🚀 go-pugleaf

In article <6157@june.cs.washington.edu> uw-june!pardo (David Keppel) writes:
>I have code of the form:
>    typedef void (*rtl_fp)( struct save_t *, int n,  rtl_t *curr );

Identifiers declared within a prototype have very short scope; thus for
example `n' has a scope that extends only to the end of the prototype.
Similarly (and more subtly), `struct save_t' has this same short scope if it
hasn't been previously declared.  When you later declare `struct save_t' it
has a nonintersecting scope, and therefore is considered a different type.

>[the error occurs] unless I precede the function declaration with
>    struct save_t;

That's the correct way to do it; if the struct tag is already declared when
the prototype is encountered, the one in the prototype becomes a reference to
it instead of a new type.

>In which case the compiler notes that there is an "empty declaration".

That is incorrect.  The struct tag is being declared.

Karl W. Z. Heuer (ima!haddock!karl or karl@haddock.isc.com), The Walking Lint