void WebAssemblyModuleRecord::link(ExecState* state, JSWebAssemblyInstance* instance)
{
VM& vm = state->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
UNUSED_PARAM(scope);
auto* globalObject = state->lexicalGlobalObject();
JSWebAssemblyModule* module = instance->module();
const Wasm::ModuleInformation& moduleInformation = module->moduleInformation();
SymbolTable* exportSymbolTable = module->exportSymbolTable();
unsigned functionImportCount = module->functionImportCount();
// FIXME wire up the imports. https://bugs.webkit.org/show_bug.cgi?id=165118
// Let exports be a list of (string, JS value) pairs that is mapped from each external value e in instance.exports as follows:
JSModuleEnvironment* moduleEnvironment = JSModuleEnvironment::create(vm, globalObject, nullptr, exportSymbolTable, JSValue(), this);
for (const auto& exp : moduleInformation.exports) {
JSValue exportedValue;
switch (exp.kind) {
case Wasm::ExternalKind::Function: {
// 1. If e is a closure c:
// i. If there is an Exported Function Exotic Object func in funcs whose func.[[Closure]] equals c, then return func.
// ii. (Note: At most one wrapper is created for any closure, so func is unique, even if there are multiple occurrances in the list. Moreover, if the item was an import that is already an Exported Function Exotic Object, then the original function object will be found. For imports that are regular JS functions, a new wrapper will be created.)
if (exp.kindIndex < functionImportCount) {
// FIXME Implement re-exporting an import. https://bugs.webkit.org/show_bug.cgi?id=165510
RELEASE_ASSERT_NOT_REACHED();
}
// iii. Otherwise:
// a. Let func be an Exported Function Exotic Object created from c.
// b. Append func to funcs.
// c. Return func.
JSWebAssemblyCallee* jsEntrypointCallee = module->jsEntrypointCalleeFromFunctionIndexSpace(exp.kindIndex);
JSWebAssemblyCallee* wasmEntrypointCallee = module->wasmEntrypointCalleeFromFunctionIndexSpace(exp.kindIndex);
Wasm::SignatureIndex signatureIndex = module->signatureIndexFromFunctionIndexSpace(exp.kindIndex);
const Wasm::Signature* signature = Wasm::SignatureInformation::get(&vm, signatureIndex);
WebAssemblyFunction* function = WebAssemblyFunction::create(vm, globalObject, signature->argumentCount(), exp.field.string(), instance, jsEntrypointCallee, wasmEntrypointCallee, signatureIndex);
exportedValue = function;
break;
}
case Wasm::ExternalKind::Table: {
// This should be guaranteed by module verification.
RELEASE_ASSERT(instance->table());
ASSERT(exp.kindIndex == 0);
exportedValue = instance->table();
break;
}
case Wasm::ExternalKind::Memory: {
ASSERT(exp.kindIndex == 0);
exportedValue = instance->memory();
break;
}
case Wasm::ExternalKind::Global: {
// Assert: the global is immutable by MVP validation constraint.
const Wasm::Global& global = moduleInformation.globals[exp.kindIndex];
ASSERT(global.mutability == Wasm::Global::Immutable);
// Return ToJSValue(v).
switch (global.type) {
case Wasm::I32:
exportedValue = JSValue(instance->loadI32Global(exp.kindIndex));
break;
case Wasm::F32:
exportedValue = JSValue(instance->loadF32Global(exp.kindIndex));
break;
case Wasm::F64:
exportedValue = JSValue(instance->loadF64Global(exp.kindIndex));
break;
default:
RELEASE_ASSERT_NOT_REACHED();
}
break;
}
}
bool shouldThrowReadOnlyError = false;
bool ignoreReadOnlyErrors = true;
bool putResult = false;
symbolTablePutTouchWatchpointSet(moduleEnvironment, state, exp.field, exportedValue, shouldThrowReadOnlyError, ignoreReadOnlyErrors, putResult);
RELEASE_ASSERT(putResult);
}
bool hasStart = !!moduleInformation.startFunctionIndexSpace;
if (hasStart) {
auto startFunctionIndexSpace = moduleInformation.startFunctionIndexSpace.value_or(0);
Wasm::SignatureIndex signatureIndex = module->signatureIndexFromFunctionIndexSpace(startFunctionIndexSpace);
const Wasm::Signature* signature = Wasm::SignatureInformation::get(&vm, signatureIndex);
// The start function must not take any arguments or return anything. This is enforced by the parser.
ASSERT(!signature->argumentCount());
ASSERT(signature->returnType() == Wasm::Void);
if (startFunctionIndexSpace < module->functionImportCount()) {
JSCell* startFunction = instance->importFunction(startFunctionIndexSpace)->get();
m_startFunction.set(vm, this, startFunction);
} else {
JSWebAssemblyCallee* jsEntrypointCallee = module->jsEntrypointCalleeFromFunctionIndexSpace(startFunctionIndexSpace);
JSWebAssemblyCallee* wasmEntrypointCallee = module->wasmEntrypointCalleeFromFunctionIndexSpace(startFunctionIndexSpace);
WebAssemblyFunction* function = WebAssemblyFunction::create(vm, globalObject, signature->argumentCount(), "start", instance, jsEntrypointCallee, wasmEntrypointCallee, signatureIndex);
m_startFunction.set(vm, this, function);
}
}
RELEASE_ASSERT(!m_instance);
m_instance.set(vm, this, instance);
m_moduleEnvironment.set(vm, this, moduleEnvironment);
}
JSValue WebAssemblyModuleRecord::evaluate(ExecState* state)
{
VM& vm = state->vm();
auto scope = DECLARE_THROW_SCOPE(vm);
{
JSWebAssemblyModule* module = m_instance->module();
const Wasm::ModuleInformation& moduleInformation = module->moduleInformation();
JSWebAssemblyTable* table = m_instance->table();
for (const Wasm::Element& element : moduleInformation.elements) {
// It should be a validation error to have any elements without a table.
// Also, it could be that a table wasn't imported, or that the table
// imported wasn't compatible. However, those should error out before
// getting here.
ASSERT(!!table);
if (!element.functionIndices.size())
continue;
uint32_t tableIndex = element.offset;
uint64_t lastWrittenIndex = static_cast<uint64_t>(tableIndex) + static_cast<uint64_t>(element.functionIndices.size()) - 1;
if (lastWrittenIndex >= table->size())
return throwException(state, scope, createJSWebAssemblyLinkError(state, vm, ASCIILiteral("Element is trying to set an out of bounds table index")));
for (uint32_t i = 0; i < element.functionIndices.size(); ++i) {
// FIXME: This essentially means we're exporting an import.
// We need a story here. We need to create a WebAssemblyFunction
// for the import.
// https://bugs.webkit.org/show_bug.cgi?id=165510
uint32_t functionIndex = element.functionIndices[i];
if (functionIndex < module->functionImportCount()) {
return JSValue::decode(
throwVMRangeError(state, scope, ASCIILiteral("Element is setting the table value with an import. This is not yet implemented. FIXME.")));
}
JSWebAssemblyCallee* jsEntrypointCallee = module->jsEntrypointCalleeFromFunctionIndexSpace(functionIndex);
JSWebAssemblyCallee* wasmEntrypointCallee = module->wasmEntrypointCalleeFromFunctionIndexSpace(functionIndex);
Wasm::SignatureIndex signatureIndex = module->signatureIndexFromFunctionIndexSpace(functionIndex);
const Wasm::Signature* signature = Wasm::SignatureInformation::get(&vm, signatureIndex);
// FIXME: Say we export local function "foo" at funciton index 0.
// What if we also set it to the table an Element w/ index 0.
// Does (new Instance(...)).exports.foo === table.get(0)?
// https://bugs.webkit.org/show_bug.cgi?id=165825
WebAssemblyFunction* function = WebAssemblyFunction::create(
vm, m_instance->globalObject(), signature->argumentCount(), String(), m_instance.get(), jsEntrypointCallee, wasmEntrypointCallee, signatureIndex);
table->setFunction(vm, tableIndex, function);
++tableIndex;
}
}
}
{
const Vector<Wasm::Segment::Ptr>& data = m_instance->module()->moduleInformation().data;
JSWebAssemblyMemory* jsMemory = m_instance->memory();
if (!data.isEmpty()) {
uint8_t* memory = reinterpret_cast<uint8_t*>(jsMemory->memory()->memory());
uint64_t sizeInBytes = jsMemory->memory()->size();
for (auto& segment : data) {
if (segment->sizeInBytes) {
uint32_t offset;
if (segment->offset.isGlobalImport())
offset = static_cast<uint32_t>(m_instance->loadI32Global(segment->offset.globalImportIndex()));
else
offset = segment->offset.constValue();
if (UNLIKELY(sizeInBytes < segment->sizeInBytes))
return dataSegmentFail(state, vm, scope, sizeInBytes, segment->sizeInBytes, offset, ASCIILiteral(", segment is too big"));
if (UNLIKELY(offset > sizeInBytes - segment->sizeInBytes))
return dataSegmentFail(state, vm, scope, sizeInBytes, segment->sizeInBytes, offset, ASCIILiteral(", segment writes outside of memory"));
RELEASE_ASSERT(memory);
memcpy(memory + offset, &segment->byte(0), segment->sizeInBytes);
}
}
}
}
if (JSCell* startFunction = m_startFunction.get()) {
CallData callData;
CallType callType = JSC::getCallData(startFunction, callData);
call(state, startFunction, callType, callData, jsUndefined(), state->emptyList());
RETURN_IF_EXCEPTION(scope, { });
}
return jsUndefined();
}