| // 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_entry.h" |
| #include "vm/debugger.h" |
| #include "vm/flags.h" |
| #include "vm/object.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."); |
| |
| |
| const char* Exceptions::kCastErrorDstName = "type cast"; |
| |
| |
| // 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, |
| const GrowableObjectArray& func_list, |
| const GrowableObjectArray& code_list, |
| const GrowableObjectArray& pc_offset_list) { |
| StackFrameIterator frames(StackFrameIterator::kDontValidateFrames); |
| StackFrame* frame = frames.NextFrame(); |
| if (frame == NULL) { |
| // We have no dart invocation frames and hence cannot find a handler |
| // to return to. |
| return false; |
| } |
| Function& func = Function::Handle(); |
| Code& code = Code::Handle(); |
| Smi& offset = Smi::Handle(); |
| while (!frame->IsEntryFrame()) { |
| if (frame->IsDartFrame()) { |
| func = frame->LookupDartFunction(); |
| code = frame->LookupDartCode(); |
| offset = Smi::New(frame->pc() - code.EntryPoint()); |
| func_list.Add(func); |
| code_list.Add(code); |
| pc_offset_list.Add(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(); |
| } |
| |
| |
| void JumpToExceptionHandler(uword program_counter, |
| uword stack_pointer, |
| uword frame_pointer, |
| const Instance& exception_object, |
| const Instance& stacktrace_object) { |
| // The no_gc StackResource is unwound through the tear down of |
| // stack resources below. |
| NoGCScope no_gc; |
| RawInstance* exception = exception_object.raw(); |
| RawInstance* stacktrace = stacktrace_object.raw(); |
| |
| // 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(); |
| } |
| |
| // Set up the appropriate register state and jump to the handler. |
| typedef void (*ExcpHandler)(uword, uword, uword, RawInstance*, RawInstance*); |
| ExcpHandler func = reinterpret_cast<ExcpHandler>( |
| StubCode::JumpToExceptionHandlerEntryPoint()); |
| func(program_counter, stack_pointer, frame_pointer, exception, stacktrace); |
| UNREACHABLE(); |
| } |
| |
| |
| void JumpToErrorHandler(uword program_counter, |
| uword stack_pointer, |
| uword frame_pointer, |
| const Error& error) { |
| // The no_gc StackResource is unwound through the tear down of |
| // stack resources below. |
| NoGCScope no_gc; |
| ASSERT(!error.IsNull()); |
| RawError* raw_error = error.raw(); |
| |
| // 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(); |
| } |
| |
| // Set up the error object as the return value in EAX and continue |
| // from the invocation stub. |
| typedef void (*ErrorHandler)(uword, uword, uword, RawError*); |
| ErrorHandler func = reinterpret_cast<ErrorHandler>( |
| StubCode::JumpToErrorHandlerEntryPoint()); |
| func(program_counter, stack_pointer, frame_pointer, raw_error); |
| UNREACHABLE(); |
| } |
| |
| |
| static void ThrowExceptionHelper(const Instance& incoming_exception, |
| const Instance& existing_stacktrace) { |
| Instance& exception = Instance::Handle(incoming_exception.raw()); |
| if (exception.IsNull()) { |
| GrowableArray<const Object*> arguments; |
| exception ^= Exceptions::Create(Exceptions::kNullThrown, arguments); |
| } |
| uword handler_pc = 0; |
| uword handler_sp = 0; |
| uword handler_fp = 0; |
| const GrowableObjectArray& func_list = |
| GrowableObjectArray::Handle(GrowableObjectArray::New()); |
| const GrowableObjectArray& code_list = |
| GrowableObjectArray::Handle(GrowableObjectArray::New()); |
| const GrowableObjectArray& pc_offset_list = |
| GrowableObjectArray::Handle(GrowableObjectArray::New()); |
| bool handler_exists = FindExceptionHandler(&handler_pc, |
| &handler_sp, |
| &handler_fp, |
| func_list, |
| code_list, |
| pc_offset_list); |
| if (handler_pc == 0) { |
| // There are no dart invocation frames on the stack so we do not |
| // have a caller to return to. This is a case where we would have |
| // to call the Isolate error handler and let it deal with the shutdown. |
| // We report an error and shutdown the process as a temporary solution |
| // until the isolate error handler stuff is implemented. |
| ASSERT(!handler_exists); |
| OS::PrintErr("Exception '%s' thrown:\n", exception.ToCString()); |
| OS::PrintErr("Exiting the process\n"); |
| OS::Exit(255); |
| } |
| // 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. |
| Stacktrace& stacktrace = Stacktrace::Handle(); |
| if (pc_offset_list.Length() != 0) { |
| if (existing_stacktrace.IsNull()) { |
| stacktrace = Stacktrace::New(func_list, code_list, pc_offset_list); |
| } else { |
| stacktrace ^= existing_stacktrace.raw(); |
| stacktrace.Append(func_list, code_list, pc_offset_list); |
| } |
| } else { |
| stacktrace ^= existing_stacktrace.raw(); |
| } |
| 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 { |
| // 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)); |
| JumpToErrorHandler(handler_pc, handler_sp, handler_fp, unhandled_exception); |
| } |
| 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); |
| JumpToErrorHandler(handler_pc, handler_sp, handler_fp, error); |
| } |
| UNREACHABLE(); |
| } |
| |
| |
| void Exceptions::ThrowByType( |
| ExceptionType type, const GrowableArray<const Object*>& 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)); |
| } |
| } |
| |
| |
| RawObject* Exceptions::Create( |
| ExceptionType type, const GrowableArray<const Object*>& arguments) { |
| Library& library = Library::Handle(); |
| String& class_name = String::Handle(); |
| switch (type) { |
| case kNone: |
| UNREACHABLE(); |
| break; |
| case kRange: |
| library = Library::CoreLibrary(); |
| class_name = Symbols::New("RangeError"); |
| break; |
| case kArgument: |
| library = Library::CoreLibrary(); |
| class_name = Symbols::New("ArgumentError"); |
| break; |
| case kNoSuchMethod: |
| library = Library::CoreLibrary(); |
| class_name = Symbols::New("NoSuchMethodError"); |
| break; |
| case kFormat: |
| library = Library::CoreLibrary(); |
| class_name = Symbols::New("FormatException"); |
| break; |
| case kStackOverflow: |
| library = Library::CoreLibrary(); |
| class_name = Symbols::New("StackOverflowError"); |
| break; |
| case kOutOfMemory: |
| library = Library::CoreLibrary(); |
| class_name = Symbols::New("OutOfMemoryError"); |
| break; |
| case kInternalError: |
| library = Library::CoreLibrary(); |
| class_name = Symbols::New("InternalError"); |
| break; |
| case kNullThrown: |
| library = Library::CoreLibrary(); |
| class_name = Symbols::New("NullThrownError"); |
| break; |
| case kIllegalJSRegExp: |
| library = Library::CoreLibrary(); |
| class_name = Symbols::New("IllegalJSRegExpException"); |
| break; |
| case kIsolateSpawn: |
| library = Library::IsolateLibrary(); |
| class_name = Symbols::New("IsolateSpawnException"); |
| break; |
| } |
| |
| return DartLibraryCalls::ExceptionCreate(library, class_name, arguments); |
| } |
| |
| } // namespace dart |
