diff options
Diffstat (limited to 'src/include/fmgr.h')
| -rw-r--r-- | src/include/fmgr.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/src/include/fmgr.h b/src/include/fmgr.h index 298cd12c77..32cadeb6b5 100644 --- a/src/include/fmgr.h +++ b/src/include/fmgr.h @@ -11,7 +11,7 @@ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/fmgr.h,v 1.50 2007/04/06 04:21:44 tgl Exp $ + * $PostgreSQL: pgsql/src/include/fmgr.h,v 1.51 2007/05/15 17:39:54 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -158,6 +158,12 @@ extern void fmgr_info_copy(FmgrInfo *dstinfo, FmgrInfo *srcinfo, * The resulting datum can be accessed using VARSIZE_ANY() and VARDATA_ANY() * (beware of multiple evaluations in those macros!) * + * WARNING: It is only safe to use PG_DETOAST_DATUM_UNPACKED() and + * VARDATA_ANY() if you really don't care about the alignment. Either because + * you're working with something like text where the alignment doesn't matter + * or because you're not going to access its constituent parts and just use + * things like memcpy on it anyways. + * * Note: it'd be nice if these could be macros, but I see no way to do that * without evaluating the arguments multiple times, which is NOT acceptable. */ @@ -174,6 +180,7 @@ extern struct varlena *pg_detoast_datum_packed(struct varlena * datum); #define PG_DETOAST_DATUM_SLICE(datum,f,c) \ pg_detoast_datum_slice((struct varlena *) DatumGetPointer(datum), \ (int32) f, (int32) c) +/* WARNING -- unaligned pointer */ #define PG_DETOAST_DATUM_PACKED(datum) \ pg_detoast_datum_packed((struct varlena *) DatumGetPointer(datum)) |