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chromium / v8 / v8 / d3d125417db0c278a2d27e4a965ad4e82c66e2af / . / src / wasm / wasm-module.cc
blob: e63ec53b03b65fc06e08a9ebcefb1aad53f72bb5 [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/compiler/wasm-compiler.h"
#include "src/debug/interface-types.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-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)
namespace {
static const int kInvalidSigIndex = -1;
static const int kPlaceholderMarker = 1000000000;
byte* raw_buffer_ptr(MaybeHandle<JSArrayBuffer> buffer, int offset) {
return static_cast<byte*>(buffer.ToHandleChecked()->backing_store()) + offset;
}
MaybeHandle<String> ExtractStringFromModuleBytes(
Isolate* isolate, Handle<WasmCompiledModule> compiled_module,
uint32_t offset, uint32_t size) {
// TODO(wasm): cache strings from modules if it's a performance win.
Handle<SeqOneByteString> module_bytes = compiled_module->module_bytes();
DCHECK_GE(module_bytes->length(), offset);
DCHECK_GE(module_bytes->length() - offset, size);
Address raw = module_bytes->GetCharsAddress() + offset;
if (!unibrow::Utf8::Validate(reinterpret_cast<const byte*>(raw), size))
return {}; // UTF8 decoding error for name.
return isolate->factory()->NewStringFromUtf8SubString(
module_bytes, static_cast<int>(offset), static_cast<int>(size));
}
void ReplaceReferenceInCode(Handle<Code> code, Handle<Object> old_ref,
Handle<Object> new_ref) {
for (RelocIterator it(*code, 1 << RelocInfo::EMBEDDED_OBJECT); !it.done();
it.next()) {
if (it.rinfo()->target_object() == *old_ref) {
it.rinfo()->set_target_object(*new_ref);
}
}
}
static void MemoryFinalizer(const v8::WeakCallbackInfo<void>& data) {
DisallowHeapAllocation no_gc;
JSArrayBuffer** p = reinterpret_cast<JSArrayBuffer**>(data.GetParameter());
JSArrayBuffer* buffer = *p;
void* memory = buffer->backing_store();
base::OS::Free(memory,
RoundUp(kWasmMaxHeapOffset, base::OS::CommitPageSize()));
data.GetIsolate()->AdjustAmountOfExternalAllocatedMemory(
-buffer->byte_length()->Number());
GlobalHandles::Destroy(reinterpret_cast<Object**>(p));
}
#if V8_TARGET_ARCH_64_BIT
const bool kGuardRegionsSupported = true;
#else
const bool kGuardRegionsSupported = false;
#endif
bool EnableGuardRegions() {
return FLAG_wasm_guard_pages && kGuardRegionsSupported;
}
void* TryAllocateBackingStore(Isolate* isolate, size_t size,
bool enable_guard_regions, bool& is_external) {
is_external = false;
// 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.
const size_t alloc_size =
RoundUp(kWasmMaxHeapOffset, base::OS::CommitPageSize());
DCHECK_EQ(0, size % base::OS::CommitPageSize());
// AllocateGuarded makes the whole region inaccessible by default.
void* memory = base::OS::AllocateGuarded(alloc_size);
if (memory == nullptr) {
return nullptr;
}
// Make the part we care about accessible.
base::OS::Unprotect(memory, size);
reinterpret_cast<v8::Isolate*>(isolate)
->AdjustAmountOfExternalAllocatedMemory(size);
is_external = true;
return memory;
} else {
void* memory = isolate->array_buffer_allocator()->Allocate(size);
return memory;
}
}
void RelocateMemoryReferencesInCode(Handle<FixedArray> code_table,
Address old_start, Address start,
uint32_t prev_size, uint32_t new_size) {
for (int i = 0; i < code_table->length(); ++i) {
DCHECK(code_table->get(i)->IsCode());
Handle<Code> code = Handle<Code>(Code::cast(code_table->get(i)));
AllowDeferredHandleDereference embedding_raw_address;
int mask = (1 << RelocInfo::WASM_MEMORY_REFERENCE) |
(1 << RelocInfo::WASM_MEMORY_SIZE_REFERENCE);
for (RelocIterator it(*code, mask); !it.done(); it.next()) {
it.rinfo()->update_wasm_memory_reference(old_start, start, prev_size,
new_size);
}
}
}
void RelocateGlobals(Handle<FixedArray> code_table, Address old_start,
Address globals_start) {
for (int i = 0; i < code_table->length(); ++i) {
DCHECK(code_table->get(i)->IsCode());
Handle<Code> code = Handle<Code>(Code::cast(code_table->get(i)));
AllowDeferredHandleDereference embedding_raw_address;
int mask = 1 << RelocInfo::WASM_GLOBAL_REFERENCE;
for (RelocIterator it(*code, 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): instead of placeholders, use a reloc_info mode.
static byte buffer[] = {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> 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());
}
}
// 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* object) {
auto instance = WasmInstanceObject::cast(object);
Address old_address = nullptr;
if (instance->has_globals_buffer()) {
old_address =
static_cast<Address>(instance->get_globals_buffer()->backing_store());
}
return old_address;
}
void InitializeParallelCompilation(
Isolate* isolate, const std::vector<WasmFunction>& functions,
std::vector<compiler::WasmCompilationUnit*>& compilation_units,
ModuleBytesEnv& 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]) !=
CancelableTaskManager::kTaskAborted) {
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, ModuleBytesEnv* module_env,
std::vector<Handle<Code>>& functions,
ErrorThrower* thrower) {
const WasmModule* module = module_env->module;
// 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, ModuleBytesEnv* module_env,
std::vector<Handle<Code>>& functions,
ErrorThrower* thrower) {
DCHECK(!thrower->error());
const WasmModule* module = 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.
Handle<Code> code = Handle<Code>::null();
// Compile the function.
code = compiler::WasmCompilationUnit::CompileWasmFunction(
thrower, isolate, module_env, &func);
if (code.is_null()) {
WasmName str = module_env->GetName(&func);
thrower->CompileError("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, WasmInstanceObject* 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->mem_size();
uint32_t default_mem_size = compiled_module->default_mem_size();
Object* mem_start = compiled_module->maybe_ptr_to_memory();
Address old_mem_address = nullptr;
Address globals_start =
GetGlobalStartAddressFromCodeTemplate(undefined, owner);
// Reset function tables.
FixedArray* function_tables = nullptr;
FixedArray* empty_function_tables = nullptr;
if (compiled_module->has_function_tables()) {
function_tables = compiled_module->ptr_to_function_tables();
empty_function_tables = compiled_module->ptr_to_empty_function_tables();
compiled_module->set_ptr_to_function_tables(empty_function_tables);
}
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) |
RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
// Patch code to update memory references, global references, and function
// table references.
Object* fct_obj = compiled_module->ptr_to_code_table();
if (fct_obj != nullptr && fct_obj != undefined &&
(old_mem_size > 0 || globals_start != nullptr || function_tables)) {
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 if (RelocInfo::IsWasmGlobalReference(mode)) {
it.rinfo()->update_wasm_global_reference(globals_start, nullptr);
changed = true;
} else if (RelocInfo::IsEmbeddedObject(mode) && function_tables) {
Object* old = it.rinfo()->target_object();
for (int j = 0; j < function_tables->length(); ++j) {
if (function_tables->get(j) == old) {
it.rinfo()->set_target_object(empty_function_tables->get(j));
changed = true;
}
}
}
}
if (changed) {
Assembler::FlushICache(isolate, code->instruction_start(),
code->instruction_size());
}
}
}
compiled_module->reset_memory();
}
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->get_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->get_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());
// Is 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->get_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();
// 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->GetInternalField(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) {
ResetCompiledModule(isolate, owner, compiled_module);
} else {
DCHECK(next->value()->IsFixedArray());
wasm_module->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(wasm_module->GetInternalField(0)));
TRACE("}\n");
}
compiled_module->reset_weak_owning_instance();
GlobalHandles::Destroy(reinterpret_cast<Object**>(p));
TRACE("}\n");
}
std::pair<int, int> GetFunctionOffsetAndLength(
Handle<WasmCompiledModule> compiled_module, int func_index) {
WasmModule* module = compiled_module->module();
if (func_index < 0 ||
static_cast<size_t>(func_index) > module->functions.size()) {
return {0, 0};
}
WasmFunction& func = module->functions[func_index];
return {static_cast<int>(func.code_start_offset),
static_cast<int>(func.code_end_offset - func.code_start_offset)};
}
} // namespace
Handle<JSArrayBuffer> wasm::NewArrayBuffer(Isolate* isolate, size_t size,
bool enable_guard_regions) {
if (size > (kV8MaxWasmMemoryPages * WasmModule::kPageSize)) {
// TODO(titzer): lift restriction on maximum memory allocated here.
return Handle<JSArrayBuffer>::null();
}
enable_guard_regions = enable_guard_regions && kGuardRegionsSupported;
bool is_external; // Set by TryAllocateBackingStore
void* memory =
TryAllocateBackingStore(isolate, size, enable_guard_regions, is_external);
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, is_external, memory,
static_cast<int>(size));
buffer->set_is_neuterable(false);
buffer->set_has_guard_region(enable_guard_regions);
if (is_external) {
// We mark the buffer as external if we allocated it here with guard
// pages. That means we need to arrange for it to be freed.
// TODO(eholk): Finalizers may not run when the main thread is shutting
// down, which means we may leak memory here.
Handle<Object> global_handle = isolate->global_handles()->Create(*buffer);
GlobalHandles::MakeWeak(global_handle.location(), global_handle.location(),
&MemoryFinalizer, v8::WeakCallbackType::kFinalizer);
}
return buffer;
}
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& 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) {
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);
if (!cell->value()) return nullptr;
return WasmInstanceObject::cast(cell->value());
}
int wasm::GetFunctionCodeOffset(Handle<WasmCompiledModule> compiled_module,
int func_index) {
return GetFunctionOffsetAndLength(compiled_module, func_index).first;
}
WasmModule::WasmModule(Zone* owned)
: owned_zone(owned), pending_tasks(new base::Semaphore(0)) {}
MaybeHandle<WasmCompiledModule> WasmModule::CompileFunctions(
Isolate* isolate, Handle<WasmModuleWrapper> module_wrapper,
ErrorThrower* thrower, const ModuleWireBytes& wire_bytes) const {
Factory* factory = isolate->factory();
MaybeHandle<WasmCompiledModule> nothing;
WasmInstance temp_instance(this);
temp_instance.context = isolate->native_context();
temp_instance.mem_size = WasmModule::kPageSize * 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>(function_tables.size());
Handle<FixedArray> function_tables =
factory->NewFixedArray(function_table_count);
for (int i = 0; i < function_table_count; ++i) {
temp_instance.function_tables[i] = factory->NewFixedArray(0);
function_tables->set(i, *temp_instance.function_tables[i]);
}
HistogramTimerScope wasm_compile_module_time_scope(
isolate->counters()->wasm_compile_module_time());
ModuleBytesEnv module_env(this, &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>(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, &module_env, results, thrower);
for (size_t i = 0; i < results.size(); ++i) {
temp_instance.function_code[i] = results[i];
}
} else {
CompileSequentially(isolate, &module_env, temp_instance.function_code,
thrower);
}
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);
RecordStats(isolate, 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, module_wrapper);
ret->set_code_table(code_table);
ret->set_min_mem_pages(min_mem_pages);
ret->set_max_mem_pages(max_mem_pages);
if (function_table_count > 0) {
ret->set_function_tables(function_tables);
ret->set_empty_function_tables(function_tables);
}
// Compile JS->WASM wrappers for exported functions.
int func_index = 0;
for (auto exp : export_table) {
if (exp.kind != kExternalFunction) continue;
Handle<Code> wasm_code =
code_table->GetValueChecked<Code>(isolate, exp.index);
Handle<Code> wrapper_code =
compiler::CompileJSToWasmWrapper(isolate, this, wasm_code, exp.index);
int export_index = static_cast<int>(functions.size() + func_index);
code_table->set(export_index, *wrapper_code);
RecordStats(isolate, *wrapper_code);
func_index++;
}
{
// TODO(wasm): only save the sections necessary to deserialize a
// {WasmModule}. E.g. function bodies could be omitted.
Handle<String> module_bytes_string =
factory->NewStringFromOneByte(wire_bytes.module_bytes, TENURED)
.ToHandleChecked();
DCHECK(module_bytes_string->IsSeqOneByteString());
ret->set_module_bytes(Handle<SeqOneByteString>::cast(module_bytes_string));
}
return ret;
}
static 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> target) {
Handle<JSFunction> func = Handle<JSFunction>::cast(target);
Handle<Code> export_wrapper_code = handle(func->code());
int found = 0;
int mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET);
Handle<Code> code;
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 ||
target->kind() == Code::WASM_TO_JS_FUNCTION) {
++found;
code = handle(target);
}
}
DCHECK(found == 1);
return code;
}
static Handle<Code> CompileImportWrapper(Isolate* isolate, int index,
FunctionSig* sig,
Handle<JSReceiver> target,
Handle<String> module_name,
MaybeHandle<String> import_name) {
Handle<Code> code;
WasmFunction* other_func = GetWasmFunctionForImportWrapper(isolate, target);
if (other_func) {
if (sig->Equals(other_func->sig)) {
// Signature matched. Unwrap the JS->WASM wrapper and return the raw
// WASM function code.
return UnwrapImportWrapper(target);
} else {
return Handle<Code>::null();
}
} else {
// Signature mismatch. Compile a new wrapper for the new signature.
return compiler::CompileWasmToJSWrapper(isolate, target, sig, index,
module_name, import_name);
}
}
static void UpdateDispatchTablesInternal(Isolate* isolate,
Handle<FixedArray> dispatch_tables,
int index, WasmFunction* function,
Handle<Code> code) {
DCHECK_EQ(0, dispatch_tables->length() % 3);
for (int i = 0; i < dispatch_tables->length(); i += 3) {
int table_index = Smi::cast(dispatch_tables->get(i + 1))->value();
Handle<FixedArray> dispatch_table(
FixedArray::cast(dispatch_tables->get(i + 2)), 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);
int sig_index = static_cast<int>(
instance->module()->function_tables[table_index].map.FindOrInsert(
function->sig));
dispatch_table->set(index, Smi::FromInt(sig_index));
dispatch_table->set(index + (dispatch_table->length() / 2), *code);
} else {
Code* code = nullptr;
dispatch_table->set(index, Smi::FromInt(-1));
dispatch_table->set(index + (dispatch_table->length() / 2), code);
}
}
}
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 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<WasmInstanceObject> Build() {
MaybeHandle<WasmInstanceObject> 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<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(
WasmCompiledModule::cast(module_object_->GetInternalField(0)));
if (original->has_weak_owning_instance()) {
owner = handle(WasmInstanceObject::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);
// 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_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);
}
module_ = reinterpret_cast<WasmModuleWrapper*>(
*compiled_module_->module_wrapper())
->get();
//--------------------------------------------------------------------------
// Allocate the instance object.
//--------------------------------------------------------------------------
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 nothing;
}
Address old_address =
owner.is_null() ? nullptr : GetGlobalStartAddressFromCodeTemplate(
isolate_->heap()->undefined_value(),
*owner.ToHandleChecked());
RelocateGlobals(code_table, old_address,
static_cast<Address>(global_buffer->backing_store()));
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()});
}
//--------------------------------------------------------------------------
// Process the imports for the module.
//--------------------------------------------------------------------------
int num_imported_functions = ProcessImports(code_table, instance);
if (num_imported_functions < 0) return nothing;
//--------------------------------------------------------------------------
// Process the initialization for the module's globals.
//--------------------------------------------------------------------------
InitGlobals();
//--------------------------------------------------------------------------
// Set up the memory for the new instance.
//--------------------------------------------------------------------------
MaybeHandle<JSArrayBuffer> old_memory;
uint32_t min_mem_pages = module_->min_mem_pages;
isolate_->counters()->wasm_min_mem_pages_count()->AddSample(min_mem_pages);
if (!memory_.is_null()) {
// Set externally passed ArrayBuffer non neuterable.
memory_->set_is_neuterable(false);
DCHECK_IMPLIES(EnableGuardRegions(), module_->origin == kAsmJsOrigin ||
memory_->has_guard_region());
} else if (min_mem_pages > 0) {
memory_ = AllocateMemory(min_mem_pages);
if (memory_.is_null()) return nothing; // failed to allocate memory
}
if (!memory_.is_null()) {
instance->set_memory_buffer(*memory_);
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_->has_memory()
? static_cast<Address>(
compiled_module_->memory()->backing_store())
: nullptr;
RelocateMemoryReferencesInCode(code_table, old_mem_start, mem_start,
old_mem_size, mem_size);
compiled_module_->set_memory(memory_);
} else {
LoadDataSegments(nullptr, 0);
}
DCHECK(wasm::IsWasmInstance(*instance));
if (instance->has_memory_object()) {
instance->get_memory_object()->AddInstance(isolate_, instance);
}
//--------------------------------------------------------------------------
// 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 exports object for the new instance.
//--------------------------------------------------------------------------
ProcessExports(code_table, instance);
//--------------------------------------------------------------------------
// Set up the indirect function tables for the new instance.
//--------------------------------------------------------------------------
if (function_table_count > 0) InitializeTables(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);
//--------------------------------------------------------------------------
// Unpack and notify signal handler of protected instructions.
//--------------------------------------------------------------------------
{
for (int i = 0; i < code_table->length(); ++i) {
Handle<Code> code = code_table->GetValueChecked<Code>(isolate_, i);
if (code->kind() != Code::WASM_FUNCTION) {
continue;
}
FixedArray* protected_instructions = code->protected_instructions();
Zone zone(isolate_->allocator(), "Wasm Module");
ZoneVector<trap_handler::ProtectedInstructionData> unpacked(&zone);
for (int i = 0; i < protected_instructions->length();
i += Code::kTrapDataSize) {
trap_handler::ProtectedInstructionData data;
data.instr_offset =
protected_instructions
->GetValueChecked<Smi>(isolate_, i + Code::kTrapCodeOffset)
->value();
data.landing_offset =
protected_instructions
->GetValueChecked<Smi>(isolate_, i + Code::kTrapLandingOffset)
->value();
unpacked.emplace_back(data);
}
// TODO(eholk): Register the protected instruction information once the
// trap handler is in place.
}
}
// 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()->get_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_->SetInternalField(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);
}
}
//--------------------------------------------------------------------------
// 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 =
code_table->GetValueChecked<Code>(isolate_, start_index);
FunctionSig* sig = module_->functions[start_index].sig;
Handle<Code> wrapper_code = compiler::CompileJSToWasmWrapper(
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);
// 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 nothing;
}
}
DCHECK(!isolate_->has_pending_exception());
TRACE("Finishing instance %d\n", compiled_module_->instance_id());
TRACE_CHAIN(WasmCompiledModule::cast(module_object_->GetInternalField(0)));
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> dispatch_table; // internal (code, sig) pairs
};
Isolate* isolate_;
WasmModule* module_;
ErrorThrower* thrower_;
Handle<JSObject> module_object_;
Handle<JSReceiver> ffi_;
Handle<JSArrayBuffer> memory_;
Handle<JSArrayBuffer> globals_;
Handle<WasmCompiledModule> compiled_module_;
std::vector<TableInstance> table_instances_;
std::vector<Handle<JSFunction>> js_wrappers_;
// 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_->TypeError(
"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_->TypeError("Import #%d module=\"%.*s\" error: %s", index,
module_name->length(), module_name->ToCString().get(),
error);
}
thrower_->TypeError("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::GetPropertyOrElement(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::GetPropertyOrElement(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;
}
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;
}
}
// Load data segments into the memory.
void LoadDataSegments(Address mem_addr, size_t mem_size) {
Handle<SeqOneByteString> module_bytes = compiled_module_->module_bytes();
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);
if (dest_offset >= mem_size || source_size >= mem_size ||
dest_offset > (mem_size - source_size)) {
thrower_->TypeError("data segment (start = %" PRIu32 ", size = %" PRIu32
") does not fit into memory (size = %" PRIuS ")",
dest_offset, source_size, mem_size);
return;
}
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 = 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 = %s\n", global.offset, num,
WasmOpcodes::TypeName(global.type));
switch (global.type) {
case kAstI32:
*GetRawGlobalPtr<int32_t>(global) = static_cast<int32_t>(num);
break;
case kAstI64:
// TODO(titzer): initialization of imported i64 globals.
UNREACHABLE();
break;
case kAstF32:
*GetRawGlobalPtr<float>(global) = static_cast<float>(num);
break;
case kAstF64:
*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 =
ExtractStringFromModuleBytes(isolate_, compiled_module_,
import.module_name_offset,
import.module_name_length)
.ToHandleChecked();
Handle<String> function_name = Handle<String>::null();
if (import.field_name_length > 0) {
function_name = ExtractStringFromModuleBytes(isolate_, compiled_module_,
import.field_name_offset,
import.field_name_length)
.ToHandleChecked();
}
MaybeHandle<Object> result =
LookupImport(index, module_name, function_name);
if (thrower_->error()) return -1;
switch (import.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(
isolate_, index, module_->functions[import.index].sig,
Handle<JSReceiver>::cast(function), module_name, function_name);
if (import_wrapper.is_null()) {
ReportFFIError("imported function does not match the expected type",
index, module_name, function_name);
return -1;
}
code_table->set(num_imported_functions, *import_wrapper);
RecordStats(isolate_, *import_wrapper);
num_imported_functions++;
break;
}
case kExternalTable: {
Handle<Object> value = result.ToHandleChecked();
if (!WasmJs::IsWasmTableObject(isolate_, value)) {
ReportFFIError("table import requires a WebAssembly.Table", index,
module_name, function_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->get_functions(), isolate_);
// TODO(titzer): import table size must match exactly for now.
int table_size = table_instance.js_wrappers->length();
if (table_size != static_cast<int>(table.min_size)) {
thrower_->TypeError(
"table import %d is wrong size (%d), expected %u", index,
table_size, table.min_size);
return -1;
}
// Allocate a new dispatch table.
table_instance.dispatch_table =
isolate_->factory()->NewFixedArray(table_size * 2);
for (int i = 0; i < table_size * 2; ++i) {
table_instance.dispatch_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_->TypeError("table import %d[%d] is not a WASM function",
index, i);
return -1;
}
int sig_index = table.map.FindOrInsert(function->sig);
table_instance.dispatch_table->set(i, Smi::FromInt(sig_index));
table_instance.dispatch_table->set(i + table_size,
*UnwrapImportWrapper(val));
}
num_imported_tables++;
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;
}
auto memory = Handle<WasmMemoryObject>::cast(object);
DCHECK(WasmJs::IsWasmMemoryObject(isolate_, memory));
instance->set_memory_object(*memory);
memory_ = Handle<JSArrayBuffer>(memory->get_buffer(), isolate_);
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();
WriteGlobalValue(module_->globals[import.index], val);
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 == kAstI64 || global.type == kAstF64)
? 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 > kV8MaxWasmMemoryPages) {
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;
}
// Process the exports, creating wrappers for functions, tables, memories,
// and globals.
void ProcessExports(Handle<FixedArray> code_table,
Handle<WasmInstanceObject> instance) {
bool needs_wrappers = module_->num_exported_functions > 0;
for (auto table_instance : table_instances_) {
if (!table_instance.js_wrappers.is_null()) {
needs_wrappers = true;
break;
}
}
for (auto table : module_->function_tables) {
if (table.exported) {
needs_wrappers = true;
break;
}
}
if (needs_wrappers) {
// 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 = instance;
if (module_->export_table.size() > 0 && 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);
// Process each export in the export table.
int export_index = 0;
for (auto exp : module_->export_table) {
Handle<String> name =
ExtractStringFromModuleBytes(isolate_, compiled_module_,
exp.name_offset, exp.name_length)
.ToHandleChecked();
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_->origin == kAsmJsOrigin) {
// For modules arising from asm.js, honor the names section.
func_name = ExtractStringFromModuleBytes(
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);
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 : kV8MaxWasmTableSize;
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.
Handle<JSArrayBuffer> buffer(instance->get_memory_buffer(),
isolate_);
memory_object = WasmMemoryObject::New(
isolate_, buffer,
(module_->max_mem_pages != 0) ? module_->max_mem_pages : -1);
instance->set_memory_object(*memory_object);
} else {
memory_object = Handle<WasmMemoryObject>(
instance->get_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 kAstI32:
num = *GetRawGlobalPtr<int32_t>(global);
break;
case kAstF32:
num = *GetRawGlobalPtr<float>(global);
break;
case kAstF64:
num = *GetRawGlobalPtr<double>(global);
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_->TypeError("export of %.*s failed.", name->length(),
name->ToCString().get());
return;
}
}
}
void InitializeTables(Handle<FixedArray> code_table,
Handle<WasmInstanceObject> instance) {
Handle<FixedArray> old_function_tables =
compiled_module_->function_tables();
int function_table_count =
static_cast<int>(module_->function_tables.size());
Handle<FixedArray> new_function_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.dispatch_table.is_null()) {
// Create a new dispatch table if necessary.
table_instance.dispatch_table =
isolate_->factory()->NewFixedArray(table_size * 2);
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.dispatch_table->set(i, Smi::FromInt(kInvalidSigIndex));
}
}
new_function_tables->set(static_cast<int>(index),
*table_instance.dispatch_table);
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 = WasmTableObject::AddDispatchTable(
isolate_, table_instance.table_object,
Handle<WasmInstanceObject>::null(), index,
Handle<FixedArray>::null());
}
// 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);
if (base > static_cast<uint32_t>(table_size) ||
(base + table_init.entries.size() >
static_cast<uint32_t>(table_size))) {
thrower_->CompileError("table initializer is out of bounds");
continue;
}
for (int i = 0; i < static_cast<int>(table_init.entries.size()); ++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.dispatch_table->set(table_index,
Smi::FromInt(sig_index));
table_instance.dispatch_table->set(table_index + table_size,
code_table->get(func_index));
if (!all_dispatch_tables.is_null()) {
Handle<Code> wasm_code(Code::cast(code_table->get(func_index)),
isolate_);
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.
WasmInstance temp_instance(module_);
temp_instance.context = isolate_->native_context();
temp_instance.mem_size = 0;
temp_instance.mem_start = nullptr;
temp_instance.globals_start = nullptr;
Handle<Code> wrapper_code = compiler::CompileJSToWasmWrapper(
isolate_, module_, wasm_code, func_index);
MaybeHandle<String> func_name;
if (module_->origin == kAsmJsOrigin) {
// For modules arising from asm.js, honor the names section.
func_name = ExtractStringFromModuleBytes(
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);
}
}
}
// 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.dispatch_table);
}
}
// Patch all code that has references to the old indirect tables.
for (int i = 0; i < code_table->length(); ++i) {
if (!code_table->get(i)->IsCode()) continue;
Handle<Code> code(Code::cast(code_table->get(i)), isolate_);
for (int j = 0; j < function_table_count; ++j) {
ReplaceReferenceInCode(
code, Handle<Object>(old_function_tables->get(j), isolate_),
Handle<Object>(new_function_tables->get(j), isolate_));
}
}
compiled_module_->set_function_tables(new_function_tables);
}
};
// Instantiates a WASM module, creating a WebAssembly.Instance from a
// WebAssembly.Module.
MaybeHandle<WasmInstanceObject> WasmModule::Instantiate(
Isolate* isolate, ErrorThrower* thrower, Handle<JSObject> wasm_module,
Handle<JSReceiver> ffi, Handle<JSArrayBuffer> memory) {
WasmInstanceBuilder builder(isolate, thrower, wasm_module, ffi, memory);
return builder.Build();
}
Handle<String> wasm::GetWasmFunctionName(Isolate* isolate,
Handle<Object> instance_or_undef,
uint32_t func_index) {
if (!instance_or_undef->IsUndefined(isolate)) {
Handle<WasmCompiledModule> compiled_module(
Handle<WasmInstanceObject>::cast(instance_or_undef)
->get_compiled_module());
MaybeHandle<String> maybe_name =
WasmCompiledModule::GetFunctionName(compiled_module, func_index);
if (!maybe_name.is_null()) return maybe_name.ToHandleChecked();
}
return isolate->factory()->NewStringFromStaticChars("<WASM UNNAMED>");
}
bool wasm::IsWasmInstance(Object* object) {
return WasmInstanceObject::IsWasmInstanceObject(object);
}
bool wasm::WasmIsAsmJs(Object* instance, Isolate* isolate) {
if (instance->IsUndefined(isolate)) return false;
DCHECK(IsWasmInstance(instance));
WasmCompiledModule* compiled_module =
WasmInstanceObject::cast(instance)->get_compiled_module();
DCHECK_EQ(compiled_module->has_asm_js_offset_table(),
compiled_module->script()->type() == Script::TYPE_NORMAL);
return compiled_module->has_asm_js_offset_table();
}
Handle<Script> wasm::GetScript(Handle<JSObject> instance) {
WasmCompiledModule* compiled_module =
WasmInstanceObject::cast(*instance)->get_compiled_module();
DCHECK(compiled_module->has_script());
return compiled_module->script();
}
Handle<WasmDebugInfo> wasm::GetDebugInfo(Handle<JSObject> object) {
auto instance = Handle<WasmInstanceObject>::cast(object);
if (instance->has_debug_info()) {
Handle<WasmDebugInfo> info(instance->get_debug_info(),
instance->GetIsolate());
return info;
}
Handle<WasmDebugInfo> new_info = WasmDebugInfo::New(instance);
instance->set_debug_info(*new_info);
return new_info;
}
// TODO(clemensh): origin can be inferred from asm_js_script; remove it.
MaybeHandle<WasmModuleObject> 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<WasmModuleObject> nothing;
ModuleResult result = DecodeWasmModule(isolate, start, end, false, origin);
if (result.failed()) {
if (result.val) delete result.val;
thrower->CompileFailed("Wasm decoding failed", result);
return nothing;
}
// 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, const_cast<WasmModule*>(result.val));
// Compile the functions of the module, producing a compiled module.
MaybeHandle<WasmCompiledModule> maybe_compiled_module =
result.val->CompileFunctions(isolate, module_wrapper, thrower,
ModuleWireBytes(start, end));
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_script());
DCHECK(!compiled_module->has_asm_js_offset_table());
if (origin == kAsmJsOrigin) {
// Set script for the asm.js source, and the offset table mapping wasm byte
// offsets to source positions.
compiled_module->set_script(asm_js_script);
size_t offset_table_len =
asm_js_offset_tables_end - asm_js_offset_tables_start;
DCHECK_GE(kMaxInt, offset_table_len);
Handle<ByteArray> offset_table =
isolate->factory()->NewByteArray(static_cast<int>(offset_table_len));
memcpy(offset_table->GetDataStartAddress(), asm_js_offset_tables_start,
offset_table_len);
compiled_module->set_asm_js_offset_table(offset_table);
} else {
// Create a new Script object representing this wasm module, store it in the
// compiled wasm module, and register it at the debugger.
Handle<Script> script =
isolate->factory()->NewScript(isolate->factory()->empty_string());
script->set_type(Script::TYPE_WASM);
DCHECK_GE(kMaxInt, end - start);
int hash = StringHasher::HashSequentialString(
reinterpret_cast<const char*>(start), static_cast<int>(end - start),
kZeroHashSeed);
const int kBufferSize = 50;
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());
script->set_wasm_compiled_module(*compiled_module);
compiled_module->set_script(script);
isolate->debug()->OnAfterCompile(script);
}
return WasmModuleObject::New(isolate, compiled_module);
}
bool wasm::ValidateModuleBytes(Isolate* isolate, const byte* start,
const byte* end, ErrorThrower* thrower,
ModuleOrigin origin) {
ModuleResult result = DecodeWasmModule(isolate, start, end, true, origin);
if (result.val) {
delete result.val;
} else {
DCHECK(!result.ok());
}
return result.ok();
}
MaybeHandle<JSArrayBuffer> wasm::GetInstanceMemory(
Isolate* isolate, Handle<WasmInstanceObject> object) {
auto instance = Handle<WasmInstanceObject>::cast(object);
if (instance->has_memory_buffer()) {
return Handle<JSArrayBuffer>(instance->get_memory_buffer(), isolate);
}
return MaybeHandle<JSArrayBuffer>();
}
void SetInstanceMemory(Handle<WasmInstanceObject> instance,
JSArrayBuffer* buffer) {
DisallowHeapAllocation no_gc;
instance->set_memory_buffer(buffer);
instance->get_compiled_module()->set_ptr_to_memory(buffer);
}
int32_t wasm::GetInstanceMemorySize(Isolate* isolate,
Handle<WasmInstanceObject> instance) {
DCHECK(IsWasmInstance(*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;
}
}
uint32_t GetMaxInstanceMemorySize(Isolate* isolate,
Handle<WasmInstanceObject> instance) {
if (instance->has_memory_object()) {
Handle<WasmMemoryObject> memory_object(instance->get_memory_object(),
isolate);
int maximum = memory_object->maximum_pages();
if (maximum > 0) return static_cast<uint32_t>(maximum);
}
uint32_t compiled_max_pages =
instance->get_compiled_module()->max_mem_pages();
isolate->counters()->wasm_max_mem_pages_count()->AddSample(
compiled_max_pages);
if (compiled_max_pages != 0) return compiled_max_pages;
return kV8MaxWasmMemoryPages;
}
Handle<JSArrayBuffer> GrowMemoryBuffer(Isolate* isolate,
MaybeHandle<JSArrayBuffer> buffer,
uint32_t pages, uint32_t max_pages) {
Handle<JSArrayBuffer> old_buffer;
Address old_mem_start = nullptr;
uint32_t old_size = 0;
if (buffer.ToHandle(&old_buffer) && old_buffer->backing_store() != nullptr) {
old_mem_start = static_cast<Address>(old_buffer->backing_store());
DCHECK_NOT_NULL(old_mem_start);
old_size = old_buffer->byte_length()->Number();
}
DCHECK(old_size + pages * WasmModule::kPageSize <=
std::numeric_limits<uint32_t>::max());
uint32_t new_size = old_size + pages * WasmModule::kPageSize;
if (new_size <= old_size || max_pages * WasmModule::kPageSize < new_size ||
kV8MaxWasmMemoryPages * WasmModule::kPageSize < new_size) {
return Handle<JSArrayBuffer>::null();
}
Handle<JSArrayBuffer> new_buffer;
if (!old_buffer.is_null() && old_buffer->has_guard_region()) {
// We don't move the backing store, we simply change the protection to make
// more of it accessible.
base::OS::Unprotect(old_buffer->backing_store(), new_size);
reinterpret_cast<v8::Isolate*>(isolate)
->AdjustAmountOfExternalAllocatedMemory(pages * WasmModule::kPageSize);
Handle<Object> new_size_object =
isolate->factory()->NewNumberFromSize(new_size);
old_buffer->set_byte_length(*new_size_object);
new_buffer = old_buffer;
} else {
const bool enable_guard_regions = false;
new_buffer = NewArrayBuffer(isolate, new_size, enable_guard_regions);
if (new_buffer.is_null()) return new_buffer;
Address new_mem_start = static_cast<Address>(new_buffer->backing_store());
if (old_size != 0) {
memcpy(new_mem_start, old_mem_start, old_size);
}
}
return new_buffer;
}
void UncheckedUpdateInstanceMemory(Isolate* isolate,
Handle<WasmInstanceObject> instance,
Address old_mem_start, uint32_t old_size) {
DCHECK(instance->has_memory_buffer());
Handle<JSArrayBuffer> new_buffer(instance->get_memory_buffer());
uint32_t new_size = new_buffer->byte_length()->Number();
DCHECK(new_size <= std::numeric_limits<uint32_t>::max());
Address new_mem_start = static_cast<Address>(new_buffer->backing_store());
DCHECK_NOT_NULL(new_mem_start);
Handle<FixedArray> code_table = instance->get_compiled_module()->code_table();
RelocateMemoryReferencesInCode(code_table, old_mem_start, new_mem_start,
old_size, new_size);
}
int32_t wasm::GrowWebAssemblyMemory(Isolate* isolate, Handle<Object> receiver,
uint32_t pages) {
DCHECK(WasmJs::IsWasmMemoryObject(isolate, receiver));
Handle<WasmMemoryObject> memory_object =
handle(WasmMemoryObject::cast(*receiver));
Handle<WasmInstanceWrapper> instance_wrapper(
memory_object->get_instances_link());
DCHECK(WasmInstanceWrapper::IsWasmInstanceWrapper(*instance_wrapper));
DCHECK(instance_wrapper->has_instance());
Handle<WasmInstanceObject> instance = instance_wrapper->instance_object();
DCHECK(IsWasmInstance(*instance));
if (pages == 0) return GetInstanceMemorySize(isolate, instance);
uint32_t max_pages = GetMaxInstanceMemorySize(isolate, instance);
// Grow memory object buffer and update instances associated with it.
MaybeHandle<JSArrayBuffer> memory_buffer =
handle(memory_object->get_buffer());
Handle<JSArrayBuffer> old_buffer;
uint32_t old_size = 0;
Address old_mem_start = nullptr;
if (memory_buffer.ToHandle(&old_buffer) &&
old_buffer->backing_store() != nullptr) {
old_size = old_buffer->byte_length()->Number();
old_mem_start = static_cast<Address>(old_buffer->backing_store());
}
Handle<JSArrayBuffer> new_buffer =
GrowMemoryBuffer(isolate, memory_buffer, pages, max_pages);
if (new_buffer.is_null()) return -1;
DCHECK(!instance_wrapper->has_previous());
SetInstanceMemory(instance, *new_buffer);
UncheckedUpdateInstanceMemory(isolate, instance, old_mem_start, old_size);
while (instance_wrapper->has_next()) {
instance_wrapper = instance_wrapper->next_wrapper();
DCHECK(WasmInstanceWrapper::IsWasmInstanceWrapper(*instance_wrapper));
Handle<WasmInstanceObject> instance = instance_wrapper->instance_object();
DCHECK(IsWasmInstance(*instance));
SetInstanceMemory(instance, *new_buffer);
UncheckedUpdateInstanceMemory(isolate, instance, old_mem_start, old_size);
}
memory_object->set_buffer(*new_buffer);
DCHECK(old_size % WasmModule::kPageSize == 0);
return (old_size / WasmModule::kPageSize);
}
int32_t wasm::GrowMemory(Isolate* isolate, Handle<WasmInstanceObject> instance,
uint32_t pages) {
if (!IsWasmInstance(*instance)) return -1;
if (pages == 0) return GetInstanceMemorySize(isolate, instance);
Handle<WasmInstanceObject> instance_obj(WasmInstanceObject::cast(*instance));
if (!instance_obj->has_memory_object()) {
// No other instances to grow, grow just the one.
MaybeHandle<JSArrayBuffer> instance_buffer =
GetInstanceMemory(isolate, instance);
Handle<JSArrayBuffer> old_buffer;
uint32_t old_size = 0;
Address old_mem_start = nullptr;
if (instance_buffer.ToHandle(&old_buffer) &&
old_buffer->backing_store() != nullptr) {
old_size = old_buffer->byte_length()->Number();
old_mem_start = static_cast<Address>(old_buffer->backing_store());
}
uint32_t max_pages = GetMaxInstanceMemorySize(isolate, instance_obj);
Handle<JSArrayBuffer> buffer =
GrowMemoryBuffer(isolate, instance_buffer, pages, max_pages);
if (buffer.is_null()) return -1;
SetInstanceMemory(instance, *buffer);
UncheckedUpdateInstanceMemory(isolate, instance, old_mem_start, old_size);
DCHECK(old_size % WasmModule::kPageSize == 0);
return (old_size / WasmModule::kPageSize);
} else {
return GrowWebAssemblyMemory(
isolate, handle(instance_obj->get_memory_object()), pages);
}
}
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->get_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->get_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->get_compiled_module();
CHECK(compiled_module->has_weak_wasm_module());
CHECK(compiled_module->ptr_to_weak_wasm_module()->cleared());
}
void WasmCompiledModule::RecreateModuleWrapper(Isolate* isolate,
Handle<FixedArray> array) {
Handle<WasmCompiledModule> compiled_module(
reinterpret_cast<WasmCompiledModule*>(*array), isolate);
WasmModule* module = nullptr;
{
Handle<SeqOneByteString> module_bytes = compiled_module->module_bytes();
// We parse the module again directly from the module bytes, so
// the underlying storage must not be moved meanwhile.
DisallowHeapAllocation no_allocation;
const byte* start =
reinterpret_cast<const byte*>(module_bytes->GetCharsAddress());
const byte* end = start + module_bytes->length();
// TODO(titzer): remember the module origin in the compiled_module
// For now, we assume serialized modules did not originate from asm.js.
ModuleResult result =
DecodeWasmModule(isolate, start, end, false, kWasmOrigin);
CHECK(result.ok());
CHECK_NOT_NULL(result.val);
module = const_cast<WasmModule*>(result.val);
}
Handle<WasmModuleWrapper> module_wrapper =
WasmModuleWrapper::New(isolate, module);
compiled_module->set_module_wrapper(module_wrapper);
DCHECK(WasmCompiledModule::IsWasmCompiledModule(*compiled_module));
}
MaybeHandle<String> WasmCompiledModule::GetFunctionName(
Handle<WasmCompiledModule> compiled_module, uint32_t func_index) {
DCHECK_LT(func_index, compiled_module->module()->functions.size());
WasmFunction& function = compiled_module->module()->functions[func_index];
Isolate* isolate = compiled_module->GetIsolate();
MaybeHandle<String> string = ExtractStringFromModuleBytes(
isolate, compiled_module, function.name_offset, function.name_length);
if (!string.is_null()) return string.ToHandleChecked();
return {};
}