// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "v8.h"
#include "api.h"
#include "bootstrapper.h"
#include "compiler.h"
#include "debug.h"
#include "execution.h"
#include "messages.h"
#include "platform.h"
#include "simulator.h"
#include "string-stream.h"
#include "vm-state-inl.h"
// TODO(isolates): move to isolate.cc. This stuff is kept here to
// simplify merging.
namespace v8 {
namespace internal {
ThreadLocalTop::ThreadLocalTop() {
InitializeInternal();
// This flag may be set using v8::V8::IgnoreOutOfMemoryException()
// before an isolate is initialized. The initialize methods below do
// not touch it to preserve its value.
ignore_out_of_memory_ = false;
}
void ThreadLocalTop::InitializeInternal() {
c_entry_fp_ = 0;
handler_ = 0;
#ifdef USE_SIMULATOR
simulator_ = NULL;
#endif
#ifdef ENABLE_LOGGING_AND_PROFILING
js_entry_sp_ = NULL;
external_callback_ = NULL;
#endif
#ifdef ENABLE_VMSTATE_TRACKING
current_vm_state_ = EXTERNAL;
#endif
try_catch_handler_address_ = NULL;
context_ = NULL;
thread_id_ = ThreadId::Invalid();
external_caught_exception_ = false;
failed_access_check_callback_ = NULL;
save_context_ = NULL;
catcher_ = NULL;
}
void ThreadLocalTop::Initialize() {
InitializeInternal();
#ifdef USE_SIMULATOR
#ifdef V8_TARGET_ARCH_ARM
simulator_ = Simulator::current(Isolate::Current());
#elif V8_TARGET_ARCH_MIPS
simulator_ = Simulator::current(Isolate::Current());
#endif
#endif
thread_id_ = ThreadId::Current();
}
v8::TryCatch* ThreadLocalTop::TryCatchHandler() {
return TRY_CATCH_FROM_ADDRESS(try_catch_handler_address());
}
Address Isolate::get_address_from_id(Isolate::AddressId id) {
return isolate_addresses_[id];
}
char* Isolate::Iterate(ObjectVisitor* v, char* thread_storage) {
ThreadLocalTop* thread = reinterpret_cast<ThreadLocalTop*>(thread_storage);
Iterate(v, thread);
return thread_storage + sizeof(ThreadLocalTop);
}
void Isolate::IterateThread(ThreadVisitor* v) {
v->VisitThread(this, thread_local_top());
}
void Isolate::IterateThread(ThreadVisitor* v, char* t) {
ThreadLocalTop* thread = reinterpret_cast<ThreadLocalTop*>(t);
v->VisitThread(this, thread);
}
void Isolate::Iterate(ObjectVisitor* v, ThreadLocalTop* thread) {
// Visit the roots from the top for a given thread.
Object* pending;
// The pending exception can sometimes be a failure. We can't show
// that to the GC, which only understands objects.
if (thread->pending_exception_->ToObject(&pending)) {
v->VisitPointer(&pending);
thread->pending_exception_ = pending; // In case GC updated it.
}
v->VisitPointer(&(thread->pending_message_obj_));
v->VisitPointer(BitCast<Object**>(&(thread->pending_message_script_)));
v->VisitPointer(BitCast<Object**>(&(thread->context_)));
Object* scheduled;
if (thread->scheduled_exception_->ToObject(&scheduled)) {
v->VisitPointer(&scheduled);
thread->scheduled_exception_ = scheduled;
}
for (v8::TryCatch* block = thread->TryCatchHandler();
block != NULL;
block = TRY_CATCH_FROM_ADDRESS(block->next_)) {
v->VisitPointer(BitCast<Object**>(&(block->exception_)));
v->VisitPointer(BitCast<Object**>(&(block->message_)));
}
// Iterate over pointers on native execution stack.
for (StackFrameIterator it(this, thread); !it.done(); it.Advance()) {
it.frame()->Iterate(v);
}
}
void Isolate::Iterate(ObjectVisitor* v) {
ThreadLocalTop* current_t = thread_local_top();
Iterate(v, current_t);
}
void Isolate::RegisterTryCatchHandler(v8::TryCatch* that) {
// The ARM simulator has a separate JS stack. We therefore register
// the C++ try catch handler with the simulator and get back an
// address that can be used for comparisons with addresses into the
// JS stack. When running without the simulator, the address
// returned will be the address of the C++ try catch handler itself.
Address address = reinterpret_cast<Address>(
SimulatorStack::RegisterCTryCatch(reinterpret_cast<uintptr_t>(that)));
thread_local_top()->set_try_catch_handler_address(address);
}
void Isolate::UnregisterTryCatchHandler(v8::TryCatch* that) {
ASSERT(thread_local_top()->TryCatchHandler() == that);
thread_local_top()->set_try_catch_handler_address(
reinterpret_cast<Address>(that->next_));
thread_local_top()->catcher_ = NULL;
SimulatorStack::UnregisterCTryCatch();
}
Handle<String> Isolate::StackTraceString() {
if (stack_trace_nesting_level_ == 0) {
stack_trace_nesting_level_++;
HeapStringAllocator allocator;
StringStream::ClearMentionedObjectCache();
StringStream accumulator(&allocator);
incomplete_message_ = &accumulator;
PrintStack(&accumulator);
Handle<String> stack_trace = accumulator.ToString();
incomplete_message_ = NULL;
stack_trace_nesting_level_ = 0;
return stack_trace;
} else if (stack_trace_nesting_level_ == 1) {
stack_trace_nesting_level_++;
OS::PrintError(
"\n\nAttempt to print stack while printing stack (double fault)\n");
OS::PrintError(
"If you are lucky you may find a partial stack dump on stdout.\n\n");
incomplete_message_->OutputToStdOut();
return factory()->empty_symbol();
} else {
OS::Abort();
// Unreachable
return factory()->empty_symbol();
}
}
Handle<JSArray> Isolate::CaptureCurrentStackTrace(
int frame_limit, StackTrace::StackTraceOptions options) {
// Ensure no negative values.
int limit = Max(frame_limit, 0);
Handle<JSArray> stack_trace = factory()->NewJSArray(frame_limit);
Handle<String> column_key = factory()->LookupAsciiSymbol("column");
Handle<String> line_key = factory()->LookupAsciiSymbol("lineNumber");
Handle<String> script_key = factory()->LookupAsciiSymbol("scriptName");
Handle<String> name_or_source_url_key =
factory()->LookupAsciiSymbol("nameOrSourceURL");
Handle<String> script_name_or_source_url_key =
factory()->LookupAsciiSymbol("scriptNameOrSourceURL");
Handle<String> function_key = factory()->LookupAsciiSymbol("functionName");
Handle<String> eval_key = factory()->LookupAsciiSymbol("isEval");
Handle<String> constructor_key =
factory()->LookupAsciiSymbol("isConstructor");
StackTraceFrameIterator it(this);
int frames_seen = 0;
while (!it.done() && (frames_seen < limit)) {
JavaScriptFrame* frame = it.frame();
// Set initial size to the maximum inlining level + 1 for the outermost
// function.
List<FrameSummary> frames(Compiler::kMaxInliningLevels + 1);
frame->Summarize(&frames);
for (int i = frames.length() - 1; i >= 0 && frames_seen < limit; i--) {
// Create a JSObject to hold the information for the StackFrame.
Handle<JSObject> stackFrame = factory()->NewJSObject(object_function());
Handle<JSFunction> fun = frames[i].function();
Handle<Script> script(Script::cast(fun->shared()->script()));
if (options & StackTrace::kLineNumber) {
int script_line_offset = script->line_offset()->value();
int position = frames[i].code()->SourcePosition(frames[i].pc());
int line_number = GetScriptLineNumber(script, position);
// line_number is already shifted by the script_line_offset.
int relative_line_number = line_number - script_line_offset;
if (options & StackTrace::kColumnOffset && relative_line_number >= 0) {
Handle<FixedArray> line_ends(FixedArray::cast(script->line_ends()));
int start = (relative_line_number == 0) ? 0 :
Smi::cast(line_ends->get(relative_line_number - 1))->value() + 1;
int column_offset = position - start;
if (relative_line_number == 0) {
// For the case where the code is on the same line as the script
// tag.
column_offset += script->column_offset()->value();
}
SetLocalPropertyNoThrow(stackFrame, column_key,
Handle<Smi>(Smi::FromInt(column_offset + 1)));
}
SetLocalPropertyNoThrow(stackFrame, line_key,
Handle<Smi>(Smi::FromInt(line_number + 1)));
}
if (options & StackTrace::kScriptName) {
Handle<Object> script_name(script->name(), this);
SetLocalPropertyNoThrow(stackFrame, script_key, script_name);
}
if (options & StackTrace::kScriptNameOrSourceURL) {
Handle<Object> script_name(script->name(), this);
Handle<JSValue> script_wrapper = GetScriptWrapper(script);
Handle<Object> property = GetProperty(script_wrapper,
name_or_source_url_key);
ASSERT(property->IsJSFunction());
Handle<JSFunction> method = Handle<JSFunction>::cast(property);
bool caught_exception;
Handle<Object> result = Execution::TryCall(method, script_wrapper, 0,
NULL, &caught_exception);
if (caught_exception) {
result = factory()->undefined_value();
}
SetLocalPropertyNoThrow(stackFrame, script_name_or_source_url_key,
result);
}
if (options & StackTrace::kFunctionName) {
Handle<Object> fun_name(fun->shared()->name(), this);
if (fun_name->ToBoolean()->IsFalse()) {
fun_name = Handle<Object>(fun->shared()->inferred_name(), this);
}
SetLocalPropertyNoThrow(stackFrame, function_key, fun_name);
}
if (options & StackTrace::kIsEval) {
int type = Smi::cast(script->compilation_type())->value();
Handle<Object> is_eval = (type == Script::COMPILATION_TYPE_EVAL) ?
factory()->true_value() : factory()->false_value();
SetLocalPropertyNoThrow(stackFrame, eval_key, is_eval);
}
if (options & StackTrace::kIsConstructor) {
Handle<Object> is_constructor = (frames[i].is_constructor()) ?
factory()->true_value() : factory()->false_value();
SetLocalPropertyNoThrow(stackFrame, constructor_key, is_constructor);
}
FixedArray::cast(stack_trace->elements())->set(frames_seen, *stackFrame);
frames_seen++;
}
it.Advance();
}
stack_trace->set_length(Smi::FromInt(frames_seen));
return stack_trace;
}
void Isolate::PrintStack() {
if (stack_trace_nesting_level_ == 0) {
stack_trace_nesting_level_++;
StringAllocator* allocator;
if (preallocated_message_space_ == NULL) {
allocator = new HeapStringAllocator();
} else {
allocator = preallocated_message_space_;
}
StringStream::ClearMentionedObjectCache();
StringStream accumulator(allocator);
incomplete_message_ = &accumulator;
PrintStack(&accumulator);
accumulator.OutputToStdOut();
InitializeLoggingAndCounters();
accumulator.Log();
incomplete_message_ = NULL;
stack_trace_nesting_level_ = 0;
if (preallocated_message_space_ == NULL) {
// Remove the HeapStringAllocator created above.
delete allocator;
}
} else if (stack_trace_nesting_level_ == 1) {
stack_trace_nesting_level_++;
OS::PrintError(
"\n\nAttempt to print stack while printing stack (double fault)\n");
OS::PrintError(
"If you are lucky you may find a partial stack dump on stdout.\n\n");
incomplete_message_->OutputToStdOut();
}
}
static void PrintFrames(StringStream* accumulator,
StackFrame::PrintMode mode) {
StackFrameIterator it;
for (int i = 0; !it.done(); it.Advance()) {
it.frame()->Print(accumulator, mode, i++);
}
}
void Isolate::PrintStack(StringStream* accumulator) {
if (!IsInitialized()) {
accumulator->Add(
"\n==== Stack trace is not available ==========================\n\n");
accumulator->Add(
"\n==== Isolate for the thread is not initialized =============\n\n");
return;
}
// The MentionedObjectCache is not GC-proof at the moment.
AssertNoAllocation nogc;
ASSERT(StringStream::IsMentionedObjectCacheClear());
// Avoid printing anything if there are no frames.
if (c_entry_fp(thread_local_top()) == 0) return;
accumulator->Add(
"\n==== Stack trace ============================================\n\n");
PrintFrames(accumulator, StackFrame::OVERVIEW);
accumulator->Add(
"\n==== Details ================================================\n\n");
PrintFrames(accumulator, StackFrame::DETAILS);
accumulator->PrintMentionedObjectCache();
accumulator->Add("=====================\n\n");
}
void Isolate::SetFailedAccessCheckCallback(
v8::FailedAccessCheckCallback callback) {
thread_local_top()->failed_access_check_callback_ = callback;
}
void Isolate::ReportFailedAccessCheck(JSObject* receiver, v8::AccessType type) {
if (!thread_local_top()->failed_access_check_callback_) return;
ASSERT(receiver->IsAccessCheckNeeded());
ASSERT(context());
// Get the data object from access check info.
JSFunction* constructor = JSFunction::cast(receiver->map()->constructor());
if (!constructor->shared()->IsApiFunction()) return;
Object* data_obj =
constructor->shared()->get_api_func_data()->access_check_info();
if (data_obj == heap_.undefined_value()) return;
HandleScope scope;
Handle<JSObject> receiver_handle(receiver);
Handle<Object> data(AccessCheckInfo::cast(data_obj)->data());
thread_local_top()->failed_access_check_callback_(
v8::Utils::ToLocal(receiver_handle),
type,
v8::Utils::ToLocal(data));
}
enum MayAccessDecision {
YES, NO, UNKNOWN
};
static MayAccessDecision MayAccessPreCheck(Isolate* isolate,
JSObject* receiver,
v8::AccessType type) {
// During bootstrapping, callback functions are not enabled yet.
if (isolate->bootstrapper()->IsActive()) return YES;
if (receiver->IsJSGlobalProxy()) {
Object* receiver_context = JSGlobalProxy::cast(receiver)->context();
if (!receiver_context->IsContext()) return NO;
// Get the global context of current top context.
// avoid using Isolate::global_context() because it uses Handle.
Context* global_context = isolate->context()->global()->global_context();
if (receiver_context == global_context) return YES;
if (Context::cast(receiver_context)->security_token() ==
global_context->security_token())
return YES;
}
return UNKNOWN;
}
bool Isolate::MayNamedAccess(JSObject* receiver, Object* key,
v8::AccessType type) {
ASSERT(receiver->IsAccessCheckNeeded());
// The callers of this method are not expecting a GC.
AssertNoAllocation no_gc;
// Skip checks for hidden properties access. Note, we do not
// require existence of a context in this case.
if (key == heap_.hidden_symbol()) return true;
// Check for compatibility between the security tokens in the
// current lexical context and the accessed object.
ASSERT(context());
MayAccessDecision decision = MayAccessPreCheck(this, receiver, type);
if (decision != UNKNOWN) return decision == YES;
// Get named access check callback
JSFunction* constructor = JSFunction::cast(receiver->map()->constructor());
if (!constructor->shared()->IsApiFunction()) return false;
Object* data_obj =
constructor->shared()->get_api_func_data()->access_check_info();
if (data_obj == heap_.undefined_value()) return false;
Object* fun_obj = AccessCheckInfo::cast(data_obj)->named_callback();
v8::NamedSecurityCallback callback =
v8::ToCData<v8::NamedSecurityCallback>(fun_obj);
if (!callback) return false;
HandleScope scope(this);
Handle<JSObject> receiver_handle(receiver, this);
Handle<Object> key_handle(key, this);
Handle<Object> data(AccessCheckInfo::cast(data_obj)->data(), this);
LOG(this, ApiNamedSecurityCheck(key));
bool result = false;
{
// Leaving JavaScript.
VMState state(this, EXTERNAL);
result = callback(v8::Utils::ToLocal(receiver_handle),
v8::Utils::ToLocal(key_handle),
type,
v8::Utils::ToLocal(data));
}
return result;
}
bool Isolate::MayIndexedAccess(JSObject* receiver,
uint32_t index,
v8::AccessType type) {
ASSERT(receiver->IsAccessCheckNeeded());
// Check for compatibility between the security tokens in the
// current lexical context and the accessed object.
ASSERT(context());
MayAccessDecision decision = MayAccessPreCheck(this, receiver, type);
if (decision != UNKNOWN) return decision == YES;
// Get indexed access check callback
JSFunction* constructor = JSFunction::cast(receiver->map()->constructor());
if (!constructor->shared()->IsApiFunction()) return false;
Object* data_obj =
constructor->shared()->get_api_func_data()->access_check_info();
if (data_obj == heap_.undefined_value()) return false;
Object* fun_obj = AccessCheckInfo::cast(data_obj)->indexed_callback();
v8::IndexedSecurityCallback callback =
v8::ToCData<v8::IndexedSecurityCallback>(fun_obj);
if (!callback) return false;
HandleScope scope(this);
Handle<JSObject> receiver_handle(receiver, this);
Handle<Object> data(AccessCheckInfo::cast(data_obj)->data(), this);
LOG(this, ApiIndexedSecurityCheck(index));
bool result = false;
{
// Leaving JavaScript.
VMState state(this, EXTERNAL);
result = callback(v8::Utils::ToLocal(receiver_handle),
index,
type,
v8::Utils::ToLocal(data));
}
return result;
}
const char* const Isolate::kStackOverflowMessage =
"Uncaught RangeError: Maximum call stack size exceeded";
Failure* Isolate::StackOverflow() {
HandleScope scope;
Handle<String> key = factory()->stack_overflow_symbol();
Handle<JSObject> boilerplate =
Handle<JSObject>::cast(GetProperty(js_builtins_object(), key));
Handle<Object> exception = Copy(boilerplate);
// TODO(1240995): To avoid having to call JavaScript code to compute
// the message for stack overflow exceptions which is very likely to
// double fault with another stack overflow exception, we use a
// precomputed message.
DoThrow(*exception, NULL);
return Failure::Exception();
}
Failure* Isolate::TerminateExecution() {
DoThrow(heap_.termination_exception(), NULL);
return Failure::Exception();
}
Failure* Isolate::Throw(Object* exception, MessageLocation* location) {
DoThrow(exception, location);
return Failure::Exception();
}
Failure* Isolate::ReThrow(MaybeObject* exception, MessageLocation* location) {
bool can_be_caught_externally = false;
ShouldReportException(&can_be_caught_externally,
is_catchable_by_javascript(exception));
thread_local_top()->catcher_ = can_be_caught_externally ?
try_catch_handler() : NULL;
// Set the exception being re-thrown.
set_pending_exception(exception);
if (exception->IsFailure()) return exception->ToFailureUnchecked();
return Failure::Exception();
}
Failure* Isolate::ThrowIllegalOperation() {
return Throw(heap_.illegal_access_symbol());
}
void Isolate::ScheduleThrow(Object* exception) {
// When scheduling a throw we first throw the exception to get the
// error reporting if it is uncaught before rescheduling it.
Throw(exception);
thread_local_top()->scheduled_exception_ = pending_exception();
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
}
Failure* Isolate::PromoteScheduledException() {
MaybeObject* thrown = scheduled_exception();
clear_scheduled_exception();
// Re-throw the exception to avoid getting repeated error reporting.
return ReThrow(thrown);
}
void Isolate::PrintCurrentStackTrace(FILE* out) {
StackTraceFrameIterator it(this);
while (!it.done()) {
HandleScope scope;
// Find code position if recorded in relocation info.
JavaScriptFrame* frame = it.frame();
int pos = frame->LookupCode()->SourcePosition(frame->pc());
Handle<Object> pos_obj(Smi::FromInt(pos));
// Fetch function and receiver.
Handle<JSFunction> fun(JSFunction::cast(frame->function()));
Handle<Object> recv(frame->receiver());
// Advance to the next JavaScript frame and determine if the
// current frame is the top-level frame.
it.Advance();
Handle<Object> is_top_level = it.done()
? factory()->true_value()
: factory()->false_value();
// Generate and print stack trace line.
Handle<String> line =
Execution::GetStackTraceLine(recv, fun, pos_obj, is_top_level);
if (line->length() > 0) {
line->PrintOn(out);
fprintf(out, "\n");
}
}
}
void Isolate::ComputeLocation(MessageLocation* target) {
*target = MessageLocation(Handle<Script>(heap_.empty_script()), -1, -1);
StackTraceFrameIterator it(this);
if (!it.done()) {
JavaScriptFrame* frame = it.frame();
JSFunction* fun = JSFunction::cast(frame->function());
Object* script = fun->shared()->script();
if (script->IsScript() &&
!(Script::cast(script)->source()->IsUndefined())) {
int pos = frame->LookupCode()->SourcePosition(frame->pc());
// Compute the location from the function and the reloc info.
Handle<Script> casted_script(Script::cast(script));
*target = MessageLocation(casted_script, pos, pos + 1);
}
}
}
bool Isolate::ShouldReportException(bool* can_be_caught_externally,
bool catchable_by_javascript) {
// Find the top-most try-catch handler.
StackHandler* handler =
StackHandler::FromAddress(Isolate::handler(thread_local_top()));
while (handler != NULL && !handler->is_try_catch()) {
handler = handler->next();
}
// Get the address of the external handler so we can compare the address to
// determine which one is closer to the top of the stack.
Address external_handler_address =
thread_local_top()->try_catch_handler_address();
// The exception has been externally caught if and only if there is
// an external handler which is on top of the top-most try-catch
// handler.
*can_be_caught_externally = external_handler_address != NULL &&
(handler == NULL || handler->address() > external_handler_address ||
!catchable_by_javascript);
if (*can_be_caught_externally) {
// Only report the exception if the external handler is verbose.
return try_catch_handler()->is_verbose_;
} else {
// Report the exception if it isn't caught by JavaScript code.
return handler == NULL;
}
}
void Isolate::DoThrow(MaybeObject* exception, MessageLocation* location) {
ASSERT(!has_pending_exception());
HandleScope scope;
Object* exception_object = Smi::FromInt(0);
bool is_object = exception->ToObject(&exception_object);
Handle<Object> exception_handle(exception_object);
// Determine reporting and whether the exception is caught externally.
bool catchable_by_javascript = is_catchable_by_javascript(exception);
// Only real objects can be caught by JS.
ASSERT(!catchable_by_javascript || is_object);
bool can_be_caught_externally = false;
bool should_report_exception =
ShouldReportException(&can_be_caught_externally, catchable_by_javascript);
bool report_exception = catchable_by_javascript && should_report_exception;
#ifdef ENABLE_DEBUGGER_SUPPORT
// Notify debugger of exception.
if (catchable_by_javascript) {
debugger_->OnException(exception_handle, report_exception);
}
#endif
// Generate the message.
Handle<Object> message_obj;
MessageLocation potential_computed_location;
bool try_catch_needs_message =
can_be_caught_externally &&
try_catch_handler()->capture_message_;
if (report_exception || try_catch_needs_message) {
if (location == NULL) {
// If no location was specified we use a computed one instead
ComputeLocation(&potential_computed_location);
location = &potential_computed_location;
}
if (!bootstrapper()->IsActive()) {
// It's not safe to try to make message objects or collect stack
// traces while the bootstrapper is active since the infrastructure
// may not have been properly initialized.
Handle<String> stack_trace;
if (FLAG_trace_exception) stack_trace = StackTraceString();
Handle<JSArray> stack_trace_object;
if (report_exception && capture_stack_trace_for_uncaught_exceptions_) {
stack_trace_object = CaptureCurrentStackTrace(
stack_trace_for_uncaught_exceptions_frame_limit_,
stack_trace_for_uncaught_exceptions_options_);
}
ASSERT(is_object); // Can't use the handle unless there's a real object.
message_obj = MessageHandler::MakeMessageObject("uncaught_exception",
location, HandleVector<Object>(&exception_handle, 1), stack_trace,
stack_trace_object);
}
}
// Save the message for reporting if the the exception remains uncaught.
thread_local_top()->has_pending_message_ = report_exception;
if (!message_obj.is_null()) {
thread_local_top()->pending_message_obj_ = *message_obj;
if (location != NULL) {
thread_local_top()->pending_message_script_ = *location->script();
thread_local_top()->pending_message_start_pos_ = location->start_pos();
thread_local_top()->pending_message_end_pos_ = location->end_pos();
}
}
// Do not forget to clean catcher_ if currently thrown exception cannot
// be caught. If necessary, ReThrow will update the catcher.
thread_local_top()->catcher_ = can_be_caught_externally ?
try_catch_handler() : NULL;
// NOTE: Notifying the debugger or generating the message
// may have caused new exceptions. For now, we just ignore
// that and set the pending exception to the original one.
if (is_object) {
set_pending_exception(*exception_handle);
} else {
// Failures are not on the heap so they neither need nor work with handles.
ASSERT(exception_handle->IsFailure());
set_pending_exception(exception);
}
}
bool Isolate::IsExternallyCaught() {
ASSERT(has_pending_exception());
if ((thread_local_top()->catcher_ == NULL) ||
(try_catch_handler() != thread_local_top()->catcher_)) {
// When throwing the exception, we found no v8::TryCatch
// which should care about this exception.
return false;
}
if (!is_catchable_by_javascript(pending_exception())) {
return true;
}
// Get the address of the external handler so we can compare the address to
// determine which one is closer to the top of the stack.
Address external_handler_address =
thread_local_top()->try_catch_handler_address();
ASSERT(external_handler_address != NULL);
// The exception has been externally caught if and only if there is
// an external handler which is on top of the top-most try-finally
// handler.
// There should be no try-catch blocks as they would prohibit us from
// finding external catcher in the first place (see catcher_ check above).
//
// Note, that finally clause would rethrow an exception unless it's
// aborted by jumps in control flow like return, break, etc. and we'll
// have another chances to set proper v8::TryCatch.
StackHandler* handler =
StackHandler::FromAddress(Isolate::handler(thread_local_top()));
while (handler != NULL && handler->address() < external_handler_address) {
ASSERT(!handler->is_try_catch());
if (handler->is_try_finally()) return false;
handler = handler->next();
}
return true;
}
void Isolate::ReportPendingMessages() {
ASSERT(has_pending_exception());
PropagatePendingExceptionToExternalTryCatch();
// If the pending exception is OutOfMemoryException set out_of_memory in
// the global context. Note: We have to mark the global context here
// since the GenerateThrowOutOfMemory stub cannot make a RuntimeCall to
// set it.
HandleScope scope;
if (thread_local_top_.pending_exception_ == Failure::OutOfMemoryException()) {
context()->mark_out_of_memory();
} else if (thread_local_top_.pending_exception_ ==
heap()->termination_exception()) {
// Do nothing: if needed, the exception has been already propagated to
// v8::TryCatch.
} else {
if (thread_local_top_.has_pending_message_) {
thread_local_top_.has_pending_message_ = false;
if (!thread_local_top_.pending_message_obj_->IsTheHole()) {
HandleScope scope;
Handle<Object> message_obj(thread_local_top_.pending_message_obj_);
if (thread_local_top_.pending_message_script_ != NULL) {
Handle<Script> script(thread_local_top_.pending_message_script_);
int start_pos = thread_local_top_.pending_message_start_pos_;
int end_pos = thread_local_top_.pending_message_end_pos_;
MessageLocation location(script, start_pos, end_pos);
MessageHandler::ReportMessage(this, &location, message_obj);
} else {
MessageHandler::ReportMessage(this, NULL, message_obj);
}
}
}
}
clear_pending_message();
}
void Isolate::TraceException(bool flag) {
FLAG_trace_exception = flag; // TODO(isolates): This is an unfortunate use.
}
bool Isolate::OptionalRescheduleException(bool is_bottom_call) {
ASSERT(has_pending_exception());
PropagatePendingExceptionToExternalTryCatch();
// Allways reschedule out of memory exceptions.
if (!is_out_of_memory()) {
bool is_termination_exception =
pending_exception() == heap_.termination_exception();
// Do not reschedule the exception if this is the bottom call.
bool clear_exception = is_bottom_call;
if (is_termination_exception) {
if (is_bottom_call) {
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
return false;
}
} else if (thread_local_top()->external_caught_exception_) {
// If the exception is externally caught, clear it if there are no
// JavaScript frames on the way to the C++ frame that has the
// external handler.
ASSERT(thread_local_top()->try_catch_handler_address() != NULL);
Address external_handler_address =
thread_local_top()->try_catch_handler_address();
JavaScriptFrameIterator it;
if (it.done() || (it.frame()->sp() > external_handler_address)) {
clear_exception = true;
}
}
// Clear the exception if needed.
if (clear_exception) {
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
return false;
}
}
// Reschedule the exception.
thread_local_top()->scheduled_exception_ = pending_exception();
clear_pending_exception();
return true;
}
void Isolate::SetCaptureStackTraceForUncaughtExceptions(
bool capture,
int frame_limit,
StackTrace::StackTraceOptions options) {
capture_stack_trace_for_uncaught_exceptions_ = capture;
stack_trace_for_uncaught_exceptions_frame_limit_ = frame_limit;
stack_trace_for_uncaught_exceptions_options_ = options;
}
bool Isolate::is_out_of_memory() {
if (has_pending_exception()) {
MaybeObject* e = pending_exception();
if (e->IsFailure() && Failure::cast(e)->IsOutOfMemoryException()) {
return true;
}
}
if (has_scheduled_exception()) {
MaybeObject* e = scheduled_exception();
if (e->IsFailure() && Failure::cast(e)->IsOutOfMemoryException()) {
return true;
}
}
return false;
}
Handle<Context> Isolate::global_context() {
GlobalObject* global = thread_local_top()->context_->global();
return Handle<Context>(global->global_context());
}
Handle<Context> Isolate::GetCallingGlobalContext() {
JavaScriptFrameIterator it;
#ifdef ENABLE_DEBUGGER_SUPPORT
if (debug_->InDebugger()) {
while (!it.done()) {
JavaScriptFrame* frame = it.frame();
Context* context = Context::cast(frame->context());
if (context->global_context() == *debug_->debug_context()) {
it.Advance();
} else {
break;
}
}
}
#endif // ENABLE_DEBUGGER_SUPPORT
if (it.done()) return Handle<Context>::null();
JavaScriptFrame* frame = it.frame();
Context* context = Context::cast(frame->context());
return Handle<Context>(context->global_context());
}
char* Isolate::ArchiveThread(char* to) {
if (RuntimeProfiler::IsEnabled() && current_vm_state() == JS) {
RuntimeProfiler::IsolateExitedJS(this);
}
memcpy(to, reinterpret_cast<char*>(thread_local_top()),
sizeof(ThreadLocalTop));
InitializeThreadLocal();
return to + sizeof(ThreadLocalTop);
}
char* Isolate::RestoreThread(char* from) {
memcpy(reinterpret_cast<char*>(thread_local_top()), from,
sizeof(ThreadLocalTop));
// This might be just paranoia, but it seems to be needed in case a
// thread_local_top_ is restored on a separate OS thread.
#ifdef USE_SIMULATOR
#ifdef V8_TARGET_ARCH_ARM
thread_local_top()->simulator_ = Simulator::current(this);
#elif V8_TARGET_ARCH_MIPS
thread_local_top()->simulator_ = Simulator::current(this);
#endif
#endif
if (RuntimeProfiler::IsEnabled() && current_vm_state() == JS) {
RuntimeProfiler::IsolateEnteredJS(this);
}
return from + sizeof(ThreadLocalTop);
}
} } // namespace v8::internal