On 2020-11-05 12:59, John Naylor wrote:
> I think we're talking past eachother. Here's a concrete example:
>
> #define BKI_ROWTYPE_OID(oid,oidmacro)
> #define DECLARE_TOAST(name,toastoid,indexoid) extern int no_such_variable
>
> I understand these to be functionally equivalent as far as what the C
> compiler sees.
The issue is that you can't have a bare semicolon at the top level of a
C compilation unit, at least on some compilers. So doing
#define FOO(stuff) /*empty*/
and then
FOO(123);
won't work. You need to fill the definition of FOO with some stuff to
make it valid.
BKI_ROWTYPE_OID on the other hand is not used at the top level like
this, so it can be defined to empty.
--
Peter Eisentraut http://www.2ndQuadrant.com/
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