bool
Module::instantiate(JSContext* cx,
Handle<FunctionVector> funcImports,
HandleWasmTableObject tableImport,
HandleWasmMemoryObject memoryImport,
const ValVector& globalImports,
HandleObject instanceProto,
MutableHandleWasmInstanceObject instanceObj) const
{
MOZ_ASSERT(funcImports.length() == metadata_->funcImports.length());
RootedWasmMemoryObject memory(cx, memoryImport);
if (!instantiateMemory(cx, &memory))
return false;
auto codeSegment = CodeSegment::create(cx, code_, linkData_, *metadata_, memory);
if (!codeSegment)
return false;
SharedTableVector tables;
if (!instantiateTable(cx, tableImport, &tables))
return false;
// To support viewing the source of an instance (Instance::createText), the
// instance must hold onto a ref of the bytecode (keeping it alive). This
// wastes memory for most users, so we try to only save the source when a
// developer actually cares: when the compartment is debuggable (which is
// true when the web console is open) or a names section is present (since
// this going to be stripped for non-developer builds).
const ShareableBytes* maybeBytecode = nullptr;
if (cx->compartment()->isDebuggee() || !metadata_->funcNames.empty())
maybeBytecode = bytecode_.get();
// Create the Instance, ensuring that it is traceable via 'instanceObj'
// before any GC can occur and invalidate the pointers stored in global
// memory.
{
instanceObj.set(WasmInstanceObject::create(cx, instanceProto));
if (!instanceObj)
return false;
auto instance = cx->make_unique<Instance>(cx,
Move(codeSegment),
*metadata_,
maybeBytecode,
memory,
Move(tables),
funcImports,
globalImports);
if (!instance)
return false;
instanceObj->init(Move(instance));
}
if (!instanceObj->instance().init(cx))
return false;
// Create the export object.
RootedObject exportObj(cx);
RootedWasmTableObject table(cx, tableImport);
if (!CreateExportObject(cx, instanceObj, &table, memory, globalImports, exports_, &exportObj))
return false;
JSAtom* atom = Atomize(cx, InstanceExportField, strlen(InstanceExportField));
if (!atom)
return false;
RootedId id(cx, AtomToId(atom));
RootedValue val(cx, ObjectValue(*exportObj));
if (!JS_DefinePropertyById(cx, instanceObj, id, val, JSPROP_ENUMERATE))
return false;
// Initialize table elements only after the instance is fully initialized
// since the Table object needs to point to a valid instance object. Perform
// initialization as the final step after the instance is fully live since
// it is observable (in the case of an imported Table object).
if (!initElems(cx, instanceObj, globalImports, table))
return false;
// Done! Notify the Debugger of the new Instance.
Debugger::onNewWasmInstance(cx, instanceObj);
// Call the start function, if there's one. By specification, it does not
// take any arguments nor does it return a value, so just create a dummy
// arguments object.
if (metadata_->hasStartFunction()) {
FixedInvokeArgs<0> args(cx);
if (!instanceObj->instance().callExport(cx, metadata_->startFuncIndex(), args))
return false;
}
return true;
}
bool
Module::instantiate(JSContext* cx,
Handle<FunctionVector> funcImports,
HandleWasmTableObject tableImport,
HandleWasmMemoryObject memoryImport,
const ValVector& globalImports,
HandleObject instanceProto,
MutableHandleWasmInstanceObject instance) const
{
if (!instantiateFunctions(cx, funcImports))
return false;
RootedWasmMemoryObject memory(cx, memoryImport);
if (!instantiateMemory(cx, &memory))
return false;
RootedWasmTableObject table(cx, tableImport);
SharedTableVector tables;
if (!instantiateTable(cx, &table, &tables))
return false;
// To support viewing the source of an instance (Instance::createText), the
// instance must hold onto a ref of the bytecode (keeping it alive). This
// wastes memory for most users, so we try to only save the source when a
// developer actually cares: when the compartment is debuggable (which is
// true when the web console is open), has code compiled with debug flag
// enabled or a names section is present (since this going to be stripped
// for non-developer builds).
const ShareableBytes* maybeBytecode = nullptr;
if (cx->compartment()->isDebuggee() || metadata_->debugEnabled ||
!metadata_->funcNames.empty())
{
maybeBytecode = bytecode_.get();
}
auto codeSegment = CodeSegment::create(cx, code_, linkData_, *metadata_, memory);
if (!codeSegment)
return false;
auto code = cx->make_unique<Code>(Move(codeSegment), *metadata_, maybeBytecode);
if (!code)
return false;
instance.set(WasmInstanceObject::create(cx,
Move(code),
memory,
Move(tables),
funcImports,
globalImports,
instanceProto));
if (!instance)
return false;
RootedObject exportObj(cx);
if (!CreateExportObject(cx, instance, funcImports, table, memory, globalImports, exports_, &exportObj))
return false;
JSAtom* atom = Atomize(cx, InstanceExportField, strlen(InstanceExportField));
if (!atom)
return false;
RootedId id(cx, AtomToId(atom));
RootedValue val(cx, ObjectValue(*exportObj));
if (!JS_DefinePropertyById(cx, instance, id, val, JSPROP_ENUMERATE))
return false;
// Register the instance with the JSCompartment so that it can find out
// about global events like profiling being enabled in the compartment.
// Registration does not require a fully-initialized instance and must
// precede initSegments as the final pre-requisite for a live instance.
if (!cx->compartment()->wasm.registerInstance(cx, instance))
return false;
// Perform initialization as the final step after the instance is fully
// constructed since this can make the instance live to content (even if the
// start function fails).
if (!initSegments(cx, instance, funcImports, memory, globalImports))
return false;
// Now that the instance is fully live and initialized, the start function.
// Note that failure may cause instantiation to throw, but the instance may
// still be live via edges created by initSegments or the start function.
if (metadata_->startFuncIndex) {
FixedInvokeArgs<0> args(cx);
if (!instance->instance().callExport(cx, *metadata_->startFuncIndex, args))
return false;
}
uint32_t mode = uint32_t(metadata().isAsmJS() ? Telemetry::ASMJS : Telemetry::WASM);
cx->runtime()->addTelemetry(JS_TELEMETRY_AOT_USAGE, mode);
return true;
}
