Re: ecpg preprocessor regression in 9.0

On 01.11.2010 15:31, Heikki Linnakangas wrote:
> This used to work in the PostgreSQL 8.4 ecpg preprocessor:
>
> EXEC SQL EXECUTE mystmt USING 1.23;
>
> but in 9.0 it throws an error:
>
> floattest.pgc:39: ERROR: variable "1" is not declared
>
> Attached is the full test case, drop it in
> src/interfaces/ecpg/test/preproc and compile.
>
> I bisected the cause to this commit:
>
> commit b2bddc2ff22f0c3d54671e43c67a2563deed7908
> Author: Michael Meskes <meskes@postgresql.org>
> Date: Thu Apr 1 08:41:01 2010 +0000
>
> Applied Zoltan's patch to make ecpg spit out warnings if a local
> variable hides a global one with the same name.
>
> I don't immediately see why that's causing it, but it doesn't seem
> intentional.

On closer look, it's quite obvious: the code added to ECPGdump_a_type
thinks that ECPGt_const is a variable type, and tries to look up the
variable. The straightforward fix is this:

diff --git a/src/interfaces/ecpg/preproc/type.c
b/src/interfaces/ecpg/preproc/type.c
index cc668a2..a53018b 100644
--- a/src/interfaces/ecpg/preproc/type.c
+++ b/src/interfaces/ecpg/preproc/type.c
@@ -246,7 +246,7 @@ ECPGdump_a_type(FILE *o, const char *name, struct
ECPGtype * type,
      struct variable *var;

      if (type->type != ECPGt_descriptor && type->type != ECPGt_sqlda &&
-        type->type != ECPGt_char_variable &&
+        type->type != ECPGt_char_variable && type->type != ECPGt_const &&
          brace_level >= 0)
      {
          char       *str;

But I wonder if there is a better way to identify variable-kind of
ECPGttypes than list the ones that are not. There's some special
ECPGttypes still missing from the above if-test, like
ECPGt_NO_INDICATOR, but I'm not sure if they can ever be passed to
ECPGdump_a_type. Seems a bit fragile anyway.

--
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com