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cobalt / cobalt / ecb76eb1e58da94893009effbde7ffbb7515f9c6 / . / src / v8 / src / execution / isolate.cc
blob: 58cc241f3e085e2f595e393434f80b84b88f018d [file] [log] [blame]
// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/execution/isolate.h"
#include <stdlib.h>
#include <atomic>
#include <fstream> // NOLINT(readability/streams)
#include <memory>
#include <sstream>
#include <unordered_map>
#include "src/api/api-inl.h"
#include "src/ast/ast-value-factory.h"
#include "src/ast/scopes.h"
#include "src/base/adapters.h"
#include "src/base/hashmap.h"
#include "src/base/platform/platform.h"
#include "src/base/sys-info.h"
#include "src/base/utils/random-number-generator.h"
#include "src/builtins/builtins-promise.h"
#include "src/builtins/constants-table-builder.h"
#include "src/codegen/assembler-inl.h"
#include "src/codegen/compilation-cache.h"
#include "src/common/ptr-compr.h"
#include "src/compiler-dispatcher/compiler-dispatcher.h"
#include "src/compiler-dispatcher/optimizing-compile-dispatcher.h"
#include "src/date/date.h"
#include "src/debug/debug-frames.h"
#include "src/debug/debug.h"
#include "src/deoptimizer/deoptimizer.h"
#include "src/diagnostics/compilation-statistics.h"
#include "src/execution/frames-inl.h"
#include "src/execution/isolate-inl.h"
#include "src/execution/messages.h"
#include "src/execution/microtask-queue.h"
#include "src/execution/runtime-profiler.h"
#include "src/execution/simulator.h"
#include "src/execution/v8threads.h"
#include "src/execution/vm-state-inl.h"
#include "src/heap/heap-inl.h"
#include "src/heap/read-only-heap.h"
#include "src/ic/stub-cache.h"
#include "src/init/bootstrapper.h"
#include "src/init/setup-isolate.h"
#include "src/init/v8.h"
#include "src/interpreter/interpreter.h"
#include "src/libsampler/sampler.h"
#include "src/logging/counters.h"
#include "src/logging/log.h"
#include "src/numbers/hash-seed-inl.h"
#include "src/objects/elements.h"
#include "src/objects/frame-array-inl.h"
#include "src/objects/hash-table-inl.h"
#include "src/objects/js-array-inl.h"
#include "src/objects/js-generator-inl.h"
#include "src/objects/module-inl.h"
#include "src/objects/promise-inl.h"
#include "src/objects/prototype.h"
#include "src/objects/slots.h"
#include "src/objects/smi.h"
#include "src/objects/stack-frame-info-inl.h"
#include "src/objects/visitors.h"
#include "src/profiler/heap-profiler.h"
#include "src/profiler/tracing-cpu-profiler.h"
#include "src/regexp/regexp-stack.h"
#include "src/snapshot/embedded/embedded-data.h"
#include "src/snapshot/embedded/embedded-file-writer.h"
#include "src/snapshot/read-only-deserializer.h"
#include "src/snapshot/startup-deserializer.h"
#include "src/strings/string-builder-inl.h"
#include "src/strings/string-stream.h"
#include "src/tasks/cancelable-task.h"
#include "src/tracing/tracing-category-observer.h"
#include "src/trap-handler/trap-handler.h"
#include "src/utils/ostreams.h"
#include "src/utils/version.h"
#include "src/wasm/wasm-code-manager.h"
#include "src/wasm/wasm-engine.h"
#include "src/wasm/wasm-objects.h"
#include "src/zone/accounting-allocator.h"
#ifdef V8_INTL_SUPPORT
#include "unicode/uobject.h"
#endif // V8_INTL_SUPPORT
#if V8_OS_STARBOARD
#include "src/poems.h"
#endif
#if defined(V8_OS_WIN_X64)
#include "src/diagnostics/unwinding-info-win64.h"
#endif
#if !defined(DISABLE_WASM_COMPILER_ISSUE_STARBOARD)
#define CONST const
#else
#define CONST
#endif
extern "C" CONST uint8_t* v8_Default_embedded_blob_;
extern "C" uint32_t v8_Default_embedded_blob_size_;
namespace v8 {
namespace internal {
#ifdef DEBUG
#define TRACE_ISOLATE(tag) \
do { \
if (FLAG_trace_isolates) { \
PrintF("Isolate %p (id %d)" #tag "\n", reinterpret_cast<void*>(this), \
id()); \
} \
} while (false)
#else
#define TRACE_ISOLATE(tag)
#endif
uint8_t* DefaultEmbeddedBlob() { return v8_Default_embedded_blob_; }
uint32_t DefaultEmbeddedBlobSize() { return v8_Default_embedded_blob_size_; }
#ifdef V8_MULTI_SNAPSHOTS
extern "C" const uint8_t* v8_Trusted_embedded_blob_;
extern "C" uint32_t v8_Trusted_embedded_blob_size_;
const uint8_t* TrustedEmbeddedBlob() { return v8_Trusted_embedded_blob_; }
uint32_t TrustedEmbeddedBlobSize() { return v8_Trusted_embedded_blob_size_; }
#endif
namespace {
// These variables provide access to the current embedded blob without requiring
// an isolate instance. This is needed e.g. by Code::InstructionStart, which may
// not have access to an isolate but still needs to access the embedded blob.
// The variables are initialized by each isolate in Init(). Writes and reads are
// relaxed since we can guarantee that the current thread has initialized these
// variables before accessing them. Different threads may race, but this is fine
// since they all attempt to set the same values of the blob pointer and size.
#if defined(DISABLE_WASM_COMPILER_ISSUE_STARBOARD)
// This is why we need the CONST workaround in this file: atomic can't be used
// with const on some compiler.
#endif
std::atomic<CONST uint8_t*> current_embedded_blob_(nullptr);
std::atomic<uint32_t> current_embedded_blob_size_(0);
// The various workflows around embedded snapshots are fairly complex. We need
// to support plain old snapshot builds, nosnap builds, and the requirements of
// subtly different serialization tests. There's two related knobs to twiddle:
//
// - The default embedded blob may be overridden by setting the sticky embedded
// blob. This is set automatically whenever we create a new embedded blob.
//
// - Lifecycle management can be either manual or set to refcounting.
//
// A few situations to demonstrate their use:
//
// - A plain old snapshot build neither overrides the default blob nor
// refcounts.
//
// - mksnapshot sets the sticky blob and manually frees the embedded
// blob once done.
//
// - Most serializer tests do the same.
//
// - Nosnapshot builds set the sticky blob and enable refcounting.
// This mutex protects access to the following variables:
// - sticky_embedded_blob_
// - sticky_embedded_blob_size_
// - enable_embedded_blob_refcounting_
// - current_embedded_blob_refs_
base::LazyMutex current_embedded_blob_refcount_mutex_ = LAZY_MUTEX_INITIALIZER;
CONST uint8_t* sticky_embedded_blob_ = nullptr;
uint32_t sticky_embedded_blob_size_ = 0;
bool enable_embedded_blob_refcounting_ = true;
int current_embedded_blob_refs_ = 0;
CONST uint8_t* StickyEmbeddedBlob() { return sticky_embedded_blob_; }
uint32_t StickyEmbeddedBlobSize() { return sticky_embedded_blob_size_; }
void SetStickyEmbeddedBlob(CONST uint8_t* blob, uint32_t blob_size) {
sticky_embedded_blob_ = blob;
sticky_embedded_blob_size_ = blob_size;
}
} // namespace
void DisableEmbeddedBlobRefcounting() {
base::MutexGuard guard(current_embedded_blob_refcount_mutex_.Pointer());
enable_embedded_blob_refcounting_ = false;
}
void FreeCurrentEmbeddedBlob() {
CHECK(!enable_embedded_blob_refcounting_);
base::MutexGuard guard(current_embedded_blob_refcount_mutex_.Pointer());
if (StickyEmbeddedBlob() == nullptr) return;
CHECK_EQ(StickyEmbeddedBlob(), Isolate::CurrentEmbeddedBlob());
InstructionStream::FreeOffHeapInstructionStream(
const_cast<uint8_t*>(Isolate::CurrentEmbeddedBlob()),
Isolate::CurrentEmbeddedBlobSize());
current_embedded_blob_.store(nullptr, std::memory_order_relaxed);
current_embedded_blob_size_.store(0, std::memory_order_relaxed);
sticky_embedded_blob_ = nullptr;
sticky_embedded_blob_size_ = 0;
}
// static
bool Isolate::CurrentEmbeddedBlobIsBinaryEmbedded() {
// In some situations, we must be able to rely on the embedded blob being
// immortal immovable. This is the case if the blob is binary-embedded.
// See blob lifecycle controls above for descriptions of when the current
// embedded blob may change (e.g. in tests or mksnapshot). If the blob is
// binary-embedded, it is immortal immovable.
const uint8_t* blob =
current_embedded_blob_.load(std::memory_order::memory_order_relaxed);
if (blob == nullptr) return false;
#ifdef V8_MULTI_SNAPSHOTS
if (blob == TrustedEmbeddedBlob()) return true;
#endif
return blob == DefaultEmbeddedBlob();
}
void Isolate::SetEmbeddedBlob(CONST uint8_t* blob, uint32_t blob_size) {
CHECK_NOT_NULL(blob);
embedded_blob_ = blob;
embedded_blob_size_ = blob_size;
current_embedded_blob_.store(blob, std::memory_order_relaxed);
current_embedded_blob_size_.store(blob_size, std::memory_order_relaxed);
#ifdef DEBUG
// Verify that the contents of the embedded blob are unchanged from
// serialization-time, just to ensure the compiler isn't messing with us.
EmbeddedData d = EmbeddedData::FromBlob();
if (d.EmbeddedBlobHash() != d.CreateEmbeddedBlobHash()) {
FATAL(
"Embedded blob checksum verification failed. This indicates that the "
"embedded blob has been modified since compilation time. A common "
"cause is a debugging breakpoint set within builtin code.");
}
#endif // DEBUG
}
void Isolate::ClearEmbeddedBlob() {
CHECK(enable_embedded_blob_refcounting_);
CHECK_EQ(embedded_blob_, CurrentEmbeddedBlob());
CHECK_EQ(embedded_blob_, StickyEmbeddedBlob());
embedded_blob_ = nullptr;
embedded_blob_size_ = 0;
current_embedded_blob_.store(nullptr, std::memory_order_relaxed);
current_embedded_blob_size_.store(0, std::memory_order_relaxed);
sticky_embedded_blob_ = nullptr;
sticky_embedded_blob_size_ = 0;
}
const uint8_t* Isolate::embedded_blob() const { return embedded_blob_; }
uint32_t Isolate::embedded_blob_size() const { return embedded_blob_size_; }
// static
const uint8_t* Isolate::CurrentEmbeddedBlob() {
return current_embedded_blob_.load(std::memory_order::memory_order_relaxed);
}
// static
uint32_t Isolate::CurrentEmbeddedBlobSize() {
return current_embedded_blob_size_.load(
std::memory_order::memory_order_relaxed);
}
size_t Isolate::HashIsolateForEmbeddedBlob() {
DCHECK(builtins_.is_initialized());
DCHECK(FLAG_embedded_builtins);
DCHECK(Builtins::AllBuiltinsAreIsolateIndependent());
DisallowHeapAllocation no_gc;
static constexpr size_t kSeed = 0;
size_t hash = kSeed;
// Hash data sections of builtin code objects.
for (int i = 0; i < Builtins::builtin_count; i++) {
Code code = heap_.builtin(i);
DCHECK(Internals::HasHeapObjectTag(code.ptr()));
uint8_t* const code_ptr =
reinterpret_cast<uint8_t*>(code.ptr() - kHeapObjectTag);
// These static asserts ensure we don't miss relevant fields. We don't hash
// instruction size and flags since they change when creating the off-heap
// trampolines. Other data fields must remain the same.
STATIC_ASSERT(Code::kInstructionSizeOffset == Code::kDataStart);
STATIC_ASSERT(Code::kFlagsOffset == Code::kInstructionSizeOffsetEnd + 1);
STATIC_ASSERT(Code::kSafepointTableOffsetOffset ==
Code::kFlagsOffsetEnd + 1);
static constexpr int kStartOffset = Code::kSafepointTableOffsetOffset;
for (int j = kStartOffset; j < Code::kUnalignedHeaderSize; j++) {
hash = base::hash_combine(hash, size_t{code_ptr[j]});
}
}
// The builtins constants table is also tightly tied to embedded builtins.
hash = base::hash_combine(
hash, static_cast<size_t>(heap_.builtins_constants_table().length()));
return hash;
}
base::Thread::LocalStorageKey Isolate::isolate_key_;
base::Thread::LocalStorageKey Isolate::per_isolate_thread_data_key_;
#if DEBUG
std::atomic<bool> Isolate::isolate_key_created_{false};
#endif
namespace {
// A global counter for all generated Isolates, might overflow.
std::atomic<int> isolate_counter{0};
} // namespace
Isolate::PerIsolateThreadData*
Isolate::FindOrAllocatePerThreadDataForThisThread() {
ThreadId thread_id = ThreadId::Current();
PerIsolateThreadData* per_thread = nullptr;
{
base::MutexGuard lock_guard(&thread_data_table_mutex_);
per_thread = thread_data_table_.Lookup(thread_id);
if (per_thread == nullptr) {
base::OS::AdjustSchedulingParams();
per_thread = new PerIsolateThreadData(this, thread_id);
thread_data_table_.Insert(per_thread);
}
DCHECK(thread_data_table_.Lookup(thread_id) == per_thread);
}
return per_thread;
}
void Isolate::DiscardPerThreadDataForThisThread() {
ThreadId thread_id = ThreadId::TryGetCurrent();
if (thread_id.IsValid()) {
DCHECK_NE(thread_manager_->mutex_owner_.load(std::memory_order_relaxed),
thread_id);
base::MutexGuard lock_guard(&thread_data_table_mutex_);
PerIsolateThreadData* per_thread = thread_data_table_.Lookup(thread_id);
if (per_thread) {
DCHECK(!per_thread->thread_state_);
thread_data_table_.Remove(per_thread);
}
}
}
Isolate::PerIsolateThreadData* Isolate::FindPerThreadDataForThisThread() {
ThreadId thread_id = ThreadId::Current();
return FindPerThreadDataForThread(thread_id);
}
Isolate::PerIsolateThreadData* Isolate::FindPerThreadDataForThread(
ThreadId thread_id) {
PerIsolateThreadData* per_thread = nullptr;
{
base::MutexGuard lock_guard(&thread_data_table_mutex_);
per_thread = thread_data_table_.Lookup(thread_id);
}
return per_thread;
}
void Isolate::InitializeOncePerProcess() {
isolate_key_ = base::Thread::CreateThreadLocalKey();
#if DEBUG
bool expected = false;
DCHECK_EQ(true, isolate_key_created_.compare_exchange_strong(
expected, true, std::memory_order_relaxed));
#endif
per_isolate_thread_data_key_ = base::Thread::CreateThreadLocalKey();
}
Address Isolate::get_address_from_id(IsolateAddressId id) {
return isolate_addresses_[id];
}
char* Isolate::Iterate(RootVisitor* v, char* thread_storage) {
ThreadLocalTop* thread = reinterpret_cast<ThreadLocalTop*>(thread_storage);
Iterate(v, thread);
return thread_storage + sizeof(ThreadLocalTop);
}
void Isolate::IterateThread(ThreadVisitor* v, char* t) {
ThreadLocalTop* thread = reinterpret_cast<ThreadLocalTop*>(t);
v->VisitThread(this, thread);
}
void Isolate::Iterate(RootVisitor* v, ThreadLocalTop* thread) {
// Visit the roots from the top for a given thread.
v->VisitRootPointer(Root::kTop, nullptr,
FullObjectSlot(&thread->pending_exception_));
v->VisitRootPointer(Root::kTop, nullptr,
FullObjectSlot(&thread->pending_message_obj_));
v->VisitRootPointer(Root::kTop, nullptr, FullObjectSlot(&thread->context_));
v->VisitRootPointer(Root::kTop, nullptr,
FullObjectSlot(&thread->scheduled_exception_));
for (v8::TryCatch* block = thread->try_catch_handler_; block != nullptr;
block = block->next_) {
// TODO(3770): Make TryCatch::exception_ an Address (and message_obj_ too).
v->VisitRootPointer(
Root::kTop, nullptr,
FullObjectSlot(reinterpret_cast<Address>(&(block->exception_))));
v->VisitRootPointer(
Root::kTop, nullptr,
FullObjectSlot(reinterpret_cast<Address>(&(block->message_obj_))));
}
// Iterate over pointers on native execution stack.
wasm::WasmCodeRefScope wasm_code_ref_scope;
for (StackFrameIterator it(this, thread); !it.done(); it.Advance()) {
it.frame()->Iterate(v);
}
}
void Isolate::Iterate(RootVisitor* v) {
ThreadLocalTop* current_t = thread_local_top();
Iterate(v, current_t);
}
void Isolate::IterateDeferredHandles(RootVisitor* visitor) {
for (DeferredHandles* deferred = deferred_handles_head_; deferred != nullptr;
deferred = deferred->next_) {
deferred->Iterate(visitor);
}
}
#ifdef DEBUG
bool Isolate::IsDeferredHandle(Address* handle) {
// Comparing unrelated pointers (not from the same array) is undefined
// behavior, so cast to Address before making arbitrary comparisons.
Address handle_as_address = reinterpret_cast<Address>(handle);
// Each DeferredHandles instance keeps the handles to one job in the
// concurrent recompilation queue, containing a list of blocks. Each block
// contains kHandleBlockSize handles except for the first block, which may
// not be fully filled.
// We iterate through all the blocks to see whether the argument handle
// belongs to one of the blocks. If so, it is deferred.
for (DeferredHandles* deferred = deferred_handles_head_; deferred != nullptr;
deferred = deferred->next_) {
std::vector<Address*>* blocks = &deferred->blocks_;
for (size_t i = 0; i < blocks->size(); i++) {
Address* block_limit = (i == 0) ? deferred->first_block_limit_
: blocks->at(i) + kHandleBlockSize;
if (reinterpret_cast<Address>(blocks->at(i)) <= handle_as_address &&
handle_as_address < reinterpret_cast<Address>(block_limit)) {
return true;
}
}
}
return false;
}
#endif // DEBUG
void Isolate::RegisterTryCatchHandler(v8::TryCatch* that) {
thread_local_top()->try_catch_handler_ = that;
}
void Isolate::UnregisterTryCatchHandler(v8::TryCatch* that) {
DCHECK(thread_local_top()->try_catch_handler_ == that);
thread_local_top()->try_catch_handler_ = that->next_;
}
Handle<String> Isolate::StackTraceString() {
if (stack_trace_nesting_level_ == 0) {
stack_trace_nesting_level_++;
HeapStringAllocator allocator;
StringStream::ClearMentionedObjectCache(this);
StringStream accumulator(&allocator);
incomplete_message_ = &accumulator;
PrintStack(&accumulator);
Handle<String> stack_trace = accumulator.ToString(this);
incomplete_message_ = nullptr;
stack_trace_nesting_level_ = 0;
return stack_trace;
} else if (stack_trace_nesting_level_ == 1) {
stack_trace_nesting_level_++;
base::OS::PrintError(
"\n\nAttempt to print stack while printing stack (double fault)\n");
base::OS::PrintError(
"If you are lucky you may find a partial stack dump on stdout.\n\n");
incomplete_message_->OutputToStdOut();
return factory()->empty_string();
} else {
base::OS::Abort();
// Unreachable
return factory()->empty_string();
}
}
void Isolate::PushStackTraceAndDie(void* ptr1, void* ptr2, void* ptr3,
void* ptr4) {
StackTraceFailureMessage message(this, ptr1, ptr2, ptr3, ptr4);
message.Print();
base::OS::Abort();
}
void StackTraceFailureMessage::Print() volatile {
// Print the details of this failure message object, including its own address
// to force stack allocation.
base::OS::PrintError(
"Stacktrace:\n ptr1=%p\n ptr2=%p\n ptr3=%p\n ptr4=%p\n "
"failure_message_object=%p\n%s",
ptr1_, ptr2_, ptr3_, ptr4_, this, &js_stack_trace_[0]);
}
StackTraceFailureMessage::StackTraceFailureMessage(Isolate* isolate, void* ptr1,
void* ptr2, void* ptr3,
void* ptr4) {
isolate_ = isolate;
ptr1_ = ptr1;
ptr2_ = ptr2;
ptr3_ = ptr3;
ptr4_ = ptr4;
// Write a stracktrace into the {js_stack_trace_} buffer.
const size_t buffer_length = arraysize(js_stack_trace_);
memset(&js_stack_trace_, 0, buffer_length);
FixedStringAllocator fixed(&js_stack_trace_[0], buffer_length - 1);
StringStream accumulator(&fixed, StringStream::kPrintObjectConcise);
isolate->PrintStack(&accumulator, Isolate::kPrintStackVerbose);
// Keeping a reference to the last code objects to increase likelyhood that
// they get included in the minidump.
const size_t code_objects_length = arraysize(code_objects_);
size_t i = 0;
StackFrameIterator it(isolate);
for (; !it.done() && i < code_objects_length; it.Advance()) {
code_objects_[i++] =
reinterpret_cast<void*>(it.frame()->unchecked_code().ptr());
}
}
namespace {
class StackFrameCacheHelper : public AllStatic {
public:
static MaybeHandle<StackTraceFrame> LookupCachedFrame(
Isolate* isolate, Handle<AbstractCode> code, int code_offset) {
if (FLAG_optimize_for_size) return MaybeHandle<StackTraceFrame>();
const auto maybe_cache = handle(code->stack_frame_cache(), isolate);
if (!maybe_cache->IsSimpleNumberDictionary())
return MaybeHandle<StackTraceFrame>();
const auto cache = Handle<SimpleNumberDictionary>::cast(maybe_cache);
const int entry = cache->FindEntry(isolate, code_offset);
if (entry != NumberDictionary::kNotFound) {
return handle(StackTraceFrame::cast(cache->ValueAt(entry)), isolate);
}
return MaybeHandle<StackTraceFrame>();
}
static void CacheFrameAndUpdateCache(Isolate* isolate,
Handle<AbstractCode> code,
int code_offset,
Handle<StackTraceFrame> frame) {
if (FLAG_optimize_for_size) return;
const auto maybe_cache = handle(code->stack_frame_cache(), isolate);
const auto cache = maybe_cache->IsSimpleNumberDictionary()
? Handle<SimpleNumberDictionary>::cast(maybe_cache)
: SimpleNumberDictionary::New(isolate, 1);
Handle<SimpleNumberDictionary> new_cache =
SimpleNumberDictionary::Set(isolate, cache, code_offset, frame);
if (*new_cache != *cache || !maybe_cache->IsSimpleNumberDictionary()) {
AbstractCode::SetStackFrameCache(code, new_cache);
}
}
};
} // anonymous namespace
class FrameArrayBuilder {
public:
enum FrameFilterMode { ALL, CURRENT_SECURITY_CONTEXT };
FrameArrayBuilder(Isolate* isolate, FrameSkipMode mode, int limit,
Handle<Object> caller, FrameFilterMode filter_mode)
: isolate_(isolate),
mode_(mode),
limit_(limit),
caller_(caller),
check_security_context_(filter_mode == CURRENT_SECURITY_CONTEXT) {
switch (mode_) {
case SKIP_FIRST:
skip_next_frame_ = true;
break;
case SKIP_UNTIL_SEEN:
DCHECK(caller_->IsJSFunction());
skip_next_frame_ = true;
break;
case SKIP_NONE:
skip_next_frame_ = false;
break;
}
elements_ = isolate->factory()->NewFrameArray(Min(limit, 10));
}
void AppendAsyncFrame(Handle<JSGeneratorObject> generator_object) {
if (full()) return;
Handle<JSFunction> function(generator_object->function(), isolate_);
if (!IsVisibleInStackTrace(function)) return;
int flags = FrameArray::kIsAsync;
if (IsStrictFrame(function)) flags |= FrameArray::kIsStrict;
Handle<Object> receiver(generator_object->receiver(), isolate_);
Handle<AbstractCode> code(
AbstractCode::cast(function->shared().GetBytecodeArray()), isolate_);
int offset = Smi::ToInt(generator_object->input_or_debug_pos());
// The stored bytecode offset is relative to a different base than what
// is used in the source position table, hence the subtraction.
offset -= BytecodeArray::kHeaderSize - kHeapObjectTag;
Handle<FixedArray> parameters = isolate_->factory()->empty_fixed_array();
if (V8_UNLIKELY(FLAG_detailed_error_stack_trace)) {
int param_count = function->shared().internal_formal_parameter_count();
parameters = isolate_->factory()->NewFixedArray(param_count);
for (int i = 0; i < param_count; i++) {
parameters->set(i, generator_object->parameters_and_registers().get(i));
}
}
elements_ = FrameArray::AppendJSFrame(elements_, receiver, function, code,
offset, flags, parameters);
}
void AppendPromiseAllFrame(Handle<Context> context, int offset) {
if (full()) return;
int flags = FrameArray::kIsAsync | FrameArray::kIsPromiseAll;
Handle<Context> native_context(context->native_context(), isolate_);
Handle<JSFunction> function(native_context->promise_all(), isolate_);
if (!IsVisibleInStackTrace(function)) return;
Handle<Object> receiver(native_context->promise_function(), isolate_);
Handle<AbstractCode> code(AbstractCode::cast(function->code()), isolate_);
// TODO(mmarchini) save Promises list from Promise.all()
Handle<FixedArray> parameters = isolate_->factory()->empty_fixed_array();
elements_ = FrameArray::AppendJSFrame(elements_, receiver, function, code,
offset, flags, parameters);
}
void AppendJavaScriptFrame(
FrameSummary::JavaScriptFrameSummary const& summary) {
// Filter out internal frames that we do not want to show.
if (!IsVisibleInStackTrace(summary.function())) return;
Handle<AbstractCode> abstract_code = summary.abstract_code();
const int offset = summary.code_offset();
const bool is_constructor = summary.is_constructor();
int flags = 0;
Handle<JSFunction> function = summary.function();
if (IsStrictFrame(function)) flags |= FrameArray::kIsStrict;
if (is_constructor) flags |= FrameArray::kIsConstructor;
Handle<FixedArray> parameters = isolate_->factory()->empty_fixed_array();
if (V8_UNLIKELY(FLAG_detailed_error_stack_trace))
parameters = summary.parameters();
elements_ = FrameArray::AppendJSFrame(
elements_, TheHoleToUndefined(isolate_, summary.receiver()), function,
abstract_code, offset, flags, parameters);
}
void AppendWasmCompiledFrame(
FrameSummary::WasmCompiledFrameSummary const& summary) {
if (summary.code()->kind() != wasm::WasmCode::kFunction) return;
Handle<WasmInstanceObject> instance = summary.wasm_instance();
int flags = 0;
if (instance->module_object().is_asm_js()) {
flags |= FrameArray::kIsAsmJsWasmFrame;
if (summary.at_to_number_conversion()) {
flags |= FrameArray::kAsmJsAtNumberConversion;
}
} else {
flags |= FrameArray::kIsWasmFrame;
}
elements_ = FrameArray::AppendWasmFrame(
elements_, instance, summary.function_index(), summary.code(),
summary.code_offset(), flags);
}
void AppendWasmInterpretedFrame(
FrameSummary::WasmInterpretedFrameSummary const& summary) {
Handle<WasmInstanceObject> instance = summary.wasm_instance();
int flags = FrameArray::kIsWasmInterpretedFrame;
DCHECK(!instance->module_object().is_asm_js());
elements_ = FrameArray::AppendWasmFrame(elements_, instance,
summary.function_index(), {},
summary.byte_offset(), flags);
}
void AppendBuiltinExitFrame(BuiltinExitFrame* exit_frame) {
Handle<JSFunction> function = handle(exit_frame->function(), isolate_);
// Filter out internal frames that we do not want to show.
if (!IsVisibleInStackTrace(function)) return;
// TODO(szuend): Remove this check once the flag is enabled
// by default.
if (!FLAG_experimental_stack_trace_frames &&
function->shared().IsApiFunction()) {
return;
}
Handle<Object> receiver(exit_frame->receiver(), isolate_);
Handle<Code> code(exit_frame->LookupCode(), isolate_);
const int offset =
static_cast<int>(exit_frame->pc() - code->InstructionStart());
int flags = 0;
if (IsStrictFrame(function)) flags |= FrameArray::kIsStrict;
if (exit_frame->IsConstructor()) flags |= FrameArray::kIsConstructor;
Handle<FixedArray> parameters = isolate_->factory()->empty_fixed_array();
if (V8_UNLIKELY(FLAG_detailed_error_stack_trace)) {
int param_count = exit_frame->ComputeParametersCount();
parameters = isolate_->factory()->NewFixedArray(param_count);
for (int i = 0; i < param_count; i++) {
parameters->set(i, exit_frame->GetParameter(i));
}
}
elements_ = FrameArray::AppendJSFrame(elements_, receiver, function,
Handle<AbstractCode>::cast(code),
offset, flags, parameters);
}
bool full() { return elements_->FrameCount() >= limit_; }
Handle<FrameArray> GetElements() {
elements_->ShrinkToFit(isolate_);
return elements_;
}
// Creates a StackTraceFrame object for each frame in the FrameArray.
Handle<FixedArray> GetElementsAsStackTraceFrameArray(
bool enable_frame_caching) {
elements_->ShrinkToFit(isolate_);
const int frame_count = elements_->FrameCount();
Handle<FixedArray> stack_trace =
isolate_->factory()->NewFixedArray(frame_count);
for (int i = 0; i < frame_count; ++i) {
// Caching stack frames only happens for user JS frames.
const bool cache_frame =
enable_frame_caching && !elements_->IsAnyWasmFrame(i) &&
elements_->Function(i).shared().IsUserJavaScript();
if (cache_frame) {
MaybeHandle<StackTraceFrame> maybe_frame =
StackFrameCacheHelper::LookupCachedFrame(
isolate_, handle(elements_->Code(i), isolate_),
Smi::ToInt(elements_->Offset(i)));
if (!maybe_frame.is_null()) {
Handle<StackTraceFrame> frame = maybe_frame.ToHandleChecked();
stack_trace->set(i, *frame);
continue;
}
}
Handle<StackTraceFrame> frame =
isolate_->factory()->NewStackTraceFrame(elements_, i);
stack_trace->set(i, *frame);
if (cache_frame) {
StackFrameCacheHelper::CacheFrameAndUpdateCache(
isolate_, handle(elements_->Code(i), isolate_),
Smi::ToInt(elements_->Offset(i)), frame);
}
}
return stack_trace;
}
private:
// Poison stack frames below the first strict mode frame.
// The stack trace API should not expose receivers and function
// objects on frames deeper than the top-most one with a strict mode
// function.
bool IsStrictFrame(Handle<JSFunction> function) {
if (!encountered_strict_function_) {
encountered_strict_function_ =
is_strict(function->shared().language_mode());
}
return encountered_strict_function_;
}
// Determines whether the given stack frame should be displayed in a stack
// trace.
bool IsVisibleInStackTrace(Handle<JSFunction> function) {
return ShouldIncludeFrame(function) && IsNotHidden(function) &&
IsInSameSecurityContext(function);
}
// This mechanism excludes a number of uninteresting frames from the stack
// trace. This can be be the first frame (which will be a builtin-exit frame
// for the error constructor builtin) or every frame until encountering a
// user-specified function.
bool ShouldIncludeFrame(Handle<JSFunction> function) {
switch (mode_) {
case SKIP_NONE:
return true;
case SKIP_FIRST:
if (!skip_next_frame_) return true;
skip_next_frame_ = false;
return false;
case SKIP_UNTIL_SEEN:
if (skip_next_frame_ && (*function == *caller_)) {
skip_next_frame_ = false;
return false;
}
return !skip_next_frame_;
}
UNREACHABLE();
}
bool IsNotHidden(Handle<JSFunction> function) {
// Functions defined not in user scripts are not visible unless directly
// exposed, in which case the native flag is set.
// The --builtins-in-stack-traces command line flag allows including
// internal call sites in the stack trace for debugging purposes.
if (!FLAG_builtins_in_stack_traces &&
!function->shared().IsUserJavaScript()) {
return function->shared().native() || function->shared().IsApiFunction();
}
return true;
}
bool IsInSameSecurityContext(Handle<JSFunction> function) {
if (!check_security_context_) return true;
return isolate_->context().HasSameSecurityTokenAs(function->context());
}
// TODO(jgruber): Fix all cases in which frames give us a hole value (e.g. the
// receiver in RegExp constructor frames.
Handle<Object> TheHoleToUndefined(Isolate* isolate, Handle<Object> in) {
return (in->IsTheHole(isolate))
? Handle<Object>::cast(isolate->factory()->undefined_value())
: in;
}
Isolate* isolate_;
const FrameSkipMode mode_;
int limit_;
const Handle<Object> caller_;
bool skip_next_frame_ = true;
bool encountered_strict_function_ = false;
const bool check_security_context_;
Handle<FrameArray> elements_;
};
bool GetStackTraceLimit(Isolate* isolate, int* result) {
Handle<JSObject> error = isolate->error_function();
Handle<String> key = isolate->factory()->stackTraceLimit_string();
Handle<Object> stack_trace_limit = JSReceiver::GetDataProperty(error, key);
if (!stack_trace_limit->IsNumber()) return false;
// Ensure that limit is not negative.
*result = Max(FastD2IChecked(stack_trace_limit->Number()), 0);
if (*result != FLAG_stack_trace_limit) {
isolate->CountUsage(v8::Isolate::kErrorStackTraceLimit);
}
return true;
}
bool NoExtension(const v8::FunctionCallbackInfo<v8::Value>&) { return false; }
bool IsBuiltinFunction(Isolate* isolate, HeapObject object,
Builtins::Name builtin_index) {
if (!object.IsJSFunction()) return false;
JSFunction const function = JSFunction::cast(object);
return function.code() == isolate->builtins()->builtin(builtin_index);
}
void CaptureAsyncStackTrace(Isolate* isolate, Handle<JSPromise> promise,
FrameArrayBuilder* builder) {
while (!builder->full()) {
// Check that the {promise} is not settled.
if (promise->status() != Promise::kPending) return;
// Check that we have exactly one PromiseReaction on the {promise}.
if (!promise->reactions().IsPromiseReaction()) return;
Handle<PromiseReaction> reaction(
PromiseReaction::cast(promise->reactions()), isolate);
if (!reaction->next().IsSmi()) return;
// Check if the {reaction} has one of the known async function or
// async generator continuations as its fulfill handler.
if (IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtins::kAsyncFunctionAwaitResolveClosure) ||
IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtins::kAsyncGeneratorAwaitResolveClosure) ||
IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtins::kAsyncGeneratorYieldResolveClosure)) {
// Now peak into the handlers' AwaitContext to get to
// the JSGeneratorObject for the async function.
Handle<Context> context(
JSFunction::cast(reaction->fulfill_handler()).context(), isolate);
Handle<JSGeneratorObject> generator_object(
JSGeneratorObject::cast(context->extension()), isolate);
CHECK(generator_object->is_suspended());
// Append async frame corresponding to the {generator_object}.
builder->AppendAsyncFrame(generator_object);
// Try to continue from here.
if (generator_object->IsJSAsyncFunctionObject()) {
Handle<JSAsyncFunctionObject> async_function_object =
Handle<JSAsyncFunctionObject>::cast(generator_object);
promise = handle(async_function_object->promise(), isolate);
} else {
Handle<JSAsyncGeneratorObject> async_generator_object =
Handle<JSAsyncGeneratorObject>::cast(generator_object);
if (async_generator_object->queue().IsUndefined(isolate)) return;
Handle<AsyncGeneratorRequest> async_generator_request(
AsyncGeneratorRequest::cast(async_generator_object->queue()),
isolate);
promise = handle(JSPromise::cast(async_generator_request->promise()),
isolate);
}
} else if (IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtins::kPromiseAllResolveElementClosure)) {
Handle<JSFunction> function(JSFunction::cast(reaction->fulfill_handler()),
isolate);
Handle<Context> context(function->context(), isolate);
// We store the offset of the promise into the {function}'s
// hash field for promise resolve element callbacks.
int const offset = Smi::ToInt(Smi::cast(function->GetIdentityHash())) - 1;
builder->AppendPromiseAllFrame(context, offset);
// Now peak into the Promise.all() resolve element context to
// find the promise capability that's being resolved when all
// the concurrent promises resolve.
int const index =
PromiseBuiltins::kPromiseAllResolveElementCapabilitySlot;
Handle<PromiseCapability> capability(
PromiseCapability::cast(context->get(index)), isolate);
if (!capability->promise().IsJSPromise()) return;
promise = handle(JSPromise::cast(capability->promise()), isolate);
} else if (IsBuiltinFunction(isolate, reaction->fulfill_handler(),
Builtins::kPromiseCapabilityDefaultResolve)) {
Handle<JSFunction> function(JSFunction::cast(reaction->fulfill_handler()),
isolate);
Handle<Context> context(function->context(), isolate);
promise =
handle(JSPromise::cast(context->get(PromiseBuiltins::kPromiseSlot)),
isolate);
} else {
// We have some generic promise chain here, so try to
// continue with the chained promise on the reaction
// (only works for native promise chains).
Handle<HeapObject> promise_or_capability(
reaction->promise_or_capability(), isolate);
if (promise_or_capability->IsJSPromise()) {
promise = Handle<JSPromise>::cast(promise_or_capability);
} else if (promise_or_capability->IsPromiseCapability()) {
Handle<PromiseCapability> capability =
Handle<PromiseCapability>::cast(promise_or_capability);
if (!capability->promise().IsJSPromise()) return;
promise = handle(JSPromise::cast(capability->promise()), isolate);
} else {
// Otherwise the {promise_or_capability} must be undefined here.
CHECK(promise_or_capability->IsUndefined(isolate));
return;
}
}
}
}
namespace {
struct CaptureStackTraceOptions {
int limit;
// 'filter_mode' and 'skip_mode' are somewhat orthogonal. 'filter_mode'
// specifies whether to capture all frames, or just frames in the same
// security context. While 'skip_mode' allows skipping the first frame.
FrameSkipMode skip_mode;
FrameArrayBuilder::FrameFilterMode filter_mode;
bool capture_builtin_exit_frames;
bool capture_only_frames_subject_to_debugging;
bool async_stack_trace;
bool enable_frame_caching;
};
Handle<Object> CaptureStackTrace(Isolate* isolate, Handle<Object> caller,
CaptureStackTraceOptions options) {
DisallowJavascriptExecution no_js(isolate);
wasm::WasmCodeRefScope code_ref_scope;
FrameArrayBuilder builder(isolate, options.skip_mode, options.limit, caller,
options.filter_mode);
// Build the regular stack trace, and remember the last relevant
// frame ID and inlined index (for the async stack trace handling
// below, which starts from this last frame).
for (StackFrameIterator it(isolate); !it.done() && !builder.full();
it.Advance()) {
StackFrame* const frame = it.frame();
switch (frame->type()) {
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION:
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH:
case StackFrame::OPTIMIZED:
case StackFrame::INTERPRETED:
case StackFrame::BUILTIN:
case StackFrame::WASM_COMPILED:
case StackFrame::WASM_INTERPRETER_ENTRY: {
// A standard frame may include many summarized frames (due to
// inlining).
std::vector<FrameSummary> frames;
StandardFrame::cast(frame)->Summarize(&frames);
for (size_t i = frames.size(); i-- != 0 && !builder.full();) {
auto& summary = frames[i];
if (options.capture_only_frames_subject_to_debugging &&
!summary.is_subject_to_debugging()) {
continue;
}
if (summary.IsJavaScript()) {
//=========================================================
// Handle a JavaScript frame.
//=========================================================
auto const& java_script = summary.AsJavaScript();
builder.AppendJavaScriptFrame(java_script);
} else if (summary.IsWasmCompiled()) {
//=========================================================
// Handle a WASM compiled frame.
//=========================================================
auto const& wasm_compiled = summary.AsWasmCompiled();
builder.AppendWasmCompiledFrame(wasm_compiled);
} else if (summary.IsWasmInterpreted()) {
//=========================================================
// Handle a WASM interpreted frame.
//=========================================================
auto const& wasm_interpreted = summary.AsWasmInterpreted();
builder.AppendWasmInterpretedFrame(wasm_interpreted);
}
}
break;
}
case StackFrame::BUILTIN_EXIT:
if (!options.capture_builtin_exit_frames) continue;
// BuiltinExitFrames are not standard frames, so they do not have
// Summarize(). However, they may have one JS frame worth showing.
builder.AppendBuiltinExitFrame(BuiltinExitFrame::cast(frame));
break;
default:
break;
}
}
// If --async-stack-traces are enabled and the "current microtask" is a
// PromiseReactionJobTask, we try to enrich the stack trace with async
// frames.
if (options.async_stack_trace) {
Handle<Object> current_microtask = isolate->factory()->current_microtask();
if (current_microtask->IsPromiseReactionJobTask()) {
Handle<PromiseReactionJobTask> promise_reaction_job_task =
Handle<PromiseReactionJobTask>::cast(current_microtask);
// Check if the {reaction} has one of the known async function or
// async generator continuations as its fulfill handler.
if (IsBuiltinFunction(isolate, promise_reaction_job_task->handler(),
Builtins::kAsyncFunctionAwaitResolveClosure) ||
IsBuiltinFunction(isolate, promise_reaction_job_task->handler(),
Builtins::kAsyncGeneratorAwaitResolveClosure) ||
IsBuiltinFunction(isolate, promise_reaction_job_task->handler(),
Builtins::kAsyncGeneratorYieldResolveClosure)) {
// Now peak into the handlers' AwaitContext to get to
// the JSGeneratorObject for the async function.
Handle<Context> context(
JSFunction::cast(promise_reaction_job_task->handler()).context(),
isolate);
Handle<JSGeneratorObject> generator_object(
JSGeneratorObject::cast(context->extension()), isolate);
if (generator_object->is_executing()) {
if (generator_object->IsJSAsyncFunctionObject()) {
Handle<JSAsyncFunctionObject> async_function_object =
Handle<JSAsyncFunctionObject>::cast(generator_object);
Handle<JSPromise> promise(async_function_object->promise(),
isolate);
CaptureAsyncStackTrace(isolate, promise, &builder);
} else {
Handle<JSAsyncGeneratorObject> async_generator_object =
Handle<JSAsyncGeneratorObject>::cast(generator_object);
Handle<AsyncGeneratorRequest> async_generator_request(
AsyncGeneratorRequest::cast(async_generator_object->queue()),
isolate);
Handle<JSPromise> promise(
JSPromise::cast(async_generator_request->promise()), isolate);
CaptureAsyncStackTrace(isolate, promise, &builder);
}
}
} else {
// The {promise_reaction_job_task} doesn't belong to an await (or
// yield inside an async generator), but we might still be able to
// find an async frame if we follow along the chain of promises on
// the {promise_reaction_job_task}.
Handle<HeapObject> promise_or_capability(
promise_reaction_job_task->promise_or_capability(), isolate);
if (promise_or_capability->IsJSPromise()) {
Handle<JSPromise> promise =
Handle<JSPromise>::cast(promise_or_capability);
CaptureAsyncStackTrace(isolate, promise, &builder);
}
}
}
}
// TODO(yangguo): Queue this structured stack trace for preprocessing on GC.
return builder.GetElementsAsStackTraceFrameArray(
options.enable_frame_caching);
}
} // namespace
Handle<Object> Isolate::CaptureSimpleStackTrace(Handle<JSReceiver> error_object,
FrameSkipMode mode,
Handle<Object> caller) {
int limit;
if (!GetStackTraceLimit(this, &limit)) return factory()->undefined_value();
CaptureStackTraceOptions options;
options.limit = limit;
options.skip_mode = mode;
options.capture_builtin_exit_frames = true;
options.async_stack_trace = FLAG_async_stack_traces;
options.filter_mode = FrameArrayBuilder::CURRENT_SECURITY_CONTEXT;
options.capture_only_frames_subject_to_debugging = false;
options.enable_frame_caching = false;
return CaptureStackTrace(this, caller, options);
}
MaybeHandle<JSReceiver> Isolate::CaptureAndSetDetailedStackTrace(
Handle<JSReceiver> error_object) {
if (capture_stack_trace_for_uncaught_exceptions_) {
// Capture stack trace for a detailed exception message.
Handle<Name> key = factory()->detailed_stack_trace_symbol();
Handle<FixedArray> stack_trace = CaptureCurrentStackTrace(
stack_trace_for_uncaught_exceptions_frame_limit_,
stack_trace_for_uncaught_exceptions_options_);
RETURN_ON_EXCEPTION(
this,
Object::SetProperty(this, error_object, key, stack_trace,
StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError)),
JSReceiver);
}
return error_object;
}
MaybeHandle<JSReceiver> Isolate::CaptureAndSetSimpleStackTrace(
Handle<JSReceiver> error_object, FrameSkipMode mode,
Handle<Object> caller) {
// Capture stack trace for simple stack trace string formatting.
Handle<Name> key = factory()->stack_trace_symbol();
Handle<Object> stack_trace =
CaptureSimpleStackTrace(error_object, mode, caller);
RETURN_ON_EXCEPTION(this,
Object::SetProperty(this, error_object, key, stack_trace,
StoreOrigin::kMaybeKeyed,
Just(ShouldThrow::kThrowOnError)),
JSReceiver);
return error_object;
}
Handle<FixedArray> Isolate::GetDetailedStackTrace(
Handle<JSObject> error_object) {
Handle<Name> key_detailed = factory()->detailed_stack_trace_symbol();
Handle<Object> stack_trace =
JSReceiver::GetDataProperty(error_object, key_detailed);
if (stack_trace->IsFixedArray()) return Handle<FixedArray>::cast(stack_trace);
return Handle<FixedArray>();
}
Address Isolate::GetAbstractPC(int* line, int* column) {
JavaScriptFrameIterator it(this);
if (it.done()) {
*line = -1;
*column = -1;
return kNullAddress;
}
JavaScriptFrame* frame = it.frame();
DCHECK(!frame->is_builtin());
Handle<SharedFunctionInfo> shared = handle(frame->function().shared(), this);
SharedFunctionInfo::EnsureSourcePositionsAvailable(this, shared);
int position = frame->position();
Object maybe_script = frame->function().shared().script();
if (maybe_script.IsScript()) {
Handle<Script> script(Script::cast(maybe_script), this);
Script::PositionInfo info;
Script::GetPositionInfo(script, position, &info, Script::WITH_OFFSET);
*line = info.line + 1;
*column = info.column + 1;
} else {
*line = position;
*column = -1;
}
if (frame->is_interpreted()) {
InterpretedFrame* iframe = static_cast<InterpretedFrame*>(frame);
Address bytecode_start =
iframe->GetBytecodeArray().GetFirstBytecodeAddress();
return bytecode_start + iframe->GetBytecodeOffset();
}
return frame->pc();
}
Handle<FixedArray> Isolate::CaptureCurrentStackTrace(
int frame_limit, StackTrace::StackTraceOptions stack_trace_options) {
CaptureStackTraceOptions options;
options.limit = Max(frame_limit, 0); // Ensure no negative values.
options.skip_mode = SKIP_NONE;
options.capture_builtin_exit_frames = false;
options.async_stack_trace = false;
options.filter_mode =
(stack_trace_options & StackTrace::kExposeFramesAcrossSecurityOrigins)
? FrameArrayBuilder::ALL
: FrameArrayBuilder::CURRENT_SECURITY_CONTEXT;
options.capture_only_frames_subject_to_debugging = true;
options.enable_frame_caching = true;
return Handle<FixedArray>::cast(
CaptureStackTrace(this, factory()->undefined_value(), options));
}
void Isolate::PrintStack(FILE* out, PrintStackMode mode) {
if (stack_trace_nesting_level_ == 0) {
stack_trace_nesting_level_++;
StringStream::ClearMentionedObjectCache(this);
HeapStringAllocator allocator;
StringStream accumulator(&allocator);
incomplete_message_ = &accumulator;
PrintStack(&accumulator, mode);
accumulator.OutputToFile(out);
InitializeLoggingAndCounters();
accumulator.Log(this);
incomplete_message_ = nullptr;
stack_trace_nesting_level_ = 0;
} else if (stack_trace_nesting_level_ == 1) {
stack_trace_nesting_level_++;
base::OS::PrintError(
"\n\nAttempt to print stack while printing stack (double fault)\n");
base::OS::PrintError(
"If you are lucky you may find a partial stack dump on stdout.\n\n");
incomplete_message_->OutputToFile(out);
}
}
static void PrintFrames(Isolate* isolate, StringStream* accumulator,
StackFrame::PrintMode mode) {
StackFrameIterator it(isolate);
for (int i = 0; !it.done(); it.Advance()) {
it.frame()->Print(accumulator, mode, i++);
}
}
void Isolate::PrintStack(StringStream* accumulator, PrintStackMode mode) {
HandleScope scope(this);
wasm::WasmCodeRefScope wasm_code_ref_scope;
DCHECK(accumulator->IsMentionedObjectCacheClear(this));
// Avoid printing anything if there are no frames.
if (c_entry_fp(thread_local_top()) == 0) return;
accumulator->Add(
"\n==== JS stack trace =========================================\n\n");
PrintFrames(this, accumulator, StackFrame::OVERVIEW);
if (mode == kPrintStackVerbose) {
accumulator->Add(
"\n==== Details ================================================\n\n");
PrintFrames(this, accumulator, StackFrame::DETAILS);
accumulator->PrintMentionedObjectCache(this);
}
accumulator->Add("=====================\n\n");
}
void Isolate::SetFailedAccessCheckCallback(
v8::FailedAccessCheckCallback callback) {
thread_local_top()->failed_access_check_callback_ = callback;
}
void Isolate::ReportFailedAccessCheck(Handle<JSObject> receiver) {
if (!thread_local_top()->failed_access_check_callback_) {
return ScheduleThrow(*factory()->NewTypeError(MessageTemplate::kNoAccess));
}
DCHECK(receiver->IsAccessCheckNeeded());
DCHECK(!context().is_null());
// Get the data object from access check info.
HandleScope scope(this);
Handle<Object> data;
{
DisallowHeapAllocation no_gc;
AccessCheckInfo access_check_info = AccessCheckInfo::Get(this, receiver);
if (access_check_info.is_null()) {
AllowHeapAllocation doesnt_matter_anymore;
return ScheduleThrow(
*factory()->NewTypeError(MessageTemplate::kNoAccess));
}
data = handle(access_check_info.data(), this);
}
// Leaving JavaScript.
VMState<EXTERNAL> state(this);
thread_local_top()->failed_access_check_callback_(
v8::Utils::ToLocal(receiver), v8::ACCESS_HAS, v8::Utils::ToLocal(data));
}
bool Isolate::MayAccess(Handle<Context> accessing_context,
Handle<JSObject> receiver) {
DCHECK(receiver->IsJSGlobalProxy() || receiver->IsAccessCheckNeeded());
// Check for compatibility between the security tokens in the
// current lexical context and the accessed object.
// During bootstrapping, callback functions are not enabled yet.
if (bootstrapper()->IsActive()) return true;
{
DisallowHeapAllocation no_gc;
if (receiver->IsJSGlobalProxy()) {
Object receiver_context = JSGlobalProxy::cast(*receiver).native_context();
if (!receiver_context.IsContext()) return false;
// Get the native context of current top context.
// avoid using Isolate::native_context() because it uses Handle.
Context native_context =
accessing_context->global_object().native_context();
if (receiver_context == native_context) return true;
if (Context::cast(receiver_context).security_token() ==
native_context.security_token())
return true;
}
}
HandleScope scope(this);
Handle<Object> data;
v8::AccessCheckCallback callback = nullptr;
{
DisallowHeapAllocation no_gc;
AccessCheckInfo access_check_info = AccessCheckInfo::Get(this, receiver);
if (access_check_info.is_null()) return false;
Object fun_obj = access_check_info.callback();
callback = v8::ToCData<v8::AccessCheckCallback>(fun_obj);
data = handle(access_check_info.data(), this);
}
LOG(this, ApiSecurityCheck());
{
// Leaving JavaScript.
VMState<EXTERNAL> state(this);
return callback(v8::Utils::ToLocal(accessing_context),
v8::Utils::ToLocal(receiver), v8::Utils::ToLocal(data));
}
}
Object Isolate::StackOverflow() {
if (FLAG_correctness_fuzzer_suppressions) {
FATAL("Aborting on stack overflow");
}
DisallowJavascriptExecution no_js(this);
HandleScope scope(this);
Handle<JSFunction> fun = range_error_function();
Handle<Object> msg = factory()->NewStringFromAsciiChecked(
MessageFormatter::TemplateString(MessageTemplate::kStackOverflow));
Handle<Object> no_caller;
Handle<Object> exception;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
this, exception,
ErrorUtils::Construct(this, fun, fun, msg, SKIP_NONE, no_caller,
ErrorUtils::StackTraceCollection::kSimple));
Throw(*exception, nullptr);
#ifdef VERIFY_HEAP
if (FLAG_verify_heap && FLAG_stress_compaction) {
heap()->CollectAllGarbage(Heap::kNoGCFlags,
GarbageCollectionReason::kTesting);
}
#endif // VERIFY_HEAP
return ReadOnlyRoots(heap()).exception();
}
Object Isolate::TerminateExecution() {
return Throw(ReadOnlyRoots(this).termination_exception(), nullptr);
}
void Isolate::CancelTerminateExecution() {
if (try_catch_handler()) {
try_catch_handler()->has_terminated_ = false;
}
if (has_pending_exception() &&
pending_exception() == ReadOnlyRoots(this).termination_exception()) {
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
}
if (has_scheduled_exception() &&
scheduled_exception() == ReadOnlyRoots(this).termination_exception()) {
thread_local_top()->external_caught_exception_ = false;
clear_scheduled_exception();
}
}
void Isolate::RequestInterrupt(InterruptCallback callback, void* data) {
ExecutionAccess access(this);
api_interrupts_queue_.push(InterruptEntry(callback, data));
stack_guard()->RequestApiInterrupt();
}
void Isolate::InvokeApiInterruptCallbacks() {
RuntimeCallTimerScope runtimeTimer(
this, RuntimeCallCounterId::kInvokeApiInterruptCallbacks);
// Note: callback below should be called outside of execution access lock.
while (true) {
InterruptEntry entry;
{
ExecutionAccess access(this);
if (api_interrupts_queue_.empty()) return;
entry = api_interrupts_queue_.front();
api_interrupts_queue_.pop();
}
VMState<EXTERNAL> state(this);
HandleScope handle_scope(this);
entry.first(reinterpret_cast<v8::Isolate*>(this), entry.second);
}
}
void ReportBootstrappingException(Handle<Object> exception,
MessageLocation* location) {
base::OS::PrintError("Exception thrown during bootstrapping\n");
if (location == nullptr || location->script().is_null()) return;
// We are bootstrapping and caught an error where the location is set
// and we have a script for the location.
// In this case we could have an extension (or an internal error
// somewhere) and we print out the line number at which the error occurred
// to the console for easier debugging.
int line_number =
location->script()->GetLineNumber(location->start_pos()) + 1;
if (exception->IsString() && location->script()->name().IsString()) {
base::OS::PrintError(
"Extension or internal compilation error: %s in %s at line %d.\n",
String::cast(*exception).ToCString().get(),
String::cast(location->script()->name()).ToCString().get(),
line_number);
} else if (location->script()->name().IsString()) {
base::OS::PrintError(
"Extension or internal compilation error in %s at line %d.\n",
String::cast(location->script()->name()).ToCString().get(),
line_number);
} else if (exception->IsString()) {
base::OS::PrintError("Extension or internal compilation error: %s.\n",
String::cast(*exception).ToCString().get());
} else {
base::OS::PrintError("Extension or internal compilation error.\n");
}
#ifdef OBJECT_PRINT
// Since comments and empty lines have been stripped from the source of
// builtins, print the actual source here so that line numbers match.
if (location->script()->source().IsString()) {
Handle<String> src(String::cast(location->script()->source()),
location->script()->GetIsolate());
PrintF("Failing script:");
int len = src->length();
if (len == 0) {
PrintF(" <not available>\n");
} else {
PrintF("\n");
int line_number = 1;
PrintF("%5d: ", line_number);
for (int i = 0; i < len; i++) {
uint16_t character = src->Get(i);
PrintF("%c", character);
if (character == '\n' && i < len - 2) {
PrintF("%5d: ", ++line_number);
}
}
PrintF("\n");
}
}
#endif
}
Object Isolate::Throw(Object raw_exception, MessageLocation* location) {
DCHECK(!has_pending_exception());
HandleScope scope(this);
Handle<Object> exception(raw_exception, this);
if (FLAG_print_all_exceptions) {
PrintF("=========================================================\n");
PrintF("Exception thrown:\n");
if (location) {
Handle<Script> script = location->script();
Handle<Object> name(script->GetNameOrSourceURL(), this);
PrintF("at ");
if (name->IsString() && String::cast(*name).length() > 0)
String::cast(*name).PrintOn(stdout);
else
PrintF("<anonymous>");
// Script::GetLineNumber and Script::GetColumnNumber can allocate on the heap to
// initialize the line_ends array, so be careful when calling them.
#ifdef DEBUG
if (AllowHeapAllocation::IsAllowed()) {
#else
if ((false)) {
#endif
PrintF(", %d:%d - %d:%d\n",
Script::GetLineNumber(script, location->start_pos()) + 1,
Script::GetColumnNumber(script, location->start_pos()),
Script::GetLineNumber(script, location->end_pos()) + 1,
Script::GetColumnNumber(script, location->end_pos()));
// Make sure to update the raw exception pointer in case it moved.
raw_exception = *exception;
} else {
PrintF(", line %d\n", script->GetLineNumber(location->start_pos()) + 1);
}
}
raw_exception.Print();
PrintF("Stack Trace:\n");
PrintStack(stdout);
PrintF("=========================================================\n");
}
// Determine whether a message needs to be created for the given exception
// depending on the following criteria:
// 1) External v8::TryCatch missing: Always create a message because any
// JavaScript handler for a finally-block might re-throw to top-level.
// 2) External v8::TryCatch exists: Only create a message if the handler
// captures messages or is verbose (which reports despite the catch).
// 3) ReThrow from v8::TryCatch: The message from a previous throw still
// exists and we preserve it instead of creating a new message.
bool requires_message = try_catch_handler() == nullptr ||
try_catch_handler()->is_verbose_ ||
try_catch_handler()->capture_message_;
bool rethrowing_message = thread_local_top()->rethrowing_message_;
thread_local_top()->rethrowing_message_ = false;
// Notify debugger of exception.
if (is_catchable_by_javascript(raw_exception)) {
debug()->OnThrow(exception);
}
// Generate the message if required.
if (requires_message && !rethrowing_message) {
MessageLocation computed_location;
// If no location was specified we try to use a computed one instead.
if (location == nullptr && ComputeLocation(&computed_location)) {
location = &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.
ReportBootstrappingException(exception, location);
} else {
Handle<Object> message_obj = CreateMessage(exception, location);
thread_local_top()->pending_message_obj_ = *message_obj;
// For any exception not caught by JavaScript, even when an external
// handler is present:
// If the abort-on-uncaught-exception flag is specified, and if the
// embedder didn't specify a custom uncaught exception callback,
// or if the custom callback determined that V8 should abort, then
// abort.
if (FLAG_abort_on_uncaught_exception) {
CatchType prediction = PredictExceptionCatcher();
if ((prediction == NOT_CAUGHT || prediction == CAUGHT_BY_EXTERNAL) &&
(!abort_on_uncaught_exception_callback_ ||
abort_on_uncaught_exception_callback_(
reinterpret_cast<v8::Isolate*>(this)))) {
// Prevent endless recursion.
FLAG_abort_on_uncaught_exception = false;
// This flag is intended for use by JavaScript developers, so
// print a user-friendly stack trace (not an internal one).
PrintF(stderr, "%s\n\nFROM\n",
MessageHandler::GetLocalizedMessage(this, message_obj).get());
PrintCurrentStackTrace(stderr);
base::OS::Abort();
}
}
}
}
// Set the exception being thrown.
set_pending_exception(*exception);
return ReadOnlyRoots(heap()).exception();
}
Object Isolate::ReThrow(Object exception) {
DCHECK(!has_pending_exception());
// Set the exception being re-thrown.
set_pending_exception(exception);
return ReadOnlyRoots(heap()).exception();
}
Object Isolate::UnwindAndFindHandler() {
Object exception = pending_exception();
auto FoundHandler = [&](Context context, Address instruction_start,
intptr_t handler_offset,
Address constant_pool_address, Address handler_sp,
Address handler_fp) {
// Store information to be consumed by the CEntry.
thread_local_top()->pending_handler_context_ = context;
thread_local_top()->pending_handler_entrypoint_ =
instruction_start + handler_offset;
thread_local_top()->pending_handler_constant_pool_ = constant_pool_address;
thread_local_top()->pending_handler_fp_ = handler_fp;
thread_local_top()->pending_handler_sp_ = handler_sp;
// Return and clear pending exception. The contract is that:
// (1) the pending exception is stored in one place (no duplication), and
// (2) within generated-code land, that one place is the return register.
// If/when we unwind back into C++ (returning to the JSEntry stub,
// or to Execution::CallWasm), the returned exception will be sent
// back to isolate->set_pending_exception(...).
clear_pending_exception();
return exception;
};
// Special handling of termination exceptions, uncatchable by JavaScript and
// Wasm code, we unwind the handlers until the top ENTRY handler is found.
bool catchable_by_js = is_catchable_by_javascript(exception);
// Compute handler and stack unwinding information by performing a full walk
// over the stack and dispatching according to the frame type.
for (StackFrameIterator iter(this);; iter.Advance()) {
// Handler must exist.
DCHECK(!iter.done());
StackFrame* frame = iter.frame();
switch (frame->type()) {
case StackFrame::ENTRY:
case StackFrame::CONSTRUCT_ENTRY: {
// For JSEntry frames we always have a handler.
StackHandler* handler = frame->top_handler();
// Restore the next handler.
thread_local_top()->handler_ = handler->next_address();
// Gather information from the handler.
Code code = frame->LookupCode();
HandlerTable table(code);
return FoundHandler(Context(), code.InstructionStart(),
table.LookupReturn(0), code.constant_pool(),
handler->address() + StackHandlerConstants::kSize,
0);
}
case StackFrame::C_WASM_ENTRY: {
StackHandler* handler = frame->top_handler();
thread_local_top()->handler_ = handler->next_address();
Code code = frame->LookupCode();
HandlerTable table(code);
Address instruction_start = code.InstructionStart();
int return_offset = static_cast<int>(frame->pc() - instruction_start);
int handler_offset = table.LookupReturn(return_offset);
DCHECK_NE(-1, handler_offset);
return FoundHandler(Context(), instruction_start, handler_offset,
code.constant_pool(), frame->sp(), frame->fp());
}
case StackFrame::WASM_COMPILED: {
if (trap_handler::IsThreadInWasm()) {
trap_handler::ClearThreadInWasm();
}
// For WebAssembly frames we perform a lookup in the handler table.
if (!catchable_by_js) break;
// This code ref scope is here to avoid a check failure when looking up
// the code. It's not actually necessary to keep the code alive as it's
// currently being executed.
wasm::WasmCodeRefScope code_ref_scope;
WasmCompiledFrame* wasm_frame = static_cast<WasmCompiledFrame*>(frame);
int stack_slots = 0; // Will contain stack slot count of frame.
int offset = wasm_frame->LookupExceptionHandlerInTable(&stack_slots);
if (offset < 0) break;
// Compute the stack pointer from the frame pointer. This ensures that
// argument slots on the stack are dropped as returning would.
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
stack_slots * kSystemPointerSize;
// This is going to be handled by Wasm, so we need to set the TLS flag
// again. It was cleared above assuming the frame would be unwound.
trap_handler::SetThreadInWasm();
// Gather information from the frame.
wasm::WasmCode* wasm_code =
wasm_engine()->code_manager()->LookupCode(frame->pc());
return FoundHandler(Context(), wasm_code->instruction_start(), offset,
wasm_code->constant_pool(), return_sp, frame->fp());
}
case StackFrame::WASM_COMPILE_LAZY: {
// Can only fail directly on invocation. This happens if an invalid
// function was validated lazily.
DCHECK_IMPLIES(trap_handler::IsTrapHandlerEnabled(),
trap_handler::IsThreadInWasm());
DCHECK(FLAG_wasm_lazy_validation);
trap_handler::ClearThreadInWasm();
break;
}
case StackFrame::OPTIMIZED: {
// For optimized frames we perform a lookup in the handler table.
if (!catchable_by_js) break;
OptimizedFrame* js_frame = static_cast<OptimizedFrame*>(frame);
int stack_slots = 0; // Will contain stack slot count of frame.
int offset =
js_frame->LookupExceptionHandlerInTable(&stack_slots, nullptr);
if (offset < 0) break;
// Compute the stack pointer from the frame pointer. This ensures
// that argument slots on the stack are dropped as returning would.
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
stack_slots * kSystemPointerSize;
// Gather information from the frame.
Code code = frame->LookupCode();
// TODO(bmeurer): Turbofanned BUILTIN frames appear as OPTIMIZED,
// but do not have a code kind of OPTIMIZED_FUNCTION.
if (code.kind() == Code::OPTIMIZED_FUNCTION &&
code.marked_for_deoptimization()) {
// If the target code is lazy deoptimized, we jump to the original
// return address, but we make a note that we are throwing, so
// that the deoptimizer can do the right thing.
offset = static_cast<int>(frame->pc() - code.entry());
set_deoptimizer_lazy_throw(true);
}
return FoundHandler(Context(), code.InstructionStart(), offset,
code.constant_pool(), return_sp, frame->fp());
}
case StackFrame::STUB: {
// Some stubs are able to handle exceptions.
if (!catchable_by_js) break;
StubFrame* stub_frame = static_cast<StubFrame*>(frame);
wasm::WasmCodeRefScope code_ref_scope;
wasm::WasmCode* wasm_code =
wasm_engine()->code_manager()->LookupCode(frame->pc());
if (wasm_code != nullptr) {
// It is safe to skip Wasm runtime stubs as none of them contain local
// exception handlers.
CHECK_EQ(wasm::WasmCode::kRuntimeStub, wasm_code->kind());
CHECK_EQ(0, wasm_code->handler_table_size());
break;
}
Code code = stub_frame->LookupCode();
if (!code.IsCode() || code.kind() != Code::BUILTIN ||
!code.has_handler_table() || !code.is_turbofanned()) {
break;
}
int stack_slots = 0; // Will contain stack slot count of frame.
int offset = stub_frame->LookupExceptionHandlerInTable(&stack_slots);
if (offset < 0) break;
// Compute the stack pointer from the frame pointer. This ensures
// that argument slots on the stack are dropped as returning would.
Address return_sp = frame->fp() +
StandardFrameConstants::kFixedFrameSizeAboveFp -
stack_slots * kSystemPointerSize;
return FoundHandler(Context(), code.InstructionStart(), offset,
code.constant_pool(), return_sp, frame->fp());
}
case StackFrame::INTERPRETED: {
// For interpreted frame we perform a range lookup in the handler table.
if (!catchable_by_js) break;
InterpretedFrame* js_frame = static_cast<InterpretedFrame*>(frame);
int register_slots = InterpreterFrameConstants::RegisterStackSlotCount(
js_frame->GetBytecodeArray().register_count());
int context_reg = 0; // Will contain register index holding context.
int offset =
js_frame->LookupExceptionHandlerInTable(&context_reg, nullptr);
if (offset < 0) break;
// Compute the stack pointer from the frame pointer. This ensures that
// argument slots on the stack are dropped as returning would.
// Note: This is only needed for interpreted frames that have been
// materialized by the deoptimizer. If there is a handler frame
// in between then {frame->sp()} would already be correct.
Address return_sp = frame->fp() -
InterpreterFrameConstants::kFixedFrameSizeFromFp -
register_slots * kSystemPointerSize;
// Patch the bytecode offset in the interpreted frame to reflect the
// position of the exception handler. The special builtin below will
// take care of continuing to dispatch at that position. Also restore
// the correct context for the handler from the interpreter register.
Context context =
Context::cast(js_frame->ReadInterpreterRegister(context_reg));
js_frame->PatchBytecodeOffset(static_cast<int>(offset));
Code code =
builtins()->builtin(Builtins::kInterpreterEnterBytecodeDispatch);
return FoundHandler(context, code.InstructionStart(), 0,
code.constant_pool(), return_sp, frame->fp());
}
case StackFrame::BUILTIN:
// For builtin frames we are guaranteed not to find a handler.
if (catchable_by_js) {
CHECK_EQ(-1,
JavaScriptFrame::cast(frame)->LookupExceptionHandlerInTable(
nullptr, nullptr));
}
break;
case StackFrame::WASM_INTERPRETER_ENTRY: {
if (trap_handler::IsThreadInWasm()) {
trap_handler::ClearThreadInWasm();
}
} break;
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH: {
// Builtin continuation frames with catch can handle exceptions.
if (!catchable_by_js) break;
JavaScriptBuiltinContinuationWithCatchFrame* js_frame =
JavaScriptBuiltinContinuationWithCatchFrame::cast(frame);
js_frame->SetException(exception);
// Reconstruct the stack pointer from the frame pointer.
Address return_sp = js_frame->fp() - js_frame->GetSPToFPDelta();
Code code = js_frame->LookupCode();
return FoundHandler(Context(), code.InstructionStart(), 0,
code.constant_pool(), return_sp, frame->fp());
} break;
default:
// All other types can not handle exception.
break;
}
if (frame->is_optimized()) {
// Remove per-frame stored materialized objects.
bool removed = materialized_object_store_->Remove(frame->fp());
USE(removed);
// If there were any materialized objects, the code should be
// marked for deopt.
DCHECK_IMPLIES(removed, frame->LookupCode().marked_for_deoptimization());
}
}
UNREACHABLE();
}
namespace {
HandlerTable::CatchPrediction PredictException(JavaScriptFrame* frame) {
HandlerTable::CatchPrediction prediction;
if (frame->is_optimized()) {
if (frame->LookupExceptionHandlerInTable(nullptr, nullptr) > 0) {
// This optimized frame will catch. It's handler table does not include
// exception prediction, and we need to use the corresponding handler
// tables on the unoptimized code objects.
std::vector<FrameSummary> summaries;
frame->Summarize(&summaries);
for (size_t i = summaries.size(); i != 0; i--) {
const FrameSummary& summary = summaries[i - 1];
Handle<AbstractCode> code = summary.AsJavaScript().abstract_code();
if (code->IsCode() && code->kind() == AbstractCode::BUILTIN) {
prediction = code->GetCode().GetBuiltinCatchPrediction();
if (prediction == HandlerTable::UNCAUGHT) continue;
return prediction;
}
// Must have been constructed from a bytecode array.
CHECK_EQ(AbstractCode::INTERPRETED_FUNCTION, code->kind());
int code_offset = summary.code_offset();
HandlerTable table(code->GetBytecodeArray());
int index = table.LookupRange(code_offset, nullptr, &prediction);
if (index <= 0) continue;
if (prediction == HandlerTable::UNCAUGHT) continue;
return prediction;
}
}
} else if (frame->LookupExceptionHandlerInTable(nullptr, &prediction) > 0) {
return prediction;
}
return HandlerTable::UNCAUGHT;
}
Isolate::CatchType ToCatchType(HandlerTable::CatchPrediction prediction) {
switch (prediction) {
case HandlerTable::UNCAUGHT:
return Isolate::NOT_CAUGHT;
case HandlerTable::CAUGHT:
return Isolate::CAUGHT_BY_JAVASCRIPT;
case HandlerTable::PROMISE:
return Isolate::CAUGHT_BY_PROMISE;
case HandlerTable::DESUGARING:
return Isolate::CAUGHT_BY_DESUGARING;
case HandlerTable::ASYNC_AWAIT:
return Isolate::CAUGHT_BY_ASYNC_AWAIT;
default:
UNREACHABLE();
}
}
} // anonymous namespace
Isolate::CatchType Isolate::PredictExceptionCatcher() {
Address external_handler = thread_local_top()->try_catch_handler_address();
if (IsExternalHandlerOnTop(Object())) return CAUGHT_BY_EXTERNAL;
// Search for an exception handler by performing a full walk over the stack.
for (StackFrameIterator iter(this); !iter.done(); iter.Advance()) {
StackFrame* frame = iter.frame();
switch (frame->type()) {
case StackFrame::ENTRY:
case StackFrame::CONSTRUCT_ENTRY: {
Address entry_handler = frame->top_handler()->next_address();
// The exception has been externally caught if and only if there is an
// external handler which is on top of the top-most JS_ENTRY handler.
if (external_handler != kNullAddress &&
!try_catch_handler()->is_verbose_) {
if (entry_handler == kNullAddress ||
entry_handler > external_handler) {
return CAUGHT_BY_EXTERNAL;
}
}
} break;
// For JavaScript frames we perform a lookup in the handler table.
case StackFrame::OPTIMIZED:
case StackFrame::INTERPRETED:
case StackFrame::BUILTIN: {
JavaScriptFrame* js_frame = JavaScriptFrame::cast(frame);
Isolate::CatchType prediction = ToCatchType(PredictException(js_frame));
if (prediction == NOT_CAUGHT) break;
return prediction;
} break;
case StackFrame::STUB: {
Handle<Code> code(frame->LookupCode(), this);
if (!code->IsCode() || code->kind() != Code::BUILTIN ||
!code->has_handler_table() || !code->is_turbofanned()) {
break;
}
CatchType prediction = ToCatchType(code->GetBuiltinCatchPrediction());
if (prediction != NOT_CAUGHT) return prediction;
} break;
case StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH: {
Handle<Code> code(frame->LookupCode(), this);
CatchType prediction = ToCatchType(code->GetBuiltinCatchPrediction());
if (prediction != NOT_CAUGHT) return prediction;
} break;
default:
// All other types can not handle exception.
break;
}
}
// Handler not found.
return NOT_CAUGHT;
}
Object Isolate::ThrowIllegalOperation() {
if (FLAG_stack_trace_on_illegal) PrintStack(stdout);
return Throw(ReadOnlyRoots(heap()).illegal_access_string());
}
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);
PropagatePendingExceptionToExternalTryCatch();
if (has_pending_exception()) {
thread_local_top()->scheduled_exception_ = pending_exception();
thread_local_top()->external_caught_exception_ = false;
clear_pending_exception();
}
}
void Isolate::RestorePendingMessageFromTryCatch(v8::TryCatch* handler) {
DCHECK(handler == try_catch_handler());
DCHECK(handler->HasCaught());
DCHECK(handler->rethrow_);
DCHECK(handler->capture_message_);
Object message(reinterpret_cast<Address>(handler->message_obj_));
DCHECK(message.IsJSMessageObject() || message.IsTheHole(this));
thread_local_top()->pending_message_obj_ = message;
}
void Isolate::CancelScheduledExceptionFromTryCatch(v8::TryCatch* handler) {
DCHECK(has_scheduled_exception());
if (reinterpret_cast<void*>(scheduled_exception().ptr()) ==
handler->exception_) {
DCHECK_NE(scheduled_exception(),
ReadOnlyRoots(heap()).termination_exception());
clear_scheduled_exception();
} else {
DCHECK_EQ(scheduled_exception(),
ReadOnlyRoots(heap()).termination_exception());
// Clear termination once we returned from all V8 frames.
if (handle_scope_implementer()->CallDepthIsZero()) {
thread_local_top()->external_caught_exception_ = false;
clear_scheduled_exception();
}
}
if (reinterpret_cast<void*>(thread_local_top()->pending_message_obj_.ptr()) ==
handler->message_obj_) {
clear_pending_message();
}
}
Object Isolate::PromoteScheduledException() {
Object thrown = scheduled_exception();
clear_scheduled_exception();
// Re-throw the exception to avoid getting repeated error reporting.
return ReThrow(thrown);
}
void Isolate::PrintCurrentStackTrace(FILE* out) {
CaptureStackTraceOptions options;
options.limit = 0;
options.skip_mode = SKIP_NONE;
options.capture_builtin_exit_frames = true;
options.async_stack_trace = FLAG_async_stack_traces;
options.filter_mode = FrameArrayBuilder::CURRENT_SECURITY_CONTEXT;
options.capture_only_frames_subject_to_debugging = false;
options.enable_frame_caching = false;
Handle<FixedArray> frames = Handle<FixedArray>::cast(
CaptureStackTrace(this, this->factory()->undefined_value(), options));
IncrementalStringBuilder builder(this);
for (int i = 0; i < frames->length(); ++i) {
Handle<StackTraceFrame> frame(StackTraceFrame::cast(frames->get(i)), this);
SerializeStackTraceFrame(this, frame, builder);
}
Handle<String> stack_trace = builder.Finish().ToHandleChecked();
stack_trace->PrintOn(out);
}
bool Isolate::ComputeLocation(MessageLocation* target) {
StackTraceFrameIterator it(this);
if (it.done()) return false;
StandardFrame* frame = it.frame();
// Compute the location from the function and the relocation info of the
// baseline code. For optimized code this will use the deoptimization
// information to get canonical location information.
std::vector<FrameSummary> frames;
wasm::WasmCodeRefScope code_ref_scope;
frame->Summarize(&frames);
FrameSummary& summary = frames.back();
Handle<SharedFunctionInfo> shared;
Handle<Object> script = summary.script();
if (!script->IsScript() ||
(Script::cast(*script).source().IsUndefined(this))) {
return false;
}
if (summary.IsJavaScript()) {
shared = handle(summary.AsJavaScript().function()->shared(), this);
}
if (summary.AreSourcePositionsAvailable()) {
int pos = summary.SourcePosition();
*target =
MessageLocation(Handle<Script>::cast(script), pos, pos + 1, shared);
} else {
*target = MessageLocation(Handle<Script>::cast(script), shared,
summary.code_offset());
}
return true;
}
bool Isolate::ComputeLocationFromException(MessageLocation* target,
Handle<Object> exception) {
if (!exception->IsJSObject()) return false;
Handle<Name> start_pos_symbol = factory()->error_start_pos_symbol();
Handle<Object> start_pos = JSReceiver::GetDataProperty(
Handle<JSObject>::cast(exception), start_pos_symbol);
if (!start_pos->IsSmi()) return false;
int start_pos_value = Handle<Smi>::cast(start_pos)->value();
Handle<Name> end_pos_symbol = factory()->error_end_pos_symbol();
Handle<Object> end_pos = JSReceiver::GetDataProperty(
Handle<JSObject>::cast(exception), end_pos_symbol);
if (!end_pos->IsSmi()) return false;
int end_pos_value = Handle<Smi>::cast(end_pos)->value();
Handle<Name> script_symbol = factory()->error_script_symbol();
Handle<Object> script = JSReceiver::GetDataProperty(
Handle<JSObject>::cast(exception), script_symbol);
if (!script->IsScript()) return false;
Handle<Script> cast_script(Script::cast(*script), this);
*target = MessageLocation(cast_script, start_pos_value, end_pos_value);
return true;
}
bool Isolate::ComputeLocationFromStackTrace(MessageLocation* target,
Handle<Object> exception) {
if (!exception->IsJSObject()) return false;
Handle<Name> key = factory()->stack_trace_symbol();
Handle<Object> property =
JSReceiver::GetDataProperty(Handle<JSObject>::cast(exception), key);
if (!property->IsFixedArray()) return false;
Handle<FrameArray> elements =
GetFrameArrayFromStackTrace(this, Handle<FixedArray>::cast(property));
const int frame_count = elements->FrameCount();
for (int i = 0; i < frame_count; i++) {
if (elements->IsWasmFrame(i) || elements->IsAsmJsWasmFrame(i)) {
Handle<WasmInstanceObject> instance(elements->WasmInstance(i), this);
uint32_t func_index =
static_cast<uint32_t>(elements->WasmFunctionIndex(i).value());
int code_offset = elements->Offset(i).value();
bool is_at_number_conversion =
elements->IsAsmJsWasmFrame(i) &&
elements->Flags(i).value() & FrameArray::kAsmJsAtNumberConversion;
// WasmCode* held alive by the {GlobalWasmCodeRef}.
wasm::WasmCode* code =
Managed<wasm::GlobalWasmCodeRef>::cast(elements->WasmCodeObject(i))
.get()
->code();
int byte_offset =
FrameSummary::WasmCompiledFrameSummary::GetWasmSourcePosition(
code, code_offset);
int pos = WasmModuleObject::GetSourcePosition(
handle(instance->module_object(), this), func_index, byte_offset,
is_at_number_conversion);
Handle<Script> script(instance->module_object().script(), this);
*target = MessageLocation(script, pos, pos + 1);
return true;
}
Handle<JSFunction> fun = handle(elements->Function(i), this);
if (!fun->shared().IsSubjectToDebugging()) continue;
Object script = fun->shared().script();
if (script.IsScript() &&
!(Script::cast(script).source().IsUndefined(this))) {
Handle<SharedFunctionInfo> shared = handle(fun->shared(), this);
AbstractCode abstract_code = elements->Code(i);
const int code_offset = elements->Offset(i).value();
Handle<Script> casted_script(Script::cast(script), this);
if (shared->HasBytecodeArray() &&
shared->GetBytecodeArray().HasSourcePositionTable()) {
int pos = abstract_code.SourcePosition(code_offset);
*target = MessageLocation(casted_script, pos, pos + 1, shared);
} else {
*target = MessageLocation(casted_script, shared, code_offset);
}
return true;
}
}
return false;
}
Handle<JSMessageObject> Isolate::CreateMessage(Handle<Object> exception,
MessageLocation* location) {
Handle<FixedArray> stack_trace_object;
if (capture_stack_trace_for_uncaught_exceptions_) {
if (exception->IsJSError()) {
// We fetch the stack trace that corresponds to this error object.
// If the lookup fails, the exception is probably not a valid Error
// object. In that case, we fall through and capture the stack trace
// at this throw site.
stack_trace_object =
GetDetailedStackTrace(Handle<JSObject>::cast(exception));
}
if (stack_trace_object.is_null()) {
// Not an error object, we capture stack and location at throw site.
stack_trace_object = CaptureCurrentStackTrace(
stack_trace_for_uncaught_exceptions_frame_limit_,
stack_trace_for_uncaught_exceptions_options_);
}
}
MessageLocation computed_location;
if (location == nullptr &&
(ComputeLocationFromException(&computed_location, exception) ||
ComputeLocationFromStackTrace(&computed_location, exception) ||
ComputeLocation(&computed_location))) {
location = &computed_location;
}
return MessageHandler::MakeMessageObject(
this, MessageTemplate::kUncaughtException, location, exception,
stack_trace_object);
}
bool Isolate::IsJavaScriptHandlerOnTop(Object exception) {
DCHECK_NE(ReadOnlyRoots(heap()).the_hole_value(), exception);
// For uncatchable exceptions, the JavaScript handler cannot be on top.
if (!is_catchable_by_javascript(exception)) return false;
// Get the top-most JS_ENTRY handler, cannot be on top if it doesn't exist.
Address entry_handler = Isolate::handler(thread_local_top());
if (entry_handler == kNullAddress) return false;
// 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 = thread_local_top()->try_catch_handler_address();
if (external_handler == kNullAddress) return true;
// The exception has been externally caught if and only if there is an
// external handler which is on top of the top-most JS_ENTRY handler.
//
// Note, that finally clauses would re-throw an exception unless it's aborted
// by jumps in control flow (like return, break, etc.) and we'll have another
// chance to set proper v8::TryCatch later.
return (entry_handler < external_handler);
}
bool Isolate::IsExternalHandlerOnTop(Object exception) {
DCHECK_NE(ReadOnlyRoots(heap()).the_hole_value(), exception);
// 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 = thread_local_top()->try_catch_handler_address();
if (external_handler == kNullAddress) return false;
// For uncatchable exceptions, the external handler is always on top.
if (!is_catchable_by_javascript(exception)) return true;
// Get the top-most JS_ENTRY handler, cannot be on top if it doesn't exist.
Address entry_handler = Isolate::handler(thread_local_top());
if (entry_handler == kNullAddress) return true;
// The exception has been externally caught if and only if there is an
// external handler which is on top of the top-most JS_ENTRY handler.
//
// Note, that finally clauses would re-throw an exception unless it's aborted
// by jumps in control flow (like return, break, etc.) and we'll have another
// chance to set proper v8::TryCatch later.
return (entry_handler > external_handler);
}
void Isolate::ReportPendingMessagesImpl(bool report_externally) {
Object exception_obj = pending_exception();
// Clear the pending message object early to avoid endless recursion.
Object message_obj = thread_local_top()->pending_message_obj_;
clear_pending_message();
// For uncatchable exceptions we do nothing. If needed, the exception and the
// message have already been propagated to v8::TryCatch.
if (!is_catchable_by_javascript(exception_obj)) return;
// Determine whether the message needs to be reported to all message handlers
// depending on whether and external v8::TryCatch or an internal JavaScript
// handler is on top.
bool should_report_exception;
if (report_externally) {
// Only report the exception if the external handler is verbose.
should_report_exception = try_catch_handler()->is_verbose_;
} else {
// Report the exception if it isn't caught by JavaScript code.
should_report_exception = !IsJavaScriptHandlerOnTop(exception_obj);
}
// Actually report the pending message to all message handlers.
if (!message_obj.IsTheHole(this) && should_report_exception) {
HandleScope scope(this);
Handle<JSMessageObject> message(JSMessageObject::cast(message_obj), this);
Handle<Object> exception(exception_obj, this);
Handle<Script> script(message->script(), this);
// Clear the exception and restore it afterwards, otherwise
// CollectSourcePositions will abort.
clear_pending_exception();
JSMessageObject::EnsureSourcePositionsAvailable(this, message);
set_pending_exception(*exception);
int start_pos = message->GetStartPosition();
int end_pos = message->GetEndPosition();
MessageLocation location(script, start_pos, end_pos);
MessageHandler::ReportMessage(this, &location, message);
}
}
void Isolate::ReportPendingMessages() {
DCHECK(AllowExceptions::IsAllowed(this));
// The embedder might run script in response to an exception.
AllowJavascriptExecutionDebugOnly allow_script(this);
Object exception = pending_exception();
// Try to propagate the exception to an external v8::TryCatch handler. If
// propagation was unsuccessful, then we will get another chance at reporting
// the pending message if the exception is re-thrown.
bool has_been_propagated = PropagatePendingExceptionToExternalTryCatch();
if (!has_been_propagated) return;
ReportPendingMessagesImpl(IsExternalHandlerOnTop(exception));
}
void Isolate::ReportPendingMessagesFromJavaScript() {
DCHECK(AllowExceptions::IsAllowed(this));
auto IsHandledByJavaScript = [=]() {
// In this situation, the exception is always a non-terminating exception.
// Get the top-most JS_ENTRY handler, cannot be on top if it doesn't exist.
Address entry_handler = Isolate::handler(thread_local_top());
DCHECK_NE(entry_handler, kNullAddress);
entry_handler = StackHandler::FromAddress(entry_handler)->next_address();
// 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 = thread_local_top()->try_catch_handler_address();
if (external_handler == kNullAddress) return true;
return (entry_handler < external_handler);
};
auto IsHandledExternally = [=]() {
Address external_handler = thread_local_top()->try_catch_handler_address();
if (external_handler == kNullAddress) return false;
// Get the top-most JS_ENTRY handler, cannot be on top if it doesn't exist.
Address entry_handler = Isolate::handler(thread_local_top());
DCHECK_NE(entry_handler, kNullAddress);
entry_handler = StackHandler::FromAddress(entry_handler)->next_address();
return (entry_handler > external_handler);
};
auto PropagateToExternalHandler = [=]() {
if (IsHandledByJavaScript()) {
thread_local_top()->external_caught_exception_ = false;
return false;
}
if (!IsHandledExternally()) {
thread_local_top()->external_caught_exception_ = false;
return true;
}
thread_local_top()->external_caught_exception_ = true;
v8::TryCatch* handler = try_catch_handler();
DCHECK(thread_local_top()->pending_message_obj_.IsJSMessageObject() ||
thread_local_top()->pending_message_obj_.IsTheHole(this));
handler->can_continue_ = true;
handler->has_terminated_ = false;
handler->exception_ = reinterpret_cast<void*>(pending_exception().ptr());
// Propagate to the external try-catch only if we got an actual message.
if (thread_local_top()->pending_message_obj_.IsTheHole(this)) return true;
handler->message_obj_ =
reinterpret_cast<void*>(thread_local_top()->pending_message_obj_.ptr());
return true;
};
// Try to propagate to an external v8::TryCatch handler.
if (!PropagateToExternalHandler()) return;
ReportPendingMessagesImpl(true);
}
bool Isolate::OptionalRescheduleException(bool clear_exception) {
DCHECK(has_pending_exception());
PropagatePendingExceptionToExternalTryCatch();
bool is_termination_exception =
pending_exception() == ReadOnlyRoots(this).termination_exception();
if (is_termination_exception) {
if (clear_exception) {
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.
DCHECK_NE(thread_local_top()->try_catch_handler_address(), kNullAddress);
Address external_handler_address =
thread_local_top()->try_catch_handler_address();
JavaScriptFrameIterator it(this);
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::PushPromise(Handle<JSObject> promise) {
ThreadLocalTop* tltop = thread_local_top();
PromiseOnStack* prev = tltop->promise_on_stack_;
Handle<JSObject> global_promise = global_handles()->Create(*promise);
tltop->promise_on_stack_ = new PromiseOnStack(global_promise, prev);
}
void Isolate::PopPromise() {
ThreadLocalTop* tltop = thread_local_top();
if (tltop->promise_on_stack_ == nullptr) return;
PromiseOnStack* prev = tltop->promise_on_stack_->prev();
Handle<Object> global_promise = tltop->promise_on_stack_->promise();
delete tltop->promise_on_stack_;
tltop->promise_on_stack_ = prev;
global_handles()->Destroy(global_promise.location());
}
namespace {
bool InternalPromiseHasUserDefinedRejectHandler(Isolate* isolate,
Handle<JSPromise> promise);
bool PromiseHandlerCheck(Isolate* isolate, Handle<JSReceiver> handler,
Handle<JSReceiver> deferred_promise) {
// Recurse to the forwarding Promise, if any. This may be due to
// - await reaction forwarding to the throwaway Promise, which has
// a dependency edge to the outer Promise.
// - PromiseIdResolveHandler forwarding to the output of .then
// - Promise.all/Promise.race forwarding to a throwaway Promise, which
// has a dependency edge to the generated outer Promise.
// Otherwise, this is a real reject handler for the Promise.
Handle<Symbol> key = isolate->factory()->promise_forwarding_handler_symbol();
Handle<Object> forwarding_handler = JSReceiver::GetDataProperty(handler, key);
if (forwarding_handler->IsUndefined(isolate)) {
return true;
}
if (!deferred_promise->IsJSPromise()) {
return true;
}
return InternalPromiseHasUserDefinedRejectHandler(
isolate, Handle<JSPromise>::cast(deferred_promise));
}
bool InternalPromiseHasUserDefinedRejectHandler(Isolate* isolate,
Handle<JSPromise> promise) {
// If this promise was marked as being handled by a catch block
// in an async function, then it has a user-defined reject handler.
if (promise->handled_hint()) return true;
// If this Promise is subsumed by another Promise (a Promise resolved
// with another Promise, or an intermediate, hidden, throwaway Promise
// within async/await), then recurse on the outer Promise.
// In this case, the dependency is one possible way that the Promise
// could be resolved, so it does not subsume the other following cases.
Handle<Symbol> key = isolate->factory()->promise_handled_by_symbol();
Handle<Object> outer_promise_obj = JSObject::GetDataProperty(promise, key);
if (outer_promise_obj->IsJSPromise() &&
InternalPromiseHasUserDefinedRejectHandler(
isolate, Handle<JSPromise>::cast(outer_promise_obj))) {
return true;
}
if (promise->status() == Promise::kPending) {
for (Handle<Object> current(promise->reactions(), isolate);
!current->IsSmi();) {
Handle<PromiseReaction> reaction = Handle<PromiseReaction>::cast(current);
Handle<HeapObject> promise_or_capability(
reaction->promise_or_capability(), isolate);
if (!promise_or_capability->IsUndefined(isolate)) {
Handle<JSPromise> promise = Handle<JSPromise>::cast(
promise_or_capability->IsJSPromise()
? promise_or_capability
: handle(Handle<PromiseCapability>::cast(promise_or_capability)
->promise(),
isolate));
if (reaction->reject_handler().IsUndefined(isolate)) {
if (InternalPromiseHasUserDefinedRejectHandler(isolate, promise)) {
return true;
}
} else {
Handle<JSReceiver> current_handler(
JSReceiver::cast(reaction->reject_handler()), isolate);
if (PromiseHandlerCheck(isolate, current_handler, promise)) {
return true;
}
}
}
current = handle(reaction->next(), isolate);
}
}
return false;
}
} // namespace
bool Isolate::PromiseHasUserDefinedRejectHandler(Handle<Object> promise) {
if (!promise->IsJSPromise()) return false;
return InternalPromiseHasUserDefinedRejectHandler(
this, Handle<JSPromise>::cast(promise));
}
Handle<Object> Isolate::GetPromiseOnStackOnThrow() {
Handle<Object> undefined = factory()->undefined_value();
ThreadLocalTop* tltop = thread_local_top();
if (tltop->promise_on_stack_ == nullptr) return undefined;
// Find the top-most try-catch or try-finally handler.
CatchType prediction = PredictExceptionCatcher();
if (prediction == NOT_CAUGHT || prediction == CAUGHT_BY_EXTERNAL) {
return undefined;
}
Handle<Object> retval = undefined;
PromiseOnStack* promise_on_stack = tltop->promise_on_stack_;
for (StackFrameIterator it(this); !it.done(); it.Advance()) {
StackFrame* frame = it.frame();
HandlerTable::CatchPrediction catch_prediction;
if (frame->is_java_script()) {
catch_prediction = PredictException(JavaScriptFrame::cast(frame));
} else if (frame->type() == StackFrame::STUB) {
Code code = frame->LookupCode();
if (!code.IsCode() || code.kind() != Code::BUILTIN ||
!code.has_handler_table() || !code.is_turbofanned()) {
continue;
}
catch_prediction = code.GetBuiltinCatchPrediction();
} else {
continue;
}
switch (catch_prediction) {
case HandlerTable::UNCAUGHT:
continue;
case HandlerTable::CAUGHT:
case HandlerTable::DESUGARING:
if (retval->IsJSPromise()) {
// Caught the result of an inner async/await invocation.
// Mark the inner promise as caught in the "synchronous case" so
// that Debug::OnException will see. In the synchronous case,
// namely in the code in an async function before the first
// await, the function which has this exception event has not yet
// returned, so the generated Promise has not yet been marked
// by AsyncFunctionAwaitCaught with promiseHandledHintSymbol.
Handle<JSPromise>::cast(retval)->set_handled_hint(true);
}
return retval;
case HandlerTable::PROMISE:
return promise_on_stack
? Handle<Object>::cast(promise_on_stack->promise())
: undefined;
case HandlerTable::ASYNC_AWAIT: {
// If in the initial portion of async/await, continue the loop to pop up
// successive async/await stack frames until an asynchronous one with
// dependents is found, or a non-async stack frame is encountered, in
// order to handle the synchronous async/await catch prediction case:
// assume that async function calls are awaited.
if (!promise_on_stack) return retval;
retval = promise_on_stack->promise();
if (PromiseHasUserDefinedRejectHandler(retval)) {
return retval;
}
promise_on_stack = promise_on_stack->prev();
continue;
}
}
}
return retval;
}
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;
}
void Isolate::SetAbortOnUncaughtExceptionCallback(
v8::Isolate::AbortOnUncaughtExceptionCallback callback) {
abort_on_uncaught_exception_callback_ = callback;
}
bool Isolate::AreWasmThreadsEnabled(Handle<Context> context) {
if (wasm_threads_enabled_callback()) {
v8::Local<v8::Context> api_context = v8::Utils::ToLocal(context);
return wasm_threads_enabled_callback()(api_context);
}
return FLAG_experimental_wasm_threads;
}
Handle<Context> Isolate::GetIncumbentContext() {
JavaScriptFrameIterator it(this);
// 1st candidate: most-recently-entered author function's context
// if it's newer than the last Context::BackupIncumbentScope entry.
//
// NOTE: This code assumes that the stack grows downward.
Address top_backup_incumbent =
top_backup_incumbent_scope()
? top_backup_incumbent_scope()->JSStackComparableAddress()
: 0;
if (!it.done() &&
(!top_backup_incumbent || it.frame()->sp() < top_backup_incumbent)) {
Context context = Context::cast(it.frame()->context());
return Handle<Context>(context.native_context(), this);
}
// 2nd candidate: the last Context::Scope's incumbent context if any.
if (top_backup_incumbent_scope()) {
return Utils::OpenHandle(
*top_backup_incumbent_scope()->backup_incumbent_context_);
}
// Last candidate: the entered context or microtask context.
// Given that there is no other author function is running, there must be
// no cross-context function running, then the incumbent realm must match
// the entry realm.
v8::Local<v8::Context> entered_context =
reinterpret_cast<v8::Isolate*>(this)->GetEnteredOrMicrotaskContext();
return Utils::OpenHandle(*entered_context);
}
char* Isolate::ArchiveThread(char* to) {
MemCopy(to, reinterpret_cast<char*>(thread_local_top()),
sizeof(ThreadLocalTop));
InitializeThreadLocal();
clear_pending_exception();
clear_pending_message();
clear_scheduled_exception();
return to + sizeof(ThreadLocalTop);
}
char* Isolate::RestoreThread(char* from) {
MemCopy(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
thread_local_top()->simulator_ = Simulator::current(this);
#endif
DCHECK(context().is_null() || context().IsContext());
return from + sizeof(ThreadLocalTop);
}
void Isolate::ReleaseSharedPtrs() {
base::MutexGuard lock(&managed_ptr_destructors_mutex_);
while (managed_ptr_destructors_head_) {
ManagedPtrDestructor* l = managed_ptr_destructors_head_;
ManagedPtrDestructor* n = nullptr;
managed_ptr_destructors_head_ = nullptr;
for (; l != nullptr; l = n) {
l->destructor_(l->shared_ptr_ptr_);
n = l->next_;
delete l;
}
}
}
void Isolate::RegisterManagedPtrDestructor(ManagedPtrDestructor* destructor) {
base::MutexGuard lock(&managed_ptr_destructors_mutex_);
DCHECK_NULL(destructor->prev_);
DCHECK_NULL(destructor->next_);
if (managed_ptr_destructors_head_) {
managed_ptr_destructors_head_->prev_ = destructor;
}
destructor->next_ = managed_ptr_destructors_head_;
managed_ptr_destructors_head_ = destructor;
}
void Isolate::UnregisterManagedPtrDestructor(ManagedPtrDestructor* destructor) {
base::MutexGuard lock(&managed_ptr_destructors_mutex_);
if (destructor->prev_) {
destructor->prev_->next_ = destructor->next_;
} else {
DCHECK_EQ(destructor, managed_ptr_destructors_head_);
managed_ptr_destructors_head_ = destructor->next_;
}
if (destructor->next_) destructor->next_->prev_ = destructor->prev_;
destructor->prev_ = nullptr;
destructor->next_ = nullptr;
}
void Isolate::SetWasmEngine(std::shared_ptr<wasm::WasmEngine> engine) {
DCHECK_NULL(wasm_engine_); // Only call once before {Init}.
wasm_engine_ = std::move(engine);
wasm_engine_->AddIsolate(this);
}
// NOLINTNEXTLINE
Isolate::PerIsolateThreadData::~PerIsolateThreadData() {
#if defined(USE_SIMULATOR)
delete simulator_;
#endif
}
Isolate::PerIsolateThreadData* Isolate::ThreadDataTable::Lookup(
ThreadId thread_id) {
auto t = table_.find(thread_id);
if (t == table_.end()) return nullptr;
return t->second;
}
void Isolate::ThreadDataTable::Insert(Isolate::PerIsolateThreadData* data) {
bool inserted = table_.insert(std::make_pair(data->thread_id_, data)).second;
CHECK(inserted);
}
void Isolate::ThreadDataTable::Remove(PerIsolateThreadData* data) {
table_.erase(data->thread_id_);
delete data;
}
void Isolate::ThreadDataTable::RemoveAllThreads() {
for (auto& x : table_) {
delete x.second;
}
table_.clear();
}
class VerboseAccountingAllocator : public AccountingAllocator {
public:
VerboseAccountingAllocator(Heap* heap, size_t allocation_sample_bytes)
: heap_(heap), allocation_sample_bytes_(allocation_sample_bytes) {}
v8::internal::Segment* AllocateSegment(size_t size) override {
v8::internal::Segment* memory = AccountingAllocator::AllocateSegment(size);
if (!memory) return nullptr;
size_t malloced_current = GetCurrentMemoryUsage();
if (last_memory_usage_ + allocation_sample_bytes_ < malloced_current) {
PrintMemoryJSON(malloced_current);
last_memory_usage_ = malloced_current;
}
return memory;
}
void ReturnSegment(v8::internal::Segment* memory) override {
AccountingAllocator::ReturnSegment(memory);
size_t malloced_current = GetCurrentMemoryUsage();
if (malloced_current + allocation_sample_bytes_ < last_memory_usage_) {
PrintMemoryJSON(malloced_current);
last_memory_usage_ = malloced_current;
}
}
void ZoneCreation(const Zone* zone) override {
PrintZoneModificationSample(zone, "zonecreation");
nesting_deepth_++;
}
void ZoneDestruction(const Zone* zone) override {
nesting_deepth_--;
PrintZoneModificationSample(zone, "zonedestruction");
}
private:
void PrintZoneModificationSample(const Zone* zone, const char* type) {
PrintF(
"{"
"\"type\": \"%s\", "
"\"isolate\": \"%p\", "
"\"time\": %f, "