Re: stdlib tweak

[Jim Meyering]

Bruno Haible wrote:
>> Considering that this will appear in nearly every .c file in gnulib/lib,
>
> You mean, in gnulib/tests/, I guess?

Yes.

>> Then, each use would be more concise:
>>
>>     GL_SIG_CHECK (atexit, int, (void (*) (void)));
>
> I like the idea: it provides an abstraction over this arcane C function 
> pointer
> syntax.
>
>> how about a macro to encapsulate whatever idiom we use?
>> Even if it means emitting that into config.h.
>
> Since it's a utility macro only for the tests, I would much prefer to have it
> in a file such as tests/macros.h, rather than polluting config.h with stuff
> that exists only for the tests. This file tests/macros.h could also contain
> the ubiquitous ASSERT macro. (I try to keep the tests as transparent and
> will as little boilerplate complexity as possible. But a macro that is used
> more than 200 times can certainly be refactored.)

That would be welcome ;-)

>>     #define GL_SIG_CHECK(fn, ret_type, param_list) \
>>       static ret_type (* _UNUSED_PARAMETER_ signature_check) param_list = fn
>
> In order to allow multiple uses of this macro in the same file, it should
> probably use __LINE__. Also better call it CHECK_SIGNATURE: 'SIG' reminds
> me too much of 'signal', and the prefix "GL_" is unneeded here.
>
>> Otherwise we'd unnecessarily pollute the linker name space.

All valid points, once I realized the target was /tests/*.c, not lib/*.c.

>> > It also means that the gnulib guarantee that _UNUSED_PARAMETER_
>> > expands to __attribute__((__unused__)) is a bit of a misnomer, as in this 
>> > case,
>> > signature_check is not a parameter.  Do we want to introduce a new alias,
>> > _GL_UNUSED, and use that instead of _UNUSED_PARAMETER_?  (Unfortunately, we
>>
>> I would prefer _GL_UNUSED, too.
>> Not only a shorter name, but also more apt.
>> If you want to deprecate _UNUSED_PARAMETER_ outside of gnulib,
>
> I would leave _UNUSED_PARAMETER_ as it is. It is well named and frequently
> used. You are now trying to use __attribute__((__unused__)) also for a
> different case; that does not mean that _UNUSED_PARAMETER_ needs to be
> changed.

Since Eric seems likely to introduce only one new use, its actual
name matters far less.