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2330 lines (2037 loc) · 83.8 KB
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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/debug/debug.h"
#include <memory>
#include "src/api.h"
#include "src/arguments.h"
#include "src/assembler-inl.h"
#include "src/bootstrapper.h"
#include "src/code-stubs.h"
#include "src/codegen.h"
#include "src/compilation-cache.h"
#include "src/compiler-dispatcher/optimizing-compile-dispatcher.h"
#include "src/compiler.h"
#include "src/debug/debug-evaluate.h"
#include "src/debug/liveedit.h"
#include "src/deoptimizer.h"
#include "src/execution.h"
#include "src/frames-inl.h"
#include "src/global-handles.h"
#include "src/globals.h"
#include "src/interpreter/interpreter.h"
#include "src/isolate-inl.h"
#include "src/list.h"
#include "src/log.h"
#include "src/messages.h"
#include "src/objects/debug-objects-inl.h"
#include "src/snapshot/natives.h"
#include "src/wasm/wasm-module.h"
#include "src/wasm/wasm-objects.h"
#include "include/v8-debug.h"
namespace v8 {
namespace internal {
Debug::Debug(Isolate* isolate)
: debug_context_(Handle<Context>()),
is_active_(false),
hook_on_function_call_(false),
is_suppressed_(false),
live_edit_enabled_(false),
break_disabled_(false),
break_points_active_(true),
break_on_exception_(false),
break_on_uncaught_exception_(false),
side_effect_check_failed_(false),
debug_info_list_(NULL),
feature_tracker_(isolate),
isolate_(isolate) {
ThreadInit();
}
BreakLocation BreakLocation::FromFrame(Handle<DebugInfo> debug_info,
JavaScriptFrame* frame) {
auto summary = FrameSummary::GetTop(frame).AsJavaScript();
int offset = summary.code_offset();
Handle<AbstractCode> abstract_code = summary.abstract_code();
BreakIterator it(debug_info);
it.SkipTo(BreakIndexFromCodeOffset(debug_info, abstract_code, offset));
return it.GetBreakLocation();
}
void BreakLocation::AllAtCurrentStatement(Handle<DebugInfo> debug_info,
JavaScriptFrame* frame,
List<BreakLocation>* result_out) {
auto summary = FrameSummary::GetTop(frame).AsJavaScript();
int offset = summary.code_offset();
Handle<AbstractCode> abstract_code = summary.abstract_code();
if (abstract_code->IsCode()) offset = offset - 1;
int statement_position;
{
BreakIterator it(debug_info);
it.SkipTo(BreakIndexFromCodeOffset(debug_info, abstract_code, offset));
statement_position = it.statement_position();
}
for (BreakIterator it(debug_info); !it.Done(); it.Next()) {
if (it.statement_position() == statement_position) {
result_out->Add(it.GetBreakLocation());
}
}
}
int BreakLocation::BreakIndexFromCodeOffset(Handle<DebugInfo> debug_info,
Handle<AbstractCode> abstract_code,
int offset) {
// Run through all break points to locate the one closest to the address.
int closest_break = 0;
int distance = kMaxInt;
DCHECK(0 <= offset && offset < abstract_code->Size());
for (BreakIterator it(debug_info); !it.Done(); it.Next()) {
// Check if this break point is closer that what was previously found.
if (it.code_offset() <= offset && offset - it.code_offset() < distance) {
closest_break = it.break_index();
distance = offset - it.code_offset();
// Check whether we can't get any closer.
if (distance == 0) break;
}
}
return closest_break;
}
bool BreakLocation::HasBreakPoint(Handle<DebugInfo> debug_info) const {
// First check whether there is a break point with the same source position.
if (!debug_info->HasBreakPoint(position_)) return false;
// Then check whether a break point at that source position would have
// the same code offset. Otherwise it's just a break location that we can
// step to, but not actually a location where we can put a break point.
DCHECK(abstract_code_->IsBytecodeArray());
BreakIterator it(debug_info);
it.SkipToPosition(position_);
return it.code_offset() == code_offset_;
}
debug::BreakLocationType BreakLocation::type() const {
switch (type_) {
case DEBUGGER_STATEMENT:
return debug::kDebuggerStatementBreakLocation;
case DEBUG_BREAK_SLOT_AT_CALL:
return debug::kCallBreakLocation;
case DEBUG_BREAK_SLOT_AT_RETURN:
return debug::kReturnBreakLocation;
default:
return debug::kCommonBreakLocation;
}
return debug::kCommonBreakLocation;
}
BreakIterator::BreakIterator(Handle<DebugInfo> debug_info)
: debug_info_(debug_info),
break_index_(-1),
source_position_iterator_(
debug_info->DebugBytecodeArray()->SourcePositionTable()) {
position_ = debug_info->shared()->start_position();
statement_position_ = position_;
// There is at least one break location.
DCHECK(!Done());
Next();
}
int BreakIterator::BreakIndexFromPosition(int source_position) {
int distance = kMaxInt;
int closest_break = break_index();
while (!Done()) {
int next_position = position();
if (source_position <= next_position &&
next_position - source_position < distance) {
closest_break = break_index();
distance = next_position - source_position;
// Check whether we can't get any closer.
if (distance == 0) break;
}
Next();
}
return closest_break;
}
void BreakIterator::Next() {
DisallowHeapAllocation no_gc;
DCHECK(!Done());
bool first = break_index_ == -1;
while (!Done()) {
if (!first) source_position_iterator_.Advance();
first = false;
if (Done()) return;
position_ = source_position_iterator_.source_position().ScriptOffset();
if (source_position_iterator_.is_statement()) {
statement_position_ = position_;
}
DCHECK(position_ >= 0);
DCHECK(statement_position_ >= 0);
DebugBreakType type = GetDebugBreakType();
if (type != NOT_DEBUG_BREAK) break;
}
break_index_++;
}
DebugBreakType BreakIterator::GetDebugBreakType() {
BytecodeArray* bytecode_array = debug_info_->OriginalBytecodeArray();
interpreter::Bytecode bytecode =
interpreter::Bytecodes::FromByte(bytecode_array->get(code_offset()));
if (bytecode == interpreter::Bytecode::kDebugger) {
return DEBUGGER_STATEMENT;
} else if (bytecode == interpreter::Bytecode::kReturn) {
return DEBUG_BREAK_SLOT_AT_RETURN;
} else if (interpreter::Bytecodes::IsCallOrConstruct(bytecode)) {
return DEBUG_BREAK_SLOT_AT_CALL;
} else if (source_position_iterator_.is_statement()) {
return DEBUG_BREAK_SLOT;
} else {
return NOT_DEBUG_BREAK;
}
}
void BreakIterator::SkipToPosition(int position) {
BreakIterator it(debug_info_);
SkipTo(it.BreakIndexFromPosition(position));
}
void BreakIterator::SetDebugBreak() {
DebugBreakType debug_break_type = GetDebugBreakType();
if (debug_break_type == DEBUGGER_STATEMENT) return;
DCHECK(debug_break_type >= DEBUG_BREAK_SLOT);
BytecodeArray* bytecode_array = debug_info_->DebugBytecodeArray();
interpreter::Bytecode bytecode =
interpreter::Bytecodes::FromByte(bytecode_array->get(code_offset()));
if (interpreter::Bytecodes::IsDebugBreak(bytecode)) return;
interpreter::Bytecode debugbreak =
interpreter::Bytecodes::GetDebugBreak(bytecode);
bytecode_array->set(code_offset(),
interpreter::Bytecodes::ToByte(debugbreak));
}
void BreakIterator::ClearDebugBreak() {
DebugBreakType debug_break_type = GetDebugBreakType();
if (debug_break_type == DEBUGGER_STATEMENT) return;
DCHECK(debug_break_type >= DEBUG_BREAK_SLOT);
BytecodeArray* bytecode_array = debug_info_->DebugBytecodeArray();
BytecodeArray* original = debug_info_->OriginalBytecodeArray();
bytecode_array->set(code_offset(), original->get(code_offset()));
}
BreakLocation BreakIterator::GetBreakLocation() {
Handle<AbstractCode> code(
AbstractCode::cast(debug_info_->DebugBytecodeArray()));
return BreakLocation(code, GetDebugBreakType(), code_offset(), position_);
}
void DebugFeatureTracker::Track(DebugFeatureTracker::Feature feature) {
uint32_t mask = 1 << feature;
// Only count one sample per feature and isolate.
if (bitfield_ & mask) return;
isolate_->counters()->debug_feature_usage()->AddSample(feature);
bitfield_ |= mask;
}
// 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_ = kNoSourcePosition;
thread_local_.last_frame_count_ = -1;
thread_local_.fast_forward_to_return_ = false;
thread_local_.ignore_step_into_function_ = Smi::kZero;
thread_local_.target_frame_count_ = -1;
thread_local_.return_value_ = Smi::kZero;
thread_local_.async_task_count_ = 0;
thread_local_.last_breakpoint_id_ = 0;
clear_suspended_generator();
thread_local_.restart_fp_ = nullptr;
base::Relaxed_Store(&thread_local_.current_debug_scope_,
static_cast<base::AtomicWord>(0));
UpdateHookOnFunctionCall();
}
char* Debug::ArchiveDebug(char* storage) {
// Simply reset state. Don't archive anything.
ThreadInit();
return storage + ArchiveSpacePerThread();
}
char* Debug::RestoreDebug(char* storage) {
// Simply reset state. Don't restore anything.
ThreadInit();
return storage + ArchiveSpacePerThread();
}
int Debug::ArchiveSpacePerThread() { return 0; }
void Debug::Iterate(RootVisitor* v) {
v->VisitRootPointer(Root::kDebug, &thread_local_.return_value_);
v->VisitRootPointer(Root::kDebug, &thread_local_.suspended_generator_);
v->VisitRootPointer(Root::kDebug, &thread_local_.ignore_step_into_function_);
}
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_ = global_handles->Create(debug_info).location();
}
DebugInfoListNode::~DebugInfoListNode() {
if (debug_info_ == nullptr) return;
GlobalHandles::Destroy(reinterpret_cast<Object**>(debug_info_));
debug_info_ = nullptr;
}
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);
PostponeInterruptsScope postpone(isolate_);
// Create the debugger context.
HandleScope scope(isolate_);
ExtensionConfiguration no_extensions;
// TODO(yangguo): we rely on the fact that first context snapshot is usable
// as debug context. This dependency is gone once we remove
// debug context completely.
static const int kFirstContextSnapshotIndex = 0;
Handle<Context> context = isolate_->bootstrapper()->CreateEnvironment(
MaybeHandle<JSGlobalProxy>(), v8::Local<ObjectTemplate>(), &no_extensions,
kFirstContextSnapshotIndex, v8::DeserializeEmbedderFieldsCallback(),
DEBUG_CONTEXT);
// Fail if no context could be created.
if (context.is_null()) return false;
debug_context_ = isolate_->global_handles()->Create(*context);
feature_tracker()->Track(DebugFeatureTracker::kActive);
return true;
}
void Debug::Unload() {
ClearAllBreakPoints();
ClearStepping();
RemoveDebugDelegate();
// Return debugger is not loaded.
if (!is_loaded()) return;
if (FLAG_block_coverage) RemoveAllCoverageInfos();
// Clear debugger context global handle.
GlobalHandles::Destroy(Handle<Object>::cast(debug_context_).location());
debug_context_ = Handle<Context>();
}
void Debug::Break(JavaScriptFrame* frame) {
// 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_);
DisableBreak no_recursive_break(this);
// Return if we fail to retrieve debug info.
Handle<JSFunction> function(frame->function());
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureBreakInfo(shared)) return;
Handle<DebugInfo> debug_info(shared->GetDebugInfo(), isolate_);
// Find the break location where execution has stopped.
BreakLocation location = BreakLocation::FromFrame(debug_info, frame);
// Find actual break points, if any, and trigger debug break event.
MaybeHandle<FixedArray> break_points_hit =
CheckBreakPoints(debug_info, &location);
if (!break_points_hit.is_null()) {
// Clear all current stepping setup.
ClearStepping();
// Notify the debug event listeners.
OnDebugBreak(break_points_hit.ToHandleChecked());
return;
}
// No break point. Check for stepping.
StepAction step_action = last_step_action();
int current_frame_count = CurrentFrameCount();
int target_frame_count = thread_local_.target_frame_count_;
int last_frame_count = thread_local_.last_frame_count_;
// StepOut at not return position was requested and return break locations
// were flooded with one shots.
if (thread_local_.fast_forward_to_return_) {
DCHECK(location.IsReturn());
// We have to ignore recursive calls to function.
if (current_frame_count > target_frame_count) return;
ClearStepping();
PrepareStep(StepOut);
return;
}
bool step_break = false;
switch (step_action) {
case StepNone:
return;
case StepOut:
// Step out should not break in a deeper frame than target frame.
if (current_frame_count > target_frame_count) return;
step_break = true;
break;
case StepNext:
// Step next should not break in a deeper frame than target frame.
if (current_frame_count > target_frame_count) return;
// Fall through.
case StepIn: {
FrameSummary summary = FrameSummary::GetTop(frame);
step_break = step_break || location.IsReturn() ||
current_frame_count != last_frame_count ||
thread_local_.last_statement_position_ !=
summary.SourceStatementPosition();
break;
}
}
// Clear all current stepping setup.
ClearStepping();
if (step_break) {
// Notify the debug event listeners.
OnDebugBreak(isolate_->factory()->empty_fixed_array());
} else {
// Re-prepare to continue.
PrepareStep(step_action);
}
}
// Find break point objects for this location, if any, and evaluate them.
// Return an array of break point objects that evaluated true, or an empty
// handle if none evaluated true.
MaybeHandle<FixedArray> Debug::CheckBreakPoints(Handle<DebugInfo> debug_info,
BreakLocation* location,
bool* has_break_points) {
bool has_break_points_to_check =
break_points_active_ && location->HasBreakPoint(debug_info);
if (has_break_points) *has_break_points = has_break_points_to_check;
if (!has_break_points_to_check) return {};
Handle<Object> break_point_objects =
debug_info->GetBreakPointObjects(location->position());
return Debug::GetHitBreakPointObjects(break_point_objects);
}
bool Debug::IsMutedAtCurrentLocation(JavaScriptFrame* frame) {
HandleScope scope(isolate_);
// A break location is considered muted if break locations on the current
// statement have at least one break point, and all of these break points
// evaluate to false. Aside from not triggering a debug break event at the
// break location, we also do not trigger one for debugger statements, nor
// an exception event on exception at this location.
FrameSummary summary = FrameSummary::GetTop(frame);
DCHECK(!summary.IsWasm());
Handle<JSFunction> function = summary.AsJavaScript().function();
if (!function->shared()->HasBreakInfo()) return false;
Handle<DebugInfo> debug_info(function->shared()->GetDebugInfo());
// Enter the debugger.
DebugScope debug_scope(this);
if (debug_scope.failed()) return false;
List<BreakLocation> break_locations;
BreakLocation::AllAtCurrentStatement(debug_info, frame, &break_locations);
bool has_break_points_at_all = false;
for (int i = 0; i < break_locations.length(); i++) {
bool has_break_points;
MaybeHandle<FixedArray> check_result =
CheckBreakPoints(debug_info, &break_locations[i], &has_break_points);
has_break_points_at_all |= has_break_points;
if (has_break_points && !check_result.is_null()) return false;
}
return has_break_points_at_all;
}
MaybeHandle<Object> Debug::CallFunction(const char* name, int argc,
Handle<Object> args[],
bool catch_exceptions) {
AllowJavascriptExecutionDebugOnly allow_script(isolate_);
PostponeInterruptsScope no_interrupts(isolate_);
AssertDebugContext();
Handle<JSReceiver> holder =
Handle<JSReceiver>::cast(isolate_->natives_utils_object());
Handle<JSFunction> fun = Handle<JSFunction>::cast(
JSReceiver::GetProperty(isolate_, holder, name).ToHandleChecked());
Handle<Object> undefined = isolate_->factory()->undefined_value();
if (catch_exceptions) {
MaybeHandle<Object> maybe_exception;
return Execution::TryCall(isolate_, fun, undefined, argc, args,
Execution::MessageHandling::kReport,
&maybe_exception);
} else {
return Execution::Call(isolate_, fun, undefined, argc, args);
}
}
// Check whether a single break point object is triggered.
bool Debug::CheckBreakPoint(Handle<Object> break_point_object) {
Factory* factory = isolate_->factory();
HandleScope scope(isolate_);
// TODO(kozyatinskiy): replace this if by DCHEK once the JS debug API has been
// removed.
if (break_point_object->IsBreakPoint()) {
Handle<BreakPoint> break_point =
Handle<BreakPoint>::cast(break_point_object);
if (!break_point->condition()->length()) return true;
Handle<String> condition(break_point->condition());
Handle<Object> result;
// Since we call CheckBreakpoint only for deoptimized frame on top of stack,
// we can use 0 as index of inlined frame.
if (!DebugEvaluate::Local(isolate_, break_frame_id(),
/* inlined_jsframe_index */ 0, condition, false)
.ToHandle(&result)) {
if (isolate_->has_pending_exception()) {
isolate_->clear_pending_exception();
}
return false;
}
return result->BooleanValue();
}
// Ignore check if break point object is not a JSObject.
if (!break_point_object->IsJSObject()) return true;
// Get the break id as an object.
Handle<Object> break_id = factory->NewNumberFromInt(Debug::break_id());
// Call IsBreakPointTriggered.
Handle<Object> argv[] = { break_id, break_point_object };
Handle<Object> result;
if (!CallFunction("IsBreakPointTriggered", arraysize(argv), argv)
.ToHandle(&result)) {
return false;
}
// Return whether the break point is triggered.
return result->IsTrue(isolate_);
}
bool Debug::SetBreakPoint(Handle<JSFunction> function,
Handle<Object> break_point_object,
int* source_position) {
HandleScope scope(isolate_);
// Make sure the function is compiled and has set up the debug info.
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureBreakInfo(shared)) return true;
CHECK(PrepareFunctionForBreakPoints(shared));
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
// Source positions starts with zero.
DCHECK(*source_position >= 0);
// Find the break point and change it.
*source_position = FindBreakablePosition(debug_info, *source_position);
DebugInfo::SetBreakPoint(debug_info, *source_position, break_point_object);
// At least one active break point now.
DCHECK(debug_info->GetBreakPointCount() > 0);
ClearBreakPoints(debug_info);
ApplyBreakPoints(debug_info);
feature_tracker()->Track(DebugFeatureTracker::kBreakPoint);
return true;
}
bool Debug::SetBreakPointForScript(Handle<Script> script,
Handle<Object> break_point_object,
int* source_position) {
if (script->type() == Script::TYPE_WASM) {
Handle<WasmCompiledModule> compiled_module(
WasmCompiledModule::cast(script->wasm_compiled_module()), isolate_);
return WasmCompiledModule::SetBreakPoint(compiled_module, source_position,
break_point_object);
}
HandleScope scope(isolate_);
// Obtain shared function info for the function.
Handle<Object> result =
FindSharedFunctionInfoInScript(script, *source_position);
if (result->IsUndefined(isolate_)) return false;
// Make sure the function has set up the debug info.
Handle<SharedFunctionInfo> shared = Handle<SharedFunctionInfo>::cast(result);
if (!EnsureBreakInfo(shared)) return false;
CHECK(PrepareFunctionForBreakPoints(shared));
// Find position within function. The script position might be before the
// source position of the first function.
if (shared->start_position() > *source_position) {
*source_position = shared->start_position();
}
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
// Find the break point and change it.
*source_position = FindBreakablePosition(debug_info, *source_position);
DebugInfo::SetBreakPoint(debug_info, *source_position, break_point_object);
// At least one active break point now.
DCHECK(debug_info->GetBreakPointCount() > 0);
ClearBreakPoints(debug_info);
ApplyBreakPoints(debug_info);
feature_tracker()->Track(DebugFeatureTracker::kBreakPoint);
return true;
}
int Debug::FindBreakablePosition(Handle<DebugInfo> debug_info,
int source_position) {
DCHECK(debug_info->HasDebugBytecodeArray());
BreakIterator it(debug_info);
it.SkipToPosition(source_position);
return it.position();
}
void Debug::ApplyBreakPoints(Handle<DebugInfo> debug_info) {
DisallowHeapAllocation no_gc;
if (debug_info->break_points()->IsUndefined(isolate_)) return;
FixedArray* break_points = debug_info->break_points();
for (int i = 0; i < break_points->length(); i++) {
if (break_points->get(i)->IsUndefined(isolate_)) continue;
BreakPointInfo* info = BreakPointInfo::cast(break_points->get(i));
if (info->GetBreakPointCount() == 0) continue;
DCHECK(debug_info->HasDebugBytecodeArray());
BreakIterator it(debug_info);
it.SkipToPosition(info->source_position());
it.SetDebugBreak();
}
}
void Debug::ClearBreakPoints(Handle<DebugInfo> debug_info) {
DisallowHeapAllocation no_gc;
DCHECK(debug_info->HasDebugBytecodeArray());
for (BreakIterator it(debug_info); !it.Done(); it.Next()) {
it.ClearDebugBreak();
}
}
void Debug::ClearBreakPoint(Handle<Object> break_point_object) {
HandleScope scope(isolate_);
for (DebugInfoListNode* node = debug_info_list_; node != NULL;
node = node->next()) {
Handle<Object> result =
DebugInfo::FindBreakPointInfo(node->debug_info(), break_point_object);
if (result->IsUndefined(isolate_)) continue;
Handle<DebugInfo> debug_info = node->debug_info();
if (DebugInfo::ClearBreakPoint(debug_info, break_point_object)) {
ClearBreakPoints(debug_info);
if (debug_info->GetBreakPointCount() == 0) {
RemoveBreakInfoAndMaybeFree(debug_info);
} else {
ApplyBreakPoints(debug_info);
}
return;
}
}
}
bool Debug::SetBreakpoint(Handle<Script> script, Handle<String> condition,
int* offset, int* id) {
*id = ++thread_local_.last_breakpoint_id_;
Handle<BreakPoint> breakpoint =
isolate_->factory()->NewBreakPoint(*id, condition);
return SetBreakPointForScript(script, breakpoint, offset);
}
void Debug::RemoveBreakpoint(int id) {
Handle<BreakPoint> breakpoint = isolate_->factory()->NewBreakPoint(
id, isolate_->factory()->empty_string());
ClearBreakPoint(breakpoint);
}
// Clear out all the debug break code.
void Debug::ClearAllBreakPoints() {
ClearAllDebugInfos([=](Handle<DebugInfo> info) {
ClearBreakPoints(info);
return info->ClearBreakInfo();
});
}
void Debug::FloodWithOneShot(Handle<SharedFunctionInfo> shared,
bool returns_only) {
if (IsBlackboxed(shared)) return;
// Make sure the function is compiled and has set up the debug info.
if (!EnsureBreakInfo(shared)) return;
CHECK(PrepareFunctionForBreakPoints(shared));
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
// Flood the function with break points.
DCHECK(debug_info->HasDebugBytecodeArray());
for (BreakIterator it(debug_info); !it.Done(); it.Next()) {
if (returns_only && !it.GetBreakLocation().IsReturn()) continue;
it.SetDebugBreak();
}
}
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_;
}
}
MaybeHandle<FixedArray> Debug::GetHitBreakPointObjects(
Handle<Object> break_point_objects) {
DCHECK(!break_point_objects->IsUndefined(isolate_));
if (!break_point_objects->IsFixedArray()) {
if (!CheckBreakPoint(break_point_objects)) return {};
Handle<FixedArray> break_points_hit = isolate_->factory()->NewFixedArray(1);
break_points_hit->set(0, *break_point_objects);
return break_points_hit;
}
Handle<FixedArray> array(FixedArray::cast(*break_point_objects));
int num_objects = array->length();
Handle<FixedArray> break_points_hit =
isolate_->factory()->NewFixedArray(num_objects);
int break_points_hit_count = 0;
for (int i = 0; i < num_objects; ++i) {
Handle<Object> break_point_object(array->get(i), isolate_);
if (CheckBreakPoint(break_point_object)) {
break_points_hit->set(break_points_hit_count++, *break_point_object);
}
}
if (break_points_hit_count == 0) return {};
break_points_hit->Shrink(break_points_hit_count);
return break_points_hit;
}
void Debug::PrepareStepIn(Handle<JSFunction> function) {
CHECK(last_step_action() >= StepIn);
if (ignore_events()) return;
if (in_debug_scope()) return;
if (break_disabled()) return;
Handle<SharedFunctionInfo> shared(function->shared());
if (IsBlackboxed(shared)) return;
if (*function == thread_local_.ignore_step_into_function_) return;
thread_local_.ignore_step_into_function_ = Smi::kZero;
FloodWithOneShot(Handle<SharedFunctionInfo>(function->shared(), isolate_));
}
void Debug::PrepareStepInSuspendedGenerator() {
CHECK(has_suspended_generator());
if (ignore_events()) return;
if (in_debug_scope()) return;
if (break_disabled()) return;
thread_local_.last_step_action_ = StepIn;
UpdateHookOnFunctionCall();
Handle<JSFunction> function(
JSGeneratorObject::cast(thread_local_.suspended_generator_)->function());
FloodWithOneShot(Handle<SharedFunctionInfo>(function->shared(), isolate_));
clear_suspended_generator();
}
void Debug::PrepareStepOnThrow() {
if (last_step_action() == StepNone) return;
if (ignore_events()) return;
if (in_debug_scope()) return;
if (break_disabled()) return;
ClearOneShot();
int current_frame_count = CurrentFrameCount();
// Iterate through the JavaScript stack looking for handlers.
JavaScriptFrameIterator it(isolate_);
while (!it.done()) {
JavaScriptFrame* frame = it.frame();
if (frame->LookupExceptionHandlerInTable(nullptr, nullptr) > 0) break;
std::vector<SharedFunctionInfo*> infos;
frame->GetFunctions(&infos);
current_frame_count -= infos.size();
it.Advance();
}
// No handler found. Nothing to instrument.
if (it.done()) return;
bool found_handler = false;
// Iterate frames, including inlined frames. First, find the handler frame.
// Then skip to the frame we want to break in, then instrument for stepping.
for (; !it.done(); it.Advance()) {
JavaScriptFrame* frame = JavaScriptFrame::cast(it.frame());
if (last_step_action() == StepIn) {
// Deoptimize frame to ensure calls are checked for step-in.
Deoptimizer::DeoptimizeFunction(frame->function());
}
std::vector<FrameSummary> summaries;
frame->Summarize(&summaries);
for (size_t i = summaries.size(); i != 0; i--, current_frame_count--) {
const FrameSummary& summary = summaries[i - 1];
if (!found_handler) {
// We have yet to find the handler. If the frame inlines multiple
// functions, we have to check each one for the handler.
// If it only contains one function, we already found the handler.
if (summaries.size() > 1) {
Handle<AbstractCode> code = summary.AsJavaScript().abstract_code();
CHECK_EQ(AbstractCode::INTERPRETED_FUNCTION, code->kind());
BytecodeArray* bytecode = code->GetBytecodeArray();
HandlerTable* table = HandlerTable::cast(bytecode->handler_table());
int code_offset = summary.code_offset();
HandlerTable::CatchPrediction prediction;
int index = table->LookupRange(code_offset, nullptr, &prediction);
if (index > 0) found_handler = true;
} else {
found_handler = true;
}
}
if (found_handler) {
// We found the handler. If we are stepping next or out, we need to
// iterate until we found the suitable target frame to break in.
if ((last_step_action() == StepNext || last_step_action() == StepOut) &&
current_frame_count > thread_local_.target_frame_count_) {
continue;
}
Handle<SharedFunctionInfo> info(
summary.AsJavaScript().function()->shared());
if (IsBlackboxed(info)) continue;
FloodWithOneShot(info);
return;
}
}
}
}
void Debug::PrepareStep(StepAction step_action) {
HandleScope scope(isolate_);
DCHECK(in_debug_scope());
// 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 frame_id = break_frame_id();
// If there is no JavaScript stack don't do anything.
if (frame_id == StackFrame::NO_ID) return;
feature_tracker()->Track(DebugFeatureTracker::kStepping);
thread_local_.last_step_action_ = step_action;
StackTraceFrameIterator frames_it(isolate_, frame_id);
StandardFrame* frame = frames_it.frame();
// Handle stepping in wasm functions via the wasm interpreter.
if (frame->is_wasm()) {
// If the top frame is compiled, we cannot step.
if (frame->is_wasm_compiled()) return;
WasmInterpreterEntryFrame* wasm_frame =
WasmInterpreterEntryFrame::cast(frame);
wasm_frame->wasm_instance()->debug_info()->PrepareStep(step_action);
return;
}
JavaScriptFrame* js_frame = JavaScriptFrame::cast(frame);
DCHECK(js_frame->function()->IsJSFunction());
// Get the debug info (create it if it does not exist).
auto summary = FrameSummary::GetTop(frame).AsJavaScript();
Handle<JSFunction> function(summary.function());
Handle<SharedFunctionInfo> shared(function->shared());
if (!EnsureBreakInfo(shared)) return;
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
BreakLocation location = BreakLocation::FromFrame(debug_info, js_frame);
// Any step at a return is a step-out and we need to schedule DebugOnFunction
// call callback.
if (location.IsReturn()) {
// On StepOut we'll ignore our further calls to current function in
// PrepareStepIn callback.
if (last_step_action() == StepOut) {
thread_local_.ignore_step_into_function_ = *function;
}
step_action = StepOut;
thread_local_.last_step_action_ = StepIn;
}
UpdateHookOnFunctionCall();
// A step-next in blackboxed function is a step-out.
if (step_action == StepNext && IsBlackboxed(shared)) step_action = StepOut;
thread_local_.last_statement_position_ =
summary.abstract_code()->SourceStatementPosition(summary.code_offset());
int current_frame_count = CurrentFrameCount();
thread_local_.last_frame_count_ = current_frame_count;
// No longer perform the current async step.
clear_suspended_generator();
switch (step_action) {
case StepNone:
UNREACHABLE();
break;
case StepOut: {
// Clear last position info. For stepping out it does not matter.
thread_local_.last_statement_position_ = kNoSourcePosition;
thread_local_.last_frame_count_ = -1;
if (!location.IsReturn() && !IsBlackboxed(shared)) {
// At not return position we flood return positions with one shots and
// will repeat StepOut automatically at next break.
thread_local_.target_frame_count_ = current_frame_count;
thread_local_.fast_forward_to_return_ = true;
FloodWithOneShot(shared, true);
return;
}
// Skip the current frame, find the first frame we want to step out to
// and deoptimize every frame along the way.
bool in_current_frame = true;
for (; !frames_it.done(); frames_it.Advance()) {
// TODO(clemensh): Implement stepping out from JS to wasm.
if (frames_it.frame()->is_wasm()) continue;
JavaScriptFrame* frame = JavaScriptFrame::cast(frames_it.frame());
if (last_step_action() == StepIn) {
// Deoptimize frame to ensure calls are checked for step-in.
Deoptimizer::DeoptimizeFunction(frame->function());
}
HandleScope scope(isolate_);
std::vector<Handle<SharedFunctionInfo>> infos;
frame->GetFunctions(&infos);
for (; !infos.empty(); current_frame_count--) {
Handle<SharedFunctionInfo> info = infos.back();
infos.pop_back();
if (in_current_frame) {
// We want to skip out, so skip the current frame.
in_current_frame = false;
continue;
}
if (IsBlackboxed(info)) continue;
FloodWithOneShot(info);
thread_local_.target_frame_count_ = current_frame_count;
return;
}
}
break;
}
case StepNext:
thread_local_.target_frame_count_ = current_frame_count;
// Fall through.
case StepIn:
// TODO(clemensh): Implement stepping from JS into wasm.
FloodWithOneShot(shared);
break;
}
}
// Simple function for returning the source positions for active break points.
Handle<Object> Debug::GetSourceBreakLocations(
Handle<SharedFunctionInfo> shared) {
Isolate* isolate = shared->GetIsolate();
if (!shared->HasBreakInfo()) {
return isolate->factory()->undefined_value();
}
Handle<DebugInfo> debug_info(shared->GetDebugInfo());
if (debug_info->GetBreakPointCount() == 0) {
return isolate->factory()->undefined_value();
}
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(isolate)) {
BreakPointInfo* break_point_info =
BreakPointInfo::cast(debug_info->break_points()->get(i));
int break_points = break_point_info->GetBreakPointCount();
if (break_points == 0) continue;
for (int j = 0; j < break_points; ++j) {
locations->set(count++,
Smi::FromInt(break_point_info->source_position()));
}
}
}
return locations;
}