On Wed, Mar 05, 2025 at 08:27:53PM +0000, Lavrentiev, Anton (NIH/NLM/NCBI) [C]
via Cygwin wrote:
> > We could change this to a macro instead:
> >
> > -static inline void setproctitle_init (int, char *[], char *[]) {}
> > +#define setproctitle_init(c, a, e)
>
> Changing to the empty marco removes the side effects in the arguments (such
> as len++, for example),
> which may silently break existing code -- so I think it's not a good idea.
> If the idea to use the empty
> arguments was not to implicitly document them (because the API was slated for
> removal, IIRC), then
> naming them just with "arg1", "arg2" (rather than leaving empty altogether)
> should help better, IMO.
>
> Anton Lavrentiev
> Contractor NIH/NLM/NCBI
If you want the side effects of the arguments and still want a macro:
#define setproctitle_init(c, a, e) \
do { (void)(c); (void)(a); (void)(e); } while (0)
or, since it is unlikely (though possible) that someone has defined a
single-letter macro for 'c', 'a', or 'b':
static inline void setproctitle_init (int c, char *a[], char *b[])
{
(void)(c);
(void)(a);
(void)(e);
}
or use the intended, more descriptive names in the prototype
static inline void setproctitle_init (int argc, char *argv[], char *envp[])
{
(void)(argc);
(void)(argv);
(void)(envp);
}
If gcc or clang, you could also add __attribute__((__unused__)),
though it should probaby be its own macro so that it could be no-op for
certain compilers:
There is also [[maybe_unused]]
https://clang.llvm.org/docs/AttributeReference.html#maybe-unused-unused
https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-4-c4189?view=msvc-170
#ifndef __attribute_unused__
#ifdef _MSC_VER
#define __attribute_unused__ [[maybe_unused]]
#else
#define __attribute_unused__ __attribute__((__unused__)),
#endif
#endif
static inline void setproctitle_init (int argc __attribute_unused__,
char *argv[] __attribute_unused__,
char *envp[] __attribute_unused__)
{
(void)(argc);
(void)(argv);
(void)(envp);
}
Cheers, Glenn
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