More -Wshadow=compatible-local warning fixes

In a similar effort to f01592f91, here we're targetting fixing the
warnings where we've deemed the shadowing variable to serve a close enough
purpose to the shadowed variable just to reuse the shadowed version and
not declare the shadowing variable at all.

By my count, this takes the warning count from 106 down to 71.

Author: Justin Pryzby
Discussion: https://postgr.es/m/20220825020839.GT2342@telsasoft.com

src/backend/access/hash/hash_xlog.c

@@ -240,7 +240,6 @@ hash_xlog_add_ovfl_page(XLogReaderState *record)
 		{
 			Page		mappage = (Page) BufferGetPage(mapbuffer);
 			uint32	   *freep = NULL;
-			char	   *data;
 			uint32	   *bitmap_page_bit;
 
 			freep = HashPageGetBitmap(mappage);

src/backend/access/transam/multixact.c

@@ -1614,7 +1614,6 @@ mXactCachePut(MultiXactId multi, int nmembers, MultiXactMember *members)
 	if (MXactCacheMembers++ >= MAX_CACHE_ENTRIES)
 	{
 		dlist_node *node;
-		mXactCacheEnt *entry;
 
 		node = dlist_tail_node(&MXactCache);
 		dlist_delete(node);

src/backend/access/transam/xlog.c

@@ -3036,8 +3036,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli,
 	pgstat_report_wait_start(WAIT_EVENT_WAL_INIT_SYNC);
 	if (pg_fsync(fd) != 0)
 	{
-		int			save_errno = errno;
-
+		save_errno = errno;
 		close(fd);
 		errno = save_errno;
 		ereport(ERROR,
@@ -4721,7 +4720,6 @@ XLogInitNewTimeline(TimeLineID endTLI, XLogRecPtr endOfLog, TimeLineID newTLI)
 
 		if (close(fd) != 0)
 		{
-			char		xlogfname[MAXFNAMELEN];
 			int			save_errno = errno;
 
 			XLogFileName(xlogfname, newTLI, startLogSegNo, wal_segment_size);

src/backend/commands/functioncmds.c

@@ -121,7 +121,6 @@ compute_return_type(TypeName *returnType, Oid languageOid,
 	{
 		char	   *typnam = TypeNameToString(returnType);
 		Oid			namespaceId;
-		AclResult	aclresult;
 		char	   *typname;
 		ObjectAddress address;
 
@@ -1112,8 +1111,6 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 	if (languageStruct->lanpltrusted)
 	{
 		/* if trusted language, need USAGE privilege */
-		AclResult	aclresult;
-
 		aclresult = pg_language_aclcheck(languageOid, GetUserId(), ACL_USAGE);
 		if (aclresult != ACLCHECK_OK)
 			aclcheck_error(aclresult, OBJECT_LANGUAGE,

src/backend/commands/tablecmds.c

@@ -16796,7 +16796,6 @@ PreCommit_on_commit_actions(void)
 	if (oids_to_drop != NIL)
 	{
 		ObjectAddresses *targetObjects = new_object_addresses();
-		ListCell   *l;
 
 		foreach(l, oids_to_drop)
 		{

src/backend/commands/vacuum.c

@@ -233,8 +233,6 @@ ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
 	 */
 	if (!(params.options & VACOPT_ANALYZE))
 	{
-		ListCell   *lc;
-
 		foreach(lc, vacstmt->rels)
 		{
 			VacuumRelation *vrel = lfirst_node(VacuumRelation, lc);

src/backend/executor/execPartition.c

@@ -768,7 +768,6 @@ ExecInitPartitionInfo(ModifyTableState *mtstate, EState *estate,
 			{
 				List	   *onconflset;
 				List	   *onconflcols;
-				bool		found_whole_row;
 
 				/*
 				 * Translate expressions in onConflictSet to account for

src/backend/executor/nodeWindowAgg.c

@@ -2062,12 +2062,13 @@ ExecWindowAgg(PlanState *pstate)
 	if (winstate->all_first)
 	{
 		int			frameOptions = winstate->frameOptions;
-		ExprContext *econtext = winstate->ss.ps.ps_ExprContext;
 		Datum		value;
 		bool		isnull;
 		int16		len;
 		bool		byval;
 
+		econtext = winstate->ss.ps.ps_ExprContext;
+
 		if (frameOptions & FRAMEOPTION_START_OFFSET)
 		{
 			Assert(winstate->startOffset != NULL);

src/backend/lib/integerset.c

@@ -565,8 +565,6 @@ intset_is_member(IntegerSet *intset, uint64 x)
 	 */
 	if (intset->num_buffered_values > 0 && x >= intset->buffered_values[0])
 	{
-		int			itemno;
-
 		itemno = intset_binsrch_uint64(x,
 									   intset->buffered_values,
 									   intset->num_buffered_values,

src/backend/libpq/auth.c

@@ -1652,8 +1652,6 @@ interpret_ident_response(const char *ident_response,
 						return false;
 					else
 					{
-						int			i;	/* Index into *ident_user */
-
 						cursor++;	/* Go over colon */
 						while (pg_isblank(*cursor))
 							cursor++;	/* skip blanks */

src/backend/optimizer/path/indxpath.c

@@ -361,7 +361,6 @@ create_index_paths(PlannerInfo *root, RelOptInfo *rel)
 	if (bitjoinpaths != NIL)
 	{
 		List	   *all_path_outers;
-		ListCell   *lc;
 
 		/* Identify each distinct parameterization seen in bitjoinpaths */
 		all_path_outers = NIL;
@@ -2188,7 +2187,7 @@ match_clause_to_index(PlannerInfo *root,
 		/* Ignore duplicates */
 		foreach(lc, clauseset->indexclauses[indexcol])
 		{
-			IndexClause *iclause = (IndexClause *) lfirst(lc);
+			iclause = (IndexClause *) lfirst(lc);
 
 			if (iclause->rinfo == rinfo)
 				return;

src/backend/optimizer/plan/planner.c

@@ -3484,8 +3484,6 @@ get_number_of_groups(PlannerInfo *root,
 
 			if (gd->hash_sets_idx)
 			{
-				ListCell   *lc;
-
 				gd->dNumHashGroups = 0;
 
 				groupExprs = get_sortgrouplist_exprs(parse->groupClause,
@@ -4720,8 +4718,6 @@ create_final_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,
 	Path	   *cheapest_input_path = input_rel->cheapest_total_path;
 	double		numDistinctRows;
 	bool		allow_hash;
-	Path	   *path;
-	ListCell   *lc;
 
 	/* Estimate number of distinct rows there will be */
 	if (parse->groupClause || parse->groupingSets || parse->hasAggs ||
@@ -4766,6 +4762,8 @@ create_final_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,
 		 * the other.)
 		 */
 		List	   *needed_pathkeys;
+		Path	   *path;
+		ListCell   *lc;
 
 		if (parse->hasDistinctOn &&
 			list_length(root->distinct_pathkeys) <
@@ -4776,7 +4774,7 @@ create_final_distinct_paths(PlannerInfo *root, RelOptInfo *input_rel,
 
 		foreach(lc, input_rel->pathlist)
 		{
-			Path	   *path = (Path *) lfirst(lc);
+			path = (Path *) lfirst(lc);
 
 			if (pathkeys_contained_in(needed_pathkeys, path->pathkeys))
 			{
@@ -5034,8 +5032,6 @@ create_ordered_paths(PlannerInfo *root,
 		 */
 		if (enable_incremental_sort && list_length(root->sort_pathkeys) > 1)
 		{
-			ListCell   *lc;
-
 			foreach(lc, input_rel->partial_pathlist)
 			{
 				Path	   *input_path = (Path *) lfirst(lc);
@@ -7607,7 +7603,6 @@ apply_scanjoin_target_to_paths(PlannerInfo *root,
 			AppendRelInfo **appinfos;
 			int			nappinfos;
 			List	   *child_scanjoin_targets = NIL;
-			ListCell   *lc;
 
 			Assert(child_rel != NULL);
 

src/backend/optimizer/plan/subselect.c

@@ -2554,8 +2554,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_Append:
 			{
-				ListCell   *l;
-
 				foreach(l, ((Append *) plan)->appendplans)
 				{
 					context.paramids =
@@ -2571,8 +2569,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_MergeAppend:
 			{
-				ListCell   *l;
-
 				foreach(l, ((MergeAppend *) plan)->mergeplans)
 				{
 					context.paramids =
@@ -2588,8 +2584,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_BitmapAnd:
 			{
-				ListCell   *l;
-
 				foreach(l, ((BitmapAnd *) plan)->bitmapplans)
 				{
 					context.paramids =
@@ -2605,8 +2599,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_BitmapOr:
 			{
-				ListCell   *l;
-
 				foreach(l, ((BitmapOr *) plan)->bitmapplans)
 				{
 					context.paramids =
@@ -2622,8 +2614,6 @@ finalize_plan(PlannerInfo *root, Plan *plan,
 
 		case T_NestLoop:
 			{
-				ListCell   *l;
-
 				finalize_primnode((Node *) ((Join *) plan)->joinqual,
 								  &context);
 				/* collect set of params that will be passed to right child */

src/backend/optimizer/prep/prepunion.c

@@ -653,7 +653,6 @@ generate_union_paths(SetOperationStmt *op, PlannerInfo *root,
 	if (partial_paths_valid)
 	{
 		Path	   *ppath;
-		ListCell   *lc;
 		int			parallel_workers = 0;
 
 		/* Find the highest number of workers requested for any subpath. */

src/backend/postmaster/autovacuum.c

@@ -1102,7 +1102,7 @@ rebuild_database_list(Oid newdb)
 		 */
 		for (i = 0; i < nelems; i++)
 		{
-			avl_dbase  *db = &(dbary[i]);
+			db = &(dbary[i]);
 
 			current_time = TimestampTzPlusMilliseconds(current_time,
 													   millis_increment);

src/backend/rewrite/rowsecurity.c

@@ -824,7 +824,6 @@ add_with_check_options(Relation rel,
 		{
 			RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
 			Expr	   *qual = QUAL_FOR_WCO(policy);
-			WithCheckOption *wco;
 
 			if (qual != NULL)
 			{

src/backend/statistics/dependencies.c

@@ -1265,7 +1265,6 @@ dependency_is_compatible_expression(Node *clause, Index relid, List *statlist, N
 	else if (is_orclause(clause))
 	{
 		BoolExpr   *bool_expr = (BoolExpr *) clause;
-		ListCell   *lc;
 
 		/* start with no expression (we'll use the first match) */
 		*expr = NULL;

src/backend/utils/adt/rangetypes_spgist.c

@@ -693,7 +693,6 @@ spg_range_quad_inner_consistent(PG_FUNCTION_ARGS)
 				 * quadrants if we're looking for a value strictly greater
 				 * than the maximum.
 				 */
-				int			cmp;
 
 				cmp = range_cmp_bounds(typcache, &centroidLower, maxLower);
 				if (cmp > 0 || (!inclusive && cmp == 0))
@@ -721,7 +720,6 @@ spg_range_quad_inner_consistent(PG_FUNCTION_ARGS)
 				 * quadrants if we're looking for a value strictly greater
 				 * than the maximum.
 				 */
-				int			cmp;
 
 				cmp = range_cmp_bounds(typcache, &centroidUpper, maxUpper);
 				if (cmp > 0 || (!inclusive && cmp == 0))

src/backend/utils/adt/ruleutils.c

@@ -1303,7 +1303,6 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 	if (!heap_attisnull(ht_idx, Anum_pg_index_indexprs, NULL))
 	{
 		Datum		exprsDatum;
-		bool		isnull;
 		char	   *exprsString;
 
 		exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
@@ -1500,7 +1499,6 @@ pg_get_indexdef_worker(Oid indexrelid, int colno,
 		{
 			Node	   *node;
 			Datum		predDatum;
-			bool		isnull;
 			char	   *predString;
 
 			/* Convert text string to node tree */
@@ -1945,7 +1943,6 @@ pg_get_partkeydef_worker(Oid relid, int prettyFlags,
 	if (!heap_attisnull(tuple, Anum_pg_partitioned_table_partexprs, NULL))
 	{
 		Datum		exprsDatum;
-		bool		isnull;
 		char	   *exprsString;
 
 		exprsDatum = SysCacheGetAttr(PARTRELID, tuple,

src/bin/pgbench/pgbench.c

@@ -3109,7 +3109,6 @@ sendCommand(CState *st, Command *command)
 			for (j = 0; commands[j] != NULL; j++)
 			{
 				PGresult   *res;
-				char		name[MAX_PREPARE_NAME];
 
 				if (commands[j]->type != SQL_COMMAND)
 					continue;
@@ -3803,8 +3802,6 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
 				/* quickly skip commands until something to do... */
 				while (true)
 				{
-					Command    *command;
-
 					command = sql_script[st->use_file].commands[st->command];
 
 					/* cannot reach end of script in that state */
@@ -3959,8 +3956,6 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
 				 */
 				if (report_per_command)
 				{
-					Command    *command;
-
 					pg_time_now_lazy(&now);
 
 					command = sql_script[st->use_file].commands[st->command];