backend/nodes cleanup: Move loop variables definitions into for statement

Started by Chao Li2 months ago9 messages

li.evan.chao@gmail.com

2 months ago

1 attachment(s)

Hi Hackers,

While working on the other patch [1]/messages/by-id/CAEoWx2m2E0xE8Kvbkv31ULh_E+5zph-WA_bEdv3UR9CLhw+3vg@mail.gmail.com that touched tbm_add_tuples() under
src/backend/nodes, I moved a loop variable into for statement by the way as
I knew Peter Eisentraut had done some efforts about that, see [2]https://git.postgresql.org/cgit/postgresql.git/commit/?id=03fbb0814c5015ab79e670ab97bb6a3349269e4b.

However, Peter removed that change from the patch and he said that should
belong to a separate cleanup patch. So I am following up and moving loop
variables into for statements wherever possible under src/backend/nodes.

[1]: /messages/by-id/CAEoWx2m2E0xE8Kvbkv31ULh_E+5zph-WA_bEdv3UR9CLhw+3vg@mail.gmail.com
/messages/by-id/CAEoWx2m2E0xE8Kvbkv31ULh_E+5zph-WA_bEdv3UR9CLhw+3vg@mail.gmail.com
[2]: https://git.postgresql.org/cgit/postgresql.git/commit/?id=03fbb0814c5015ab79e670ab97bb6a3349269e4b
https://git.postgresql.org/cgit/postgresql.git/commit/?id=03fbb0814c5015ab79e670ab97bb6a3349269e4b

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/

Attachments:

v1-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchapplication/octet-stream; name=v1-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchDownload

From 460569ce899062d5000ba921e43e70d4fc1bc311 Mon Sep 17 00:00:00 2001
From: "Chao Li (Evan)" <lic@highgo.com>
Date: Wed, 12 Nov 2025 15:53:15 +0800
Subject: [PATCH v1] backend/nodes cleanup: Move loop variables definitions
 into for statement

---
 src/backend/nodes/bitmapset.c |  9 +++------
 src/backend/nodes/nodeFuncs.c |  4 +---
 src/backend/nodes/outfuncs.c  | 13 +++++--------
 src/backend/nodes/params.c    |  6 ++----
 src/backend/nodes/tidbitmap.c | 16 ++++++----------
 5 files changed, 17 insertions(+), 31 deletions(-)

diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c
index b4ecf0b0390..7b1e9d94103 100644
--- a/src/backend/nodes/bitmapset.c
+++ b/src/backend/nodes/bitmapset.c
@@ -538,7 +538,6 @@ bms_is_member(int x, const Bitmapset *a)
 int
 bms_member_index(Bitmapset *a, int x)
 {
-	int			i;
 	int			bitnum;
 	int			wordnum;
 	int			result = 0;
@@ -554,7 +553,7 @@ bms_member_index(Bitmapset *a, int x)
 	bitnum = BITNUM(x);
 
 	/* count bits in preceding words */
-	for (i = 0; i < wordnum; i++)
+	for (int i = 0; i < wordnum; i++)
 	{
 		bitmapword	w = a->words[i];
 
@@ -1306,7 +1305,6 @@ int
 bms_next_member(const Bitmapset *a, int prevbit)
 {
 	int			nwords;
-	int			wordnum;
 	bitmapword	mask;
 
 	Assert(bms_is_valid_set(a));
@@ -1316,7 +1314,7 @@ bms_next_member(const Bitmapset *a, int prevbit)
 	nwords = a->nwords;
 	prevbit++;
 	mask = (~(bitmapword) 0) << BITNUM(prevbit);
-	for (wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
+	for (int wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
 	{
 		bitmapword	w = a->words[wordnum];
 
@@ -1366,7 +1364,6 @@ bms_next_member(const Bitmapset *a, int prevbit)
 int
 bms_prev_member(const Bitmapset *a, int prevbit)
 {
-	int			wordnum;
 	int			ushiftbits;
 	bitmapword	mask;
 
@@ -1391,7 +1388,7 @@ bms_prev_member(const Bitmapset *a, int prevbit)
 
 	ushiftbits = BITS_PER_BITMAPWORD - (BITNUM(prevbit) + 1);
 	mask = (~(bitmapword) 0) >> ushiftbits;
-	for (wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
+	for (int wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
 	{
 		bitmapword	w = a->words[wordnum];
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index ede838cd40c..d228318dc72 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4826,9 +4826,7 @@ planstate_walk_members(PlanState **planstates, int nplans,
 					   planstate_tree_walker_callback walker,
 					   void *context)
 {
-	int			j;
-
-	for (j = 0; j < nplans; j++)
+	for (int j = 0; j < nplans; j++)
 	{
 		if (PSWALK(planstates[j]))
 			return true;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index d9fe21a07e0..1ba590b71d6 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -346,8 +346,7 @@ outBitmapset(StringInfo str, const Bitmapset *bms)
 void
 outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 {
-	Size		length,
-				i;
+	Size		length;
 	char	   *s;
 
 	length = datumGetSize(value, typbyval, typlen);
@@ -356,7 +355,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 	{
 		s = (char *) (&value);
 		appendStringInfo(str, "%u [ ", (unsigned int) length);
-		for (i = 0; i < (Size) sizeof(Datum); i++)
+		for (int i = 0; i < (Size) sizeof(Datum); i++)
 			appendStringInfo(str, "%d ", (int) (s[i]));
 		appendStringInfoChar(str, ']');
 	}
@@ -368,7 +367,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 		else
 		{
 			appendStringInfo(str, "%u [ ", (unsigned int) length);
-			for (i = 0; i < length; i++)
+			for (int i = 0; i < length; i++)
 				appendStringInfo(str, "%d ", (int) (s[i]));
 			appendStringInfoChar(str, ']');
 		}
@@ -434,8 +433,6 @@ _outBoolExpr(StringInfo str, const BoolExpr *node)
 static void
 _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 {
-	int			i;
-
 	WRITE_NODE_TYPE("FOREIGNKEYOPTINFO");
 
 	WRITE_UINT_FIELD(con_relid);
@@ -450,10 +447,10 @@ _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 	WRITE_INT_FIELD(nmatched_ri);
 	/* for compactness, just print the number of matches per column: */
 	appendStringInfoString(str, " :eclass");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", (node->eclass[i] != NULL));
 	appendStringInfoString(str, " :rinfos");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", list_length(node->rinfos[i]));
 }
 
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index ec5946c5777..aeb8ace2c54 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -166,13 +166,12 @@ paramlist_param_ref(ParseState *pstate, ParamRef *pref)
 Size
 EstimateParamListSpace(ParamListInfo paramLI)
 {
-	int			i;
 	Size		sz = sizeof(int);
 
 	if (paramLI == NULL || paramLI->numParams <= 0)
 		return sz;
 
-	for (i = 0; i < paramLI->numParams; i++)
+	for (int i = 0; i < paramLI->numParams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
@@ -229,7 +228,6 @@ void
 SerializeParamList(ParamListInfo paramLI, char **start_address)
 {
 	int			nparams;
-	int			i;
 
 	/* Write number of parameters. */
 	if (paramLI == NULL || paramLI->numParams <= 0)
@@ -240,7 +238,7 @@ SerializeParamList(ParamListInfo paramLI, char **start_address)
 	*start_address += sizeof(int);
 
 	/* Write each parameter in turn. */
-	for (i = 0; i < nparams; i++)
+	for (int i = 0; i < nparams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index 23d97b3a6c8..1f83d0d55f5 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -369,10 +369,9 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointerData *tids, int ntids,
 {
 	BlockNumber currblk = InvalidBlockNumber;
 	PagetableEntry *page = NULL;	/* only valid when currblk is valid */
-	int			i;
 
 	Assert(tbm->iterating == TBM_NOT_ITERATING);
-	for (i = 0; i < ntids; i++)
+	for (int i = 0; i < ntids; i++)
 	{
 		BlockNumber blk = ItemPointerGetBlockNumber(tids + i);
 		OffsetNumber off = ItemPointerGetOffsetNumber(tids + i);
@@ -471,12 +470,11 @@ static void
 tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 {
 	PagetableEntry *apage;
-	int			wordnum;
 
 	if (bpage->ischunk)
 	{
 		/* Scan b's chunk, mark each indicated page lossy in a */
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = bpage->words[wordnum];
 
@@ -511,7 +509,7 @@ tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 		else
 		{
 			/* Both pages are exact, merge at the bit level */
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 				apage->words[wordnum] |= bpage->words[wordnum];
 			apage->recheck |= bpage->recheck;
 		}
@@ -579,14 +577,13 @@ static bool
 tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 {
 	const PagetableEntry *bpage;
-	int			wordnum;
 
 	if (apage->ischunk)
 	{
 		/* Scan each bit in chunk, try to clear */
 		bool		candelete = true;
 
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = apage->words[wordnum];
 
@@ -640,7 +637,7 @@ tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 		{
 			/* Both pages are exact, merge at the bit level */
 			Assert(!bpage->ischunk);
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 			{
 				apage->words[wordnum] &= bpage->words[wordnum];
 				if (apage->words[wordnum] != 0)
@@ -904,10 +901,9 @@ tbm_extract_page_tuple(TBMIterateResult *iteritem,
 					   uint32 max_offsets)
 {
 	PagetableEntry *page = iteritem->internal_page;
-	int			wordnum;
 	int			ntuples = 0;
 
-	for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+	for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 	{
 		bitmapword	w = page->words[wordnum];
 
-- 
2.39.5 (Apple Git-154)

Chao Li

li.evan.chao@gmail.com

about 2 months ago

In reply to: Chao Li (#1)

1 attachment(s)

Re: backend/nodes cleanup: Move loop variables definitions into for statement

On Wed, Nov 12, 2025 at 4:00 PM Chao Li <li.evan.chao@gmail.com> wrote:

Hi Hackers,

While working on the other patch [1] that touched tbm_add_tuples() under
src/backend/nodes, I moved a loop variable into for statement by the way as
I knew Peter Eisentraut had done some efforts about that, see [2].

However, Peter removed that change from the patch and he said that should
belong to a separate cleanup patch. So I am following up and moving loop
variables into for statements wherever possible under src/backend/nodes.

[1]
/messages/by-id/CAEoWx2m2E0xE8Kvbkv31ULh_E+5zph-WA_bEdv3UR9CLhw+3vg@mail.gmail.com
[2]
https://git.postgresql.org/cgit/postgresql.git/commit/?id=03fbb0814c5015ab79e670ab97bb6a3349269e4b

Rebased to V2.

Best regards,
Chao Li (Evan)
---------------------
HighGo Software Co., Ltd.
https://www.highgo.com/

Attachments:

v2-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchapplication/octet-stream; name=v2-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchDownload

From 70937ae52f12e861a9bfa6e43823779b7d757f1d Mon Sep 17 00:00:00 2001
From: "Chao Li (Evan)" <lic@highgo.com>
Date: Wed, 12 Nov 2025 15:53:15 +0800
Subject: [PATCH v2] backend/nodes cleanup: Move loop variables definitions
 into for statement

---
 src/backend/nodes/bitmapset.c |  9 +++------
 src/backend/nodes/nodeFuncs.c |  4 +---
 src/backend/nodes/outfuncs.c  | 13 +++++--------
 src/backend/nodes/params.c    |  6 ++----
 src/backend/nodes/readfuncs.c |  7 +++----
 src/backend/nodes/tidbitmap.c | 16 ++++++----------
 6 files changed, 20 insertions(+), 35 deletions(-)

diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c
index b4ecf0b0390..7b1e9d94103 100644
--- a/src/backend/nodes/bitmapset.c
+++ b/src/backend/nodes/bitmapset.c
@@ -538,7 +538,6 @@ bms_is_member(int x, const Bitmapset *a)
 int
 bms_member_index(Bitmapset *a, int x)
 {
-	int			i;
 	int			bitnum;
 	int			wordnum;
 	int			result = 0;
@@ -554,7 +553,7 @@ bms_member_index(Bitmapset *a, int x)
 	bitnum = BITNUM(x);
 
 	/* count bits in preceding words */
-	for (i = 0; i < wordnum; i++)
+	for (int i = 0; i < wordnum; i++)
 	{
 		bitmapword	w = a->words[i];
 
@@ -1306,7 +1305,6 @@ int
 bms_next_member(const Bitmapset *a, int prevbit)
 {
 	int			nwords;
-	int			wordnum;
 	bitmapword	mask;
 
 	Assert(bms_is_valid_set(a));
@@ -1316,7 +1314,7 @@ bms_next_member(const Bitmapset *a, int prevbit)
 	nwords = a->nwords;
 	prevbit++;
 	mask = (~(bitmapword) 0) << BITNUM(prevbit);
-	for (wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
+	for (int wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
 	{
 		bitmapword	w = a->words[wordnum];
 
@@ -1366,7 +1364,6 @@ bms_next_member(const Bitmapset *a, int prevbit)
 int
 bms_prev_member(const Bitmapset *a, int prevbit)
 {
-	int			wordnum;
 	int			ushiftbits;
 	bitmapword	mask;
 
@@ -1391,7 +1388,7 @@ bms_prev_member(const Bitmapset *a, int prevbit)
 
 	ushiftbits = BITS_PER_BITMAPWORD - (BITNUM(prevbit) + 1);
 	mask = (~(bitmapword) 0) >> ushiftbits;
-	for (wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
+	for (int wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
 	{
 		bitmapword	w = a->words[wordnum];
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index ede838cd40c..d228318dc72 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4826,9 +4826,7 @@ planstate_walk_members(PlanState **planstates, int nplans,
 					   planstate_tree_walker_callback walker,
 					   void *context)
 {
-	int			j;
-
-	for (j = 0; j < nplans; j++)
+	for (int j = 0; j < nplans; j++)
 	{
 		if (PSWALK(planstates[j]))
 			return true;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index d9fe21a07e0..1ba590b71d6 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -346,8 +346,7 @@ outBitmapset(StringInfo str, const Bitmapset *bms)
 void
 outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 {
-	Size		length,
-				i;
+	Size		length;
 	char	   *s;
 
 	length = datumGetSize(value, typbyval, typlen);
@@ -356,7 +355,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 	{
 		s = (char *) (&value);
 		appendStringInfo(str, "%u [ ", (unsigned int) length);
-		for (i = 0; i < (Size) sizeof(Datum); i++)
+		for (int i = 0; i < (Size) sizeof(Datum); i++)
 			appendStringInfo(str, "%d ", (int) (s[i]));
 		appendStringInfoChar(str, ']');
 	}
@@ -368,7 +367,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 		else
 		{
 			appendStringInfo(str, "%u [ ", (unsigned int) length);
-			for (i = 0; i < length; i++)
+			for (int i = 0; i < length; i++)
 				appendStringInfo(str, "%d ", (int) (s[i]));
 			appendStringInfoChar(str, ']');
 		}
@@ -434,8 +433,6 @@ _outBoolExpr(StringInfo str, const BoolExpr *node)
 static void
 _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 {
-	int			i;
-
 	WRITE_NODE_TYPE("FOREIGNKEYOPTINFO");
 
 	WRITE_UINT_FIELD(con_relid);
@@ -450,10 +447,10 @@ _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 	WRITE_INT_FIELD(nmatched_ri);
 	/* for compactness, just print the number of matches per column: */
 	appendStringInfoString(str, " :eclass");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", (node->eclass[i] != NULL));
 	appendStringInfoString(str, " :rinfos");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", list_length(node->rinfos[i]));
 }
 
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index ec5946c5777..aeb8ace2c54 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -166,13 +166,12 @@ paramlist_param_ref(ParseState *pstate, ParamRef *pref)
 Size
 EstimateParamListSpace(ParamListInfo paramLI)
 {
-	int			i;
 	Size		sz = sizeof(int);
 
 	if (paramLI == NULL || paramLI->numParams <= 0)
 		return sz;
 
-	for (i = 0; i < paramLI->numParams; i++)
+	for (int i = 0; i < paramLI->numParams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
@@ -229,7 +228,6 @@ void
 SerializeParamList(ParamListInfo paramLI, char **start_address)
 {
 	int			nparams;
-	int			i;
 
 	/* Write number of parameters. */
 	if (paramLI == NULL || paramLI->numParams <= 0)
@@ -240,7 +238,7 @@ SerializeParamList(ParamListInfo paramLI, char **start_address)
 	*start_address += sizeof(int);
 
 	/* Write each parameter in turn. */
-	for (i = 0; i < nparams; i++)
+	for (int i = 0; i < nparams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 2f933e95cb9..609da808f32 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -599,8 +599,7 @@ parseNodeString(void)
 Datum
 readDatum(bool typbyval)
 {
-	Size		length,
-				i;
+	Size		length;
 	int			tokenLength;
 	const char *token;
 	Datum		res;
@@ -623,7 +622,7 @@ readDatum(bool typbyval)
 			elog(ERROR, "byval datum but length = %zu", length);
 		res = (Datum) 0;
 		s = (char *) (&res);
-		for (i = 0; i < (Size) sizeof(Datum); i++)
+		for (int i = 0; i < (Size) sizeof(Datum); i++)
 		{
 			token = pg_strtok(&tokenLength);
 			s[i] = (char) atoi(token);
@@ -634,7 +633,7 @@ readDatum(bool typbyval)
 	else
 	{
 		s = (char *) palloc(length);
-		for (i = 0; i < length; i++)
+		for (int i = 0; i < length; i++)
 		{
 			token = pg_strtok(&tokenLength);
 			s[i] = (char) atoi(token);
diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index 23d97b3a6c8..1f83d0d55f5 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -369,10 +369,9 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointerData *tids, int ntids,
 {
 	BlockNumber currblk = InvalidBlockNumber;
 	PagetableEntry *page = NULL;	/* only valid when currblk is valid */
-	int			i;
 
 	Assert(tbm->iterating == TBM_NOT_ITERATING);
-	for (i = 0; i < ntids; i++)
+	for (int i = 0; i < ntids; i++)
 	{
 		BlockNumber blk = ItemPointerGetBlockNumber(tids + i);
 		OffsetNumber off = ItemPointerGetOffsetNumber(tids + i);
@@ -471,12 +470,11 @@ static void
 tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 {
 	PagetableEntry *apage;
-	int			wordnum;
 
 	if (bpage->ischunk)
 	{
 		/* Scan b's chunk, mark each indicated page lossy in a */
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = bpage->words[wordnum];
 
@@ -511,7 +509,7 @@ tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 		else
 		{
 			/* Both pages are exact, merge at the bit level */
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 				apage->words[wordnum] |= bpage->words[wordnum];
 			apage->recheck |= bpage->recheck;
 		}
@@ -579,14 +577,13 @@ static bool
 tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 {
 	const PagetableEntry *bpage;
-	int			wordnum;
 
 	if (apage->ischunk)
 	{
 		/* Scan each bit in chunk, try to clear */
 		bool		candelete = true;
 
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = apage->words[wordnum];
 
@@ -640,7 +637,7 @@ tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 		{
 			/* Both pages are exact, merge at the bit level */
 			Assert(!bpage->ischunk);
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 			{
 				apage->words[wordnum] &= bpage->words[wordnum];
 				if (apage->words[wordnum] != 0)
@@ -904,10 +901,9 @@ tbm_extract_page_tuple(TBMIterateResult *iteritem,
 					   uint32 max_offsets)
 {
 	PagetableEntry *page = iteritem->internal_page;
-	int			wordnum;
 	int			ntuples = 0;
 
-	for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+	for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 	{
 		bitmapword	w = page->words[wordnum];
 
-- 
2.39.5 (Apple Git-154)

Chao Li

li.evan.chao@gmail.com

about 2 months ago

In reply to: Chao Li (#2)

Re: backend/nodes cleanup: Move loop variables definitions into for statement

Added to CF: https://commitfest.postgresql.org/patch/6227/

On Nov 14, 2025, at 21:52, Chao Li <li.evan.chao@gmail.com> wrote:

On Wed, Nov 12, 2025 at 4:00 PM Chao Li <li.evan.chao@gmail.com> wrote:
Hi Hackers,

While working on the other patch [1] that touched tbm_add_tuples() under src/backend/nodes, I moved a loop variable into for statement by the way as I knew Peter Eisentraut had done some efforts about that, see [2].

However, Peter removed that change from the patch and he said that should belong to a separate cleanup patch. So I am following up and moving loop variables into for statements wherever possible under src/backend/nodes.

[1] /messages/by-id/CAEoWx2m2E0xE8Kvbkv31ULh_E+5zph-WA_bEdv3UR9CLhw+3vg@mail.gmail.com
[2] https://git.postgresql.org/cgit/postgresql.git/commit/?id=03fbb0814c5015ab79e670ab97bb6a3349269e4b

Rebased to V2.

Best regards,
Chao Li (Evan)
---------------------
HighGo Software Co., Ltd.
https://www.highgo.com/

<v2-0001-backend-nodes-cleanup-Move-loop-variables-definit.patch>

--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/

Peter Eisentraut

peter@eisentraut.org

about 2 months ago

In reply to: Chao Li (#1)

Re: backend/nodes cleanup: Move loop variables definitions into for statement

On 12.11.25 09:00, Chao Li wrote:

While working on the other patch [1] that touched tbm_add_tuples() under
src/backend/nodes, I moved a loop variable into for statement by the way
as I knew Peter Eisentraut had done some efforts about that, see [2].

However, Peter removed that change from the patch and he said that
should belong to a separate cleanup patch. So I am following up and
moving loop variables into for statements wherever possible under src/
backend/nodes.

In a couple of cases, you are changing the type of the loop variable
from Size to int. I would not expect such a change in a patch of this
nature. If you have a reason to change it, please explain it (but I
doubt the change is correct).

Chao Li

li.evan.chao@gmail.com

about 2 months ago

In reply to: Peter Eisentraut (#4)

1 attachment(s)

Re: backend/nodes cleanup: Move loop variables definitions into for statement

On Wed, Nov 19, 2025 at 5:36 PM Peter Eisentraut <peter@eisentraut.org>
wrote:

In a couple of cases, you are changing the type of the loop variable
from Size to int. I would not expect such a change in a patch of this
nature. If you have a reason to change it, please explain it (but I
doubt the change is correct).

That was a mistake. I fixed it in v3.

Best regards,
Chao Li (Evan)
---------------------
HighGo Software Co., Ltd.
https://www.highgo.com/

Attachments:

v3-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchapplication/octet-stream; name=v3-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchDownload

From 19dd35a44725059d4a41793d86fcd839b3b1a70a Mon Sep 17 00:00:00 2001
From: "Chao Li (Evan)" <lic@highgo.com>
Date: Wed, 12 Nov 2025 15:53:15 +0800
Subject: [PATCH v3] backend/nodes cleanup: Move loop variables definitions
 into for statement

---
 src/backend/nodes/bitmapset.c |  9 +++------
 src/backend/nodes/nodeFuncs.c |  4 +---
 src/backend/nodes/outfuncs.c  | 13 +++++--------
 src/backend/nodes/params.c    |  6 ++----
 src/backend/nodes/readfuncs.c |  7 +++----
 src/backend/nodes/tidbitmap.c | 16 ++++++----------
 6 files changed, 20 insertions(+), 35 deletions(-)

diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c
index b4ecf0b0390..7b1e9d94103 100644
--- a/src/backend/nodes/bitmapset.c
+++ b/src/backend/nodes/bitmapset.c
@@ -538,7 +538,6 @@ bms_is_member(int x, const Bitmapset *a)
 int
 bms_member_index(Bitmapset *a, int x)
 {
-	int			i;
 	int			bitnum;
 	int			wordnum;
 	int			result = 0;
@@ -554,7 +553,7 @@ bms_member_index(Bitmapset *a, int x)
 	bitnum = BITNUM(x);
 
 	/* count bits in preceding words */
-	for (i = 0; i < wordnum; i++)
+	for (int i = 0; i < wordnum; i++)
 	{
 		bitmapword	w = a->words[i];
 
@@ -1306,7 +1305,6 @@ int
 bms_next_member(const Bitmapset *a, int prevbit)
 {
 	int			nwords;
-	int			wordnum;
 	bitmapword	mask;
 
 	Assert(bms_is_valid_set(a));
@@ -1316,7 +1314,7 @@ bms_next_member(const Bitmapset *a, int prevbit)
 	nwords = a->nwords;
 	prevbit++;
 	mask = (~(bitmapword) 0) << BITNUM(prevbit);
-	for (wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
+	for (int wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
 	{
 		bitmapword	w = a->words[wordnum];
 
@@ -1366,7 +1364,6 @@ bms_next_member(const Bitmapset *a, int prevbit)
 int
 bms_prev_member(const Bitmapset *a, int prevbit)
 {
-	int			wordnum;
 	int			ushiftbits;
 	bitmapword	mask;
 
@@ -1391,7 +1388,7 @@ bms_prev_member(const Bitmapset *a, int prevbit)
 
 	ushiftbits = BITS_PER_BITMAPWORD - (BITNUM(prevbit) + 1);
 	mask = (~(bitmapword) 0) >> ushiftbits;
-	for (wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
+	for (int wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
 	{
 		bitmapword	w = a->words[wordnum];
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index ede838cd40c..d228318dc72 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4826,9 +4826,7 @@ planstate_walk_members(PlanState **planstates, int nplans,
 					   planstate_tree_walker_callback walker,
 					   void *context)
 {
-	int			j;
-
-	for (j = 0; j < nplans; j++)
+	for (int j = 0; j < nplans; j++)
 	{
 		if (PSWALK(planstates[j]))
 			return true;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index d9fe21a07e0..1ba590b71d6 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -346,8 +346,7 @@ outBitmapset(StringInfo str, const Bitmapset *bms)
 void
 outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 {
-	Size		length,
-				i;
+	Size		length;
 	char	   *s;
 
 	length = datumGetSize(value, typbyval, typlen);
@@ -356,7 +355,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 	{
 		s = (char *) (&value);
 		appendStringInfo(str, "%u [ ", (unsigned int) length);
-		for (i = 0; i < (Size) sizeof(Datum); i++)
+		for (int i = 0; i < (Size) sizeof(Datum); i++)
 			appendStringInfo(str, "%d ", (int) (s[i]));
 		appendStringInfoChar(str, ']');
 	}
@@ -368,7 +367,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 		else
 		{
 			appendStringInfo(str, "%u [ ", (unsigned int) length);
-			for (i = 0; i < length; i++)
+			for (int i = 0; i < length; i++)
 				appendStringInfo(str, "%d ", (int) (s[i]));
 			appendStringInfoChar(str, ']');
 		}
@@ -434,8 +433,6 @@ _outBoolExpr(StringInfo str, const BoolExpr *node)
 static void
 _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 {
-	int			i;
-
 	WRITE_NODE_TYPE("FOREIGNKEYOPTINFO");
 
 	WRITE_UINT_FIELD(con_relid);
@@ -450,10 +447,10 @@ _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 	WRITE_INT_FIELD(nmatched_ri);
 	/* for compactness, just print the number of matches per column: */
 	appendStringInfoString(str, " :eclass");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", (node->eclass[i] != NULL));
 	appendStringInfoString(str, " :rinfos");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", list_length(node->rinfos[i]));
 }
 
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index ec5946c5777..aeb8ace2c54 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -166,13 +166,12 @@ paramlist_param_ref(ParseState *pstate, ParamRef *pref)
 Size
 EstimateParamListSpace(ParamListInfo paramLI)
 {
-	int			i;
 	Size		sz = sizeof(int);
 
 	if (paramLI == NULL || paramLI->numParams <= 0)
 		return sz;
 
-	for (i = 0; i < paramLI->numParams; i++)
+	for (int i = 0; i < paramLI->numParams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
@@ -229,7 +228,6 @@ void
 SerializeParamList(ParamListInfo paramLI, char **start_address)
 {
 	int			nparams;
-	int			i;
 
 	/* Write number of parameters. */
 	if (paramLI == NULL || paramLI->numParams <= 0)
@@ -240,7 +238,7 @@ SerializeParamList(ParamListInfo paramLI, char **start_address)
 	*start_address += sizeof(int);
 
 	/* Write each parameter in turn. */
-	for (i = 0; i < nparams; i++)
+	for (int i = 0; i < nparams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 2f933e95cb9..9a8ca27ec10 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -599,8 +599,7 @@ parseNodeString(void)
 Datum
 readDatum(bool typbyval)
 {
-	Size		length,
-				i;
+	Size		length;
 	int			tokenLength;
 	const char *token;
 	Datum		res;
@@ -623,7 +622,7 @@ readDatum(bool typbyval)
 			elog(ERROR, "byval datum but length = %zu", length);
 		res = (Datum) 0;
 		s = (char *) (&res);
-		for (i = 0; i < (Size) sizeof(Datum); i++)
+		for (Size i = 0; i < (Size) sizeof(Datum); i++)
 		{
 			token = pg_strtok(&tokenLength);
 			s[i] = (char) atoi(token);
@@ -634,7 +633,7 @@ readDatum(bool typbyval)
 	else
 	{
 		s = (char *) palloc(length);
-		for (i = 0; i < length; i++)
+		for (Size i = 0; i < length; i++)
 		{
 			token = pg_strtok(&tokenLength);
 			s[i] = (char) atoi(token);
diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index 23d97b3a6c8..1f83d0d55f5 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -369,10 +369,9 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointerData *tids, int ntids,
 {
 	BlockNumber currblk = InvalidBlockNumber;
 	PagetableEntry *page = NULL;	/* only valid when currblk is valid */
-	int			i;
 
 	Assert(tbm->iterating == TBM_NOT_ITERATING);
-	for (i = 0; i < ntids; i++)
+	for (int i = 0; i < ntids; i++)
 	{
 		BlockNumber blk = ItemPointerGetBlockNumber(tids + i);
 		OffsetNumber off = ItemPointerGetOffsetNumber(tids + i);
@@ -471,12 +470,11 @@ static void
 tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 {
 	PagetableEntry *apage;
-	int			wordnum;
 
 	if (bpage->ischunk)
 	{
 		/* Scan b's chunk, mark each indicated page lossy in a */
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = bpage->words[wordnum];
 
@@ -511,7 +509,7 @@ tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 		else
 		{
 			/* Both pages are exact, merge at the bit level */
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 				apage->words[wordnum] |= bpage->words[wordnum];
 			apage->recheck |= bpage->recheck;
 		}
@@ -579,14 +577,13 @@ static bool
 tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 {
 	const PagetableEntry *bpage;
-	int			wordnum;
 
 	if (apage->ischunk)
 	{
 		/* Scan each bit in chunk, try to clear */
 		bool		candelete = true;
 
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = apage->words[wordnum];
 
@@ -640,7 +637,7 @@ tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 		{
 			/* Both pages are exact, merge at the bit level */
 			Assert(!bpage->ischunk);
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 			{
 				apage->words[wordnum] &= bpage->words[wordnum];
 				if (apage->words[wordnum] != 0)
@@ -904,10 +901,9 @@ tbm_extract_page_tuple(TBMIterateResult *iteritem,
 					   uint32 max_offsets)
 {
 	PagetableEntry *page = iteritem->internal_page;
-	int			wordnum;
 	int			ntuples = 0;
 
-	for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+	for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 	{
 		bitmapword	w = page->words[wordnum];
 
-- 
2.39.5 (Apple Git-154)

Peter Eisentraut

peter@eisentraut.org

about 2 months ago

In reply to: Chao Li (#5)

Re: backend/nodes cleanup: Move loop variables definitions into for statement

On 19.11.25 11:32, Chao Li wrote:

On Wed, Nov 19, 2025 at 5:36 PM Peter Eisentraut <peter@eisentraut.org
<mailto:peter@eisentraut.org>> wrote:

In a couple of cases, you are changing the type of the loop variable
from Size to int. I would not expect such a change in a patch of this
nature. If you have a reason to change it, please explain it (but I
doubt the change is correct).

That was a mistake. I fixed it in v3.

Still not correct in outDatum().

Chao Li

li.evan.chao@gmail.com

about 2 months ago

In reply to: Peter Eisentraut (#6)

1 attachment(s)

Re: backend/nodes cleanup: Move loop variables definitions into for statement

On Mon, Nov 24, 2025 at 11:00 PM Peter Eisentraut <peter@eisentraut.org>
wrote:

On 19.11.25 11:32, Chao Li wrote:

On Wed, Nov 19, 2025 at 5:36 PM Peter Eisentraut <peter@eisentraut.org
<mailto:peter@eisentraut.org>> wrote:

In a couple of cases, you are changing the type of the loop variable
from Size to int. I would not expect such a change in a patch of

this

nature. If you have a reason to change it, please explain it (but I
doubt the change is correct).

That was a mistake. I fixed it in v3.

Still not correct in outDatum().

Oops! Fixed in v4.

Best regards,
Chao Li (Evan)
---------------------
HighGo Software Co., Ltd.
https://www.highgo.com/

Attachments:

v4-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchapplication/octet-stream; name=v4-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchDownload

From d11a41943be3e768c0ff7115fc92eb985df91f29 Mon Sep 17 00:00:00 2001
From: "Chao Li (Evan)" <lic@highgo.com>
Date: Wed, 12 Nov 2025 15:53:15 +0800
Subject: [PATCH v4] backend/nodes cleanup: Move loop variables definitions
 into for statement

---
 src/backend/nodes/bitmapset.c |  9 +++------
 src/backend/nodes/nodeFuncs.c |  4 +---
 src/backend/nodes/outfuncs.c  | 13 +++++--------
 src/backend/nodes/params.c    |  6 ++----
 src/backend/nodes/readfuncs.c |  7 +++----
 src/backend/nodes/tidbitmap.c | 16 ++++++----------
 6 files changed, 20 insertions(+), 35 deletions(-)

diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c
index b4ecf0b0390..7b1e9d94103 100644
--- a/src/backend/nodes/bitmapset.c
+++ b/src/backend/nodes/bitmapset.c
@@ -538,7 +538,6 @@ bms_is_member(int x, const Bitmapset *a)
 int
 bms_member_index(Bitmapset *a, int x)
 {
-	int			i;
 	int			bitnum;
 	int			wordnum;
 	int			result = 0;
@@ -554,7 +553,7 @@ bms_member_index(Bitmapset *a, int x)
 	bitnum = BITNUM(x);
 
 	/* count bits in preceding words */
-	for (i = 0; i < wordnum; i++)
+	for (int i = 0; i < wordnum; i++)
 	{
 		bitmapword	w = a->words[i];
 
@@ -1306,7 +1305,6 @@ int
 bms_next_member(const Bitmapset *a, int prevbit)
 {
 	int			nwords;
-	int			wordnum;
 	bitmapword	mask;
 
 	Assert(bms_is_valid_set(a));
@@ -1316,7 +1314,7 @@ bms_next_member(const Bitmapset *a, int prevbit)
 	nwords = a->nwords;
 	prevbit++;
 	mask = (~(bitmapword) 0) << BITNUM(prevbit);
-	for (wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
+	for (int wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
 	{
 		bitmapword	w = a->words[wordnum];
 
@@ -1366,7 +1364,6 @@ bms_next_member(const Bitmapset *a, int prevbit)
 int
 bms_prev_member(const Bitmapset *a, int prevbit)
 {
-	int			wordnum;
 	int			ushiftbits;
 	bitmapword	mask;
 
@@ -1391,7 +1388,7 @@ bms_prev_member(const Bitmapset *a, int prevbit)
 
 	ushiftbits = BITS_PER_BITMAPWORD - (BITNUM(prevbit) + 1);
 	mask = (~(bitmapword) 0) >> ushiftbits;
-	for (wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
+	for (int wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
 	{
 		bitmapword	w = a->words[wordnum];
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index ede838cd40c..d228318dc72 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4826,9 +4826,7 @@ planstate_walk_members(PlanState **planstates, int nplans,
 					   planstate_tree_walker_callback walker,
 					   void *context)
 {
-	int			j;
-
-	for (j = 0; j < nplans; j++)
+	for (int j = 0; j < nplans; j++)
 	{
 		if (PSWALK(planstates[j]))
 			return true;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index d9fe21a07e0..0abca9f803b 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -346,8 +346,7 @@ outBitmapset(StringInfo str, const Bitmapset *bms)
 void
 outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 {
-	Size		length,
-				i;
+	Size		length;
 	char	   *s;
 
 	length = datumGetSize(value, typbyval, typlen);
@@ -356,7 +355,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 	{
 		s = (char *) (&value);
 		appendStringInfo(str, "%u [ ", (unsigned int) length);
-		for (i = 0; i < (Size) sizeof(Datum); i++)
+		for (Size i = 0; i < (Size) sizeof(Datum); i++)
 			appendStringInfo(str, "%d ", (int) (s[i]));
 		appendStringInfoChar(str, ']');
 	}
@@ -368,7 +367,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 		else
 		{
 			appendStringInfo(str, "%u [ ", (unsigned int) length);
-			for (i = 0; i < length; i++)
+			for (Size i = 0; i < length; i++)
 				appendStringInfo(str, "%d ", (int) (s[i]));
 			appendStringInfoChar(str, ']');
 		}
@@ -434,8 +433,6 @@ _outBoolExpr(StringInfo str, const BoolExpr *node)
 static void
 _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 {
-	int			i;
-
 	WRITE_NODE_TYPE("FOREIGNKEYOPTINFO");
 
 	WRITE_UINT_FIELD(con_relid);
@@ -450,10 +447,10 @@ _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 	WRITE_INT_FIELD(nmatched_ri);
 	/* for compactness, just print the number of matches per column: */
 	appendStringInfoString(str, " :eclass");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", (node->eclass[i] != NULL));
 	appendStringInfoString(str, " :rinfos");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", list_length(node->rinfos[i]));
 }
 
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index ec5946c5777..aeb8ace2c54 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -166,13 +166,12 @@ paramlist_param_ref(ParseState *pstate, ParamRef *pref)
 Size
 EstimateParamListSpace(ParamListInfo paramLI)
 {
-	int			i;
 	Size		sz = sizeof(int);
 
 	if (paramLI == NULL || paramLI->numParams <= 0)
 		return sz;
 
-	for (i = 0; i < paramLI->numParams; i++)
+	for (int i = 0; i < paramLI->numParams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
@@ -229,7 +228,6 @@ void
 SerializeParamList(ParamListInfo paramLI, char **start_address)
 {
 	int			nparams;
-	int			i;
 
 	/* Write number of parameters. */
 	if (paramLI == NULL || paramLI->numParams <= 0)
@@ -240,7 +238,7 @@ SerializeParamList(ParamListInfo paramLI, char **start_address)
 	*start_address += sizeof(int);
 
 	/* Write each parameter in turn. */
-	for (i = 0; i < nparams; i++)
+	for (int i = 0; i < nparams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 2f933e95cb9..9a8ca27ec10 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -599,8 +599,7 @@ parseNodeString(void)
 Datum
 readDatum(bool typbyval)
 {
-	Size		length,
-				i;
+	Size		length;
 	int			tokenLength;
 	const char *token;
 	Datum		res;
@@ -623,7 +622,7 @@ readDatum(bool typbyval)
 			elog(ERROR, "byval datum but length = %zu", length);
 		res = (Datum) 0;
 		s = (char *) (&res);
-		for (i = 0; i < (Size) sizeof(Datum); i++)
+		for (Size i = 0; i < (Size) sizeof(Datum); i++)
 		{
 			token = pg_strtok(&tokenLength);
 			s[i] = (char) atoi(token);
@@ -634,7 +633,7 @@ readDatum(bool typbyval)
 	else
 	{
 		s = (char *) palloc(length);
-		for (i = 0; i < length; i++)
+		for (Size i = 0; i < length; i++)
 		{
 			token = pg_strtok(&tokenLength);
 			s[i] = (char) atoi(token);
diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index 23d97b3a6c8..1f83d0d55f5 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -369,10 +369,9 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointerData *tids, int ntids,
 {
 	BlockNumber currblk = InvalidBlockNumber;
 	PagetableEntry *page = NULL;	/* only valid when currblk is valid */
-	int			i;
 
 	Assert(tbm->iterating == TBM_NOT_ITERATING);
-	for (i = 0; i < ntids; i++)
+	for (int i = 0; i < ntids; i++)
 	{
 		BlockNumber blk = ItemPointerGetBlockNumber(tids + i);
 		OffsetNumber off = ItemPointerGetOffsetNumber(tids + i);
@@ -471,12 +470,11 @@ static void
 tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 {
 	PagetableEntry *apage;
-	int			wordnum;
 
 	if (bpage->ischunk)
 	{
 		/* Scan b's chunk, mark each indicated page lossy in a */
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = bpage->words[wordnum];
 
@@ -511,7 +509,7 @@ tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 		else
 		{
 			/* Both pages are exact, merge at the bit level */
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 				apage->words[wordnum] |= bpage->words[wordnum];
 			apage->recheck |= bpage->recheck;
 		}
@@ -579,14 +577,13 @@ static bool
 tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 {
 	const PagetableEntry *bpage;
-	int			wordnum;
 
 	if (apage->ischunk)
 	{
 		/* Scan each bit in chunk, try to clear */
 		bool		candelete = true;
 
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = apage->words[wordnum];
 
@@ -640,7 +637,7 @@ tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 		{
 			/* Both pages are exact, merge at the bit level */
 			Assert(!bpage->ischunk);
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 			{
 				apage->words[wordnum] &= bpage->words[wordnum];
 				if (apage->words[wordnum] != 0)
@@ -904,10 +901,9 @@ tbm_extract_page_tuple(TBMIterateResult *iteritem,
 					   uint32 max_offsets)
 {
 	PagetableEntry *page = iteritem->internal_page;
-	int			wordnum;
 	int			ntuples = 0;
 
-	for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+	for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 	{
 		bitmapword	w = page->words[wordnum];
 
-- 
2.39.5 (Apple Git-154)

Chao Li

li.evan.chao@gmail.com

about 2 months ago

In reply to: Chao Li (#7)

1 attachment(s)

Re: backend/nodes cleanup: Move loop variables definitions into for statement

On Tue, Nov 25, 2025 at 7:38 AM Chao Li <li.evan.chao@gmail.com> wrote:

On Mon, Nov 24, 2025 at 11:00 PM Peter Eisentraut <peter@eisentraut.org>
wrote:

On 19.11.25 11:32, Chao Li wrote:

On Wed, Nov 19, 2025 at 5:36 PM Peter Eisentraut <peter@eisentraut.org
<mailto:peter@eisentraut.org>> wrote:

In a couple of cases, you are changing the type of the loop variable
from Size to int. I would not expect such a change in a patch of

this

nature. If you have a reason to change it, please explain it (but I
doubt the change is correct).

That was a mistake. I fixed it in v3.

Still not correct in outDatum().

Oops! Fixed in v4.

Rebased to v5.

Chao Li (Evan)
---------------------
HighGo Software Co., Ltd.
https://www.highgo.com/

Attachments:

v5-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchapplication/octet-stream; name=v5-0001-backend-nodes-cleanup-Move-loop-variables-definit.patchDownload

From ba4fa56bff961ddf35bb26147d92c097c46b0bda Mon Sep 17 00:00:00 2001
From: "Chao Li (Evan)" <lic@highgo.com>
Date: Wed, 12 Nov 2025 15:53:15 +0800
Subject: [PATCH v5] backend/nodes cleanup: Move loop variables definitions
 into for statement

---
 src/backend/nodes/bitmapset.c |  9 +++------
 src/backend/nodes/nodeFuncs.c |  4 +---
 src/backend/nodes/outfuncs.c  | 13 +++++--------
 src/backend/nodes/params.c    |  6 ++----
 src/backend/nodes/readfuncs.c |  7 +++----
 src/backend/nodes/tidbitmap.c | 16 ++++++----------
 6 files changed, 20 insertions(+), 35 deletions(-)

diff --git a/src/backend/nodes/bitmapset.c b/src/backend/nodes/bitmapset.c
index b4ecf0b0390..7b1e9d94103 100644
--- a/src/backend/nodes/bitmapset.c
+++ b/src/backend/nodes/bitmapset.c
@@ -538,7 +538,6 @@ bms_is_member(int x, const Bitmapset *a)
 int
 bms_member_index(Bitmapset *a, int x)
 {
-	int			i;
 	int			bitnum;
 	int			wordnum;
 	int			result = 0;
@@ -554,7 +553,7 @@ bms_member_index(Bitmapset *a, int x)
 	bitnum = BITNUM(x);
 
 	/* count bits in preceding words */
-	for (i = 0; i < wordnum; i++)
+	for (int i = 0; i < wordnum; i++)
 	{
 		bitmapword	w = a->words[i];
 
@@ -1306,7 +1305,6 @@ int
 bms_next_member(const Bitmapset *a, int prevbit)
 {
 	int			nwords;
-	int			wordnum;
 	bitmapword	mask;
 
 	Assert(bms_is_valid_set(a));
@@ -1316,7 +1314,7 @@ bms_next_member(const Bitmapset *a, int prevbit)
 	nwords = a->nwords;
 	prevbit++;
 	mask = (~(bitmapword) 0) << BITNUM(prevbit);
-	for (wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
+	for (int wordnum = WORDNUM(prevbit); wordnum < nwords; wordnum++)
 	{
 		bitmapword	w = a->words[wordnum];
 
@@ -1366,7 +1364,6 @@ bms_next_member(const Bitmapset *a, int prevbit)
 int
 bms_prev_member(const Bitmapset *a, int prevbit)
 {
-	int			wordnum;
 	int			ushiftbits;
 	bitmapword	mask;
 
@@ -1391,7 +1388,7 @@ bms_prev_member(const Bitmapset *a, int prevbit)
 
 	ushiftbits = BITS_PER_BITMAPWORD - (BITNUM(prevbit) + 1);
 	mask = (~(bitmapword) 0) >> ushiftbits;
-	for (wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
+	for (int wordnum = WORDNUM(prevbit); wordnum >= 0; wordnum--)
 	{
 		bitmapword	w = a->words[wordnum];
 
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index ede838cd40c..d228318dc72 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -4826,9 +4826,7 @@ planstate_walk_members(PlanState **planstates, int nplans,
 					   planstate_tree_walker_callback walker,
 					   void *context)
 {
-	int			j;
-
-	for (j = 0; j < nplans; j++)
+	for (int j = 0; j < nplans; j++)
 	{
 		if (PSWALK(planstates[j]))
 			return true;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index d9fe21a07e0..0abca9f803b 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -346,8 +346,7 @@ outBitmapset(StringInfo str, const Bitmapset *bms)
 void
 outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 {
-	Size		length,
-				i;
+	Size		length;
 	char	   *s;
 
 	length = datumGetSize(value, typbyval, typlen);
@@ -356,7 +355,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 	{
 		s = (char *) (&value);
 		appendStringInfo(str, "%u [ ", (unsigned int) length);
-		for (i = 0; i < (Size) sizeof(Datum); i++)
+		for (Size i = 0; i < (Size) sizeof(Datum); i++)
 			appendStringInfo(str, "%d ", (int) (s[i]));
 		appendStringInfoChar(str, ']');
 	}
@@ -368,7 +367,7 @@ outDatum(StringInfo str, Datum value, int typlen, bool typbyval)
 		else
 		{
 			appendStringInfo(str, "%u [ ", (unsigned int) length);
-			for (i = 0; i < length; i++)
+			for (Size i = 0; i < length; i++)
 				appendStringInfo(str, "%d ", (int) (s[i]));
 			appendStringInfoChar(str, ']');
 		}
@@ -434,8 +433,6 @@ _outBoolExpr(StringInfo str, const BoolExpr *node)
 static void
 _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 {
-	int			i;
-
 	WRITE_NODE_TYPE("FOREIGNKEYOPTINFO");
 
 	WRITE_UINT_FIELD(con_relid);
@@ -450,10 +447,10 @@ _outForeignKeyOptInfo(StringInfo str, const ForeignKeyOptInfo *node)
 	WRITE_INT_FIELD(nmatched_ri);
 	/* for compactness, just print the number of matches per column: */
 	appendStringInfoString(str, " :eclass");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", (node->eclass[i] != NULL));
 	appendStringInfoString(str, " :rinfos");
-	for (i = 0; i < node->nkeys; i++)
+	for (int i = 0; i < node->nkeys; i++)
 		appendStringInfo(str, " %d", list_length(node->rinfos[i]));
 }
 
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index ec5946c5777..aeb8ace2c54 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -166,13 +166,12 @@ paramlist_param_ref(ParseState *pstate, ParamRef *pref)
 Size
 EstimateParamListSpace(ParamListInfo paramLI)
 {
-	int			i;
 	Size		sz = sizeof(int);
 
 	if (paramLI == NULL || paramLI->numParams <= 0)
 		return sz;
 
-	for (i = 0; i < paramLI->numParams; i++)
+	for (int i = 0; i < paramLI->numParams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
@@ -229,7 +228,6 @@ void
 SerializeParamList(ParamListInfo paramLI, char **start_address)
 {
 	int			nparams;
-	int			i;
 
 	/* Write number of parameters. */
 	if (paramLI == NULL || paramLI->numParams <= 0)
@@ -240,7 +238,7 @@ SerializeParamList(ParamListInfo paramLI, char **start_address)
 	*start_address += sizeof(int);
 
 	/* Write each parameter in turn. */
-	for (i = 0; i < nparams; i++)
+	for (int i = 0; i < nparams; i++)
 	{
 		ParamExternData *prm;
 		ParamExternData prmdata;
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 2f933e95cb9..9a8ca27ec10 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -599,8 +599,7 @@ parseNodeString(void)
 Datum
 readDatum(bool typbyval)
 {
-	Size		length,
-				i;
+	Size		length;
 	int			tokenLength;
 	const char *token;
 	Datum		res;
@@ -623,7 +622,7 @@ readDatum(bool typbyval)
 			elog(ERROR, "byval datum but length = %zu", length);
 		res = (Datum) 0;
 		s = (char *) (&res);
-		for (i = 0; i < (Size) sizeof(Datum); i++)
+		for (Size i = 0; i < (Size) sizeof(Datum); i++)
 		{
 			token = pg_strtok(&tokenLength);
 			s[i] = (char) atoi(token);
@@ -634,7 +633,7 @@ readDatum(bool typbyval)
 	else
 	{
 		s = (char *) palloc(length);
-		for (i = 0; i < length; i++)
+		for (Size i = 0; i < length; i++)
 		{
 			token = pg_strtok(&tokenLength);
 			s[i] = (char) atoi(token);
diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index 23d97b3a6c8..1f83d0d55f5 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -369,10 +369,9 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointerData *tids, int ntids,
 {
 	BlockNumber currblk = InvalidBlockNumber;
 	PagetableEntry *page = NULL;	/* only valid when currblk is valid */
-	int			i;
 
 	Assert(tbm->iterating == TBM_NOT_ITERATING);
-	for (i = 0; i < ntids; i++)
+	for (int i = 0; i < ntids; i++)
 	{
 		BlockNumber blk = ItemPointerGetBlockNumber(tids + i);
 		OffsetNumber off = ItemPointerGetOffsetNumber(tids + i);
@@ -471,12 +470,11 @@ static void
 tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 {
 	PagetableEntry *apage;
-	int			wordnum;
 
 	if (bpage->ischunk)
 	{
 		/* Scan b's chunk, mark each indicated page lossy in a */
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = bpage->words[wordnum];
 
@@ -511,7 +509,7 @@ tbm_union_page(TIDBitmap *a, const PagetableEntry *bpage)
 		else
 		{
 			/* Both pages are exact, merge at the bit level */
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 				apage->words[wordnum] |= bpage->words[wordnum];
 			apage->recheck |= bpage->recheck;
 		}
@@ -579,14 +577,13 @@ static bool
 tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 {
 	const PagetableEntry *bpage;
-	int			wordnum;
 
 	if (apage->ischunk)
 	{
 		/* Scan each bit in chunk, try to clear */
 		bool		candelete = true;
 
-		for (wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
+		for (int wordnum = 0; wordnum < WORDS_PER_CHUNK; wordnum++)
 		{
 			bitmapword	w = apage->words[wordnum];
 
@@ -640,7 +637,7 @@ tbm_intersect_page(TIDBitmap *a, PagetableEntry *apage, const TIDBitmap *b)
 		{
 			/* Both pages are exact, merge at the bit level */
 			Assert(!bpage->ischunk);
-			for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+			for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 			{
 				apage->words[wordnum] &= bpage->words[wordnum];
 				if (apage->words[wordnum] != 0)
@@ -904,10 +901,9 @@ tbm_extract_page_tuple(TBMIterateResult *iteritem,
 					   uint32 max_offsets)
 {
 	PagetableEntry *page = iteritem->internal_page;
-	int			wordnum;
 	int			ntuples = 0;
 
-	for (wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
+	for (int wordnum = 0; wordnum < WORDS_PER_PAGE; wordnum++)
 	{
 		bitmapword	w = page->words[wordnum];
 
-- 
2.39.5 (Apple Git-154)

Peter Eisentraut

peter@eisentraut.org

about 2 months ago

In reply to: Chao Li (#8)

Re: backend/nodes cleanup: Move loop variables definitions into for statement

On 25.11.25 04:46, Chao Li wrote:

On Tue, Nov 25, 2025 at 7:38 AM Chao Li <li.evan.chao@gmail.com
<mailto:li.evan.chao@gmail.com>> wrote:

On Mon, Nov 24, 2025 at 11:00 PM Peter Eisentraut
<peter@eisentraut.org <mailto:peter@eisentraut.org>> wrote:

On 19.11.25 11:32, Chao Li wrote:

On Wed, Nov 19, 2025 at 5:36 PM Peter Eisentraut

<peter@eisentraut.org <mailto:peter@eisentraut.org>

<mailto:peter@eisentraut.org <mailto:peter@eisentraut.org>>>

wrote:

In a couple of cases, you are changing the type of the

loop variable

from Size to int. I would not expect such a change in a

patch of this

nature. If you have a reason to change it, please

explain it (but I

doubt the change is correct).

That was a mistake. I fixed it in v3.

Still not correct in outDatum().

Oops! Fixed in v4.

Rebased to v5.

committed