From 3205de7906abab9d12e614e86e2c182a41420698 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Fri, 27 Oct 2017 15:01:40 -0600
Subject: [PATCH] Make the NullPool HB_INTERNAL shared

Saves 2k of .bss section.
---
 src/hb-open-type-private.hh | 10 ++++++----
 src/hb-ot-layout.cc         |  3 +++
 src/main.cc                 |  1 +
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/hb-open-type-private.hh b/src/hb-open-type-private.hh
index f0ff2ff59..f1c90474a 100644
--- a/src/hb-open-type-private.hh
+++ b/src/hb-open-type-private.hh
@@ -130,14 +130,16 @@ static inline Type& StructAfter(TObject &X)
  */
 
 /* Global nul-content Null pool.  Enlarge as necessary. */
-/* TODO This really should be a extern HB_INTERNAL and defined somewhere... */
-static const void *_NullPool[(256+8) / sizeof (void *)];
+
+#define HB_NULL_POOL_SIZE 264
+static_assert (HB_NULL_POOL_SIZE % sizeof (void *) == 0, "Align HB_NULL_POOL_SIZE.");
+extern HB_INTERNAL const void *_hb_NullPool[HB_NULL_POOL_SIZE / sizeof (void *)];
 
 /* Generic nul-content Null objects. */
 template <typename Type>
 static inline const Type& Null (void) {
-  static_assert ((sizeof (Type) <= sizeof (_NullPool)), "");
-  return *CastP<Type> (_NullPool);
+  static_assert (sizeof (Type) <= HB_NULL_POOL_SIZE, "Increase HB_NULL_POOL_SIZE.");
+  return *CastP<Type> (_hb_NullPool);
 }
 
 /* Specializaiton for arbitrary-content arbitrary-sized Null objects. */
diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index 71e782686..4850f720d 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -39,6 +39,9 @@
 #include "hb-ot-map-private.hh"
 
 
+const void *OT::_hb_NullPool[HB_NULL_POOL_SIZE / sizeof (void *)];
+
+
 hb_ot_layout_t *
 _hb_ot_layout_create (hb_face_t *face)
 {
diff --git a/src/main.cc b/src/main.cc
index 93c3b46af..eb1711ed6 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -38,6 +38,7 @@
 
 using namespace OT;
 
+const void *OT::_hb_NullPool[HB_NULL_POOL_SIZE / sizeof (void *)];
 
 int
 main (int argc, char **argv)