Re: [rfc,patch] PL/Proxy in core

On 5/15/08, Marko Kreen <markokr(at)gmail(dot)com> wrote:
> On 5/15/08, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> > "Marko Kreen" <markokr(at)gmail(dot)com> writes:
> > > Hmm.. Now that I think about it, in my effort to remove malloc() calls
> > > in both scanner and parser I told bison to use alloca(). Is it portability
> > > concern?
> >
> > Yes.
>
>
> How about following patch? I have bison 2.3 and it seems not to do
> global allocation, so it should be fine. There may be early exit
> with elog(ERRROR) inside so I'd like to avoid malloc() itself.
>
> Is there some older bison that keeps allocations around?
> They would need bit more work...
>
> --- src/parser.y 14 May 2008 12:25:00 -0000 1.7
> +++ src/parser.y 15 May 2008 07:34:53 -0000
> @@ -24,7 +24,9 @@
> void plproxy_yy_scan_bytes(const char *bytes, int len);
>
> /* avoid permanent allocations */
> -#define YYSTACK_USE_ALLOCA 1
> +#define YYMALLOC palloc
> +#define YYFREE pfree
> +
> /* remove unused code */
> #define YY_LOCATION_PRINT(File, Loc) (0)
> #define YY_(x) (x)
>
> I will roll new full patch when more comments have appeared.

Checked bison 1.875, and it does not use YYMALLOC/YYFREE.
But luckily its allocation pattern seems sane, so following should work:

--- src/parser.y 14 May 2008 12:25:00 -0000 1.7
+++ src/parser.y 15 May 2008 08:18:14 -0000
@@ -24,7 +24,9 @@
void plproxy_yy_scan_bytes(const char *bytes, int len);

/* avoid permanent allocations */
-#define YYSTACK_USE_ALLOCA 1
+#define malloc palloc
+#define free pfree
+
/* remove unused code */
#define YY_LOCATION_PRINT(File, Loc) (0)
#define YY_(x) (x)

--
marko