// Copyright 2015 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/wasm/wasm-objects.h"
#include "src/utils.h"
#include "src/assembler-inl.h"
#include "src/base/iterator.h"
#include "src/compiler/wasm-compiler.h"
#include "src/debug/debug-interface.h"
#include "src/macro-assembler-inl.h"
#include "src/objects-inl.h"
#include "src/objects/debug-objects-inl.h"
#include "src/trap-handler/trap-handler.h"
#include "src/wasm/module-compiler.h"
#include "src/wasm/module-decoder.h"
#include "src/wasm/wasm-code-manager.h"
#include "src/wasm/wasm-code-specialization.h"
#include "src/wasm/wasm-engine.h"
#include "src/wasm/wasm-memory.h"
#include "src/wasm/wasm-module.h"
#include "src/wasm/wasm-objects-inl.h"
#include "src/wasm/wasm-text.h"
#define TRACE(...) \
do { \
if (FLAG_trace_wasm_instances) PrintF(__VA_ARGS__); \
} while (false)
#define TRACE_IFT(...) \
do { \
if (false) PrintF(__VA_ARGS__); \
} while (false)
namespace v8 {
namespace internal {
// Import a few often used types from the wasm namespace.
using WasmFunction = wasm::WasmFunction;
using WasmModule = wasm::WasmModule;
namespace {
// Manages the natively-allocated memory for a WasmInstanceObject. Since
// an instance finalizer is not guaranteed to run upon isolate shutdown,
// we must use a Managed<WasmInstanceNativeAllocations> to guarantee
// it is freed.
// Native allocations are the signature ids and targets for indirect call
// targets, as well as the call targets for imported functions.
class WasmInstanceNativeAllocations {
public:
// Helper macro to set an internal field and the corresponding field
// on an instance.
#define SET(instance, field, value) \
{ \
auto v = value; \
this->field##_ = v; \
instance->set_##field(v); \
}
// Allocates initial native storage for a given instance.
WasmInstanceNativeAllocations(Handle<WasmInstanceObject> instance,
size_t num_imported_functions,
size_t num_imported_mutable_globals) {
SET(instance, imported_function_targets,
reinterpret_cast<Address*>(
calloc(num_imported_functions, sizeof(Address))));
SET(instance, imported_mutable_globals,
reinterpret_cast<Address*>(
calloc(num_imported_mutable_globals, sizeof(Address))));
}
~WasmInstanceNativeAllocations() { free(); }
// Frees natively-allocated storage.
void free() {
::free(indirect_function_table_sig_ids_);
::free(indirect_function_table_targets_);
::free(imported_function_targets_);
::free(imported_mutable_globals_);
indirect_function_table_sig_ids_ = nullptr;
indirect_function_table_targets_ = nullptr;
imported_function_targets_ = nullptr;
imported_mutable_globals_ = nullptr;
}
// Resizes the indirect function table.
void resize_indirect_function_table(Isolate* isolate,
Handle<WasmInstanceObject> instance,
uint32_t new_size) {
uint32_t old_size = instance->indirect_function_table_size();
void* new_sig_ids = nullptr;
void* new_targets = nullptr;
Handle<FixedArray> new_instances;
if (indirect_function_table_sig_ids_) {
// Reallocate the old storage.
new_sig_ids = realloc(indirect_function_table_sig_ids_,
new_size * sizeof(uint32_t));
new_targets =
realloc(indirect_function_table_targets_, new_size * sizeof(Address));
Handle<FixedArray> old(instance->indirect_function_table_instances(),
isolate);
new_instances = isolate->factory()->CopyFixedArrayAndGrow(
old, static_cast<int>(new_size - old_size));
} else {
// Allocate new storage.
new_sig_ids = malloc(new_size * sizeof(uint32_t));
new_targets = malloc(new_size * sizeof(Address));
new_instances =
isolate->factory()->NewFixedArray(static_cast<int>(new_size));
}
// Initialize new entries.
instance->set_indirect_function_table_size(new_size);
SET(instance, indirect_function_table_sig_ids,
reinterpret_cast<uint32_t*>(new_sig_ids));
SET(instance, indirect_function_table_targets,
reinterpret_cast<Address*>(new_targets));
instance->set_indirect_function_table_instances(*new_instances);
for (uint32_t j = old_size; j < new_size; j++) {
IndirectFunctionTableEntry(*instance, static_cast<int>(j)).clear();
}
}
uint32_t* indirect_function_table_sig_ids_ = nullptr;
Address* indirect_function_table_targets_ = nullptr;
Address* imported_function_targets_ = nullptr;
Address* imported_mutable_globals_ = nullptr;
#undef SET
};
WasmInstanceNativeAllocations* GetNativeAllocations(
WasmInstanceObject* instance) {
return reinterpret_cast<Managed<WasmInstanceNativeAllocations>*>(
instance->managed_native_allocations())
->raw();
}
// An iterator that returns first the module itself, then all modules linked via
// next, then all linked via prev.
class CompiledModulesIterator
: public v8::base::iterator<std::input_iterator_tag,
Handle<WasmCompiledModule>> {
public:
CompiledModulesIterator(Isolate* isolate,
Handle<WasmCompiledModule> start_module, bool at_end)
: isolate_(isolate),
start_module_(start_module),
current_(
at_end ? Handle<WasmCompiledModule>::null()
: Handle<WasmCompiledModule>::New(*start_module, isolate)) {}
Handle<WasmCompiledModule> operator*() const {
DCHECK(!current_.is_null());
return current_;
}
void operator++() { Advance(); }
bool operator!=(const CompiledModulesIterator& other) {
DCHECK(start_module_.is_identical_to(other.start_module_));
return !current_.is_identical_to(other.current_);
}
private:
void Advance() {
DCHECK(!current_.is_null());
if (!is_backwards_) {
if (current_->has_next_instance()) {
*current_.location() = current_->next_instance();
return;
}
// No more modules in next-links, now try the previous-links.
is_backwards_ = true;
current_ = start_module_;
}
if (current_->has_prev_instance()) {
*current_.location() = current_->prev_instance();
return;
}
current_ = Handle<WasmCompiledModule>::null();
}
friend class CompiledModuleInstancesIterator;
Isolate* isolate_;
Handle<WasmCompiledModule> start_module_;
Handle<WasmCompiledModule> current_;
bool is_backwards_ = false;
};
// An iterator based on the CompiledModulesIterator, but it returns all live
// instances, not the WasmCompiledModules itself.
class CompiledModuleInstancesIterator
: public v8::base::iterator<std::input_iterator_tag,
Handle<WasmInstanceObject>> {
public:
CompiledModuleInstancesIterator(Isolate* isolate,
Handle<WasmCompiledModule> start_module,
bool at_end)
: it(isolate, start_module, at_end) {
while (NeedToAdvance()) ++it;
}
Handle<WasmInstanceObject> operator*() {
return handle(
WasmInstanceObject::cast((*it)->weak_owning_instance()->value()),
it.isolate_);
}
void operator++() {
do {
++it;
} while (NeedToAdvance());
}
bool operator!=(const CompiledModuleInstancesIterator& other) {
return it != other.it;
}
private:
bool NeedToAdvance() {
return !it.current_.is_null() && !it.current_->has_instance();
}
CompiledModulesIterator it;
};
v8::base::iterator_range<CompiledModuleInstancesIterator>
iterate_compiled_module_instance_chain(
Isolate* isolate, Handle<WasmCompiledModule> compiled_module) {
return {CompiledModuleInstancesIterator(isolate, compiled_module, false),
CompiledModuleInstancesIterator(isolate, compiled_module, true)};
}
#ifdef DEBUG
bool IsBreakablePosition(WasmSharedModuleData* shared, int func_index,
int offset_in_func) {
DisallowHeapAllocation no_gc;
AccountingAllocator alloc;
Zone tmp(&alloc, ZONE_NAME);
wasm::BodyLocalDecls locals(&tmp);
const byte* module_start = shared->module_bytes()->GetChars();
WasmFunction& func = shared->module()->functions[func_index];
wasm::BytecodeIterator iterator(module_start + func.code.offset(),
module_start + func.code.end_offset(),
&locals);
DCHECK_LT(0, locals.encoded_size);
for (uint32_t offset : iterator.offsets()) {
if (offset > static_cast<uint32_t>(offset_in_func)) break;
if (offset == static_cast<uint32_t>(offset_in_func)) return true;
}
return false;
}
#endif // DEBUG
enum DispatchTableElements : int {
kDispatchTableInstanceOffset,
kDispatchTableIndexOffset,
kDispatchTableFunctionTableOffset,
// Marker:
kDispatchTableNumElements
};
} // namespace
Handle<WasmModuleObject> WasmModuleObject::New(
Isolate* isolate, Handle<WasmCompiledModule> compiled_module) {
Handle<JSFunction> module_cons(
isolate->native_context()->wasm_module_constructor());
auto module_object = Handle<WasmModuleObject>::cast(
isolate->factory()->NewJSObject(module_cons));
module_object->set_compiled_module(*compiled_module);
Handle<WeakCell> link_to_module =
isolate->factory()->NewWeakCell(module_object);
compiled_module->set_weak_wasm_module(*link_to_module);
compiled_module->LogWasmCodes(isolate);
return module_object;
}
void WasmModuleObject::ValidateStateForTesting(
Isolate* isolate, Handle<WasmModuleObject> module_obj) {
DisallowHeapAllocation no_gc;
WasmCompiledModule* compiled_module = module_obj->compiled_module();
CHECK(compiled_module->has_weak_wasm_module());
CHECK_EQ(compiled_module->weak_wasm_module()->value(), *module_obj);
CHECK(!compiled_module->has_prev_instance());
CHECK(!compiled_module->has_next_instance());
CHECK(!compiled_module->has_instance());
}
Handle<WasmTableObject> WasmTableObject::New(Isolate* isolate, uint32_t initial,
int64_t maximum,
Handle<FixedArray>* js_functions) {
Handle<JSFunction> table_ctor(
isolate->native_context()->wasm_table_constructor());
auto table_obj = Handle<WasmTableObject>::cast(
isolate->factory()->NewJSObject(table_ctor));
*js_functions = isolate->factory()->NewFixedArray(initial);
Object* null = isolate->heap()->null_value();
for (int i = 0; i < static_cast<int>(initial); ++i) {
(*js_functions)->set(i, null);
}
table_obj->set_functions(**js_functions);
DCHECK_EQ(maximum, static_cast<int>(maximum));
Handle<Object> max = isolate->factory()->NewNumber(maximum);
table_obj->set_maximum_length(*max);
table_obj->set_dispatch_tables(isolate->heap()->empty_fixed_array());
return Handle<WasmTableObject>::cast(table_obj);
}
void WasmTableObject::AddDispatchTable(Isolate* isolate,
Handle<WasmTableObject> table_obj,
Handle<WasmInstanceObject> instance,
int table_index) {
Handle<FixedArray> dispatch_tables(table_obj->dispatch_tables());
int old_length = dispatch_tables->length();
DCHECK_EQ(0, old_length % kDispatchTableNumElements);
if (instance.is_null()) return;
// TODO(titzer): use weak cells here to avoid leaking instances.
// Grow the dispatch table and add a new entry at the end.
Handle<FixedArray> new_dispatch_tables =
isolate->factory()->CopyFixedArrayAndGrow(dispatch_tables,
kDispatchTableNumElements);
new_dispatch_tables->set(old_length + kDispatchTableInstanceOffset,
*instance);
new_dispatch_tables->set(old_length + kDispatchTableIndexOffset,
Smi::FromInt(table_index));
table_obj->set_dispatch_tables(*new_dispatch_tables);
}
void WasmTableObject::Grow(Isolate* isolate, uint32_t count) {
if (count == 0) return; // Degenerate case: nothing to do.
Handle<FixedArray> dispatch_tables(this->dispatch_tables());
DCHECK_EQ(0, dispatch_tables->length() % kDispatchTableNumElements);
uint32_t old_size = functions()->length();
// Tables are stored in the instance object, no code patching is
// necessary. We simply have to grow the raw tables in each instance
// that has imported this table.
// TODO(titzer): replace the dispatch table with a weak list of all
// the instances that import a given table.
for (int i = 0; i < dispatch_tables->length();
i += kDispatchTableNumElements) {
Handle<WasmInstanceObject> instance(
WasmInstanceObject::cast(dispatch_tables->get(i)), isolate);
DCHECK_EQ(old_size, instance->indirect_function_table_size());
uint32_t new_size = old_size + count;
WasmInstanceObject::EnsureIndirectFunctionTableWithMinimumSize(instance,
new_size);
}
}
void WasmTableObject::Set(Isolate* isolate, Handle<WasmTableObject> table,
int32_t table_index, Handle<JSFunction> function) {
Handle<FixedArray> array(table->functions(), isolate);
if (function.is_null()) {
ClearDispatchTables(table, table_index); // Degenerate case of null value.
array->set(table_index, isolate->heap()->null_value());
return;
}
// TODO(titzer): Change this to MaybeHandle<WasmExportedFunction>
DCHECK(WasmExportedFunction::IsWasmExportedFunction(*function));
auto exported_function = Handle<WasmExportedFunction>::cast(function);
Handle<WasmInstanceObject> other_instance(exported_function->instance());
int func_index = exported_function->function_index();
auto* wasm_function = &other_instance->module()->functions[func_index];
DCHECK_NOT_NULL(wasm_function);
DCHECK_NOT_NULL(wasm_function->sig);
wasm::WasmCode* wasm_code = exported_function->GetWasmCode();
UpdateDispatchTables(isolate, table, table_index, wasm_function->sig,
handle(exported_function->instance()), wasm_code);
array->set(table_index, *function);
}
void WasmTableObject::UpdateDispatchTables(
Isolate* isolate, Handle<WasmTableObject> table, int table_index,
wasm::FunctionSig* sig, Handle<WasmInstanceObject> from_instance,
wasm::WasmCode* wasm_code) {
// We simply need to update the IFTs for each instance that imports
// this table.
DisallowHeapAllocation no_gc;
FixedArray* dispatch_tables = table->dispatch_tables();
DCHECK_EQ(0, dispatch_tables->length() % kDispatchTableNumElements);
for (int i = 0; i < dispatch_tables->length();
i += kDispatchTableNumElements) {
// Note that {SignatureMap::Find} may return {-1} if the signature is
// not found; it will simply never match any check.
WasmInstanceObject* to_instance = WasmInstanceObject::cast(
dispatch_tables->get(i + kDispatchTableInstanceOffset));
auto sig_id = to_instance->module()->signature_map.Find(sig);
IndirectFunctionTableEntry(to_instance, table_index)
.set(sig_id, *from_instance, wasm_code);
}
}
void WasmTableObject::ClearDispatchTables(Handle<WasmTableObject> table,
int index) {
DisallowHeapAllocation no_gc;
FixedArray* dispatch_tables = table->dispatch_tables();
DCHECK_EQ(0, dispatch_tables->length() % kDispatchTableNumElements);
for (int i = 0; i < dispatch_tables->length();
i += kDispatchTableNumElements) {
WasmInstanceObject* target_instance = WasmInstanceObject::cast(
dispatch_tables->get(i + kDispatchTableInstanceOffset));
DCHECK_LT(index, target_instance->indirect_function_table_size());
IndirectFunctionTableEntry(target_instance, index).clear();
}
}
namespace {
MaybeHandle<JSArrayBuffer> GrowMemoryBuffer(Isolate* isolate,
Handle<JSArrayBuffer> old_buffer,
uint32_t pages,
uint32_t maximum_pages,
bool use_trap_handler) {
if (!old_buffer->is_growable()) return {};
void* old_mem_start = old_buffer->backing_store();
uint32_t old_size = 0;
CHECK(old_buffer->byte_length()->ToUint32(&old_size));
DCHECK_EQ(0, old_size % wasm::kWasmPageSize);
uint32_t old_pages = old_size / wasm::kWasmPageSize;
DCHECK_GE(std::numeric_limits<uint32_t>::max(),
old_size + pages * wasm::kWasmPageSize);
if (old_pages > maximum_pages || pages > maximum_pages - old_pages) return {};
size_t new_size =
static_cast<size_t>(old_pages + pages) * wasm::kWasmPageSize;
if (new_size > FLAG_wasm_max_mem_pages * wasm::kWasmPageSize ||
new_size > kMaxInt) {
return {};
}
// Reusing the backing store from externalized buffers causes problems with
// Blink's array buffers. The connection between the two is lost, which can
// lead to Blink not knowing about the other reference to the buffer and
// freeing it too early.
if (!old_buffer->is_external() && old_size != 0 &&
((new_size < old_buffer->allocation_length()) || old_size == new_size)) {
DCHECK_NOT_NULL(old_buffer->backing_store());
if (old_size != new_size) {
// If adjusting permissions fails, propagate error back to return
// failure to grow.
DCHECK(!isolate->wasm_engine()->memory_tracker()->IsEmptyBackingStore(
old_mem_start));
if (!i::SetPermissions(old_mem_start, new_size,
PageAllocator::kReadWrite)) {
return {};
}
reinterpret_cast<v8::Isolate*>(isolate)
->AdjustAmountOfExternalAllocatedMemory(pages * wasm::kWasmPageSize);
}
// NOTE: We must allocate a new array buffer here because the spec
// assumes that ArrayBuffers do not change size.
void* backing_store = old_buffer->backing_store();
bool is_external = old_buffer->is_external();
// Disconnect buffer early so GC won't free it.
i::wasm::DetachMemoryBuffer(isolate, old_buffer, false);
Handle<JSArrayBuffer> new_buffer =
wasm::SetupArrayBuffer(isolate, backing_store, new_size, is_external);
return new_buffer;
} else {
// We couldn't reuse the old backing store, so create a new one and copy the
// old contents in.
Handle<JSArrayBuffer> new_buffer;
if (!wasm::NewArrayBuffer(isolate, new_size, use_trap_handler)
.ToHandle(&new_buffer)) {
return {};
}
if (old_size == 0) return new_buffer;
memcpy(new_buffer->backing_store(), old_mem_start, old_size);
DCHECK(old_buffer.is_null() || !old_buffer->is_shared());
constexpr bool free_memory = true;
i::wasm::DetachMemoryBuffer(isolate, old_buffer, free_memory);
return new_buffer;
}
}
// May GC, because SetSpecializationMemInfoFrom may GC
void SetInstanceMemory(Isolate* isolate, Handle<WasmInstanceObject> instance,
Handle<JSArrayBuffer> buffer) {
instance->SetRawMemory(reinterpret_cast<byte*>(buffer->backing_store()),
buffer->byte_length()->Number());
#if DEBUG
// To flush out bugs earlier, in DEBUG mode, check that all pages of the
// memory are accessible by reading and writing one byte on each page.
byte* mem_start = instance->memory_start();
uintptr_t mem_size = instance->memory_size();
for (uint32_t offset = 0; offset < mem_size; offset += wasm::kWasmPageSize) {
byte val = mem_start[offset];
USE(val);
mem_start[offset] = val;
}
#endif
}
} // namespace
Handle<WasmMemoryObject> WasmMemoryObject::New(
Isolate* isolate, MaybeHandle<JSArrayBuffer> maybe_buffer,
int32_t maximum) {
// TODO(kschimpf): Do we need to add an argument that defines the
// style of memory the user prefers (with/without trap handling), so
// that the memory will match the style of the compiled wasm module.
// See issue v8:7143
Handle<JSFunction> memory_ctor(
isolate->native_context()->wasm_memory_constructor());
auto memory_obj = Handle<WasmMemoryObject>::cast(
isolate->factory()->NewJSObject(memory_ctor, TENURED));
Handle<JSArrayBuffer> buffer;
if (maybe_buffer.is_null()) {
// If no buffer was provided, create a 0-length one.
buffer = wasm::SetupArrayBuffer(isolate, nullptr, 0, false);
} else {
buffer = maybe_buffer.ToHandleChecked();
// Paranoid check that the buffer size makes sense.
uint32_t mem_size = 0;
CHECK(buffer->byte_length()->ToUint32(&mem_size));
}
memory_obj->set_array_buffer(*buffer);
memory_obj->set_maximum_pages(maximum);
return memory_obj;
}
uint32_t WasmMemoryObject::current_pages() {
uint32_t byte_length;
CHECK(array_buffer()->byte_length()->ToUint32(&byte_length));
return byte_length / wasm::kWasmPageSize;
}
void WasmMemoryObject::AddInstance(Isolate* isolate,
Handle<WasmMemoryObject> memory,
Handle<WasmInstanceObject> instance) {
Handle<FixedArrayOfWeakCells> old_instances =
memory->has_instances()
? Handle<FixedArrayOfWeakCells>(memory->instances(), isolate)
: Handle<FixedArrayOfWeakCells>::null();
Handle<FixedArrayOfWeakCells> new_instances =
FixedArrayOfWeakCells::Add(old_instances, instance);
memory->set_instances(*new_instances);
Handle<JSArrayBuffer> buffer(memory->array_buffer(), isolate);
SetInstanceMemory(isolate, instance, buffer);
}
void WasmMemoryObject::RemoveInstance(Isolate* isolate,
Handle<WasmMemoryObject> memory,
Handle<WasmInstanceObject> instance) {
if (memory->has_instances()) {
memory->instances()->Remove(instance);
}
}
// static
int32_t WasmMemoryObject::Grow(Isolate* isolate,
Handle<WasmMemoryObject> memory_object,
uint32_t pages) {
Handle<JSArrayBuffer> old_buffer(memory_object->array_buffer());
if (!old_buffer->is_growable()) return -1;
uint32_t old_size = 0;
CHECK(old_buffer->byte_length()->ToUint32(&old_size));
DCHECK_EQ(0, old_size % wasm::kWasmPageSize);
Handle<JSArrayBuffer> new_buffer;
uint32_t maximum_pages = FLAG_wasm_max_mem_pages;
if (memory_object->has_maximum_pages()) {
maximum_pages = Min(FLAG_wasm_max_mem_pages,
static_cast<uint32_t>(memory_object->maximum_pages()));
}
// TODO(kschimpf): We need to fix this by adding a field to WasmMemoryObject
// that defines the style of memory being used.
if (!GrowMemoryBuffer(isolate, old_buffer, pages, maximum_pages,
trap_handler::IsTrapHandlerEnabled())
.ToHandle(&new_buffer)) {
return -1;
}
if (memory_object->has_instances()) {
Handle<FixedArrayOfWeakCells> instances(memory_object->instances(),
isolate);
for (int i = 0; i < instances->Length(); i++) {
Object* elem = instances->Get(i);
if (!elem->IsWasmInstanceObject()) continue;
Handle<WasmInstanceObject> instance(WasmInstanceObject::cast(elem),
isolate);
SetInstanceMemory(isolate, instance, new_buffer);
}
}
memory_object->set_array_buffer(*new_buffer);
return old_size / wasm::kWasmPageSize;
}
// static
MaybeHandle<WasmGlobalObject> WasmGlobalObject::New(
Isolate* isolate, MaybeHandle<JSArrayBuffer> maybe_buffer,
wasm::ValueType type, int32_t offset, bool is_mutable) {
Handle<JSFunction> global_ctor(
isolate->native_context()->wasm_global_constructor());
auto global_obj = Handle<WasmGlobalObject>::cast(
isolate->factory()->NewJSObject(global_ctor));
uint32_t type_size = TypeSize(type);
Handle<JSArrayBuffer> buffer;
if (!maybe_buffer.ToHandle(&buffer)) {
// If no buffer was provided, create one long enough for the given type.
buffer =
isolate->factory()->NewJSArrayBuffer(SharedFlag::kNotShared, TENURED);
const bool initialize = true;
if (!JSArrayBuffer::SetupAllocatingData(buffer, isolate, type_size,
initialize)) {
return {};
}
}
// Check that the offset is in bounds.
uint32_t buffer_size = 0;
CHECK(buffer->byte_length()->ToUint32(&buffer_size));
CHECK(offset + type_size <= buffer_size);
global_obj->set_array_buffer(*buffer);
global_obj->set_flags(0);
global_obj->set_type(type);
global_obj->set_offset(offset);
global_obj->set_is_mutable(is_mutable);
return global_obj;
}
void IndirectFunctionTableEntry::clear() {
instance_->indirect_function_table_sig_ids()[index_] = -1;
instance_->indirect_function_table_targets()[index_] = 0;
instance_->indirect_function_table_instances()->set(
index_, instance_->GetIsolate()->heap()->undefined_value());
}
void IndirectFunctionTableEntry::set(int sig_id, WasmInstanceObject* instance,
const wasm::WasmCode* wasm_code) {
TRACE_IFT("IFT entry %p[%d] = {sig_id=%d, instance=%p, target=%p}\n",
instance_, index_, sig_id, instance,
wasm_code->instructions().start());
instance_->indirect_function_table_sig_ids()[index_] = sig_id;
instance_->indirect_function_table_targets()[index_] =
wasm_code->instruction_start();
instance_->indirect_function_table_instances()->set(index_, instance);
}
WasmInstanceObject* IndirectFunctionTableEntry::instance() {
return WasmInstanceObject::cast(
instance_->indirect_function_table_instances()->get(index_));
}
int IndirectFunctionTableEntry::sig_id() {
return instance_->indirect_function_table_sig_ids()[index_];
}
Address IndirectFunctionTableEntry::target() {
return instance_->indirect_function_table_targets()[index_];
}
void ImportedFunctionEntry::set(JSReceiver* callable,
const wasm::WasmCode* wasm_to_js_wrapper) {
TRACE_IFT("Import callable %p[%d] = {callable=%p, target=%p}\n", instance_,
index_, callable, wasm_to_js_wrapper->instructions().start());
DCHECK_EQ(wasm::WasmCode::kWasmToJsWrapper, wasm_to_js_wrapper->kind());
instance_->imported_function_instances()->set(index_, instance_);
instance_->imported_function_callables()->set(index_, callable);
instance_->imported_function_targets()[index_] =
wasm_to_js_wrapper->instruction_start();
}
void ImportedFunctionEntry::set(WasmInstanceObject* instance,
const wasm::WasmCode* wasm_code) {
TRACE_IFT("Import WASM %p[%d] = {instance=%p, target=%p}\n", instance_,
index_, instance, wasm_code->instructions().start());
instance_->imported_function_instances()->set(index_, instance);
instance_->imported_function_callables()->set(
index_, instance_->GetHeap()->undefined_value());
instance_->imported_function_targets()[index_] =
wasm_code->instruction_start();
}
WasmInstanceObject* ImportedFunctionEntry::instance() {
return WasmInstanceObject::cast(
instance_->imported_function_instances()->get(index_));
}
JSReceiver* ImportedFunctionEntry::callable() {
return JSReceiver::cast(
instance_->imported_function_callables()->get(index_));
}
Address ImportedFunctionEntry::target() {
return instance_->imported_function_targets()[index_];
}
bool ImportedFunctionEntry::is_js_receiver_entry() {
return instance_->imported_function_callables()->get(index_)->IsJSReceiver();
}
bool WasmInstanceObject::EnsureIndirectFunctionTableWithMinimumSize(
Handle<WasmInstanceObject> instance, uint32_t minimum_size) {
uint32_t old_size = instance->indirect_function_table_size();
if (old_size >= minimum_size) return false; // Nothing to do.
Isolate* isolate = instance->GetIsolate();
HandleScope scope(isolate);
auto native_allocations = GetNativeAllocations(*instance);
native_allocations->resize_indirect_function_table(isolate, instance,
minimum_size);
return true;
}
void WasmInstanceObject::SetRawMemory(byte* mem_start, uint32_t mem_size) {
DCHECK_LE(mem_size, wasm::kV8MaxWasmMemoryPages * wasm::kWasmPageSize);
uint32_t mem_size64 = mem_size;
uint32_t mem_mask64 = base::bits::RoundUpToPowerOfTwo32(mem_size) - 1;
DCHECK_LE(mem_size, mem_mask64 + 1);
set_memory_start(mem_start);
set_memory_size(mem_size64);
set_memory_mask(mem_mask64);
}
WasmModuleObject* WasmInstanceObject::module_object() {
return compiled_module()->wasm_module();
}
WasmModule* WasmInstanceObject::module() {
return compiled_module()->shared()->module();
}
Handle<WasmDebugInfo> WasmInstanceObject::GetOrCreateDebugInfo(
Handle<WasmInstanceObject> instance) {
if (instance->has_debug_info()) return handle(instance->debug_info());
Handle<WasmDebugInfo> new_info = WasmDebugInfo::New(instance);
DCHECK(instance->has_debug_info());
return new_info;
}
Handle<WasmInstanceObject> WasmInstanceObject::New(
Isolate* isolate, Handle<WasmCompiledModule> compiled_module) {
Handle<JSFunction> instance_cons(
isolate->native_context()->wasm_instance_constructor());
Handle<JSObject> instance_object =
isolate->factory()->NewJSObject(instance_cons, TENURED);
Handle<WasmInstanceObject> instance(
reinterpret_cast<WasmInstanceObject*>(*instance_object), isolate);
// Initialize the imported function arrays.
auto num_imported_functions =
compiled_module->shared()->module()->num_imported_functions;
auto num_imported_mutable_globals =
compiled_module->shared()->module()->num_imported_mutable_globals;
auto native_allocations = Managed<WasmInstanceNativeAllocations>::Allocate(
isolate, instance, num_imported_functions, num_imported_mutable_globals);
instance->set_managed_native_allocations(*native_allocations);
Handle<FixedArray> imported_function_instances =
isolate->factory()->NewFixedArray(num_imported_functions);
instance->set_imported_function_instances(*imported_function_instances);
Handle<FixedArray> imported_function_callables =
isolate->factory()->NewFixedArray(num_imported_functions);
instance->set_imported_function_callables(*imported_function_callables);
instance->SetRawMemory(nullptr, 0);
instance->set_globals_start(nullptr);
instance->set_indirect_function_table_size(0);
instance->set_indirect_function_table_sig_ids(nullptr);
instance->set_indirect_function_table_targets(nullptr);
instance->set_compiled_module(*compiled_module);
return instance;
}
void WasmInstanceObject::ValidateInstancesChainForTesting(
Isolate* isolate, Handle<WasmModuleObject> module_obj, int instance_count) {
CHECK_GE(instance_count, 0);
DisallowHeapAllocation no_gc;
WasmCompiledModule* compiled_module = module_obj->compiled_module();
CHECK_EQ(JSObject::cast(compiled_module->weak_wasm_module()->value()),
*module_obj);
Object* prev = nullptr;
int found_instances = compiled_module->has_instance() ? 1 : 0;
WasmCompiledModule* current_instance = compiled_module;
while (current_instance->has_next_instance()) {
CHECK((prev == nullptr && !current_instance->has_prev_instance()) ||
current_instance->prev_instance() == prev);
CHECK_EQ(current_instance->weak_wasm_module()->value(), *module_obj);
CHECK(current_instance->weak_owning_instance()
->value()
->IsWasmInstanceObject());
prev = current_instance;
current_instance =
WasmCompiledModule::cast(current_instance->next_instance());
++found_instances;
CHECK_LE(found_instances, instance_count);
}
CHECK_EQ(found_instances, instance_count);
}
void WasmInstanceObject::ValidateOrphanedInstanceForTesting(
Isolate* isolate, Handle<WasmInstanceObject> instance) {
DisallowHeapAllocation no_gc;
WasmCompiledModule* compiled_module = instance->compiled_module();
CHECK(compiled_module->has_weak_wasm_module());
CHECK(compiled_module->weak_wasm_module()->cleared());
}
namespace {
void InstanceFinalizer(const v8::WeakCallbackInfo<void>& data) {
DisallowHeapAllocation no_gc;
JSObject** p = reinterpret_cast<JSObject**>(data.GetParameter());
WasmInstanceObject* instance = reinterpret_cast<WasmInstanceObject*>(*p);
Isolate* isolate = reinterpret_cast<Isolate*>(data.GetIsolate());
// If a link to shared memory instances exists, update the list of memory
// instances before the instance is destroyed.
WasmCompiledModule* compiled_module = instance->compiled_module();
wasm::NativeModule* native_module = compiled_module->GetNativeModule();
if (native_module) {
TRACE("Finalizing %zu {\n", native_module->instance_id);
} else {
TRACE("Finalized already cleaned up compiled module\n");
}
WeakCell* weak_wasm_module = compiled_module->weak_wasm_module();
// Since the order of finalizers is not guaranteed, it can be the case
// that {instance->compiled_module()->module()}, which is a
// {Managed<WasmModule>} has been collected earlier in this GC cycle.
// Weak references to this instance won't be cleared until
// the next GC cycle, so we need to manually break some links (such as
// the weak references from {WasmMemoryObject::instances}.
if (instance->has_memory_object()) {
WasmMemoryObject::RemoveInstance(isolate, handle(instance->memory_object()),
handle(instance));
}
// weak_wasm_module may have been cleared, meaning the module object
// was GC-ed. We still want to maintain the links between instances, to
// release the WasmCompiledModule corresponding to the WasmModuleInstance
// being finalized here.
WasmModuleObject* wasm_module = nullptr;
if (!weak_wasm_module->cleared()) {
wasm_module = WasmModuleObject::cast(weak_wasm_module->value());
WasmCompiledModule* current_template = wasm_module->compiled_module();
DCHECK(!current_template->has_prev_instance());
if (current_template == compiled_module) {
if (!compiled_module->has_next_instance()) {
WasmCompiledModule::Reset(isolate, compiled_module);
} else {
WasmModuleObject::cast(wasm_module)
->set_compiled_module(compiled_module->next_instance());
}
}
}
// Free raw C++ memory associated with the instance.
GetNativeAllocations(instance)->free();
compiled_module->RemoveFromChain();
GlobalHandles::Destroy(reinterpret_cast<Object**>(p));
TRACE("}\n");
}
} // namespace
void WasmInstanceObject::InstallFinalizer(Isolate* isolate,
Handle<WasmInstanceObject> instance) {
Handle<Object> global_handle = isolate->global_handles()->Create(*instance);
GlobalHandles::MakeWeak(global_handle.location(), global_handle.location(),
InstanceFinalizer, v8::WeakCallbackType::kFinalizer);
}
bool WasmExportedFunction::IsWasmExportedFunction(Object* object) {
if (!object->IsJSFunction()) return false;
Handle<JSFunction> js_function(JSFunction::cast(object));
if (Code::JS_TO_WASM_FUNCTION != js_function->code()->kind()) return false;
#ifdef DEBUG
// Any function having code of {JS_TO_WASM_FUNCTION} kind must be an exported
// function and hence will have a property holding the instance object.
Handle<Symbol> symbol(
js_function->GetIsolate()->factory()->wasm_instance_symbol());
MaybeHandle<Object> result =
JSObject::GetPropertyOrElement(js_function, symbol);
DCHECK(result.ToHandleChecked()->IsWasmInstanceObject());
#endif
return true;
}
WasmExportedFunction* WasmExportedFunction::cast(Object* object) {
DCHECK(IsWasmExportedFunction(object));
return reinterpret_cast<WasmExportedFunction*>(object);
}
WasmInstanceObject* WasmExportedFunction::instance() {
DisallowHeapAllocation no_allocation;
Handle<Symbol> symbol(GetIsolate()->factory()->wasm_instance_symbol());
MaybeHandle<Object> result =
JSObject::GetPropertyOrElement(handle(this), symbol);
return WasmInstanceObject::cast(*(result.ToHandleChecked()));
}
int WasmExportedFunction::function_index() {
DisallowHeapAllocation no_allocation;
Handle<Symbol> symbol = GetIsolate()->factory()->wasm_function_index_symbol();
MaybeHandle<Object> result =
JSObject::GetPropertyOrElement(handle(this), symbol);
return result.ToHandleChecked()->Number();
}
Handle<WasmExportedFunction> WasmExportedFunction::New(
Isolate* isolate, Handle<WasmInstanceObject> instance,
MaybeHandle<String> maybe_name, int func_index, int arity,
Handle<Code> export_wrapper) {
DCHECK_EQ(Code::JS_TO_WASM_FUNCTION, export_wrapper->kind());
Handle<String> name;
if (!maybe_name.ToHandle(&name)) {
EmbeddedVector<char, 16> buffer;
int length = SNPrintF(buffer, "%d", func_index);
name = isolate->factory()
->NewStringFromOneByte(
Vector<uint8_t>::cast(buffer.SubVector(0, length)))
.ToHandleChecked();
}
NewFunctionArgs args = NewFunctionArgs::ForWasm(
name, export_wrapper, isolate->sloppy_function_without_prototype_map());
Handle<JSFunction> js_function = isolate->factory()->NewFunction(args);
// According to the spec, exported functions should not have a [[Construct]]
// method.
DCHECK(!js_function->IsConstructor());
js_function->shared()->set_length(arity);
js_function->shared()->set_internal_formal_parameter_count(arity);
Handle<Symbol> instance_symbol(isolate->factory()->wasm_instance_symbol());
JSObject::AddProperty(js_function, instance_symbol, instance, DONT_ENUM);
Handle<Symbol> function_index_symbol(
isolate->factory()->wasm_function_index_symbol());
JSObject::AddProperty(js_function, function_index_symbol,
isolate->factory()->NewNumber(func_index), DONT_ENUM);
return Handle<WasmExportedFunction>::cast(js_function);
}
wasm::WasmCode* WasmExportedFunction::GetWasmCode() {
DisallowHeapAllocation no_gc;
Handle<Code> export_wrapper_code = handle(this->code());
DCHECK_EQ(export_wrapper_code->kind(), Code::JS_TO_WASM_FUNCTION);
int mask = RelocInfo::ModeMask(RelocInfo::JS_TO_WASM_CALL);
RelocIterator it(*export_wrapper_code, mask);
DCHECK(!it.done());
wasm::WasmCode* target =
GetIsolate()->wasm_engine()->code_manager()->LookupCode(
it.rinfo()->js_to_wasm_address());
#ifdef DEBUG
// There should only be this one call to wasm code.
it.next();
DCHECK(it.done());
#endif
return target;
}
WasmModule* WasmSharedModuleData::module() const {
return Managed<WasmModule>::cast(managed_module())->raw();
}
Handle<WasmSharedModuleData> WasmSharedModuleData::New(
Isolate* isolate, Handle<Foreign> managed_module,
Handle<SeqOneByteString> module_bytes, Handle<Script> script,
Handle<ByteArray> asm_js_offset_table) {
Handle<WasmSharedModuleData> data = Handle<WasmSharedModuleData>::cast(
isolate->factory()->NewStruct(WASM_SHARED_MODULE_DATA_TYPE, TENURED));
data->set_managed_module(*managed_module);
if (!module_bytes.is_null()) {
data->set_module_bytes(*module_bytes);
}
if (!script.is_null()) {
data->set_script(*script);
}
if (!asm_js_offset_table.is_null()) {
data->set_asm_js_offset_table(*asm_js_offset_table);
}
return data;
}
bool WasmSharedModuleData::is_asm_js() {
bool asm_js = module()->is_asm_js();
DCHECK_EQ(asm_js, script()->IsUserJavaScript());
DCHECK_EQ(asm_js, has_asm_js_offset_table());
return asm_js;
}
namespace {
int GetBreakpointPos(Isolate* isolate, Object* break_point_info_or_undef) {
if (break_point_info_or_undef->IsUndefined(isolate)) return kMaxInt;
return BreakPointInfo::cast(break_point_info_or_undef)->source_position();
}
int FindBreakpointInfoInsertPos(Isolate* isolate,
Handle<FixedArray> breakpoint_infos,
int position) {
// Find insert location via binary search, taking care of undefined values on
// the right. Position is always greater than zero.
DCHECK_LT(0, position);
int left = 0; // inclusive
int right = breakpoint_infos->length(); // exclusive
while (right - left > 1) {
int mid = left + (right - left) / 2;
Object* mid_obj = breakpoint_infos->get(mid);
if (GetBreakpointPos(isolate, mid_obj) <= position) {
left = mid;
} else {
right = mid;
}
}
int left_pos = GetBreakpointPos(isolate, breakpoint_infos->get(left));
return left_pos < position ? left + 1 : left;
}
} // namespace
void WasmSharedModuleData::AddBreakpoint(Handle<WasmSharedModuleData> shared,
int position,
Handle<BreakPoint> break_point) {
Isolate* isolate = shared->GetIsolate();
Handle<FixedArray> breakpoint_infos;
if (shared->has_breakpoint_infos()) {
breakpoint_infos = handle(shared->breakpoint_infos(), isolate);
} else {
breakpoint_infos = isolate->factory()->NewFixedArray(4, TENURED);
shared->set_breakpoint_infos(*breakpoint_infos);
}
int insert_pos =
FindBreakpointInfoInsertPos(isolate, breakpoint_infos, position);
// If a BreakPointInfo object already exists for this position, add the new
// breakpoint object and return.
if (insert_pos < breakpoint_infos->length() &&
GetBreakpointPos(isolate, breakpoint_infos->get(insert_pos)) ==
position) {
Handle<BreakPointInfo> old_info(
BreakPointInfo::cast(breakpoint_infos->get(insert_pos)), isolate);
BreakPointInfo::SetBreakPoint(old_info, break_point);
return;
}
// Enlarge break positions array if necessary.
bool need_realloc = !breakpoint_infos->get(breakpoint_infos->length() - 1)
->IsUndefined(isolate);
Handle<FixedArray> new_breakpoint_infos = breakpoint_infos;
if (need_realloc) {
new_breakpoint_infos = isolate->factory()->NewFixedArray(
2 * breakpoint_infos->length(), TENURED);
shared->set_breakpoint_infos(*new_breakpoint_infos);
// Copy over the entries [0, insert_pos).
for (int i = 0; i < insert_pos; ++i)
new_breakpoint_infos->set(i, breakpoint_infos->get(i));
}
// Move elements [insert_pos, ...] up by one.
for (int i = breakpoint_infos->length() - 1; i >= insert_pos; --i) {
Object* entry = breakpoint_infos->get(i);
if (entry->IsUndefined(isolate)) continue;
new_breakpoint_infos->set(i + 1, entry);
}
// Generate new BreakpointInfo.
Handle<BreakPointInfo> breakpoint_info =
isolate->factory()->NewBreakPointInfo(position);
BreakPointInfo::SetBreakPoint(breakpoint_info, break_point);
// Now insert new position at insert_pos.
new_breakpoint_infos->set(insert_pos, *breakpoint_info);
}
void WasmSharedModuleData::SetBreakpointsOnNewInstance(
Handle<WasmSharedModuleData> shared, Handle<WasmInstanceObject> instance) {
if (!shared->has_breakpoint_infos()) return;
Isolate* isolate = shared->GetIsolate();
Handle<WasmDebugInfo> debug_info =
WasmInstanceObject::GetOrCreateDebugInfo(instance);
Handle<FixedArray> breakpoint_infos(shared->breakpoint_infos(), isolate);
// If the array exists, it should not be empty.
DCHECK_LT(0, breakpoint_infos->length());
for (int i = 0, e = breakpoint_infos->length(); i < e; ++i) {
Handle<Object> obj(breakpoint_infos->get(i), isolate);
if (obj->IsUndefined(isolate)) {
for (; i < e; ++i) {
DCHECK(breakpoint_infos->get(i)->IsUndefined(isolate));
}
break;
}
Handle<BreakPointInfo> breakpoint_info = Handle<BreakPointInfo>::cast(obj);
int position = breakpoint_info->source_position();
// Find the function for this breakpoint, and set the breakpoint.
int func_index = shared->GetContainingFunction(position);
DCHECK_LE(0, func_index);
WasmFunction& func = shared->module()->functions[func_index];
int offset_in_func = position - func.code.offset();
WasmDebugInfo::SetBreakpoint(debug_info, func_index, offset_in_func);
}
}
namespace {
enum AsmJsOffsetTableEntryLayout {
kOTEByteOffset,
kOTECallPosition,
kOTENumberConvPosition,
kOTESize
};
Handle<ByteArray> GetDecodedAsmJsOffsetTable(
Handle<WasmSharedModuleData> shared, Isolate* isolate) {
DCHECK(shared->is_asm_js());
Handle<ByteArray> offset_table(shared->asm_js_offset_table(), isolate);
// The last byte in the asm_js_offset_tables ByteArray tells whether it is
// still encoded (0) or decoded (1).
enum AsmJsTableType : int { Encoded = 0, Decoded = 1 };
int table_type = offset_table->get(offset_table->length() - 1);
DCHECK(table_type == Encoded || table_type == Decoded);
if (table_type == Decoded) return offset_table;
wasm::AsmJsOffsetsResult asm_offsets;
{
DisallowHeapAllocation no_gc;
byte* bytes_start = offset_table->GetDataStartAddress();
byte* bytes_end = reinterpret_cast<byte*>(
reinterpret_cast<Address>(bytes_start) + offset_table->length() - 1);
asm_offsets = wasm::DecodeAsmJsOffsets(bytes_start, bytes_end);
}
// Wasm bytes must be valid and must contain asm.js offset table.
DCHECK(asm_offsets.ok());
DCHECK_GE(kMaxInt, asm_offsets.val.size());
int num_functions = static_cast<int>(asm_offsets.val.size());
int num_imported_functions =
static_cast<int>(shared->module()->num_imported_functions);
DCHECK_EQ(shared->module()->functions.size(),
static_cast<size_t>(num_functions) + num_imported_functions);
int num_entries = 0;
for (int func = 0; func < num_functions; ++func) {
size_t new_size = asm_offsets.val[func].size();
DCHECK_LE(new_size, static_cast<size_t>(kMaxInt) - num_entries);
num_entries += static_cast<int>(new_size);
}
// One byte to encode that this is a decoded table.
DCHECK_GE(kMaxInt,
1 + static_cast<uint64_t>(num_entries) * kOTESize * kIntSize);
int total_size = 1 + num_entries * kOTESize * kIntSize;
Handle<ByteArray> decoded_table =
isolate->factory()->NewByteArray(total_size, TENURED);
decoded_table->set(total_size - 1, AsmJsTableType::Decoded);
shared->set_asm_js_offset_table(*decoded_table);
int idx = 0;
std::vector<WasmFunction>& wasm_funs = shared->module()->functions;
for (int func = 0; func < num_functions; ++func) {
std::vector<wasm::AsmJsOffsetEntry>& func_asm_offsets =
asm_offsets.val[func];
if (func_asm_offsets.empty()) continue;
int func_offset = wasm_funs[num_imported_functions + func].code.offset();
for (wasm::AsmJsOffsetEntry& e : func_asm_offsets) {
// Byte offsets must be strictly monotonously increasing:
DCHECK_IMPLIES(idx > 0, func_offset + e.byte_offset >
decoded_table->get_int(idx - kOTESize));
decoded_table->set_int(idx + kOTEByteOffset, func_offset + e.byte_offset);
decoded_table->set_int(idx + kOTECallPosition, e.source_position_call);
decoded_table->set_int(idx + kOTENumberConvPosition,
e.source_position_number_conversion);
idx += kOTESize;
}
}
DCHECK_EQ(total_size, idx * kIntSize + 1);
return decoded_table;
}
} // namespace
int WasmSharedModuleData::GetSourcePosition(Handle<WasmSharedModuleData> shared,
uint32_t func_index,
uint32_t byte_offset,
bool is_at_number_conversion) {
Isolate* isolate = shared->GetIsolate();
const WasmModule* module = shared->module();
if (!module->is_asm_js()) {
// for non-asm.js modules, we just add the function's start offset
// to make a module-relative position.
return byte_offset + shared->GetFunctionOffset(func_index);
}
// asm.js modules have an additional offset table that must be searched.
Handle<ByteArray> offset_table = GetDecodedAsmJsOffsetTable(shared, isolate);
DCHECK_LT(func_index, module->functions.size());
uint32_t func_code_offset = module->functions[func_index].code.offset();
uint32_t total_offset = func_code_offset + byte_offset;
// Binary search for the total byte offset.
int left = 0; // inclusive
int right = offset_table->length() / kIntSize / kOTESize; // exclusive
DCHECK_LT(left, right);
while (right - left > 1) {
int mid = left + (right - left) / 2;
int mid_entry = offset_table->get_int(kOTESize * mid);
DCHECK_GE(kMaxInt, mid_entry);
if (static_cast<uint32_t>(mid_entry) <= total_offset) {
left = mid;
} else {
right = mid;
}
}
// There should be an entry for each position that could show up on the stack
// trace:
DCHECK_EQ(total_offset, offset_table->get_int(kOTESize * left));
int idx = is_at_number_conversion ? kOTENumberConvPosition : kOTECallPosition;
return offset_table->get_int(kOTESize * left + idx);
}
v8::debug::WasmDisassembly WasmSharedModuleData::DisassembleFunction(
int func_index) {
DisallowHeapAllocation no_gc;
if (func_index < 0 ||
static_cast<uint32_t>(func_index) >= module()->functions.size())
return {};
SeqOneByteString* module_bytes_str = module_bytes();
Vector<const byte> module_bytes(module_bytes_str->GetChars(),
module_bytes_str->length());
std::ostringstream disassembly_os;
v8::debug::WasmDisassembly::OffsetTable offset_table;
PrintWasmText(module(), module_bytes, static_cast<uint32_t>(func_index),
disassembly_os, &offset_table);
return {disassembly_os.str(), std::move(offset_table)};
}
bool WasmSharedModuleData::GetPossibleBreakpoints(
const v8::debug::Location& start, const v8::debug::Location& end,
std::vector<v8::debug::BreakLocation>* locations) {
DisallowHeapAllocation no_gc;
std::vector<WasmFunction>& functions = module()->functions;
if (start.GetLineNumber() < 0 || start.GetColumnNumber() < 0 ||
(!end.IsEmpty() &&
(end.GetLineNumber() < 0 || end.GetColumnNumber() < 0)))
return false;
// start_func_index, start_offset and end_func_index is inclusive.
// end_offset is exclusive.
// start_offset and end_offset are module-relative byte offsets.
uint32_t start_func_index = start.GetLineNumber();
if (start_func_index >= functions.size()) return false;
int start_func_len = functions[start_func_index].code.length();
if (start.GetColumnNumber() > start_func_len) return false;
uint32_t start_offset =
functions[start_func_index].code.offset() + start.GetColumnNumber();
uint32_t end_func_index;
uint32_t end_offset;
if (end.IsEmpty()) {
// Default: everything till the end of the Script.
end_func_index = static_cast<uint32_t>(functions.size() - 1);
end_offset = functions[end_func_index].code.end_offset();
} else {
// If end is specified: Use it and check for valid input.
end_func_index = static_cast<uint32_t>(end.GetLineNumber());
// Special case: Stop before the start of the next function. Change to: Stop
// at the end of the function before, such that we don't disassemble the
// next function also.
if (end.GetColumnNumber() == 0 && end_func_index > 0) {
--end_func_index;
end_offset = functions[end_func_index].code.end_offset();
} else {
if (end_func_index >= functions.size()) return false;
end_offset =
functions[end_func_index].code.offset() + end.GetColumnNumber();
if (end_offset > functions[end_func_index].code.end_offset())
return false;
}
}
AccountingAllocator alloc;
Zone tmp(&alloc, ZONE_NAME);
const byte* module_start = module_bytes()->GetChars();
for (uint32_t func_idx = start_func_index; func_idx <= end_func_index;
++func_idx) {
WasmFunction& func = functions[func_idx];
if (func.code.length() == 0) continue;
wasm::BodyLocalDecls locals(&tmp);
wasm::BytecodeIterator iterator(module_start + func.code.offset(),
module_start + func.code.end_offset(),
&locals);
DCHECK_LT(0u, locals.encoded_size);
for (uint32_t offset : iterator.offsets()) {
uint32_t total_offset = func.code.offset() + offset;
if (total_offset >= end_offset) {
DCHECK_EQ(end_func_index, func_idx);
break;
}
if (total_offset < start_offset) continue;
locations->emplace_back(func_idx, offset, debug::kCommonBreakLocation);
}
}
return true;
}
MaybeHandle<FixedArray> WasmSharedModuleData::CheckBreakPoints(
Isolate* isolate, Handle<WasmSharedModuleData> shared, int position) {
if (!shared->has_breakpoint_infos()) return {};
Handle<FixedArray> breakpoint_infos(shared->breakpoint_infos(), isolate);
int insert_pos =
FindBreakpointInfoInsertPos(isolate, breakpoint_infos, position);
if (insert_pos >= breakpoint_infos->length()) return {};
Handle<Object> maybe_breakpoint_info(breakpoint_infos->get(insert_pos),
isolate);
if (maybe_breakpoint_info->IsUndefined(isolate)) return {};
Handle<BreakPointInfo> breakpoint_info =
Handle<BreakPointInfo>::cast(maybe_breakpoint_info);
if (breakpoint_info->source_position() != position) return {};
// There is no support for conditional break points. Just assume that every
// break point always hits.
Handle<Object> break_points(breakpoint_info->break_points(), isolate);
if (break_points->IsFixedArray()) {
return Handle<FixedArray>::cast(break_points);
}
Handle<FixedArray> break_points_hit = isolate->factory()->NewFixedArray(1);
break_points_hit->set(0, *break_points);
return break_points_hit;
}
Handle<WasmCompiledModule> WasmCompiledModule::New(
Isolate* isolate, WasmModule* module, Handle<FixedArray> export_wrappers,
wasm::ModuleEnv& env) {
Handle<WasmCompiledModule> compiled_module = Handle<WasmCompiledModule>::cast(
isolate->factory()->NewStruct(WASM_COMPILED_MODULE_TYPE, TENURED));
Handle<WeakCell> weak_native_context =
isolate->factory()->NewWeakCell(isolate->native_context());
compiled_module->set_weak_native_context(*weak_native_context);
compiled_module->set_use_trap_handler(env.use_trap_handler);
if (!export_wrappers.is_null()) {
compiled_module->set_export_wrappers(*export_wrappers);
}
compiled_module->set_weak_owning_instance(isolate->heap()->empty_weak_cell());
{
auto native_module =
isolate->wasm_engine()->code_manager()->NewNativeModule(*module, env);
Handle<Foreign> native_module_wrapper =
Managed<wasm::NativeModule>::FromUniquePtr(isolate,
std::move(native_module));
compiled_module->set_native_module(*native_module_wrapper);
compiled_module->GetNativeModule()->SetCompiledModule(compiled_module);
}
// TODO(mtrofin): copy the rest of the specialization parameters over.
// We're currently OK because we're only using defaults.
return compiled_module;
}
Handle<WasmCompiledModule> WasmCompiledModule::Clone(
Isolate* isolate, Handle<WasmCompiledModule> module) {
Handle<FixedArray> code_copy;
Handle<WasmCompiledModule> ret = Handle<WasmCompiledModule>::cast(
isolate->factory()->NewStruct(WASM_COMPILED_MODULE_TYPE, TENURED));
ret->set_shared(module->shared());
ret->set_weak_native_context(module->weak_native_context());
ret->set_export_wrappers(module->export_wrappers());
ret->set_weak_wasm_module(module->weak_wasm_module());
ret->set_weak_owning_instance(isolate->heap()->empty_weak_cell());
ret->set_native_module(module->native_module());
ret->set_use_trap_handler(module->use_trap_handler());
Handle<FixedArray> export_copy = isolate->factory()->CopyFixedArray(
handle(module->export_wrappers(), isolate));
ret->set_export_wrappers(*export_copy);
auto native_module = module->GetNativeModule()->Clone();
// construct the wrapper in 2 steps, because its construction may trigger GC,
// which would shift the this pointer in set_native_module.
Handle<Foreign> native_module_wrapper =
Managed<wasm::NativeModule>::FromUniquePtr(isolate,
std::move(native_module));
ret->set_native_module(*native_module_wrapper);
ret->GetNativeModule()->SetCompiledModule(ret);
return ret;
}
wasm::NativeModule* WasmCompiledModule::GetNativeModule() const {
if (!has_native_module()) return nullptr;
return Managed<wasm::NativeModule>::cast(native_module())->raw();
}
void WasmCompiledModule::Reset(Isolate* isolate,
WasmCompiledModule* compiled_module) {
DisallowHeapAllocation no_gc;
compiled_module->reset_prev_instance();
compiled_module->reset_next_instance();
wasm::NativeModule* native_module = compiled_module->GetNativeModule();
if (native_module == nullptr) return;
native_module->SetExecutable(false);
TRACE("Resetting %zu\n", native_module->instance_id);
if (compiled_module->use_trap_handler()) {
native_module->ReleaseProtectedInstructions();
}
// Patch code to update memory references, global references, and function
// table references.
wasm::CodeSpecialization code_specialization;
for (uint32_t i = native_module->num_imported_functions(),
end = native_module->FunctionCount();
i < end; ++i) {
wasm::WasmCode* code = native_module->GetCode(i);
// Skip lazy compile stubs.
if (code == nullptr || code->kind() != wasm::WasmCode::kFunction) continue;
bool changed = code_specialization.ApplyToWasmCode(code, SKIP_ICACHE_FLUSH);
// TODO(wasm): Check if this is faster than passing FLUSH_ICACHE_IF_NEEDED
// above.
if (changed) {
Assembler::FlushICache(code->instructions().start(),
code->instructions().size());
}
}
}
MaybeHandle<String> WasmSharedModuleData::ExtractUtf8StringFromModuleBytes(
Isolate* isolate, Handle<WasmSharedModuleData> shared,
wasm::WireBytesRef ref) {
// TODO(wasm): cache strings from modules if it's a performance win.
Handle<SeqOneByteString> module_bytes(shared->module_bytes(), isolate);
return ExtractUtf8StringFromModuleBytes(isolate, module_bytes, ref);
}
MaybeHandle<String> WasmSharedModuleData::ExtractUtf8StringFromModuleBytes(
Isolate* isolate, Handle<SeqOneByteString> module_bytes,
wasm::WireBytesRef ref) {
DCHECK_GE(module_bytes->length(), ref.end_offset());
// UTF8 validation happens at decode time.
DCHECK(unibrow::Utf8::ValidateEncoding(
reinterpret_cast<const byte*>(module_bytes->GetCharsAddress() +
ref.offset()),
ref.length()));
DCHECK_GE(kMaxInt, ref.offset());
DCHECK_GE(kMaxInt, ref.length());
return isolate->factory()->NewStringFromUtf8SubString(
module_bytes, static_cast<int>(ref.offset()),
static_cast<int>(ref.length()));
}
void WasmCompiledModule::PrintInstancesChain() {
#if DEBUG
if (!FLAG_trace_wasm_instances) return;
for (WasmCompiledModule* current = this; current != nullptr;) {
PrintF("->%zu", current->GetNativeModule()->instance_id);
if (!current->has_next_instance()) break;
current = current->next_instance();
}
PrintF("\n");
#endif
}
void WasmCompiledModule::InsertInChain(WasmModuleObject* module) {
DisallowHeapAllocation no_gc;
WasmCompiledModule* original = module->compiled_module();
set_next_instance(original);
original->set_prev_instance(this);
set_weak_wasm_module(original->weak_wasm_module());
}
void WasmCompiledModule::RemoveFromChain() {
DisallowHeapAllocation no_gc;
Isolate* isolate = GetIsolate();
Object* next = raw_next_instance();
Object* prev = raw_prev_instance();
if (!prev->IsUndefined(isolate)) {
WasmCompiledModule::cast(prev)->set_raw_next_instance(next);
}
if (!next->IsUndefined(isolate)) {
WasmCompiledModule::cast(next)->set_raw_prev_instance(prev);
}
}
void WasmCompiledModule::ReinitializeAfterDeserialization(
Isolate* isolate, Handle<WasmCompiledModule> compiled_module) {
// Reset, but don't delete any global handles, because their owning instance
// may still be active.
WasmCompiledModule::Reset(isolate, *compiled_module);
}
MaybeHandle<String> WasmSharedModuleData::GetModuleNameOrNull(
Isolate* isolate, Handle<WasmSharedModuleData> shared) {
WasmModule* module = shared->module();
if (!module->name.is_set()) return {};
return ExtractUtf8StringFromModuleBytes(isolate, shared, module->name);
}
MaybeHandle<String> WasmSharedModuleData::GetFunctionNameOrNull(
Isolate* isolate, Handle<WasmSharedModuleData> shared,
uint32_t func_index) {
DCHECK_LT(func_index, shared->module()->functions.size());
wasm::WireBytesRef name =
shared->module()->LookupName(shared->module_bytes(), func_index);
if (!name.is_set()) return {};
return ExtractUtf8StringFromModuleBytes(isolate, shared, name);
}
Handle<String> WasmSharedModuleData::GetFunctionName(
Isolate* isolate, Handle<WasmSharedModuleData> shared,
uint32_t func_index) {
MaybeHandle<String> name = GetFunctionNameOrNull(isolate, shared, func_index);
if (!name.is_null()) return name.ToHandleChecked();
return isolate->factory()->NewStringFromStaticChars("<WASM UNNAMED>");
}
Vector<const uint8_t> WasmSharedModuleData::GetRawFunctionName(
uint32_t func_index) {
DCHECK_GT(module()->functions.size(), func_index);
SeqOneByteString* bytes = module_bytes();
wasm::WireBytesRef name = module()->LookupName(bytes, func_index);
DCHECK_GE(bytes->length(), name.end_offset());
return Vector<const uint8_t>(
reinterpret_cast<uint8_t*>(bytes->GetCharsAddress() + name.offset()),
name.length());
}
int WasmSharedModuleData::GetFunctionOffset(uint32_t func_index) {
std::vector<WasmFunction>& functions = module()->functions;
if (static_cast<uint32_t>(func_index) >= functions.size()) return -1;
DCHECK_GE(kMaxInt, functions[func_index].code.offset());
return static_cast<int>(functions[func_index].code.offset());
}
int WasmSharedModuleData::GetContainingFunction(uint32_t byte_offset) {
std::vector<WasmFunction>& functions = module()->functions;
// Binary search for a function containing the given position.
int left = 0; // inclusive
int right = static_cast<int>(functions.size()); // exclusive
if (right == 0) return false;
while (right - left > 1) {
int mid = left + (right - left) / 2;
if (functions[mid].code.offset() <= byte_offset) {
left = mid;
} else {
right = mid;
}
}
// If the found function does not contains the given position, return -1.
WasmFunction& func = functions[left];
if (byte_offset < func.code.offset() ||
byte_offset >= func.code.end_offset()) {
return -1;
}
return left;
}
bool WasmSharedModuleData::GetPositionInfo(uint32_t position,
Script::PositionInfo* info) {
int func_index = GetContainingFunction(position);
if (func_index < 0) return false;
WasmFunction& function = module()->functions[func_index];
info->line = func_index;
info->column = position - function.code.offset();
info->line_start = function.code.offset();
info->line_end = function.code.end_offset();
return true;
}
bool WasmCompiledModule::SetBreakPoint(
Handle<WasmCompiledModule> compiled_module, int* position,
Handle<BreakPoint> break_point) {
Isolate* isolate = compiled_module->GetIsolate();
Handle<WasmSharedModuleData> shared(compiled_module->shared(), isolate);
// Find the function for this breakpoint.
int func_index = shared->GetContainingFunction(*position);
if (func_index < 0) return false;
WasmFunction& func = shared->module()->functions[func_index];
int offset_in_func = *position - func.code.offset();
// According to the current design, we should only be called with valid
// breakable positions.
DCHECK(IsBreakablePosition(*shared, func_index, offset_in_func));
// Insert new break point into break_positions of shared module data.
WasmSharedModuleData::AddBreakpoint(shared, *position, break_point);
// Iterate over all instances of this module and tell them to set this new
// breakpoint.
for (Handle<WasmInstanceObject> instance :
iterate_compiled_module_instance_chain(isolate, compiled_module)) {
Handle<WasmDebugInfo> debug_info =
WasmInstanceObject::GetOrCreateDebugInfo(instance);
WasmDebugInfo::SetBreakpoint(debug_info, func_index, offset_in_func);
}
return true;
}
void WasmCompiledModule::LogWasmCodes(Isolate* isolate) {
if (!wasm::WasmCode::ShouldBeLogged(isolate)) return;
wasm::NativeModule* native_module = GetNativeModule();
if (native_module == nullptr) return;
const uint32_t number_of_codes = native_module->FunctionCount();
if (has_shared()) {
Handle<WasmSharedModuleData> shared_handle(shared(), isolate);
for (uint32_t i = 0; i < number_of_codes; i++) {
wasm::WasmCode* code = native_module->GetCode(i);
if (code == nullptr) continue;
code->LogCode(isolate);
}
}
}
#undef TRACE
#undef TRACE_IFT
} // namespace internal
} // namespace v8