Add utility functions for creating and accessing Dart_CObject structures

runtime/bin/dartutils.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 "bin/dartutils.h"
 
 #include "bin/file.h"
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/globals.h"
@@ skipping 234 matching lines @@
   if (canonical_filename == NULL) {
     return absolute_filename;
   }
   free(absolute_filename);
   return canonical_filename;
 }
 
 
 bool DartUtils::PostNull(Dart_Port port_id) {
   // Post a message with just the null object.
-  Dart_CObject object;
-  object.type = Dart_CObject::kNull;
-  return Dart_PostCObject(port_id, &object);
+  return Dart_PostCObject(port_id, CObject::Null()->AsApiCObject());
 }
 
 
 bool DartUtils::PostInt32(Dart_Port port_id, int32_t value) {
   // Post a message with the integer value.
   int32_t min = 0xc0000000;  // -1073741824
   int32_t max = 0x3fffffff;  // 1073741823
   ASSERT(min <= value && value < max);
   Dart_CObject object;
   object.type = Dart_CObject::kInt32;
   object.value.as_int32 = value;
   return Dart_PostCObject(port_id, &object);
 }
+
+
+// Statically allocated Dart_CObject instances for immutable
+// objects. As these will be used by different threads the use of
+// these depends on the fact that the marking internally in the
+// Dart_CObject structure is not marking simple value objects.
+Dart_CObject CObject::api_null_ = { Dart_CObject::kNull , { 0 } };
+Dart_CObject CObject::api_true_ = { Dart_CObject::kBool , { true } };
+Dart_CObject CObject::api_false_ = { Dart_CObject::kBool, { false } };
+CObject CObject::null_ = CObject(&api_null_);
+CObject CObject::true_ = CObject(&api_true_);
+CObject CObject::false_ = CObject(&api_false_);
+
+
+CObject* CObject::Null() {
+  return &null_;
+}
+
+
+CObject* CObject::True() {
+  return &true_;
+}
+
+
+CObject* CObject::False() {
+  return &false_;
+}
+
+
+CObject* CObject::Bool(bool value) {
+  return value ? &true_ : &false_;
+}
+
+
+Dart_CObject* CObject::New(Dart_CObject::Type type, int additional_bytes) {
+  Dart_CObject* cobject = reinterpret_cast<Dart_CObject*>(
+      Dart_ScopeAllocate(sizeof(Dart_CObject) + additional_bytes));
+  cobject->type = type;
+  return cobject;
+}
+
+
+Dart_CObject* CObject::NewInt32(int32_t value) {
+  Dart_CObject* cobject = New(Dart_CObject::kInt32);
+  cobject->value.as_int32 = value;
+  return cobject;
+}
+
+
+Dart_CObject* CObject::NewInt64(int64_t value) {
+  Dart_CObject* cobject = New(Dart_CObject::kInt64);
+  cobject->value.as_int64 = value;
+  return cobject;
+}
+
+
+Dart_CObject* CObject::NewDouble(double value) {
+  Dart_CObject* cobject = New(Dart_CObject::kDouble);
+  cobject->value.as_double = value;
+  return cobject;
+}
+
+
+Dart_CObject* CObject::NewString(int length) {
+  Dart_CObject* cobject = New(Dart_CObject::kString, length + 1);
+  cobject->value.as_string = reinterpret_cast<char*>(cobject + 1);
+  return cobject;
+}
+
+
+Dart_CObject* CObject::NewString(const char* str) {
+  int length = strlen(str);
+  Dart_CObject* cobject = NewString(length);
+  memmove(cobject->value.as_string, str, length + 1);
+  return cobject;
+}
+
+
+Dart_CObject* CObject::NewArray(int length) {
+  Dart_CObject* cobject =
+      New(Dart_CObject::kArray, length * sizeof(Dart_CObject*));  // NOLINT
+  cobject->value.as_array.length = length;
+  cobject->value.as_array.values =
+      reinterpret_cast<Dart_CObject**>(cobject + 1);
+  return cobject;
+}