| // Copyright (c) 2011, 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/exceptions.h" |
| |
| #include "vm/dart_api_impl.h" |
| #include "vm/dart_entry.h" |
| #include "vm/debugger.h" |
| #include "vm/flags.h" |
| #include "vm/object.h" |
| #include "vm/object_store.h" |
| #include "vm/stack_frame.h" |
| #include "vm/stub_code.h" |
| #include "vm/symbols.h" |
| |
| namespace dart { |
| |
| DEFINE_FLAG(bool, print_stacktrace_at_throw, false, |
| "Prints a stack trace everytime a throw occurs."); |
| DEFINE_FLAG(bool, heap_profile_out_of_memory, false, |
| "Writes a heap profile on unhandled out-of-memory exceptions."); |
| DEFINE_FLAG(bool, verbose_stacktrace, false, |
| "Stack traces will include methods marked invisible."); |
| |
| const char* Exceptions::kCastErrorDstName = "type cast"; |
| |
| |
| class StacktraceBuilder : public ValueObject { |
| public: |
| StacktraceBuilder() { } |
| virtual ~StacktraceBuilder() { } |
| |
| virtual void AddFrame(const Function& func, |
| const Code& code, |
| const Smi& offset) = 0; |
| }; |
| |
| |
| class RegularStacktraceBuilder : public StacktraceBuilder { |
| public: |
| RegularStacktraceBuilder() |
| : func_list_(GrowableObjectArray::Handle(GrowableObjectArray::New())), |
| code_list_(GrowableObjectArray::Handle(GrowableObjectArray::New())), |
| pc_offset_list_( |
| GrowableObjectArray::Handle(GrowableObjectArray::New())) { } |
| ~RegularStacktraceBuilder() { } |
| |
| const GrowableObjectArray& func_list() const { return func_list_; } |
| const GrowableObjectArray& code_list() const { return code_list_; } |
| const GrowableObjectArray& pc_offset_list() const { return pc_offset_list_; } |
| |
| virtual void AddFrame(const Function& func, |
| const Code& code, |
| const Smi& offset) { |
| func_list_.Add(func); |
| code_list_.Add(code); |
| pc_offset_list_.Add(offset); |
| } |
| |
| private: |
| const GrowableObjectArray& func_list_; |
| const GrowableObjectArray& code_list_; |
| const GrowableObjectArray& pc_offset_list_; |
| |
| DISALLOW_COPY_AND_ASSIGN(RegularStacktraceBuilder); |
| }; |
| |
| |
| class PreallocatedStacktraceBuilder : public StacktraceBuilder { |
| public: |
| explicit PreallocatedStacktraceBuilder(const Stacktrace& stacktrace) |
| : stacktrace_(stacktrace), |
| cur_index_(0) { |
| ASSERT(stacktrace_.raw() == |
| Isolate::Current()->object_store()->preallocated_stack_trace()); |
| } |
| ~PreallocatedStacktraceBuilder() { } |
| |
| virtual void AddFrame(const Function& func, |
| const Code& code, |
| const Smi& offset); |
| |
| private: |
| static const int kNumTopframes = 3; |
| |
| const Stacktrace& stacktrace_; |
| intptr_t cur_index_; |
| |
| DISALLOW_COPY_AND_ASSIGN(PreallocatedStacktraceBuilder); |
| }; |
| |
| |
| void PreallocatedStacktraceBuilder::AddFrame(const Function& func, |
| const Code& code, |
| const Smi& offset) { |
| if (cur_index_ >= Stacktrace::kPreallocatedStackdepth) { |
| // The number of frames is overflowing the preallocated stack trace object. |
| Function& frame_func = Function::Handle(); |
| Code& frame_code = Code::Handle(); |
| Smi& frame_offset = Smi::Handle(); |
| intptr_t start = Stacktrace::kPreallocatedStackdepth - (kNumTopframes - 1); |
| intptr_t null_slot = start - 2; |
| // Add an empty slot to indicate the overflow so that the toString |
| // method can account for the overflow. |
| if (stacktrace_.FunctionAtFrame(null_slot) != Function::null()) { |
| stacktrace_.SetFunctionAtFrame(null_slot, frame_func); |
| stacktrace_.SetCodeAtFrame(null_slot, frame_code); |
| } |
| // Move frames one slot down so that we can accomadate the new frame. |
| for (intptr_t i = start; i < Stacktrace::kPreallocatedStackdepth; i++) { |
| intptr_t prev = (i - 1); |
| frame_func = stacktrace_.FunctionAtFrame(i); |
| frame_code = stacktrace_.CodeAtFrame(i); |
| frame_offset = stacktrace_.PcOffsetAtFrame(i); |
| stacktrace_.SetFunctionAtFrame(prev, frame_func); |
| stacktrace_.SetCodeAtFrame(prev, frame_code); |
| stacktrace_.SetPcOffsetAtFrame(prev, frame_offset); |
| } |
| cur_index_ = (Stacktrace::kPreallocatedStackdepth - 1); |
| } |
| stacktrace_.SetFunctionAtFrame(cur_index_, func); |
| stacktrace_.SetCodeAtFrame(cur_index_, code); |
| stacktrace_.SetPcOffsetAtFrame(cur_index_, offset); |
| cur_index_ += 1; |
| } |
| |
| |
| static bool ShouldShowFunction(const Function& function) { |
| if (FLAG_verbose_stacktrace) { |
| return true; |
| } |
| return function.is_visible(); |
| } |
| |
| |
| // Iterate through the stack frames and try to find a frame with an |
| // exception handler. Once found, set the pc, sp and fp so that execution |
| // can continue in that frame. |
| static bool FindExceptionHandler(uword* handler_pc, |
| uword* handler_sp, |
| uword* handler_fp, |
| StacktraceBuilder* builder) { |
| StackFrameIterator frames(StackFrameIterator::kDontValidateFrames); |
| StackFrame* frame = frames.NextFrame(); |
| ASSERT(frame != NULL); // We expect to find a dart invocation frame. |
| Function& func = Function::Handle(); |
| Code& code = Code::Handle(); |
| Smi& offset = Smi::Handle(); |
| while (!frame->IsEntryFrame()) { |
| if (frame->IsDartFrame()) { |
| code = frame->LookupDartCode(); |
| if (code.is_optimized()) { |
| // For optimized frames, extract all the inlined functions if any |
| // into the stack trace. |
| for (InlinedFunctionsIterator it(frame); !it.Done(); it.Advance()) { |
| func = it.function(); |
| code = it.code(); |
| uword pc = it.pc(); |
| ASSERT(pc != 0); |
| ASSERT(code.EntryPoint() <= pc); |
| ASSERT(pc < (code.EntryPoint() + code.Size())); |
| if (ShouldShowFunction(func)) { |
| offset = Smi::New(pc - code.EntryPoint()); |
| builder->AddFrame(func, code, offset); |
| } |
| } |
| } else { |
| offset = Smi::New(frame->pc() - code.EntryPoint()); |
| func = code.function(); |
| if (ShouldShowFunction(func)) { |
| builder->AddFrame(func, code, offset); |
| } |
| } |
| if (frame->FindExceptionHandler(handler_pc)) { |
| *handler_sp = frame->sp(); |
| *handler_fp = frame->fp(); |
| return true; |
| } |
| } |
| frame = frames.NextFrame(); |
| ASSERT(frame != NULL); |
| } |
| ASSERT(frame->IsEntryFrame()); |
| *handler_pc = frame->pc(); |
| *handler_sp = frame->sp(); |
| *handler_fp = frame->fp(); |
| return false; |
| } |
| |
| |
| static void FindErrorHandler(uword* handler_pc, |
| uword* handler_sp, |
| uword* handler_fp) { |
| // TODO(turnidge): Is there a faster way to get the next entry frame? |
| StackFrameIterator frames(StackFrameIterator::kDontValidateFrames); |
| StackFrame* frame = frames.NextFrame(); |
| ASSERT(frame != NULL); |
| while (!frame->IsEntryFrame()) { |
| frame = frames.NextFrame(); |
| ASSERT(frame != NULL); |
| } |
| ASSERT(frame->IsEntryFrame()); |
| *handler_pc = frame->pc(); |
| *handler_sp = frame->sp(); |
| *handler_fp = frame->fp(); |
| } |
| |
| |
| static void JumpToExceptionHandler(uword program_counter, |
| uword stack_pointer, |
| uword frame_pointer, |
| const Object& exception_object, |
| const Object& stacktrace_object) { |
| // The no_gc StackResource is unwound through the tear down of |
| // stack resources below. |
| NoGCScope no_gc; |
| RawObject* raw_exception = exception_object.raw(); |
| RawObject* raw_stacktrace = stacktrace_object.raw(); |
| |
| #if defined(USING_SIMULATOR) |
| // Unwinding of the C++ frames and destroying of their stack resources is done |
| // by the simulator, because the target stack_pointer is a simulated stack |
| // pointer and not the C++ stack pointer. |
| |
| // Continue simulating at the given pc in the given frame after setting up the |
| // exception object in the kExceptionObjectReg register and the stacktrace |
| // object (may be raw null) in the kStackTraceObjectReg register. |
| Simulator::Current()->Longjmp(program_counter, stack_pointer, frame_pointer, |
| raw_exception, raw_stacktrace); |
| #else |
| // Prepare for unwinding frames by destroying all the stack resources |
| // in the previous frames. |
| Isolate* isolate = Isolate::Current(); |
| while (isolate->top_resource() != NULL && |
| (reinterpret_cast<uword>(isolate->top_resource()) < stack_pointer)) { |
| isolate->top_resource()->~StackResource(); |
| } |
| |
| // Call a stub to set up the exception object in kExceptionObjectReg, |
| // to set up the stacktrace object in kStackTraceObjectReg, and to |
| // continue execution at the given pc in the given frame. |
| typedef void (*ExcpHandler)(uword, uword, uword, RawObject*, RawObject*); |
| ExcpHandler func = reinterpret_cast<ExcpHandler>( |
| StubCode::JumpToExceptionHandlerEntryPoint()); |
| func(program_counter, stack_pointer, frame_pointer, |
| raw_exception, raw_stacktrace); |
| #endif |
| UNREACHABLE(); |
| } |
| |
| |
| static void ThrowExceptionHelper(const Instance& incoming_exception, |
| const Instance& existing_stacktrace) { |
| bool use_preallocated_stacktrace = false; |
| Isolate* isolate = Isolate::Current(); |
| Instance& exception = Instance::Handle(isolate, incoming_exception.raw()); |
| if (exception.IsNull()) { |
| exception ^= Exceptions::Create(Exceptions::kNullThrown, |
| Object::empty_array()); |
| } else if (exception.raw() == isolate->object_store()->out_of_memory() || |
| exception.raw() == isolate->object_store()->stack_overflow()) { |
| use_preallocated_stacktrace = true; |
| } |
| uword handler_pc = 0; |
| uword handler_sp = 0; |
| uword handler_fp = 0; |
| Stacktrace& stacktrace = Stacktrace::Handle(isolate); |
| bool handler_exists = false; |
| if (use_preallocated_stacktrace) { |
| stacktrace ^= isolate->object_store()->preallocated_stack_trace(); |
| PreallocatedStacktraceBuilder frame_builder(stacktrace); |
| handler_exists = FindExceptionHandler(&handler_pc, |
| &handler_sp, |
| &handler_fp, |
| &frame_builder); |
| } else { |
| RegularStacktraceBuilder frame_builder; |
| handler_exists = FindExceptionHandler(&handler_pc, |
| &handler_sp, |
| &handler_fp, |
| &frame_builder); |
| // TODO(5411263): At some point we can optimize by figuring out if a |
| // stack trace is needed based on whether the catch code specifies a |
| // stack trace object or there is a rethrow in the catch clause. |
| if (frame_builder.pc_offset_list().Length() != 0) { |
| // Create arrays for function, code and pc_offset triplet for each frame. |
| const Array& func_array = |
| Array::Handle(isolate, Array::MakeArray(frame_builder.func_list())); |
| const Array& code_array = |
| Array::Handle(isolate, Array::MakeArray(frame_builder.code_list())); |
| const Array& pc_offset_array = |
| Array::Handle(isolate, |
| Array::MakeArray(frame_builder.pc_offset_list())); |
| if (existing_stacktrace.IsNull()) { |
| stacktrace = Stacktrace::New(func_array, code_array, pc_offset_array); |
| } else { |
| stacktrace ^= existing_stacktrace.raw(); |
| stacktrace.Append(func_array, code_array, pc_offset_array); |
| // Since we are re throwing and appending to the existing stack trace |
| // we clear out the catch trace collected in the existing stack trace |
| // as that trace will not be valid anymore. |
| stacktrace.SetCatchStacktrace(Object::empty_array(), |
| Object::empty_array(), |
| Object::empty_array()); |
| } |
| } else { |
| stacktrace ^= existing_stacktrace.raw(); |
| // Since we are re throwing and appending to the existing stack trace |
| // we clear out the catch trace collected in the existing stack trace |
| // as that trace will not be valid anymore. |
| stacktrace.SetCatchStacktrace(Object::empty_array(), |
| Object::empty_array(), |
| Object::empty_array()); |
| } |
| } |
| // We expect to find a handler_pc, if the exception is unhandled |
| // then we expect to at least have the dart entry frame on the |
| // stack as Exceptions::Throw should happen only after a dart |
| // invocation has been done. |
| ASSERT(handler_pc != 0); |
| |
| if (FLAG_print_stacktrace_at_throw) { |
| OS::Print("Exception '%s' thrown:\n", exception.ToCString()); |
| OS::Print("%s\n", stacktrace.ToCString()); |
| } |
| if (handler_exists) { |
| // Found a dart handler for the exception, jump to it. |
| JumpToExceptionHandler(handler_pc, |
| handler_sp, |
| handler_fp, |
| exception, |
| stacktrace); |
| } else { |
| if (FLAG_heap_profile_out_of_memory) { |
| if (exception.raw() == isolate->object_store()->out_of_memory()) { |
| isolate->heap()->ProfileToFile("out-of-memory"); |
| } |
| } |
| // No dart exception handler found in this invocation sequence, |
| // so we create an unhandled exception object and return to the |
| // invocation stub so that it returns this unhandled exception |
| // object. The C++ code which invoked this dart sequence can check |
| // and do the appropriate thing (rethrow the exception to the |
| // dart invocation sequence above it, print diagnostics and terminate |
| // the isolate etc.). |
| const UnhandledException& unhandled_exception = UnhandledException::Handle( |
| UnhandledException::New(exception, stacktrace)); |
| stacktrace = Stacktrace::null(); |
| JumpToExceptionHandler(handler_pc, |
| handler_sp, |
| handler_fp, |
| unhandled_exception, |
| stacktrace); |
| } |
| UNREACHABLE(); |
| } |
| |
| |
| // Static helpers for allocating, initializing, and throwing an error instance. |
| |
| // Return the script of the Dart function that called the native entry or the |
| // runtime entry. The frame iterator points to the callee. |
| RawScript* Exceptions::GetCallerScript(DartFrameIterator* iterator) { |
| StackFrame* caller_frame = iterator->NextFrame(); |
| ASSERT(caller_frame != NULL && caller_frame->IsDartFrame()); |
| const Function& caller = Function::Handle(caller_frame->LookupDartFunction()); |
| ASSERT(!caller.IsNull()); |
| return caller.script(); |
| } |
| |
| |
| // Allocate a new instance of the given class name. |
| // TODO(hausner): Rename this NewCoreInstance to call out the fact that |
| // the class name is resolved in the core library implicitly? |
| RawInstance* Exceptions::NewInstance(const char* class_name) { |
| const String& cls_name = String::Handle(Symbols::New(class_name)); |
| const Library& core_lib = Library::Handle(Library::CoreLibrary()); |
| Class& cls = Class::Handle(core_lib.LookupClass(cls_name)); |
| ASSERT(!cls.IsNull()); |
| // There are no parameterized error types, so no need to set type arguments. |
| return Instance::New(cls); |
| } |
| |
| |
| // Assign the value to the field given by its name in the given instance. |
| void Exceptions::SetField(const Instance& instance, |
| const Class& cls, |
| const char* field_name, |
| const Object& value) { |
| const Field& field = Field::Handle(cls.LookupInstanceField( |
| String::Handle(Symbols::New(field_name)))); |
| ASSERT(!field.IsNull()); |
| instance.SetField(field, value); |
| } |
| |
| |
| // Initialize the fields 'url', 'line', and 'column' in the given instance |
| // according to the given token location in the given script. |
| void Exceptions::SetLocationFields(const Instance& instance, |
| const Class& cls, |
| const Script& script, |
| intptr_t location) { |
| SetField(instance, cls, "url", String::Handle(script.url())); |
| intptr_t line, column; |
| script.GetTokenLocation(location, &line, &column); |
| SetField(instance, cls, "line", Smi::Handle(Smi::New(line))); |
| SetField(instance, cls, "column", Smi::Handle(Smi::New(column))); |
| } |
| |
| |
| // Allocate, initialize, and throw a TypeError. |
| void Exceptions::CreateAndThrowTypeError(intptr_t location, |
| const String& src_type_name, |
| const String& dst_type_name, |
| const String& dst_name, |
| const String& malformed_error) { |
| // Allocate a new instance of TypeError or CastError. |
| Instance& type_error = Instance::Handle(); |
| Class& cls = Class::Handle(); |
| if (dst_name.Equals(kCastErrorDstName)) { |
| type_error = NewInstance("CastErrorImplementation"); |
| cls = type_error.clazz(); |
| cls = cls.SuperClass(); |
| } else { |
| type_error = NewInstance("TypeErrorImplementation"); |
| cls = type_error.clazz(); |
| } |
| |
| // Initialize 'url', 'line', and 'column' fields. |
| DartFrameIterator iterator; |
| const Script& script = Script::Handle(GetCallerScript(&iterator)); |
| // Location fields are defined in AssertionError, the superclass of TypeError. |
| const Class& assertion_error_class = Class::Handle(cls.SuperClass()); |
| SetLocationFields(type_error, assertion_error_class, script, location); |
| |
| // Initialize field 'failedAssertion' in AssertionError superclass. |
| // Printing the src_obj value would be possible, but ToString() is expensive |
| // and not meaningful for all classes, so we just print '$expr instanceof...'. |
| // Users should look at TypeError.ToString(), which contains more useful |
| // information than AssertionError.failedAssertion. |
| String& failed_assertion = String::Handle(String::New("$expr instanceof ")); |
| failed_assertion = String::Concat(failed_assertion, dst_type_name); |
| SetField(type_error, |
| assertion_error_class, |
| "failedAssertion", |
| failed_assertion); |
| |
| // Initialize field 'srcType'. |
| SetField(type_error, cls, "srcType", src_type_name); |
| |
| // Initialize field 'dstType'. |
| SetField(type_error, cls, "dstType", dst_type_name); |
| |
| // Initialize field 'dstName'. |
| SetField(type_error, cls, "dstName", dst_name); |
| |
| // Initialize field 'malformedError'. |
| SetField(type_error, cls, "malformedError", malformed_error); |
| |
| // Type errors in the core library may be difficult to diagnose. |
| // Print type error information before throwing the error when debugging. |
| if (FLAG_print_stacktrace_at_throw) { |
| if (!malformed_error.IsNull()) { |
| OS::Print("%s\n", malformed_error.ToCString()); |
| } |
| intptr_t line, column; |
| script.GetTokenLocation(location, &line, &column); |
| OS::Print("'%s': Failed type check: line %"Pd" pos %"Pd": ", |
| String::Handle(script.url()).ToCString(), line, column); |
| if (!dst_name.IsNull() && (dst_name.Length() > 0)) { |
| OS::Print("type '%s' is not a subtype of type '%s' of '%s'.\n", |
| src_type_name.ToCString(), |
| dst_type_name.ToCString(), |
| dst_name.ToCString()); |
| } else { |
| OS::Print("malformed type used.\n"); |
| } |
| } |
| // Throw TypeError instance. |
| Exceptions::Throw(type_error); |
| UNREACHABLE(); |
| } |
| |
| |
| void Exceptions::Throw(const Instance& exception) { |
| Isolate* isolate = Isolate::Current(); |
| isolate->debugger()->SignalExceptionThrown(exception); |
| // Null object is a valid exception object. |
| ThrowExceptionHelper(exception, Instance::Handle(isolate)); |
| } |
| |
| |
| void Exceptions::ReThrow(const Instance& exception, |
| const Instance& stacktrace) { |
| // Null object is a valid exception object. |
| ThrowExceptionHelper(exception, stacktrace); |
| } |
| |
| |
| void Exceptions::PropagateError(const Error& error) { |
| ASSERT(Isolate::Current()->top_exit_frame_info() != 0); |
| if (error.IsUnhandledException()) { |
| // If the error object represents an unhandled exception, then |
| // rethrow the exception in the normal fashion. |
| const UnhandledException& uhe = UnhandledException::Cast(error); |
| const Instance& exc = Instance::Handle(uhe.exception()); |
| const Instance& stk = Instance::Handle(uhe.stacktrace()); |
| Exceptions::ReThrow(exc, stk); |
| } else { |
| // Return to the invocation stub and return this error object. The |
| // C++ code which invoked this dart sequence can check and do the |
| // appropriate thing. |
| uword handler_pc = 0; |
| uword handler_sp = 0; |
| uword handler_fp = 0; |
| FindErrorHandler(&handler_pc, &handler_sp, &handler_fp); |
| JumpToExceptionHandler(handler_pc, handler_sp, handler_fp, error, |
| Stacktrace::Handle()); // Null stacktrace. |
| } |
| UNREACHABLE(); |
| } |
| |
| |
| void Exceptions::ThrowByType(ExceptionType type, const Array& arguments) { |
| const Object& result = Object::Handle(Create(type, arguments)); |
| if (result.IsError()) { |
| // We got an error while constructing the exception object. |
| // Propagate the error instead of throwing the exception. |
| PropagateError(Error::Cast(result)); |
| } else { |
| ASSERT(result.IsInstance()); |
| Throw(Instance::Cast(result)); |
| } |
| } |
| |
| |
| void Exceptions::ThrowOOM() { |
| Isolate* isolate = Isolate::Current(); |
| const Instance& oom = Instance::Handle( |
| isolate, isolate->object_store()->out_of_memory()); |
| Throw(oom); |
| } |
| |
| |
| void Exceptions::ThrowStackOverflow() { |
| Isolate* isolate = Isolate::Current(); |
| const Instance& stack_overflow = Instance::Handle( |
| isolate, isolate->object_store()->stack_overflow()); |
| Throw(stack_overflow); |
| } |
| |
| |
| RawObject* Exceptions::Create(ExceptionType type, const Array& arguments) { |
| Library& library = Library::Handle(); |
| const String* class_name = NULL; |
| const String* constructor_name = &Symbols::Dot(); |
| switch (type) { |
| case kNone: |
| UNREACHABLE(); |
| break; |
| case kRange: |
| library = Library::CoreLibrary(); |
| class_name = &Symbols::RangeError(); |
| break; |
| case kArgument: |
| library = Library::CoreLibrary(); |
| class_name = &Symbols::ArgumentError(); |
| break; |
| case kNoSuchMethod: |
| library = Library::CoreLibrary(); |
| class_name = &Symbols::NoSuchMethodError(); |
| constructor_name = &String::Handle(Symbols::New("._withType")); |
| break; |
| case kFormat: |
| library = Library::CoreLibrary(); |
| class_name = &Symbols::FormatException(); |
| break; |
| case kUnsupported: |
| library = Library::CoreLibrary(); |
| class_name = &Symbols::UnsupportedError(); |
| break; |
| case kStackOverflow: |
| library = Library::CoreLibrary(); |
| class_name = &Symbols::StackOverflowError(); |
| break; |
| case kOutOfMemory: |
| library = Library::CoreLibrary(); |
| class_name = &Symbols::OutOfMemoryError(); |
| break; |
| case kInternalError: |
| library = Library::CoreLibrary(); |
| class_name = &Symbols::InternalError(); |
| break; |
| case kNullThrown: |
| library = Library::CoreLibrary(); |
| class_name = &Symbols::NullThrownError(); |
| break; |
| case kIsolateSpawn: |
| library = Library::IsolateLibrary(); |
| class_name = &Symbols::IsolateSpawnException(); |
| break; |
| case kIsolateUnhandledException: |
| library = Library::IsolateLibrary(); |
| class_name = &Symbols::IsolateUnhandledException(); |
| break; |
| } |
| |
| return DartLibraryCalls::ExceptionCreate(library, |
| *class_name, |
| *constructor_name, |
| arguments); |
| } |
| |
| } // namespace dart |
