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

contrib/hstore/hstore_gin.c

@@ -118,9 +118,7 @@ gin_extract_hstore_query(PG_FUNCTION_ARGS)
 					j;
 		text	   *item;
 
-		deconstruct_array(query,
-						  TEXTOID, -1, false, TYPALIGN_INT,
-						  &key_datums, &key_nulls, &key_count);
+		deconstruct_array_builtin(query, TEXTOID, &key_datums, &key_nulls, &key_count);
 
 		entries = (Datum *) palloc(sizeof(Datum) * key_count);
 

contrib/hstore/hstore_gist.c

@@ -560,9 +560,7 @@ ghstore_consistent(PG_FUNCTION_ARGS)
 		int			key_count;
 		int			i;
 
-		deconstruct_array(query,
-						  TEXTOID, -1, false, TYPALIGN_INT,
-						  &key_datums, &key_nulls, &key_count);
+		deconstruct_array_builtin(query, TEXTOID, &key_datums, &key_nulls, &key_count);
 
 		for (i = 0; res && i < key_count; ++i)
 		{
@@ -583,9 +581,7 @@ ghstore_consistent(PG_FUNCTION_ARGS)
 		int			key_count;
 		int			i;
 
-		deconstruct_array(query,
-						  TEXTOID, -1, false, TYPALIGN_INT,
-						  &key_datums, &key_nulls, &key_count);
+		deconstruct_array_builtin(query, TEXTOID, &key_datums, &key_nulls, &key_count);
 
 		res = false;
 

contrib/hstore/hstore_io.c

@@ -567,9 +567,7 @@ hstore_from_arrays(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
 				 errmsg("wrong number of array subscripts")));
 
-	deconstruct_array(key_array,
-					  TEXTOID, -1, false, TYPALIGN_INT,
-					  &key_datums, &key_nulls, &key_count);
+	deconstruct_array_builtin(key_array, TEXTOID, &key_datums, &key_nulls, &key_count);
 
 	/* see discussion in hstoreArrayToPairs() */
 	if (key_count > MaxAllocSize / sizeof(Pairs))
@@ -606,9 +604,7 @@ hstore_from_arrays(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
 					 errmsg("arrays must have same bounds")));
 
-		deconstruct_array(value_array,
-						  TEXTOID, -1, false, TYPALIGN_INT,
-						  &value_datums, &value_nulls, &value_count);
+		deconstruct_array_builtin(value_array, TEXTOID, &value_datums, &value_nulls, &value_count);
 
 		Assert(key_count == value_count);
 	}
@@ -696,9 +692,7 @@ hstore_from_array(PG_FUNCTION_ARGS)
 					 errmsg("wrong number of array subscripts")));
 	}
 
-	deconstruct_array(in_array,
-					  TEXTOID, -1, false, TYPALIGN_INT,
-					  &in_datums, &in_nulls, &in_count);
+	deconstruct_array_builtin(in_array, TEXTOID, &in_datums, &in_nulls, &in_count);
 
 	count = in_count / 2;
 

contrib/hstore/hstore_op.c

@@ -80,9 +80,7 @@ hstoreArrayToPairs(ArrayType *a, int *npairs)
 	int			i,
 				j;
 
-	deconstruct_array(a,
-					  TEXTOID, -1, false, TYPALIGN_INT,
-					  &key_datums, &key_nulls, &key_count);
+	deconstruct_array_builtin(a, TEXTOID, &key_datums, &key_nulls, &key_count);
 
 	if (key_count == 0)
 	{
@@ -582,9 +580,7 @@ hstore_slice_to_array(PG_FUNCTION_ARGS)
 	int			key_count;
 	int			i;
 
-	deconstruct_array(key_array,
-					  TEXTOID, -1, false, TYPALIGN_INT,
-					  &key_datums, &key_nulls, &key_count);
+	deconstruct_array_builtin(key_array, TEXTOID, &key_datums, &key_nulls, &key_count);
 
 	if (key_count == 0)
 	{
@@ -719,8 +715,7 @@ hstore_akeys(PG_FUNCTION_ARGS)
 		d[i] = PointerGetDatum(t);
 	}
 
-	a = construct_array(d, count,
-						TEXTOID, -1, false, TYPALIGN_INT);
+	a = construct_array_builtin(d, count, TEXTOID);
 
 	PG_RETURN_POINTER(a);
 }

contrib/pageinspect/btreefuncs.c

@@ -425,11 +425,7 @@ bt_page_print_tuples(struct user_args *uargs)
 		tids_datum = (Datum *) palloc(nposting * sizeof(Datum));
 		for (int i = 0; i < nposting; i++)
 			tids_datum[i] = ItemPointerGetDatum(&tids[i]);
-		values[j++] = PointerGetDatum(construct_array(tids_datum,
-													  nposting,
-													  TIDOID,
-													  sizeof(ItemPointerData),
-													  false, TYPALIGN_SHORT));
+		values[j++] = PointerGetDatum(construct_array_builtin(tids_datum, nposting, TIDOID));
 		pfree(tids_datum);
 	}
 	else

contrib/pageinspect/ginfuncs.c

@@ -166,9 +166,7 @@ gin_page_opaque_info(PG_FUNCTION_ARGS)
 
 	values[0] = Int64GetDatum(opaq->rightlink);
 	values[1] = Int32GetDatum(opaq->maxoff);
-	values[2] = PointerGetDatum(construct_array(flags, nflags,
-												TEXTOID,
-												-1, false, TYPALIGN_INT));
+	values[2] = PointerGetDatum(construct_array_builtin(flags, nflags, TEXTOID));
 
 	/* Build and return the result tuple. */
 	resultTuple = heap_form_tuple(tupdesc, values, nulls);
@@ -273,11 +271,7 @@ gin_leafpage_items(PG_FUNCTION_ARGS)
 		tids_datum = (Datum *) palloc(ndecoded * sizeof(Datum));
 		for (i = 0; i < ndecoded; i++)
 			tids_datum[i] = ItemPointerGetDatum(&tids[i]);
-		values[2] = PointerGetDatum(construct_array(tids_datum,
-													ndecoded,
-													TIDOID,
-													sizeof(ItemPointerData),
-													false, TYPALIGN_SHORT));
+		values[2] = PointerGetDatum(construct_array_builtin(tids_datum, ndecoded, TIDOID));
 		pfree(tids_datum);
 		pfree(tids);
 

contrib/pageinspect/gistfuncs.c

@@ -104,9 +104,7 @@ gist_page_opaque_info(PG_FUNCTION_ARGS)
 	values[0] = LSNGetDatum(PageGetLSN(page));
 	values[1] = LSNGetDatum(GistPageGetNSN(page));
 	values[2] = Int64GetDatum(opaq->rightlink);
-	values[3] = PointerGetDatum(construct_array(flags, nflags,
-												TEXTOID,
-												-1, false, TYPALIGN_INT));
+	values[3] = PointerGetDatum(construct_array_builtin(flags, nflags, TEXTOID));
 
 	/* Build and return the result tuple. */
 	resultTuple = heap_form_tuple(tupdesc, values, nulls);

contrib/pageinspect/hashfuncs.c

@@ -564,21 +564,11 @@ hash_metapage_info(PG_FUNCTION_ARGS)
 
 	for (i = 0; i < HASH_MAX_SPLITPOINTS; i++)
 		spares[i] = Int64GetDatum((int64) metad->hashm_spares[i]);
-	values[j++] = PointerGetDatum(construct_array(spares,
-												  HASH_MAX_SPLITPOINTS,
-												  INT8OID,
-												  sizeof(int64),
-												  FLOAT8PASSBYVAL,
-												  TYPALIGN_DOUBLE));
+	values[j++] = PointerGetDatum(construct_array_builtin(spares, HASH_MAX_SPLITPOINTS, INT8OID));
 
 	for (i = 0; i < HASH_MAX_BITMAPS; i++)
 		mapp[i] = Int64GetDatum((int64) metad->hashm_mapp[i]);
-	values[j++] = PointerGetDatum(construct_array(mapp,
-												  HASH_MAX_BITMAPS,
-												  INT8OID,
-												  sizeof(int64),
-												  FLOAT8PASSBYVAL,
-												  TYPALIGN_DOUBLE));
+	values[j++] = PointerGetDatum(construct_array_builtin(mapp, HASH_MAX_BITMAPS, INT8OID));
 
 	tuple = heap_form_tuple(tupleDesc, values, nulls);
 

contrib/pageinspect/heapfuncs.c

@@ -590,7 +590,7 @@ heap_tuple_infomask_flags(PG_FUNCTION_ARGS)
 
 	/* build value */
 	Assert(cnt <= bitcnt);
-	a = construct_array(flags, cnt, TEXTOID, -1, false, TYPALIGN_INT);
+	a = construct_array_builtin(flags, cnt, TEXTOID);
 	values[0] = PointerGetDatum(a);
 
 	/*
@@ -612,7 +612,7 @@ heap_tuple_infomask_flags(PG_FUNCTION_ARGS)
 	if (cnt == 0)
 		a = construct_empty_array(TEXTOID);
 	else
-		a = construct_array(flags, cnt, TEXTOID, -1, false, TYPALIGN_INT);
+		a = construct_array_builtin(flags, cnt, TEXTOID);
 	pfree(flags);
 	values[1] = PointerGetDatum(a);
 

contrib/pg_trgm/trgm_op.c

@@ -977,12 +977,7 @@ show_trgm(PG_FUNCTION_ARGS)
 		d[i] = PointerGetDatum(item);
 	}
 
-	a = construct_array(d,
-						ARRNELEM(trg),
-						TEXTOID,
-						-1,
-						false,
-						TYPALIGN_INT);
+	a = construct_array_builtin(d, ARRNELEM(trg), TEXTOID);
 
 	for (i = 0; i < ARRNELEM(trg); i++)
 		pfree(DatumGetPointer(d[i]));

contrib/pgcrypto/pgp-pgsql.c

@@ -774,13 +774,8 @@ parse_key_value_arrays(ArrayType *key_array, ArrayType *val_array,
 	if (nkdims == 0)
 		return 0;
 
-	deconstruct_array(key_array,
-					  TEXTOID, -1, false, TYPALIGN_INT,
-					  &key_datums, &key_nulls, &key_count);
-
-	deconstruct_array(val_array,
-					  TEXTOID, -1, false, TYPALIGN_INT,
-					  &val_datums, &val_nulls, &val_count);
+	deconstruct_array_builtin(key_array, TEXTOID, &key_datums, &key_nulls, &key_count);
+	deconstruct_array_builtin(val_array, TEXTOID, &val_datums, &val_nulls, &val_count);
 
 	if (key_count != val_count)
 		ereport(ERROR,