database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-25 01:02:05 +03:00
Code Activity

Make pgbench's expression lexer reentrant.

Browse Source 
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
0ea9efbe9e.

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.
This commit is contained in:
Tom Lane
2016-03-19 16:35:41 -04:00
parent 1038bc91ca
commit 429ee5a822
4 changed files with 117 additions and 64 deletions
Download Patch File Download Diff File Expand all files Collapse all files

57
src/bin/pgbench/exprparse.y
View File

@ -7,6 +7,8 @@
* Portions Copyright (c) 1996-2016, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/bin/pgbench/exprparse.y
*
*-------------------------------------------------------------------------
*/
@ -19,16 +21,19 @@ PgBenchExpr *expr_parse_result;
static PgBenchExprList *make_elist(PgBenchExpr *exp, PgBenchExprList *list);
static PgBenchExpr *make_integer_constant(int64 ival);
static PgBenchExpr *make_variable(char *varname);
static PgBenchExpr *make_op(const char *operator, PgBenchExpr *lexpr,
PgBenchExpr *rexpr);
static int find_func(const char *fname);
static PgBenchExpr *make_func(const int fnumber, PgBenchExprList *args);
static PgBenchExpr *make_op(yyscan_t yyscanner, const char *operator,
PgBenchExpr *lexpr, PgBenchExpr *rexpr);
static int find_func(yyscan_t yyscanner, const char *fname);
static PgBenchExpr *make_func(yyscan_t yyscanner, int fnumber, PgBenchExprList *args);
%}
%expect 0
%name-prefix="expr_yy"
%parse-param {yyscan_t yyscanner}
%lex-param {yyscan_t yyscanner}
%union
{
int64 ival;
@ -43,7 +48,6 @@ static PgBenchExpr *make_func(const int fnumber, PgBenchExprList *args);
%type <str> VARIABLE FUNCTION
%token INTEGER VARIABLE FUNCTION
%token CHAR_ERROR /* never used, will raise a syntax error */
/* Precedence: lowest to highest */
%left '+' '-'
@ -61,18 +65,19 @@ elist: { $$ = NULL; }
expr: '(' expr ')' { $$ = $2; }
| '+' expr %prec UMINUS { $$ = $2; }
| '-' expr %prec UMINUS { $$ = make_op("-", make_integer_constant(0), $2); }
| expr '+' expr { $$ = make_op("+", $1, $3); }
| expr '-' expr { $$ = make_op("-", $1, $3); }
| expr '*' expr { $$ = make_op("*", $1, $3); }
| expr '/' expr { $$ = make_op("/", $1, $3); }
| expr '%' expr { $$ = make_op("%", $1, $3); }
| '-' expr %prec UMINUS { $$ = make_op(yyscanner, "-",
make_integer_constant(0), $2); }
| expr '+' expr { $$ = make_op(yyscanner, "+", $1, $3); }
| expr '-' expr { $$ = make_op(yyscanner, "-", $1, $3); }
| expr '*' expr { $$ = make_op(yyscanner, "*", $1, $3); }
| expr '/' expr { $$ = make_op(yyscanner, "/", $1, $3); }
| expr '%' expr { $$ = make_op(yyscanner, "%", $1, $3); }
| INTEGER { $$ = make_integer_constant($1); }
| VARIABLE { $$ = make_variable($1); }
| function '(' elist ')'{ $$ = make_func($1, $3); }
| function '(' elist ')' { $$ = make_func(yyscanner, $1, $3); }
;
function: FUNCTION { $$ = find_func($1); pg_free($1); }
function: FUNCTION { $$ = find_func(yyscanner, $1); pg_free($1); }
;
%%
@ -98,9 +103,10 @@ make_variable(char *varname)
}
static PgBenchExpr *
make_op(const char *operator, PgBenchExpr *lexpr, PgBenchExpr *rexpr)
make_op(yyscan_t yyscanner, const char *operator,
PgBenchExpr *lexpr, PgBenchExpr *rexpr)
{
return make_func(find_func(operator),
return make_func(yyscanner, find_func(yyscanner, operator),
make_elist(rexpr, make_elist(lexpr, NULL)));
}
@ -139,7 +145,7 @@ static struct
* or fail if the function is unknown.
*/
static int
find_func(const char * fname)
find_func(yyscan_t yyscanner, const char *fname)
{
int i = 0;
@ -150,7 +156,7 @@ find_func(const char * fname)
i++;
}
expr_yyerror_more("unexpected function name", fname);
expr_yyerror_more(yyscanner, "unexpected function name", fname);
/* not reached */
return -1;
@ -198,7 +204,7 @@ elist_length(PgBenchExprList *list)
/* Build function call expression */
static PgBenchExpr *
make_func(const int fnumber, PgBenchExprList *args)
make_func(yyscan_t yyscanner, int fnumber, PgBenchExprList *args)
{
PgBenchExpr *expr = pg_malloc(sizeof(PgBenchExpr));
@ -206,13 +212,13 @@ make_func(const int fnumber, PgBenchExprList *args)
if (PGBENCH_FUNCTIONS[fnumber].nargs >= 0 &&
PGBENCH_FUNCTIONS[fnumber].nargs != elist_length(args))
expr_yyerror_more("unexpected number of arguments",
expr_yyerror_more(yyscanner, "unexpected number of arguments",
PGBENCH_FUNCTIONS[fnumber].fname);
/* check at least one arg for min & max */
if (PGBENCH_FUNCTIONS[fnumber].nargs == -1 &&
elist_length(args) == 0)
expr_yyerror_more("at least one argument expected",
expr_yyerror_more(yyscanner, "at least one argument expected",
PGBENCH_FUNCTIONS[fnumber].fname);
expr->etype = ENODE_FUNCTION;
@ -226,4 +232,15 @@ make_func(const int fnumber, PgBenchExprList *args)
return expr;
}
/*
* exprscan.l is compiled as part of exprparse.y. Currently, this is
* unavoidable because exprparse does not create a .h file to export
* its token symbols. If these files ever grow large enough to be
* worth compiling separately, that could be fixed; but for now it
* seems like useless complication.
*/
/* First, get rid of "#define yyscan_t" from pgbench.h */
#undef yyscan_t
#include "exprscan.c"