Fix non-C89-compatible coding in pgbench.

C89 says that compound initializers may only contain constant expressions;
a restriction violated by commit 89d00cb.  While we've had no actual field
complaints about this, C89 is still the project standard, and it's not
saving all that much code to break compatibility here.  So let's adhere to
the old restriction.

In passing, replace a bunch of hardwired constants "256" with
sizeof(target-variable), just because the latter is more readable and
less breakable.  And const-ify where possible.

Back-patch to 9.3 where the nonportable code was added.

Andres Freund and Tom Lane

Author: tglsfdc

contrib/pgbench/pgbench.c

@@ -1548,8 +1548,9 @@ disconnect_all(CState *state, int length)
 static void
 init(bool is_no_vacuum)
 {
-/* The scale factor at/beyond which 32bit integers are incapable of storing
- * 64bit values.
+/*
+ * The scale factor at/beyond which 32-bit integers are insufficient for
+ * storing TPC-B account IDs.
  *
  * Although the actual threshold is 21474, we use 20000 because it is easier to
  * document and remember, and isn't that far away from the real threshold.
@@ -1561,50 +1562,51 @@ init(bool is_no_vacuum)
 	 * fields in these table declarations were intended to comply with that.
 	 * The pgbench_accounts table complies with that because the "filler"
 	 * column is set to blank-padded empty string. But for all other tables
-	 * the column defaults to NULL and so don't actually take any space.  We
+	 * the columns default to NULL and so don't actually take any space.  We
 	 * could fix that by giving them non-null default values.  However, that
 	 * would completely break comparability of pgbench results with prior
 	 * versions. Since pgbench has never pretended to be fully TPC-B compliant
 	 * anyway, we stick with the historical behavior.
 	 */
 	struct ddlinfo
 	{
-		char	   *table;
-		char	   *cols;
+		const char *table;		/* table name */
+		const char *smcols;		/* column decls if accountIDs are 32 bits */
+		const char *bigcols;	/* column decls if accountIDs are 64 bits */
 		int			declare_fillfactor;
 	};
-	struct ddlinfo DDLs[] = {
+	static const struct ddlinfo DDLs[] = {
 		{
 			"pgbench_history",
-			scale >= SCALE_32BIT_THRESHOLD
-			? "tid int,bid int,aid bigint,delta int,mtime timestamp,filler char(22)"
-			: "tid int,bid int,aid    int,delta int,mtime timestamp,filler char(22)",
+			"tid int,bid int,aid    int,delta int,mtime timestamp,filler char(22)",
+			"tid int,bid int,aid bigint,delta int,mtime timestamp,filler char(22)",
 			0
 		},
 		{
 			"pgbench_tellers",
 			"tid int not null,bid int,tbalance int,filler char(84)",
+			"tid int not null,bid int,tbalance int,filler char(84)",
 			1
 		},
 		{
 			"pgbench_accounts",
-			scale >= SCALE_32BIT_THRESHOLD
-			? "aid bigint not null,bid int,abalance int,filler char(84)"
-			: "aid    int not null,bid int,abalance int,filler char(84)",
+			"aid    int not null,bid int,abalance int,filler char(84)",
+			"aid bigint not null,bid int,abalance int,filler char(84)",
 			1
 		},
 		{
 			"pgbench_branches",
 			"bid int not null,bbalance int,filler char(88)",
+			"bid int not null,bbalance int,filler char(88)",
 			1
 		}
 	};
-	static char *DDLAFTERs[] = {
+	static const char *const DDLINDEXes[] = {
 		"alter table pgbench_branches add primary key (bid)",
 		"alter table pgbench_tellers add primary key (tid)",
 		"alter table pgbench_accounts add primary key (aid)"
 	};
-	static char *DDLKEYs[] = {
+	static const char *const DDLKEYs[] = {
 		"alter table pgbench_tellers add foreign key (bid) references pgbench_branches",
 		"alter table pgbench_accounts add foreign key (bid) references pgbench_branches",
 		"alter table pgbench_history add foreign key (bid) references pgbench_branches",
@@ -1632,30 +1634,34 @@ init(bool is_no_vacuum)
 	{
 		char		opts[256];
 		char		buffer[256];
-		struct ddlinfo *ddl = &DDLs[i];
+		const struct ddlinfo *ddl = &DDLs[i];
+		const char *cols;
 
 		/* Remove old table, if it exists. */
-		snprintf(buffer, 256, "drop table if exists %s", ddl->table);
+		snprintf(buffer, sizeof(buffer), "drop table if exists %s", ddl->table);
 		executeStatement(con, buffer);
 
 		/* Construct new create table statement. */
 		opts[0] = '\0';
 		if (ddl->declare_fillfactor)
-			snprintf(opts + strlen(opts), 256 - strlen(opts),
+			snprintf(opts + strlen(opts), sizeof(opts) - strlen(opts),
 					 " with (fillfactor=%d)", fillfactor);
 		if (tablespace != NULL)
 		{
 			char	   *escape_tablespace;
 
 			escape_tablespace = PQescapeIdentifier(con, tablespace,
 												   strlen(tablespace));
-			snprintf(opts + strlen(opts), 256 - strlen(opts),
+			snprintf(opts + strlen(opts), sizeof(opts) - strlen(opts),
 					 " tablespace %s", escape_tablespace);
 			PQfreemem(escape_tablespace);
 		}
-		snprintf(buffer, 256, "create%s table %s(%s)%s",
+
+		cols = (scale >= SCALE_32BIT_THRESHOLD) ? ddl->bigcols : ddl->smcols;
+
+		snprintf(buffer, sizeof(buffer), "create%s table %s(%s)%s",
 				 unlogged_tables ? " unlogged" : "",
-				 ddl->table, ddl->cols, opts);
+				 ddl->table, cols, opts);
 
 		executeStatement(con, buffer);
 	}
@@ -1665,14 +1671,17 @@ init(bool is_no_vacuum)
 	for (i = 0; i < nbranches * scale; i++)
 	{
 		/* "filler" column defaults to NULL */
-		snprintf(sql, 256, "insert into pgbench_branches(bid,bbalance) values(%d,0)", i + 1);
+		snprintf(sql, sizeof(sql),
+				 "insert into pgbench_branches(bid,bbalance) values(%d,0)",
+				 i + 1);
 		executeStatement(con, sql);
 	}
 
 	for (i = 0; i < ntellers * scale; i++)
 	{
 		/* "filler" column defaults to NULL */
-		snprintf(sql, 256, "insert into pgbench_tellers(tid,bid,tbalance) values (%d,%d,0)",
+		snprintf(sql, sizeof(sql),
+			"insert into pgbench_tellers(tid,bid,tbalance) values (%d,%d,0)",
 				 i + 1, i / ntellers + 1);
 		executeStatement(con, sql);
 	}
@@ -1702,7 +1711,9 @@ init(bool is_no_vacuum)
 		int64		j = k + 1;
 
 		/* "filler" column defaults to blank padded empty string */
-		snprintf(sql, 256, INT64_FORMAT "\t" INT64_FORMAT "\t%d\t\n", j, k / naccounts + 1, 0);
+		snprintf(sql, sizeof(sql),
+				 INT64_FORMAT "\t" INT64_FORMAT "\t%d\t\n",
+				 j, k / naccounts + 1, 0);
 		if (PQputline(con, sql))
 		{
 			fprintf(stderr, "PQputline failed\n");
@@ -1774,19 +1785,19 @@ init(bool is_no_vacuum)
 	 * create indexes
 	 */
 	fprintf(stderr, "set primary keys...\n");
-	for (i = 0; i < lengthof(DDLAFTERs); i++)
+	for (i = 0; i < lengthof(DDLINDEXes); i++)
 	{
 		char		buffer[256];
 
-		strncpy(buffer, DDLAFTERs[i], 256);
+		strlcpy(buffer, DDLINDEXes[i], sizeof(buffer));
 
 		if (index_tablespace != NULL)
 		{
 			char	   *escape_tablespace;
 
 			escape_tablespace = PQescapeIdentifier(con, index_tablespace,
 												   strlen(index_tablespace));
-			snprintf(buffer + strlen(buffer), 256 - strlen(buffer),
+			snprintf(buffer + strlen(buffer), sizeof(buffer) - strlen(buffer),
 					 " using index tablespace %s", escape_tablespace);
 			PQfreemem(escape_tablespace);
 		}
@@ -1806,7 +1817,6 @@ init(bool is_no_vacuum)
 		}
 	}
 
-
 	fprintf(stderr, "done.\n");
 	PQfinish(con);
 }