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chromium / v8 / v8 / acb080bc00b217d3dc85086d049c7c6f94ef57d7 / . / src / wasm / wasm-module.cc
blob: 1533f2412f7aa0a61b662a3f5eb28e89b1e7ed74 [file] [log] [blame]
// 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 <memory>
#include "src/asmjs/asm-js.h"
#include "src/assembler-inl.h"
#include "src/base/atomic-utils.h"
#include "src/base/utils/random-number-generator.h"
#include "src/code-stubs.h"
#include "src/compiler/wasm-compiler.h"
#include "src/debug/interface-types.h"
#include "src/frames-inl.h"
#include "src/objects.h"
#include "src/property-descriptor.h"
#include "src/simulator.h"
#include "src/snapshot/snapshot.h"
#include "src/trap-handler/trap-handler.h"
#include "src/v8.h"
#include "src/wasm/function-body-decoder.h"
#include "src/wasm/module-decoder.h"
#include "src/wasm/wasm-code-specialization.h"
#include "src/wasm/wasm-js.h"
#include "src/wasm/wasm-limits.h"
#include "src/wasm/wasm-module.h"
#include "src/wasm/wasm-objects.h"
#include "src/wasm/wasm-result.h"
using namespace v8::internal;
using namespace v8::internal::wasm;
namespace base = v8::base;
#define TRACE(...) \
do { \
if (FLAG_trace_wasm_instances) PrintF(__VA_ARGS__); \
} while (false)
#define TRACE_CHAIN(instance) \
do { \
instance->PrintInstancesChain(); \
} while (false)
#define TRACE_COMPILE(...) \
do { \
if (FLAG_trace_wasm_compiler) PrintF(__VA_ARGS__); \
} while (false)
namespace {
static const int kInvalidSigIndex = -1;
byte* raw_buffer_ptr(MaybeHandle<JSArrayBuffer> buffer, int offset) {
return static_cast<byte*>(buffer.ToHandleChecked()->backing_store()) + offset;
}
static void RecordStats(Isolate* isolate, Code* code, bool is_sync) {
if (is_sync) {
// TODO(karlschimpf): Make this work when asynchronous.
// https://bugs.chromium.org/p/v8/issues/detail?id=6361
isolate->counters()->wasm_generated_code_size()->Increment(
code->body_size());
isolate->counters()->wasm_reloc_size()->Increment(
code->relocation_info()->length());
}
}
static void RecordStats(Isolate* isolate, Handle<FixedArray> functions,
bool is_sync) {
DisallowHeapAllocation no_gc;
for (int i = 0; i < functions->length(); ++i) {
RecordStats(isolate, Code::cast(functions->get(i)), is_sync);
}
}
void* TryAllocateBackingStore(Isolate* isolate, size_t size,
bool enable_guard_regions, void*& allocation_base,
size_t& allocation_length) {
// TODO(eholk): Right now enable_guard_regions has no effect on 32-bit
// systems. It may be safer to fail instead, given that other code might do
// things that would be unsafe if they expected guard pages where there
// weren't any.
if (enable_guard_regions && kGuardRegionsSupported) {
// TODO(eholk): On Windows we want to make sure we don't commit the guard
// pages yet.
// We always allocate the largest possible offset into the heap, so the
// addressable memory after the guard page can be made inaccessible.
allocation_length = RoundUp(kWasmMaxHeapOffset, base::OS::CommitPageSize());
DCHECK_EQ(0, size % base::OS::CommitPageSize());
// AllocateGuarded makes the whole region inaccessible by default.
allocation_base =
isolate->array_buffer_allocator()->Reserve(allocation_length);
if (allocation_base == nullptr) {
return nullptr;
}
void* memory = allocation_base;
// Make the part we care about accessible.
isolate->array_buffer_allocator()->SetProtection(
memory, size, v8::ArrayBuffer::Allocator::Protection::kReadWrite);
reinterpret_cast<v8::Isolate*>(isolate)
->AdjustAmountOfExternalAllocatedMemory(size);
return memory;
} else {
void* memory = isolate->array_buffer_allocator()->Allocate(size);
allocation_base = memory;
allocation_length = size;
return memory;
}
}
void FlushICache(Isolate* isolate, Handle<FixedArray> code_table) {
for (int i = 0; i < code_table->length(); ++i) {
Handle<Code> code = code_table->GetValueChecked<Code>(isolate, i);
Assembler::FlushICache(isolate, code->instruction_start(),
code->instruction_size());
}
}
Handle<Script> CreateWasmScript(Isolate* isolate,
const ModuleWireBytes& wire_bytes) {
Handle<Script> script =
isolate->factory()->NewScript(isolate->factory()->empty_string());
script->set_context_data(isolate->native_context()->debug_context_id());
script->set_type(Script::TYPE_WASM);
int hash = StringHasher::HashSequentialString(
reinterpret_cast<const char*>(wire_bytes.start()),
static_cast<int>(wire_bytes.length()), kZeroHashSeed);
const int kBufferSize = 32;
char buffer[kBufferSize];
int url_chars = SNPrintF(ArrayVector(buffer), "wasm://wasm/%08x", hash);
DCHECK(url_chars >= 0 && url_chars < kBufferSize);
MaybeHandle<String> url_str = isolate->factory()->NewStringFromOneByte(
Vector<const uint8_t>(reinterpret_cast<uint8_t*>(buffer), url_chars),
TENURED);
script->set_source_url(*url_str.ToHandleChecked());
int name_chars = SNPrintF(ArrayVector(buffer), "wasm-%08x", hash);
DCHECK(name_chars >= 0 && name_chars < kBufferSize);
MaybeHandle<String> name_str = isolate->factory()->NewStringFromOneByte(
Vector<const uint8_t>(reinterpret_cast<uint8_t*>(buffer), name_chars),
TENURED);
script->set_name(*name_str.ToHandleChecked());
return script;
}
class JSToWasmWrapperCache {
public:
Handle<Code> CloneOrCompileJSToWasmWrapper(Isolate* isolate,
const wasm::WasmModule* module,
Handle<Code> wasm_code,
uint32_t index) {
const wasm::WasmFunction* func = &module->functions[index];
int cached_idx = sig_map_.Find(func->sig);
if (cached_idx >= 0) {
Handle<Code> code = isolate->factory()->CopyCode(code_cache_[cached_idx]);
// Now patch the call to wasm code.
for (RelocIterator it(*code, RelocInfo::kCodeTargetMask);; it.next()) {
DCHECK(!it.done());
Code* target =
Code::GetCodeFromTargetAddress(it.rinfo()->target_address());
if (target->kind() == Code::WASM_FUNCTION ||
target->kind() == Code::WASM_TO_JS_FUNCTION ||
target->builtin_index() == Builtins::kIllegal ||
target->builtin_index() == Builtins::kWasmCompileLazy) {
it.rinfo()->set_target_address(isolate,
wasm_code->instruction_start());
break;
}
}
return code;
}
Handle<Code> code =
compiler::CompileJSToWasmWrapper(isolate, module, wasm_code, index);
uint32_t new_cache_idx = sig_map_.FindOrInsert(func->sig);
DCHECK_EQ(code_cache_.size(), new_cache_idx);
USE(new_cache_idx);
code_cache_.push_back(code);
return code;
}
private:
// sig_map_ maps signatures to an index in code_cache_.
wasm::SignatureMap sig_map_;
std::vector<Handle<Code>> code_cache_;
};
// Ensure that the code object in <code_table> at offset <func_index> has
// deoptimization data attached. This is needed for lazy compile stubs which are
// called from JS_TO_WASM functions or via exported function tables. The deopt
// data is used to determine which function this lazy compile stub belongs to.
Handle<Code> EnsureExportedLazyDeoptData(Isolate* isolate,
Handle<WasmInstanceObject> instance,
Handle<FixedArray> code_table,
int func_index) {
Handle<Code> code(Code::cast(code_table->get(func_index)), isolate);
if (code->builtin_index() != Builtins::kWasmCompileLazy) {
// No special deopt data needed for compiled functions, and imported
// functions, which map to Illegal at this point (they get compiled at
// instantiation time).
DCHECK(code->kind() == Code::WASM_FUNCTION ||
code->kind() == Code::WASM_TO_JS_FUNCTION ||
code->builtin_index() == Builtins::kIllegal);
return code;
}
// deopt_data:
// #0: weak instance
// #1: func_index
// might be extended later for table exports (see
// EnsureTableExportLazyDeoptData).
Handle<FixedArray> deopt_data(code->deoptimization_data());
DCHECK_EQ(0, deopt_data->length() % 2);
if (deopt_data->length() == 0) {
code = isolate->factory()->CopyCode(code);
code_table->set(func_index, *code);
deopt_data = isolate->factory()->NewFixedArray(2, TENURED);
code->set_deoptimization_data(*deopt_data);
if (!instance.is_null()) {
Handle<WeakCell> weak_instance =
isolate->factory()->NewWeakCell(instance);
deopt_data->set(0, *weak_instance);
}
deopt_data->set(1, Smi::FromInt(func_index));
}
DCHECK_IMPLIES(!instance.is_null(),
WeakCell::cast(code->deoptimization_data()->get(0))->value() ==
*instance);
DCHECK_EQ(func_index,
Smi::cast(code->deoptimization_data()->get(1))->value());
return code;
}
// Ensure that the code object in <code_table> at offset <func_index> has
// deoptimization data attached. This is needed for lazy compile stubs which are
// called from JS_TO_WASM functions or via exported function tables. The deopt
// data is used to determine which function this lazy compile stub belongs to.
Handle<Code> EnsureTableExportLazyDeoptData(
Isolate* isolate, Handle<WasmInstanceObject> instance,
Handle<FixedArray> code_table, int func_index,
Handle<FixedArray> export_table, int export_index,
std::unordered_map<uint32_t, uint32_t>& table_export_count) {
Handle<Code> code =
EnsureExportedLazyDeoptData(isolate, instance, code_table, func_index);
if (code->builtin_index() != Builtins::kWasmCompileLazy) return code;
// deopt_data:
// #0: weak instance
// #1: func_index
// [#2: export table
// #3: export table index]
// [#4: export table
// #5: export table index]
// ...
// table_export_count counts down and determines the index for the new export
// table entry.
auto table_export_entry = table_export_count.find(func_index);
DCHECK(table_export_entry != table_export_count.end());
DCHECK_LT(0, table_export_entry->second);
uint32_t this_idx = 2 * table_export_entry->second;
--table_export_entry->second;
Handle<FixedArray> deopt_data(code->deoptimization_data());
DCHECK_EQ(0, deopt_data->length() % 2);
if (deopt_data->length() == 2) {
// Then only the "header" (#0 and #1) exists. Extend for the export table
// entries (make space for this_idx + 2 elements).
deopt_data = isolate->factory()->CopyFixedArrayAndGrow(deopt_data, this_idx,
TENURED);
code->set_deoptimization_data(*deopt_data);
}
DCHECK_LE(this_idx + 2, deopt_data->length());
DCHECK(deopt_data->get(this_idx)->IsUndefined(isolate));
DCHECK(deopt_data->get(this_idx + 1)->IsUndefined(isolate));
deopt_data->set(this_idx, *export_table);
deopt_data->set(this_idx + 1, Smi::FromInt(export_index));
return code;
}
bool compile_lazy(const WasmModule* module) {
return FLAG_wasm_lazy_compilation ||
(FLAG_asm_wasm_lazy_compilation && module->is_asm_js());
}
// A helper for compiling an entire module.
class CompilationHelper {
public:
// The compilation helper takes ownership of the {WasmModule}.
// In {CompileToModuleObject}, it will transfer ownership to the generated
// {WasmModuleWrapper}. If this method is not called, ownership may be
// reclaimed by explicitely releasing the {module_} field.
CompilationHelper(Isolate* isolate, std::unique_ptr<WasmModule> module,
bool is_sync)
: isolate_(isolate),
module_(std::move(module)),
is_sync_(is_sync),
executed_units_(
isolate->random_number_generator(),
(isolate->heap()->memory_allocator()->code_range()->valid()
? isolate->heap()->memory_allocator()->code_range()->size()
: isolate->heap()->code_space()->Capacity()) /
2),
num_background_tasks_(Min(
static_cast<size_t>(FLAG_wasm_num_compilation_tasks),
V8::GetCurrentPlatform()->NumberOfAvailableBackgroundThreads())),
stopped_compilation_tasks_(num_background_tasks_) {}
bool GetNextUncompiledFunctionId(size_t* index) {
DCHECK_NOT_NULL(index);
// - 1 because AtomicIncrement returns the value after the atomic increment.
*index = next_unit_.Increment(1) - 1;
return *index < compilation_units_.size();
}
// The actual runnable task that performs compilations in the background.
class CompilationTask : public CancelableTask {
public:
CompilationHelper* helper_;
explicit CompilationTask(CompilationHelper* helper)
: CancelableTask(helper->isolate_, &helper->background_task_manager_),
helper_(helper) {}
void RunInternal() override {
size_t index = 0;
while (helper_->executed_units_.CanAcceptWork() &&
helper_->GetNextUncompiledFunctionId(&index)) {
helper_->CompileAndSchedule(index);
}
helper_->OnBackgroundTaskStopped();
}
};
void OnBackgroundTaskStopped() {
base::LockGuard<base::Mutex> guard(&tasks_mutex_);
++stopped_compilation_tasks_;
DCHECK_LE(stopped_compilation_tasks_, num_background_tasks_);
}
void CompileAndSchedule(size_t index) {
DisallowHeapAllocation no_allocation;
DisallowHandleAllocation no_handles;
DisallowHandleDereference no_deref;
DisallowCodeDependencyChange no_dependency_change;
DCHECK_LT(index, compilation_units_.size());
std::unique_ptr<compiler::WasmCompilationUnit> unit =
std::move(compilation_units_.at(index));
unit->ExecuteCompilation();
{
base::LockGuard<base::Mutex> guard(&result_mutex_);
executed_units_.Schedule(std::move(unit));
}
}
class CodeGenerationSchedule {
public:
explicit CodeGenerationSchedule(
base::RandomNumberGenerator* random_number_generator,
size_t max_memory = 0);
void Schedule(std::unique_ptr<compiler::WasmCompilationUnit>&& item);
bool IsEmpty() const { return schedule_.empty(); }
std::unique_ptr<compiler::WasmCompilationUnit> GetNext();
bool CanAcceptWork() const;
void EnableThrottling() { throttle_ = true; }
private:
size_t GetRandomIndexInSchedule();
base::RandomNumberGenerator* random_number_generator_ = nullptr;
std::vector<std::unique_ptr<compiler::WasmCompilationUnit>> schedule_;
const size_t max_memory_;
bool throttle_ = false;
base::AtomicNumber<size_t> allocated_memory_{0};
};
Isolate* isolate_;
std::unique_ptr<WasmModule> module_;
bool is_sync_;
std::vector<std::unique_ptr<compiler::WasmCompilationUnit>>
compilation_units_;
CodeGenerationSchedule executed_units_;
base::Mutex result_mutex_;
base::AtomicNumber<size_t> next_unit_;
const size_t num_background_tasks_ = 0;
CancelableTaskManager background_task_manager_;
// Run by each compilation task and by the main thread.
bool FetchAndExecuteCompilationUnit() {
DisallowHeapAllocation no_allocation;
DisallowHandleAllocation no_handles;
DisallowHandleDereference no_deref;
DisallowCodeDependencyChange no_dependency_change;
// - 1 because AtomicIncrement returns the value after the atomic increment.
size_t index = next_unit_.Increment(1) - 1;
if (index >= compilation_units_.size()) {
return false;
}
std::unique_ptr<compiler::WasmCompilationUnit> unit =
std::move(compilation_units_.at(index));
unit->ExecuteCompilation();
base::LockGuard<base::Mutex> guard(&result_mutex_);
executed_units_.Schedule(std::move(unit));
return true;
}
size_t InitializeParallelCompilation(
const std::vector<WasmFunction>& functions, ModuleBytesEnv& module_env) {
uint32_t start = module_env.module_env.module->num_imported_functions +
FLAG_skip_compiling_wasm_funcs;
uint32_t num_funcs = static_cast<uint32_t>(functions.size());
uint32_t funcs_to_compile = start > num_funcs ? 0 : num_funcs - start;
compilation_units_.reserve(funcs_to_compile);
for (uint32_t i = start; i < num_funcs; ++i) {
const WasmFunction* func = &functions[i];
constexpr bool is_sync = true;
compilation_units_.push_back(
std::unique_ptr<compiler::WasmCompilationUnit>(
new compiler::WasmCompilationUnit(isolate_, &module_env, func,
!is_sync)));
}
return funcs_to_compile;
}
void RestartCompilationTasks() {
base::LockGuard<base::Mutex> guard(&tasks_mutex_);
for (; stopped_compilation_tasks_ > 0; --stopped_compilation_tasks_) {
V8::GetCurrentPlatform()->CallOnBackgroundThread(
new CompilationTask(this), v8::Platform::kShortRunningTask);
}
}
void WaitForCompilationTasks(uint32_t* task_ids) {
for (size_t i = 0; i < num_background_tasks_; ++i) {
// If the task has not started yet, then we abort it. Otherwise we wait
// for it to finish.
if (isolate_->cancelable_task_manager()->TryAbort(task_ids[i]) !=
CancelableTaskManager::kTaskAborted) {
module_->pending_tasks.get()->Wait();
}
}
}
size_t FinishCompilationUnits(std::vector<Handle<Code>>& results,
ErrorThrower* thrower) {
size_t finished = 0;
while (true) {
int func_index = -1;
Handle<Code> result = FinishCompilationUnit(thrower, &func_index);
if (func_index < 0) break;
results[func_index] = result;
++finished;
}
RestartCompilationTasks();
return finished;
}
Handle<Code> FinishCompilationUnit(ErrorThrower* thrower, int* func_index) {
std::unique_ptr<compiler::WasmCompilationUnit> unit;
{
base::LockGuard<base::Mutex> guard(&result_mutex_);
if (executed_units_.IsEmpty()) return Handle<Code>::null();
unit = executed_units_.GetNext();
}
*func_index = unit->func_index();
Handle<Code> result = unit->FinishCompilation(thrower);
return result;
}
void CompileInParallel(ModuleBytesEnv* module_env,
std::vector<Handle<Code>>& results,
ErrorThrower* thrower) {
const WasmModule* module = module_env->module_env.module;
// Data structures for the parallel compilation.
//-----------------------------------------------------------------------
// For parallel compilation:
// 1) The main thread allocates a compilation unit for each wasm function
// and stores them in the vector {compilation_units}.
// 2) The main thread spawns {CompilationTask} instances which run on
// the background threads.
// 3.a) The background threads and the main thread pick one compilation
// unit at a time and execute the parallel phase of the compilation
// unit. After finishing the execution of the parallel phase, the
// result is enqueued in {executed_units}.
// 3.b) If {executed_units} contains a compilation unit, the main thread
// dequeues it and finishes the compilation.
// 4) After the parallel phase of all compilation units has started, the
// main thread waits for all {CompilationTask} instances to finish.
// 5) The main thread finishes the compilation.
// Turn on the {CanonicalHandleScope} so that the background threads can
// use the node cache.
CanonicalHandleScope canonical(isolate_);
// 1) The main thread allocates a compilation unit for each wasm function
// and stores them in the vector {compilation_units}.
InitializeParallelCompilation(module->functions, *module_env);
executed_units_.EnableThrottling();
// 2) The main thread spawns {CompilationTask} instances which run on
// the background threads.
RestartCompilationTasks();
size_t finished_functions = 0;
while (finished_functions < compilation_units_.size()) {
// 3.a) The background threads and the main thread pick one compilation
// unit at a time and execute the parallel phase of the compilation
// unit. After finishing the execution of the parallel phase, the
// result is enqueued in {executed_units}.
size_t index = 0;
if (GetNextUncompiledFunctionId(&index)) {
CompileAndSchedule(index);
}
// 3.b) If {executed_units} contains a compilation unit, the main thread
// dequeues it and finishes the compilation unit. Compilation units
// are finished concurrently to the background threads to save
// memory.
finished_functions += FinishCompilationUnits(results, thrower);
}
// 4) After the parallel phase of all compilation units has started, the
// main thread waits for all {CompilationTask} instances to finish -
// which happens once they all realize there's no next work item to
// process.
background_task_manager_.CancelAndWait();
}
void CompileSequentially(ModuleBytesEnv* module_env,
std::vector<Handle<Code>>& results,
ErrorThrower* thrower) {
DCHECK(!thrower->error());
const WasmModule* module = module_env->module_env.module;
for (uint32_t i = FLAG_skip_compiling_wasm_funcs;
i < module->functions.size(); ++i) {
const WasmFunction& func = module->functions[i];
if (func.imported)
continue; // Imports are compiled at instantiation time.
// Compile the function.
Handle<Code> code = compiler::WasmCompilationUnit::CompileWasmFunction(
thrower, isolate_, module_env, &func);
if (code.is_null()) {
WasmName str = module_env->wire_bytes.GetName(&func);
thrower->CompileError("Compilation of #%d:%.*s failed.", i,
str.length(), str.start());
break;
}
results[i] = code;
}
}
MaybeHandle<WasmModuleObject> CompileToModuleObject(
ErrorThrower* thrower, const ModuleWireBytes& wire_bytes,
Handle<Script> asm_js_script,
Vector<const byte> asm_js_offset_table_bytes) {
Factory* factory = isolate_->factory();
WasmInstance temp_instance(module_.get());
temp_instance.context = isolate_->native_context();
temp_instance.mem_size = WasmModule::kPageSize * module_->min_mem_pages;
temp_instance.mem_start = nullptr;
temp_instance.globals_start = nullptr;
// Initialize the indirect tables with placeholders.
int function_table_count =
static_cast<int>(module_->function_tables.size());
Handle<FixedArray> function_tables =
factory->NewFixedArray(function_table_count, TENURED);
Handle<FixedArray> signature_tables =
factory->NewFixedArray(function_table_count, TENURED);
for (int i = 0; i < function_table_count; ++i) {
temp_instance.function_tables[i] = factory->NewFixedArray(1, TENURED);
temp_instance.signature_tables[i] = factory->NewFixedArray(1, TENURED);
function_tables->set(i, *temp_instance.function_tables[i]);
signature_tables->set(i, *temp_instance.signature_tables[i]);
}
if (is_sync_) {
// TODO(karlschimpf): Make this work when asynchronous.
// https://bugs.chromium.org/p/v8/issues/detail?id=6361
HistogramTimerScope wasm_compile_module_time_scope(
module_->is_wasm()
? isolate_->counters()->wasm_compile_wasm_module_time()
: isolate_->counters()->wasm_compile_asm_module_time());
return CompileToModuleObjectInternal(
thrower, wire_bytes, asm_js_script, asm_js_offset_table_bytes,
factory, &temp_instance, &function_tables, &signature_tables);
}
return CompileToModuleObjectInternal(
thrower, wire_bytes, asm_js_script, asm_js_offset_table_bytes, factory,
&temp_instance, &function_tables, &signature_tables);
}
private:
MaybeHandle<WasmModuleObject> CompileToModuleObjectInternal(
ErrorThrower* thrower, const ModuleWireBytes& wire_bytes,
Handle<Script> asm_js_script,
Vector<const byte> asm_js_offset_table_bytes, Factory* factory,
WasmInstance* temp_instance, Handle<FixedArray>* function_tables,
Handle<FixedArray>* signature_tables) {
ModuleBytesEnv module_env(module_.get(), temp_instance, wire_bytes);
// The {code_table} array contains import wrappers and functions (which
// are both included in {functions.size()}, and export wrappers.
int code_table_size = static_cast<int>(module_->functions.size() +
module_->num_exported_functions);
Handle<FixedArray> code_table =
factory->NewFixedArray(static_cast<int>(code_table_size), TENURED);
// Check whether lazy compilation is enabled for this module.
bool lazy_compile = compile_lazy(module_.get());
// If lazy compile: Initialize the code table with the lazy compile builtin.
// Otherwise: Initialize with the illegal builtin. All call sites will be
// patched at instantiation.
Handle<Code> init_builtin = lazy_compile
? isolate_->builtins()->WasmCompileLazy()
: isolate_->builtins()->Illegal();
for (int i = 0, e = static_cast<int>(module_->functions.size()); i < e;
++i) {
code_table->set(i, *init_builtin);
temp_instance->function_code[i] = init_builtin;
}
if (is_sync_)
// TODO(karlschimpf): Make this work when asynchronous.
// https://bugs.chromium.org/p/v8/issues/detail?id=6361
(module_->is_wasm()
? isolate_->counters()->wasm_functions_per_wasm_module()
: isolate_->counters()->wasm_functions_per_asm_module())
->AddSample(static_cast<int>(module_->functions.size()));
if (!lazy_compile) {
size_t funcs_to_compile =
module_->functions.size() - module_->num_imported_functions;
if (!FLAG_trace_wasm_decoder && FLAG_wasm_num_compilation_tasks != 0 &&
funcs_to_compile > 1) {
// Avoid a race condition by collecting results into a second vector.
std::vector<Handle<Code>> results(temp_instance->function_code);
CompileInParallel(&module_env, results, thrower);
temp_instance->function_code.swap(results);
} else {
CompileSequentially(&module_env, temp_instance->function_code, thrower);
}
if (thrower->error()) return {};
}
// At this point, compilation has completed. Update the code table.
for (size_t i = FLAG_skip_compiling_wasm_funcs;
i < temp_instance->function_code.size(); ++i) {
Code* code = *temp_instance->function_code[i];
code_table->set(static_cast<int>(i), code);
RecordStats(isolate_, code, is_sync_);
}
// Create heap objects for script, module bytes and asm.js offset table to
// be stored in the shared module data.
Handle<Script> script;
Handle<ByteArray> asm_js_offset_table;
if (asm_js_script.is_null()) {
script = CreateWasmScript(isolate_, wire_bytes);
} else {
script = asm_js_script;
asm_js_offset_table =
isolate_->factory()->NewByteArray(asm_js_offset_table_bytes.length());
asm_js_offset_table->copy_in(0, asm_js_offset_table_bytes.start(),
asm_js_offset_table_bytes.length());
}
// TODO(wasm): only save the sections necessary to deserialize a
// {WasmModule}. E.g. function bodies could be omitted.
Handle<String> module_bytes =
factory
->NewStringFromOneByte({wire_bytes.start(), wire_bytes.length()},
TENURED)
.ToHandleChecked();
DCHECK(module_bytes->IsSeqOneByteString());
// The {module_wrapper} will take ownership of the {WasmModule} object,
// and it will be destroyed when the GC reclaims the wrapper object.
Handle<WasmModuleWrapper> module_wrapper =
WasmModuleWrapper::New(isolate_, module_.release());
WasmModule* module = module_wrapper->get();
// Create the shared module data.
// TODO(clemensh): For the same module (same bytes / same hash), we should
// only have one WasmSharedModuleData. Otherwise, we might only set
// breakpoints on a (potentially empty) subset of the instances.
Handle<WasmSharedModuleData> shared = WasmSharedModuleData::New(
isolate_, module_wrapper, Handle<SeqOneByteString>::cast(module_bytes),
script, asm_js_offset_table);
if (lazy_compile) WasmSharedModuleData::PrepareForLazyCompilation(shared);
// Create the compiled module object, and populate with compiled functions
// and information needed at instantiation time. This object needs to be
// serializable. Instantiation may occur off a deserialized version of this
// object.
Handle<WasmCompiledModule> compiled_module = WasmCompiledModule::New(
isolate_, shared, code_table, *function_tables, *signature_tables);
// If we created a wasm script, finish it now and make it public to the
// debugger.
if (asm_js_script.is_null()) {
script->set_wasm_compiled_module(*compiled_module);
isolate_->debug()->OnAfterCompile(script);
}
// Compile JS->WASM wrappers for exported functions.
JSToWasmWrapperCache js_to_wasm_cache;
int func_index = 0;
for (auto exp : module->export_table) {
if (exp.kind != kExternalFunction) continue;
Handle<Code> wasm_code = EnsureExportedLazyDeoptData(
isolate_, Handle<WasmInstanceObject>::null(), code_table, exp.index);
Handle<Code> wrapper_code =
js_to_wasm_cache.CloneOrCompileJSToWasmWrapper(isolate_, module,
wasm_code, exp.index);
int export_index =
static_cast<int>(module->functions.size() + func_index);
code_table->set(export_index, *wrapper_code);
RecordStats(isolate_, *wrapper_code, is_sync_);
func_index++;
}
return WasmModuleObject::New(isolate_, compiled_module);
}
size_t stopped_compilation_tasks_ = 0;
base::Mutex tasks_mutex_;
};
CompilationHelper::CodeGenerationSchedule::CodeGenerationSchedule(
base::RandomNumberGenerator* random_number_generator, size_t max_memory)
: random_number_generator_(random_number_generator),
max_memory_(max_memory) {
DCHECK_NOT_NULL(random_number_generator_);
DCHECK_GT(max_memory_, 0);
}
void CompilationHelper::CodeGenerationSchedule::Schedule(
std::unique_ptr<compiler::WasmCompilationUnit>&& item) {
size_t cost = item->memory_cost();
schedule_.push_back(std::move(item));
allocated_memory_.Increment(cost);
}
bool CompilationHelper::CodeGenerationSchedule::CanAcceptWork() const {
return (!throttle_ || allocated_memory_.Value() <= max_memory_);
}
std::unique_ptr<compiler::WasmCompilationUnit>
CompilationHelper::CodeGenerationSchedule::GetNext() {
DCHECK(!IsEmpty());
size_t index = GetRandomIndexInSchedule();
auto ret = std::move(schedule_[index]);
std::swap(schedule_[schedule_.size() - 1], schedule_[index]);
schedule_.pop_back();
allocated_memory_.Decrement(ret->memory_cost());
return ret;
}
size_t CompilationHelper::CodeGenerationSchedule::GetRandomIndexInSchedule() {
double factor = random_number_generator_->NextDouble();
size_t index = (size_t)(factor * schedule_.size());
DCHECK_GE(index, 0);
DCHECK_LT(index, schedule_.size());
return index;
}
static void MemoryInstanceFinalizer(Isolate* isolate,
WasmInstanceObject* instance) {
DisallowHeapAllocation no_gc;
// If the memory object is destroyed, nothing needs to be done here.
if (!instance->has_memory_object()) return;
Handle<WasmInstanceWrapper> instance_wrapper =
handle(instance->instance_wrapper());
DCHECK(WasmInstanceWrapper::IsWasmInstanceWrapper(*instance_wrapper));
DCHECK(instance_wrapper->has_instance());
bool has_prev = instance_wrapper->has_previous();
bool has_next = instance_wrapper->has_next();
Handle<WasmMemoryObject> memory_object(instance->memory_object());
if (!has_prev && !has_next) {
memory_object->ResetInstancesLink(isolate);
return;
} else {
Handle<WasmInstanceWrapper> next_wrapper, prev_wrapper;
if (!has_prev) {
Handle<WasmInstanceWrapper> next_wrapper =
instance_wrapper->next_wrapper();
next_wrapper->reset_previous_wrapper();
// As this is the first link in the memory object, destroying
// without updating memory object would corrupt the instance chain in
// the memory object.
memory_object->set_instances_link(*next_wrapper);
} else if (!has_next) {
instance_wrapper->previous_wrapper()->reset_next_wrapper();
} else {
DCHECK(has_next && has_prev);
Handle<WasmInstanceWrapper> prev_wrapper =
instance_wrapper->previous_wrapper();
Handle<WasmInstanceWrapper> next_wrapper =
instance_wrapper->next_wrapper();
prev_wrapper->set_next_wrapper(*next_wrapper);
next_wrapper->set_previous_wrapper(*prev_wrapper);
}
// Reset to avoid dangling pointers
instance_wrapper->reset();
}
}
static void InstanceFinalizer(const v8::WeakCallbackInfo<void>& data) {
DisallowHeapAllocation no_gc;
JSObject** p = reinterpret_cast<JSObject**>(data.GetParameter());
WasmInstanceObject* owner = 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.
if (owner->has_instance_wrapper()) MemoryInstanceFinalizer(isolate, owner);
WasmCompiledModule* compiled_module = owner->compiled_module();
TRACE("Finalizing %d {\n", compiled_module->instance_id());
DCHECK(compiled_module->has_weak_wasm_module());
WeakCell* weak_wasm_module = compiled_module->ptr_to_weak_wasm_module();
if (trap_handler::UseTrapHandler()) {
Handle<FixedArray> code_table = compiled_module->code_table();
for (int i = 0; i < code_table->length(); ++i) {
Handle<Code> code = code_table->GetValueChecked<Code>(isolate, i);
int index = code->trap_handler_index()->value();
if (index >= 0) {
trap_handler::ReleaseHandlerData(index);
code->set_trap_handler_index(Smi::FromInt(-1));
}
}
}
// weak_wasm_module may have been cleared, meaning the module object
// was GC-ed. In that case, there won't be any new instances created,
// and we don't need to maintain the links between instances.
if (!weak_wasm_module->cleared()) {
JSObject* wasm_module = JSObject::cast(weak_wasm_module->value());
WasmCompiledModule* current_template =
WasmCompiledModule::cast(wasm_module->GetEmbedderField(0));
TRACE("chain before {\n");
TRACE_CHAIN(current_template);
TRACE("}\n");
DCHECK(!current_template->has_weak_prev_instance());
WeakCell* next = compiled_module->maybe_ptr_to_weak_next_instance();
WeakCell* prev = compiled_module->maybe_ptr_to_weak_prev_instance();
if (current_template == compiled_module) {
if (next == nullptr) {
WasmCompiledModule::Reset(isolate, compiled_module);
} else {
DCHECK(next->value()->IsFixedArray());
wasm_module->SetEmbedderField(0, next->value());
DCHECK_NULL(prev);
WasmCompiledModule::cast(next->value())->reset_weak_prev_instance();
}
} else {
DCHECK(!(prev == nullptr && next == nullptr));
// the only reason prev or next would be cleared is if the
// respective objects got collected, but if that happened,
// we would have relinked the list.
if (prev != nullptr) {
DCHECK(!prev->cleared());
if (next == nullptr) {
WasmCompiledModule::cast(prev->value())->reset_weak_next_instance();
} else {
WasmCompiledModule::cast(prev->value())
->set_ptr_to_weak_next_instance(next);
}
}
if (next != nullptr) {
DCHECK(!next->cleared());
if (prev == nullptr) {
WasmCompiledModule::cast(next->value())->reset_weak_prev_instance();
} else {
WasmCompiledModule::cast(next->value())
->set_ptr_to_weak_prev_instance(prev);
}
}
}
TRACE("chain after {\n");
TRACE_CHAIN(WasmCompiledModule::cast(wasm_module->GetEmbedderField(0)));
TRACE("}\n");
}
compiled_module->reset_weak_owning_instance();
GlobalHandles::Destroy(reinterpret_cast<Object**>(p));
TRACE("}\n");
}
int AdvanceSourcePositionTableIterator(SourcePositionTableIterator& iterator,
int offset) {
DCHECK(!iterator.done());
int byte_pos;
do {
byte_pos = iterator.source_position().ScriptOffset();
iterator.Advance();
} while (!iterator.done() && iterator.code_offset() <= offset);
return byte_pos;
}
int ExtractDirectCallIndex(wasm::Decoder& decoder, const byte* pc) {
DCHECK_EQ(static_cast<int>(kExprCallFunction), static_cast<int>(*pc));
// Read the leb128 encoded u32 value (up to 5 bytes starting at pc + 1).
decoder.Reset(pc + 1, pc + 6);
uint32_t call_idx = decoder.consume_u32v("call index");
DCHECK(decoder.ok());
DCHECK_GE(kMaxInt, call_idx);
return static_cast<int>(call_idx);
}
void RecordLazyCodeStats(Isolate* isolate, Code* code) {
isolate->counters()->wasm_lazily_compiled_functions()->Increment();
isolate->counters()->wasm_generated_code_size()->Increment(code->body_size());
isolate->counters()->wasm_reloc_size()->Increment(
code->relocation_info()->length());
}
} // namespace
Handle<JSArrayBuffer> wasm::SetupArrayBuffer(Isolate* isolate,
void* allocation_base,
size_t allocation_length,
void* backing_store, size_t size,
bool is_external,
bool enable_guard_regions) {
Handle<JSArrayBuffer> buffer = isolate->factory()->NewJSArrayBuffer();
JSArrayBuffer::Setup(buffer, isolate, is_external, allocation_base,
allocation_length, backing_store,
static_cast<int>(size));
buffer->set_is_neuterable(false);
buffer->set_is_wasm_buffer(true);
buffer->set_has_guard_region(enable_guard_regions);
return buffer;
}
Handle<JSArrayBuffer> wasm::NewArrayBuffer(Isolate* isolate, size_t size,
bool enable_guard_regions) {
if (size > (FLAG_wasm_max_mem_pages * WasmModule::kPageSize)) {
// TODO(titzer): lift restriction on maximum memory allocated here.
return Handle<JSArrayBuffer>::null();
}
enable_guard_regions = enable_guard_regions && kGuardRegionsSupported;
void* allocation_base = nullptr; // Set by TryAllocateBackingStore
size_t allocation_length = 0; // Set by TryAllocateBackingStore
void* memory = TryAllocateBackingStore(isolate, size, enable_guard_regions,
allocation_base, allocation_length);
if (memory == nullptr) {
return Handle<JSArrayBuffer>::null();
}
#if DEBUG
// Double check the API allocator actually zero-initialized the memory.
const byte* bytes = reinterpret_cast<const byte*>(memory);
for (size_t i = 0; i < size; ++i) {
DCHECK_EQ(0, bytes[i]);
}
#endif
const bool is_external = false;
return SetupArrayBuffer(isolate, allocation_base, allocation_length, memory,
size, is_external, enable_guard_regions);
}
void wasm::UnpackAndRegisterProtectedInstructions(
Isolate* isolate, Handle<FixedArray> code_table) {
for (int i = 0; i < code_table->length(); ++i) {
Handle<Code> code;
// This is sometimes undefined when we're called from cctests.
if (!code_table->GetValue<Code>(isolate, i).ToHandle(&code)) {
continue;
}
if (code->kind() != Code::WASM_FUNCTION) {
continue;
}
const intptr_t base = reinterpret_cast<intptr_t>(code->entry());
Zone zone(isolate->allocator(), "Wasm Module");
ZoneVector<trap_handler::ProtectedInstructionData> unpacked(&zone);
const int mode_mask =
RelocInfo::ModeMask(RelocInfo::WASM_PROTECTED_INSTRUCTION_LANDING);
for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
trap_handler::ProtectedInstructionData data;
data.instr_offset = it.rinfo()->data();
data.landing_offset = reinterpret_cast<intptr_t>(it.rinfo()->pc()) - base;
unpacked.emplace_back(data);
}
if (unpacked.size() > 0) {
int size = code->CodeSize();
const int index = RegisterHandlerData(reinterpret_cast<void*>(base), size,
unpacked.size(), &unpacked[0]);
// TODO(eholk): if index is negative, fail.
DCHECK(index >= 0);
code->set_trap_handler_index(Smi::FromInt(index));
}
}
}
std::ostream& wasm::operator<<(std::ostream& os, const WasmFunctionName& name) {
os << "#" << name.function_->func_index;
if (name.function_->name_offset > 0) {
if (name.name_.start()) {
os << ":";
os.write(name.name_.start(), name.name_.length());
}
} else {
os << "?";
}
return os;
}
WasmInstanceObject* wasm::GetOwningWasmInstance(Code* code) {
DisallowHeapAllocation no_gc;
DCHECK(code->kind() == Code::WASM_FUNCTION ||
code->kind() == Code::WASM_INTERPRETER_ENTRY);
FixedArray* deopt_data = code->deoptimization_data();
DCHECK_EQ(code->kind() == Code::WASM_INTERPRETER_ENTRY ? 1 : 2,
deopt_data->length());
Object* weak_link = deopt_data->get(0);
DCHECK(weak_link->IsWeakCell());
WeakCell* cell = WeakCell::cast(weak_link);
if (cell->cleared()) return nullptr;
return WasmInstanceObject::cast(cell->value());
}
WasmModule::WasmModule(std::unique_ptr<Zone> owned)
: signature_zone(std::move(owned)), pending_tasks(new base::Semaphore(0)) {}
namespace {
WasmFunction* GetWasmFunctionForImportWrapper(Isolate* isolate,
Handle<Object> target) {
if (target->IsJSFunction()) {
Handle<JSFunction> func = Handle<JSFunction>::cast(target);
if (func->code()->kind() == Code::JS_TO_WASM_FUNCTION) {
auto exported = Handle<WasmExportedFunction>::cast(func);
Handle<WasmInstanceObject> other_instance(exported->instance(), isolate);
int func_index = exported->function_index();
return &other_instance->module()->functions[func_index];
}
}
return nullptr;
}
static Handle<Code> UnwrapImportWrapper(Handle<Object> import_wrapper) {
Handle<JSFunction> func = Handle<JSFunction>::cast(import_wrapper);
Handle<Code> export_wrapper_code = handle(func->code());
int mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET);
for (RelocIterator it(*export_wrapper_code, mask);; it.next()) {
DCHECK(!it.done());
Code* target = Code::GetCodeFromTargetAddress(it.rinfo()->target_address());
if (target->kind() != Code::WASM_FUNCTION &&
target->kind() != Code::WASM_TO_JS_FUNCTION &&
target->kind() != Code::WASM_INTERPRETER_ENTRY)
continue;
// There should only be this one call to wasm code.
#ifdef DEBUG
for (it.next(); !it.done(); it.next()) {
Code* code = Code::GetCodeFromTargetAddress(it.rinfo()->target_address());
DCHECK(code->kind() != Code::WASM_FUNCTION &&
code->kind() != Code::WASM_TO_JS_FUNCTION &&
code->kind() != Code::WASM_INTERPRETER_ENTRY);
}
#endif
return handle(target);
}
UNREACHABLE();
return Handle<Code>::null();
}
Handle<Code> CompileImportWrapper(Isolate* isolate, int index, FunctionSig* sig,
Handle<JSReceiver> target,
Handle<String> module_name,
MaybeHandle<String> import_name,
ModuleOrigin origin) {
WasmFunction* other_func = GetWasmFunctionForImportWrapper(isolate, target);
if (other_func) {
if (!sig->Equals(other_func->sig)) return Handle<Code>::null();
// Signature matched. Unwrap the JS->WASM wrapper and return the raw
// WASM function code.
return UnwrapImportWrapper(target);
}
// No wasm function or being debugged. Compile a new wrapper for the new
// signature.
return compiler::CompileWasmToJSWrapper(isolate, target, sig, index,
module_name, import_name, origin);
}
void UpdateDispatchTablesInternal(Isolate* isolate,
Handle<FixedArray> dispatch_tables, int index,
WasmFunction* function, Handle<Code> code) {
DCHECK_EQ(0, dispatch_tables->length() % 4);
for (int i = 0; i < dispatch_tables->length(); i += 4) {
int table_index = Smi::cast(dispatch_tables->get(i + 1))->value();
Handle<FixedArray> function_table(
FixedArray::cast(dispatch_tables->get(i + 2)), isolate);
Handle<FixedArray> signature_table(
FixedArray::cast(dispatch_tables->get(i + 3)), isolate);
if (function) {
// TODO(titzer): the signature might need to be copied to avoid
// a dangling pointer in the signature map.
Handle<WasmInstanceObject> instance(
WasmInstanceObject::cast(dispatch_tables->get(i)), isolate);
auto& func_table = instance->module()->function_tables[table_index];
uint32_t sig_index = func_table.map.FindOrInsert(function->sig);
signature_table->set(index, Smi::FromInt(static_cast<int>(sig_index)));
function_table->set(index, *code);
} else {
signature_table->set(index, Smi::FromInt(-1));
function_table->set(index, Smi::kZero);
}
}
}
} // namespace
void wasm::UpdateDispatchTables(Isolate* isolate,
Handle<FixedArray> dispatch_tables, int index,
Handle<JSFunction> function) {
if (function.is_null()) {
UpdateDispatchTablesInternal(isolate, dispatch_tables, index, nullptr,
Handle<Code>::null());
} else {
UpdateDispatchTablesInternal(
isolate, dispatch_tables, index,
GetWasmFunctionForImportWrapper(isolate, function),
UnwrapImportWrapper(function));
}
}
// A helper class to simplify instantiating a module from a compiled module.
// It closes over the {Isolate}, the {ErrorThrower}, the {WasmCompiledModule},
// etc.
class InstantiationHelper {
public:
InstantiationHelper(Isolate* isolate, ErrorThrower* thrower,
Handle<WasmModuleObject> module_object,
MaybeHandle<JSReceiver> ffi,
MaybeHandle<JSArrayBuffer> memory)
: isolate_(isolate),
module_(module_object->compiled_module()->module()),
thrower_(thrower),
module_object_(module_object),
ffi_(ffi.is_null() ? Handle<JSReceiver>::null()
: ffi.ToHandleChecked()),
memory_(memory.is_null() ? Handle<JSArrayBuffer>::null()
: memory.ToHandleChecked()) {}
// Build an instance, in all of its glory.
MaybeHandle<WasmInstanceObject> Build() {
// Check that an imports argument was provided, if the module requires it.
// No point in continuing otherwise.
if (!module_->import_table.empty() && ffi_.is_null()) {
thrower_->TypeError(
"Imports argument must be present and must be an object");
return {};
}
// Record build time into correct bucket, then build instance.
HistogramTimerScope wasm_instantiate_module_time_scope(
module_->is_wasm()
? isolate_->counters()->wasm_instantiate_wasm_module_time()
: isolate_->counters()->wasm_instantiate_asm_module_time());
Factory* factory = isolate_->factory();
//--------------------------------------------------------------------------
// Reuse the compiled module (if no owner), otherwise clone.
//--------------------------------------------------------------------------
Handle<FixedArray> code_table;
// We keep around a copy of the old code table, because we'll be replacing
// imports for the new instance, and then we need the old imports to be
// able to relocate.
Handle<FixedArray> old_code_table;
MaybeHandle<WasmInstanceObject> owner;
TRACE("Starting new module instantiation\n");
{
// Root the owner, if any, before doing any allocations, which
// may trigger GC.
// Both owner and original template need to be in sync. Even
// after we lose the original template handle, the code
// objects we copied from it have data relative to the
// instance - such as globals addresses.
Handle<WasmCompiledModule> original;
{
DisallowHeapAllocation no_gc;
original = handle(module_object_->compiled_module());
if (original->has_weak_owning_instance()) {
owner = handle(WasmInstanceObject::cast(
original->weak_owning_instance()->value()));
}
}
DCHECK(!original.is_null());
if (original->has_weak_owning_instance()) {
// Clone, but don't insert yet the clone in the instances chain.
// We do that last. Since we are holding on to the owner instance,
// the owner + original state used for cloning and patching
// won't be mutated by possible finalizer runs.
DCHECK(!owner.is_null());
TRACE("Cloning from %d\n", original->instance_id());
old_code_table = original->code_table();
compiled_module_ = WasmCompiledModule::Clone(isolate_, original);
code_table = compiled_module_->code_table();
// Avoid creating too many handles in the outer scope.
HandleScope scope(isolate_);
// Clone the code for WASM functions and exports.
for (int i = 0; i < code_table->length(); ++i) {
Handle<Code> orig_code(Code::cast(code_table->get(i)), isolate_);
switch (orig_code->kind()) {
case Code::WASM_TO_JS_FUNCTION:
// Imports will be overwritten with newly compiled wrappers.
break;
case Code::BUILTIN:
DCHECK_EQ(Builtins::kWasmCompileLazy, orig_code->builtin_index());
// If this code object has deoptimization data, then we need a
// unique copy to attach updated deoptimization data.
if (orig_code->deoptimization_data()->length() > 0) {
Handle<Code> code = factory->CopyCode(orig_code);
Handle<FixedArray> deopt_data =
factory->NewFixedArray(2, TENURED);
deopt_data->set(1, Smi::FromInt(i));
code->set_deoptimization_data(*deopt_data);
code_table->set(i, *code);
}
break;
case Code::JS_TO_WASM_FUNCTION:
case Code::WASM_FUNCTION: {
Handle<Code> code = factory->CopyCode(orig_code);
code_table->set(i, *code);
break;
}
default:
UNREACHABLE();
}
}
RecordStats(isolate_, code_table, is_sync_);
} else {
// There was no owner, so we can reuse the original.
compiled_module_ = original;
old_code_table =
factory->CopyFixedArray(compiled_module_->code_table());
code_table = compiled_module_->code_table();
TRACE("Reusing existing instance %d\n",
compiled_module_->instance_id());
}
compiled_module_->set_native_context(isolate_->native_context());
}
//--------------------------------------------------------------------------
// Allocate the instance object.
//--------------------------------------------------------------------------
Zone instantiation_zone(isolate_->allocator(), ZONE_NAME);
CodeSpecialization code_specialization(isolate_, &instantiation_zone);
Handle<WasmInstanceObject> instance =
WasmInstanceObject::New(isolate_, compiled_module_);
//--------------------------------------------------------------------------
// Set up the globals for the new instance.
//--------------------------------------------------------------------------
MaybeHandle<JSArrayBuffer> old_globals;
uint32_t globals_size = module_->globals_size;
if (globals_size > 0) {
const bool enable_guard_regions = false;
Handle<JSArrayBuffer> global_buffer =
NewArrayBuffer(isolate_, globals_size, enable_guard_regions);
globals_ = global_buffer;
if (globals_.is_null()) {
thrower_->RangeError("Out of memory: wasm globals");
return {};
}
Address old_globals_start = compiled_module_->GetGlobalsStartOrNull();
Address new_globals_start =
static_cast<Address>(global_buffer->backing_store());
code_specialization.RelocateGlobals(old_globals_start, new_globals_start);
// The address of the backing buffer for the golbals is in native memory
// and, thus, not moving. We need it saved for
// serialization/deserialization purposes - so that the other end
// understands how to relocate the references. We still need to save the
// JSArrayBuffer on the instance, to keep it all alive.
WasmCompiledModule::SetGlobalsStartAddressFrom(factory, compiled_module_,
global_buffer);
instance->set_globals_buffer(*global_buffer);
}
//--------------------------------------------------------------------------
// Prepare for initialization of function tables.
//--------------------------------------------------------------------------
int function_table_count =
static_cast<int>(module_->function_tables.size());
table_instances_.reserve(module_->function_tables.size());
for (int index = 0; index < function_table_count; ++index) {
table_instances_.push_back(
{Handle<WasmTableObject>::null(), Handle<FixedArray>::null(),
Handle<FixedArray>::null(), Handle<FixedArray>::null()});
}
//--------------------------------------------------------------------------
// Process the imports for the module.
//--------------------------------------------------------------------------
int num_imported_functions = ProcessImports(code_table, instance);
if (num_imported_functions < 0) return {};
//--------------------------------------------------------------------------
// Process the initialization for the module's globals.
//--------------------------------------------------------------------------
InitGlobals();
//--------------------------------------------------------------------------
// Set up the indirect function tables for the new instance.
//--------------------------------------------------------------------------
if (function_table_count > 0)
InitializeTables(instance, &code_specialization);
//--------------------------------------------------------------------------
// Set up the memory for the new instance.
//--------------------------------------------------------------------------
uint32_t min_mem_pages = module_->min_mem_pages;
(module_->is_wasm() ? isolate_->counters()->wasm_wasm_min_mem_pages_count()
: isolate_->counters()->wasm_asm_min_mem_pages_count())
->AddSample(min_mem_pages);
if (!memory_.is_null()) {
// Set externally passed ArrayBuffer non neuterable.
memory_->set_is_neuterable(false);
memory_->set_is_wasm_buffer(true);
DCHECK_IMPLIES(EnableGuardRegions(),
module_->is_asm_js() || memory_->has_guard_region());
} else if (min_mem_pages > 0) {
memory_ = AllocateMemory(min_mem_pages);
if (memory_.is_null()) return {}; // failed to allocate memory
}
//--------------------------------------------------------------------------
// Check that indirect function table segments are within bounds.
//--------------------------------------------------------------------------
for (WasmTableInit& table_init : module_->table_inits) {
DCHECK(table_init.table_index < table_instances_.size());
uint32_t base = EvalUint32InitExpr(table_init.offset);
uint32_t table_size =
table_instances_[table_init.table_index].function_table->length();
if (!in_bounds(base, static_cast<uint32_t>(table_init.entries.size()),
table_size)) {
thrower_->LinkError("table initializer is out of bounds");
return {};
}
}
//--------------------------------------------------------------------------
// Check that memory segments are within bounds.
//--------------------------------------------------------------------------
for (WasmDataSegment& seg : module_->data_segments) {
uint32_t base = EvalUint32InitExpr(seg.dest_addr);
uint32_t mem_size = memory_.is_null()
? 0 : static_cast<uint32_t>(memory_->byte_length()->Number());
if (!in_bounds(base, seg.source_size, mem_size)) {
thrower_->LinkError("data segment is out of bounds");
return {};
}
}
//--------------------------------------------------------------------------
// Initialize memory.
//--------------------------------------------------------------------------
if (!memory_.is_null()) {
Address mem_start = static_cast<Address>(memory_->backing_store());
uint32_t mem_size =
static_cast<uint32_t>(memory_->byte_length()->Number());
LoadDataSegments(mem_start, mem_size);
uint32_t old_mem_size = compiled_module_->mem_size();
Address old_mem_start = compiled_module_->GetEmbeddedMemStartOrNull();
// We might get instantiated again with the same memory. No patching
// needed in this case.
if (old_mem_start != mem_start || old_mem_size != mem_size) {
code_specialization.RelocateMemoryReferences(
old_mem_start, old_mem_size, mem_start, mem_size);
}
// Just like with globals, we need to keep both the JSArrayBuffer
// and save the start pointer.
instance->set_memory_buffer(*memory_);
WasmCompiledModule::SetSpecializationMemInfoFrom(
factory, compiled_module_, memory_);
}
//--------------------------------------------------------------------------
// Set up the runtime support for the new instance.
//--------------------------------------------------------------------------
Handle<WeakCell> weak_link = factory->NewWeakCell(instance);
for (int i = num_imported_functions + FLAG_skip_compiling_wasm_funcs,
num_functions = static_cast<int>(module_->functions.size());
i < num_functions; ++i) {
Handle<Code> code = handle(Code::cast(code_table->get(i)), isolate_);
if (code->kind() == Code::WASM_FUNCTION) {
Handle<FixedArray> deopt_data = factory->NewFixedArray(2, TENURED);
deopt_data->set(0, *weak_link);
deopt_data->set(1, Smi::FromInt(i));
code->set_deoptimization_data(*deopt_data);
continue;
}
DCHECK_EQ(Builtins::kWasmCompileLazy, code->builtin_index());
if (code->deoptimization_data()->length() == 0) continue;
DCHECK_LE(2, code->deoptimization_data()->length());
DCHECK_EQ(i, Smi::cast(code->deoptimization_data()->get(1))->value());
code->deoptimization_data()->set(0, *weak_link);
}
//--------------------------------------------------------------------------
// Set up the exports object for the new instance.
//--------------------------------------------------------------------------
ProcessExports(code_table, instance, compiled_module_);
//--------------------------------------------------------------------------
// Add instance to Memory object
//--------------------------------------------------------------------------
DCHECK(wasm::IsWasmInstance(*instance));
if (instance->has_memory_object()) {
instance->memory_object()->AddInstance(isolate_, instance);
}
//--------------------------------------------------------------------------
// Initialize the indirect function tables.
//--------------------------------------------------------------------------
if (function_table_count > 0) LoadTableSegments(code_table, instance);
// Patch all code with the relocations registered in code_specialization.
code_specialization.RelocateDirectCalls(instance);
code_specialization.ApplyToWholeInstance(*instance, SKIP_ICACHE_FLUSH);
FlushICache(isolate_, code_table);
//--------------------------------------------------------------------------
// Unpack and notify signal handler of protected instructions.
//--------------------------------------------------------------------------
if (trap_handler::UseTrapHandler()) {
UnpackAndRegisterProtectedInstructions(isolate_, code_table);
}
//--------------------------------------------------------------------------
// Set up and link the new instance.
//--------------------------------------------------------------------------
{
Handle<Object> global_handle =
isolate_->global_handles()->Create(*instance);
Handle<WeakCell> link_to_clone = factory->NewWeakCell(compiled_module_);
Handle<WeakCell> link_to_owning_instance = factory->NewWeakCell(instance);
MaybeHandle<WeakCell> link_to_original;
MaybeHandle<WasmCompiledModule> original;
if (!owner.is_null()) {
// prepare the data needed for publishing in a chain, but don't link
// just yet, because
// we want all the publishing to happen free from GC interruptions, and
// so we do it in
// one GC-free scope afterwards.
original = handle(owner.ToHandleChecked()->compiled_module());
link_to_original = factory->NewWeakCell(original.ToHandleChecked());
}
// Publish the new instance to the instances chain.
{
DisallowHeapAllocation no_gc;
if (!link_to_original.is_null()) {
compiled_module_->set_weak_next_instance(
link_to_original.ToHandleChecked());
original.ToHandleChecked()->set_weak_prev_instance(link_to_clone);
compiled_module_->set_weak_wasm_module(
original.ToHandleChecked()->weak_wasm_module());
}
module_object_->SetEmbedderField(0, *compiled_module_);
compiled_module_->set_weak_owning_instance(link_to_owning_instance);
GlobalHandles::MakeWeak(global_handle.location(),
global_handle.location(), &InstanceFinalizer,
v8::WeakCallbackType::kFinalizer);
}
}
//--------------------------------------------------------------------------
// Debugging support.
//--------------------------------------------------------------------------
// Set all breakpoints that were set on the shared module.
WasmSharedModuleData::SetBreakpointsOnNewInstance(
compiled_module_->shared(), instance);
if (FLAG_wasm_interpret_all && module_->is_wasm()) {
Handle<WasmDebugInfo> debug_info =
WasmInstanceObject::GetOrCreateDebugInfo(instance);
std::vector<int> func_indexes;
for (int func_index = num_imported_functions,
num_wasm_functions = static_cast<int>(module_->functions.size());
func_index < num_wasm_functions; ++func_index) {
func_indexes.push_back(func_index);
}
WasmDebugInfo::RedirectToInterpreter(
debug_info, Vector<int>(func_indexes.data(),
static_cast<int>(func_indexes.size())));
}
//--------------------------------------------------------------------------
// Run the start function if one was specified.
//--------------------------------------------------------------------------
if (module_->start_function_index >= 0) {
HandleScope scope(isolate_);
int start_index = module_->start_function_index;
Handle<Code> startup_code = EnsureExportedLazyDeoptData(
isolate_, instance, code_table, start_index);
FunctionSig* sig = module_->functions[start_index].sig;
Handle<Code> wrapper_code =
js_to_wasm_cache_.CloneOrCompileJSToWasmWrapper(
isolate_, module_, startup_code, start_index);
Handle<WasmExportedFunction> startup_fct = WasmExportedFunction::New(
isolate_, instance, MaybeHandle<String>(), start_index,
static_cast<int>(sig->parameter_count()), wrapper_code);
RecordStats(isolate_, *startup_code, is_sync_);
// Call the JS function.
Handle<Object> undefined = factory->undefined_value();
MaybeHandle<Object> retval =
Execution::Call(isolate_, startup_fct, undefined, 0, nullptr);
if (retval.is_null()) {
DCHECK(isolate_->has_pending_exception());
isolate_->OptionalRescheduleException(false);
// It's unfortunate that the new instance is already linked in the
// chain. However, we need to set up everything before executing the
// start function, such that stack trace information can be generated
// correctly already in the start function.
return {};
}
}
DCHECK(!isolate_->has_pending_exception());
TRACE("Finishing instance %d\n", compiled_module_->instance_id());
TRACE_CHAIN(module_object_->compiled_module());
return instance;
}
private:
// Represents the initialized state of a table.
struct TableInstance {
Handle<WasmTableObject> table_object; // WebAssembly.Table instance
Handle<FixedArray> js_wrappers; // JSFunctions exported
Handle<FixedArray> function_table; // internal code array
Handle<FixedArray> signature_table; // internal sig array
};
Isolate* isolate_;
WasmModule* const module_;
constexpr static bool is_sync_ = true;
ErrorThrower* thrower_;
Handle<WasmModuleObject> module_object_;
Handle<JSReceiver> ffi_; // TODO(titzer): Use MaybeHandle
Handle<JSArrayBuffer> memory_; // TODO(titzer): Use MaybeHandle
Handle<JSArrayBuffer> globals_;
Handle<WasmCompiledModule> compiled_module_;
std::vector<TableInstance> table_instances_;
std::vector<Handle<JSFunction>> js_wrappers_;
JSToWasmWrapperCache js_to_wasm_cache_;
// Helper routines to print out errors with imports.
#define ERROR_THROWER_WITH_MESSAGE(TYPE) \
void Report##TYPE(const char* error, uint32_t index, \
Handle<String> module_name, Handle<String> import_name) { \
thrower_->TYPE("Import #%d module=\"%.*s\" function=\"%.*s\" error: %s", \
index, module_name->length(), \
module_name->ToCString().get(), import_name->length(), \
import_name->ToCString().get(), error); \
} \
\
MaybeHandle<Object> Report##TYPE(const char* error, uint32_t index, \
Handle<String> module_name) { \
thrower_->TYPE("Import #%d module=\"%.*s\" error: %s", index, \
module_name->length(), module_name->ToCString().get(), \
error); \
return MaybeHandle<Object>(); \
}
ERROR_THROWER_WITH_MESSAGE(LinkError)
ERROR_THROWER_WITH_MESSAGE(TypeError)
// Look up an import value in the {ffi_} object.
MaybeHandle<Object> LookupImport(uint32_t index, Handle<String> module_name,
Handle<String> import_name) {
// We pre-validated in the js-api layer that the ffi object is present, and
// a JSObject, if the module has imports.
DCHECK(!ffi_.is_null());
// Look up the module first.
MaybeHandle<Object> result =
Object::GetPropertyOrElement(ffi_, module_name);
if (result.is_null()) {
return ReportTypeError("module not found", index, module_name);
}
Handle<Object> module = result.ToHandleChecked();
// Look up the value in the module.
if (!module->IsJSReceiver()) {
return ReportTypeError("module is not an object or function", index,
module_name);
}
result = Object::GetPropertyOrElement(module, import_name);
if (result.is_null()) {
ReportLinkError("import not found", index, module_name, import_name);
return MaybeHandle<JSFunction>();
}
return result;
}
uint32_t EvalUint32InitExpr(const WasmInitExpr& expr) {
switch (expr.kind) {
case WasmInitExpr::kI32Const:
return expr.val.i32_const;
case WasmInitExpr::kGlobalIndex: {
uint32_t offset = module_->globals[expr.val.global_index].offset;
return *reinterpret_cast<uint32_t*>(raw_buffer_ptr(globals_, offset));
}
default:
UNREACHABLE();
return 0;
}
}
bool in_bounds(uint32_t offset, uint32_t size, uint32_t upper) {
return offset + size <= upper && offset + size >= offset;
}
// Load data segments into the memory.
void LoadDataSegments(Address mem_addr, size_t mem_size) {
Handle<SeqOneByteString> module_bytes(compiled_module_->module_bytes(),
isolate_);
for (const WasmDataSegment& segment : module_->data_segments) {
uint32_t source_size = segment.source_size;
// Segments of size == 0 are just nops.
if (source_size == 0) continue;
uint32_t dest_offset = EvalUint32InitExpr(segment.dest_addr);
DCHECK(in_bounds(dest_offset, source_size,
static_cast<uint32_t>(mem_size)));
byte* dest = mem_addr + dest_offset;
const byte* src = reinterpret_cast<const byte*>(
module_bytes->GetCharsAddress() + segment.source_offset);
memcpy(dest, src, source_size);
}
}
void WriteGlobalValue(WasmGlobal& global, Handle<Object> value) {
double num = value->Number();
TRACE("init [globals+%u] = %lf, type = %s\n", global.offset, num,
WasmOpcodes::TypeName(global.type));
switch (global.type) {
case kWasmI32:
*GetRawGlobalPtr<int32_t>(global) = static_cast<int32_t>(num);
break;
case kWasmI64:
// TODO(titzer): initialization of imported i64 globals.
UNREACHABLE();
break;
case kWasmF32:
*GetRawGlobalPtr<float>(global) = static_cast<float>(num);
break;
case kWasmF64:
*GetRawGlobalPtr<double>(global) = static_cast<double>(num);
break;
default:
UNREACHABLE();
}
}
// Process the imports, including functions, tables, globals, and memory, in
// order, loading them from the {ffi_} object. Returns the number of imported
// functions.
int ProcessImports(Handle<FixedArray> code_table,
Handle<WasmInstanceObject> instance) {
int num_imported_functions = 0;
int num_imported_tables = 0;
for (int index = 0; index < static_cast<int>(module_->import_table.size());
++index) {
WasmImport& import = module_->import_table[index];
Handle<String> module_name;
MaybeHandle<String> maybe_module_name =
WasmCompiledModule::ExtractUtf8StringFromModuleBytes(
isolate_, compiled_module_, import.module_name_offset,
import.module_name_length);
if (!maybe_module_name.ToHandle(&module_name)) return -1;
Handle<String> import_name;
MaybeHandle<String> maybe_import_name =
WasmCompiledModule::ExtractUtf8StringFromModuleBytes(
isolate_, compiled_module_, import.field_name_offset,
import.field_name_length);
if (!maybe_import_name.ToHandle(&import_name)) return -1;
MaybeHandle<Object> result =
LookupImport(index, module_name, import_name);
if (thrower_->error()) return -1;
Handle<Object> value = result.ToHandleChecked();
switch (import.kind) {
case kExternalFunction: {
// Function imports must be callable.
if (!value->IsCallable()) {
ReportLinkError("function import requires a callable", index,
module_name, import_name);
return -1;
}
Handle<Code> import_wrapper = CompileImportWrapper(
isolate_, index, module_->functions[import.index].sig,
Handle<JSReceiver>::cast(value), module_name, import_name,
module_->get_origin());
if (import_wrapper.is_null()) {
ReportLinkError(
"imported function does not match the expected type", index,
module_name, import_name);
return -1;
}
code_table->set(num_imported_functions, *import_wrapper);
RecordStats(isolate_, *import_wrapper, is_sync_);
num_imported_functions++;
break;
}
case kExternalTable: {
if (!WasmJs::IsWasmTableObject(isolate_, value)) {
ReportLinkError("table import requires a WebAssembly.Table", index,
module_name, import_name);
return -1;
}
WasmIndirectFunctionTable& table =
module_->function_tables[num_imported_tables];
TableInstance& table_instance = table_instances_[num_imported_tables];
table_instance.table_object = Handle<WasmTableObject>::cast(value);
table_instance.js_wrappers = Handle<FixedArray>(
table_instance.table_object->functions(), isolate_);
int imported_cur_size = table_instance.js_wrappers->length();
if (imported_cur_size < static_cast<int>(table.min_size)) {
thrower_->LinkError(
"table import %d is smaller than minimum %d, got %u", index,
table.min_size, imported_cur_size);
return -1;
}
if (table.has_max) {
int64_t imported_max_size =
table_instance.table_object->maximum_length();
if (imported_max_size < 0) {
thrower_->LinkError(
"table import %d has no maximum length, expected %d", index,
table.max_size);
return -1;
}
if (imported_max_size > table.max_size) {
thrower_->LinkError(
"table import %d has maximum larger than maximum %d, "
"got %" PRIx64,
index, table.max_size, imported_max_size);
return -1;
}
}
// Allocate a new dispatch table and signature table.
int table_size = imported_cur_size;
table_instance.function_table =
isolate_->factory()->NewFixedArray(table_size);
table_instance.signature_table =
isolate_->factory()->NewFixedArray(table_size);
for (int i = 0; i < table_size; ++i) {
table_instance.signature_table->set(i,
Smi::FromInt(kInvalidSigIndex));
}
// Initialize the dispatch table with the (foreign) JS functions
// that are already in the table.
for (int i = 0; i < table_size; ++i) {
Handle<Object> val(table_instance.js_wrappers->get(i), isolate_);
if (!val->IsJSFunction()) continue;
WasmFunction* function =
GetWasmFunctionForImportWrapper(isolate_, val);
if (function == nullptr) {
thrower_->LinkError("table import %d[%d] is not a WASM function",
index, i);
return -1;
}
int sig_index = table.map.FindOrInsert(function->sig);
table_instance.signature_table->set(i, Smi::FromInt(sig_index));
table_instance.function_table->set(i, *UnwrapImportWrapper(val));
}
num_imported_tables++;
break;
}
case kExternalMemory: {
// Validation should have failed if more than one memory object was
// provided.
DCHECK(!instance->has_memory_object());
if (!WasmJs::IsWasmMemoryObject(isolate_, value)) {
ReportLinkError("memory import must be a WebAssembly.Memory object",
index, module_name, import_name);
return -1;
}
auto memory = Handle<WasmMemoryObject>::cast(value);
DCHECK(WasmJs::IsWasmMemoryObject(isolate_, memory));
instance->set_memory_object(*memory);
memory_ = Handle<JSArrayBuffer>(memory->buffer(), isolate_);
uint32_t imported_cur_pages = static_cast<uint32_t>(
memory_->byte_length()->Number() / WasmModule::kPageSize);
if (imported_cur_pages < module_->min_mem_pages) {
thrower_->LinkError(
"memory import %d is smaller than maximum %u, got %u", index,
module_->min_mem_pages, imported_cur_pages);
}
int32_t imported_max_pages = memory->maximum_pages();
if (module_->has_max_mem) {
if (imported_max_pages < 0) {
thrower_->LinkError(
"memory import %d has no maximum limit, expected at most %u",
index, imported_max_pages);
return -1;
}
if (static_cast<uint32_t>(imported_max_pages) >
module_->max_mem_pages) {
thrower_->LinkError(
"memory import %d has larger maximum than maximum %u, got %d",
index, module_->max_mem_pages, imported_max_pages);
return -1;
}
}
break;
}
case kExternalGlobal: {
// Global imports are converted to numbers and written into the
// {globals_} array buffer.
if (module_->globals[import.index].type == kWasmI64) {
ReportLinkError("global import cannot have type i64", index,
module_name, import_name);
return -1;
}
if (module_->is_asm_js()) {
if (module_->globals[import.index].type == kWasmI32) {
value = Object::ToInt32(isolate_, value).ToHandleChecked();
} else {
value = Object::ToNumber(value).ToHandleChecked();
}
}
if (!value->IsNumber()) {
ReportLinkError("global import must be a number", index,
module_name, import_name);
return -1;
}
WriteGlobalValue(module_->globals[import.index], value);
break;
}
default:
UNREACHABLE();
break;
}
}
return num_imported_functions;
}
template <typename T>
T* GetRawGlobalPtr(WasmGlobal& global) {
return reinterpret_cast<T*>(raw_buffer_ptr(globals_, global.offset));
}
// Process initialization of globals.
void InitGlobals() {
for (auto global : module_->globals) {
switch (global.init.kind) {
case WasmInitExpr::kI32Const:
*GetRawGlobalPtr<int32_t>(global) = global.init.val.i32_const;
break;
case WasmInitExpr::kI64Const:
*GetRawGlobalPtr<int64_t>(global) = global.init.val.i64_const;
break;
case WasmInitExpr::kF32Const:
*GetRawGlobalPtr<float>(global) = global.init.val.f32_const;
break;
case WasmInitExpr::kF64Const:
*GetRawGlobalPtr<double>(global) = global.init.val.f64_const;
break;
case WasmInitExpr::kGlobalIndex: {
// Initialize with another global.
uint32_t new_offset = global.offset;
uint32_t old_offset =
module_->globals[global.init.val.global_index].offset;
TRACE("init [globals+%u] = [globals+%d]\n", global.offset,
old_offset);
size_t size = (global.type == kWasmI64 || global.type == kWasmF64)
? sizeof(double)
: sizeof(int32_t);
memcpy(raw_buffer_ptr(globals_, new_offset),
raw_buffer_ptr(globals_, old_offset), size);
break;
}
case WasmInitExpr::kNone:
// Happens with imported globals.
break;
default:
UNREACHABLE();
break;
}
}
}
// Allocate memory for a module instance as a new JSArrayBuffer.
Handle<JSArrayBuffer> AllocateMemory(uint32_t min_mem_pages) {
if (min_mem_pages > FLAG_wasm_max_mem_pages) {
thrower_->RangeError("Out of memory: wasm memory too large");
return Handle<JSArrayBuffer>::null();
}
const bool enable_guard_regions = EnableGuardRegions();
Handle<JSArrayBuffer> mem_buffer = NewArrayBuffer(
isolate_, min_mem_pages * WasmModule::kPageSize, enable_guard_regions);
if (mem_buffer.is_null()) {
thrower_->RangeError("Out of memory: wasm memory");
}
return mem_buffer;
}
bool NeedsWrappers() {
if (module_->num_exported_functions > 0) return true;
for (auto table_instance : table_instances_) {
if (!table_instance.js_wrappers.is_null()) return true;
}
for (auto table : module_->function_tables) {
if (table.exported) return true;
}
return false;
}
// Process the exports, creating wrappers for functions, tables, memories,
// and globals.
void ProcessExports(Handle<FixedArray> code_table,
Handle<WasmInstanceObject> instance,
Handle<WasmCompiledModule> compiled_module) {
if (NeedsWrappers()) {
// Fill the table to cache the exported JSFunction wrappers.
js_wrappers_.insert(js_wrappers_.begin(), module_->functions.size(),
Handle<JSFunction>::null());
}
Handle<JSObject> exports_object;
if (module_->is_wasm()) {
// Create the "exports" object.
exports_object = isolate_->factory()->NewJSObjectWithNullProto();
} else if (module_->is_asm_js()) {
Handle<JSFunction> object_function = Handle<JSFunction>(
isolate_->native_context()->object_function(), isolate_);
exports_object = isolate_->factory()->NewJSObject(object_function);
} else {
UNREACHABLE();
}
Handle<String> exports_name =
isolate_->factory()->InternalizeUtf8String("exports");
JSObject::AddProperty(instance, exports_name, exports_object, NONE);
Handle<String> single_function_name =
isolate_->factory()->InternalizeUtf8String(AsmJs::kSingleFunctionName);
PropertyDescriptor desc;
desc.set_writable(module_->is_asm_js());
desc.set_enumerable(true);
desc.set_configurable(module_->is_asm_js());
// Store weak references to all exported functions.
Handle<FixedArray> weak_exported_functions;
if (compiled_module->has_weak_exported_functions()) {
weak_exported_functions = compiled_module->weak_exported_functions();
} else {
int export_count = 0;
for (WasmExport& exp : module_->export_table) {
if (exp.kind == kExternalFunction) ++export_count;
}
weak_exported_functions =
isolate_->factory()->NewFixedArray(export_count);
compiled_module->set_weak_exported_functions(weak_exported_functions);
}
// Process each export in the export table.
int export_index = 0; // Index into {weak_exported_functions}.
for (WasmExport& exp : module_->export_table) {
Handle<String> name =
WasmCompiledModule::ExtractUtf8StringFromModuleBytes(
isolate_, compiled_module_, exp.name_offset, exp.name_length)
.ToHandleChecked();
Handle<JSObject> export_to;
if (module_->is_asm_js() && exp.kind == kExternalFunction &&
String::Equals(name, single_function_name)) {
export_to = instance;
} else {
export_to = exports_object;
}
switch (exp.kind) {
case kExternalFunction: {
// Wrap and export the code as a JSFunction.
WasmFunction& function = module_->functions[exp.index];
int func_index =
static_cast<int>(module_->functions.size() + export_index);
Handle<JSFunction> js_function = js_wrappers_[exp.index];
if (js_function.is_null()) {
// Wrap the exported code as a JSFunction.
Handle<Code> export_code =
code_table->GetValueChecked<Code>(isolate_, func_index);
MaybeHandle<String> func_name;
if (module_->is_asm_js()) {
// For modules arising from asm.js, honor the names section.
func_name = WasmCompiledModule::ExtractUtf8StringFromModuleBytes(
isolate_, compiled_module_, function.name_offset,
function.name_length)
.ToHandleChecked();
}
js_function = WasmExportedFunction::New(
isolate_, instance, func_name, function.func_index,
static_cast<int>(function.sig->parameter_count()), export_code);
js_wrappers_[exp.index] = js_function;
}
desc.set_value(js_function);
Handle<WeakCell> weak_export =
isolate_->factory()->NewWeakCell(js_function);
DCHECK_GT(weak_exported_functions->length(), export_index);
weak_exported_functions->set(export_index, *weak_export);
export_index++;
break;
}
case kExternalTable: {
// Export a table as a WebAssembly.Table object.
TableInstance& table_instance = table_instances_[exp.index];
WasmIndirectFunctionTable& table =
module_->function_tables[exp.index];
if (table_instance.table_object.is_null()) {
uint32_t maximum =
table.has_max ? table.max_size : FLAG_wasm_max_table_size;
table_instance.table_object = WasmTableObject::New(
isolate_, table.min_size, maximum, &table_instance.js_wrappers);
}
desc.set_value(table_instance.table_object);
break;
}
case kExternalMemory: {
// Export the memory as a WebAssembly.Memory object.
Handle<WasmMemoryObject> memory_object;
if (!instance->has_memory_object()) {
// If there was no imported WebAssembly.Memory object, create one.
memory_object = WasmMemoryObject::New(
isolate_,
(instance->has_memory_buffer())
? handle(instance->memory_buffer())
: Handle<JSArrayBuffer>::null(),
(module_->max_mem_pages != 0) ? module_->max_mem_pages : -1);
instance->set_memory_object(*memory_object);
} else {
memory_object =
Handle<WasmMemoryObject>(instance->memory_object(), isolate_);
DCHECK(WasmJs::IsWasmMemoryObject(isolate_, memory_object));
memory_object->ResetInstancesLink(isolate_);
}
desc.set_value(memory_object);
break;
}
case kExternalGlobal: {
// Export the value of the global variable as a number.
WasmGlobal& global = module_->globals[exp.index];
double num = 0;
switch (global.type) {
case kWasmI32:
num = *GetRawGlobalPtr<int32_t>(global);
break;
case kWasmF32:
num = *GetRawGlobalPtr<float>(global);
break;
case kWasmF64:
num = *GetRawGlobalPtr<double>(global);
break;
case kWasmI64:
thrower_->LinkError(
"export of globals of type I64 is not allowed.");
break;
default:
UNREACHABLE();
}
desc.set_value(isolate_->factory()->NewNumber(num));
break;
}
default:
UNREACHABLE();
break;
}
v8::Maybe<bool> status = JSReceiver::DefineOwnProperty(
isolate_, export_to, name, &desc, Object::THROW_ON_ERROR);
if (!status.IsJust()) {
thrower_->LinkError("export of %.*s failed.", name->length(),
name->ToCString().get());
return;
}
}
DCHECK_EQ(export_index, weak_exported_functions->length());
if (module_->is_wasm()) {
v8::Maybe<bool> success = JSReceiver::SetIntegrityLevel(
exports_object, FROZEN, Object::DONT_THROW);
DCHECK(success.FromMaybe(false));
USE(success);
}
}
void InitializeTables(Handle<WasmInstanceObject> instance,
CodeSpecialization* code_specialization) {
int function_table_count =
static_cast<int>(module_->function_tables.size());
Handle<FixedArray> new_function_tables =
isolate_->factory()->NewFixedArray(function_table_count);
Handle<FixedArray> new_signature_tables =
isolate_->factory()->NewFixedArray(function_table_count);
for (int index = 0; index < function_table_count; ++index) {
WasmIndirectFunctionTable& table = module_->function_tables[index];
TableInstance& table_instance = table_instances_[index];
int table_size = static_cast<int>(table.min_size);
if (table_instance.function_table.is_null()) {
// Create a new dispatch table if necessary.
table_instance.function_table =
isolate_->factory()->NewFixedArray(table_size);
table_instance.signature_table =
isolate_->factory()->NewFixedArray(table_size);
for (int i = 0; i < table_size; ++i) {
// Fill the table with invalid signature indexes so that
// uninitialized entries will always fail the signature check.
table_instance.signature_table->set(i,
Smi::FromInt(kInvalidSigIndex));
}
} else {
// Table is imported, patch table bounds check
DCHECK(table_size <= table_instance.function_table->length());
if (table_size < table_instance.function_table->length()) {
code_specialization->PatchTableSize(
table_size, table_instance.function_table->length());
}
}
new_function_tables->set(static_cast<int>(index),
*table_instance.function_table);
new_signature_tables->set(static_cast<int>(index),
*table_instance.signature_table);
}
FixedArray* old_function_tables =
compiled_module_->ptr_to_function_tables();
DCHECK_EQ(old_function_tables->length(), new_function_tables->length());
for (int i = 0, e = new_function_tables->length(); i < e; ++i) {
code_specialization->RelocateObject(
handle(old_function_tables->get(i), isolate_),
handle(new_function_tables->get(i), isolate_));
}
FixedArray* old_signature_tables =
compiled_module_->ptr_to_signature_tables();
DCHECK_EQ(old_signature_tables->length(), new_signature_tables->length());
for (int i = 0, e = new_signature_tables->length(); i < e; ++i) {
code_specialization->RelocateObject(
handle(old_signature_tables->get(i), isolate_),
handle(new_signature_tables->get(i), isolate_));
}
compiled_module_->set_function_tables(new_function_tables);
compiled_module_->set_signature_tables(new_signature_tables);
}
void LoadTableSegments(Handle<FixedArray> code_table,
Handle<WasmInstanceObject> instance) {
int function_table_count =
static_cast<int>(module_->function_tables.size());
for (int index = 0; index < function_table_count; ++index) {
WasmIndirectFunctionTable& table = module_->function_tables[index];
TableInstance& table_instance = table_instances_[index];
Handle<FixedArray> all_dispatch_tables;
if (!table_instance.table_object.is_null()) {
// Get the existing dispatch table(s) with the WebAssembly.Table object.
all_dispatch_tables =
handle(table_instance.table_object->dispatch_tables());
}
// Count the number of table exports for each function (needed for lazy
// compilation).
std::unordered_map<uint32_t, uint32_t> num_table_exports;
if (compile_lazy(module_)) {
for (auto table_init : module_->table_inits) {
for (uint32_t func_index : table_init.entries) {
Code* code =
Code::cast(code_table->get(static_cast<int>(func_index)));
// Only increase the counter for lazy compile builtins (it's not
// needed otherwise).
if (code->is_wasm_code()) continue;
DCHECK_EQ(Builtins::kWasmCompileLazy, code->builtin_index());
++num_table_exports[func_index];
}
}
}
// TODO(titzer): this does redundant work if there are multiple tables,
// since initializations are not sorted by table index.
for (auto table_init : module_->table_inits) {
uint32_t base = EvalUint32InitExpr(table_init.offset);
DCHECK(in_bounds(base, static_cast<uint32_t>(table_init.entries.size()),
table_instance.function_table->length()));
for (int i = 0, e = static_cast<int>(table_init.entries.size()); i < e;
++i) {
uint32_t func_index = table_init.entries[i];
WasmFunction* function = &module_->functions[func_index];
int table_index = static_cast<int>(i + base);
int32_t sig_index = table.map.Find(function->sig);
DCHECK_GE(sig_index, 0);
table_instance.signature_table->set(table_index,
Smi::FromInt(sig_index));
Handle<Code> wasm_code = EnsureTableExportLazyDeoptData(
isolate_, instance, code_table, func_index,
table_instance.function_table, table_index, num_table_exports);
table_instance.function_table->set(table_index, *wasm_code);
if (!all_dispatch_tables.is_null()) {
if (js_wrappers_[func_index].is_null()) {
// No JSFunction entry yet exists for this function. Create one.
// TODO(titzer): We compile JS->WASM wrappers for functions are
// not exported but are in an exported table. This should be done
// at module compile time and cached instead.
Handle<Code> wrapper_code =
js_to_wasm_cache_.CloneOrCompileJSToWasmWrapper(
isolate_, module_, wasm_code, func_index);
MaybeHandle<String> func_name;
if (module_->is_asm_js()) {
// For modules arising from asm.js, honor the names section.
func_name =
WasmCompiledModule::ExtractUtf8StringFromModuleBytes(
isolate_, compiled_module_, function->name_offset,
function->name_length)
.ToHandleChecked();
}
Handle<WasmExportedFunction> js_function =
WasmExportedFunction::New(
isolate_, instance, func_name, func_index,
static_cast<int>(function->sig->parameter_count()),
wrapper_code);
js_wrappers_[func_index] = js_function;
}
table_instance.js_wrappers->set(table_index,
*js_wrappers_[func_index]);
UpdateDispatchTablesInternal(isolate_, all_dispatch_tables,
table_index, function, wasm_code);
}
}
}
#ifdef DEBUG
// Check that the count of table exports was accurate. The entries are
// decremented on each export, so all should be zero now.
for (auto e : num_table_exports) {
DCHECK_EQ(0, e.second);
}
#endif
// TODO(titzer): we add the new dispatch table at the end to avoid
// redundant work and also because the new instance is not yet fully
// initialized.
if (!table_instance.table_object.is_null()) {
// Add the new dispatch table to the WebAssembly.Table object.
all_dispatch_tables = WasmTableObject::AddDispatchTable(
isolate_, table_instance.table_object, instance, index,
table_instance.function_table, table_instance.signature_table);
}
}
}
};
bool wasm::IsWasmInstance(Object* object) {
return WasmInstanceObject::IsWasmInstanceObject(object);
}
Handle<Script> wasm::GetScript(Handle<JSObject> instance) {
WasmCompiledModule* compiled_module =
WasmInstanceObject::cast(*instance)->compiled_module();
return handle(compiled_module->script());
}
bool wasm::IsWasmCodegenAllowed(Isolate* isolate, Handle<Context> context) {
return isolate->allow_code_gen_callback() == nullptr ||
isolate->allow_code_gen_callback()(v8::Utils::ToLocal(context));
}
void wasm::DetachWebAssemblyMemoryBuffer(Isolate* isolate,
Handle<JSArrayBuffer> buffer,
bool free_memory) {
int64_t byte_length =
buffer->byte_length()->IsNumber()
? static_cast<uint32_t>(buffer->byte_length()->Number())
: 0;
if (buffer.is_null() || byte_length == 0) return;
const bool is_external = buffer->is_external();
DCHECK(!buffer->is_neuterable());
if (!is_external) {
buffer->set_is_external(true);
isolate->heap()->UnregisterArrayBuffer(*buffer);
if (free_memory) {
// We need to free the memory before neutering the buffer because
// FreeBackingStore reads buffer->allocation_base(), which is nulled out
// by Neuter. This means there is a dangling pointer until we neuter the
// buffer. Since there is no way for the user to directly call
// FreeBackingStore, we can ensure this is safe.
buffer->FreeBackingStore();
}
}
buffer->set_is_neuterable(true);
buffer->Neuter();
}
void testing::ValidateInstancesChain(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->ptr_to_weak_wasm_module()->value()),
*module_obj);
Object* prev = nullptr;
int found_instances = compiled_module->has_weak_owning_instance() ? 1 : 0;
WasmCompiledModule* current_instance = compiled_module;
while (current_instance->has_weak_next_instance()) {
CHECK((prev == nullptr && !current_instance->has_weak_prev_instance()) ||
current_instance->ptr_to_weak_prev_instance()->value() == prev);
CHECK_EQ(current_instance->ptr_to_weak_wasm_module()->value(), *module_obj);
CHECK(IsWasmInstance(
current_instance->ptr_to_weak_owning_instance()->value()));
prev = current_instance;
current_instance = WasmCompiledModule::cast(
current_instance->ptr_to_weak_next_instance()->value());
++found_instances;
CHECK_LE(found_instances, instance_count);
}
CHECK_EQ(found_instances, instance_count);
}
void testing::ValidateModuleState(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->ptr_to_weak_wasm_module()->value(), *module_obj);
CHECK(!compiled_module->has_weak_prev_instance());
CHECK(!compiled_module->has_weak_next_instance());
CHECK(!compiled_module->has_weak_owning_instance());
}
void testing::ValidateOrphanedInstance(Isolate* isolate,
Handle<WasmInstanceObject> instance) {
DisallowHeapAllocation no_gc;
WasmCompiledModule* compiled_module = instance->compiled_module();
CHECK(compiled_module->has_weak_wasm_module());
CHECK(compiled_module->ptr_to_weak_wasm_module()->cleared());
}
Handle<JSArray> wasm::GetImports(Isolate* isolate,
Handle<WasmModuleObject> module_object) {
Handle<WasmCompiledModule> compiled_module(module_object->compiled_module(),
isolate);
Factory* factory = isolate->factory();
Handle<String> module_string = factory->InternalizeUtf8String("module");
Handle<String> name_string = factory->InternalizeUtf8String("name");
Handle<String> kind_string = factory->InternalizeUtf8String("kind");
Handle<String> function_string = factory->InternalizeUtf8String("function");
Handle<String> table_string = factory->InternalizeUtf8String("table");
Handle<String> memory_string = factory->InternalizeUtf8String("memory");
Handle<String> global_string = factory->InternalizeUtf8String("global");
// Create the result array.
WasmModule* module = compiled_module->module();
int num_imports = static_cast<int>(module->import_table.size());
Handle<JSArray> array_object = factory->NewJSArray(FAST_ELEMENTS, 0, 0);
Handle<FixedArray> storage = factory->NewFixedArray(num_imports);
JSArray::SetContent(array_object, storage);
array_object->set_length(Smi::FromInt(num_imports));
Handle<JSFunction> object_function =
Handle<JSFunction>(isolate->native_context()->object_function(), isolate);
// Populate the result array.
for (int index = 0; index < num_imports; ++index) {
WasmImport& import = module->import_table[index];
Handle<JSObject> entry = factory->NewJSObject(object_function);
Handle<String> import_kind;
switch (import.kind) {
case kExternalFunction:
import_kind = function_string;
break;
case kExternalTable:
import_kind = table_string;
break;
case kExternalMemory:
import_kind = memory_string;
break;
case kExternalGlobal:
import_kind = global_string;
break;
default:
UNREACHABLE();
}
MaybeHandle<String> import_module =
WasmCompiledModule::ExtractUtf8StringFromModuleBytes(
isolate, compiled_module, import.module_name_offset,
import.module_name_length);
MaybeHandle<String> import_name =
WasmCompiledModule::ExtractUtf8StringFromModuleBytes(
isolate, compiled_module, import.field_name_offset,
import.field_name_length);
JSObject::AddProperty(entry, module_string, import_module.ToHandleChecked(),
NONE);
JSObject::AddProperty(entry, name_string, import_name.ToHandleChecked(),
NONE);
JSObject::AddProperty(entry, kind_string, import_kind, NONE);
storage->set(index, *entry);
}
return array_object;
}
Handle<JSArray> wasm::GetExports(Isolate* isolate,
Handle<WasmModuleObject> module_object) {
Handle<WasmCompiledModule> compiled_module(module_object->compiled_module(),
isolate);
Factory* factory = isolate->factory();
Handle<String> name_string = factory->InternalizeUtf8String("name");
Handle<String> kind_string = factory->InternalizeUtf8String("kind");
Handle<String> function_string = factory->InternalizeUtf8String("function");
Handle<String> table_string = factory->InternalizeUtf8String("table");
Handle<String> memory_string = factory->InternalizeUtf8String("memory");
Handle<String> global_string = factory->InternalizeUtf8String("global");
// Create the result array.
WasmModule* module = compiled_module->module();
int num_exports = static_cast<int>(module->export_table.size());
Handle<JSArray> array_object = factory->NewJSArray(FAST_ELEMENTS, 0, 0);
Handle<FixedArray> storage = factory->NewFixedArray(num_exports);
JSArray::SetContent(array_object, storage);
array_object->set_length(Smi::FromInt(num_exports));
Handle<JSFunction> object_function =
Handle<JSFunction>(isolate->native_context()->object_function(), isolate);
// Populate the result array.
for (int index = 0; index < num_exports; ++index) {
WasmExport& exp = module->export_table[index];
Handle<String> export_kind;
switch (exp.kind) {
case kExternalFunction:
export_kind = function_string;
break;
case kExternalTable:
export_kind = table_string;
break;
case kExternalMemory:
export_kind = memory_string;
break;
case kExternalGlobal:
export_kind = global_string;
break;
default:
UNREACHABLE();
}
Handle<JSObject> entry = factory->NewJSObject(object_function);
MaybeHandle<String> export_name =
WasmCompiledModule::ExtractUtf8StringFromModuleBytes(
isolate, compiled_module, exp.name_offset, exp.name_length);
JSObject::AddProperty(entry, name_string, export_name.ToHandleChecked(),
NONE);
JSObject::AddProperty(entry, kind_string, export_kind, NONE);
storage->set(index, *entry);
}
return array_object;
}
Handle<JSArray> wasm::GetCustomSections(Isolate* isolate,
Handle<WasmModuleObject> module_object,
Handle<String> name,
ErrorThrower* thrower) {
Handle<WasmCompiledModule> compiled_module(module_object->compiled_module(),
isolate);
Factory* factory = isolate->factory();
std::vector<CustomSectionOffset> custom_sections;
{
DisallowHeapAllocation no_gc; // for raw access to string bytes.
Handle<SeqOneByteString> module_bytes(compiled_module->module_bytes(),
isolate);
const byte* start =
reinterpret_cast<const byte*>(module_bytes->GetCharsAddress());
const byte* end = start + module_bytes->length();
custom_sections = DecodeCustomSections(start, end);
}
std::vector<Handle<Object>> matching_sections;
// Gather matching sections.
for (auto section : custom_sections) {
MaybeHandle<String> section_name =
WasmCompiledModule::ExtractUtf8StringFromModuleBytes(
isolate, compiled_module, section.name_offset, section.name_length);
if (!name->Equals(*section_name.ToHandleChecked())) continue;
// Make a copy of the payload data in the section.
void* allocation_base = nullptr; // Set by TryAllocateBackingStore
size_t allocation_length = 0; // Set by TryAllocateBackingStore
const bool enable_guard_regions = false;
void* memory = TryAllocateBackingStore(isolate, section.payload_length,
enable_guard_regions,
allocation_base, allocation_length);
Handle<Object> section_data = factory->undefined_value();
if (memory) {
Handle<JSArrayBuffer> buffer = isolate->factory()->NewJSArrayBuffer();
const bool is_external = false;
JSArrayBuffer::Setup(buffer, isolate, is_external, allocation_base,
allocation_length, memory,
static_cast<int>(section.payload_length));
DisallowHeapAllocation no_gc; // for raw access to string bytes.
Handle<SeqOneByteString> module_bytes(compiled_module->module_bytes(),
isolate);
const byte* start =
reinterpret_cast<const byte*>(module_bytes->GetCharsAddress());
memcpy(memory, start + section.payload_offset, section.payload_length);
section_data = buffer;
} else {
thrower->RangeError("out of memory allocating custom section data");
return Handle<JSArray>();
}
matching_sections.push_back(section_data);
}
int num_custom_sections = static_cast<int>(matching_sections.size());
Handle<JSArray> array_object = factory->NewJSArray(FAST_ELEMENTS, 0, 0);
Handle<FixedArray> storage = factory->NewFixedArray(num_custom_sections);
JSArray::SetContent(array_object, storage);
array_object->set_length(Smi::FromInt(num_custom_sections));
for (int i = 0; i < num_custom_sections; i++) {
storage->set(i, *matching_sections[i]);
}
return array_object;
}
bool wasm::SyncValidate(Isolate* isolate, const ModuleWireBytes& bytes) {
if (bytes.start() == nullptr || bytes.length() == 0) return false;
ModuleResult result =
DecodeWasmModule(isolate, bytes.start(), bytes.end(), true, kWasmOrigin);
return result.ok();
}
MaybeHandle<WasmModuleObject> wasm::SyncCompileTranslatedAsmJs(
Isolate* isolate, ErrorThrower* thrower, const ModuleWireBytes& bytes,
Handle<Script> asm_js_script,
Vector<const byte> asm_js_offset_table_bytes) {
ModuleResult result = DecodeWasmModule(isolate, bytes.start(), bytes.end(),
false, kAsmJsOrigin);
if (result.failed()) {
thrower->CompileFailed("Wasm decoding failed", result);
return {};
}
// Transfer ownership to the {WasmModuleWrapper} generated in
// {CompileToModuleObject}.
constexpr bool is_sync = true;
CompilationHelper helper(isolate, std::move(result.val), is_sync);
return helper.CompileToModuleObject(thrower, bytes, asm_js_script,
asm_js_offset_table_bytes);
}
MaybeHandle<WasmModuleObject> wasm::SyncCompile(Isolate* isolate,
ErrorThrower* thrower,
const ModuleWireBytes& bytes) {
if (!IsWasmCodegenAllowed(isolate, isolate->native_context())) {
thrower->CompileError("Wasm code generation disallowed in this context");
return {};
}
// TODO(titzer): only make a copy of the bytes if SharedArrayBuffer
std::unique_ptr<byte[]> copy(new byte[bytes.length()]);
memcpy(copy.get(), bytes.start(), bytes.length());
ModuleWireBytes bytes_copy(copy.get(), copy.get() + bytes.length());
ModuleResult result = DecodeWasmModule(isolate, bytes_copy.start(),
bytes_copy.end(), false, kWasmOrigin);
if (result.failed()) {
thrower->CompileFailed("Wasm decoding failed", result);
return {};
}
// Transfer ownership to the {WasmModuleWrapper} generated in
// {CompileToModuleObject}.
constexpr bool is_sync = true;
CompilationHelper helper(isolate, std::move(result.val), is_sync);
return helper.CompileToModuleObject(thrower, bytes_copy, Handle<Script>(),
Vector<const byte>());
}
MaybeHandle<WasmInstanceObject> wasm::SyncInstantiate(
Isolate* isolate, ErrorThrower* thrower,
Handle<WasmModuleObject> module_object, MaybeHandle<JSReceiver> imports,
MaybeHandle<JSArrayBuffer> memory) {
InstantiationHelper helper(isolate, thrower, module_object, imports, memory);
return helper.Build();
}
namespace {
void RejectPromise(Isolate* isolate, Handle<Context> context,
ErrorThrower& thrower, Handle<JSPromise> promise) {
v8::Local<v8::Promise::Resolver> resolver =
v8::Utils::PromiseToLocal(promise).As<v8::Promise::Resolver>();
auto maybe = resolver->Reject(v8::Utils::ToLocal(context),
v8::Utils::ToLocal(thrower.Reify()));
CHECK_IMPLIES(!maybe.FromMaybe(false), isolate->has_scheduled_exception());
}
void ResolvePromise(Isolate* isolate, Handle<Context> context,
Handle<JSPromise> promise, Handle<Object> result) {
v8::Local<v8::Promise::Resolver> resolver =
v8::Utils::PromiseToLocal(promise).As<v8::Promise::Resolver>();
auto maybe = resolver->Resolve(v8::Utils::ToLocal(context),
v8::Utils::ToLocal(result));
CHECK_IMPLIES(!maybe.FromMaybe(false), isolate->has_scheduled_exception());
}
} // namespace
void wasm::AsyncInstantiate(Isolate* isolate, Handle<JSPromise> promise,
Handle<WasmModuleObject> module_object,
MaybeHandle<JSReceiver> imports) {
ErrorThrower thrower(isolate, nullptr);
MaybeHandle<WasmInstanceObject> instance_object = SyncInstantiate(
isolate, &thrower, module_object, imports, Handle<JSArrayBuffer>::null());
if (thrower.error()) {
RejectPromise(isolate, handle(isolate->context()), thrower, promise);
return;
}
ResolvePromise(isolate, handle(isolate->context()), promise,
instance_object.ToHandleChecked());
}
// Encapsulates all the state and steps of an asynchronous compilation.
// An asynchronous compile job consists of a number of tasks that are executed
// as foreground and background tasks. Any phase that touches the V8 heap or
// allocates on the V8 heap (e.g. creating the module object) must be a
// foreground task. All other tasks (e.g. decoding and validating, the majority
// of the work of compilation) can be background tasks.
// TODO(wasm): factor out common parts of this with the synchronous pipeline.
//
// Note: In predictable mode, DoSync and DoAsync execute the referenced function
// immediately before returning. Thus we handle the predictable mode specially,
// e.g. when we synchronizing tasks or when we delete the AyncCompileJob.
class AsyncCompileJob {
// TODO(ahaas): Fix https://bugs.chromium.org/p/v8/issues/detail?id=6263 to
// make sure that d8 does not shut down before the AsyncCompileJob is
// finished.
public:
explicit AsyncCompileJob(Isolate* isolate, std::unique_ptr<byte[]> bytes_copy,
size_t length, Handle<Context> context,
Handle<JSPromise> promise)
: isolate_(isolate),
bytes_copy_(std::move(bytes_copy)),
wire_bytes_(bytes_copy_.get(), bytes_copy_.get() + length) {
// The handles for the context and promise must be deferred.
DeferredHandleScope deferred(isolate);
context_ = Handle<Context>(*context);
module_promise_ = Handle<JSPromise>(*promise);
deferred_handles_.push_back(deferred.Detach());
}
void Start() {
DoAsync<DecodeModule>(); // --
}
~AsyncCompileJob() {
for (auto d : deferred_handles_) delete d;
}
private:
Isolate* isolate_;
std::unique_ptr<byte[]> bytes_copy_;
ModuleWireBytes wire_bytes_;
Handle<Context> context_;
Handle<JSPromise> module_promise_;
std::unique_ptr<CompilationHelper> helper_;
std::unique_ptr<ModuleBytesEnv> module_bytes_env_;
bool failed_ = false;
std::vector<DeferredHandles*> deferred_handles_;
Handle<WasmModuleObject> module_object_;
Handle<FixedArray> function_tables_;
Handle<FixedArray> signature_tables_;
Handle<WasmCompiledModule> compiled_module_;
Handle<FixedArray> code_table_;
std::unique_ptr<WasmInstance> temp_instance_ = nullptr;
size_t outstanding_units_ = 0;
size_t num_background_tasks_ = 0;
void ReopenHandlesInDeferredScope() {
DeferredHandleScope deferred(isolate_);
function_tables_ = handle(*function_tables_, isolate_);
signature_tables_ = handle(*signature_tables_, isolate_);
code_table_ = handle(*code_table_, isolate_);
temp_instance_->ReopenHandles(isolate_);
for (auto& unit : helper_->compilation_units_) {
unit->ReopenCentryStub();
}
deferred_handles_.push_back(deferred.Detach());
}
void AsyncCompileFailed(ErrorThrower& thrower) {
RejectPromise(isolate_, context_, thrower, module_promise_);
// The AsyncCompileJob is finished, we resolved the promise, we do not need
// the data anymore. We can delete the AsyncCompileJob object.
if (!FLAG_verify_predictable) delete this;
}
void AsyncCompileSucceeded(Handle<Object> result) {
ResolvePromise(isolate_, context_, module_promise_, result);
// The AsyncCompileJob is finished, we resolved the promise, we do not need
// the data anymore. We can delete the AsyncCompileJob object.
if (!FLAG_verify_predictable) delete this;
}
enum TaskType { SYNC, ASYNC };
// A closure to run a compilation step (either as foreground or background
// task) and schedule the next step(s), if any.
class CompileTask : NON_EXPORTED_BASE(public v8::Task) {
public:
AsyncCompileJob* job_ = nullptr;
CompileTask() {}
void Run() override = 0; // Force sub-classes to override Run().
};
class AsyncCompileTask : public CompileTask {};
class SyncCompileTask : public CompileTask {
public:
void Run() final {
SaveContext saved_context(job_->isolate_);
job_->isolate_->set_context(*job_->context_);
RunImpl();
}
protected:
virtual void RunImpl() = 0;
};
template <typename Task, typename... Args>
void DoSync(Args&&... args) {
static_assert(std::is_base_of<SyncCompileTask, Task>::value,
"Scheduled type must be sync");
Task* task = new Task(std::forward<Args>(args)...);
task->job_ = this;
V8::GetCurrentPlatform()->CallOnForegroundThread(
reinterpret_cast<v8::Isolate*>(isolate_), task);
}
template <typename Task, typename... Args>
void DoAsync(Args&&... args) {
static_assert(std::is_base_of<AsyncCompileTask, Task>::value,
"Scheduled type must be async");
Task* task = new Task(std::forward<Args>(args)...);
task->job_ = this;
V8::GetCurrentPlatform()->CallOnBackgroundThread(
task, v8::Platform::kShortRunningTask);
}
//==========================================================================
// Step 1: (async) Decode the module.
//==========================================================================
class DecodeModule : public AsyncCompileTask {
void Run() override {
ModuleResult result;
{
DisallowHandleAllocation no_handle;
DisallowHeapAllocation no_allocation;
// Decode the module bytes.
TRACE_COMPILE("(1) Decoding module...\n");
constexpr bool is_sync = true;
result = DecodeWasmModule(job_->isolate_, job_->wire_bytes_.start(),
job_->wire_bytes_.end(), false, kWasmOrigin,
!is_sync);
}
if (result.failed()) {
// Decoding failure; reject the promise and clean up.
job_->DoSync<DecodeFail>(std::move(result));
} else {
// Decode passed.
job_->DoSync<PrepareAndStartCompile>(std::move(result.val));
}
}
};
//==========================================================================
// Step 1b: (sync) Fail decoding the module.
//==========================================================================
class DecodeFail : public SyncCompileTask {
public:
explicit DecodeFail(ModuleResult result) : result_(std::move(result)) {}
private:
ModuleResult result_;
void RunImpl() override {
TRACE_COMPILE("(1b) Decoding failed.\n");
HandleScope scope(job_->isolate_);
ErrorThrower thrower(job_->isolate_, "AsyncCompile");
thrower.CompileFailed("Wasm decoding failed", result_);
// {job_} is deleted in AsyncCompileFailed, therefore the {return}.
return job_->AsyncCompileFailed(thrower);
}
};
//==========================================================================
// Step 2 (sync): Create heap-allocated data and start compile.
//==========================================================================
class PrepareAndStartCompile : public SyncCompileTask {
public:
explicit PrepareAndStartCompile(std::unique_ptr<WasmModule> module)
: module_(std::move(module)) {}
private:
std::unique_ptr<WasmModule> module_;
void RunImpl() override {
TRACE_COMPILE("(2) Prepare and start compile...\n");
HandleScope scope(job_->isolate_);
Factory* factory = job_->isolate_->factory();
job_->temp_instance_.reset(new WasmInstance(module_.get()));
job_->temp_instance_->context = job_->context_;
job_->temp_instance_->mem_size =
WasmModule::kPageSize * module_->min_mem_pages;
job_->temp_instance_->mem_start = nullptr;
job_->temp_instance_->globals_start = nullptr;
// Initialize the indirect tables with placeholders.
int function_table_count =
static_cast<int>(module_->function_tables.size());
job_->function_tables_ =
factory->NewFixedArray(function_table_count, TENURED);
job_->signature_tables_ =
factory->NewFixedArray(function_table_count, TENURED);
for (int i = 0; i < function_table_count; ++i) {
job_->temp_instance_->function_tables[i] =
factory->NewFixedArray(1, TENURED);
job_->temp_instance_->signature_tables[i] =
factory->NewFixedArray(1, TENURED);
job_->function_tables_->set(i,
*job_->temp_instance_->function_tables[i]);
job_->signature_tables_->set(
i, *job_->temp_instance_->signature_tables[i]);
}
// The {code_table} array contains import wrappers and functions (which
// are both included in {functions.size()}, and export wrappers.
// The results of compilation will be written into it.
int code_table_size = static_cast<int>(module_->functions.size() +
module_->num_exported_functions);
job_->code_table_ = factory->NewFixedArray(code_table_size, TENURED);
// Initialize {code_table_} with the illegal builtin. All call sites
// will be patched at instantiation.
Handle<Code> illegal_builtin = job_->isolate_->builtins()->Illegal();
// TODO(wasm): Fix this for lazy compilation.
for (uint32_t i = 0; i < module_->functions.size(); ++i) {
job_->code_table_->set(static_cast<int>(i), *illegal_builtin);
job_->temp_instance_->function_code[i] = illegal_builtin;
}
job_->isolate_->counters()->wasm_functions_per_wasm_module()->AddSample(
static_cast<int>(module_->functions.size()));
// Transfer ownership of the {WasmModule} to the {CompilationHelper}, but
// keep a pointer.
WasmModule* module = module_.get();
constexpr bool is_sync = true;
job_->helper_.reset(
new CompilationHelper(job_->isolate_, std::move(module_), !is_sync));
DCHECK_LE(module->num_imported_functions, module->functions.size());
size_t num_functions =
module->functions.size() - module->num_imported_functions;
if (num_functions == 0) {
job_->ReopenHandlesInDeferredScope();
// Degenerate case of an empty module.
job_->DoSync<FinishCompile>();
return;
}
// Start asynchronous compilation tasks.
job_->num_background_tasks_ =
Max(static_cast<size_t>(1),
Min(num_functions,
Min(static_cast<size_t>(FLAG_wasm_num_compilation_tasks),
V8::GetCurrentPlatform()
->NumberOfAvailableBackgroundThreads())));
job_->module_bytes_env_.reset(new ModuleBytesEnv(
module, job_->temp_instance_.get(), job_->wire_bytes_));
job_->outstanding_units_ = job_->helper_->InitializeParallelCompilation(
module->functions, *job_->module_bytes_env_);
// Reopen all handles which should survive in the DeferredHandleScope.
job_->ReopenHandlesInDeferredScope();
for (size_t i = 0; i < job_->num_background_tasks_; ++i) {
job_->DoAsync<ExecuteCompilationUnits>();
}
}
};
//==========================================================================
// Step 3 (async x K tasks): Execute compilation units.
//==========================================================================
class ExecuteCompilationUnits : public AsyncCompileTask {
void Run() override {
TRACE_COMPILE("(3) Compiling...\n");
for (;;) {
{
DisallowHandleAllocation no_handle;
DisallowHeapAllocation no_allocation;
if (!job_->helper_->FetchAndExecuteCompilationUnit()) break;
}
// TODO(ahaas): Create one FinishCompilationUnit job for all compilation
// units.
job_->DoSync<FinishCompilationUnit>();
// TODO(ahaas): Limit the number of outstanding compilation units to be
// finished to reduce memory overhead.
}
// Special handling for predictable mode, see above.
if (!FLAG_verify_predictable)
job_->helper_->module_->pending_tasks.get()->Signal();
}
};
//==========================================================================
// Step 4 (sync x each function): Finish a single compilation unit.
//==========================================================================
class FinishCompilationUnit : public SyncCompileTask {
void RunImpl() override {
TRACE_COMPILE("(4a) Finishing compilation unit...\n");
HandleScope scope(job_->isolate_);
if (job_->failed_) return; // already failed
int func_index = -1;
ErrorThrower thrower(job_->isolate_, "AsyncCompile");
Handle<Code> result =
job_->helper_->FinishCompilationUnit(&thrower, &func_index);
if (thrower.error()) {
job_->failed_ = true;
} else {
DCHECK(func_index >= 0);
job_->code_table_->set(func_index, *(result));
}
if (thrower.error() || --job_->outstanding_units_ == 0) {
// All compilation units are done. We still need to wait for the
// background tasks to shut down and only then is it safe to finish the
// compile and delete this job. We can wait for that to happen also
// in a background task.
job_->DoAsync<WaitForBackgroundTasks>(std::move(thrower));
}
}
};
//==========================================================================
// Step 4b (async): Wait for all background tasks to finish.
//==========================================================================
class WaitForBackgroundTasks : public AsyncCompileTask {
public:
explicit WaitForBackgroundTasks(ErrorThrower thrower)
: thrower_(std::move(thrower)) {}
private:
ErrorThrower thrower_;
void Run() override {
TRACE_COMPILE("(4b) Waiting for background tasks...\n");
// Bump next_unit_, such that background tasks stop processing the queue.
job_->helper_->next_unit_.SetValue(
job_->helper_->compilation_units_.size());
// Special handling for predictable mode, see above.
if (!FLAG_verify_predictable) {
for (size_t i = 0; i < job_->num_background_tasks_; ++i) {
// We wait for it to finish.
job_->helper_->module_->pending_tasks.get()->Wait();
}
}
if (thrower_.error()) {
job_->DoSync<FailCompile>(std::move(thrower_));
} else {
job_->DoSync<FinishCompile>();
}
}
};
//==========================================================================
// Step 5a (sync): Fail compilation (reject promise).
//==========================================================================
class FailCompile : public SyncCompileTask {
public:
explicit FailCompile(ErrorThrower thrower) : thrower_(std::move(thrower)) {}
private:
ErrorThrower thrower_;
void RunImpl() override {
TRACE_COMPILE("(5a) Fail compilation...\n");
HandleScope scope(job_->isolate_);
return job_->AsyncCompileFailed(thrower_);
}
};
//==========================================================================
// Step 5b (sync): Finish heap-allocated data structures.
//==========================================================================
class FinishCompile : public SyncCompileTask {
void RunImpl() override {
TRACE_COMPILE("(5b) Finish compile...\n");
HandleScope scope(job_->isolate_);
// At this point, compilation has completed. Update the code table.
constexpr bool is_sync = true;
for (size_t i = FLAG_skip_compiling_wasm_funcs;
i < job_->temp_instance_->function_code.size(); ++i) {
Code* code = Code::cast(job_->code_table_->get(static_cast<int>(i)));
RecordStats(job_->isolate_, code, !is_sync);
}
// Create heap objects for script and module bytes to be stored in the
// shared module data. Asm.js is not compiled asynchronously.
Handle<Script> script =
CreateWasmScript(job_->isolate_, job_->wire_bytes_);
Handle<ByteArray> asm_js_offset_table;
// TODO(wasm): Improve efficiency of storing module wire bytes.
// 1. Only store relevant sections, not function bodies
// 2. Don't make a second copy of the bytes here; reuse the copy made
// for asynchronous compilation and store it as an external one
// byte string for serialization/deserialization.
Handle<String> module_bytes =
job_->isolate_->factory()
->NewStringFromOneByte(
{job_->wire_bytes_.start(), job_->wire_bytes_.length()},
TENURED)
.ToHandleChecked();
DCHECK(module_bytes->IsSeqOneByteString());
// The {module_wrapper} will take ownership of the {WasmModule} object,
// and it will be destroyed when the GC reclaims the wrapper object.
Handle<WasmModuleWrapper> module_wrapper = WasmModuleWrapper::New(
job_->isolate_, job_->helper_->module_.release());
// Create the shared module data.
// TODO(clemensh): For the same module (same bytes / same hash), we should
// only have one WasmSharedModuleData. Otherwise, we might only set
// breakpoints on a (potentially empty) subset of the instances.
Handle<WasmSharedModuleData> shared = WasmSharedModuleData::New(
job_->isolate_, module_wrapper,
Handle<SeqOneByteString>::cast(module_bytes), script,
asm_js_offset_table);
// Create the compiled module object and populate with compiled functions
// and information needed at instantiation time. This object needs to be
// serializable. Instantiation may occur off a deserialized version of
// this object.
job_->compiled_module_ = WasmCompiledModule::New(
job_->isolate_, shared, job_->code_table_, job_->function_tables_,
job_->signature_tables_);
// Finish the WASM script now and make it public to the debugger.
script->set_wasm_compiled_module(*job_->compiled_module_);
job_->isolate_->debug()->OnAfterCompile(script);
DeferredHandleScope deferred(job_->isolate_);
job_->compiled_module_ = handle(*job_->compiled_module_, job_->isolate_);
job_->deferred_handles_.push_back(deferred.Detach());
// TODO(wasm): compiling wrappers should be made async as well.
job_->DoSync<CompileWrappers>();
}
};
//==========================================================================
// Step 6 (sync): Compile JS->WASM wrappers.
//==========================================================================
class CompileWrappers : public SyncCompileTask {
void RunImpl() override {
TRACE_COMPILE("(6) Compile wrappers...\n");
// Compile JS->WASM wrappers for exported functions.
HandleScope scope(job_->isolate_);
JSToWasmWrapperCache js_to_wasm_cache;
int func_index = 0;
constexpr bool is_sync = true;
WasmModule* module = job_->compiled_module_->module();
for (auto exp : module->export_table) {
if (exp.kind != kExternalFunction) continue;
Handle<Code> wasm_code(Code::cast(job_->code_table_->get(exp.index)),
job_->isolate_);
Handle<Code> wrapper_code =
js_to_wasm_cache.CloneOrCompileJSToWasmWrapper(
job_->isolate_, module, wasm_code, exp.index);
int export_index =
static_cast<int>(module->functions.size() + func_index);
job_->code_table_->set(export_index, *wrapper_code);
RecordStats(job_->isolate_, *wrapper_code, !is_sync);
func_index++;
}
job_->DoSync<FinishModule>();
}
};
//==========================================================================
// Step 7 (sync): Finish the module and resolve the promise.
//==========================================================================
class FinishModule : public SyncCompileTask {
void RunImpl() override {
TRACE_COMPILE("(7) Finish module...\n");
HandleScope scope(job_->isolate_);
Handle<WasmModuleObject> result =
WasmModuleObject::New(job_->isolate_, job_->compiled_module_);
// {job_} is deleted in AsyncCompileSucceeded, therefore the {return}.
return job_->AsyncCompileSucceeded(result);
}
};
};
void wasm::AsyncCompile(Isolate* isolate, Handle<JSPromise> promise,
const ModuleWireBytes& bytes) {
if (!FLAG_wasm_async_compilation) {
ErrorThrower thrower(isolate, "WasmCompile");
// Compile the module.
MaybeHandle<WasmModuleObject> module_object =
SyncCompile(isolate, &thrower, bytes);
if (thrower.error()) {
RejectPromise(isolate, handle(isolate->context()), thrower, promise);
return;
}
Handle<WasmModuleObject> module = module_object.ToHandleChecked();
ResolvePromise(isolate, handle(isolate->context()), promise, module);
return;
}
// Make a copy of the wire bytes in case the user program changes them
// during asynchronous compilation.
std::unique_ptr<byte[]> copy(new byte[bytes.length()]);
memcpy(copy.get(), bytes.start(), bytes.length());
auto job = new AsyncCompileJob(isolate, std::move(copy), bytes.length(),
handle(isolate->context()), promise);
job->Start();
// Special handling for predictable mode, see above.
if (FLAG_verify_predictable) delete job;
}
Handle<Code> wasm::CompileLazy(Isolate* isolate) {
HistogramTimerScope lazy_time_scope(
isolate->counters()->wasm_lazy_compilation_time());
// Find the wasm frame which triggered the lazy compile, to get the wasm
// instance.
StackFrameIterator it(isolate);
// First frame: C entry stub.
DCHECK(!it.done());
DCHECK_EQ(StackFrame::EXIT, it.frame()->type());
it.Advance();
// Second frame: WasmCompileLazy builtin.
DCHECK(!it.done());
Handle<Code> lazy_compile_code(it.frame()->LookupCode(), isolate);
DCHECK_EQ(Builtins::kWasmCompileLazy, lazy_compile_code->builtin_index());
Handle<WasmInstanceObject> instance;
Handle<FixedArray> exp_deopt_data;
int func_index = -1;
if (lazy_compile_code->deoptimization_data()->length() > 0) {
// Then it's an indirect call or via JS->WASM wrapper.
DCHECK_LE(2, lazy_compile_code->deoptimization_data()->length());
exp_deopt_data = handle(lazy_compile_code->deoptimization_data(), isolate);
auto* weak_cell = WeakCell::cast(exp_deopt_data->get(0));
instance = handle(WasmInstanceObject::cast(weak_cell->value()), isolate);
func_index = Smi::cast(exp_deopt_data->get(1))->value();
}
it.Advance();
// Third frame: The calling wasm code or js-to-wasm wrapper.
DCHECK(!it.done());
DCHECK(it.frame()->is_js_to_wasm() || it.frame()->is_wasm_compiled());
Handle<Code> caller_code = handle(it.frame()->LookupCode(), isolate);
if (it.frame()->is_js_to_wasm()) {
DCHECK(!instance.is_null());
} else if (instance.is_null()) {
instance = handle(wasm::GetOwningWasmInstance(*caller_code), isolate);
} else {
DCHECK(*instance == wasm::GetOwningWasmInstance(*caller_code));
}
int offset =
static_cast<int>(it.frame()->pc() - caller_code->instruction_start());
// Only patch the caller code if this is *no* indirect call.
// exp_deopt_data will be null if the called function is not exported at all,
// and its length will be <= 2 if all entries in tables were already patched.
// Note that this check is conservative: If the first call to an exported
// function is direct, we will just patch the export tables, and only on the
// second call we will patch the caller.
bool patch_caller = caller_code->kind() == Code::JS_TO_WASM_FUNCTION ||
exp_deopt_data.is_null() || exp_deopt_data->length() <= 2;
Handle<Code> compiled_code = WasmCompiledModule::CompileLazy(
isolate, instance, caller_code, offset, func_index, patch_caller);
if (!exp_deopt_data.is_null() && exp_deopt_data->length() > 2) {
// See EnsureExportedLazyDeoptData: exp_deopt_data[2...(len-1)] are pairs of
// <export_table, index> followed by undefined values.
// Use this information here to patch all export tables.
DCHECK_EQ(0, exp_deopt_data->length() % 2);
for (int idx = 2, end = exp_deopt_data->length(); idx < end; idx += 2) {
if (exp_deopt_data->get(idx)->IsUndefined(isolate)) break;
FixedArray* exp_table = FixedArray::cast(exp_deopt_data->get(idx));
int exp_index = Smi::cast(exp_deopt_data->get(idx + 1))->value();
DCHECK(exp_table->get(exp_index) == *lazy_compile_code);
exp_table->set(exp_index, *compiled_code);
}
// After processing, remove the list of exported entries, such that we don't
// do the patching redundantly.
Handle<FixedArray> new_deopt_data =
isolate->factory()->CopyFixedArrayUpTo(exp_deopt_data, 2, TENURED);
lazy_compile_code->set_deoptimization_data(*new_deopt_data);
}
return compiled_code;
}
void LazyCompilationOrchestrator::CompileFunction(
Isolate* isolate, Handle<WasmInstanceObject> instance, int func_index) {
Handle<WasmCompiledModule> compiled_module(instance->compiled_module(),
isolate);
if (Code::cast(compiled_module->code_table()->get(func_index))->kind() ==
Code::WASM_FUNCTION) {
return;
}
size_t num_function_tables =
compiled_module->module()->function_tables.size();
// Store a vector of handles to be embedded in the generated code.
// TODO(clemensh): For concurrent compilation, these will have to live in a
// DeferredHandleScope.
std::vector<Handle<FixedArray>> fun_tables(num_function_tables);
std::vector<Handle<FixedArray>> sig_tables(num_function_tables);
for (size_t i = 0; i < num_function_tables; ++i) {
Object* fun_table =
compiled_module->function_tables()->get(static_cast<int>(i));
fun_tables[i] = handle(FixedArray::cast(fun_table), isolate);
Object* sig_table =
compiled_module->signature_tables()->get(static_cast<int>(i));
sig_tables[i] = handle(FixedArray::cast(sig_table), isolate);
}
wasm::ModuleEnv module_env(compiled_module->module(), &fun_tables,
&sig_tables);
uint8_t* module_start = compiled_module->module_bytes()->GetChars();
const WasmFunction* func = &module_env.module->functions[func_index];
wasm::FunctionBody body{func->sig, module_start,
module_start + func->code_start_offset,
module_start + func->code_end_offset};
// TODO(wasm): Refactor this to only get the name if it is really needed for
// tracing / debugging.
std::string func_name;
{
wasm::WasmName name = Vector<const char>::cast(
compiled_module->GetRawFunctionName(func_index));
// Copy to std::string, because the underlying string object might move on
// the heap.
func_name.assign(name.start(), static_cast<size_t>(name.length()));
}
ErrorThrower thrower(isolate, "WasmLazyCompile");
compiler::WasmCompilationUnit unit(isolate, &module_env, body,
CStrVector(func_name.c_str()), func_index);
unit.ExecuteCompilation();
Handle<Code> code = unit.FinishCompilation(&thrower);
// If there is a pending error, something really went wrong. The module was
// verified before starting execution with lazy compilation.
// This might be OOM, but then we cannot continue execution anyway.
CHECK(!thrower.error());
Handle<FixedArray> deopt_data = isolate->factory()->NewFixedArray(2, TENURED);
Handle<WeakCell> weak_instance = isolate->factory()->NewWeakCell(instance);
// TODO(wasm): Introduce constants for the indexes in wasm deopt data.
deopt_data->set(0, *weak_instance);
deopt_data->set(1, Smi::FromInt(func_index));
code->set_deoptimization_data(*deopt_data);
DCHECK_EQ(Builtins::kWasmCompileLazy,
Code::cast(compiled_module->code_table()->get(func_index))
->builtin_index());
compiled_module->code_table()->set(func_index, *code);
// Now specialize the generated code for this instance.
Zone specialization_zone(isolate->allocator(), ZONE_NAME);
CodeSpecialization code_specialization(isolate, &specialization_zone);
if (module_env.module->globals_size) {
Address globals_start =
reinterpret_cast<Address>(compiled_module->globals_start());
code_specialization.RelocateGlobals(nullptr, globals_start);
}
if (instance->has_memory_buffer()) {
Address mem_start =
reinterpret_cast<Address>(instance->memory_buffer()->backing_store());
int mem_size = instance->memory_buffer()->byte_length()->Number();
DCHECK_IMPLIES(mem_size == 0, mem_start == nullptr);
if (mem_size > 0) {
code_specialization.RelocateMemoryReferences(nullptr, 0, mem_start,
mem_size);
}
}
code_specialization.RelocateDirectCalls(instance);
code_specialization.ApplyToWasmCode(*code, SKIP_ICACHE_FLUSH);
Assembler::FlushICache(isolate, code->instruction_start(),
code->instruction_size());
RecordLazyCodeStats(isolate, *code);
}
Handle<Code> LazyCompilationOrchestrator::CompileLazy(
Isolate* isolate, Handle<WasmInstanceObject> instance, Handle<Code> caller,
int call_offset, int exported_func_index, bool patch_caller) {
struct NonCompiledFunction {
int offset;
int func_index;
};
std::vector<NonCompiledFunction> non_compiled_functions;
int func_to_return_idx = exported_func_index;
wasm::Decoder decoder(nullptr, nullptr);
bool is_js_to_wasm = caller->kind() == Code::JS_TO_WASM_FUNCTION;
Handle<WasmCompiledModule> compiled_module(instance->compiled_module(),
isolate);
if (is_js_to_wasm) {
non_compiled_functions.push_back({0, exported_func_index});
} else if (patch_caller) {
DisallowHeapAllocation no_gc;
SeqOneByteString* module_bytes = compiled_module->module_bytes();
SourcePositionTableIterator source_pos_iterator(
caller->SourcePositionTable());
DCHECK_EQ(2, caller->deoptimization_data()->length());
int caller_func_index =
Smi::cast(caller->deoptimization_data()->get(1))->value();
const byte* func_bytes =
module_bytes->GetChars() + compiled_module->module()
->functions[caller_func_index]
.code_start_offset;
for (RelocIterator it(*caller, RelocInfo::kCodeTargetMask); !it.done();
it.next()) {
Code* callee =
Code::GetCodeFromTargetAddress(it.rinfo()->target_address());
if (callee->builtin_index() != Builtins::kWasmCompileLazy) continue;
// TODO(clemensh): Introduce safe_cast<T, bool> which (D)CHECKS
// (depending on the bool) against limits of T and then static_casts.
size_t offset_l = it.rinfo()->pc() - caller->instruction_start();
DCHECK_GE(kMaxInt, offset_l);
int offset = static_cast<int>(offset_l);
int byte_pos =
AdvanceSourcePositionTableIterator(source_pos_iterator, offset);
int called_func_index =
ExtractDirectCallIndex(decoder, func_bytes + byte_pos);
non_compiled_functions.push_back({offset, called_func_index});
// Call offset one instruction after the call. Remember the last called
// function before that offset.
if (offset < call_offset) func_to_return_idx = called_func_index;
}
}
// TODO(clemensh): compile all functions in non_compiled_functions in
// background, wait for func_to_return_idx.
CompileFunction(isolate, instance, func_to_return_idx);
if (is_js_to_wasm || patch_caller) {
DisallowHeapAllocation no_gc;
// Now patch the code object with all functions which are now compiled.
int idx = 0;
for (RelocIterator it(*caller, RelocInfo::kCodeTargetMask); !it.done();
it.next()) {
Code* callee =
Code::GetCodeFromTargetAddress(it.rinfo()->target_address());
if (callee->builtin_index() != Builtins::kWasmCompileLazy) continue;
DCHECK_GT(non_compiled_functions.size(), idx);
int called_func_index = non_compiled_functions[idx].func_index;
// Check that the callee agrees with our assumed called_func_index.
DCHECK_IMPLIES(
callee->deoptimization_data()->length() > 0,
Smi::cast(callee->deoptimization_data()->get(1))->value() ==
called_func_index);
if (is_js_to_wasm) {
DCHECK_EQ(func_to_return_idx, called_func_index);
} else {
DCHECK_EQ(non_compiled_functions[idx].offset,
it.rinfo()->pc() - caller->instruction_start());
}
++idx;
Handle<Code> callee_compiled(
Code::cast(compiled_module->code_table()->get(called_func_index)));
if (callee_compiled->builtin_index() == Builtins::kWasmCompileLazy) {
DCHECK_NE(func_to_return_idx, called_func_index);
continue;
}
DCHECK_EQ(Code::WASM_FUNCTION, callee_compiled->kind());
it.rinfo()->set_target_address(isolate,
callee_compiled->instruction_start());
}
DCHECK_EQ(non_compiled_functions.size(), idx);
}
Code* ret =
Code::cast(compiled_module->code_table()->get(func_to_return_idx));
DCHECK_EQ(Code::WASM_FUNCTION, ret->kind());
return handle(ret, isolate);
}