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 <ranier.vf@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/9847b13c-b785-f4e2-75c3-12ec77a3b05c@enterprisedb.com

src/backend/commands/dbcommands.c

@@ -689,8 +689,8 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	volatile Oid dst_deftablespace;
 	Relation	pg_database_rel;
 	HeapTuple	tuple;
-	Datum		new_record[Natts_pg_database];
-	bool		new_record_nulls[Natts_pg_database];
+	Datum		new_record[Natts_pg_database] = {0};
+	bool		new_record_nulls[Natts_pg_database] = {0};
 	Oid			dboid = InvalidOid;
 	Oid			datdba;
 	ListCell   *option;
@@ -1296,9 +1296,6 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 		   (dblocprovider != COLLPROVIDER_ICU && !dbiculocale));
 
 	/* Form tuple */
-	MemSet(new_record, 0, sizeof(new_record));
-	MemSet(new_record_nulls, false, sizeof(new_record_nulls));
-
 	new_record[Anum_pg_database_oid - 1] = ObjectIdGetDatum(dboid);
 	new_record[Anum_pg_database_datname - 1] =
 		DirectFunctionCall1(namein, CStringGetDatum(dbname));
@@ -1822,9 +1819,6 @@ movedb(const char *dbname, const char *tblspcname)
 				newtuple;
 	Oid			src_tblspcoid,
 				dst_tblspcoid;
-	Datum		new_record[Natts_pg_database];
-	bool		new_record_nulls[Natts_pg_database];
-	bool		new_record_repl[Natts_pg_database];
 	ScanKeyData scankey;
 	SysScanDesc sysscan;
 	AclResult	aclresult;
@@ -2003,6 +1997,10 @@ movedb(const char *dbname, const char *tblspcname)
 	PG_ENSURE_ERROR_CLEANUP(movedb_failure_callback,
 							PointerGetDatum(&fparms));
 	{
+		Datum		new_record[Natts_pg_database] = {0};
+		bool		new_record_nulls[Natts_pg_database] = {0};
+		bool		new_record_repl[Natts_pg_database] = {0};
+
 		/*
 		 * Copy files from the old tablespace to the new one
 		 */
@@ -2042,10 +2040,6 @@ movedb(const char *dbname, const char *tblspcname)
 					(errcode(ERRCODE_UNDEFINED_DATABASE),
 					 errmsg("database \"%s\" does not exist", dbname)));
 
-		MemSet(new_record, 0, sizeof(new_record));
-		MemSet(new_record_nulls, false, sizeof(new_record_nulls));
-		MemSet(new_record_repl, false, sizeof(new_record_repl));
-
 		new_record[Anum_pg_database_dattablespace - 1] = ObjectIdGetDatum(dst_tblspcoid);
 		new_record_repl[Anum_pg_database_dattablespace - 1] = true;
 
@@ -2194,9 +2188,9 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	DefElem    *dallowconnections = NULL;
 	DefElem    *dconnlimit = NULL;
 	DefElem    *dtablespace = NULL;
-	Datum		new_record[Natts_pg_database];
-	bool		new_record_nulls[Natts_pg_database];
-	bool		new_record_repl[Natts_pg_database];
+	Datum		new_record[Natts_pg_database] = {0};
+	bool		new_record_nulls[Natts_pg_database] = {0};
+	bool		new_record_repl[Natts_pg_database] = {0};
 
 	/* Extract options from the statement node tree */
 	foreach(option, stmt->options)
@@ -2305,10 +2299,6 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 	/*
 	 * Build an updated tuple, perusing the information just obtained
 	 */
-	MemSet(new_record, 0, sizeof(new_record));
-	MemSet(new_record_nulls, false, sizeof(new_record_nulls));
-	MemSet(new_record_repl, false, sizeof(new_record_repl));
-
 	if (distemplate)
 	{
 		new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(dbistemplate);
@@ -2492,8 +2482,8 @@ AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
 	if (datForm->datdba != newOwnerId)
 	{
 		Datum		repl_val[Natts_pg_database];
-		bool		repl_null[Natts_pg_database];
-		bool		repl_repl[Natts_pg_database];
+		bool		repl_null[Natts_pg_database] = {0};
+		bool		repl_repl[Natts_pg_database] = {0};
 		Acl		   *newAcl;
 		Datum		aclDatum;
 		bool		isNull;
@@ -2521,9 +2511,6 @@ AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
 					(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 					 errmsg("permission denied to change owner of database")));
 
-		memset(repl_null, false, sizeof(repl_null));
-		memset(repl_repl, false, sizeof(repl_repl));
-
 		repl_repl[Anum_pg_database_datdba - 1] = true;
 		repl_val[Anum_pg_database_datdba - 1] = ObjectIdGetDatum(newOwnerId);
 

src/backend/commands/event_trigger.c

@@ -1310,14 +1310,11 @@ pg_event_trigger_dropped_objects(PG_FUNCTION_ARGS)
 	{
 		SQLDropObject *obj;
 		int			i = 0;
-		Datum		values[12];
-		bool		nulls[12];
+		Datum		values[12] = {0};
+		bool		nulls[12] = {0};
 
 		obj = slist_container(SQLDropObject, next, iter.cur);
 
-		MemSet(values, 0, sizeof(values));
-		MemSet(nulls, 0, sizeof(nulls));
-
 		/* classid */
 		values[i++] = ObjectIdGetDatum(obj->address.classId);
 
@@ -1840,7 +1837,7 @@ pg_event_trigger_ddl_commands(PG_FUNCTION_ARGS)
 	{
 		CollectedCommand *cmd = lfirst(lc);
 		Datum		values[9];
-		bool		nulls[9];
+		bool		nulls[9] = {0};
 		ObjectAddress addr;
 		int			i = 0;
 
@@ -1858,8 +1855,6 @@ pg_event_trigger_ddl_commands(PG_FUNCTION_ARGS)
 			!OidIsValid(cmd->d.simple.address.objectId))
 			continue;
 
-		MemSet(nulls, 0, sizeof(nulls));
-
 		switch (cmd->type)
 		{
 			case SCT_Simple:

src/backend/commands/functioncmds.c

@@ -1806,8 +1806,8 @@ CreateTransform(CreateTransformStmt *stmt)
 	AclResult	aclresult;
 	Form_pg_proc procstruct;
 	Datum		values[Natts_pg_transform];
-	bool		nulls[Natts_pg_transform];
-	bool		replaces[Natts_pg_transform];
+	bool		nulls[Natts_pg_transform] = {0};
+	bool		replaces[Natts_pg_transform] = {0};
 	Oid			transformid;
 	HeapTuple	tuple;
 	HeapTuple	newtuple;
@@ -1913,8 +1913,6 @@ CreateTransform(CreateTransformStmt *stmt)
 	values[Anum_pg_transform_trffromsql - 1] = ObjectIdGetDatum(fromsqlfuncid);
 	values[Anum_pg_transform_trftosql - 1] = ObjectIdGetDatum(tosqlfuncid);
 
-	MemSet(nulls, false, sizeof(nulls));
-
 	relation = table_open(TransformRelationId, RowExclusiveLock);
 
 	tuple = SearchSysCache2(TRFTYPELANG,
@@ -1931,7 +1929,6 @@ CreateTransform(CreateTransformStmt *stmt)
 							format_type_be(typeid),
 							stmt->lang)));
 
-		MemSet(replaces, false, sizeof(replaces));
 		replaces[Anum_pg_transform_trffromsql - 1] = true;
 		replaces[Anum_pg_transform_trftosql - 1] = true;
 

src/backend/commands/prepare.c

@@ -685,12 +685,10 @@ pg_prepared_statement(PG_FUNCTION_ARGS)
 		{
 			TupleDesc	result_desc;
 			Datum		values[8];
-			bool		nulls[8];
+			bool		nulls[8] = {0};
 
 			result_desc = prep_stmt->plansource->resultDesc;
 
-			MemSet(nulls, 0, sizeof(nulls));
-
 			values[0] = CStringGetTextDatum(prep_stmt->stmt_name);
 			values[1] = CStringGetTextDatum(prep_stmt->plansource->query_string);
 			values[2] = TimestampTzGetDatum(prep_stmt->prepare_time);

src/backend/commands/tablecmds.c

@@ -8988,15 +8988,15 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 						  bool recurse, bool recursing, LOCKMODE lockmode)
 {
 	Relation	pkrel;
-	int16		pkattnum[INDEX_MAX_KEYS];
-	int16		fkattnum[INDEX_MAX_KEYS];
-	Oid			pktypoid[INDEX_MAX_KEYS];
-	Oid			fktypoid[INDEX_MAX_KEYS];
-	Oid			opclasses[INDEX_MAX_KEYS];
-	Oid			pfeqoperators[INDEX_MAX_KEYS];
-	Oid			ppeqoperators[INDEX_MAX_KEYS];
-	Oid			ffeqoperators[INDEX_MAX_KEYS];
-	int16		fkdelsetcols[INDEX_MAX_KEYS];
+	int16		pkattnum[INDEX_MAX_KEYS] = {0};
+	int16		fkattnum[INDEX_MAX_KEYS] = {0};
+	Oid			pktypoid[INDEX_MAX_KEYS] = {0};
+	Oid			fktypoid[INDEX_MAX_KEYS] = {0};
+	Oid			opclasses[INDEX_MAX_KEYS] = {0};
+	Oid			pfeqoperators[INDEX_MAX_KEYS] = {0};
+	Oid			ppeqoperators[INDEX_MAX_KEYS] = {0};
+	Oid			ffeqoperators[INDEX_MAX_KEYS] = {0};
+	int16		fkdelsetcols[INDEX_MAX_KEYS] = {0};
 	int			i;
 	int			numfks,
 				numpks,
@@ -9088,16 +9088,6 @@ ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	 * Look up the referencing attributes to make sure they exist, and record
 	 * their attnums and type OIDs.
 	 */
-	MemSet(pkattnum, 0, sizeof(pkattnum));
-	MemSet(fkattnum, 0, sizeof(fkattnum));
-	MemSet(pktypoid, 0, sizeof(pktypoid));
-	MemSet(fktypoid, 0, sizeof(fktypoid));
-	MemSet(opclasses, 0, sizeof(opclasses));
-	MemSet(pfeqoperators, 0, sizeof(pfeqoperators));
-	MemSet(ppeqoperators, 0, sizeof(ppeqoperators));
-	MemSet(ffeqoperators, 0, sizeof(ffeqoperators));
-	MemSet(fkdelsetcols, 0, sizeof(fkdelsetcols));
-
 	numfks = transformColumnNameList(RelationGetRelid(rel),
 									 fkconstraint->fk_attrs,
 									 fkattnum, fktypoid);
@@ -11473,7 +11463,7 @@ validateForeignKeyConstraint(char *conname,
 {
 	TupleTableSlot *slot;
 	TableScanDesc scan;
-	Trigger		trig;
+	Trigger		trig = {0};
 	Snapshot	snapshot;
 	MemoryContext oldcxt;
 	MemoryContext perTupCxt;
@@ -11484,7 +11474,6 @@ validateForeignKeyConstraint(char *conname,
 	/*
 	 * Build a trigger call structure; we'll need it either way.
 	 */
-	MemSet(&trig, 0, sizeof(trig));
 	trig.tgoid = InvalidOid;
 	trig.tgname = conname;
 	trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN;
@@ -12758,15 +12747,11 @@ ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
 
 			int			one = 1;
 			bool		isNull;
-			Datum		valuesAtt[Natts_pg_attribute];
-			bool		nullsAtt[Natts_pg_attribute];
-			bool		replacesAtt[Natts_pg_attribute];
+			Datum		valuesAtt[Natts_pg_attribute] = {0};
+			bool		nullsAtt[Natts_pg_attribute] = {0};
+			bool		replacesAtt[Natts_pg_attribute] = {0};
 			HeapTuple	newTup;
 
-			MemSet(valuesAtt, 0, sizeof(valuesAtt));
-			MemSet(nullsAtt, false, sizeof(nullsAtt));
-			MemSet(replacesAtt, false, sizeof(replacesAtt));
-
 			missingval = array_get_element(missingval,
 										   1,
 										   &one,
@@ -19192,7 +19177,7 @@ ATDetachCheckNoForeignKeyRefs(Relation partition)
 		HeapTuple	tuple;
 		Form_pg_constraint constrForm;
 		Relation	rel;
-		Trigger		trig;
+		Trigger		trig = {0};
 
 		tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constrOid));
 		if (!HeapTupleIsValid(tuple))
@@ -19205,7 +19190,6 @@ ATDetachCheckNoForeignKeyRefs(Relation partition)
 		/* prevent data changes into the referencing table until commit */
 		rel = table_open(constrForm->conrelid, ShareLock);
 
-		MemSet(&trig, 0, sizeof(trig));
 		trig.tgoid = InvalidOid;
 		trig.tgname = NameStr(constrForm->conname);
 		trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN;

src/backend/commands/tablespace.c

@@ -238,7 +238,7 @@ CreateTableSpace(CreateTableSpaceStmt *stmt)
 #ifdef HAVE_SYMLINK
 	Relation	rel;
 	Datum		values[Natts_pg_tablespace];
-	bool		nulls[Natts_pg_tablespace];
+	bool		nulls[Natts_pg_tablespace] = {0};
 	HeapTuple	tuple;
 	Oid			tablespaceoid;
 	char	   *location;
@@ -340,8 +340,6 @@ CreateTableSpace(CreateTableSpaceStmt *stmt)
 	 */
 	rel = table_open(TableSpaceRelationId, RowExclusiveLock);
 
-	MemSet(nulls, false, sizeof(nulls));
-
 	if (IsBinaryUpgrade)
 	{
 		/* Use binary-upgrade override for tablespace oid */

src/backend/commands/typecmds.c

@@ -2570,9 +2570,9 @@ AlterDomainDefault(List *names, Node *defaultRaw)
 	Relation	rel;
 	char	   *defaultValue;
 	Node	   *defaultExpr = NULL; /* NULL if no default specified */
-	Datum		new_record[Natts_pg_type];
-	bool		new_record_nulls[Natts_pg_type];
-	bool		new_record_repl[Natts_pg_type];
+	Datum		new_record[Natts_pg_type] = {0};
+	bool		new_record_nulls[Natts_pg_type] = {0};
+	bool		new_record_repl[Natts_pg_type] = {0};
 	HeapTuple	newtuple;
 	Form_pg_type typTup;
 	ObjectAddress address;
@@ -2593,9 +2593,6 @@ AlterDomainDefault(List *names, Node *defaultRaw)
 	checkDomainOwner(tup);
 
 	/* Setup new tuple */
-	MemSet(new_record, (Datum) 0, sizeof(new_record));
-	MemSet(new_record_nulls, false, sizeof(new_record_nulls));
-	MemSet(new_record_repl, false, sizeof(new_record_repl));
 
 	/* Store the new default into the tuple */
 	if (defaultRaw)

src/backend/commands/user.c

@@ -74,8 +74,8 @@ CreateRole(ParseState *pstate, CreateRoleStmt *stmt)
 	Relation	pg_authid_rel;
 	TupleDesc	pg_authid_dsc;
 	HeapTuple	tuple;
-	Datum		new_record[Natts_pg_authid];
-	bool		new_record_nulls[Natts_pg_authid];
+	Datum		new_record[Natts_pg_authid] = {0};
+	bool		new_record_nulls[Natts_pg_authid] = {0};
 	Oid			roleid;
 	ListCell   *item;
 	ListCell   *option;
@@ -338,12 +338,8 @@ CreateRole(ParseState *pstate, CreateRoleStmt *stmt)
 	/*
 	 * Build a tuple to insert
 	 */
-	MemSet(new_record, 0, sizeof(new_record));
-	MemSet(new_record_nulls, false, sizeof(new_record_nulls));
-
 	new_record[Anum_pg_authid_rolname - 1] =
 		DirectFunctionCall1(namein, CStringGetDatum(stmt->role));
-
 	new_record[Anum_pg_authid_rolsuper - 1] = BoolGetDatum(issuper);
 	new_record[Anum_pg_authid_rolinherit - 1] = BoolGetDatum(inherit);
 	new_record[Anum_pg_authid_rolcreaterole - 1] = BoolGetDatum(createrole);
@@ -492,9 +488,9 @@ CreateRole(ParseState *pstate, CreateRoleStmt *stmt)
 Oid
 AlterRole(ParseState *pstate, AlterRoleStmt *stmt)
 {
-	Datum		new_record[Natts_pg_authid];
-	bool		new_record_nulls[Natts_pg_authid];
-	bool		new_record_repl[Natts_pg_authid];
+	Datum		new_record[Natts_pg_authid] = {0};
+	bool		new_record_nulls[Natts_pg_authid] = {0};
+	bool		new_record_repl[Natts_pg_authid] = {0};
 	Relation	pg_authid_rel;
 	TupleDesc	pg_authid_dsc;
 	HeapTuple	tuple,
@@ -691,9 +687,6 @@ AlterRole(ParseState *pstate, AlterRoleStmt *stmt)
 	/*
 	 * Build an updated tuple, perusing the information just obtained
 	 */
-	MemSet(new_record, 0, sizeof(new_record));
-	MemSet(new_record_nulls, false, sizeof(new_record_nulls));
-	MemSet(new_record_repl, false, sizeof(new_record_repl));
 
 	/*
 	 * issuper/createrole/etc
@@ -1440,9 +1433,9 @@ AddRoleMems(const char *rolename, Oid roleid,
 		Oid			memberid = lfirst_oid(iditem);
 		HeapTuple	authmem_tuple;
 		HeapTuple	tuple;
-		Datum		new_record[Natts_pg_auth_members];
-		bool		new_record_nulls[Natts_pg_auth_members];
-		bool		new_record_repl[Natts_pg_auth_members];
+		Datum		new_record[Natts_pg_auth_members] = {0};
+		bool		new_record_nulls[Natts_pg_auth_members] = {0};
+		bool		new_record_repl[Natts_pg_auth_members] = {0};
 
 		/*
 		 * pg_database_owner is never a role member.  Lifting this restriction
@@ -1500,10 +1493,6 @@ AddRoleMems(const char *rolename, Oid roleid,
 		}
 
 		/* Build a tuple to insert or update */
-		MemSet(new_record, 0, sizeof(new_record));
-		MemSet(new_record_nulls, false, sizeof(new_record_nulls));
-		MemSet(new_record_repl, false, sizeof(new_record_repl));
-
 		new_record[Anum_pg_auth_members_roleid - 1] = ObjectIdGetDatum(roleid);
 		new_record[Anum_pg_auth_members_member - 1] = ObjectIdGetDatum(memberid);
 		new_record[Anum_pg_auth_members_grantor - 1] = ObjectIdGetDatum(grantorId);
@@ -1614,15 +1603,11 @@ DelRoleMems(const char *rolename, Oid roleid,
 		{
 			/* Just turn off the admin option */
 			HeapTuple	tuple;
-			Datum		new_record[Natts_pg_auth_members];
-			bool		new_record_nulls[Natts_pg_auth_members];
-			bool		new_record_repl[Natts_pg_auth_members];
+			Datum		new_record[Natts_pg_auth_members] = {0};
+			bool		new_record_nulls[Natts_pg_auth_members] = {0};
+			bool		new_record_repl[Natts_pg_auth_members] = {0};
 
 			/* Build a tuple to update with */
-			MemSet(new_record, 0, sizeof(new_record));
-			MemSet(new_record_nulls, false, sizeof(new_record_nulls));
-			MemSet(new_record_repl, false, sizeof(new_record_repl));
-
 			new_record[Anum_pg_auth_members_admin_option - 1] = BoolGetDatum(false);
 			new_record_repl[Anum_pg_auth_members_admin_option - 1] = true;