Make pgbench's expression lexer reentrant.

This is a necessary preliminary step for making it play with psqlscan.l
given the way I set up the lexer input-buffer sharing mechanism in commit
0ea9efbe9ec1bf07.

I've not tried to make it *actually* reentrant; there's still some static
variables laying about.  But flex thinks it's reentrant, and that's what
counts.

In support of that, fix exprparse.y to pass through the yyscan_t from the
caller.  Also do some minor code beautification, like not casting away
const.

1 files changed, 10 insertions, 5 deletions

diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 4606fb00158..dab1ed4114e 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -2495,17 +2495,22 @@ process_commands(char *buf, const char *source, const int lineno)
 		}
 		else if (pg_strcasecmp(my_commands->argv[0], "set") == 0)
 		{
+			yyscan_t	yyscanner;
+
 			if (my_commands->argc < 3)
 			{
 				syntax_error(source, lineno, my_commands->line, my_commands->argv[0],
 							 "missing argument", NULL, -1);
 			}
 
-			expr_scanner_init(my_commands->argv[2], source, lineno,
-							  my_commands->line, my_commands->argv[0],
-							  my_commands->cols[2] - 1);
+			yyscanner = expr_scanner_init(my_commands->argv[2],
+										  source,
+										  lineno,
+										  my_commands->line,
+										  my_commands->argv[0],
+										  my_commands->cols[2] - 1);
 
-			if (expr_yyparse() != 0)
+			if (expr_yyparse(yyscanner) != 0)
 			{
 				/* dead code: exit done from syntax_error called by yyerror */
 				exit(1);
@@ -2513,7 +2518,7 @@ process_commands(char *buf, const char *source, const int lineno)
 
 			my_commands->expr = expr_parse_result;
 
-			expr_scanner_finish();
+			expr_scanner_finish(yyscanner);
 		}
 		else if (pg_strcasecmp(my_commands->argv[0], "sleep") == 0)
 		{