From 1e503f587b3ce368b6b759c1927aa9708096c8f3 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Tue, 5 Jul 2022 15:44:58 -0600
Subject: [PATCH] [null] Add DECLARE_NULL_NAMESPACE_BYTES_TEMPLATE1

---
 src/hb-aat-layout-common.hh | 13 +------------
 src/hb-null.hh              | 13 ++++++++++++-
 src/hb-static.cc            |  3 +--
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/src/hb-aat-layout-common.hh b/src/hb-aat-layout-common.hh
index dcc0289e0..6cbed8269 100644
--- a/src/hb-aat-layout-common.hh
+++ b/src/hb-aat-layout-common.hh
@@ -415,18 +415,7 @@ struct Lookup
   public:
   DEFINE_SIZE_UNION (2, format);
 };
-/* Lookup 0 has unbounded size (dependant on num_glyphs).  So we need to defined
- * special NULL objects for Lookup<> objects, but since it's template our macros
- * don't work.  So we have to hand-code them here.  UGLY. */
-} /* Close namespace. */
-/* Ugly hand-coded null objects for template Lookup<> :(. */
-extern HB_INTERNAL const unsigned char _hb_Null_AAT_Lookup[2];
-template <typename T>
-struct Null<AAT::Lookup<T>> {
-  static AAT::Lookup<T> const & get_null ()
-  { return *reinterpret_cast<const AAT::Lookup<T> *> (_hb_Null_AAT_Lookup); }
-};
-namespace AAT {
+DECLARE_NULL_NAMESPACE_BYTES_TEMPLATE1 (AAT, Lookup, 2);
 
 enum { DELETED_GLYPH = 0xFFFF };
 
diff --git a/src/hb-null.hh b/src/hb-null.hh
index 78eb6474d..d59f123fa 100644
--- a/src/hb-null.hh
+++ b/src/hb-null.hh
@@ -117,8 +117,19 @@ struct NullHelper
 	}; \
 	namespace Namespace { \
 	static_assert (true, "") /* Require semicolon after. */
+#define DECLARE_NULL_NAMESPACE_BYTES_TEMPLATE1(Namespace, Type, Size) \
+	} /* Close namespace. */ \
+	extern HB_INTERNAL const unsigned char _hb_Null_##Namespace##_##Type[Size]; \
+	template <typename Spec> \
+	struct Null<Namespace::Type<Spec>> { \
+	  static Namespace::Type<Spec> const & get_null () { \
+	    return *reinterpret_cast<const Namespace::Type<Spec> *> (_hb_Null_##Namespace##_##Type); \
+	  } \
+	}; \
+	namespace Namespace { \
+	static_assert (true, "") /* Require semicolon after. */
 #define DEFINE_NULL_NAMESPACE_BYTES(Namespace, Type) \
-	const unsigned char _hb_Null_##Namespace##_##Type[hb_null_size (Namespace::Type)]
+	const unsigned char _hb_Null_##Namespace##_##Type[sizeof (_hb_Null_##Namespace##_##Type)]
 
 /* Specializations for arbitrary-content Null objects expressed as struct initializer. */
 #define DECLARE_NULL_INSTANCE(Type) \
diff --git a/src/hb-static.cc b/src/hb-static.cc
index 5c5ecce88..c72aa96b0 100644
--- a/src/hb-static.cc
+++ b/src/hb-static.cc
@@ -49,8 +49,7 @@ DEFINE_NULL_NAMESPACE_BYTES (OT, LangSys) = {0x00,0x00, 0xFF,0xFF, 0x00,0x00};
 DEFINE_NULL_NAMESPACE_BYTES (OT, RangeRecord) = {0x00,0x01, 0x00,0x00, 0x00, 0x00};
 DEFINE_NULL_NAMESPACE_BYTES (OT, CmapSubtableLongGroup) = {0x00,0x00,0x00,0x01, 0x00,0x00,0x00,0x00, 0x00,0x00,0x00,0x00};
 DEFINE_NULL_NAMESPACE_BYTES (AAT, SettingName) = {0xFF,0xFF, 0xFF,0xFF};
-/* Hand-coded because Lookup is a template.  Sad. */
-const unsigned char _hb_Null_AAT_Lookup[2] = {0xFF, 0xFF};
+DEFINE_NULL_NAMESPACE_BYTES (AAT, Lookup) = {0xFF,0xFF};
 
 
 /* hb_map_t */