Feedback-ID: ie3de48e3:Fastmail
Date: Mon, 19 Jan 2026 22:10:25 +0100
From: =?utf-8?Q?=C3=81lvaro?= Herrera <alvherre@kurilemu.de>
To: Peter Eisentraut <peter@eisentraut.org>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: anonymous unions (C11)
Message-ID: <202601192106.zcdi3yu2gzti@alvherre.pgsql>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="kiw4bymtmgixtbkr"
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <f00a9968-388e-4f8c-b5ef-5102e962d997@eisentraut.org>
Archived-At: 
 <https://www.postgresql.org/message-id/202601192106.zcdi3yu2gzti%40alvherre.pgsql>
Precedence: bulk


--kiw4bymtmgixtbkr
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit

On 2025-Sep-23, Peter Eisentraut wrote:

> Here is another patch set to sprinkle some C11 features around the
> code.  My aim is to make a little bit of use of several C11 features
> as examples and encouragement for future code, and to test compilers
> (although we're not yet at the point where this should really stress
> any compiler).

I was going over patch [1] today and came across the union in
relopt_value.  Vaguely remembering this thread, I patched it out
(attached) ... and now that I come here to post it, I realize that it's
probably identical to your patch 0009 here.

Would you push it or can I?

[1] https://postgr.es/m/4047390.3Lj2Plt8kZ@thinkpad-pgpro

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

--kiw4bymtmgixtbkr
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment;
	filename="0001-Make-some-use-of-anonymous-unions.patch"

From 23d94cc1c30aa00d2340c1368b01856b1fe95ecd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lvaro=20Herrera?= <alvherre@kurilemu.de>
Date: Mon, 19 Jan 2026 18:27:13 +0100
Subject: [PATCH] Make some use of anonymous unions

In the spirit of commit 4b7e6c73b0df and following, which see for more
details; it appears to have been quite an uncontroversial C11 feature to
use.
---
 src/backend/access/common/reloptions.c | 34 +++++++++++++-------------
 src/include/access/reloptions.h        |  2 +-
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 0b83f98ed5f..d9729ebf17f 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -587,7 +587,7 @@ static void parse_one_reloption(relopt_value *option, char *text_str,
  * relation options.
  */
 #define GET_STRING_RELOPTION_LEN(option) \
-	((option).isset ? strlen((option).values.string_val) : \
+	((option).isset ? strlen((option).string_val) : \
 	 ((relopt_string *) (option).gen)->default_len)
 
 /*
@@ -1618,7 +1618,7 @@ parse_one_reloption(relopt_value *option, char *text_str, int text_len,
 	{
 		case RELOPT_TYPE_BOOL:
 			{
-				parsed = parse_bool(value, &option->values.bool_val);
+				parsed = parse_bool(value, &option->bool_val);
 				if (validate && !parsed)
 					ereport(ERROR,
 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
@@ -1630,14 +1630,14 @@ parse_one_reloption(relopt_value *option, char *text_str, int text_len,
 			{
 				relopt_int *optint = (relopt_int *) option->gen;
 
-				parsed = parse_int(value, &option->values.int_val, 0, NULL);
+				parsed = parse_int(value, &option->int_val, 0, NULL);
 				if (validate && !parsed)
 					ereport(ERROR,
 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 							 errmsg("invalid value for integer option \"%s\": %s",
 									option->gen->name, value)));
-				if (validate && (option->values.int_val < optint->min ||
-								 option->values.int_val > optint->max))
+				if (validate && (option->int_val < optint->min ||
+								 option->int_val > optint->max))
 					ereport(ERROR,
 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 							 errmsg("value %s out of bounds for option \"%s\"",
@@ -1650,14 +1650,14 @@ parse_one_reloption(relopt_value *option, char *text_str, int text_len,
 			{
 				relopt_real *optreal = (relopt_real *) option->gen;
 
-				parsed = parse_real(value, &option->values.real_val, 0, NULL);
+				parsed = parse_real(value, &option->real_val, 0, NULL);
 				if (validate && !parsed)
 					ereport(ERROR,
 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 							 errmsg("invalid value for floating point option \"%s\": %s",
 									option->gen->name, value)));
-				if (validate && (option->values.real_val < optreal->min ||
-								 option->values.real_val > optreal->max))
+				if (validate && (option->real_val < optreal->min ||
+								 option->real_val > optreal->max))
 					ereport(ERROR,
 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 							 errmsg("value %s out of bounds for option \"%s\"",
@@ -1676,7 +1676,7 @@ parse_one_reloption(relopt_value *option, char *text_str, int text_len,
 				{
 					if (pg_strcasecmp(value, elt->string_val) == 0)
 					{
-						option->values.enum_val = elt->symbol_val;
+						option->enum_val = elt->symbol_val;
 						parsed = true;
 						break;
 					}
@@ -1694,14 +1694,14 @@ parse_one_reloption(relopt_value *option, char *text_str, int text_len,
 				 * not asked to validate, just use the default numeric value.
 				 */
 				if (!parsed)
-					option->values.enum_val = optenum->default_val;
+					option->enum_val = optenum->default_val;
 			}
 			break;
 		case RELOPT_TYPE_STRING:
 			{
 				relopt_string *optstring = (relopt_string *) option->gen;
 
-				option->values.string_val = value;
+				option->string_val = value;
 				nofree = true;
 				if (validate && optstring->validate_cb)
 					(optstring->validate_cb) (value);
@@ -1743,7 +1743,7 @@ allocateReloptStruct(Size base, relopt_value *options, int numoptions)
 
 			if (optstr->fill_cb)
 			{
-				const char *val = optval->isset ? optval->values.string_val :
+				const char *val = optval->isset ? optval->string_val :
 					optstr->default_isnull ? NULL : optstr->default_val;
 
 				size += optstr->fill_cb(val, NULL);
@@ -1804,28 +1804,28 @@ fillRelOptions(void *rdopts, Size basesize,
 				{
 					case RELOPT_TYPE_BOOL:
 						*(bool *) itempos = options[i].isset ?
-							options[i].values.bool_val :
+							options[i].bool_val :
 							((relopt_bool *) options[i].gen)->default_val;
 						break;
 					case RELOPT_TYPE_INT:
 						*(int *) itempos = options[i].isset ?
-							options[i].values.int_val :
+							options[i].int_val :
 							((relopt_int *) options[i].gen)->default_val;
 						break;
 					case RELOPT_TYPE_REAL:
 						*(double *) itempos = options[i].isset ?
-							options[i].values.real_val :
+							options[i].real_val :
 							((relopt_real *) options[i].gen)->default_val;
 						break;
 					case RELOPT_TYPE_ENUM:
 						*(int *) itempos = options[i].isset ?
-							options[i].values.enum_val :
+							options[i].enum_val :
 							((relopt_enum *) options[i].gen)->default_val;
 						break;
 					case RELOPT_TYPE_STRING:
 						optstring = (relopt_string *) options[i].gen;
 						if (options[i].isset)
-							string_val = options[i].values.string_val;
+							string_val = options[i].string_val;
 						else if (!optstring->default_isnull)
 							string_val = optstring->default_val;
 						else
diff --git a/src/include/access/reloptions.h b/src/include/access/reloptions.h
index 2f08e1b0cf0..40a1369646b 100644
--- a/src/include/access/reloptions.h
+++ b/src/include/access/reloptions.h
@@ -84,7 +84,7 @@ typedef struct relopt_value
 		double		real_val;
 		int			enum_val;
 		char	   *string_val; /* allocated separately */
-	}			values;
+	};
 } relopt_value;
 
 /* reloptions records for specific variable types */
-- 
2.47.3


--kiw4bymtmgixtbkr--