| // Copyright (c) 2017, 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/stack_trace.h" |
| |
| #include "vm/compiler/frontend/bytecode_reader.h" |
| #include "vm/dart_api_impl.h" |
| #include "vm/stack_frame.h" |
| #include "vm/symbols.h" |
| |
| namespace dart { |
| |
| // Keep in sync with |
| // sdk/lib/async/stream_controller.dart:_StreamController._STATE_SUBSCRIBED. |
| const intptr_t kStreamController_StateSubscribed = 1; |
| |
| RawClosure* FindClosureInFrame(RawObject** last_object_in_caller, |
| const Function& function, |
| bool is_interpreted) { |
| NoSafepointScope nsp; |
| |
| // The callee has function signature |
| // :async_op([result, exception, stack]) |
| // So we are guaranteed to |
| // a) have only tagged arguments on the stack until we find the :async_op |
| // closure, and |
| // b) find the async closure. |
| auto& closure = Closure::Handle(); |
| for (intptr_t i = 0; i < 4; i++) { |
| // KBC builds the stack upwards instead of the usual downwards stack. |
| RawObject* arg = last_object_in_caller[(is_interpreted ? -i : i)]; |
| if (arg->IsHeapObject() && arg->GetClassId() == kClosureCid) { |
| closure = Closure::RawCast(arg); |
| if (closure.function() == function.raw()) { |
| return closure.raw(); |
| } |
| } |
| } |
| UNREACHABLE(); |
| } |
| |
| // Find current yield index from async closure. |
| // Async closures contains a variable, :await_jump_var that holds the index into |
| // async wrapper. |
| intptr_t GetYieldIndex(const Closure& receiver_closure) { |
| const auto& function = Function::Handle(receiver_closure.function()); |
| if (!function.IsAsyncClosure() && !function.IsAsyncGenClosure()) { |
| return RawPcDescriptors::kInvalidYieldIndex; |
| } |
| const auto& await_jump_var = |
| Object::Handle(Context::Handle(receiver_closure.context()) |
| .At(Context::kAwaitJumpVarIndex)); |
| ASSERT(await_jump_var.IsSmi()); |
| return Smi::Cast(await_jump_var).Value(); |
| } |
| |
| intptr_t FindPcOffset(const PcDescriptors& pc_descs, intptr_t yield_index) { |
| if (yield_index == RawPcDescriptors::kInvalidYieldIndex) { |
| return 0; |
| } |
| PcDescriptors::Iterator iter(pc_descs, RawPcDescriptors::kAnyKind); |
| while (iter.MoveNext()) { |
| if (iter.YieldIndex() == yield_index) { |
| return iter.PcOffset(); |
| } |
| } |
| UNREACHABLE(); // If we cannot find it we have a bug. |
| } |
| |
| #if !defined(DART_PRECOMPILED_RUNTIME) |
| intptr_t FindPcOffset(const Bytecode& bytecode, intptr_t yield_index) { |
| if (yield_index == RawPcDescriptors::kInvalidYieldIndex) { |
| return 0; |
| } |
| intptr_t last_yield_point = 0; |
| kernel::BytecodeSourcePositionsIterator iter(Thread::Current()->zone(), |
| bytecode); |
| while (iter.MoveNext()) { |
| if (iter.IsYieldPoint()) { |
| last_yield_point++; |
| } |
| if (last_yield_point == yield_index) { |
| return iter.PcOffset(); |
| } |
| } |
| UNREACHABLE(); // If we cannot find it we have a bug. |
| } |
| #endif |
| |
| // Helper class for finding the closure of the caller. |
| // This is done via the _AsyncAwaitCompleter which holds a |
| // FutureResultOrListeners which in turn holds a callback. |
| class CallerClosureFinder { |
| public: |
| // Instance caches library and field references. |
| // This way we don't have to do the look-ups for every frame in the stack. |
| explicit CallerClosureFinder(Zone* zone) |
| : receiver_context_(Context::Handle(zone)), |
| receiver_function_(Function::Handle(zone)), |
| context_entry_(Object::Handle(zone)), |
| future_(Object::Handle(zone)), |
| listener_(Object::Handle(zone)), |
| callback_(Object::Handle(zone)), |
| controller_(Object::Handle(zone)), |
| state_(Object::Handle(zone)), |
| var_data_(Object::Handle(zone)), |
| future_impl_class(Class::Handle(zone)), |
| async_await_completer_class(Class::Handle(zone)), |
| future_listener_class(Class::Handle(zone)), |
| async_start_stream_controller_class(Class::Handle(zone)), |
| stream_controller_class(Class::Handle(zone)), |
| controller_subscription_class(Class::Handle(zone)), |
| buffering_stream_subscription_class(Class::Handle(zone)), |
| async_stream_controller_class(Class::Handle(zone)), |
| completer_future_field(Field::Handle(zone)), |
| future_result_or_listeners_field(Field::Handle(zone)), |
| callback_field(Field::Handle(zone)), |
| controller_controller_field(Field::Handle(zone)), |
| var_data_field(Field::Handle(zone)), |
| state_field(Field::Handle(zone)), |
| on_data_field(Field::Handle(zone)) { |
| const auto& async_lib = Library::Handle(zone, Library::AsyncLibrary()); |
| // Look up classes: |
| // - async: |
| future_impl_class = |
| async_lib.LookupClassAllowPrivate(Symbols::FutureImpl()); |
| ASSERT(!future_impl_class.IsNull()); |
| async_await_completer_class = |
| async_lib.LookupClassAllowPrivate(Symbols::_AsyncAwaitCompleter()); |
| ASSERT(!async_await_completer_class.IsNull()); |
| future_listener_class = |
| async_lib.LookupClassAllowPrivate(Symbols::_FutureListener()); |
| ASSERT(!future_listener_class.IsNull()); |
| // - async*: |
| async_start_stream_controller_class = async_lib.LookupClassAllowPrivate( |
| Symbols::_AsyncStarStreamController()); |
| ASSERT(!async_start_stream_controller_class.IsNull()); |
| stream_controller_class = |
| async_lib.LookupClassAllowPrivate(Symbols::_StreamController()); |
| ASSERT(!stream_controller_class.IsNull()); |
| async_stream_controller_class = |
| async_lib.LookupClassAllowPrivate(Symbols::_AsyncStreamController()); |
| ASSERT(!async_stream_controller_class.IsNull()); |
| controller_subscription_class = |
| async_lib.LookupClassAllowPrivate(Symbols::_ControllerSubscription()); |
| ASSERT(!controller_subscription_class.IsNull()); |
| buffering_stream_subscription_class = async_lib.LookupClassAllowPrivate( |
| Symbols::_BufferingStreamSubscription()); |
| ASSERT(!buffering_stream_subscription_class.IsNull()); |
| |
| // Look up fields: |
| // - async: |
| completer_future_field = |
| async_await_completer_class.LookupFieldAllowPrivate(Symbols::_future()); |
| ASSERT(!completer_future_field.IsNull()); |
| future_result_or_listeners_field = |
| future_impl_class.LookupFieldAllowPrivate( |
| Symbols::_resultOrListeners()); |
| ASSERT(!future_result_or_listeners_field.IsNull()); |
| callback_field = |
| future_listener_class.LookupFieldAllowPrivate(Symbols::callback()); |
| ASSERT(!callback_field.IsNull()); |
| // - async*: |
| controller_controller_field = |
| async_start_stream_controller_class.LookupFieldAllowPrivate( |
| Symbols::controller()); |
| ASSERT(!controller_controller_field.IsNull()); |
| state_field = |
| stream_controller_class.LookupFieldAllowPrivate(Symbols::_state()); |
| ASSERT(!state_field.IsNull()); |
| var_data_field = |
| stream_controller_class.LookupFieldAllowPrivate(Symbols::_varData()); |
| ASSERT(!var_data_field.IsNull()); |
| on_data_field = buffering_stream_subscription_class.LookupFieldAllowPrivate( |
| Symbols::_onData()); |
| ASSERT(!on_data_field.IsNull()); |
| } |
| |
| RawClosure* FindCallerInAsyncClosure(const Context& receiver_context) { |
| context_entry_ = receiver_context.At(Context::kAsyncCompleterIndex); |
| ASSERT(context_entry_.IsInstance()); |
| ASSERT(context_entry_.GetClassId() == async_await_completer_class.id()); |
| |
| const Instance& completer = Instance::Cast(context_entry_); |
| future_ = completer.GetField(completer_future_field); |
| ASSERT(!future_.IsNull()); |
| ASSERT(future_.GetClassId() == future_impl_class.id()); |
| |
| listener_ = |
| Instance::Cast(future_).GetField(future_result_or_listeners_field); |
| if (listener_.GetClassId() != future_listener_class.id()) { |
| return Closure::null(); |
| } |
| |
| callback_ = Instance::Cast(listener_).GetField(callback_field); |
| // This happens for e.g.: await f().catchError(..); |
| if (callback_.IsNull()) { |
| return Closure::null(); |
| } |
| ASSERT(callback_.IsClosure()); |
| |
| return Closure::Cast(callback_).raw(); |
| } |
| |
| RawClosure* FindCallerInAsyncGenClosure(const Context& receiver_context) { |
| context_entry_ = receiver_context.At(Context::kControllerIndex); |
| ASSERT(context_entry_.IsInstance()); |
| ASSERT(context_entry_.GetClassId() == |
| async_start_stream_controller_class.id()); |
| |
| const Instance& controller = Instance::Cast(context_entry_); |
| controller_ = controller.GetField(controller_controller_field); |
| ASSERT(!controller_.IsNull()); |
| ASSERT(controller_.GetClassId() == async_stream_controller_class.id()); |
| |
| state_ = Instance::Cast(controller_).GetField(state_field); |
| ASSERT(state_.IsSmi()); |
| if (Smi::Cast(state_).Value() != kStreamController_StateSubscribed) { |
| return Closure::null(); |
| } |
| |
| var_data_ = Instance::Cast(controller_).GetField(var_data_field); |
| ASSERT(var_data_.GetClassId() == controller_subscription_class.id()); |
| |
| callback_ = Instance::Cast(var_data_).GetField(on_data_field); |
| ASSERT(callback_.IsClosure()); |
| |
| return Closure::Cast(callback_).raw(); |
| } |
| |
| RawClosure* FindCaller(const Closure& receiver_closure) { |
| receiver_function_ = receiver_closure.function(); |
| receiver_context_ = receiver_closure.context(); |
| |
| if (receiver_function_.IsAsyncClosure()) { |
| return FindCallerInAsyncClosure(receiver_context_); |
| } else if (receiver_function_.IsAsyncGenClosure()) { |
| return FindCallerInAsyncGenClosure(receiver_context_); |
| } |
| |
| return Closure::null(); |
| } |
| |
| private: |
| Context& receiver_context_; |
| Function& receiver_function_; |
| |
| Object& context_entry_; |
| Object& future_; |
| Object& listener_; |
| Object& callback_; |
| Object& controller_; |
| Object& state_; |
| Object& var_data_; |
| |
| Class& future_impl_class; |
| Class& async_await_completer_class; |
| Class& future_listener_class; |
| Class& async_start_stream_controller_class; |
| Class& stream_controller_class; |
| Class& controller_subscription_class; |
| Class& buffering_stream_subscription_class; |
| Class& async_stream_controller_class; |
| |
| Field& completer_future_field; |
| Field& future_result_or_listeners_field; |
| Field& callback_field; |
| Field& controller_controller_field; |
| Field& var_data_field; |
| Field& state_field; |
| Field& on_data_field; |
| }; |
| |
| void StackTraceUtils::CollectFramesLazy( |
| Thread* thread, |
| const GrowableObjectArray& code_array, |
| const GrowableObjectArray& pc_offset_array, |
| int skip_frames) { |
| Zone* zone = thread->zone(); |
| DartFrameIterator frames(thread, StackFrameIterator::kNoCrossThreadIteration); |
| StackFrame* frame = frames.NextFrame(); |
| ASSERT(frame != nullptr); // We expect to find a dart invocation frame. |
| auto& function = Function::Handle(zone); |
| auto& code = Code::Handle(zone); |
| auto& bytecode = Bytecode::Handle(zone); |
| auto& offset = Smi::Handle(zone); |
| |
| auto& closure = Closure::Handle(zone); |
| CallerClosureFinder caller_closure_finder(zone); |
| auto& pc_descs = PcDescriptors::Handle(); |
| |
| for (; frame != nullptr;) { |
| if (skip_frames > 0) { |
| skip_frames--; |
| frame = frames.NextFrame(); |
| continue; |
| } |
| |
| function = frame->LookupDartFunction(); |
| |
| // Case 1: This is an async frame; Follow callbacks instead of stack. |
| if (function.IsAsyncClosure() || function.IsAsyncGenClosure()) { |
| // Start by adding the async function in the frame. |
| if (frame->is_interpreted()) { |
| bytecode = frame->LookupDartBytecode(); |
| ASSERT(function.raw() == bytecode.function()); |
| code_array.Add(bytecode); |
| const intptr_t pc_offset = frame->pc() - bytecode.PayloadStart(); |
| ASSERT(pc_offset >= 0 && pc_offset < bytecode.Size()); |
| offset = Smi::New(pc_offset); |
| } else { |
| code = frame->LookupDartCode(); |
| ASSERT(function.raw() == code.function()); |
| code_array.Add(code); |
| offset = Smi::New(frame->pc() - code.PayloadStart()); |
| } |
| pc_offset_array.Add(offset); |
| |
| // Next, look up caller's closure on the stack and walk backwards through |
| // the yields. |
| frame = frames.NextFrame(); |
| RawObject** last_caller_obj = reinterpret_cast<RawObject**>(frame->sp()); |
| closure = FindClosureInFrame(last_caller_obj, function, |
| frame->is_interpreted()); |
| |
| // If this async function hasn't yielded yet, we're still dealing with a |
| // normal stack. Continue to next frame as usual. |
| if (GetYieldIndex(closure) <= 0) { |
| // Don't advance frame since we already did so just above. |
| continue; |
| } |
| |
| // Inject async suspension marker. |
| code_array.Add(StubCode::AsynchronousGapMarker()); |
| offset = Smi::New(0); |
| pc_offset_array.Add(offset); |
| |
| // Skip: Already handled this frame's function above. |
| closure = caller_closure_finder.FindCaller(closure); |
| |
| for (; !closure.IsNull(); |
| closure = caller_closure_finder.FindCaller(closure)) { |
| function = closure.function(); |
| // In hot-reload-test-mode we sometimes have to do this: |
| if (!function.HasCode() && !function.HasBytecode()) { |
| function.EnsureHasCode(); |
| } |
| if (function.HasBytecode()) { |
| #if !defined(DART_PRECOMPILED_RUNTIME) |
| bytecode = function.bytecode(); |
| code_array.Add(bytecode); |
| offset = Smi::New(FindPcOffset(bytecode, GetYieldIndex(closure))); |
| #else |
| UNREACHABLE(); |
| #endif // !defined(DART_PRECOMPILED_RUNTIME) |
| } else if (function.HasCode()) { |
| code = function.CurrentCode(); |
| code_array.Add(code); |
| pc_descs = code.pc_descriptors(); |
| offset = Smi::New(FindPcOffset(pc_descs, GetYieldIndex(closure))); |
| } else { |
| UNREACHABLE(); |
| } |
| ASSERT(offset.Value() >= 0); |
| pc_offset_array.Add(offset); |
| // Inject async suspension marker. |
| code_array.Add(StubCode::AsynchronousGapMarker()); |
| offset = Smi::New(0); |
| pc_offset_array.Add(offset); |
| } |
| |
| // Ignore the rest of the stack; already unwound all async calls. |
| return; |
| } else { |
| // Case 2: This is a sync frame; handle normally. |
| |
| if (frame->is_interpreted()) { |
| bytecode = frame->LookupDartBytecode(); |
| ASSERT(function.raw() == bytecode.function()); |
| code_array.Add(bytecode); |
| offset = Smi::New(frame->pc() - bytecode.PayloadStart()); |
| pc_offset_array.Add(offset); |
| } else { |
| code = frame->LookupDartCode(); |
| ASSERT(function.raw() == code.function()); |
| code_array.Add(code); |
| offset = Smi::New(frame->pc() - code.PayloadStart()); |
| pc_offset_array.Add(offset); |
| } |
| } |
| |
| frame = frames.NextFrame(); |
| } |
| |
| return; |
| } |
| |
| // Count the number of frames that are on the stack. |
| intptr_t StackTraceUtils::CountFrames(Thread* thread, |
| int skip_frames, |
| const Function& async_function, |
| bool* sync_async_end) { |
| Zone* zone = thread->zone(); |
| intptr_t frame_count = 0; |
| StackFrameIterator frames(ValidationPolicy::kDontValidateFrames, thread, |
| StackFrameIterator::kNoCrossThreadIteration); |
| StackFrame* frame = frames.NextFrame(); |
| ASSERT(frame != NULL); // We expect to find a dart invocation frame. |
| Function& function = Function::Handle(zone); |
| Code& code = Code::Handle(zone); |
| Bytecode& bytecode = Bytecode::Handle(zone); |
| String& function_name = String::Handle(zone); |
| const bool async_function_is_null = async_function.IsNull(); |
| int sync_async_gap_frames = -1; |
| ASSERT(async_function_is_null || sync_async_end != NULL); |
| for (; frame != NULL && sync_async_gap_frames != 0; |
| frame = frames.NextFrame()) { |
| if (!frame->IsDartFrame()) { |
| continue; |
| } |
| if (skip_frames > 0) { |
| skip_frames--; |
| continue; |
| } |
| if (frame->is_interpreted()) { |
| bytecode = frame->LookupDartBytecode(); |
| function = bytecode.function(); |
| if (function.IsNull()) { |
| continue; |
| } |
| } else { |
| code = frame->LookupDartCode(); |
| function = code.function(); |
| } |
| if (sync_async_gap_frames > 0) { |
| function_name = function.QualifiedScrubbedName(); |
| if (!CheckAndSkipAsync(&sync_async_gap_frames, function_name)) { |
| *sync_async_end = false; |
| return frame_count; |
| } |
| } else { |
| frame_count++; |
| } |
| if (!async_function_is_null && |
| (async_function.raw() == function.parent_function())) { |
| sync_async_gap_frames = kSyncAsyncFrameGap; |
| } |
| } |
| if (!async_function_is_null) { |
| *sync_async_end = sync_async_gap_frames == 0; |
| } |
| return frame_count; |
| } |
| |
| intptr_t StackTraceUtils::CollectFrames(Thread* thread, |
| const Array& code_array, |
| const Array& pc_offset_array, |
| intptr_t array_offset, |
| intptr_t count, |
| int skip_frames) { |
| Zone* zone = thread->zone(); |
| StackFrameIterator frames(ValidationPolicy::kDontValidateFrames, thread, |
| StackFrameIterator::kNoCrossThreadIteration); |
| StackFrame* frame = frames.NextFrame(); |
| ASSERT(frame != NULL); // We expect to find a dart invocation frame. |
| Function& function = Function::Handle(zone); |
| Code& code = Code::Handle(zone); |
| Bytecode& bytecode = Bytecode::Handle(zone); |
| Smi& offset = Smi::Handle(zone); |
| intptr_t collected_frames_count = 0; |
| for (; (frame != NULL) && (collected_frames_count < count); |
| frame = frames.NextFrame()) { |
| if (!frame->IsDartFrame()) { |
| continue; |
| } |
| if (skip_frames > 0) { |
| skip_frames--; |
| continue; |
| } |
| if (frame->is_interpreted()) { |
| bytecode = frame->LookupDartBytecode(); |
| function = bytecode.function(); |
| if (function.IsNull()) { |
| continue; |
| } |
| offset = Smi::New(frame->pc() - bytecode.PayloadStart()); |
| code_array.SetAt(array_offset, bytecode); |
| } else { |
| code = frame->LookupDartCode(); |
| offset = Smi::New(frame->pc() - code.PayloadStart()); |
| code_array.SetAt(array_offset, code); |
| } |
| pc_offset_array.SetAt(array_offset, offset); |
| array_offset++; |
| collected_frames_count++; |
| } |
| return collected_frames_count; |
| } |
| |
| intptr_t StackTraceUtils::ExtractAsyncStackTraceInfo( |
| Thread* thread, |
| Function* async_function, |
| StackTrace* async_stack_trace_out, |
| Array* async_code_array, |
| Array* async_pc_offset_array) { |
| if (thread->async_stack_trace() == StackTrace::null()) { |
| return 0; |
| } |
| *async_stack_trace_out = thread->async_stack_trace(); |
| ASSERT(!async_stack_trace_out->IsNull()); |
| const StackTrace& async_stack_trace = |
| StackTrace::Handle(thread->async_stack_trace()); |
| const intptr_t async_stack_trace_length = async_stack_trace.Length(); |
| // At least two entries (0: gap marker, 1: async function). |
| ASSERT(async_stack_trace_length >= 2); |
| // Validate the structure of this stack trace. |
| *async_code_array = async_stack_trace.code_array(); |
| ASSERT(!async_code_array->IsNull()); |
| *async_pc_offset_array = async_stack_trace.pc_offset_array(); |
| ASSERT(!async_pc_offset_array->IsNull()); |
| // We start with the asynchronous gap marker. |
| ASSERT(async_code_array->At(0) != Code::null()); |
| ASSERT(async_code_array->At(0) == StubCode::AsynchronousGapMarker().raw()); |
| const Object& code_object = Object::Handle(async_code_array->At(1)); |
| if (code_object.IsCode()) { |
| *async_function = Code::Cast(code_object).function(); |
| } else { |
| ASSERT(code_object.IsBytecode()); |
| *async_function = Bytecode::Cast(code_object).function(); |
| } |
| ASSERT(!async_function->IsNull()); |
| ASSERT(async_function->IsAsyncFunction() || |
| async_function->IsAsyncGenerator()); |
| return async_stack_trace_length; |
| } |
| |
| } // namespace dart |
