Re: Grammar-problems with pl/pgsql in gram.y

Klaus Reger wrote:
> Hi,
>
> I want to learn, how the pl/plsql-parser/compiler works. Therefore I planned
> to implement a simple ELSIF, like oracle does.
>
> I added the following K_ELSIF branch to gram.y, in the hope that, when ELSIF
> is parsed, simply another if-structure in inserted.
>
> ---------------------------------------------------------
> stmt_else :
> {
> PLpgSQL_stmts *new;
>
> new = malloc(sizeof(PLpgSQL_stmts));
> memset(new, 0, sizeof(PLpgSQL_stmts));
> $$ = new;
> elog(NOTICE, "empty ELSE detected");
> }
> | K_ELSIF expr_until_then proc_sect stmt_else
> {
> PLpgSQL_stmt_if *new;
> elog(NOTICE, "ELSIF detected");
> new = malloc(sizeof(PLpgSQL_stmt_if));
> memset(new, 0, sizeof(PLpgSQL_stmt_if));
> new->cmd_type = PLPGSQL_STMT_IF;
> // new->lineno = $2;
> new->cond = $2;
> new->true_body = $3;
> new->false_body = $4;
>
> $$ = (PLpgSQL_stmts *)new;

Here it is. stmt_else is defined as type <stmts>, not <stmt>.
The PLpgSQL_stmt_if struct has a condition query and two
statement lists (type <stmts>). You're trying to put a single
statement into the else part instead of a list of statements.

Maybe it'll work if you surround it with another
PLpgSQL_stmts struct where your new PLpgSQL_stmt_if is the
only statement in it's list. Since I have some bigger work
outstanding for PL/pgSQL, send the resulting patch (if you
get it to work) directly to me.

Jan

--

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