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

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.

diff --git a/src/backend/access/common/heaptuple.c b/src/backend/access/common/heaptuple.c
index 1ece4f02bf3c99e546492911fdb2639ca2a78baa..8d770a368b4708b57b75bb24a35f856ac0e11afd 100644 (file)
--- a/src/backend/access/common/heaptuple.c
+++ b/src/backend/access/common/heaptuple.c
@@ -50,7 +50,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/access/common/heaptuple.c,v 1.129 2010/01/02 16:57:33 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/access/common/heaptuple.c,v 1.130 2010/01/10 04:26:36 rhaas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -323,8 +323,7 @@ heap_attisnull(HeapTuple tup, int attnum)
 Datum
 nocachegetattr(HeapTuple tuple,
                           int attnum,
-                          TupleDesc tupleDesc,
-                          bool *isnull)
+                          TupleDesc tupleDesc)
 {
        HeapTupleHeader tup = tuple->t_data;
        Form_pg_attribute *att = tupleDesc->attrs;
@@ -333,8 +332,6 @@ nocachegetattr(HeapTuple tuple,
        bool            slow = false;   /* do we have to walk attrs? */
        int                     off;                    /* current offset within data */
 
-       (void) isnull;                          /* not used */
-
        /* ----------------
         *       Three cases:
         *
@@ -344,68 +341,32 @@ nocachegetattr(HeapTuple tuple,
         * ----------------
         */
 
-#ifdef IN_MACRO
-/* This is handled in the macro */
-       Assert(attnum > 0);
-
-       if (isnull)
-               *isnull = false;
-#endif
-
        attnum--;
 
-       if (HeapTupleNoNulls(tuple))
-       {
-#ifdef IN_MACRO
-/* This is handled in the macro */
-               if (att[attnum]->attcacheoff >= 0)
-               {
-                       return fetchatt(att[attnum],
-                                                       (char *) tup + tup->t_hoff +
-                                                       att[attnum]->attcacheoff);
-               }
-#endif
-       }
-       else
+       if (!HeapTupleNoNulls(tuple))
        {
                /*
                 * there's a null somewhere in the tuple
                 *
-                * check to see if desired att is null
+                * check to see if any preceding bits are null...
                 */
+               int byte = attnum >> 3;
+               int                     finalbit = attnum & 0x07;
 
-#ifdef IN_MACRO
-/* This is handled in the macro */
-               if (att_isnull(attnum, bp))
-               {
-                       if (isnull)
-                               *isnull = true;
-                       return (Datum) NULL;
-               }
-#endif
-
-               /*
-                * Now check to see if any preceding bits are null...
-                */
+               /* check for nulls "before" final bit of last byte */
+               if ((~bp[byte]) & ((1 << finalbit) - 1))
+                       slow = true;
+               else
                {
-                       int byte = attnum >> 3;
-                       int                     finalbit = attnum & 0x07;
+                       /* check for nulls in any "earlier" bytes */
+                       int                     i;
 
-                       /* check for nulls "before" final bit of last byte */
-                       if ((~bp[byte]) & ((1 << finalbit) - 1))
-                               slow = true;
-                       else
+                       for (i = 0; i < byte; i++)
                        {
-                               /* check for nulls in any "earlier" bytes */
-                               int                     i;
-
-                               for (i = 0; i < byte; i++)
+                               if (bp[i] != 0xFF)
                                {
-                                       if (bp[i] != 0xFF)
-                                       {
-                                               slow = true;
-                                               break;
-                                       }
+                                       slow = true;
+                                       break;
                                }
                        }
                }
@@ -567,8 +528,7 @@ heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc, bool *isnull)
        Assert(tup);
 
        /* Currently, no sys attribute ever reads as NULL. */
-       if (isnull)
-               *isnull = false;
+       *isnull = false;
 
        switch (attnum)
        {

diff --git a/src/backend/access/common/indextuple.c b/src/backend/access/common/indextuple.c
index 61d7f61997ae102a42cfaa504cf56ca87c46256b..3ce377b8545142869584d41485f697b32b1f5cf0 100644 (file)
--- a/src/backend/access/common/indextuple.c
+++ b/src/backend/access/common/indextuple.c
@@ -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...
                 */

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index a787dc43da806a8086450c82ddc2546b55457d61..de061279a14d1f2f81d5280511cf1fc562da7d73 100644 (file)
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.280 2010/01/02 16:57:34 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.281 2010/01/10 04:26:36 rhaas Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -834,7 +834,7 @@ fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
        return (
                        (attnum) > 0 ?
                        (
-                        ((isnull) ? (*(isnull) = false) : (dummyret) NULL),
+                        (*(isnull) = false),
                         HeapTupleNoNulls(tup) ?
                         (
                          (tupleDesc)->attrs[(attnum) - 1]->attcacheoff >= 0 ?
@@ -844,18 +844,18 @@ fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
                                                (tupleDesc)->attrs[(attnum) - 1]->attcacheoff)
                           )
                          :
-                         nocachegetattr((tup), (attnum), (tupleDesc), (isnull))
+                         nocachegetattr((tup), (attnum), (tupleDesc))
                          )
                         :
                         (
                          att_isnull((attnum) - 1, (tup)->t_data->t_bits) ?
                          (
-                          ((isnull) ? (*(isnull) = true) : (dummyret) NULL),
+                          (*(isnull) = true),
                           (Datum) NULL
                           )
                          :
                          (
-                          nocachegetattr((tup), (attnum), (tupleDesc), (isnull))
+                          nocachegetattr((tup), (attnum), (tupleDesc))
                           )
                          )
                         )

diff --git a/src/include/access/htup.h b/src/include/access/htup.h
index 1982ea4da8431081c9d9ea361c7f91d809569c67..e5478a21b680aa4e2bc606068a1d5e0195d33ab7 100644 (file)
--- a/src/include/access/htup.h
+++ b/src/include/access/htup.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/htup.h,v 1.109 2010/01/02 16:58:00 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/access/htup.h,v 1.110 2010/01/10 04:26:36 rhaas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -763,7 +763,7 @@ extern void HeapTupleHeaderAdjustCmax(HeapTupleHeader tup,
 #define fastgetattr(tup, attnum, tupleDesc, isnull)                                    \
 (                                                                                                                                      \
        AssertMacro((attnum) > 0),                                                                              \
-       (((isnull) != NULL) ? (*(isnull) = false) : (dummyret)NULL),    \
+       (*(isnull) = false),                                                                                    \
        HeapTupleNoNulls(tup) ?                                                                                 \
        (                                                                                                                               \
                (tupleDesc)->attrs[(attnum)-1]->attcacheoff >= 0 ?                      \
@@ -773,18 +773,18 @@ extern void HeapTupleHeaderAdjustCmax(HeapTupleHeader tup,
                                        (tupleDesc)->attrs[(attnum)-1]->attcacheoff)    \
                )                                                                                                                       \
                :                                                                                                                       \
-                       nocachegetattr((tup), (attnum), (tupleDesc), (isnull))  \
+                       nocachegetattr((tup), (attnum), (tupleDesc))                    \
        )                                                                                                                               \
        :                                                                                                                               \
        (                                                                                                                               \
                att_isnull((attnum)-1, (tup)->t_data->t_bits) ?                         \
                (                                                                                                                       \
-                       (((isnull) != NULL) ? (*(isnull) = true) : (dummyret)NULL),             \
+                       (*(isnull) = true),                                                                             \
                        (Datum)NULL                                                                                             \
                )                                                                                                                       \
                :                                                                                                                       \
                (                                                                                                                       \
-                       nocachegetattr((tup), (attnum), (tupleDesc), (isnull))  \
+                       nocachegetattr((tup), (attnum), (tupleDesc))                    \
                )                                                                                                                       \
        )                                                                                                                               \
 )
@@ -818,7 +818,7 @@ extern Datum fastgetattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
                ( \
                        ((attnum) > (int) HeapTupleHeaderGetNatts((tup)->t_data)) ? \
                        ( \
-                               (((isnull) != NULL) ? (*(isnull) = true) : (dummyret)NULL), \
+                               (*(isnull) = true), \
                                (Datum)NULL \
                        ) \
                        : \
@@ -838,7 +838,7 @@ extern void heap_fill_tuple(TupleDesc tupleDesc,
                                uint16 *infomask, bits8 *bit);
 extern bool heap_attisnull(HeapTuple tup, int attnum);
 extern Datum nocachegetattr(HeapTuple tup, int attnum,
-                          TupleDesc att, bool *isnull);
+                          TupleDesc att);
 extern Datum heap_getsysattr(HeapTuple tup, int attnum, TupleDesc tupleDesc,
                                bool *isnull);
 extern HeapTuple heap_copytuple(HeapTuple tuple);

diff --git a/src/include/access/itup.h b/src/include/access/itup.h
index fea09c4880f2004e743546e57376aeeae49bbe3e..a2522337d7c6b08b0ea5696e2833e85d54ca375d 100644 (file)
--- a/src/include/access/itup.h
+++ b/src/include/access/itup.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/itup.h,v 1.53 2010/01/02 16:58:00 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/access/itup.h,v 1.54 2010/01/10 04:26:36 rhaas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -110,7 +110,7 @@ typedef IndexAttributeBitMapData *IndexAttributeBitMap;
                        + (tupleDesc)->attrs[(attnum)-1]->attcacheoff) \
                ) \
                : \
-                       nocache_index_getattr((tup), (attnum), (tupleDesc), (isnull)) \
+                       nocache_index_getattr((tup), (attnum), (tupleDesc)) \
        ) \
        : \
        ( \
@@ -121,7 +121,7 @@ typedef IndexAttributeBitMapData *IndexAttributeBitMap;
                ) \
                : \
                ( \
-                       nocache_index_getattr((tup), (attnum), (tupleDesc), (isnull)) \
+                       nocache_index_getattr((tup), (attnum), (tupleDesc)) \
                ) \
        ) \
 )
@@ -142,7 +142,7 @@ typedef IndexAttributeBitMapData *IndexAttributeBitMap;
 extern IndexTuple index_form_tuple(TupleDesc tupleDescriptor,
                                 Datum *values, bool *isnull);
 extern Datum nocache_index_getattr(IndexTuple tup, int attnum,
-                                         TupleDesc tupleDesc, bool *isnull);
+                                         TupleDesc tupleDesc);
 extern void index_deform_tuple(IndexTuple tup, TupleDesc tupleDescriptor,
                                 Datum *values, bool *isnull);
 extern IndexTuple CopyIndexTuple(IndexTuple source);