Date: Mon, 9 Dec 2024 13:16:38 -0600
From: Nathan Bossart <nathandbossart@gmail.com>
To: pgsql-hackers@postgresql.org
Subject: unused-but-set-variable warning on REL_13_STABLE
Message-ID: <Z1dCFnzrP24O8WNR@nathan>
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My compiler emits the following warning on REL_13_STABLE when assertions
are disabled:

	reorderbuffer.c:2471:8: warning: variable 'spilled' set but not used [-Wunused-but-set-variable]
	 2471 |         Size            spilled = 0;
	      |                         ^

Adding PG_USED_FOR_ASSERTS_ONLY (as in the attached patch) seems sufficient
to suppress this warning.  On newer versions, this variable is used for
more than assertions, so the patch only needs to be applied to v13.  Since
this is trivial, I plan to commit it shortly.

-- 
nathan

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diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index c7f8fa6216..56c25e3a6d 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -2468,7 +2468,7 @@ ReorderBufferSerializeTXN(ReorderBuffer *rb, ReorderBufferTXN *txn)
 	dlist_mutable_iter change_i;
 	int			fd = -1;
 	XLogSegNo	curOpenSegNo = 0;
-	Size		spilled = 0;
+	Size		spilled PG_USED_FOR_ASSERTS_ONLY = 0;
 
 	elog(DEBUG2, "spill %u changes in XID %u to disk",
 		 (uint32) txn->nentries_mem, txn->xid);

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