Re: RFC/RFHelp: c-decl.c rewrite - almost but not quite

[Zack Weinberg <zack at codesourcery dot com>]

"Joseph S. Myers" <jsm@polyomino.org.uk> writes:

> On Tue, 16 Mar 2004, Zack Weinberg wrote:
>
>> +                 warning ("its scope is only this definition or declaration,"
>> +                          " which is probably not what you want");
>
> Should be inform ().

Preexisting condition.

>> -void bar2 () {} /* { dg-warning "old-style parameter declaration" } */
>> +void bar2 () {} /* { dg-bogus "old-style function definition" } */
>
> I don't see how this warning is bogus.  The intention of 
> -Wold-style-definition, which this testcase tests, is to warn for *all* 
> old-style definitions, even if there is a prior prototype.  In particular, 
> it should warn when () is used instead of (void).

C99 6.7.5.3p14:

    An identifier list declares only the identifiers of the parameters
    of the function. An empty list in a function declarator that is
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    part of a definition of that function specifies that the function
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    has no parameters. The empty list in a function declarator that is
    ^^^^^^^^^^^^^^^^^^
    not part of a definition of that function specifies that no
    information about the number or types of the parameters is
    supplied.

I read this to indicate that *in a function definition* () is the same
as (void), and should not be taken as an old-style definition.

zw