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dart/sdk/e5e85af5a1141ed11fe2a94de6502ebbcd66ae69/./runtime/vm/debugger.cc
blob: 3f62815675cca43377d2fdfbc8c9bd05accda7a3 [file]
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/debugger.h"
#include "include/dart_api.h"
#include "vm/bytecode_reader.h"
#include "vm/closure_functions_cache.h"
#include "vm/code_descriptors.h"
#include "vm/code_patcher.h"
#include "vm/compiler/api/deopt_id.h"
#include "vm/compiler/assembler/disassembler.h"
#include "vm/compiler/assembler/disassembler_kbc.h"
#include "vm/compiler/jit/compiler.h"
#include "vm/dart_entry.h"
#include "vm/flags.h"
#include "vm/globals.h"
#include "vm/isolate_reload.h"
#include "vm/json_stream.h"
#include "vm/kernel.h"
#include "vm/longjump.h"
#include "vm/message_handler.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/os.h"
#include "vm/parser.h"
#include "vm/port.h"
#include "vm/runtime_entry.h"
#include "vm/service.h"
#include "vm/service_event.h"
#include "vm/service_isolate.h"
#include "vm/stack_frame.h"
#include "vm/stack_trace.h"
#include "vm/stub_code.h"
#include "vm/symbols.h"
#include "vm/thread_interrupter.h"
#include "vm/timeline.h"
#include "vm/token_position.h"
#include "vm/visitor.h"
#include "vm/zone_text_buffer.h"
#if !defined(DART_PRECOMPILED_RUNTIME)
#include "vm/deopt_instructions.h"
#endif // !defined(DART_PRECOMPILED_RUNTIME)
namespace dart {
DEFINE_FLAG(bool,
trace_debugger_stacktrace,
false,
"Trace debugger stacktrace collection");
DEFINE_FLAG(bool,
trace_debugger_stacktrace_verbose,
false,
"Additional output when tracing debugger stacktraces");
DEFINE_FLAG(bool, trace_rewind, false, "Trace frame rewind");
DEFINE_FLAG(bool, verbose_debug, false, "Verbose debugger messages");
DECLARE_FLAG(bool, trace_deoptimization);
DECLARE_FLAG(bool, warn_on_pause_with_no_debugger);
#ifndef PRODUCT
// Create an unresolved breakpoint in given token range and script.
BreakpointLocation::BreakpointLocation(
Debugger* debugger,
const GrowableHandlePtrArray<const Script>& scripts,
TokenPosition token_pos,
TokenPosition end_token_pos,
intptr_t requested_line_number,
intptr_t requested_column_number)
: debugger_(debugger),
scripts_(MallocGrowableArray<ScriptPtr>(scripts.length())),
url_(scripts.At(0).url()),
line_number_lock_(new SafepointRwLock()),
line_number_(-1), // lazily computed
token_pos_(token_pos),
end_token_pos_(end_token_pos),
next_(nullptr),
conditions_(nullptr),
requested_line_number_(requested_line_number),
requested_column_number_(requested_column_number),
code_token_pos_(TokenPosition::kNoSource) {
ASSERT(scripts.length() > 0);
ASSERT(token_pos.IsReal());
for (intptr_t i = 0; i < scripts.length(); ++i) {
scripts_.Add(scripts.At(i).ptr());
}
}
// Create a latent breakpoint at given url and line number.
BreakpointLocation::BreakpointLocation(Debugger* debugger,
const String& url,
intptr_t requested_line_number,
intptr_t requested_column_number)
: debugger_(debugger),
scripts_(MallocGrowableArray<ScriptPtr>(0)),
url_(url.ptr()),
line_number_lock_(new SafepointRwLock()),
line_number_(-1), // lazily computed
token_pos_(TokenPosition::kNoSource),
end_token_pos_(TokenPosition::kNoSource),
next_(nullptr),
conditions_(nullptr),
requested_line_number_(requested_line_number),
requested_column_number_(requested_column_number),
code_token_pos_(TokenPosition::kNoSource) {
ASSERT(requested_line_number_ >= 0);
}
BreakpointLocation::~BreakpointLocation() {
Breakpoint* bpt = breakpoints();
while (bpt != nullptr) {
Breakpoint* temp = bpt;
bpt = bpt->next();
delete temp;
}
}
bool BreakpointLocation::AnyEnabled() const {
Breakpoint* bpt = breakpoints();
while (bpt != nullptr) {
if (bpt->is_enabled()) {
return true;
}
bpt = bpt->next();
}
return false;
}
void BreakpointLocation::SetResolved(const Function& func,
TokenPosition token_pos) {
#if defined(DEBUG)
const Script& func_script = Script::Handle(func.script());
const String& func_url = String::Handle(func_script.url());
const String& script_url = String::Handle(url_);
ASSERT(script_url.Equals(func_url));
#endif // defined(DEBUG)
ASSERT(!IsLatent());
ASSERT(token_pos.IsWithin(func.token_pos(), func.end_token_pos()));
ASSERT(func.is_debuggable());
token_pos_.store(token_pos);
end_token_pos_.store(token_pos);
code_token_pos_ = token_pos;
}
void BreakpointLocation::GetCodeLocation(Script* script,
TokenPosition* pos) const {
if (IsLatent()) {
*script = Script::null();
*pos = TokenPosition::kNoSource;
} else {
*script = this->script();
*pos = token_pos_;
}
}
intptr_t BreakpointLocation::line_number() {
// Compute line number lazily since it causes scanning of the script.
{
SafepointReadRwLocker sl(Thread::Current(), line_number_lock());
if (line_number_ >= 0) {
return line_number_;
}
}
SafepointWriteRwLocker sl(Thread::Current(), line_number_lock());
if (line_number_ < 0) {
Script::Handle(script()).GetTokenLocation(token_pos(), &line_number_);
}
return line_number_;
}
void Breakpoint::set_bpt_location(BreakpointLocation* new_bpt_location) {
// Only latent breakpoints can be moved.
ASSERT((new_bpt_location == nullptr) || bpt_location_->IsLatent());
bpt_location_ = new_bpt_location;
}
void Breakpoint::VisitObjectPointers(ObjectPointerVisitor* visitor) {
visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&closure_));
}
void BreakpointLocation::VisitObjectPointers(ObjectPointerVisitor* visitor) {
for (intptr_t i = 0; i < scripts_.length(); ++i) {
visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&scripts_.data()[i]));
}
visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&url_));
Breakpoint* bpt = conditions_;
while (bpt != nullptr) {
bpt->VisitObjectPointers(visitor);
bpt = bpt->next();
}
}
void Breakpoint::PrintJSON(JSONStream* stream) {
JSONObject jsobj(stream);
jsobj.AddProperty("type", "Breakpoint");
jsobj.AddFixedServiceId("breakpoints/%" Pd "", id());
jsobj.AddProperty("enabled", enabled_);
jsobj.AddProperty("breakpointNumber", id());
jsobj.AddProperty("resolved", bpt_location_->IsResolved());
if (bpt_location_->IsResolved()) {
jsobj.AddLocation(bpt_location_);
} else {
jsobj.AddUnresolvedLocation(bpt_location_);
}
}
void CodeBreakpoint::VisitObjectPointers(ObjectPointerVisitor* visitor) {
visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&code_));
visitor->VisitPointer(reinterpret_cast<ObjectPtr*>(&saved_value_));
}
const char* CodeBreakpoint::ToCString() const {
if (breakpoint_locations_.length() == 0) {
return "unlinked breakpoint";
}
char buffer[1024];
BufferFormatter f(buffer, sizeof(buffer));
// Pick the first, all other should have same script/line number.
BreakpointLocation* breakpoint_location = breakpoint_locations_.At(0);
String& source_url = String::Handle(breakpoint_location->url());
intptr_t line_number = breakpoint_location->line_number();
f.Printf("breakpoint at %s:%" Pd, source_url.ToCString(), line_number);
return Thread::Current()->zone()->MakeCopyOfString(buffer);
}
ActivationFrame::ActivationFrame(uword pc,
uword fp,
uword sp,
const Function& function,
const Object& code_or_bytecode,
const Array& deopt_frame,
intptr_t deopt_frame_offset)
: pc_(pc),
fp_(fp),
sp_(sp),
code_or_bytecode_(Object::ZoneHandle(code_or_bytecode.ptr())),
function_(Function::ZoneHandle(function.ptr())),
closure_(Closure::null_closure()),
deopt_frame_(Array::ZoneHandle(deopt_frame.ptr())),
deopt_frame_offset_(deopt_frame_offset),
kind_(kRegular),
desc_indices_(8),
pc_desc_(PcDescriptors::ZoneHandle()) {
ASSERT(!function.IsNull());
ASSERT(code_or_bytecode.IsCode() || code_or_bytecode.IsBytecode());
}
ActivationFrame::ActivationFrame(uword pc,
const Function& function,
const Object& code_or_bytecode,
const Closure& closure)
: pc_(pc),
code_or_bytecode_(Object::ZoneHandle(code_or_bytecode.ptr())),
function_(Function::ZoneHandle(function.ptr())),
closure_(Closure::ZoneHandle(closure.ptr())),
deopt_frame_(Array::empty_array()),
deopt_frame_offset_(0),
kind_(kAsyncAwaiter) {
ASSERT(code_or_bytecode.IsCode() || code_or_bytecode.IsBytecode());
}
ActivationFrame::ActivationFrame(Kind kind)
: code_or_bytecode_(Object::null_object()),
function_(Function::null_function()),
closure_(Closure::null_closure()),
deopt_frame_(Array::empty_array()),
deopt_frame_offset_(0),
kind_(kind) {
ASSERT(kind == kAsyncSuspensionMarker);
}
bool Debugger::NeedsIsolateEvents() {
ASSERT(isolate_ == Isolate::Current());
return !Isolate::IsSystemIsolate(isolate_) &&
Service::isolate_stream.enabled();
}
bool Debugger::NeedsDebugEvents() {
if (Isolate::Current() == nullptr) {
// E.g., NoActiveIsolateScope.
return false;
}
RELEASE_ASSERT(isolate_ == Isolate::Current());
ASSERT(!Isolate::IsSystemIsolate(isolate_));
return FLAG_warn_on_pause_with_no_debugger || Service::debug_stream.enabled();
}
static void InvokeEventHandler(ServiceEvent* event) {
ASSERT(!event->IsPause()); // For pause events, call Pause instead.
Service::HandleEvent(event, /*enter_safepoint*/ false);
}
ErrorPtr Debugger::PauseInterrupted() {
return PauseRequest(ServiceEvent::kPauseInterrupted);
}
ErrorPtr Debugger::PausePostRequest() {
return PauseRequest(ServiceEvent::kPausePostRequest);
}
ErrorPtr Debugger::PauseRequest(ServiceEvent::EventKind kind) {
if (ignore_breakpoints_ || IsPaused()) {
// We don't let the isolate get interrupted if we are already
// paused or ignoring breakpoints.
return Thread::Current()->StealStickyError();
}
ServiceEvent event(isolate_, kind);
DebuggerStackTrace* trace = DebuggerStackTrace::Collect();
if (trace->Length() > 0) {
event.set_top_frame(trace->FrameAt(0));
}
CacheStackTraces(trace, DebuggerStackTrace::CollectAsyncAwaiters());
set_resume_action(kContinue);
Pause(&event);
HandleSteppingRequest();
ClearCachedStackTraces();
// If any error occurred while in the debug message loop, return it here.
NoSafepointScope no_safepoint;
ErrorPtr error = Thread::Current()->StealStickyError();
ASSERT((error == Error::null()) || error->IsUnwindError());
return error;
}
void Debugger::SendBreakpointEvent(ServiceEvent::EventKind kind,
Breakpoint* bpt) {
if (NeedsDebugEvents()) {
// TODO(turnidge): Currently we send single-shot breakpoint events
// to the vm service. Do we want to change this?
ServiceEvent event(isolate_, kind);
event.set_breakpoint(bpt);
InvokeEventHandler(&event);
}
}
void BreakpointLocation::AddBreakpoint(Breakpoint* bpt, Debugger* dbg) {
bpt->set_next(breakpoints());
set_breakpoints(bpt);
bpt->Enable();
dbg->group_debugger()->SyncBreakpointLocation(this);
dbg->SendBreakpointEvent(ServiceEvent::kBreakpointAdded, bpt);
}
Breakpoint* BreakpointLocation::AddRepeated(Debugger* dbg) {
return AddBreakpoint(dbg, Closure::Handle(), /*single_shot=*/false);
}
Breakpoint* BreakpointLocation::AddSingleShot(Debugger* dbg) {
return AddBreakpoint(dbg, Closure::Handle(), /*single_shot=*/true);
}
Breakpoint* BreakpointLocation::AddBreakpoint(Debugger* dbg,
const Closure& closure,
bool single_shot) {
Breakpoint* bpt = breakpoints();
while (bpt != nullptr) {
if ((bpt->closure() == closure.ptr()) &&
(bpt->is_single_shot() == single_shot)) {
break;
}
bpt = bpt->next();
}
if (bpt == nullptr) {
bpt = new Breakpoint(dbg->nextId(), this, single_shot, closure);
AddBreakpoint(bpt, dbg);
}
return bpt;
}
static const char* QualifiedFunctionName(const Function& func) {
const String& func_name = String::Handle(func.name());
Class& func_class = Class::Handle(func.Owner());
String& class_name = String::Handle(func_class.Name());
return OS::SCreate(Thread::Current()->zone(), "%s%s%s",
func_class.IsTopLevel() ? "" : class_name.ToCString(),
func_class.IsTopLevel() ? "" : ".", func_name.ToCString());
}
// Returns true if the function |func| overlaps the token range
// [|token_pos|, |end_token_pos|] in |script|.
static bool FunctionOverlaps(const Function& func,
const String& script_url,
TokenPosition token_pos,
TokenPosition end_token_pos) {
const TokenPosition& func_start = func.token_pos();
if (token_pos.IsWithin(func_start, func.end_token_pos()) ||
func_start.IsWithin(token_pos, end_token_pos)) {
// Check script equality last because it allocates handles as a side effect.
Script& func_script = Script::Handle(func.script());
String& url = String::Handle(func_script.url());
return script_url.Equals(url);
}
return false;
}
static bool IsImplicitFunction(const Function& func) {
switch (func.kind()) {
case UntaggedFunction::kImplicitGetter:
case UntaggedFunction::kImplicitSetter:
case UntaggedFunction::kImplicitStaticGetter:
case UntaggedFunction::kFieldInitializer:
case UntaggedFunction::kMethodExtractor:
case UntaggedFunction::kNoSuchMethodDispatcher:
case UntaggedFunction::kInvokeFieldDispatcher:
case UntaggedFunction::kRecordFieldGetter:
return true;
default:
if (func.token_pos() == func.end_token_pos()) {
// |func| could be an implicit constructor for example.
return true;
}
}
return false;
}
bool GroupDebugger::HasCodeBreakpointInFunctionUnsafe(const Function& func) {
DEBUG_ASSERT(code_breakpoints_lock()->IsCurrentThreadReader() ||
Thread::Current()->IsInStoppedMutatorsScope());
CodeBreakpoint* cbpt = code_breakpoints_;
while (cbpt != nullptr) {
if (func.ptr() == cbpt->function()) {
return true;
}
cbpt = cbpt->next_;
}
return false;
}
bool GroupDebugger::HasCodeBreakpointInFunction(const Function& func) {
auto thread = Thread::Current();
// Don't need to worry about the lock if mutators are stopped.
if (thread->IsInStoppedMutatorsScope()) {
return HasCodeBreakpointInFunctionUnsafe(func);
} else {
SafepointReadRwLocker sl(thread, code_breakpoints_lock());
return HasCodeBreakpointInFunctionUnsafe(func);
}
}
bool GroupDebugger::HasBreakpointInCode(const Code& code) {
auto thread = Thread::Current();
SafepointReadRwLocker sl(thread, code_breakpoints_lock());
CodeBreakpoint* cbpt = code_breakpoints_;
while (cbpt != nullptr) {
if (code.ptr() == cbpt->code_) {
return true;
}
cbpt = cbpt->next_;
}
return false;
}
void Debugger::PrintBreakpointsToJSONArray(JSONArray* jsarr) const {
PrintBreakpointsListToJSONArray(breakpoint_locations_, jsarr);
PrintBreakpointsListToJSONArray(latent_locations_, jsarr);
}
void Debugger::PrintBreakpointsListToJSONArray(BreakpointLocation* sbpt,
JSONArray* jsarr) const {
while (sbpt != nullptr) {
Breakpoint* bpt = sbpt->breakpoints();
while (bpt != nullptr) {
jsarr->AddValue(bpt);
bpt = bpt->next();
}
sbpt = sbpt->next_;
}
}
void Debugger::PrintSettingsToJSONObject(JSONObject* jsobj) const {
// This won't cut it when we support filtering by class, etc.
switch (GetExceptionPauseInfo()) {
case kNoPauseOnExceptions:
jsobj->AddProperty("_exceptions", "none");
break;
case kPauseOnAllExceptions:
jsobj->AddProperty("_exceptions", "all");
break;
case kPauseOnUnhandledExceptions:
jsobj->AddProperty("_exceptions", "unhandled");
break;
default:
UNREACHABLE();
}
}
ActivationFrame::Relation ActivationFrame::CompareTo(bool is_interpreted,
uword fp,
uword other_fp) {
if (fp == other_fp) {
return kSelf;
}
#if defined(DART_DYNAMIC_MODULES)
if (is_interpreted) {
// Unlike compiled code, interpreted stacks grow towards higher addresses.
return fp > other_fp ? kCallee : kCaller;
}
#endif
return IsCalleeFrameOf(other_fp, fp) ? kCallee : kCaller;
}
StringPtr ActivationFrame::QualifiedFunctionName() {
return String::New(::dart::QualifiedFunctionName(function()));
}
StringPtr ActivationFrame::SourceUrl() {
const Script& script = Script::Handle(SourceScript());
return script.url();
}
ScriptPtr ActivationFrame::SourceScript() {
return function().script();
}
LibraryPtr ActivationFrame::Library() {
const Class& cls = Class::Handle(function().Owner());
return cls.library();
}
void ActivationFrame::GetPcDescriptors() {
ASSERT(!IsInterpreted());
if (pc_desc_.IsNull()) {
pc_desc_ = code().pc_descriptors();
ASSERT(!pc_desc_.IsNull());
}
}
// If not token_pos_initialized_, compute token_pos_, try_index_ and,
// if not IsInterpreted(), also compute deopt_id_.
TokenPosition ActivationFrame::TokenPos() {
if (!token_pos_initialized_) {
token_pos_ = TokenPosition::kNoSource;
if (IsInterpreted()) {
token_pos_ = bytecode().GetTokenIndexOfPC(pc_);
try_index_ = bytecode().GetTryIndexAtPc(pc_);
} else {
GetPcDescriptors();
PcDescriptors::Iterator iter(pc_desc_, UntaggedPcDescriptors::kAnyKind);
const uword pc_offset = pc_ - code().PayloadStart();
while (iter.MoveNext()) {
if (iter.PcOffset() == pc_offset) {
try_index_ = iter.TryIndex();
token_pos_ = iter.TokenPos();
deopt_id_ = iter.DeoptId();
break;
}
}
}
token_pos_initialized_ = true;
}
return token_pos_;
}
intptr_t ActivationFrame::TryIndex() {
if (!token_pos_initialized_) {
TokenPos(); // Side effect: computes token_pos_initialized_, try_index_.
}
return try_index_;
}
intptr_t ActivationFrame::DeoptId() {
ASSERT(!IsInterpreted());
if (!token_pos_initialized_) {
TokenPos(); // Side effect: computes token_pos_initialized_, try_index_.
}
return deopt_id_;
}
intptr_t ActivationFrame::LineNumber() {
// Compute line number lazily since it causes scanning of the script.
const TokenPosition& token_pos = TokenPos().ToRealIfSynthetic();
if ((line_number_ < 0) && token_pos.IsReal()) {
const Script& script = Script::Handle(SourceScript());
script.GetTokenLocation(token_pos, &line_number_, &column_number_);
}
return line_number_;
}
intptr_t ActivationFrame::ColumnNumber() {
// Compute column number lazily since it causes scanning of the script.
const TokenPosition& token_pos = TokenPos().ToRealIfSynthetic();
if ((column_number_ < 0) && token_pos.IsReal()) {
const Script& script = Script::Handle(SourceScript());
script.GetTokenLocation(token_pos, &line_number_, &column_number_);
}
return column_number_;
}
void ActivationFrame::GetVarDescriptors() {
if (var_descriptors_.IsNull()) {
if (IsInterpreted()) {
#if defined(DART_PRECOMPILED_RUNTIME)
UNREACHABLE();
#else
var_descriptors_ = bytecode().GetLocalVarDescriptors();
ASSERT(!var_descriptors_.IsNull());
#endif
return;
}
Code& unoptimized_code = Code::Handle(function().unoptimized_code());
if (unoptimized_code.IsNull()) {
if (function().ForceOptimize()) {
var_descriptors_ = Object::empty_var_descriptors().ptr();
return;
}
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
const Error& error = Error::Handle(
zone, Compiler::EnsureUnoptimizedCode(thread, function()));
if (!error.IsNull()) {
Exceptions::PropagateError(error);
}
unoptimized_code = function().unoptimized_code();
}
ASSERT(!unoptimized_code.IsNull());
var_descriptors_ = unoptimized_code.GetLocalVarDescriptors();
ASSERT(!var_descriptors_.IsNull());
}
}
bool ActivationFrame::IsDebuggable() const {
ASSERT(!function().IsNull());
return Debugger::IsDebuggable(function());
}
void ActivationFrame::PrintContextLevelError(const char* message) {
OS::PrintErr("Cannot locate context level: %s\n", message);
OS::PrintErr("function %s\n", function().ToQualifiedCString());
OS::PrintErr("pc_ %" Px "\n", pc_);
OS::PrintErr("deopt_id_ %" Px "\n", deopt_id_);
OS::PrintErr("context_level_ %" Px "\n", context_level_);
OS::PrintErr("token_pos_ %s\n", token_pos_.ToCString());
if (IsInterpreted() && bytecode().HasLocalVariablesInfo()) {
#if defined(DART_DYNAMIC_MODULES)
Zone* const zone = Thread::Current()->zone();
ZoneTextBuffer buffer(zone);
KernelBytecodeDisassembler::PrintLocalVariablesInfo(
zone, &buffer, bytecode(), PayloadStart());
OS::PrintErr("%s\n", buffer.buffer());
#endif
} else {
DisassembleToStdout formatter;
code().Disassemble(&formatter);
PcDescriptors::Handle(code().pc_descriptors()).Print();
}
StackFrameIterator frames(ValidationPolicy::kDontValidateFrames,
Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
StackFrame* frame = frames.NextFrame();
while (frame != nullptr) {
OS::PrintErr("%s\n", frame->ToCString());
frame = frames.NextFrame();
}
OS::Abort();
}
// Calculate the context level at the current pc of the frame.
intptr_t ActivationFrame::ContextLevel() {
ASSERT(kind_ == kRegular);
const Context& ctx = GetSavedCurrentContext();
if (context_level_ < 0 && !ctx.IsNull()) {
ASSERT(IsInterpreted() || !code().is_optimized());
bool found = false;
if (IsInterpreted()) {
#if defined(DART_DYNAMIC_MODULES) && !defined(PRODUCT) && \
!defined(DART_PRECOMPILED_RUNTIME)
const intptr_t pc_offset = pc() - PayloadStart();
DEBUG_ONLY(intptr_t closest_start = 0);
bytecode::BytecodeLocalVariablesIterator local_vars(
Thread::Current()->zone(), bytecode());
while (local_vars.MoveNext()) {
if (local_vars.IsScope()) {
if (local_vars.StartPC() <= pc_offset &&
pc_offset <= local_vars.EndPC()) {
DEBUG_ASSERT(!found || local_vars.StartPC() > closest_start);
found = true;
context_level_ = local_vars.ContextLevel();
DEBUG_ONLY(closest_start = local_vars.StartPC());
} else if (local_vars.StartPC() > pc_offset) {
// The scopes in the local variables info are ordered by starting
// PC offset, so no need to search further.
break;
}
}
}
if (!found) {
PrintContextLevelError(
"No Scope local variable info for the current PC");
}
#else
UNREACHABLE();
#endif
} else {
GetVarDescriptors();
intptr_t var_desc_len = var_descriptors_.Length();
// We store the deopt ids as real token positions.
intptr_t deopt_id = DeoptId();
if (deopt_id == DeoptId::kNone) {
PrintContextLevelError("Missing deopt id");
}
const TokenPosition to_compare = TokenPosition::Deserialize(deopt_id);
for (intptr_t cur_idx = 0; cur_idx < var_desc_len; cur_idx++) {
UntaggedLocalVarDescriptors::VarInfo var_info;
var_descriptors_.GetInfo(cur_idx, &var_info);
const int8_t kind = var_info.kind();
if ((kind == UntaggedLocalVarDescriptors::kContextLevel) &&
to_compare.IsWithin(var_info.begin_pos, var_info.end_pos)) {
context_level_ = var_info.index();
found = true;
break;
}
}
if (!found) {
PrintContextLevelError(
"No ContextLevel var descriptor that contains the deopt id");
}
}
ASSERT(context_level_ >= 0);
}
return context_level_;
}
bool ActivationFrame::HandlesException(const Instance& exc_obj) {
if (kind_ == kAsyncSuspensionMarker) {
return false;
}
intptr_t try_index = TryIndex();
auto& handlers = ExceptionHandlers::Handle();
if (IsInterpreted()) {
handlers = bytecode().exception_handlers();
} else {
handlers = code().exception_handlers();
}
ASSERT(!handlers.IsNull());
if ((try_index < 0) && !handlers.has_async_handler()) {
return false;
}
Array& handled_types = Array::Handle();
AbstractType& type = Type::Handle();
intptr_t num_handlers_checked = 0;
while (try_index != kInvalidTryIndex) {
// Detect circles in the exception handler data.
num_handlers_checked++;
ASSERT(num_handlers_checked <= handlers.num_entries());
// Only consider user written handlers and ignore synthesized try/catch in
// async methods as well as synthetic try/catch hiding inside try/finally.
if (!handlers.IsGenerated(try_index)) {
handled_types = handlers.GetHandledTypes(try_index);
const intptr_t num_types = handled_types.Length();
for (intptr_t k = 0; k < num_types; k++) {
type ^= handled_types.At(k);
ASSERT(!type.IsNull());
// Uninstantiated types are not added to ExceptionHandlers data.
ASSERT(type.IsInstantiated());
if (type.IsDynamicType()) {
return true;
}
if (exc_obj.IsInstanceOf(type, Object::null_type_arguments(),
Object::null_type_arguments())) {
return true;
}
}
}
try_index = handlers.OuterTryIndex(try_index);
}
return false;
}
// Get the saved current context of this activation.
const Context& ActivationFrame::GetSavedCurrentContext(intptr_t* index) {
// If the index of the variable was requested, do the retrieval again.
if (context_initialized_ && index == nullptr) return ctx_;
context_initialized_ = true;
GetVarDescriptors();
intptr_t var_desc_len = var_descriptors_.Length();
Object& obj = Object::Handle();
for (intptr_t i = 0; i < var_desc_len; i++) {
UntaggedLocalVarDescriptors::VarInfo var_info;
var_descriptors_.GetInfo(i, &var_info);
const int8_t kind = var_info.kind();
if (kind == UntaggedLocalVarDescriptors::kSavedCurrentContext) {
if (index != nullptr) {
*index = var_info.index();
}
const auto variable_index = VariableIndex(var_info.index());
obj = GetStackVar(variable_index);
if (function_.IsImplicitInstanceClosureFunction()) {
// The context of an implicit instance closure contains only one slot
// for "this", so the instance is stored as the context and accessed
// directly by generated code to avoid allocating a separate context.
// Here, we create the elided context object for debugging purposes.
ctx_ = Context::New(1);
ctx_.SetAt(0, obj);
} else if (obj.IsClosure()) {
ASSERT(function().IsClosureCallDispatcher());
// Closure.call frames.
ctx_ = Closure::Cast(obj).GetContext();
} else if (obj.IsContext()) {
ctx_ = Context::Cast(obj).ptr();
} else {
ASSERT(obj.IsNull() || obj.ptr() == Object::optimized_out().ptr());
ctx_ = Context::null();
}
return ctx_;
}
}
return ctx_;
}
ActivationFrame* DebuggerStackTrace::GetHandlerFrame(
const Instance& exc_obj) const {
if (FLAG_trace_debugger_stacktrace) {
OS::PrintErr("GetHandlerFrame(%s)\n", exc_obj.ToCString());
}
for (intptr_t frame_index = 0; frame_index < Length(); frame_index++) {
ActivationFrame* frame = FrameAt(frame_index);
const bool can_handle = frame->HandlesException(exc_obj);
if (FLAG_trace_debugger_stacktrace) {
OS::PrintErr(" #%04" Pd " (%s) %s", frame_index,
can_handle ? "+" : "-", frame->ToCString());
}
if (can_handle) {
return frame;
}
}
return nullptr;
}
void ActivationFrame::GetDescIndices() {
if (vars_initialized_) {
return;
}
GetVarDescriptors();
TokenPosition activation_token_pos = TokenPos();
if (!activation_token_pos.IsDebugPause() || kind_ != kRegular) {
// We don't have a token position for this frame, so can't determine
// which variables are visible.
vars_initialized_ = true;
return;
}
GrowableArray<String*> var_names(8);
intptr_t var_desc_len = var_descriptors_.Length();
for (intptr_t cur_idx = 0; cur_idx < var_desc_len; cur_idx++) {
ASSERT(var_names.length() == desc_indices_.length());
UntaggedLocalVarDescriptors::VarInfo var_info;
var_descriptors_.GetInfo(cur_idx, &var_info);
const int8_t kind = var_info.kind();
if ((kind != UntaggedLocalVarDescriptors::kStackVar) &&
(kind != UntaggedLocalVarDescriptors::kContextVar)) {
continue;
}
if (!activation_token_pos.IsWithin(var_info.begin_pos, var_info.end_pos)) {
continue;
}
if ((kind == UntaggedLocalVarDescriptors::kContextVar) &&
(ContextLevel() < var_info.scope_id)) {
// The variable is textually in scope but the context level
// at the activation frame's PC is lower than the context
// level of the variable. The context containing the variable
// has already been removed from the chain. This can happen when we
// break at a return statement, since the contexts get discarded
// before the debugger gets called.
continue;
}
// The current variable is textually in scope. Now check whether
// there is another local variable with the same name that shadows
// or is shadowed by this variable.
String& var_name = String::Handle(var_descriptors_.GetName(cur_idx));
intptr_t indices_len = desc_indices_.length();
bool name_match_found = false;
for (intptr_t i = 0; i < indices_len; i++) {
if (var_name.Equals(*var_names[i])) {
// Found two local variables with the same name. Now determine
// which one is shadowed.
name_match_found = true;
UntaggedLocalVarDescriptors::VarInfo i_var_info;
var_descriptors_.GetInfo(desc_indices_[i], &i_var_info);
if (i_var_info.begin_pos < var_info.begin_pos) {
// The variable we found earlier is in an outer scope
// and is shadowed by the current variable. Replace the
// descriptor index of the previously found variable
// with the descriptor index of the current variable.
desc_indices_[i] = cur_idx;
} else {
// The variable we found earlier is in an inner scope
// and shadows the current variable. Skip the current
// variable. (Nothing to do.)
}
break; // Stop looking for name matches.
}
}
if (!name_match_found) {
// No duplicate name found. Add the current descriptor index to the
// list of visible variables.
desc_indices_.Add(cur_idx);
var_names.Add(&var_name);
}
}
vars_initialized_ = true;
}
intptr_t ActivationFrame::NumLocalVariables() {
GetDescIndices();
return desc_indices_.length();
}
DART_FORCE_INLINE static ObjectPtr GetVariableValue(uword addr) {
return *reinterpret_cast<ObjectPtr*>(addr);
}
// Caution: GetParameter only works for fixed parameters.
ObjectPtr ActivationFrame::GetParameter(intptr_t index) {
intptr_t num_parameters = function().num_fixed_parameters();
ASSERT(0 <= index && index < num_parameters);
// fp will be a nullptr if the frame isn't active on the stack.
if (fp() == 0) {
return Object::null();
}
if (function().MakesCopyOfParameters()) {
// Function parameters are copied to a fixed place in the callee's frame.
if (function().IsSuspendableFunction()) {
++index; // Skip slot reserved for :suspend_state variable.
}
if (IsInterpreted()) {
return GetStackVar(VariableIndex(-index));
}
return GetVariableValue(LocalVarAddress(
fp(), runtime_frame_layout.FrameSlotForVariableIndex(-index)));
} else {
intptr_t reverse_index = num_parameters - index;
if (IsInterpreted()) {
return GetStackVar(VariableIndex(reverse_index));
}
return GetVariableValue(ParamAddress(fp(), reverse_index));
}
}
ClosurePtr ActivationFrame::GetClosure() {
ASSERT(function().IsClosureFunction());
Object& param = Object::Handle(GetParameter(0));
ASSERT(param.IsInstance());
ASSERT(Instance::Cast(param).IsClosure());
return Closure::Cast(param).ptr();
}
ObjectPtr ActivationFrame::GetSuspendStateVar() {
ASSERT(function().IsSuspendableFunction());
return GetStackVar(VariableIndex(SuspendState::kSuspendStateVarIndex));
}
ObjectPtr ActivationFrame::GetSuspendableFunctionData() {
Object& suspend_state = Object::Handle(GetSuspendStateVar());
if (suspend_state.IsSuspendState()) {
return SuspendState::Cast(suspend_state).function_data();
}
return suspend_state.ptr();
}
ObjectPtr ActivationFrame::GetStackVar(VariableIndex variable_index) {
if (IsInterpreted()) {
intptr_t slot_index = -variable_index.value();
if (slot_index < 0) {
slot_index -= kKBCParamEndSlotFromFp; // Accessing a parameter.
}
return GetVariableValue(fp() + slot_index * kWordSize);
}
const intptr_t slot_index =
runtime_frame_layout.FrameSlotForVariableIndex(variable_index.value());
if (deopt_frame_.IsNull()) {
return GetVariableValue(LocalVarAddress(fp(), slot_index));
} else {
return deopt_frame_.At(LocalVarIndex(deopt_frame_offset_, slot_index));
}
}
bool ActivationFrame::IsRewindable() const {
if (deopt_frame_.IsNull()) {
return true;
}
// TODO(turnidge): This is conservative. It looks at all values in
// the deopt_frame_ even though some of them may correspond to other
// inlined frames.
Object& obj = Object::Handle();
for (int i = 0; i < deopt_frame_.Length(); i++) {
obj = deopt_frame_.At(i);
if (obj.ptr() == Object::optimized_out().ptr()) {
return false;
}
}
return true;
}
void ActivationFrame::PrintContextMismatchError(intptr_t ctx_slot,
intptr_t frame_ctx_level,
intptr_t var_ctx_level) {
OS::PrintErr(
"-------------------------\n"
"Encountered context mismatch\n"
"\tctx_slot: %" Pd
"\n"
"\tframe_ctx_level: %" Pd
"\n"
"\tvar_ctx_level: %" Pd "\n\n",
ctx_slot, frame_ctx_level, var_ctx_level);
OS::PrintErr(
"-------------------------\n"
"Current frame:\n%s\n",
this->ToCString());
OS::PrintErr(
"-------------------------\n"
"Context contents:\n");
const Context& ctx = GetSavedCurrentContext();
ctx.Dump(8);
OS::PrintErr(
"-------------------------\n"
"Debugger stack trace...\n\n");
DebuggerStackTrace* stack = Isolate::Current()->debugger()->StackTrace();
intptr_t num_frames = stack->Length();
for (intptr_t i = 0; i < num_frames; i++) {
ActivationFrame* frame = stack->FrameAt(i);
OS::PrintErr("#%04" Pd " %s", i, frame->ToCString());
}
OS::PrintErr(
"-------------------------\n"
"All frames...\n\n");
StackFrameIterator iterator(ValidationPolicy::kDontValidateFrames,
Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
StackFrame* frame = iterator.NextFrame();
intptr_t num = 0;
while ((frame != nullptr)) {
OS::PrintErr("#%04" Pd " %s\n", num++, frame->ToCString());
frame = iterator.NextFrame();
}
}
void ActivationFrame::VariableAt(intptr_t i,
String* name,
TokenPosition* declaration_token_pos,
TokenPosition* visible_start_token_pos,
TokenPosition* visible_end_token_pos,
Object* value,
AbstractType* static_type) {
GetDescIndices();
ASSERT(i < desc_indices_.length());
intptr_t desc_index = desc_indices_[i];
ASSERT(name != nullptr);
*name = var_descriptors_.GetName(desc_index);
UntaggedLocalVarDescriptors::VarInfo var_info;
var_descriptors_.GetInfo(desc_index, &var_info);
ASSERT(declaration_token_pos != nullptr);
*declaration_token_pos = var_info.declaration_pos;
ASSERT(visible_start_token_pos != nullptr);
*visible_start_token_pos = var_info.begin_pos;
ASSERT(visible_end_token_pos != nullptr);
*visible_end_token_pos = var_info.end_pos;
ASSERT(value != nullptr);
const int8_t kind = var_info.kind();
const auto variable_index = VariableIndex(var_info.index());
if (kind == UntaggedLocalVarDescriptors::kStackVar) {
*value = GetStackVar(variable_index);
} else {
ASSERT(kind == UntaggedLocalVarDescriptors::kContextVar);
*value = GetContextVar(var_info.scope_id, variable_index.value());
}
if (static_type != nullptr) {
*static_type = var_descriptors_.GetStaticType(desc_index);
}
}
ObjectPtr ActivationFrame::GetContextVar(intptr_t var_ctx_level,
intptr_t ctx_slot) {
// The context level at the PC/token index of this activation frame.
intptr_t frame_ctx_level = ContextLevel();
return GetRelativeContextVar(var_ctx_level, ctx_slot, frame_ctx_level);
}
ObjectPtr ActivationFrame::GetRelativeContextVar(intptr_t var_ctx_level,
intptr_t ctx_slot,
intptr_t frame_ctx_level) {
const Context& ctx = GetSavedCurrentContext();
// It's possible that ctx was optimized out as no locals were captured by the
// context. See issue #38182.
if (ctx.IsNull()) {
return Object::optimized_out().ptr();
}
intptr_t level_diff = frame_ctx_level - var_ctx_level;
if (level_diff == 0) {
if ((ctx_slot < 0) || (ctx_slot >= ctx.num_variables())) {
PrintContextMismatchError(ctx_slot, frame_ctx_level, var_ctx_level);
}
ASSERT((ctx_slot >= 0) && (ctx_slot < ctx.num_variables()));
return ctx.At(ctx_slot);
} else if (level_diff > 0) {
Context& var_ctx = Context::Handle(ctx.ptr());
while (level_diff > 0 && !var_ctx.IsNull()) {
level_diff--;
var_ctx = var_ctx.parent();
}
if (var_ctx.IsNull() || (ctx_slot < 0) ||
(ctx_slot >= var_ctx.num_variables())) {
PrintContextMismatchError(ctx_slot, frame_ctx_level, var_ctx_level);
}
ASSERT(!var_ctx.IsNull());
ASSERT((ctx_slot >= 0) && (ctx_slot < var_ctx.num_variables()));
return var_ctx.At(ctx_slot);
} else {
PrintContextMismatchError(ctx_slot, frame_ctx_level, var_ctx_level);
return Object::null();
}
}
ObjectPtr ActivationFrame::GetReceiver() {
GetDescIndices();
intptr_t num_variables = desc_indices_.length();
String& var_name = String::Handle();
Instance& value = Instance::Handle();
for (intptr_t i = 0; i < num_variables; i++) {
TokenPosition ignore = TokenPosition::kNoSource;
VariableAt(i, &var_name, &ignore, &ignore, &ignore, &value, nullptr);
if (var_name.Equals(Symbols::This())) {
return value.ptr();
}
}
return Object::optimized_out().ptr();
}
static bool IsSyntheticVariableName(const String& var_name) {
return (var_name.Length() >= 1) && (var_name.CharAt(0) == ':');
}
static bool IsPrivateVariableName(const String& var_name) {
return (var_name.Length() >= 1) && (var_name.CharAt(0) == '_');
}
ObjectPtr ActivationFrame::EvaluateCompiledExpression(
const ExternalTypedData& kernel_buffer,
const Array& type_definitions,
const Array& arguments,
const TypeArguments& type_arguments) {
auto thread = Thread::Current();
auto zone = thread->zone();
// The expression evaluation function will get all it's captured state passed
// as parameters (with `this` being the exception). As a result, we treat the
// expression evaluation function as either a top-level, static or instance
// method.
const auto& outermost =
Function::Handle(zone, function().GetOutermostFunction());
const auto& klass = Class::Handle(zone, outermost.Owner());
const auto& library = Library::Handle(zone, klass.library());
auto& receiver = Object::Handle(zone);
if (!klass.IsTopLevel() && !outermost.is_static()) {
receiver = GetReceiver();
RELEASE_ASSERT(receiver.IsInstance() ||
receiver.ptr() == Object::optimized_out().ptr());
}
return Instance::EvaluateCompiledExpression(thread, receiver, library, klass,
kernel_buffer, type_definitions,
arguments, type_arguments);
}
TypeArgumentsPtr ActivationFrame::BuildParameters(
const GrowableObjectArray& param_names,
const GrowableObjectArray& param_values,
const GrowableObjectArray& type_params_names,
const GrowableObjectArray& type_params_bounds,
const GrowableObjectArray& type_params_defaults) {
GetDescIndices();
bool type_arguments_available = false;
String& name = String::Handle();
String& existing_name = String::Handle();
Object& value = Instance::Handle();
TypeArguments& type_arguments = TypeArguments::Handle();
intptr_t num_variables = desc_indices_.length();
for (intptr_t i = 0; i < num_variables; i++) {
TokenPosition ignore = TokenPosition::kNoSource;
VariableAt(i, &name, &ignore, &ignore, &ignore, &value, nullptr);
if (name.Equals(Symbols::FunctionTypeArgumentsVar())) {
type_arguments_available = true;
type_arguments ^= value.ptr();
} else if (
!name.Equals(Symbols::This()) && !IsSyntheticVariableName(name) &&
value.ptr() != Object::optimized_out().ptr() &&
// TODO(57048): We currently pretend that uninitialized late variables
// don't exist to avoid crashing when evaluating expressions that need
// to access the late variables' values. The CFE team is working on a
// better solution.
value.ptr() != Object::sentinel().ptr()) {
if (IsPrivateVariableName(name)) {
name = Symbols::New(Thread::Current(), String::ScrubName(name));
}
bool conflict = false;
for (intptr_t j = 0; j < param_names.Length(); j++) {
existing_name ^= param_names.At(j);
if (name.Equals(existing_name)) {
conflict = true;
break;
}
}
// If local has the same name as a binding in the incoming scope, prefer
// the one from the incoming scope, since it is logically a child scope
// of the activation's current scope.
if (!conflict) {
param_names.Add(name);
param_values.Add(value);
}
}
}
if ((function().IsGeneric() || function().HasGenericParent()) &&
type_arguments_available) {
intptr_t num_vars = function().NumTypeArguments();
type_params_names.Grow(num_vars);
type_params_names.SetLength(num_vars);
type_params_bounds.Grow(num_vars);
type_params_bounds.SetLength(num_vars);
type_params_defaults.Grow(num_vars);
type_params_defaults.SetLength(num_vars);
AbstractType& bound = AbstractType::Handle();
AbstractType& defaultType = AbstractType::Handle();
TypeParameters& type_params = TypeParameters::Handle();
Function& current = Function::Handle(function().ptr());
intptr_t mapping_offset = num_vars;
for (; !current.IsNull(); current = current.parent_function()) {
type_params = current.type_parameters();
if (type_params.IsNull()) continue;
intptr_t size = current.NumTypeParameters();
ASSERT(size > 0 && type_params.Length() == size);
ASSERT(mapping_offset >= size);
mapping_offset -= size;
for (intptr_t j = 0; j < size; ++j) {
name = type_params.NameAt(j);
bound = type_params.BoundAt(j);
defaultType = type_params.DefaultAt(j);
// Write the names in backwards in terms of chain of functions.
// But keep the order of names within the same function. so they
// match up with the order of the types in 'type_arguments'.
// Index:0 1 2 3 ...
// |Names in Grandparent| |Names in Parent| ..|Names in Child|
type_params_names.SetAt(mapping_offset + j, name);
type_params_bounds.SetAt(mapping_offset + j, bound);
type_params_defaults.SetAt(mapping_offset + j, defaultType);
}
}
if (!type_arguments.IsNull()) {
if (type_arguments.Length() == 0) {
for (intptr_t i = 0; i < num_vars; ++i) {
type_arguments.SetTypeAt(i, Object::dynamic_type());
}
}
ASSERT(type_arguments.Length() == num_vars);
}
}
return type_arguments.ptr();
}
const char* ActivationFrame::ToCString() {
if (function().IsNull()) {
return Thread::Current()->zone()->PrintToString("[ Frame kind: %s]\n",
KindToCString(kind_));
}
const String& url = String::Handle(SourceUrl());
intptr_t line = LineNumber();
const char* func_name = function().ToFullyQualifiedCString();
if (kind_ == kRegular) {
return Thread::Current()->zone()->PrintToString(
"[ Frame pc(0x%" Px ") fp(0x%" Px ") sp(0x%" Px
")\n"
"\t%s offset = 0x%" Px
"\n"
"\tfunction = %s\n"
"\turl = %s\n"
"\tline = %" Pd
"\n"
"\tcontext = %s\n"
"\tcontext level = %" Pd " ]\n",
pc(), fp(), sp(), IsInterpreted() ? "bytecode" : "code",
pc() - PayloadStart(), func_name, url.ToCString(), line,
ctx_.ToCString(), ContextLevel());
} else {
return Thread::Current()->zone()->PrintToString(
"[ Frame code function = %s\n"
"\turl = %s\n"
"\tline = %" Pd
"\n"
"\tcontext = %s]\n",
func_name, url.ToCString(), line, ctx_.ToCString());
}
}
void ActivationFrame::PrintToJSONObject(JSONObject* jsobj) {
if (kind_ == kRegular) {
PrintToJSONObjectRegular(jsobj);
} else if (kind_ == kAsyncAwaiter) {
PrintToJSONObjectAsyncAwaiter(jsobj);
} else if (kind_ == kAsyncSuspensionMarker) {
PrintToJSONObjectAsyncSuspensionMarker(jsobj);
} else {
UNIMPLEMENTED();
}
}
void ActivationFrame::PrintToJSONObjectRegular(JSONObject* jsobj) {
const Script& script = Script::Handle(SourceScript());
jsobj->AddProperty("type", "Frame");
jsobj->AddProperty("kind", KindToCString(kind_));
const TokenPosition& pos = TokenPos();
jsobj->AddLocation(script, pos);
jsobj->AddProperty("function", function());
if (IsInterpreted()) {
jsobj->AddProperty("code", bytecode());
} else {
jsobj->AddProperty("code", code());
}
{
JSONArray jsvars(jsobj, "vars");
const int num_vars = NumLocalVariables();
for (intptr_t v = 0; v < num_vars; v++) {
String& var_name = String::Handle();
Instance& var_value = Instance::Handle();
AbstractType& static_type = AbstractType::Handle();
TokenPosition declaration_token_pos = TokenPosition::kNoSource;
TokenPosition visible_start_token_pos = TokenPosition::kNoSource;
TokenPosition visible_end_token_pos = TokenPosition::kNoSource;
VariableAt(v, &var_name, &declaration_token_pos, &visible_start_token_pos,
&visible_end_token_pos, &var_value, &static_type);
if (!IsSyntheticVariableName(var_name)) {
JSONObject jsvar(&jsvars);
jsvar.AddProperty("type", "BoundVariable");
const char* scrubbed_var_name = String::ScrubName(var_name);
jsvar.AddProperty("name", scrubbed_var_name);
jsvar.AddProperty("value", var_value);
// Where was the variable declared?
jsvar.AddProperty("declarationTokenPos", declaration_token_pos);
// When the variable becomes visible to the scope.
jsvar.AddProperty("scopeStartTokenPos", visible_start_token_pos);
// When the variable stops being visible to the scope.
jsvar.AddProperty("scopeEndTokenPos", visible_end_token_pos);
jsvar.AddProperty("staticType", static_type);
}
}
}
}
void ActivationFrame::PrintToJSONObjectAsyncAwaiter(JSONObject* jsobj) {
jsobj->AddProperty("type", "Frame");
jsobj->AddProperty("kind", KindToCString(kind_));
const Script& script = Script::Handle(SourceScript());
const TokenPosition& pos = TokenPos();
jsobj->AddLocation(script, pos);
jsobj->AddProperty("function", function());
if (IsInterpreted()) {
jsobj->AddProperty("code", bytecode());
} else {
jsobj->AddProperty("code", code());
}
}
void ActivationFrame::PrintToJSONObjectAsyncSuspensionMarker(
JSONObject* jsobj) {
jsobj->AddProperty("type", "Frame");
jsobj->AddProperty("kind", KindToCString(kind_));
jsobj->AddProperty("marker", "AsynchronousSuspension");
}
static bool IsFunctionVisible(const Function& function) {
return FLAG_show_invisible_frames || function.is_visible();
}
void DebuggerStackTrace::AddActivation(ActivationFrame* frame) {
if (IsFunctionVisible(frame->function())) {
trace_.Add(frame);
}
}
void DebuggerStackTrace::AddAsyncSuspension() {
// We might start asynchronous unwinding in one of the internal
// dart:async functions which would make synchronous part of the
// stack empty. This would not happen normally but might happen
// with stress flags.
if (trace_.is_empty() ||
trace_.Last()->kind() != ActivationFrame::kAsyncSuspensionMarker) {
if (FLAG_trace_debugger_stacktrace) {
OS::PrintErr(" async suspension\n");
}
trace_.Add(new ActivationFrame(ActivationFrame::kAsyncSuspensionMarker));
} else if (FLAG_trace_debugger_stacktrace &&
FLAG_trace_debugger_stacktrace_verbose) {
OS::PrintErr(" skipping repeated async suspension\n");
}
}
void DebuggerStackTrace::AddAsyncAwaiterFrame(uword pc,
const Function& function,
const Object& code_or_bytecode,
const Closure& closure) {
trace_.Add(new ActivationFrame(pc, function, code_or_bytecode, closure));
}
const uint8_t kSafepointKind = UntaggedPcDescriptors::kIcCall |
UntaggedPcDescriptors::kUnoptStaticCall |
UntaggedPcDescriptors::kRuntimeCall;
CodeBreakpoint::CodeBreakpoint(const Code& code,
BreakpointLocation* breakpoint_location,
uword pc,
UntaggedPcDescriptors::Kind kind)
: code_(code.ptr()),
bytecode_(Bytecode::null()),
pc_(pc),
enabled_count_(0),
next_(nullptr),
breakpoint_kind_(kind),
saved_value_(Code::null()),
saved_opcode_(kMaxUint32) {
ASSERT(!code.IsNull());
ASSERT(pc_ != 0);
ASSERT((breakpoint_kind_ & kSafepointKind) != 0);
AddBreakpointLocation(breakpoint_location);
ASSERT(breakpoint_location->token_pos().IsReal());
}
CodeBreakpoint::CodeBreakpoint(const Bytecode& bytecode,
BreakpointLocation* breakpoint_location,
uword pc)
: code_(Code::null()),
bytecode_(bytecode.ptr()),
pc_(pc),
enabled_count_(0),
next_(nullptr),
breakpoint_kind_(UntaggedPcDescriptors::kRuntimeCall),
saved_value_(Code::null()),
saved_opcode_(kMaxUint32) {
ASSERT(!bytecode.IsNull());
ASSERT(pc_ != 0);
AddBreakpointLocation(breakpoint_location);
ASSERT(breakpoint_location->token_pos().IsReal());
}
CodeBreakpoint::~CodeBreakpoint() {
// Make sure we don't leave patched code behind.
ASSERT(!IsEnabled());
// Poison the data so we catch use after free errors.
#ifdef DEBUG
code_ = Code::null();
bytecode_ = Bytecode::null();
pc_ = 0ul;
next_ = nullptr;
breakpoint_kind_ = UntaggedPcDescriptors::kOther;
#endif
}
void CodeBreakpoint::Enable() {
if (enabled_count_ == 0) {
if (bytecode_ != Bytecode::null()) {
#if defined(DART_DYNAMIC_MODULES)
ASSERT_EQUAL(saved_opcode_, kMaxUint32);
saved_opcode_ =
BytecodePatcher::AddBreakpointAt(pc_, Bytecode::Handle(bytecode_));
#else
UNREACHABLE();
#endif
} else {
PatchCode();
}
}
++enabled_count_;
}
void CodeBreakpoint::Disable() {
if (enabled_count_ == 1) {
if (bytecode_ != Bytecode::null()) {
#if defined(DART_DYNAMIC_MODULES)
BytecodePatcher::RemoveBreakpointAt(pc_, Bytecode::Handle(bytecode_),
saved_opcode_);
saved_opcode_ = kMaxUint32;
#else
UNREACHABLE();
#endif
} else {
RestoreCode();
}
}
--enabled_count_;
}
bool CodeBreakpoint::HasBreakpointLocation(
BreakpointLocation* breakpoint_location) {
for (intptr_t i = 0; i < breakpoint_locations_.length(); i++) {
if (breakpoint_locations_[i] == breakpoint_location) {
return true;
}
}
return false;
}
bool CodeBreakpoint::FindAndDeleteBreakpointLocation(
BreakpointLocation* breakpoint_location) {
for (intptr_t i = 0; i < breakpoint_locations_.length(); i++) {
if (breakpoint_locations_[i] == breakpoint_location) {
breakpoint_locations_.EraseAt(i);
return true;
}
}
return false;
}
BreakpointLocation* CodeBreakpoint::FindBreakpointForDebugger(
Debugger* debugger) {
for (intptr_t i = 0; i < breakpoint_locations_.length(); i++) {
if (breakpoint_locations_[i]->debugger() == debugger) {
return breakpoint_locations_[i];
}
}
return nullptr;
}
GroupDebugger::GroupDebugger(IsolateGroup* isolate_group)
: isolate_group_(isolate_group),
code_breakpoints_lock_(new SafepointRwLock()),
code_breakpoints_(nullptr),
breakpoint_locations_lock_(new SafepointRwLock()),
single_stepping_set_lock_(new RwLock()),
needs_breakpoint_cleanup_(false) {}
GroupDebugger::~GroupDebugger() {
while (code_breakpoints_ != nullptr) {
CodeBreakpoint* cbpt = code_breakpoints_;
code_breakpoints_ = code_breakpoints_->next();
ASSERT(!cbpt->IsEnabled());
delete cbpt;
}
}
Debugger::Debugger(Isolate* isolate)
: isolate_(isolate),
next_id_(1),
latent_locations_(nullptr),
breakpoint_locations_(nullptr),
resume_action_(kContinue),
resume_frame_index_(-1),
post_deopt_frame_index_(-1),
ignore_breakpoints_(false),
pause_event_(nullptr),
stack_trace_(nullptr),
async_awaiter_stack_trace_(nullptr),
stepping_fp_(0),
last_stepping_fp_(0),
last_stepping_pos_(TokenPosition::kNoSource),
exc_pause_info_(kNoPauseOnExceptions) {}
Debugger::~Debugger() {
ASSERT(!IsPaused());
ASSERT(latent_locations_ == nullptr);
ASSERT(breakpoint_locations_ == nullptr);
ASSERT(stack_trace_ == nullptr);
ASSERT(async_awaiter_stack_trace_ == nullptr);
}
void Debugger::Shutdown() {
// TODO(johnmccutchan): Do not create a debugger for isolates that don't need
// them. Then, assert here that isolate_ is not one of those isolates.
if (Isolate::IsSystemIsolate(isolate_)) {
return;
}
{
SafepointWriteRwLocker sl(Thread::Current(),
group_debugger()->breakpoint_locations_lock());
while (breakpoint_locations_ != nullptr) {
BreakpointLocation* loc = breakpoint_locations_;
group_debugger()->UnlinkCodeBreakpoints(loc);
group_debugger()->UnregisterBreakpointLocation(loc);
breakpoint_locations_ = breakpoint_locations_->next();
delete loc;
}
while (latent_locations_ != nullptr) {
BreakpointLocation* loc = latent_locations_;
group_debugger()->UnlinkCodeBreakpoints(loc);
group_debugger()->UnregisterBreakpointLocation(loc);
latent_locations_ = latent_locations_->next();
delete loc;
}
}
if (NeedsIsolateEvents()) {
ServiceEvent event(isolate_, ServiceEvent::kIsolateExit);
InvokeEventHandler(&event);
}
}
static ActivationFrame* TopDartFrame();
static bool IsAtAsyncJump(ActivationFrame* top_frame);
bool Debugger::SetupStepOverAsyncSuspension(const char** error) {
ActivationFrame* top_frame = TopDartFrame();
if (!IsAtAsyncJump(top_frame)) {
// Not at an async operation.
if (error != nullptr) {
*error = "Isolate must be paused at an async suspension point";
}
return false;
}
ASSERT(top_frame->function().IsAsyncFunction() ||
top_frame->function().IsAsyncGenerator());
const auto& function_data =
Object::Handle(top_frame->GetSuspendableFunctionData());
SetBreakpointAtResumption(function_data);
return true;
}
static bool CanRewindFrame(intptr_t frame_index, const char** error);
bool Debugger::SetResumeAction(ResumeAction action,
intptr_t frame_index,
const char** error) {
if (error != nullptr) {
*error = nullptr;
}
resume_frame_index_ = -1;
switch (action) {
case kStepInto:
case kStepOver:
case kStepOut:
case kContinue:
set_resume_action(action);
return true;
case kStepRewind:
if (!CanRewindFrame(frame_index, error)) {
return false;
}
set_resume_action(kStepRewind);
resume_frame_index_ = frame_index;
return true;
case kStepOverAsyncSuspension:
return SetupStepOverAsyncSuspension(error);
default:
UNREACHABLE();
return false;
}
}
// Deoptimize all functions in the isolate.
// TODO(hausner): Actually we only need to deoptimize those functions
// that inline the function that contains the newly created breakpoint.
// We currently don't have this info so we deoptimize all functions.
void Debugger::DeoptimizeWorld() {
#if defined(DART_PRECOMPILED_RUNTIME)
UNREACHABLE();
#else
if (FLAG_trace_deoptimization) {
THR_Print("Deopt for debugger\n");
}
isolate_->group()->set_has_attempted_stepping(true);
DeoptimizeFunctionsOnStack();
// Iterate over all classes, deoptimize functions.
// TODO(hausner): Could possibly be combined with RemoveOptimizedCode()
const ClassTable& class_table = *isolate_->group()->class_table();
auto thread = Thread::Current();
auto isolate_group = thread->isolate_group();
auto zone = thread->zone();
CallSiteResetter resetter(zone);
Class& cls = Class::Handle(zone);
Array& functions = Array::Handle(zone);
Function& function = Function::Handle(zone);
Code& code = Code::Handle(zone);
const intptr_t num_classes = class_table.NumCids();
const intptr_t num_tlc_classes = class_table.NumTopLevelCids();
SafepointWriteRwLocker ml(thread, isolate_group->program_lock());
for (intptr_t i = kInstanceCid; i < num_classes + num_tlc_classes; i++) {
const intptr_t cid =
i < num_classes ? i : ClassTable::CidFromTopLevelIndex(i - num_classes);
if (!class_table.HasValidClassAt(cid)) {
continue;
}
cls = class_table.At(cid);
HANDLESCOPE(thread);
// Disable optimized functions.
functions = cls.functions();
ASSERT(!functions.IsNull());
intptr_t num_functions = functions.Length();
for (intptr_t pos = 0; pos < num_functions; pos++) {
function ^= functions.At(pos);
ASSERT(!function.IsNull());
// Force-optimized functions don't have unoptimized code and can't
// deoptimize. Their optimized codes are still valid.
if (!function.ForceOptimize()) {
if (function.HasOptimizedCode()) {
function.SwitchToUnoptimizedCode();
}
code = function.unoptimized_code();
if (!code.IsNull()) {
resetter.ResetSwitchableCalls(code);
}
}
// Also disable any optimized implicit closure functions.
if (function.HasImplicitClosureFunction()) {
function = function.ImplicitClosureFunction();
if (!function.ForceOptimize()) {
if (function.HasOptimizedCode()) {
function.SwitchToUnoptimizedCode();
}
code = function.unoptimized_code();
if (!code.IsNull()) {
resetter.ResetSwitchableCalls(code);
}
}
}
}
}
// Disable optimized closure functions.
ClosureFunctionsCache::ForAllClosureFunctions([&](const Function& function) {
if (!function.ForceOptimize()) {
if (function.HasOptimizedCode()) {
function.SwitchToUnoptimizedCode();
}
code = function.unoptimized_code();
if (!code.IsNull()) {
resetter.ResetSwitchableCalls(code);
}
}
return true; // Continue iteration.
});
#endif // defined(DART_PRECOMPILED_RUNTIME)
}
void Debugger::RunWithStoppedDeoptimizedWorld(std::function<void()> fun) {
#if !defined(DART_PRECOMPILED_RUNTIME)
// RELOAD_OPERATION_SCOPE is used here because is is guaranteed that
// isolates at reload safepoints hold no safepoint locks.
RELOAD_OPERATION_SCOPE(Thread::Current());
group_debugger()->isolate_group()->RunWithStoppedMutators([&]() {
DeoptimizeWorld();
fun();
});
#endif
}
void Debugger::NotifySingleStepping(bool value) {
RELEASE_ASSERT(isolate_->mutator_thread() != nullptr);
if (value) {
// Setting breakpoint requires unoptimized code, make sure we stop all
// isolates to prevent racing reoptimization.
RunWithStoppedDeoptimizedWorld([&] {
isolate_->mutator_thread()->set_single_step(value);
// Ensure other isolates in the isolate group keep
// unoptimized code unoptimized, won't attempt to optimize it.
group_debugger()->RegisterSingleSteppingDebugger(Thread::Current(), this);
});
} else {
isolate_->mutator_thread()->set_single_step(value);
group_debugger()->UnregisterSingleSteppingDebugger(Thread::Current(), this);
}
}
static ActivationFrame* CollectDartFrame(uword pc,
StackFrame* frame,
const Function& function,
const Object& code_or_bytecode,
const Array& deopt_frame,
intptr_t deopt_frame_offset) {
ASSERT((code_or_bytecode.IsCode() &&
Code::Cast(code_or_bytecode).ContainsInstructionAt(pc)) ||
(code_or_bytecode.IsBytecode() &&
Bytecode::Cast(code_or_bytecode).ContainsInstructionAt(pc)));
ActivationFrame* activation =
new ActivationFrame(pc, frame->fp(), frame->sp(), function,
code_or_bytecode, deopt_frame, deopt_frame_offset);
if (FLAG_trace_debugger_stacktrace) {
intptr_t index = -1;
const Context& ctx = activation->GetSavedCurrentContext(&index);
if (index >= 0) {
OS::PrintErr(" Current context (index %" Pu "): %s\n", index,
ctx.ToCString());
} else if (!ctx.IsNull()) {
OS::PrintErr(" Current context: %s\n", ctx.ToCString());
}
OS::PrintErr(" Line number: %" Pd "\n", activation->LineNumber());
}
return activation;
}
#if !defined(DART_PRECOMPILED_RUNTIME)
static ArrayPtr DeoptimizeToArray(Thread* thread,
StackFrame* frame,
const Code& code) {
ASSERT(code.can_be_deoptimized());
// Create the DeoptContext for this deoptimization.
DeoptContext* deopt_context =
new DeoptContext(frame, code, DeoptContext::kDestIsAllocated, nullptr,
nullptr, true, false /* deoptimizing_code */);
thread->set_deopt_context(deopt_context);
deopt_context->FillDestFrame();
deopt_context->MaterializeDeferredObjects();
const Array& dest_frame =
Array::Handle(thread->zone(), deopt_context->DestFrameAsArray());
thread->set_deopt_context(nullptr);
delete deopt_context;
return dest_frame.ptr();
}
#endif // !defined(DART_PRECOMPILED_RUNTIME)
DebuggerStackTrace* DebuggerStackTrace::Collect() {
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
auto& function = Function::Handle(zone);
auto& code = Code::Handle(zone);
auto& bytecode = Bytecode::Handle(zone);
DebuggerStackTrace* stack_trace = new DebuggerStackTrace(8);
if (FLAG_trace_debugger_stacktrace) {
OS::PrintErr("CollectStackTrace: starting collection\n");
}
StackFrameIterator iterator(ValidationPolicy::kDontValidateFrames, thread,
StackFrameIterator::kNoCrossThreadIteration);
for (StackFrame* frame = iterator.NextFrame(); frame != nullptr;
frame = iterator.NextFrame()) {
ASSERT(frame->IsValid());
if (frame->IsDartFrame()) {
if (FLAG_trace_debugger_stacktrace) {
// StackFrame::ToCString() prepends two spaces in its output.
OS::PrintErr("%s\n", frame->ToCString());
}
if (frame->is_interpreted()) {
function = frame->LookupDartFunction();
bytecode = frame->LookupDartBytecode();
stack_trace->AppendBytecodeFrame(frame, function, bytecode);
} else {
code = frame->LookupDartCode();
stack_trace->AppendCodeFrames(frame, code);
}
} else if (FLAG_trace_debugger_stacktrace &&
FLAG_trace_debugger_stacktrace_verbose) {
// StackFrame::ToCString() prepends two spaces in its output.
OS::PrintErr("%s\n", frame->ToCString());
OS::PrintErr(" non-Dart frame skipped\n");
}
}
if (FLAG_trace_debugger_stacktrace) {
OS::PrintErr("CollectStackTrace: collection finished\n\n");
}
return stack_trace;
}
// Appends at least one stack frame. Multiple frames will be appended
// if |code| at the frame's pc contains inlined functions.
void DebuggerStackTrace::AppendCodeFrames(StackFrame* frame, const Code& code) {
auto& function = Function::Handle(zone_, code.function());
#if !defined(DART_PRECOMPILED_RUNTIME)
if (code.is_optimized()) {
// TODO(61635): handle code generated by modular AOT.
if (!code.can_be_deoptimized()) {
if (FLAG_trace_debugger_stacktrace) {
ASSERT(!function.IsNull());
OS::PrintErr(" skipping function which cannot be deoptimized: %s\n",
function.ToFullyQualifiedCString());
}
return; // Skip frame of force-optimized (and non-debuggable) function.
}
// TODO(rmacnak): Use CodeSourceMap
deopt_frame_ = DeoptimizeToArray(thread_, frame, code);
for (InlinedFunctionsIterator it(code, frame->pc()); !it.Done();
it.Advance()) {
inlined_code_ = it.code();
function = it.function();
if (FLAG_trace_debugger_stacktrace) {
ASSERT(!function.IsNull());
OS::PrintErr(" visiting inlined function: %s\n",
function.ToFullyQualifiedCString());
}
intptr_t deopt_frame_offset = it.GetDeoptFpOffset();
AddActivation(CollectDartFrame(it.pc(), frame, function, inlined_code_,
deopt_frame_, deopt_frame_offset));
}
return;
}
#endif // !defined(DART_PRECOMPILED_RUNTIME)
AddActivation(CollectDartFrame(frame->pc(), frame, function, code,
Object::null_array(), 0));
}
// Appends one interpreted stack frame.
void DebuggerStackTrace::AppendBytecodeFrame(StackFrame* frame,
const Function& function,
const Bytecode& bytecode) {
AddActivation(CollectDartFrame(frame->pc(), frame, function, bytecode,
Object::null_array(), 0));
}
DebuggerStackTrace* DebuggerStackTrace::CollectAsyncAwaiters() {
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
Function& function = Function::Handle(zone);
constexpr intptr_t kDefaultStackAllocation = 8;
auto stack_trace = new DebuggerStackTrace(kDefaultStackAllocation);
if (FLAG_trace_debugger_stacktrace) {
OS::PrintErr("CollectStackTrace: starting async awaiters collection\n");
}
bool has_async = false;
bool has_async_catch_error = false;
StackTraceUtils::CollectFrames(
thread, /*skip_frames=*/0,
[&](const StackTraceUtils::Frame& frame) {
if (frame.code_or_bytecode.IsNull()) return;
if (frame.frame != nullptr) { // Synchronous portion of the stack.
if (FLAG_trace_debugger_stacktrace) {
// StackFrame::ToCString() prepends two spaces in its output.
OS::PrintErr("%s\n", frame.frame->ToCString());
}
if (frame.HasBytecode()) {
function = frame.frame->LookupDartFunction();
stack_trace->AppendBytecodeFrame(frame.frame, function,
frame.bytecode());
} else {
stack_trace->AppendCodeFrames(frame.frame, frame.code());
}
} else {
has_async = true;
if (frame.HasCode() &&
frame.code().ptr() == StubCode::AsynchronousGapMarker().ptr()) {
stack_trace->AddAsyncSuspension();
return;
}
uword pc_offset = frame.pc_offset;
// Closures listening to futures are invoked with the result of the
// future when it completes, so async awaiter frames for future
// listeners have a "return address" of the entry point.
const bool is_future_listener =
pc_offset == StackTraceUtils::kFutureListenerPcOffset;
uword start = 0;
const Object* obj = nullptr;
const char* name = nullptr;
if (frame.HasBytecode()) {
function = frame.bytecode().function();
start = frame.bytecode().PayloadStart();
if (is_future_listener) {
// All bytecode methods use the payload start as the entry point.
pc_offset = 0;
}
obj = &frame.bytecode();
if (FLAG_trace_debugger_stacktrace) {
name = frame.bytecode().FullyQualifiedName();
}
} else {
function = frame.code().function();
start = frame.code().PayloadStart();
if (is_future_listener) {
pc_offset = frame.code().EntryPoint() - start;
}
obj = &frame.code();
if (FLAG_trace_debugger_stacktrace) {
name = frame.code().QualifiedName(
NameFormattingParams(Object::kInternalName));
}
}
ASSERT(!function.IsNull());
if (!function.is_visible()) {
return;
}
const uword absolute_pc = start + frame.pc_offset;
if (FLAG_trace_debugger_stacktrace) {
OS::PrintErr(" async awaiter: %s+%#" Px "\n", name,
absolute_pc - start);
}
stack_trace->AddAsyncAwaiterFrame(absolute_pc, function, *obj,
frame.closure);
}
},
&has_async_catch_error);
// If the entire stack is sync, return no (async) trace.
if (!has_async) {
if (FLAG_trace_debugger_stacktrace) {
OS::PrintErr(
"CollectStackTrace: discarding async awaiters collection\n\n");
}
return nullptr;
}
stack_trace->set_has_async_catch_error(has_async_catch_error);
if (FLAG_trace_debugger_stacktrace) {
OS::PrintErr("CollectStackTrace: async awaiters collection finished\n\n");
}
return stack_trace;
}
static ActivationFrame* TopDartFrame() {
StackFrameIterator iterator(ValidationPolicy::kDontValidateFrames,
Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
StackFrame* frame;
while (true) {
frame = iterator.NextFrame();
RELEASE_ASSERT(frame != nullptr);
if (!frame->IsDartFrame()) {
continue;
}
auto& function = Function::Handle();
auto& code_or_bytecode = Object::Handle();
if (frame->is_interpreted()) {
code_or_bytecode = frame->LookupDartBytecode();
function = frame->LookupDartFunction();
} else {
code_or_bytecode = frame->LookupDartCode();
function = Code::Cast(code_or_bytecode).function();
}
ActivationFrame* activation =
new ActivationFrame(frame->pc(), frame->fp(), frame->sp(), function,
code_or_bytecode, Object::null_array(), 0);
return activation;
}
}
DebuggerStackTrace* Debugger::StackTrace() {
return (stack_trace_ != nullptr) ? stack_trace_
: DebuggerStackTrace::Collect();
}
DebuggerStackTrace* Debugger::AsyncAwaiterStackTrace() {
return (async_awaiter_stack_trace_ != nullptr)
? async_awaiter_stack_trace_
: DebuggerStackTrace::CollectAsyncAwaiters();
}
DebuggerStackTrace* DebuggerStackTrace::From(const class StackTrace& ex_trace) {
DebuggerStackTrace* stack_trace = new DebuggerStackTrace(8);
Function& function = Function::Handle();
Object& code_object = Object::Handle();
Code& code = Code::Handle();
const uword fp = 0;
const uword sp = 0;
const Array& deopt_frame = Array::Handle();
const intptr_t deopt_frame_offset = -1;
for (intptr_t i = 0; i < ex_trace.Length(); i++) {
code_object = ex_trace.CodeAtFrame(i);
// Pre-allocated StackTraces may include empty slots, either (a) to indicate
// where frames were omitted in the case a stack has more frames than the
// pre-allocated trace (such as a stack overflow) or (b) because a stack has
// fewer frames that the pre-allocated trace (such as memory exhaustion with
// a shallow stack).
function = Function::null();
uword start = 0;
bool is_optimized_code = false;
if (code_object.IsCode()) {
const auto& code = Code::Cast(code_object);
ASSERT(code.IsFunctionCode());
function = code.function();
start = code.PayloadStart();
is_optimized_code = code.is_optimized();
} else if (code_object.IsBytecode()) {
const auto& bytecode = Bytecode::Cast(code_object);
function = bytecode.function();
start = bytecode.PayloadStart();
}
if (function.IsNull() || !function.is_visible()) continue;
const uword pc = start + ex_trace.PcOffsetAtFrame(i);
if (is_optimized_code && ex_trace.expand_inlined()) {
// Traverse inlined frames.
code ^= code_object.ptr();
for (InlinedFunctionsIterator it(code, pc); !it.Done(); it.Advance()) {
function = it.function();
code = it.code();
ASSERT(function.ptr() == code.function());
uword pc = it.pc();
ASSERT(pc != 0);
ASSERT(code.PayloadStart() <= pc);
ASSERT(pc < (code.PayloadStart() + code.Size()));
auto* const activation = new ActivationFrame(
pc, fp, sp, function, code, deopt_frame, deopt_frame_offset);
stack_trace->AddActivation(activation);
}
}
auto* const activation = new ActivationFrame(
pc, fp, sp, function, code_object, deopt_frame, deopt_frame_offset);
stack_trace->AddActivation(activation);
}
return stack_trace;
}
void Debugger::SetExceptionPauseInfo(Dart_ExceptionPauseInfo pause_info) {
ASSERT((pause_info == kNoPauseOnExceptions) ||
(pause_info == kPauseOnUnhandledExceptions) ||
(pause_info == kPauseOnAllExceptions));
exc_pause_info_ = pause_info;
}
Dart_ExceptionPauseInfo Debugger::GetExceptionPauseInfo() const {
return exc_pause_info_;
}
bool Debugger::ShouldPauseOnException(DebuggerStackTrace* stack_trace,
const Instance& exception) {
if (exc_pause_info_ == kNoPauseOnExceptions) {
return false;
}
if (exc_pause_info_ == kPauseOnAllExceptions) {
return true;
}
ASSERT(exc_pause_info_ == kPauseOnUnhandledExceptions);
// There might be no Dart stack if we hit an exception in the runtime, most
// likely OutOfMemory.
if (stack_trace->Length() == 0) {
return false;
}
// Exceptions coming from invalid token positions should be skipped
ActivationFrame* top_frame = stack_trace->FrameAt(0);
// If this is an async awaiter stack trace, skip over
// an initial async suspend marker.
if (top_frame->kind() == ActivationFrame::kAsyncSuspensionMarker) {
top_frame = stack_trace->FrameAt(1);
}
if (!top_frame->TokenPos().IsReal() && top_frame->TryIndex() != -1) {
return false;
}
ActivationFrame* handler_frame = stack_trace->GetHandlerFrame(exception);
if (handler_frame == nullptr) {
// Did not find an exception handler that catches this exception.
// Note that this check is not precise, since we can't check
// uninstantiated types, i.e. types containing type parameters.
// Thus, we may report an exception as unhandled when in fact
// it will be caught once we unwind the stack.
return !stack_trace->has_async_catch_error();
}
auto& handler_function = Function::Handle(handler_frame->function().ptr());
// If handler_frame's function is annotated with
// @pragma('vm:notify-debugger-on-exception'), we specifically want to notify
// the debugger of this otherwise ignored exception.
if (!handler_function.IsNull() &&
Library::FindPragma(Thread::Current(), /*only_core=*/false,
handler_function,
Symbols::vm_notify_debugger_on_exception())) {
return true;
}
return false;
}
void Debugger::PauseException(const Instance& exc) {
if (FLAG_stress_async_stacks) {
DebuggerStackTrace::CollectAsyncAwaiters();
}
// We ignore this exception event when the VM is executing code invoked
// by the debugger to evaluate variables values, when we see a nested
// breakpoint or exception event, or if the debugger is not
// interested in exception events.
if (ignore_breakpoints_ || IsPaused() ||
(exc_pause_info_ == kNoPauseOnExceptions)) {
return;
}
DebuggerStackTrace* async_awaiter_stack_trace =
DebuggerStackTrace::CollectAsyncAwaiters();
DebuggerStackTrace* stack_trace = DebuggerStackTrace::Collect();
if (async_awaiter_stack_trace != nullptr) {
if (!ShouldPauseOnException(async_awaiter_stack_trace, exc)) {
return;
}
} else {
if (!ShouldPauseOnException(stack_trace, exc)) {
return;
}
}
ServiceEvent event(isolate_, ServiceEvent::kPauseException);
event.set_exception(&exc);
if (stack_trace->Length() > 0) {
event.set_top_frame(stack_trace->FrameAt(0));
}
CacheStackTraces(stack_trace, async_awaiter_stack_trace);
Pause(&event);
HandleSteppingRequest(); // we may get a rewind request
ClearCachedStackTraces();
}
// Helper that refines the resolved token pos.
//
// If |requested_column| is |-1|, then |exact_token_pos| must be
// |TokenPosition::kNoSource|.
static void RefineBreakpointPos(const Script& script,
TokenPosition pos,
TokenPosition next_closest_token_position,
TokenPosition requested_token_pos,
TokenPosition last_token_pos,
intptr_t requested_column,
TokenPosition exact_token_pos,
TokenPosition* best_fit_pos,
intptr_t* best_column,
intptr_t* best_line) {
ASSERT(
(requested_column == -1 && exact_token_pos == TokenPosition::kNoSource) ||
requested_column > -1);
intptr_t token_start_column = -1;
intptr_t token_line = -1;
if (requested_column >= 0) {
TokenPosition ignored = TokenPosition::kNoSource;
TokenPosition end_of_line_pos = TokenPosition::kNoSource;
script.GetTokenLocation(pos, &token_line, &token_start_column);
script.TokenRangeAtLine(token_line, &ignored, &end_of_line_pos);
TokenPosition token_end_pos = TokenPosition::Min(
TokenPosition::Deserialize(next_closest_token_position.Pos() - 1),
end_of_line_pos);
if ((token_end_pos.IsReal() && exact_token_pos.IsReal() &&
(token_end_pos < exact_token_pos)) ||
(token_start_column > *best_column)) {
// We prefer the token with the lowest column number compatible with the
// requested column. The current token under consideration either ends
// before the requested column, and is thus incompatible with it, or
// has a higher column number than the best token we've found so far, so
// we reject the current token under consideration.
return;
}
}
// Prefer the lowest (first) token pos.
if (pos < *best_fit_pos) {
*best_fit_pos = pos;
*best_line = token_line;
*best_column = token_start_column;
}
}
// Returns the best fit token position for a breakpoint.
//
// Takes a range of tokens [requested_token_pos, last_token_pos] and
// an optional column (requested_column). The range of tokens usually
// represents one line of the program text, but can represent a larger
// range on recursive calls.
//
// If |requested_column| is |-1|, then |exact_token_pos| must be
// |TokenPosition::kNoSource|.
//
// The best fit is found in two passes.
//
// The first pass finds a candidate token which:
//
// - is a safepoint,
// - has the lowest column number compatible with the requested column
// if a column has been specified,
// and:
// - has the lowest token position number which satisfies the above.
//
// When we consider a column number, we look for the token which
// intersects the desired column. For example:
//
// 1 2 3
// 12345678901234567890 0
//
// var x = function(function(y));
// ^
//
// If we request a breakpoint at column 14, the lowest column number
// compatible with that would for column 11 (beginning of the
// 'function' token) in the example above.
//
// Once this candidate token from the first pass is found, we then
// have a second pass which considers only those tokens on the same
// line as the candidate token.
//
// The second pass finds a best fit token which:
//
// - is a safepoint,
// - has the same column number as the candidate token (perhaps
// more than one token has the same column number),
// and:
// - has the lowest code address in the generated code.
//
// We prefer the lowest compiled code address, because this tends to
// select the first subexpression on a line. For example in a line
// with nested function calls f(g(x)), the call to g() will have a
// lower compiled code address than the call to f().
//
// If no best fit token can be found, the search is expanded,
// searching through the rest of the current function by calling this
// function recursively.
//
// TODO(turnidge): Given that we usually call this function with a
// token range restricted to a single line, this could be a one-pass
// algorithm, which would be simpler. I believe that it only needs
// two passes to support the recursive try-the-whole-function case.
// Rewrite this later, once there are more tests in place.
static TokenPosition ResolveBreakpointPos(const Function& func,
TokenPosition requested_token_pos,
TokenPosition last_token_pos,
intptr_t requested_column,
TokenPosition exact_token_pos) {
ASSERT(!func.HasOptimizedCode());
ASSERT(
(requested_column == -1 && exact_token_pos == TokenPosition::kNoSource) ||
requested_column > -1);
requested_token_pos =
TokenPosition::Max(requested_token_pos, func.token_pos());
last_token_pos = TokenPosition::Min(last_token_pos, func.end_token_pos());
Zone* zone = Thread::Current()->zone();
Script& script = Script::Handle(zone, func.script());
PcDescriptors& desc = PcDescriptors::Handle(zone);
#if defined(DART_DYNAMIC_MODULES)
auto& bytecode = Bytecode::Handle(zone);
#endif
if (func.HasBytecode()) {
#if defined(DART_DYNAMIC_MODULES)
bytecode = func.GetBytecode();
ASSERT(!bytecode.IsNull());
if (!bytecode.HasSourcePositions()) {
return TokenPosition::kNoSource;
}
#else
UNREACHABLE();
#endif
} else {
ASSERT(func.HasCode());
const auto& code = Code::Handle(zone, func.unoptimized_code());
ASSERT(!code.IsNull());
desc = code.pc_descriptors();
}
// First pass: find the safe point which is closest to the beginning
// of the given token range.
TokenPosition best_fit_pos = TokenPosition::kMaxSource;
intptr_t best_column = INT_MAX;
intptr_t best_line = INT_MAX;
if (func.HasBytecode()) {
#if defined(DART_DYNAMIC_MODULES)
// Only compiled code has synthetic token positions.
ASSERT(!requested_token_pos.IsSynthetic());
bytecode::BytecodeSourcePositionsIterator iter(zone, bytecode);
while (iter.MoveNext()) {
const TokenPosition& pos = iter.TokenPos();
if (!pos.IsWithin(requested_token_pos, last_token_pos)) {
// Token is not in the target range.
continue;
}
TokenPosition next_closest_token_position = TokenPosition::kMaxSource;
if (requested_column >= 0) {
// Find next closest emitted source position.
bytecode::BytecodeSourcePositionsIterator iter2(zone, bytecode);
while (iter2.MoveNext()) {
const TokenPosition& next = iter2.TokenPos();
if (!next.IsReal()) continue;
if ((pos < next) && (next < next_closest_token_position)) {
next_closest_token_position = next;
}
}
}
RefineBreakpointPos(script, pos, next_closest_token_position,
requested_token_pos, last_token_pos, requested_column,
exact_token_pos, &best_fit_pos, &best_column,
&best_line);
}
#endif
} else {
PcDescriptors::Iterator iter(desc, kSafepointKind);
while (iter.MoveNext()) {
const TokenPosition& pos = iter.TokenPos();
if (pos.IsSynthetic() && pos == requested_token_pos) {
// if there's a safepoint for a synthetic function start and the start
// was requested, we're done.
return pos;
}
if (!pos.IsWithin(requested_token_pos, last_token_pos)) {
// Token is not in the target range.
continue;
}
TokenPosition next_closest_token_position = TokenPosition::kMaxSource;
if (requested_column >= 0) {
// Find next closest safepoint
PcDescriptors::Iterator iter2(desc, kSafepointKind);
while (iter2.MoveNext()) {
const TokenPosition& next = iter2.TokenPos();
if (!next.IsReal()) continue;
if ((pos < next) && (next < next_closest_token_position)) {
next_closest_token_position = next;
}
}
}
RefineBreakpointPos(script, pos, next_closest_token_position,
requested_token_pos, last_token_pos, requested_column,
exact_token_pos, &best_fit_pos, &best_column,
&best_line);
}
}
// Second pass (if we found a safe point in the first pass). Find
// the token on the line which is at the best fit column (if column
// was specified) and has the lowest code address.
if (best_fit_pos != TokenPosition::kMaxSource) {
ASSERT(best_fit_pos.IsReal());
const Script& script = Script::Handle(zone, func.script());
const TokenPosition begin_pos = best_fit_pos;
TokenPosition end_of_line_pos = TokenPosition::kNoSource;
if (best_line < 0) {
script.GetTokenLocation(begin_pos, &best_line);
}
ASSERT(best_line > 0);
TokenPosition ignored = TokenPosition::kNoSource;
script.TokenRangeAtLine(best_line, &ignored, &end_of_line_pos);
end_of_line_pos = TokenPosition::Max(end_of_line_pos, begin_pos);
uword lowest_pc_offset = kUwordMax;
if (func.HasBytecode()) {
#if defined(DART_DYNAMIC_MODULES)
bytecode::BytecodeSourcePositionsIterator iter(zone, bytecode);
while (iter.MoveNext()) {
const TokenPosition& pos = iter.TokenPos();
uword pc_offset = iter.PcOffset();
if (requested_column >= 0) {
if (pos != best_fit_pos) {
// Not an match for the requested column.
continue;
}
} else if (!pos.IsWithin(begin_pos, end_of_line_pos)) {
// Token is not on same line as best fit.
continue;
}
// Prefer the lowest pc offset.
if (pc_offset < lowest_pc_offset) {
lowest_pc_offset = pc_offset;
best_fit_pos = pos;
}
}
#endif
} else {
PcDescriptors::Iterator iter(desc, kSafepointKind);
while (iter.MoveNext()) {
const TokenPosition& pos = iter.TokenPos();
if (requested_column >= 0) {
if (pos != best_fit_pos) {
// Not an match for the requested column.
continue;
}
} else if (!pos.IsWithin(begin_pos, end_of_line_pos)) {
// Token is not on same line as best fit.
continue;
}
// Prefer the lowest pc offset.
if (iter.PcOffset() < lowest_pc_offset) {
lowest_pc_offset = iter.PcOffset();
best_fit_pos = pos;
}
}
}
return best_fit_pos;
}
return TokenPosition::kNoSource;
}
bool BreakpointLocation::EnsureIsResolved(const Function& target_function,
TokenPosition exact_token_pos) {
if (IsResolved()) {
return true;
}
// Resolve source breakpoint in the newly compiled function.
TokenPosition resolved_pos =
ResolveBreakpointPos(target_function, token_pos(), end_token_pos(),
requested_column_number(), exact_token_pos);
if (!resolved_pos.IsDebugPause()) {
if (FLAG_verbose_debug) {
OS::PrintErr("Failed resolving breakpoint for function '%s'\n",
target_function.ToFullyQualifiedCString());
}
return false;
}
TokenPosition requested_pos = token_pos();
TokenPosition requested_end_pos = end_token_pos();
SetResolved(target_function, resolved_pos);
Breakpoint* breakpoint = breakpoints();
while (breakpoint != nullptr) {
if (FLAG_verbose_debug) {
OS::PrintErr("Resolved breakpoint %" Pd
" to pos %s, function '%s' (requested range %s-%s, "
"requested col %" Pd ")\n",
breakpoint->id(), token_pos().ToCString(),
target_function.ToFullyQualifiedCString(),
requested_pos.ToCString(), requested_end_pos.ToCString(),
requested_column_number());
}
debugger()->SendBreakpointEvent(ServiceEvent::kBreakpointResolved,
breakpoint);
breakpoint = breakpoint->next();
}
return true;
}
void GroupDebugger::MakeCodeBreakpointAtUnsafe(Thread* thread,
const Function& func,
BreakpointLocation* loc) {
DEBUG_ASSERT(thread->IsInStoppedMutatorsScope() ||
code_breakpoints_lock()->IsCurrentThreadWriter());
ASSERT(loc->token_pos().IsReal());
ASSERT((loc != nullptr) && loc->IsResolved());
auto* zone = thread->zone();
auto& code = Code::Handle(zone);
auto& bytecode = Bytecode::Handle(zone);
uword start = 0;
uword lowest_pc_offset = kUwordMax;
UntaggedPcDescriptors::Kind lowest_kind = UntaggedPcDescriptors::kAnyKind;
// Find the safe point with the lowest compiled code address
// that maps to the token position of the source breakpoint.
if (func.HasBytecode()) {
#if defined(DART_DYNAMIC_MODULES)
bytecode = func.GetBytecode();
ASSERT(!bytecode.IsNull());
if (!bytecode.HasSourcePositions()) {
return;
}
start = bytecode.PayloadStart();
bytecode::BytecodeSourcePositionsIterator iter(zone, bytecode);
while (iter.MoveNext()) {
if (iter.TokenPos() == loc->token_pos_) {
// Breakpoints are set and located using the address of the instruction
// following the breakpoint instruction, since frames contain
// return addresses.
const uword pc_offset =
KernelBytecode::Next(start + iter.PcOffset()) - start;
if (pc_offset < lowest_pc_offset) {
lowest_pc_offset = pc_offset;
}
}
}
#else
UNREACHABLE();
#endif
} else {
ASSERT(func.HasCode());
ASSERT(!func.HasOptimizedCode());
code = func.unoptimized_code();
ASSERT(!code.IsNull());
start = code.PayloadStart();
const auto& desc = PcDescriptors::Handle(zone, code.pc_descriptors());
PcDescriptors::Iterator iter(desc, kSafepointKind);
while (iter.MoveNext()) {
if (iter.TokenPos() == loc->token_pos_) {
if (iter.PcOffset() < lowest_pc_offset) {
lowest_pc_offset = iter.PcOffset();
lowest_kind = iter.Kind();
}
}
}
}
if (lowest_pc_offset == kUwordMax) {
return;
}
uword lowest_pc = start + lowest_pc_offset;
CodeBreakpoint* code_bpt = GetCodeBreakpoint(lowest_pc);
if (code_bpt == nullptr) {
// No code breakpoint for this code exists; create one.
if (!bytecode.IsNull()) {
code_bpt = new CodeBreakpoint(bytecode, loc, lowest_pc);
} else {
code_bpt = new CodeBreakpoint(code, loc, lowest_pc, lowest_kind);
}
if (FLAG_verbose_debug) {
OS::PrintErr("Setting code breakpoint at pos %s pc %#" Px " offset %#" Px
"\n",
loc->token_pos().ToCString(), lowest_pc, lowest_pc - start);
}
RegisterCodeBreakpoint(code_bpt);
} else {
if (FLAG_verbose_debug) {
OS::PrintErr(
"Adding location to existing code breakpoint at pos %s pc %#" Px
" offset %#" Px "\n",
loc->token_pos().ToCString(), lowest_pc, lowest_pc - start);
}
if (!code_bpt->HasBreakpointLocation(loc)) {
code_bpt->AddBreakpointLocation(loc);
}
}
if (loc->AnyEnabled()) {
code_bpt->Enable();
}
}
void GroupDebugger::MakeCodeBreakpointAt(const Function& func,
BreakpointLocation* loc) {
auto thread = Thread::Current();
if (thread->IsInStoppedMutatorsScope()) {
MakeCodeBreakpointAtUnsafe(thread, func, loc);
} else {
SafepointWriteRwLocker sl(thread, code_breakpoints_lock());
MakeCodeBreakpointAtUnsafe(thread, func, loc);
}
}
ErrorPtr Debugger::FindAndCompileMatchingFunctions(
const GrowableHandlePtrArray<const Script>& scripts,
TokenPosition start_pos,
TokenPosition end_pos,
GrowableObjectArray& code_function_list) const {
auto thread = Thread::Current();
auto zone = thread->zone();
HANDLESCOPE(thread);
Script& script = Script::Handle(zone);
Object& ensure_has_code_result = Object::Handle(zone);
Class& cls = Class::Handle(zone);
Array& functions = Array::Handle(zone);
Function& function = Function::Handle(zone);
Array& fields = Array::Handle(zone);
Field& field = Field::Handle(zone);
const ClassTable& class_table = *isolate_->group()->class_table();
const intptr_t num_classes = class_table.NumCids();
const intptr_t num_tlc_classes = class_table.NumTopLevelCids();
for (intptr_t i = 0; i < scripts.length(); ++i) {
script = scripts.At(i).ptr();
{
HANDLESCOPE(thread);
ClosureFunctionsCache::ForAllClosureFunctions(
[&](const Function& function) {
ASSERT(!function.IsNull());
if ((function.token_pos() == start_pos) &&
(function.end_token_pos() == end_pos) &&
(function.script() == script.ptr()) &&
function.is_debuggable()) {
// If we've found a matching function, ensure it's compiled so
// the breakpoint currently being set can be resolved immediately.
ensure_has_code_result = function.EnsureHasCodeNoThrow();
if (ensure_has_code_result.IsError()) {
return false; // Stop iterating.
}
code_function_list.Add(function);
ASSERT(!function.HasImplicitClosureFunction());
}
return true; // Continue iterating.
});
}
if (ensure_has_code_result.IsError()) {
return Error::Cast(ensure_has_code_result).ptr();
}
for (intptr_t i = kInstanceCid; i < num_classes + num_tlc_classes; i++) {
const intptr_t cid =
i < num_classes ? i
: ClassTable::CidFromTopLevelIndex(i - num_classes);
if (!class_table.HasValidClassAt(cid)) {
continue;
}
cls = class_table.At(cid);
// If the class is not finalized, e.g. if it hasn't been parsed
// yet entirely, we can ignore it. If it contains a function with
// an unresolved breakpoint, we will detect it if and when the
// function gets compiled.
if (!cls.is_finalized()) {
continue;
}
HANDLESCOPE(thread);
// Note: we need to check the functions of this class even if
// the class is defined in a different 'script'. There could
// be mixin functions from the given script in this class.
functions = cls.current_functions();
ASSERT(!functions.IsNull());
const intptr_t num_functions = functions.Length();
for (intptr_t pos = 0; pos < num_functions; pos++) {
function ^= functions.At(pos);
ASSERT(!function.IsNull());
bool function_added = false;
if (function.is_debuggable() && function.token_pos() == start_pos &&
function.end_token_pos() == end_pos &&
function.script() == script.ptr()) {
// If we've found a matching function, ensure it's compiled so
// the breakpoint currently being set can be resolved immediately.
ensure_has_code_result = function.EnsureHasCodeNoThrow();
if (ensure_has_code_result.IsError()) {
return Error::Cast(ensure_has_code_result).ptr();
}
code_function_list.Add(function);
function_added = true;
}
if (function_added && function.HasImplicitClosureFunction()) {
function = function.ImplicitClosureFunction();
if (function.is_debuggable()) {
// Ensure that the implicit closure function is compiled so the
// breakpoint currently being set can be resolved immediately.
ensure_has_code_result = function.EnsureHasCodeNoThrow();
if (ensure_has_code_result.IsError()) {
return Error::Cast(ensure_has_code_result).ptr();
}
code_function_list.Add(function);
}
}
}
fields = cls.fields();
ASSERT(!fields.IsNull());
const intptr_t num_fields = fields.Length();
for (intptr_t pos = 0; pos < num_fields; pos++) {
field ^= fields.At(pos);
ASSERT(!field.IsNull());
if (field.Script() != script.ptr()) {
continue;
}
if (!field.has_nontrivial_initializer()) {
continue;
}
function = field.EnsureInitializerFunction();
ASSERT(!function.IsNull());
if (function.is_debuggable() && function.HasCode() &&
function.token_pos() == start_pos &&
function.end_token_pos() == end_pos &&
function.script() == script.ptr()) {
ensure_has_code_result = function.EnsureHasCodeNoThrow();
if (ensure_has_code_result.IsError()) {
return Error::Cast(ensure_has_code_result).ptr();
}
code_function_list.Add(function);
}
}
}
}
return Error::null();
}
static void UpdateBestFit(Function* best_fit, const Function& func) {
if (best_fit->IsNull()) {
*best_fit = func.ptr();
} else if ((best_fit->token_pos().IsSynthetic() ||
func.token_pos().IsSynthetic() ||
(best_fit->token_pos() < func.token_pos())) &&
(func.end_token_pos() <= best_fit->end_token_pos())) {
*best_fit = func.ptr();
}
}
// If a best fit function is found, stores that function in |best_fit| and
// returns |true|.
// Note that in some cases, there may be a closure that is a better fit that the
// function returned in |best_fit|, because |FindBestFit| is only able to detect
// that closure if the function containing it has already been compiled.
bool Debugger::FindBestFit(const Script& script,
TokenPosition token_pos,
TokenPosition last_token_pos,
Function* best_fit) {
auto thread = Thread::Current();
auto isolate_group = thread->isolate_group();
Zone* zone = thread->zone();
Library& lib = Library::Handle(zone);
Class& cls = Class::Handle(zone);
Array& functions = Array::Handle(zone);
Function& function = Function::Handle(zone);
Array& fields = Array::Handle(zone);
Field& field = Field::Handle(zone);
Array& scripts = Array::Handle(zone);
String& script_url = String::Handle(zone);
Error& error = Error::Handle(zone);
const ClassTable& class_table = *isolate_->group()->class_table();
const intptr_t num_classes = class_table.NumCids();
const intptr_t num_tlc_classes = class_table.NumTopLevelCids();
// A single script can belong to several libraries because of mixins.
// Go through all libraries and for each that contains the script, try to find
// a fit there.
// Return the first fit found, but if a library doesn't contain a fit,
// process the next one.
const GrowableObjectArray& libs = GrowableObjectArray::Handle(
zone, isolate_group->object_store()->libraries());
for (int i = 0; i < libs.Length(); i++) {
lib ^= libs.At(i);
ASSERT(!lib.IsNull());
scripts = lib.LoadedScripts();
bool lib_has_script = false;
for (intptr_t j = 0; j < scripts.Length(); j++) {
if (scripts.At(j) == script.ptr()) {
lib_has_script = true;
break;
}
}
if (!lib_has_script) {
continue;
}
if (!lib.IsDebuggable()) {
if (FLAG_verbose_debug) {
OS::PrintErr("Library '%s' has been marked as non-debuggable\n",
lib.ToCString());
}
continue;
}
script_url = script.url();
{
HANDLESCOPE(thread);
ClosureFunctionsCache::ForAllClosureFunctions([&](const Function& fun) {
if (fun.script() == script.ptr() &&
FunctionOverlaps(fun, script_url, token_pos, last_token_pos)) {
// Select the inner most closure.
UpdateBestFit(best_fit, fun);
}
return true; // Continue iteration
});
}
if (!best_fit->IsNull()) {
// The inner most closure found will be the best fit. Going
// over class functions below will not help in any further
// narrowing.
return true;
}
for (intptr_t i = kInstanceCid; i < num_classes + num_tlc_classes; i++) {
const intptr_t cid =
i < num_classes ? i
: ClassTable::CidFromTopLevelIndex(i - num_classes);
if (!class_table.HasValidClassAt(cid)) {
continue;
}
cls = class_table.At(cid);
// This class is relevant to us only if it belongs to the
// library to which |script| belongs.
if (cls.library() != lib.ptr()) {
continue;
}
// Parse class definition if not done yet.
error = cls.EnsureIsFinalized(Thread::Current());
if (!error.IsNull()) {
// Ignore functions in this class.
// TODO(hausner): Should we propagate this error? How?
// EnsureIsFinalized only returns an error object if there
// is no longjump base on the stack.
continue;
}
HANDLESCOPE(thread);
functions = cls.current_functions();
ASSERT(!functions.IsNull());
const intptr_t num_functions = functions.Length();
for (intptr_t pos = 0; pos < num_functions; pos++) {
function ^= functions.At(pos);
ASSERT(!function.IsNull());
if (IsImplicitFunction(function) || function.is_synthetic() ||
!function.token_pos().IsReal() ||
!function.end_token_pos().IsReal() || !function.is_debuggable()) {
// We skip implicit functions and synthetic functions because they
// do not have user specifiable source locations. We also skip
// functions marked as undebuggable.
continue;
}
if (FunctionOverlaps(function, script_url, token_pos, last_token_pos)) {
// Closures and inner functions within a class method are not
// present in the functions of a class. Hence, we can return
// right away as looking through other functions of a class
// will not narrow down to any inner function/closure.
*best_fit = function.ptr();
return true;
}
}
// If none of the functions in the class contain token_pos, then we check
// if it falls within a function literal initializer of a field.
fields = cls.fields();
ASSERT(!fields.IsNull());
const intptr_t num_fields = fields.Length();
for (intptr_t pos = 0; pos < num_fields; pos++) {
TokenPosition start = TokenPosition::kNoSource;
TokenPosition end = TokenPosition::kNoSource;
field ^= fields.At(pos);
ASSERT(!field.IsNull());
if (field.Script() != script.ptr()) {
// The field should be defined in the script we want to set
// the breakpoint in.
continue;
}
if (!field.has_nontrivial_initializer()) {
continue;
}
start = field.token_pos();
end = field.end_token_pos();
if (token_pos.IsWithin(start, end) ||
start.IsWithin(token_pos, last_token_pos)) {
*best_fit = field.EnsureInitializerFunction();
return true;
}
}
}
}
return false;
}
// If |requested_column| is |-1|, then |exact_token_pos| must be
// |TokenPosition::kNoSource|.
BreakpointLocation* Debugger::SetCodeBreakpoints(
const GrowableHandlePtrArray<const Script>& scripts,
TokenPosition token_pos,
TokenPosition last_token_pos,
intptr_t requested_line,
intptr_t requested_column,
TokenPosition exact_token_pos,
const GrowableObjectArray& functions) {
ASSERT(
(requested_column == -1 && exact_token_pos == TokenPosition::kNoSource) ||
requested_column > -1);
Function& function = Function::Handle();
function ^= functions.At(0);
TokenPosition breakpoint_pos = ResolveBreakpointPos(
function, token_pos, last_token_pos, requested_column, exact_token_pos);
if (!breakpoint_pos.IsReal()) {
return nullptr;
}
const String& script_url = String::Handle(scripts.At(0).url());
BreakpointLocation* loc =
GetResolvedBreakpointLocation(script_url, breakpoint_pos);
if (loc == nullptr) {
// Find an existing unresolved breakpoint location.
loc = GetBreakpointLocation(script_url, token_pos, requested_line,
requested_column);
}
if (loc == nullptr) {
loc = new BreakpointLocation(this, scripts, breakpoint_pos, breakpoint_pos,
requested_line, requested_column);
RegisterBreakpointLocation(loc);
}
// A source breakpoint for this location may already exists, but it may
// not yet be resolved in code.
if (loc->IsResolved()) {
return loc;
}
loc->SetResolved(function, breakpoint_pos);
// Create code breakpoints for all compiled functions we found.
Function& func = Function::Handle();
const intptr_t num_functions = functions.Length();
for (intptr_t i = 0; i < num_functions; i++) {
func ^= functions.At(i);
ASSERT(func.HasCode());
group_debugger()->MakeCodeBreakpointAt(func, loc);
}
if (FLAG_verbose_debug) {
intptr_t line_number = -1;
intptr_t column_number = -1;
scripts.At(0).GetTokenLocation(breakpoint_pos, &line_number,
&column_number);
OS::PrintErr("Resolved code breakpoint for function '%s' at line %" Pd
" col %" Pd "\n",
func.ToFullyQualifiedCString(), line_number, column_number);
}
return loc;
}
#if !defined(DART_PRECOMPILED_RUNTIME)
static TokenPosition FindExactTokenPosition(const Script& script,
TokenPosition start_of_line,
intptr_t column_number);
#endif // !defined(DART_PRECOMPILED_RUNTIME)
ErrorPtr Debugger::SetBreakpoint(
const Script& script,
TokenPosition token_pos,
TokenPosition last_token_pos,
intptr_t requested_line,
intptr_t requested_column,
const Function& function,
BreakpointLocation** result_breakpoint_location) {
GrowableHandlePtrArray<const Script> scripts(Thread::Current()->zone(), 1);
scripts.Add(script);
return SetBreakpoint(scripts, token_pos, last_token_pos, requested_line,
requested_column, function, result_breakpoint_location);
}
ErrorPtr Debugger::SetBreakpoint(
const GrowableHandlePtrArray<const Script>& scripts,
TokenPosition token_pos,
TokenPosition last_token_pos,
intptr_t requested_line,
intptr_t requested_column,
const Function& function,
BreakpointLocation** result_breakpoint_location) {
ASSERT(scripts.length() > 0);
ASSERT(result_breakpoint_location != nullptr);
Function& func = Function::Handle();
const Script& script = scripts.At(0);
if (function.IsNull()) {
if (!FindBestFit(script, token_pos, last_token_pos, &func)) {
return Object::no_debuggable_code_error().ptr();
}
ASSERT(!func.IsNull());
// There may be closures that were not considered by the first call to
// |FindBestFit| because the functions containing them were not yet
// compiled. So, we must recursively compile functions until we converge
// at a true best fit function.
Function& tmp = Function::Handle();
Object& ensure_has_code_result = Object::Handle();
do {
ensure_has_code_result = func.EnsureHasCodeNoThrow();
if (ensure_has_code_result.IsError()) {
return Error::Cast(ensure_has_code_result).ptr();
}
tmp = func.ptr();
FindBestFit(script, token_pos, last_token_pos, &func);
ASSERT(!func.IsNull());
} while (tmp.ptr() != func.ptr());
} else {
func = function.ptr();
if (!func.token_pos().IsReal()) {
// Missing source positions?
return Object::no_debuggable_code_error().ptr();
}
}
if (!func.IsNull()) {
// There may be more than one function object for a given function in source
// code. There may be implicit closure functions, and there may be copies of
// mixin functions. Compile and collect all functions whose source code
// range matches exactly the best fit function we found. We compile all of
// theses functions eagerly so that the breakpoint currently being set can
// be resolved immediately.
GrowableObjectArray& code_functions =
GrowableObjectArray::Handle(GrowableObjectArray::New());
const Error& error = Error::Handle(FindAndCompileMatchingFunctions(
scripts, func.token_pos(), func.end_token_pos(), code_functions));
if (!error.IsNull()) {
return error.ptr();
}
if (code_functions.Length() > 0) {
// One or more function object containing this breakpoint location
// have already been compiled. We can resolve the breakpoint now.
// If requested_column is larger than zero, [token_pos, last_token_pos]
// governs one single line of code.
TokenPosition exact_token_pos = TokenPosition::kNoSource;
#if !defined(DART_PRECOMPILED_RUNTIME)
if (token_pos != last_token_pos && requested_column >= 0) {
exact_token_pos =
FindExactTokenPosition(script, token_pos, requested_column);
}
#endif // !defined(DART_PRECOMPILED_RUNTIME)
BreakpointLocation* loc = nullptr;
// Ensure that code stays deoptimized (and background compiler disabled)
// until we have installed the breakpoint (at which point the compiler
// will not try to optimize it anymore).
RunWithStoppedDeoptimizedWorld([&] {
loc = SetCodeBreakpoints(scripts, token_pos, last_token_pos,
requested_line, requested_column,
exact_token_pos, code_functions);
});
if (loc != nullptr) {
*result_breakpoint_location = loc;
return Error::null();
}
}
}
// There is no debuggable code at all at |token_pos|, so we leave
// |*result_breakpoint_location| as null.
return Error::null();
}
// Synchronize the enabled/disabled state of all code breakpoints
// associated with the breakpoint location loc.
void GroupDebugger::SyncBreakpointLocation(BreakpointLocation* loc) {
bool any_enabled = loc->AnyEnabled();
SafepointWriteRwLocker sl(Thread::Current(), code_breakpoints_lock());
CodeBreakpoint* cbpt = code_breakpoints_;
while (cbpt != nullptr) {
if (cbpt->HasBreakpointLocation(loc)) {
if (any_enabled) {
cbpt->Enable();
} else {
cbpt->Disable();
}
}
cbpt = cbpt->next();
}
}
ErrorPtr Debugger::SetBreakpointAtEntry(const Function& target_function,
bool single_shot,
Breakpoint** result_breakpoint) {
ASSERT(!target_function.IsNull());
ASSERT(result_breakpoint != nullptr);
if (!target_function.is_debuggable()) {
return Object::no_debuggable_code_error().ptr();
}
const Script& script = Script::Handle(target_function.script());
BreakpointLocation* bpt_location = nullptr;
const Error& error = Error::Handle(SetBreakpoint(
script, target_function.token_pos(), target_function.end_token_pos(), -1,
-1 /* no requested line/col */, target_function, &bpt_location));
if (!error.IsNull()) {
return error.ptr();
}
ASSERT(bpt_location != nullptr);
if (single_shot) {
*result_breakpoint = bpt_location->AddSingleShot(this);
} else {
*result_breakpoint = bpt_location->AddRepeated(this);
}
return Error::null();
}
ErrorPtr Debugger::SetBreakpointAtActivation(const Instance& closure,
bool single_shot,
Breakpoint** result_breakpoint) {
ASSERT(result_breakpoint != nullptr);
if (!closure.IsClosure()) {
return Object::no_debuggable_code_error().ptr();
}
const Function& func = Function::Handle(Closure::Cast(closure).function());
const Script& script = Script::Handle(func.script());
BreakpointLocation* bpt_location = nullptr;
const Error& error = Error::Handle(
SetBreakpoint(script, func.token_pos(), func.end_token_pos(), -1,
-1 /* no line/col */, func, &bpt_location));
if (!error.IsNull()) {
return error.ptr();
}
ASSERT(bpt_location != nullptr);
*result_breakpoint =
bpt_location->AddBreakpoint(this, Closure::Cast(closure), single_shot);
return Error::null();
}
Breakpoint* Debugger::BreakpointAtActivation(const Instance& closure) {
if (!closure.IsClosure()) {
return nullptr;
}
BreakpointLocation* loc = breakpoint_locations_;
while (loc != nullptr) {
Breakpoint* bpt = loc->breakpoints();
while (bpt != nullptr) {
if (closure.ptr() == bpt->closure()) {
return bpt;
}
bpt = bpt->next();
}
loc = loc->next();
}
return nullptr;
}
void Debugger::SetBreakpointAtResumption(const Object& function_data) {
ASSERT(!function_data.IsNull());
ASSERT(function_data.IsInstance());
breakpoints_at_resumption_.Add(function_data.ptr());
isolate_->set_has_resumption_breakpoints(true);
}
void Debugger::ResumptionBreakpoint() {
ASSERT(!breakpoints_at_resumption_.is_empty());
ASSERT(isolate_->has_resumption_breakpoints());
ActivationFrame* top_frame = TopDartFrame();
ASSERT(top_frame->function().IsSuspendableFunction());
const auto& function_data =
Object::Handle(top_frame->GetSuspendableFunctionData());
for (intptr_t i = 0, n = breakpoints_at_resumption_.length(); i < n; ++i) {
if (breakpoints_at_resumption_[i] == function_data.ptr()) {
breakpoints_at_resumption_.RemoveAt(i);
if (breakpoints_at_resumption_.is_empty()) {
isolate_->set_has_resumption_breakpoints(false);
}
if (FLAG_verbose_debug) {
OS::PrintErr(
"ResumptionBreakpoint - hit a breakpoint, continue single "
"stepping\n");
}
// Resumption breakpoints are for stepping out of await expressions,
// so record its information to avoid pausing within it.
SetLastSteppingInformation(top_frame);
EnterSingleStepMode();
return;
}
}
}
ErrorPtr Debugger::SetBreakpointAtLineCol(const String& script_url,
intptr_t line_number,
intptr_t column_number,
Breakpoint** result_breakpoint) {
// Prevent future tests from calling this function in the wrong
// execution state. If you hit this assert, consider using
// Dart_SetBreakpoint instead.
ASSERT(Thread::Current()->execution_state() == Thread::kThreadInVM);
ASSERT(result_breakpoint != nullptr);
BreakpointLocation* loc = nullptr;
const Error& error = Error::Handle(BreakpointLocationAtLineCol(
script_url, line_number, column_number, &loc));
if (!error.IsNull()) {
return error.ptr();
}
ASSERT(loc != nullptr);
*result_breakpoint = loc->AddRepeated(this);
return Error::null();
}
ErrorPtr Debugger::BreakpointLocationAtLineCol(
const String& script_url,
intptr_t line_number,
intptr_t column_number,
BreakpointLocation** result_breakpoint_location) {
ASSERT(result_breakpoint_location != nullptr);
Zone* zone = Thread::Current()->zone();
Library& lib = Library::Handle(zone);
GrowableHandlePtrArray<const Script> scripts(zone, 1);
const GrowableObjectArray& libs = GrowableObjectArray::Handle(
isolate_->group()->object_store()->libraries());
bool is_package = script_url.StartsWith(Symbols::PackageScheme());
bool is_dart_colon = script_url.StartsWith(Symbols::DartScheme());
Script& script_for_lib = Script::Handle(zone);
for (intptr_t i = 0; i < libs.Length(); i++) {
lib ^= libs.At(i);
// Ensure that all top-level members are loaded so their scripts
// are available for look up. When certain script only contains
// top level functions, scripts could still be loaded correctly.
lib.EnsureTopLevelClassIsFinalized();
bool useResolvedUri = !is_package && !is_dart_colon;
script_for_lib = lib.LookupScript(script_url, useResolvedUri);
if (!script_for_lib.IsNull()) {
scripts.Add(script_for_lib);
}
}
if (scripts.length() == 0) {
// No script found with given url. Create a latent breakpoint which
// will be set if the url is loaded later.
BreakpointLocation* latent_bpt =
GetLatentBreakpoint(script_url, line_number, column_number);
if (FLAG_verbose_debug) {
OS::PrintErr(
"Set latent breakpoint in url '%s' at "
"line %" Pd " col %" Pd "\n",
script_url.ToCString(), line_number, column_number);
}
*result_breakpoint_location = latent_bpt;
return Error::null();
}
TokenPosition first_token_idx = TokenPosition::kNoSource;
TokenPosition last_token_idx = TokenPosition::kNoSource;
// Assume all scripts with the same URL have the same token positions.
scripts.At(0).TokenRangeAtLine(line_number, &first_token_idx,
&last_token_idx);
if (!first_token_idx.IsReal()) {
// Script does not contain the given line number.
if (FLAG_verbose_debug) {
OS::PrintErr("Script '%s' does not contain line number %" Pd "\n",
script_url.ToCString(), line_number);
}
return Object::no_debuggable_code_error().ptr();
} else if (!last_token_idx.IsReal()) {
// Line does not contain any tokens.
if (FLAG_verbose_debug) {
OS::PrintErr("No executable code at line %" Pd " in '%s'\n", line_number,
script_url.ToCString());
}
return Object::no_debuggable_code_error().ptr();
}
ASSERT(first_token_idx <= last_token_idx);
Error& error = Error::Handle();
while ((*result_breakpoint_location == nullptr) &&
(first_token_idx <= last_token_idx)) {
HANDLESCOPE(Thread::Current());
error = SetBreakpoint(scripts, first_token_idx, last_token_idx, line_number,
column_number, Function::Handle(),
result_breakpoint_location);
if (!error.IsNull() &&
error.ptr() != Object::no_debuggable_code_error().ptr()) {
// We do not return an error immediately if |SetBreakpoint| returns
// |Object::no_debuggable_code_error().ptr()|, because there is a chance
// that |SetBreakpoint| will succeed if called again after
// |first_token_idx| is advanced.
return error.ptr();
}
first_token_idx = first_token_idx.Next();
}
if (*result_breakpoint_location == nullptr) {
if (FLAG_verbose_debug) {
OS::PrintErr("No executable code at line %" Pd " in '%s'\n", line_number,
script_url.ToCString());
}
return Object::no_debuggable_code_error().ptr();
}
return Error::null();
}
// Return innermost closure contained in 'function' that contains
// the given token position.
static FunctionPtr FindInnermostClosure(Zone* zone,
const Function& function,
TokenPosition token_pos) {
ASSERT(function.end_token_pos().IsReal());
const TokenPosition& func_start = function.token_pos();
const Script& outer_origin = Script::Handle(zone, function.script());
Function& best_fit = Function::Handle(zone);
ClosureFunctionsCache::ForAllClosureFunctions([&](const Function& closure) {
const TokenPosition& closure_start = closure.token_pos();
const TokenPosition& closure_end = closure.end_token_pos();
// We're only interested in closures that have real ending token positions.
// The starting token position can be synthetic.
if (closure_end.IsReal() && (function.end_token_pos() > closure_end) &&
(!closure_start.IsReal() || !func_start.IsReal() ||
(closure_start > func_start)) &&
token_pos.IsWithin(closure_start, closure_end) &&
(closure.script() == outer_origin.ptr())) {
UpdateBestFit(&best_fit, closure);
}
return true; // Continue iteration.
});
return best_fit.ptr();
}
bool GroupDebugger::EnsureLocationIsInFunction(Zone* zone,
const Function& function,
BreakpointLocation* location) {
const String& url = String::Handle(zone, location->url());
if (!FunctionOverlaps(function, url, location->token_pos(),
location->end_token_pos())) {
return false;
}
TokenPosition token_pos = location->token_pos();
#if !defined(DART_PRECOMPILED_RUNTIME)
TokenPosition end_token_pos = location->end_token_pos();
if (token_pos != end_token_pos && location->requested_column_number() >= 0) {
// Narrow down the token position range to a single value
// if requested column number is provided so that inner
// Closure won't be missed.
const Script& script = Script::Handle(location->script());
token_pos = FindExactTokenPosition(script, token_pos,
location->requested_column_number());
}
#endif // !defined(DART_PRECOMPILED_RUNTIME)
const Function& inner_function =
Function::Handle(zone, FindInnermostClosure(zone, function, token_pos));
if (!inner_function.IsNull()) {
if (FLAG_verbose_debug) {
OS::PrintErr(
"Pending breakpoint remains unresolved in "
"inner function '%s'\n",
inner_function.ToFullyQualifiedCString());
}
return false;
}
// There is no local function within function that contains the
// breakpoint token position.
return true;
}
void GroupDebugger::NotifyCompilation(const Function& function) {
if (!function.is_debuggable()) {
return;
}
Function& resolved_function = Function::Handle(function.ptr());
auto thread = Thread::Current();
auto zone = thread->zone();
// Going through BreakpointLocations of all isolates and debuggers looking
// for those that can be resolved and added code breakpoints at now.
//
// The check below is used instead of breakpoint_locations_lock acquisition.
// We don't need to acquire the lock if always run with stopped mutators.
// We can't acquire the lock if we run with stopped mutators as that could
// result in deadlock.
RELEASE_ASSERT(thread->IsInStoppedMutatorsScope());
for (intptr_t i = 0; i < breakpoint_locations_.length(); i++) {
BreakpointLocation* location = breakpoint_locations_.At(i);
if (EnsureLocationIsInFunction(zone, resolved_function, location)) {
// All mutators are stopped (see RELEASE_ASSERT above). We temporarily
// enter the isolate for which the breakpoint was registered.
// The code path below may issue service events which will use the active
// isolate's object-id ring for naming VM objects.
ActiveIsolateScope active_isolate(thread,
location->debugger()->isolate());
// Ensure the location is resolved for the original function.
TokenPosition exact_token_pos = TokenPosition::kNoSource;
#if !defined(DART_PRECOMPILED_RUNTIME)
if (location->token_pos() != location->end_token_pos() &&
location->requested_column_number() >= 0) {
exact_token_pos = FindExactTokenPosition(
Script::Handle(location->script()), location->token_pos(),
location->requested_column_number());
}
#endif // !defined(DART_PRECOMPILED_RUNTIME)
location->EnsureIsResolved(function, exact_token_pos);
if (FLAG_verbose_debug) {
Breakpoint* bpt = location->breakpoints();
while (bpt != nullptr) {
OS::PrintErr("Setting breakpoint %" Pd " for %s '%s'\n", bpt->id(),
function.IsClosureFunction() ? "closure" : "function",
function.ToFullyQualifiedCString());
bpt = bpt->next();
}
}
MakeCodeBreakpointAt(function, location);
}
}
}
void GroupDebugger::VisitObjectPointers(ObjectPointerVisitor* visitor) {
CodeBreakpoint* cbpt = code_breakpoints_;
while (cbpt != nullptr) {
cbpt->VisitObjectPointers(visitor);
cbpt = cbpt->next();
}
}
// static
void Debugger::VisitObjectPointers(ObjectPointerVisitor* visitor) {
ASSERT(visitor != nullptr);
BreakpointLocation* loc = breakpoint_locations_;
while (loc != nullptr) {
loc->VisitObjectPointers(visitor);
loc = loc->next();
}
loc = latent_locations_;
while (loc != nullptr) {
loc->VisitObjectPointers(visitor);
loc = loc->next();
}
for (intptr_t i = 0, n = breakpoints_at_resumption_.length(); i < n; ++i) {
visitor->VisitPointer(&breakpoints_at_resumption_[i]);
}
}
void Debugger::Pause(ServiceEvent* event) {
ASSERT(event->IsPause()); // Should call InvokeEventHandler instead.
ASSERT(!ignore_breakpoints_); // We shouldn't get here when ignoring bpts.
ASSERT(!IsPaused()); // No recursive pausing.
pause_event_ = event;
pause_event_->UpdateTimestamp();
// We are about to invoke the debugger's event handler. Disable
// interrupts for this thread while waiting for debug commands over
// the service protocol.
{
Thread* thread = Thread::Current();
DisableThreadInterruptsScope dtis(thread);
TIMELINE_DURATION(thread, Debugger, "Debugger Pause");
// Send the pause event.
Service::HandleEvent(event);
{
TransitionVMToNative transition(thread);
isolate_->PauseEventHandler();
}
// Notify the service that we have resumed.
const Error& error = Error::Handle(Thread::Current()->sticky_error());
ASSERT(error.IsNull() || error.IsUnwindError() ||
error.IsUnhandledException());
// Only send a resume event when the isolate is not unwinding.
if (!error.IsUnwindError()) {
ServiceEvent resume_event(event->isolate(), ServiceEvent::kResume);
resume_event.set_top_frame(event->top_frame());
Service::HandleEvent(&resume_event);
}
}
group_debugger()->Pause();
pause_event_ = nullptr;
}
void GroupDebugger::Pause() {
SafepointWriteRwLocker sl(Thread::Current(), code_breakpoints_lock());
if (needs_breakpoint_cleanup_) {
RemoveUnlinkedCodeBreakpoints();
}
}
void Debugger::EnterSingleStepMode() {
ResetSteppingFramePointer();
NotifySingleStepping(true);
}
void Debugger::ResetSteppingFramePointer() {
stepping_fp_ = 0;
#if defined(DART_DYNAMIC_MODULES)
stepping_fp_from_interpreted_frame_ = false;
#endif
}
void Debugger::ResetLastSteppingInformation() {
last_stepping_fp_ = 0;
last_stepping_pos_ = TokenPosition::kNoSource;
}
void Debugger::SetLastSteppingInformation(ActivationFrame* frame) {
last_stepping_fp_ = frame->fp();
last_stepping_pos_ = frame->TokenPos();
}
void Debugger::SetLastSteppingInformation(BreakpointLocation* bpt_location) {
// Continue stepping until we reach a token position that is not the one at
// which the breakpoint was set.
last_stepping_fp_ = 0;
last_stepping_pos_ = bpt_location->token_pos();
}
bool Debugger::MatchesLastSteppingInformation(ActivationFrame* frame) {
// No information for the last event emitted was recorded.
if (last_stepping_pos_ == TokenPosition::kNoSource) {
return false;
}
// If a specific FP was recorded, then it must match as well.
if (last_stepping_fp_ != 0 && last_stepping_fp_ != frame->fp()) {
return false;
}
return last_stepping_pos_ == frame->TokenPos();
}
void Debugger::SetSyncSteppingFramePointer(ActivationFrame* frame) {
stepping_fp_ = frame->fp();
#if defined(DART_DYNAMIC_MODULES)
stepping_fp_from_interpreted_frame_ = frame->IsInterpreted();
#endif
}
void Debugger::HandleSteppingRequest() {
ResetSteppingFramePointer();
if (resume_action_ == kStepInto) {
// When single stepping, we need to deoptimize because we might be
// stepping into optimized code. This happens in particular if
// the isolate has been interrupted, but can happen in other cases
// as well. We need to deoptimize the world in case we are about
// to call an optimized function.
NotifySingleStepping(true);
if (FLAG_verbose_debug) {
OS::PrintErr("HandleSteppingRequest - kStepInto\n");
}
} else if (resume_action_ == kStepOver) {
NotifySingleStepping(true);
if (stack_trace_->Length() > 0) {
SetSyncSteppingFramePointer(stack_trace_->FrameAt(0));
}
if (FLAG_verbose_debug) {
OS::PrintErr("HandleSteppingRequest - kStepOver stepping_fp=%" Px "\n",
stepping_fp_);
}
} else if (resume_action_ == kStepOut) {
auto* const trace = async_awaiter_stack_trace_ != nullptr
? async_awaiter_stack_trace_
: stack_trace_;
ActivationFrame* sync_caller = nullptr;
ActivationFrame* last_awaiter = nullptr;
for (intptr_t i = 1; i < trace->Length(); i++) {
auto* const frame = trace->FrameAt(i);
if (frame->kind() == ActivationFrame::kAsyncSuspensionMarker) {
last_awaiter = async_awaiter_stack_trace_->FrameAt(i + 1);
} else if (frame->IsDebuggable()) {
if (last_awaiter != nullptr) {
AsyncStepInto(last_awaiter->closure());
if (FLAG_verbose_debug) {
OS::PrintErr(
"HandleSteppingRequest - continue to async awaiter %s\n",
Function::Handle(last_awaiter->closure().function())
.ToFullyQualifiedCString());
}
return;
}
sync_caller = frame;
break;
}
}
// If there is no debuggable synchronous caller (i.e., an attempt to step
// out of the main function), just use the closest caller so the debugger
// doesn't emit another pause in the current function before exiting.
if (sync_caller == nullptr) {
ASSERT(trace->Length() > 1);
if (FLAG_verbose_debug) {
OS::PrintErr("HandleSteppingRequest - no debuggable callers\n");
}
sync_caller = trace->FrameAt(1);
}
NotifySingleStepping(true);
SetSyncSteppingFramePointer(sync_caller);
if (FLAG_verbose_debug) {
OS::PrintErr("HandleSteppingRequest- kStepOut %" Px "\n", stepping_fp_);
}
} else if (resume_action_ == kStepRewind) {
if (FLAG_trace_rewind) {
OS::PrintErr("Rewinding to frame %" Pd "\n", resume_frame_index_);
OS::PrintErr(
"-------------------------\n"
"All frames...\n\n");
StackFrameIterator iterator(ValidationPolicy::kDontValidateFrames,
Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
StackFrame* frame = iterator.NextFrame();
intptr_t num = 0;
while ((frame != nullptr)) {
OS::PrintErr("#%04" Pd " %s\n", num++, frame->ToCString());
frame = iterator.NextFrame();
}
}
RewindToFrame(resume_frame_index_);
UNREACHABLE();
}
}
void Debugger::CacheStackTraces(DebuggerStackTrace* stack_trace,
DebuggerStackTrace* async_awaiter_stack_trace) {
ASSERT(stack_trace_ == nullptr);
stack_trace_ = stack_trace;
ASSERT(async_awaiter_stack_trace_ == nullptr);
async_awaiter_stack_trace_ = async_awaiter_stack_trace;
}
void Debugger::ClearCachedStackTraces() {
stack_trace_ = nullptr;
async_awaiter_stack_trace_ = nullptr;
}
static intptr_t FindNextRewindFrameIndex(DebuggerStackTrace* stack,
intptr_t frame_index) {
for (intptr_t i = frame_index + 1; i < stack->Length(); i++) {
ActivationFrame* frame = stack->FrameAt(i);
if (frame->IsRewindable()) {
return i;
}
}
return -1;
}
// Can we rewind to the indicated frame?
static bool CanRewindFrame(intptr_t frame_index, const char** error) {
// check rewind pc is found
DebuggerStackTrace* stack = Isolate::Current()->debugger()->StackTrace();
intptr_t num_frames = stack->Length();
if (frame_index < 1 || frame_index >= num_frames) {
if (error != nullptr) {
*error = Thread::Current()->zone()->PrintToString(
"Frame must be in bounds [1..%" Pd
"]: "
"saw %" Pd "",
num_frames - 1, frame_index);
}
return false;
}
ActivationFrame* frame = stack->FrameAt(frame_index);
if (!frame->IsRewindable()) {
intptr_t next_index = FindNextRewindFrameIndex(stack, frame_index);
if (next_index > 0) {
*error = Thread::Current()->zone()->PrintToString(
"Cannot rewind to frame %" Pd
" due to conflicting compiler "
"optimizations. "
"Run the vm with --no-prune-dead-locals to disallow these "
"optimizations. "
"Next valid rewind frame is %" Pd ".",
frame_index, next_index);
} else {
*error = Thread::Current()->zone()->PrintToString(
"Cannot rewind to frame %" Pd
" due to conflicting compiler "
"optimizations. "
"Run the vm with --no-prune-dead-locals to disallow these "
"optimizations.",
frame_index);
}
return false;
}
return true;
}
// Given a return address, find the "rewind" pc, which is the pc
// before the corresponding call.
static uword LookupRewindPc(const Code& code, uword return_address) {
ASSERT(!code.is_optimized());
ASSERT(code.ContainsInstructionAt(return_address));
uword pc_offset = return_address - code.PayloadStart();
const PcDescriptors& descriptors =
PcDescriptors::Handle(code.pc_descriptors());
PcDescriptors::Iterator iter(descriptors,
UntaggedPcDescriptors::kRewind |
UntaggedPcDescriptors::kIcCall |
UntaggedPcDescriptors::kUnoptStaticCall);
intptr_t rewind_deopt_id = -1;
uword rewind_pc = 0;
while (iter.MoveNext()) {
if (iter.Kind() == UntaggedPcDescriptors::kRewind) {
// Remember the last rewind so we don't need to iterator twice.
rewind_pc = code.PayloadStart() + iter.PcOffset();
rewind_deopt_id = iter.DeoptId();
}
if ((pc_offset == iter.PcOffset()) && (iter.DeoptId() == rewind_deopt_id)) {
return rewind_pc;
}
}
return 0;
}
void Debugger::RewindToFrame(intptr_t frame_index) {
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
Code& code = Code::Handle(zone);
Function& function = Function::Handle(zone);
// Find the requested frame.
StackFrameIterator iterator(ValidationPolicy::kDontValidateFrames,
Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
intptr_t current_frame = 0;
for (StackFrame* frame = iterator.NextFrame(); frame != nullptr;
frame = iterator.NextFrame()) {
ASSERT(frame->IsValid());
if (frame->IsDartFrame()) {
code = frame->LookupDartCode();
function = code.function();
if (!IsFunctionVisible(function)) {
continue;
}
if (code.is_optimized()) {
intptr_t sub_index = 0;
for (InlinedFunctionsIterator it(code, frame->pc()); !it.Done();
it.Advance()) {
if (current_frame == frame_index) {
RewindToOptimizedFrame(frame, code, sub_index);
UNREACHABLE();
}
current_frame++;
sub_index++;
}
} else {
if (current_frame == frame_index) {
// We are rewinding to an unoptimized frame.
RewindToUnoptimizedFrame(frame, code);
UNREACHABLE();
}
current_frame++;
}
}
}
UNIMPLEMENTED();
}
void Debugger::RewindToUnoptimizedFrame(StackFrame* frame, const Code& code) {
// We will be jumping out of the debugger rather than exiting this
// function, so prepare the debugger state.
ClearCachedStackTraces();
set_resume_action(kContinue);
resume_frame_index_ = -1;
EnterSingleStepMode();
uword rewind_pc = LookupRewindPc(code, frame->pc());
if (FLAG_trace_rewind && rewind_pc == 0) {
OS::PrintErr("Unable to find rewind pc for pc(%" Px ")\n", frame->pc());
}
ASSERT(rewind_pc != 0);
if (FLAG_trace_rewind) {
OS::PrintErr(
"===============================\n"
"Rewinding to unoptimized frame:\n"
" rewind_pc(0x%" Px " offset:0x%" Px ") sp(0x%" Px ") fp(0x%" Px
")\n"
"===============================\n",
rewind_pc, rewind_pc - code.PayloadStart(), frame->sp(), frame->fp());
}
Exceptions::JumpToFrame(Thread::Current(), rewind_pc, frame->sp(),
frame->fp(), true /* clear lazy deopt at target */);
UNREACHABLE();
}
void Debugger::RewindToOptimizedFrame(StackFrame* frame,
const Code& optimized_code,
intptr_t sub_index) {
post_deopt_frame_index_ = sub_index;
// We will be jumping out of the debugger rather than exiting this
// function, so prepare the debugger state.
ClearCachedStackTraces();
set_resume_action(kContinue);
resume_frame_index_ = -1;
EnterSingleStepMode();
if (FLAG_trace_rewind) {
OS::PrintErr(
"===============================\n"
"Deoptimizing frame for rewind:\n"
" deopt_pc(0x%" Px ") sp(0x%" Px ") fp(0x%" Px
")\n"
"===============================\n",
frame->pc(), frame->sp(), frame->fp());
}
Thread* thread = Thread::Current();
thread->set_resume_pc(frame->pc());
uword deopt_stub_pc = StubCode::DeoptForRewind().EntryPoint();
Exceptions::JumpToFrame(thread, deopt_stub_pc, frame->sp(), frame->fp(),
true /* clear lazy deopt at target */);
UNREACHABLE();
}
void Debugger::RewindPostDeopt() {
intptr_t rewind_frame = post_deopt_frame_index_;
post_deopt_frame_index_ = -1;
if (FLAG_trace_rewind) {
OS::PrintErr("Post deopt, jumping to frame %" Pd "\n", rewind_frame);
OS::PrintErr(
"-------------------------\n"
"All frames...\n\n");
StackFrameIterator iterator(ValidationPolicy::kDontValidateFrames,
Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
StackFrame* frame = iterator.NextFrame();
intptr_t num = 0;
while ((frame != nullptr)) {
OS::PrintErr("#%04" Pd " %s\n", num++, frame->ToCString());
frame = iterator.NextFrame();
}
}
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
Code& code = Code::Handle(zone);
StackFrameIterator iterator(ValidationPolicy::kDontValidateFrames,
Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
intptr_t current_frame = 0;
for (StackFrame* frame = iterator.NextFrame(); frame != nullptr;
frame = iterator.NextFrame()) {
ASSERT(frame->IsValid());
if (frame->IsDartFrame()) {
code = frame->LookupDartCode();
ASSERT(!code.is_optimized());
if (current_frame == rewind_frame) {
RewindToUnoptimizedFrame(frame, code);
UNREACHABLE();
}
current_frame++;
}
}
}
// static
bool Debugger::IsDebuggable(const Function& func) {
if (!func.is_debuggable()) {
return false;
}
const Class& cls = Class::Handle(func.Owner());
const Library& lib = Library::Handle(cls.library());
return lib.IsDebuggable();
}
void GroupDebugger::RegisterSingleSteppingDebugger(Thread* thread,
const Debugger* debugger) {
WriteRwLocker sl(Thread::Current(), single_stepping_set_lock());
single_stepping_set_.Insert(debugger);
}
void GroupDebugger::UnregisterSingleSteppingDebugger(Thread* thread,
const Debugger* debugger) {
WriteRwLocker sl(Thread::Current(), single_stepping_set_lock());
single_stepping_set_.Remove(debugger);
}
bool GroupDebugger::HasBreakpointUnsafe(Thread* thread,
const Function& function) {
DEBUG_ASSERT(thread->IsInStoppedMutatorsScope() ||
breakpoint_locations_lock()->IsCurrentThreadReader());
// Check if function has any breakpoints.
String& url = String::Handle(thread->zone());
for (intptr_t i = 0; i < breakpoint_locations_.length(); i++) {
BreakpointLocation* location = breakpoint_locations_.At(i);
url = location->url();
if (FunctionOverlaps(function, url, location->token_pos(),
location->end_token_pos())) {
return true;
}
}
return false;
}
bool GroupDebugger::HasBreakpoint(Thread* thread, const Function& function) {
bool hasBreakpoint = false;
// Don't need to worry about the lock if mutators are stopped.
if (thread->IsInStoppedMutatorsScope()) {
hasBreakpoint = HasBreakpointUnsafe(thread, function);
} else {
SafepointReadRwLocker sl(thread, breakpoint_locations_lock());
hasBreakpoint = HasBreakpointUnsafe(thread, function);
}
if (hasBreakpoint) {
return true;
}
// TODO(aam): do we have to iterate over both code breakpoints and
// breakpoint locations? Wouldn't be sufficient to iterate over only
// one list? Could you have a CodeBreakpoint without corresponding
// BreakpointLocation?
if (HasCodeBreakpointInFunction(function)) {
return true;
}
return false;
}
bool GroupDebugger::IsDebugging(Thread* thread, const Function& function) {
{
ReadRwLocker ml(thread, single_stepping_set_lock());
if (!single_stepping_set_.IsEmpty()) {
return true;
}
}
return HasBreakpoint(thread, function);
}
void Debugger::set_resume_action(ResumeAction resume_action) {
auto thread = Thread::Current();
if (resume_action == kContinue) {
group_debugger()->UnregisterSingleSteppingDebugger(thread, this);
} else {
group_debugger()->RegisterSingleSteppingDebugger(thread, this);
}
resume_action_ = resume_action;
}
void Debugger::SignalPausedEvent(ActivationFrame* top_frame, Breakpoint* bpt) {
set_resume_action(kContinue);
ResetSteppingFramePointer();
NotifySingleStepping(false);
ASSERT(!IsPaused());
if ((bpt != nullptr) && bpt->is_single_shot()) {
RemoveBreakpoint(bpt->id());
bpt = nullptr;
}
ServiceEvent event(isolate_, ServiceEvent::kPauseBreakpoint);
event.set_top_frame(top_frame);
event.set_breakpoint(bpt);
event.set_at_async_jump(IsAtAsyncJump(top_frame));
Pause(&event);
}
static bool IsAtAsyncJump(ActivationFrame* top_frame) {
Thread* const thread = Thread::Current();
Zone* const zone = thread->zone();
if (!top_frame->function().IsAsyncFunction() &&
!top_frame->function().IsAsyncGenerator()) {
return false;
}
if (top_frame->IsInterpreted()) {
#if defined(DART_DYNAMIC_MODULES)
const auto& bytecode = top_frame->bytecode();
ASSERT(bytecode.HasSourcePositions());
const uword pc_offset = top_frame->pc() - bytecode.PayloadStart();
// pc_offset could equal to bytecode size if the last instruction is Throw.
ASSERT(pc_offset <= static_cast<uword>(bytecode.Size()));
bytecode::BytecodeSourcePositionsIterator iter(zone, bytecode);
bool is_yield_point = false;
while (iter.MoveNext()) {
if (pc_offset <= iter.PcOffset()) {
break;
}
is_yield_point = iter.IsYieldPoint();
}
return is_yield_point;
#else
UNREACHABLE();
#endif
} else {
const TokenPosition looking_for = top_frame->TokenPos();
const auto& pc_descriptors =
PcDescriptors::Handle(zone, top_frame->code().pc_descriptors());
if (!pc_descriptors.IsNull()) {
PcDescriptors::Iterator it(pc_descriptors, UntaggedPcDescriptors::kOther);
while (it.MoveNext()) {
if (it.TokenPos() == looking_for &&
it.YieldIndex() != UntaggedPcDescriptors::kInvalidYieldIndex) {
return true;
}
}
}
}
return false;
}
#if defined(DART_DYNAMIC_MODULES)
static ActivationFrame::Relation CompareTopDartFrameTo(uword other_fp,
bool is_interpreted) {
StackFrameIterator iterator(ValidationPolicy::kDontValidateFrames,
Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
for (auto* frame = iterator.NextFrame(); frame != nullptr;
frame = iterator.NextFrame()) {
if (frame->IsDartFrame() && (frame->is_interpreted() == is_interpreted)) {
// The current frame's FP can be directly compared to the provided FP to
// provide an answer, since they're using the same stack.
//
// Since this function is only called if the top Dart frame is interpreted
// but the stepping frame is not or vice versa, the current frame is not
// the top Dart frame, so a result of kSelf means the top Dart frame
// is a callee.
return ActivationFrame::CompareTo(is_interpreted, frame->fp(),
other_fp) == ActivationFrame::kCaller
? ActivationFrame::kCaller
: ActivationFrame::kCallee;
}
}
// If there were no frames of the same type on the stack, this must have been
// a caller of the original jump into the interpreter.
ASSERT(is_interpreted);
return ActivationFrame::kCaller;
}
#endif
ErrorPtr Debugger::PauseStepping() {
ASSERT(Thread::Current()->single_step());
// Don't pause recursively.
if (IsPaused()) {
return Error::null();
}
ActivationFrame* frame = TopDartFrame();
ASSERT(frame != nullptr);
if (stepping_fp_ != 0) {
// Check whether we are in a Dart function that the user is
// interested in. If we saved the frame pointer of a stack frame
// the user is interested in, we ignore the single step if we are
// in a callee of that frame.
#if defined(DART_DYNAMIC_MODULES)
auto const relation =
stepping_fp_from_interpreted_frame_ == frame->IsInterpreted()
? frame->CompareTo(stepping_fp_)
// Since interpreted code and compiled code use different stacks,
// finding the relation to the top Dart frame requires some amount
// of stack frame iteration.
: CompareTopDartFrameTo(stepping_fp_,
stepping_fp_from_interpreted_frame_);
#else
// Note that we assume that the stack grows towards lower addresses.
auto const relation = frame->CompareTo(stepping_fp_);
#endif
// There is an "interesting frame" set. Only pause at appropriate
// locations in this frame.
if (relation == ActivationFrame::kCallee) {
// We are in a callee of the frame we're interested in.
// Ignore this stepping break.
return Error::null();
} else if (relation == ActivationFrame::kCaller) {
// We returned from the "interesting frame", there can be no more
// stepping breaks for it. Pause at the next appropriate location
// and let the user set the "interesting" frame again.
ResetSteppingFramePointer();
}
}
if (!frame->IsDebuggable()) {
return Error::null();
}
if (!frame->TokenPos().IsDebugPause()) {
return Error::null();
}
if (MatchesLastSteppingInformation(frame)) {
// Do not stop multiple times for the same token position.
// Several 'debug checked' opcodes may be issued in the same token range,
// a breakpoint could be set at a given pause point, or we could be in the
// bytecode interpreter which checks single stepping at each instruction.
return Error::null();
}
// If there is an active breakpoint at this pc, then the last stepping
// information should have been set appropriately to bail out above.
ASSERT(!group_debugger()->HasActiveBreakpoint(frame->pc()));
// TODO(dartbug.com/48378): Consider aligning async/async* functions
// with regular function wrt the first stop in the function prologue.
if ((frame->function().IsAsyncFunction() ||
frame->function().IsAsyncGenerator()) &&
frame->GetSuspendStateVar() == Object::null()) {
return Error::null();
}
if (FLAG_verbose_debug) {
OS::PrintErr(">>> single step break at %s:%" Pd ":%" Pd
" (func %s token %s address %#" Px " offset %#" Px ")\n",
String::Handle(frame->SourceUrl()).ToCString(),
frame->LineNumber(), frame->ColumnNumber(),
String::Handle(frame->QualifiedFunctionName()).ToCString(),
frame->TokenPos().ToCString(), frame->pc(),
frame->pc() - frame->PayloadStart());
}
SetLastSteppingInformation(frame);
CacheStackTraces(DebuggerStackTrace::Collect(),
DebuggerStackTrace::CollectAsyncAwaiters());
SignalPausedEvent(frame, nullptr);
HandleSteppingRequest();
ClearCachedStackTraces();
// If any error occurred while in the debug message loop, return it here.
return Thread::Current()->StealStickyError();
}
ErrorPtr Debugger::PauseBreakpoint() {
// We ignore this breakpoint when the VM is executing code invoked
// by the debugger to evaluate variables values, or when we see a nested
// breakpoint or exception event.
if (ignore_breakpoints_ || IsPaused()) {
return Error::null();
}
DebuggerStackTrace* stack_trace = DebuggerStackTrace::Collect();
ASSERT(stack_trace->Length() > 0);
ActivationFrame* top_frame = stack_trace->FrameAt(0);
ASSERT(top_frame != nullptr);
if (!Library::Handle(top_frame->Library()).IsDebuggable()) {
return Error::null();
}
BreakpointLocation* bpt_location = nullptr;
const char* cbpt_tostring = nullptr;
{
SafepointReadRwLocker cbl(Thread::Current(),
group_debugger()->code_breakpoints_lock());
CodeBreakpoint* cbpt = nullptr;
bpt_location = group_debugger()->GetBreakpointLocationFor(
this, top_frame->pc(), &cbpt);
if (bpt_location == nullptr) {
// There might be no breakpoint locations for this isolate/debugger.
return Error::null();
}
ASSERT(cbpt != nullptr);
if (FLAG_verbose_debug) {
cbpt_tostring = cbpt->ToCString();
}
}
Breakpoint* bpt_hit = bpt_location->FindHitBreakpoint(top_frame);
if (bpt_hit == nullptr) {
return Error::null();
}
if (FLAG_verbose_debug) {
OS::PrintErr(">>> hit %" Pd
" %s"
" (func %s token %s address %#" Px " offset %#" Px ")\n",
bpt_hit->id(), cbpt_tostring,
String::Handle(top_frame->QualifiedFunctionName()).ToCString(),
bpt_location->token_pos().ToCString(), top_frame->pc(),
top_frame->pc() - top_frame->PayloadStart());
}
// Set the last stepping information before handling the stepping request in
// case the breakpoint is disabled either because it is a one shot or because
// a service call disables it before the next stepping request.
SetLastSteppingInformation(bpt_location);
CacheStackTraces(stack_trace, DebuggerStackTrace::CollectAsyncAwaiters());
SignalPausedEvent(top_frame, bpt_hit);
HandleSteppingRequest();
ClearCachedStackTraces();
// If any error occurred while in the debug message loop, return it here.
return Thread::Current()->StealStickyError();
}
Breakpoint* BreakpointLocation::FindHitBreakpoint(ActivationFrame* top_frame) {
// There may be more than one applicable breakpoint at this location, but we
// will report only one as reached. If there is a single-shot breakpoint, we
// favor it; then a closure-specific breakpoint ; then an general breakpoint.
// First check for a single-shot breakpoint.
Breakpoint* bpt = breakpoints();
while (bpt != nullptr) {
if (bpt->is_single_shot() && bpt->closure() == Instance::null()) {
return bpt;
}
bpt = bpt->next();
}
// Now check for a closure-specific breakpoint.
bpt = breakpoints();
while (bpt != nullptr) {
if (bpt->closure() != Instance::null() &&
bpt->closure() == top_frame->GetClosure()) {
return bpt;
}
bpt = bpt->next();
}
// Finally, check for a general breakpoint.
bpt = breakpoints();
while (bpt != nullptr) {
if (!bpt->is_single_shot() && bpt->closure() == Instance::null()) {
return bpt;
}
bpt = bpt->next();
}
return nullptr;
}
void Debugger::PauseDeveloper(const String& msg) {
// We ignore this breakpoint when the VM is executing code invoked
// by the debugger to evaluate variables values, or when we see a nested
// breakpoint or exception event.
//
// Also ignore it if single stepping, as the debugger already generated
// an appropriate pause for the user call to the function before this point.
if (ignore_breakpoints_ || IsPaused() || IsSingleStepping()) {
return;
}
DebuggerStackTrace* stack_trace = DebuggerStackTrace::Collect();
ASSERT(stack_trace->Length() > 0);
CacheStackTraces(stack_trace, DebuggerStackTrace::CollectAsyncAwaiters());
// We are in the native call to Developer_debugger. the developer
// gets a better experience by not seeing this call. To accomplish
// this, we continue execution until the call exits (step out).
SetResumeAction(kStepOut);
// Reset the last stepping information to ensure we pause after stepping out.
ResetLastSteppingInformation();
HandleSteppingRequest();
ClearCachedStackTraces();
}
void Debugger::NotifyIsolateCreated() {
if (NeedsIsolateEvents()) {
ServiceEvent event(isolate_, ServiceEvent::kIsolateStart);
InvokeEventHandler(&event);
}
}
#if !defined(DART_PRECOMPILED_RUNTIME)
// |reference_pos_on_line| may specify the position of any column on a
// particular line. This function will return the position of column
// [column_number] on that same line.
static TokenPosition FindExactTokenPosition(const Script& script,
TokenPosition reference_pos_on_line,
intptr_t column_number) {
intptr_t line;
intptr_t col;
if (script.GetTokenLocation(reference_pos_on_line, &line, &col)) {
return TokenPosition::Deserialize(reference_pos_on_line.Pos() +
(column_number - col));
}
return TokenPosition::kNoSource;
}
#endif // !defined(DART_PRECOMPILED_RUNTIME)
void Debugger::NotifyDoneLoading() {
if (latent_locations_ == nullptr) {
// Common, fast path.
return;
}
auto thread = Thread::Current();
auto isolate_group = thread->isolate_group();
auto zone = thread->zone();
Library& lib = Library::Handle(zone);
Script& script = Script::Handle(zone);
String& url = String::Handle(zone);
BreakpointLocation* loc = latent_locations_;
BreakpointLocation* prev_loc = nullptr;
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(isolate_group->object_store()->libraries());
GrowableHandlePtrArray<const Script> scripts(zone, 1);
while (loc != nullptr) {
url = loc->url();
bool found_match = false;
bool is_package = url.StartsWith(Symbols::PackageScheme());
for (intptr_t i = 0; i < libs.Length(); i++) {
lib ^= libs.At(i);
script = lib.LookupScript(url, !is_package);
if (!script.IsNull()) {
scripts.Add(script);
}
}
if (scripts.length() > 0) {
// Found a script with matching url for this latent breakpoint.
// Unlink the latent breakpoint from the list.
found_match = true;
BreakpointLocation* matched_loc = loc;
loc = loc->next();
if (prev_loc == nullptr) {
latent_locations_ = loc;
} else {
prev_loc->set_next(loc);
}
// Now find the token range at the requested line and make a
// new unresolved source breakpoint.
intptr_t line_number = matched_loc->requested_line_number();
intptr_t column_number = matched_loc->requested_column_number();
ASSERT(line_number >= 0);
TokenPosition first_token_pos = TokenPosition::kNoSource;
TokenPosition last_token_pos = TokenPosition::kNoSource;
scripts.At(0).TokenRangeAtLine(line_number, &first_token_pos,
&last_token_pos);
if (!first_token_pos.IsDebugPause() || !last_token_pos.IsDebugPause()) {
// Script does not contain the given line number or there are no
// tokens on the line. Drop the breakpoint silently.
Breakpoint* bpt = matched_loc->breakpoints();
while (bpt != nullptr) {
if (FLAG_verbose_debug) {
OS::PrintErr("No code found at line %" Pd
": "
"dropping latent breakpoint %" Pd " in '%s'\n",
line_number, bpt->id(), url.ToCString());
}
Breakpoint* prev = bpt;
bpt = bpt->next();
delete prev;
}
delete matched_loc;
} else {
// We don't expect to already have a breakpoint for this location.
// If there is one, assert in debug build but silently drop
// the latent breakpoint in release build.
BreakpointLocation* existing_loc =
GetBreakpointLocation(url, first_token_pos, -1, column_number);
ASSERT(existing_loc == nullptr);
if (existing_loc == nullptr) {
// Create and register a new source breakpoint for the
// latent breakpoint.
BreakpointLocation* unresolved_loc = new BreakpointLocation(
this, scripts, first_token_pos, last_token_pos, line_number,
column_number);
RegisterBreakpointLocation(unresolved_loc);
// Move breakpoints over.
Breakpoint* bpt = matched_loc->breakpoints();
unresolved_loc->set_breakpoints(bpt);
matched_loc->set_breakpoints(nullptr);
while (bpt != nullptr) {
bpt->set_bpt_location(unresolved_loc);
if (FLAG_verbose_debug) {
OS::PrintErr(
"Converted latent breakpoint "
"%" Pd " in '%s' at line %" Pd " col %" Pd "\n",
bpt->id(), url.ToCString(), line_number, column_number);
}
bpt = bpt->next();
}
group_debugger()->SyncBreakpointLocation(unresolved_loc);
}
delete matched_loc;
// Break out of the iteration over loaded libraries. If the
// same url has been loaded into more than one library, we
// only set a breakpoint in the first one.
// TODO(hausner): There is one possible pitfall here.
// If the user sets a latent breakpoint using a partial url that
// ends up matching more than one script, the breakpoint might
// get set in the wrong script.
// It would be better if we could warn the user if multiple
// scripts are matching.
break;
}
}
if (!found_match) {
// No matching url found in any of the libraries.
if (FLAG_verbose_debug) {
Breakpoint* bpt = loc->breakpoints();
while (bpt != nullptr) {
OS::PrintErr(
"No match found for latent breakpoint id "
"%" Pd " with url '%s'\n",
bpt->id(), url.ToCString());
bpt = bpt->next();
}
}
loc = loc->next();
}
}
}
// TODO(hausner): Could potentially make this faster by checking
// whether the call target at pc is a debugger stub.
bool GroupDebugger::HasActiveBreakpoint(uword pc) {
SafepointReadRwLocker sl(Thread::Current(), code_breakpoints_lock());
CodeBreakpoint* cbpt = GetCodeBreakpoint(pc);
return (cbpt != nullptr) && (cbpt->IsEnabled());
}
CodeBreakpoint* GroupDebugger::GetCodeBreakpoint(uword breakpoint_address) {
CodeBreakpoint* cbpt = code_breakpoints_;
while (cbpt != nullptr) {
if (cbpt->pc() == breakpoint_address) {
return cbpt;
}
cbpt = cbpt->next();
}
return nullptr;
}
BreakpointLocation* GroupDebugger::GetBreakpointLocationFor(
Debugger* debugger,
uword breakpoint_address,
CodeBreakpoint** pcbpt) {
ASSERT(pcbpt != nullptr);
SafepointReadRwLocker sl(Thread::Current(), code_breakpoints_lock());
*pcbpt = code_breakpoints_;
while (*pcbpt != nullptr) {
if ((*pcbpt)->pc() == breakpoint_address) {
return (*pcbpt)->FindBreakpointForDebugger(debugger);
}
*pcbpt = (*pcbpt)->next();
}
return nullptr;
}
void GroupDebugger::RegisterCodeBreakpoint(CodeBreakpoint* cbpt) {
ASSERT(cbpt->next() == nullptr);
DEBUG_ASSERT(code_breakpoints_lock()->IsCurrentThreadWriter() ||
Thread::Current()->IsInStoppedMutatorsScope());
cbpt->set_next(code_breakpoints_);
code_breakpoints_ = cbpt;
}
CodePtr GroupDebugger::GetPatchedStubAddress(uword breakpoint_address) {
SafepointReadRwLocker sl(Thread::Current(), code_breakpoints_lock());
CodeBreakpoint* cbpt = GetCodeBreakpoint(breakpoint_address);
if (cbpt != nullptr) {
return cbpt->OrigStubAddress();
}
UNREACHABLE();
return Code::null();
}
uint32_t GroupDebugger::GetPatchedOpcode(uword breakpoint_address) {
SafepointReadRwLocker sl(Thread::Current(), code_breakpoints_lock());
CodeBreakpoint* cbpt = GetCodeBreakpoint(breakpoint_address);
if (cbpt != nullptr) {
return cbpt->OrigOpcode();
}
UNREACHABLE();
return kMaxUint32;
}
bool Debugger::SetBreakpointState(Breakpoint* bpt, bool enable) {
SafepointWriteRwLocker sl(Thread::Current(),
group_debugger()->breakpoint_locations_lock());
if (bpt->is_enabled() != enable) {
if (FLAG_verbose_debug) {
OS::PrintErr("Setting breakpoint %" Pd " to state: %s\n", bpt->id(),
enable ? "enabled" : "disabled");
}
enable ? bpt->Enable() : bpt->Disable();
group_debugger()->SyncBreakpointLocation(bpt->bpt_location());
return true;
}
return false;
}
// Remove and delete the source breakpoint bpt and its associated
// code breakpoints.
void Debugger::RemoveBreakpoint(intptr_t bp_id) {
SafepointWriteRwLocker sl(Thread::Current(),
group_debugger()->breakpoint_locations_lock());
if (RemoveBreakpointFromTheList(bp_id, &breakpoint_locations_)) {
return;
}
RemoveBreakpointFromTheList(bp_id, &latent_locations_);
}
// Remove and delete the source breakpoint bpt and its associated
// code breakpoints. Returns true, if breakpoint was found and removed,
// returns false, if breakpoint was not found.
bool Debugger::RemoveBreakpointFromTheList(intptr_t bp_id,
BreakpointLocation** list) {
BreakpointLocation* prev_loc = nullptr;
BreakpointLocation* curr_loc = *list;
while (curr_loc != nullptr) {
Breakpoint* prev_bpt = nullptr;
Breakpoint* curr_bpt = curr_loc->breakpoints();
while (curr_bpt != nullptr) {
if (curr_bpt->id() == bp_id) {
if (prev_bpt == nullptr) {
curr_loc->set_breakpoints(curr_bpt->next());
} else {
prev_bpt->set_next(curr_bpt->next());
}
// Send event to client before the breakpoint's fields are
// poisoned and deleted.
SendBreakpointEvent(ServiceEvent::kBreakpointRemoved, curr_bpt);
curr_bpt->set_next(nullptr);
curr_bpt->set_bpt_location(nullptr);
// Remove possible references to the breakpoint.
if (pause_event_ != nullptr && pause_event_->breakpoint() == curr_bpt) {
pause_event_->set_breakpoint(nullptr);
}
delete curr_bpt;
curr_bpt = nullptr;
// Delete the breakpoint location object if there are no more
// breakpoints at that location.
if (curr_loc->breakpoints() == nullptr) {
if (prev_loc == nullptr) {
*list = curr_loc->next();
} else {
prev_loc->set_next(curr_loc->next());
}
if (!curr_loc->IsLatent()) {
// Remove references from code breakpoints to this breakpoint
// location and disable them.
// Latent breakpoint locations won't have code breakpoints.
group_debugger()->UnlinkCodeBreakpoints(curr_loc);
}
group_debugger()->UnregisterBreakpointLocation(curr_loc);
BreakpointLocation* next_loc = curr_loc->next();
delete curr_loc;
curr_loc = next_loc;
}
// The code breakpoints will be deleted when the VM resumes
// after the pause event.
return true;
}
prev_bpt = curr_bpt;
curr_bpt = curr_bpt->next();
}
prev_loc = curr_loc;
curr_loc = curr_loc->next();
}
// breakpoint with bp_id does not exist, nothing to do.
return false;
}
void GroupDebugger::RegisterBreakpointLocation(BreakpointLocation* location) {
DEBUG_ASSERT(breakpoint_locations_lock()->IsCurrentThreadWriter() ||
Thread::Current()->IsInStoppedMutatorsScope());
breakpoint_locations_.Add(location);
}
void GroupDebugger::UnregisterBreakpointLocation(BreakpointLocation* location) {
ASSERT(breakpoint_locations_lock()->IsCurrentThreadWriter());
for (intptr_t i = 0; i < breakpoint_locations_.length(); i++) {
if (breakpoint_locations_.At(i) == location) {
breakpoint_locations_.EraseAt(i);
return;
}
}
}
// Unlink code breakpoints from the given breakpoint location.
// They will later be deleted when control returns from the pause event
// callback. Also, disable the breakpoint so it no longer fires if it
// should be hit before it gets deleted.
void GroupDebugger::UnlinkCodeBreakpoints(BreakpointLocation* bpt_location) {
ASSERT(bpt_location != nullptr);
SafepointWriteRwLocker sl(Thread::Current(), code_breakpoints_lock());
CodeBreakpoint* curr_bpt = code_breakpoints_;
while (curr_bpt != nullptr) {
if (curr_bpt->FindAndDeleteBreakpointLocation(bpt_location)) {
curr_bpt->Disable();
needs_breakpoint_cleanup_ = true;
}
curr_bpt = curr_bpt->next();
}
}
// Remove and delete unlinked code breakpoints, i.e. breakpoints that
// are not associated with a breakpoint location.
void GroupDebugger::RemoveUnlinkedCodeBreakpoints() {
DEBUG_ASSERT(code_breakpoints_lock()->IsCurrentThreadWriter() ||
Thread::Current()->IsInStoppedMutatorsScope());
CodeBreakpoint* prev_bpt = nullptr;
CodeBreakpoint* curr_bpt = code_breakpoints_;
while (curr_bpt != nullptr) {
if (curr_bpt->HasNoBreakpointLocations()) {
if (prev_bpt == nullptr) {
code_breakpoints_ = code_breakpoints_->next();
} else {
prev_bpt->set_next(curr_bpt->next());
}
CodeBreakpoint* temp_bpt = curr_bpt;
curr_bpt = curr_bpt->next();
delete temp_bpt;
} else {
prev_bpt = curr_bpt;
curr_bpt = curr_bpt->next();
}
}
needs_breakpoint_cleanup_ = false;
}
BreakpointLocation* Debugger::GetResolvedBreakpointLocation(
const String& script_url,
TokenPosition code_token_pos) {
BreakpointLocation* loc = breakpoint_locations_;
String& loc_url = String::Handle();
while (loc != nullptr) {
loc_url = loc->url();
if (script_url.Equals(loc_url) && loc->code_token_pos_ == code_token_pos) {
return loc;
}
loc = loc->next();
}
return nullptr;
}
BreakpointLocation* Debugger::GetBreakpointLocation(
const String& script_url,
TokenPosition token_pos,
intptr_t requested_line,
intptr_t requested_column,
TokenPosition code_token_pos) {
BreakpointLocation* loc = breakpoint_locations_;
String& loc_url = String::Handle();
while (loc != nullptr) {
loc_url = loc->url();
if (script_url.Equals(loc_url) &&
(!token_pos.IsReal() || (loc->token_pos() == token_pos)) &&
((requested_line == -1) ||
(loc->requested_line_number_ == requested_line)) &&
((requested_column == -1) ||
(loc->requested_column_number_ == requested_column)) &&
(!code_token_pos.IsReal() ||
(loc->code_token_pos_ == code_token_pos))) {
return loc;
}
loc = loc->next();
}
return nullptr;
}
Breakpoint* Debugger::GetBreakpointById(intptr_t id) {
Breakpoint* bpt = GetBreakpointByIdInTheList(id, breakpoint_locations_);
if (bpt != nullptr) {
return bpt;
}
return GetBreakpointByIdInTheList(id, latent_locations_);
}
Breakpoint* Debugger::GetBreakpointByIdInTheList(intptr_t id,
BreakpointLocation* list) {
BreakpointLocation* loc = list;
while (loc != nullptr) {
Breakpoint* bpt = loc->breakpoints();
while (bpt != nullptr) {
if (bpt->id() == id) {
return bpt;
}
bpt = bpt->next();
}
loc = loc->next();
}
return nullptr;
}
void Debugger::AsyncStepInto(const Closure& awaiter) {
Zone* zone = Thread::Current()->zone();
auto& suspend_state = SuspendState::Handle(zone);
if (StackTraceUtils::GetSuspendState(awaiter, &suspend_state)) {
const auto& function_data =
Object::Handle(zone, suspend_state.function_data());
SetBreakpointAtResumption(function_data);
} else {
// We intentionally discard the value stored into the following variable.
Breakpoint* _ = nullptr;
const Error& error = Error::Handle(
SetBreakpointAtActivation(awaiter, /*single_shot=*/true, &_));
// This method cannot be called while responding to a Service RPC, so we
// know that the top error handler is an exit frame.
DEBUG_ASSERT(Thread::Current()->TopErrorHandlerIsExitFrame());
if (!error.IsNull()) {
if (error.ptr() == Object::out_of_memory_error().ptr()) {
Exceptions::ThrowOOM();
UNREACHABLE();
}
if (error.IsLanguageError()) {
Exceptions::ThrowCompileTimeError(LanguageError::Cast(error));
UNREACHABLE();
}
Exceptions::PropagateError(Error::Cast(error));
UNREACHABLE();
}
}
Continue();
}
void Debugger::Continue() {
SetResumeAction(kContinue);
ResetSteppingFramePointer();
NotifySingleStepping(false);
}
BreakpointLocation* Debugger::GetLatentBreakpoint(const String& url,
intptr_t line,
intptr_t column) {
BreakpointLocation* loc = latent_locations_;
String& bpt_url = String::Handle();
while (loc != nullptr) {
bpt_url = loc->url();
if (bpt_url.Equals(url) && (loc->requested_line_number() == line) &&
(loc->requested_column_number() == column)) {
return loc;
}
loc = loc->next();
}
// No breakpoint for this location requested. Allocate new one.
loc = new BreakpointLocation(this, url, line, column);
loc->set_next(latent_locations_);
latent_locations_ = loc;
return loc;
}
void Debugger::RegisterBreakpointLocationUnsafe(BreakpointLocation* loc) {
DEBUG_ASSERT(
group_debugger()->breakpoint_locations_lock()->IsCurrentThreadWriter() ||
Thread::Current()->IsInStoppedMutatorsScope());
ASSERT(loc->next() == nullptr);
loc->set_next(breakpoint_locations_);
breakpoint_locations_ = loc;
group_debugger()->RegisterBreakpointLocation(loc);
}
void Debugger::RegisterBreakpointLocation(BreakpointLocation* loc) {
auto thread = Thread::Current();
if (thread->IsInStoppedMutatorsScope()) {
RegisterBreakpointLocationUnsafe(loc);
} else {
SafepointWriteRwLocker sl(thread,
group_debugger()->breakpoint_locations_lock());
RegisterBreakpointLocationUnsafe(loc);
}
}
#endif // !PRODUCT
} // namespace dart