Replace many MemSet calls with struct initialization

This replaces all MemSet() calls with struct initialization where that
is easily and obviously possible.  (For example, some cases have to
worry about padding bits, so I left those.)

(The same could be done with appropriate memset() calls, but this
patch is part of an effort to phase out MemSet(), so it doesn't touch
memset() calls.)

Reviewed-by: Ranier Vilela <[email protected]>
Reviewed-by: Alvaro Herrera <[email protected]>
Discussion: https://www.postgresql.org/message-id/[email protected]

12 files changed, 31 insertions, 76 deletions

diff --git a/contrib/amcheck/verify_heapam.c b/contrib/amcheck/verify_heapam.c
index e488f5e234b..d33f33f1703 100644
--- a/contrib/amcheck/verify_heapam.c
+++ b/contrib/amcheck/verify_heapam.c
@@ -554,12 +554,10 @@ report_corruption_internal(Tuplestorestate *tupstore, TupleDesc tupdesc,
 						   BlockNumber blkno, OffsetNumber offnum,
 						   AttrNumber attnum, char *msg)
 {
-	Datum		values[HEAPCHECK_RELATION_COLS];
-	bool		nulls[HEAPCHECK_RELATION_COLS];
+	Datum		values[HEAPCHECK_RELATION_COLS] = {0};
+	bool		nulls[HEAPCHECK_RELATION_COLS] = {0};
 	HeapTuple	tuple;
 
-	MemSet(values, 0, sizeof(values));
-	MemSet(nulls, 0, sizeof(nulls));
 	values[0] = Int64GetDatum(blkno);
 	values[1] = Int32GetDatum(offnum);
 	values[2] = Int32GetDatum(attnum);
diff --git a/contrib/bloom/blcost.c b/contrib/bloom/blcost.c
index d42e4e96284..d4b1c763034 100644
--- a/contrib/bloom/blcost.c
+++ b/contrib/bloom/blcost.c
@@ -26,9 +26,7 @@ blcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 			   double *indexPages)
 {
 	IndexOptInfo *index = path->indexinfo;
-	GenericCosts costs;
-
-	MemSet(&costs, 0, sizeof(costs));
+	GenericCosts costs = {0};
 
 	/* We have to visit all index tuples anyway */
 	costs.numIndexTuples = index->tuples;
diff --git a/contrib/pageinspect/brinfuncs.c b/contrib/pageinspect/brinfuncs.c
index 879276e6dec..f4c959ecab9 100644
--- a/contrib/pageinspect/brinfuncs.c
+++ b/contrib/pageinspect/brinfuncs.c
@@ -202,7 +202,7 @@ brin_page_items(PG_FUNCTION_ARGS)
 	for (;;)
 	{
 		Datum		values[7];
-		bool		nulls[7];
+		bool		nulls[7] = {0};
 
 		/*
 		 * This loop is called once for every attribute of every tuple in the
@@ -230,8 +230,6 @@ brin_page_items(PG_FUNCTION_ARGS)
 		else
 			attno++;
 
-		MemSet(nulls, 0, sizeof(nulls));
-
 		if (unusedItem)
 		{
 			values[0] = UInt16GetDatum(offset);
@@ -334,7 +332,7 @@ brin_metapage_info(PG_FUNCTION_ARGS)
 	BrinMetaPageData *meta;
 	TupleDesc	tupdesc;
 	Datum		values[4];
-	bool		nulls[4];
+	bool		nulls[4] = {0};
 	HeapTuple	htup;
 
 	if (!superuser())
@@ -354,7 +352,6 @@ brin_metapage_info(PG_FUNCTION_ARGS)
 
 	/* Extract values from the metapage */
 	meta = (BrinMetaPageData *) PageGetContents(page);
-	MemSet(nulls, 0, sizeof(nulls));
 	values[0] = CStringGetTextDatum(psprintf("0x%08X", meta->brinMagic));
 	values[1] = Int32GetDatum(meta->brinVersion);
 	values[2] = Int32GetDatum(meta->pagesPerRange);
diff --git a/contrib/pageinspect/hashfuncs.c b/contrib/pageinspect/hashfuncs.c
index 5287dbe1a30..81815392d70 100644
--- a/contrib/pageinspect/hashfuncs.c
+++ b/contrib/pageinspect/hashfuncs.c
@@ -238,7 +238,7 @@ hash_page_stats(PG_FUNCTION_ARGS)
 	Page		page;
 	int			j;
 	Datum		values[9];
-	bool		nulls[9];
+	bool		nulls[9] = {0};
 	HashPageStat stat;
 	HeapTuple	tuple;
 	TupleDesc	tupleDesc;
@@ -261,8 +261,6 @@ hash_page_stats(PG_FUNCTION_ARGS)
 		elog(ERROR, "return type must be a row type");
 	tupleDesc = BlessTupleDesc(tupleDesc);
 
-	MemSet(nulls, 0, sizeof(nulls));
-
 	j = 0;
 	values[j++] = Int32GetDatum(stat.live_items);
 	values[j++] = Int32GetDatum(stat.dead_items);
@@ -303,7 +301,7 @@ hash_page_items(PG_FUNCTION_ARGS)
 	Page		page;
 	Datum		result;
 	Datum		values[3];
-	bool		nulls[3];
+	bool		nulls[3] = {0};
 	uint32		hashkey;
 	HeapTuple	tuple;
 	FuncCallContext *fctx;
@@ -361,8 +359,6 @@ hash_page_items(PG_FUNCTION_ARGS)
 
 		itup = (IndexTuple) PageGetItem(uargs->page, id);
 
-		MemSet(nulls, 0, sizeof(nulls));
-
 		j = 0;
 		values[j++] = Int32GetDatum((int32) uargs->offset);
 		values[j++] = PointerGetDatum(&itup->t_tid);
@@ -409,7 +405,7 @@ hash_bitmap_info(PG_FUNCTION_ARGS)
 	int			i,
 				j;
 	Datum		values[3];
-	bool		nulls[3];
+	bool		nulls[3] = {0};
 	uint32	   *freep;
 
 	if (!superuser())
@@ -495,8 +491,6 @@ hash_bitmap_info(PG_FUNCTION_ARGS)
 		elog(ERROR, "return type must be a row type");
 	tupleDesc = BlessTupleDesc(tupleDesc);
 
-	MemSet(nulls, 0, sizeof(nulls));
-
 	j = 0;
 	values[j++] = Int64GetDatum((int64) bitmapblkno);
 	values[j++] = Int32GetDatum(bitmapbit);
@@ -526,7 +520,7 @@ hash_metapage_info(PG_FUNCTION_ARGS)
 	int			i,
 				j;
 	Datum		values[16];
-	bool		nulls[16];
+	bool		nulls[16] = {0};
 	Datum		spares[HASH_MAX_SPLITPOINTS];
 	Datum		mapp[HASH_MAX_BITMAPS];
 
@@ -544,8 +538,6 @@ hash_metapage_info(PG_FUNCTION_ARGS)
 
 	metad = HashPageGetMeta(page);
 
-	MemSet(nulls, 0, sizeof(nulls));
-
 	j = 0;
 	values[j++] = Int64GetDatum((int64) metad->hashm_magic);
 	values[j++] = Int64GetDatum((int64) metad->hashm_version);
diff --git a/contrib/pageinspect/heapfuncs.c b/contrib/pageinspect/heapfuncs.c
index a654234c6bd..2ff70405cf8 100644
--- a/contrib/pageinspect/heapfuncs.c
+++ b/contrib/pageinspect/heapfuncs.c
@@ -507,8 +507,8 @@ Datum
 heap_tuple_infomask_flags(PG_FUNCTION_ARGS)
 {
 #define HEAP_TUPLE_INFOMASK_COLS 2
-	Datum		values[HEAP_TUPLE_INFOMASK_COLS];
-	bool		nulls[HEAP_TUPLE_INFOMASK_COLS];
+	Datum		values[HEAP_TUPLE_INFOMASK_COLS] = {0};
+	bool		nulls[HEAP_TUPLE_INFOMASK_COLS] = {0};
 	uint16		t_infomask = PG_GETARG_INT16(0);
 	uint16		t_infomask2 = PG_GETARG_INT16(1);
 	int			cnt = 0;
@@ -530,10 +530,6 @@ heap_tuple_infomask_flags(PG_FUNCTION_ARGS)
 	bitcnt = pg_popcount((const char *) &t_infomask, sizeof(uint16)) +
 		pg_popcount((const char *) &t_infomask2, sizeof(uint16));
 
-	/* Initialize values and NULL flags arrays */
-	MemSet(values, 0, sizeof(values));
-	MemSet(nulls, 0, sizeof(nulls));
-
 	/* If no flags, return a set of empty arrays */
 	if (bitcnt <= 0)
 	{
diff --git a/contrib/pg_prewarm/autoprewarm.c b/contrib/pg_prewarm/autoprewarm.c
index 13eee4a1379..ee20e9b0850 100644
--- a/contrib/pg_prewarm/autoprewarm.c
+++ b/contrib/pg_prewarm/autoprewarm.c
@@ -814,12 +814,11 @@ apw_detach_shmem(int code, Datum arg)
 static void
 apw_start_leader_worker(void)
 {
-	BackgroundWorker worker;
+	BackgroundWorker worker = {0};
 	BackgroundWorkerHandle *handle;
 	BgwHandleStatus status;
 	pid_t		pid;
 
-	MemSet(&worker, 0, sizeof(BackgroundWorker));
 	worker.bgw_flags = BGWORKER_SHMEM_ACCESS;
 	worker.bgw_start_time = BgWorkerStart_ConsistentState;
 	strcpy(worker.bgw_library_name, "pg_prewarm");
@@ -856,10 +855,9 @@ apw_start_leader_worker(void)
 static void
 apw_start_database_worker(void)
 {
-	BackgroundWorker worker;
+	BackgroundWorker worker = {0};
 	BackgroundWorkerHandle *handle;
 
-	MemSet(&worker, 0, sizeof(BackgroundWorker));
 	worker.bgw_flags =
 		BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION;
 	worker.bgw_start_time = BgWorkerStart_ConsistentState;
diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c
index 4acfddcdb87..b4d4231dc61 100644
--- a/contrib/pg_stat_statements/pg_stat_statements.c
+++ b/contrib/pg_stat_statements/pg_stat_statements.c
@@ -1854,8 +1854,8 @@ pg_stat_statements_info(PG_FUNCTION_ARGS)
 {
 	pgssGlobalStats stats;
 	TupleDesc	tupdesc;
-	Datum		values[PG_STAT_STATEMENTS_INFO_COLS];
-	bool		nulls[PG_STAT_STATEMENTS_INFO_COLS];
+	Datum		values[PG_STAT_STATEMENTS_INFO_COLS] = {0};
+	bool		nulls[PG_STAT_STATEMENTS_INFO_COLS] = {0};
 
 	if (!pgss || !pgss_hash)
 		ereport(ERROR,
@@ -1866,9 +1866,6 @@ pg_stat_statements_info(PG_FUNCTION_ARGS)
 	if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
 		elog(ERROR, "return type must be a row type");
 
-	MemSet(values, 0, sizeof(values));
-	MemSet(nulls, 0, sizeof(nulls));
-
 	/* Read global statistics for pg_stat_statements */
 	{
 		volatile pgssSharedState *s = (volatile pgssSharedState *) pgss;
diff --git a/contrib/pg_visibility/pg_visibility.c b/contrib/pg_visibility/pg_visibility.c
index 4e2e9ea9bbe..a95f73ec796 100644
--- a/contrib/pg_visibility/pg_visibility.c
+++ b/contrib/pg_visibility/pg_visibility.c
@@ -75,7 +75,7 @@ pg_visibility_map(PG_FUNCTION_ARGS)
 	Buffer		vmbuffer = InvalidBuffer;
 	TupleDesc	tupdesc;
 	Datum		values[2];
-	bool		nulls[2];
+	bool		nulls[2] = {0};
 
 	rel = relation_open(relid, AccessShareLock);
 
@@ -88,7 +88,6 @@ pg_visibility_map(PG_FUNCTION_ARGS)
 				 errmsg("invalid block number")));
 
 	tupdesc = pg_visibility_tupdesc(false, false);
-	MemSet(nulls, 0, sizeof(nulls));
 
 	mapbits = (int32) visibilitymap_get_status(rel, blkno, &vmbuffer);
 	if (vmbuffer != InvalidBuffer)
@@ -117,7 +116,7 @@ pg_visibility(PG_FUNCTION_ARGS)
 	Page		page;
 	TupleDesc	tupdesc;
 	Datum		values[3];
-	bool		nulls[3];
+	bool		nulls[3] = {0};
 
 	rel = relation_open(relid, AccessShareLock);
 
@@ -130,7 +129,6 @@ pg_visibility(PG_FUNCTION_ARGS)
 				 errmsg("invalid block number")));
 
 	tupdesc = pg_visibility_tupdesc(false, true);
-	MemSet(nulls, 0, sizeof(nulls));
 
 	mapbits = (int32) visibilitymap_get_status(rel, blkno, &vmbuffer);
 	if (vmbuffer != InvalidBuffer)
@@ -188,10 +186,9 @@ pg_visibility_map_rel(PG_FUNCTION_ARGS)
 	if (info->next < info->count)
 	{
 		Datum		values[3];
-		bool		nulls[3];
+		bool		nulls[3] = {0};
 		HeapTuple	tuple;
 
-		MemSet(nulls, 0, sizeof(nulls));
 		values[0] = Int64GetDatum(info->next);
 		values[1] = BoolGetDatum((info->bits[info->next] & (1 << 0)) != 0);
 		values[2] = BoolGetDatum((info->bits[info->next] & (1 << 1)) != 0);
@@ -233,10 +230,9 @@ pg_visibility_rel(PG_FUNCTION_ARGS)
 	if (info->next < info->count)
 	{
 		Datum		values[4];
-		bool		nulls[4];
+		bool		nulls[4] = {0};
 		HeapTuple	tuple;
 
-		MemSet(nulls, 0, sizeof(nulls));
 		values[0] = Int64GetDatum(info->next);
 		values[1] = BoolGetDatum((info->bits[info->next] & (1 << 0)) != 0);
 		values[2] = BoolGetDatum((info->bits[info->next] & (1 << 1)) != 0);
@@ -266,7 +262,7 @@ pg_visibility_map_summary(PG_FUNCTION_ARGS)
 	int64		all_frozen = 0;
 	TupleDesc	tupdesc;
 	Datum		values[2];
-	bool		nulls[2];
+	bool		nulls[2] = {0};
 
 	rel = relation_open(relid, AccessShareLock);
 
@@ -300,7 +296,6 @@ pg_visibility_map_summary(PG_FUNCTION_ARGS)
 	TupleDescInitEntry(tupdesc, (AttrNumber) 2, "all_frozen", INT8OID, -1, 0);
 	tupdesc = BlessTupleDesc(tupdesc);
 
-	MemSet(nulls, 0, sizeof(nulls));
 	values[0] = Int64GetDatum(all_visible);
 	values[1] = Int64GetDatum(all_frozen);
 
diff --git a/contrib/pg_walinspect/pg_walinspect.c b/contrib/pg_walinspect/pg_walinspect.c
index a082dfb3310..90817876347 100644
--- a/contrib/pg_walinspect/pg_walinspect.c
+++ b/contrib/pg_walinspect/pg_walinspect.c
@@ -229,8 +229,8 @@ pg_get_wal_record_info(PG_FUNCTION_ARGS)
 {
 #define PG_GET_WAL_RECORD_INFO_COLS 11
 	Datum		result;
-	Datum		values[PG_GET_WAL_RECORD_INFO_COLS];
-	bool		nulls[PG_GET_WAL_RECORD_INFO_COLS];
+	Datum		values[PG_GET_WAL_RECORD_INFO_COLS] = {0};
+	bool		nulls[PG_GET_WAL_RECORD_INFO_COLS] = {0};
 	XLogRecPtr	lsn;
 	XLogRecPtr	curr_lsn;
 	XLogRecPtr	first_record;
@@ -266,9 +266,6 @@ pg_get_wal_record_info(PG_FUNCTION_ARGS)
 				 errmsg("could not read WAL at %X/%X",
 						LSN_FORMAT_ARGS(first_record))));
 
-	MemSet(values, 0, sizeof(values));
-	MemSet(nulls, 0, sizeof(nulls));
-
 	GetWALRecordInfo(xlogreader, first_record, values, nulls,
 					 PG_GET_WAL_RECORD_INFO_COLS);
 
@@ -334,8 +331,8 @@ GetWALRecordsInfo(FunctionCallInfo fcinfo, XLogRecPtr start_lsn,
 	XLogRecPtr	first_record;
 	XLogReaderState *xlogreader;
 	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
-	Datum		values[PG_GET_WAL_RECORDS_INFO_COLS];
-	bool		nulls[PG_GET_WAL_RECORDS_INFO_COLS];
+	Datum		values[PG_GET_WAL_RECORDS_INFO_COLS] = {0};
+	bool		nulls[PG_GET_WAL_RECORDS_INFO_COLS] = {0};
 
 	SetSingleFuncCall(fcinfo, 0);
 
@@ -343,9 +340,6 @@ GetWALRecordsInfo(FunctionCallInfo fcinfo, XLogRecPtr start_lsn,
 
 	Assert(xlogreader);
 
-	MemSet(values, 0, sizeof(values));
-	MemSet(nulls, 0, sizeof(nulls));
-
 	while (ReadNextXLogRecord(xlogreader, first_record) &&
 		   xlogreader->EndRecPtr <= end_lsn)
 	{
@@ -556,17 +550,15 @@ GetWalStats(FunctionCallInfo fcinfo, XLogRecPtr start_lsn,
 #define PG_GET_WAL_STATS_COLS 9
 	XLogRecPtr	first_record;
 	XLogReaderState *xlogreader;
-	XLogStats	stats;
+	XLogStats	stats = {0};
 	ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
-	Datum		values[PG_GET_WAL_STATS_COLS];
-	bool		nulls[PG_GET_WAL_STATS_COLS];
+	Datum		values[PG_GET_WAL_STATS_COLS] = {0};
+	bool		nulls[PG_GET_WAL_STATS_COLS] = {0};
 
 	SetSingleFuncCall(fcinfo, 0);
 
 	xlogreader = InitXLogReaderState(start_lsn, &first_record);
 
-	MemSet(&stats, 0, sizeof(stats));
-
 	while (ReadNextXLogRecord(xlogreader, first_record) &&
 		   xlogreader->EndRecPtr <= end_lsn)
 	{
@@ -578,9 +570,6 @@ GetWalStats(FunctionCallInfo fcinfo, XLogRecPtr start_lsn,
 	pfree(xlogreader->private_data);
 	XLogReaderFree(xlogreader);
 
-	MemSet(values, 0, sizeof(values));
-	MemSet(nulls, 0, sizeof(nulls));
-
 	GetXLogSummaryStats(&stats, rsinfo, values, nulls,
 						PG_GET_WAL_STATS_COLS,
 						stats_per_record);
diff --git a/contrib/pgstattuple/pgstatindex.c b/contrib/pgstattuple/pgstatindex.c
index e1048e47ff3..d69ac1c93df 100644
--- a/contrib/pgstattuple/pgstatindex.c
+++ b/contrib/pgstattuple/pgstatindex.c
@@ -575,7 +575,7 @@ pgstathashindex(PG_FUNCTION_ARGS)
 	HeapTuple	tuple;
 	TupleDesc	tupleDesc;
 	Datum		values[8];
-	bool		nulls[8];
+	bool		nulls[8] = {0};
 	Buffer		metabuf;
 	HashMetaPage metap;
 	float8		free_percent;
@@ -697,7 +697,6 @@ pgstathashindex(PG_FUNCTION_ARGS)
 	/*
 	 * Build and return the tuple
 	 */
-	MemSet(nulls, 0, sizeof(nulls));
 	values[0] = Int32GetDatum(stats.version);
 	values[1] = Int64GetDatum((int64) stats.bucket_pages);
 	values[2] = Int64GetDatum((int64) stats.overflow_pages);
diff --git a/contrib/postgres_fdw/connection.c b/contrib/postgres_fdw/connection.c
index cffb6f83107..939d114f02e 100644
--- a/contrib/postgres_fdw/connection.c
+++ b/contrib/postgres_fdw/connection.c
@@ -1678,8 +1678,8 @@ postgres_fdw_get_connections(PG_FUNCTION_ARGS)
 	while ((entry = (ConnCacheEntry *) hash_seq_search(&scan)))
 	{
 		ForeignServer *server;
-		Datum		values[POSTGRES_FDW_GET_CONNECTIONS_COLS];
-		bool		nulls[POSTGRES_FDW_GET_CONNECTIONS_COLS];
+		Datum		values[POSTGRES_FDW_GET_CONNECTIONS_COLS] = {0};
+		bool		nulls[POSTGRES_FDW_GET_CONNECTIONS_COLS] = {0};
 
 		/* We only look for open remote connections */
 		if (!entry->conn)
@@ -1687,9 +1687,6 @@ postgres_fdw_get_connections(PG_FUNCTION_ARGS)
 
 		server = GetForeignServerExtended(entry->serverid, FSV_MISSING_OK);
 
-		MemSet(values, 0, sizeof(values));
-		MemSet(nulls, 0, sizeof(nulls));
-
 		/*
 		 * The foreign server may have been dropped in current explicit
 		 * transaction. It is not possible to drop the server from another
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index 955a428e3da..cfac5390084 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -3307,7 +3307,7 @@ estimate_path_cost_size(PlannerInfo *root,
 		{
 			RelOptInfo *outerrel = fpinfo->outerrel;
 			PgFdwRelationInfo *ofpinfo;
-			AggClauseCosts aggcosts;
+			AggClauseCosts aggcosts = {0};
 			double		input_rows;
 			int			numGroupCols;
 			double		numGroups = 1;
@@ -3331,7 +3331,6 @@ estimate_path_cost_size(PlannerInfo *root,
 			input_rows = ofpinfo->rows;
 
 			/* Collect statistics about aggregates for estimating costs. */
-			MemSet(&aggcosts, 0, sizeof(AggClauseCosts));
 			if (root->parse->hasAggs)
 			{
 				get_agg_clause_costs(root, AGGSPLIT_SIMPLE, &aggcosts);