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Remove partial, broken support for NULL pointers when fetching attributes.

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Previously, fastgetattr() and heap_getattr() tested their fourth argument
against a null pointer, but any attempt to use them with a literal-NULL
fourth argument evaluated to *(void *)0, resulting in a compiler error.
Remove these NULL tests to avoid leading future readers of this code to
believe that this has a chance of working.  Also clean up related legacy
code in nocachegetattr(), heap_getsysattr(), and nocache_index_getattr().

The new coding standard is that any code which calls a getattr-type
function or macro which takes an isnull argument MUST pass a valid
boolean pointer.  Per discussion with Bruce Momjian, Tom Lane, Alvaro
Herrera.
This commit is contained in:
Robert Haas
2010-01-10 04:26:36 +00:00
parent 8b9fa7a93a
commit 84b6d5f359
5 changed files with 36 additions and 109 deletions
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39
src/backend/access/common/indextuple.c
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@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/common/indextuple.c,v 1.90 2010/01/02 16:57:33 momjian Exp $
* $PostgreSQL: pgsql/src/backend/access/common/indextuple.c,v 1.91 2010/01/10 04:26:36 rhaas Exp $
*
*-------------------------------------------------------------------------
*/
@@ -200,8 +200,7 @@ index_form_tuple(TupleDesc tupleDescriptor,
Datum
nocache_index_getattr(IndexTuple tup,
int attnum,
TupleDesc tupleDesc,
bool *isnull)
TupleDesc tupleDesc)
{
Form_pg_attribute *att = tupleDesc->attrs;
char *tp; /* ptr to data part of tuple */
@@ -210,8 +209,6 @@ nocache_index_getattr(IndexTuple tup,
int data_off; /* tuple data offset */
int off; /* current offset within data */
(void) isnull; /* not used */
/* ----------------
* Three cases:
*
@@ -221,31 +218,11 @@ nocache_index_getattr(IndexTuple tup,
* ----------------
*/
#ifdef IN_MACRO
/* This is handled in the macro */
Assert(PointerIsValid(isnull));
Assert(attnum > 0);
*isnull = false;
#endif
data_off = IndexInfoFindDataOffset(tup->t_info);
attnum--;
if (!IndexTupleHasNulls(tup))
{
#ifdef IN_MACRO
/* This is handled in the macro */
if (att[attnum]->attcacheoff >= 0)
{
return fetchatt(att[attnum],
(char *) tup + data_off +
att[attnum]->attcacheoff);
}
#endif
}
else
if (IndexTupleHasNulls(tup))
{
/*
* there's a null somewhere in the tuple
@@ -256,16 +233,6 @@ nocache_index_getattr(IndexTuple tup,
/* XXX "knows" t_bits are just after fixed tuple header! */
bp = (bits8 *) ((char *) tup + sizeof(IndexTupleData));
#ifdef IN_MACRO
/* This is handled in the macro */
if (att_isnull(attnum, bp))
{
*isnull = true;
return (Datum) NULL;
}
#endif
/*
* Now check to see if any preceding bits are null...
*/