- Implement a first cut for const String.env in the VM to allow

runtime/lib/bool.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 "include/dart_api.h"
+#include "vm/dart_api_impl.h"
+#include "vm/isolate.h"
+#include "vm/native_entry.h"
+#include "vm/object.h"
+
+namespace dart {
+
+DEFINE_NATIVE_ENTRY(Boolean_fromEnvironment, 3) {
+  GET_NON_NULL_NATIVE_ARGUMENT(String, name, arguments->NativeArgAt(1));
+  GET_NATIVE_ARGUMENT(Integer, default_value, arguments->NativeArgAt(2));
+  // Call the embedder to supply us with the environment.
+  Dart_EnvironmentCallback callback = isolate->environment_callback();
+  if (callback != NULL) {
+    Dart_Handle result = callback(kBoolEnvironment,
+                                  Api::NewHandle(isolate, name.raw()));
+    if (!Dart_IsError(result)) {
+      const Object& value = Object::Handle(isolate, Api::UnwrapHandle(result));
+      if (value.IsBool()) {
+        return value.raw();
+      }
+    }
+  }
+  return default_value.raw();
+}
+
+}  // namespace dart