Fix filtered_base_yylex() to save and restore base_yylval and base_yylloc

properly when doing a lookahead.  The lack of this was causing various
interesting misbehaviors when one tries to use "with" as a plain identifier.
This commit is contained in:
Tom Lane 2007-01-06 19:14:17 +00:00
parent e85ef6e51e
commit 063560bb8e

View File

@ -14,7 +14,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/parser/parser.c,v 1.69 2007/01/05 22:19:34 momjian Exp $
* $PostgreSQL: pgsql/src/backend/parser/parser.c,v 1.70 2007/01/06 19:14:17 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -28,8 +28,10 @@
List *parsetree; /* result of parsing is left here */
static int lookahead_token; /* one-token lookahead */
static bool have_lookahead; /* lookahead_token set? */
static bool have_lookahead; /* is lookahead info valid? */
static int lookahead_token; /* one-token lookahead */
static YYSTYPE lookahead_yylval; /* yylval for lookahead token */
static YYLTYPE lookahead_yylloc; /* yylloc for lookahead token */
/*
@ -77,11 +79,16 @@ int
filtered_base_yylex(void)
{
int cur_token;
int next_token;
YYSTYPE cur_yylval;
YYLTYPE cur_yylloc;
/* Get next token --- we might already have it */
if (have_lookahead)
{
cur_token = lookahead_token;
base_yylval = lookahead_yylval;
base_yylloc = lookahead_yylloc;
have_lookahead = false;
}
else
@ -102,8 +109,10 @@ filtered_base_yylex(void)
* (perhaps for SQL99 recursive queries), come back and simplify
* this code.
*/
lookahead_token = base_yylex();
switch (lookahead_token)
cur_yylval = base_yylval;
cur_yylloc = base_yylloc;
next_token = base_yylex();
switch (next_token)
{
case CASCADED:
cur_token = WITH_CASCADED;
@ -115,7 +124,14 @@ filtered_base_yylex(void)
cur_token = WITH_CHECK;
break;
default:
/* save the lookahead token for next time */
lookahead_token = next_token;
lookahead_yylval = base_yylval;
lookahead_yylloc = base_yylloc;
have_lookahead = true;
/* and back up the output info to cur_token */
base_yylval = cur_yylval;
base_yylloc = cur_yylloc;
break;
}
break;