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chromium / v8 / v8 / e902b69d881059cce739a88d3e5f9ce95b5e0625 / . / src / wasm / wasm-module.cc
blob: f133832a89b7eb7e83bfa65a4704bd4739caf586 [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/base/atomic-utils.h"
#include "src/code-stubs.h"
#include "src/macro-assembler.h"
#include "src/objects.h"
#include "src/property-descriptor.h"
#include "src/simulator.h"
#include "src/snapshot/snapshot.h"
#include "src/v8.h"
#include "src/wasm/ast-decoder.h"
#include "src/wasm/module-decoder.h"
#include "src/wasm/wasm-debug.h"
#include "src/wasm/wasm-function-name-table.h"
#include "src/wasm/wasm-js.h"
#include "src/wasm/wasm-module.h"
#include "src/wasm/wasm-result.h"
#include "src/compiler/wasm-compiler.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)
namespace {
static const int kPlaceholderMarker = 1000000000;
enum JSFunctionExportInternalField {
kInternalModuleInstance,
kInternalArity,
kInternalSignature
};
// Internal constants for the layout of the module object.
enum WasmInstanceObjectFields {
kWasmCompiledModule = 0,
kWasmModuleFunctionTable,
kWasmModuleCodeTable,
kWasmMemObject,
kWasmMemArrayBuffer,
kWasmGlobalsArrayBuffer,
kWasmDebugInfo,
kWasmModuleInternalFieldCount
};
enum WasmImportData {
kImportKind, // Smi. an ExternalKind
kImportGlobalType, // Smi. Type for globals.
kImportIndex, // Smi. index for the import.
kModuleName, // String
kFunctionName, // maybe String
kOutputCount, // Smi. an uint32_t
kSignature, // ByteArray. A copy of the data in FunctionSig
kWasmImportDataSize // Sentinel value.
};
enum WasmExportData {
kExportKind, // Smi. an ExternalKind
kExportGlobalType, // Smi. Type for globals.
kExportName, // String
kExportArity, // Smi, an int
kExportIndex, // Smi, an uint32_t
kExportedSignature, // ByteArray. A copy of the data in FunctionSig
kWasmExportDataSize // Sentinel value.
};
enum WasmGlobalInitData {
kGlobalInitKind, // 0 = constant, 1 = global index
kGlobalInitType, // Smi. Type for globals.
kGlobalInitIndex, // Smi, an uint32_t
kGlobalInitValue, // Number.
kWasmGlobalInitDataSize
};
enum WasmSegmentInfo {
kDestAddrKind, // 0 = constant, 1 = global index
kDestAddrValue, // Smi. an uint32_t
kSourceSize, // Smi. an uint32_t
kWasmSegmentInfoSize // Sentinel value.
};
enum WasmIndirectFunctionTableData {
kSize, // Smi. an uint32_t
kTable, // FixedArray of indirect function table
kWasmIndirectFunctionTableDataSize // Sentinel value.
};
byte* raw_buffer_ptr(MaybeHandle<JSArrayBuffer> buffer, int offset) {
return static_cast<byte*>(buffer.ToHandleChecked()->backing_store()) + offset;
}
uint32_t GetMinModuleMemSize(const WasmModule* module) {
return WasmModule::kPageSize * module->min_mem_pages;
}
void SaveDataSegmentInfo(Factory* factory, const WasmModule* module,
Handle<WasmCompiledModule> compiled_module) {
Handle<FixedArray> segments = factory->NewFixedArray(
static_cast<int>(module->data_segments.size()), TENURED);
uint32_t data_size = 0;
for (const WasmDataSegment& segment : module->data_segments) {
if (segment.source_size == 0) continue;
data_size += segment.source_size;
}
Handle<ByteArray> data = factory->NewByteArray(data_size, TENURED);
uint32_t last_insertion_pos = 0;
for (uint32_t i = 0; i < module->data_segments.size(); ++i) {
const WasmDataSegment& segment = module->data_segments[i];
if (segment.source_size == 0) continue;
Handle<ByteArray> js_segment =
factory->NewByteArray(kWasmSegmentInfoSize * sizeof(uint32_t), TENURED);
if (segment.dest_addr.kind == WasmInitExpr::kGlobalIndex) {
// The destination address is the value of a global variable.
js_segment->set_int(kDestAddrKind, 1);
uint32_t offset =
module->globals[segment.dest_addr.val.global_index].offset;
js_segment->set_int(kDestAddrValue, static_cast<int>(offset));
} else {
// The destination address is a constant.
CHECK_EQ(WasmInitExpr::kI32Const, segment.dest_addr.kind);
js_segment->set_int(kDestAddrKind, 0);
js_segment->set_int(kDestAddrValue, segment.dest_addr.val.i32_const);
}
js_segment->set_int(kSourceSize, segment.source_size);
segments->set(i, *js_segment);
data->copy_in(last_insertion_pos,
module->module_start + segment.source_offset,
segment.source_size);
last_insertion_pos += segment.source_size;
}
compiled_module->set_data_segments_info(segments);
compiled_module->set_data_segments(data);
}
void PatchFunctionTable(Handle<Code> code,
Handle<FixedArray> old_indirect_table,
Handle<FixedArray> new_indirect_table) {
for (RelocIterator it(*code, 1 << RelocInfo::EMBEDDED_OBJECT); !it.done();
it.next()) {
if (it.rinfo()->target_object() == *old_indirect_table) {
it.rinfo()->set_target_object(*new_indirect_table);
}
}
}
Handle<JSArrayBuffer> NewArrayBuffer(Isolate* isolate, size_t size) {
if (size > (WasmModule::kMaxMemPages * WasmModule::kPageSize)) {
// TODO(titzer): lift restriction on maximum memory allocated here.
return Handle<JSArrayBuffer>::null();
}
void* memory = isolate->array_buffer_allocator()->Allocate(size);
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
Handle<JSArrayBuffer> buffer = isolate->factory()->NewJSArrayBuffer();
JSArrayBuffer::Setup(buffer, isolate, false, memory, static_cast<int>(size));
buffer->set_is_neuterable(false);
return buffer;
}
void RelocateInstanceCode(Handle<JSObject> instance, Address old_start,
Address start, uint32_t prev_size,
uint32_t new_size) {
Handle<FixedArray> functions = Handle<FixedArray>(
FixedArray::cast(instance->GetInternalField(kWasmModuleCodeTable)));
for (int i = 0; i < functions->length(); ++i) {
Handle<Code> function = Handle<Code>(Code::cast(functions->get(i)));
AllowDeferredHandleDereference embedding_raw_address;
int mask = (1 << RelocInfo::WASM_MEMORY_REFERENCE) |
(1 << RelocInfo::WASM_MEMORY_SIZE_REFERENCE);
for (RelocIterator it(*function, mask); !it.done(); it.next()) {
it.rinfo()->update_wasm_memory_reference(old_start, start, prev_size,
new_size);
}
}
}
void RelocateGlobals(Handle<JSObject> instance, Address old_start,
Address globals_start) {
Handle<FixedArray> functions = Handle<FixedArray>(
FixedArray::cast(instance->GetInternalField(kWasmModuleCodeTable)));
uint32_t function_count = static_cast<uint32_t>(functions->length());
for (uint32_t i = 0; i < function_count; ++i) {
Handle<Code> function = Handle<Code>(Code::cast(functions->get(i)));
AllowDeferredHandleDereference embedding_raw_address;
int mask = 1 << RelocInfo::WASM_GLOBAL_REFERENCE;
for (RelocIterator it(*function, mask); !it.done(); it.next()) {
it.rinfo()->update_wasm_global_reference(old_start, globals_start);
}
}
}
Handle<Code> CreatePlaceholder(Factory* factory, uint32_t index,
Code::Kind kind) {
// Create a placeholder code object and encode the corresponding index in
// the {constant_pool_offset} field of the code object.
// TODO(titzer): placeholder code objects are somewhat dangerous.
static byte buffer[] = {0, 0, 0, 0, 0, 0, 0, 0}; // fake instructions.
static CodeDesc desc = {
buffer, arraysize(buffer), arraysize(buffer), 0, 0, nullptr, 0, nullptr};
Handle<Code> code = factory->NewCode(desc, Code::KindField::encode(kind),
Handle<Object>::null());
code->set_constant_pool_offset(static_cast<int>(index) + kPlaceholderMarker);
return code;
}
bool LinkFunction(Handle<Code> unlinked,
std::vector<Handle<Code>>& code_table) {
bool modified = false;
int mode_mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET);
AllowDeferredHandleDereference embedding_raw_address;
for (RelocIterator it(*unlinked, mode_mask); !it.done(); it.next()) {
RelocInfo::Mode mode = it.rinfo()->rmode();
if (RelocInfo::IsCodeTarget(mode)) {
Code* target =
Code::GetCodeFromTargetAddress(it.rinfo()->target_address());
if (target->constant_pool_offset() < kPlaceholderMarker) continue;
switch (target->kind()) {
case Code::WASM_FUNCTION: // fall through
case Code::WASM_TO_JS_FUNCTION: // fall through
case Code::JS_TO_WASM_FUNCTION: {
// Patch direct calls to placeholder code objects.
uint32_t index = target->constant_pool_offset() - kPlaceholderMarker;
Handle<Code> new_target = code_table[index];
if (target != *new_target) {
it.rinfo()->set_target_address(new_target->instruction_start(),
UPDATE_WRITE_BARRIER,
SKIP_ICACHE_FLUSH);
modified = true;
}
break;
}
default:
break;
}
}
}
return modified;
}
void FlushICache(Isolate* isolate, Handle<FixedArray> functions) {
for (int i = 0; i < functions->length(); ++i) {
Handle<Code> code = functions->GetValueChecked<Code>(isolate, i);
Assembler::FlushICache(isolate, code->instruction_start(),
code->instruction_size());
}
}
// Fetches the compilation unit of a wasm function and executes its parallel
// phase.
bool FetchAndExecuteCompilationUnit(
Isolate* isolate,
std::vector<compiler::WasmCompilationUnit*>* compilation_units,
std::queue<compiler::WasmCompilationUnit*>* executed_units,
base::Mutex* result_mutex, base::AtomicNumber<size_t>* next_unit) {
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;
}
compiler::WasmCompilationUnit* unit = compilation_units->at(index);
if (unit != nullptr) {
unit->ExecuteCompilation();
base::LockGuard<base::Mutex> guard(result_mutex);
executed_units->push(unit);
}
return true;
}
class WasmCompilationTask : public CancelableTask {
public:
WasmCompilationTask(
Isolate* isolate,
std::vector<compiler::WasmCompilationUnit*>* compilation_units,
std::queue<compiler::WasmCompilationUnit*>* executed_units,
base::Semaphore* on_finished, base::Mutex* result_mutex,
base::AtomicNumber<size_t>* next_unit)
: CancelableTask(isolate),
isolate_(isolate),
compilation_units_(compilation_units),
executed_units_(executed_units),
on_finished_(on_finished),
result_mutex_(result_mutex),
next_unit_(next_unit) {}
void RunInternal() override {
while (FetchAndExecuteCompilationUnit(isolate_, compilation_units_,
executed_units_, result_mutex_,
next_unit_)) {
}
on_finished_->Signal();
}
Isolate* isolate_;
std::vector<compiler::WasmCompilationUnit*>* compilation_units_;
std::queue<compiler::WasmCompilationUnit*>* executed_units_;
base::Semaphore* on_finished_;
base::Mutex* result_mutex_;
base::AtomicNumber<size_t>* next_unit_;
};
static void RecordStats(Isolate* isolate, Code* code) {
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) {
DisallowHeapAllocation no_gc;
for (int i = 0; i < functions->length(); ++i) {
RecordStats(isolate, Code::cast(functions->get(i)));
}
}
Address GetGlobalStartAddressFromCodeTemplate(Object* undefined,
JSObject* owner) {
Address old_address = nullptr;
Object* stored_value = owner->GetInternalField(kWasmGlobalsArrayBuffer);
if (stored_value != undefined) {
old_address = static_cast<Address>(
JSArrayBuffer::cast(stored_value)->backing_store());
}
return old_address;
}
Handle<FixedArray> EncodeImports(Factory* factory, const WasmModule* module) {
// TODO(wasm): Encode this in one big FixedArray.
Handle<FixedArray> ret = factory->NewFixedArray(
static_cast<int>(module->import_table.size()), TENURED);
for (size_t i = 0; i < module->import_table.size(); ++i) {
const WasmImport& import = module->import_table[i];
Handle<FixedArray> encoded_import =
factory->NewFixedArray(kWasmImportDataSize, TENURED);
encoded_import->set(kImportKind, Smi::FromInt(import.kind));
encoded_import->set(kImportIndex, Smi::FromInt(import.index));
// Add the module and function name.
WasmName module_name = module->GetNameOrNull(import.module_name_offset,
import.module_name_length);
WasmName function_name = module->GetNameOrNull(import.field_name_offset,
import.field_name_length);
Handle<String> module_name_string =
factory->InternalizeUtf8String(module_name);
encoded_import->set(kModuleName, *module_name_string);
if (!function_name.is_empty()) {
Handle<String> function_name_string =
factory->InternalizeUtf8String(function_name);
encoded_import->set(kFunctionName, *function_name_string);
}
switch (import.kind) {
case kExternalFunction: {
// Encode the signature into the import.
FunctionSig* fsig = module->functions[import.index].sig;
Handle<ByteArray> sig = factory->NewByteArray(
static_cast<int>(fsig->parameter_count() + fsig->return_count()),
TENURED);
sig->copy_in(0, reinterpret_cast<const byte*>(fsig->raw_data()),
sig->length());
encoded_import->set(
kOutputCount, Smi::FromInt(static_cast<int>(fsig->return_count())));
encoded_import->set(kSignature, *sig);
break;
}
case kExternalTable:
// Nothing extra required for imported tables.
break;
case kExternalMemory:
// Nothing extra required for imported memories.
break;
case kExternalGlobal: {
// Encode the offset and the global type into the import.
const WasmGlobal& global = module->globals[import.index];
TRACE("import[%zu].type = %s\n", i, WasmOpcodes::TypeName(global.type));
encoded_import->set(
kImportGlobalType,
Smi::FromInt(WasmOpcodes::LocalTypeCodeFor(global.type)));
encoded_import->set(kImportIndex, Smi::FromInt(global.offset));
break;
}
}
ret->set(static_cast<int>(i), *encoded_import);
}
return ret;
}
void InitializeParallelCompilation(
Isolate* isolate, const std::vector<WasmFunction>& functions,
std::vector<compiler::WasmCompilationUnit*>& compilation_units,
ModuleEnv& module_env, ErrorThrower* thrower) {
for (uint32_t i = FLAG_skip_compiling_wasm_funcs; i < functions.size(); ++i) {
const WasmFunction* func = &functions[i];
compilation_units[i] =
func->imported ? nullptr : new compiler::WasmCompilationUnit(
thrower, isolate, &module_env, func, i);
}
}
uint32_t* StartCompilationTasks(
Isolate* isolate,
std::vector<compiler::WasmCompilationUnit*>& compilation_units,
std::queue<compiler::WasmCompilationUnit*>& executed_units,
base::Semaphore* pending_tasks, base::Mutex& result_mutex,
base::AtomicNumber<size_t>& next_unit) {
const size_t num_tasks =
Min(static_cast<size_t>(FLAG_wasm_num_compilation_tasks),
V8::GetCurrentPlatform()->NumberOfAvailableBackgroundThreads());
uint32_t* task_ids = new uint32_t[num_tasks];
for (size_t i = 0; i < num_tasks; ++i) {
WasmCompilationTask* task =
new WasmCompilationTask(isolate, &compilation_units, &executed_units,
pending_tasks, &result_mutex, &next_unit);
task_ids[i] = task->id();
V8::GetCurrentPlatform()->CallOnBackgroundThread(
task, v8::Platform::kShortRunningTask);
}
return task_ids;
}
void WaitForCompilationTasks(Isolate* isolate, uint32_t* task_ids,
base::Semaphore* pending_tasks) {
const size_t num_tasks =
Min(static_cast<size_t>(FLAG_wasm_num_compilation_tasks),
V8::GetCurrentPlatform()->NumberOfAvailableBackgroundThreads());
for (size_t i = 0; i < num_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])) {
pending_tasks->Wait();
}
}
}
void FinishCompilationUnits(
std::queue<compiler::WasmCompilationUnit*>& executed_units,
std::vector<Handle<Code>>& results, base::Mutex& result_mutex) {
while (true) {
compiler::WasmCompilationUnit* unit = nullptr;
{
base::LockGuard<base::Mutex> guard(&result_mutex);
if (executed_units.empty()) {
break;
}
unit = executed_units.front();
executed_units.pop();
}
int j = unit->index();
results[j] = unit->FinishCompilation();
delete unit;
}
}
void CompileInParallel(Isolate* isolate, const WasmModule* module,
std::vector<Handle<Code>>& functions,
ErrorThrower* thrower, ModuleEnv* module_env) {
// Data structures for the parallel compilation.
std::vector<compiler::WasmCompilationUnit*> compilation_units(
module->functions.size());
std::queue<compiler::WasmCompilationUnit*> executed_units;
//-----------------------------------------------------------------------
// 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 {WasmCompilationTask} 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 {WasmCompilationTask} 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(isolate, module->functions, compilation_units,
*module_env, thrower);
// Objects for the synchronization with the background threads.
base::Mutex result_mutex;
base::AtomicNumber<size_t> next_unit(
static_cast<size_t>(FLAG_skip_compiling_wasm_funcs));
// 2) The main thread spawns {WasmCompilationTask} instances which run on
// the background threads.
std::unique_ptr<uint32_t[]> task_ids(StartCompilationTasks(
isolate, compilation_units, executed_units, module->pending_tasks.get(),
result_mutex, next_unit));
// 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}.
while (FetchAndExecuteCompilationUnit(isolate, &compilation_units,
&executed_units, &result_mutex,
&next_unit)) {
// 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.
FinishCompilationUnits(executed_units, functions, result_mutex);
}
// 4) After the parallel phase of all compilation units has started, the
// main thread waits for all {WasmCompilationTask} instances to finish.
WaitForCompilationTasks(isolate, task_ids.get(), module->pending_tasks.get());
// Finish the compilation of the remaining compilation units.
FinishCompilationUnits(executed_units, functions, result_mutex);
}
void CompileSequentially(Isolate* isolate, const WasmModule* module,
std::vector<Handle<Code>>& functions,
ErrorThrower* thrower, ModuleEnv* module_env) {
DCHECK(!thrower->error());
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.
WasmName str = module->GetName(func.name_offset, func.name_length);
Handle<Code> code = Handle<Code>::null();
// Compile the function.
code = compiler::WasmCompilationUnit::CompileWasmFunction(
thrower, isolate, module_env, &func);
if (code.is_null()) {
thrower->Error("Compilation of #%d:%.*s failed.", i, str.length(),
str.start());
break;
}
// Install the code into the linker table.
functions[i] = code;
}
}
void PatchDirectCalls(Handle<FixedArray> old_functions,
Handle<FixedArray> new_functions, int start) {
DCHECK_EQ(new_functions->length(), old_functions->length());
DisallowHeapAllocation no_gc;
std::map<Code*, Code*> old_to_new_code;
for (int i = 0; i < new_functions->length(); ++i) {
old_to_new_code.insert(std::make_pair(Code::cast(old_functions->get(i)),
Code::cast(new_functions->get(i))));
}
int mode_mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET);
AllowDeferredHandleDereference embedding_raw_address;
for (int i = start; i < new_functions->length(); ++i) {
Code* wasm_function = Code::cast(new_functions->get(i));
for (RelocIterator it(wasm_function, mode_mask); !it.done(); it.next()) {
Code* old_code =
Code::GetCodeFromTargetAddress(it.rinfo()->target_address());
if (old_code->kind() == Code::WASM_TO_JS_FUNCTION ||
old_code->kind() == Code::WASM_FUNCTION) {
auto found = old_to_new_code.find(old_code);
DCHECK(found != old_to_new_code.end());
Code* new_code = found->second;
if (new_code != old_code) {
it.rinfo()->set_target_address(new_code->instruction_start(),
UPDATE_WRITE_BARRIER,
SKIP_ICACHE_FLUSH);
}
}
}
}
}
static void ResetCompiledModule(Isolate* isolate, JSObject* owner,
WasmCompiledModule* compiled_module) {
TRACE("Resetting %d\n", compiled_module->instance_id());
Object* undefined = *isolate->factory()->undefined_value();
uint32_t old_mem_size = compiled_module->has_heap()
? compiled_module->mem_size()
: compiled_module->default_mem_size();
uint32_t default_mem_size = compiled_module->default_mem_size();
Object* mem_start = compiled_module->ptr_to_heap();
Address old_mem_address = nullptr;
Address globals_start =
GetGlobalStartAddressFromCodeTemplate(undefined, owner);
if (old_mem_size > 0) {
CHECK_NE(mem_start, undefined);
old_mem_address =
static_cast<Address>(JSArrayBuffer::cast(mem_start)->backing_store());
}
int mode_mask = RelocInfo::ModeMask(RelocInfo::WASM_MEMORY_REFERENCE) |
RelocInfo::ModeMask(RelocInfo::WASM_MEMORY_SIZE_REFERENCE) |
RelocInfo::ModeMask(RelocInfo::WASM_GLOBAL_REFERENCE);
Object* fct_obj = compiled_module->ptr_to_code_table();
if (fct_obj != nullptr && fct_obj != undefined &&
(old_mem_size > 0 || globals_start != nullptr)) {
FixedArray* functions = FixedArray::cast(fct_obj);
for (int i = 0; i < functions->length(); ++i) {
Code* code = Code::cast(functions->get(i));
bool changed = false;
for (RelocIterator it(code, mode_mask); !it.done(); it.next()) {
RelocInfo::Mode mode = it.rinfo()->rmode();
if (RelocInfo::IsWasmMemoryReference(mode) ||
RelocInfo::IsWasmMemorySizeReference(mode)) {
it.rinfo()->update_wasm_memory_reference(
old_mem_address, nullptr, old_mem_size, default_mem_size);
changed = true;
} else {
CHECK(RelocInfo::IsWasmGlobalReference(mode));
it.rinfo()->update_wasm_global_reference(globals_start, nullptr);
changed = true;
}
}
if (changed) {
Assembler::FlushICache(isolate, code->instruction_start(),
code->instruction_size());
}
}
}
compiled_module->reset_heap();
}
static void InstanceFinalizer(const v8::WeakCallbackInfo<void>& data) {
JSObject** p = reinterpret_cast<JSObject**>(data.GetParameter());
JSObject* owner = *p;
WasmCompiledModule* compiled_module = GetCompiledModule(owner);
TRACE("Finalizing %d {\n", compiled_module->instance_id());
Isolate* isolate = reinterpret_cast<Isolate*>(data.GetIsolate());
DCHECK(compiled_module->has_weak_module_object());
WeakCell* weak_module_obj = compiled_module->ptr_to_weak_module_object();
// weak_module_obj 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_module_obj->cleared()) {
JSObject* module_obj = JSObject::cast(weak_module_obj->value());
WasmCompiledModule* current_template =
WasmCompiledModule::cast(module_obj->GetInternalField(0));
TRACE("chain before {\n");
TRACE_CHAIN(current_template);
TRACE("}\n");
DCHECK(!current_template->has_weak_prev_instance());
WeakCell* next = compiled_module->ptr_to_weak_next_instance();
WeakCell* prev = compiled_module->ptr_to_weak_prev_instance();
if (current_template == compiled_module) {
if (next == nullptr) {
ResetCompiledModule(isolate, owner, compiled_module);
} else {
DCHECK(next->value()->IsFixedArray());
module_obj->SetInternalField(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(module_obj->GetInternalField(0)));
TRACE("}\n");
}
compiled_module->reset_weak_owning_instance();
GlobalHandles::Destroy(reinterpret_cast<Object**>(p));
TRACE("}\n");
}
Handle<FixedArray> SetupIndirectFunctionTable(
Isolate* isolate, Handle<FixedArray> wasm_functions,
Handle<FixedArray> indirect_table_template,
Handle<FixedArray> tables_to_replace) {
Factory* factory = isolate->factory();
Handle<FixedArray> cloned_indirect_tables =
factory->CopyFixedArray(indirect_table_template);
for (int i = 0; i < cloned_indirect_tables->length(); ++i) {
Handle<FixedArray> orig_metadata =
cloned_indirect_tables->GetValueChecked<FixedArray>(isolate, i);
Handle<FixedArray> cloned_metadata = factory->CopyFixedArray(orig_metadata);
cloned_indirect_tables->set(i, *cloned_metadata);
Handle<FixedArray> orig_table =
cloned_metadata->GetValueChecked<FixedArray>(isolate, kTable);
Handle<FixedArray> cloned_table = factory->CopyFixedArray(orig_table);
cloned_metadata->set(kTable, *cloned_table);
// Patch the cloned code to refer to the cloned kTable.
Handle<FixedArray> table_to_replace =
tables_to_replace->GetValueChecked<FixedArray>(isolate, i)
->GetValueChecked<FixedArray>(isolate, kTable);
for (int fct_index = 0; fct_index < wasm_functions->length(); ++fct_index) {
Handle<Code> wasm_function =
wasm_functions->GetValueChecked<Code>(isolate, fct_index);
PatchFunctionTable(wasm_function, table_to_replace, cloned_table);
}
}
return cloned_indirect_tables;
}
} // namespace
const char* wasm::SectionName(WasmSectionCode code) {
switch (code) {
case kUnknownSectionCode:
return "Unknown";
case kTypeSectionCode:
return "Type";
case kImportSectionCode:
return "Import";
case kFunctionSectionCode:
return "Function";
case kTableSectionCode:
return "Table";
case kMemorySectionCode:
return "Memory";
case kGlobalSectionCode:
return "Global";
case kExportSectionCode:
return "Export";
case kStartSectionCode:
return "Start";
case kCodeSectionCode:
return "Code";
case kElementSectionCode:
return "Element";
case kDataSectionCode:
return "Data";
case kNameSectionCode:
return "Name";
default:
return "<unknown>";
}
}
std::ostream& wasm::operator<<(std::ostream& os, const WasmModule& module) {
os << "WASM module with ";
os << (module.min_mem_pages * module.kPageSize) << " min mem";
os << (module.max_mem_pages * module.kPageSize) << " max mem";
os << module.functions.size() << " functions";
os << module.functions.size() << " globals";
os << module.functions.size() << " data segments";
return os;
}
std::ostream& wasm::operator<<(std::ostream& os, const WasmFunction& function) {
os << "WASM function with signature " << *function.sig;
os << " code bytes: "
<< (function.code_end_offset - function.code_start_offset);
return os;
}
std::ostream& wasm::operator<<(std::ostream& os, const WasmFunctionName& pair) {
os << "#" << pair.function_->func_index << ":";
if (pair.function_->name_offset > 0) {
if (pair.module_) {
WasmName name = pair.module_->GetName(pair.function_->name_offset,
pair.function_->name_length);
os.write(name.start(), name.length());
} else {
os << "+" << pair.function_->func_index;
}
} else {
os << "?";
}
return os;
}
Handle<JSFunction> wasm::WrapExportCodeAsJSFunction(
Isolate* isolate, Handle<Code> export_code, Handle<String> name, int arity,
MaybeHandle<ByteArray> maybe_signature, Handle<JSObject> module_instance) {
Handle<SharedFunctionInfo> shared =
isolate->factory()->NewSharedFunctionInfo(name, export_code, false);
shared->set_length(arity);
shared->set_internal_formal_parameter_count(arity);
Handle<JSFunction> function = isolate->factory()->NewFunction(
isolate->wasm_function_map(), name, export_code);
function->set_shared(*shared);
function->SetInternalField(kInternalModuleInstance, *module_instance);
// add another Internal Field as the function arity
function->SetInternalField(kInternalArity, Smi::FromInt(arity));
// add another Internal Field as the signature of the foreign function
Handle<ByteArray> signature;
if (maybe_signature.ToHandle(&signature)) {
function->SetInternalField(kInternalSignature, *signature);
}
return function;
}
Object* wasm::GetOwningWasmInstance(Code* code) {
DCHECK(code->kind() == Code::WASM_FUNCTION);
DisallowHeapAllocation no_gc;
FixedArray* deopt_data = code->deoptimization_data();
DCHECK_NOT_NULL(deopt_data);
DCHECK(deopt_data->length() == 2);
Object* weak_link = deopt_data->get(0);
if (!weak_link->IsWeakCell()) return nullptr;
WeakCell* cell = WeakCell::cast(weak_link);
return cell->value();
}
int wasm::GetNumImportedFunctions(Handle<JSObject> wasm_object) {
// TODO(wasm): Cache this number if it ever becomes a performance problem.
DCHECK(IsWasmObject(*wasm_object));
WasmCompiledModule* compiled_module = GetCompiledModule(*wasm_object);
Handle<FixedArray> imports =
WasmCompiledModule::cast(compiled_module)->imports();
int num_imports = imports->length();
int num_imported_functions = 0;
for (int i = 0; i < num_imports; ++i) {
FixedArray* encoded_import = FixedArray::cast(imports->get(i));
int kind = Smi::cast(encoded_import->get(kImportKind))->value();
if (kind == kExternalFunction) ++num_imported_functions;
}
return num_imported_functions;
}
WasmModule::WasmModule(byte* module_start)
: module_start(module_start),
module_end(nullptr),
min_mem_pages(0),
max_mem_pages(0),
mem_export(false),
start_function_index(-1),
origin(kWasmOrigin),
globals_size(0),
num_imported_functions(0),
num_declared_functions(0),
num_exported_functions(0),
pending_tasks(new base::Semaphore(0)) {}
namespace {
void EncodeInit(const WasmModule* module, Factory* factory,
Handle<FixedArray> entry, int kind_index, int value_index,
const WasmInitExpr& expr) {
entry->set(kind_index, Smi::kZero);
Handle<Object> value;
switch (expr.kind) {
case WasmInitExpr::kGlobalIndex: {
TRACE(" kind = 1, global index %u\n", expr.val.global_index);
entry->set(kind_index, Smi::FromInt(1));
uint32_t offset = module->globals[expr.val.global_index].offset;
entry->set(value_index, Smi::FromInt(offset));
return;
}
case WasmInitExpr::kI32Const:
TRACE(" kind = 0, i32 = %d\n", expr.val.i32_const);
value = factory->NewNumber(expr.val.i32_const);
break;
case WasmInitExpr::kI64Const:
// TODO(titzer): implement initializers for i64 globals.
UNREACHABLE();
break;
case WasmInitExpr::kF32Const:
TRACE(" kind = 0, f32 = %f\n", expr.val.f32_const);
value = factory->NewNumber(expr.val.f32_const);
break;
case WasmInitExpr::kF64Const:
TRACE(" kind = 0, f64 = %lf\n", expr.val.f64_const);
value = factory->NewNumber(expr.val.f64_const);
break;
default:
UNREACHABLE();
}
entry->set(value_index, *value);
}
} // namespace
MaybeHandle<WasmCompiledModule> WasmModule::CompileFunctions(
Isolate* isolate, ErrorThrower* thrower) const {
Factory* factory = isolate->factory();
MaybeHandle<WasmCompiledModule> nothing;
WasmInstance temp_instance(this);
temp_instance.context = isolate->native_context();
temp_instance.mem_size = GetMinModuleMemSize(this);
temp_instance.mem_start = nullptr;
temp_instance.globals_start = nullptr;
MaybeHandle<FixedArray> indirect_table =
function_tables.size()
? factory->NewFixedArray(static_cast<int>(function_tables.size()),
TENURED)
: MaybeHandle<FixedArray>();
for (uint32_t i = 0; i < function_tables.size(); ++i) {
Handle<FixedArray> values = wasm::BuildFunctionTable(isolate, i, this);
temp_instance.function_tables[i] = values;
Handle<FixedArray> metadata = isolate->factory()->NewFixedArray(
kWasmIndirectFunctionTableDataSize, TENURED);
metadata->set(kSize, Smi::FromInt(function_tables[i].size));
metadata->set(kTable, *values);
indirect_table.ToHandleChecked()->set(i, *metadata);
}
HistogramTimerScope wasm_compile_module_time_scope(
isolate->counters()->wasm_compile_module_time());
ModuleEnv module_env;
module_env.module = this;
module_env.instance = &temp_instance;
module_env.origin = origin;
// 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>(functions.size() + num_exported_functions);
Handle<FixedArray> code_table =
factory->NewFixedArray(static_cast<int>(code_table_size), TENURED);
// Initialize the code table with placeholders.
for (uint32_t i = 0; i < functions.size(); ++i) {
Code::Kind kind = Code::WASM_FUNCTION;
if (i < num_imported_functions) kind = Code::WASM_TO_JS_FUNCTION;
Handle<Code> placeholder = CreatePlaceholder(factory, i, kind);
code_table->set(static_cast<int>(i), *placeholder);
temp_instance.function_code[i] = placeholder;
}
isolate->counters()->wasm_functions_per_module()->AddSample(
static_cast<int>(functions.size()));
if (!FLAG_trace_wasm_decoder && FLAG_wasm_num_compilation_tasks != 0) {
// Avoid a race condition by collecting results into a second vector.
std::vector<Handle<Code>> results;
results.reserve(temp_instance.function_code.size());
for (size_t i = 0; i < temp_instance.function_code.size(); ++i) {
results.push_back(temp_instance.function_code[i]);
}
CompileInParallel(isolate, this, results, thrower, &module_env);
for (size_t i = 0; i < results.size(); ++i) {
temp_instance.function_code[i] = results[i];
}
} else {
CompileSequentially(isolate, this, temp_instance.function_code, thrower,
&module_env);
}
if (thrower->error()) return nothing;
// 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);
}
// Link the functions in the module.
for (size_t i = FLAG_skip_compiling_wasm_funcs;
i < temp_instance.function_code.size(); ++i) {
Handle<Code> code = temp_instance.function_code[i];
bool modified = LinkFunction(code, temp_instance.function_code);
if (modified) {
// TODO(mtrofin): do we need to flush the cache here?
Assembler::FlushICache(isolate, code->instruction_start(),
code->instruction_size());
}
}
// 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> ret =
WasmCompiledModule::New(isolate, min_mem_pages, globals_size, origin);
ret->set_code_table(code_table);
if (!indirect_table.is_null()) {
ret->set_indirect_function_tables(indirect_table.ToHandleChecked());
}
// Create and set import data.
Handle<FixedArray> imports = EncodeImports(factory, this);
ret->set_imports(imports);
// Create and set export data.
int export_size = static_cast<int>(export_table.size());
if (export_size > 0) {
Handle<FixedArray> exports = factory->NewFixedArray(export_size, TENURED);
int index = 0;
int func_index = 0;
for (const WasmExport& exp : export_table) {
if (thrower->error()) return nothing;
Handle<FixedArray> encoded_export =
factory->NewFixedArray(kWasmExportDataSize, TENURED);
WasmName str = GetName(exp.name_offset, exp.name_length);
Handle<String> name = factory->InternalizeUtf8String(str);
encoded_export->set(kExportKind, Smi::FromInt(exp.kind));
encoded_export->set(kExportName, *name);
encoded_export->set(kExportIndex,
Smi::FromInt(static_cast<int>(exp.index)));
exports->set(index, *encoded_export);
switch (exp.kind) {
case kExternalFunction: {
// Copy the signature and arity.
FunctionSig* funcSig = functions[exp.index].sig;
Handle<ByteArray> exportedSig = factory->NewByteArray(
static_cast<int>(funcSig->parameter_count() +
funcSig->return_count()),
TENURED);
exportedSig->copy_in(
0, reinterpret_cast<const byte*>(funcSig->raw_data()),
exportedSig->length());
encoded_export->set(kExportedSignature, *exportedSig);
encoded_export->set(
kExportArity,
Smi::FromInt(static_cast<int>(funcSig->parameter_count())));
// Compile a wrapper for an exported function.
Handle<Code> code =
code_table->GetValueChecked<Code>(isolate, exp.index);
Handle<Code> export_code = compiler::CompileJSToWasmWrapper(
isolate, &module_env, code, exp.index);
int code_table_index =
static_cast<int>(functions.size() + func_index);
code_table->set(code_table_index, *export_code);
encoded_export->set(kExportIndex, Smi::FromInt(code_table_index));
++func_index;
}
case kExternalTable:
// Nothing special about exported tables.
break;
case kExternalMemory:
// Nothing special about exported tables.
break;
case kExternalGlobal: {
// Encode the global type and the global offset.
const WasmGlobal& global = globals[exp.index];
encoded_export->set(
kExportGlobalType,
Smi::FromInt(WasmOpcodes::LocalTypeCodeFor(global.type)));
encoded_export->set(kExportIndex, Smi::FromInt(global.offset));
break;
}
}
++index;
}
ret->set_exports(exports);
}
// Create and set init data.
int init_size = static_cast<int>(globals.size());
if (init_size > 0) {
Handle<FixedArray> inits = factory->NewFixedArray(init_size, TENURED);
int index = 0;
for (const WasmGlobal& global : globals) {
// Skip globals that have no initializer (e.g. imported ones).
if (global.init.kind == WasmInitExpr::kNone) continue;
Handle<FixedArray> encoded_init =
factory->NewFixedArray(kWasmGlobalInitDataSize, TENURED);
inits->set(index, *encoded_init);
TRACE("init[%d].type = %s\n", index, WasmOpcodes::TypeName(global.type));
encoded_init->set(
kGlobalInitType,
Smi::FromInt(WasmOpcodes::LocalTypeCodeFor(global.type)));
encoded_init->set(kGlobalInitIndex, Smi::FromInt(global.offset));
EncodeInit(this, factory, encoded_init, kGlobalInitKind, kGlobalInitValue,
global.init);
++index;
}
inits->Shrink(index);
ret->set_inits(inits);
}
// Record data for startup function.
if (start_function_index >= 0) {
HandleScope scope(isolate);
Handle<FixedArray> startup_data =
factory->NewFixedArray(kWasmExportDataSize, TENURED);
startup_data->set(kExportArity, Smi::kZero);
startup_data->set(kExportIndex, Smi::FromInt(start_function_index));
ret->set_startup_function(startup_data);
}
// TODO(wasm): saving the module bytes for debugging is wasteful. We should
// consider downloading this on-demand.
{
size_t module_bytes_len = module_end - module_start;
DCHECK_LE(module_bytes_len, static_cast<size_t>(kMaxInt));
Vector<const uint8_t> module_bytes_vec(module_start,
static_cast<int>(module_bytes_len));
Handle<String> module_bytes_string =
factory->NewStringFromOneByte(module_bytes_vec, TENURED)
.ToHandleChecked();
DCHECK(module_bytes_string->IsSeqOneByteString());
ret->set_module_bytes(Handle<SeqOneByteString>::cast(module_bytes_string));
}
Handle<ByteArray> function_name_table =
BuildFunctionNamesTable(isolate, module_env.module);
ret->set_function_names(function_name_table);
if (data_segments.size() > 0) SaveDataSegmentInfo(factory, this, ret);
DCHECK_EQ(ret->default_mem_size(), temp_instance.mem_size);
return ret;
}
// A helper class to simplify instantiating a module from a compiled module.
// It closes over the {Isolate}, the {ErrorThrower}, the {WasmCompiledModule},
// etc.
class WasmInstanceBuilder {
public:
WasmInstanceBuilder(Isolate* isolate, ErrorThrower* thrower,
Handle<JSObject> module_object, Handle<JSReceiver> ffi,
Handle<JSArrayBuffer> memory)
: isolate_(isolate),
thrower_(thrower),
module_object_(module_object),
ffi_(ffi),
memory_(memory) {}
// Build an instance, in all of its glory.
MaybeHandle<JSObject> Build() {
MaybeHandle<JSObject> nothing;
HistogramTimerScope wasm_instantiate_module_time_scope(
isolate_->counters()->wasm_instantiate_module_time());
Factory* factory = isolate_->factory();
//--------------------------------------------------------------------------
// Reuse the compiled module (if no owner), otherwise clone.
//--------------------------------------------------------------------------
Handle<FixedArray> code_table;
Handle<FixedArray> old_code_table;
MaybeHandle<JSObject> 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(
WasmCompiledModule::cast(module_object_->GetInternalField(0)));
if (original->has_weak_owning_instance()) {
owner =
handle(JSObject::cast(original->weak_owning_instance()->value()));
}
}
DCHECK(!original.is_null());
// Always make a new copy of the code_table, since the old_code_table
// may still have placeholders for imports.
old_code_table = original->code_table();
code_table = factory->CopyFixedArray(old_code_table);
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());
compiled_module_ = WasmCompiledModule::Clone(isolate_, original);
// Clone the code for WASM functions and exports.
for (int i = 0; i < code_table->length(); ++i) {
Handle<Code> orig_code =
code_table->GetValueChecked<Code>(isolate_, i);
switch (orig_code->kind()) {
case Code::WASM_TO_JS_FUNCTION:
// Imports will be overwritten with newly compiled wrappers.
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);
} else {
// There was no owner, so we can reuse the original.
compiled_module_ = original;
TRACE("Reusing existing instance %d\n",
compiled_module_->instance_id());
}
compiled_module_->set_code_table(code_table);
}
//--------------------------------------------------------------------------
// Allocate the instance object.
//--------------------------------------------------------------------------
Handle<Map> map = factory->NewMap(
JS_OBJECT_TYPE,
JSObject::kHeaderSize + kWasmModuleInternalFieldCount * kPointerSize);
Handle<JSObject> instance = factory->NewJSObjectFromMap(map, TENURED);
instance->SetInternalField(kWasmModuleCodeTable, *code_table);
instance->SetInternalField(kWasmMemObject, *factory->undefined_value());
//--------------------------------------------------------------------------
// Set up the globals for the new instance.
//--------------------------------------------------------------------------
MaybeHandle<JSArrayBuffer> old_globals;
MaybeHandle<JSArrayBuffer> globals;
uint32_t globals_size = compiled_module_->globals_size();
if (globals_size > 0) {
Handle<JSArrayBuffer> global_buffer =
NewArrayBuffer(isolate_, globals_size);
globals = global_buffer;
if (globals.is_null()) {
thrower_->Error("Out of memory: wasm globals");
return nothing;
}
Address old_address = owner.is_null()
? nullptr
: GetGlobalStartAddressFromCodeTemplate(
*factory->undefined_value(),
JSObject::cast(*owner.ToHandleChecked()));
RelocateGlobals(instance, old_address,
static_cast<Address>(global_buffer->backing_store()));
instance->SetInternalField(kWasmGlobalsArrayBuffer, *global_buffer);
}
//--------------------------------------------------------------------------
// Process the imports for the module.
//--------------------------------------------------------------------------
int num_imported_functions = ProcessImports(globals, code_table, instance);
if (num_imported_functions < 0) return nothing;
//--------------------------------------------------------------------------
// Process the initialization for the module's globals.
//--------------------------------------------------------------------------
ProcessInits(globals);
//--------------------------------------------------------------------------
// Set up the memory for the new instance.
//--------------------------------------------------------------------------
MaybeHandle<JSArrayBuffer> old_memory;
// TODO(titzer): handle imported memory properly.
uint32_t min_mem_pages = compiled_module_->min_memory_pages();
isolate_->counters()->wasm_min_mem_pages_count()->AddSample(min_mem_pages);
// TODO(wasm): re-enable counter for max_mem_pages when we use that field.
if (memory_.is_null() && min_mem_pages > 0) {
memory_ = AllocateMemory(min_mem_pages);
if (memory_.is_null()) return nothing; // failed to allocate memory
}
if (!memory_.is_null()) {
instance->SetInternalField(kWasmMemArrayBuffer, *memory_);
Address mem_start = static_cast<Address>(memory_->backing_store());
uint32_t mem_size =
static_cast<uint32_t>(memory_->byte_length()->Number());
LoadDataSegments(globals, mem_start, mem_size);
uint32_t old_mem_size = compiled_module_->has_heap()
? compiled_module_->mem_size()
: compiled_module_->default_mem_size();
Address old_mem_start =
compiled_module_->has_heap()
? static_cast<Address>(compiled_module_->heap()->backing_store())
: nullptr;
RelocateInstanceCode(instance, old_mem_start, mem_start, old_mem_size,
mem_size);
compiled_module_->set_heap(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;
i < code_table->length(); ++i) {
Handle<Code> code = code_table->GetValueChecked<Code>(isolate_, i);
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(static_cast<int>(i)));
deopt_data->set_length(2);
code->set_deoptimization_data(*deopt_data);
}
}
//--------------------------------------------------------------------------
// Set up the indirect function tables for the new instance.
//--------------------------------------------------------------------------
{
std::vector<Handle<Code>> functions(
static_cast<size_t>(code_table->length()));
for (int i = 0; i < code_table->length(); ++i) {
functions[i] = code_table->GetValueChecked<Code>(isolate_, i);
}
if (compiled_module_->has_indirect_function_tables()) {
Handle<FixedArray> indirect_tables_template =
compiled_module_->indirect_function_tables();
Handle<FixedArray> to_replace =
owner.is_null() ? indirect_tables_template
: handle(FixedArray::cast(
owner.ToHandleChecked()->GetInternalField(
kWasmModuleFunctionTable)));
Handle<FixedArray> indirect_tables = SetupIndirectFunctionTable(
isolate_, code_table, indirect_tables_template, to_replace);
for (int i = 0; i < indirect_tables->length(); ++i) {
Handle<FixedArray> metadata =
indirect_tables->GetValueChecked<FixedArray>(isolate_, i);
uint32_t size = Smi::cast(metadata->get(kSize))->value();
Handle<FixedArray> table =
metadata->GetValueChecked<FixedArray>(isolate_, kTable);
PopulateFunctionTable(table, size, &functions);
}
instance->SetInternalField(kWasmModuleFunctionTable, *indirect_tables);
}
}
//--------------------------------------------------------------------------
// Set up the exports object for the new instance.
//--------------------------------------------------------------------------
ProcessExports(globals, code_table, instance);
if (num_imported_functions > 0 || !owner.is_null()) {
// If the code was cloned, or new imports were compiled, patch.
PatchDirectCalls(old_code_table, code_table, num_imported_functions);
}
FlushICache(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(GetCompiledModule(*owner.ToHandleChecked()));
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_module_object(
original.ToHandleChecked()->weak_module_object());
}
module_object_->SetInternalField(0, *compiled_module_);
instance->SetInternalField(kWasmCompiledModule, *compiled_module_);
compiled_module_->set_weak_owning_instance(link_to_owning_instance);
GlobalHandles::MakeWeak(global_handle.location(),
global_handle.location(), &InstanceFinalizer,
v8::WeakCallbackType::kFinalizer);
}
}
//--------------------------------------------------------------------------
// Run the start function if one was specified.
//--------------------------------------------------------------------------
if (compiled_module_->has_startup_function()) {
Handle<FixedArray> startup_data = compiled_module_->startup_function();
HandleScope scope(isolate_);
int32_t start_index =
startup_data->GetValueChecked<Smi>(isolate_, kExportIndex)->value();
Handle<Code> startup_code =
code_table->GetValueChecked<Code>(isolate_, start_index);
int arity = Smi::cast(startup_data->get(kExportArity))->value();
MaybeHandle<ByteArray> startup_signature =
startup_data->GetValue<ByteArray>(isolate_, kExportedSignature);
Handle<JSFunction> startup_fct = WrapExportCodeAsJSFunction(
isolate_, startup_code, factory->InternalizeUtf8String("start"),
arity, startup_signature, instance);
RecordStats(isolate_, *startup_code);
// 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()) {
thrower_->Error("WASM.instantiateModule(): start function failed");
// 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 nothing;
}
}
DCHECK(wasm::IsWasmObject(*instance));
TRACE("Finishing instance %d\n", compiled_module_->instance_id());
TRACE_CHAIN(WasmCompiledModule::cast(module_object_->GetInternalField(0)));
return instance;
}
private:
Isolate* isolate_;
ErrorThrower* thrower_;
Handle<JSObject> module_object_;
Handle<JSReceiver> ffi_;
Handle<JSArrayBuffer> memory_;
Handle<WasmCompiledModule> compiled_module_;
// Helper routine to print out errors with imports (FFI).
MaybeHandle<JSFunction> ReportFFIError(const char* error, uint32_t index,
Handle<String> module_name,
MaybeHandle<String> function_name) {
Handle<String> function_name_handle;
if (function_name.ToHandle(&function_name_handle)) {
thrower_->Error("Import #%d module=\"%.*s\" function=\"%.*s\" error: %s",
index, module_name->length(),
module_name->ToCString().get(),
function_name_handle->length(),
function_name_handle->ToCString().get(), error);
} else {
thrower_->Error("Import #%d module=\"%.*s\" error: %s", index,
module_name->length(), module_name->ToCString().get(),
error);
}
thrower_->Error("Import ");
return MaybeHandle<JSFunction>();
}
// Look up an import value in the {ffi_} object.
MaybeHandle<Object> LookupImport(uint32_t index, Handle<String> module_name,
MaybeHandle<String> import_name) {
if (ffi_.is_null()) {
return ReportFFIError("FFI is not an object", index, module_name,
import_name);
}
// Look up the module first.
MaybeHandle<Object> result = Object::GetProperty(ffi_, module_name);
if (result.is_null()) {
return ReportFFIError("module not found", index, module_name,
import_name);
}
Handle<Object> module = result.ToHandleChecked();
if (!import_name.is_null()) {
// Look up the value in the module.
if (!module->IsJSReceiver()) {
return ReportFFIError("module is not an object or function", index,
module_name, import_name);
}
result = Object::GetProperty(module, import_name.ToHandleChecked());
if (result.is_null()) {
return ReportFFIError("import not found", index, module_name,
import_name);
}
} else {
// No function specified. Use the "default export".
result = module;
}
return result;
}
// Load data segments into the memory.
void LoadDataSegments(MaybeHandle<JSArrayBuffer> globals, Address mem_addr,
size_t mem_size) {
CHECK(compiled_module_->has_data_segments() ==
compiled_module_->has_data_segments_info());
// If we have neither, we're done.
if (!compiled_module_->has_data_segments()) return;
Handle<ByteArray> data = compiled_module_->data_segments();
Handle<FixedArray> segments = compiled_module_->data_segments_info();
uint32_t last_extraction_pos = 0;
for (int i = 0; i < segments->length(); ++i) {
Handle<ByteArray> segment =
Handle<ByteArray>(ByteArray::cast(segments->get(i)));
uint32_t dest_addr =
static_cast<uint32_t>(segment->get_int(kDestAddrValue));
if (segment->get_int(kDestAddrKind) == 1) {
// The destination address is the value of a global variable.
dest_addr =
*reinterpret_cast<uint32_t*>(raw_buffer_ptr(globals, dest_addr));
}
uint32_t source_size =
static_cast<uint32_t>(segment->get_int(kSourceSize));
// TODO(titzer): These should be runtime errors and not CHECKs if
// dest_addr is global (and therefore initialized at linktime to an
// possibly-invalid value).
CHECK_LT(dest_addr, mem_size);
CHECK_LE(source_size, mem_size);
CHECK_LE(dest_addr, mem_size - source_size);
byte* addr = mem_addr + dest_addr;
data->copy_out(last_extraction_pos, addr, source_size);
last_extraction_pos += source_size;
}
}
Handle<Code> CompileImportWrapper(int index, Handle<FixedArray> data,
Handle<JSReceiver> target,
Handle<String> module_name,
MaybeHandle<String> import_name) {
// TODO(mtrofin): this is an uint32_t, actually. We should rationalize
// it when we rationalize signed/unsigned stuff.
int ret_count = Smi::cast(data->get(kOutputCount))->value();
CHECK_GE(ret_count, 0);
Handle<ByteArray> sig_data =
data->GetValueChecked<ByteArray>(isolate_, kSignature);
int sig_data_size = sig_data->length();
int param_count = sig_data_size - ret_count;
CHECK(param_count >= 0);
Handle<Code> code;
bool isMatch = false;
Handle<Code> export_wrapper_code;
if (target->IsJSFunction()) {
Handle<JSFunction> func = Handle<JSFunction>::cast(target);
export_wrapper_code = handle(func->code());
if (export_wrapper_code->kind() == Code::JS_TO_WASM_FUNCTION) {
int exported_param_count =
Smi::cast(func->GetInternalField(kInternalArity))->value();
Handle<ByteArray> exportedSig = Handle<ByteArray>(
ByteArray::cast(func->GetInternalField(kInternalSignature)));
if (exported_param_count == param_count &&
exportedSig->length() == sig_data->length() &&
memcmp(exportedSig->GetDataStartAddress(),
sig_data->GetDataStartAddress(),
exportedSig->length()) == 0) {
isMatch = true;
}
}
}
if (isMatch) {
int wasm_count = 0;
int const mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET);
for (RelocIterator it(*export_wrapper_code, mask); !it.done();
it.next()) {
RelocInfo* rinfo = it.rinfo();
Address target_address = rinfo->target_address();
Code* target = Code::GetCodeFromTargetAddress(target_address);
if (target->kind() == Code::WASM_FUNCTION) {
++wasm_count;
code = handle(target);
}
}
DCHECK(wasm_count == 1);
return code;
} else {
// Copy the signature to avoid a raw pointer into a heap object when
// GC can happen.
Zone zone(isolate_->allocator());
MachineRepresentation* reps =
zone.NewArray<MachineRepresentation>(sig_data_size);
memcpy(reps, sig_data->GetDataStartAddress(),
sizeof(MachineRepresentation) * sig_data_size);
FunctionSig sig(ret_count, param_count, reps);
return compiler::CompileWasmToJSWrapper(isolate_, target, &sig, index,
module_name, import_name);
}
}
void WriteGlobalValue(MaybeHandle<JSArrayBuffer> globals, uint32_t offset,
Handle<Object> value, int type) {
double num = 0;
if (value->IsSmi()) {
num = Smi::cast(*value)->value();
} else if (value->IsHeapNumber()) {
num = HeapNumber::cast(*value)->value();
} else {
UNREACHABLE();
}
TRACE("init [globals+%u] = %lf, type = %d\n", offset, num, type);
byte* ptr = raw_buffer_ptr(globals, offset);
switch (type) {
case kLocalI32:
*reinterpret_cast<int32_t*>(ptr) = static_cast<int32_t>(num);
break;
case kLocalI64:
// TODO(titzer): initialization of imported i64 globals.
UNREACHABLE();
break;
case kLocalF32:
*reinterpret_cast<float*>(ptr) = static_cast<float>(num);
break;
case kLocalF64:
*reinterpret_cast<double*>(ptr) = 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(MaybeHandle<JSArrayBuffer> globals,
Handle<FixedArray> code_table, Handle<JSObject> instance) {
int num_imported_functions = 0;
if (!compiled_module_->has_imports()) return num_imported_functions;
Handle<FixedArray> imports = compiled_module_->imports();
for (int index = 0; index < imports->length(); ++index) {
Handle<FixedArray> data =
imports->GetValueChecked<FixedArray>(isolate_, index);
Handle<String> module_name =
data->GetValueChecked<String>(isolate_, kModuleName);
MaybeHandle<String> function_name =
data->GetValue<String>(isolate_, kFunctionName);
MaybeHandle<Object> result =
LookupImport(index, module_name, function_name);
if (thrower_->error()) return -1;
WasmExternalKind kind = static_cast<WasmExternalKind>(
Smi::cast(data->get(kImportKind))->value());
switch (kind) {
case kExternalFunction: {
// Function imports must be callable.
Handle<Object> function = result.ToHandleChecked();
if (!function->IsCallable()) {
ReportFFIError("function import requires a callable", index,
module_name, function_name);
return -1;
}
Handle<Code> import_wrapper = CompileImportWrapper(
index, data, Handle<JSReceiver>::cast(function), module_name,
function_name);
int func_index = Smi::cast(data->get(kImportIndex))->value();
code_table->set(func_index, *import_wrapper);
RecordStats(isolate_, *import_wrapper);
num_imported_functions++;
break;
}
case kExternalTable:
// TODO(titzer): Table imports must be a WebAssembly.Table.
break;
case kExternalMemory: {
Handle<Object> object = result.ToHandleChecked();
if (!WasmJs::IsWasmMemoryObject(isolate_, object)) {
ReportFFIError("memory import must be a WebAssembly.Memory object",
index, module_name, function_name);
return -1;
}
instance->SetInternalField(kWasmMemObject, *object);
memory_ = WasmJs::GetWasmMemoryArrayBuffer(isolate_, object);
break;
}
case kExternalGlobal: {
// Global imports are converted to numbers and written into the
// {globals} array buffer.
Handle<Object> object = result.ToHandleChecked();
MaybeHandle<Object> number = Object::ToNumber(object);
if (number.is_null()) {
ReportFFIError("global import could not be converted to number",
index, module_name, function_name);
return -1;
}
Handle<Object> val = number.ToHandleChecked();
int offset = Smi::cast(data->get(kImportIndex))->value();
int type = Smi::cast(data->get(kImportGlobalType))->value();
WriteGlobalValue(globals, offset, val, type);
break;
}
default:
UNREACHABLE();
break;
}
}
return num_imported_functions;
}
// Process initialization of globals.
void ProcessInits(MaybeHandle<JSArrayBuffer> globals) {
if (!compiled_module_->has_inits()) return;
Handle<FixedArray> inits = compiled_module_->inits();
for (int index = 0; index < inits->length(); ++index) {
Handle<FixedArray> data =
inits->GetValueChecked<FixedArray>(isolate_, index);
int offset = Smi::cast(data->get(kGlobalInitIndex))->value();
Handle<Object> val(data->get(kGlobalInitValue), isolate_);
int type = Smi::cast(data->get(kGlobalInitType))->value();
if (Smi::cast(data->get(kGlobalInitKind))->value() == 0) {
// Initialize with a constant.
WriteGlobalValue(globals, offset, val, type);
} else {
// Initialize with another global.
int old_offset = Smi::cast(*val)->value();
TRACE("init [globals+%u] = [globals+%d]\n", offset, old_offset);
int size = sizeof(int32_t);
if (type == kLocalI64 || type == kLocalF64) size = sizeof(double);
memcpy(raw_buffer_ptr(globals, offset),
raw_buffer_ptr(globals, old_offset), size);
}
}
}
// Allocate memory for a module instance as a new JSArrayBuffer.
Handle<JSArrayBuffer> AllocateMemory(uint32_t min_mem_pages) {
if (min_mem_pages > WasmModule::kMaxMemPages) {
thrower_->Error("Out of memory: wasm memory too large");
return Handle<JSArrayBuffer>::null();
}
Handle<JSArrayBuffer> mem_buffer =
NewArrayBuffer(isolate_, min_mem_pages * WasmModule::kPageSize);
if (mem_buffer.is_null()) {
thrower_->Error("Out of memory: wasm memory");
}
return mem_buffer;
}
// Process the exports, creating wrappers for functions, tables, memories,
// and globals.
void ProcessExports(MaybeHandle<JSArrayBuffer> globals,
Handle<FixedArray> code_table,
Handle<JSObject> instance) {
if (!compiled_module_->has_exports()) return;
Handle<JSObject> exports_object = instance;
if (compiled_module_->origin() == kWasmOrigin) {
// Create the "exports" object.
Handle<JSFunction> object_function = Handle<JSFunction>(
isolate_->native_context()->object_function(), isolate_);
exports_object =
isolate_->factory()->NewJSObject(object_function, TENURED);
Handle<String> exports_name =
isolate_->factory()->InternalizeUtf8String("exports");
JSObject::AddProperty(instance, exports_name, exports_object, READ_ONLY);
}
PropertyDescriptor desc;
desc.set_writable(false);
Handle<FixedArray> exports = compiled_module_->exports();
for (int i = 0; i < exports->length(); ++i) {
Handle<FixedArray> export_data =
exports->GetValueChecked<FixedArray>(isolate_, i);
Handle<String> name =
export_data->GetValueChecked<String>(isolate_, kExportName);
WasmExternalKind kind = static_cast<WasmExternalKind>(
Smi::cast(export_data->get(kExportKind))->value());
switch (kind) {
case kExternalFunction: {
// Wrap and export the code as a JSFunction.
int code_table_index =
Smi::cast(export_data->get(kExportIndex))->value();
Handle<Code> export_code =
code_table->GetValueChecked<Code>(isolate_, code_table_index);
int arity = Smi::cast(export_data->get(kExportArity))->value();
MaybeHandle<ByteArray> signature =
export_data->GetValue<ByteArray>(isolate_, kExportedSignature);
desc.set_value(WrapExportCodeAsJSFunction(
isolate_, export_code, name, arity, signature, instance));
break;
}
case kExternalTable:
// TODO(titzer): create a WebAssembly.Table instance.
// TODO(titzer): should it have the same identity as an import?
break;
case kExternalMemory: {
// Export the memory as a WebAssembly.Memory object.
Handle<Object> memory_object(
instance->GetInternalField(kWasmMemObject), isolate_);
if (memory_object->IsUndefined(isolate_)) {
// If there was no imported WebAssembly.Memory object, create one.
Handle<JSArrayBuffer> buffer(
JSArrayBuffer::cast(
instance->GetInternalField(kWasmMemArrayBuffer)),
isolate_);
memory_object =
WasmJs::CreateWasmMemoryObject(isolate_, buffer, false, 0);
instance->SetInternalField(kWasmMemObject, *memory_object);
}
desc.set_value(memory_object);
break;
}
case kExternalGlobal: {
// Export the value of the global variable as a number.
int offset = Smi::cast(export_data->get(kExportIndex))->value();
byte* ptr = raw_buffer_ptr(globals, offset);
double num = 0;
switch (Smi::cast(export_data->get(kExportGlobalType))->value()) {
case kLocalI32:
num = *reinterpret_cast<int32_t*>(ptr);
break;
case kLocalF32:
num = *reinterpret_cast<float*>(ptr);
break;
case kLocalF64:
num = *reinterpret_cast<double*>(ptr);
break;
default:
UNREACHABLE();
}
desc.set_value(isolate_->factory()->NewNumber(num));
break;
}
default:
UNREACHABLE();
break;
}
v8::Maybe<bool> status = JSReceiver::DefineOwnProperty(
isolate_, exports_object, name, &desc, Object::THROW_ON_ERROR);
if (!status.IsJust()) {
thrower_->Error("export of %.*s failed.", name->length(),
name->ToCString().get());
return;
}
}
}
};
// Instantiates a WASM module, creating a WebAssembly.Instance from a
// WebAssembly.Module.
MaybeHandle<JSObject> WasmModule::Instantiate(Isolate* isolate,
ErrorThrower* thrower,
Handle<JSObject> module_object,
Handle<JSReceiver> ffi,
Handle<JSArrayBuffer> memory) {
WasmInstanceBuilder builder(isolate, thrower, module_object, ffi, memory);
return builder.Build();
}
Handle<WasmCompiledModule> WasmCompiledModule::New(Isolate* isolate,
uint32_t min_memory_pages,
uint32_t globals_size,
ModuleOrigin origin) {
Handle<FixedArray> ret =
isolate->factory()->NewFixedArray(PropertyIndices::Count, TENURED);
// Globals size is expected to fit into an int without overflow. This is not
// supported by the spec at the moment, however, we don't support array
// buffer sizes over 1g, so, for now, we avoid alocating a HeapNumber for
// the globals size. The CHECK guards this assumption.
CHECK_GE(static_cast<int>(globals_size), 0);
ret->set(kID_min_memory_pages,
Smi::FromInt(static_cast<int>(min_memory_pages)));
ret->set(kID_globals_size, Smi::FromInt(static_cast<int>(globals_size)));
ret->set(kID_origin, Smi::FromInt(static_cast<int>(origin)));
// WasmCompiledModule::cast would fail since module bytes are not set yet.
Handle<WasmCompiledModule> module(reinterpret_cast<WasmCompiledModule*>(*ret),
isolate);
module->Init();
return module;
}
void WasmCompiledModule::Init() {
#if DEBUG
static uint32_t instance_id_counter = 0;
set(kID_instance_id, Smi::FromInt(instance_id_counter++));
TRACE("New compiled module id: %d\n", instance_id());
#endif
}
bool WasmCompiledModule::IsWasmCompiledModule(Object* obj) {
if (!obj->IsFixedArray()) return false;
FixedArray* arr = FixedArray::cast(obj);
if (arr->length() != PropertyIndices::Count) return false;
Isolate* isolate = arr->GetIsolate();
#define WCM_CHECK_SMALL_NUMBER(TYPE, NAME) \
if (!arr->get(kID_##NAME)->IsSmi()) return false;
#define WCM_CHECK_OBJECT_OR_WEAK(TYPE, NAME) \
if (!arr->get(kID_##NAME)->IsUndefined(isolate) && \
!arr->get(kID_##NAME)->Is##TYPE()) \
return false;
#define WCM_CHECK_OBJECT(TYPE, NAME) WCM_CHECK_OBJECT_OR_WEAK(TYPE, NAME)
#define WCM_CHECK_WEAK_LINK(TYPE, NAME) WCM_CHECK_OBJECT_OR_WEAK(WeakCell, NAME)
#define WCM_CHECK(KIND, TYPE, NAME) WCM_CHECK_##KIND(TYPE, NAME)
WCM_PROPERTY_TABLE(WCM_CHECK)
#undef WCM_CHECK
// All checks passed.
return true;
}
void WasmCompiledModule::PrintInstancesChain() {
#if DEBUG
if (!FLAG_trace_wasm_instances) return;
for (WasmCompiledModule* current = this; current != nullptr;) {
PrintF("->%d", current->instance_id());
if (current->ptr_to_weak_next_instance() == nullptr) break;
CHECK(!current->ptr_to_weak_next_instance()->cleared());
current =
WasmCompiledModule::cast(current->ptr_to_weak_next_instance()->value());
}
PrintF("\n");
#endif
}
Handle<Object> wasm::GetWasmFunctionNameOrNull(Isolate* isolate,
Handle<Object> wasm,
uint32_t func_index) {
if (!wasm->IsUndefined(isolate)) {
DCHECK(IsWasmObject(*wasm));
WasmCompiledModule* compiled_module =
GetCompiledModule(JSObject::cast(*wasm));
Handle<ByteArray> func_names = compiled_module->function_names();
// TODO(clemens): Extract this from the module bytes; skip whole function
// name table.
Handle<Object> name;
if (GetWasmFunctionNameFromTable(func_names, func_index).ToHandle(&name)) {
return name;
}
}
return isolate->factory()->null_value();
}
Handle<String> wasm::GetWasmFunctionName(Isolate* isolate, Handle<Object> wasm,
uint32_t func_index) {
Handle<Object> name_or_null =
GetWasmFunctionNameOrNull(isolate, wasm, func_index);
if (!name_or_null->IsNull(isolate)) {
return Handle<String>::cast(name_or_null);
}
return isolate->factory()->NewStringFromStaticChars("<WASM UNNAMED>");
}
bool wasm::IsWasmObject(Object* object) {
if (!object->IsJSObject()) return false;
JSObject* obj = JSObject::cast(object);
Isolate* isolate = obj->GetIsolate();
if (obj->GetInternalFieldCount() != kWasmModuleInternalFieldCount) {
return false;
}
Object* mem = obj->GetInternalField(kWasmMemArrayBuffer);
if (!obj->GetInternalField(kWasmModuleCodeTable)->IsFixedArray() ||
!(mem->IsUndefined(isolate) || mem->IsJSArrayBuffer()) ||
!WasmCompiledModule::IsWasmCompiledModule(
obj->GetInternalField(kWasmCompiledModule))) {
return false;
}
// All checks passed.
return true;
}
WasmCompiledModule* wasm::GetCompiledModule(JSObject* wasm) {
return WasmCompiledModule::cast(wasm->GetInternalField(kWasmCompiledModule));
}
bool wasm::WasmIsAsmJs(Object* wasm, Isolate* isolate) {
if (wasm->IsUndefined(isolate)) return false;
DCHECK(IsWasmObject(wasm));
WasmCompiledModule* compiled_module = GetCompiledModule(JSObject::cast(wasm));
return compiled_module->has_asm_js_script();
}
Handle<Script> wasm::GetAsmWasmScript(Handle<JSObject> wasm) {
DCHECK(IsWasmObject(*wasm));
WasmCompiledModule* compiled_module = GetCompiledModule(*wasm);
return compiled_module->asm_js_script();
}
int wasm::GetAsmWasmSourcePosition(Handle<JSObject> wasm, int func_index,
int byte_offset) {
return WasmDebugInfo::GetAsmJsSourcePosition(GetDebugInfo(wasm), func_index,
byte_offset);
}
Handle<SeqOneByteString> wasm::GetWasmBytes(Handle<JSObject> wasm) {
DCHECK(IsWasmObject(*wasm));
WasmCompiledModule* compiled_module = GetCompiledModule(*wasm);
return compiled_module->module_bytes();
}
Handle<WasmDebugInfo> wasm::GetDebugInfo(Handle<JSObject> wasm) {
Handle<Object> info(wasm->GetInternalField(kWasmDebugInfo),
wasm->GetIsolate());
if (!info->IsUndefined(wasm->GetIsolate()))
return Handle<WasmDebugInfo>::cast(info);
Handle<WasmDebugInfo> new_info = WasmDebugInfo::New(wasm);
wasm->SetInternalField(kWasmDebugInfo, *new_info);
return new_info;
}
bool wasm::UpdateWasmModuleMemory(Handle<JSObject> object, Address old_start,
Address new_start, uint32_t old_size,
uint32_t new_size) {
DisallowHeapAllocation no_allocation;
if (!IsWasmObject(*object)) {
return false;
}
// Get code table associated with the module js_object
Object* obj = object->GetInternalField(kWasmModuleCodeTable);
Handle<FixedArray> code_table(FixedArray::cast(obj));
// Iterate through the code objects in the code table and update relocation
// information
for (int i = 0; i < code_table->length(); ++i) {
obj = code_table->get(i);
Handle<Code> code(Code::cast(obj));
int mode_mask = RelocInfo::ModeMask(RelocInfo::WASM_MEMORY_REFERENCE) |
RelocInfo::ModeMask(RelocInfo::WASM_MEMORY_SIZE_REFERENCE);
for (RelocIterator it(*code, mode_mask); !it.done(); it.next()) {
RelocInfo::Mode mode = it.rinfo()->rmode();
if (RelocInfo::IsWasmMemoryReference(mode) ||
RelocInfo::IsWasmMemorySizeReference(mode)) {
it.rinfo()->update_wasm_memory_reference(old_start, new_start, old_size,
new_size);
}
}
}
return true;
}
Handle<FixedArray> wasm::BuildFunctionTable(Isolate* isolate, uint32_t index,
const WasmModule* module) {
const WasmIndirectFunctionTable* table = &module->function_tables[index];
DCHECK_EQ(table->size, table->values.size());
DCHECK_GE(table->max_size, table->size);
Handle<FixedArray> values =
isolate->factory()->NewFixedArray(2 * table->max_size, TENURED);
for (uint32_t i = 0; i < table->size; ++i) {
const WasmFunction* function = &module->functions[table->values[i]];
int32_t index = table->map.Find(function->sig);
DCHECK_GE(index, 0);
values->set(i, Smi::FromInt(index));
values->set(i + table->max_size, Smi::FromInt(table->values[i]));
}
// Set the remaining elements to -1 (instead of "undefined"). These
// elements are accessed directly as SMIs (without a check). On 64-bit
// platforms, it is possible to have the top bits of "undefined" take
// small integer values (or zero), which are more likely to be equal to
// the signature index we check against.
for (uint32_t i = table->size; i < table->max_size; ++i) {
values->set(i, Smi::FromInt(-1));
}
return values;
}
void wasm::PopulateFunctionTable(Handle<FixedArray> table, uint32_t table_size,
const std::vector<Handle<Code>>* code_table) {
uint32_t max_size = table->length() / 2;
for (uint32_t i = max_size; i < max_size + table_size; ++i) {
int index = Smi::cast(table->get(static_cast<int>(i)))->value();
DCHECK_GE(index, 0);
DCHECK_LT(static_cast<size_t>(index), code_table->size());
table->set(static_cast<int>(i), *(*code_table)[index]);
}
}
int wasm::GetNumberOfFunctions(Handle<JSObject> wasm) {
DCHECK(IsWasmObject(*wasm));
WasmCompiledModule* compiled_module = GetCompiledModule(*wasm);
ByteArray* func_names_arr = compiled_module->ptr_to_function_names();
// TODO(clemensh): this looks inside an array constructed elsewhere. Refactor.
return func_names_arr->get_int(0);
}
Handle<JSObject> wasm::CreateCompiledModuleObject(
Isolate* isolate, Handle<WasmCompiledModule> compiled_module,
ModuleOrigin origin) {
Handle<JSObject> module_obj;
if (origin == ModuleOrigin::kWasmOrigin) {
Handle<JSFunction> module_cons(
isolate->native_context()->wasm_module_constructor());
module_obj = isolate->factory()->NewJSObject(module_cons);
} else {
DCHECK(origin == ModuleOrigin::kAsmJsOrigin);
Handle<Map> map = isolate->factory()->NewMap(
JS_OBJECT_TYPE, JSObject::kHeaderSize + kPointerSize);
module_obj = isolate->factory()->NewJSObjectFromMap(map, TENURED);
}
module_obj->SetInternalField(0, *compiled_module);
if (origin == ModuleOrigin::kWasmOrigin) {
Handle<Symbol> module_sym(isolate->native_context()->wasm_module_sym());
Object::SetProperty(module_obj, module_sym, module_obj, STRICT).Check();
}
Handle<WeakCell> link_to_module = isolate->factory()->NewWeakCell(module_obj);
compiled_module->set_weak_module_object(link_to_module);
return module_obj;
}
// TODO(clemensh): origin can be inferred from asm_js_script; remove it.
MaybeHandle<JSObject> wasm::CreateModuleObjectFromBytes(
Isolate* isolate, const byte* start, const byte* end, ErrorThrower* thrower,
ModuleOrigin origin, Handle<Script> asm_js_script,
const byte* asm_js_offset_tables_start,
const byte* asm_js_offset_tables_end) {
MaybeHandle<JSObject> nothing;
Zone zone(isolate->allocator());
ModuleResult result =
DecodeWasmModule(isolate, &zone, start, end, false, origin);
std::unique_ptr<const WasmModule> decoded_module(result.val);
if (result.failed()) {
thrower->Failed("Wasm decoding failed", result);
return nothing;
}
MaybeHandle<WasmCompiledModule> maybe_compiled_module =
decoded_module->CompileFunctions(isolate, thrower);
if (maybe_compiled_module.is_null()) return nothing;
Handle<WasmCompiledModule> compiled_module =
maybe_compiled_module.ToHandleChecked();
DCHECK_EQ(origin == kAsmJsOrigin, !asm_js_script.is_null());
DCHECK(!compiled_module->has_asm_js_script());
DCHECK(!compiled_module->has_asm_js_offset_tables());
if (origin == kAsmJsOrigin) {
compiled_module->set_asm_js_script(asm_js_script);
size_t offset_tables_len =
asm_js_offset_tables_end - asm_js_offset_tables_start;
DCHECK_GE(static_cast<size_t>(kMaxInt), offset_tables_len);
Handle<ByteArray> offset_tables =
isolate->factory()->NewByteArray(static_cast<int>(offset_tables_len));
memcpy(offset_tables->GetDataStartAddress(), asm_js_offset_tables_start,
offset_tables_len);
compiled_module->set_asm_js_offset_tables(offset_tables);
}
return CreateCompiledModuleObject(isolate, compiled_module, origin);
}
bool wasm::ValidateModuleBytes(Isolate* isolate, const byte* start,
const byte* end, ErrorThrower* thrower,
ModuleOrigin origin) {
Zone zone(isolate->allocator());
ModuleResult result =
DecodeWasmModule(isolate, &zone, start, end, false, origin);
if (result.ok()) {
DCHECK_NOT_NULL(result.val);
delete result.val;
return true;
}
return false;
}
MaybeHandle<JSArrayBuffer> wasm::GetInstanceMemory(Isolate* isolate,
Handle<JSObject> instance) {
Object* mem = instance->GetInternalField(kWasmMemArrayBuffer);
DCHECK(IsWasmObject(*instance));
if (mem->IsUndefined(isolate)) return MaybeHandle<JSArrayBuffer>();
return Handle<JSArrayBuffer>(JSArrayBuffer::cast(mem));
}
void SetInstanceMemory(Handle<JSObject> instance, JSArrayBuffer* buffer) {
DisallowHeapAllocation no_gc;
DCHECK(IsWasmObject(*instance));
instance->SetInternalField(kWasmMemArrayBuffer, buffer);
WasmCompiledModule* compiled_module = GetCompiledModule(*instance);
compiled_module->set_ptr_to_heap(buffer);
}
int32_t wasm::GetInstanceMemorySize(Isolate* isolate,
Handle<JSObject> instance) {
MaybeHandle<JSArrayBuffer> maybe_mem_buffer =
GetInstanceMemory(isolate, instance);
Handle<JSArrayBuffer> buffer;
if (!maybe_mem_buffer.ToHandle(&buffer)) {
return 0;
} else {
return buffer->byte_length()->Number() / WasmModule::kPageSize;
}
}
int32_t wasm::GrowInstanceMemory(Isolate* isolate, Handle<JSObject> instance,
uint32_t pages) {
if (pages == 0) {
return GetInstanceMemorySize(isolate, instance);
}
Address old_mem_start = nullptr;
uint32_t old_size = 0, new_size = 0;
MaybeHandle<JSArrayBuffer> maybe_mem_buffer =
GetInstanceMemory(isolate, instance);
Handle<JSArrayBuffer> old_buffer;
if (!maybe_mem_buffer.ToHandle(&old_buffer)) {
// If module object does not have linear memory associated with it,
// Allocate new array buffer of given size.
// TODO(gdeepti): Fix bounds check to take into account size of memtype.
new_size = pages * WasmModule::kPageSize;
// The code generated in the wasm compiler guarantees this precondition.
DCHECK(pages <= WasmModule::kMaxMemPages);
} else {
old_mem_start = static_cast<Address>(old_buffer->backing_store());
old_size = old_buffer->byte_length()->Number();
// If the old memory was zero-sized, we should have been in the
// "undefined" case above.
DCHECK_NOT_NULL(old_mem_start);
DCHECK_NE(0, old_size);
DCHECK(old_size + pages * WasmModule::kPageSize <=
std::numeric_limits<uint32_t>::max());
new_size = old_size + pages * WasmModule::kPageSize;
}
if (new_size <= old_size ||
WasmModule::kMaxMemPages * WasmModule::kPageSize <= new_size) {
return -1;
}
Handle<JSArrayBuffer> buffer = NewArrayBuffer(isolate, new_size);
if (buffer.is_null()) return -1;
Address new_mem_start = static_cast<Address>(buffer->backing_store());
if (old_size != 0) {
memcpy(new_mem_start, old_mem_start, old_size);
}
SetInstanceMemory(instance, *buffer);
if (!UpdateWasmModuleMemory(instance, old_mem_start, new_mem_start, old_size,
new_size)) {
return -1;
}
DCHECK(old_size % WasmModule::kPageSize == 0);
return (old_size / WasmModule::kPageSize);
}
void testing::ValidateInstancesChain(Isolate* isolate,
Handle<JSObject> module_obj,
int instance_count) {
CHECK_GE(instance_count, 0);
DisallowHeapAllocation no_gc;
WasmCompiledModule* compiled_module =
WasmCompiledModule::cast(module_obj->GetInternalField(0));
CHECK_EQ(
JSObject::cast(compiled_module->ptr_to_weak_module_object()->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_module_object()->value(),
*module_obj);
CHECK(
IsWasmObject(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<JSObject> module_obj) {
DisallowHeapAllocation no_gc;
WasmCompiledModule* compiled_module =
WasmCompiledModule::cast(module_obj->GetInternalField(0));
CHECK(compiled_module->has_weak_module_object());
CHECK_EQ(compiled_module->ptr_to_weak_module_object()->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<JSObject> instance) {
DisallowHeapAllocation no_gc;
CHECK(IsWasmObject(*instance));
WasmCompiledModule* compiled_module = GetCompiledModule(*instance);
CHECK(compiled_module->has_weak_module_object());
CHECK(compiled_module->ptr_to_weak_module_object()->cleared());
}