On Thu, Jun 15, 2023 at 02:30:34PM +0900, Kyotaro Horiguchi wrote:
> At Wed, 14 Jun 2023 15:46:08 -0700, Nathan Bossart <nathandboss...@gmail.com> 
> wrote in 
>> Hm.  IIUC modifying the argv pointers on AIX will modify the process title,
>> which could cause 'ps' to temporarily show duplicate/missing arguments
>> during option parsing.  That doesn't seem too terrible, but if pointer
>> assignments aren't atomic, maybe 'ps' could be sent off to another part of
>> memory, which does seem terrible.
> 
> Hmm, the discussion seems to be based on the assumption that argv[0]
> can be safely redirected to a different memory location. If that's the
> case, we can prpbably rearrange the array, even if there's a small
> window where ps might display a confusing command line, right?

If that's the extent of the breakage, then it seems alright to me.  I've
attached a new version of the patch that omits the POSIXLY_CORRECT stuff.

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
>From 89ec098d2515d7cf03b630b787e8f53ca25916b9 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nat...@postgresql.org>
Date: Fri, 9 Jun 2023 15:51:58 -0700
Subject: [PATCH v2 1/1] Teach in-tree getopt_long() to move non-options to the
 end of argv.

---
 src/bin/scripts/t/040_createuser.pl | 10 +++++----
 src/port/getopt_long.c              | 34 +++++++++++++++++++++++++----
 2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/src/bin/scripts/t/040_createuser.pl b/src/bin/scripts/t/040_createuser.pl
index 9ca282181d..ba40ab11a3 100644
--- a/src/bin/scripts/t/040_createuser.pl
+++ b/src/bin/scripts/t/040_createuser.pl
@@ -42,9 +42,9 @@ $node->issues_sql_like(
 	'add a role as a member with admin option of the newly created role');
 $node->issues_sql_like(
 	[
-		'createuser', '-m',
-		'regress_user3', '-m',
-		'regress user #4', 'REGRESS_USER5'
+		'createuser', 'REGRESS_USER5',
+		'-m', 'regress_user3',
+		'-m', 'regress user #4'
 	],
 	qr/statement: CREATE ROLE "REGRESS_USER5" NOSUPERUSER NOCREATEDB NOCREATEROLE INHERIT LOGIN NOREPLICATION NOBYPASSRLS ROLE regress_user3,"regress user #4";/,
 	'add a role as a member of the newly created role');
@@ -73,11 +73,13 @@ $node->issues_sql_like(
 	qr/statement: CREATE ROLE regress_user11 NOSUPERUSER NOCREATEDB NOCREATEROLE INHERIT LOGIN NOREPLICATION NOBYPASSRLS IN ROLE regress_user1;/,
 	'--role');
 $node->issues_sql_like(
-	[ 'createuser', '--member-of', 'regress_user1', 'regress_user12' ],
+	[ 'createuser', 'regress_user12', '--member-of', 'regress_user1' ],
 	qr/statement: CREATE ROLE regress_user12 NOSUPERUSER NOCREATEDB NOCREATEROLE INHERIT LOGIN NOREPLICATION NOBYPASSRLS IN ROLE regress_user1;/,
 	'--member-of');
 
 $node->command_fails([ 'createuser', 'regress_user1' ],
 	'fails if role already exists');
+$node->command_fails([ 'createuser', 'regress_user1', '-m', 'regress_user2', 'regress_user3' ],
+	'fails for too many non-options');
 
 done_testing();
diff --git a/src/port/getopt_long.c b/src/port/getopt_long.c
index c989276988..4bbd8e0b85 100644
--- a/src/port/getopt_long.c
+++ b/src/port/getopt_long.c
@@ -50,8 +50,8 @@
  * This implementation does not use optreset.  Instead, we guarantee that
  * it can be restarted on a new argv array after a previous call returned -1,
  * if the caller resets optind to 1 before the first call of the new series.
- * (Internally, this means we must be sure to reset "place" to EMSG before
- * returning -1.)
+ * (Internally, this means we must be sure to reset "place" to EMSG and
+ * nonopt_start to -1 before returning -1.)
  */
 int
 getopt_long(int argc, char *const argv[],
@@ -60,21 +60,45 @@ getopt_long(int argc, char *const argv[],
 {
 	static char *place = EMSG;	/* option letter processing */
 	char	   *oli;			/* option letter list index */
+	static int	nonopt_start = -1;
 
 	if (!*place)
 	{							/* update scanning pointer */
 		if (optind >= argc)
 		{
 			place = EMSG;
+			nonopt_start = -1;
 			return -1;
 		}
 
+retry:
 		place = argv[optind];
 
 		if (place[0] != '-')
 		{
-			place = EMSG;
-			return -1;
+			char	  **args = (char **) argv;
+
+			/*
+			 * If only non-options remain, return -1.  Else, move the
+			 * non-option to the end and try again.
+			 */
+			if (optind == nonopt_start)
+			{
+				place = EMSG;
+				nonopt_start = -1;
+				return -1;
+			}
+
+			for (int i = optind; i < argc - 1; i++)
+				args[i] = args[i + 1];
+			args[argc - 1] = place;
+
+			if (nonopt_start == -1)
+				nonopt_start = argc - 1;
+			else
+				nonopt_start--;
+
+			goto retry;
 		}
 
 		place++;
@@ -83,6 +107,7 @@ getopt_long(int argc, char *const argv[],
 		{
 			/* treat "-" as not being an option */
 			place = EMSG;
+			nonopt_start = -1;
 			return -1;
 		}
 
@@ -91,6 +116,7 @@ getopt_long(int argc, char *const argv[],
 			/* found "--", treat it as end of options */
 			++optind;
 			place = EMSG;
+			nonopt_start = -1;
 			return -1;
 		}
 
-- 
2.25.1

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