);
if (caught_exception) {
// Silently ignore exceptions from debug event listeners.
}
}
}
}
void Debugger::SetMessageHandler(v8::DebugMessageHandler handler, void* data) {
debug_message_handler_ = handler;
debug_message_handler_data_ = data;
if (!message_thread_) {
message_thread_ = new DebugMessageThread();
message_thread_->Start();
}
UpdateActiveDebugger();
}
void Debugger::SendMessage(Vector< uint16_t> message) {
if (debug_message_handler_ != NULL) {
debug_message_handler_(message.start(), message.length(),
debug_message_handler_data_);
}
}
void Debugger::ProcessCommand(Vector<const uint16_t> command) {
if (message_thread_ != NULL) {
message_thread_->ProcessCommand(
Vector<uint16_t>(const_cast<uint16_t *>(command.start()),
command.length()));
}
}
void Debugger::UpdateActiveDebugger() {
v8::NeanderArray listeners(Factory::debug_event_listeners());
int length = listeners.length();
bool active_listener = false;
for (int i = 0; i < length && !active_listener; i++) {
active_listener = !listeners.get(i)->IsUndefined();
}
set_debugger_active((Debugger::message_thread_ != NULL &&
Debugger::debug_message_handler_ != NULL) ||
active_listener);
if (!debugger_active() && message_thread_)
message_thread_->OnDebuggerInactive();
}
DebugMessageThread::DebugMessageThread()
: host_running_(true),
event_json_(Vector<uint16_t>::empty()),
command_(Vector<uint16_t>::empty()),
result_(Vector<uint16_t>::empty()) {
command_received_ = OS::CreateSemaphore(0);
debug_event_ = OS::CreateSemaphore(0);
debug_command_ = OS::CreateSemaphore(0);
debug_result_ = OS::CreateSemaphore(0);
}
DebugMessageThread::~DebugMessageThread() {
}
void DebugMessageThread::SetEventJSON(Vector<uint16_t> event_json) {
SetVector(&event_json_, event_json);
}
void DebugMessageThread::SetEventJSONFromEvent(Handle<Object> event_data) {
v8::HandleScope scope;
// Call toJSONProtocol on the debug event object.
v8::Local<v8::Object> api_event_data =
v8::Utils::ToLocal(Handle<JSObject>::cast(event_data));
v8::Local<v8::String> fun_name = v8::String::New("toJSONProtocol");
v8::Local<v8::Function> fun =
v8::Function::Cast(*api_event_data->Get(fun_name));
v8::TryCatch try_catch;
v8::Local<v8::Value> json_result = *fun->Call(api_event_data, 0, NULL);
v8::Local<v8::String> json_result_string;
if (!try_catch.HasCaught()) {
if (!json_result->IsUndefined()) {
json_result_string = json_result->ToString();
if (FLAG_trace_debug_json) {
PrintLn(json_result_string);
}
v8::String::Value val(json_result_string);
Vector<uint16_t> str(reinterpret_cast<uint16_t*>(*val),
json_result_string->Length());
SetEventJSON(str);
} else {
SetEventJSON(Vector<uint16_t>::empty());
}
} else {
PrintLn(try_catch.Exception());
SetEventJSON(Vector<uint16_t>::empty());
}
}
void DebugMessageThread::SetCommand(Vector<uint16_t> command) {
SetVector(&command_, command);
}
void DebugMessageThread::SetResult(const char* result) {
int len = strlen(result);
uint16_t* tmp = NewArray<uint16_t>(len);
for (int i = 0; i < len; i++) {
tmp[i] = result[i];
}
SetResult(Vector<uint16_t>(tmp, len));
DeleteArray(tmp);
}
void DebugMessageThread::SetResult(Vector<uint16_t> result) {
SetVector(&result_, result);
}
void DebugMessageThread::SetVector(Vector<uint16_t>* vector,
Vector<uint16_t> value) {
// Deallocate current result.
if (!vector->is_empty()) {
vector->Dispose();
*vector = Vector<uint16_t>::empty();
}
// Allocate a copy of the new result.
if (!value.is_empty()) {
*vector = value.Clone();
}
}
// Compare a two byte string to an null terminated ASCII string.
bool DebugMessageThread::TwoByteEqualsAscii(Vector<uint16_t> two_byte,
const char* ascii) {
for (int i = 0; i < two_byte.length(); i++) {
if (ascii[i] == '\0') {
return false;
}
if (two_byte[i] != static_cast<uint16_t>(ascii[i])) {
return false;
}
}
return ascii[two_byte.length()] == '\0';
}
void DebugMessageThread::CommandResult(Vector<uint16_t> result) {
SetResult(result);
debug_result_->Signal();
}
void DebugMessageThread::Run() {
// Process commands and debug events.
while (true) {
// Set the current command prompt
Semaphore* sems[2];
sems[0] = command_received_;
sems[1] = debug_event_;
int signal = Select(2, sems).WaitSingle();
if (signal == 0) {
if (command_.length() > 0) {
HandleCommand();
if (result_.length() > 0) {
Debugger::SendMessage(result_);
SetResult(Vector<uint16_t>::empty());
}
}
} else {
// Send the the current event as JSON to the debugger.
Debugger::SendMessage(event_json_);
}
}
}
// This method is called by the V8 thread whenever a debug event occours in the
// vm.
void DebugMessageThread::DebugEvent(v8::DebugEvent event,
Handle<Object> exec_state,
Handle<Object> event_data) {
if (!Debug::Load()) {
return;
}
// Process the individual events.
bool interactive = false;
switch (event) {
case v8::Break:
interactive = true; // Break event is always interavtive
break;
case v8::Exception:
interactive = true; // Exception event is always interavtive
break;
case v8::BeforeCompile:
break;
case v8::AfterCompile:
break;
case v8::NewFunction:
break;
case v8::PendingRequestProcessed: {
// For a processed pending request the event_data is the JSON response
// string.
v8::Handle<v8::String> str =
v8::Handle<v8::String>(
Utils::ToLocal(Handle<String>::cast(event_data)));
v8::String::Value val(str);
SetEventJSON(Vector<uint16_t>(reinterpret_cast<uint16_t*>(*val),
str->Length()));
debug_event_->Signal();
break;
}
default:
UNREACHABLE();
}
// Done if not interactive.
if (!interactive) return;
// Get the DebugCommandProcessor.
v8::Local<v8::Object> api_exec_state =
v8::Utils::ToLocal(Handle<JSObject>::cast(exec_state));
v8::Local<v8::String> fun_name =
v8::String::New("debugCommandProcessor");
v8::Local<v8::Function> fun =
v8::Function::Cast(*api_exec_state->Get(fun_name));
v8::TryCatch try_catch;
v8::Local<v8::Object> cmd_processor =
v8::Object::Cast(*fun->Call(api_exec_state, 0, NULL));
if (try_catch.HasCaught()) {
PrintLn(try_catch.Exception());
return;
}
// Notify the debug session thread that a debug event has occoured.
host_running_ = false;
event_ = event;
SetEventJSONFromEvent(event_data);
debug_event_->Signal();
// Wait for commands from the debug session.
while (true) {
debug_command_->Wait();
ASSERT(!host_running_);
if (!Debugger::debugger_active()) {
host_running_ = true;
return;
}
// Invoke the JavaScript to convert the debug command line to a JSON
// request, invoke the JSON request and convert the JSON respose to a text
// representation.
v8::Local<v8::String> fun_name;
v8::Local<v8::Function> fun;
v8::Local<v8::Value> args[1];
v8::TryCatch try_catch;
fun_name = v8::String::New("processDebugCommand");
fun = v8::Function::Cast(*cmd_processor->Get(fun_name));
args[0] = v8::String::New(reinterpret_cast<uint16_t*>(command_.start()),
command_.length());
v8::Local<v8::Value> result_val = fun->Call(cmd_processor, 1, args);
// Get the result of the command.
v8::Local<v8::String> result_string;
bool running = false;
if (!try_catch.HasCaught()) {
// Get the result as an object.
v8::Local<v8::Object> result = v8::Object::Cast(*result_val);
// Log the JSON request/response.
if (FLAG_trace_debug_json) {
PrintLn(result->Get(v8::String::New("request")));
PrintLn(result->Get(v8::String::New("response")));
}
// Get the running state.
running = result->Get(v8::String::New("running"))->ToBoolean()->Value();
// Get result text.
v8::Local<v8::Value> text_result =
result->Get(v8::String::New("response"));
if (!text_result->IsUndefined()) {
result_string = text_result->ToString();
} else {
result_string = v8::String::New("");
}
} else {
// In case of failure the result text is the exception text.
result_string = try_catch.Exception()->ToString();
}
// Convert text result to C string.
v8::String::Value val(result_string);
Vector<uint16_t> str(reinterpret_cast<uint16_t*>(*val),
result_string->Length());
// Change the prompt if VM is running after this command.
if (running) {
host_running_ = true;
}
// Return the result.
CommandResult(str);
// Return from debug event processing is VM should be running.
if (running) {
return;
}
}
}
void DebugMessageThread::HandleCommand() {
// Handle the command.
if (TwoByteEqualsAscii(command_, "b") ||
TwoByteEqualsAscii(command_, "break")) {
v8::Debug::DebugBreak();
SetResult("request queued");
} else if (host_running_) {
// Send the JSON command to the running VM.
Debugger::DebugRequest(command_.start(), command_.length());
SetResult("request queued");
} else {
debug_command_->Signal();
debug_result_->Wait();
}
}
void DebugMessageThread::ProcessCommand(Vector<uint16_t> command) {
SetCommand(command);
command_received_->Signal();
}
void DebugMessageThread::OnDebuggerInactive() {
if (!host_running_) {
debug_command_->Signal();
SetResult("");
}
}
} } // namespace v8::internal
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