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);
}
