1 files changed, 104 insertions, 0 deletions
diff --git a/dom/media/doctor/DDLoggedTypeTraits.h b/dom/media/doctor/DDLoggedTypeTraits.h
new file mode 100644
index 0000000000..2c9de4dbc5
--- /dev/null
+++ b/dom/media/doctor/DDLoggedTypeTraits.h
@@ -0,0 +1,104 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DDLoggedTypeTraits_h_
+#define DDLoggedTypeTraits_h_
+
+#include <type_traits>
+
+namespace mozilla {
+
+// Templated struct carrying compile-time information about C++ types that may
+// log messages (including about their lifetime and links to other objects.)
+// Classes should declare a specialization by using one of the macros below.
+template <typename T>
+struct DDLoggedTypeTraits;
+
+#define DDLoggedTypeName(TYPE)                                 \
+  template <>                                                  \
+  struct DDLoggedTypeTraits<TYPE> {                            \
+    using Type = TYPE;                                         \
+    static constexpr const char* Name() { return #TYPE; }      \
+    using HasBase = std::false_type;                           \
+    using BaseType = TYPE;                                     \
+    static constexpr const char* BaseTypeName() { return ""; } \
+  }
+
+#define DDLoggedTypeNameAndBase(TYPE, BASE)               \
+  template <>                                             \
+  struct DDLoggedTypeTraits<TYPE> {                       \
+    using Type = TYPE;                                    \
+    static constexpr const char* Name() { return #TYPE; } \
+    using HasBase = std::true_type;                       \
+    using BaseType = BASE;                                \
+    static constexpr const char* BaseTypeName() {         \
+      return DDLoggedTypeTraits<BASE>::Name();            \
+    }                                                     \
+  }
+
+#define DDLoggedTypeCustomName(TYPE, NAME)                     \
+  template <>                                                  \
+  struct DDLoggedTypeTraits<TYPE> {                            \
+    using Type = TYPE;                                         \
+    static constexpr const char* Name() { return #NAME; }      \
+    using HasBase = std::false_type;                           \
+    using BaseType = TYPE;                                     \
+    static constexpr const char* BaseTypeName() { return ""; } \
+  }
+
+#define DDLoggedTypeCustomNameAndBase(TYPE, NAME, BASE)   \
+  template <>                                             \
+  struct DDLoggedTypeTraits<TYPE> {                       \
+    using Type = TYPE;                                    \
+    static constexpr const char* Name() { return #NAME; } \
+    using HasBase = std::true_type;                       \
+    using BaseType = BASE;                                \
+    static constexpr const char* BaseTypeName() {         \
+      return DDLoggedTypeTraits<BASE>::Name();            \
+    }                                                     \
+  }
+
+// Variants with built-in forward-declaration, will only work
+// - in mozilla namespace,
+// - with unqualified mozilla-namespace type names.
+#define DDLoggedTypeDeclName(TYPE) \
+  class TYPE;                      \
+  DDLoggedTypeName(TYPE);
+#define DDLoggedTypeDeclNameAndBase(TYPE, BASE) \
+  class TYPE;                                   \
+  DDLoggedTypeNameAndBase(TYPE, BASE);
+#define DDLoggedTypeDeclCustomName(TYPE, NAME) \
+  class TYPE;                                  \
+  DDLoggedTypeCustomName(TYPE, NAME);
+#define DDLoggedTypeDeclCustomNameAndBase(TYPE, NAME, BASE) \
+  class TYPE;                                               \
+  DDLoggedTypeCustomNameAndBase(TYPE, NAME, BASE);
+
+}  // namespace mozilla
+
+// Some essential types that live outside of the media stack.
+class nsPIDOMWindowInner;
+class nsPIDOMWindowOuter;
+
+namespace mozilla {
+
+namespace dom {
+class Document;
+class HTMLAudioElement;
+class HTMLMediaElement;
+class HTMLVideoElement;
+}  // namespace dom
+
+DDLoggedTypeName(nsPIDOMWindowInner);
+DDLoggedTypeName(nsPIDOMWindowOuter);
+DDLoggedTypeName(dom::Document);
+DDLoggedTypeName(dom::HTMLMediaElement);
+DDLoggedTypeNameAndBase(dom::HTMLAudioElement, dom::HTMLMediaElement);
+DDLoggedTypeNameAndBase(dom::HTMLVideoElement, dom::HTMLMediaElement);
+
+}  // namespace mozilla
+
+#endif  // DDLoggedTypeTraits_h_