Feedback-ID: ie3de48e3:Fastmail
Date: Wed, 3 Dec 2025 15:36:05 +0100
From: =?utf-8?Q?=C3=81lvaro?= Herrera <alvherre@kurilemu.de>
To: Chao Li <li.evan.chao@gmail.com>
Cc: Peter Smith <smithpb2250@gmail.com>,
	Peter Eisentraut <peter@eisentraut.org>,
 Postgres hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Cleanup shadows variable warnings, round 1
Message-ID: <202512031432.cpvnk5irwygr@alvherre.pgsql>
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On 2025-Dec-03, Chao Li wrote:

> Unfortunately that doesn’t work for my compiler (clang on MacOS),
> that’s why I renamed “I" to “u”.

I think you're missing his point.  He's suggesting to change not only
this variable, but also the other uses of "i" in this function.

I'd also change "unsigned" to "unsigned int", just because I dislike
using unadorned "unsigned" as a type name (I know it's a legal type
name.)  This could be left alone, I guess -- not important.

diff --git a/src/backend/backup/basebackup_incremental.c b/src/backend/backup/basebackup_incremental.c
index 852ab577045..322d8997400 100644
--- a/src/backend/backup/basebackup_incremental.c
+++ b/src/backend/backup/basebackup_incremental.c
@@ -270,7 +270,6 @@ PrepareForIncrementalBackup(IncrementalBackupInfo *ib,
 	ListCell   *lc;
 	TimeLineHistoryEntry **tlep;
 	int			num_wal_ranges;
-	int			i;
 	bool		found_backup_start_tli = false;
 	TimeLineID	earliest_wal_range_tli = 0;
 	XLogRecPtr	earliest_wal_range_start_lsn = InvalidXLogRecPtr;
@@ -312,7 +311,7 @@ PrepareForIncrementalBackup(IncrementalBackupInfo *ib,
 	 */
 	expectedTLEs = readTimeLineHistory(backup_state->starttli);
 	tlep = palloc0(num_wal_ranges * sizeof(TimeLineHistoryEntry *));
-	for (i = 0; i < num_wal_ranges; ++i)
+	for (int i = 0; i < num_wal_ranges; ++i)
 	{
 		backup_wal_range *range = list_nth(ib->manifest_wal_ranges, i);
 		bool		saw_earliest_wal_range_tli = false;
@@ -400,7 +399,7 @@ PrepareForIncrementalBackup(IncrementalBackupInfo *ib,
 	 * anything here. However, if there's a problem staring us right in the
 	 * face, it's best to report it, so we do.
 	 */
-	for (i = 0; i < num_wal_ranges; ++i)
+	for (int i = 0; i < num_wal_ranges; ++i)
 	{
 		backup_wal_range *range = list_nth(ib->manifest_wal_ranges, i);
 
@@ -595,15 +594,14 @@ PrepareForIncrementalBackup(IncrementalBackupInfo *ib,
 
 			while (1)
 			{
-				unsigned	nblocks;
-				unsigned	i;
+				unsigned int	nblocks;
 
 				nblocks = BlockRefTableReaderGetBlocks(reader, blocks,
 													   BLOCKS_PER_READ);
 				if (nblocks == 0)
 					break;
 
-				for (i = 0; i < nblocks; ++i)
+				for (unsigned int i = 0; i < nblocks; ++i)
 					BlockRefTableMarkBlockModified(ib->brtab, &rlocator,
 												   forknum, blocks[i]);
 			}

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/