[HACKERS] Verbosity of Function Return Type Checks

Index: src/pl/plpgsql/src/pl_exec.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v
retrieving revision 1.216
diff -u -r1.216 pl_exec.c
--- src/pl/plpgsql/src/pl_exec.c 16 May 2008 18:34:51 -0000 1.216
+++ src/pl/plpgsql/src/pl_exec.c 8 Aug 2008 11:52:02 -0000
@@ -190,7 +190,7 @@
Oid reqtype, int32 reqtypmod,
bool isnull);
static void exec_init_tuple_store(PLpgSQL_execstate *estate);
-static bool compatible_tupdesc(TupleDesc td1, TupleDesc td2);
+static void validate_tupdesc_compat(TupleDesc td1, TupleDesc td2);
static void exec_set_found(PLpgSQL_execstate *estate, bool state);
static void plpgsql_create_econtext(PLpgSQL_execstate *estate);
static void free_var(PLpgSQL_var *var);
@@ -386,11 +386,12 @@
{
case TYPEFUNC_COMPOSITE:
/* got the expected result rowtype, now check it */
- if (estate.rettupdesc == NULL ||
- !compatible_tupdesc(estate.rettupdesc, tupdesc))
+ if (!estate.rettupdesc)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("returned record type does not match expected record type")));
+ errmsg("returned record type does not match "
+ "expected record type")));
+ validate_tupdesc_compat(tupdesc, estate.rettupdesc);
break;
case TYPEFUNC_RECORD:

@@ -707,11 +708,8 @@
rettup = NULL;
else
{
- if (!compatible_tupdesc(estate.rettupdesc,
- trigdata->tg_relation->rd_att))
- ereport(ERROR,
- (errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("returned tuple structure does not match table of trigger event")));
+ validate_tupdesc_compat(trigdata->tg_relation->rd_att,
+ estate.rettupdesc);
/* Copy tuple to upper executor memory */
rettup = SPI_copytuple((HeapTuple) DatumGetPointer(estate.retval));
}
@@ -2202,10 +2200,7 @@
errmsg("record \"%s\" is not assigned yet",
rec->refname),
errdetail("The tuple structure of a not-yet-assigned record is indeterminate.")));
- if (!compatible_tupdesc(tupdesc, rec->tupdesc))
- ereport(ERROR,
- (errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("wrong record type supplied in RETURN NEXT")));
+ validate_tupdesc_compat(rec->tupdesc, tupdesc);
tuple = rec->tup;
}
break;
@@ -2311,10 +2306,7 @@
stmt->params);
}

- if (!compatible_tupdesc(estate->rettupdesc, portal->tupDesc))
- ereport(ERROR,
- (errcode(ERRCODE_DATATYPE_MISMATCH),
- errmsg("structure of query does not match function result type")));
+ validate_tupdesc_compat(portal->tupDesc, estate->rettupdesc);

while (true)
{
@@ -5138,23 +5130,32 @@
}

/*
- * Check two tupledescs have matching number and types of attributes
+ * Validates compatibility of supplied TupleDesc's by checking # and type of
+ * available arguments.
*/
-static bool
-compatible_tupdesc(TupleDesc td1, TupleDesc td2)
+static void
+validate_tupdesc_compat(TupleDesc td1, TupleDesc td2)
{
- int i;
+ int i;

if (td1->natts != td2->natts)
- return false;
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("Number of returned columns (%d) does not match "
+ "expected column count (%d).",
+ td1->natts, td2->natts)));

for (i = 0; i < td1->natts; i++)
- {
if (td1->attrs[i]->atttypid != td2->attrs[i]->atttypid)
- return false;
- }
-
- return true;
+ ereport(ERROR,
+ (errcode(ERRCODE_DATATYPE_MISMATCH),
+ errmsg("Returned record type (%s) does not match "
+ "expected record type (%s) in column %d (%s).",
+ format_type_with_typemod(td1->attrs[i]->atttypid,
+ td1->attrs[i]->atttypmod),
+ format_type_with_typemod(td2->attrs[i]->atttypid,
+ td2->attrs[i]->atttypmod),
+ (1+i), NameStr(td2->attrs[i]->attname))));
}

/* ----------
Hi,

Yesterday I needed to fiddle with PostgreSQL internals to be able to
debug a PL/pgSQL procedure returning a set of records. I attached the
patch I used to increase the verbosity of error messages related with
function return type checks. I'll be appreciated if any developer could
commit this patch (or a similar one) into the core.

Regards.