Implement Function.apply in vm (issue 5670).

runtime/lib/function.cc

+// Copyright (c) 2012, 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/bootstrap_natives.h"
+
+#include "vm/compiler.h"
+#include "vm/dart_entry.h"
+#include "vm/exceptions.h"
+#include "vm/native_entry.h"
+#include "vm/object.h"
+#include "vm/symbols.h"
+
+namespace dart {
+
+DEFINE_NATIVE_ENTRY(Function_apply, 2) {
+  const Array& fun_arguments = Array::CheckedHandle(arguments->NativeArgAt(0));
+  const Array& fun_arg_names = Array::CheckedHandle(arguments->NativeArgAt(1));
+  // TODO(regis): Simply call DartEntry::InvokeClosure once it is modified to
+  // take an arguments descriptor array and an arguments array.
+  Instance& instance = Instance::Handle();
+  instance ^= fun_arguments.At(0);
+  // Get the entrypoint corresponding to the closure function or to the call
+  // method of the instance. This will result in a compilation of the function
+  // if it is not already compiled.
+  Function& function = Function::Handle();
+  Context& context = Context::Handle();
+  if (!instance.IsCallable(&function, &context)) {
+    const String& call_symbol = String::Handle(Symbols::Call());
+    const Object& null_object = Object::Handle();
+    GrowableArray<const Object*> dart_arguments(5);
+    dart_arguments.Add(&instance);
+    dart_arguments.Add(&call_symbol);
+    dart_arguments.Add(&fun_arguments);  // Including instance.
+    dart_arguments.Add(&null_object);  // TODO(regis): Provide names.
+    // If a function "call" with different arguments exists, it will have been
+    // invoked above, so no need to handle this case here.
+    Exceptions::ThrowByType(Exceptions::kNoSuchMethod, dart_arguments);
+    UNREACHABLE();
+    return Object::null();
+  }
+  ASSERT(!function.IsNull());
+  if (!function.HasCode()) {
+    const Error& error = Error::Handle(Compiler::CompileFunction(function));
+    if (!error.IsNull()) {
+      Exceptions::PropagateError(error);
+    }
+  }
+  // Set up arguments as GrowableArray.
+  const int num_arguments = fun_arguments.Length();
+  GrowableArray<const Object*> args(num_arguments);
+  for (int i = 0; i < num_arguments; i++) {
+    args.Add(&Object::ZoneHandle(fun_arguments.At(i)));
+  }
+  // Now call the invoke stub which will invoke the closure.
+  DartEntry::invokestub entrypoint = reinterpret_cast<DartEntry::invokestub>(
+      StubCode::InvokeDartCodeEntryPoint());
+  ASSERT(context.isolate() == Isolate::Current());
+  const Code& code = Code::Handle(function.CurrentCode());
+  ASSERT(!code.IsNull());
+  const Array& fun_args_desc =
+      Array::Handle(ArgumentsDescriptor::New(num_arguments, fun_arg_names));
+  const Object& result = Object::Handle(
+      entrypoint(code.EntryPoint(), fun_args_desc, args.data(), context));
+  if (result.IsError()) {
+    Exceptions::PropagateError(Error::Cast(result));
+  }
+  return result.raw();
+}
+
+}  // namespace dart