diff options
Diffstat (limited to 'src/backend/access/tupmacs.h')
| -rw-r--r-- | src/backend/access/tupmacs.h | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/src/backend/access/tupmacs.h b/src/backend/access/tupmacs.h index 9a9bcce3b41..168a4669c3b 100644 --- a/src/backend/access/tupmacs.h +++ b/src/backend/access/tupmacs.h @@ -6,7 +6,7 @@ * * Copyright (c) 1994, Regents of the University of California * - * $Id: tupmacs.h,v 1.1.1.1 1996/07/09 06:21:09 scrappy Exp $ + * $Id: tupmacs.h,v 1.2 1996/08/21 04:25:37 scrappy Exp $ * *------------------------------------------------------------------------- */ @@ -22,6 +22,12 @@ * given a AttributeTupleForm and a pointer into a tuple's data * area, return the correct value or pointer. * + * We return a 4 byte (char *) value in all cases. If the attribute has + * "byval" false or has variable length, we return the same pointer + * into the tuple data area that we're passed. Otherwise, we return + * the 1, 2, or 4 bytes pointed to by it, properly extended to 4 + * bytes, depending on the length of the attribute. + * * note that T must already be properly LONGALIGN/SHORTALIGN'd for * this to work correctly. * @@ -30,9 +36,15 @@ * sign-extension may get weird if you use an integer type that * isn't the same size as (char *) for the first cast. (on the other * hand, it's safe to use another type for the (foo *)(T).) + * + * attbyval seems to be fairly redundant. We have to return a pointer if + * the value is longer than 4 bytes or has variable length; returning the + * value would be useless. In fact, for at least the variable length case, + * the caller assumes we return a pointer regardless of attbyval. + * I would eliminate attbyval altogether, but I don't know how. -BRYANH. */ #define fetchatt(A, T) \ - ((*(A))->attbyval \ + ((*(A))->attbyval && (*(A))->attlen != -1 \ ? ((*(A))->attlen > sizeof(int16) \ ? (char *) (long) *((int32 *)(T)) \ : ((*(A))->attlen < sizeof(int16) \ |