> There are two ways we could attack this: (1) put a "pad" field into
> struct AclItem (prolly two uint8s) to try to ensure that compilers
> would think it is 8 bytes long, or (2) make the size field for aclitem
> in pg_type.h read "sizeof(AclItem)". I think the latter is a better
> long-term solution, because it eliminates having to try to guess
> what a compiler will do with a struct declaration. But there are
> several possible counterarguments:
>
> * It might require patching the scripts that read pg_type.h --- I
> am not sure if they'd work unmodified.
>
> * We'd either need to #include acl.h into pg_type.h or push the
> declarations for AclItem into some more-widely-used header.
>
> * In theory this would represent an initdb change and couldn't
> be applied before 6.6. In practice, Postgres isn't working right
> now on any platform where sizeof(AclItem) != 8, so initdb would
> *not* be needed for any working installation.
>
> I don't think any of these counterarguments is a big deal, but
> maybe someone else will have a different opinion.
My guess is that we are looking at different solutions for 6.5.1 and
6.6. A good argument for a source tree split.
Currently, initdb runs through pg_type.h using sed/awk, so it can't
see any of the sizeof() defines. One hokey solution would be to have
the compile process run a small C program that dumps out the acl size
into a file, and have initdb pick up that. That is a terrible solution,
though. I guess we don't have any other 'struct' data types that need
to know the size of the struct on a give OS. Maybe padding with an
Assert() to make sure it stays at the fixed size we specify is a good
solution.
-- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610)
853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill,
Pennsylvania19026