blob: c38f9d628a6a3ff28fa116c90bbe29fa5ba7ad0d [file] [log] [blame]
// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/compiler/ffi/callback.h"
#include "vm/class_finalizer.h"
#include "vm/symbols.h"
namespace dart {
namespace compiler {
namespace ffi {
FunctionPtr NativeCallbackFunction(const FunctionType& c_signature,
const Function& dart_target,
const Instance& exceptional_return) {
Thread* const thread = Thread::Current();
const int32_t callback_id = thread->AllocateFfiCallbackId();
// Create a new Function named '<target>_FfiCallback' and stick it in the
// 'dart:ffi' library. Note that these functions will never be invoked by
// Dart, so they may have duplicate names.
Zone* const zone = thread->zone();
const auto& name = String::Handle(
zone, Symbols::FromConcat(thread, Symbols::FfiCallback(),
const Library& lib = Library::Handle(zone, Library::FfiLibrary());
const Class& owner_class = Class::Handle(zone, lib.toplevel_class());
const Function& function =
Function::Handle(zone, Function::New(Object::null_function_type(), name,
/*is_native=*/false, owner_class,
// Set callback-specific fields which the flow-graph builder needs to generate
// the body.
// We need to load the exceptional return value as a constant in the generated
// function. Even though the FE ensures that it is a constant, it could still
// be a literal allocated in new space. We need to copy it into old space in
// that case.
// Exceptional return values currently cannot be pointers because we don't
// have constant pointers.
ASSERT(exceptional_return.IsNull() || exceptional_return.IsNumber());
if (!exceptional_return.IsSmi() && exceptional_return.IsNew()) {
zone, exceptional_return.CopyShallowToOldSpace(thread)));
} else {
return function.ptr();
} // namespace ffi
} // namespace compiler
} // namespace dart