From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Wed, 1 Jul 2026 17:44:45 +0000 (-0400)
Subject: Fix macro-redefinition warning introduced by aeb07c55f.
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=85656c1bef4af031f8e9801d927cdaeaaae95566;p=thirdparty%2Fpostgresql.git

Fix macro-redefinition warning introduced by aeb07c55f.

Some platforms provide a definition of unreachable() in standard C
headers, leading to a conflict with unreachable() in the new
timezone code.  It seems best for our purposes to conform to what
pg_unreachable() does, so #undef away the platform version.

Reported-by: Tristan Partin <tristan@partin.io>
Discussion: https://postgr.es/m/DJNDN9UQS9GP.11L4NJ1HHE1ZJ@partin.io
---

diff --git a/src/timezone/private.h b/src/timezone/private.h
index 0d02e620b6f..2a1a64d43c9 100644
--- a/src/timezone/private.h
+++ b/src/timezone/private.h
@@ -184,6 +184,8 @@
  */
 #define INITIALIZE(x)	((x) = 0)
 
+/* Some platforms provide unreachable(), but let's rely on our own version */
+#undef unreachable
 #define unreachable() pg_unreachable()
 
 /*