Re: [PATCH][BZ #21326] Ensure C99 and C11 interfaces are available for C++

[Jonathan Wakely <jwakely at redhat dot com>]

On 09/10/17 15:24 +0200, Florian Weimer wrote:
> On 09/22/2017 08:16 PM, Jonathan Wakely wrote:
> > +#ifdef __cplusplus
> > +/* This is to enable compatibility for ISO C++17.  */
> > +#if __cplusplus >= 201703L
> > +# define __USE_ISOC11	1
> > +#endif
> >  /* This is to enable compatibility for ISO C++11.
>
> The inner #if/#endif should be indented (similar to the inner #define).
>
> > -
> > -   So far g++ does not provide a macro.  Check the temporary macro for
> > -   now, too.  */
> > -#if ((defined __cplusplus && __cplusplus >= 201103L)			      \
> > -     || defined __GXX_EXPERIMENTAL_CXX0X__)
> > +   Check the temporary macro for now, too.  */
> > +#if __cplusplus >= 201103L || defined __GXX_EXPERIMENTAL_CXX0X__
> >  # define __USE_ISOCXX11	1
> > +# define __USE_ISOC99	1
> > +#endif
> >  #endif
>
> I think there is a preexisting issue here which will trigger macro 
> redefinition warnings with -Wsystem-headers.  But perhaps I'm 
> mistaken.

Even though both definitions are identical?

I think there's no redefinition warning for:

#define __USE_ISOC99 1
#define __USE_ISOC99 1

Only if the macro's replacement-list differs on the redefinition.

> Apart from that, the substance of the patch looks okay to me.

Thanks. Here's an updated patch against current master, with the fixed
indentation.

Tested again on x86_64-pc-linux-gnu (Fedora 26).

Attachment: 0001-BZ-21326-Ensure-C99-and-C11-interfaces-are-available.patch
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