From: Tom Lane <tgl@sss.pgh.pa.us>
To: Nathan Bossart <nathandbossart@gmail.com>
cc: Zhihong Yu <zyu@yugabyte.com>,
        PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: silence compiler warning in brin.c
In-reply-to: <20220601173824.GA2396891@nathanxps13>
References: <20220601163537.GA2331988@nathanxps13>
 <CALNJ-vTvL-kvQ0CAbZxOvSR=PuOi1MbtywE=tdG2hhqSnZVkRw@mail.gmail.com>
 <626379.1654103181@sss.pgh.pa.us> <20220601173824.GA2396891@nathanxps13>
Comments: In-reply-to Nathan Bossart <nathandbossart@gmail.com>
	message dated "Wed, 01 Jun 2022 10:38:24 -0700"
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Date: Wed, 01 Jun 2022 17:08:03 -0400
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Nathan Bossart <nathandbossart@gmail.com> writes:
> On Wed, Jun 01, 2022 at 01:06:21PM -0400, Tom Lane wrote:
>> It looks like
>> AtEOXact_GUC asserts nestLevel > 0, so that either 0 or -1 would
>> do as an "invalid" value; I'd lean a bit to using 0.

> I only chose -1 to follow a117ceb's example in amcheck.  I have no
> preference.

Hmm, if we're following amcheck's example it should be more like this:

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index 52f171772d..0de1441dc6 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1051,7 +1051,13 @@ brin_summarize_range(PG_FUNCTION_ARGS)
         save_nestlevel = NewGUCNestLevel();
     }
     else
+    {
         heapRel = NULL;
+        /* Set these just to suppress "uninitialized variable" warnings */
+        save_userid = InvalidOid;
+        save_sec_context = -1;
+        save_nestlevel = -1;
+    }
 
     indexRel = index_open(indexoid, ShareUpdateExclusiveLock);
 
I like this better anyway since the fact that the other two variables
aren't warned about seems like an implementation artifact.

			regards, tom lane