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Tweak plpgsql's expression reader to be smarter about parentheses and

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to give more useful error messages.  Stephen Szabo's example of this
morning ('loop' used as a variable name inside a subselect) works
correctly now, and a FOR that is misinterpreted as an integer FOR will
draw 'missing .. at end of SQL expression', which is at least
marginally helpful.
This commit is contained in:
Tom Lane 2001-11-29 22:57:37 +00:00
parent d1a2a01f38
commit 8830ce54d6
2 changed files with 68 additions and 84 deletions
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148
src/pl/plpgsql/src/gram.y
View File

@ -4,7 +4,7 @@
* procedural language
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v 1.28 2001/11/15 23:31:09 tgl Exp $
* $Header: /cvsroot/pgsql/src/pl/plpgsql/src/gram.y,v 1.29 2001/11/29 22:57:37 tgl Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@ -39,7 +39,11 @@
#include "plpgsql.h"
static PLpgSQL_expr *read_sqlstmt(int until, char *s, char *sqlstart);
static PLpgSQL_expr *read_sql_construct(int until,
const char *expected,
bool isexpression,
const char *sqlstart);
static PLpgSQL_expr *read_sql_stmt(const char *sqlstart);
static PLpgSQL_type *read_datatype(int tok);
static PLpgSQL_stmt *make_select_stmt(void);
static PLpgSQL_stmt *make_fetch_stmt(void);
@ -407,7 +411,7 @@ decl_cursor_query :
PLpgSQL_expr *query;
plpgsql_ns_setlocal(false);
query = plpgsql_read_expression(';', ";");
query = read_sql_stmt("SELECT ");
plpgsql_ns_setlocal(true);
$$ = query;
@ -1002,74 +1006,20 @@ fori_varname : T_VARIABLE
fori_lower :
{
int tok;
int lno;
PLpgSQL_dstring ds;
int nparams = 0;
int params[1024];
char buf[32];
PLpgSQL_expr *expr;
int firsttok = 1;
int tok;
lno = yylineno;
plpgsql_dstring_init(&ds);
plpgsql_dstring_append(&ds, "SELECT ");
$$.reverse = 0;
while((tok = yylex()) != K_DOTDOT)
tok = yylex();
if (tok == K_REVERSE)
{
if (firsttok)
{
firsttok = 0;
if (tok == K_REVERSE)
{
$$.reverse = 1;
continue;
}
}
if (tok == ';') break;
if (plpgsql_SpaceScanned)
plpgsql_dstring_append(&ds, " ");
switch (tok)
{
case T_VARIABLE:
params[nparams] = yylval.var->varno;
sprintf(buf, " $%d ", ++nparams);
plpgsql_dstring_append(&ds, buf);
break;
case T_RECFIELD:
params[nparams] = yylval.recfield->rfno;
sprintf(buf, " $%d ", ++nparams);
plpgsql_dstring_append(&ds, buf);
break;
case T_TGARGV:
params[nparams] = yylval.trigarg->dno;
sprintf(buf, " $%d ", ++nparams);
plpgsql_dstring_append(&ds, buf);
break;
default:
if (tok == 0)
{
plpgsql_error_lineno = lno;
elog(ERROR, "missing .. to terminate lower bound of for loop");
}
plpgsql_dstring_append(&ds, yytext);
break;
}
$$.reverse = 1;
}
else
{
$$.reverse = 0;
plpgsql_push_back_token(tok);
}
expr = malloc(sizeof(PLpgSQL_expr) + sizeof(int) * nparams - sizeof(int));
expr->dtype = PLPGSQL_DTYPE_EXPR;
expr->query = strdup(plpgsql_dstring_get(&ds));
expr->plan = NULL;
expr->nparams = nparams;
while(nparams-- > 0)
expr->params[nparams] = params[nparams];
plpgsql_dstring_free(&ds);
$$.expr = expr;
$$.expr = plpgsql_read_expression(K_DOTDOT, "..");
}
stmt_fors : opt_label K_FOR lno fors_target K_IN K_SELECT expr_until_loop loop_body
@ -1308,7 +1258,7 @@ stmt_execsql : execsql_start lno
new = malloc(sizeof(PLpgSQL_stmt_execsql));
new->cmd_type = PLPGSQL_STMT_EXECSQL;
new->lineno = $2;
new->sqlstmt = read_sqlstmt(';', ";", $1);
new->sqlstmt = read_sql_stmt($1);
$$ = (PLpgSQL_stmt *)new;
}
@ -1353,11 +1303,11 @@ stmt_open : K_OPEN lno cursor_varptr
switch (tok)
{
case K_SELECT:
new->query = plpgsql_read_expression(';', ";");
new->query = read_sql_stmt("SELECT ");
break;
case K_EXECUTE:
new->dynquery = plpgsql_read_expression(';', ";");
new->dynquery = read_sql_stmt("SELECT ");
break;
default:
@ -1380,7 +1330,7 @@ stmt_open : K_OPEN lno cursor_varptr
elog(ERROR, "cursor %s has arguments", $3->refname);
}
new->argquery = read_sqlstmt(';', ";", "SELECT ");
new->argquery = read_sql_stmt("SELECT ");
/* Remove the trailing right paren,
* because we want "select 1, 2", not
* "select (1, 2)".
@ -1521,18 +1471,27 @@ lno :
PLpgSQL_expr *
plpgsql_read_expression (int until, char *s)
plpgsql_read_expression(int until, const char *expected)
{
return read_sqlstmt(until, s, "SELECT ");
return read_sql_construct(until, expected, true, "SELECT ");
}
static PLpgSQL_expr *
read_sql_stmt(const char *sqlstart)
{
return read_sql_construct(';', ";", false, sqlstart);
}
static PLpgSQL_expr *
read_sqlstmt (int until, char *s, char *sqlstart)
read_sql_construct(int until,
const char *expected,
bool isexpression,
const char *sqlstart)
{
int tok;
int lno;
PLpgSQL_dstring ds;
int parenlevel = 0;
int nparams = 0;
int params[1024];
char buf[32];
@ -1540,20 +1499,43 @@ read_sqlstmt (int until, char *s, char *sqlstart)
lno = yylineno;
plpgsql_dstring_init(&ds);
plpgsql_dstring_append(&ds, sqlstart);
plpgsql_dstring_append(&ds, (char *) sqlstart);
while((tok = yylex()) != until)
for (;;)
{
if (tok == ';') break;
tok = yylex();
if (tok == '(')
parenlevel++;
else if (tok == ')')
{
parenlevel--;
if (parenlevel < 0)
elog(ERROR, "mismatched parentheses");
}
else if (parenlevel == 0 && tok == until)
break;
/*
* End of function definition is an error, and we don't expect to
* hit a semicolon either (unless it's the until symbol, in which
* case we should have fallen out above).
*/
if (tok == 0 || tok == ';')
{
plpgsql_error_lineno = lno;
if (parenlevel != 0)
elog(ERROR, "mismatched parentheses");
if (isexpression)
elog(ERROR, "missing %s at end of SQL expression",
expected);
else
elog(ERROR, "missing %s at end of SQL statement",
expected);
break;
}
if (plpgsql_SpaceScanned)
plpgsql_dstring_append(&ds, " ");
switch (tok)
{
case 0:
plpgsql_error_lineno = lno;
elog(ERROR, "missing %s at end of SQL statement", s);
break;
case T_VARIABLE:
params[nparams] = yylval.var->varno;
sprintf(buf, " $%d ", ++nparams);
@ -1618,6 +1600,8 @@ read_datatype(int tok)
if (tok == 0)
{
plpgsql_error_lineno = lno;
if (parenlevel != 0)
elog(ERROR, "mismatched parentheses");
elog(ERROR, "incomplete datatype declaration");
}
/* Possible followers for datatype in a declaration */

4
src/pl/plpgsql/src/plpgsql.h
View File

@ -3,7 +3,7 @@
* procedural language
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.23 2001/11/15 23:31:09 tgl Exp $
* $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.24 2001/11/29 22:57:37 tgl Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@ -606,7 +606,7 @@ extern void plpgsql_dumptree(PLpgSQL_function * func);
* Externs in gram.y and scan.l
* ----------
*/
extern PLpgSQL_expr *plpgsql_read_expression(int until, char *s);
extern PLpgSQL_expr *plpgsql_read_expression(int until, const char *expected);
extern int plpgsql_yyparse(void);
extern int plpgsql_base_yylex(void);
extern int plpgsql_yylex(void);