Add construct_array_builtin, deconstruct_array_builtin

There were many calls to construct_array() and deconstruct_array() for
built-in types, for example, when dealing with system catalog columns.
These all hardcoded the type attributes necessary to pass to these
functions.

To simplify this a bit, add construct_array_builtin(),
deconstruct_array_builtin() as wrappers that centralize this hardcoded
knowledge.  This simplifies many call sites and reduces the amount of
hardcoded stuff that is spread around.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/2914356f-9e5f-8c59-2995-5997fc48bcba%40enterprisedb.com

9 files changed, 21 insertions, 48 deletions

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 2da6b75a155..07613c38b5c 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -1688,10 +1688,7 @@ update_attstats(Oid relid, bool inh, int natts, VacAttrStats **vacattrstats)
 
 				for (n = 0; n < nnum; n++)
 					numdatums[n] = Float4GetDatum(stats->stanumbers[k][n]);
-				/* XXX knows more than it should about type float4: */
-				arry = construct_array(numdatums, nnum,
-									   FLOAT4OID,
-									   sizeof(float4), true, TYPALIGN_INT);
+				arry = construct_array_builtin(numdatums, nnum, FLOAT4OID);
 				values[i++] = PointerGetDatum(arry);	/* stanumbersN */
 			}
 			else
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index 46425278811..f46f86474aa 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -351,8 +351,7 @@ filter_list_to_array(List *filterlist)
 		pfree(result);
 	}
 
-	return PointerGetDatum(construct_array(data, l, TEXTOID,
-										   -1, false, TYPALIGN_INT));
+	return PointerGetDatum(construct_array_builtin(data, l, TEXTOID));
 }
 
 /*
diff --git a/src/backend/commands/extension.c b/src/backend/commands/extension.c
index 767d9b96190..7b3aceee119 100644
--- a/src/backend/commands/extension.c
+++ b/src/backend/commands/extension.c
@@ -2251,9 +2251,7 @@ convert_requires_to_datum(List *requires)
 		datums[ndatums++] =
 			DirectFunctionCall1(namein, CStringGetDatum(curreq));
 	}
-	a = construct_array(datums, ndatums,
-						NAMEOID,
-						NAMEDATALEN, false, TYPALIGN_CHAR);
+	a = construct_array_builtin(datums, ndatums, NAMEOID);
 	return PointerGetDatum(a);
 }
 
@@ -2433,9 +2431,7 @@ pg_extension_config_dump(PG_FUNCTION_ARGS)
 		arrayLength = 0;
 		arrayIndex = 1;
 
-		a = construct_array(&elementDatum, 1,
-							OIDOID,
-							sizeof(Oid), true, TYPALIGN_INT);
+		a = construct_array_builtin(&elementDatum, 1, OIDOID);
 	}
 	else
 	{
@@ -2486,9 +2482,7 @@ pg_extension_config_dump(PG_FUNCTION_ARGS)
 		if (arrayLength != 0)
 			elog(ERROR, "extconfig and extcondition arrays do not match");
 
-		a = construct_array(&elementDatum, 1,
-							TEXTOID,
-							-1, false, TYPALIGN_INT);
+		a = construct_array_builtin(&elementDatum, 1, TEXTOID);
 	}
 	else
 	{
@@ -2630,14 +2624,12 @@ extension_config_remove(Oid extensionoid, Oid tableoid)
 		int			i;
 
 		/* We already checked there are no nulls */
-		deconstruct_array(a, OIDOID, sizeof(Oid), true, TYPALIGN_INT,
-						  &dvalues, NULL, &nelems);
+		deconstruct_array_builtin(a, OIDOID, &dvalues, NULL, &nelems);
 
 		for (i = arrayIndex; i < arrayLength - 1; i++)
 			dvalues[i] = dvalues[i + 1];
 
-		a = construct_array(dvalues, arrayLength - 1,
-							OIDOID, sizeof(Oid), true, TYPALIGN_INT);
+		a = construct_array_builtin(dvalues, arrayLength - 1, OIDOID);
 
 		repl_val[Anum_pg_extension_extconfig - 1] = PointerGetDatum(a);
 	}
@@ -2676,14 +2668,12 @@ extension_config_remove(Oid extensionoid, Oid tableoid)
 		int			i;
 
 		/* We already checked there are no nulls */
-		deconstruct_array(a, TEXTOID, -1, false, TYPALIGN_INT,
-						  &dvalues, NULL, &nelems);
+		deconstruct_array_builtin(a, TEXTOID, &dvalues, NULL, &nelems);
 
 		for (i = arrayIndex; i < arrayLength - 1; i++)
 			dvalues[i] = dvalues[i + 1];
 
-		a = construct_array(dvalues, arrayLength - 1,
-							TEXTOID, -1, false, TYPALIGN_INT);
+		a = construct_array_builtin(dvalues, arrayLength - 1, TEXTOID);
 
 		repl_val[Anum_pg_extension_extcondition - 1] = PointerGetDatum(a);
 	}
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 00a6d282cfd..b016eecb2cd 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -468,10 +468,8 @@ interpret_function_parameter_list(ParseState *pstate,
 
 	if (outCount > 0 || varCount > 0)
 	{
-		*allParameterTypes = construct_array(allTypes, parameterCount, OIDOID,
-											 sizeof(Oid), true, TYPALIGN_INT);
-		*parameterModes = construct_array(paramModes, parameterCount, CHAROID,
-										  1, true, TYPALIGN_CHAR);
+		*allParameterTypes = construct_array_builtin(allTypes, parameterCount, OIDOID);
+		*parameterModes = construct_array_builtin(paramModes, parameterCount, CHAROID);
 		if (outCount > 1)
 			*requiredResultType = RECORDOID;
 		/* otherwise we set requiredResultType correctly above */
@@ -489,8 +487,7 @@ interpret_function_parameter_list(ParseState *pstate,
 			if (paramNames[i] == PointerGetDatum(NULL))
 				paramNames[i] = CStringGetTextDatum("");
 		}
-		*parameterNames = construct_array(paramNames, parameterCount, TEXTOID,
-										  -1, false, TYPALIGN_INT);
+		*parameterNames = construct_array_builtin(paramNames, parameterCount, TEXTOID);
 	}
 	else
 		*parameterNames = NULL;
@@ -1222,8 +1219,7 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt *stmt)
 		i = 0;
 		foreach(lc, trftypes_list)
 			arr[i++] = ObjectIdGetDatum(lfirst_oid(lc));
-		trftypes = construct_array(arr, list_length(trftypes_list),
-								   OIDOID, sizeof(Oid), true, TYPALIGN_INT);
+		trftypes = construct_array_builtin(arr, list_length(trftypes_list), OIDOID);
 	}
 	else
 	{
diff --git a/src/backend/commands/policy.c b/src/backend/commands/policy.c
index a59ee3b9477..d9dff9ecaab 100644
--- a/src/backend/commands/policy.c
+++ b/src/backend/commands/policy.c
@@ -500,8 +500,7 @@ RemoveRoleFromObjectPolicy(Oid roleid, Oid classid, Oid policy_id)
 		memset(isnull, 0, sizeof(isnull));
 
 		/* This is the array for the new tuple */
-		role_ids = construct_array(role_oids, num_roles, OIDOID,
-								   sizeof(Oid), true, TYPALIGN_INT);
+		role_ids = construct_array_builtin(role_oids, num_roles, OIDOID);
 
 		replaces[Anum_pg_policy_polroles - 1] = true;
 		values[Anum_pg_policy_polroles - 1] = PointerGetDatum(role_ids);
@@ -617,8 +616,7 @@ CreatePolicy(CreatePolicyStmt *stmt)
 
 	/* Collect role ids */
 	role_oids = policy_role_list_to_array(stmt->roles, &nitems);
-	role_ids = construct_array(role_oids, nitems, OIDOID,
-							   sizeof(Oid), true, TYPALIGN_INT);
+	role_ids = construct_array_builtin(role_oids, nitems, OIDOID);
 
 	/* Parse the supplied clause */
 	qual_pstate = make_parsestate(NULL);
@@ -801,8 +799,7 @@ AlterPolicy(AlterPolicyStmt *stmt)
 	if (stmt->roles != NULL)
 	{
 		role_oids = policy_role_list_to_array(stmt->roles, &nitems);
-		role_ids = construct_array(role_oids, nitems, OIDOID,
-								   sizeof(Oid), true, TYPALIGN_INT);
+		role_ids = construct_array_builtin(role_oids, nitems, OIDOID);
 	}
 
 	/* Get id of table.  Also handles permissions checks. */
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 80738547ed8..633c9a40bbc 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -722,8 +722,6 @@ build_regtype_array(Oid *param_types, int num_params)
 	for (i = 0; i < num_params; i++)
 		tmp_ary[i] = ObjectIdGetDatum(param_types[i]);
 
-	/* XXX: this hardcodes assumptions about the regtype type */
-	result = construct_array(tmp_ary, num_params, REGTYPEOID,
-							 4, true, TYPALIGN_INT);
+	result = construct_array_builtin(tmp_ary, num_params, REGTYPEOID);
 	return PointerGetDatum(result);
 }
diff --git a/src/backend/commands/statscmds.c b/src/backend/commands/statscmds.c
index 2e716743dd6..cd5e2f2b6b0 100644
--- a/src/backend/commands/statscmds.c
+++ b/src/backend/commands/statscmds.c
@@ -467,7 +467,7 @@ CreateStatistics(CreateStatsStmt *stmt)
 	if (build_expressions)
 		types[ntypes++] = CharGetDatum(STATS_EXT_EXPRESSIONS);
 	Assert(ntypes > 0 && ntypes <= lengthof(types));
-	stxkind = construct_array(types, ntypes, CHAROID, 1, true, TYPALIGN_CHAR);
+	stxkind = construct_array_builtin(types, ntypes, CHAROID);
 
 	/* convert the expressions (if any) to a text datum */
 	if (stxexprs != NIL)
diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 83e6eae855f..e2852286a7d 100644
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -494,8 +494,7 @@ publicationListToArray(List *publist)
 
 	MemoryContextSwitchTo(oldcxt);
 
-	arr = construct_array(datums, list_length(publist),
-						  TEXTOID, -1, false, TYPALIGN_INT);
+	arr = construct_array_builtin(datums, list_length(publist), TEXTOID);
 
 	MemoryContextDelete(memcxt);
 
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 9b92b042420..4f5e7c7ccb2 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -1893,12 +1893,9 @@ makeMultirangeConstructors(const char *name, Oid namespace,
 	/* n-arg constructor - vararg */
 	argtypes = buildoidvector(&rangeArrayOid, 1);
 	allParamTypes = ObjectIdGetDatum(rangeArrayOid);
-	allParameterTypes = construct_array(&allParamTypes,
-										1, OIDOID,
-										sizeof(Oid), true, TYPALIGN_INT);
+	allParameterTypes = construct_array_builtin(&allParamTypes, 1, OIDOID);
 	paramModes = CharGetDatum(FUNC_PARAM_VARIADIC);
-	parameterModes = construct_array(&paramModes, 1, CHAROID,
-									 1, true, TYPALIGN_CHAR);
+	parameterModes = construct_array_builtin(&paramModes, 1, CHAROID);
 	myself = ProcedureCreate(name,	/* name: same as multirange type */
 							 namespace,
 							 false, /* replace */