Fix for loop variables

A number of for loops used loop variables that did not match the type
of the end condition.  This could lead to wraparound or
signed/unsigned mismatches.  Probably none of these are a problem in
practice, but it's fragile code.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/d639aede-209f-412b-927a-d38d4848b370%40eisentraut.org

contrib/pageinspect/fsmfuncs.c

@@ -38,7 +38,6 @@ fsm_page_contents(PG_FUNCTION_ARGS)
 	StringInfoData sinfo;
 	Page		page;
 	FSMPage		fsmpage;
-	int			i;
 
 	if (!superuser())
 		ereport(ERROR,
@@ -54,10 +53,10 @@ fsm_page_contents(PG_FUNCTION_ARGS)
 
 	initStringInfo(&sinfo);
 
-	for (i = 0; i < NodesPerPage; i++)
+	for (size_t i = 0; i < NodesPerPage; i++)
 	{
 		if (fsmpage->fp_nodes[i] != 0)
-			appendStringInfo(&sinfo, "%d: %d\n", i, fsmpage->fp_nodes[i]);
+			appendStringInfo(&sinfo, "%zu: %d\n", i, fsmpage->fp_nodes[i]);
 	}
 	appendStringInfo(&sinfo, "fp_next_slot: %d\n", fsmpage->fp_next_slot);
 

contrib/pageinspect/hashfuncs.c

@@ -404,8 +404,7 @@ hash_bitmap_info(PG_FUNCTION_ARGS)
 	int32		bitmappage,
 				bitmapbit;
 	HeapTuple	tuple;
-	int			i,
-				j;
+	int			j;
 	Datum		values[3];
 	bool		nulls[3] = {0};
 	uint32	   *freep;
@@ -456,7 +455,7 @@ hash_bitmap_info(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("invalid overflow block number %u",
 						(BlockNumber) ovflblkno)));
-	for (i = 0; i < metap->hashm_nmaps; i++)
+	for (uint32 i = 0; i < metap->hashm_nmaps; i++)
 		if (metap->hashm_mapp[i] == ovflblkno)
 			ereport(ERROR,
 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),

contrib/pg_logicalinspect/pg_logicalinspect.c

@@ -170,7 +170,7 @@ pg_get_logical_snapshot_info(PG_FUNCTION_ARGS)
 
 		arrayelems = (Datum *) palloc(ondisk.builder.committed.xcnt * sizeof(Datum));
 
-		for (int j = 0; j < ondisk.builder.committed.xcnt; j++)
+		for (size_t j = 0; j < ondisk.builder.committed.xcnt; j++)
 			arrayelems[j] = TransactionIdGetDatum(ondisk.builder.committed.xip[j]);
 
 		values[i++] = PointerGetDatum(construct_array_builtin(arrayelems,
@@ -187,7 +187,7 @@ pg_get_logical_snapshot_info(PG_FUNCTION_ARGS)
 
 		arrayelems = (Datum *) palloc(ondisk.builder.catchange.xcnt * sizeof(Datum));
 
-		for (int j = 0; j < ondisk.builder.catchange.xcnt; j++)
+		for (size_t j = 0; j < ondisk.builder.catchange.xcnt; j++)
 			arrayelems[j] = TransactionIdGetDatum(ondisk.builder.catchange.xip[j]);
 
 		values[i++] = PointerGetDatum(construct_array_builtin(arrayelems,

contrib/pg_plan_advice/pgpa_identifier.c

@@ -355,7 +355,7 @@ pgpa_compute_rti_from_identifier(int rtable_length,
 {
 	Index		result = 0;
 
-	for (Index rti = 1; rti <= rtable_length; ++rti)
+	for (int rti = 1; rti <= rtable_length; ++rti)
 	{
 		pgpa_identifier *rti_rid = &rt_identifiers[rti - 1];
 

contrib/pg_plan_advice/pgpa_join.c

@@ -231,7 +231,6 @@ pgpa_build_unrolled_join(pgpa_plan_walker_context *walker,
 						 pgpa_join_unroller *join_unroller)
 {
 	pgpa_unrolled_join *ujoin;
-	int			i;
 
 	/*
 	 * We shouldn't have gone even so far as to create a join unroller unless
@@ -260,7 +259,7 @@ pgpa_build_unrolled_join(pgpa_plan_walker_context *walker,
 	 * the reverse of that order, so we need to flip the order of the arrays
 	 * when constructing the final result.
 	 */
-	for (i = 0; i < join_unroller->nused; ++i)
+	for (unsigned i = 0; i < join_unroller->nused; ++i)
 	{
 		int			k = join_unroller->nused - i - 1;
 

contrib/pg_plan_advice/pgpa_output.c

@@ -95,7 +95,7 @@ pgpa_output_advice(StringInfo buf, pgpa_plan_walker_context *walker,
 	 * portion of the query didn't make it into the final plan.
 	 */
 	context.rid_strings = palloc0_array(const char *, rtable_length);
-	for (int i = 0; i < rtable_length; ++i)
+	for (Index i = 0; i < rtable_length; ++i)
 		if (rt_identifiers[i].alias_name != NULL)
 			context.rid_strings[i] = pgpa_identifier_string(&rt_identifiers[i]);
 
@@ -173,7 +173,7 @@ pgpa_output_unrolled_join(pgpa_output_context *context,
 {
 	pgpa_output_join_member(context, &join->outer);
 
-	for (int k = 0; k < join->ninner; ++k)
+	for (unsigned k = 0; k < join->ninner; ++k)
 	{
 		pgpa_join_member *member = &join->inner[k];
 

contrib/pg_plan_advice/pgpa_walker.c

@@ -502,7 +502,7 @@ pgpa_process_unrolled_join(pgpa_plan_walker_context *walker,
 	/* If this fails, we didn't unroll properly. */
 	Assert(ujoin->outer.unrolled_join == NULL);
 
-	for (int k = 0; k < ujoin->ninner; ++k)
+	for (unsigned k = 0; k < ujoin->ninner; ++k)
 	{
 		pgpa_join_member *member = &ujoin->inner[k];
 		Bitmapset  *relids;

contrib/pg_trgm/trgm_gist.c

@@ -535,10 +535,9 @@ gtrgm_distance(PG_FUNCTION_ARGS)
 static int32
 unionkey(BITVECP sbase, TRGM *add, int siglen)
 {
-	int32		i;
-
 	if (ISSIGNKEY(add))
 	{
+		int32		i;
 		BITVECP		sadd = GETSIGN(add);
 
 		if (ISALLTRUE(add))
@@ -552,7 +551,7 @@ unionkey(BITVECP sbase, TRGM *add, int siglen)
 		trgm	   *ptr = GETARR(add);
 		int32		tmp = 0;
 
-		for (i = 0; i < ARRNELEM(add); i++)
+		for (unsigned i = 0; i < ARRNELEM(add); i++)
 		{
 			CPTRGM(&tmp, ptr + i);
 			HASH(sbase, tmp, siglen);

src/backend/access/gin/ginget.c

@@ -507,8 +507,6 @@ static void
 startScanKey(GinState *ginstate, GinScanOpaque so, GinScanKey key)
 {
 	MemoryContext oldCtx = CurrentMemoryContext;
-	int			i;
-	int			j;
 	int		   *entryIndexes;
 
 	ItemPointerSetMin(&key->curItem);
@@ -545,11 +543,14 @@ startScanKey(GinState *ginstate, GinScanOpaque so, GinScanKey key)
 		key->nrequired = 0;
 		key->nadditional = key->nentries;
 		key->additionalEntries = palloc(key->nadditional * sizeof(GinScanEntry));
-		for (i = 0; i < key->nadditional; i++)
+		for (int i = 0; i < key->nadditional; i++)
 			key->additionalEntries[i] = key->scanEntry[i];
 	}
 	else if (key->nentries > 1)
 	{
+		uint32		i;
+		int			j;
+
 		MemoryContextSwitchTo(so->tempCtx);
 
 		entryIndexes = palloc_array(int, key->nentries);
@@ -581,10 +582,10 @@ startScanKey(GinState *ginstate, GinScanOpaque so, GinScanKey key)
 		key->additionalEntries = palloc(key->nadditional * sizeof(GinScanEntry));
 
 		j = 0;
-		for (i = 0; i < key->nrequired; i++)
-			key->requiredEntries[i] = key->scanEntry[entryIndexes[j++]];
-		for (i = 0; i < key->nadditional; i++)
-			key->additionalEntries[i] = key->scanEntry[entryIndexes[j++]];
+		for (int k = 0; k < key->nrequired; k++)
+			key->requiredEntries[k] = key->scanEntry[entryIndexes[j++]];
+		for (int k = 0; k < key->nadditional; k++)
+			key->additionalEntries[k] = key->scanEntry[entryIndexes[j++]];
 
 		/* clean up after consistentFn calls (also frees entryIndexes) */
 		MemoryContextReset(so->tempCtx);
@@ -1007,7 +1008,6 @@ keyGetItem(GinState *ginstate, MemoryContext tempCtx, GinScanKey key,
 {
 	ItemPointerData minItem;
 	ItemPointerData curPageLossy;
-	uint32		i;
 	bool		haveLossyEntry;
 	GinScanEntry entry;
 	GinTernaryValue res;
@@ -1034,7 +1034,7 @@ keyGetItem(GinState *ginstate, MemoryContext tempCtx, GinScanKey key,
 	 */
 	ItemPointerSetMax(&minItem);
 	allFinished = true;
-	for (i = 0; i < key->nrequired; i++)
+	for (int i = 0; i < key->nrequired; i++)
 	{
 		entry = key->requiredEntries[i];
 
@@ -1116,7 +1116,7 @@ keyGetItem(GinState *ginstate, MemoryContext tempCtx, GinScanKey key,
 	 * decide with partial information, that could be a big loss. So, load all
 	 * the additional entries, before calling the consistent function.
 	 */
-	for (i = 0; i < key->nadditional; i++)
+	for (int i = 0; i < key->nadditional; i++)
 	{
 		entry = key->additionalEntries[i];
 
@@ -1176,7 +1176,7 @@ keyGetItem(GinState *ginstate, MemoryContext tempCtx, GinScanKey key,
 	ItemPointerSetLossyPage(&curPageLossy,
 							GinItemPointerGetBlockNumber(&key->curItem));
 	haveLossyEntry = false;
-	for (i = 0; i < key->nentries; i++)
+	for (uint32 i = 0; i < key->nentries; i++)
 	{
 		entry = key->scanEntry[i];
 		if (entry->isFinished == false &&
@@ -1224,7 +1224,7 @@ keyGetItem(GinState *ginstate, MemoryContext tempCtx, GinScanKey key,
 	 *
 	 * Prepare entryRes array to be passed to consistentFn.
 	 */
-	for (i = 0; i < key->nentries; i++)
+	for (uint32 i = 0; i < key->nentries; i++)
 	{
 		entry = key->scanEntry[i];
 		if (entry->isFinished)
@@ -1625,13 +1625,11 @@ collectMatchesForHeapRow(IndexScanDesc scan, pendingPosition *pos)
 	OffsetNumber attrnum;
 	Page		page;
 	IndexTuple	itup;
-	int			i,
-				j;
 
 	/*
 	 * Reset all entryRes and hasMatchKey flags
 	 */
-	for (i = 0; i < so->nkeys; i++)
+	for (uint32 i = 0; i < so->nkeys; i++)
 	{
 		GinScanKey	key = so->keys + i;
 
@@ -1655,11 +1653,11 @@ collectMatchesForHeapRow(IndexScanDesc scan, pendingPosition *pos)
 
 		page = BufferGetPage(pos->pendingBuffer);
 
-		for (i = 0; i < so->nkeys; i++)
+		for (uint32 i = 0; i < so->nkeys; i++)
 		{
 			GinScanKey	key = so->keys + i;
 
-			for (j = 0; j < key->nentries; j++)
+			for (uint32 j = 0; j < key->nentries; j++)
 			{
 				GinScanEntry entry = key->scanEntry[j];
 				OffsetNumber StopLow = pos->firstOffset,
@@ -1821,7 +1819,7 @@ collectMatchesForHeapRow(IndexScanDesc scan, pendingPosition *pos)
 	 * GIN_CAT_EMPTY_QUERY scanEntry always matches.  So return "true" if all
 	 * non-excludeOnly scan keys have at least one match.
 	 */
-	for (i = 0; i < so->nkeys; i++)
+	for (uint32 i = 0; i < so->nkeys; i++)
 	{
 		if (pos->hasMatchKey[i] == false && !so->keys[i].excludeOnly)
 			return false;
@@ -1840,7 +1838,6 @@ scanPendingInsert(IndexScanDesc scan, TIDBitmap *tbm, int64 *ntids)
 	MemoryContext oldCtx;
 	bool		recheck,
 				match;
-	int			i;
 	pendingPosition pos;
 	Buffer		metabuffer = ReadBuffer(scan->indexRelation, GIN_METAPAGE_BLKNO);
 	Page		page;
@@ -1899,7 +1896,7 @@ scanPendingInsert(IndexScanDesc scan, TIDBitmap *tbm, int64 *ntids)
 		recheck = false;
 		match = true;
 
-		for (i = 0; i < so->nkeys; i++)
+		for (uint32 i = 0; i < so->nkeys; i++)
 		{
 			GinScanKey	key = so->keys + i;
 

src/backend/access/gin/ginlogic.c

@@ -148,8 +148,7 @@ static GinTernaryValue
 shimTriConsistentFn(GinScanKey key)
 {
 	int			nmaybe;
-	int			maybeEntries[MAX_MAYBE_ENTRIES];
-	int			i;
+	uint32		maybeEntries[MAX_MAYBE_ENTRIES];
 	bool		boolResult;
 	bool		recheck;
 	GinTernaryValue curResult;
@@ -160,7 +159,7 @@ shimTriConsistentFn(GinScanKey key)
 	 * test all combinations, so give up and return MAYBE.
 	 */
 	nmaybe = 0;
-	for (i = 0; i < key->nentries; i++)
+	for (uint32 i = 0; i < key->nentries; i++)
 	{
 		if (key->entryRes[i] == GIN_MAYBE)
 		{
@@ -178,13 +177,15 @@ shimTriConsistentFn(GinScanKey key)
 		return directBoolConsistentFn(key);
 
 	/* First call consistent function with all the maybe-inputs set FALSE */
-	for (i = 0; i < nmaybe; i++)
+	for (int i = 0; i < nmaybe; i++)
 		key->entryRes[maybeEntries[i]] = GIN_FALSE;
 	curResult = directBoolConsistentFn(key);
 	recheck = key->recheckCurItem;
 
 	for (;;)
 	{
+		int			i;
+
 		/* Twiddle the entries for next combination. */
 		for (i = 0; i < nmaybe; i++)
 		{
@@ -214,7 +215,7 @@ shimTriConsistentFn(GinScanKey key)
 		curResult = GIN_MAYBE;
 
 	/* We must restore the original state of the entryRes array */
-	for (i = 0; i < nmaybe; i++)
+	for (int i = 0; i < nmaybe; i++)
 		key->entryRes[maybeEntries[i]] = GIN_MAYBE;
 
 	return curResult;

src/backend/access/gin/ginscan.c

@@ -268,7 +268,6 @@ ginNewScanKey(IndexScanDesc scan)
 {
 	ScanKey		scankey = scan->keyData;
 	GinScanOpaque so = (GinScanOpaque) scan->opaque;
-	int			i;
 	int			numExcludeOnly;
 	bool		hasNullQuery = false;
 	bool		attrHasNormalScan[INDEX_MAX_KEYS] = {false};
@@ -294,7 +293,7 @@ ginNewScanKey(IndexScanDesc scan)
 
 	so->isVoidRes = false;
 
-	for (i = 0; i < scan->numberOfKeys; i++)
+	for (int i = 0; i < scan->numberOfKeys; i++)
 	{
 		ScanKey		skey = &scankey[i];
 		Datum	   *queryValues;
@@ -393,7 +392,7 @@ ginNewScanKey(IndexScanDesc scan)
 	 * and be set to normal (excludeOnly = false).
 	 */
 	numExcludeOnly = 0;
-	for (i = 0; i < so->nkeys; i++)
+	for (uint32 i = 0; i < so->nkeys; i++)
 	{
 		GinScanKey	key = &so->keys[i];
 
@@ -427,7 +426,7 @@ ginNewScanKey(IndexScanDesc scan)
 		/* Re-order the keys ... */
 		iNormalKey = 0;
 		iExcludeOnly = so->nkeys - numExcludeOnly;
-		for (i = 0; i < so->nkeys; i++)
+		for (uint32 i = 0; i < so->nkeys; i++)
 		{
 			GinScanKey	key = &so->keys[i];
 

src/backend/access/nbtree/nbtpage.c

@@ -3049,7 +3049,7 @@ _bt_pendingfsm_finalize(Relation rel, BTVacState *vstate)
 	 */
 	GetOldestNonRemovableTransactionId(heaprel);
 
-	for (int i = 0; i < vstate->npendingpages; i++)
+	for (unsigned int i = 0; i < vstate->npendingpages; i++)
 	{
 		BlockNumber target = vstate->pendingpages[i].target;
 		FullTransactionId safexid = vstate->pendingpages[i].safexid;

src/backend/access/rmgrdesc/logicalmsgdesc.c

@@ -34,7 +34,7 @@ logicalmsg_desc(StringInfo buf, XLogReaderState *record)
 						 xlrec->transactional ? "transactional" : "non-transactional",
 						 prefix, xlrec->message_size);
 		/* Write message payload as a series of hex bytes */
-		for (int cnt = 0; cnt < xlrec->message_size; cnt++)
+		for (Size cnt = 0; cnt < xlrec->message_size; cnt++)
 		{
 			appendStringInfo(buf, "%s%02X", sep, (unsigned char) message[cnt]);
 			sep = " ";

src/backend/executor/execCurrent.c

@@ -95,14 +95,13 @@ execCurrentOf(CurrentOfExpr *cexpr,
 	if (queryDesc->estate->es_rowmarks)
 	{
 		ExecRowMark *erm;
-		Index		i;
 
 		/*
 		 * Here, the query must have exactly one FOR UPDATE/SHARE reference to
 		 * the target table, and we dig the ctid info out of that.
 		 */
 		erm = NULL;
-		for (i = 0; i < queryDesc->estate->es_range_table_size; i++)
+		for (int i = 0; i < queryDesc->estate->es_range_table_size; i++)
 		{
 			ExecRowMark *thiserm = queryDesc->estate->es_rowmarks[i];
 

src/backend/jit/llvm/llvmjit.c

@@ -530,7 +530,7 @@ llvm_copy_attributes(LLVMValueRef v_from, LLVMValueRef v_to)
 	/* and each function parameter's attribute */
 	param_count = LLVMCountParams(v_from);
 
-	for (int paramidx = 1; paramidx <= param_count; paramidx++)
+	for (uint32 paramidx = 1; paramidx <= param_count; paramidx++)
 		llvm_copy_attributes_at_index(v_from, v_to, paramidx);
 }
 
@@ -1138,7 +1138,7 @@ llvm_resolve_symbols(LLVMOrcDefinitionGeneratorRef GeneratorObj, void *Ctx,
 	LLVMErrorRef error;
 	LLVMOrcMaterializationUnitRef mu;
 
-	for (int i = 0; i < LookupSetSize; i++)
+	for (size_t i = 0; i < LookupSetSize; i++)
 	{
 		const char *name = LLVMOrcSymbolStringPoolEntryStr(LookupSet[i].Name);
 

src/backend/lib/hyperloglog.c

@@ -187,9 +187,8 @@ estimateHyperLogLog(hyperLogLogState *cState)
 {
 	double		result;
 	double		sum = 0.0;
-	int			i;
 
-	for (i = 0; i < cState->nRegisters; i++)
+	for (Size i = 0; i < cState->nRegisters; i++)
 	{
 		sum += 1.0 / pow(2.0, cState->hashesArr[i]);
 	}
@@ -202,7 +201,7 @@ estimateHyperLogLog(hyperLogLogState *cState)
 		/* Small range correction */
 		int			zero_count = 0;
 
-		for (i = 0; i < cState->nRegisters; i++)
+		for (Size i = 0; i < cState->nRegisters; i++)
 		{
 			if (cState->hashesArr[i] == 0)
 				zero_count++;

src/backend/parser/parse_relation.c

@@ -1081,7 +1081,7 @@ markNullableIfNeeded(ParseState *pstate, Var *var)
 	Bitmapset  *relids;
 
 	/* Find the appropriate pstate */
-	for (int lv = 0; lv < var->varlevelsup; lv++)
+	for (Index lv = 0; lv < var->varlevelsup; lv++)
 		pstate = pstate->parentParseState;
 
 	/* Find currently-relevant join relids for the Var's rel */

src/backend/parser/parse_target.c

@@ -1620,7 +1620,7 @@ expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
 					ParseState	mypstate = {0};
 
 					/* this loop must work, since GetRTEByRangeTablePosn did */
-					for (Index level = 0; level < netlevelsup; level++)
+					for (int level = 0; level < netlevelsup; level++)
 						pstate = pstate->parentParseState;
 					mypstate.parentParseState = pstate;
 					mypstate.p_rtable = rte->subquery->rtable;

src/backend/port/win32/socket.c

@@ -521,7 +521,6 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c
 										 * 2*FD_SETSIZE sockets */
 	SOCKET		sockets[FD_SETSIZE * 2];
 	int			numevents = 0;
-	int			i;
 	int			r;
 	DWORD		timeoutval = WSA_INFINITE;
 	FD_SET		outreadfds;
@@ -548,7 +547,7 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c
 	 */
 	if (writefds != NULL)
 	{
-		for (i = 0; i < writefds->fd_count; i++)
+		for (u_int i = 0; i < writefds->fd_count; i++)
 		{
 			char		c;
 			WSABUF		buf;
@@ -583,7 +582,7 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c
 
 	if (readfds != NULL)
 	{
-		for (i = 0; i < readfds->fd_count; i++)
+		for (u_int i = 0; i < readfds->fd_count; i++)
 		{
 			events[numevents] = WSACreateEvent();
 			sockets[numevents] = readfds->fd_array[i];
@@ -592,7 +591,7 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c
 	}
 	if (writefds != NULL)
 	{
-		for (i = 0; i < writefds->fd_count; i++)
+		for (u_int i = 0; i < writefds->fd_count; i++)
 		{
 			if (!readfds ||
 				!FD_ISSET(writefds->fd_array[i], readfds))
@@ -605,7 +604,7 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c
 		}
 	}
 
-	for (i = 0; i < numevents; i++)
+	for (int i = 0; i < numevents; i++)
 	{
 		int			flags = 0;
 
@@ -637,7 +636,7 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c
 		 */
 		WSANETWORKEVENTS resEvents;
 
-		for (i = 0; i < numevents; i++)
+		for (int i = 0; i < numevents; i++)
 		{
 			ZeroMemory(&resEvents, sizeof(resEvents));
 			if (WSAEnumNetworkEvents(sockets[i], events[i], &resEvents) != 0)
@@ -670,7 +669,7 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c
 	}
 
 	/* Clean up all the event objects */
-	for (i = 0; i < numevents; i++)
+	for (int i = 0; i < numevents; i++)
 	{
 		WSAEventSelect(sockets[i], NULL, 0);
 		WSACloseEvent(events[i]);

src/backend/replication/logical/reorderbuffer.c

@@ -1288,7 +1288,7 @@ ReorderBufferIterTXNInit(ReorderBuffer *rb, ReorderBufferTXN *txn,
 	Size		nr_txns = 0;
 	ReorderBufferIterTXNState *state;
 	dlist_iter	cur_txn_i;
-	int32		off;
+	Size		off;
 
 	*iter_state = NULL;
 
@@ -1505,7 +1505,7 @@ static void
 ReorderBufferIterTXNFinish(ReorderBuffer *rb,
 						   ReorderBufferIterTXNState *state)
 {
-	int32		off;
+	Size		off;
 
 	for (off = 0; off < state->nr_txns; off++)
 	{
@@ -3252,7 +3252,6 @@ ReorderBufferImmediateInvalidation(ReorderBuffer *rb, uint32 ninvalidations,
 	bool		use_subtxn = IsTransactionOrTransactionBlock();
 	MemoryContext ccxt = CurrentMemoryContext;
 	ResourceOwner cowner = CurrentResourceOwner;
-	int			i;
 
 	if (use_subtxn)
 		BeginInternalSubTransaction("replay");
@@ -3266,7 +3265,7 @@ ReorderBufferImmediateInvalidation(ReorderBuffer *rb, uint32 ninvalidations,
 	if (use_subtxn)
 		AbortCurrentTransaction();
 
-	for (i = 0; i < ninvalidations; i++)
+	for (uint32 i = 0; i < ninvalidations; i++)
 		LocalExecuteInvalidationMessage(&invalidations[i]);
 
 	if (use_subtxn)
@@ -3636,9 +3635,7 @@ ReorderBufferAddDistributedInvalidations(ReorderBuffer *rb, TransactionId xid,
 static void
 ReorderBufferExecuteInvalidations(uint32 nmsgs, SharedInvalidationMessage *msgs)
 {
-	int			i;
-
-	for (i = 0; i < nmsgs; i++)
+	for (uint32 i = 0; i < nmsgs; i++)
 		LocalExecuteInvalidationMessage(&msgs[i]);
 }
 

src/backend/replication/logical/snapbuild.c

@@ -866,7 +866,6 @@ SnapBuildAddCommittedTxn(SnapBuild *builder, TransactionId xid)
 static void
 SnapBuildPurgeOlderTxn(SnapBuild *builder)
 {
-	int			off;
 	TransactionId *workspace;
 	int			surviving_xids = 0;
 
@@ -880,7 +879,7 @@ SnapBuildPurgeOlderTxn(SnapBuild *builder)
 						   builder->committed.xcnt * sizeof(TransactionId));
 
 	/* copy xids that still are interesting to workspace */
-	for (off = 0; off < builder->committed.xcnt; off++)
+	for (size_t off = 0; off < builder->committed.xcnt; off++)
 	{
 		if (NormalTransactionIdPrecedes(builder->committed.xip[off],
 										builder->xmin))
@@ -906,6 +905,8 @@ SnapBuildPurgeOlderTxn(SnapBuild *builder)
 	 */
 	if (builder->catchange.xcnt > 0)
 	{
+		size_t		off;
+
 		/*
 		 * Since catchange.xip is sorted, we find the lower bound of xids that
 		 * are still interesting.

src/backend/statistics/dependencies.c

@@ -436,7 +436,6 @@ statext_dependencies_build(StatsBuildData *data)
 bytea *
 statext_dependencies_serialize(MVDependencies *dependencies)
 {
-	int			i;
 	bytea	   *output;
 	char	   *tmp;
 	Size		len;
@@ -445,7 +444,7 @@ statext_dependencies_serialize(MVDependencies *dependencies)
 	len = VARHDRSZ + SizeOfHeader;
 
 	/* and also include space for the actual attribute numbers and degrees */
-	for (i = 0; i < dependencies->ndeps; i++)
+	for (uint32 i = 0; i < dependencies->ndeps; i++)
 		len += SizeOfItem(dependencies->deps[i]->nattributes);
 
 	output = (bytea *) palloc0(len);
@@ -462,7 +461,7 @@ statext_dependencies_serialize(MVDependencies *dependencies)
 	tmp += sizeof(uint32);
 
 	/* store number of attributes and attribute numbers for each dependency */
-	for (i = 0; i < dependencies->ndeps; i++)
+	for (uint32 i = 0; i < dependencies->ndeps; i++)
 	{
 		MVDependency *d = dependencies->deps[i];
 
@@ -491,7 +490,6 @@ statext_dependencies_serialize(MVDependencies *dependencies)
 MVDependencies *
 statext_dependencies_deserialize(bytea *data)
 {
-	int			i;
 	Size		min_expected_size;
 	MVDependencies *dependencies;
 	char	   *tmp;
@@ -539,7 +537,7 @@ statext_dependencies_deserialize(bytea *data)
 	dependencies = repalloc(dependencies, offsetof(MVDependencies, deps)
 							+ (dependencies->ndeps * sizeof(MVDependency *)));
 
-	for (i = 0; i < dependencies->ndeps; i++)
+	for (uint32 i = 0; i < dependencies->ndeps; i++)
 	{
 		double		degree;
 		AttrNumber	k;
@@ -585,7 +583,7 @@ statext_dependencies_deserialize(bytea *data)
 void
 statext_dependencies_free(MVDependencies *dependencies)
 {
-	for (int i = 0; i < dependencies->ndeps; i++)
+	for (uint32 i = 0; i < dependencies->ndeps; i++)
 		pfree(dependencies->deps[i]);
 	pfree(dependencies);
 }
@@ -610,7 +608,7 @@ statext_dependencies_validate(const MVDependencies *dependencies,
 	int			attnum_expr_lowbound = 0 - numexprs;
 
 	/* Scan through each dependency entry */
-	for (int i = 0; i < dependencies->ndeps; i++)
+	for (uint32 i = 0; i < dependencies->ndeps; i++)
 	{
 		const MVDependency *dep = dependencies->deps[i];
 
@@ -913,8 +911,6 @@ static MVDependency *
 find_strongest_dependency(MVDependencies **dependencies, int ndependencies,
 						  Bitmapset *attnums)
 {
-	int			i,
-				j;
 	MVDependency *strongest = NULL;
 
 	/* number of attnums in clauses */
@@ -925,9 +921,9 @@ find_strongest_dependency(MVDependencies **dependencies, int ndependencies,
 	 * fully-matched dependencies. We do the cheap checks first, before
 	 * matching it against the attnums.
 	 */
-	for (i = 0; i < ndependencies; i++)
+	for (int i = 0; i < ndependencies; i++)
 	{
-		for (j = 0; j < dependencies[i]->ndeps; j++)
+		for (uint32 j = 0; j < dependencies[i]->ndeps; j++)
 		{
 			MVDependency *dependency = dependencies[i]->deps[j];
 
@@ -1369,7 +1365,6 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 	int			total_ndeps;
 	MVDependency **dependencies;
 	int			ndependencies;
-	int			i;
 	AttrNumber	attnum_offset;
 	RangeTblEntry *rte = planner_rt_fetch(rel->relid, root);
 
@@ -1439,7 +1434,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 				Assert(expr != NULL);
 
 				/* If the expression is duplicate, use the same attnum. */
-				for (i = 0; i < unique_exprs_cnt; i++)
+				for (int i = 0; i < unique_exprs_cnt; i++)
 				{
 					if (equal(unique_exprs[i], expr))
 					{
@@ -1482,7 +1477,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 	 * Now that we know how many expressions there are, we can offset the
 	 * values just enough to build the bitmapset.
 	 */
-	for (i = 0; i < list_length(clauses); i++)
+	for (int i = 0; i < list_length(clauses); i++)
 	{
 		AttrNumber	attnum;
 
@@ -1587,7 +1582,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 
 		/* count matching expressions */
 		nexprs = 0;
-		for (i = 0; i < unique_exprs_cnt; i++)
+		for (int i = 0; i < unique_exprs_cnt; i++)
 		{
 			ListCell   *lc;
 
@@ -1638,15 +1633,14 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 		 */
 		if (unique_exprs_cnt > 0 || stat->exprs != NIL)
 		{
-			int			ndeps = 0;
+			uint32		ndeps = 0;
 
-			for (i = 0; i < deps->ndeps; i++)
+			for (uint32 i = 0; i < deps->ndeps; i++)
 			{
 				bool		skip = false;
 				MVDependency *dep = deps->deps[i];
-				int			j;
 
-				for (j = 0; j < dep->nattributes; j++)
+				for (int j = 0; j < dep->nattributes; j++)
 				{
 					int			idx;
 					Node	   *expr;
@@ -1797,7 +1791,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
 										   list_attnums, estimatedclauses);
 
 	/* free deserialized functional dependencies (and then the array) */
-	for (i = 0; i < nfunc_dependencies; i++)
+	for (int i = 0; i < nfunc_dependencies; i++)
 		pfree(func_dependencies[i]);
 
 	pfree(dependencies);

src/backend/statistics/mcv.c

@@ -618,7 +618,6 @@ statext_mcv_load(Oid mvoid, bool inh)
 bytea *
 statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 {
-	int			i;
 	int			dim;
 	int			ndims = mcvlist->ndimensions;
 
@@ -668,7 +667,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 		/* allocate space for values in the attribute and collect them */
 		values[dim] = palloc0_array(Datum, mcvlist->nitems);
 
-		for (i = 0; i < mcvlist->nitems; i++)
+		for (uint32 i = 0; i < mcvlist->nitems; i++)
 		{
 			/* skip NULL values - we don't need to deduplicate those */
 			if (mcvlist->items[i].isnull[dim])
@@ -700,7 +699,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 		 * element.
 		 */
 		ndistinct = 1;			/* number of distinct values */
-		for (i = 1; i < counts[dim]; i++)
+		for (int i = 1; i < counts[dim]; i++)
 		{
 			/* expect sorted array */
 			Assert(compare_datums_simple(values[dim][i - 1], values[dim][i], &ssup[dim]) <= 0);
@@ -752,7 +751,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 		{
 			info[dim].nbytes = 0;
 			info[dim].nbytes_aligned = 0;
-			for (i = 0; i < info[dim].nvalues; i++)
+			for (int i = 0; i < info[dim].nvalues; i++)
 			{
 				Size		len;
 
@@ -780,7 +779,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 		{
 			info[dim].nbytes = 0;
 			info[dim].nbytes_aligned = 0;
-			for (i = 0; i < info[dim].nvalues; i++)
+			for (int i = 0; i < info[dim].nvalues; i++)
 			{
 				Size		len;
 
@@ -818,7 +817,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 	total_length += ndims * sizeof(DimensionInfo);
 
 	/* add space for the arrays of deduplicated values */
-	for (i = 0; i < ndims; i++)
+	for (int i = 0; i < ndims; i++)
 		total_length += info[i].nbytes;
 
 	/*
@@ -863,7 +862,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 		/* remember the starting point for Asserts later */
 		char	   *start PG_USED_FOR_ASSERTS_ONLY = ptr;
 
-		for (i = 0; i < info[dim].nvalues; i++)
+		for (int i = 0; i < info[dim].nvalues; i++)
 		{
 			Datum		value = values[dim][i];
 
@@ -925,7 +924,7 @@ statext_mcv_serialize(MCVList *mcvlist, VacAttrStats **stats)
 	}
 
 	/* Serialize the items, with uint16 indexes instead of the values. */
-	for (i = 0; i < mcvlist->nitems; i++)
+	for (uint32 i = 0; i < mcvlist->nitems; i++)
 	{
 		MCVItem    *mcvitem = &mcvlist->items[i];
 
@@ -1652,7 +1651,7 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 			 * can skip items that were already ruled out, and terminate if
 			 * there are no remaining MCV items that might possibly match.
 			 */
-			for (int i = 0; i < mcvlist->nitems; i++)
+			for (uint32 i = 0; i < mcvlist->nitems; i++)
 			{
 				bool		match = true;
 				MCVItem    *item = &mcvlist->items[i];
@@ -1759,7 +1758,7 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 			 * can skip items that were already ruled out, and terminate if
 			 * there are no remaining MCV items that might possibly match.
 			 */
-			for (int i = 0; i < mcvlist->nitems; i++)
+			for (uint32 i = 0; i < mcvlist->nitems; i++)
 			{
 				int			j;
 				bool		match = !expr->useOr;
@@ -1830,7 +1829,7 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 			 * can skip items that were already ruled out, and terminate if
 			 * there are no remaining MCV items that might possibly match.
 			 */
-			for (int i = 0; i < mcvlist->nitems; i++)
+			for (uint32 i = 0; i < mcvlist->nitems; i++)
 			{
 				bool		match = false;	/* assume mismatch */
 				MCVItem    *item = &mcvlist->items[i];
@@ -1855,7 +1854,6 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 		{
 			/* AND/OR clause, with all subclauses being compatible */
 
-			int			i;
 			BoolExpr   *bool_clause = ((BoolExpr *) clause);
 			List	   *bool_clauses = bool_clause->args;
 
@@ -1874,7 +1872,7 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 			 * current one. We need to consider if we're evaluating AND or OR
 			 * condition when merging the results.
 			 */
-			for (i = 0; i < mcvlist->nitems; i++)
+			for (uint32 i = 0; i < mcvlist->nitems; i++)
 				matches[i] = RESULT_MERGE(matches[i], is_or, bool_matches[i]);
 
 			pfree(bool_matches);
@@ -1883,7 +1881,6 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 		{
 			/* NOT clause, with all subclauses compatible */
 
-			int			i;
 			BoolExpr   *not_clause = ((BoolExpr *) clause);
 			List	   *not_args = not_clause->args;
 
@@ -1902,7 +1899,7 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 			 * current one. We're handling a NOT clause, so invert the result
 			 * before merging it into the global bitmap.
 			 */
-			for (i = 0; i < mcvlist->nitems; i++)
+			for (uint32 i = 0; i < mcvlist->nitems; i++)
 				matches[i] = RESULT_MERGE(matches[i], is_or, !not_matches[i]);
 
 			pfree(not_matches);
@@ -1923,7 +1920,7 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 			 * can skip items that were already ruled out, and terminate if
 			 * there are no remaining MCV items that might possibly match.
 			 */
-			for (int i = 0; i < mcvlist->nitems; i++)
+			for (uint32 i = 0; i < mcvlist->nitems; i++)
 			{
 				MCVItem    *item = &mcvlist->items[i];
 				bool		match = false;
@@ -1949,7 +1946,7 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
 			 * can skip items that were already ruled out, and terminate if
 			 * there are no remaining MCV items that might possibly match.
 			 */
-			for (int i = 0; i < mcvlist->nitems; i++)
+			for (uint32 i = 0; i < mcvlist->nitems; i++)
 			{
 				bool		match;
 				MCVItem    *item = &mcvlist->items[i];
@@ -2049,7 +2046,6 @@ mcv_clauselist_selectivity(PlannerInfo *root, StatisticExtInfo *stat,
 						   RelOptInfo *rel,
 						   Selectivity *basesel, Selectivity *totalsel)
 {
-	int			i;
 	MCVList    *mcv;
 	Selectivity s = 0.0;
 	RangeTblEntry *rte = root->simple_rte_array[rel->relid];
@@ -2067,7 +2063,7 @@ mcv_clauselist_selectivity(PlannerInfo *root, StatisticExtInfo *stat,
 	/* sum frequencies for all the matching MCV items */
 	*basesel = 0.0;
 	*totalsel = 0.0;
-	for (i = 0; i < mcv->nitems; i++)
+	for (uint32 i = 0; i < mcv->nitems; i++)
 	{
 		*totalsel += mcv->items[i].frequency;
 
@@ -2128,7 +2124,6 @@ mcv_clause_selectivity_or(PlannerInfo *root, StatisticExtInfo *stat,
 {
 	Selectivity s = 0.0;
 	bool	   *new_matches;
-	int			i;
 
 	/* build the OR-matches bitmap, if not built already */
 	if (*or_matches == NULL)
@@ -2147,7 +2142,7 @@ mcv_clause_selectivity_or(PlannerInfo *root, StatisticExtInfo *stat,
 	*overlap_mcvsel = 0.0;
 	*overlap_basesel = 0.0;
 	*totalsel = 0.0;
-	for (i = 0; i < mcv->nitems; i++)
+	for (uint32 i = 0; i < mcv->nitems; i++)
 	{
 		*totalsel += mcv->items[i].frequency;
 
@@ -2178,7 +2173,7 @@ mcv_clause_selectivity_or(PlannerInfo *root, StatisticExtInfo *stat,
 void
 statext_mcv_free(MCVList *mcvlist)
 {
-	for (int i = 0; i < mcvlist->nitems; i++)
+	for (uint32 i = 0; i < mcvlist->nitems; i++)
 	{
 		MCVItem    *item = &mcvlist->items[i];
 

src/backend/statistics/mvdistinct.c

@@ -86,7 +86,7 @@ statext_ndistinct_build(double totalrows, StatsBuildData *data)
 {
 	MVNDistinct *result;
 	int			k;
-	int			itemcnt;
+	uint32		itemcnt;
 	int			numattrs = data->nattnums;
 	int			numcombs = num_combinations(numattrs);
 
@@ -175,7 +175,6 @@ statext_ndistinct_load(Oid mvoid, bool inh)
 bytea *
 statext_ndistinct_serialize(MVNDistinct *ndistinct)
 {
-	int			i;
 	bytea	   *output;
 	char	   *tmp;
 	Size		len;
@@ -190,7 +189,7 @@ statext_ndistinct_serialize(MVNDistinct *ndistinct)
 	len = VARHDRSZ + SizeOfHeader;
 
 	/* and also include space for the actual attribute numbers */
-	for (i = 0; i < ndistinct->nitems; i++)
+	for (uint32 i = 0; i < ndistinct->nitems; i++)
 	{
 		int			nmembers;
 
@@ -216,7 +215,7 @@ statext_ndistinct_serialize(MVNDistinct *ndistinct)
 	/*
 	 * store number of attributes and attribute numbers for each entry
 	 */
-	for (i = 0; i < ndistinct->nitems; i++)
+	for (uint32 i = 0; i < ndistinct->nitems; i++)
 	{
 		MVNDistinctItem item = ndistinct->items[i];
 		int			nmembers = item.nattributes;
@@ -246,7 +245,6 @@ statext_ndistinct_serialize(MVNDistinct *ndistinct)
 MVNDistinct *
 statext_ndistinct_deserialize(bytea *data)
 {
-	int			i;
 	Size		minimum_size;
 	MVNDistinct ndist;
 	MVNDistinct *ndistinct;
@@ -296,7 +294,7 @@ statext_ndistinct_deserialize(bytea *data)
 	ndistinct->type = ndist.type;
 	ndistinct->nitems = ndist.nitems;
 
-	for (i = 0; i < ndistinct->nitems; i++)
+	for (uint32 i = 0; i < ndistinct->nitems; i++)
 	{
 		MVNDistinctItem *item = &ndistinct->items[i];
 
@@ -331,7 +329,7 @@ statext_ndistinct_deserialize(bytea *data)
 void
 statext_ndistinct_free(MVNDistinct *ndistinct)
 {
-	for (int i = 0; i < ndistinct->nitems; i++)
+	for (uint32 i = 0; i < ndistinct->nitems; i++)
 		pfree(ndistinct->items[i].attributes);
 	pfree(ndistinct);
 }
@@ -356,7 +354,7 @@ statext_ndistinct_validate(const MVNDistinct *ndistinct,
 	int			attnum_expr_lowbound = 0 - numexprs;
 
 	/* Scan through each MVNDistinct entry */
-	for (int i = 0; i < ndistinct->nitems; i++)
+	for (uint32 i = 0; i < ndistinct->nitems; i++)
 	{
 		MVNDistinctItem item = ndistinct->items[i];
 

src/backend/storage/aio/aio_init.c

@@ -190,7 +190,7 @@ AioShmemInit(void *arg)
 	pgaio_ctl->iovecs = AioHandleIOVShmemPtr;
 	pgaio_ctl->handle_data = AioHandleDataShmemPtr;
 
-	for (int procno = 0; procno < AioProcs(); procno++)
+	for (uint32 procno = 0; procno < AioProcs(); procno++)
 	{
 		PgAioBackend *bs = &pgaio_ctl->backend_state[procno];
 

src/backend/storage/aio/method_io_uring.c

@@ -544,7 +544,7 @@ pgaio_uring_drain_locked(PgAioUringContext *context)
 
 		ready -= ncqes;
 
-		for (int i = 0; i < ncqes; i++)
+		for (uint32 i = 0; i < ncqes; i++)
 		{
 			struct io_uring_cqe *cqe = cqes[i];
 			PgAioHandle *ioh = io_uring_cqe_get_data(cqe);

src/backend/storage/file/fd.c

@@ -3181,9 +3181,7 @@ void
 AtEOSubXact_Files(bool isCommit, SubTransactionId mySubid,
 				  SubTransactionId parentSubid)
 {
-	Index		i;
-
-	for (i = 0; i < numAllocatedDescs; i++)
+	for (int i = 0; i < numAllocatedDescs; i++)
 	{
 		if (allocatedDescs[i].create_subid == mySubid)
 		{

src/backend/storage/ipc/shmem.c

@@ -1162,7 +1162,6 @@ pg_get_shmem_allocations_numa(PG_FUNCTION_ARGS)
 	/* output all allocated entries */
 	while ((ent = (ShmemIndexEnt *) hash_seq_search(&hstat)) != NULL)
 	{
-		int			i;
 		char	   *startptr,
 				   *endptr;
 		Size		total_len;
@@ -1194,7 +1193,7 @@ pg_get_shmem_allocations_numa(PG_FUNCTION_ARGS)
 		 * pages, so that inquiry about NUMA memory node doesn't return -2
 		 * (ENOENT, which indicates unmapped/unallocated pages).
 		 */
-		for (i = 0; i < shm_ent_page_count; i++)
+		for (uint64 i = 0; i < shm_ent_page_count; i++)
 		{
 			page_ptrs[i] = startptr + (i * os_page_size);
 
@@ -1210,7 +1209,7 @@ pg_get_shmem_allocations_numa(PG_FUNCTION_ARGS)
 		/* Count number of NUMA nodes used for this shared memory entry */
 		memset(nodes, 0, sizeof(Size) * (max_nodes + 2));
 
-		for (i = 0; i < shm_ent_page_count; i++)
+		for (uint64 i = 0; i < shm_ent_page_count; i++)
 		{
 			int			s = pages_status[i];
 
@@ -1239,7 +1238,7 @@ pg_get_shmem_allocations_numa(PG_FUNCTION_ARGS)
 		 * Add one entry for each NUMA node, including those without allocated
 		 * memory for this segment.
 		 */
-		for (i = 0; i <= max_nodes; i++)
+		for (uint64 i = 0; i <= max_nodes; i++)
 		{
 			values[0] = CStringGetTextDatum(ent->key);
 			values[1] = Int32GetDatum(i);

src/backend/storage/lmgr/lock.c

@@ -3122,7 +3122,6 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode, int *countp)
 	 */
 	if (ConflictsWithRelationFastPath(locktag, lockmode))
 	{
-		int			i;
 		Oid			relid = locktag->locktag_field2;
 		VirtualTransactionId vxid;
 
@@ -3139,7 +3138,7 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode, int *countp)
 		 * time we return the value and the time the caller does something
 		 * with it.
 		 */
-		for (i = 0; i < ProcGlobal->allProcCount; i++)
+		for (uint32 i = 0; i < ProcGlobal->allProcCount; i++)
 		{
 			PGPROC	   *proc = GetPGProcByNumber(i);
 			uint32		j;
@@ -3780,7 +3779,6 @@ GetLockStatusData(void)
 	HASH_SEQ_STATUS seqstat;
 	int			els;
 	int			el;
-	int			i;
 
 	data = palloc_object(LockData);
 
@@ -3801,7 +3799,7 @@ GetLockStatusData(void)
 	 * lockGroupLeader field without holding all lock partition locks, and
 	 * it's not worth that.)
 	 */
-	for (i = 0; i < ProcGlobal->allProcCount; ++i)
+	for (uint32 i = 0; i < ProcGlobal->allProcCount; ++i)
 	{
 		PGPROC	   *proc = GetPGProcByNumber(i);
 
@@ -3900,7 +3898,7 @@ GetLockStatusData(void)
 	 *
 	 * Must grab LWLocks in partition-number order to avoid LWLock deadlock.
 	 */
-	for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
+	for (int i = 0; i < NUM_LOCK_PARTITIONS; i++)
 		LWLockAcquire(LockHashPartitionLockByIndex(i), LW_SHARED);
 
 	/* Now we can safely count the number of proclocks */
@@ -3944,7 +3942,7 @@ GetLockStatusData(void)
 	 * until it can get all the locks it needs. (2) This avoids O(N^2)
 	 * behavior inside LWLockRelease.
 	 */
-	for (i = NUM_LOCK_PARTITIONS; --i >= 0;)
+	for (int i = NUM_LOCK_PARTITIONS; --i >= 0;)
 		LWLockRelease(LockHashPartitionLockByIndex(i));
 
 	Assert(el == data->nelements);

src/backend/tsearch/spell.c

@@ -1988,7 +1988,6 @@ void
 NISortAffixes(IspellDict *Conf)
 {
 	AFFIX	   *Affix;
-	size_t		i;
 	CMPDAffix  *ptr;
 	int			firstsuffix = Conf->naffixes;
 
@@ -2001,7 +2000,7 @@ NISortAffixes(IspellDict *Conf)
 	Conf->CompoundAffix = ptr = palloc_array(CMPDAffix, Conf->naffixes);
 	ptr->affix = NULL;
 
-	for (i = 0; i < Conf->naffixes; i++)
+	for (int i = 0; i < Conf->naffixes; i++)
 	{
 		Affix = &(((AFFIX *) Conf->Affix)[i]);
 		if (Affix->type == FF_SUFFIX && i < firstsuffix)

src/backend/utils/adt/json.c

@@ -1676,7 +1676,7 @@ escape_json_with_len(StringInfo buf, const char *str, int len)
 		 * Per-byte loop for Vector8s containing special chars and for
 		 * processing the tail of the string.
 		 */
-		for (int b = 0; b < sizeof(Vector8); b++)
+		for (size_t b = 0; b < sizeof(Vector8); b++)
 		{
 			/* check if we've finished */
 			if (i == len)

src/backend/utils/adt/pg_dependencies.c

@@ -819,7 +819,7 @@ pg_dependencies_out(PG_FUNCTION_ARGS)
 	initStringInfo(&str);
 	appendStringInfoChar(&str, '[');
 
-	for (int i = 0; i < dependencies->ndeps; i++)
+	for (uint32 i = 0; i < dependencies->ndeps; i++)
 	{
 		MVDependency *dependency = dependencies->deps[i];
 

src/backend/utils/adt/pg_locale.c

@@ -1270,7 +1270,7 @@ get_collation_actual_version(char collprovider, const char *collcollate)
 static size_t
 strlower_c(char *dst, size_t dstsize, const char *src, size_t srclen)
 {
-	int			i;
+	size_t		i;
 
 	for (i = 0; i < srclen && i < dstsize; i++)
 		dst[i] = pg_ascii_tolower(src[i]);
@@ -1284,7 +1284,7 @@ static size_t
 strtitle_c(char *dst, size_t dstsize, const char *src, size_t srclen)
 {
 	bool		wasalnum = false;
-	int			i;
+	size_t		i;
 
 	for (i = 0; i < srclen && i < dstsize; i++)
 	{
@@ -1308,7 +1308,7 @@ strtitle_c(char *dst, size_t dstsize, const char *src, size_t srclen)
 static size_t
 strupper_c(char *dst, size_t dstsize, const char *src, size_t srclen)
 {
-	int			i;
+	size_t		i;
 
 	for (i = 0; i < srclen && i < dstsize; i++)
 		dst[i] = pg_ascii_toupper(src[i]);

src/backend/utils/adt/pg_locale_icu.c

@@ -712,7 +712,7 @@ static size_t
 downcase_ident_icu(char *dst, size_t dstsize, const char *src,
 				   size_t srclen, pg_locale_t locale)
 {
-	int			i;
+	size_t		i;
 	bool		libc_lower;
 	locale_t	lt = locale->icu.lt;
 

src/backend/utils/adt/pg_locale_libc.c

@@ -372,7 +372,7 @@ downcase_ident_libc_sb(char *dst, size_t dstsize, const char *src,
 					   size_t srclen, pg_locale_t locale)
 {
 	locale_t	loc = locale->lt;
-	int			i;
+	size_t		i;
 
 	for (i = 0; i < srclen && i < dstsize; i++)
 	{

src/backend/utils/adt/pg_ndistinct.c

@@ -793,13 +793,12 @@ pg_ndistinct_out(PG_FUNCTION_ARGS)
 {
 	bytea	   *data = PG_GETARG_BYTEA_PP(0);
 	MVNDistinct *ndist = statext_ndistinct_deserialize(data);
-	int			i;
 	StringInfoData str;
 
 	initStringInfo(&str);
 	appendStringInfoChar(&str, '[');
 
-	for (i = 0; i < ndist->nitems; i++)
+	for (uint32 i = 0; i < ndist->nitems; i++)
 	{
 		MVNDistinctItem item = ndist->items[i];
 

src/backend/utils/adt/selfuncs.c

@@ -4687,7 +4687,6 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
 	 */
 	if (stats)
 	{
-		int			i;
 		List	   *newlist = NIL;
 		MVNDistinctItem *item = NULL;
 		ListCell   *lc2;
@@ -4777,9 +4776,8 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
 		}
 
 		/* Find the specific item that exactly matches the combination */
-		for (i = 0; i < stats->nitems; i++)
+		for (uint32 i = 0; i < stats->nitems; i++)
 		{
-			int			j;
 			MVNDistinctItem *tmpitem = &stats->items[i];
 
 			if (tmpitem->nattributes != bms_num_members(matched))
@@ -4789,7 +4787,7 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
 			item = tmpitem;
 
 			/* check that all item attributes/expressions fit the match */
-			for (j = 0; j < tmpitem->nattributes; j++)
+			for (int j = 0; j < tmpitem->nattributes; j++)
 			{
 				AttrNumber	attnum = tmpitem->attributes[j];
 

src/backend/utils/adt/tsgistidx.c

@@ -365,10 +365,9 @@ gtsvector_consistent(PG_FUNCTION_ARGS)
 static int32
 unionkey(BITVECP sbase, SignTSVector *add, int siglen)
 {
-	int32		i;
-
 	if (ISSIGNKEY(add))
 	{
+		int32		i;
 		BITVECP		sadd = GETSIGN(add);
 
 		if (ISALLTRUE(add))
@@ -383,7 +382,7 @@ unionkey(BITVECP sbase, SignTSVector *add, int siglen)
 	{
 		int32	   *ptr = GETARR(add);
 
-		for (i = 0; i < ARRNELEM(add); i++)
+		for (uint32 i = 0; i < ARRNELEM(add); i++)
 			HASH(sbase, ptr[i], siglen);
 	}
 	return 0;

src/backend/utils/adt/tsquery.c

@@ -1227,8 +1227,7 @@ tsqueryrecv(PG_FUNCTION_ARGS)
 {
 	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
 	TSQuery		query;
-	int			i,
-				len;
+	int			len;
 	QueryItem  *item;
 	int			datalen;
 	char	   *ptr;
@@ -1250,7 +1249,7 @@ tsqueryrecv(PG_FUNCTION_ARGS)
 	item = GETQUERY(query);
 
 	datalen = 0;
-	for (i = 0; i < size; i++)
+	for (uint32 i = 0; i < size; i++)
 	{
 		item->type = (int8) pq_getmsgint(buf, sizeof(int8));
 
@@ -1335,7 +1334,7 @@ tsqueryrecv(PG_FUNCTION_ARGS)
 	Assert(!needcleanup);
 
 	/* Copy operands to output struct */
-	for (i = 0; i < size; i++)
+	for (uint32 i = 0; i < size; i++)
 	{
 		if (item->type == QI_VAL)
 		{

src/backend/utils/adt/tsquery_gist.c

@@ -119,10 +119,9 @@ gtsquery_same(PG_FUNCTION_ARGS)
 static int
 sizebitvec(TSQuerySign sign)
 {
-	int			size = 0,
-				i;
+	int			size = 0;
 
-	for (i = 0; i < TSQS_SIGLEN; i++)
+	for (size_t i = 0; i < TSQS_SIGLEN; i++)
 		size += 0x01 & (sign >> i);
 
 	return size;

src/backend/utils/adt/varbit.c

@@ -1247,8 +1247,7 @@ bit_and(PG_FUNCTION_ARGS)
 	VarBit	   *result;
 	int			len,
 				bitlen1,
-				bitlen2,
-				i;
+				bitlen2;
 	uint8	   *p1,
 			   *p2,
 			   *r;
@@ -1268,7 +1267,7 @@ bit_and(PG_FUNCTION_ARGS)
 	p1 = VARBITS(arg1);
 	p2 = VARBITS(arg2);
 	r = VARBITS(result);
-	for (i = 0; i < VARBITBYTES(arg1); i++)
+	for (size_t i = 0; i < VARBITBYTES(arg1); i++)
 		*r++ = *p1++ & *p2++;
 
 	/* Padding is not needed as & of 0 pads is 0 */
@@ -1288,8 +1287,7 @@ bit_or(PG_FUNCTION_ARGS)
 	VarBit	   *result;
 	int			len,
 				bitlen1,
-				bitlen2,
-				i;
+				bitlen2;
 	uint8	   *p1,
 			   *p2,
 			   *r;
@@ -1308,7 +1306,7 @@ bit_or(PG_FUNCTION_ARGS)
 	p1 = VARBITS(arg1);
 	p2 = VARBITS(arg2);
 	r = VARBITS(result);
-	for (i = 0; i < VARBITBYTES(arg1); i++)
+	for (size_t i = 0; i < VARBITBYTES(arg1); i++)
 		*r++ = *p1++ | *p2++;
 
 	/* Padding is not needed as | of 0 pads is 0 */
@@ -1328,8 +1326,7 @@ bitxor(PG_FUNCTION_ARGS)
 	VarBit	   *result;
 	int			len,
 				bitlen1,
-				bitlen2,
-				i;
+				bitlen2;
 	uint8	   *p1,
 			   *p2,
 			   *r;
@@ -1349,7 +1346,7 @@ bitxor(PG_FUNCTION_ARGS)
 	p1 = VARBITS(arg1);
 	p2 = VARBITS(arg2);
 	r = VARBITS(result);
-	for (i = 0; i < VARBITBYTES(arg1); i++)
+	for (size_t i = 0; i < VARBITBYTES(arg1); i++)
 		*r++ = *p1++ ^ *p2++;
 
 	/* Padding is not needed as ^ of 0 pads is 0 */
@@ -1701,7 +1698,6 @@ bitposition(PG_FUNCTION_ARGS)
 	VarBit	   *substr = PG_GETARG_VARBIT_P(1);
 	int			substr_length,
 				str_length,
-				i,
 				is;
 	uint8	   *s,				/* pointer into substring */
 			   *p;				/* pointer into str */
@@ -1727,7 +1723,7 @@ bitposition(PG_FUNCTION_ARGS)
 	/* Initialise the padding masks */
 	end_mask = BITMASK << VARBITPAD(substr);
 	str_mask = BITMASK << VARBITPAD(str);
-	for (i = 0; i < VARBITBYTES(str) - VARBITBYTES(substr) + 1; i++)
+	for (size_t i = 0; i < VARBITBYTES(str) - VARBITBYTES(substr) + 1; i++)
 	{
 		for (is = 0; is < BITS_PER_BYTE; is++)
 		{

src/backend/utils/mb/conversion_procs/euc_tw_and_big5/big5.c

@@ -291,13 +291,12 @@ unsigned short
 BIG5toCNS(unsigned short big5, unsigned char *lc)
 {
 	unsigned short cns = 0;
-	int			i;
 
 	if (big5 < 0xc940U)
 	{
 		/* level 1 */
 
-		for (i = 0; i < sizeof(b1c4) / (sizeof(unsigned short) * 2); i++)
+		for (size_t i = 0; i < sizeof(b1c4) / (sizeof(unsigned short) * 2); i++)
 		{
 			if (b1c4[i][0] == big5)
 			{
@@ -318,7 +317,7 @@ BIG5toCNS(unsigned short big5, unsigned char *lc)
 	else
 	{
 		/* level 2 */
-		for (i = 0; i < sizeof(b2c3) / (sizeof(unsigned short) * 2); i++)
+		for (size_t i = 0; i < sizeof(b2c3) / (sizeof(unsigned short) * 2); i++)
 		{
 			if (b2c3[i][0] == big5)
 			{
@@ -343,7 +342,6 @@ BIG5toCNS(unsigned short big5, unsigned char *lc)
 unsigned short
 CNStoBIG5(unsigned short cns, unsigned char lc)
 {
-	int			i;
 	unsigned int big5 = 0;
 
 	cns &= 0x7f7f;
@@ -357,14 +355,14 @@ CNStoBIG5(unsigned short cns, unsigned char lc)
 			big5 = BinarySearchRange(cnsPlane2ToBig5Level2, 47, cns);
 			break;
 		case LC_CNS11643_3:
-			for (i = 0; i < sizeof(b2c3) / (sizeof(unsigned short) * 2); i++)
+			for (size_t i = 0; i < sizeof(b2c3) / (sizeof(unsigned short) * 2); i++)
 			{
 				if (b2c3[i][1] == cns)
 					return b2c3[i][0];
 			}
 			break;
 		case LC_CNS11643_4:
-			for (i = 0; i < sizeof(b1c4) / (sizeof(unsigned short) * 2); i++)
+			for (size_t i = 0; i < sizeof(b1c4) / (sizeof(unsigned short) * 2); i++)
 			{
 				if (b1c4[i][1] == cns)
 					return b1c4[i][0];

src/backend/utils/misc/injection_point.c

@@ -292,7 +292,7 @@ InjectionPointAttach(const char *name,
 	max_inuse = pg_atomic_read_u32(&ActiveInjectionPoints->max_inuse);
 	free_idx = -1;
 
-	for (int idx = 0; idx < max_inuse; idx++)
+	for (uint32 idx = 0; idx < max_inuse; idx++)
 	{
 		entry = &ActiveInjectionPoints->entries[idx];
 		generation = pg_atomic_read_u64(&entry->generation);
@@ -458,7 +458,7 @@ InjectionPointCacheRefresh(const char *name)
 	 * cases.
 	 */
 	namelen = strlen(name);
-	for (int idx = 0; idx < max_inuse; idx++)
+	for (uint32 idx = 0; idx < max_inuse; idx++)
 	{
 		InjectionPointEntry *entry = &ActiveInjectionPoints->entries[idx];
 		uint64		generation;

src/backend/utils/misc/pg_config.c

@@ -26,13 +26,12 @@ pg_config(PG_FUNCTION_ARGS)
 	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
 	ConfigData *configdata;
 	size_t		configdata_len;
-	int			i = 0;
 
 	/* initialize our tuplestore */
 	InitMaterializedSRF(fcinfo, 0);
 
 	configdata = get_configdata(my_exec_path, &configdata_len);
-	for (i = 0; i < configdata_len; i++)
+	for (size_t i = 0; i < configdata_len; i++)
 	{
 		Datum		values[2];
 		bool		nulls[2];

src/backend/utils/mmgr/dsa.c

@@ -620,7 +620,6 @@ void
 dsa_release_in_place(void *place)
 {
 	dsa_area_control *control = (dsa_area_control *) place;
-	int			i;
 
 	LWLockAcquire(&control->lock, LW_EXCLUSIVE);
 	Assert(control->segment_header.magic ==
@@ -628,7 +627,7 @@ dsa_release_in_place(void *place)
 	Assert(control->refcnt > 0);
 	if (--control->refcnt == 0)
 	{
-		for (i = 0; i <= control->high_segment_index; ++i)
+		for (dsa_segment_index i = 0; i <= control->high_segment_index; ++i)
 		{
 			dsm_handle	handle;
 
@@ -649,13 +648,11 @@ dsa_release_in_place(void *place)
 void
 dsa_pin_mapping(dsa_area *area)
 {
-	int			i;
-
 	if (area->resowner != NULL)
 	{
 		area->resowner = NULL;
 
-		for (i = 0; i <= area->high_segment_index; ++i)
+		for (dsa_segment_index i = 0; i <= area->high_segment_index; ++i)
 			if (area->segment_maps[i].segment != NULL)
 				dsm_pin_mapping(area->segment_maps[i].segment);
 	}
@@ -1246,7 +1243,7 @@ size_t
 dsa_minimum_size(void)
 {
 	size_t		size;
-	int			pages = 0;
+	size_t		pages = 0;
 
 	size = MAXALIGN(sizeof(dsa_area_control)) +
 		MAXALIGN(sizeof(FreePageManager));
@@ -1277,7 +1274,6 @@ create_internal(void *place, size_t size,
 	size_t		usable_pages;
 	size_t		total_pages;
 	size_t		metadata_bytes;
-	int			i;
 
 	/* Check the initial and maximum block sizes */
 	Assert(init_segment_size >= DSA_MIN_SEGMENT_SIZE);
@@ -1320,7 +1316,7 @@ create_internal(void *place, size_t size,
 	control->max_total_segment_size = (size_t) -1;
 	control->total_segment_size = size;
 	control->segment_handles[0] = control_handle;
-	for (i = 0; i < DSA_NUM_SEGMENT_BINS; ++i)
+	for (int i = 0; i < DSA_NUM_SEGMENT_BINS; ++i)
 		control->segment_bins[i] = DSA_SEGMENT_INDEX_NONE;
 	control->refcnt = 1;
 	control->lwlock_tranche_id = tranche_id;
@@ -1337,7 +1333,7 @@ create_internal(void *place, size_t size,
 	area->high_segment_index = 0;
 	area->freed_segment_counter = 0;
 	LWLockInitialize(&control->lock, control->lwlock_tranche_id);
-	for (i = 0; i < DSA_NUM_SIZE_CLASSES; ++i)
+	for (size_t i = 0; i < DSA_NUM_SIZE_CLASSES; ++i)
 		LWLockInitialize(DSA_SCLASS_LOCK(area, i),
 						 control->lwlock_tranche_id);
 
@@ -2001,10 +1997,8 @@ add_span_to_fullness_class(dsa_area *area, dsa_area_span *span,
 void
 dsa_detach(dsa_area *area)
 {
-	int			i;
-
 	/* Detach from all segments. */
-	for (i = 0; i <= area->high_segment_index; ++i)
+	for (dsa_segment_index i = 0; i <= area->high_segment_index; ++i)
 		if (area->segment_maps[i].segment != NULL)
 			dsm_detach(area->segment_maps[i].segment);
 
@@ -2367,13 +2361,12 @@ static void
 check_for_freed_segments_locked(dsa_area *area)
 {
 	size_t		freed_segment_counter;
-	int			i;
 
 	Assert(LWLockHeldByMe(DSA_AREA_LOCK(area)));
 	freed_segment_counter = area->control->freed_segment_counter;
 	if (unlikely(area->freed_segment_counter != freed_segment_counter))
 	{
-		for (i = 0; i <= area->high_segment_index; ++i)
+		for (dsa_segment_index i = 0; i <= area->high_segment_index; ++i)
 		{
 			if (area->segment_maps[i].header != NULL &&
 				area->segment_maps[i].header->freed)

src/backend/utils/resowner/resowner.c

@@ -304,7 +304,7 @@ ResourceOwnerSort(ResourceOwner owner)
 		 */
 		uint32		dst = 0;
 
-		for (int idx = 0; idx < owner->capacity; idx++)
+		for (uint32 idx = 0; idx < owner->capacity; idx++)
 		{
 			if (owner->hash[idx].kind != NULL)
 			{
@@ -852,7 +852,7 @@ ResourceOwnerReleaseAllOfKind(ResourceOwner owner, const ResourceOwnerDesc *kind
 	}
 
 	/* Then hash */
-	for (int i = 0; i < owner->capacity; i++)
+	for (uint32 i = 0; i < owner->capacity; i++)
 	{
 		if (owner->hash[i].kind == kind)
 		{

src/backend/utils/time/snapmgr.c

@@ -1121,7 +1121,6 @@ ExportSnapshot(Snapshot snapshot)
 	int			addTopXid;
 	StringInfoData buf;
 	FILE	   *f;
-	int			i;
 	MemoryContext oldcxt;
 	char		path[MAXPGPATH];
 	char		pathtmp[MAXPGPATH];
@@ -1218,7 +1217,7 @@ ExportSnapshot(Snapshot snapshot)
 	addTopXid = (TransactionIdIsValid(topXid) &&
 				 TransactionIdPrecedes(topXid, snapshot->xmax)) ? 1 : 0;
 	appendStringInfo(&buf, "xcnt:%d\n", snapshot->xcnt + addTopXid);
-	for (i = 0; i < snapshot->xcnt; i++)
+	for (uint32 i = 0; i < snapshot->xcnt; i++)
 		appendStringInfo(&buf, "xip:%u\n", snapshot->xip[i]);
 	if (addTopXid)
 		appendStringInfo(&buf, "xip:%u\n", topXid);
@@ -1234,9 +1233,9 @@ ExportSnapshot(Snapshot snapshot)
 	{
 		appendStringInfoString(&buf, "sof:0\n");
 		appendStringInfo(&buf, "sxcnt:%d\n", snapshot->subxcnt + nchildren);
-		for (i = 0; i < snapshot->subxcnt; i++)
+		for (int32 i = 0; i < snapshot->subxcnt; i++)
 			appendStringInfo(&buf, "sxp:%u\n", snapshot->subxip[i]);
-		for (i = 0; i < nchildren; i++)
+		for (int32 i = 0; i < nchildren; i++)
 			appendStringInfo(&buf, "sxp:%u\n", children[i]);
 	}
 	appendStringInfo(&buf, "rec:%u\n", snapshot->takenDuringRecovery);

src/bin/pg_amcheck/pg_amcheck.c

@@ -232,7 +232,6 @@ main(int argc, char *argv[])
 	uint64		pageschecked = 0;
 	uint64		pagestotal = 0;
 	uint64		relprogress = 0;
-	int			pattern_id;
 
 	static struct option long_options[] = {
 		/* Connection options */
@@ -640,7 +639,7 @@ main(int argc, char *argv[])
 	 * Check that all inclusion patterns matched at least one schema or
 	 * relation that we can check.
 	 */
-	for (pattern_id = 0; pattern_id < opts.include.len; pattern_id++)
+	for (size_t pattern_id = 0; pattern_id < opts.include.len; pattern_id++)
 	{
 		PatternInfo *pat = &opts.include.data[pattern_id];
 
@@ -1539,13 +1538,12 @@ static bool
 append_db_pattern_cte(PQExpBuffer buf, const PatternInfoArray *pia,
 					  PGconn *conn, bool inclusive)
 {
-	int			pattern_id;
 	const char *comma;
 	bool		have_values;
 
 	comma = "";
 	have_values = false;
-	for (pattern_id = 0; pattern_id < pia->len; pattern_id++)
+	for (size_t pattern_id = 0; pattern_id < pia->len; pattern_id++)
 	{
 		PatternInfo *info = &pia->data[pattern_id];
 
@@ -1555,7 +1553,7 @@ append_db_pattern_cte(PQExpBuffer buf, const PatternInfoArray *pia,
 			if (!have_values)
 				appendPQExpBufferStr(buf, "\nVALUES");
 			have_values = true;
-			appendPQExpBuffer(buf, "%s\n(%d, ", comma, pattern_id);
+			appendPQExpBuffer(buf, "%s\n(%zu, ", comma, pattern_id);
 			appendStringLiteralConn(buf, info->db_regex, conn);
 			appendPQExpBufferChar(buf, ')');
 			comma = ",";
@@ -1777,20 +1775,19 @@ static void
 append_rel_pattern_raw_cte(PQExpBuffer buf, const PatternInfoArray *pia,
 						   PGconn *conn)
 {
-	int			pattern_id;
 	const char *comma;
 	bool		have_values;
 
 	comma = "";
 	have_values = false;
-	for (pattern_id = 0; pattern_id < pia->len; pattern_id++)
+	for (size_t pattern_id = 0; pattern_id < pia->len; pattern_id++)
 	{
 		PatternInfo *info = &pia->data[pattern_id];
 
 		if (!have_values)
 			appendPQExpBufferStr(buf, "\nVALUES");
 		have_values = true;
-		appendPQExpBuffer(buf, "%s\n(%d::INTEGER, ", comma, pattern_id);
+		appendPQExpBuffer(buf, "%s\n(%zu::INTEGER, ", comma, pattern_id);
 		if (info->db_regex == NULL)
 			appendPQExpBufferStr(buf, "NULL");
 		else

src/bin/pg_basebackup/pg_recvlogical.c

@@ -223,7 +223,6 @@ StreamLogicalLog(void)
 	PGresult   *res;
 	char	   *copybuf = NULL;
 	TimestampTz last_status = -1;
-	int			i;
 	PQExpBuffer query;
 	XLogRecPtr	cur_record_lsn;
 
@@ -256,7 +255,7 @@ StreamLogicalLog(void)
 	if (noptions)
 		appendPQExpBufferStr(query, " (");
 
-	for (i = 0; i < noptions; i++)
+	for (size_t i = 0; i < noptions; i++)
 	{
 		/* separator */
 		if (i > 0)

src/bin/pg_combinebackup/reconstruct.c

@@ -105,7 +105,6 @@ reconstruct_from_incremental_file(char *input_filename,
 	rfile	  **sourcemap;
 	off_t	   *offsetmap;
 	unsigned	block_length;
-	unsigned	i;
 	unsigned	sidx = n_prior_backups;
 	bool		full_copy_possible = true;
 	int			copy_source_index = -1;
@@ -147,7 +146,7 @@ reconstruct_from_incremental_file(char *input_filename,
 	 * output but would not have needed to be found in an older backup if it
 	 * had not been present.
 	 */
-	for (i = 0; i < latest_source->num_blocks; ++i)
+	for (unsigned i = 0; i < latest_source->num_blocks; ++i)
 	{
 		BlockNumber b = latest_source->relative_block_numbers[i];
 
@@ -261,7 +260,7 @@ reconstruct_from_incremental_file(char *input_filename,
 		 * Since we found another incremental file, source all blocks from it
 		 * that we need but don't yet have.
 		 */
-		for (i = 0; i < s->num_blocks; ++i)
+		for (unsigned i = 0; i < s->num_blocks; ++i)
 		{
 			BlockNumber b = s->relative_block_numbers[i];
 
@@ -359,7 +358,7 @@ reconstruct_from_incremental_file(char *input_filename,
 	/*
 	 * Close files and release memory.
 	 */
-	for (i = 0; i <= n_prior_backups; ++i)
+	for (int i = 0; i <= n_prior_backups; ++i)
 	{
 		rfile	   *s = source[i];
 
@@ -383,9 +382,7 @@ reconstruct_from_incremental_file(char *input_filename,
 static void
 debug_reconstruction(int n_source, rfile **sources, bool dry_run)
 {
-	unsigned	i;
-
-	for (i = 0; i < n_source; ++i)
+	for (int i = 0; i < n_source; ++i)
 	{
 		rfile	   *s = sources[i];
 

src/bin/pg_config/pg_config.c

@@ -116,9 +116,7 @@ show_item(const char *configname,
 		  ConfigData *configdata,
 		  size_t configdata_len)
 {
-	int			i;
-
-	for (i = 0; i < configdata_len; i++)
+	for (size_t i = 0; i < configdata_len; i++)
 	{
 		if (strcmp(configname, configdata[i].name) == 0)
 			printf("%s\n", configdata[i].setting);
@@ -131,15 +129,13 @@ main(int argc, char **argv)
 	ConfigData *configdata;
 	size_t		configdata_len;
 	char		my_exec_path[MAXPGPATH];
-	int			i;
-	int			j;
 
 	set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_config"));
 
 	progname = get_progname(argv[0]);
 
 	/* check for --help */
-	for (i = 1; i < argc; i++)
+	for (int i = 1; i < argc; i++)
 	{
 		if (strcmp(argv[i], "--help") == 0 || strcmp(argv[i], "-?") == 0)
 		{
@@ -158,14 +154,16 @@ main(int argc, char **argv)
 	/* no arguments -> print everything */
 	if (argc < 2)
 	{
-		for (i = 0; i < configdata_len; i++)
+		for (size_t i = 0; i < configdata_len; i++)
 			printf("%s = %s\n", configdata[i].name, configdata[i].setting);
 		exit(0);
 	}
 
 	/* otherwise print requested items */
-	for (i = 1; i < argc; i++)
+	for (int i = 1; i < argc; i++)
 	{
+		int			j;
+
 		for (j = 0; info_items[j].switchname != NULL; j++)
 		{
 			if (strcmp(argv[i], info_items[j].switchname) == 0)

src/bin/pg_ctl/pg_ctl.c

@@ -1907,8 +1907,6 @@ CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo, bool as_ser
 static PTOKEN_PRIVILEGES
 GetPrivilegesToDelete(HANDLE hToken)
 {
-	int			i,
-				j;
 	DWORD		length;
 	PTOKEN_PRIVILEGES tokenPrivs;
 	LUID		luidLockPages;
@@ -1946,12 +1944,12 @@ GetPrivilegesToDelete(HANDLE hToken)
 		return NULL;
 	}
 
-	for (i = 0; i < tokenPrivs->PrivilegeCount; i++)
+	for (DWORD i = 0; i < tokenPrivs->PrivilegeCount; i++)
 	{
 		if (memcmp(&tokenPrivs->Privileges[i].Luid, &luidLockPages, sizeof(LUID)) == 0 ||
 			memcmp(&tokenPrivs->Privileges[i].Luid, &luidChangeNotify, sizeof(LUID)) == 0)
 		{
-			for (j = i; j < tokenPrivs->PrivilegeCount - 1; j++)
+			for (DWORD j = i; j < tokenPrivs->PrivilegeCount - 1; j++)
 				tokenPrivs->Privileges[j] = tokenPrivs->Privileges[j + 1];
 			tokenPrivs->PrivilegeCount--;
 		}

src/bin/pg_dump/dumputils.c

@@ -981,7 +981,7 @@ generate_restrict_key(void)
 	if (!pg_strong_random(buf, sizeof(buf)))
 		return NULL;
 
-	for (int i = 0; i < sizeof(buf) - 1; i++)
+	for (size_t i = 0; i < sizeof(buf) - 1; i++)
 	{
 		uint8		idx = buf[i] % strlen(restrict_chars);
 

src/bin/pg_dump/pg_backup_archiver.c

@@ -2058,13 +2058,11 @@ TocIDRequired(ArchiveHandle *AH, DumpId id)
 size_t
 WriteOffset(ArchiveHandle *AH, pgoff_t o, int wasSet)
 {
-	int			off;
-
 	/* Save the flag */
 	AH->WriteBytePtr(AH, wasSet);
 
 	/* Write out pgoff_t smallest byte first, prevents endian mismatch */
-	for (off = 0; off < sizeof(pgoff_t); off++)
+	for (size_t off = 0; off < sizeof(pgoff_t); off++)
 	{
 		AH->WriteBytePtr(AH, o & 0xFF);
 		o >>= 8;
@@ -2076,7 +2074,6 @@ int
 ReadOffset(ArchiveHandle *AH, pgoff_t *o)
 {
 	int			i;
-	int			off;
 	int			offsetFlg;
 
 	/* Initialize to zero */
@@ -2122,7 +2119,7 @@ ReadOffset(ArchiveHandle *AH, pgoff_t *o)
 	/*
 	 * Read the bytes
 	 */
-	for (off = 0; off < AH->offSize; off++)
+	for (size_t off = 0; off < AH->offSize; off++)
 	{
 		if (off < sizeof(pgoff_t))
 			*o |= ((pgoff_t) (AH->ReadBytePtr(AH))) << (off * 8);
@@ -2139,8 +2136,6 @@ ReadOffset(ArchiveHandle *AH, pgoff_t *o)
 size_t
 WriteInt(ArchiveHandle *AH, int i)
 {
-	int			b;
-
 	/*
 	 * This is a bit yucky, but I don't want to make the binary format very
 	 * dependent on representation, and not knowing much about it, I write out
@@ -2158,7 +2153,7 @@ WriteInt(ArchiveHandle *AH, int i)
 	else
 		AH->WriteBytePtr(AH, 0);
 
-	for (b = 0; b < AH->intSize; b++)
+	for (size_t b = 0; b < AH->intSize; b++)
 	{
 		AH->WriteBytePtr(AH, i & 0xFF);
 		i >>= 8;
@@ -2171,8 +2166,7 @@ int
 ReadInt(ArchiveHandle *AH)
 {
 	int			res = 0;
-	int			bv,
-				b;
+	int			bv;
 	int			sign = 0;		/* Default positive */
 	int			bitShift = 0;
 
@@ -2180,7 +2174,7 @@ ReadInt(ArchiveHandle *AH)
 		/* Read a sign byte */
 		sign = AH->ReadBytePtr(AH);
 
-	for (b = 0; b < AH->intSize; b++)
+	for (size_t b = 0; b < AH->intSize; b++)
 	{
 		bv = AH->ReadBytePtr(AH) & 0xFF;
 		if (bv != 0)

src/bin/psql/crosstabview.c

@@ -291,8 +291,7 @@ printCrosstab(const PGresult *result,
 {
 	printQueryOpt popt = pset.popt;
 	printTableContent cont;
-	int			i,
-				rn;
+	int			rn;
 	char		col_align;
 	int		   *horiz_map;
 	Oid			col_ftype = PQftype(result, field_for_columns);
@@ -316,7 +315,7 @@ printCrosstab(const PGresult *result,
 	 * This avoids an O(N^2) loop later.
 	 */
 	horiz_map = pg_malloc_array(int, num_columns);
-	for (i = 0; i < num_columns; i++)
+	for (int i = 0; i < num_columns; i++)
 		horiz_map[piv_columns[i].rank] = i;
 
 	/*
@@ -324,7 +323,7 @@ printCrosstab(const PGresult *result,
 	 */
 	col_align = column_type_alignment(data_ftype);
 
-	for (i = 0; i < num_columns; i++)
+	for (int i = 0; i < num_columns; i++)
 	{
 		char	   *colname;
 
@@ -335,7 +334,7 @@ printCrosstab(const PGresult *result,
 	pg_free(horiz_map);
 
 	/* Step 2: set row names in the first output column (vertical header) */
-	for (i = 0; i < num_rows; i++)
+	for (int i = 0; i < num_rows; i++)
 	{
 		int			k = piv_rows[i].rank;
 		int			idx = k * (num_columns + 1);
@@ -414,7 +413,7 @@ printCrosstab(const PGresult *result,
 	 * The non-initialized cells must be set to an empty string for the print
 	 * functions
 	 */
-	for (i = 0; i < cont.cellsadded; i++)
+	for (uint64 i = 0; i < cont.cellsadded; i++)
 	{
 		if (cont.cells[i] == NULL)
 			cont.cells[i] = "";

src/common/hmac.c

@@ -137,7 +137,6 @@ pg_hmac_create(pg_cryptohash_type type)
 int
 pg_hmac_init(pg_hmac_ctx *ctx, const uint8 *key, size_t len)
 {
-	int			i;
 	int			digest_size;
 	int			block_size;
 	uint8	   *shrinkbuf = NULL;
@@ -192,7 +191,7 @@ pg_hmac_init(pg_hmac_ctx *ctx, const uint8 *key, size_t len)
 		pg_cryptohash_free(hash_ctx);
 	}
 
-	for (i = 0; i < len; i++)
+	for (size_t i = 0; i < len; i++)
 	{
 		ctx->k_ipad[i] ^= key[i];
 		ctx->k_opad[i] ^= key[i];

src/common/unicode_case.c

@@ -342,7 +342,7 @@ check_final_sigma(const unsigned char *str, size_t len, size_t offset)
 	int			ulen;
 
 	/* iterate backwards looking for preceding character */
-	for (int i = offset; i > 0;)
+	for (size_t i = offset; i > 0;)
 	{
 		/* skip backwards through continuation bytes */
 		i--;
@@ -370,7 +370,7 @@ check_final_sigma(const unsigned char *str, size_t len, size_t offset)
 	ulen = utf8_mblen((const unsigned char *) str + offset);
 
 	/* iterate forward looking for following character */
-	for (int i = offset + ulen; i < len;)
+	for (size_t i = offset + ulen; i < len;)
 	{
 		ulen = utf8_mblen((const unsigned char *) str + i);
 

src/fe_utils/print.c

@@ -1569,8 +1569,8 @@ print_aligned_vertical(const printTableContent *cont,
 		if (cont->opt->format == PRINT_WRAPPED && cont->ncolumns > 0)
 		{
 			width_wrap = pg_malloc_array(unsigned int, cont->ncolumns);
-			for (i = 0; i < cont->ncolumns; i++)
-				width_wrap[i] = dwidth;
+			for (int j = 0; j < cont->ncolumns; j++)
+				width_wrap[j] = dwidth;
 		}
 
 		IsPagerNeeded(cont, width_wrap, true, &fout, &is_pager);

src/include/lib/radixtree.h

@@ -585,13 +585,13 @@ typedef struct RT_NODE_256
  */
 
 #if SIZEOF_DSA_POINTER < 8
-#define RT_FANOUT_16_LO	((96 - offsetof(RT_NODE_16, children)) / sizeof(RT_PTR_ALLOC))
-#define RT_FANOUT_16_HI	Min(RT_FANOUT_16_MAX, (160 - offsetof(RT_NODE_16, children)) / sizeof(RT_PTR_ALLOC))
-#define RT_FANOUT_48	Min(RT_FANOUT_48_MAX, (512 - offsetof(RT_NODE_48, children)) / sizeof(RT_PTR_ALLOC))
+#define RT_FANOUT_16_LO	((int) ((96 - offsetof(RT_NODE_16, children)) / sizeof(RT_PTR_ALLOC)))
+#define RT_FANOUT_16_HI	((int) Min(RT_FANOUT_16_MAX, (160 - offsetof(RT_NODE_16, children)) / sizeof(RT_PTR_ALLOC)))
+#define RT_FANOUT_48	((int) Min(RT_FANOUT_48_MAX, (512 - offsetof(RT_NODE_48, children)) / sizeof(RT_PTR_ALLOC)))
 #else
-#define RT_FANOUT_16_LO	((160 - offsetof(RT_NODE_16, children)) / sizeof(RT_PTR_ALLOC))
-#define RT_FANOUT_16_HI	Min(RT_FANOUT_16_MAX, (320 - offsetof(RT_NODE_16, children)) / sizeof(RT_PTR_ALLOC))
-#define RT_FANOUT_48	Min(RT_FANOUT_48_MAX, (768 - offsetof(RT_NODE_48, children)) / sizeof(RT_PTR_ALLOC))
+#define RT_FANOUT_16_LO	((int) ((160 - offsetof(RT_NODE_16, children)) / sizeof(RT_PTR_ALLOC)))
+#define RT_FANOUT_16_HI	((int) Min(RT_FANOUT_16_MAX, (320 - offsetof(RT_NODE_16, children)) / sizeof(RT_PTR_ALLOC)))
+#define RT_FANOUT_48	((int) Min(RT_FANOUT_48_MAX, (768 - offsetof(RT_NODE_48, children)) / sizeof(RT_PTR_ALLOC)))
 #endif							/* SIZEOF_DSA_POINTER < 8 */
 
 #else							/* ! RT_SHMEM */
@@ -675,7 +675,7 @@ static const RT_SIZE_CLASS_ELEM RT_SIZE_CLASS_INFO[] = {
 	},
 };
 
-#define RT_NUM_SIZE_CLASSES lengthof(RT_SIZE_CLASS_INFO)
+#define RT_NUM_SIZE_CLASSES ((int) lengthof(RT_SIZE_CLASS_INFO))
 
 #ifdef RT_SHMEM
 /* A magic value used to identify our radix tree */

src/interfaces/ecpg/test/expected/sql-sqljson.c

@@ -414,8 +414,8 @@ if (sqlca.sqlcode < 0) sqlprint();}
 if (sqlca.sqlcode < 0) sqlprint();}
 #line 114 "sqljson.pgc"
 
-	  for (int i = 0; i < sizeof(is_json); i++)
-		  printf("Found is_json[%d]: %s\n", i, is_json[i] ? "true" : "false");
+	  for (size_t i = 0; i < sizeof(is_json); i++)
+		  printf("Found is_json[%zu]: %s\n", i, is_json[i] ? "true" : "false");
 
   { ECPGdisconnect(__LINE__, "CURRENT");
 #line 118 "sqljson.pgc"

src/interfaces/ecpg/test/sql/sqljson.pgc

@@ -112,8 +112,8 @@ EXEC SQL END DECLARE SECTION;
 		  INTO :is_json[0], :is_json[1], :is_json[2], :is_json[3], :is_json[4],
 		  :is_json[5], :is_json[6], :is_json[7]
 		  FROM val;
-	  for (int i = 0; i < sizeof(is_json); i++)
-		  printf("Found is_json[%d]: %s\n", i, is_json[i] ? "true" : "false");
+	  for (size_t i = 0; i < sizeof(is_json); i++)
+		  printf("Found is_json[%zu]: %s\n", i, is_json[i] ? "true" : "false");
 
   EXEC SQL DISCONNECT;
 

src/interfaces/libpq-oauth/oauth-curl.c

@@ -1704,7 +1704,7 @@ debug_callback(CURL *handle, curl_infotype type, char *data, size_t size,
 	 * are included in a single call. We also don't allow unprintable ASCII
 	 * through without a basic <XX> escape.
 	 */
-	for (int i = 0; i < size; i++)
+	for (size_t i = 0; i < size; i++)
 	{
 		char		c = data[i];
 

src/interfaces/libpq/fe-connect.c

@@ -5517,10 +5517,10 @@ ldapServiceLookup(const char *purl, PQconninfoOption *options,
 	int			port = LDAP_DEF_PORT,
 				scope,
 				rc,
-				size,
 				state,
 				oldstate,
 				i;
+	size_t		size;
 #ifndef WIN32
 	int			msgid;
 #endif

src/interfaces/libpq/win32.c

@@ -277,11 +277,10 @@ const char *
 winsock_strerror(int err, char *strerrbuf, size_t buflen)
 {
 	unsigned long flags;
-	int			offs,
-				i;
+	int			offs;
 	int			success = LookupWSErrorMessage(err, strerrbuf);
 
-	for (i = 0; !success && i < DLLS_SIZE; i++)
+	for (size_t i = 0; !success && i < DLLS_SIZE; i++)
 	{
 
 		if (!dlls[i].loaded)

src/test/modules/test_aio/test_aio.c

@@ -564,7 +564,7 @@ evict_rel(PG_FUNCTION_ARGS)
 
 			nblocks = smgrnblocks(smgr, forknum);
 
-			for (int blkno = 0; blkno < nblocks; blkno++)
+			for (BlockNumber blkno = 0; blkno < nblocks; blkno++)
 			{
 				invalidate_one_block(rel, forknum, blkno);
 			}

src/test/modules/test_binaryheap/test_binaryheap.c

@@ -259,7 +259,7 @@ test_binaryheap(PG_FUNCTION_ARGS)
 {
 	static const int test_sizes[] = {1, 2, 3, 10, 100, 1000};
 
-	for (int i = 0; i < sizeof(test_sizes) / sizeof(int); i++)
+	for (size_t i = 0; i < sizeof(test_sizes) / sizeof(int); i++)
 	{
 		int			size = test_sizes[i];
 

src/test/modules/test_escape/test_escape.c

@@ -355,7 +355,7 @@ escape_replace(PGconn *conn, PQExpBuffer target,
 
 	appendPQExpBufferChar(target, '\'');
 
-	for (int i = 0; i < unescaped_len; i++)
+	for (size_t i = 0; i < unescaped_len; i++)
 	{
 		char		c = *s;
 

src/test/modules/test_integerset/test_integerset.c

@@ -182,7 +182,7 @@ test_pattern(const test_spec *spec)
 	{
 		uint64		x = 0;
 
-		for (int i = 0; i < pattern_num_values && n < spec->num_values; i++)
+		for (uint64 i = 0; i < pattern_num_values && n < spec->num_values; i++)
 		{
 			x = last_int + pattern_values[i];
 
@@ -283,7 +283,7 @@ test_pattern(const test_spec *spec)
 	last_int = 0;
 	while (n < spec->num_values)
 	{
-		for (int i = 0; i < pattern_num_values && n < spec->num_values; i++)
+		for (uint64 i = 0; i < pattern_num_values && n < spec->num_values; i++)
 		{
 			uint64		expected = last_int + pattern_values[i];
 			uint64		x;

src/test/modules/test_predtest/test_predtest.c

@@ -51,7 +51,6 @@ test_predtest(PG_FUNCTION_ARGS)
 				weak_refuted_by;
 	Datum		values[8];
 	bool		nulls[8] = {0};
-	int			i;
 
 	/* We use SPI to parse, plan, and execute the test query */
 	SPI_connect();
@@ -76,7 +75,7 @@ test_predtest(PG_FUNCTION_ARGS)
 		elog(ERROR, "test_predtest query must yield two boolean columns");
 
 	s_i_holds = w_i_holds = s_r_holds = w_r_holds = true;
-	for (i = 0; i < SPI_processed; i++)
+	for (uint64 i = 0; i < SPI_processed; i++)
 	{
 		HeapTuple	tup = SPI_tuptable->vals[i];
 		Datum		dat;

src/test/modules/test_radixtree/test_radixtree.c

@@ -320,7 +320,7 @@ test_random(void)
 	/* add some random values */
 	pg_prng_seed(&state, seed);
 	keys = (TestValueType *) palloc(sizeof(uint64) * num_keys);
-	for (uint64 i = 0; i < num_keys; i++)
+	for (int i = 0; i < num_keys; i++)
 	{
 		uint64		key = pg_prng_uint64(&state) & filter;
 		TestValueType val = (TestValueType) key;
@@ -333,7 +333,7 @@ test_random(void)
 
 	rt_stats(radixtree);
 
-	for (uint64 i = 0; i < num_keys; i++)
+	for (int i = 0; i < num_keys; i++)
 	{
 		TestValueType *value;
 
@@ -348,7 +348,7 @@ test_random(void)
 	qsort(keys, num_keys, sizeof(uint64), key_cmp);
 
 	/* should not find numbers in between the keys */
-	for (uint64 i = 0; i < num_keys - 1; i++)
+	for (int i = 0; i < num_keys - 1; i++)
 	{
 		TestValueType *value;
 
@@ -410,7 +410,7 @@ test_random(void)
 	pg_prng_seed(&state, seed);
 
 	/* delete in original random order */
-	for (uint64 i = 0; i < num_keys; i++)
+	for (int i = 0; i < num_keys; i++)
 	{
 		uint64		key = pg_prng_uint64(&state) & filter;