From 99d4c1877bcea7e108a307160178fc95d22b15bc Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki@neon.tech>
Date: Mon, 7 Oct 2024 19:49:27 +0300
Subject: [PATCH] Replace BUFFERTAGS_EQUAL compatibility macro with new-style
 function (#9294)

In PostgreSQL v16, BUFFERTAGS_EQUAL was replaced with a static inline
macro, BufferTagsEqual. Let's use the new name going forward, and have
backwards-compatibility glue to allow using the new name on v14 and v15,
rather than the other way round. This also makes BufferTagsEquals
consistent with InitBufferTag, for which we were already using the new
name.
---
 pgxn/neon/neon_pgversioncompat.h | 20 ++++++++++++++++----
 pgxn/neon/pagestore_smgr.c       |  4 ++--
 pgxn/neon_walredo/walredoproc.c  |  2 +-
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/pgxn/neon/neon_pgversioncompat.h b/pgxn/neon/neon_pgversioncompat.h
index e4754ec7ea..6b4b355672 100644
--- a/pgxn/neon/neon_pgversioncompat.h
+++ b/pgxn/neon/neon_pgversioncompat.h
@@ -7,6 +7,7 @@
 #define NEON_PGVERSIONCOMPAT_H
 
 #include "fmgr.h"
+#include "storage/buf_internals.h"
 
 #if PG_MAJORVERSION_NUM < 17
 #define NRelFileInfoBackendIsTemp(rinfo) (rinfo.backend != InvalidBackendId)
@@ -20,11 +21,24 @@
 	NInfoGetRelNumber(a) == NInfoGetRelNumber(b) \
 )
 
-/* buftag population & RelFileNode/RelFileLocator rework */
+/* These macros were turned into static inline functions in v16 */
 #if PG_MAJORVERSION_NUM < 16
+static inline bool
+BufferTagsEqual(const BufferTag *tag1, const BufferTag *tag2)
+{
+	return BUFFERTAGS_EQUAL(*tag1, *tag2);
+}
 
-#define InitBufferTag(tag, rfn, fn, bn) INIT_BUFFERTAG(*tag, *rfn, fn, bn)
+static inline void
+InitBufferTag(BufferTag *tag, const RelFileNode *rnode,
+			  ForkNumber forkNum, BlockNumber blockNum)
+{
+	INIT_BUFFERTAG(*tag, *rnode, forkNum, blockNum);
+}
+#endif
 
+/* RelFileNode -> RelFileLocator rework */
+#if PG_MAJORVERSION_NUM < 16
 #define USE_RELFILENODE
 
 #define RELFILEINFO_HDR "storage/relfilenode.h"
@@ -73,8 +87,6 @@
 
 #define USE_RELFILELOCATOR
 
-#define BUFFERTAGS_EQUAL(a, b) BufferTagsEqual(&(a), &(b))
-
 #define RELFILEINFO_HDR "storage/relfilelocator.h"
 
 #define NRelFileInfo RelFileLocator
diff --git a/pgxn/neon/pagestore_smgr.c b/pgxn/neon/pagestore_smgr.c
index 49ac16158e..672f70c144 100644
--- a/pgxn/neon/pagestore_smgr.c
+++ b/pgxn/neon/pagestore_smgr.c
@@ -215,7 +215,7 @@ typedef struct PrfHashEntry
 	sizeof(BufferTag) \
 )
 
-#define SH_EQUAL(tb, a, b)	(BUFFERTAGS_EQUAL((a)->buftag, (b)->buftag))
+#define SH_EQUAL(tb, a, b)	(BufferTagsEqual(&(a)->buftag, &(b)->buftag))
 #define SH_SCOPE			static inline
 #define SH_DEFINE
 #define SH_DECLARE
@@ -853,7 +853,7 @@ Retry:
 			Assert(slot->status != PRFS_UNUSED);
 			Assert(MyPState->ring_last <= ring_index &&
 				   ring_index < MyPState->ring_unused);
-			Assert(BUFFERTAGS_EQUAL(slot->buftag, hashkey.buftag));
+			Assert(BufferTagsEqual(&slot->buftag, &hashkey.buftag));
 
 			/*
 			 * If the caller specified a request LSN to use, only accept
diff --git a/pgxn/neon_walredo/walredoproc.c b/pgxn/neon_walredo/walredoproc.c
index f98aa1cbe7..6a656c8d38 100644
--- a/pgxn/neon_walredo/walredoproc.c
+++ b/pgxn/neon_walredo/walredoproc.c
@@ -992,7 +992,7 @@ redo_block_filter(XLogReaderState *record, uint8 block_id)
 	 * If this block isn't one we are currently restoring, then return 'true'
 	 * so that this gets ignored
 	 */
-	return !BUFFERTAGS_EQUAL(target_tag, target_redo_tag);
+	return !BufferTagsEqual(&target_tag, &target_redo_tag);
 }
 
 /*